release-notes.txt

= Release Notes for ION =

%%%%%%%%%%%
= GENERAL =
%%%%%%%%%%%

The ION (interplanetary overlay network) software is a suite of communication
protocol implementations designed to support mission operation communications
across an end-to-end interplanetary network, which might include on-board
(flight) subnets, in-situ planetary or lunar networks, proximity links, deep
space links, and terrestrial internets.  Included in the ION software
distribution are the following packages:

- ici (interplanetary communication infrastructure), a set of libraries
  that provide flight-software-compatible support for functions on which
  the other packages rely, such as dynamic memory management, non-volatile
  storage management, and inter-task communication via shared memory.
  The ici libraries are designed to make the porting of IPN software to
  multiple operating systems - Linux, VxWorks, Solaris, etc. - as easy as
  possible. Ici now includes zco (zero-copy object), a library that
  minimizes the copying of application data as it is encapsulated in
  multiple layers of protocol structure while traversing the protocol
  stack.

- bp (bundle protocol), an implementation of the Delay-Tolerant
  Networking (DTN) architecture's Bundle Protocol.

- ltp (licklider transmission protocol), a DTN convergence layer protocol
  for reliable transmission over links characterized by long or highly
  variable delay.

- dgr (datagram retransmission), an alternative implementation of ltp
  that is designed for use over the Internet protocol stack.  dgr
  implements congestion control and is designed for relatively high
  performance.

- bssp (bundle streaming service protocol), a DTN convergence layer protocol
  for reliable transmission of streaming data.

- ams - an implementation of the CCSDS Asynchronous Message Service.

- cfdp - a class-1 (Unacknowledged) implementation of the CCSDS File
  Delivery Protocol.

- bss - a Bundle Streaming Service (BSS) for disruption-tolerant reliable
  data streaming.  BSS supports real-time streaming applications by
  passing the bundle payloads to the associated application for immediate
  display of the most recent data while storing all bundle payloads
  received into a database for user-directed playback.

- dtpc (delay-tolerant payload conditioning), an application framework
  providing TCP-like support for end-to-end retransmission and data delivery
  in transmission order without duplication or omission.

Features included:

- cgr - Contract graph routing: a method of dynamic routing designed for
  space based applications of ION, but still usable for terrestrial
  applications. It computes routes using scheduled communication and deals
  with time-varying network topology.

- brs - Bundle relay service: provides interconnectivity between networks
  that do not allow servers (those behind NAT for example). For more
  information, check man brsscla and man brsccla.

February 2026

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.4 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

This final release of ION 4.1.4 represents the culmination of extensive security
hardening, protocol enhancements, and platform portability improvements since the
4.1.4-b.1 beta release. The release includes 288 commits addressing critical security
vulnerabilities, implementing CCSDS Orange Book custody transfer specifications, adding
new convergence layer adapters, and improving system stability across all supported
platforms.

Critical Security Fixes

- **File Transfer Security**: Fixed multiple critical vulnerabilities in sendfile/recvfile:
  - Path traversal vulnerability allowing access outside designated directories
  - Stack overflow in file path handling
  - Time-of-check/time-of-use (TOCTOU) race conditions
  - Resource leaks and improper memory cleanup
  - Added input validation and secure path canonicalization

- **BPSec Policy Engine**: Added NULL checks for security policy radix trees to prevent
  crashes during rule lookup with missing or invalid policy configurations.

- **Input Validation**: Enhanced validation throughout the codebase including:
  - Canonical extension block number validation (must be < 255)
  - Stricter sscanf return value checking to prevent buffer overflows
  - Improved error handling for malformed configuration inputs

Custody Transfer and Bundle Management (CCSDS Orange Book Compliance)

- **Aggregate Custody Signals (CBR/CT)**: Complete implementation of CCSDS Custody
  Transfer and Bundle Refusal specifications:
  - CTEB (Custody Transfer Extension Block) for custody metadata
  - CREB (Custody Refusal Extension Block) for refusal reasons
  - CRS (Compressed Reporting Signals) using CBOR encoding
  - Custody-originated tracking and bundle detention mechanisms
  - Support for non-zero sequence IDs in custody signals
  - Comprehensive test suite with isolated subtests for each feature
  - Full API documentation and man pages

- **Bundle Lifecycle Management**: Enhanced bundle state tracking throughout custody
  transfer operations with proper validation of custody acceptance/refusal conditions.

New Convergence Layer Adapters

- **File CLA**: Production implementation of file-based convergence layer adapter
  for applications requiring file system-based bundle exchange, with complete
  documentation and man pages.

- **SPP/EPP CLA Prototypes**: Initial prototypes for specialized convergence layers:
  - SPP (Space Packet Protocol) CLA with loopback provider stub
  - EPP (Encapsulation Packet Protocol) CLA with loopback provider stub
  - Regression test templates and online documentation
  - Error handling improvements for transmission success/failure cases

LTP Protocol Enhancements

- **Statistics Collection**: Implemented C11 atomic operations for lock-free LTP
  statistics batching, significantly improving performance under high load.

- **Session Management**:
  - Fixed checkpoint timer cancellation when receiving partial segment coverage,
    preventing sender from getting stuck in limbo state
  - Added import session inactivity timeout to prevent denial-of-service from
    incomplete sessions
  - Improved LTP cancel segment acknowledgment for completed sessions

- **Monitoring Tools**:
  - New ltpstats utility for real-time LTP performance monitoring
  - Enhanced ltpwatch with improved reporting capabilities

Bundle Protocol (BP) Improvements

- **Statistics and Monitoring**:
  - Implemented C11 atomic operations for lock-free BP statistics collection
  - Fixed BP statistics naming inconsistencies
  - Exposed numBundlesDeleted counter in bpnmtest
  - Corrected bpstats delivery (dlv) reporting

- **Extension Block Management**:
  - Fixed extension block number duplication when cloning bundles for multicast
    or fragmentation
  - Added verification that payload block number is always 1
  - Improved extension block documentation explaining ION's behavior and rationales
  - Removed obsolete HIRR (Hop-in-Route-Record) code

- **Routing Enhancements**:
  - Allow best-effort bundles to use reliable CLAs when no unreliable CLA available
  - Fixed TOCTOU race in contact state checking during bundle transmission
  - Fixed egress plan configuration errors

SDR (Simple Data Recorder) Enhancements

- **Performance Instrumentation**: Added comprehensive SDR transaction performance
  monitoring controlled by --enable-sdr-perf configure option:
  - Transaction timing and throughput measurement
  - Caller tracking for performance profiling
  - Improved diagnostics for SDR modification sources

- **Reversibility and Recovery**:
  - Enhanced ionrestart recovery with defensive checks for transaction cancellation
  - Fixed SDR owner mismatch during ionrestart
  - Improved sdr_exit_xn to trigger proper cancellation instead of aborting
  - Converted fatal CHKZERO assertions in sdr_list operations to defensive warnings
  - Added documentation on SDR reversibility mechanisms

Error Handling and Reliability

- **CHK Assertion Improvements**:
  - Added fail-fast mode for CHK assertion macros
  - Implemented stack trace support for FreeBSD, macOS, and Linux
  - Graceful error handling for CHK assertions during shutdown/ionrestart
  - Defensive ownership checks before SDR writes to handle transaction cancellation

- **Daemon Management**:
  - Daemonized psmwatch and sdrwatch with automatic configuration detection
  - Fixed ionrestart race conditions in daemon startup
  - Improved ionexit hang handling after TCP outduct stop/start
  - Enhanced monitoring utility descriptions and usage documentation

- **Semaphore Management**:
  - Fixed POSIX named semaphore race conditions causing segmentation faults in bpcp
  - Implemented reference counting and deferred deletion for semaphores
  - Fixed sm_SemTake to return 0 when semaphore is ended
  - Resolved semaphore cleanup ordering issues

CFDP (File Delivery Protocol) Improvements

- **Race Condition Fixes**:
  - Fixed CFDP event queue race condition with producer-consumer mutex pattern
  - Proper semaphore state management and cleanup ordering
  - Fixed event_wait_id handling to prevent segmentation faults

- **Compilation Fixes**:
  - Fixed checksum function signature compatibility with --enable-high-speed option

Network Management and Administration APIs

- **Bulk Removal APIs**: Added runtime reconfiguration capabilities for:
  - Outducts and inducts
  - Endpoints and spans
  - Seats and egress plans
  - Complete test coverage in admin_public_api/bulk_removal

- **AMP/NM Enhancements**:
  - Fixed bp_agent ADM type mismatches with ION-specific extensions
  - Fixed zero timestamp in AMP agent registration messages
  - Updated conformance test infrastructure with Python 3.9+ requirement

Platform Portability

- **macOS**:
  - Added newline to ltpcancel.c to quiet compiler warnings
  - Fixed watchdog test termination issues
  - Fixed ipaddr-caching tests for mDNS-enabled systems

- **FreeBSD**:
  - Fixed date command syntax compatibility
  - Improved backtrace linking
  - Updated stack trace support
  - Fixed LTP cancel tests with prerequisite checks
  - Excluded problematic CFDP tcputa tests due to timing issues

- **Solaris**:
  - Replaced bzero with memset for POSIX compliance (gf-complete build)
  - Fixed grep compatibility for POSIX compliance
  - Improved UDP buffer handling for larger Solaris defaults
  - Added Solaris-specific test adjustments

Testing Infrastructure

- **Test Framework Enhancements**:
  - Added --from and --to options to runtests for selective test execution
  - Implemented stress test mode for debugging
  - Added timeout support to prevent tests from hanging
  - Improved test cleanup scripts and IPC artifact management
  - Skip tests gracefully when required tools or conditions are missing

- **CI/CD Improvements**:
  - Added Fedora 42 to BETR platform regression testing
  - Added merge queue support to required CI workflows
  - Updated RTEMS regression test PR status reporting
  - Improved workflow permissions for security compliance

Build System and Dependencies

- **Third-Party Libraries**:
  - Switched from ZFEC to Jerasure and GF-Complete libraries for erasure coding
  - Updated licensing terms and TC README for third-party dependencies
  - Added pkg-config support with comprehensive documentation

- **Code Quality**:
  - Added EditorConfig and clang-format configuration files
  - Enforced .git-blame-ignore-revs for mass formatting changes
  - Removed obsolete code (BPv6 references, ACS infrastructure, ECLSA v2)
  - Fixed hundreds of compiler warnings across all warning levels

Documentation Improvements

- **Man Pages**:
  - Fixed cross-references and formatting across all man pages
  - Corrected DTPC typos to DTPC throughout documentation
  - Added missing man pages for CBR/CT APIs
  - Enhanced ionsecadmin, ionrc, ipnadmin, and other admin utility documentation
  - Improved CFDP, TC, and DTKA utility documentation

- **Technical Documentation**:
  - Added SDR reversibility documents
  - Reorganized documentation categorization
  - Added IPN name transition document
  - Enhanced documentation on monitoring tools usage
  - Added regression test documentation for EXPERT setting

Code Cleanup

- **Standards Compliance**:
  - Compliant #include guard names throughout codebase
  - Proper #endif comments for all include guards
  - Fixed header inclusion ordering and dependencies
  - Removed redundant and commented-out code

- **Removed Legacy Code**:
  - Removed all BPv6-related code and configuration
  - Removed bpversion utility (superseded by version commands in admin tools)
  - Removed bprecvfile2 (obsolete)
  - Removed duplicate source files (ams/library crypt.c and marshal.c)
  - Cleaned up obsolete demos and redundant tests

Bug Fixes

- **Bundle Processing**:
  - Fixed acquireEid return value check and bundleZco leak
  - Fixed parseEidString concurrency issue with internal copy
  - Fixed bpecho spurious "!" output and added TTL option
  - Fixed bpcancel to use strtouvast() for creationMsec parsing
  - Fixed bss-multicast infinite loop when stdin is redirected

- **Network Operations**:
  - Fixed CLA loopback tests leaving orphaned processes
  - Fixed TCP outduct receive thread shutdown
  - Fixed bpcp Remote_Remote transfer race condition on exit
  - Fixed stdout redirection pattern compatibility

- **Memory and Resource Management**:
  - Fixed unsigned underflow in SDR performance time difference macro
  - Improved reference counter management throughout codebase
  - Fixed qualifier and const restriction issues

Miscellaneous

- **Command Line Tools**:
  - Added linenoise library for command history support in interactive tools
  - Updated system_up script to check only required programs per test
  - Improved error messages and diagnostic output

- **Development Tools**:
  - Renamed dev makefile platform from i86_64-fedora to x86_64-linux
  - Updated build configuration for TC module integration
  - Fixed ionwatch compilation issues

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.4-b.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

This beta release represents a major milestone with the completion of the RTEMS 6.1
port, significant improvements to code quality and portability, new networking
capabilities, and enhanced utilities for bundle management and CFDP file transfers.

RTEMS 6.1 Real-Time Operating System Port

- Full RTEMS 6.1 Port: ION has been successfully ported to RTEMS 6.1 for ARM64
  (AArch64) platforms, featuring:
  - Support for RTEMS libbsd (FreeBSD network stack) integration
  - UDP-based LTP networking tested and verified in QEMU simulation
  - 64-bit addressing support (SPACE_ORDER=3)
  - ION Admin Public API for configuration (no configuration files required)
  - Comprehensive documentation in arch-rtems/ directory
  - Template implementation for adaptation to specific hardware platforms
  - CI/CD workflow integration for RTEMS builds

Dual-Stack IPv4/IPv6 Networking Support

**IMPORTANT NOTE ON DUAL-STACK NETWORKING**: The dual-stack IPv4/IPv6 capability
will automatically use the network address family returned by hostname resolution.
Most operating systems return IPv6 addresses first when available, and ION's network
stack will use the first entry returned. If a host is not properly configured for
the returned address family, this may cause network address family conflicts,
resulting in connection failures for TCP, UDP, and LTPCLA (which runs over UDP).
The most reliable approach is to use explicit IP addresses if known. If using
hostnames, ensure all hosts resolve to the correct address family as the first entry
in DNS resolution.

- LTPCL Dual-Stack: Added experimental dual-stack IPv4 and IPv6 support for the
  LTP Convergence Layer, allowing nodes to communicate over both protocol versions
  simultaneously.

- TCPCL Dual-Stack: Implemented dual-stack IPv4 and IPv6 support for the TCP
  Convergence Layer with regression tests.

- UDPCL Dual-Stack: Previously introduced in 4.1.4-a.2, further refined and tested
  for production use.

New Bundle Management Utilities

- bpinspect: New utility for inspecting, filtering, and managing bundles in ION's
  custody. Features include:
  - Bundle listing with detailed metadata
  - Filtering by source, destination, creation time, and other attributes
  - Suspend and resume operations for selective bundle processing
  - Critical bug fix for bp_suspend functionality

- bptracker: Enhanced interactive mode for demonstration of bundle tracking
  capabilities, providing fine-grained control over individual bundles with:
  - Flexible send syntax
  - Real-time bundle status monitoring
  - Source routing record (SRR) parsing improvements

- bpcrash_hard: New testing utility for validating ION's crash recovery and
  reversibility features under extreme failure conditions.

CFDP Enhancements

- Enhanced cfdptest Utility: Major improvements to the CFDP testing tool:
  - Transaction tracking and summary display
  - Per-transaction control commands (cancel, suspend, resume)
  - Terminology updates (ack → closure-reqt) for RFC compliance
  - Reset command (R) to clear source/destination filenames
  - Version command (v) for build information
  - Updated man pages and usage documentation

- Empty File Transfer: ION now correctly handles CFDP transfers of zero-byte files.

- Automatic Proxy Launch: CFDP server proxy (bpcpd) can now be automatically
  launched through cfdprc configuration file.

- Event Reporting: Enhanced CFDP event reporting API with more detailed file
  transfer status and progress information, including closureRequested field.

LTP Protocol Improvements

- Dynamic Parameter Control: New capability for direct configuration of LTP
  maxRetries and segment loss rate parameters with updated regression tests.

- Default Value Behavior: Updated default parameter handling for improved
  reliability and performance.

Code Quality and Standards Compliance

- C18/C99 Compliance: Updated build system to prefer C18 (ISO 9899:2018) standard
  with fallback to C99, ensuring maximum portability and standards compliance.

- Strict Compiler Warnings: Enforced -Wextra, -Wstrict-prototypes, and -pedantic
  compiler flags across the entire codebase, resolving hundreds of warnings to
  improve code quality and catch potential bugs.

- Thread Safety: Implemented thread-safe versions of iToa, uToa, vastToa, and
  uvastToa functions with proper type-specific conversions for 32-bit systems.

- POSIX Compliance: Refactored POSIX named semaphore implementation with reference
  counting and deferred deletion to mitigate race conditions, particularly for
  bpcp utility.

Security and Stability Fixes

- Extension Block Overflow: Fixed buffer overflow vulnerability when processing
  non-standard extension blocks. Added regression test for memory allocation
  vulnerabilities.

