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| author | Allan Stephens <allan.stephens@windriver.com> | 2008-06-04 17:29:39 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-06-04 17:29:39 -0700 |
| commit | a686e6859e976712e28f6af927cd52a6a3bb372a (patch) | |
| tree | 2d1f1092416394e8dba4ffc38eec03c9aedd4ebf /net | |
| parent | e0d4e3d0d72cfae7b7eac14e39e12dfc6b406313 (diff) | |
| download | linux-a686e6859e976712e28f6af927cd52a6a3bb372a.tar.gz linux-a686e6859e976712e28f6af927cd52a6a3bb372a.tar.bz2 linux-a686e6859e976712e28f6af927cd52a6a3bb372a.zip | |
tipc: Fix minor bugs in link session number handling
This patch introduces a new, out-of-range value to indicate that
a link endpoint does not have an existing session established
with its peer, eliminating the risk that the previously used
"invalid session number" value (i.e. zero) might eventually be
assigned as a valid session number and cause incorrect link
behavior.
The patch also introduces explicit bit masking when assigning a
new link session number to ensure it does not exceed 16 bits.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/tipc/link.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c index bd206ebe4eea..b8c1231e3147 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -51,6 +51,12 @@ /* + * Out-of-range value for link session numbers + */ + +#define INVALID_SESSION 0x10000 + +/* * Limit for deferred reception queue: */ @@ -464,7 +470,7 @@ struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer, msg = l_ptr->pmsg; msg_init(msg, LINK_PROTOCOL, RESET_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr); msg_set_size(msg, sizeof(l_ptr->proto_msg)); - msg_set_session(msg, tipc_random); + msg_set_session(msg, (tipc_random & 0xffff)); msg_set_bearer_id(msg, b_ptr->identity); strcpy((char *)msg_data(msg), if_name); @@ -705,10 +711,10 @@ void tipc_link_reset(struct link *l_ptr) u32 checkpoint = l_ptr->next_in_no; int was_active_link = tipc_link_is_active(l_ptr); - msg_set_session(l_ptr->pmsg, msg_session(l_ptr->pmsg) + 1); + msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff)); - /* Link is down, accept any session: */ - l_ptr->peer_session = 0; + /* Link is down, accept any session */ + l_ptr->peer_session = INVALID_SESSION; /* Prepare for max packet size negotiation */ link_init_max_pkt(l_ptr); @@ -2275,7 +2281,8 @@ static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf) switch (msg_type(msg)) { case RESET_MSG: - if (!link_working_unknown(l_ptr) && l_ptr->peer_session) { + if (!link_working_unknown(l_ptr) && + (l_ptr->peer_session != INVALID_SESSION)) { if (msg_session(msg) == l_ptr->peer_session) { dbg("Duplicate RESET: %u<->%u\n", msg_session(msg), l_ptr->peer_session); |