From 818f4da526656a100c637b098be06316fd4624e4 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Fri, 16 Nov 2012 13:51:29 +0800 Subject: tipc: remove supportable flag from bclink structure The "supportable" flag in bclink structure is a compatibility flag indicating whether a peer node is capable of receiving TIPC broadcast messages. However, all TIPC versions since tipc-1.5, and after the inclusion in the upstream Linux kernel in 2006, support this capability. It is highly unlikely that anybody is still using such an old version of TIPC, let alone that they want to mix it with TIPC-2.0 nodes. Therefore, we now remove the "supportable" flag. Signed-off-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: Paul Gortmaker --- net/tipc/node.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'net/tipc/node.c') diff --git a/net/tipc/node.c b/net/tipc/node.c index d21db204e25..6f3e9b35d27 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -264,11 +264,9 @@ static void node_established_contact(struct tipc_node *n_ptr) { tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr); - if (n_ptr->bclink.supportable) { - n_ptr->bclink.acked = tipc_bclink_get_last_sent(); - tipc_bclink_add_node(n_ptr->addr); - n_ptr->bclink.supported = 1; - } + n_ptr->bclink.acked = tipc_bclink_get_last_sent(); + tipc_bclink_add_node(n_ptr->addr); + n_ptr->bclink.supported = 1; } static void node_name_purge_complete(unsigned long node_addr) -- cgit v1.2.3-70-g09d2 From 389dd9bcf65e10929cedfeb79c49bd02069b8899 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Fri, 16 Nov 2012 13:51:30 +0800 Subject: tipc: rename supported flag to recv_permitted Rename the "supported" flag in bclink structure to "recv_permitted" to better reflect what it is used for. When this flag is set for a given node, we are permitted to receive and acknowledge broadcast messages from that node. Convert it to a bool at the same time, since it is not used to store any numerical values. Signed-off-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: Paul Gortmaker --- net/tipc/bcast.c | 6 +++--- net/tipc/link.c | 8 ++++---- net/tipc/node.c | 6 +++--- net/tipc/node.h | 4 ++-- 4 files changed, 12 insertions(+), 12 deletions(-) (limited to 'net/tipc/node.c') diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index 40da098eeb3..54f89f90ac3 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -347,7 +347,7 @@ static void bclink_peek_nack(struct tipc_msg *msg) tipc_node_lock(n_ptr); - if (n_ptr->bclink.supported && + if (n_ptr->bclink.recv_permitted && (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) && (n_ptr->bclink.last_in == msg_bcgap_after(msg))) n_ptr->bclink.oos_state = 2; @@ -429,7 +429,7 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf) goto exit; tipc_node_lock(node); - if (unlikely(!node->bclink.supported)) + if (unlikely(!node->bclink.recv_permitted)) goto unlock; /* Handle broadcast protocol message */ @@ -564,7 +564,7 @@ exit: u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr) { - return (n_ptr->bclink.supported && + return (n_ptr->bclink.recv_permitted && (tipc_bclink_get_last_sent() != n_ptr->bclink.acked)); } diff --git a/net/tipc/link.c b/net/tipc/link.c index f3a078fe70c..20f128fc2be 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1426,8 +1426,8 @@ static void link_retransmit_failure(struct tipc_link *l_ptr, tipc_addr_string_fill(addr_string, n_ptr->addr); pr_info("Broadcast link info for %s\n", addr_string); - pr_info("Supported: %d, Acked: %u\n", - n_ptr->bclink.supported, + pr_info("Reception permitted: %d, Acked: %u\n", + n_ptr->bclink.recv_permitted, n_ptr->bclink.acked); pr_info("Last in: %u, Oos state: %u, Last sent: %u\n", n_ptr->bclink.last_in, @@ -1640,7 +1640,7 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr) ackd = msg_ack(msg); /* Release acked messages */ - if (n_ptr->bclink.supported) + if (n_ptr->bclink.recv_permitted) tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); crs = l_ptr->first_out; @@ -2067,7 +2067,7 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf) } /* Protocol message before retransmits, reduce loss risk */ - if (l_ptr->owner->bclink.supported) + if (l_ptr->owner->bclink.recv_permitted) tipc_bclink_update_link_state(l_ptr->owner, msg_last_bcast(msg)); diff --git a/net/tipc/node.c b/net/tipc/node.c index 6f3e9b35d27..283a59f0f1c 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -266,7 +266,7 @@ static void node_established_contact(struct tipc_node *n_ptr) n_ptr->bclink.acked = tipc_bclink_get_last_sent(); tipc_bclink_add_node(n_ptr->addr); - n_ptr->bclink.supported = 1; + n_ptr->bclink.recv_permitted = true; } static void node_name_purge_complete(unsigned long node_addr) @@ -292,7 +292,7 @@ static void node_lost_contact(struct tipc_node *n_ptr) tipc_addr_string_fill(addr_string, n_ptr->addr)); /* Flush broadcast link info associated with lost node */ - if (n_ptr->bclink.supported) { + if (n_ptr->bclink.recv_permitted) { while (n_ptr->bclink.deferred_head) { struct sk_buff *buf = n_ptr->bclink.deferred_head; n_ptr->bclink.deferred_head = buf->next; @@ -308,7 +308,7 @@ static void node_lost_contact(struct tipc_node *n_ptr) tipc_bclink_remove_node(n_ptr->addr); tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); - n_ptr->bclink.supported = 0; + n_ptr->bclink.recv_permitted = false; } /* Abort link changeover */ diff --git a/net/tipc/node.h b/net/tipc/node.h index 3ac905f36b0..3c189b35b10 100644 --- a/net/tipc/node.h +++ b/net/tipc/node.h @@ -67,7 +67,6 @@ * @permit_changeover: non-zero if node has redundant links to this system * @signature: node instance identifier * @bclink: broadcast-related info - * @supported: non-zero if node supports TIPC b'cast capability * @acked: sequence # of last outbound b'cast message acknowledged by node * @last_in: sequence # of last in-sequence b'cast message received from node * @last_sent: sequence # of last b'cast message sent by node @@ -76,6 +75,7 @@ * @deferred_head: oldest OOS b'cast message received from node * @deferred_tail: newest OOS b'cast message received from node * @defragm: list of partially reassembled b'cast message fragments from node + * @recv_permitted: true if node is allowed to receive b'cast messages */ struct tipc_node { u32 addr; @@ -91,7 +91,6 @@ struct tipc_node { int permit_changeover; u32 signature; struct { - u8 supported; u32 acked; u32 last_in; u32 last_sent; @@ -100,6 +99,7 @@ struct tipc_node { struct sk_buff *deferred_head; struct sk_buff *deferred_tail; struct sk_buff *defragm; + bool recv_permitted; } bclink; }; -- cgit v1.2.3-70-g09d2 From c64f7a6a1fb13565687ae5415736095f82557880 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Fri, 16 Nov 2012 13:51:31 +0800 Subject: tipc: introduce message to synchronize broadcast link Upon establishing a first link between two nodes, there is currently a risk that the two endpoints will disagree on exactly which sequence number reception and acknowleding of broadcast packets should start. The following scenarios may happen: 1: Node A sends an ACTIVATE message to B, telling it to start acking packets from sequence number N. 2: Node A sends out broadcast N, but does not expect an acknowledge from B, since B is not yet in its broadcast receiver's list. 3: Node A receives ACK for N from all nodes except B, and releases packet N. 4: Node B receives the ACTIVATE, activates its link endpoint, and stores the value N as sequence number of first expected packet. 5: Node B sends a NAME_DISTR message to A. 6: Node A receives the NAME_DISTR message, and activates its endpoint. At this moment B is added to A's broadcast receiver's set. Node A also sets sequence number 0 as the first broadcast packet to be received from B. 7: Node A sends broadcast N+1. 8: B receives N+1, determines there is a gap in the sequence, since it is expecting N, and sends a NACK for N back to A. 9: Node A has already released N, so no retransmission is possible. The broadcast link in direction A->B is stale. In addition to, or instead of, 7-9 above, the following may happen: 10: Node B sends broadcast M > 0 to A. 11: Node A receives M, falsely decides there must be a gap, since it is expecting packet 0, and asks for retransmission of packets [0,M-1]. 12: Node B has already released these packets, so the broadcast link is stale in direction B->A. We solve this problem by introducing a new unicast message type, BCAST_PROTOCOL/STATE, to convey the sequence number of the next sent broadcast packet to the other endpoint, at exactly the moment that endpoint is added to the own node's broadcast receivers list, and before any other unicast messages are permitted to be sent. Furthermore, we don't allow any node to start receiving and processing broadcast packets until this new synchronization message has been received. To maintain backwards compatibility, we still open up for broadcast reception if we receive a NAME_DISTR message without any preceding broadcast sync message. In this case, we must assume that the other end has an older code version, and will never send out the new synchronization message. Hence, for mixed old and new nodes, the issue arising in 7-12 of the above may happen with the same probability as before. Signed-off-by: Jon Maloy Signed-off-by: Ying Xue Signed-off-by: Paul Gortmaker --- net/tipc/link.