autoconf, cmake: fix generated pcap-config and libpcap.pc.

In libpcap.pc, don't put libraries into Libs.private if we can just put
the package to which the libraries belong in Requires.private and let
pkg-config do the work.

When configuring with CMake, make sure that we do *NOT* put library full
paths into the lists of libraries required when linking statically
against libpcap.

In the configure script, do a push settings/pop settings
operation before checking various libraries similar to what's done in
CMake files, to make sure that the results of the tests aren't affected
by tests done previously.

Have the macros for autoconf that run pcap-config take arbitrary
arguments rather than a single flag value, to allow testing with --libs
and --static.

This should fix issue #1062.

1 files changed, 193 insertions, 68 deletions

diff --git a/configure.ac b/configure.ac
index ebd8b997..ce48942b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,6 +20,86 @@ AC_INIT(pcap, m4_esyscmd_s([cat VERSION]))
 AC_CONFIG_SRCDIR(pcap.c)
 AC_SUBST(PACKAGE_NAME)
 
+#
+# These are the variables that are used in Makefile, pcap-config, and
+# libpcap.pc.
+#
+# CFLAGS: inherited from the environment, not modified by us (except
+# temporarily during tests that involve compilation).  Used only when
+# compiling C source.
+#
+# CXXFLAGS: inherited from the environment, not modified by us.  Used only
+# when compiling C++ source.
+#
+# LDFLAGS: inherited from the environment, not modified by us.
+#
+# LIBS: inherited from the environment; we add libraries required by
+# libpcap.  Librares that the core libpcap code requires are added
+# first; libraries required by additional pcap modules are first
+# added to ADDITIONAL_LIBS, and only added to LIBS at the end, after
+# we're finished doing configuration tests for the modules.
+#
+# LIBS_STATIC: libraries with which a program using the libpcap *static*
+# library needs to be linked.  This is a superset of LIBS, used in
+# pcap-config, so that "pcap-config --libs --static" will report them.
+# Initialized to LIBS.
+#
+# REQUIRES_PRIVATE: pkg-config package names for additional libraries
+# with which a program using the libpcap *static* library needs to be
+# linked and for which a .pc file exists.  This is used in libpcap.pc,
+# so that "pkg-config --libs --static" will report them, and so that
+# those libraries will be determined using the library's .pc file, not
+# from our .pc file.  Initialized to an empty string.
+#
+# V_CCOPT: additional compiler flags other than -I and -D flags
+# needed when compiling libpcap.  Used in Makefile for both C and
+# C++ source.
+#
+# V_DEFS: additional -D compiler flags needed when compiling
+# libpcap.  Used in Makefile for both C and C++ source.
+#
+# V_INCLS: additional -I compiler flags needed when compiling
+# libpcap.  Used in Makefile for both C and C++ source.
+#
+# ADDITIONAL_LIBS: additional libraries with which the libpcap dynamic
+# library needs to be linked.  Used in Makwfile; not used in pcap-config
+# or libpcap.pc, as, in all platforms on which we run, if a dynamic
+# library is linked with other dynamic libraries, a program using
+# that dynamic library doesn't have to link with those libraries -
+# they will be automatically loaded at run time.  Initialized to an
+# empty string.
+#
+# ADDITIONAL_LIBS_STATIC: additional libraries with which a program
+# using the libpcap *static* library needs to be linked.  This is used
+# in pcap-config, so that "pcap-config --libs --static" will report
+# them.  Initialized to an empty string.
+#
+# REQUIRES_PRIVATE: pkg-config package names for additional libraries
+# with which a program using the libpcap *static* library needs to be
+# linked and for which a .pc file exists.  This is used in libpcap.pc,
+# so that "pkg-config --libs --static" will report them, and so that
+# those libraries will be determined using the library's .pc file, not
+# from our .pc file.  Initialized to an empty string.
+#
+# LIBS_PRIVATE: pkg-config package names for additional libraries with
+# which a program using the libpcap *static* library needs to be linked
+# and for which a .pc file does not exist.  This is used in libpcap.pc,
+# so that "pkg-config --libs --static" will report them (those libraries
+# cannot be determined using the library's .pc file, as there is no such
+# file, so it has to come from our .pc file.  Initialized to an empty
+# string.
+#
+LIBS_STATIC=""
+REQUIRES_PRIVATE=""
+LIBS_PRIVATE=""
+
+AC_SUBST(V_CCOPT)
+AC_SUBST(V_DEFS)
+AC_SUBST(V_INCLS)
+AC_SUBST(LIBS_STATIC)
+AC_SUBST(REQUIRES_PRIVATE)
+AC_SUBST(LIBS_PRIVATE)
+
 AC_CANONICAL_SYSTEM
 