- BPSec Configuration: Corrected handling of bundles with no CRC and no BIB,
  with tests to verify proper rejection of invalid security configurations.

- NULL Source EID Handling: Fixed bug in handling NULL source EIDs and state
  changes between bundle list and cancel operations.

- Race Condition Fixes: Addressed semaphore cleanup race conditions in bpcp and
  resource lock initialization issues.

Contact Graph Routing (CGR) Enhancements

- Adjacent Contact Support: Prototype support for adjacent contact routing with
  documentation and test cases.

- Routing Visualization: Automated generation of routing visualization data
  through cgrfetch utility improvements, enabling graphical analysis of routing
  decisions.

- CGR Analysis Tools: Refactored cgr-test and asymmetric-range tests to produce
  sample CGR analysis data with comprehensive usage documentation.

Platform Portability Improvements

- macOS Compatibility: Resolved multiple platform-specific issues including
  compilation syntax errors and system() call restrictions with active child
  processes.

- FreeBSD Support: Updated for compatibility with FreeBSD networking stack and
  build environment, including tar-over-ssh deployment for CI/CD.

- Solaris Support: Addressed compiler warnings specific to Solaris and added
  timeout protections for test suite stability.

- ARM Architecture: Fixed ARM default unsigned char issues in tcpcli.c and other
  platform-specific type handling.

- MUSL libc: Enhanced compatibility with MUSL C library and Clang compiler, though
  semaphore limitations require single-instance deployment per host.

Build System Enhancements

- Configure Options: New options to selectively disable DGR and BSSP modules
  (--disable-dgr, --disable-bssp) for minimal builds.

- ion-core Build: Per-extension build options for customized ion-core package
  configurations.

- Development Makefiles: Continued maintenance and updates to manual Makefile.dev
  system for i86_64-fedora platform, including support for new executables:
  - SPP convergence layer (sppcli, sppclo)
  - New test utilities (entropy_test, sdr_test_util)
  - Bundle inspection tool (bpinspect)
  - Additional diagnostic tools

Testing and CI/CD Improvements

- Regression Test Suite: Enhanced test infrastructure with:
  - Optional test designation for non-critical tests
  - Improved cleanup handling for failed tests
  - Timeout mechanisms to prevent hanging tests
  - Preservation of test logs (PRESERVE_TEST_LOG default to 1)
  - Automated ION security database initialization

- GitHub Actions Workflows: Updated CI/CD pipelines with:
  - RTEMS-specific build workflow
  - Submodule initialization improvements
  - Workspace cleanup between runs
  - ion.log capture and custom timeout support
  - JSON dependency validation

- Cross-Platform Testing: Expanded test coverage across Linux, macOS, FreeBSD,
  and Solaris platforms with platform-specific accommodations.

Documentation Updates

- Public API Documentation: Added comprehensive online documentation for ION's
  public administrative API set.

- RTEMS Documentation: Complete documentation package for RTEMS 6.1 port in
  arch-rtems/ directory, including:
  - Installation and build instructions
  - Key fixes and troubleshooting guide (KEY-FIXES-SUMMARY.md)
  - UDP network status and configuration (UDP-NETWORK-STATUS.md)
  - Platform-specific customization guidelines

- Man Page Updates: Updated documentation for LTP maxRetries parameter
  clarification and deprecated maxber usage in regression tests.

Deprecations and Cleanup

- maxber Parameter: Deprecated use of maxber in regression tests; updated
  documentation to clarify proper usage.

- Legacy Code Removal: Continued cleanup of obsolete code including old dtnperf
  (now part of dtnsuite).

- SBSP References: Removed confusing SBSP references from build flags and include
  paths.

Known Issues and Limitations

- MUSL libc: Named semaphore limitations restrict deployment to one ION instance
  per host; many regression tests will fail due to this constraint.

- RTEMS Port: Template implementation requires adaptation to specific hardware
  platforms and BSPs; loopback testing defaults to 127.0.0.1.

- Dual-Stack Networking: IPv4/IPv6 dual-stack features remain experimental;
  production deployments should be thoroughly tested.

Developer Notes

- Thread Synchronization: Refactored libams to use platform abstraction layer for
  thread synchronization.

- Type Conversions: Created type-specific ToString functions (vastToa, uvastToa,
  size_tToa) for improved type safety and 32/64-bit compatibility.

This beta release includes 162 commits since ION 4.1.4-a.2, representing extensive
testing, refinement, and new capabilities. Users are encouraged to test thoroughly
in their environments and report any issues through the GitHub issue tracker.

= Release Notes for ION 4.1.4-a.2 =

September 19, 2025


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.4-a.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

This release introduces several new experimental features, key updates, and
bug fixes while removing obsolete code.

Removal of BPv6

The BPv6 codebase has been removed starting with this release. This legacy
code had remained unchanged since ION version 3.7.4. For users who still
require BPv6, the final stable release containing it is ION 4.1.3s.

Experimental Features

- Dual-Stack for UDPCLA: Introduced experimental support for IPv4 and IPv6
  dual-stack networking in the UDP Convergence Layer Adapter.

- 'IPN' URI Scheme: Added a prototype implementation for the updated 'IPN'
  URI scheme, as specified in RFC 9758.

- SPP Convergence Layer: Included a prototype of the Space Packet Protocol
  (SPP) convergence layer adapter for experimentation.

Improvements & Stability Fixes

- Security: A new, robust, and platform-native entropy polling module has
  been added to meet high-integrity standards for cryptographic key generation.

- Networking: An address caching and re-resolution mechanism was added for
  the UDPCL output and LSO daemons (UDPCLO/UDPLSO).

- The ION codebase has been decoupled from GNU-C extensions to improve
  portability.

- ION can now be compiled on MUSL libc using the Clang compiler.
    Due to limitation of the maximum allowed named semaphores for MUSL, it
    is recommended that user deploy only 1 instance of ION per host. Many
    regression tests are expected to fail since they require multiple instances
    of ION running simultaneously on the same host.

- Fixed a bug in the ionlauncher capability.

- Resolved an issue in the ionTerminate function that caused crashes
  during the ION shutdown process.

- Corrected a bug that allowed a node to source a bundle with an incorrect
  node number.

- The cfdptest program was updated to provide detailed event reporting and
  a new directory listing command. The event reporting API was also enhanced
  to deliver more detailed file transfer status and progress.

- The obsolete civetweb-based REST API for the network management module
  has been removed.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.4-a.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Beginning with ION 4.1.4, alpha and beta releases will be issued between the
releases to make new features and bugfixes available for community testing.

Alpha and Beta releases are tested on a limited number of platforms and may
contain known bugs/idiosyncrasies, which will be documented in the release
notes.

Updates for alpha release #1:

update-4.1.4-cfdp-out-of-order-eof
  * Updates CFDP algorithm handling of out-of-order arrival PDUs.

update-4.1.4-a1-bpsec-config-doc
  * Adds BpSec configuration example to online documentation.

multicast-issue-273-4.1.4
  * Fixes an issue related to Multicast startup order requirement.

multicast-issue-273-4.1.4
  * Fixes issue with multicast startup order

update-4.1.4-keygentime-fix
  * Fixes a specific DTKA configuration issue.

update-4.1.4-freebsd-update
  * Update to address various freebsd build issues

update-4.1.4-fix-ovrd-crash
  * Fix crash caused by reading deleted bundle's ovrd metadata in SDR.

update-4.1.4-unibo-cgr-relocate
  * Relocate unibo-cgr code to contrib folder as a git submodule referencing external repository where code is actively maintained. This change also applies to the dtnsuite and dtnperf source code in the contrib folder. Removed the RGR extension block code that contains security vulnerability; notify the developer of Unibo-CGR to update the code upstream.

update-4.1.4-resource-lock-fix
  * This resolved the main issue of correctly initializing the mutex (the previous mutex was repeatedly initialized); upgrade to POSIX recursive mutex to simply operation. For older SVR4 Unix-based systems, such as Solaris predating v10, it may not work. Similarly, on Windows, older mingw may not work.

update-4.1.4-lockPartition-concurrency-fix
  * Fix concurrency issues of partitionLock

update-4.1.4-windows-build
  * Update instructions and dependency installation scripts for windows 10 build prototype

update-4.1.4-address-sanitizer-rebase
  * Fix buffer and various memory overflow discovered by address sanitizer instrumentation.

update-4.1.4-issue_455_mc_doc
  * Adds best practices for multicast to documentation

update-4.1.4-tc-dtka-duration
  * Reduce regression test time for dtka using only 1 key type; can be changed by env variables set at test time.

update-4.1.4-ionterminate
  * Fixes a segfault whenever ION shutdown routines are called (ionTerminate)
    and ensures ION shared resources are released.
  * This is work-in-progress due to concurrency issues: if another process tries
    to access the SDR while ionTerminate() is running, that other process has
    been observed to segfault; but the shutdown routine itself still finishes
    successfully and releases shared resources. This is an improvement over the
    previous unavoidable segfault in ionTerminate() that always left the SDR
    shared memory in an unusable and unrecoverable state, from then on
    triggering failures or segfaults in processes attempting to attach to or
    reinitialize the SDR.

%%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.3s =
%%%%%%%%%%%%%%%%%%%%%%%%%%%

Beginning with the ION 4.1.3s release, ION will include support for compilation
with Mbed TLS cryptographic library. ION version 4.1.3s includes support for Mbed TLS version 2.28.

To enable use of Mbed TLS cryptogrpahic library in ION, you must have already built the Mbed TLS
  version 2.28.x shared libraries with #define MBEDTLS_NIST_KW_C enabled (see mbedtls/include/mbedtls/config.h).

  Make sure the Mbed TLS assets are installed in /usr/local/include/ and
  /usr/local/lib with correct permissions, or you can define alternate
  locations by running:
    ./configure --enable-crypto-mbedtls MBED_LIB_PATH=/path/to/libraries MBED_INC_PATH=/path/to/includes

To build Mbed TLS:
  1. Download the Mbed-TLS 2.28.2 source code.
  2. Open mbedtls-2.28.x/include/mbedtls/config.h and uncomment the line
    that has #define MBEDTLS_NIST_KW_C commented out by default.
  3. Run the following commands:
    Linux and MacOS)
        make SHARED=1
        sudo make install
    Windows 7)
        make CC="gcc -std=c99" WINDOWS_BUILD=1 SHARED=1
        make CC="gcc -std=c99" WINDOWS_BUILD=1 install
        * NOTE: this should install things in /msys/local which is okay

To compile ION with MBEDTLS_SUITES configure with:
  ./configure --enable-crypto-mbedtls

To enable BPSec logging (recommended for verification of BPSec functionality and required by BPSec regression tests)
    use the following configuration flag:
    --enable-bpsec-debugging

The following code changes have been made to support this option:
  * Added ici/MBEDTLS_SUITES folder.
  * Updated configure.ac and Makefile.am to allow for linking against
    MBEDTLS libraries.

ION 4.1.3s provides a 'enable_manual_build.sh' script that switches ION from autoconf build system (the default)
to the manual developmental build system based consisting of a Makefile at the root of ION source tree and a set of Makefiles
under the directories of individual components of ION. See the online documentation for more details.

Branches included in this release:

update-4.1.3s-ion-documentation
  * Update ION documentation files.

update-4.1.3s-bpcounter-delivery-release
  * Updates the bpcounter.c program so it releases the pilot bundle.

update-4.1.3s-dtnnone-vulnerability
  * Addresses a vulnerability that freezes ION if a bundle with
    null-endpoint were injected into ION node.

update-4.1.3s-imc-pnb-extblock-crash
  * Fixes a vulnerability when a pnb extension block contains invalid eid
    (or say imc scheme for a node that does not recognize it) causing a crash
    of the bundle acquisition process.

update-4.1.4-test-suite
  * General improvements to the test scripts.

update-4.1.3s-cgrfetch
  * Fixes a segfault at the end of cgrfetch call.

update-4.1.3s_libmetadata_libsecypt
  * Includes branch update-4.1.3s_bpsec_updates and also update-4.1.3s_secfix_testfix

feature-msys2-update
  * Adds autoconf build process for Windows 10 using msys2 and mingw64.
  * This update is experimental and has not been tested against MBEDTLS_SUITES
    (just NULL crypto suites).

update-4.1.3s-bpcp-and-test
  * Support for how ion-core builds bpcp.
  * Creates tests that can imported into ion-core for LTP and STCP
    convergence layers.

4.1.3s_makefile_correction
  * Remove incorrect inclusions of libsecrypt and libmetadata from libbp.

update-4.1.4-extension-block-crc16
  * Turn on CRC16 for all blocks.

bpsec-fixes-5-27-2024
  * APL fix for a specific case where BPSec may allow a bundle to fail BIB/BCB
    but still be accepted.
  * Allow relay nodes not to have a policy.

bpsec-fix-1-June-2024
  * Fix accounting issue with ZCO when using BIBE with BPSec.

update-4.1.4-ionstart-upgrade
  * Update start script to support syntax that allows multiple ionrc files
    to be specified.

update-4.1.4-bssrecv
  * Updates to bssrecv program and documentation.

integration-4.1.3s-util-signals-fix
  * Added signal handler for SIGINT to properly shut down child processes.
  * Added signal handler for SIGTERM for graceful termination of the process.

integration-4.1.3s-smart-file-update
  * Updated smart file transfer utilities with file size reporting and improved
  message logging.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.3 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

Branches included in this release:

update-4.1.3-ams
  * Add AMS demo (benchtest).
  * Update AMS programmer's guide (v3.0).
  * Fix amshello demonstration program (resolves multi-thread errors).

update-4.1.3-ams-test-fix
   * Update AMS regression tests (ams-sana and issue-319-parseSocketSpec).
   * Fix pointer arithmetic error on big-endian OS.

update-4.1.3-android
  * ION 361 port for Android 64bit snapdragon 855 HDK.

update-4.1.3-bench-ltp-fix
  * Update bench test for faster machines like Mac M1.

update-4.1.3-bss
  * Update man pages for bss applications.
  * Fix bssOpen, bssClose, bssStop, bssExit, bsscounter, and bssdriver.
  * Fix memory leak due to premature ionDetach.
  * Fix bpcounter handling of late pilot bundle.

update-4.1.3-bug-report-url
  * Replace old SourceForge email with GitHub URL for issue reporting in manpages.

update-4.1.3-commandline-history
  * Update admin programs to have commandline history option.
  * Configure with --enable-commandline-history when building ION.

update-4.1.3-contrib-kari-ion-config
  * KARI-provided ION configs used for testing ION with non-ION DTN implementations.

update-4.1.3-demo-tests
  * Fix eval conditions in demo tests.

update-4.1.3-dispatchBundle
  * Fix loopback problem with imc and CRC parsing for multiple bundle ZCO.

update-4.1.3-enhance-wchar
  * Add bp level information such as node number, and service number to enhanced
    watch character.
  * Convert watch character from char to string.
  * Configure with --enable-ewchar when building ION.

update-4.1.3-extension-zco-bpdequeue
  * Fix bpsec extension block ZCO accounting.

update-4.1.3-gcc12fix
  * Fix errors from gcc12.

update-4.1.3-ionrestart
  * Updated ionrestart program to prevent restart loop.

update-4.1.3-key-value
  * Prevent unique key value from turning negative.

update-4.1.3-killm
  * Updates to killm script to work correctly (and nearly the same) on all
    supported non-windows platforms (and fixing solaris)

update-4.1.3-ltp-udplso
  * Import fix for udplso hanging at shutdown from IONe.

update-4.1.3-malformed_eid_fix
  * Fix copies eid string to correct critical malformed EID error.

update-4.1.3-misc
  * Remove ION_OPEN_SOURCE conditions in start and stop scripts.
  * Add and update various man pages.
  * Update LTP config tools and documentation.

