/* * net/tipc/link.c: TIPC link code * * Copyright (c) 1996-2007, 2012-2016, 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 "subscr.h" #include "link.h" #include "bcast.h" #include "socket.h" #include "name_distr.h" #include "discover.h" #include "netlink.h" #include "monitor.h" #include <linux/pkt_sched.h> struct tipc_stats { u32 sent_pkts; u32 recv_pkts; u32 sent_states; u32 recv_states; u32 sent_probes; u32 recv_probes; u32 sent_nacks; u32 recv_nacks; u32 sent_acks; u32 sent_bundled; u32 sent_bundles; u32 recv_bundled; u32 recv_bundles; u32 retransmitted; u32 sent_fragmented; u32 sent_fragments; u32 recv_fragmented; u32 recv_fragments; u32 link_congs; /* # port sends blocked by congestion */ u32 deferred_recv; u32 duplicates; u32 max_queue_sz; /* send queue size high water mark */ u32 accu_queue_sz; /* used for send queue size profiling */ u32 queue_sz_counts; /* used for send queue size profiling */ u32 msg_length_counts; /* used for message length profiling */ u32 msg_lengths_total; /* used for message length profiling */ u32 msg_length_profile[7]; /* used for msg. length profiling */ }; /** * struct tipc_link - TIPC link data structure * @addr: network address of link's peer node * @name: link name character string * @media_addr: media address to use when sending messages over link * @timer: link timer * @net: pointer to namespace struct * @refcnt: reference counter for permanent references (owner node & timer) * @peer_session: link session # being used by peer end of link * @peer_bearer_id: bearer id used by link's peer endpoint * @bearer_id: local bearer id used by link * @tolerance: minimum link continuity loss needed to reset link [in ms] * @abort_limit: # of unacknowledged continuity probes needed to reset link * @state: current state of link FSM * @peer_caps: bitmap describing capabilities of peer node * @silent_intv_cnt: # of timer intervals without any reception from peer * @proto_msg: template for control messages generated by link * @pmsg: convenience pointer to "proto_msg" field * @priority: current link priority * @net_plane: current link network plane ('A' through 'H') * @mon_state: cookie with information needed by link monitor * @backlog_limit: backlog queue congestion thresholds (indexed by importance) * @exp_msg_count: # of tunnelled messages expected during link changeover * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset * @mtu: current maximum packet size for this link * @advertised_mtu: advertised own mtu when link is being established * @transmitq: queue for sent, non-acked messages * @backlogq: queue for messages waiting to be sent * @snt_nxt: next sequence number to use for outbound messages * @last_retransmitted: sequence number of most recently retransmitted message * @stale_cnt: counter for number of identical retransmit attempts * @stale_limit: time when repeated identical retransmits must force link reset * @ackers: # of peers that needs to ack each packet before it can be released * @acked: # last packet acked by a certain peer. Used for broadcast. * @rcv_nxt: next sequence number to expect for inbound messages * @deferred_queue: deferred queue saved OOS b'cast message received from node * @unacked_window: # of inbound messages rx'd without ack'ing back to peer * @inputq: buffer queue for messages to be delivered upwards * @namedq: buffer queue for name table messages to be delivered upwards * @next_out: ptr to first unsent outbound message in queue * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate * @long_msg_seq_no: next identifier to use for outbound fragmented messages * @reasm_buf: head of partially reassembled inbound message fragments * @bc_rcvr: marks that this is a broadcast receiver link * @stats: collects statistics regarding link activity */ struct tipc_link { u32 addr; char name[TIPC_MAX_LINK_NAME]; struct net *net; /* Management and link supervision data */ u16 peer_session; u16 session; u16 snd_nxt_state; u16 rcv_nxt_state; u32 peer_bearer_id; u32 bearer_id; u32 tolerance; u32 