 AC_LBL_C_INIT_BEFORE_CC(V_CCOPT, V_INCLS)
@@ -98,6 +178,7 @@ dnl
 AC_CHECK_HEADERS(sys/ioccom.h sys/sockio.h)
 AC_CHECK_HEADERS(netpacket/packet.h)
 
+AC_LBL_SAVE_CHECK_STATE
 case "$host_os" in
 haiku*)
 	#
@@ -112,6 +193,7 @@ haiku*)
 esac
 
 AC_LBL_FIXINCLUDES
+AC_LBL_RESTORE_CHECK_STATE
 
 AC_CHECK_FUNCS(strerror)
 AC_CHECK_FUNC(strerror_r,
@@ -847,6 +929,8 @@ dlpi)
 	AC_CHECK_LIB(dlpi, dlpi_walk,
 		[
 			LIBS="-ldlpi $LIBS"
+			LIBS_STATIC="-ldlpi $LIBS_STATIC"
+			LIBS_PRIVATE="-ldlpi $LIBS_PRIVATE"
 			V_PCAP=libdlpi
 
 			#
@@ -956,7 +1040,9 @@ linux)
 		    [
 			pkg_config_found_libnl=yes
 			V_INCLS="$V_INCLS $LIBNL_CFLAGS"
-			LIBS="$LIBNL_LIBS $LIBS"
+			ADDITIONAL_LIBS="$LIBNL_LIBS $ADDITIONAL_LIBS"
+			ADDITIONAL_LIBS_STATIC="$LIBNL_LIBS_STATIC $ADDITIONAL_LIBS_STATIC"
+			REQUIRES_PRIVATE="libnl-genl-3.0 $REQUIRES_PRIVATE"
 			AC_DEFINE(HAVE_LIBNL,1,[if libnl exists])
 		    ])
 
@@ -985,7 +1071,9 @@ linux)
 				#
 				# Yes, we have libnl 3.x.
 				#
-				LIBS="${libnldir} -lnl-genl-3 -lnl-3 $LIBS"
+				ADDITIONAL_LIBS="${libnldir} -lnl-genl-3 -lnl-3 $ADDITIONAL_LIBS"
+				ADDITIONAL_LIBS_STATIC="${libnldir} -lnl-genl-3 -lnl-3 $ADDITIONAL_LIBS_STATIC"
+				LIBS_PRIVATE="${libnldir} -lnl-genl-3 -lnl-3 $LIBS_PRIVATE"
 				AC_DEFINE(HAVE_LIBNL,1,[if libnl exists])
 				V_INCLS="$V_INCLS ${incdir}"
 			],[
@@ -1290,9 +1378,10 @@ if test "$want_dag" != no; then
 		fi
 	fi
 
-	save_CFLAGS="$CFLAGS"
+	AC_LBL_SAVE_CHECK_STATE
 	CFLAGS="$CFLAGS -I$dag_include_dir"
 	AC_CHECK_HEADERS([dagapi.h])
+	AC_LBL_RESTORE_CHECK_STATE
 
