X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7f260fa85e82f3921c1ef45d805f35360f124eec..0e15d065d56be3dcaee6fb95be38d69559338b21:/cmake/Modules/FindPCAP.cmake

diff --git a/cmake/Modules/FindPCAP.cmake b/cmake/Modules/FindPCAP.cmake
index 22e4fceb..64d0901d 100644
--- a/cmake/Modules/FindPCAP.cmake
+++ b/cmake/Modules/FindPCAP.cmake
@@ -1,154 +1,325 @@
 #
 # Try to find libpcap.
 #
+# To tell this module where to look, a user may set the environment variable
+# PCAP_ROOT to point cmake to the *root* of a directory with include and
+# lib subdirectories for pcap.dll (e.g WpdPack or npcap-sdk).
+# Alternatively, PCAP_ROOT may also be set from cmake command line or GUI
+# (e.g cmake -DPCAP_ROOT=C:\path\to\pcap [...])
+#
 
-find_program(PCAP_CONFIG pcap-config)
-if(PCAP_CONFIG)
+if(WIN32)
   #
-  # We have pcap-config; use it.
-  # XXX - what if this is on Windows?  If you're using, for example,
-  # MinGW, that might be the right thing to do, *if* pcap-config
-  # were made to work properly on Windows, but what about MSVC?
+  # Building for Windows.
   #
-  # First, get the include directory.
+  # libpcap isn't set up to install .pc files or pcap-config on Windows,
+  # and it's not clear that either of them would work without a lot
+  # of additional effort.  WinPcap doesn't supply them, and neither
+  # does Npcap.
   #
-  execute_process(COMMAND "${PCAP_CONFIG}" "--cflags"
-    RESULT_VARIABLE PCAP_CONFIG_RESULT
-    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-  )
-  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
-    message(FATAL_ERROR "pcap-config --cflags failed")
-  endif()
+  # So just search for them directly.  Look for both pcap and wpcap.
+  # Don't bother looking for static libraries; unlike most UN*Xes
+  # (with the exception of AIX), where different extensions are used
+  # for shared and static, Windows uses .lib both for import libraries
+  # for DLLs and for static libraries.
   #
-  # XXX - this assumes that there's only one -I flag in the output
-  # of pcap-config --cflags.  That *should* be the case.
+  # We don't directly set PCAP_INCLUDE_DIRS or PCAP_LIBRARIES, as
+  # they're not supposed to be cache entries, and find_path() and
+  # find_library() set cache entries.
   #
-  string(REGEX REPLACE "-I" "" _pcap_include_dir "${PCAP_CONFIG_OUTPUT}")
-
-  # Try to find the header
-  # We use what pcap-config provided as a hint, because the
-  # pcap-config that ships with macOS bogusly supplies
-  # -I/usr/local/include even though the header isn't
-  # there (it may be under /usr/include or it may be
-  # buried in the Xcode app bundle).
-  find_path(PCAP_INCLUDE_DIRS pcap.h HINTS ${_pcap_include_dir})
-
-  # Now, get the libraries.
-  execute_process(COMMAND "${PCAP_CONFIG}" "--libs"
-    RESULT_VARIABLE PCAP_CONFIG_RESULT
-    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-  )
-  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
-    message(FATAL_ERROR "pcap-config --libs failed")
+  find_path(PCAP_INCLUDE_DIR pcap.h)
+
+  # The 64-bit Packet.lib is located under /x64
+  if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+    #
+    # For the WinPcap and Npcap SDKs, the Lib subdirectory of the top-level
+    # directory contains 32-bit libraries; the 64-bit libraries are in the
+    # Lib/x64 directory.
+    #
+    # The only way to *FORCE* CMake to look in the Lib/x64 directory
+    # without searching in the Lib directory first appears to be to set
+    # CMAKE_LIBRARY_ARCHITECTURE to "x64".