update-4.1.3-named_posix_semaphores
  * Added a test for the semaphore subsystem called sm_subsystem that performs
    a stress test on whatever low-level OS semaphore system was configured to
    look for problems that have occurred in previous versions
  * Added a new platform-dependent semaphore system based on Posix Named
    Semaphores. The old default was to use the AT&T System V Release 4 (SVR4)
    semaphores that are supported on just about ANY OS platform. Those
    semaphores predate modern multi-core architectures and multi-thread
    instructions and rely instead on system calls for all operations, which
    makes them extremely slow. Posix Named Semaphores will use modern CPU
    multi-core instructions when available on most platforms so that most
    signal() and lock() semaphore operations can be performed in user-space
    in the current process/thread. Our tests show decrease in signal()/lock()
    times from 50% to 3300% depending on the platform. The end effect is
    that, when using small bundle sizes (less than 1000 bytes), network data
    throughput using LTP (as one example, but applies to all convergence
    layers) increases at least 11% (Solaris Intel VM) and as much as 350%
    (Ubuntu Intel VM) with no other changes. Improvement varies greatly
    between different CPUs and systems, but was always faster than the old
    system.
  * When built on Linux / Solaris / MacOS, the ION build system will default
    to using the new Posix Named Semaphores.
    To use the old SVR4 semaphores instead, configure using
      ./configure  --enable-force-svr4-semaphores
  * When built on all other platforms, the ION build system will default to
    using the previous semaphore subsystem default (SVR4 for most systems)
    You can try to force the new semaphores instead by configuring with
       ./configure    --enable-force-posix-named-semaphores
    Note that we haven't tested the new semaphores on any systems other than
    the ones for which the build system recommends their use.
  * The quickest way to see if the new semaphores are being used is to run
    the sm_subsystem test, which will identify the semaphore system when it
    starts. It will also tell how many Posix Named Semaphores are configured
    into the system. The output will also tell you how many lock()/signal()
    operations per second it can run if you want to do your own comparisons.
  * Like the SVR4 semaphores, the new Posix Named Semaphores require an
    internal data structure which occupies a small amount of memory per
    configured semaphore and per process. The current default build system
    creates 2048 semaphores. That's more than a single production
    instance of ION is likely to need by a factor of 10 (likely). A modern
    multiprocessor OS would consider that extra memory negligible, but on a
    constrained platform, that setting should be tuned more carefully to save
    memory. The system keeps track of the maximum number of Posix Named
    Semaphores ever used, but there is currently no interface to provide that
    number (see routine _semPrintTable() ).
  * Like the SVR4 semaphores, the new Posix Named Semaphores are global to
    ALL running instances of ION on the local computer, so the max number
    configured must support all local ION instances

update-4.1.3-platform-c
  * Fixed isprintf() parsing bug.

update-4.1.3-psm
  * Fixed problems with psm and sptrace.

update-4.1.3-runtests_scripts
  * Enhancements to runtests script to quiet unnecessary output and add
    progress files.
  * Now also creates a file called "progress" (also with a date as file name
    suffix for archiving results) that lists the test date, testing host,
    testing kernel, and the results of each test without all the noisy
    output. This makes it easier to check on the status of a
    long-running test session that has many individual tests.
  * Setting environment variable as in:
      export RUNTESTS_OUTPUTDIR="/tmp"
    will save the detailed output from EACH test in its own file of the form
    /tmp/results.bping   (using the directory in the envariable)
    INSTEAD of on the screen to make it easier to find the output from a
    failed test in the middle of a long run.

update-4.1.3-sdrxn
  * Disable reversibility if there is no transaction modification.
  * Add bpcrash to developmental Makefile.

update-4.1.3-smart-file-transfer
  * Add new file transfer utilities: sendfile and recvfile with cryptographic and
    metadata-based features, including file naming (with optional sequencing or
    overwrite), time-to-delivery tracking, auxiliary command strings, and HMA
    key-based AEAD encryption and decryption. By default, these utilities use
    bpsendfile and bprecvfile commands but also provide additional parameters for
    security keys (enabling encryption and decryption) and the auxiliary command
    strings.
  * Included Library Objects:
      libmetadata and libsecrypt (an interface to MBEDTLS 2.28.x).

update-4.1.3-srr-flags
  * Fixes for status report request flag parsing from bundle processing flag.
    Fix for both transmit and receive side.

update-4.1.3-testset
  * General updates to regression tests to improve reliability.

update-4.1.3_clang_compiler_updates
  * Eliminate warnings and errors from newer versions of the Clang compiler.

update-bping-multiple-instances
  * Updated bpv7 bping to correctly check for its PID in the response bundles and
    ignore bundles with no pid present or a mismatched PID.

Feature-4.1.3-bpsendtest-bprecvtest
  * Added two new utilities for testing connectivity and throughput between
    nodes - bpsendtest and bprecvtest. They act similarly to bpsendfile and
    bprecvfile, but differ in the following ways:
    - bprecvtest:
      * Discards all incoming data, just tracking the quantity of data received.
    - bpsendtest:
      * Ingests the file to memory once and allows sending the generated bundle
        repeatedly without needing to reopen the file.
      * Accepts a -nofile option, allowing one to specify the length of a bundle
        to send in bytes; random data of that length will be generated and sent.
  * These act as an improvement to the testing suite available as bpdriver/bpcounter
    have performance issues with generating small bundles rapidly enough to saturate
    higher bandwidth links due to generating new data for each bundle.
  * They also improve upon using bpsendfile/bprecvfile as they allow for sending the
    same data multiple times without needing to rerun the sending utility or reopen
    the file, and do not run into storage or memory bottlenecks on the receiving
    side as the received data is not being saved (this also results in easier
    cleanup than when using bpsendfile/bprecvfile in a similar manner).

Feature-4.1.3-bptrace_update
  * Updated bpv7 bptrace utility to (optionally) display received reports to the
    terminal in a rudimentary way.
    - Prior argument format is still supported, should be fully back-compatible with
      old testing scripts which may have used bptrace.
    - bptrace will output to the log file as before when using this legacy format,
      when the reportEid is on a different node from the sender, or the reportEid
      is an admin endpoint.
    - Added bptrace_terminal_test (bpv7 only), which tests bptrace for compatibility
      with the legacy argument format, with output to the terminal, and with log
      file output when using new argument format with an admin endpoint for the
      report endpoint.

feature-4.1.3-dtka-mbedtls
  * Updates crypto library from PolarSSL to mbedtls. Makefile needs to be updated
    include -lmbedtls -lmbedcrypto when -DCRYPTO_SOFTWARE_INSTALLED is set.
  * Updates tests to handle issues with multicast.

feature-ionlauncher
  * Add ionlauncher utility to simplify configuring and starting an ION node.

debug-4.1.3-bpsec-etc
  * Bug fixes for bpsec subsystem (resolves all known critical issues).

1010-pingpong-ct-robustness-jun2024
  * Adds robustness against timing changes, low poll rates and more iterations.

bibe-updates
  * Makes the bcla structure (managed by bibeadmin) more powerful, such that you now
    use it to configure all of the “bp_send” parameters for the encapsulating
    bundles (BPDUs). For example, it now enables you to request bundle status
    reports pertaining to the encapsulating bundles.
  * Simplifies the configuration elements that cause source bundles to be
    encapsulated. No need for class-of-service overrides: when you assert the
    routing override that causes the bundles to be forwarded to the BIBE peer node,
    you just note in that override the BIBE outduct that you want used for
    transmission to that node.

integration-4.1.3-quiet-posix-semaphores
  * Fixes for posix named semaphore logging to remove the amount of redundant
    status information going into the ION log.

integration-4.1.3-update-bpv6-bssp-test
  * Fixes the bssp and bssp-planrule tests failure.

python-test-fixes
  * Bug fixes for bpsec Python test suite.
  * Add configure option that changes logging level so that bpsec Python tests will
    execute properly. Configure with --enable-bpsec-debugging when building ION.

Bugfix-4.1.3-ams-local-host-lookup
  * Changed getAddressOfHost() to use 127.0.0.1 as the default when looking up your
    own hostname fails.
  * Changed 10 instances where the functionality provided by getAddressOfHost() was
    re-implemented to correctly call the subroutine instead.

BugFix-4.1.3-ltp_init_config
  * Removed ignored second argument to ltpadmin initialize command from configs.

bugfix-4.1.3-ltpheapmax
  * Enables runtime changes to LTP heapmax.

bugfix-4.1.3-reversibilitychecks
  * Address failure of reversibility checks 1 and 2 on Ubuntu. Includes some tweaks
    to ionrestart and a major reorganizing of the steps in both reversibility
    check 1, and 2 to clarify the configuration and the actions in each test.

Bugfix-4.1.3-sdr-transaction
  * Fixes modified flag bug for nested transaction.

Bugfix-4.1.3-tests-shebang-fix
  * Fix multiple tests where shebang (#!/bin/bash) is not the script's first entry.

bugfix-integration-4.1.3-status-assertion-encoding
  * Added cbor_encode_boolean, cbor_decode_boolean functions to the cbor files.
  * Updated serializeStatusRpt, parseStatusRpt functions to correctly utilize
    these boolean constants.


%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

Branches included in this release:

118-provide-initial-rfc9172-rfc9173-support
  * added support for BPSec (RFC 9172) and default security contexts (RFC 9173)

125-update-ion-4-1-1-amp-implementation-with-current-enhancements-and-bugfixes
  * added network management updates

apl-4.1.2-updates
  * The implementation of BPSec in ION Open Source (IOS) 4.1.2 is not
    feature-complete and is considered to be a “beta” version of BPSec.
    This early release of the code allows users to begin to integrate BPSec into
    their projects, as core functionality is implemented, as well as encourages
    early testing and feedback for the major BPSec release in IOS 4.2.

    A feature-complete implementation of BPSec (RFC 9172) will be provided in the
    ION Open Source 4.2 release. Additional information is provided in the file:
      IOS_4.1.2_BPSEC_Release_Notes.pdf

Bugfix-4.1.2-nm_manager-database-connection-issue
  * added fixed nm/contrib/amp-sql-1.0.1.tar.gz

bugfix-4.1.2-tcpbso
  * fixed tcpbso parsing of 0.0.0.0
  * added tcpbso connection memo

bugfix-4.1.2-bssp-max-block
  * fixed max-block transaction crash

bugfix-4.1.2-crc-parsing
  * fixed issue with parsing CBOR encoded CRCs

bugfix-4.1.2-ltp
  * updated default maxber for ltp
  * fixed ionwm memory leak
  * added status message for CLOSED_EXPORTS_ENABLED

bugfix-4.1.2-custodyRefusedCountBytes
  * fix for Source Forge bug report #162

bugfix-4.1.2-cp-duplicate-reddata
  * fixed CP handling with duplicate data
  * fixed out-of-order red part reception

dso-bprecvfile-integration-4.1.2
  * new bprecvfile2 application that adds filename and pipe capabilities

Makefile-cleanup-integration-4.1.2
  * added remove for .so files for developmental Makefiles
  * added uninstall target for developmental Makefiles

update-4.1.2-bssp-wchar
  * updated bssp watch characters

update-4.1.2-shared-mem
  * fix various shared memory issues with detaching from and resetting the
    ION database

update-4.1.2-tcpcl-tests
  * fix various issues in TCP related tests

update-4.1.2-makefile
  * updated developmental Makefiles to accept commandline flags

update-4.1.2-psmwatch
  * resolved assertion failures issued during psmwatch
  * fixed inconsistent alteration of the map -> status value

update-4.1.2-developmental-makefiles
  * updated fedora developmental Makefiles to build a single libbp to match
    what the autoconf system does. This allows for "mixed-mode" builds on
    generic Linux platforms where ION is originally built using autoconf and
    then individual modules are rebuilt using the developmental Makefiles.

update-ams-documentation-4.1.2
  * fixed errors in AMS documentation

upgrade-4.1.2-ams-sana-numbers
  * lowered the AMS cell census period from 90 seconds to 9 seconds
  * replaced hard coded cell census values with appropriate preprocessor
    directives
  * increased the maximum allowed AMS Continuum number from 20 to 32767


Added new TCPCL_LOW_CYCLE macro and configure option (--enable-tcpcl-low-cycle)
  * This option reduces the TCP connection timeout from several minutes down to
    a few seconds and lowers the frequency of repeated connection attempts with
    TCPCL peer nodes that are not responding to handshaking messages.
    This is an experimental feature only available on Ubuntu as of ION 4.1.2.

To verify the SHA256 hash provided with the release, please
  contact Jay Gao at Jay.L.Gao@jpl.nasa.gov

If you have any issues, please submit a SourceForge ticket here:
  https://sourceforge.net/p/ion-dtn/bugs/new/

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

Beginning with the ION 4.1.1 release, we will no longer be distributing
two separate .tar.gz files (one that builds with BP version 6 by default and
one that builds with BP version 7 by default). Instead, we will distribute a
single ION .tar.gz file that builds with BP version 7 by default. If you wish
to use ION with BP version 6, you can use use the --enable-bpv6 configure
option. If you are building ION from source on Windows for BP version 6, you
will need to run the command "make bpv6".

After ION version 4, all BP version 6 related changes will be bug fixes
unless explicitly identified as otherwise.

Branches included in this release:

misc-4.1.1-fixes
  * Improve the killm script
  * Update pilot delay and add rate control for bpdriver
  * Change SourceCustodyRequired to NoCustodyRequested for AMS
  * Add a version of the req-003-multicast test for BP version 7
  * Fix a bug in librams.c that caused AMS petition assert/cancel
    flip-flop
  * Various updates for Makefiles (autoconf and manual)

apl-4.1.1-security-patches
  * Added BPSec Python test suite
  * Added accommodation of NULL terminator in security policy parameters
  * Added checks for NULL pointer references when a BCB targets an
    extension block
  * Added TEST_POINT macros to BIB and BCB code to log test events

last-pre-git-tweaks
  * Add a warning about potential forwarding loops
  * Fix a typo in biberc documentation

autoconf-updates-MacOS_M1-WSL
  * Fix line ending encoding error in install_macos_sysctl.sh script
  * Add support for building ION on MacOS using the new M1 processor
    * At this time, ION works correctly on the M! processor with MacOS
      version 11.6 (Big Sur) but does not run properly on version
      12.0.1 (Monterey)
  * Add support to configure ION to build on WSL2 but not WSL1
  * ION has also now been tested on RedHat Linux


%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.1.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

ION 4.1.0 is the first release in which the BPv7 implementation is
conformant to the BPv7 protocol specification that will shortly be
published by IETF as a standards-track RFC.

The accompanying BPsec implementation is similarly conformant to
the BPSec specification that will also soon be a standard-track RFC.
NOTE, though, that the TCP convergence-layer protocol implementation
in ION 4.1.0 still conforms to the original TCPCL specification (RFC
7242), NOT to the upcoming TCPCL standards-track RFC; that upgrade
will be supported in a future release.

Another key change in this release is that Aggregate Custody Signaling
is no longer enabled by default.  (Due to some new features in ACS
configuration, when ACS is enabled the bpv6 bpclock daemon will no
longer run successfully unless the ACS database is initialized.
Since not all ION bpv6 users currently initialize ACS in node startup,
disabling ACS by default seems to be the best way forward.)  If you
DO want ACS for your bpv6 environment, include the "enable-acs" switch
when you generate the Makefile, e.g.:

	./configure --enable-acs

Additionally, three new features are included in ION version 4.1.0
(along with various bug fixes).

First, an option is provided that will enable ION to run at much higher
speeds over those portions of a bundle's end-to-end path that are
supported by TCP/IP at the convergence layer.  To enable this option,
include the "--enable-high-speed" switch when generating the bpv7 Makefile.

Also, it is now possible for ION's LTP implementation to utilize multiple
different underlying link service protocols on input as well as on
output.  The latter have always been configured by means of the "LSO
command" associated with the "span" for LTP segment transmission to a
remote LTP engine.  The former may now be configured by means of "LSI
commands" associated with multiple LTP segment reception "seats" at
the local LTP engine.  See the ltprc(5) man page for more information.

Finally, a mechanism has been introduced that will automatically
synchronize a contact plan among all nodes that are cited in the
contacts listed in that contact plan.  This synchronization requires
that the nodes be configured for bundle multicast; it is controlled
by means of the new "!" command as processed by ionadmin.  See the
cpsync test case (in ion-open-source/tests) for an example.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.0.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

The main driver for this release is integration of the security policy
procedures, which ensure that Bundle Protocol Security mechanisms are
enacted appropriately for each bundle.  A detailed description of these
procedures and the modifications to ION that they entailed is provided
in a supplementary file of Release Notes.

Additional features of the 4.0.2 release:

-  A plug-in module for Contact Graph Routing, developed by the University
	of Bologna, can now optionally be used instead of the original CGR
	implementation in ION.  Unibo-CGR includes options for some additional
  features that can improve performance and guard against routing loops.

-  Several errors in CRC computation, discovered during testing at the
	European Space Agency, have been corrected.

-  Several problems in the implementation of Bundle-in-Bundle Encapsulation,
	discovered during Keith Scott's testing for DevKit upgrades, have
	been addressed.  Previously there was no way to configure ION for
	BIBE transmission to a topologically adjacent node, but a
	mechanism built on routing overrides has fixed that; see the
	biberc(5) man page for details.  NOTE: in BPv7, custody transfer
	is a feature of BIBE rather than BP, so it needs to be configured
	in BIBE configuration.  You can still request custody transfer for
	an individual bundle when you call bp_send but when you do that,
	IF ANY NODE ON THE END-TO-END PATH TO THE DESTINATION IS NOT
	CONFIGURED FOR BIBE FORWARDING THEN THE BUNDLE WILL BE DISCARDED
	AS UNFORWARDABLE.  BE CAREFUL.

