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-rw-r--r--net/tipc/discover.c103
1 files changed, 59 insertions, 44 deletions
diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index 09ce231..2345268 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -119,17 +119,21 @@ static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
{
+ struct tipc_node *n_ptr;
struct link *link;
- struct tipc_media_addr media_addr;
+ struct tipc_media_addr media_addr, *addr;
+ struct sk_buff *rbuf;
struct tipc_msg *msg = buf_msg(buf);
u32 dest = msg_dest_domain(msg);
u32 orig = msg_prevnode(msg);
u32 net_id = msg_bc_netid(msg);
u32 type = msg_type(msg);
+ int link_fully_up;
msg_get_media_addr(msg, &media_addr);
buf_discard(buf);
+ /* Validate discovery message from requesting node */
if (net_id != tipc_net_id)
return;
if (!tipc_addr_domain_valid(dest))
@@ -143,56 +147,67 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
}
if (!tipc_in_scope(dest, tipc_own_addr))
return;
- if (in_own_cluster(orig)) {
- /* Always accept link here */
- struct sk_buff *rbuf;
- struct tipc_media_addr *addr;
- struct tipc_node *n_ptr = tipc_node_find(orig);
- int link_fully_up;
-
- if (n_ptr == NULL) {
- n_ptr = tipc_node_create(orig);
- if (!n_ptr)
- return;
- }
- spin_lock_bh(&n_ptr->lock);
-
- /* Don't talk to neighbor during cleanup after last session */
+ if (!in_own_cluster(orig))
+ return;
- if (n_ptr->cleanup_required) {
- spin_unlock_bh(&n_ptr->lock);
+ /* Locate structure corresponding to requesting node */
+ n_ptr = tipc_node_find(orig);
+ if (!n_ptr) {
+ n_ptr = tipc_node_create(orig);
+ if (!n_ptr)
return;
- }
+ }
+ tipc_node_lock(n_ptr);
+
+ /* Don't talk to neighbor during cleanup after last session */
+ if (n_ptr->cleanup_required) {
+ tipc_node_unlock(n_ptr);
+ return;
+ }
- link = n_ptr->links[b_ptr->identity];
+ link = n_ptr->links[b_ptr->identity];
+
+ /* Create a link endpoint for this bearer, if necessary */
+ if (!link) {
+ link = tipc_link_create(b_ptr, orig, &media_addr);
if (!link) {
- link = tipc_link_create(b_ptr, orig, &media_addr);
- if (!link) {
- spin_unlock_bh(&n_ptr->lock);
- return;
- }
- }
- addr = &link->media_addr;
- if (memcmp(addr, &media_addr, sizeof(*addr))) {
- if (tipc_link_is_up(link) || (!link->started)) {
- disc_dupl_alert(b_ptr, orig, &media_addr);
- spin_unlock_bh(&n_ptr->lock);
- return;
- }
- warn("Resetting link <%s>, peer interface address changed\n",
- link->name);
- memcpy(addr, &media_addr, sizeof(*addr));
- tipc_link_reset(link);
+ tipc_node_unlock(n_ptr);
+ return;
}
- link_fully_up = link_working_working(link);
- spin_unlock_bh(&n_ptr->lock);
- if ((type == DSC_RESP_MSG) || link_fully_up)
+ }
+
+ /*
+ * Ensure requesting node's media address is correct
+ *
+ * If media address doesn't match and the link is working, reject the
+ * request (must be from a duplicate node).
+ *
+ * If media address doesn't match and the link is not working, accept
+ * the new media address and reset the link to ensure it starts up
+ * cleanly.
+ */
+ addr = &link->media_addr;
+ if (memcmp(addr, &media_addr, sizeof(*addr))) {
+ if (tipc_link_is_up(link) || (!link->started)) {
+ disc_dupl_alert(b_ptr, orig, &media_addr);
+ tipc_node_unlock(n_ptr);
return;
- rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
- if (rbuf != NULL) {
- b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
- buf_discard(rbuf);
}
+ warn("Resetting link <%s>, peer interface address changed\n",
+ link->name);
+ memcpy(addr, &media_addr, sizeof(*addr));
+ tipc_link_reset(link);
+ }
+
+ /* Accept discovery message & send response, if necessary */
+ link_fully_up = link_working_working(link);
+ tipc_node_unlock(n_ptr);
+ if ((type == DSC_RESP_MSG) || link_fully_up)
+ return;
+ rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
+ if (rbuf != NULL) {
+ b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
+ buf_discard(rbuf);
}
}
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