diff options
Diffstat (limited to 'net/sctp/associola.c')
| -rw-r--r-- | net/sctp/associola.c | 252 |
1 files changed, 172 insertions, 80 deletions
diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 4f6d6f9d1274..9de23a222d3f 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -55,6 +55,7 @@ #include <net/sctp/sm.h> /* Forward declarations for internal functions. */ +static void sctp_select_active_and_retran_path(struct sctp_association *asoc); static void sctp_assoc_bh_rcv(struct work_struct *work); static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc); @@ -330,7 +331,7 @@ void sctp_association_free(struct sctp_association *asoc) /* Only real associations count against the endpoint, so * don't bother for if this is a temporary association. */ - if (!asoc->temp) { + if (!list_empty(&asoc->asocs)) { list_del(&asoc->asocs); /* Decrement the backlog value for a TCP-style listening @@ -774,9 +775,6 @@ void sctp_assoc_control_transport(struct sctp_association *asoc, sctp_transport_cmd_t command, sctp_sn_error_t error) { - struct sctp_transport *t = NULL; - struct sctp_transport *first; - struct sctp_transport *second; struct sctp_ulpevent *event; struct sockaddr_storage addr; int spc_state = 0; @@ -829,13 +827,14 @@ void sctp_assoc_control_transport(struct sctp_association *asoc, return; } - /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the - * user. + /* Generate and send a SCTP_PEER_ADDR_CHANGE notification + * to the user. */ if (ulp_notify) { memset(&addr, 0, sizeof(struct sockaddr_storage)); memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len); + event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, 0, spc_state, error, GFP_ATOMIC); if (event) @@ -843,60 +842,7 @@ void sctp_assoc_control_transport(struct sctp_association *asoc, } /* Select new active and retran paths. */ - - /* Look for the two most recently used active transports. - * - * This code produces the wrong ordering whenever jiffies - * rolls over, but we still get usable transports, so we don't - * worry about it. - */ - first = NULL; second = NULL; - - list_for_each_entry(t, &asoc->peer.transport_addr_list, - transports) { - - if ((t->state == SCTP_INACTIVE) || - (t->state == SCTP_UNCONFIRMED) || - (t->state == SCTP_PF)) - continue; - if (!first || t->last_time_heard > first->last_time_heard) { - second = first; - first = t; - } else if (!second || - t->last_time_heard > second->last_time_heard) - second = t; - } - - /* RFC 2960 6.4 Multi-Homed SCTP Endpoints - * - * By default, an endpoint should always transmit to the - * primary path, unless the SCTP user explicitly specifies the - * destination transport address (and possibly source - * transport address) to use. - * - * [If the primary is active but not most recent, bump the most - * recently used transport.] - */ - if (((asoc->peer.primary_path->state == SCTP_ACTIVE) || - (asoc->peer.primary_path->state == SCTP_UNKNOWN)) && - first != asoc->peer.primary_path) { - second = first; - first = asoc->peer.primary_path; - } - - if (!second) - second = first; - /* If we failed to find a usable transport, just camp on the - * primary, even if it is inactive. - */ - if (!first) { - first = asoc->peer.primary_path; - second = asoc->peer.primary_path; - } - - /* Set the active and retran transports. */ - asoc->peer.active_path = first; - asoc->peer.retran_path = second; + sctp_select_active_and_retran_path(asoc); } /* Hold a reference to an association. */ @@ -1090,7 +1036,7 @@ static void sctp_assoc_bh_rcv(struct work_struct *work) } if (chunk->transport) - chunk->transport->last_time_heard = jiffies; + chunk->transport->last_time_heard = ktime_get(); /* Run through the state machine. */ error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, @@ -1278,13 +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) @@ -1325,6 +1299,76 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc) __func__, asoc, &asoc->peer.retran_path->ipaddr.sa); } +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) + 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)) { + trans_sec = trans_pri; + trans_pri = trans; + } else if (trans_sec == NULL || + ktime_after(trans->last_time_heard, + trans_sec->last_time_heard)) { + trans_sec = trans; + } + } + + /* RFC 2960 6.4 Multi-Homed SCTP Endpoints + * + * By default, an endpoint should always transmit to the primary + * path, unless the SCTP user explicitly specifies the + * destination transport address (and possibly source transport + * address) to use. [If the primary is active but not most recent, + * bump the most recently