From 406e1759dc6a4c18f6a38c3d7571aacb177487c6 Mon Sep 17 00:00:00 2001
From: Romain Naour <romain.naour@gmail.com>
Date: Sun, 28 May 2017 00:25:11 +0200
Subject: [PATCH] [FIX]: use pcap-config to fix static linking with libpcap

When linking demo_mn_console statically with pcap, the CMake build
system forget to link with other libraries linked with libpcap
(-lnl-genl-3 -lnl-3 -ldbus-1 -pthread).

[100%] Linking C executable demo_mn_console
lib64/libpcap.a(pcap-linux.o): In function nl80211_init': pcap-linux.c:(.text+0x41e): undefined reference tonl_socket_alloc'

To fix this, the build system could use pcap-config:
pcap-config --libs --static
-L/path/to/sysroot/usr/lib -lpcap -L/path/to/sysroot/usr/lib/.libs
-lnl-genl-3 -lnl-3 -L/path/to/sysroot/usr/lib -ldbus-1 -pthread

Fixes:
http://autobuild.buildroot.net/results/f43/f437d09ac6c689c911e1885b95da33b692f2cb3c
http://autobuild.buildroot.net/results/385/3859dc0f4de7e3284a96d5841f040f69f71842df
https://github.com/OpenAutomationTechnologies/openPOWERLINK_V2/issues/187

Signed-off-by: Romain Naour <romain.naour@gmail.com>
---
 apps/demo_cn_console/linux.cmake             | 20 ++++++++++++++++++++
 apps/demo_mn_console/linux.cmake             | 20 ++++++++++++++++++++
 apps/demo_mn_qt/linux.cmake                  | 22 +++++++++++++++++++++-
 drivers/linux/drv_daemon_pcap/CMakeLists.txt | 22 +++++++++++++++++++++-
 4 files changed, 82 insertions(+), 2 deletions(-)

diff --git a/apps/demo_cn_console/linux.cmake b/apps/demo_cn_console/linux.cmake
index 1c6f51c..7752917 100644
--- a/apps/demo_cn_console/linux.cmake
+++ b/apps/demo_cn_console/linux.cmake
@@ -46,8 +46,28 @@ SET (DEMO_ARCH_SOURCES
 ################################################################################
 # Set architecture specific libraries
 
+IF (NOT CFG_COMPILE_SHARED_LIBRARY)
+    SET(PCAP_CONFIG_OPTS --static)
+ENDIF()
+
 IF (CFG_KERNEL_STACK_DIRECTLINK OR CFG_KERNEL_STACK_USERSPACE_DAEMON)
+
+find_program(PCAP_CONFIG  NAMES pcap-config PATHS)
+
+if (PCAP_CONFIG)
+    message (STATUS "Looking for pcap-config... ${PCAP_CONFIG}")
+
+    execute_process (COMMAND ${PCAP_CONFIG} --libs ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_LDFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process (COMMAND ${PCAP_CONFIG} --cflags ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_CFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+   SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} ${PCAP_LDFLAGS})
+else (PCAP_CONFIG)
+    message (STATUS "pcap-config not found, using defaults...")
     SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pcap)
+endif (PCAP_CONFIG)
+
 ENDIF (CFG_KERNEL_STACK_DIRECTLINK OR CFG_KERNEL_STACK_USERSPACE_DAEMON)
 SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pthread rt)
 
diff --git a/apps/demo_mn_console/linux.cmake b/apps/demo_mn_console/linux.cmake
index d24e4fc..5951dbf 100644
--- a/apps/demo_mn_console/linux.cmake
+++ b/apps/demo_mn_console/linux.cmake
@@ -46,8 +46,28 @@ SET (DEMO_ARCH_SOURCES
 ################################################################################
 # Set architecture specific libraries
 
