增加pcap解析工具(#4033 #4034)

cmake/FindPCAP.cmake

@@ -0,0 +1,23 @@
+# - Try to find libpcap
+#
+# Once done this will define
+#  PCAP_FOUND        - System has libpcap
+#  PCAP_INCLUDE_DIRS - The libpcap include directories
+#  PCAP_LIBRARIES    - The libpcap library
+
+# Find libpcap
+FIND_PATH(
+    PCAP_INCLUDE_DIRS
+    NAMES pcap.h
+)
+
+FIND_LIBRARY(
+    PCAP_LIBRARIES
+    NAMES pcap
+)
+
+message(STATUS "PCAP LIBRARIES: " ${PCAP_LIBRARIES})
+message(STATUS "PCAP INCLUDE DIRS: " ${PCAP_INCLUDE_DIRS})
+
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(PCAP DEFAULT_MSG PCAP_LIBRARIES PCAP_INCLUDE_DIRS)