used transport.] + */ + if ((asoc->peer.primary_path->state == SCTP_ACTIVE || + asoc->peer.primary_path->state == SCTP_UNKNOWN) && + asoc->peer.primary_path != trans_pri) { + trans_sec = trans_pri; + trans_pri = asoc->peer.primary_path; + } + + /* We did not find anything useful for a possible retransmission + * path; either primary path that we found is the the same as + * the current one, or we didn't generally find an active one. + */ + if (trans_sec == NULL) + trans_sec = trans_pri; + + /* If we failed to find a usable transport, just camp on the + * 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 = 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; + } + + /* Set the active and retran transports. */ + asoc->peer.active_path = trans_pri; + asoc->peer.retran_path = trans_sec; +} + struct sctp_transport * sctp_assoc_choose_alter_transport(struct sctp_association *asoc, struct sctp_transport *last_sent_to) @@ -1395,35 +1439,44 @@ static inline bool sctp_peer_needs_update(struct sctp_association *asoc) return false; } -/* Update asoc's rwnd for the approximated state in the buffer, - * and check whether SACK needs to be sent. - */ -void sctp_assoc_rwnd_update(struct sctp_association *asoc, bool update_peer) +/* Increase asoc's rwnd by len and send any window update SACK if needed. */ +void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len) { - int rx_count; struct sctp_chunk *sack; struct timer_list *timer; - if (asoc->ep->rcvbuf_policy) - rx_count = atomic_read(&asoc->rmem_alloc); - else - rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); + if (asoc->rwnd_over) { + if (asoc->rwnd_over >= len) { + asoc->rwnd_over -= len; + } else { + asoc->rwnd += (len - asoc->rwnd_over); + asoc->rwnd_over = 0; + } + } else { + asoc->rwnd += len; + } - if ((asoc->base.sk->sk_rcvbuf - rx_count) > 0) - asoc->rwnd = (asoc->base.sk->sk_rcvbuf - rx_count) >> 1; - else - asoc->rwnd = 0; + /* If we had window pressure, start recovering it + * once our rwnd had reached the accumulated pressure + * threshold. The idea is to recover slowly, but up + * to the initial advertised window. + */ + if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) { + int change = min(asoc->pathmtu, asoc->rwnd_press); + asoc->rwnd += change; + asoc->rwnd_press -= change; + } - pr_debug("%s: asoc:%p rwnd=%u, rx_count=%d, sk_rcvbuf=%d\n", - __func__, asoc, asoc->rwnd, rx_count, - asoc->base.sk->sk_rcvbuf); + pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n", + __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, + asoc->a_rwnd); /* Send a window update SACK if the rwnd has increased by at least the * minimum of the association's PMTU and half of the receive buffer. * The algorithm used is similar to the one described in * Section 4.2.3.3 of RFC 1122. */ - if (update_peer && sctp_peer_needs_update(asoc)) { + if (sctp_peer_needs_update(asoc)) { asoc->a_rwnd = asoc->rwnd; pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u " @@ -1445,6 +1498,45 @@ void sctp_assoc_rwnd_update(struct sctp_association *asoc, bool update_peer) } } +/* Decrease asoc's rwnd by len. */ +void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len) +{ + int rx_count; + int over = 0; + + if (unlikely(!asoc->rwnd || asoc->rwnd_over)) + pr_debug("%s: association:%p has asoc->rwnd:%u, " + "asoc->rwnd_over:%u!\n", __func__, asoc, + asoc->rwnd, asoc->rwnd_over); + + if (asoc->ep->rcvbuf_policy) + rx_count = atomic_read(&asoc->rmem_alloc); + else + rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); + + /* If we've reached or overflowed our receive buffer, announce + * a 0 rwnd if rwnd would still be positive. Store the + * the potential pressure overflow so that the window can be restored + * back to original value. + */ + if (rx_count >= asoc->base.sk->sk_rcvbuf) + over = 1; + + if (asoc->rwnd >= len) { + asoc->rwnd -= len; + if (over) { + asoc->rwnd_press += asoc->rwnd; + asoc->rwnd = 0; + } + } else { + asoc->rwnd_over = len - asoc->rwnd; + asoc->rwnd = 0; + } + + pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n", + __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, + asoc->rwnd_press); +} /* Build the bind address list for the association based on info from the * local endpoint and the remote peer. @@ -1499,7 +1591,7 @@ int sctp_assoc_lookup_laddr(struct sctp_association *asoc, /* Set an association id for a given association */ int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp) { - bool preload = gfp & __GFP_WAIT; + bool preload = !!(gfp & __GFP_WAIT); int ret; /* If the id is already assigned, keep it. */ |
