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authorGravatar Denys Vlasenko <vda.linux@googlemail.com>2019-06-03 14:16:52 +0200
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2019-06-03 14:16:52 +0200
commit45e3967c20b5020bf720b9497592e231104398f3 (patch)
tree364a53e80d1c2246e33fb00c4f6bb26e854912ae
parent498cec202adbf69a7a72af5e204260682d614183 (diff)
downloadbusybox-45e3967c20b5020bf720b9497592e231104398f3.tar.gz
busybox-45e3967c20b5020bf720b9497592e231104398f3.tar.bz2
libbb: move netlink socket binding to the utility function
function old new delta create_and_bind_to_netlink - 134 +134 ifplugd_main 1117 1052 -65 uevent_main 399 306 -93 mdev_main 314 215 -99 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/3 up/down: 134/-257) Total: -123 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--include/libbb.h1
-rw-r--r--libbb/xconnect.c35
-rw-r--r--networking/ifplugd.c10
-rw-r--r--util-linux/mdev.c28
-rw-r--r--util-linux/uevent.c37
5 files changed, 55 insertions, 56 deletions
diff --git a/include/libbb.h b/include/libbb.h
index 3a870bf80..100d6b606 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -688,6 +688,7 @@ int xsocket_stream(len_and_sockaddr **lsap) FAST_FUNC;
/* NB: these set SO_REUSEADDR before bind */
int create_and_bind_stream_or_die(const char *bindaddr, int port) FAST_FUNC;
int create_and_bind_dgram_or_die(const char *bindaddr, int port) FAST_FUNC;
+int create_and_bind_to_netlink(int proto, int grp, unsigned rcvbuf) FAST_FUNC;
/* Create client TCP socket connected to peer:port. Peer cannot be NULL.
* Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname,
* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index 39e56b223..ea5fe173f 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -11,6 +11,9 @@
#include <netinet/in.h>
#include <net/if.h>
#include <sys/un.h>
+#if ENABLE_IFPLUGD || ENABLE_FEATURE_MDEV_DAEMON || ENABLE_UEVENT
+# include <linux/netlink.h>
+#endif
#include "libbb.h"
int FAST_FUNC setsockopt_int(int fd, int level, int optname, int optval)
@@ -412,6 +415,38 @@ int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port)
}
+#if ENABLE_IFPLUGD || ENABLE_FEATURE_MDEV_DAEMON || ENABLE_UEVENT
+int FAST_FUNC create_and_bind_to_netlink(int proto, int grp, unsigned rcvbuf)
+{
+ struct sockaddr_nl sa;
+ int fd;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.nl_family = AF_NETLINK;
+ sa.nl_pid = getpid();
+ sa.nl_groups = grp;
+ fd = xsocket(AF_NETLINK, SOCK_DGRAM, proto);
+ xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
+ close_on_exec_on(fd);
+
+ if (rcvbuf != 0) {
+ // SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
+ setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, rcvbuf);
+ setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, rcvbuf);
+# if 0
+ {
+ int z;
+ socklen_t zl = sizeof(z);
+ getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &z, &zl);
+ bb_error_msg("SO_RCVBUF:%d", z);
+ }
+# endif
+ }
+
+ return fd;
+}
+#endif
+
int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port)
{
int fd;
diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index 1426709cb..b7b26c113 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -604,15 +604,7 @@ int ifplugd_main(int argc UNUSED_PARAM, char **argv)
xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
if (opts & FLAG_MONITOR) {
- struct sockaddr_nl addr;
- int fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
-
- memset(&addr, 0, sizeof(addr));
- addr.nl_family = AF_NETLINK;
- addr.nl_groups = RTMGRP_LINK;
- addr.nl_pid = getpid();
-
- xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
+ int fd = create_and_bind_to_netlink(NETLINK_ROUTE, RTMGRP_LINK, 0);
xmove_fd(fd, netlink_fd);
}
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 88c82b6fb..9cb3586f1 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1225,28 +1225,16 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
/*
* Daemon mode listening on uevent netlink socket.
*/
- struct sockaddr_nl sa;
int fd;
-//TODO: reuse same code in uevent
- // Subscribe for UEVENT kernel messages
- sa.nl_family = AF_NETLINK;
- sa.nl_pad = 0;
- sa.nl_pid = getpid();
- sa.nl_groups = 1 << 0;
- fd = xsocket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
- xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
- close_on_exec_on(fd);
-
- // Without a sufficiently big RCVBUF, a ton of simultaneous events
- // can trigger ENOBUFS on read, which is unrecoverable.
- // Reproducer:
- // mdev -d
- // find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
- //
- // SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
- setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, RCVBUF);
- setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, RCVBUF);
+ /* Subscribe for UEVENT kernel messages */
+ /* Without a sufficiently big RCVBUF, a ton of simultaneous events
+ * can trigger ENOBUFS on read, which is unrecoverable.
+ * Reproducer:
+ * mdev -d
+ * find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
+ */
+ fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0, RCVBUF);
/*
* Make inital scan after the uevent socket is alive and
diff --git a/util-linux/uevent.c b/util-linux/uevent.c
index 761743f45..2f8990ed9 100644
--- a/util-linux/uevent.c
+++ b/util-linux/uevent.c
@@ -46,37 +46,19 @@ enum { RCVBUF = 2 * 1024 * 1024 };
int uevent_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int uevent_main(int argc UNUSED_PARAM, char **argv)
{
- struct sockaddr_nl sa;
int fd;
INIT_G();
argv++;
- // Subscribe for UEVENT kernel messages
- sa.nl_family = AF_NETLINK;
- sa.nl_pad = 0;
- sa.nl_pid = getpid();
- sa.nl_groups = 1 << 0;
- fd = xsocket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
- xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
- close_on_exec_on(fd);
-
+ // Subscribe for UEVENT kernel messages.
// Without a sufficiently big RCVBUF, a ton of simultaneous events
// can trigger ENOBUFS on read, which is unrecoverable.
// Reproducer:
// uevent mdev &
// find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
- //
- // SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
- setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, RCVBUF);
- setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, RCVBUF);
- if (0) {
- int z;
- socklen_t zl = sizeof(z);
- getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &z, &zl);
- bb_error_msg("SO_RCVBUF:%d", z);
- }
+ fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, /*groups:*/ 1 << 0, RCVBUF);
for (;;) {
char *netbuf;
@@ -118,14 +100,15 @@ int uevent_main(int argc UNUSED_PARAM, char **argv)
}
env[idx] = NULL;
- idx = 0;
- while (env[idx])
- putenv(env[idx++]);
- if (argv[0])
+ if (argv[0]) {
+ idx = 0;
+ while (env[idx])
+ putenv(env[idx++]);
spawn_and_wait(argv);
- idx = 0;
- while (env[idx])
- bb_unsetenv(env[idx++]);
+ idx = 0;
+ while (env[idx])
+ bb_unsetenv(env[idx++]);
+ }
munmap(netbuf, BUFFER_SIZE);
}