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author | Vlad Yasevich <vladislav.yasevich@hp.com> | 2009-11-23 15:54:01 -0500 |
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committer | Vlad Yasevich <vladislav.yasevich@hp.com> | 2009-11-23 15:54:01 -0500 |
commit | 4814326b59db0cfd18ac652626d955ad3f57fb0f (patch) | |
tree | 41975c6b2eea1812012802bdb2337c43fa240178 /net/sctp | |
parent | da85b7396f3b6cb3fea7d77091498bfa1051ef7c (diff) | |
download | kernel_samsung_smdk4412-4814326b59db0cfd18ac652626d955ad3f57fb0f.zip kernel_samsung_smdk4412-4814326b59db0cfd18ac652626d955ad3f57fb0f.tar.gz kernel_samsung_smdk4412-4814326b59db0cfd18ac652626d955ad3f57fb0f.tar.bz2 |
sctp: prevent too-fast association id reuse
We use the idr subsystem and always ask for an id
at or above 1. This results in a id reuse when one
association is terminated while another is created.
To prevent re-use, we keep track of the last id returned
and ask for that id + 1 as a base for each query. We let
the idr spin lock protect this base id as well.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Diffstat (limited to 'net/sctp')
-rw-r--r-- | net/sctp/associola.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 6e96f83..df5abbf 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -63,6 +63,12 @@ static void sctp_assoc_bh_rcv(struct work_struct *work); static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); +/* Keep track of the new idr low so that we don't re-use association id + * numbers too fast. It is protected by they idr spin lock is in the + * range of 1 - INT_MAX. + */ +static u32 idr_low = 1; + /* 1st Level Abstractions. */ @@ -1553,7 +1559,12 @@ retry: spin_lock_bh(&sctp_assocs_id_lock); error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, - 1, &assoc_id); + idr_low, &assoc_id); + if (!error) { + idr_low = assoc_id + 1; + if (idr_low == INT_MAX) + idr_low = 1; + } spin_unlock_bh(&sctp_assocs_id_lock); if (error == -EAGAIN) goto retry; |