-  A shortcut option for resuming the operation of a node that has been
	"stopped" (all daemon tasks ave been terminated) but not destroyed
	(node state has been preserved) has been added: just pass command
	file name "!" to each of the core administration utilities (ionadmin,
	ltpadmin, bpadmin, cfdpadmin).

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.0.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

Branches:

cgr-multicast (bpv7 only)
     Bundle multicast is made simpler and more resilient: multicast bundle
     propagation is driven by routes computed by the contact graph routing
     system, so no infrastructural spanning tree is needed.  The imcadmin
     utility is deprecated.

trustedCollective
     The prototype Delay-Tolerant Key Administration system in "contrib"
     has been refactored into (a) a general-purpose "trusted collective"
     mechanism ("tc") that relies on the new bundle multicast mechanism
     and (b) an initial application of that mechanism, the delay-tolerant
     key administration system.  Both are now in the main line of supported
     ION code, no longer in "contrib".

bpsec-completion
     The BPsec implementation in ION (bpv7 only) has been reorganized and
     has been upgraded to support features that were not fully supported
     in ION 4.0.0: target multiplicity, interim security sources, and block
     canonicalization.  Block Integrity Blocks may now target primary and
     extension blocks as well as the payload block.  No support yet for
     Block Confidentiality Blocks that target extension blocks.

ION 4 NM Release Notes:

    NM Manager has been updated with expanded support for the latest AMP
    MySQL Database Schema. Note that functionality may not be complete for
    all data types in this release.

    Configure the build with "--with-mysql" to enable. Requires the MySQL C
    Client API <= 8.0.0 or any version of MariaDB (default for most Linux
    distributions when installing “mysql” via your package manager).

    To automatically connect to the database on startup, specify connection
    information at the command line. Ie:
    nm_mgr ipn:1.3 --sql-user amp --sql-pass amp --sql-db amp_core --sql-host db
    Run “nm_mgr” without arguments for full usage information.

    The MySQL schema can be found under nm/contrib/amp-sql.  See the included
    README file for details.

    The CAMP tool has been updated, including added support for generating MySQL
    definition files.  The generated SQL files are included in the packaged
    amp-sql schema.

    NEW: The “amp.me” tool has been added to nm/contrib/ampme.  This is an
    experimental tool providing both command line and browser based interfaces
    to interact with the database, and to provide transcoding of AMP messages
    between CBOR, URI, and other reference views. See the included README file
    for details.

Other changes:

- A new MULTISEND option has been added for underlying UDP transmission in
     LTP, thanks to Eric Yeh and others at Boeing.  The new UDP option
     uses sendmmsg to enable transmission of a large number of small LTP
     segments (minimizing the effect of IP fragmentation) in a single
     system call (minimizing system call overhead).

- A new TRACKRFXEVENTS compile-time switch enables user-written code to
     monitor system events processed by the rfxclock daemon.

- Reconnection and shutdown processing has been somewhat stabilized in the
     TCPCL convergence-layer implementation and in UDP transmission under
     LTP, BSSP, and BP.

- The Deployment Guide and Design Guide have been updated.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 4.0.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

The focus of ION version 4.0.0 was implementation of the new version of Bundle
Protocol - BPv7 - that is currently being standardized within the IETF DTN
Working Group.

Branches:

ion-4.0.0
	* BPv7 (Bundle Protocol version 7) was implemented.
	* BPSEC replaced SBSP for BPv7.
	* An enhanced BIBE implementation replaced Aggregate Custody Signaling
	      (ACS) for BPv7.
	* All of this new code is in a new "bpv7" subdirectory of the
	      ion-open-source root directory.
	* NOTE that the original bpv6 implementation is still included in ION
	      and is still supported.  But it has been moved to a new "bpv6"
	      subdirectory of the ion-open-source root directory.

fix-unibo-contrib - Updates were made to ECLSAv4 and the dtnsuite
     (dtnbox, dtnfog, dtnperf, dtnproxy).

cfdpv1-updates - CFDP was revised based on the CFDPV1 pink sheets including a
     fix for CRC computation.

bp-configure-switch - Updates were made to the autoconf system to enable
     configuration of ION with bpv6 or bpv7. It is important to note that to
     minimize application program changes, bpv6 and bpv7 builds use the same
     library and utility program names. As a side effect, to ensure you are
     running the expected code, make sure you remove any old libraries and
     executable programs before rebuilding with a different bp version so bpv7
     utilities do not pull in bpv6 libraries or vice versa. Also, the testing
     architecture has been enhanced to allow tests to be distinguished as bpv6
     or bpv7 only.

ION 4 NM Release Notes:

NM has been upgraded to support the latest revision of the AMP specification.
     Prior releases were based on AMPv6. This version has been updated to
     support AMPv8.

These updates change the format of the CBOR-encoded messages and, as such,
     break backwards compatibility when enabled. The updated specification
     optimizes the size of the CBOR encodings by eliminating selected CBOR
     container delimiters when not required for processing by NM through the
     newly introduced concept of 'OCTETS'.

An OCTETS sequence is functionally equivalent to a CBOR indefinite-length array
     for which the header and size bytes are omitted from the encoded CBOR
     data. The NM application explicitly instructs the QCBOR encoder as to the
     start and end of an octets sequence. This enables the entirety of the
     OCTETS sequence to be counted as a single element in any encapsulating
     CBOR array and for error detection (ie: of unmatched array opens & closes)
     to proceed as normal.

Two new (experimental) UI features have been added to aide automation. The
     'Automator UI mode' provides a simple shell-style interface to the Manager
     optimized for scripted usage. The second is a preliminary REST API. This
     API is subject change in future releases.

Command line options have been added to nm_mgr for configuration of expanded
     file logging capabilities.  See the man page for details.

This release includes also includes several bug fixes, updates to the CAMP tool
     for generating ADM source files, and the inclusion of Doxygen
     documentation.  See nm/docs/doxygen/README.md for instructions on
     generating Doxygen output.

NOTE for Solaris users: This version of network management is NOT fully
     functioning on Solaris at this time. There is a segmentation fault that we
     have not yet fully diagnosed.


Other ways that bpv7 differs from bpv6:

- CBOR encoding replaced the SDNV encoding scheme.

- qos was renamed to bpq to avoid build problems resulting from existing
     qos implementations.


Other changes:

- A new test for prioritized transmission including priority override has been
     added.

- A new BIBE custody transfer test for BPv7 has been added.

- llcv was updated to help stabilize TCP reconnection.

- bpversion, a utility that prints the version of BP ION was compiled with,
     has been added.

- The Windows(mingw) build was updated to use local/ locations rather than opt/.

- The Deployment Guide was updated with additional information about
     multi-node operations and configuring for bundle-in-bundle encapsulation.

- Deterministic data loss capability was added to owltsim.

- cgrfetch was repaired.

- Assorted bugs were fixed.

- SourceForge Bug #133: documentation of the standard build process was added
     to ION.pdf

- SourceForge Feature Request #54: the ion-open-source folder has been renamed
     ion-open-source-VERSION for the official release tarball.

- SourceForge Feature Request #72: bpchat was enabled for Windows builds and
     man pages were added for bpstats2 and bpchat.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.7.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

For ION 3.7.0 we focused mainly on upgrading the routing and forwarding
modules.  We made significant progress, but the final step will be to
enable forwarding - both unicast and multicast - across multiple "regions"
of a potentially very large network; we're not there yet.  The groundwork
has been laid, though, and inter-regional routing should be supported by
sometime next summer.  Meanwhile, here's what is in the 3.7.0 release:

- Management functions for declaring "region" membership and managing
     "passageways" between regions have been implemented.

- Discovered contacts are now logged, to serve as the basis for computing
     predicted contacts.

- A new protocol (implemented using BP administrative messages) has been
     developed for exchanging logs of discovered contacts, to improve
     all nodes' understanding of unplanned contact patterns.

- Opportunistic CGR has been augmented with contact prediction based on
     logs of discovered contacts, and an overhead-limiting mechanism
     inspired by Spray and Wait routing has been added.

- Network management has been overhauled.  In particular, QCBOR has
     replaced TinyCBOR as the mechanism for CBOR encoding and decoding
     of network management messages.

- Updated implementations of DTNperf and the Erasure Coding link service
     adapter, from University of Bologna, have been added.

- Individual threads can now be named, for easier management in embedded
     deployments.  NOTE: this feature won't be available for the uClibc
     platform in 3.7.0, as the version of uClibc we're working with
     does not include an implementation of pthread_setname_np.

- CFDP has been updated to conform to the latest CFDP Red Book.

- ionxnowner, a utility that identifies the owner of the current SDR
     transaction, has been added.

- SDNV encoding has been optimized, thanks to Cheol Koo of KARI.

- A bug in handling the "verbose" flag in owltsim has been fixed, courtesy of
     Pete Gonzalez, Johnson Space Center.

- Errors in the accumulation of reception statistics have been corrected.

- CGR has been updated to conform to the new CCSDS Schedule-Aware Bundle
     Routing specification, including anticipatory fragmentation.

- LTP has been simplified for higher performance.  "Screening" control
     has been reinstated, reception rate control has been removed,
     tracking of closed export sessions has been made optional.

- SourceForge Bugs #69 and #138: the UDP rate control algorithms in udpclo
     and udplso have been made more stable and more accurate, and rate
     control limits are now automatically obtained from the contact plan.

- SourceForge Bug #134: the time values that ION operates on are now
     explicitly recognized as being "ctime" values (Unix epoch time)
     rather than UTC time values.  Conversion from ION time values to
     UTC is still supported by O/S services, e.g., gmtime.

- SourceForge Bug #135: to prevent circular references at build time,
     the administrative functions for managing BP and LTP security rules
     have been relocated from ionsecadmin to new bpsecadmin and ltpsecadmin
     utilities.  This enables validation of ciphersuite specifications
     when SBSP rules are added.

- SourceForge Bug #144: a fix has been made to prevent ipnfw from crashing
     when CGR attempts to compute a new route through a contact just as the
     contact is ending.

- SourceForge Feature Request #53: network administrator can now specify
     a routing override that supersedes the routes computed by CGR.

- SourceForge Feature Request #61: network administrator can now specify
     a bundle priority that overrides the priority declared by the
     application that sourced the bundle.

- SourceForge Feature Request #74: all remaining reliance on BP libraries
     has been removed from CFDP (except bputa).

One more note: support for explicitly detaching an Outduct from the Egress
     Plan to which it is currently attached has been added.  Unfortunately,
     this feature requires that each Outduct be attached only to a single
     Egress Plan.  That has been the intent of the architecture all along,
     but making it explicit has uncovered a problem in the regression tests
     for Aggregate Custody Signaling: those tests rely on the use of a single
     Outduct for transmission to two different nodes.  Consequently those
     tests now fail and will continue to fail until they are rewritten.
     ACS itself is unaffected by the new feature, and when we temporarily
     disable that restriction on Outduct attachment the ACS regression
     tests all pass.  ACS still works just as well as ever.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.6.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

The most significant change in ION 3.6.2 is the addition of a fully built
out implementation of network management based on the Asynchronous Management
Protocol specification.  Other changes:

- SourceForge Bug #96: Defined a threshold bundle size above which the payload
     to be encrypted will be copied to a temporary file but below which it
     will be copied to a temporary SDR heap object.

- SourceForge Bug #100: This bug could not be recreated as originally reported
     in 2016 so the ticket has been closed.

- SourceForge Bug #111: Fixed CGR route computation as described in the
     CCSDS Schedule-Aware Bundle Routing White Book.

- SourceForge Bug #112: Uncommented acsadmin makefile commands for Windows and
     added a couple of include directories so that acsadmin now builds.

- SourceForge Bug #118: Fixed deterministic crash in cgrfetch.

- SourceForge Bug #120: Fixed unrecoverable SDR error when attempting to
     transfer a directory using cfdp.

- SourceForge Bug #121: Revised the heap size in the configuration for the
     bench-ltp demo to prevent the test from crashing.

- SourceForge Bug #122: Ensured that the ionunlock man page is installed.

- SourceForge Bug #123: Removed obsolete tutorial, replacing it with link
     to new online tutorial website.

- SourceForge Bug #124: ION Design and Deployment guides updated.

- SourceForge Bug #125: Fixed bpadmin "stop outduct" segmentation fault.

- SourceForge Bug #127: Fixed sdrwatch lockup when using the "-z" option,
      clarified the sdrwatch command-line control parameters.

- SourceForge Bug #128: Added a call to watchSocket to TCPCL and STCP
     to try to control an issue with TCPCL failing to disconnect a TCP
     connection after a neighboring node is reset.

- SourceForge Bug #130: This bug was an issue with how to install libexpat1-dev
     on Centos 7 and was not related to the ION source code.

- SourceForge Bug #131: Ensured that the bpclm man page is installed.

- SourceForge Bug #132: Fixed bug in bpadmin "i endpoint" command syntax.

- SourceForge Bug #133: Build system documentation updated in the ION Design
      Guide.

- SourceForge Bug #136: Fixed bugs in the Android development kit.

- SourceForge Bug #139: Fixed compile error using memcpy in
     dgr/test/file2udp.c.

- SourceForge Bug #140: Changed overdue time to the end of the current contact.

- SourceForge Bug #141: Fixed ipnd crash on Mac OSX versions 10.12 and 12.13.

- SourceForge Feature Request #67: Added the ability to monitor the LTP
     segment retransmission rate.

- SourceForge Feature Request #72: The following programs cannot be built on
     Windows using the MinGW/MSYS environment:
     - amshello - uses fork(), which doesn't exist for mingw
     - bpstats2 - uses SIGUSR1 which doesn't exist for mingw
     - bpchat - builds but test does not pass - not building
     - bpcp - relies on waitpid, kill, WIFEXITED, and WEXITSTATUS
     - bpcpd - daemon for bpcp so doesn't make sense to build if bpcp doesn't
     - owlttb - needs SIGPIPE which Windows does not support
     - dccplsi - excluded on platforms other than Linux in config.h
     - dccplso - excluded on platforms other than Linux in config.h
     - dccpcli - relies on dccplsi and dccplso which cannot be built
     - dccpclo - relies on dccplsi and dccplso which cannot be built
     * Also note that man pages are still needed for bpstats2 and bpchat.

- SourceForge Feature Request #73: The following programs are now being built
     on Windows:
     - beacon
     - node
     - cgrfetch
     - ionexit
     - ionunlock

Added enforcement of security policy on bundle reception.

Improved UDP transmission rate control in udplso.

Fixed a bug in LTP: segment buffer size was not being expanded to accommodate
      changes in max segment size.

Fixed bug in the auto-restarting of LTP after a recoverable system crash.

Reinstated control over LTP screening, for research purposes.

Cleaned up wild-card removal of contacts and ranges in ionadmin.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.6.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

ION version 3.6.1 includes the following changes:

- A new Android development kit for ION-based applications is now available.
     It's large, so it's provided in a separate file.
- A new installer for the Windows port of ION is also now available, likewise
     in a separate file.
- A "deadly embrace" in tcpcli was causing nodes to lock up during heavy
     continuous bidirectional file transfer. That is now fixed.
- The erasure-coded link service adapter from University of Bologna has been
     updated, now including proactive fragmentation for improved performance.
- The "bpsec" bundle security system has been renamed "sbsp" (Streamlined
     Bundle Security Protocol) to align with specifications that are being
     standardized by the Consultative Committee for Space Data Systems (CCSDS).
- Asynchronous Message Service and Bundle Streaming Service have been added to
     the RTEMs port.
- Contact Graph Routing in the Bundle Protocol has been updated to align with
     the new Schedule-Aware Bundle Routing (SABR) specification that is being
     standardized by CCSDS.
- The delay-tolerant key administration system in the "contrib" directory has
     been updated with a model for optimizing the configuration of an aggregate
     key authority, plus scripts for testing various key authority
     configurations.
- The ION Design Guide has finally been updated.
- Loopback transmission has been restored to the TCPCL convergence-layer
     adapter.

No changes to operational interfaces or APIs this time.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.6.0b=
%%%%%%%%%%%%%%%%%%%%%%%%%%

Version 3.6.0b is an interim release aimed at improving the ability of ION to
tolerate continuous heavy relay traffic at the DTN gateway for the
International Space Station.  The changes made to accomplish this are mostly
invisible, but they include the deployment of a new "ltpdeliv" daemon (for
data acquisition rate control) and resolution of a particularly subtle race
condition.

In addition, this version includes the following upgrades:

- A new "ionunlock" utility has been added, for unfreezing an ION node that
     has gotten locked up due to some thread having been destroyed while
     still the owner of the ION system mutex.

- In the "contrib" directory, the build for DTKA has been modified to fit into
     the ION 3.6 environment.

- Also in the "contrib" directory, dtnperf has been tweaked to build properly
     in the ION 3.6 environment and ECLSA has been updated in a number of ways.

- The ION implementation of Asynchronous Management Protocol has been
     upgraded in many ways, including optional support for data storage
     in MySQL.

