diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 8e4de46c052ec7d78188f203df2b69b0a0b423ab..c2035c96a2ee150a833ab28aa71e510abab72a5b 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -388,27 +388,6 @@ static inline int sctp_list_single_entry(struct list_head *head) 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 12c7e01c267711ef19878f6c1da1e66e257ecf7e..2e9ada10fd846c10bc6281c30f29cf1fed02ca3c 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -424,8 +424,9 @@ static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write, 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 7dd672fa651f979ae6b93578fc678254a7317b6b..b10e047bbd15548b405393837047b437e4802d26 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -594,15 +594,16 @@ void sctp_transport_burst_reset(struct sctp_transport *t) } /* 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 */