+    #
+    set(CMAKE_LIBRARY_ARCHITECTURE "x64")
   endif()
-  separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
-  set(_pcap_library_dirs)
-  set(PCAP_LIBRARIES)
-  foreach(_arg IN LISTS LIBS_LIST)
-    if(_arg MATCHES "^-L")
-      # Add this directory to _pcap_library_dirs
-      string(REGEX REPLACE "-L" "" _dir ${_arg})
-      list(APPEND _pcap_library_dirs ${_dir})
-    elseif(_arg MATCHES "^-l")
-      string(REGEX REPLACE "-l" "" _lib ${_arg})
-      #
-      # Try to find that library, so we get its full path.
-      # CMake *really* doesn't like the notion of specifying "here are
-      # the directories in which to look for libraries" except in
-      # find_library() calls; it *really* prefers using full paths to
-      # library files, rather than library names.
-      #
-      # Furthermore, the pcap-config shipped with macOS reports
-      # -I/usr/local/include for --cflags and -L/usr/local/lib for
-      # --libs, rather than reporting the appropriate system (or
-      # Xcode application) directory.
-      #
-      find_library(_libfullpath ${_lib} HINTS ${__pcap_library_dirs})
-      list(APPEND PCAP_LIBRARIES ${_libfullpath})
-    endif()
-  endforeach()
+  find_library(PCAP_LIBRARY NAMES pcap wpcap)
 
-  # Now, get the library directories and libraries for static linking.
-  execute_process(COMMAND "${PCAP_CONFIG}" "--libs" "--static"
-    RESULT_VARIABLE PCAP_CONFIG_RESULT
-    OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+  #
+  # Do the standard arg processing, including failing if it's a
+  # required package.
+  #
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(PCAP
+    DEFAULT_MSG
+    PCAP_INCLUDE_DIR
+    PCAP_LIBRARY
   )
-  if(NOT PCAP_CONFIG_RESULT EQUAL 0)
-    message(FATAL_ERROR "pcap-config --libs --static failed")
+  mark_as_advanced(
+    PCAP_INCLUDE_DIR
+    PCAP_LIBRARY
+  )
+  if(PCAP_FOUND)
+    set(PCAP_LIBRARIES ${PCAP_LIBRARY})
+    set(PCAP_INCLUDE_DIRS ${PCAP_INCLUDE_DIR})
   endif()
-  separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
-  set(_pcap_static_library_dirs)
-  set(PCAP_STATIC_LIBRARIES)
-  foreach(_arg IN LISTS LIBS_LIST)
-    if(_arg MATCHES "^-L")
-      # Add this directory to _pcap_static_library_dirs
-      string(REGEX REPLACE "-L" "" _dir ${_arg})
-      list(APPEND _pcap_static_library_dirs ${_dir})
-    elseif(_arg MATCHES "^-l")
-      string(REGEX REPLACE "-l" "" _lib ${_arg})
-      #
-      # Try to find that library, so we get its full path, as
-      # we do with dynamic libraries.
-      #
-      find_library(_libfullpath ${_lib} HINTS ${__pcap_static_library_dirs})
-      list(APPEND PCAP_STATIC_LIBRARIES ${_libfullpath})
-    endif()
-  endforeach()
-else(PCAP_CONFIG)
+else(WIN32)
   #
-  # We don't have pcap-config.
-  # Try to find the header by just looking for it in whatever
-  # directories find_path() uses by default.
+  # Building for UN*X.
   #
-  find_path(PCAP_INCLUDE_DIRS pcap.h)
+  # See whether we were handed a QUIET argument, so we can pass it on
+  # to pkg_search_module.  Do *NOT* pass on the REQUIRED argument,
+  # because, if pkg-config isn't found, or it is but it has no .pc
+  # files for libpcap, that is *not* necessarily an indication that
+  # libpcap isn't available - not all systems ship pkg-config, and
+  # libpcap didn't have .pc files until libpcap 1.9.0.
+  #
+  if(PCAP_FIND_QUIETLY)
+    set(_quiet "QUIET")
+  endif()
+
+  #
+  # First, try pkg-config.
