Merge branch 'sctp'
Daniel Borkmann says:
====================
Misc SCTP updates
Daniel Borkmann (2):
net: sctp: improve timer slack calculation for transport HBs
net: sctp: only warn in proc_sctp_do_alpha_beta if write
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 8e4de46..c2035c9 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -388,27 +388,6 @@
return (head->next != head) && (head->next == head->prev);
}
-/* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
-static inline __s32 sctp_jitter(__u32 rto)
-{
- static __u32 sctp_rand;
- __s32 ret;
-
- /* Avoid divide by zero. */
- if (!rto)
- rto = 1;
-
- sctp_rand += jiffies;
- sctp_rand ^= (sctp_rand << 12);
- sctp_rand ^= (sctp_rand >> 20);
-
- /* Choose random number from 0 to rto, then move to -50% ~ +50%
- * of rto.
- */
- ret = sctp_rand % rto - (rto >> 1);
- return ret;
-}
-
/* Break down data chunks at this point. */
static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
{
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 12c7e01..2e9ada1 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -424,8 +424,9 @@
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
- pr_warn_once("Changing rto_alpha or rto_beta may lead to "
- "suboptimal rtt/srtt estimations!\n");
+ if (write)
+ pr_warn_once("Changing rto_alpha or rto_beta may lead to "
+ "suboptimal rtt/srtt estimations!\n");
return proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
}
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 7dd672f..b10e047 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -594,15 +594,16 @@
}
/* What is the next timeout value for this transport? */
-unsigned long sctp_transport_timeout(struct sctp_transport *t)
+unsigned long sctp_transport_timeout(struct sctp_transport *trans)
{
- unsigned long timeout;
- timeout = t->rto + sctp_jitter(t->rto);
- if ((t->state != SCTP_UNCONFIRMED) &&
- (t->state != SCTP_PF))
- timeout += t->hbinterval;
- timeout += jiffies;
- return timeout;
+ /* RTO + timer slack +/- 50% of RTO */
+ unsigned long timeout = (trans->rto >> 1) + prandom_u32_max(trans->rto);
+
+ if (trans->state != SCTP_UNCONFIRMED &&
+ trans->state != SCTP_PF)
+ timeout += trans->hbinterval;
+
+ return timeout + jiffies;
}
/* Reset transport variables to their initial values */