/* * net/tipc/link.c: TIPC link code * * Copyright (c) 1996-2007, 2012-2014, Ericsson AB * Copyright (c) 2004-2007, 2010-2013, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "core.h" #include "link.h" #include "socket.h" #include "name_distr.h" #include "discover.h" #include "config.h" #include /* * Error message prefixes */ static const char *link_co_err = "Link changeover error, "; static const char *link_rst_msg = "Resetting link "; static const char *link_unk_evt = "Unknown link event "; /* * Out-of-range value for link session numbers */ #define INVALID_SESSION 0x10000 /* * Link state events: */ #define STARTING_EVT 856384768 /* link processing trigger */ #define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */ #define TIMEOUT_EVT 560817u /* link timer expired */ /* * The following two 'message types' is really just implementation * data conveniently stored in the message header. * They must not be considered part of the protocol */ #define OPEN_MSG 0 #define CLOSED_MSG 1 /* * State value stored in 'exp_msg_count' */ #define START_CHANGEOVER 100000u static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr, struct sk_buff *buf); static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf); static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr, struct sk_buff **buf); static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance); static void link_state_event(struct tipc_link *l_ptr, u32 event); static void link_reset_statistics(struct tipc_link *l_ptr); static void link_print(struct tipc_link *l_ptr, const char *str); static void tipc_link_sync_xmit(struct tipc_link *l); static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf); static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf); static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf); /* * Simple link routines */ static unsigned int align(unsigned int i) { return (i + 3) & ~3u; } static void link_init_max_pkt(struct tipc_link *l_ptr) { struct tipc_bearer *b_ptr; u32 max_pkt; rcu_read_lock(); b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]); if (!b_ptr) { rcu_read_unlock(); return; } max_pkt = (b_ptr->mtu & ~3); rcu_read_unlock(); if (max_pkt > MAX_MSG_SIZE) max_pkt = MAX_MSG_SIZE; l_ptr->max_pkt_target = max_pkt; if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT) l_ptr->max_pkt = l_ptr->max_pkt_target; else l_ptr->max_pkt = MAX_PKT_DEFAULT; l_ptr->max_pkt_probes = 0; } static u32 link_next_sent(struct tipc_link *l_ptr) { if (l_ptr->next_out) return buf_seqno(l_ptr->next_out); return mod(l_ptr->next_out_no); } static u32 link_last_sent(struct tipc_link *l_ptr) { return mod(link_next_sent(l_ptr) - 1); } /* * Simple non-static link routines (i.e. referenced outside this file) */ int tipc_link_is_up(struct tipc_link *l_ptr) { if (!l_ptr) return 0; return link_working_working(l_ptr) || link_working_unknown(l_ptr); } int tipc_link_is_active(struct tipc_link *l_ptr) { return (l_ptr->owner->active_links[0] == l_ptr) || (l_ptr->owner->active_links[1] == l_ptr); } /** * link_timeout - handle expiration of link timer * @l_ptr: pointer to link */ static void link_timeout(struct tipc_link *l_ptr) { tipc_node_lock(l_ptr->owner); /* update counters used in statistical profiling of send traffic */ l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size; l_ptr->stats.queue_sz_counts++; if (l_ptr->first_out) { struct tipc_msg *msg = buf_msg(l_ptr->first_out); u32 length = msg_size(msg); if ((msg_user(msg) == MSG_FRAGMENTER) && (msg_type(msg) == FIRST_FRAGMENT)) { length = msg_size(msg_get_wrapped(msg)); } if (length) { l_ptr->stats.msg_lengths_total += length; l_ptr->stats.msg_length_counts++; if (length <= 64) l_ptr->stats.msg_length_profile[0]++; else if (length <= 256) l_ptr->stats.msg_length_profile[1]++; else if (length <= 1024) l_ptr->stats.msg_length_profile[2]++; else if (length <= 4096) l_ptr->stats.msg_length_profile[3]++; else if (length <= 16384) l_ptr->stats.msg_length_profile[4]++; else if (length <= 32768) l_ptr->stats.msg_length_profile[5]++; else l_ptr->stats.msg_length_profile[6]++; } } /* do all other link processing performed on a periodic basis */ link_state_event(l_ptr, TIMEOUT_EVT); if (l_ptr->next_out) tipc_link_push_queue(l_ptr); tipc_node_unlock(l_ptr->owner); } static void link_set_timer(struct tipc_link *l_ptr, u32 time) { k_start_timer(&l_ptr->timer, time); } /** * tipc_link_create - create a new link * @n_ptr: pointer to associated node * @b_ptr: pointer to associated bearer * @media_addr: media address to use when sending messages over link * * Returns pointer to link. */ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr, struct tipc_bearer *b_ptr, const struct tipc_media_addr *media_addr) { struct tipc_link *l_ptr; struct tipc_msg *msg; char *if_name; char addr_string[16]; u32 peer = n_ptr->addr; if (n_ptr->link_cnt >= MAX_BEARERS) { tipc_addr_string_fill(addr_string, n_ptr->addr); pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n", n_ptr->link_cnt, addr_string, MAX_BEARERS); return NULL; } if (n_ptr->links[b_ptr->identity]) { tipc_addr_string_fill(addr_string, n_ptr->addr); pr_err("Attempt to establish second link on <%s> to %s\n", b_ptr->name, addr_string); return NULL; } l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC); if (!l_ptr) { pr_warn("Link creation failed, no memory\n"); return NULL; } l_ptr->addr = peer; if_name = strchr(b_ptr->name, ':') + 1; sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown", tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr), tipc_node(tipc_own_addr), if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer)); /* note: peer i/f name is updated by reset/activate message */ memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr)); l_ptr->owner = n_ptr; l_ptr->checkpoint = 1; l_ptr->peer_session = INVALID_SESSION; l_ptr->bearer_id = b_ptr->identity; link_set_supervision_props(l_ptr, b_ptr->tolerance); l_ptr->state = RESET_UNKNOWN; l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg; msg = l_ptr->pmsg; tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr); msg_set_size(msg, sizeof(l_ptr->proto_msg)); msg_set_session(msg, (tipc_random & 0xffff)); msg_set_bearer_id(msg, b_ptr->identity); strcpy((char *)msg_data(msg), if_name); l_ptr->priority = b_ptr->priority; tipc_link_set_queue_limits(l_ptr, b_ptr->window); l_ptr->net_plane = b_ptr->net_plane; link_init_max_pkt(l_ptr); l_ptr->next_out_no = 1; __skb_queue_head_init(&l_ptr->waiting_sks); link_reset_statistics(l_ptr); tipc_node_attach_link(n_ptr, l_ptr); k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr); link_state_event(l_ptr, STARTING_EVT); return l_ptr; } void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down) { struct tipc_link *l_ptr; struct tipc_node *n_ptr; rcu_read_lock(); list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { tipc_node_lock(n_ptr); l_ptr = n_ptr->links[bearer_id]; if (l_ptr) { tipc_link_reset(l_ptr); if (shutting_down || !tipc_node_is_up(n_ptr)) { tipc_node_detach_link(l_ptr->owner, l_ptr); tipc_link_reset_fragments(l_ptr); tipc_node_unlock(n_ptr); /* Nobody else can access this link now: */ del_timer_sync(&l_ptr->timer); kfree(l_ptr); } else { /* Detach/delete when failover is finished: */ l_ptr->flags |= LINK_STOPPED; tipc_node_unlock(n_ptr); del_timer_sync(&l_ptr->timer); } continue; } tipc_node_unlock(n_ptr); } rcu_read_unlock(); } /** * link_schedule_user - schedule user for wakeup after congestion * @link: congested link * @oport: sending port * @chain_sz: size of buffer chain that was attempted sent * @imp: importance of message attempted sent * Create pseudo msg to send back to user when congestion abates */ static bool link_schedule_user(struct tipc_link *link, u32 oport, uint chain_sz, uint imp) { struct sk_buff *buf; buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, tipc_own_addr, tipc_own_addr, oport, 0, 0); if (!buf) return false; TIPC_SKB_CB(buf)->chain_sz = chain_sz; TIPC_SKB_CB(buf)->chain_imp = imp; __skb_queue_tail(&link->waiting_sks, buf); link->stats.link_congs++; return true; } /** * link_prepare_wakeup - prepare users for wakeup after congestion * @link: congested link * Move a number of waiting users, as permitted by available space in * the send queue, from link wait queue to node wait queue for wakeup */ static void link_prepare_wakeup(struct tipc_link *link) { struct sk_buff_head *wq = &link->waiting_sks; struct sk_buff *buf; uint pend_qsz = link->out_queue_size; for (buf = skb_peek(wq); buf; buf = skb_peek(wq)) { if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(buf)->chain_imp]) break; pend_qsz += TIPC_SKB_CB(buf)->chain_sz; __skb_queue_tail(&link->owner->waiting_sks, __skb_dequeue(wq)); } } /** * link_release_outqueue - purge link's outbound message queue * @l_ptr: pointer to link */ static void link_release_outqueue(struct tipc_link *l_ptr) { kfree_skb_list(l_ptr->first_out); l_ptr->first_out = NULL; l_ptr->out_queue_size = 0; } /** * tipc_link_reset_fragments - purge link's inbound message fragments queue * @l_ptr: pointer to link */ void tipc_link_reset_fragments(struct tipc_link *l_ptr) { kfree_skb(l_ptr->reasm_buf); l_ptr->reasm_buf = NULL; } /** * tipc_link_purge_queues - purge all pkt queues associated with link * @l_ptr: pointer to link */ void tipc_link_purge_queues(struct tipc_link *l_ptr) { kfree_skb_list(l_ptr->oldest_deferred_in); kfree_skb_list(l_ptr->first_out); tipc_link_reset_fragments(l_ptr); kfree_skb(l_ptr->proto_msg_queue); l_ptr->proto_msg_queue = NULL; } void tipc_link_reset(struct tipc_link *l_ptr) { u32 prev_state = l_ptr->state; u32 checkpoint = l_ptr->next_in_no; int was_active_link = tipc_link_is_active(l_ptr); struct tipc_node *owner = l_ptr->owner; msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff)); /* Link is down, accept any session */ l_ptr->peer_session = INVALID_SESSION; /* Prepare for max packet size negotiation */ link_init_max_pkt(l_ptr); l_ptr->state = RESET_UNKNOWN; if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET)) return; tipc_node_link_down(l_ptr->owner, l_ptr); tipc_bearer_remove_dest(l_ptr->bearer_id, l_ptr->addr); if (was_active_link && tipc_node_active_links(l_ptr->owner)) { l_ptr->reset_checkpoint = checkpoint; l_ptr->exp_msg_count = START_CHANGEOVER; } /* Clean up all queues: */ link_release_outqueue(l_ptr); kfree_skb(l_ptr->proto_msg_queue); l_ptr->proto_msg_queue = NULL; kfree_skb_list(l_ptr->oldest_deferred_in); if (!skb_queue_empty(&l_ptr->waiting_sks)) { skb_queue_splice_init(&l_ptr->waiting_sks, &owner->waiting_sks); owner->action_flags |= TIPC_WAKEUP_USERS; } l_ptr->retransm_queue_head = 0; l_ptr->retransm_queue_size = 0; l_ptr->last_out = NULL; l_ptr->first_out = NULL; l_ptr->next_out = NULL; l_ptr->unacked_window = 0; l_ptr->checkpoint = 1; l_ptr->next_out_no = 1; l_ptr->deferred_inqueue_sz = 0; l_ptr->oldest_deferred_in = NULL; l_ptr->newest_deferred_in = NULL; l_ptr->fsm_msg_cnt = 0; l_ptr->stale_count = 0; link_reset_statistics(l_ptr); } void tipc_link_reset_list(unsigned int bearer_id) { struct tipc_link *l_ptr; struct tipc_node *n_ptr; rcu_read_lock(); list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { tipc_node_lock(n_ptr); l_ptr = n_ptr->links[bearer_id]; if (l_ptr) tipc_link_reset(l_ptr); tipc_node_unlock(n_ptr); } rcu_read_unlock(); } static void link_activate(struct tipc_link *l_ptr) { l_ptr->next_in_no = l_ptr->stats.recv_info = 1; tipc_node_link_up(l_ptr->owner, l_ptr); tipc_bearer_add_dest(l_ptr->bearer_id, l_ptr->addr); } /** * link_state_event - link finite state machine * @l_ptr: pointer to link * @event: state machine event to process */ static void link_state_event(struct tipc_link *l_ptr, unsigned int event) { struct tipc_link *other; u32 cont_intv = l_ptr->continuity_interval; if (l_ptr->flags & LINK_STOPPED) return; if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT)) return; /* Not yet. */ /* Check whether changeover is going on */ if (l_ptr->exp_msg_count) { if (event == TIMEOUT_EVT) link_set_timer(l_ptr, cont_intv); return; } switch (l_ptr->state) { case WORKING_WORKING: switch (event) { case TRAFFIC_MSG_EVT: case ACTIVATE_MSG: break; case TIMEOUT_EVT: if (l_ptr->next_in_no != l_ptr->checkpoint) { l_ptr->checkpoint = l_ptr->next_in_no; if (tipc_bclink_acks_missing(l_ptr->owner)) { tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) { tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; } link_set_timer(l_ptr, cont_intv); break; } l_ptr->state = WORKING_UNKNOWN; l_ptr->fsm_msg_cnt = 0; tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv / 4); break; case RESET_MSG: pr_info("%s<%s>, requested by peer\n", link_rst_msg, l_ptr->name); tipc_link_reset(l_ptr); l_ptr->state = RESET_RESET; l_ptr->fsm_msg_cnt = 0; tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); break; default: pr_err("%s%u in WW state\n", link_unk_evt, event); } break; case WORKING_UNKNOWN: switch (event) { case TRAFFIC_MSG_EVT: case ACTIVATE_MSG: l_ptr->state = WORKING_WORKING; l_ptr->fsm_msg_cnt = 0; link_set_timer(l_ptr, cont_intv); break; case RESET_MSG: pr_info("%s<%s>, requested by peer while probing\n", link_rst_msg, l_ptr->name); tipc_link_reset(l_ptr); l_ptr->state = RESET_RESET; l_ptr->fsm_msg_cnt = 0; tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); break; case TIMEOUT_EVT: if (l_ptr->next_in_no != l_ptr->checkpoint) { l_ptr->state = WORKING_WORKING; l_ptr->fsm_msg_cnt = 0; l_ptr->checkpoint = l_ptr->next_in_no; if (tipc_bclink_acks_missing(l_ptr->owner)) { tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; } link_set_timer(l_ptr, cont_intv); } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) { tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv / 4); } else { /* Link has failed */ pr_warn("%s<%s>, peer not responding\n", link_rst_msg, l_ptr->name); tipc_link_reset(l_ptr); l_ptr->state = RESET_UNKNOWN; l_ptr->fsm_msg_cnt = 0; tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); } break; default: pr_err("%s%u in WU state\n", link_unk_evt, event); } break; case RESET_UNKNOWN: switch (event) { case TRAFFIC_MSG_EVT: break; case ACTIVATE_MSG: other = l_ptr->owner->active_links[0]; if (other && link_working_unknown(other)) break; l_ptr->state = WORKING_WORKING; l_ptr->fsm_msg_cnt = 0; link_activate(l_ptr); tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; if (l_ptr->owner->working_links == 1) tipc_link_sync_xmit(l_ptr); link_set_timer(l_ptr, cont_intv); break; case RESET_MSG: l_ptr->state = RESET_RESET; l_ptr->fsm_msg_cnt = 0; tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); break; case STARTING_EVT: l_ptr->flags |= LINK_STARTED; /* fall through */ case TIMEOUT_EVT: tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); break; default: pr_err("%s%u in RU state\n", link_unk_evt, event); } break; case RESET_RESET: switch (event) { case TRAFFIC_MSG_EVT: case ACTIVATE_MSG: other = l_ptr->owner->active_links[0]; if (other && link_working_unknown(other)) break; l_ptr->state = WORKING_WORKING; l_ptr->fsm_msg_cnt = 0; link_activate(l_ptr); tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; if (l_ptr->owner->working_links == 1) tipc_link_sync_xmit(l_ptr); link_set_timer(l_ptr, cont_intv); break; case RESET_MSG: break; case TIMEOUT_EVT: tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0); l_ptr->fsm_msg_cnt++; link_set_timer(l_ptr, cont_intv); break; default: pr_err("%s%u in RR state\n", link_unk_evt, event); } break; default: pr_err("Unknown link state %u/%u\n", l_ptr->state, event); } } /* tipc_link_cong: determine return value and how to treat the * sent buffer during link congestion. * - For plain, errorless user data messages we keep the buffer and * return -ELINKONG. * - For all other messages we discard the buffer and return -EHOSTUNREACH * - For TIPC internal messages we also reset the link */ static int tipc_link_cong(struct tipc_link *link, struct sk_buff *buf) { struct tipc_msg *msg = buf_msg(buf); uint imp = tipc_msg_tot_importance(msg); u32 oport = msg_tot_origport(msg); if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) { pr_warn("%s<%s>, send queue full", link_rst_msg, link->name); tipc_link_reset(link); goto drop; } if (unlikely(msg_errcode(msg))) goto drop; if (unlikely(msg_reroute_cnt(msg))) goto drop; if (TIPC_SKB_CB(buf)->wakeup_pending) return -ELINKCONG; if (link_schedule_user(link, oport, TIPC_SKB_CB(buf)->chain_sz, imp)) return -ELINKCONG; drop: kfree_skb_list(buf); return -EHOSTUNREACH; } /** * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked * @link: link to use * @buf: chain of buffers containing message * Consumes the buffer chain, except when returning -ELINKCONG * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket * user data messages) or -EHOSTUNREACH (all other messages/senders) * Only the socket functions tipc_send_stream() and tipc_send_packet() need * to act on the return value, since they may need to do more send attempts. */ int __tipc_link_xmit(struct tipc_link *link, struct sk_buff *buf) { struct tipc_msg *msg = buf_msg(buf); uint psz = msg_size(msg); uint qsz = link->out_queue_size; uint sndlim = link->queue_limit[0]; uint imp = tipc_msg_tot_importance(msg); uint mtu = link->max_pkt; uint ack = mod(link->next_in_no - 1); uint seqno = link->next_out_no; uint bc_last_in = link->owner->bclink.last_in; struct tipc_media_addr *addr = &link->media_addr; struct sk_buff *next = buf->next; /* Match queue limits against msg importance: */ if (unlikely(qsz >= link->queue_limit[imp])) return tipc_link_cong(link, buf); /* Has valid packet limit been used ? */ if (unlikely(psz > mtu)) { kfree_skb_list(buf); return -EMSGSIZE; } /* Prepare each packet for sending, and add to outqueue: */ while (buf) { next = buf->next; msg = buf_msg(buf); msg_set_word(msg, 2, ((ack << 16) | mod(seqno))); msg_set_bcast_ack(msg, bc_last_in); if (!link->first_out) { link->first_out = buf; } else if (qsz < sndlim) { link->last_out->next = buf; } else if (tipc_msg_bundle(link->last_out, buf, mtu)) { link->stats.sent_bundled++; buf = next; next = buf->next; continue; } else if (tipc_msg_make_bundle(&buf, mtu, link->addr)) { link->stats.sent_bundled++; link->stats.sent_bundles++; link->last_out->next = buf; if (!link->next_out) link->next_out = buf; } else { link->last_out->next = buf; if (!link->next_out) link->next_out = buf; } /* Send packet if possible: */ if (likely(++qsz <= sndlim)) { tipc_bearer_send(link->bearer_id, buf, addr); link->next_out = next; link->unacked_window = 0; } seqno++; link->last_out = buf; buf = next; } link->next_out_no = seqno; link->out_queue_size = qsz; return 0; } /** * tipc_link_xmit() is the general link level function for message sending * @buf: chain of buffers containing message * @dsz: amount of user data to be sent * @dnode: address of destination node * @selector: a number used for deterministic link selection * Consumes the buffer chain, except when returning -ELINKCONG * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE */ int tipc_link_xmit(struct sk_buff *buf, u32 dnode, u32 selector) { struct tipc_link *link = NULL; struct tipc_node *node; int rc = -EHOSTUNREACH; node = tipc_node_find(dnode); if (node) { tipc_node_lock(node); link = node->active_links[selector & 1]; if (link) rc = __tipc_link_xmit(link, buf); tipc_node_unlock(node); } if (link) return rc; if (likely(in_own_node(dnode))) return tipc_sk_rcv(buf); kfree_skb_list(buf); return rc; } /* * tipc_link_sync_xmit - 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_sync_xmit(struct tipc_link *link) { 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, link->addr); msg_set_last_bcast(msg, link->owner->bclink.acked); __tipc_link_xmit(link, buf); } /* * tipc_link_sync_rcv - 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_sync_rcv(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_push_packet: Push one unsent packet to the media */ static u32 tipc_link_push_packet(struct tipc_link *l_ptr) { struct sk_buff *buf = l_ptr->first_out; u32 r_q_size = l_ptr->retransm_queue_size; u32 r_q_head = l_ptr->retransm_queue_head; /* Step to position where retransmission failed, if any, */ /* consider that buffers may have been released in meantime */ if (r_q_size && buf) { u32 last = lesser(mod(r_q_head + r_q_size), link_last_sent(l_ptr)); u32 first = buf_seqno(buf); while (buf && less(first, r_q_head)) { first = mod(first + 1); buf = buf->next; } l_ptr->retransm_queue_head = r_q_head = first; l_ptr->retransm_queue_size = r_q_size = mod(last - first); } /* Continue retransmission now, if there is anything: */ if (r_q_size && buf) { msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1)); msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in); tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr); l_ptr->retransm_queue_head = mod(++r_q_head); l_ptr->retransm_queue_size = --r_q_size; l_ptr->stats.retransmitted++; return 0; } /* Send deferred protocol message, if any: */ buf = l_ptr->proto_msg_queue; if (buf) { msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1)); msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in); tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr); l_ptr->unacked_window = 0; kfree_skb(buf); l_ptr->proto_msg_queue = NULL; return 0; } /* Send one deferred data message, if send window not full: */ buf = l_ptr->next_out; if (buf) { struct tipc_msg *msg = buf_msg(buf); u32 next = msg_seqno(msg); u32 first = buf_seqno(l_ptr->first_out); if (mod(next - first) < l_ptr->queue_limit[0]) { msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr); if (msg_user(msg) == MSG_BUNDLER) msg_set_type(msg, BUNDLE_CLOSED); l_ptr->next_out = buf->next; return 0; } } return 1; } /* * push_queue(): push out the unsent messages of a link where * congestion has abated. Node is locked */ void tipc_link_push_queue(struct tipc_link *l_ptr) { u32 res; do { res = tipc_link_push_packet(l_ptr); } while (!res); } void tipc_link_reset_all(struct tipc_node *node) { char addr_string[16]; u32 i; tipc_node_lock(node); pr_warn("Resetting all links to %s\n", tipc_addr_string_fill(addr_string, node->addr)); for (i = 0; i < MAX_BEARERS; i++) { if (node->links[i]) { link_print(node->links[i], "Resetting link\n"); tipc_link_reset(node->links[i]); } } tipc_node_unlock(node); } static void link_retransmit_failure(struct tipc_link *l_ptr, struct sk_buff *buf) { struct tipc_msg *msg = buf_msg(buf); pr_warn("Retransmission failure on link <%s>\n", l_ptr->name); if (l_ptr->addr) { /* Handle failure on standard link */ link_print(l_ptr, "Resetting link\n"); tipc_link_reset(l_ptr); } else { /* Handle failure on broadcast link */ struct tipc_node *n_ptr; char addr_string[16]; pr_info("Msg seq number: %u, ", msg_seqno(msg)); pr_cont("Outstanding acks: %lu\n", (unsigned long) TIPC_SKB_CB(buf)->handle); n_ptr = tipc_bclink_retransmit_to(); tipc_node_lock(n_ptr); tipc_addr_string_fill(addr_string, n_ptr->addr); pr_info("Broadcast link info for %s\n", addr_string); 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, n_ptr->bclink.oos_state, n_ptr->bclink.last_sent); tipc_node_unlock(n_ptr); tipc_bclink_set_flags(TIPC_BCLINK_RESET); l_ptr->stale_count = 0; } } void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf, u32 retransmits) { struct tipc_msg *msg; if (!buf) return; msg = buf_msg(buf); /* Detect repeated retransmit failures */ if (l_ptr->last_retransmitted == msg_seqno(msg)) { if (++l_ptr->stale_count > 100) { link_retransmit_failure(l_ptr, buf); return; } } else { l_ptr->last_retransmitted = msg_seqno(msg); l_ptr->stale_count = 1; } while (retransmits && (buf != l_ptr->next_out) && buf) { msg = buf_msg(buf); msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr); buf = buf->next; retransmits--; l_ptr->stats.retransmitted++; } l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0; } /** * link_insert_deferred_queue - insert deferred messages back into receive chain */ static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr, struct sk_buff *buf) { u32 seq_no; if (l_ptr->oldest_deferred_in == NULL) return buf; seq_no = buf_seqno(l_ptr->oldest_deferred_in); if (seq_no == mod(l_ptr->next_in_no)) { l_ptr->newest_deferred_in->next = buf; buf = l_ptr->oldest_deferred_in; l_ptr->oldest_deferred_in = NULL; l_ptr->deferred_inqueue_sz = 0; } return buf; } /** * link_recv_buf_validate - validate basic format of received message * * This routine ensures a TIPC message has an acceptable header, and at least * as much data as the header indicates it should. The routine also ensures * that the entire message header is stored in the main fragment of the message * buffer, to simplify future access to message header fields. * * Note: Having extra info present in the message header or data areas is OK. * TIPC will ignore the excess, under the assumption that it is optional info * introduced by a later release of the protocol. */ static int link_recv_buf_validate(struct sk_buff *buf) { static u32 min_data_hdr_size[8] = { SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE }; struct tipc_msg *msg; u32 tipc_hdr[2]; u32 size; u32 hdr_size; u32 min_hdr_size; /* If this packet comes from the defer queue, the skb has already * been validated */ if (unlikely(TIPC_SKB_CB(buf)->deferred)) return 1; if (unlikely(buf->len < MIN_H_SIZE)) return 0; msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr); if (msg == NULL) return 0; if (unlikely(msg_version(msg) != TIPC_VERSION)) return 0; size = msg_size(msg); hdr_size = msg_hdr_sz(msg); min_hdr_size = msg_isdata(msg) ? min_data_hdr_size[msg_type(msg)] : INT_H_SIZE; if (unlikely((hdr_size < min_hdr_size) || (size < hdr_size) || (buf->len < size) || (size - hdr_size > TIPC_MAX_USER_MSG_SIZE))) return 0; return pskb_may_pull(buf, hdr_size); } /** * tipc_rcv - process TIPC packets/messages arriving from off-node * @head: pointer to message buffer chain * @b_ptr: pointer to bearer message arrived on * * Invoked with no locks held. Bearer pointer must point to a valid bearer * structure (i.e. cannot be NULL), but bearer can be inactive. */ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr) { while (head) { struct tipc_node *n_ptr; struct tipc_link *l_ptr; struct sk_buff *crs; struct sk_buff *buf = head; struct tipc_msg *msg; u32 seq_no; u32 ackd; u32 released = 0; head = head->next; buf->next = NULL; /* Ensure message is well-formed */ if (unlikely(!link_recv_buf_validate(buf))) goto discard; /* Ensure message data is a single contiguous unit */ if (unlikely(skb_linearize(buf))) goto discard; /* Handle arrival of a non-unicast link message */ msg = buf_msg(buf); if (unlikely(msg_non_seq(msg))) { if (msg_user(msg) == LINK_CONFIG) tipc_disc_rcv(buf, b_ptr); else tipc_bclink_rcv(buf); continue; } /* Discard unicast link messages destined for another node */ if (unlikely(!msg_short(msg) && (msg_destnode(msg) != tipc_own_addr))) goto discard; /* Locate neighboring node that sent message */ n_ptr = tipc_node_find(msg_prevnode(msg)); if (unlikely(!n_ptr)) goto discard; tipc_node_lock(n_ptr); /* Locate unicast link endpoint that should handle message */ l_ptr = n_ptr->links[b_ptr->identity]; if (unlikely(!l_ptr)) goto unlock_discard; /* Verify that communication with node is currently allowed */ if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) && msg_user(msg) == LINK_PROTOCOL && (msg_type(msg) == RESET_MSG || msg_type(msg) == ACTIVATE_MSG) && !msg_redundant_link(msg)) n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN; if (tipc_node_blocked(n_ptr)) goto unlock_discard; /* Validate message sequence number info */ seq_no = msg_seqno(msg); ackd = msg_ack(msg); /* Release acked messages */ if (n_ptr->bclink.recv_permitted) tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); crs = l_ptr->first_out; while ((crs != l_ptr->next_out) && less_eq(buf_seqno(crs), ackd)) { struct sk_buff *next = crs->next; kfree_skb(crs); crs = next; released++; } if (released) { l_ptr->first_out = crs; l_ptr->out_queue_size -= released; } /* Try sending any messages link endpoint has pending */ if (unlikely(l_ptr->next_out)) tipc_link_push_queue(l_ptr); if (released && !skb_queue_empty(&l_ptr->waiting_sks)) { link_prepare_wakeup(l_ptr); l_ptr->owner->action_flags |= TIPC_WAKEUP_USERS; } /* Process the incoming packet */ if (unlikely(!link_working_working(l_ptr))) { if (msg_user(msg) == LINK_PROTOCOL) { tipc_link_proto_rcv(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 buffer in front of queue */ buf->next = head; head = buf; tipc_node_unlock(n_ptr); continue; } goto unlock_discard; } /* Link is now in state WORKING_WORKING */ if (unlikely(seq_no != mod(l_ptr->next_in_no))) { link_handle_out_of_seq_msg(l_ptr, buf); head = link_insert_deferred_queue(l_ptr, head); tipc_node_unlock(n_ptr); continue; } l_ptr->next_in_no++; if (unlikely(l_ptr->oldest_deferred_in)) head = link_insert_deferred_queue(l_ptr, head); if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) { l_ptr->stats.sent_acks++; tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); } if (tipc_link_prepare_input(l_ptr, &buf)) { tipc_node_unlock(n_ptr); continue; } tipc_node_unlock(n_ptr); msg = buf_msg(buf); if (tipc_link_input(l_ptr, buf) != 0) goto discard; continue; unlock_discard: tipc_node_unlock(n_ptr); discard: kfree_skb(buf); } } /** * tipc_link_prepare_input - process TIPC link messages * * returns nonzero if the message was consumed * * Node lock must be held */ static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf) { struct tipc_node *n; struct tipc_msg *msg; int res = -EINVAL; n = l->owner; msg = buf_msg(*buf); switch (msg_user(msg)) { case CHANGEOVER_PROTOCOL: if (tipc_link_tunnel_rcv(n, buf)) res = 0; break; case MSG_FRAGMENTER: l->stats.recv_fragments++; if (tipc_buf_append(&l->reasm_buf, buf)) { l->stats.recv_fragmented++; res = 0; } else if (!l->reasm_buf) { tipc_link_reset(l); } break; case MSG_BUNDLER: l->stats.recv_bundles++; l->stats.recv_bundled += msg_msgcnt(msg); res = 0; break; case NAME_DISTRIBUTOR: n->bclink.recv_permitted = true; res = 0; break; case BCAST_PROTOCOL: tipc_link_sync_rcv(n, *buf); break; default: res = 0; } return res; } /** * tipc_link_input - Deliver message too higher layers */ static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf) { struct tipc_msg *msg = buf_msg(buf); int res = 0; switch (msg_user(msg)) { case TIPC_LOW_IMPORTANCE: case TIPC_MEDIUM_IMPORTANCE: case TIPC_HIGH_IMPORTANCE: case TIPC_CRITICAL_IMPORTANCE: case CONN_MANAGER: tipc_sk_rcv(buf); break; case NAME_DISTRIBUTOR: tipc_named_rcv(buf); break; case MSG_BUNDLER: tipc_link_bundle_rcv(buf); break; default: res = -EINVAL; } return res; } /** * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue * * Returns increase in queue length (i.e. 0 or 1) */ u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail, struct sk_buff *buf) { struct sk_buff *queue_buf; struct sk_buff **prev; u32 seq_no = buf_seqno(buf); buf->next = NULL; /* Empty queue ? */ if (*head == NULL) { *head = *tail = buf; return 1; } /* Last ? */ if (less(buf_seqno(*tail), seq_no)) { (*tail)->next = buf; *tail = buf; return 1; } /* Locate insertion point in queue, then insert; discard if duplicate */ prev = head; queue_buf = *head; for (;;) { u32 curr_seqno = buf_seqno(queue_buf); if (seq_no == curr_seqno) { kfree_skb(buf); return 0; } if (less(seq_no, curr_seqno)) break; prev = &queue_buf->next; queue_buf = queue_buf->next; } buf->next = queue_buf; *prev = buf; return 1; } /* * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet */ static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr, struct sk_buff *buf) { u32 seq_no = buf_seqno(buf); if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) { tipc_link_proto_rcv(l_ptr, buf); return; } /* Record OOS packet arrival (force mismatch on next timeout) */ l_ptr->checkpoint--; /* * Discard packet if a duplicate; otherwise add it to deferred queue * and notify peer of gap as per protocol specification */ if (less(seq_no, mod(l_ptr->next_in_no))) { l_ptr->stats.duplicates++; kfree_skb(buf); return; } if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in, &l_ptr->newest_deferred_in, buf)) { l_ptr->deferred_inqueue_sz++; l_ptr->stats.deferred_recv++; TIPC_SKB_CB(buf)->deferred = true; if ((l_ptr->deferred_inqueue_sz % 16) == 1) tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); } else l_ptr->stats.duplicates++; } /* * Send protocol message to the other endpoint. */ void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg, u32 gap, u32 tolerance, u32 priority, u32 ack_mtu) { struct sk_buff *buf = NULL; struct tipc_msg *msg = l_ptr->pmsg; u32 msg_size = sizeof(l_ptr->proto_msg); int r_flag; /* Discard any previous message that was deferred due to congestion */ if (l_ptr->proto_msg_queue) { kfree_skb(l_ptr->proto_msg_queue); l_ptr->proto_msg_queue = NULL; } /* Don't send protocol message during link changeover */ if (l_ptr->exp_msg_count) return; /* Abort non-RESET send if communication with node is prohibited */ if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG)) return; /* Create protocol message with "out-of-sequence" sequence number */ msg_set_type(msg, msg_typ); msg_set_net_plane(msg, l_ptr->net_plane); msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); msg_set_last_bcast(msg, tipc_bclink_get_last_sent()); if (msg_typ == STATE_MSG) { u32 next_sent = mod(l_ptr->next_out_no); if (!tipc_link_is_up(l_ptr)) return; if (l_ptr->next_out) next_sent = buf_seqno(l_ptr->next_out); msg_set_next_sent(msg, next_sent); if (l_ptr->oldest_deferred_in) { u32 rec = buf_seqno(l_ptr->oldest_deferred_in); gap = mod(rec - mod(l_ptr->next_in_no)); } msg_set_seq_gap(msg, gap); if (gap) l_ptr->stats.sent_nacks++; msg_set_link_tolerance(msg, tolerance); msg_set_linkprio(msg, priority); msg_set_max_pkt(msg, ack_mtu); msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); msg_set_probe(msg, probe_msg != 0); if (probe_msg) { u32 mtu = l_ptr->max_pkt; if ((mtu < l_ptr->max_pkt_target) && link_working_working(l_ptr) && l_ptr->fsm_msg_cnt) { msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3; if (l_ptr->max_pkt_probes == 10) { l_ptr->max_pkt_target = (msg_size - 4); l_ptr->max_pkt_probes = 0; msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3; } l_ptr->max_pkt_probes++; } l_ptr->stats.sent_probes++; } l_ptr->stats.sent_states++; } else { /* RESET_MSG or ACTIVATE_MSG */ msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1)); msg_set_seq_gap(msg, 0); msg_set_next_sent(msg, 1); msg_set_probe(msg, 0); msg_set_link_tolerance(msg, l_ptr->tolerance); msg_set_linkprio(msg, l_ptr->priority); msg_set_max_pkt(msg, l_ptr->max_pkt_target); } r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr)); msg_set_redundant_link(msg, r_flag); msg_set_linkprio(msg, l_ptr->priority); msg_set_size(msg, msg_size); msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2))); buf = tipc_buf_acquire(msg_size); if (!buf) return; skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg)); buf->priority = TC_PRIO_CONTROL; tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr); l_ptr->unacked_window = 0; kfree_skb(buf); } /* * Receive protocol message : * Note that network plane id propagates through the network, and may * change at any time. The node with lowest address rules */ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf) { u32 rec_gap = 0; u32 max_pkt_info; u32 max_pkt_ack; u32 msg_tol; struct tipc_msg *msg = buf_msg(buf); /* Discard protocol message during link changeover */ if (l_ptr->exp_msg_count) goto exit; if (l_ptr->net_plane != msg_net_plane(msg)) if (tipc_own_addr > msg_prevnode(msg)) l_ptr->net_plane = msg_net_plane(msg); switch (msg_type(msg)) { case RESET_MSG: if (!link_working_unknown(l_ptr) && (l_ptr->peer_session != INVALID_SESSION)) { if (less_eq(msg_session(msg), l_ptr->peer_session)) break; /* duplicate