+  #
+  find_package(PkgConfig)
+  pkg_search_module(CONFIG_PCAP ${_quiet} libpcap)
+
+  if(NOT CONFIG_PCAP_FOUND)
+    #
+    # That didn't work.  Try pcap-config.
+    #
+    find_program(PCAP_CONFIG pcap-config)
+    if(PCAP_CONFIG)
+      #
+      # We have pcap-config; use it.
+      #
+      if(NOT "${_quiet}" STREQUAL "QUIET")
+        message(STATUS "Found pcap-config")
+      endif()
+
+      #
+      # if this is macOS or some other Darwin-based OS, check whether
+      # it's the system-supplied one.
+      #
+      if(APPLE AND "${PCAP_CONFIG}" STREQUAL /usr/bin/pcap-config)
+        #
+        # It is - remember that, so that if it provides -I/usr/local/include
+        # with --cflags, or -L/usr/local/lib with --libs, we ignore it;
+        # the macOS pcap-config does that even though the headers aren't
+        # under /usr/local/include and the library isn't in /usr/local/lib.
+        #
+        set(_broken_apple_pcap_config TRUE)
+      endif()
 
-  # Try to find the library
-  if(WIN32)
-    # The 64-bit Packet.lib is located under /x64
-    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
       #
-      # For the WinPcap and Npcap SDKs, the Lib subdirectory of the top-level
-      # directory contains 32-bit libraries; the 64-bit libraries are in the
-      # Lib/x64 directory.
+      # Now get the include directories.
       #
-      # The only way to *FORCE* CMake to look in the Lib/x64 directory
-      # without searching in the Lib directory first appears to be to set
-      # CMAKE_LIBRARY_ARCHITECTURE to "x64".
+      execute_process(COMMAND "${PCAP_CONFIG}" "--cflags"
+        RESULT_VARIABLE PCAP_CONFIG_RESULT
+        OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+        message(FATAL_ERROR "pcap-config --cflags failed")
+      endif()
+      separate_arguments(CFLAGS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
+      set(CONFIG_PCAP_INCLUDE_DIRS "")
+      foreach(_arg IN LISTS CFLAGS_LIST)
+        if(_arg MATCHES "^-I")
+          #
+          # Extract the directory by removing the -I.
+          #
+          string(REGEX REPLACE "-I" "" _dir ${_arg})
+          #
+          # Work around macOS (and probably other Darwin) brokenness,
+          # by not adding /usr/local/include if it's from the broken
+          # Apple pcap-config.
+          #
+          if(NOT _broken_apple_pcap_config OR
+             NOT "${_dir}" STREQUAL /usr/local/include)
+            # Add it to CONFIG_PCAP_INCLUDE_DIRS
+            list(APPEND CONFIG_PCAP_INCLUDE_DIRS ${_dir})
+          endif()
+        endif()
+      endforeach()
+
       #
-      set(CMAKE_LIBRARY_ARCHITECTURE "x64")
+      # Now, get the library directories and libraries for dynamic linking.
+      #
+      execute_process(COMMAND "${PCAP_CONFIG}" "--libs"
+        RESULT_VARIABLE PCAP_CONFIG_RESULT
+        OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+        message(FATAL_ERROR "pcap-config --libs failed")
+      endif()
+      separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
+      set(CONFIG_PCAP_LIBRARY_DIRS "")
+      set(CONFIG_PCAP_LIBRARIES "")
+      foreach(_arg IN LISTS LIBS_LIST)
+        if(_arg MATCHES "^-L")
+          #
+          # Extract the directory by removing the -L.
+          #
+          string(REGEX REPLACE "-L" "" _dir ${_arg})
+          #
+          # Work around macOS (and probably other Darwin) brokenness,
+          # by not adding /usr/local/lib if it's from the broken
+          # Apple pcap-config.
