From: Alyssa Ross <hi@alyssa.is>
Date: Sun, 2 Apr 2023 23:29:40 +0000 (+0000)
Subject: build: use pkg-config for libpcap
X-Git-Tag: v1.8.10~67
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=aed58f545bec0712bcdbe14e2b8386db0c650a91;p=thirdparty%2Fiptables.git

build: use pkg-config for libpcap

If building statically, with libpcap built with libnl support, linking
will fail, as the compiler won't be able to find the libnl symbols
since static libraries don't contain dependency information.  To fix
this, use pkg-config to find the flags for linking libpcap, since the
pkg-config files contain the neccesary dependency information.

autoconf will add code to the configure script for initializing
pkg-config the first time it seems PKG_CHECK_MODULES, so make the
libnfnetlink check the first one in the script, so the initialization
code is run unconditionally.

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Signed-off-by: Phil Sutter <phil@nwl.cc>
---

diff --git a/configure.ac b/configure.ac
index bc2ed47b..488c01eb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -113,14 +113,15 @@ AM_CONDITIONAL([ENABLE_SYNCONF], [test "$enable_nfsynproxy" = "yes"])
 AM_CONDITIONAL([ENABLE_NFTABLES], [test "$enable_nftables" = "yes"])
 AM_CONDITIONAL([ENABLE_CONNLABEL], [test "$enable_connlabel" = "yes"])
 
-if test "x$enable_bpfc" = "xyes" || test "x$enable_nfsynproxy" = "xyes"; then
-	AC_CHECK_LIB(pcap, pcap_compile,, AC_MSG_ERROR(missing libpcap library required by bpf compiler or nfsynproxy tool))
-fi
-
 PKG_CHECK_MODULES([libnfnetlink], [libnfnetlink >= 1.0],
 	[nfnetlink=1], [nfnetlink=0])
 AM_CONDITIONAL([HAVE_LIBNFNETLINK], [test "$nfnetlink" = 1])
 
+if test "x$enable_bpfc" = "xyes" || test "x$enable_nfsynproxy" = "xyes"; then
+	PKG_CHECK_MODULES([libpcap], [libpcap], [], [
+		AC_MSG_ERROR(missing libpcap library required by bpf compiler or nfsynproxy tool)])
+fi
+
 if test "x$enable_nftables" = "xyes"; then
 	PKG_CHECK_MODULES([libmnl], [libmnl >= 1.0], [mnl=1], [mnl=0])
 
diff --git a/utils/Makefile.am b/utils/Makefile.am
index e9eec48f..34056514 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -2,7 +2,7 @@
 
 AM_CFLAGS = ${regular_CFLAGS}
 AM_CPPFLAGS = ${regular_CPPFLAGS} -I${top_builddir}/include \
-              -I${top_srcdir}/include ${libnfnetlink_CFLAGS}
+              -I${top_srcdir}/include ${libnfnetlink_CFLAGS} ${libpcap_CFLAGS}
 AM_LDFLAGS = ${regular_LDFLAGS}
 
 sbin_PROGRAMS =
@@ -25,12 +25,12 @@ endif
 if ENABLE_BPFC
 man_MANS += nfbpf_compile.8
 sbin_PROGRAMS += nfbpf_compile
-nfbpf_compile_LDADD = -lpcap
+nfbpf_compile_LDADD = ${libpcap_LIBS}
 endif
 
 if ENABLE_SYNCONF
 sbin_PROGRAMS += nfsynproxy
-nfsynproxy_LDADD = -lpcap
+nfsynproxy_LDADD = ${libpcap_LIBS}
 endif
 
 CLEANFILES = nfnl_osf.8 nfbpf_compile.8