snmp: borrow dummy plugin as a start point

Add: ChatGPT in_snmp

Add: snmp get with fix request

Add: snmp with log recorder

Add: print value by sprint_realloc_by_type

Fix: refine code.

Add: walk get values

TMP

Author: k402xxxcenxxx

CMakeLists.txt

@@ -92,6 +92,7 @@ include(GNUInstallDirs)
 include(ExternalProject)
 include(cmake/FindJournald.cmake)
 include(cmake/FindMonkey.cmake)
+include(cmake/FindNetsnmp.cmake)
 include(cmake/macros.cmake)
 include(cmake/platform_feature_checks.cmake)
 set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/sanitizers-cmake/cmake" ${CMAKE_MODULE_PATH})
@@ -191,6 +192,7 @@ option(FLB_IN_HEAD                     "Enable Head input plugin"
 option(FLB_IN_PROC                     "Enable Process input plugin"                  Yes)
 option(FLB_IN_SYSTEMD                  "Enable Systemd input plugin"                  Yes)
 option(FLB_IN_DUMMY                    "Enable Dummy input plugin"                    Yes)
+option(FLB_IN_SNMP                     "Enable SNMP input plugin"                     Yes)
 option(FLB_IN_NGINX_EXPORTER_METRICS   "Enable Nginx Metrics input plugin"            Yes)
 option(FLB_IN_NETIF                    "Enable NetworkIF input plugin"                Yes)
 option(FLB_IN_WINLOG                   "Enable Windows Log input plugin"               No)

cmake/FindNetsnmp.cmake

@@ -0,0 +1,73 @@
+# - Find Net-SNMP
+#
+# -*- cmake -*-
+#
+# Find the Net-SNMP module
+#
+#  NETSNMP_INCLUDE_DIR - where to find Net-SNMP.h, etc.
+#  NETSNMP_LIBRARIES   - List of libraries when using Net-SNMP.
+#  NETSNMP_FOUND       - True if Net-SNMP found.
+
+IF (NETSNMP_INCLUDE_DIR)
+  # Already in cache, be silent
+  SET(NETSNMP_FIND_QUIETLY TRUE)
+ENDIF (NETSNMP_INCLUDE_DIR)
+
+FIND_PATH(NETSNMP_INCLUDE_DIR snmp.h
+  /usr/include/net-snmp/library
+)
+
+SET(NETSNMP_NAMES netsnmp)
+FIND_LIBRARY(NETSNMP_LIBRARY
+  NAMES ${NETSNMP_NAMES}
+  PATHS /usr/lib /usr/local/lib
+)
+
+SET(NETSNMPAGENT_NAMES netsnmpagent)
+FIND_LIBRARY(NETSNMPAGENT_LIBRARY
+  NAMES ${NETSNMPAGENT_NAMES}
+  PATHS /usr/lib /usr/local/lib
+)
+
+SET(NETSNMPHELPERS_NAMES netsnmphelpers)
+FIND_LIBRARY(NETSNMPHELPERS_LIBRARY
+  NAMES ${NETSNMPHELPERS_NAMES}
+  PATHS /usr/lib /usr/local/lib
+)
+
+SET(NETSNMPMIBS_NAMES netsnmpmibs)
+FIND_LIBRARY(NETSNMPMIBS_LIBRARY
+  NAMES ${NETSNMPMIBS_NAMES}
+  PATHS /usr/lib /usr/local/lib
+)
+
+SET(NETSNMPTRAPD_NAMES netsnmptrapd)
+FIND_LIBRARY(NETSNMPTRAPD_LIBRARY
+  NAMES ${NETSNMPTRAPD_NAMES}
+  PATHS /usr/lib /usr/local/lib
+)
+
+SET(NETSNMP_LIBRARIES
+  ${NETSNMP_LIBRARY}
+  ${NETSNMPAGENT_LIBRARY}
+  ${NETSNMPHELPERS_LIBRARY}
+  ${NETSNMPMIBS_LIBRARY}
+#  ${NETSNMPTRAPD_LIBRARY}
+)
+
+
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(NETSNMP
+  DEFAULT_MSG
+  NETSNMP_INCLUDE_DIR
+  NETSNMP_LIBRARIES
+)
+
+MARK_AS_ADVANCED(
+  NETSNMP_LIBRARY
+  NETSNMPAGENT_LIBRARY
+  NETSNMPHELPERS_LIBRARY
+  NETSNMPMIBS_LIBRARY
+  NETSNMPTRAPD_LIBRARY
+  NETSNMP_INCLUDE_DIR
+  )

plugins/CMakeLists.txt

@@ -216,6 +216,7 @@ REGISTER_IN_PLUGIN("in_prometheus_scrape")
 REGISTER_IN_PLUGIN("in_emitter")
 REGISTER_IN_PLUGIN("in_tail")
 REGISTER_IN_PLUGIN("in_dummy")
+REGISTER_IN_PLUGIN("in_snmp")
 REGISTER_IN_PLUGIN("in_head")
 REGISTER_IN_PLUGIN("in_health")
 REGISTER_IN_PLUGIN("in_http")

plugins/in_snmp/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(NETSNMP_LIBRARIES ${NETSNMP_LIBRARY})
+set(NETSNMP_INCLUDE_DIRS ${NETSNMP_INCLUDE_DIR})
+
+set(src
+  in_snmp.c)
+
+FLB_PLUGIN(in_snmp "${src}" "")
+target_link_libraries(flb-plugin-in_snmp ${NETSNMP_LIBRARIES})