 	if test "$ac_cv_header_dagapi_h" = yes; then
 
@@ -1305,42 +1394,52 @@ if test "$want_dag" != no; then
 		# Check for various DAG API functions.
 		# Don't need to save and restore LIBS to prevent -ldag being
 		# included if there's a found-action (arg 3).
-		save_LDFLAGS="$LDFLAGS"
+		AC_LBL_SAVE_CHECK_STATE
 		LDFLAGS="-L$dag_lib_dir"
 		AC_CHECK_LIB([dag], [dag_attach_stream],
-		    [],
+		    [
+			#
+			# We assume that if we have libdag we have
+			# libdagconf, as they're installed at the
+			# same time from the same package.
+			#
+			ADDITIONAL_LIBS="-L$dag_lib_dir $ADDITIONAL_LIBS -ldag -ldagconf"
+			ADDITIONAL_LIBS_STATIC="-L$dag_lib_dir $ADDITIONAL_LIBS_STATIC -ldag -ldagconf"
+			LIBS_PRIVATE="-L$dag_lib_dir $LIBS_PRIVATE -ldag -ldagconf"
+		    ],
 		    [AC_MSG_ERROR(DAG library lacks streams support)])
 		AC_CHECK_LIB([dag], [dag_attach_stream64], [dag_large_streams="1"], [dag_large_streams="0"])
 		AC_CHECK_LIB([dag],[dag_get_erf_types], [
 			AC_DEFINE(HAVE_DAG_GET_ERF_TYPES, 1, [define if you have dag_get_erf_types()])])
 		AC_CHECK_LIB([dag],[dag_get_stream_erf_types], [
 			AC_DEFINE(HAVE_DAG_GET_STREAM_ERF_TYPES, 1, [define if you have dag_get_stream_erf_types()])])
-
-		LDFLAGS="$save_LDFLAGS"
+		AC_LBL_RESTORE_CHECK_STATE
 
 		#
 		# We assume that if we have libdag we have libdagconf,
 		# as they're installed at the same time from the same
 		# package.
 		#
-		LIBS="$LIBS -ldag -ldagconf"
-		LDFLAGS="$LDFLAGS -L$dag_lib_dir"
-
 		if test "$dag_large_streams" = 1; then
 			AC_DEFINE(HAVE_DAG_LARGE_STREAMS_API, 1, [define if you have large streams capable DAG API])
+			AC_LBL_SAVE_CHECK_STATE
+			LIBS="$LIBS -ldag -ldagconf"
+			LDFLAGS="$LDFLAGS -L$dag_lib_dir"
 			AC_CHECK_LIB([vdag],[vdag_set_device_info], [ac_dag_have_vdag="1"], [ac_dag_have_vdag="0"])
+			AC_LBL_RESTORE_CHECK_STATE
 			if test "$ac_dag_have_vdag" = 1; then
 				AC_DEFINE(HAVE_DAG_VDAG, 1, [define if you have vdag_set_device_info()])
 				if test "$ac_lbl_have_pthreads" != "found"; then
 					AC_MSG_ERROR([DAG requires pthreads, but we didn't find them])
 				fi
-				LIBS="$LIBS $PTHREAD_LIBS"
+				ADDITIONAL_LIBS="$ADDITIONAL_LIBS $PTHREAD_LIBS"
+				ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $PTHREAD_LIBS"
+				LIBS_PRIVATE="$LIBS_PRIVATE $PTHREAD_LIBS"
 			fi
 		fi
 
 		AC_DEFINE(HAVE_DAG_API, 1, [define if you have the DAG API])
 	else
-
 		if test "$V_PCAP" = dag; then
 			# User requested "dag" capture type but we couldn't
 			# find the DAG API support.
@@ -1508,10 +1607,10 @@ if test "$with_snf" != no; then
 
 	if test -f "$snf_include_dir/snf.h"; then
 		# We found a header; make sure we can link with the library
-		save_LDFLAGS="$LDFLAGS"
+		AC_LBL_SAVE_CHECK_STATE
 		LDFLAGS="$LDFLAGS -L$snf_lib_dir"
 		AC_CHECK_LIB([snf], [snf_init], [ac_cv_lbl_snf_api="yes"])
-		LDFLAGS="$save_LDFLAGS"
+		AC_LBL_RESTORE_CHECK_STATE
 		if test "$ac_cv_lbl_snf_api" = no; then
 			AC_MSG_ERROR(SNF API cannot correctly be linked; check config.log)
 		fi
@@ -1521,8 +1620,9 @@ if test "$with_snf" != no; then
 		AC_MSG_RESULT([yes ($snf_root)])
 
 		V_INCLS="$V_INCLS -I$snf_include_dir"
-		LIBS="$LIBS -lsnf"
-		LDFLAGS="$LDFLAGS -L$snf_lib_dir"
+		ADDITIONAL_LIBS="$ADDITIONAL_LIBS -L$snf_lib_dir -lsnf"
+		ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC -L$snf_lib_dir -lsnf"
+		LIBS_PRIVATE="$LIBS_PRIVATE -L$snf_lib_dir -lsnf"
 
 		if test "$V_PCAP" != snf ; then
 			MODULE_C_SRC="$MODULE_C_SRC pcap-snf.c"
@@ -1579,12 +1679,12 @@ if test "$want_turbocap" != no; then
 