-  Most regression test failures for ION running in recent versions of Mac
     OS X have been addressed.  ION now once again runs in this environment,
     though there still may be a few rough edges.

- The build and test environment for Windows has been greatly improved.

Version 3.6.1 will focus on some more visible enhancements to ION but will
of course retain all of these upgrades as well.

--- A note on Windows operating environments ---

Building ION on Windows requires at a minimum the MinGW-w64
[http://mingw-w64.org/] compiler package, and most likely a utilities
package to provide a shell. For this release, testing was done with the
following configurations:
- 32-bit Windows ION is built with i686-4.9.3-release-posix-dwarf-rt_v4-rev1.7z
- 64-bit Windows ION is built with x86_64-7.1.0-release-win32-seh-rt_v5-rev1.7z
Both system variants use the MinGW-MSYS utilities bundle MSYS-20111123.

During testing of 3.6.0b the current set of instructions for installation
and operation of ION on Windows was found to be partially outdated and in
need of revision. In particular, running the built-in validation tests
requires additional setup steps beyond the basic ION deployment. Revised
documentation will be provided in release 3.6.1.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.6.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #103: Made pthread_t variable access abstract for POSIX task
     signal management.

- SourceForge Bug #104: Fixed segmentation fault in the ipnd neighbor discovery
     task that caused a crash when a beaconing node that it has been listening
     to abruptly terminates.

- SourceForge Bug #106: Fix a bug using lseek on Windows machines when trying
     to transfer large files (over 2GB in size).

- SourceForge Bug #107: Updated to a new convergence layer management system.
     (See ION interface changes in version 3.6.0 note below for more
     information).

- SourceForge Bug #110: Fix flow control to reserve ZCO before allocating SDR
     heapspace.

- SourceForge Bug #112: Added include directories needed to successfully build
     acsadmin on Windows.

- SourceForge Bug #115: Fix a bug in bpadmin that caused a segmentation fault
     and subsequent lock up if "s outduct" was entered without any parameters.

- SourceForge Feature Request #56: Added a TTL option to bpsendfile so the user
     can specify a TTL longer than 300 seconds if needed.

- SourceForge Feature Request #58: LTP performance enhancements.

- SourceForge Feature Request #59: Added ECLSA an implementation of erasure
     coding under LTP.

- SourceForge Feature Request #60: Enabled custodial retransmission when using
     the UDP convergence-layer adapter by adding an optional retransmission
     timeout interval (RTT) that defaults to 0.

- SourceForge Feature Request #63: Added an option to allow automatic discard
     of status messages for a CFDP transfer in a recipient does not want to
     process them.

- Added a new system to disable tests that you do not want to run when using
     the runtests script.

--- ION interface changes in version 3.6.0 ---

In ION version 3.6.0 we introduce a new degree of indirection between routing
(next-hop bundle-layer endpoint selection) and forwarding (next-hop
convergence-layer endpoint selection).  This new capability, named "convergence
layer management" (CLM), provides a number of important benefits.
Unfortunately, in order to realize those benefits we had to revise some ION
interfaces more drastically than we usually do in moving to a new version.
Please be aware of the following significant changes as you adjust your test
and deployment environments to utilize ION 3.6.0.

-- API changes

None of the "public" application programming interfaces in ION are affected
by the introduction of CLM, but the Bundle Protocol private internal API has
changed in some significant ways; these changes particularly affect the
implementation of convergence-layer adapters.  Most important of these is a
change to the function prototype for bpDequeue; see the comments in the bpP.h
header file.

-- Behavioral changes

BP flow control is now exerted at node granularity, in a new daemon process
named "bpclm", rather than at outduct granularity. One effect of this change
is that the data rates declared in the contact plan now are enforced for all
convergence-layer protocols, not just LTP.  Another is that the plan for
bundle egress to a given neighboring node may now comprise multiple
convergence-layer outducts, not just one; the ipnadmin and dtn2admin utilities
don't support this option, but new commands implemented in the bpadmin utility
do.

-- Configuration changes

Several changes in ION 3.6.0 may affect your configuration files.

There are no longer any "promiscuous" outducts.  The "*" command-line argument
to udpclo is no longer valid: you need a separate udpclo task, allocated to an
explicit socket expression (<ip_address> [:<port_number>]), for each neighbor
to which you will transmit bundle by UDP.  This change affects "outduct"
commands passed to bpadmin and also "plan" commands passed to ipnadmin and
dtn2admin.  There is a similar impact on the DGR convergence-layer adapter:
the dgrcla daemon no longer exists, having been replaced by dgrcli and dgrclo
daemons; see the man pages for these new daemon programs.

There are no longer any "plan rules" that override default egress plan
directives.  User-written outduct selection functions may be inserted at
compile time to achieve the objectives of plan rules (and much more), but
at this time no such functions are delivered with ION 3.6.0.

The operation of the dtn2admin utility has been expanded, conceptually
enabling the declaration of egress plans for sets of nodes whose EIDs conform
to any wild-carded EID string regardless of URL scheme, without any sensitivity
to trailing "/" characters or "demux" strings.  Enabling this expansion,
though, it is now necessary to include scheme name and ":" (in addition to
the scheme-specific part of the EID) when declaring, editing, or deleting a
plan.

Finally, the TCP convergence-layer protocol implementation has been
significantly revised: it now enables bundle to be transmitted to a
neighboring node over a TCP connection that was established by that node,
i.e., not declared a priori in local outduct commands.  That is, it is
no longer necessary to declare outducts for all neighboring nodes to which
you want to be able to send bundles by tcpcl.  However, these revisions
are fairly complex and were time-consuming to debug; tcpcl loopback
introduces a whole additional layer of complexity, particularly in fault
handling, so at least for now tcpcl loopback is not supported in ION 3.6.0.
Everything one might want to demonstrate or test using tcpcl loopback can be
more cleanly and convincingly accomplished using two nodes exercising tcpcl
on the same machine, so we don't see removal of this limitation as urgent.

- NOTE for MacOS X users:  At this time, ION 3.6.0 will NOT run on any recent
     version of MacOS. Our tests on MacOS 10.11 show failures in the semaphore
     locking system that we have not yet fully diagnosed.  No work-around is
     available.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.5.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #94: Warnings printed at compile time on 64-bit Windows
     were fixed.

- SourceForge Bug #98: Fixed bug in the dtn2 directive lookup function
     that ignored egress plans and rules citing CL protocols of classes that
     don't match the protocol class indicated by the bundle's required quality
     of service for plans that cite the "forwarding" directive.

- SourceForge Feature Request #48: Improved the portability of Alarms and
     enabled them to be used in flight code as they no longer spawn new threads
     but instead are implemented as events in the RFX timeline that are clocked
     out by rfxclock at 1-second granularity.

- The BP security and Asynchronous Management Protocol (bpsec) replaced the
     previous BP security mechanism bsp.

- Added opportunistic contact graph routing (ocgr) based on predicted contacts.
     This system is still experimental but is ready for others to experiment
     with.

- Fixes for bugs in AMS uncovered in IPAS demonstration environment development.

- Added tcpcl-ack-resilience-test.

- Fixed issue-265-bpdriver-ttl-option test by adding support for BSD netcat.

- NOTE for MacOS X users:  At this time, ON 3.5.0 will NOT run on any recent
     version of MacOS. Our tests on MacOS 10.11 show failures in the semaphore
     locking system that we have not yet fully diagnosed.  No work-around is
     available.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.4.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #60: The ION killm script no longer fails to clean up shared
     memory allocations from the current user when their username is longer
     than 10 characters.

- SourceForge Bug #89: The ION TCPCL has been updated to implement bundle
     acknowledgments, which are listed as an optional feature in the TCPCL
     specification (RFC 7242).
     Bundle acknowledgments can help improve reliability of TCPCL transmissions
     by alleviating issues that can occur during a window after a disconnection
     but before a timeout.
     During this time the CLO may finish its send() call without error and
     trigger BP to delete the bundle before the timeout fires and it is
     discovered the transmission did not succeed and can no longer be
     retransmitted.

- SourceForge Bug #91: The ION autoconf configuration has been streamlined by
     merging the libipnfw and libdtn2fw libraries directly into libbp.
     This should improve portability and alleviate any build issues that some
     users reported having in ION v3.4.0.

- SourceForge Feature Request #50: ION now supports an abstract "bulk" storage
     type for zero-copy objects.
     This allows FPGAs to receive inbound data into bulk storage and invoke
     ION data acquisition logic that will encapsulate the bulk storage objects
     in ZCOs for LTP and BP processing.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.4.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #61: Fixed bug in using FreeBSD semaphores that could cause
     unexpected behavior and lockoups under FreeBSD.

- SourceForge Bug #74: Fixed bug where semaphore IDs were only properly
     reclaimed on certain RTEMS operating systems (VxWorks, POSIX).
     This could cause ION to exhaust the pool of semaphore IDs and create
     outduct lockups.  ION now properly reuses obsolete semaphore IDs under
     Windows and SVRr4.

- SourceForge Bug #79: Fixed bug where removing and re-adding an outduct could
     cause a bundle transmission failure.

- SourceForge Bug #81: Fixed bug where ION child processes could become
     zombie processes.
     The sm_TaskSpawn() function in ION now properly forces child processes to
     be re-parented by the "init" process which periodically reaps the
     zombie processes.

- SourceForge Bug #83: Fixed bug where ION would presume bi-directional BAB were
     enabled when BAB was only specified as unidirectional in a configuration.
     This would cause the non-BAB bundles to be declared inauthentic despite no
     BAB rule being specified in that direction.

- SourceForge Bug #84: Fixed bug where continuously sending BCB-enabled bundles
     could cause erroneous generation of truncated bundles in the source node.
     This was due to the Linux file system was having trouble keeping up with
     the rate of temporary file creation when BCB's ARC4 ciphersuite used a
     temporary file for ciphertext.
     ION now does the crypto in place, overwriting the contents of the
     payload ZCO.

- SourceForge Bug #85: Fixed bug where the number of rules that were entered
     into ionsecrc would not match the number of messages when cleared in
     ionsecadmin.

- SourceForge Bug #86: Fixed bug that caused LTP block reassembly to be very
     CPU-intensive when the block was transmitted in small segments.
     This could cause delays in processing the block that would incur the
     expiration of the senders ack timer and ultimately result in session
     cancellation.
     ION now receives the block directly into the correct location in a
     temporary acquisition file and wraps the delivery ZCO around that file.

- SourceForge Bug #87: Fixed bug where BSSP block acknowledgments were sent via
     TCP rather than UDP, which could result in the volume of TCP BSSP
     acknowledgment traffic becoming so heavy that the sending BSSP UDP
     congestion loss would increase to the point of degrading visual quality.

- SourceForge Bug #88: Fixed a bug where the CFDP UTO ZCO request could become
     interrupted by moving the "attendant" structure into the BP volatile
     database to keep it stable.

- SourceForge Feature Request #29: The ION testing subsystem has been updated
     to begin tests immediately after subsystem initialization.  Previously ION
     used hard timeouts to wait for subsystem initialization which could be
     overly-aggressive timings on slower systems or overly-conservative on fast
     systems.

- SourceForge Feature Request #33: The ION CGR implementation now supports
     probabilistic contacts.  These are opportunistic contacts with
     probabilities less than 1.0.
     ION now accepts contacts with probabilities less than 1.0 and will forward
     multiple copies of a bundle through different discovered contacts until
     the bundle's computed net delivery probability exceeds a hard-coded
     threshold value.

- SourceForge Feature Request #34: ION now supports proactive bundle
     bundle fragmentation in LTPCLO.

- SourceForge Feature Request #35: ION now properly blocks and unblocks non-LTP
     links in a contact plan.
     Previously, ION only explicitly blocked and unblocked links operating LTP.

- SourceForge Feature Request #37: The ION CFDP implementation has been updated
     per new CCSDS CFDP specification revisions.
     CFDP now uses a managed configuration parameter obtained via a Management
     Information Base (MIB) as its checksum type.
     Previously, this value was hard coded into the EOF PDU layout.

- Fixed several miscellaneous bugs with IP Neighbor Discovery.

- ION now only attempts to rebuild the ION.pdf design document if all required
     tools are detected.

- New and updated tools are now available in the ION contrib subdirectory:
     - Updates have been applied to DTNPerf, and tool for testing DTN
       performance testing.
     - Added BPTAP, a tool that enables BP to act like Ethernet underlying IP.
     - Added Delay Tolerant Key Administration (DTKA), a tool enabling
       trustworthy delay-tolerant distribution of public keys.
       NOTE: DTKA is not built by default.
             See /contrib/dtka/README.txt for special instructions on building
             the DTKA tool.

Public API changes:
     - bp.h:  the new function bp_memo is added.  It was previously exposed only
              in the BP private API.

     - zco.h: the new functions zco_revise, zco_create_obj_ref, and
              zco_destroy_obj_ref are added.

Operational interface changes:
     - cfdpadmin (cfdprc):
            - Added support for explicitly adding remote entities and
              specifying their UT-layer endpoints.

     - ipnadmin (ipnrc):
            - "groups" have been renamed "exits" to avoid a terminology clash
              with multicast "groups".  However, the older "group" terminology
              is still accepted by ipnadmin for backward compatibility.

BUILD NOTE:
Substantial changes have been made in this version as to how ION is built.  As
a result, some platforms (particularly older Linux platforms) may encounter
linker warnings when building ION 3.4.0.  These issues will be resolved in the
next release, but in the meantime an alternate Makefile has been provided that
may resolve this issue on affected platforms.  If you encounter any linker
warnings, try the following procedure to build from this alternate Makefile:
     1.) cd <top of ION directory>
     2.) cp Makefile.am.alt Makefile.am
     3.) autoreconf -fi (requires libtool and autoconf to be installed)
     4.) ./configure
     5.) make

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.3.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #37: The ION tutorial has been updated.

- SourceForge Bug #73: Fixed two bugs introduced by the dynamic generation of
     LTP reports.  See the SourceForge Bug #47 entry and the ltprc(5) man
     page for details on dynamic LTP report generation.

     1.) The computation of the segment loss rate (errors per segment) was
               incorrect and now uses the following corrected formula:

               segmentLossRate = 1.0 - ((1.0 - maxber) ** (maxSegmentSize * 8))

     2.) The retransmission limit on the number of times any single report or
               checkpoint may be retransmitted is now computed dynamically as a
               function of segment loss rate rather than a static number.

- SourceForge Bug #74: Obsolete IPCs are now properly reclaimed when running
     under Windows and SVr4.
     - ION now tracks the release of semaphores in winion's array of IPC handles
       as well as the semaphore tables themselves.
     - Previously, the release of obsolete semaphores was not tracked by the winion
       daemon, which could be easily saturated given low semaphore limits and
       recently-expanded semaphore usage in ION (CGR, ionStartAttendant).

- SourceForge Feature Request #40: The bping ION application has been ported to
     Windows.  A dtnperf port for Windows is slated for a later release.

- SourceForge Feature Request #42: ION now resolves host names when socket
     connections are made rather than resolving them all on ION startup.

- Fixed a memory leak in CFDP that could occur when TargetFFS is defined.

- Several fixes have been applied in response to the successful completion of
     CCSDS BP interoperability testing.

- Delay Tolerant Payload Conditioning (DTPC) has been updated for conformance
     the specification.

- The CGR algorithm has been updated to omit downstream contacts that end
     before initial contact on route.

- ION no longer requires pdfjam to build man pages into the ION documentation.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.3.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #47: ION's LTP implementation now computes limits on
     "report" segment generation dynamically, based on block size, segment
     size, and anticipated bit error rate.  This enables LTP to "try
     harder" to complete block transmission when rates of data loss are
     high.  See the notes below on configuration interface changes.

- SourceForge Bug #54: Fixed bug that could cause multithreaded applications
     under VxWorks to refuse bundles with the error message:
        "Can't receive: not owner of endpoint."

     For this purpose, a thread that will only send (never receive) bundles
     can use a BpSAP created by calling bp_open_source rather than bp_open;
     in this circumstance, sending and receiving threads may use different
     bpSAPs tagged with the same endpoint ID.

     IMPORTANT: see the notes below on application interface changes!

- SourceForge Bug #62: Fixed several miscellaneous implementation bugs in the
     Contact Graph Routing (CGR) engine dealing with Earliest Transmission
     Opportunities (ETO) and Overbooking management (OB).

- SourceForge Bug #63: Removed restrictions on possible CBHE node and
     service numbers.
     MAX_CBHE_NODE_NBR may now be any unsigned long number (2^64-1).
     MAX_CBHE_SERVICE_NBR may now be any unsigned int number (2^32-1).

- SourceForge Bug #65: Removed duct-level support for LTP "green" transmission.
     "Green" transmission is now selected on a bundle-by-bundle basis via the
     bundle's extended class of service options.

