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| author | Brandon L Black <blblack@gmail.com> | 2010-03-26 16:18:03 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-03-27 08:29:01 -0700 |
| commit | 71c5c1595c04852d6fbf3c4882b47b30b61a4d32 (patch) | |
| tree | d95c64c5b752d37e7d1235e52f0c1fceb816c2ec | |
| parent | f49c57e141c7f53353e4265a31dc2324e6215037 (diff) | |
| download | lwn-71c5c1595c04852d6fbf3c4882b47b30b61a4d32.tar.gz lwn-71c5c1595c04852d6fbf3c4882b47b30b61a4d32.zip | |
net: Add MSG_WAITFORONE flag to recvmmsg
Add new flag MSG_WAITFORONE for the recvmmsg() syscall.
When this flag is specified for a blocking socket, recvmmsg()
will only block until at least 1 packet is available. The
default behavior is to block until all vlen packets are
available. This flag has no effect on non-blocking sockets
or when used in combination with MSG_DONTWAIT.
Signed-off-by: Brandon L Black <blblack@gmail.com>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/socket.h | 1 | ||||
| -rw-r--r-- | net/socket.c | 4 |
2 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/socket.h b/include/linux/socket.h index 7b3aae2052a6..354cc5617f8b 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -255,6 +255,7 @@ struct ucred { #define MSG_ERRQUEUE 0x2000 /* Fetch message from error queue */ #define MSG_NOSIGNAL 0x4000 /* Do not generate SIGPIPE */ #define MSG_MORE 0x8000 /* Sender will send more */ +#define MSG_WAITFORONE 0x10000 /* recvmmsg(): block until 1+ packets avail */ #define MSG_EOF MSG_FIN diff --git a/net/socket.c b/net/socket.c index 769c386bd428..f55ffe9f8c87 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2135,6 +2135,10 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, break; ++datagrams; + /* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */ + if (flags & MSG_WAITFORONE) + flags |= MSG_DONTWAIT; + if (timeout) { ktime_get_ts(timeout); *timeout = timespec_sub(end_time, *timeout); |