+IF (NOT CFG_COMPILE_SHARED_LIBRARY)
+    SET(PCAP_CONFIG_OPTS --static)
+ENDIF()
+
 IF (CFG_KERNEL_STACK_DIRECTLINK OR CFG_KERNEL_STACK_USERSPACE_DAEMON)
+
+find_program(PCAP_CONFIG  NAMES pcap-config PATHS)
+
+if (PCAP_CONFIG)
+    message (STATUS "Looking for pcap-config... ${PCAP_CONFIG}")
+
+    execute_process (COMMAND ${PCAP_CONFIG} --libs ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_LDFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process (COMMAND ${PCAP_CONFIG} --cflags ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_CFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+   SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} ${PCAP_LDFLAGS})
+else (PCAP_CONFIG)
+    message (STATUS "pcap-config not found, using defaults...")
     SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pcap)
+endif (PCAP_CONFIG)
+
 ENDIF (CFG_KERNEL_STACK_DIRECTLINK OR CFG_KERNEL_STACK_USERSPACE_DAEMON)
 SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pthread rt)
 
diff --git a/apps/demo_mn_qt/linux.cmake b/apps/demo_mn_qt/linux.cmake
index 6ed75ee..c69dbd9 100644
--- a/apps/demo_mn_qt/linux.cmake
+++ b/apps/demo_mn_qt/linux.cmake
@@ -37,8 +37,28 @@
 ################################################################################
 # Set architecture specific libraries
 
+IF (NOT CFG_COMPILE_SHARED_LIBRARY)
+    SET(PCAP_CONFIG_OPTS --static)
+ENDIF()
+
 IF(CFG_KERNEL_STACK_DIRECTLINK OR CFG_KERNEL_STACK_USERSPACE_DAEMON)
-    SET(ARCH_LIBRARIES ${ARCH_LIBRARIES} pcap)
+
+find_program(PCAP_CONFIG  NAMES pcap-config PATHS)
+
+if (PCAP_CONFIG)
+    message (STATUS "Looking for pcap-config... ${PCAP_CONFIG}")
+
+    execute_process (COMMAND ${PCAP_CONFIG} --libs ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_LDFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process (COMMAND ${PCAP_CONFIG} --cflags ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_CFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+   SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} ${PCAP_LDFLAGS})
+else (PCAP_CONFIG)
+    message (STATUS "pcap-config not found, using defaults...")
+    SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pcap)
+endif (PCAP_CONFIG)
+
 ENDIF()
 SET(ARCH_LIBRARIES ${ARCH_LIBRARIES} pthread rt)
 
diff --git a/drivers/linux/drv_daemon_pcap/CMakeLists.txt b/drivers/linux/drv_daemon_pcap/CMakeLists.txt
index 2b4a2c1..98f693f 100644
--- a/drivers/linux/drv_daemon_pcap/CMakeLists.txt
+++ b/drivers/linux/drv_daemon_pcap/CMakeLists.txt
@@ -134,7 +134,27 @@ INCLUDE_DIRECTORIES(
     ${CONTRIB_SOURCE_DIR}
     )
 
-SET (ARCH_LIBRARIES pcap pthread rt)
+IF (NOT CFG_COMPILE_SHARED_LIBRARY)
+    SET(PCAP_CONFIG_OPTS --static)
+ENDIF()
+
+find_program(PCAP_CONFIG  NAMES pcap-config PATHS)
+
+if (PCAP_CONFIG)
+    message (STATUS "Looking for pcap-config... ${PCAP_CONFIG}")
+
+    execute_process (COMMAND ${PCAP_CONFIG} --libs ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_LDFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+    execute_process (COMMAND ${PCAP_CONFIG} --cflags ${PCAP_CONFIG_OPTS}
+        OUTPUT_VARIABLE PCAP_CFLAGS OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+   SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} ${PCAP_LDFLAGS})
+else (PCAP_CONFIG)
+    message (STATUS "pcap-config not found, using defaults...")
+    SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pcap)
+endif (PCAP_CONFIG)
+
+SET (ARCH_LIBRARIES ${ARCH_LIBRARIES} pthread rt)
 
 ADD_EXECUTABLE(${EXE_NAME} ${DRV_SOURCES})
 SET_PROPERTY(TARGET ${EXE_NAME} PROPERTY COMPILE_DEFINITIONS_DEBUG DEBUG;DEF_DEBUG_LVL=${CFG_DEBUG_LVL})
-- 
2.9.4