This patch is to add a function to process the incoming reconf chunk,
in which it verifies the chunk, and traverses the param and process
it with the right function one by one.

sctp_sf_do_reconf would be the process function of reconf chunk event.

Note that to support multi-params in response chunk, it also adds a
function sctp_merge_reconf_chunk to merge two reconf chunk into one.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 include/net/sctp/sm.h    |  8 +++++
 net/sctp/sm_make_chunk.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/sctp/sm_statefuns.c  | 68 +++++++++++++++++++++++++++++++++++
 3 files changed, 170 insertions(+)

diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 7c2f956..17984eb 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -135,6 +135,7 @@ sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
 sctp_state_fn_t sctp_sf_cookie_echoed_err;
 sctp_state_fn_t sctp_sf_do_asconf;
 sctp_state_fn_t sctp_sf_do_asconf_ack;
+sctp_state_fn_t sctp_sf_do_reconf;
 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
@@ -277,6 +278,13 @@ struct sctp_chunk *sctp_make_strreset_tsnresp(
 struct sctp_chunk *sctp_make_strreset_addstrm(
                                const struct sctp_association *asoc,
                                __u16 out, __u16 in);
+struct sctp_chunk *sctp_merge_reconf_chunk(
+                               struct sctp_association *asoc,
+                               struct sctp_chunk *last,
+                               struct sctp_chunk *reply);
+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 *);
 
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index f1efba6..74c3fee 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -3819,3 +3819,97 @@ struct sctp_chunk *sctp_make_strreset_addstrm(
 
        return retval;
 }
+
+struct sctp_chunk *sctp_merge_reconf_chunk(
+                               struct sctp_association *asoc,
+                               struct sctp_chunk *last,
+                               struct sctp_chunk *reply)
+{
+       struct sctp_chunk *retval = NULL;
+       __u16 lsize, rsize;
+
+       if (!reply)
+               return last;
+
+       rsize = ntohs(reply->param_hdr.p->length);
+       lsize = ntohs(last->param_hdr.p->length);
+
+       retval = sctp_make_reconf(asoc, lsize + rsize);
+       if (!retval)
+               goto out;
+
+       sctp_addto_chunk(retval, lsize, last->param_hdr.v);
+       sctp_addto_chunk(retval, rsize, reply->param_hdr.v);
+
+out:
+       if (asoc->strreset_chunk) {
+               sctp_chunk_put(asoc->strreset_chunk);
+               asoc->strreset_chunk = retval;
+               if (asoc->strreset_chunk)
+                       sctp_chunk_hold(asoc->strreset_chunk);
+       }
+
+       sctp_chunk_free(reply);
+       sctp_chunk_free(last);
+
+       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;
+}
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index c06b134..4b05bd5 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3834,6 +3834,74 @@ sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
        return SCTP_DISPOSITION_DISCARD;
 }
 
+/* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk.  */
+sctp_disposition_t sctp_sf_do_reconf(struct net *net,
+                                    const struct sctp_endpoint *ep,
+                                    const struct sctp_association *asoc,
+                                    const sctp_subtype_t type, void *arg,
+                                    sctp_cmd_seq_t *commands)
+{
+       struct sctp_paramhdr *err_param = NULL;
+       struct sctp_chunk *reply = NULL;
+       struct sctp_chunk *last = NULL;
+       struct sctp_chunk *chunk = arg;
+       struct sctp_reconf_chunk *hdr;
+       union sctp_params param;
+
+       if (!sctp_vtag_verify(chunk, asoc)) {
+               sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+                               SCTP_NULL());
+               return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+       }
+
+       /* Make sure that the RECONF chunk has a valid length.  */
+       if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
+               return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+                                                 commands);
+
+       if (!sctp_verify_reconf(asoc, chunk, &err_param))
+               return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+                                                 (void *)err_param, commands);
+
+       hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
+       sctp_walk_params(param, hdr, params) {
+               struct sctp_ulpevent *ev = NULL;
+
+               if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
+                       reply = sctp_process_strreset_outreq(
+                               (struct sctp_association *)asoc, param, &ev);
+               else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
+                       reply = sctp_process_strreset_inreq(
+                               (struct sctp_association *)asoc, param, &ev);
+               else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
+                       reply = sctp_process_strreset_tsnreq(
+                               (struct sctp_association *)asoc, param, &ev);
+               else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
+                       reply = sctp_process_strreset_addstrm_out(
+                               (struct sctp_association *)asoc, param, &ev);
+               else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
+                       reply = sctp_process_strreset_addstrm_in(
+                               (struct sctp_association *)asoc, param, &ev);
+               else if (param.p->type == SCTP_PARAM_RESET_RESPONSE)
+                       reply = sctp_process_strreset_resp(
+                               (struct sctp_association *)asoc, param, &ev);
+
+               if (ev)
+                       sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+                                       SCTP_ULPEVENT(ev));
+
+               if (last)
+                       reply = sctp_merge_reconf_chunk(
+                               (struct sctp_association *)asoc, last, reply);
+               last = reply;
+       }
+
+       if (reply)
+               sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+       return SCTP_DISPOSITION_CONSUME;
+}
+
 /*
  * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
  *
-- 
2.1.0

Reply via email to