+          #
+          if(NOT _broken_apple_pcap_config OR
+             NOT "${_dir}" STREQUAL /usr/local/lib)
+            # Add this directory to CONFIG_PCAP_LIBRARY_DIRS
+            list(APPEND CONFIG_PCAP_LIBRARY_DIRS ${_dir})
+          endif()
+        elseif(_arg MATCHES "^-l")
+          string(REGEX REPLACE "-l" "" _lib ${_arg})
+          list(APPEND CONFIG_PCAP_LIBRARIES ${_lib})
+        endif()
+      endforeach()
+
+      #
+      # Now, get the library directories and libraries for static linking.
+      #
+      execute_process(COMMAND "${PCAP_CONFIG}" "--libs" "--static"
+        RESULT_VARIABLE PCAP_CONFIG_RESULT
+        OUTPUT_VARIABLE PCAP_CONFIG_OUTPUT
+      )
+      if(NOT PCAP_CONFIG_RESULT EQUAL 0)
+        message(FATAL_ERROR "pcap-config --libs --static failed")
+      endif()
+      separate_arguments(LIBS_LIST UNIX_COMMAND ${PCAP_CONFIG_OUTPUT})
+      set(CONFIG_PCAP_STATIC_LIBRARY_DIRS "")
+      set(CONFIG_PCAP_STATIC_LIBRARIES "")
+      foreach(_arg IN LISTS LIBS_LIST)
+        if(_arg MATCHES "^-L")
+          #
+          # Extract the directory by removing the -L.
+          #
+          string(REGEX REPLACE "-L" "" _dir ${_arg})
+          #
+          # Work around macOS (and probably other Darwin) brokenness,
+          # by not adding /usr/local/lib if it's from the broken
+          # Apple pcap-config.
+          #
+          if(NOT _broken_apple_pcap_config OR
+             NOT "${_dir}" STREQUAL /usr/local/lib)
+            # Add this directory to CONFIG_PCAP_STATIC_LIBRARY_DIRS
+            list(APPEND CONFIG_PCAP_STATIC_LIBRARY_DIRS ${_dir})
+          endif()
+        elseif(_arg MATCHES "^-l")
+          string(REGEX REPLACE "-l" "" _lib ${_arg})
+          #
+          # Try to find that library, so we get its full path, as
+          # we do with dynamic libraries.
+          #
+          list(APPEND CONFIG_PCAP_STATIC_LIBRARIES ${_lib})
+        endif()
+      endforeach()
+
+      #
+      # We've set CONFIG_PCAP_INCLUDE_DIRS, CONFIG_PCAP_LIBRARIES, and
+      # CONFIG_PCAP_STATIC_LIBRARIES above; set CONFIG_PCAP_FOUND.
+      #
+      set(CONFIG_PCAP_FOUND YES)
     endif()
   endif()
 
-  find_library(PCAP_LIBRARIES pcap)
-  if(WIN32)
-    if(NOT PCAP_LIBRARIES)
+  #
+  # If CONFIG_PCAP_FOUND is set, we have information from pkg-config and
+  # pcap-config; we need to convert library names to library full paths.
+  #
+  # If it's not set, we have to look for the libpcap headers and library
+  # ourselves.
+  #
+  if(CONFIG_PCAP_FOUND)
+    #
+    # Use CONFIG_PCAP_INCLUDE_DIRS as the value for PCAP_INCLUDE_DIRS.
+    #
+    set(PCAP_INCLUDE_DIRS "${CONFIG_PCAP_INCLUDE_DIRS}")
+
+    #
+    # CMake *really* doesn't like the notion of specifying
+    # "here are the directories in which to look for libraries"
+    # except in find_library() calls; it *really* prefers using
+    # full paths to library files, rather than library names.
+    #
+    foreach(_lib IN LISTS CONFIG_PCAP_LIBRARIES)
+      find_library(_libfullpath ${_lib} HINTS ${CONFIG_PCAP_LIBRARY_DIRS})
+      list(APPEND PCAP_LIBRARIES ${_libfullpath})
       #
-      # OK, look for it under the name wpcap.