- SourceForge Bug #67: Updated the Previous Hop Node extension block (PHN)
     implementation to be compliant with the specification in RFC 6259.
     The sending node's EID is now represented by two distinct NULL-terminated
     strings (Scheme Name and SSP) rather than one NULL-terminated EID.

- SourceForge Bug #68: Fixed bug where the sockets of links utilizing STCP
     could prematurely close if the other side did not respond for several
     hours. ION now respects the EHOSTUNREACH errno value and periodically
     attempts to reconnect rather than closes the socket.

- SourceForge Bug #70: Fixed bug with ION's uClibC macros that caused ION
     compilation to fail in environments that use uClibC.

- SourceForge Feature Request #13: Optimizations have been made to improve
     ION's reactive forwarding implementation:
     - When a bundle is reforwarded due to expiration of its xmitOverdue timer
       ION now considers the possibility that forwarding the bundle back to the
       node it received the bundle from may now actually be the optimal route.
     - ION now sends Custody Refused signals back to the sending nodes when
       forwarding the bundle is not possible, even when custody transfer was
       not requested.  This enables a mechanism for backtracking the bundle
       through the network when forward progress through a route is blocked.

- SourceForge Feature Request #19: ION now supports Bundle-in-Bundle
     Encapsulation (bibe) per the draft-irtf-burleigh-bibe Internet Draft.
     Bundle-in-Bundle Encapsulation enables the Streamlined Bundle Security
     Protocol (SBSP), which omits security destinations from the security
     extension blocks, to function in cross-domain solutions by encapsulating
     bundles whose destination is the selected security destination.

- SourceForge Feature Request #29: Optimizations have been applied to the ION
     test suite to reduce the amount of time needed to initialize each test.

- SourceForge Feature Request #31: ION's public API is now more "const-correct"
     which enables better interopability with C++ interfaces.

- SourceForge Feature Request #32: zero-copy-object space allocation has been
     enhanced to enable bidirectional flow control on convergence-layer
     protocols that back-propagate blocking on buffer space requests.

- SourceForge Feature Request #33: ION now supports probabilistic contacts.
     These are contacts with probabilities less than 1.0 that could potentially
     be handled by the CGR algorithms to enable the possibility for more
     efficient routing decisions to be made by the CGR engine.

- ION now supports the Streamlined Bundle Security Protocol (SBSP) in place
     of the Bundle Security Protocol defined in RFC 6257.  For details,
     see https://datatracker.ietf.org/doc/draft-birrane-dtn-sbsp/.

- Fixes have been applied to the ION.pdf construction procedure to enable
     proper formatting of the appended man pages.

- Man page creation can now be disabled.
     Man pages are still built by default.
     To disable man page creation, use "./configure --disable-manpages".

**Configuration interface changes**

Because buffer space for "zero-copy objects" in ION has been split into
     separate pools for inbound and outbound data, the ionrc command for
     managing "occupancy" has been split into two commands, "inbound"
     and "outbound".  See the ionrc(5) man page for details.

Migrating ION from standard Bundle Security Protocol to the new Streamlined
     Bundle Security Protocol has entailed changing some of the ionsecrc
     commands: "bsppibrule" is replaced by "bspbibrule", and "bsppcbrule"
     is replaced by "bspbcbrule".  See the ionsecrc(5) man page for details.

Limits on retransmission in LTP are now computed dynamically to account
     for differences in bundle size, segment size, and bit error rate.
     For this purpose, the default value for maximum bit error rate at a
     given LTP engine is hard-coded to be 10^-6 (one uncorrected flipped
     bit per million).  This value can be overridden by the new ltprc
     command for managing "maxber"; see the ltprc(5) man page for details.

**Application programming interface changes**

Again because of the splitting of ZCO buffer space into two pools, many
     of the zco library function prototypes have been changed: in most
     cases, an additional ZcoAcct parameter (ZcoInbound or ZcoOutbound)
     has been added.  Also:

- A new zco_status function has been added, to print a brief report
     of the buffer status.

- New zco_extent_too_large and zco_get_aggregate_length functions
     have been added to aid in resource management.

- Other new functions include zco_acct, zco_header_text, and
     zco_trailer_text.

- Passing a negative value of extent length to zco_create or
     zco_append_extent indicates that (a) the actual extent length
     is the additive inverse of the value provided and (b) it is
     asserted that this length does not violate the configured limits
     on ZCO buffer space occupancy.

See the zco(3) man page for details of these changes.

Leveraging these upgrades to enable more flexible resource management,
     the ionCreateZco and ionAppendZcoExtent function prototypes have
     been modified and the ion function library now includes several
     new functions that provide better control of "blocking" behavior
     in ZCO buffer space allocation: ionStartAttendant,
     ionPauseAttendant, ionResumeAttendant, ionStopAttendant,
     ionRequestZcoSpace, ionShred.  See the ion(3) man page for details
     of these changes.

NOTE: The changes made to address SourceForge Bug #54 (described above)
     have the potential to BREAK APPLICATIONS!

     If your application code currently makes any use of the bundle
     address that is returned when bp_send() is called, then YOU MUST
     MAKE BOTH OF THE FOLLOWING CHANGES IN YOUR CODE:

     1.) Use bp_open_source() with the "detain" flag set to 1 INSTEAD OF
               bp_open() to obtain the BpSAP handle that you pass to
               bp_send().

     2.) Call bp_release() as soon as possible (for example, immediately
               after passing the new bundles address to bp_track()) to
               end the detention of any bundle created by passing that
               detaining BpSAP handle to any invocation of bp_send().

     If you need to receive bundles as well as send them, then the BpSAP
     handle that you pass to bp_receive() must be a different handle that
     is obtained by calling bp_open() in the usual way.

**Operational changes**

An additional daemon task named "bptransit" has been added to standard
     ION operations.  bptransit is responsible for presenting to the
     forwarding daemon(s) bundles that were received from other nodes
     (i.e., that reside in Inbound ZCO space) and are destined for yet
     other nodes; in doing so, it migrates these bundles from Inbound
     buffer space to Outbound buffer space on the same prioritized
     basis as the insertion of locally sourced outbound bundles.
     Management of the bptransit daemon is automatic.  See the
     bptransit(1) man page for details.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.2.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- SourceForge Bug #32: Improved Windows support
     - MinGW makefiles now build a wider array of ION applications.
     - ION-based applications can now be developed in Visual Studio via the new
       "winimplib.bat" batch script which creates import libraries suitable for
       linking ION DLLs.
     - See "BuildingIONonWindowsForUseWithVisualStudio.pdf" for documentation
       on how to build ION-based applications in Visual Studio.

- SourceForge Bug #49: ION now sends a "Depleted Storage" custody refusal
     signal back to the current custodian when an ION node lacks sufficient
     ZCO space to contain a bundle.

- SourceForge Bug #50: ION now behaves more consistently across platforms
     when ionadmin is unable to open its designated configuration file.
     - The ionadmin application now considers being unable to open its
       configuration file to be a serious error and will stop the ION
       initialization routines at this point.  This gives clearer and more
       immediate feedback to the user that an error was encountered that they
       must resolve to resume normal ION operation.
     - Previously, ionadmin would load a default configuration if it was unable
       to open its configuration file EXCEPT under vxWorks 6.3 PowerPC where
       ionadmin would cease with a "can't open SDR config file" message.

- SourceForge Bug #51: The "ionconfig" man page has been updated.
     Some examples of entries that were obsolete are as follows:
     - The pathName parameter should not be encased in quotes.  Previously, the
       example showed a pathName that was encased in quotes.
     - The default config flag is 13, which corresponds to
             SDR_IN_DRAM | SDR_REVERSIBLE | SDR_BOUNDED
       Previously, the documentation gave an incorrect default config flag of 1.
     - The default wmKey is 65281.  Previously, this was reported to be 65537.

- SourceForge Bug #52: The "bping" application has been updated for better
     compatibility under VxWorks.  This was made possible by adding an option
     to run bping as a lightweight task with positional runtime arguments.

- SourceForge Bug #53: Fixed bug in command argument parsing in the
     "bprecvfile" application under VxWorks.  Previously the "a1" argument was
     reused for both the "EID" and "maxFiles" fields.

- SourceForge Bug #55: Fixed bugs in the "bpcancel" application.
     - The bpcancel application now prints a message when it is unable to
       cancel the transmission of a bundle.
     - The man page for the bpcancel application has been updated to clarify
       that the application attempts to cancel the transmission of a specified
       bundle rather than destroy the specified bundle.
     - Note that it is not always possible to cancel the transmission of a
       bundle for which multiple internal copies exist due to being transmitted
       at different times or to different nodes.

- SourceForge Bug #56: ION now builds properly under OSX 10.9.5.

- SourceForge Bug #57: ION now has PARTIAL support for FreeBSD.
     - ION now builds properly under FreeBSD 10.

     - IMPORTANT NOTE: Several key ION applications have not yet been updated
                       to run properly in a FreeBSD environment.  These
                       applications will be updated in a later ION release.
                       These updates may also become available in the short
                       term in the form of an official ION patch.

- SourceForge Bug #59: Fixed bug in the "dtpcadmin" application where it failed
     to accept a valid parameter of zero in the "maxRtx", "aggrSizeLimit", and
     "aggrTimeLimit" fields.

- SourceForge Feature Request #18: The "cgrfetch" application now has an option
     to list all valid outducts.  This should simplify usage by making it
     easier to identify an outduct to run the application against.

- SourceForge Feature Request #20: ION has been updated to better support the
     CFS environment.  CFS can now leverage many standalone ION executables via
     an alternative API where the application's "main()" is replaced with a
     callable function.

- SourceForge Feature Request #21: ION now allows users to adjust the maximum
     block size that LTP will receive directly into the SDR heap rather than a
     temporary file.  This allows users to ensure that a bundle's receive-
     generate-forward chain can be handled entirely in memory.  This often
     improves efficiency by alleviating the need to write to a disk medium.

- SourceForge Feature Request #22: ION now has an option to support handling
     database reversibility mechanisms in memory rather than files.

- SourceForge Feature Request #23: As a performance optimization, ION now has
     better documented support for using pointer de-references rather than
     memcpy() when executing read-only database operations.

- SourceForge Feature Request #24: ION's mechanisms to prevent resource leaks
     when ION is killed and restarted rather than shut down cleanly have been
     modified to support the CFS environment.  Note that this problem occurs
     most commonly when transaction reversibility is disabled because task
     termination locks the datastore until all tasks are killed. If utilizing
     a file on disk for transaction reversibility would be too slow, consider
     utilizing the new functionality to support database reversibility
     mechanisms in memory (SourceForge Feature Request #22) rather than
     disabling transaction reversibility entirely.

- SourceForge Feature Request #26: The CFDP implementation has been updated to
     conform to the proposed CFDP V1 specification. Further updates will be
     required when the specification revisions are completed and approved by
     CCSDS.

     - The interface changes are as follows:

           The function prototypes for the CFDP functions cfdp_put() and
           cfdp_preview() have changed to accommodate proposed updates to the CFDP
           specification.

           File offsets and lengths in all CFDP function calls are
           now of type uvast (rather than unsigned int), because CFDP can now be
           used to send files larger than 4 GB.

           See the cfdp(3) man page for details.

     - The cfdptest test program has been updated to enable specification of
       closure latency and segment metadata.

           See the cfdptest(1) man page for details.

- SourceForge Feature Request #27: ION now provides support for the DTN
     Metadata Extension Block as specified in RFC 6258.

- SourceForge Feature Request #29: The ION test suite has been revamped to
     dynamically detect when ION applications are initialized rather than wait
     preset amounts of time for them to initialize.  This provides faster
     execution of the test suite when applications initialize faster than these
     preset times and more reliable execution of the test suite when
     applications initialize slower than the preset times.

- The "DTNperf" application now builds properly under sparc architectures.
     DTNperf is an external utility that is included with ION in "/contrib".

- Several compilation issues with the "icinm.h" header file implementation have
     been resolved.

- Improvements have been made to the TCPCLO.
     - The receiveBundles() thread no longer terminates prematurely under
       some circumstances when a connection is broken.
     - The sending rate is no longer artifically capped at 1 bundle/sec.

- The "ionscript" application has been updated to support dtpcadmin
     configuration files.

- ION's collection of man pages was previously included in "ION.pdf" but is now
     available as a separate document, "ION-manpages.pdf".

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.2.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Feature Request #8: Improvements have been made in how ION infers the node
     number of the sending node.
     ION now implements the Previous Hop Insertion Block (here called
     Previous Hop Node, phn) extension block, which contains the identifying
     singleton endpoint of the sending node.  Previously, ION utilized
     mechanisms for inferring the node number from convergence-layer EIDs,
     which could generate false information, especially when multiple nodes
     were resident on the same machine.

- Feature Request #14: The stream of "watch" characters that ION generates when
     significant bundle events occur can now be redirected in a manner
     similar to the way log messages may be redirected.

- Feature Request #15: Per specification, ION's LTP implementation now supports
     LTP Authentication as described in RFC 5327.

- Feature Request #16: In preparation for the deployment of delay-tolerant
     security key administration (DTKA), ION now includes several new features
     dealing with public/private key management in the ION security database.
     DTKA itself has been prototyped but is still pending approval for open
     source release.

- Feature Request #17: A significant overhaul of the Bundle Streaming Service
     (BSS) has been implemented to resolve a fundamental incompatibility with
     implementing BSS with multicast.  The new BSS forwarding implementation
     (BSSP) resides at the convergence layer directly under BP so BSS channel
     acknowledgments can be disambiguated.  Previously, the BSS forwarder
     design relied on BP custody transfer to control BSS data forwarding over
     reliable and unreliable channels, which was incompatible with multicast
     because custody transfer can't distinguish among the multiple identical
     copies of a bundle that are forwarded at a multicast branch point.

- Bug #21: The interface for the internal smlist "deletion" callback has been
     modified to be more consistent with the interfaces for the "lyst" and
     "sdrlist" modules.  The API now accepts the address of the element to
     delete rather than its content.

- Bug #24: Fixed an error in the implementation of previously-released bugfix
     where source or destination CFDP entity IDs could become malformed when
     their entityNbrLengths differ.

- Bug #30: Applied various updates to LTP notices to be more compliant with the
     RFC 5326 specification.
     - LtpExportSessionStart notice is now delivered properly.
     - Reception claims in on-the-wire segments now have offsets that are
       relative to the report segment lower bound rather than relative to the
       start of the block.

- Bug #33: LTP Green segment traffic is no longer terminated prematurely when a
     partly-red partly-green block is sent.
     - As a Receiver:
          Previously, closure of an import session (on reception of report-ACK)
          could incorrectly suppress the processing of subsequently received
          Green segments for the same session.
     - As a Sender:
          Previously, processing of an "all-received" Report segment could
          incorrectly closes the export session, which should not occur until
          the EOB has also been sent.

- Bug #34: The Service Data Aggregation (SDA) in LTP has been updated to be
     compliant with the latest specifications.  The SDA now properly passes
     the client ID to the client data unit length determination callback.

- Bug #36: Fixed specific compilation problems with dtnperf under the
     Scientific Linux 5.5 (gcc 4.1.2) operating system.

- Bug #39: Per specification, ION's LTP implementation now rejects LTP
   segments that do not contain the proper version number identifier (0b0000).
   Previously, ION would process segments regardless of version number.

- Bug #40: Per specification, ION's LTP implementation now rejects LTP blocks
     with a session number of 0, as the specifications requires session numbers
     chosen by LTP senders to be in the range [1, 2^32-1].
     Previously, ION would process such blocks with a cancel segment code 3.

- Bug #41: Added checks in the AMS TCP connection pool implementation to help
     detect and guard against data corruption.

- Bug #42: Improvements have been made to the rate control implementation of BP
     to better handle cases where the available residual capacity on the
     channel to a neighboring node is overstated.

- Bug #43: Per specification, ION's LTP implementation now marks bundles as
     "malformed" when there are gaps in the  sequence of green data segments.
     Previously, ION inserted fill data to saturate the gaps, which could
     result in the delivery of a damaged bundle.

- Bug #44: Various man pages have been updated to be more compliant with the
     man page specification.

- Bug #45: Added/updated man pages for various parts of the AMS subsystem.

- Bug #46: Fixed bug in ionscript where a bss/ipn mutual exclusion error was
     presented when creating a monolithic configuration file and not specifying
     existing bss and ipn configuration files as input.
     Ionscript now properly outputs a monolithic configuration file that
     contains neither a BSS nor an IPN subsection.

- Bug #48: Fixed a contact graph routing bug when recomputing routes wherein
     ION could exclude the potentially-optimal route from consideration if it
     is the initial contact on any remaining route.
     Due to the recent inclusion of CGR Payload Classes, it is no longer
     correct to exclude such routes from consideration.

- Patch #5: The Delay Tolerant Network Management Protocol (DTNMP) reference
     implementation has been updated to the version that was used for testing
     and demonstration earlier in the year.

