Enable SNMP syslog, like in OSAL use -DUSE_SYSLOG

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

cmake/Linux.cmake

@@ -18,6 +18,10 @@ if (PNET_OPTION_SNMP)
   find_package(NetSNMPAgent REQUIRED)
 endif()
 
+option (USE_SYSLOG
+  "Use syslog instead of logging to stdout"
+  OFF)
+
 target_include_directories(profinet
   PRIVATE
   src/ports/linux
@@ -51,6 +55,7 @@ target_compile_options(profinet
   -Wno-unused-parameter
   -ffunction-sections
   -fdata-sections
+  $<$<BOOL:${USE_SYSLOG}>:-DUSE_SYSLOG>
   INTERFACE
   $<$<CONFIG:Coverage>:--coverage>
   )

src/ports/linux/pnal_snmp.c

@@ -39,7 +39,11 @@ static void pnal_snmp_thread (void * arg)
 {
    struct pnet * pnet = arg;
 
+#ifndef USE_SYSLOG
    snmp_disable_log();
+#else
+   snmp_enable_syslog();
+#endif
 
    /* make us an agentx client. */
    netsnmp_enable_subagent();