From 81054476453640159149cb6704e834893e16736b Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 17 Feb 2017 12:45:39 +0800 Subject: [PATCH] sctp: implement receiver-side procedures for the Outgoing SSN Reset Request Parameter This patch is to implement Receiver-Side Procedures for the Outgoing SSN Reset Request Parameter described in rfc6525 section 5.2.2. Note that some checks must be after request_seq check, as even those checks fail, strreset_inseq still has to be increase by 1. Signed-off-by: Xin Long Signed-off-by: David S. Miller --- include/net/sctp/sm.h | 6 +++ net/sctp/stream.c | 113 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 119 insertions(+) diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h index 8a85dd7fc1ec..c0f9bea4fa92 100644 --- a/include/net/sctp/sm.h +++ b/include/net/sctp/sm.h @@ -280,6 +280,12 @@ struct sctp_chunk *sctp_make_strreset_tsnresp( void sctp_chunk_assign_tsn(struct sctp_chunk *); void sctp_chunk_assign_ssn(struct sctp_chunk *); +/* Prototypes for stream-processing functions. */ +struct sctp_chunk *sctp_process_strreset_outreq( + struct sctp_association *asoc, + union sctp_params param, + struct sctp_ulpevent **evp); + /* Prototypes for statetable processing. */ int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, diff --git a/net/sctp/stream.c b/net/sctp/stream.c index eb02490245ba..531fcc4cd112 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -294,3 +294,116 @@ int sctp_send_add_streams(struct sctp_association *asoc, out: return retval; } + +static sctp_paramhdr_t *sctp_chunk_lookup_strreset_param( + struct sctp_association *asoc, __u32 resp_seq) +{ + struct sctp_chunk *chunk = asoc->strreset_chunk; + struct sctp_reconf_chunk *hdr; + union sctp_params param; + + if (ntohl(resp_seq) != asoc->strreset_outseq || !chunk) + return NULL; + + hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; + sctp_walk_params(param, hdr, params) { + /* sctp_strreset_tsnreq is actually the basic structure + * of all stream reconf params, so it's safe to use it + * to access request_seq. + */ + struct sctp_strreset_tsnreq *req = param.v; + + if (req->request_seq == resp_seq) + return param.v; + } + + return NULL; +} + +struct sctp_chunk *sctp_process_strreset_outreq( + struct sctp_association *asoc, + union sctp_params param, + struct sctp_ulpevent **evp) +{ + struct sctp_strreset_outreq *outreq = param.v; + struct sctp_stream *stream = asoc->stream; + __u16 i, nums, flags = 0, *str_p = NULL; + __u32 result = SCTP_STRRESET_DENIED; + __u32 request_seq; + + request_seq = ntohl(outreq->request_seq); + + if (ntohl(outreq->send_reset_at_tsn) > + sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) { + result = SCTP_STRRESET_IN_PROGRESS; + goto out; + } + + if (request_seq > asoc->strreset_inseq) { + result = SCTP_STRRESET_ERR_BAD_SEQNO; + goto out; + } else if (request_seq == asoc->strreset_inseq) { + asoc->strreset_inseq++; + } + + /* Check strreset_enable after inseq inc, as sender cannot tell + * the peer doesn't enable strreset after receiving response with + * result denied, as well as to keep consistent with bsd. + */ + if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) + goto out; + + if (asoc->strreset_chunk) { + sctp_paramhdr_t *param_hdr; + struct sctp_transport *t; + + param_hdr = sctp_chunk_lookup_strreset_param( + asoc, outreq->response_seq); + if (!param_hdr || param_hdr->type != + SCTP_PARAM_RESET_IN_REQUEST) { + /* same process with outstanding isn't 0 */ + result = SCTP_STRRESET_ERR_IN_PROGRESS; + goto out; + } + + asoc->strreset_outstanding--; + asoc->strreset_outseq++; + + if (!asoc->strreset_outstanding) { + t = asoc->strreset_chunk->transport; + if (del_timer(&t->reconf_timer)) + sctp_transport_put(t); + + sctp_chunk_put(asoc->strreset_chunk); + asoc->strreset_chunk = NULL; + } + + flags = SCTP_STREAM_RESET_INCOMING_SSN; + } + + nums = (ntohs(param.p->length) - sizeof(*outreq)) / 2; + if (nums) { + str_p = outreq->list_of_streams; + for (i = 0; i < nums; i++) { + if (ntohs(str_p[i]) >= stream->incnt) { + result = SCTP_STRRESET_ERR_WRONG_SSN; + goto out; + } + } + + for (i = 0; i < nums; i++) + stream->in[ntohs(str_p[i])].ssn = 0; + } else { + for (i = 0; i < stream->incnt; i++) + stream->in[i].ssn = 0; + } + + result = SCTP_STRRESET_PERFORMED; + + *evp = sctp_ulpevent_make_stream_reset_event(asoc, + flags | SCTP_STREAM_RESET_OUTGOING_SSN, nums, str_p, + GFP_ATOMIC); + +out: + return sctp_make_strreset_resp(asoc, result, request_seq); +} -- 2.30.2