or old reset: ignore */ } if (!msg_redundant_link(msg) && (link_working_working(l_ptr) || link_working_unknown(l_ptr))) { /* * peer has lost contact -- don't allow peer's links * to reactivate before we recognize loss & clean up */ l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN; } link_state_event(l_ptr, RESET_MSG); /* fall thru' */ case ACTIVATE_MSG: /* Update link settings according other endpoint's values */ strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg)); msg_tol = msg_link_tolerance(msg); if (msg_tol > l_ptr->tolerance) link_set_supervision_props(l_ptr, msg_tol); if (msg_linkprio(msg) > l_ptr->priority) l_ptr->priority = msg_linkprio(msg); max_pkt_info = msg_max_pkt(msg); if (max_pkt_info) { if (max_pkt_info < l_ptr->max_pkt_target) l_ptr->max_pkt_target = max_pkt_info; if (l_ptr->max_pkt > l_ptr->max_pkt_target) l_ptr->max_pkt = l_ptr->max_pkt_target; } else { l_ptr->max_pkt = l_ptr->max_pkt_target; } /* Synchronize broadcast link info, if not done previously */ if (!tipc_node_is_up(l_ptr->owner)) { l_ptr->owner->bclink.last_sent = l_ptr->owner->bclink.last_in = msg_last_bcast(msg); l_ptr->owner->bclink.oos_state = 0; } l_ptr->peer_session = msg_session(msg); l_ptr->peer_bearer_id = msg_bearer_id(msg); if (msg_type(msg) == ACTIVATE_MSG) link_state_event(l_ptr, ACTIVATE_MSG); break; case STATE_MSG: msg_tol = msg_link_tolerance(msg); if (msg_tol) link_set_supervision_props(l_ptr, msg_tol); if (msg_linkprio(msg) && (msg_linkprio(msg) != l_ptr->priority)) { pr_warn("%s<%s>, priority change %u->%u\n", link_rst_msg, l_ptr->name, l_ptr->priority, msg_linkprio(msg)); l_ptr->priority = msg_linkprio(msg); tipc_link_reset(l_ptr); /* Enforce change to take effect */ break; } /* Record reception; force mismatch at next timeout: */ l_ptr->checkpoint--; link_state_event(l_ptr, TRAFFIC_MSG_EVT); l_ptr->stats.recv_states++; if (link_reset_unknown(l_ptr)) break; if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) { rec_gap = mod(msg_next_sent(msg) - mod(l_ptr->next_in_no)); } max_pkt_ack = msg_max_pkt(msg); if (max_pkt_ack > l_ptr->max_pkt) { l_ptr->max_pkt = max_pkt_ack; l_ptr->max_pkt_probes = 0; } max_pkt_ack = 0; if (msg_probe(msg)) { l_ptr->stats.recv_probes++; if (msg_size(msg) > sizeof(l_ptr->proto_msg)) max_pkt_ack = msg_size(msg); } /* Protocol message before retransmits, reduce loss risk */ if (l_ptr->owner->bclink.recv_permitted) tipc_bclink_update_link_state(l_ptr->owner, msg_last_bcast(msg)); if (rec_gap || (msg_probe(msg))) { tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0, 0, max_pkt_ack); } if (msg_seq_gap(msg)) { l_ptr->stats.recv_nacks++; tipc_link_retransmit(l_ptr, l_ptr->first_out, msg_seq_gap(msg)); } break; } exit: kfree_skb(buf); } /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to * a different bearer. Owner node is locked. */ static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr, struct tipc_msg *tunnel_hdr, struct tipc_msg *msg, u32 selector) { struct tipc_link *tunnel; struct sk_buff *buf; u32 length = msg_size(msg); tunnel = l_ptr->owner->active_links[selector & 1]; if (!tipc_link_is_up(tunnel)) { pr_warn("%stunnel link no longer available\n", link_co_err); return; } msg_set_size(tunnel_hdr, length + INT_H_SIZE); buf = tipc_buf_acquire(length + INT_H_SIZE); if (!buf) { pr_warn("%sunable to send tunnel msg\n", link_co_err); return; } skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE); skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length); __tipc_link_xmit(tunnel, buf); } /* tipc_link_failover_send_queue(): A link has gone down, but a second * link is still active. We can do failover. Tunnel the failing link's * whole send queue via the remaining link. This way, we don't lose * any packets, and sequence order is preserved for subsequent traffic * sent over the remaining link. Owner node is locked. */ void tipc_link_failover_send_queue(struct tipc_link *l_ptr) { u32 msgcount = l_ptr->out_queue_size; struct sk_buff *crs = l_ptr->first_out; struct tipc_link *tunnel = l_ptr->owner->active_links[0]; struct tipc_msg tunnel_hdr; int split_bundles; if (!tunnel) return; tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL, ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr); msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id); msg_set_msgcnt(&tunnel_hdr, msgcount); if (!l_ptr->first_out) { struct sk_buff *buf; buf = tipc_buf_acquire(INT_H_SIZE); if (buf) { skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE); msg_set_size(&tunnel_hdr, INT_H_SIZE); __tipc_link_xmit(tunnel, buf); } else { pr_warn("%sunable to send changeover msg\n", link_co_err); } return; } split_bundles = (l_ptr->owner->active_links[0] != l_ptr->owner->active_links[1]); while (crs) { struct tipc_msg *msg = buf_msg(crs); if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) { struct tipc_msg *m = msg_get_wrapped(msg); unchar *pos = (unchar *)m; msgcount = msg_msgcnt(msg); while (msgcount--) { msg_set_seqno(m, msg_seqno(msg)); tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m, msg_link_selector(m)); pos += align(msg_size(m)); m = (struct tipc_msg *)pos; } } else { tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg, msg_link_selector(msg)); } crs = crs->next; } } /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a * duplicate of the first link's send queue via the new link. This way, we * are guaranteed that currently queued packets from a socket are delivered * before future traffic from the same socket, even if this is using the * new link. The last arriving copy of each duplicate packet is dropped at * the receiving end by the regular protocol check, so packet cardinality * and sequence order is preserved per sender/receiver socket pair. * Owner node is locked. */ void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *tunnel) { struct sk_buff *iter; struct tipc_msg tunnel_hdr; tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL, DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr); msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size); msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id); iter = l_ptr->first_out; while (iter) { struct sk_buff *outbuf; struct tipc_msg *msg = buf_msg(iter); u32 length = msg_size(msg); if (msg_user(msg) == MSG_BUNDLER) msg_set_type(msg, CLOSED_MSG); msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */ msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); msg_set_size(&tunnel_hdr, length + INT_H_SIZE); outbuf = tipc_buf_acquire(length + INT_H_SIZE); if (outbuf == NULL) { pr_warn("%sunable to send duplicate msg\n", link_co_err); return; } skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE); skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data, length); __tipc_link_xmit(tunnel, outbuf); if (!tipc_link_is_up(l_ptr)) return; iter = iter->next; } } /** * buf_extract - extracts embedded TIPC message from another message * @skb: encapsulating message buffer * @from_pos: offset to extract from * * Returns a new message buffer containing an embedded message. The * encapsulating message itself is left unchanged. */ static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos) { struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos); u32 size = msg_size(msg); struct sk_buff *eb; eb = tipc_buf_acquire(size); if (eb) skb_copy_to_linear_data(eb, msg, size); return eb; } /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet. * Owner node is locked. */ static void tipc_link_dup_rcv(struct tipc_link *l_ptr, struct sk_buff *t_buf) { struct sk_buff *buf; if (!tipc_link_is_up(l_ptr)) return; buf = buf_extract(t_buf, INT_H_SIZE); if (buf == NULL) { pr_warn("%sfailed to extract inner dup pkt\n", link_co_err); return; } /* Add buffer to deferred queue, if applicable: */ link_handle_out_of_seq_msg(l_ptr, buf); } /* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet * Owner node is locked. */ static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr, struct sk_buff *t_buf) { struct tipc_msg *t_msg = buf_msg(t_buf); struct sk_buff *buf = NULL; struct tipc_msg *msg; if (tipc_link_is_up(l_ptr)) tipc_link_reset(l_ptr); /* First failover packet? */ if (l_ptr->exp_msg_count == START_CHANGEOVER) l_ptr->exp_msg_count = msg_msgcnt(t_msg); /* Should there be an inner packet? */ if (l_ptr->exp_msg_count) { l_ptr->exp_msg_count--; buf = buf_extract(t_buf, INT_H_SIZE); if (buf == NULL) { pr_warn("%sno inner failover pkt\n", link_co_err); goto exit; } msg = buf_msg(buf); if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) { kfree_skb(buf); buf = NULL; goto exit; } if (msg_user(msg) == MSG_FRAGMENTER) { l_ptr->stats.recv_fragments++; tipc_buf_append(&l_ptr->reasm_buf, &buf); } } exit: if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) { tipc_node_detach_link(l_ptr->owner, l_ptr); kfree(l_ptr); } return buf; } /* tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent * via other link as result of a failover (ORIGINAL_MSG) or * a new active link (DUPLICATE_MSG). Failover packets are * returned to the active link for delivery upwards. * Owner node is locked. */ static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr, struct sk_buff **buf) { struct sk_buff *t_buf = *buf; struct tipc_link *l_ptr; struct tipc_msg *t_msg = buf_msg(t_buf); u32 bearer_id = msg_bearer_id(t_msg); *buf = NULL; if (bearer_id >= MAX_BEARERS) goto exit; l_ptr = n_ptr->links[bearer_id]; if (!l_ptr) goto exit; if (msg_type(t_msg) == DUPLICATE_MSG) tipc_link_dup_rcv(l_ptr, t_buf); else if (msg_type(t_msg) == ORIGINAL_MSG) *buf = tipc_link_failover_rcv(l_ptr, t_buf); else pr_warn("%sunknown tunnel pkt received\n", link_co_err); exit: kfree_skb(t_buf); return *buf != NULL; } /* * Bundler functionality: */ void tipc_link_bundle_rcv(struct sk_buff *buf) { u32 msgcount = msg_msgcnt(buf_msg(buf)); u32 pos = INT_H_SIZE; struct sk_buff *obuf; struct tipc_msg *omsg; while (msgcount--) { obuf = buf_extract(buf, pos); if (obuf == NULL) { pr_warn("Link unable to unbundle message(s)\n"); break; } omsg = buf_msg(obuf); pos += align(msg_size(omsg)); if (msg_isdata(omsg)) { if (unlikely(msg_type(omsg) == TIPC_MCAST_MSG)) tipc_sk_mcast_rcv(obuf); else tipc_sk_rcv(obuf); } else if (msg_user(omsg) == CONN_MANAGER) { tipc_sk_rcv(obuf); } else if (msg_user(omsg) == NAME_DISTRIBUTOR) { tipc_named_rcv(obuf); } else { pr_warn("Illegal bundled msg: %u\n", msg_user(omsg)); kfree_skb(obuf); } } kfree_skb(buf); } static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance) { if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL)) return; l_ptr->tolerance = tolerance; l_ptr->continuity_interval = ((tolerance / 4) > 500) ? 500 : tolerance / 4; l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4); } void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window) { /* Data messages from this node, inclusive FIRST_FRAGM */ l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window; l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4; l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5; l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6; /* Transiting data messages,inclusive FIRST_FRAGM */ l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300; l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600; l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900; l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200; l_ptr->queue_limit[CONN_MANAGER] = 1200; l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500; l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000; /* FRAGMENT and LAST_FRAGMENT packets */ l_ptr->queue_limit[MSG_FRAGMENTER] = 4000; } /* tipc_link_find_owner - locate owner node of link by link's name * @name: pointer to link name string * @bearer_id: pointer to index in 'node->links' array where the link was found. * * Returns pointer to node owning the link, or 0 if no matching link is found. */ static struct tipc_node *tipc_link_find_owner(const char *link_name, unsigned int *bearer_id) { struct tipc_link *l_ptr; struct tipc_node *n_ptr; struct tipc_node *found_node = 0; int i; *bearer_id = 0; rcu_read_lock(); list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { tipc_node_lock(n_ptr); for (i = 0; i < MAX_BEARERS; i++) { l_ptr = n_ptr->links[i]; if (l_ptr && !strcmp(l_ptr->name, link_name)) { *bearer_id = i; found_node = n_ptr; break; } } tipc_node_unlock(n_ptr); if (found_node) break; } rcu_read_unlock(); return found_node; } /** * link_value_is_valid -- validate proposed link tolerance/priority/window * * @cmd: value type (TIPC_CMD_SET_LINK_*) * @new_value: the new value * * Returns 1 if value is within range, 0 if not. */ static int link_value_is_valid(u16 cmd, u32 new_value) { switch (cmd) { case TIPC_CMD_SET_LINK_TOL: return (new_value >= TIPC_MIN_LINK_TOL) && (new_value <= TIPC_MAX_LINK_TOL); case TIPC_CMD_SET_LINK_PRI: return (new_value <= TIPC_MAX_LINK_PRI); case TIPC_CMD_SET_LINK_WINDOW: return (new_value >= TIPC_MIN_LINK_WIN) && (new_value <= TIPC_MAX_LINK_WIN); } return 0; } /** * link_cmd_set_value - change priority/tolerance/window for link/bearer/media * @name: ptr to link, bearer, or media name * @new_value: new value of link, bearer, or media setting * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*) * * Caller must hold RTNL lock to ensure link/bearer/media is not deleted. * * Returns 0 if value updated and negative value on error. */ static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd) { struct tipc_node *node; struct tipc_link *l_ptr; struct tipc_bearer *b_ptr; struct tipc_media *m_ptr; int bearer_id; int res = 0; node = tipc_link_find_owner(name, &bearer_id); if (node) { tipc_node_lock(node); l_ptr = node->links[bearer_id]; if (l_ptr) { switch (cmd) { case TIPC_CMD_SET_LINK_TOL: link_set_supervision_props(l_ptr, new_value); tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, new_value, 0, 0); break; case TIPC_CMD_SET_LINK_PRI: l_ptr->priority = new_value; tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, new_value, 0); break; case TIPC_CMD_SET_LINK_WINDOW: tipc_link_set_queue_limits(l_ptr, new_value); break; default: res = -EINVAL; break; } } tipc_node_unlock(node); return res; } b_ptr = tipc_bearer_find(name); if (b_ptr) { switch (cmd) { case TIPC_CMD_SET_LINK_TOL: b_ptr->tolerance = new_value; break; case TIPC_CMD_SET_LINK_PRI: b_ptr->priority = new_value; break; case TIPC_CMD_SET_LINK_WINDOW: b_ptr->window = new_value; break; default: res = -EINVAL; break; } return res; } m_ptr = tipc_media_find(name); if (!m_ptr) return -ENODEV; switch (cmd) { case TIPC_CMD_SET_LINK_TOL: m_ptr->tolerance = new_value; break; case TIPC_CMD_SET_LINK_PRI: m_ptr->priority = new_value; break; case TIPC_CMD_SET_LINK_WINDOW: m_ptr->window = new_value; break; default: res = -EINVAL; break; } return res; } struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space, u16 cmd) { struct tipc_link_config *args; u32 new_value; int res; if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG)) return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); args = (struct tipc_link_config *)TLV_DATA(req_tlv_area); new_value = ntohl(args->value); if (!link_value_is_valid(cmd, new_value)) return tipc_cfg_reply_error_string( "cannot change, value invalid"); if (!strcmp(args->name, tipc_bclink_name)) { if ((cmd == TIPC_CMD_SET_LINK_WINDOW) && (tipc_bclink_set_queue_limits(new_value) == 0)) return tipc_cfg_reply_none(); return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED " (cannot change setting on broadcast link)"); } res = link_cmd_set_value(args->name, new_value, cmd); if (res) return tipc_cfg_reply_error_string("cannot change link setting"); return tipc_cfg_reply_none(); } /** * link_reset_statistics - reset link statistics * @l_ptr: pointer to link */ static void link_reset_statistics(struct tipc_link *l_ptr) { memset(&l_ptr->stats, 0, sizeof(l_ptr->stats)); l_ptr->stats.sent_info = l_ptr->next_out_no; l_ptr->stats.recv_info = l_ptr->next_in_no; } struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space) { char *link_name; struct tipc_link *l_ptr; struct tipc_node *node; unsigned int bearer_id; if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME)) return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); link_name = (char *)TLV_DATA(req_tlv_area); if (!strcmp(link_name, tipc_bclink_name)) { if (tipc_bclink_reset_stats()) return tipc_cfg_reply_error_string("link not found"); return tipc_cfg_reply_none(); } node = tipc_link_find_owner(link_name, &bearer_id); if (!node) return tipc_cfg_reply_error_string("link not found"); tipc_node_lock(node); l_ptr = node->links[bearer_id]; if (!l_ptr) { tipc_node_unlock(node); return tipc_cfg_reply_error_string("link not found"); } link_reset_statistics(l_ptr); tipc_node_unlock(node); return tipc_cfg_reply_none(); } /** * percent - convert count to a percentage of total (rounding up or down) */ static u32 percent(u32 count, u32 total) { return (count * 100 + (total / 2)) / total; } /** * tipc_link_stats - print link statistics * @name: link name * @buf: print buffer area * @buf_size: size of print buffer area * * Returns length of print buffer data string (or 0 if error) */ static int tipc_link_stats(const char *name, char *buf, const u32 buf_size) { struct tipc_link *l; struct tipc_stats *s; struct tipc_node *node; char *status; u32 profile_total = 0; unsigned int bearer_id; int ret; if (!strcmp(name, tipc_bclink_name)) return tipc_bclink_stats(buf, buf_size); node = tipc_link_find_owner(name, &bearer_id); if (!node) return 0; tipc_node_lock(node); l = node->links[bearer_id]; if (!l) { tipc_node_unlock(node); return 0; } s = &l->stats; if (tipc_link_is_active(l)) status = "ACTIVE"; else if (tipc_link_is_up(l)) status = "STANDBY"; else status = "DEFUNCT"; ret = tipc_snprintf(buf, buf_size, "Link <%s>\n" " %s MTU:%u Priority:%u Tolerance:%u ms" " Window:%u packets\n", l->name, status, l->max_pkt, l->priority, l->tolerance, l->queue_limit[0]); ret += tipc_snprintf(buf + ret, buf_size - ret, " RX packets:%u fragments:%u/%u bundles:%u/%u\n", l->next_in_no - s->recv_info, s->recv_fragments, s->recv_fragmented, s->recv_bundles, s->recv_bundled); ret += tipc_snprintf(buf + ret, buf_size - ret, " TX packets:%u fragments:%u/%u bundles:%u/%u\n", l->next_out_no - s->sent_info, s->sent_fragments, s->sent_fragmented, s->sent_bundles, s->sent_bundled); profile_total = s->msg_length_counts; if (!profile_total) profile_total = 1; ret += tipc_snprintf(buf + ret, buf_size - ret, " TX profile sample:%u packets average:%u octets\n" " 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% " "-16384:%u%% -32768:%u%% -66000:%u%%\n", s->msg_length_counts, s->msg_lengths_total / profile_total, percent(s->msg_length_profile[0], profile_total), percent(s->msg_length_profile[1], profile_total), percent(s->msg_length_profile[2], profile_total), percent(s->msg_length_profile[3], profile_total), percent(s->msg_length_profile[4], profile_total), percent(s->msg_length_profile[5], profile_total), percent(s->msg_length_profile[6], profile_total)); ret += tipc_snprintf(buf + ret, buf_size - ret, " RX states:%u probes:%u naks:%u defs:%u" " dups:%u\n", s->recv_states, s->recv_probes, s->recv_nacks, s->deferred_recv, s->duplicates); ret += tipc_snprintf(buf + ret, buf_size - ret, " TX states:%u probes:%u naks:%u acks:%u" " dups:%u\n", s->sent_states, s->sent_probes, s->sent_nacks, s->sent_acks, s->retransmitted); ret += tipc_snprintf(buf + ret, buf_size - ret, " Congestion link:%u Send queue" " max:%u avg:%u\n", s->link_congs, s->max_queue_sz, s->queue_sz_counts ? (s->accu_queue_sz / s->queue_sz_counts) : 0); tipc_node_unlock(node); return ret; } struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space) { struct sk_buff *buf; struct tlv_desc *rep_tlv; int str_len; int pb_len; char *pb; if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME)) return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN)); if (!buf) return NULL; rep_tlv = (struct tlv_desc *)buf->data; pb = TLV_DATA(rep_tlv); pb_len = ULTRA_STRING_MAX_LEN; str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area), pb, pb_len); if (!str_len) { kfree_skb(buf); return tipc_cfg_reply_error_string("link not found"); } str_len += 1; /* for "\0" */ skb_put(buf, TLV_SPACE(str_len)); TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len); return buf; } /** * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination * @dest: network address of destination node * @selector: used to select from set of active links * * If no active link can be found, uses default maximum packet size. */ u32 tipc_link_get_max_pkt(u32 dest, u32 selector) { struct tipc_node *n_ptr; struct tipc_link *l_ptr; u32 res = MAX_PKT_DEFAULT; if (dest == tipc_own_addr) return MAX_MSG_SIZE; n_ptr = tipc_node_find(dest); if (n_ptr) { tipc_node_lock(n_ptr); l_ptr = n_ptr->active_links[selector & 1]; if (l_ptr) res = l_ptr->max_pkt; tipc_node_unlock(n_ptr); } return res; } static void link_print(struct tipc_link *l_ptr, const char *str) { struct tipc_bearer *b_ptr; rcu_read_lock(); b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]); if (b_ptr) pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name); rcu_read_unlock(); if (link_working_unknown(l_ptr)) pr_cont(":WU\n"); else if (link_reset_reset(l_ptr)) pr_cont(":RR\n"); else if (link_reset_unknown(l_ptr)) pr_cont(":RU\n"); else if (link_working_working(l_ptr)) pr_cont(":WW\n"); else pr_cont("\n"); }