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authorAllan Stephens <allan.stephens@windriver.com>2008-06-05 04:29:39 +0400
committerDavid S. Miller <davem@davemloft.net>2008-06-05 04:29:39 +0400
commita686e6859e976712e28f6af927cd52a6a3bb372a (patch)
tree2d1f1092416394e8dba4ffc38eec03c9aedd4ebf /net/tipc
parente0d4e3d0d72cfae7b7eac14e39e12dfc6b406313 (diff)
downloadlinux-a686e6859e976712e28f6af927cd52a6a3bb372a.tar.xz
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/tipc')
-rw-r--r--net/tipc/link.c17
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);