 	AC_MSG_CHECKING(whether TurboCap is supported)
 
-	save_CFLAGS="$CFLAGS"
-	save_LIBS="$LIBS"
+	AC_LBL_SAVE_CHECK_STATE
 	if test ! -z "$turbocap_root"; then
 		TURBOCAP_CFLAGS="-I$turbocap_root/include"
-		TURBOCAP_LIBS="-L$turbocap_root/lib"
+		TURBOCAP_LDFLAGS="-L$turbocap_root/lib"
 		CFLAGS="$CFLAGS $TURBOCAP_CFLAGS"
+		LDFLAGS="$LDFLAGS $TURBOCAP_LDFLAGS"
 	fi
 
 	AC_TRY_COMPILE(
@@ -1598,13 +1698,15 @@ if test "$want_turbocap" != no; then
 	],
 	ac_cv_lbl_turbocap_api=yes)
 
-	CFLAGS="$save_CFLAGS"
+	AC_LBL_RESTORE_CHECK_STATE
 	if test $ac_cv_lbl_turbocap_api = yes; then
 		AC_MSG_RESULT(yes)
 
 		MODULE_C_SRC="$MODULE_C_SRC pcap-tc.c"
 		V_INCLS="$V_INCLS $TURBOCAP_CFLAGS"
-		LIBS="$LIBS $TURBOCAP_LIBS -lTcApi -lpthread -lstdc++"
+		ADDITIONAL_LIBS="$ADDITIONAL_LIBS $TURBOCAP_LDFLAGS -lTcApi -lpthread -lstdc++"
+		ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $TURBOCAP_LDFLAGS -lTcApi -lpthread -lstdc++"
+		LIBS_PRIVATE="$LIBS_PRIVATE $TURBOCAP_LDFLAGS -lTcApi -lpthread -lstdc++"
 
 		AC_DEFINE(HAVE_TC_API, 1, [define if you have the TurboCap API])
 	else
@@ -1710,6 +1812,7 @@ yes)	AC_MSG_RESULT(yes)
 		# We found OpenSSL/libressl.
 		#
 		HAVE_OPENSSL=yes
+		REQUIRES_PRIVATE="openssl $REQUIRES_PRIVATE"
 	    ])
 	PKG_CONFIG_PATH="$save_PKG_CONFIG_PATH"
 
@@ -1740,6 +1843,8 @@ yes)	AC_MSG_RESULT(yes)
 			openssl_path=`$BREW --prefix openssl`
 			OPENSSL_CFLAGS="-I$openssl_path/include"
 			OPENSSL_LIBS="-L$openssl_path/lib -lssl -lcrypto"
+			OPENSSL_LIBS_STATIC="-L$openssl_path/lib -lssl -lcrypto"
+			OPENSSL_LIBS_PRIVATE="-L$openssl_path/lib -lssl -lcrypto"
 		else
 			AC_MSG_RESULT(no)
 		fi
@@ -1760,8 +1865,7 @@ yes)	AC_MSG_RESULT(yes)
 	# in others.
 	#
 	if test "x$HAVE_OPENSSL" != "xyes" -a -d "/usr/local/include" -a -d "/usr/local/lib"; then
-		save_CFLAGS="$CFLAGS"
-		save_LIBS="$LIBS"
+		AC_LBL_SAVE_CHECK_STATE
 		CFLAGS="$CFLAGS -I/usr/local/include"
 		LIBS="$LIBS -L/usr/local/lib -lssl -lcrypto"
 		AC_MSG_CHECKING(whether we have OpenSSL/libressl in /usr/local that we can use)
@@ -1778,10 +1882,11 @@ return 0;
 			HAVE_OPENSSL=yes
 			OPENSSL_CFLAGS="-I/usr/local/include"
 			OPENSSL_LIBS="-L/usr/local/lib -lssl -lcrypto"
-		    ],
+			OPENSSL_LIBS_STATIC="-L/usr/local/lib -lssl -lcrypto"
+			OPENSSL_LIBS_PRIVATE="-L/usr/local/lib -lssl -lcrypto"
+		    ],nnn
 		    AC_MSG_RESULT(no))
-		CFLAGS="$save_CFLAGS"
-		LIBS="$save_LIBS"
+		AC_LBL_RESTORE_CHECK_STATE
 	fi
 
