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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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15
net/sctp/sm_make_chunk.c
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@ -1939,7 +1939,6 @@ int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
* association.
*/
if (!asoc->temp) {
int assoc_id;
int error;
asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
@ -1947,19 +1946,9 @@ int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
if (!asoc->ssnmap)
goto clean_up;
retry:
if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
error = sctp_assoc_set_id(asoc, gfp);
if (error)
goto clean_up;
spin_lock_bh(&sctp_assocs_id_lock);
error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, 1,
&assoc_id);
spin_unlock_bh(&sctp_assocs_id_lock);
if (error == -EAGAIN)
goto retry;
else if (error)
goto clean_up;
asoc->assoc_id = (sctp_assoc_t) assoc_id;
}
/* ADDIP Section 4.1 ASCONF Chunk Procedures