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[SCTP]: Set assoc_id correctly during INIT collision.

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During the INIT/COOKIE-ACK collision cases, it's possible to get
into a situation where the association id is not yet set at the time
of the user event generation.  As a result, user events have an
association id set to 0 which will confuse applications.

This happens if we hit case B of duplicate cookie processing.
In the particular example found and provided by Oscar Isaula
<Oscar.Isaula@motorola.com>, flow looks like this:
A				B
---- INIT------->  (lost)
	    <---------INIT------
---- INIT-ACK--->
	    <------ Cookie ECHO

When the Cookie Echo is received, we end up trying to update the
association that was created on A as a result of the (lost) INIT,
but that association doesn't have the ID set yet.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vlad Yasevich
2007-05-04 13:55:27 -07:00
committed by David S. Miller
parent 827bf12236
commit 07d9396771
6 changed files with 80 additions and 31 deletions
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29
net/sctp/sm_statefuns.c
View File

@@ -1656,7 +1656,6 @@ static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
struct sctp_association *new_asoc)
{
sctp_init_chunk_t *peer_init;
struct sctp_ulpevent *ev;
struct sctp_chunk *repl;
/* new_asoc is a brand-new association, so these are not yet
@@ -1687,34 +1686,28 @@ static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
* D) IMPLEMENTATION NOTE: An implementation may choose to
* send the Communication Up notification to the SCTP user
* upon reception of a valid COOKIE ECHO chunk.
*
* Sadly, this needs to be implemented as a side-effect, because
* we are not guaranteed to have set the association id of the real
* association and so these notifications need to be delayed until
* the association id is allocated.
*/
ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
new_asoc->c.sinit_num_ostreams,
new_asoc->c.sinit_max_instreams,
NULL, GFP_ATOMIC);
if (!ev)
goto nomem_ev;
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaptation Layer Indication parameter , SCTP
* delivers this notification to inform the application that of the
* peers requested adaptation layer.
*
* This also needs to be done as a side effect for the same reason as
* above.
*/
if (asoc->peer.adaptation_ind) {
ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
if (!ev)
goto nomem_ev;
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
SCTP_ULPEVENT(ev));
}
if (asoc->peer.adaptation_ind)
sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
return SCTP_DISPOSITION_CONSUME;
nomem_ev:
sctp_chunk_free(repl);
nomem:
return SCTP_DISPOSITION_NOMEM;
}