diff options
| author | Denys Vlasenko | 2019-06-03 14:16:52 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2019-06-03 14:16:52 +0200 |
| commit | 45e3967c20b5020bf720b9497592e231104398f3 (patch) | |
| tree | 364a53e80d1c2246e33fb00c4f6bb26e854912ae /util-linux/mdev.c | |
| parent | 498cec202adbf69a7a72af5e204260682d614183 (diff) | |
| download | busybox-45e3967c20b5020bf720b9497592e231104398f3.zip busybox-45e3967c20b5020bf720b9497592e231104398f3.tar.gz | |
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>
Diffstat (limited to 'util-linux/mdev.c')
| -rw-r--r-- | util-linux/mdev.c | 28 |
1 files changed, 8 insertions, 20 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c index 88c82b6..9cb3586 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 |