Commit 4ea0c32f authored by Xin Long's avatar Xin Long Committed by David S. Miller

sctp: add support for MSG_MORE

This patch is to add support for MSG_MORE on sctp.

It adds force_delay in sctp_datamsg to save MSG_MORE, and sets it after
creating datamsg according to the send flag. sctp_packet_can_append_data
then uses it to decide if the chunks of this msg will be sent at once or
delay it.

Note that unlike [1], this patch saves MSG_MORE in datamsg, instead of
in assoc. As sctp enqueues the chunks first, then dequeue them one by
one. If it's saved in assoc,the current msg's send flag (MSG_MORE) may
affect other chunks' bundling.

Since last patch, sctp flush out queue once assoc state falls into
SHUTDOWN_PENDING, the close block problem mentioned in [1] has been
solved as well.

[1] https://patchwork.ozlabs.org/patch/372404/Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b7018d0b
...@@ -497,6 +497,7 @@ struct sctp_datamsg { ...@@ -497,6 +497,7 @@ struct sctp_datamsg {
/* Did the messenge fail to send? */ /* Did the messenge fail to send? */
int send_error; int send_error;
u8 send_failed:1, u8 send_failed:1,
force_delay:1,
can_delay; /* should this message be Nagle delayed */ can_delay; /* should this message be Nagle delayed */
}; };
......
...@@ -704,18 +704,15 @@ static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, ...@@ -704,18 +704,15 @@ static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet,
* unacknowledged. * unacknowledged.
*/ */
if (sctp_sk(asoc->base.sk)->nodelay) if ((sctp_sk(asoc->base.sk)->nodelay || inflight == 0) &&
/* Nagle disabled */ !chunk->msg->force_delay)
/* Nothing unacked */
return SCTP_XMIT_OK; return SCTP_XMIT_OK;
if (!sctp_packet_empty(packet)) if (!sctp_packet_empty(packet))
/* Append to packet */ /* Append to packet */
return SCTP_XMIT_OK; return SCTP_XMIT_OK;
if (inflight == 0)
/* Nothing unacked */
return SCTP_XMIT_OK;
if (!sctp_state(asoc, ESTABLISHED)) if (!sctp_state(asoc, ESTABLISHED))
return SCTP_XMIT_OK; return SCTP_XMIT_OK;
......
...@@ -1964,6 +1964,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) ...@@ -1964,6 +1964,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
err = PTR_ERR(datamsg); err = PTR_ERR(datamsg);
goto out_free; goto out_free;
} }
datamsg->force_delay = !!(msg->msg_flags & MSG_MORE);
/* Now send the (possibly) fragmented message. */ /* Now send the (possibly) fragmented message. */
list_for_each_entry(chunk, &datamsg->chunks, frag_list) { list_for_each_entry(chunk, &datamsg->chunks, frag_list) {
......
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