On Sat, May 1, 2021 at 12:57 PM Leppanen, Jere (Nokia - FI/Espoo)
[off-list ref] wrote:

On Fri, 30 Apr 2021, Xin Long wrote:

quoted

The same thing should be done for sctp_sf_do_dupcook_b().
Meanwhile, SCTP_CMD_UPDATE_ASSOC cmd can be removed.

v1->v2:
 - Fix the return value in sctp_sf_do_assoc_update().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
include/net/sctp/command.h |  1 -
net/sctp/sm_sideeffect.c   | 26 -------------------------
net/sctp/sm_statefuns.c    | 47 +++++++++++++++++++++++++++++-----------------
3 files changed, 30 insertions(+), 44 deletions(-)

diff --git a/include/net/sctp/command.h b/include/net/sctp/command.h
index e8df72e..5e84888 100644
--- a/include/net/sctp/command.h
+++ b/include/net/sctp/command.h

@@ -68,7 +68,6 @@ enum sctp_verb {
      SCTP_CMD_ASSOC_FAILED,   /* Handle association failure. */
      SCTP_CMD_DISCARD_PACKET, /* Discard the whole packet. */
      SCTP_CMD_GEN_SHUTDOWN,   /* Generate a SHUTDOWN chunk. */
-     SCTP_CMD_UPDATE_ASSOC,   /* Update association information. */
      SCTP_CMD_PURGE_OUTQUEUE, /* Purge all data waiting to be sent. */
      SCTP_CMD_SETUP_T2,       /* Hi-level, setup T2-shutdown parms.  */
      SCTP_CMD_RTO_PENDING,    /* Set transport's rto_pending. */

diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index 0948f14..ce15d59 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c

@@ -826,28 +826,6 @@ static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
      asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;

}

-static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
-                               struct sctp_association *asoc,
-                               struct sctp_association *new)
-{
-     struct net *net = asoc->base.net;
-     struct sctp_chunk *abort;
-
-     if (!sctp_assoc_update(asoc, new))
-             return;
-
-     abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
-     if (abort) {
-             sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
-             sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
-     }
-     sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
-     sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
-                     SCTP_PERR(SCTP_ERROR_RSRC_LOW));
-     SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
-     SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
-}
-
/* Helper function to change the state of an association. */
static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
                             struct sctp_association *asoc,

@@ -1301,10 +1279,6 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type,
                      sctp_endpoint_add_asoc(ep, asoc);
                      break;

-             case SCTP_CMD_UPDATE_ASSOC:
-                    sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
-                    break;
-
              case SCTP_CMD_PURGE_OUTQUEUE:
                     sctp_outq_teardown(&asoc->outqueue);
                     break;

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index e8ccc4e..a428449 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c

@@ -1773,6 +1773,30 @@ enum sctp_disposition sctp_sf_do_5_2_3_initack(
              return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);

}

+static int sctp_sf_do_assoc_update(struct sctp_association *asoc,
+                                struct sctp_association *new,
+                                struct sctp_cmd_seq *cmds)
+{
+     struct net *net = asoc->base.net;
+     struct sctp_chunk *abort;
+
+     if (!sctp_assoc_update(asoc, new))
+             return 0;
+
+     abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
+     if (abort) {
+             sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
+             sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+     }
+     sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
+     sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
+                     SCTP_PERR(SCTP_ERROR_RSRC_LOW));
+     SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+     SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+
+     return -ENOMEM;
+}
+
/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
 *
 * Section 5.2.4

@@ -1853,21 +1877,8 @@ static enum sctp_disposition sctp_sf_do_dupcook_a(
      sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());

      /* Update the content of current association. */
-     if (sctp_assoc_update((struct sctp_association *)asoc, new_asoc)) {
-             struct sctp_chunk *abort;
-
-             abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
-             if (abort) {
-                     sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
-                     sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
-             }
-             sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
-             sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
-                             SCTP_PERR(SCTP_ERROR_RSRC_LOW));
-             SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
-             SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+     if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
              goto nomem;
-     }

      repl = sctp_make_cookie_ack(asoc, chunk);
      if (!repl)

@@ -1940,14 +1951,16 @@ static enum sctp_disposition sctp_sf_do_dupcook_b(
      if (!sctp_auth_chunk_verify(net, chunk, new_asoc))
              return SCTP_DISPOSITION_DISCARD;

-     /* Update the content of current association.  */
-     sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
      sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
                      SCTP_STATE(SCTP_STATE_ESTABLISHED));
      SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
      sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());

-     repl = sctp_make_cookie_ack(new_asoc, chunk);
+     /* Update the content of current association.  */
+     if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
+             goto nomem;

Wouldn't it be better to do the update before SCTP_CMD_NEW_STATE?
Or do we have some reason to move to SCTP_STATE_ESTABLISHED even
if the update fails?

Yes, as sctp_sf_do_assoc_update() adds SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB),
and before that we have to keep SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB) added
in there, which is normally right after NEW_STATE cmd with ESTABLISHED.

quoted

+
+     repl = sctp_make_cookie_ack(asoc, chunk);
      if (!repl)
              goto nomem;

--
2.1.0