FreeBSD: link against libpcap

[dancrossnyc]

On FreeBSD, one must actually link against libpcap (or give the path to a shared object at link
time). That is, it is not a header-only library
on that platform.

Account for this by adding a new boolean variable
in platform-quirks.cmake: NEED_PCAP_LIBRARY,
which defaults to false. Condition pcap library
discovery and link argument modifications on that
variable in FindPCAP.cmake and dep-link.cmake.

[dancrossnyc]

Gentle ping on this?

[markpizz]

FYI, the makefile build produces completely useful simulators with PCAP network support that works just fine on FreeBSD 14.3. I suspect the same with 15.0.

mark@FreeBSD:~/open-simh $ gmake pdp11
lib paths are: /lib /usr/lib /usr/lib/compat /usr/local/lib /usr/local/lib/compat/pkg /usr/local/lib/gcc13 /usr/local/lib/perl5/5.40/mach/CORE /lib/ /usr/lib/
include paths are:  /usr/local/lib/gcc13/gcc/x86_64-portbld-freebsd14.2/13.3.0/include /usr/local/include /usr/include /usr/local/include
using libm: /usr/lib/libm.so
using librt: /usr/lib/librt.so
using libpthread: /usr/lib/libpthread.so /usr/include/pthread.h
using libpcre: /usr/local/lib/libpcre.so /usr/local/include/pcre.h
using semaphore: /usr/include/semaphore.h
using libdl: /usr/lib/libdl.so /usr/include/dlfcn.h
using libedit: /usr/local/include/editline/readline.h
using libpng: /usr/local/lib/libpng.so /usr/local/include/png.h
using zlib: /usr/lib/libz.so /usr/include/zlib.h
using mman: /usr/include/sys/mman.h
using libSDL2: /usr/local/include/SDL2/SDL.h
*** No SDL ttf support available.  BESM-6 video panel disabled.
***
*** Info *** Install the development components of libSDL2-ttf packaged by your
*** Info *** operating system distribution and rebuild your simulator to
*** Info *** enable this extra functionality.
using libpcap: /usr/include/pcap.h
***
*** pdp11 Simulator being built with:
*** - compiler optimizations and no debugging support. GCC Version: 13.3.0.
*** - dynamic networking support using FreeBSD provided libpcap components.
*** - Local LAN packet transports: PCAP TAP NAT(SLiRP)
*** - video capabilities provided by libSDL2 (Simple Directmedia Layer).
*** - Per simulator tests will be run.
***
*** git commit id is 4d38373206cd7c0ce8b94f5e16bd4429cb96430f.
*** git commit time is 2025-10-12T07:58:51+0200.
***
gcc -std=gnu99 -U__STRICT_ANSI__  -O2 -DNDEBUG=1 -finline-functions -fgcse-after-reload -fpredictive-commoning -fipa-cp-clone -fno-unsafe-loop-optimizations -fno-strict-overflow -DSIM_GIT_COMMIT_ID=4d38373206cd7c0ce8b94f5e16bd4429cb96430f -DSIM_GIT_COMMIT_TIME=2025-10-12T07:58:51+0200  -DSIM_COMPILER="GCC Version: 13.3.0" -DSIM_BUILD_TOOL=simh-makefile -I . -Werror -D_GNU_SOURCE -I/usr/local/include -DHAVE_PCRE_H -DHAVE_SEMAPHORE -DHAVE_SYS_IOCTL -DSIM_HAVE_DLOPEN=so -DHAVE_EDITLINE -DHAVE_UTIME -DHAVE_LIBPNG -DHAVE_ZLIB -DHAVE_GLOB -DHAVE_SHM_OPEN  ./PDP11/pdp11_fp.c ./PDP11/pdp11_cpu.c ./PDP11/pdp11_dz.c ./PDP11/pdp11_cis.c ./PDP11/pdp11_lp.c ./PDP11/pdp11_rk.c ./PDP11/pdp11_rl.c ./PDP11/pdp11_rp.c ./PDP11/pdp11_rx.c ./PDP11/pdp11_stddev.c ./PDP11/pdp11_sys.c ./PDP11/pdp11_tc.c ./PDP11/pdp11_tm.c ./PDP11/pdp11_ts.c ./PDP11/pdp11_io.c ./PDP11/pdp11_rq.c ./PDP11/pdp11_tq.c ./PDP11/pdp11_pclk.c ./PDP11/pdp11_ry.c ./PDP11/pdp11_pt.c ./PDP11/pdp11_hk.c ./PDP11/pdp11_xq.c ./PDP11/pdp11_xu.c ./PDP11/pdp11_vh.c ./PDP11/pdp11_rh.c ./PDP11/pdp11_tu.c ./PDP11/pdp11_cpumod.c ./PDP11/pdp11_cr.c ./PDP11/pdp11_rf.c ./PDP11/pdp11_dl.c ./PDP11/pdp11_ta.c ./PDP11/pdp11_rc.c ./PDP11/pdp11_kg.c ./PDP11/pdp11_ke.c ./PDP11/pdp11_dc.c ./PDP11/pdp11_dmc.c ./PDP11/pdp11_kmc.c ./PDP11/pdp11_dup.c ./PDP11/pdp11_rs.c ./PDP11/pdp11_vt.c ./PDP11/pdp11_td.c ./PDP11/pdp11_io_lib.c ./PDP11/pdp11_rom.c ./PDP11/pdp11_ch.c ./PDP11/pdp11_dh.c ./PDP11/pdp11_ng.c ./PDP11/pdp11_daz.c ./PDP11/pdp11_tv.c ./PDP11/pdp11_mb.c ./PDP11/pdp11_rr.c ./display/display.c ./display/sim_ws.c ./display/ng.c ./display/vt11.c ./scp.c ./sim_console.c ./sim_fio.c ./sim_timer.c ./sim_sock.c ./sim_tmxr.c ./sim_ether.c ./sim_tape.c ./sim_disk.c ./sim_serial.c ./sim_video.c ./sim_imd.c ./sim_card.c -DVM_PDP11 -I ./PDP11 -DHAVE_PCAP_NETWORK -I/usr/include/ -DBPF_CONST_STRING -DUSE_SHARED -DHAVE_TAP_NETWORK -DHAVE_BSDTUNTAP -Islirp -Islirp_glue -Islirp_glue/qemu -DHAVE_SLIRP_NETWORK -DUSE_SIMH_SLIRP_DEBUG slirp/*.c slirp_glue/*.c -DUSE_DISPLAY -DHAVE_LIBSDL -DUSE_SIM_VIDEO `sdl2-config --cflags` `sdl2-config --libs` -DUSE_READER_THREAD -DSIM_ASYNCH_IO -o BIN/pdp11 -L/lib -L/usr/lib -L/usr/lib/compat -L/usr/local/lib -L/usr/local/lib/compat/pkg -L/usr/local/lib/gcc13 -L/usr/local/lib/perl5/5.40/mach/CORE -L/lib/ -L/usr/lib/ -lm -lrt -lpthread -lpcre -L/usr/local/lib/ -ldl -ledit -ltermcap -lpng -lz
BIN/pdp11 RegisterSanityCheck  </dev/null
 Running internal register sanity checks on PDP-11 simulator.
*** Good Registers in PDP-11 simulator.
mark@FreeBSD:~/open-simh $ su
Password:
root@FreeBSD:/home/mark/open-simh # BIN/pdp11