 	#
@@ -1795,7 +1900,7 @@ return 0;
 	# in others.
 	#
 	if test "x$HAVE_OPENSSL" != "xyes"; then
-		save_LIBS="$LIBS"
+		AC_LBL_SAVE_CHECK_STATE
 		LIBS="$LIBS -lssl -lcrypto"
 		AC_MSG_CHECKING(whether we have a system OpenSSL/libressl that we can use)
 		AC_TRY_LINK(
@@ -1810,9 +1915,11 @@ return 0;
 			AC_MSG_RESULT(yes)
 			HAVE_OPENSSL=yes
 			OPENSSL_LIBS="-lssl -lcrypto"
+			OPENSSL_LIBS_STATIC="-lssl -lcrypto"
+			OPENSSL_LIBS_PRIVATE="-lssl -lcrypto"
 		    ],
 		    AC_MSG_RESULT(no))
-		LIBS="$save_LIBS"
+		AC_LBL_RESTORE_CHECK_STATE
 	fi
 
 	#
@@ -1820,8 +1927,11 @@ return 0;
 	#
 	if test "x$HAVE_OPENSSL" = "xyes"; then
 		AC_DEFINE([HAVE_OPENSSL], [1], [Use OpenSSL])
-		CFLAGS="$CFLAGS $OPENSSL_CFLAGS"
-		LIBS="$LIBS $OPENSSL_LIBS"
+		V_INCLS="$V_INCLS $OPENSSL_CFLAGS"
+		ADDITIONAL_LIBS="$ADDITIONAL_LIBS $OPENSSL_LIBS"
+		ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $OPENSSL_LIBS_STATIC"
+		LIBS_PRIVATE="$LIBS_PRIVATE $OPENSSL_LIBS_PRIVATE"
+		REQUIRES_PRIVATE="$REQUIRES_PRIVATE $OPENSSL_REQUIRES_PRIVATE"
 	else
 		AC_MSG_NOTICE(OpenSSL not found)
 	fi
@@ -2128,7 +2238,7 @@ darwin*)
 			# fat.
 			#
 			AC_MSG_CHECKING(whether building for 32-bit x86 is supported)
-			save_CFLAGS="$CFLAGS"
+			AC_LBL_SAVE_CHECK_STATE
 			CFLAGS="$CFLAGS -arch i386"
 			AC_TRY_LINK(
 			    [],
@@ -2175,7 +2285,7 @@ darwin*)
 					;;
 				esac
 			    ])
-			CFLAGS="$save_CFLAGS"
+			AC_LBL_RESTORE_CHECK_STATE
 			;;
 
 		darwin19*)
@@ -2209,8 +2319,7 @@ darwin*)
 			#
 			if test "$HAVE_OPENSSL" = yes; then
 				AC_MSG_CHECKING(whether building fat with libssl is supported)
-				save_CFLAGS="$CFLAGS"
-				save_LDFLAGS="$LDFLAGS"
+				AC_LBL_SAVE_CHECK_STATE
 				CFLAGS="$CFLAGS -arch x86_64 -arch arm64"
 				LDFLAGS="$LDFLAGS $OPENSSL_LIBS"
 				AC_TRY_LINK(
@@ -2230,8 +2339,7 @@ darwin*)
 				    ],
 				    [AC_MSG_RESULT(no)]
 				)
-				CFLAGS="$save_CFLAGS"
-				LDFLAGS="$save_LDFLAGS"
+				AC_LBL_RESTORE_CHECK_STATE
 			else
 				V_LIB_CCOPT_FAT="-arch x86_64 -arch arm64"
 				V_LIB_LDFLAGS_FAT="-arch x86_64 -arch arm64"
@@ -2644,41 +2752,43 @@ if test "$want_dpdk" != no; then
 		# We call rte_eth_dev_count_avail(), and older versions
 		# of DPDK didn't have it, so check for it.
 		#
-		save_CFLAGS="$CFLAGS"
-		save_LIBS="$LIBS"
-		save_LDFLAGS="$LDFLAGS"
+		AC_LBL_SAVE_CHECK_STATE
 		CFLAGS="$CFLAGS $DPDK_CFLAGS"
 		LIBS="$LIBS $DPDK_LIBS"
-		LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
 		AC_CHECK_FUNC(rte_eth_dev_count_avail)
-		CFLAGS="$save_CFLAGS"
-		LIBS="$save_LIBS"
-		LDFLAGS="$save_LDFLAGS"
+		AC_LBL_RESTORE_CHECK_STATE
 	fi
 
