diff options
| -rw-r--r-- | net/tipc/discover.c | 103 |
1 files changed, 59 insertions, 44 deletions
diff --git a/net/tipc/discover.c b/net/tipc/discover.c index 09ce2318b89e..2345268ca64b 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); } } |