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Use libbsd for strlcpy if available

PATCH Superseded Luca Boccassi 3 participants 6 messages Oct 29, 2018 – Nov 1, 2018

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Luca Boccassi

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#0 lore raw

PATCH 1/1 Use libbsd for strlcpy if available

If libc does not provide strlcpy check for libbsd with pkg-config to avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
This allows distro maintainers to be able to choose to reduce duplication and let this code be maintained in one place, in the external library.

 configure | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
configure +10 -2
index 744d6282..1dd9ce84 100755
@@ -330,8 +330,16 @@ EOF
     then
 	echo "no"
     else
-	echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
-	echo "yes"
+	if ${PKG_CONFIG} libbsd --exists
+	then
+		echo 'CFLAGS += -include' `${PKG_CONFIG} libbsd --variable=includedir`'/bsd/string.h' \
+			`${PKG_CONFIG} libbsd --cflags` >>$CONFIG
+		echo 'LDLIBS +=' `${PKG_CONFIG} libbsd --libs` >> $CONFIG
+		echo "no"
+	else
+		echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
+		echo "yes"
+	fi
     fi
     rm -f $TMPDIR/strtest.c $TMPDIR/strtest
 }
Signature · 1 line
2.19.1
#1 lore raw
Quoted 26 lines · Luca Boccassi

If libc does not provide strlcpy check for libbsd with pkg-config to avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
This allows distro maintainers to be able to choose to reduce duplication and let this code be maintained in one place, in the external library.

 configure | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
configure +3 -2
index 744d6282..1dd9ce84 100755
@@ -330,8 +330,16 @@ EOF
     then
 	echo "no"
     else
-	echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
-	echo "yes"
+	if ${PKG_CONFIG} libbsd --exists
+	then
+		echo 'CFLAGS += -include' `${PKG_CONFIG} libbsd --variable=includedir`'/bsd/string.h' \

configure EOF · line 345

Quoted 10 lines
configure +7 -0
+			`${PKG_CONFIG} libbsd --cflags` >>$CONFIG
+		echo 'LDLIBS +=' `${PKG_CONFIG} libbsd --libs` >> $CONFIG
+		echo "no"
+	else
+		echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
+		echo "yes"
+	fi
     fi
     rm -f $TMPDIR/strtest.c $TMPDIR/strtest
 }

How long has libbsd had an implementation of strlcpy? Would be safer to have a compile test to verify libbsd has it.

author
#2 lore raw
Quoted 36 lines · David Ahern
Quoted 35 lines · Luca Boccassi

If libc does not provide strlcpy check for libbsd with pkg-config to
avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
This allows distro maintainers to be able to choose to reduce duplication and let this code be maintained in one place, in the external library.

 configure | 12 ++++++++++--

 1 file changed, 10 insertions(+), 2 deletions(-)
configure +0 -0
index 744d6282..1dd9ce84 100755
@@ -330,8 +330,16 @@ EOF

     then
  echo "no"
     else

configure +3 -2
-	echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
-	echo "yes"
+	if ${PKG_CONFIG} libbsd --exists
+	then
+		echo 'CFLAGS += -include' `${PKG_CONFIG} libbsd --

variable=includedir`'/bsd/string.h' \

configure +2 -0
+			`${PKG_CONFIG} libbsd --cflags` >>$CONFIG
+		echo 'LDLIBS +=' `${PKG_CONFIG} libbsd --libs` >>

$CONFIG

configure +5 -0
+		echo "no"
+	else
+		echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
+		echo "yes"
+	fi
Quoted 8 lines
Quoted 4 lines

     fi
     rm -f $TMPDIR/strtest.c $TMPDIR/strtest
 }

How long has libbsd had an implementation of strlcpy? Would be safer to
have a compile test to verify libbsd has it.