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- net/tipc/node.c | 5 ++--- 2 files changed, 60 insertions(+), 6 deletions(-) (limited to 'net/tipc/node.c') diff --git a/net/tipc/link.c b/net/tipc/link.c index 20f128fc2be..87bf5aad704 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1,7 +1,7 @@ /* * net/tipc/link.c: TIPC link code * - * Copyright (c) 1996-2007, Ericsson AB + * Copyright (c) 1996-2007, 2012, Ericsson AB * Copyright (c) 2004-2007, 2010-2011, Wind River Systems * All rights reserved. * @@ -103,6 +103,8 @@ static void link_reset_statistics(struct tipc_link *l_ptr); static void link_print(struct tipc_link *l_ptr, const char *str); static void link_start(struct tipc_link *l_ptr); static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf); +static void tipc_link_send_sync(struct tipc_link *l); +static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf); /* * Simple link routines @@ -712,6 +714,8 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event) link_activate(l_ptr); tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; + if (l_ptr->owner->working_links == 1) + tipc_link_send_sync(l_ptr); link_set_timer(l_ptr, cont_intv); break; case RESET_MSG: @@ -745,6 +749,8 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event) link_activate(l_ptr); tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; + if (l_ptr->owner->working_links == 1) + tipc_link_send_sync(l_ptr); link_set_timer(l_ptr, cont_intv); break; case RESET_MSG: @@ -941,7 +947,48 @@ int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector) return res; } -/** +/* + * tipc_link_send_sync - synchronize broadcast link endpoints. + * + * Give a newly added peer node the sequence number where it should + * start receiving and acking broadcast packets. + * + * Called with node locked + */ +static void tipc_link_send_sync(struct tipc_link *l) +{ + struct sk_buff *buf; + struct tipc_msg *msg; + + buf = tipc_buf_acquire(INT_H_SIZE); + if (!buf) + return; + + msg = buf_msg(buf); + tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, l->addr); + msg_set_last_bcast(msg, l->owner->bclink.acked); + link_add_chain_to_outqueue(l, buf, 0); + tipc_link_push_queue(l); +} + +/* + * tipc_link_recv_sync - synchronize broadcast link endpoints. + * Receive the sequence number where we should start receiving and + * acking broadcast packets from a newly added peer node, and open + * up for reception of such packets. + * + * Called with node locked + */ +static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf) +{ + struct tipc_msg *msg = buf_msg(buf); + + n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg); + n->bclink.recv_permitted = true; + kfree_skb(buf); +} + +/* * tipc_link_send_names - send name table entries to new neighbor * * Send routine for bulk delivery of name table messages when contact @@ -1691,9 +1738,14 @@ deliver: tipc_link_recv_bundle(buf); continue; case NAME_DISTRIBUTOR: + n_ptr->bclink.recv_permitted = true; tipc_node_unlock(n_ptr); tipc_named_recv(buf); continue; + case BCAST_PROTOCOL: + tipc_link_recv_sync(n_ptr, buf); + tipc_node_unlock(n_ptr); + continue; case CONN_MANAGER: tipc_node_unlock(n_ptr); tipc_port_recv_proto_msg(buf); @@ -1736,16 +1788,19 @@ deliver: continue; } + /* Link is not in state WORKING_WORKING */ if (msg_user(msg) == LINK_PROTOCOL) { link_recv_proto_msg(l_ptr, buf); head = link_insert_deferred_queue(l_ptr, head); tipc_node_unlock(n_ptr); continue; } + + /* Traffic message. Conditionally activate link */ link_state_event(l_ptr, TRAFFIC_MSG_EVT); if (link_working_working(l_ptr)) { - /* Re-insert in front of queue */ + /* Re-insert buffer in front of queue */ buf->next = head; head = buf; tipc_node_unlock(n_ptr); diff --git a/net/tipc/node.c b/net/tipc/node.c index 283a59f0f1c..48f39dd3eae 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -1,7 +1,7 @@ /* * net/tipc/node.c: TIPC node management routines * - * Copyright (c) 2000-2006, Ericsson AB + * Copyright (c) 2000-2006, 2012 Ericsson AB * Copyright (c) 2005-2006, 2010-2011, Wind River Systems * All rights reserved. * @@ -263,10 +263,9 @@ void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) static void node_established_contact(struct tipc_node *n_ptr) { tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr); - + n_ptr->bclink.oos_state = 0; n_ptr->bclink.acked = tipc_bclink_get_last_sent(); tipc_bclink_add_node(n_ptr->addr); - n_ptr->bclink.recv_permitted = true; } static void node_name_purge_complete(unsigned long node_addr) -- cgit v1.2.3-70-g09d2