PDP-11 simulator Open SIMH V4.1-0 Current        git commit id: 4d383732
sim> show eth
ETH devices:
 eth0   hn0                                  (No description available)
 eth1   tap:tapN                             (Integrated Tun/Tap support)
 eth2   nat:{optional-nat-parameters}        (Integrated NAT (SLiRP) support)
 eth3   udp:sourceport:remotehost:remoteport (Integrated UDP bridge support)
sim> show ver
PDP-11 simulator Open SIMH V4.1-0 Current
    Simulator Framework Capabilities:
        32b data
        32b addresses
        Threaded Ethernet Packet transports:PCAP:TAP:NAT:UDP
        Idle/Throttling support is available
        Virtual Hard Disk (VHD) support
        Asynchronous I/O support (Lock free asynchronous event queue)
        Asynchronous Clock support
        FrontPanel API Version 12
    Host Platform:
        Compiler: GCC 13.3.0
        Simulator Compiled as C arch: x64 (Release Build) on Jan 21 2026 at 11:19:10
        Build Tool: simh-makefile
        Memory Access: Little Endian
        Memory Pointer Size: 64 bits
        Large File (>2GB) support
        SDL Video support: SDL Version 2.32.8, PNG Version 1.6.49, zlib: 1.3.1
        PCRE RegEx (Version 8.45 2021-06-15) support for EXPECT commands
        OS clock resolution: 1ms
        Time taken by msleep(1): 1ms
        Ethernet packet info: libpcap version 1.10.5
        OS: FreeBSD FreeBSD 14.3-RELEASE FreeBSD 14.3-RELEASE releng/14.3-n271432-8c9ce319fef7 GENERIC amd64
        tar tool: bsdtar 3.7.7 - libarchive 3.7.7 zlib/1.3.1 liblzma/5.8.1 bz2lib/1.0.8 libzstd/1.5.2
        curl tool: curl 8.14.1 (amd64-portbld-freebsd14.2) libcurl/8.14.1 OpenSSL/3.0.16 zlib/1.3.1 brotli/1.1.0 zstd/1.5.7 libidn2/2.3.8 libpsl/0.21.5 libssh2/1.11.1 nghttp2/1.66.0
        git commit id: 4d383732
        git commit time: 2025-10-12T07:58:51+0200
sim>

[dancrossnyc]

Yes. But not with cmake. :-)