Hi,

0.0 from 10+ years ago has it, so I think we are safe :-)

https://gitlab.freedesktop.org/libbsd/libbsd/blob/0.0/include/bsd/string.h#L34

Signature · 2 lines
Kind regards,
Luca Boccassi
#3 lore raw
In reply to Luca Boccassi
Quoted 9 lines · On Mon, 29 Oct 2018 10:46:50 +0000 Luca Boccassi <[email protected]> wrote:

If libc does not provide strlcpy check for libbsd with pkg-config to avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
This allows distro maintainers to be able to choose to reduce duplication and let this code be maintained in one place, in the external library.

I like the idea, but it causes warnings on Debian testing, and maybe other distros.

ipnetns.c:2: warning: "_ATFILE_SOURCE" redefined
#define _ATFILE_SOURCE

In file included from /usr/include/x86_64-linux-gnu/bits/libc-header-start.h:33,

                 from /usr/include/string.h:26,
                 from /usr/include/bsd/string.h:30,
                 from <command-line>:
/usr/include/features.h:326: note: this is the location of the previous definition
 # define _ATFILE_SOURCE 1

Please figure out how to handle this and resubmit. SUSE open build service might also work to test multiple distro's

author
#4 lore raw
Quoted 27 lines · Stephen Hemminger
Quoted 10 lines · On Mon, 29 Oct 2018 10:46:50 +0000 Luca Boccassi <[email protected]> wrote:

If libc does not provide strlcpy check for libbsd with pkg-config to
avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
This allows distro maintainers to be able to choose to reduce duplication and let this code be maintained in one place, in the external library.

I like the idea, but it causes warnings on Debian testing, and maybe other distros.

ipnetns.c:2: warning: "_ATFILE_SOURCE" redefined
 #define _ATFILE_SOURCE

In file included from /usr/include/x86_64-linux-gnu/bits/libc-header- start.h:33,
                 from /usr/include/string.h:26,
                 from /usr/include/bsd/string.h:30,
                 from <command-line>:
/usr/include/features.h:326: note: this is the location of the previous definition

Quoted 6 lines
 # define _ATFILE_SOURCE 1

Please figure out how to handle this and resubmit.  SUSE open build service might
also work to test multiple distro's

Ah missed that. That happens because features.h defines _ATFILE_SOURCE to 1, but ip/ipnetns.c defines it without a value. According to the spec either way doesn't change the result.

This happens because of the quick hack of using -include /usr/include/bsd/string.h which was, well, a quick hack and didn't require to add the include manually everywhere strlcpy was used, even in the future. But it has side effects like this.

So I'll send v2 with a less hacky fix, which means defining HAVE_LIBBSD in configure and doing #ifdef HAVE_LIBBSD #include <bsd/string.h> in every file. It also means that this needs to be done for every future use of strlcpy, or the build with libbsd will break.

If you or David prefer the hacky way, I can instead send a v3 that does the quick hack, and also changes _ATFILE_SOURCE to 1 so that there is no complaint from the compiler, as the values will be the same.

Signature · 2 lines
Kind regards,
Luca Boccassi
author
#5 lore raw

PATCH v2 1/1 Use libbsd for strlcpy if available

In reply to Luca Boccassi

If libc does not provide strlcpy check for libbsd with pkg-config to avoid relying on inline version.

Signed-off-by Luca Boccassi <[email protected]>

---
Changed from -include /usr/include/bsd/string.h hack to HAVE_LIBBSD and proper includes in each file that uses strlcpy.
The hack causes a compiler warning as ip/ipnetns.c defines _ATFILE_SOURCE without a value, but system headers use 1, so there's a mismatch.

