From a728750e4f0c9500741406299f1817022d411d33 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 28 Feb 2011 10:03:05 -0500 Subject: tipc: Cosmetic changes to neighbor discovery logic Reworks the appearance of the routine that processes incoming LINK_CONFIG messages to keep the main logic flow at a consistent level of indentation, and to add comments outlining the various phases involved in processing each message. This rework is being done to allow upcoming enhancements to this routine to be integrated more cleanly. The diff isn't really readable, so know that it was a case of the old code being like: tipc_disc_recv_msg(..) { if (in_own_cluster(orig)) { ... lines and lines of stuff ... } } which is now replaced with the more sane: tipc_disc_recv_msg(..) { if (!in_own_cluster(orig)) return; ... lines and lines of stuff ... } Instances of spin locking within the reindented block were replaced with the identical tipc_node_[un]lock() abstractions. Note that all these changes are cosmetic in nature, and do not change the way LINK_CONFIG messages are processed. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/discover.c | 103 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 59 insertions(+), 44 deletions(-) (limited to 'net/tipc/discover.c') 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); } } -- cgit v1.2.2 From fa2bae2d5bede252445cc457737d00f9036c41c3 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 28 Feb 2011 10:56:23 -0500 Subject: tipc: Give Tx of discovery responses priority over link messages Delay releasing the node lock when processing a neighbor discovery message until after the optional discovery response message has been sent. This helps ensure that any link protocol messages sent by a link endpoint created as a result of a neighbor discovery request are received after the discovery response is received, thereby giving the receiving node a chance to create a peer link endpoint to consume those link protocol messages, if one does not already exist. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/discover.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'net/tipc/discover.c') diff --git a/net/tipc/discover.c b/net/tipc/discover.c index 2345268ca64b..580b50a79e43 100644 --- a/net/tipc/discover.c +++ b/net/tipc/discover.c @@ -201,14 +201,16 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) /* 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); + + if ((type == DSC_REQ_MSG) && !link_fully_up) { + rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr); + if (rbuf) { + b_ptr->media->send_msg(rbuf, b_ptr, &media_addr); + buf_discard(rbuf); + } } + + tipc_node_unlock(n_ptr); } /** -- cgit v1.2.2 From 37b9c08a88f9a82456bb11fa050cccb544e8dc60 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 28 Feb 2011 11:32:27 -0500 Subject: tipc: Optimizations to link creation code Enhances link creation code as follows: 1) Detects illegal attempts to add a requested link earlier in the link creation process. This prevents TIPC from wasting time initializing a link object it then throws away, and also eliminates the code needed to do the throwing away. 2) Passes in the node object associated with the requested link. This allows TIPC to eliminate a search to locate the node object, as well as code that attempted to create the node if it doesn't exist. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/discover.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/tipc/discover.c') diff --git a/net/tipc/discover.c b/net/tipc/discover.c index 580b50a79e43..caac5c93b7f7 100644 --- a/net/tipc/discover.c +++ b/net/tipc/discover.c @@ -169,7 +169,7 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) /* Create a link endpoint for this bearer, if necessary */ if (!link) { - link = tipc_link_create(b_ptr, orig, &media_addr); + link = tipc_link_create(n_ptr, b_ptr, &media_addr); if (!link) { tipc_node_unlock(n_ptr); return; -- cgit v1.2.2 From d901a42b271dbd94983b798955403dcf1afa60ac Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 28 Feb 2011 16:02:30 -0500 Subject: tipc: Eliminate unnecessary constant for neighbor discovery msg size Eliminates an unnecessary constant that defines the size of a LINK_CONFIG message, and uses one of the existing standard message size symbols in its place. (The defunct constant was located in the wrong place anyway, since it was grouped with other constants that define message users instead of message sizes.) Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/discover.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/tipc/discover.c') diff --git a/net/tipc/discover.c b/net/tipc/discover.c index caac5c93b7f7..2c14d6dbc3d7 100644 --- a/net/tipc/discover.c +++ b/net/tipc/discover.c @@ -75,12 +75,12 @@ static struct sk_buff *tipc_disc_init_msg(u32 type, u32 dest_domain, struct tipc_bearer *b_ptr) { - struct sk_buff *buf = tipc_buf_acquire(DSC_H_SIZE); + struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE); struct tipc_msg *msg; if (buf) { msg = buf_msg(buf); - tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain); + tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain); msg_set_non_seq(msg, 1); msg_set_dest_domain(msg, dest_domain); msg_set_bc_netid(msg, tipc_net_id); -- cgit v1.2.2 From f9107ebe7d18a04f07d2a990a912efa2a2ac1873 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 28 Feb 2011 11:04:08 -0500 Subject: tipc: Don't respond to neighbor discovery request on blocked bearer Adds a check to prevent TIPC from trying to respond to an incoming LINK_CONFIG request message if the associated bearer is currently prohibited from sending messages. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/discover.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/tipc/discover.c') diff --git a/net/tipc/discover.c b/net/tipc/discover.c index 2c14d6dbc3d7..491eff56b9da 100644 --- a/net/tipc/discover.c +++ b/net/tipc/discover.c @@ -202,7 +202,7 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) /* Accept discovery message & send response, if necessary */ link_fully_up = link_working_working(link); - if ((type == DSC_REQ_MSG) && !link_fully_up) { + if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) { rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr); if (rbuf) { b_ptr->media->send_msg(rbuf, b_ptr, &media_addr); -- cgit v1.2.2