From 12aa68d10fdcc5bd2d9385506d11aed3a0c2eaf1 Mon Sep 17 00:00:00 2001 From: Jan Klötzke Date: Mon, 16 Dec 2019 22:56:49 +0100 Subject: libbb: set netlink socket revbuf size before binding As soon as the socket is bound it will receive messages. Make sure the recieve buffer size is increased before the first message is received. Signed-off-by: Jan Klötzke Signed-off-by: Denys Vlasenko --- libbb/xconnect.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/libbb/xconnect.c b/libbb/xconnect.c index e9a2470..5dd9cfd 100644 --- a/libbb/xconnect.c +++ b/libbb/xconnect.c @@ -422,17 +422,14 @@ 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); + /* Set receive buffer size before binding the socket + * We want to have enough space before we start receiving messages. + */ 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_RCVBUF, rcvbuf); + /* SO_RCVBUFFORCE (root only) can go above net.core.rmem_max */ setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, rcvbuf); # if 0 { @@ -444,6 +441,13 @@ int FAST_FUNC create_and_bind_to_netlink(int proto, int grp, unsigned rcvbuf) # endif } + memset(&sa, 0, sizeof(sa)); + sa.nl_family = AF_NETLINK; + sa.nl_pid = getpid(); + sa.nl_groups = grp; + xbind(fd, (struct sockaddr *) &sa, sizeof(sa)); + close_on_exec_on(fd); + return fd; } #endif -- cgit v1.1