 	if test "$ac_cv_func_rte_eth_dev_count_avail" = yes; then
 		#
-		# We found a usable DPDK.  Build with it.
-		#
-		CFLAGS="$CFLAGS $DPDK_CFLAGS"
-		LIBS="$LIBS $DPDK_LIBS"
-		LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
-		V_INCLS="$V_INCLS $DPDK_CFLAGS"
-		AC_DEFINE(PCAP_SUPPORT_DPDK, 1, [target host supports DPDK])
-		if test $V_PCAP != dpdk ; then
-			MODULE_C_SRC="$MODULE_C_SRC pcap-dpdk.c"
-		fi
-
+		# We found a usable DPDK.
 		#
 		# Check whether the rte_ether.h file defines
 		# struct ether_addr or struct rte_ether_addr.
 		#
 		# ("API compatibility?  That's for losers!")
 		#
+		AC_LBL_SAVE_CHECK_STATE
+		CFLAGS="$CFLAGS $DPDK_CFLAGS"
+		LIBS="$LIBS $DPDK_LIBS"
 		AC_CHECK_TYPES(struct rte_ether_addr,,,
 		    [
 			#include <rte_ether.h>
 		    ])
+		AC_LBL_RESTORE_CHECK_STATE
+
+		#
+		# We can build with DPDK.
+		#
+		V_INCLS="$V_INCLS $DPDK_CFLAGS"
+AC_MSG_WARN([DPDK_LIBS_STATIC is $DPDK_LIBS_STATIC])
+		ADDITIONAL_LIBS="$ADDITIONAL_LIBS $DPDK_LIBS"
+		ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $DPDK_LIBS_STATIC"
+		REQUIRES_PRIVATE="libdpdk $REQUIRES_PRIVATE"
+		AC_DEFINE(PCAP_SUPPORT_DPDK, 1, [target host supports DPDK])
+		if test $V_PCAP != dpdk ; then
+			MODULE_C_SRC="$MODULE_C_SRC pcap-dpdk.c"
+		fi
 	else
 		#
 		# We didn't find a usable DPDK.
@@ -2896,8 +3006,7 @@ fi
 if test "x$enable_dbus" != "xno"; then
 	PKG_CHECK_MODULES(DBUS, dbus-1,
 	    [
-		save_CFLAGS="$CFLAGS"
-		save_LIBS="$LIBS"
+		AC_LBL_SAVE_CHECK_STATE
 		CFLAGS="$CFLAGS $DBUS_CFLAGS"
 		LIBS="$LIBS $DBUS_LIBS"
 		AC_MSG_CHECKING(whether the D-Bus library defines dbus_connection_read_write)
@@ -2914,15 +3023,17 @@ if test "x$enable_dbus" != "xno"; then
 			AC_DEFINE(PCAP_SUPPORT_DBUS, 1, [support D-Bus sniffing])
 			MODULE_C_SRC="$MODULE_C_SRC pcap-dbus.c"
 			V_INCLS="$V_INCLS $DBUS_CFLAGS"
+			ADDITIONAL_LIBS="$ADDITIONAL_LIBS $DBUS_LIBS"
+			ADDITIONAL_LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $DBUS_LIBS_STATIC"
+			REQUIRES_PRIVATE="dbus-1 $REQUIRES_PRIVATE"
 		    ],
 		    [
 			AC_MSG_RESULT([no])
 			if test "x$enable_dbus" = "xyes"; then
 			    AC_MSG_ERROR([--enable-dbus was given, but the D-Bus library doesn't define dbus_connection_read_write()])
 			fi
-			LIBS="$save_LIBS"
 		     ])
-		CFLAGS="$save_CFLAGS"
+		AC_LBL_RESTORE_CHECK_STATE
 	    ],
 	    [
 		if test "x$enable_dbus" = "xyes"; then
@@ -2947,6 +3058,7 @@ if test "x$enable_rdma" != "xno"; then
 	PKG_CHECK_MODULES(LIBIBVERBS, libibverbs,
 	    [
 		found_libibverbs=yes
+		LIBIBVERBS_REQUIRES_PRIVATE="libibverbs"
 	    ])
 
