diff options
| -rw-r--r-- | include/net/sctp/structs.h | 24 | ||||
| -rw-r--r-- | net/sctp/associola.c | 58 | ||||
| -rw-r--r-- | net/sctp/outqueue.c | 29 | ||||
| -rw-r--r-- | net/sctp/sm_make_chunk.c | 12 | ||||
| -rw-r--r-- | net/sctp/sm_statefuns.c | 64 |
5 files changed, 143 insertions, 44 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 8a0808eab81..fa87873fee7 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -744,6 +744,7 @@ struct sctp_chunk { __u8 tsn_missing_report; /* Data chunk missing counter. */ __u8 data_accepted; /* At least 1 chunk in this packet accepted */ __u8 auth; /* IN: was auth'ed | OUT: needs auth */ + __u8 has_asconf; /* IN: have seen an asconf before */ }; void sctp_chunk_hold(struct sctp_chunk *); @@ -1785,20 +1786,16 @@ struct sctp_association { */ struct sctp_chunk *addip_last_asconf; - /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. + /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. * - * IMPLEMENTATION NOTE: As an optimization a receiver may wish - * to save the last ASCONF-ACK for some predetermined period - * of time and instead of re-processing the ASCONF (with the - * same serial number) it may just re-transmit the - * ASCONF-ACK. It may wish to use the arrival of a new serial - * number to discard the previously saved ASCONF-ACK or any - * other means it may choose to expire the saved ASCONF-ACK. + * This is needed to implement itmes E1 - E4 of the updated + * spec. Here is the justification: * - * [This is our saved ASCONF-ACK. We invalidate it when a new - * ASCONF serial number arrives.] + * Since the peer may bundle multiple ASCONF chunks toward us, + * we now need the ability to cache multiple ACKs. The section + * describes in detail how they are cached and cleaned up. */ - struct sctp_chunk *addip_last_asconf_ack; + struct list_head asconf_ack_list; /* These ASCONF chunks are waiting to be sent. * @@ -1947,6 +1944,11 @@ int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, struct sctp_cookie*, gfp_t gfp); int sctp_assoc_set_id(struct sctp_association *, gfp_t); +void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); +struct sctp_chunk *sctp_assoc_lookup_asconf_ack( + const struct sctp_association *asoc, + __be32 serial); + int sctp_cmp_addr_exact(const union sctp_addr *ss1, const union sctp_addr *ss2); diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 61bebb9b96e..a016e78061f 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -61,6 +61,7 @@ /* Forward declarations for internal functions. */ static void sctp_assoc_bh_rcv(struct work_struct *work); +static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); /* 1st Level Abstractions. */ @@ -242,6 +243,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a asoc->addip_serial = asoc->c.initial_tsn; INIT_LIST_HEAD(&asoc->addip_chunk_list); + INIT_LIST_HEAD(&asoc->asconf_ack_list); /* Make an empty list of remote transport addresses. */ INIT_LIST_HEAD(&asoc->peer.transport_addr_list); @@ -431,8 +433,7 @@ void sctp_association_free(struct sctp_association *asoc) asoc->peer.transport_count = 0; /* Free any cached ASCONF_ACK chunk. */ - if (asoc->addip_last_asconf_ack) - sctp_chunk_free(asoc->addip_last_asconf_ack); + sctp_assoc_free_asconf_acks(asoc); /* Free any cached ASCONF chunk. */ if (asoc->addip_last_asconf) @@ -1485,3 +1486,56 @@ retry: asoc->assoc_id = (sctp_assoc_t) assoc_id; return error; } + +/* Free asconf_ack cache */ +static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc) +{ + struct sctp_chunk *ack; + struct sctp_chunk *tmp; + + list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, + transmitted_list) { + list_del_init(&ack->transmitted_list); + sctp_chunk_free(ack); + } +} + +/* Clean up the ASCONF_ACK queue */ +void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc) +{ + struct sctp_chunk *ack; + struct sctp_chunk *tmp; + + /* We can remove all the entries from the queue upto + * the "Peer-Sequence-Number". + */ + list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, + transmitted_list) { + if (ack->subh.addip_hdr->serial == + htonl(asoc->peer.addip_serial)) + break; + + list_del_init(&ack->transmitted_list); + sctp_chunk_free(ack); + } +} + +/* Find the ASCONF_ACK whose serial number matches ASCONF */ +struct sctp_chunk *sctp_assoc_lookup_asconf_ack( + const struct sctp_association *asoc, + __be32 serial) +{ + struct sctp_chunk *ack = NULL; + + /* Walk through the list of cached ASCONF-ACKs and find the + * ack chunk whose serial number matches that of the request. + */ + list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) { + if (ack->subh.addip_hdr->serial == serial) { + sctp_chunk_hold(ack); + break; + } + } + + return ack; +} diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index fa76f235169..a42af865c2e 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -716,7 +716,29 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) new_transport = chunk->transport; if (!new_transport) { - new_transport = asoc->peer.active_path; + /* + * If we have a prior transport pointer, see if + * the destination address of the chunk + * matches the destination address of the + * current transport. If not a match, then + * try to look up the transport with a given + * destination address. We do this because + * after processing ASCONFs, we may have new + * transports created. + */ + if (transport && + sctp_cmp_addr_exact(&chunk->dest, + &transport->ipaddr)) + new_transport = transport; + else + new_transport = sctp_assoc_lookup_paddr(asoc, + &chunk->dest); + + /* if we still don't have a new transport, then + * use the current active path. + */ + if (!new_transport) + new_transport = asoc->peer.active_path; } else if ((new_transport->state == SCTP_INACTIVE) || (new_transport->state == SCTP_UNCONFIRMED)) { /* If the chunk is Heartbeat or Heartbeat Ack, @@ -729,9 +751,12 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) * address of the IP datagram containing the * HEARTBEAT chunk to which this ack is responding. * ... + * + * ASCONF_ACKs also must be sent to the source. */ if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && - chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK) + chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK && + chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK) new_transport = asoc->peer.active_path; } diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 8138bbd9321..7fd6a6b6861 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1275,6 +1275,9 @@ nodata: /* Release the memory occupied by a chunk. */ static void sctp_chunk_destroy(struct sctp_chunk *chunk) { + BUG_ON(!list_empty(&chunk->list)); + list_del_init(&chunk->transmitted_list); + /* Free the chunk skb data and the SCTP_chunk stub itself. */ dev_kfree_skb(chunk->skb); @@ -1285,9 +1288,6 @@ static void sctp_chunk_destroy(struct sctp_chunk *chunk) /* Possibly, free the chunk. */ void sctp_chunk_free(struct sctp_chunk *chunk) { - BUG_ON(!list_empty(&chunk->list)); - list_del_init(&chunk->transmitted_list); - /* Release our reference on the message tracker. */ if (chunk->msg) sctp_datamsg_put(chunk->msg); @@ -2980,11 +2980,9 @@ done: * after freeing the reference to old asconf ack if any. */ if (asconf_ack) { - if (asoc->addip_last_asconf_ack) - sctp_chunk_free(asoc->addip_last_asconf_ack); - sctp_chunk_hold(asconf_ack); - asoc->addip_last_asconf_ack = asconf_ack; + list_add_tail(&asconf_ack->transmitted_list, + &asoc->asconf_ack_list); } return asconf_ack; diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index b6aaa7e97d8..a1be9d93f1a 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -3402,48 +3402,68 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep, /* Verify the ASCONF chunk before processing it. */ if (!sctp_verify_asconf(asoc, - (sctp_paramhdr_t *)((void *)addr_param + length), - (void *)chunk->chunk_end, - &err_param)) + (sctp_paramhdr_t *)((void *)addr_param + length), + (void *)chunk->chunk_end, + &err_param)) return sctp_sf_violation_paramlen(ep, asoc, type, - (void *)&err_param, commands); + (void *)&err_param, commands); - /* ADDIP 4.2 C1) Compare the value of the serial number to the value + /* ADDIP 5.2 E1) Compare the value of the serial number to the value * the endpoint stored in a new association variable * 'Peer-Serial-Number'. */ if (serial == asoc->peer.addip_serial + 1) { - /* ADDIP 4.2 C2) If the value found in the serial number is - * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST - * do V1-V5. + /* If this is the first instance of ASCONF in the packet, + * we can clean our old ASCONF-ACKs. + */ + if (!chunk->has_asconf) + sctp_assoc_clean_asconf_ack_cache(asoc); + + /* ADDIP 5.2 E4) When the Sequence Number matches the next one + * expected, process the ASCONF as described below and after + * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to + * the response packet and cache a copy of it (in the event it + * later needs to be retransmitted). + * + * Essentially, do V1-V5. */ asconf_ack = sctp_process_asconf((struct sctp_association *) asoc, chunk); if (!asconf_ack) return SCTP_DISPOSITION_NOMEM; - } else if (serial == asoc->peer.addip_serial) { - /* ADDIP 4.2 C3) If the value found in the serial number is - * equal to the value stored in the 'Peer-Serial-Number' - * IMPLEMENTATION NOTE: As an optimization a receiver may wish - * to save the last ASCONF-ACK for some predetermined period of - * time and instead of re-processing the ASCONF (with the same - * serial number) it may just re-transmit the ASCONF-ACK. + } else if (serial < asoc->peer.addip_serial + 1) { + /* ADDIP 5.2 E2) + * If the value found in the Sequence Number is less than the + * ('Peer- Sequence-Number' + 1), simply skip to the next + * ASCONF, and include in the outbound response packet + * any previously cached ASCONF-ACK response that was + * sent and saved that matches the Sequence Number of the + * ASCONF. Note: It is possible that no cached ASCONF-ACK + * Chunk exists. This will occur when an older ASCONF + * arrives out of order. In such a case, the receiver + * should skip the ASCONF Chunk and not include ASCONF-ACK + * Chunk for that chunk. */ - if (asoc->addip_last_asconf_ack) - asconf_ack = asoc->addip_last_asconf_ack; - else + asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial); + if (!asconf_ack) return SCTP_DISPOSITION_DISCARD; } else { - /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since + /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since * it must be either a stale packet or from an attacker. */ return SCTP_DISPOSITION_DISCARD; } - /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent - * back to the source address contained in the IP header of the ASCONF - * being responded to. + /* ADDIP 5.2 E6) The destination address of the SCTP packet + * containing the ASCONF-ACK Chunks MUST be the source address of + * the SCTP packet that held the ASCONF Chunks. + * + * To do this properly, we'll set the destination address of the chunk + * and at the transmit time, will try look up the transport to use. + * Since ASCONFs may be bundled, the correct transport may not be + * created untill we process the entire packet, thus this workaround. */ + asconf_ack->dest = chunk->source; sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); return SCTP_DISPOSITION_CONSUME; |