If Host-A sends an ASCONF request for adding IP-A address, Host-Z may sent ASCONF-ACK which contains Error Cause: Request Refused(error = 0x00A4), for the local security policy or other problems. See below chart: Host-A Host-Z -------ASCONF(ADDIP[IP-A])----------> <------ASCONF-ACK(error=0x00A4)------ Host-Z would thought the operation of adding IP-A at Host-A is fail, and the IP-A address is not part of this association. So, If Host-Z sends HEARBEAT to check the IP-A path, Host-A should treat this chunk as OOTB. However, because there is no implementation of local security policy settings in sctp protocol, ASCONF-ACK chunk which contains Request Refused error never be sent, and will be ignored by the receiver.(when received ASCONF-ACK, no more further treatment.) So, If Host-Z sends HEARBEAT to check the IP-A path, Host-A doesn't treat this chunk as OOTB, and sends HEARTBEAT-ACK from primary address. Although Freebsd and Linux still does not send ASCONF-ACK (error = 0x00A4), but we can not guarantee that other systems will not too. Therefore, It's necessary to do something when receiving ASCONF-ACK(error = 0x00A4). The current handle is to send ABORT terminates the association, but this will lead to termination of other paths in the association. Is there better way to fix it? Signed-off-by: Shan Wei <shanwei@xxxxxxxxxxxxxx> --- net/sctp/sm_make_chunk.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 246f929..147cca4 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -3344,6 +3344,10 @@ int sctp_process_asconf_ack(struct sctp_association *asoc, break; case SCTP_ERROR_REQ_REFUSED: + if (asconf_param->param_hdr.type == SCTP_PARAM_ADD_IP) + retval = 1; + break; + case SCTP_ERROR_DEL_LAST_IP: case SCTP_ERROR_DEL_SRC_IP: default: -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
