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authorXin Long2021-07-25 13:42:51 -0400
committerDavid S. Miller2021-07-25 23:06:02 +0100
commiteacf078cf4c7aa23e9591738511f142cc39b5186 (patch)
tree0004a2401d2477cc7176caef1efa159af62df47f
parent058e6e0ed0eace43401c945082dec1d669b5b231 (diff)
sctp: send pmtu probe only if packet loss in Search Complete state
This patch is to introduce last_rtx_chunks into sctp_transport to detect if there's any packet retransmission/loss happened by checking against asoc's rtx_data_chunks in sctp_transport_pl_send(). If there is, namely, transport->last_rtx_chunks != asoc->rtx_data_chunks, the pmtu probe will be sent out. Otherwise, increment the pl.raise_count and return when it's in Search Complete state. With this patch, if in Search Complete state, which is a long period, it doesn't need to keep probing the current pmtu unless there's data packet loss. This will save quite some traffic. v1->v2: - add the missing Fixes tag. Fixes: 0dac127c0557 ("sctp: do black hole detection in search complete state") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/sctp/structs.h1
-rw-r--r--net/sctp/transport.c6
2 files changed, 6 insertions, 1 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index f3d414ed208e..651bba654d77 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -984,6 +984,7 @@ struct sctp_transport {
} cacc;
struct {
+ __u32 last_rtx_chunks;
__u16 pmtu;
__u16 probe_size;
__u16 probe_high;
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 23e7bd3e3bd4..a3d3ca6dd63d 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -263,6 +263,7 @@ bool sctp_transport_pl_send(struct sctp_transport *t)
if (t->pl.probe_count < SCTP_MAX_PROBES)
goto out;
+ t->pl.last_rtx_chunks = t->asoc->rtx_data_chunks;
t->pl.probe_count = 0;
if (t->pl.state == SCTP_PL_BASE) {
if (t->pl.probe_size == SCTP_BASE_PLPMTU) { /* BASE_PLPMTU Confirmation Failed */
@@ -298,8 +299,10 @@ bool sctp_transport_pl_send(struct sctp_transport *t)
out:
if (t->pl.state == SCTP_PL_COMPLETE && t->pl.raise_count < 30 &&
- !t->pl.probe_count)
+ !t->pl.probe_count && t->pl.last_rtx_chunks == t->asoc->rtx_data_chunks) {
t->pl.raise_count++;
+ return false;
+ }
pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, high: %d\n",
__func__, t, t->pl.state, t->pl.pmtu, t->pl.probe_size, t->pl.probe_high);
@@ -313,6 +316,7 @@ bool sctp_transport_pl_recv(struct sctp_transport *t)
pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, high: %d\n",
__func__, t, t->pl.state, t->pl.pmtu, t->pl.probe_size, t->pl.probe_high);
+ t->pl.last_rtx_chunks = t->asoc->rtx_data_chunks;
t->pl.pmtu = t->pl.probe_size;
t->pl.probe_count = 0;
if (t->pl.state == SCTP_PL_BASE) {