[git commit] libbb: introduce and use bb_getsockname()
Denys Vlasenko
vda.linux at googlemail.com
Sun Feb 11 13:55:46 UTC 2018
commit: https://git.busybox.net/busybox/commit/?id=ba3b9dbf065438402d89655d7baefb0ccc6f0663
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
bb_getsockname - 18 +18
xrtnl_open 88 83 -5
do_iplink 1216 1209 -7
arping_main 1686 1668 -18
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/3 up/down: 18/-30) Total: -12 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
include/libbb.h | 1 +
libbb/bb_getsockname.c | 19 +++++++++++++++++++
networking/arping.c | 15 +++++----------
networking/inetd.c | 5 ++---
networking/libiproute/iplink.c | 4 +---
networking/libiproute/libnetlink.c | 5 +----
6 files changed, 29 insertions(+), 20 deletions(-)
diff --git a/include/libbb.h b/include/libbb.h
index e2bedaf41..2c34859a2 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -636,6 +636,7 @@ void setsockopt_reuseaddr(int fd) FAST_FUNC; /* On Linux this never fails. */
int setsockopt_keepalive(int fd) FAST_FUNC;
int setsockopt_broadcast(int fd) FAST_FUNC;
int setsockopt_bindtodevice(int fd, const char *iface) FAST_FUNC;
+int bb_getsockname(int sockfd, void *addr, socklen_t addrlen) FAST_FUNC;
/* NB: returns port in host byte order */
unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port) FAST_FUNC;
typedef struct len_and_sockaddr {
diff --git a/libbb/bb_getsockname.c b/libbb/bb_getsockname.c
new file mode 100644
index 000000000..1af9b39b9
--- /dev/null
+++ b/libbb/bb_getsockname.c
@@ -0,0 +1,19 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+//kbuild:lib-y += bb_getsockname.o
+
+#include "libbb.h"
+
+int FAST_FUNC bb_getsockname(int sockfd, void *addr, socklen_t addrlen)
+{
+ /* The usefullness of this function is that for getsockname(),
+ * addrlen must go on stack (to _have_ an address to be passed),
+ * but many callers do not need its modified value.
+ * By using this shim, they can avoid unnecessary stack spillage.
+ */
+ return getsockname(sockfd, (struct sockaddr *)addr, &addrlen);
+}
diff --git a/networking/arping.c b/networking/arping.c
index a16f04b9f..59092a7d7 100644
--- a/networking/arping.c
+++ b/networking/arping.c
@@ -363,15 +363,13 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
} else { /* !(option_mask32 & DAD) case */
/* Find IP address on this iface */
- socklen_t alen = sizeof(saddr);
-
saddr.sin_port = htons(1025);
saddr.sin_addr = dst;
if (setsockopt_SOL_SOCKET_1(probe_fd, SO_DONTROUTE) != 0)
bb_perror_msg("setsockopt(%s)", "SO_DONTROUTE");
xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
- getsockname(probe_fd, (struct sockaddr *) &saddr, &alen);
+ bb_getsockname(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
//never happens:
//if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1)
// bb_perror_msg_and_die("getsockname");
@@ -387,13 +385,10 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
me.sll_protocol = htons(ETH_P_ARP);
xbind(sock_fd, (struct sockaddr *) &me, sizeof(me));
- {
- socklen_t alen = sizeof(me);
- getsockname(sock_fd, (struct sockaddr *) &me, &alen);
- //never happens:
- //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1)
- // bb_perror_msg_and_die("getsockname");
- }
+ bb_getsockname(sock_fd, (struct sockaddr *) &me, sizeof(me));
+ //never happens:
+ //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1)
+ // bb_perror_msg_and_die("getsockname");
if (me.sll_halen == 0) {
bb_error_msg(err_str, "is not ARPable (no ll address)");
BUILD_BUG_ON(DAD != 2);
diff --git a/networking/inetd.c b/networking/inetd.c
index 4dfa0089a..6843845fb 100644
--- a/networking/inetd.c
+++ b/networking/inetd.c
@@ -497,10 +497,9 @@ static void register_rpc(servtab_t *sep)
{
int n;
struct sockaddr_in ir_sin;
- socklen_t size;
- size = sizeof(ir_sin);
- if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
+ if (bb_getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, sizeof(ir_sin)) < 0) {
+//TODO: verify that such failure is even possible in Linux kernel
bb_perror_msg("getsockname");
return;
}
diff --git a/networking/libiproute/iplink.c b/networking/libiproute/iplink.c
index aef5f6490..f38fba055 100644
--- a/networking/libiproute/iplink.c
+++ b/networking/libiproute/iplink.c
@@ -132,7 +132,6 @@ static int get_address(char *dev, int *htype)
{
struct ifreq ifr;
struct sockaddr_ll me;
- socklen_t alen;
int s;
s = xsocket(PF_PACKET, SOCK_DGRAM, 0);
@@ -146,8 +145,7 @@ static int get_address(char *dev, int *htype)
me.sll_ifindex = ifr.ifr_ifindex;
me.sll_protocol = htons(ETH_P_LOOP);
xbind(s, (struct sockaddr*)&me, sizeof(me));
- alen = sizeof(me);
- getsockname(s, (struct sockaddr*)&me, &alen);
+ bb_getsockname(s, (struct sockaddr*)&me, sizeof(me));
//never happens:
//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
// bb_perror_msg_and_die("getsockname");
diff --git a/networking/libiproute/libnetlink.c b/networking/libiproute/libnetlink.c
index f08d862d0..40955fcae 100644
--- a/networking/libiproute/libnetlink.c
+++ b/networking/libiproute/libnetlink.c
@@ -15,16 +15,13 @@
void FAST_FUNC xrtnl_open(struct rtnl_handle *rth/*, unsigned subscriptions*/)
{
- socklen_t addr_len;
-
memset(rth, 0, sizeof(*rth));
rth->fd = xsocket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
rth->local.nl_family = AF_NETLINK;
/*rth->local.nl_groups = subscriptions;*/
xbind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
- addr_len = sizeof(rth->local);
- getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len);
+ bb_getsockname(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local));
/* too much paranoia
if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0)
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