- ION no longer requires libexpat by default in order to build.
     Expat is still required in order to use XML configuration files for AMS.
     To build against libexpat, use "./configure --with-expat".

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.2.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #364: Added support for Delay Tolerant Payload Conditioning (DTPC).
    - DTPC adds (optional) end-to-end functionality similar to terrestrial
      transport-layer protocols on top of the Bundle Protocol.
    - DTPC offers the following additional enhancements:
        - Application data record aggregation into large ADUs.
          This reduces the BP overhead by preventing the proliferation of large
          numbers of small bundles.
        - Elision of redundant application data records.
          This optimizes the utilization of low-capacity communication links.

- Feature Request #5: Several bugfixes and performance enhancements have been
  applied to the DCCP convergence layer.
    - Proper handling for the SIGPIPE signal.
    - Usage of keepalives (rather than terminating idle connections) and
      improved retry capability with an exponential backoff.
    - CCID and Transmission Queue Length are now configurable within ION.
    - Support added for the 0.0.0.0 (any) IP address.
    - Various other refinements to standardize the DCCP CL with the other
      ION convergence layers.

- Feature Request #9: Added support for the DTN Network Monitoring reference
  implementation (DTNMP).  DTNMP is an API added to ION that is used to produce
  and monitor BP, LTP, and ICI instrumentation data.

- Feature Request #11: ION now provides the TTL of each received bundle in order
  to accomodate a CCSDS Blue Book service requirement.

- Feature Request #12: Added support for DTNperf.
  DTNperf is a utility provided in ION's "contrib" directory that can be used
  to invoke performance testing between BP nodes.

- Bug #22: Improved support for the Extended Class Of Service block (ECOS).
  ION now uses the "best effort" / "streaming" flag in ECOS to decide between
  UDP and TCP transmission.

- Bug #24: Fixed a bug in CFDP where the destination entity ID could become
  malformed when the length of the compressed destination entity ID was smaller
  than the length of the compressed source entity ID.

- Bug #25: Updated ION to be conformant with several new build warnings
  introduced in GCC 4.8.

- Bug #26: Increased the default stack size for the tcpcli and tcpclo processes
  to prevent crashes under RTEMS and VxWorks.

- Bug #27: Fixed a memory leak that could arise when sending anonymous bundles
  (bundles with a source EID of "dtn:none") while BSP was enabled.

- Bug #28: Fixed bug where reforwarded bundles were sometimes not being
  properly purged from the forwarding queue.

- Bug #29: Fixed bug where the ltp_get_notice() operation could return a bad
  value in its "data" value if the operation was interrupted.
  ltp_get_notice() now properly sets the "data" to zero if interrupted.

- Bug #29: Errors in production of notices in LTP have been corrected.

- An option to limit the length of checkpoint and report serial numbers in LTP
  has been added.  The default limit is 2 bytes.

- Added generalized service data aggregation to LTP.

- Added controls to help understand and debug CGR routing decisions.
     - The CGR routing engine can now dynamically log diagnostic trace messages
       by enabling its "trace" flag.
     - A new "cgrfetch" utility can used to invoke the creation of JSON
       input files that describe the CGR routes that were considered.
       These JSON input files can be used in conjunction with the CGR Viewer
       web application to produced PDF files that provides illustrated graphs
       for all considered routes.

       See /contrib/cgr-viewer/Readme.md for more information.

- Added man pages for the Asynchronous Message Service (AMS) subsystem.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.1.3 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Feature Request #6: LTP screening is now disabled (rather than enabled)
  by default.  This should eliminate one often mystifying source of apparent
  connectivity loss.

- Bug #23: Updated build configuration to fix build problems due to problems
  linking various pthread libraries when using bleeding-edge automake tools.

- Bug #20: Child process of fork() was unable to write to log file if
  exec() failed.

- Bug #19: Lifetime expiration of fragmentary bundles could cause a crash.

- Bug #18: A cosmetic fix -- an informative log message has been added to
  explain an alarming message issued by the ACS system.

- Bug #17: Various "admin" utility program function were broken when the
  new restart capability was added.

- Bug #16: Errors in the generation of LTP checkpoint serial numbers have
  been fixed.  In particular, no more duplicate checkpoint serial numbers.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.1.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Bug #13: Migrated admission control facilities into the ZCO subsystem so that
  they can be used outside of the BP subsystem.

- Bug #14: Fixed bug where CFDP headers could be stripped by the ZCO subsystem.

- Bug #15: Fixed various bugs that could affect ION's stability.
    - Fixed possible deadlock if the bpcp/bpcpd were terminated via a signal
      while in the middle of an SDR transaction.
    - Fixed bug in the outducts of several convergence layers and forwarder
      daemons that could cause them to not shut down properly due to an
      unintended interaction between the erasure of a taskVar semaphore with
      their internal looping constructs.

- Feature Request #1: Implemented "payload classes" to enable more
  sophisticated contact graph routing functionality.
  Extended CGR to compute routes on a per-payload-class basis that respects
  the maximum bundle size that can be sent along each route.
  The current payload classes are as follows:
    - Payloads up to 1024 bytes (1 KB)
    - Payloads between 1024 bytes (1 KB) and 1048576 bytes (1 MB)
    - Payloads between 1048576 bytes (1 MB) and 1073741824 bytes (1 GB)
    - Payloads larger than 1073741824 bytes (1 GB)

- Feature Request #4: Updated SDNV decoder and corresponding APIs to support
  up to 64-bit SDNV's on 32-bit systems, allowing for a wider space of possible
  IPN values.

- Added uClibc support for ION.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.1.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Bug #9:  Fixed several bugs in the TCP convergence layer.
    - TCPCLO would not reconnect to its neighbor if the neighbor was unreachable
      on startup.
      Fixed by instituting a default keepalive (currently 15 seconds).
    - Fixed a TCPCL interoperability bug when an external implementation uses
      full-duplex TCP connections where the tcpclo would fail to receive bundles
      from this implementation if the TCP connection had ever been previously
      lost.
    - Capped the maximum TCP reconnection timeout to 1 hour down from 24 hours.

- Bug #11: Fixed bug with transaction reversibility enabled where unpredictable
  behavior could occur when a transaction reversal was forced and the state of
  the SDR and working memory were out of sync.
  ION now reinitializes working memory from the SDR to ensure data consistency.

- Bug #12: Fixed a bug in the red-black tree data structure used in LTP by which
  sm_rbt_destroy() didn't release the tree's mutex to the OS which could
  ultimately lead to consumption of all semaphores on the system and crash the
  node.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.1.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Began transitioning to the SourceForge issue tracker for code management.
  SourceForge-originated issues are designated as "Bugs" or "Feature Requests".

- Bug #1: Fixed bug where the contact graph routing engine would prefer a
  multi-hop route to the source over the "no-hop" loopback connection.

- Bug #2: Fixed bug in contact graph routing engine where erroneous routes
  could be selected if route caching was enabled and any "downstream" contact on
  a route had an end time earlier than the end time of the first contact on the
  route.

- Bug #3: Updated code and configurations to always use the dotted-string
  representation of the sender's IP address rather than hostname.  This was done
  to mitigate problems that can arise due to aliasing and multihoming.

- Bug #7: Fixed bug where ionadmin would duplicate all currently-added contacts
  and ranges that were added in the ION configuration files before starting
  ION with the 's' command.

- Bug #8: Fixed bug where bundles that expired while in the limbo queue were not
  properly deallocated.

- Bug #10: Updated the ionstart/ionscript/killm scripts with support for the
  following ION administrative modules:
    - Bundle streaming service (BSS)
    - Interplanetary multicast (IMC)
    - Aggregate custody signals (ACS)

- Feature Request #2: Added support for bundle age extension blocks to help
  accomodate platforms that may not be able to provide a stable clock.
  For more information on the bundle age extension, refer to internet draft
      draft-irtf-dtnrg-bundle-age-block-01

- Feature Request #3: Added support for bundle multicast.

- Issue #195: Finished replacement of pthreads-based semaphore "unwedge"
  function with simpler platform-specific equivalents, begun in ION 2.4.0.

- Issue #306: Implemented several improvements to congestion forecasting.
    - Improved the accuracy of the forecast of maximum storage occupancy
      by incorporating estimations based on the rate of data being
      transmitted in and out of the internal data heaps.

    - ION now raises an alarm if expected peak volume of data is larger than
      ION's allocated file storage size.

    - Added new utility called "ionwarn" that is used for computing congestion
      forecast at an ION node based on contact plan.

- Issue #311: Added a Bundle Streaming Service (BSS) regression test that
  does not require the use of "xterm".

- Issue #339: Fixed bug in aggregate custody signals implementation that
  prevented successful completion of regression tests on some platforms.

- Issue #349: Optimized the LTP engine to achieve faster data rates by by
  substituting red-black trees and hash tables for linked lists where
  appropriate.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.0.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #280: Fixed a deadlock scenario when using "ionstart" to start two nodes
  nodes in parallel.

- Issue #349: Applied some optimizations to the LTP engine to help it operate
  at data rates that can exceed 80Mbps.

- Issue #357: Fixed compilation issues that prevented ION from building properly
  on some kfreebsd systems.

- Issue #358: Fixed a bug in computing the CFDP inactivity deadline.
  Updated the "cfdprc" man page to expose the parameters for configuring the
  CFDP inactivity timeout interval.

- Issue #360: Updated the MinGW port of ION to supply definitions for various
  required macros that are no longer supplied by newer versions of MinGW.

- Issue #361: Fixed compilation issues that prevented ION from building properly
  on some debian-unstable systems.

- Issue #362: Fixed a bug where transplantation of man pages into ION.pdf could
  fail if an obsolete version of man was used, causing compilation to fail.  ION
  now detects if the required "-l" option for man is supported, and does not
  attempt to transplant the man pages if the option is not found.

- Issue #363: Fixed several memory leaks where SDR heap space was allocated but
  not freed.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.0.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- *Issue #347: Included a test exercizing the fix for the TCPCL reconnection
  bug that was made available in ion-open-source v3.0.0.

- Issue #348:  Refreshed the MinGW and RTEMS ports of ION to build properly.

- Issue #352: BPCP, an rcp-like remote copy utility that transfers files via
  CFDP, is a new utility now included with ION.  It is built and installed by
  default and has an interface similar to rcp, with support for local to
  remote, remote to local, and remote to remote transfers in recursive and
  non-recursive modes.

- Issue #353:  Scrubbed various test configurations in the test suite that
  produced superfluous messages regarding the bundle security database not
  being initialized properly.

- Issue #354:  Slightly changed the behavior of "make retest", a directive that
  reruns tests that failed on the previous test run.
  Previously "make retest" would re-run the entire test suite if issued
  immediately following a completely sucessful test run.
  "make retest" now returns SUCCESS immediately if issued following a
  completely successful test run, a behavior more amenable to automated
  testing.

- Issue #355:  Updated the ION build process to be compatible with the latest
  versions of autotools, particularly automake v1.12.

- Issue #356:  Enhanced the bptrace application with file-sending capabilities.

- ION has now been ported to the "bionic" libc implementation, the first
  step toward porting ION to the Android operating system.

- Starting from this release the ION manual "ION.pdf" will be distributed with
  an appendix containing up-to-date man pages for all ION applications.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 3.0.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #242: Removed unnecessary recursion from the CGR implementation to help
  protect against overflows from incorrect configurations.

- Issue #262: ION is now wired with a rudimentary instrumentation framework for
  insight into run-time status, including bundle processing statistics and node
  state metrics.  This is in preparation for standardized network management.

- Issue #302: Implemented red-black trees as an alternative data structure to
  linked lists for some performance-sensitive applications.  Migrated the BP
  timeline to use red-black trees.

- Issue #304: Optimized CGR route computation by developing a new algorithm that
  employs Dijkstra's Algorithm.

- Issue #308: Several updates to ION's Payload Integrity Blocks (PIB) and
  Payload Confidentiality Blocks (PCB):
    - Bundle Security Protocol (BSP) utilities now support PIB and PCB.
    - PIB and PCB extension block code has been added.
    - Roughly 40 new test cases for PIB, PCB, and BAB combinations have been
      introduced.

- Issue #311: Bundle Streaming Service (BSS) support has been added to ION.
  BSS passes "real-time" bundle payloads to an application callback while also
  storing the bundle payloads to a database for user-directed playback.

- Issue #314: Standardized spelling of the word "semaphore" throughout the ION
  codebase.

- Issue #322: Improved reliability for custodial retransmissions when the next
  custodian is a neighbor by making the following tweaks in libbpP.c:
    - Changed the bpDequeue "stewardship accepted" flag to a custodial timeout
      interval value (in seconds) that is computed by the CL output daemon,
      based on CL-specific knowledge, in the event that the CL protocol is not
      reliable and therefore can't accept stewardship of the bundle.
    - Added the same custodial timeout interval value to bpHandleXmitSuccess, to
      trigger reforwarding of the bundle even when stewardship has been taken
      and CL transmission has been nominally successful and reliable, in the
      event that the CL transmission ultimately (unexpectedly) does not succeed.

- Issue #325: Fixed a bug that could cause ION to crash when sending bundles for
  which the destination endpoint is not a singleton.

- Issue #329: ION now supports sending (rather than just receiving) fragmented
  bundles.  (NOTE: this entailed several changes to the ZCO API.)

- Issue #339: Aggregate Custody Signals (ACS) have been added to ION.
    - ACS is a technology that combines information from various separate
      custody signals into a single bundle, which has the potential to save
      "ack channel" bandwidth.
    - For more information on ACS, see the following document:
        <http://bioserve.colorado.edu/bp-acs/draft-kuzminsky-aggregate-custody-signals-02.txt>

- Issue #342: Changed several invocations of lyst_create() to
  lyst_create_using(), to ensure that ION's private memory management is always
  used.

- Issue #343: Fixed bugs in LTP that could cause crashes at high data loss rates
    - Fixed mechanisms for preventing resurrection of closed Import sessions.
    - Fixed issue where the same report number could become assigned to two
      different reports, resulting in link service daemons crashing.

- Issue #344: Added a "-t <ttl>" command line parameter to set the time-to-live
  for bundles sent from the bpsource application.  Previously bundles were
  hard-coded with lifetimes of 300 seconds, which is now the default if the TTL
  is not explicitly specified.

- Issue #345: The ION Deployment Guide is now bundled with ION.  It provides
  FAQ-style documentation for helping new users familiarize themselves with ION.

- Issue #347: Fixed bug in re-establishing connectivity via TCPCL when a node
  shuts down and then restarts.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.5.3 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #271: Various autotools changes to update how CFDP is built.

- Issue #288: Fixed bug in CFDP implementation where performing a proxy "puts"
  operation without supplying a flow label would trigger an assertion failure.

- Issue #290: Fixed bug in CFDP implementation where an internal SDR list was
  improperly referenced.

- Issue #316: Fixed several unresolved symbolic links in the "limbo" subsection
  of the test suite.

- Issue #318: Fixed bug in CFDP implementation where an assertion was triggered
  when a remote directory listing was performed for a directory that did not
  exist.

- Issue #323: Fixed bug in BP implementation where an integer overflow in the
  congestion forecasting code would cause BP to refuse bundles from local user
  applications on 32-bit machines with long, busy contacts.

- Issue #328: Fixed bug in CFDP implementation where internal calculations for
  its CFDP Directory Listing Response user messages were one character shorter
  than they should be.

- Issue #330: Fixed bug in CFDP implementation where cfdpclock would remove
  unsent FDUs that did not contain any actual file data.

- Issue #331: Fixed bug in CFDP implementation where user messages were not
  restricted to a maximum of 255 characters in length, as per the CFDP
  specification.

- Issue #333: Fixed bug in CFDP implementation where originating transaction ID
  messages were not wrapped as CFDP user messages as per the CFDP specification,
  resulting in messages that contained the wrong type codes.

- Issue #334: Fixed bug in CFDP implementation where the cfdp_put() and
  cfdp_get() operations returned "0" as transactionId rather than the actual
  CFDP transaction number.

- Issue #338: Modified test suite to use relative times instead of absolute
  times wherever possible.  This fixes several tests with configurations that
  became obsolete after the start of 2012 and ensures better resilience of the
  test suite to any kind of absolute time boundaries.

- Issue #340: Several minor updates have been applied to the DCCP implementation
  to detect and build DCCP for linux kernels that meet or exceed version 3.2.0,
  which puts several key DCCP fixes into the kernel baseline.

