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authorWillem de Bruijn <willemb@google.com>2018-04-26 20:42:20 +0300
committerDavid S. Miller <davem@davemloft.net>2018-04-26 22:08:51 +0300
commit2e8de8576343ab540856082916bfb84d17288b08 (patch)
tree211c9efb376d6499bfc992065bd925bfb85d571e /net/ipv4/udp.c
parent15e36f5b8e982debe43e425d2e12d34e022d51e9 (diff)
downloadlinux-2e8de8576343ab540856082916bfb84d17288b08.tar.xz
udp: add gso segment cmsg
Allow specifying segment size in the send call. The new control message performs the same function as socket option UDP_SEGMENT while avoiding the extra system call. [ Export udp_cmsg_send for ipv6. -DaveM ] Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r--net/ipv4/udp.c44
1 files changed, 42 insertions, 2 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index bda022c5480b..794aeafeb782 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -853,6 +853,43 @@ out:
}
EXPORT_SYMBOL(udp_push_pending_frames);
+static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
+{
+ switch (cmsg->cmsg_type) {
+ case UDP_SEGMENT:
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
+ return -EINVAL;
+ *gso_size = *(__u16 *)CMSG_DATA(cmsg);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
+{
+ struct cmsghdr *cmsg;
+ bool need_ip = false;
+ int err;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_UDP) {
+ need_ip = true;
+ continue;
+ }
+
+ err = __udp_cmsg_send(cmsg, gso_size);
+ if (err)
+ return err;
+ }
+
+ return need_ip;
+}
+EXPORT_SYMBOL_GPL(udp_cmsg_send);
+
int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct inet_sock *inet = inet_sk(sk);
@@ -941,8 +978,11 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
ipc.gso_size = up->gso_size;
if (msg->msg_controllen) {
- err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6);
- if (unlikely(err)) {
+ err = udp_cmsg_send(sk, msg, &ipc.gso_size);
+ if (err > 0)
+ err = ip_cmsg_send(sk, msg, &ipc,
+ sk->sk_family == AF_INET6);
+ if (unlikely(err < 0)) {
kfree(ipc.opt);
return err;
}