+      # Remove that from the cache; we're using it as a local variable,
+      # but find_library insists on making it a cache variable.
       #
-      find_library(PCAP_LIBRARIES wpcap)
-    endif(NOT PCAP_LIBRARIES)
-  endif(WIN32)
-  if(NOT WIN32)
+      unset(_libfullpath CACHE)
+   endforeach()
+
+    #
+    # Now do the same for the static libraries.
+    #
+    set(SAVED_CMAKE_FIND_LIBRARY_SUFFIXES "${CMAKE_FIND_LIBRARY_SUFFIXES}")
+    set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
+    foreach(_lib IN LISTS CONFIG_PCAP_STATIC_LIBRARIES)
+      find_library(_libfullpath ${_lib} HINTS ${CONFIG_PCAP_LIBRARY_DIRS})
+      list(APPEND PCAP_STATIC_LIBRARIES ${_libfullpath})
+      #
+      # Remove that from the cache; we're using it as a local variable,
+      # but find_library insists on making it a cache variable.
+      #
+      unset(_libfullpath CACHE)
+    endforeach()
+    set(CMAKE_FIND_LIBRARY_SUFFIXES "${SAVED_CMAKE_FIND_LIBRARY_SUFFIXES}")
+
+    #
+    # We found libpcap using pkg-config or pcap-config.
+    #
+    set(PCAP_FOUND YES)
+  else(CONFIG_PCAP_FOUND)
+    #
+    # We didn't have pkg-config, or we did but it didn't have .pc files
+    # for libpcap, and we don't have pkg-config, so we have to look for
+    # the headers and libraries ourself.
+    #
+    # We don't directly set PCAP_INCLUDE_DIRS or PCAP_LIBRARIES, as
+    # they're not supposed to be cache entries, and find_path() and
+    # find_library() set cache entries.
+    #
+    # Try to find the header file.
+    #
+    find_path(PCAP_INCLUDE_DIR pcap.h)
+
+    #
+    # Try to find the library
+    #
+    find_library(PCAP_LIBRARY pcap)
+
     # Try to find the static library (XXX - what about AIX?)
-    include(CMakePushCheckState)
-    cmake_push_check_state()
+    set(SAVED_CMAKE_FIND_LIBRARY_SUFFIXES "${CMAKE_FIND_LIBRARY_SUFFIXES}")
     set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
-    find_library(PCAP_STATIC_LIBRARIES pcap)
-    cmake_pop_check_state()
-  endif(NOT WIN32)
-endif(PCAP_CONFIG)
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(PCAP
-  DEFAULT_MSG
-  PCAP_INCLUDE_DIRS
-  PCAP_LIBRARIES
-)
-
-mark_as_advanced(
-  PCAP_INCLUDE_DIR
-  PCAP_LIBRARY
-  PCAP_STATIC_LIBRARY
-)
+    find_library(PCAP_STATIC_LIBRARY pcap)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES "${SAVED_CMAKE_FIND_LIBRARY_SUFFIXES}")
+
+    #
+    # This will fail if REQUIRED is set and PCAP_INCLUDE_DIR or
+    # PCAP_LIBRARY aren't set.
+    #
+    include(FindPackageHandleStandardArgs)
+    find_package_handle_standard_args(PCAP
+      DEFAULT_MSG
+      PCAP_INCLUDE_DIR
+      PCAP_LIBRARY
+    )
+
+    mark_as_advanced(
+      PCAP_INCLUDE_DIR
+      PCAP_LIBRARY
+      PCAP_STATIC_LIBRARY
+    )
+
+    if(PCAP_FOUND)
+      set(PCAP_INCLUDE_DIRS ${PCAP_INCLUDE_DIR})
+      set(PCAP_LIBRARIES ${PCAP_LIBRARY})
+      set(PCAP_STATIC_LIBRARIES ${PCAP_STATIC_LIBRARY})
+    endif(PCAP_FOUND)
+  endif(CONFIG_PCAP_FOUND)
+endif(WIN32)