- Status reporting support has been added to cfdptest.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.5.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #297: The ION design guide "ION.pdf" now dynamically incorporates the
  ION manpages.
  This feature requires ghostscript, psutils, groff, and groff-base.
  If not all are present, ION will build but ION.pdf will not have the latest
  manpages appended.
  ION.pdf is built automatically via the "make" command.
  To explicitly build the ION design guide document, use the following command:
     make ION.pdf

- Issue #298+: Fixed build incompatibility between gcc v4.6.1 and later with
  valgrind v3.6.1 and earlier.  If needed to compile with Valgrind support,
  ION will add -Wno-unused-but-set-variable to AM_CFLAGS.
  Valgrind inclusion can also be explicitly controlled via the following flags:
     ./configure --enable-valgrind:  Build with Valgrind support
     ./configure --disable-valgrind: Build without Valgrind support

- Issue #299: ION now prints a warning when given any BAB rule that is not for a
  wild-carded EID signifying "all endpoints at the indicated node".

- Issue #300: Fixed several bugs in ipnfw:
    - lookupRule() function of libipnfw.c incorrectly used srcServiceNbr
      instead of srcNodeNbr.
    - Several IPN function calls in ipnadmin.c have been wrapped in
      sdr_begin_xn/sdr_exit_xn blocks to protect against assertion failures.
    - Before putting a bundle into the Limbo list, ipnfw now searches for
      blocked outducts and discards the bundle if none are found.

- Issue #301: Fixed issue where Ctl+C no longer terminated the bpsink and
  bprecvfile utilities.

- Issue #303: Fixed issue where new all-green transmission sessions could be
  inhibited by the LTP limit on the total number of export sessions.
  Since LTP green is unreliable, LTP green sessions don't need to occupy
  resources at the sender for retransmissions, so the sessions need not be
  restricted.

- Issue #307: Fixed overflow bugs in the increaseScalar() and reduceScalar()
  functions.
  Added Scalar to SDNV conversion functions.

- Issue #313: Fixed issue with overlapping bundle source/destination memory
  addresses that could cause bundle corruption on 64-bit systems.

- Issue #319: Fixed issue with AMS where the parseSocketSpec() function could
  return INADDR_ANY, which isn't an acceptable IP address within AMS.
  Now possible to enable  AMS debug output via the following configure flag:
     ./configure --enable-ams-debug:  Build with AMS debugging output

- Issue #324: Fixed issue where LTP could accumulate block acquisision files
  after the block acquisition had already been completed.  This was generally
  due to unnecessary retransmitted segments that arrived late.  Since the
  blocks had already been delivered, the ensuing files were never destroyed.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.5.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #185: ION now supports binding to INADDR_ANY in UDP/TCP ports and link
  service adapters.

- Issue #298: Code scrub to remove unused variable warnings that prevent
  compilation of ION under the default settings of gcc 4.6.1.

- Issue #310: Fixed broken Windows support.  Fixed several minor issues.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.5.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #189/#250/#252: ION shutdown utility added.

- Issue #196: The congestion checking subroutines have been implemented more
  efficiently.

- Issue #265: The "bpdriver" application now allows users to set the TTL value
  dynamically via a the "t<ttl>" command line parameter.

- Issue #276: Loopback range can now be set to a non-zero value.

- Issue #279: Fixed issue where calling bpMemo twice created timeline events
  that could not be removed.

- Issue #286: Fixed issue where erroneous input to several administrative
  applications could cause them to crash.

- Issue #292: Fixed issue where pid-checking routines can give false-negatives
  for vxworks processes.

- Issue #296: Corrected usage of internal _xxxConstants() functions to ensure
  they are only used with invariant values.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.4.2 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue #264: Removed checks for maximum block size in LTP, simplifying LTP
  configuration and fixing a bug.
  Related to the fix for issue #293, upgrading the LTP configuration worksheet.

- Issue #269: Clean up platform (portability) files, making it easier to add
  new ports.
  Removed support for some obsolete platforms (e.g., HP-UX).

- Issue #270: Fixed issue in cfdptest that prevented the "Custody Requested"
  switch from being set.

- Issue #275: ION now has support for code coverage analysis via lcov/gcov.
  To enable this feature, use "./configure --with-gcov".
  Building with code coverage support enables the following new directives:
     make cov: creates a "coverage" subfolder from the top of the ION
               directory where HTML coverage results are stored
     make cov clean: removes the trace files and the "coverage" subdirectory

- Issue #281: Fixed issue that terminated bputa when it was directed
  to write to a file without sufficient write permissions.

- Issue #282: Fixed issue where LTP segments received outside of a contact
  were mishandled.

- Issue #283: Fixed issue where the CFDP FDU didn't load the database before
  using it, resulting in erroneous data being fed into the CFDP event queue.

- Issue #284: Fixed issue where CFDP mishandled extent merges, resulting
  in checksum failures.

- Issue #285: Fixed issue in cfdpadmin where malformed commands could cause the
  application to crash.

- Issue #287: Fixed issue that prevented the reporting of user messages and
  filestore responses in cfdptest.

- Issue #293: Fixed issue in the ION LTP Worksheet where the spreadsheet
  doesn't account for a small aggregation size limit when calculating
  export blocks

- Issue #295: ION's internal contact graph routing routines have been
  parameterized to enable better support for deployment-specific variations
  of the algorithm.

- ION now has native Windows support via MingW.
  Support for Cygwin and Interix has been removed.

- Added support for inactivity timer in CFDP.

- Fixed race conditions in support for multithreaded AMS.

- Fixed memory leaks in AMS shutdown.

- Added ability to update AMS modules' management information bases while the
  modules are running, by using the new amsmib utility.  Modified amsstop to
  use a similar mechanism.

- Added AMS Programmer's Guide to distribution.

- Various minor bug fixes.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.4.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- *Issue #240: Added DCCP link service adapters to ION for the purpose of
  providing congestion control without reliability guarantees, which is
  beneficial for LTP deployments over IP networks, particularly when traversing
  the Internet. The sender program is called "dccplso" and the receiver program
  is called "dccplsi".

- *Issue #241: Added DCCP convergence layer for BP. The sender program is called
  "dccpclo" and the receiver program is called "dccpcli".

- Issue #245: Added support for using the character "*" as a wildcard to remove
  multiple contacts and ranges at once.

- Issue #257: Fixed issue where bundles would remain in the limbo queue after
  an outduct was blocked rather than be reforwarded.

- Issue #263: Fixed issue with pthread_t.  pthread_t is now treated as an
  opaque type for the purpose of improving code correctness and portability.

- Issue #273: Added a ".hgignore" file that can be populated with regular
  expressions of files to suppress when the "hg status" command is run.

- Issue #277: Fixed 3-node-stcp-ltp configuration to remove an unintentional
  connection between nodes 1 and 3.


- Issue #278: Updated various test configuration files to have more recent
  contact times.

- Tests have been scrubbed to adopt the new security syntax enhancements
  introduced in Issue #247.

* Note: Due to an immature DCCP implementation in most native OS kernels at the
        time of release, formal DCCP testing on 64-bit systems has yet to be
        conducted.  Currently an experimental kernel containing several DCCP
        fixes must be built to achieve acceptable performance.  These fixes are
        expected to become standard in the native linux 3.1 kernel.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.4.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Issue 105: Add correlation blocks to the bundle protocol block extension
  interface.

- Issue 106: Extract bundle block-related functionality into separate source .c
  and .h files to allow for future modular development of block extensions.

- Issue 161: Corrected some redundant and/or circular library linking when
  using autotools.

- Issue 176: Upgrade ltp-cla to better conform to current ltpcla draft in the
  DTNRG.  Particularly the new "green" service handling.

- Issue 195: sm_SemUnwedge() in platform_sm.c uses a pthread to ensure a
  semaphore is not already taken.  Some platforms do not include pthreads and
  the function can be implemented using semaphore trywait semantics().

- Issue 233: Some additional LTP debugging hooks added.

- Issue 238: Fixed possible leak of custodianEid in sendCtSignal.

- Issue 247: Updating the syntax of ionsecadmin for flexibility and readability.

- Issue 248: Fixed a timeline ordering bug in LTP.

- Issue 249: Added support to ION's LTP for section 6.21 of RFC 5326, the LTP
  specification.  Specifically detecting "red" and "green" segments that
  overlap: an error-state.

- Issue 253: Fixed a tcpcl bug: When connection is lost to a node, a keepalive
  needs to be at the end of the backoff period. TCPCL waits backoff period +
  keepalive period to send the keepalive.

- Issue 254: Fixed LTP report serial number bug.

- Issue 255: Fixed bug where pseudoshell can cause duplicate parent processes.

- Issue 256: Fixed uninitialized memory read in reverseEnqueue().

- Issue 258: ZCO referenced file progress.

- Issue 260: Teach memcheck about MTAKE/MRELEASE for improved testing using
  valgrind.

- Various bugfixes and features for AMS package.

- Various bugfixes and features for CFDP package.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.3.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Modified administrative startup commands to block until startup is complete,
  rather than return immediately even if the node hasn't been fully initialized.

- Fixed a bug which truncated dtn-scheme bundle source EIDs.

- Modified some tests (1000.loopback) to run compiled objects instead of shell
  scripts.  This eliminates the need for shell scripting and allows automated
  tests to function on platforms without shell access.

- Combined similar test configurations to use the shared /configs directory.
  This will provide a standard set of updated configurations.

- Test suite has been modified to support multiple test sets.  Creating a
  text file in the tests directory containing a list of tests is all that
  is needed to create a test set.
  Examples: make test-all ; make test-branch ; make test-<anything>

- Added "limbo" queue to support suspension and resumption.  This allows the
  node to handle unexpected convergence layer failure as opposed to scheduled
  or static contact termination.

- Code scrub of DGR.

- Added bping, bpchat, and bpstats2 utilities.

- Custody transfer is now optional in both bptrace and bpsend.

- Added feature for "convergence-layer stewardship"; CL's can initiate
  reforwarding of bundles on transmission failure without explicit
  bundle-layer custodianship.

- Enhanced LTP's udplso with a transmission rate limiter.

- Added new AOS CLA for LTP.

- Bug fixes to: LTP, CGR, SDR mutex, bpcounter, ionscript, tcpcl, stcp,
  PSM mutex, SDR, bpsink, and others.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.2.1 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Corrected bug in LTP's data acquisition into file-system storage.  Didn't
  handle data loss and retransmission properly.

- Fixed bugs in LTP session cancellation that caused slow storage leaks.

- Upgraded the LTP configuration spreadsheet and its documentation, to
  provide better guidance when most data are sent from or acquired into
  file system storage.

- Updated the Design and Operations Guide to document new features and
  API changes.

- Various other bug fixes and tweaks.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.2.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Store bundles in ZCO.

- Added feature to store bundles directly to file-system memory, allowing
  much larger bundles to be handled by the node.

- Added feature to allow all stdout output to be redirected to log files.
  Feature is enabled by #defining FSWLOGGER.

- Code scrub BP, CFDP, ICI, LTP.

- Add support for asymmetric link-delay (range) in contacts.

- Add option to configure LTP spans for "purge" behavior on contact termination.

- Fixed handling of dtn:none eids.

- Optimize contact graph routing.

- Various bug fixes and tweaks.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.1.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Port to FreeBSD and RTEMS (via manual makefiles).

- Various fixes and tweaks.

- Added comprehensive automated testing suite.

- Fixed various compiler bugs

- Modified custodian EID generated from dtn://hostname to dtn://hostname.dtn

- Modified the loopback and ion-dtn2 configuration files for the new command
  syntax.

- Added BSP implementation using "stub" versions of hmac and sha1 for public
  release.

- Added CFDP implementation.

- Bug fixes in LTP, BRS, and some BP applications.

- Tweaks related to running on VxWorks.

- Added assertions.

- Bug fixes in the TCP convergence layer, particularly in the interest of
  interoperability with dtn2.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 2.0.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Based on JPL revision 255:6443ed8258e1

- Converted underlying version control system to Mercurial from Subversion.

- Add ionsecadmin for managing the security policy database.

- Added better support for cross-scheme routing.

- Add support for the previous-hop-node extension.

- Update route computation to current CBHE draft standard.

- Addresses memory leak problem identified by U. of Colorado in long-duration
  tests.

- LTP heavily modified to become more flexible and powerful.

- dtnadmin and associated utilities renamed to dtn2admin.

- Configuration file syntax changes slightly in ionadmin, bpadmin, ipnadmin,
  dtn2admin; heavily changes syntax of ltpadmin.  Included ION-LTP-Configuration
  document and spreadsheet to explain new syntax and calculate values.

- Bug fixes.

- Documentation updates.

- Various testing applications in earlier releases are split from the ion
  release.

%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 1.1.0 =
%%%%%%%%%%%%%%%%%%%%%%%%%%

- Based on JPL revision 226.

- Experimental new tcp convergence layer compatible with the standard defined
  by draft-irtf-dtnrg-tcp-clayer-02.  This convergence layer is titled tcp,
  with other programs tcpcli tcpclo, and is suitable for connectivity with the
  DTN2 reference implementation.  Currently only unidirectional, unacknowledged
  communication is supported.  Some bugs still present.

- ION-specific tcp-based convergence layer is renamed stcp (stcpcli stcpclo)
  and still functions as expected.

- Adds user-contributed applications bping bping bpmon bpalive.

- some LTP related bugs are not yet squashed.

- Updates to various user-contrib programs; added a bpmon_query program to work
  with SNMP.

- Revise LTP to use randomly selected session numbers rather than recycling
  small session numbers - prevent data loss and corruption due to application of
  late-arriving segments to sessions that are re-using the session numbers of
  earlier sessions.

- added the bplive program.

- Updated for sbp_api.h and abp_api.c

- brought over basic working draft-tcpcl standards-compliant code with help of
  patch submitted by Andrew.Jenkins@colorado.edu

- manually applied patches from seb@highlab.com, adding sanity-checks and more
  consistent comment-line detection to the admin programs

- Add fixes to eliminate compiler warnings, per Ohio U.  Remove all ppc-vxworks
  makefile directories, replacing them with arch-vxworks5 directories because
  the VxWorks build varies with VxWorks version number and not with the hardware
  platform that you build for.  Add "expat", which is needed by AMS and is not
  provided with VxWorks.  Fix segfault bug in dtnfw reported by U. of Colorado.
  Fix bug in support for trackingElts list.

- applied the patch from Andrew.Jenkins@colorado.edu about dtnfw's rule/plan but

- added new ION.pdf to the in-development release

- overhauled ionstart, ionscript, ionstart.awk to account for the dtnadmin need
  for a node name as well as the bpadmin/dtnadmin/ipnadmin startup order bug
  found by Andrew.Jenkins@colorado.edu

- Revise routing to match applicable backlog (based on bundle's priority; not
  necessarily total backlog) against aggregate capacity when determining route
  viability.  (Per JIRA item DINET-107)  Add implementation of extension block
  for extended class of service, which includes an additional 256 "ordinal"
  priority sub-levels within priority 2.

- Upgrade AMS implementation to Red Book 2.

- Add interface for inserting BP extensions.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 1.0_r203 =
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

- Based on jpl r203.

- Adds LTP package.

- Supports contact graph routing.

- Compilation changed to autoconf and automake; compilation tested on:
  Ubuntu 7.04, 7.10, 8.04, Gentoo, Fedora 3, Fedora 7, OSX 10.5, and Solaris 10.

- Killm updated to work on OSX 10.4, due to an ipcs incompatibility; also
  updated to make sure all processes are killed.

- Removed multiple compiler warnings.

- Includes bundle relay programs brsscla and brsccla; brsscla acts as the
  server, brsccla acts as the client.

- Zco package rolled into ici.

- Ionscript added for configuration file management; ionstart and ionstop
  rewritten.

- Various bug fixes.

- 2008-11-11 Added the ION Design and Operation manual v1.6.

%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 0.3 =
%%%%%%%%%%%%%%%%%%%%%%%%

- Based on jpl r105.

- Simplified and cleaned up SDR implementation in the ici package.

- ion package and utilities renamed to "bp" for "bundle protocol."

- Restructured congestion control to be based on rate control.

- Implements BP version 6.

- Revised the zco package.

- Added capability for dynamic routing based on network topology that changes
  with the passage of time.

- Fixed various bugs.

- All administrative and application errors are reported to ion.log

- Added ionstart and ionstop scripts.

%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 0.2 =
%%%%%%%%%%%%%%%%%%%%%%%%

- The ion package, which implements the DTN Bundle Protocol (BP), has been
  upgraded to conform to BP version 5, submitted to IETF in December 2006.
  The changes are almost exclusively internal to the software and protocol:
  the format of bundles exchanged through the delay-tolerant network is altered,
  but the API for ION is mostly unchanged.  Note that this release of ION is
  not interoperable with implementations of BP version 4.

- The Remote AMS functionality of AMS has been upgraded to conform to the
  specification most recently posted to the public documents list of the CCSDS
  CWE site for AMS.  The API for AMS is unchanged.

- A variety of miscellaneous bugs have been fixed.

%%%%%%%%%%%%%%%%%%%%%%%%
= NOTES ON RELEASE 0.1 =
%%%%%%%%%%%%%%%%%%%%%%%%

- Initial code released for review.