diff options
| -rw-r--r-- | net/sctp/associola.c | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 620c99e19e77..58bbb731fd26 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -1224,13 +1224,41 @@ static u8 sctp_trans_score(const struct sctp_transport *trans) return sctp_trans_state_to_prio_map[trans->state]; } +static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1, + struct sctp_transport *trans2) +{ + if (trans1->error_count > trans2->error_count) { + return trans2; + } else if (trans1->error_count == trans2->error_count && + ktime_after(trans2->last_time_heard, + trans1->last_time_heard)) { + return trans2; + } else { + return trans1; + } +} + static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr, struct sctp_transport *best) { + u8 score_curr, score_best; + if (best == NULL) return curr; - return sctp_trans_score(curr) > sctp_trans_score(best) ? curr : best; + score_curr = sctp_trans_score(curr); + score_best = sctp_trans_score(best); + + /* First, try a score-based selection if both transport states + * differ. If we're in a tie, lets try to make a more clever + * decision here based on error counts and last time heard. + */ + if (score_curr > score_best) + return curr; + else if (score_curr == score_best) + return sctp_trans_elect_tie(curr, best); + else + return best; } void sctp_assoc_update_retran_path(struct sctp_association *asoc) @@ -1274,14 +1302,23 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc) static void sctp_select_active_and_retran_path(struct sctp_association *asoc) { struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL; + struct sctp_transport *trans_pf = NULL; /* Look for the two most recently used active transports. */ list_for_each_entry(trans, &asoc->peer.transport_addr_list, transports) { + /* Skip uninteresting transports. */ if (trans->state == SCTP_INACTIVE || - trans->state == SCTP_UNCONFIRMED || - trans->state == SCTP_PF) + trans->state == SCTP_UNCONFIRMED) continue; + /* Keep track of the best PF transport from our + * list in case we don't find an active one. + */ + if (trans->state == SCTP_PF) { + trans_pf = sctp_trans_elect_best(trans, trans_pf); + continue; + } + /* For active transports, pick the most recent ones. */ if (trans_pri == NULL || ktime_after(trans->last_time_heard, trans_pri->last_time_heard)) { @@ -1317,10 +1354,13 @@ static void sctp_select_active_and_retran_path(struct sctp_association *asoc) trans_sec = trans_pri; /* If we failed to find a usable transport, just camp on the - * primary, even if they are inactive. + * primary or retran, even if they are inactive, if possible + * pick a PF iff it's the better choice. */ if (trans_pri == NULL) { - trans_pri = asoc->peer.primary_path; + trans_pri = sctp_trans_elect_best(asoc->peer.primary_path, + asoc->peer.retran_path); + trans_pri = sctp_trans_elect_best(trans_pri, trans_pf); trans_sec = asoc->peer.primary_path; } |