Allow the path in which DPDK is installed to be specified.

For autotools, if --with-dpdk={path} was specified, prepend
{PATH}/pkgconfig to PKG_CONFIG_PATH before running pkg-config, and
restore PKG_CONFIG_PATH afterwards.

For CMake, if dpdk_ROOT is defined, prepend ${dpdk_ROOT}/pkgconfig to
PKG_CONFIG_PATH before running pkg-config, and restore PKG_CONFIG_PATH
afterwards.

Fix some typoes in comments while we're at it.

(cherry picked from commit 0a51499d12afc9f54d1d0690881873766bf9db02)

4 files changed, 32 insertions, 4 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index da19e22a..6c5f08dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -185,6 +185,7 @@ if(WIN32)
     option(USE_STATIC_RT "Use static Runtime" ON)
 endif(WIN32)
 option(BUILD_SHARED_LIBS "Build shared libraries" ON)
+set(dpdk_ROOT "" CACHE PATH "Path to directory with include and lib subdirectories for DPDK")
 if(WIN32)
     set(Packet_ROOT "" CACHE PATH "Path to directory with include and lib subdirectories for packet.dll")
     set(AirPcap_ROOT "" CACHE PATH "Path to directory with include and lib subdirectories for airpcap.dll")
diff --git a/cmake/Modules/Finddpdk.cmake b/cmake/Modules/Finddpdk.cmake
index 9eb8d1f6..d245fa0e 100644
--- a/cmake/Modules/Finddpdk.cmake
+++ b/cmake/Modules/Finddpdk.cmake
@@ -10,11 +10,11 @@
 # We only try to find DPDK using pkg-config; DPDK is *SO*
 # complicated - DPDK 19.02, for example, has about 117(!)
 # libraries, and the precise set of libraries required has
-# changed ver time  - so attempting to guess which libraries
+# changed over time  - so attempting to guess which libraries
 # you need, and hardcoding that in an attempt to find the
 # libraries without DPDK, rather than relying on DPDK to
 # tell you, with a .pc file, what libraries are needed,
-# is *EXTREELY* fragile and has caused some bug reports,
+# is *EXTREMELY* fragile and has caused some bug reports,
 # so we're just not going to do it.
 #
 # If that causes a problem, the only thing we will do is
@@ -24,8 +24,17 @@
 # as pkg-config with *ALL* versions of DPDK that provide a
 # libdpdk.pc file).
 #
+# If dpdk_ROOT is set, add ${dpdk_ROOT}/pkgconfig
+# to PKG_CONFIG_PATH, so we look for the .pc file there,
+# first.
+#
 if(PKG_CONFIG_FOUND)
+  set(save_PKG_CONFIG_PATH $ENV{PKG_CONFIG_PATH})
+  if(dpdk_ROOT)
+    set(ENV{PKG_CONFIG_PATH} "${dpdk_ROOT}/pkgconfig:$ENV{PKG_CONFIG_PATH}")
+  endif()
   pkg_check_modules(dpdk QUIET libdpdk)
+  set(ENV{PKG_CONFIG_PATH} "${save_PKG_CONFIG_PATH}")
 endif()
 
 mark_as_advanced(dpdk_INCLUDE_DIRS ${dpdk_LIBRARIES})
diff --git a/configure b/configure
index 2dc3ab9c..13256df7 100755
--- a/configure
+++ b/configure
@@ -11940,7 +11940,7 @@ if test "$want_dpdk" != no; then
 	# you need, and hardcoding that in an attempt to find the
 	# libraries without DPDK, rather than relying on DPDK to
 	# tell you, with a .pc file, what libraries are needed,
-	# is *EXTREELY* fragile and has caused some bug reports,
+	# is *EXTREMELY* fragile and has caused some bug reports,
 	# so we're just not going to do it.
 	#
 	# If that causes a problem, the only thing we will do is
@@ -11950,6 +11950,14 @@ if test "$want_dpdk" != no; then
 	# as pkg-config with *ALL* versions of DPDK that provide a
 	# libdpdk.pc file).
 	#
+	# If --with-dpdk={path} was specified, add {path}/pkgconfig
+	# to PKG_CONFIG_PATH, so we look for the .pc file there,
+	# first.
+	#
+	save_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+	if test -n "$dpdk_dir"; then
+		PKG_CONFIG_PATH="$dpdk_dir:$PKG_CONFIG_PATH"
+	fi
 
 
 pkg_failed=no
@@ -12065,6 +12073,7 @@ $as_echo "not found" >&6; }
 
 fi
 
+	PKG_CONFIG_PATH="$save_PKG_CONFIG_PATH"
 
 	#
 	# Did we find DPDK?
diff --git a/configure.ac b/configure.ac
index 8daf6e65..f394a3cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2534,7 +2534,7 @@ if test "$want_dpdk" != no; then
 	# you need, and hardcoding that in an attempt to find the
 	# libraries without DPDK, rather than relying on DPDK to
 	# tell you, with a .pc file, what libraries are needed,
-	# is *EXTREELY* fragile and has caused some bug reports,
+	# is *EXTREMELY* fragile and has caused some bug reports,
 	# so we're just not going to do it.
 	#
 	# If that causes a problem, the only thing we will do is
@@ -2544,10 +2544,19 @@ if test "$want_dpdk" != no; then
 	# as pkg-config with *ALL* versions of DPDK that provide a
 	# libdpdk.pc file).
 	#
+	# If --with-dpdk={path} was specified, add {path}/pkgconfig
+	# to PKG_CONFIG_PATH, so we look for the .pc file there,
+	# first.
+	#
+	save_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+	if test -n "$dpdk_dir"; then
+		PKG_CONFIG_PATH="$dpdk_dir:$PKG_CONFIG_PATH"
+	fi
 	PKG_CHECK_MODULES(DPDK, libdpdk,
 	    [
 		found_dpdk=yes
 	    ])
+	PKG_CONFIG_PATH="$save_PKG_CONFIG_PATH"
 
 	#
 	# Did we find DPDK?