sctp: add a function to verify the sctp reconf chunk

This patch is to add a function sctp_verify_reconf to do some length
check and multi-params check for sctp stream reconf according to rfc6525
section 3.1.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2017-02-17 12:45:41 +08:00 committed by David S. Miller
parent 16e1a91965
commit ea62504373
2 changed files with 62 additions and 0 deletions

View File

@ -277,6 +277,9 @@ struct sctp_chunk *sctp_make_strreset_tsnresp(
struct sctp_association *asoc,
__u32 result, __u32 sn,
__u32 sender_tsn, __u32 receiver_tsn);
bool sctp_verify_reconf(const struct sctp_association *asoc,
struct sctp_chunk *chunk,
struct sctp_paramhdr **errp);
void sctp_chunk_assign_tsn(struct sctp_chunk *);
void sctp_chunk_assign_ssn(struct sctp_chunk *);

View File

@ -3801,3 +3801,62 @@ struct sctp_chunk *sctp_make_strreset_tsnresp(
return retval;
}
bool sctp_verify_reconf(const struct sctp_association *asoc,
struct sctp_chunk *chunk,
struct sctp_paramhdr **errp)
{
struct sctp_reconf_chunk *hdr;
union sctp_params param;
__u16 last = 0, cnt = 0;
hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
sctp_walk_params(param, hdr, params) {
__u16 length = ntohs(param.p->length);
*errp = param.p;
if (cnt++ > 2)
return false;
switch (param.p->type) {
case SCTP_PARAM_RESET_OUT_REQUEST:
if (length < sizeof(struct sctp_strreset_outreq) ||
(last && last != SCTP_PARAM_RESET_RESPONSE &&
last != SCTP_PARAM_RESET_IN_REQUEST))
return false;
break;
case SCTP_PARAM_RESET_IN_REQUEST:
if (length < sizeof(struct sctp_strreset_inreq) ||
(last && last != SCTP_PARAM_RESET_OUT_REQUEST))
return false;
break;
case SCTP_PARAM_RESET_RESPONSE:
if ((length != sizeof(struct sctp_strreset_resp) &&
length != sizeof(struct sctp_strreset_resptsn)) ||
(last && last != SCTP_PARAM_RESET_RESPONSE &&
last != SCTP_PARAM_RESET_OUT_REQUEST))
return false;
break;
case SCTP_PARAM_RESET_TSN_REQUEST:
if (length !=
sizeof(struct sctp_strreset_tsnreq) || last)
return false;
break;
case SCTP_PARAM_RESET_ADD_IN_STREAMS:
if (length != sizeof(struct sctp_strreset_addstrm) ||
(last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
return false;
break;
case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
if (length != sizeof(struct sctp_strreset_addstrm) ||
(last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
return false;
break;
default:
return false;
}
last = param.p->type;
}
return true;
}