diff options
Diffstat (limited to 'net/sctp/sm_statefuns.c')
| -rw-r--r-- | net/sctp/sm_statefuns.c | 64 |
1 files changed, 42 insertions, 22 deletions
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; |