[PATCH v2] lib: fix multiple strlcpy definition

Baruch Siach
2017-09-28T18:03:07Z

Some C libraries, like uClibc and musl, provide BSD compatible
strlcpy(). Add check_strlcpy() to configure, and avoid defining strlcpy
and strlcat when the C library provides them.

This fixes the following static link error with uClibc-ng:

.../sysroot/usr/lib/libc.a(strlcpy.os): In function `strlcpy':
strlcpy.c:(.text+0x0): multiple definition of `strlcpy'
../lib/libutil.a(utils.o):utils.c:(.text+0x1ddc): first defined here
collect2: error: ld returned 1 exit status

Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
v2: Fix the order of strlcpy parameters
---
configure | 24 ++++++++++++++++++++++++
lib/Makefile | 4 ++++
lib/utils.c | 2 ++
3 files changed, 30 insertions(+)

diff --git a/configure b/configure
index 7be8fb113cc9..e0982f34a992 100755
--- a/configure
+++ b/configure
@@ -326,6 +326,27 @@ EOF
rm -f $TMPDIR/dbtest.c $TMPDIR/dbtest
}

+check_strlcpy()
+{
+ cat >$TMPDIR/strtest.c <<EOF
+#include <string.h>
+int main(int argc, char **argv) {
+ char dst[10];
+ strlcpy(dst, "test", sizeof(dst));
+ return 0;
+}
+EOF
+ $CC -I$INCLUDE -o $TMPDIR/strtest $TMPDIR/strtest.c >/dev/null 2>&1
+ if [ $? -eq 0 ]
+ then
+ echo "no"
+ else
+ echo "NEED_STRLCPY:=y" >>$CONFIG
+ echo "yes"
+ fi
+ rm -f $TMPDIR/strtest.c $TMPDIR/strtest
+}
+
quiet_config()
{
cat <<EOF
@@ -397,6 +418,9 @@ check_mnl
echo -n "Berkeley DB: "
check_berkeley_db

+echo -n "need for strlcpy: "
+check_strlcpy
+
echo
echo -n "docs:"
check_docs
diff --git a/lib/Makefile b/lib/Makefile
index 0fbdf4c31f50..132ad00c3335 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,5 +1,9 @@
include ../config.mk

+ifeq ($(NEED_STRLCPY),y)
+ CFLAGS += -DNEED_STRLCPY
+endif
+
CFLAGS += -fPIC

UTILOBJ = utils.o rt_names.o ll_types.o ll_proto.o ll_addr.o \
diff --git a/lib/utils.c b/lib/utils.c
index bbd3cbc46a0e..240e7426a810 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -1231,6 +1231,7 @@ int get_real_family(int rtm_type, int rtm_family)
return rtm_family;
}

+#ifdef NEED_STRLCPY
size_t strlcpy(char *dst, const char *src, size_t size)
{
size_t srclen = strlen(src);
@@ -1253,3 +1254,4 @@ size_t strlcat(char *dst, const char *src, size_t size)

return dlen + strlcpy(dst + dlen, src, size - dlen);
}
+#endif
--
2.14.2