 configure             | 11 +++++++++--
 genl/ctrl.c           |  3 +++
 ip/iplink.c           |  3 +++
 ip/ipnetns.c          |  3 +++
 ip/iproute_lwtunnel.c |  3 +++
 ip/ipvrf.c            |  3 +++
 ip/ipxfrm.c           |  3 +++
 ip/tunnel.c           |  3 +++
 ip/xfrm_state.c       |  3 +++
 lib/bpf.c             |  3 +++
 lib/fs.c              |  3 +++
 lib/inet_proto.c      |  3 +++
 misc/ss.c             |  3 +++
 tc/em_ipset.c         |  3 +++
 tc/m_pedit.c          |  3 +++
 15 files changed, 51 insertions(+), 2 deletions(-)
configure +9 -2
index 744d6282..c5655978 100755
@@ -330,8 +330,15 @@ EOF
     then
 	echo "no"
     else
-	echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
-	echo "yes"
+	if ${PKG_CONFIG} libbsd --exists
+	then
+		echo 'CFLAGS += -DHAVE_LIBBSD' `${PKG_CONFIG} libbsd --cflags` >>$CONFIG
+		echo 'LDLIBS +=' `${PKG_CONFIG} libbsd --libs` >> $CONFIG
+		echo "no"
+	else
+		echo 'CFLAGS += -DNEED_STRLCPY' >>$CONFIG
+		echo "yes"
+	fi
     fi
     rm -f $TMPDIR/strtest.c $TMPDIR/strtest
 }
genl/ctrl.c +3 -0
index 6133336a..fef6aaa9 100644
@@ -18,6 +18,9 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 
 #include "utils.h"
 #include "genl_utils.h"
ip/iplink.c +3 -0
index b5519201..067f5409 100644
@@ -24,6 +24,9 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <sys/ioctl.h>
 #include <stdbool.h>
 #include <linux/mpls.h>
ip/ipnetns.c +3 -0
index 0eac18cf..da019d76 100644
@@ -8,6 +8,9 @@
 #include <sys/syscall.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <sched.h>
 #include <fcntl.h>
 #include <dirent.h>
ip/iproute_lwtunnel.c +3 -0
index 8f497015..2285bc1d 100644
@@ -16,6 +16,9 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <linux/ila.h>
 #include <linux/lwtunnel.h>
 #include <linux/mpls_iptunnel.h>
ip/ipvrf.c +3 -0
index 8a6b7f97..8572b4f2 100644
@@ -21,6 +21,9 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <dirent.h>
 #include <errno.h>
 #include <limits.h>
ip/ipxfrm.c +3 -0
index 17ab4abe..b02f30a6 100644
@@ -28,6 +28,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <time.h>
ip/tunnel.c +3 -0
index d0d55f37..73abb2e2 100644
@@ -24,6 +24,9 @@
 
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>
ip/xfrm_state.c +3 -0
index e8c01746..18e0c6fa 100644
@@ -27,6 +27,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <netdb.h>
 #include "utils.h"
 #include "xfrm.h"
lib/bpf.c +3 -0
index 45f279fa..35d7c45a 100644
@@ -15,6 +15,9 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <stdbool.h>
 #include <stdint.h>
 #include <errno.h>
lib/fs.c +3 -0
index 86efd4ed..af36bea0 100644
@@ -20,6 +20,9 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <errno.h>
 #include <limits.h>
lib/inet_proto.c +3 -0
index 0836a4c9..b379d8f8 100644
@@ -18,6 +18,9 @@
 #include <netinet/in.h>
 #include <netdb.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 
 #include "rt_names.h"
 #include "utils.h"
misc/ss.c +3 -0
index 4d12fb5d..c472fbd9 100644
@@ -19,6 +19,9 @@
 #include <sys/sysmacros.h>
 #include <netinet/in.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <errno.h>
 #include <netdb.h>
 #include <arpa/inet.h>
tc/em_ipset.c +3 -0
index 48b287f5..550b2101 100644
@@ -20,6 +20,9 @@
 #include <netdb.h>
 #include <unistd.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <stdlib.h>
 #include <getopt.h>
tc/m_pedit.c +3 -0
index 2aeb56d9..baacc80d 100644
@@ -23,6 +23,9 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <string.h>
+#ifdef HAVE_LIBBSD
+#include <bsd/string.h>
+#endif
 #include <dlfcn.h>
 #include "utils.h"
 #include "tc_util.h"
Signature · 1 line
2.19.1