 	if test "x$found_libibverbs" != "xyes"; then
@@ -2955,15 +3067,21 @@ if test "x$enable_rdma" != "xno"; then
 			found_libibverbs=yes
 			LIBIBVERBS_CFLAGS=""
 			LIBIBVERBS_LIBS="-libverbs"
+			# XXX - at least on Ubuntu 20.04, there are many more
+			# libraries needed; is there any platform where
+			# libibverbs is available but where pkg-config isn't
+			# available or libibverbs doesn't use it?  If not,
+			# we should only use pkg-config for it.
+			LIBIBVERBS_LIBS_STATIC="-libverbs"
+			LIBIBVERBS_LIBS_PRIVATE="-libverbs"
 		    ]
 		)
 	fi
 
 	if test "x$found_libibverbs" = "xyes"; then
-		save_CFLAGS="$CFLAGS"
-		save_LIBS="$LIBS"
-		CFLAGS="$LIBIBVERBS_CFLAGS"
-		LIBS="$LIBIBVERBS_LIBS"
+		AC_LBL_SAVE_CHECK_STATE
+		CFLAGS="$CFLAGS $LIBIBVERBS_CFLAGS"
+		LIBS="$LIBS $LIBIBVERBS_LIBS"
 		AC_CHECK_HEADER(infiniband/verbs.h, [
 			#
 			# ibv_create_flow may be defined as a static inline
@@ -2994,8 +3112,7 @@ if test "x$enable_rdma" != "xno"; then
 				]
 			)
 		])
-		CFLAGS="$save_CFLAGS"
-		LIBS="$save_LIBS"
+		AC_LBL_RESTORE_CHECK_STATE
 	fi
 
 	if test "x$found_usable_libibverbs" = "xyes"
@@ -3003,7 +3120,11 @@ if test "x$enable_rdma" != "xno"; then
 		AC_DEFINE(PCAP_SUPPORT_RDMASNIFF, , [target host supports RDMA sniffing])
 		MODULE_C_SRC="$MODULE_C_SRC pcap-rdmasniff.c"
 		CFLAGS="$LIBIBVERBS_CFLAGS $CFLAGS"
-		LIBS="$LIBIBVERBS_LIBS $LIBS"
+AC_MSG_WARN([LIBIBVERBS_LIBS_STATIC is $LIBIBVERBS_LIBS_STATIC])
+		ADDITIONAL_LIBS="$LIBIBVERBS_LIBS $ADDITIONAL_LIBS"
+		ADDITIONAL_LIBS_STATIC="$LIBIBVERBS_LIBS_STATIC $ADDITIONAL_LIBS_STATIC"
+		LIBS_PRIVATE="$LIBIBVERBS_LIBS_PRIVATE $LIBS_PRIVATE"
+		REQUIRES_PRIVATE="$LIBIBVERBS_REQUIRES_PRIVATE $REQUIRES_PRIVATE"
 	fi
 	AC_SUBST(PCAP_SUPPORT_RDMASNIFF)
 fi
@@ -3067,9 +3188,6 @@ AC_PROG_INSTALL
 
 AC_CONFIG_HEADER(config.h)
 
-AC_SUBST(V_CCOPT)
-AC_SUBST(V_DEFS)
-AC_SUBST(V_INCLS)
 AC_SUBST(V_SHLIB_CCOPT)
 AC_SUBST(V_SHLIB_CMD)
 AC_SUBST(V_SHLIB_OPT)
@@ -3086,6 +3204,13 @@ AC_SUBST(BUILD_RPCAPD)
 AC_SUBST(INSTALL_RPCAPD)
 AC_SUBST(RPCAPD_LIBS)
 
+#
+# We're done with configuration operations; add ADDITIONAL_LIBS and
+# ADDITIONAL_LIBS_STATIC to LIBS and LIBS_STATIC, respectively.
+#
+LIBS="$ADDITIONAL_LIBS $LIBS"
+LIBS_STATIC="$ADDITIONAL_LIBS_STATIC $LIBS_STATIC"
+
 AC_OUTPUT_COMMANDS([if test -f .devel; then
 	echo timestamp > stamp-h
 	cat $srcdir/Makefile-devel-adds >> Makefile