abort_limit; u32 state; u16 peer_caps; bool in_session; bool active; u32 silent_intv_cnt; char if_name[TIPC_MAX_IF_NAME]; u32 priority; char net_plane; struct tipc_mon_state mon_state; u16 rst_cnt; /* Failover/synch */ u16 drop_point; struct sk_buff *failover_reasm_skb; /* Max packet negotiation */ u16 mtu; u16 advertised_mtu; /* Sending */ struct sk_buff_head transmq; struct sk_buff_head backlogq; struct { u16 len; u16 limit; } backlog[5]; u16 snd_nxt; u16 last_retransm; u16 window; u16 stale_cnt; unsigned long stale_limit; /* Reception */ u16 rcv_nxt; u32 rcv_unacked; struct sk_buff_head deferdq; struct sk_buff_head *inputq; struct sk_buff_head *namedq; /* Congestion handling */ struct sk_buff_head wakeupq; /* Fragmentation/reassembly */ struct sk_buff *reasm_buf; /* Broadcast */ u16 ackers; u16 acked; struct tipc_link *bc_rcvlink; struct tipc_link *bc_sndlink; unsigned long prev_retr; u16 prev_from; u16 prev_to; u8 nack_state; bool bc_peer_is_up; /* Statistics */ struct tipc_stats stats; }; /* * Error message prefixes */ static const char *link_co_err = "Link tunneling error, "; static const char *link_rst_msg = "Resetting link "; /* Send states for broadcast NACKs */ enum { BC_NACK_SND_CONDITIONAL, BC_NACK_SND_UNCONDITIONAL, BC_NACK_SND_SUPPRESS, }; #define TIPC_BC_RETR_LIMIT 10 /* [ms] */ /* * Interval between NACKs when packets arrive out of order */ #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2) /* Link FSM states: */ enum { LINK_ESTABLISHED = 0xe, LINK_ESTABLISHING = 0xe << 4, LINK_RESET = 0x1 << 8, LINK_RESETTING = 0x2 << 12, LINK_PEER_RESET = 0xd << 16, LINK_FAILINGOVER = 0xf << 20, LINK_SYNCHING = 0xc << 24 }; /* Link FSM state checking routines */ static int link_is_up(struct tipc_link *l) { return l->state & (LINK_ESTABLISHED | LINK_SYNCHING); } static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq); static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, bool probe_reply, u16 rcvgap, int tolerance, int priority, struct sk_buff_head *xmitq); static void link_print(struct tipc_link *l, const char *str); static int tipc_link_build_nack_msg(struct tipc_link *l, struct sk_buff_head *xmitq); static void tipc_link_build_bc_init_msg(struct tipc_link *l, struct sk_buff_head *xmitq); static bool tipc_link_release_pkts(struct tipc_link *l, u16 to); /* * Simple non-static link routines (i.e. referenced outside this file) */ bool tipc_link_is_up(struct tipc_link *l) { return link_is_up(l); } bool tipc_link_peer_is_down(struct tipc_link *l) { return l->state == LINK_PEER_RESET; } bool tipc_link_is_reset(struct tipc_link *l) { return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING); } bool tipc_link_is_establishing(struct tipc_link *l) { return l->state == LINK_ESTABLISHING; } bool tipc_link_is_synching(struct tipc_link *l) { return l->state == LINK_SYNCHING; } bool tipc_link_is_failingover(struct tipc_link *l) { return l->state == LINK_FAILINGOVER; } bool tipc_link_is_blocked(struct tipc_link *l) { return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER); } static bool link_is_bc_sndlink(struct tipc_link *l) { return !l->bc_sndlink; } static bool link_is_bc_rcvlink(struct tipc_link *l) { return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l)); } void tipc_link_set_active(struct tipc_link *l, bool active) { l->active = active; } u32 tipc_link_id(struct tipc_link *l) { return l->peer_bearer_id << 16 | l->bearer_id; } int tipc_link_window(struct tipc_link *l) { return l->window; } int tipc_link_prio(struct tipc_link *l) { return l->priority; } unsigned long tipc_link_tolerance(struct tipc_link *l) { return l->tolerance; } struct sk_buff_head *tipc_link_inputq(struct tipc_link *l) { return l->inputq; } char tipc_link_plane(struct tipc_link *l) { return l->net_plane; } void tipc_link_update_caps(struct tipc_link *l, u16 capabilities) { l->peer_caps = capabilities; } void tipc_link_add_bc_peer(struct tipc_link *snd_l, struct tipc_link *uc_l, struct sk_buff_head *xmitq) { struct tipc_link *rcv_l = uc_l->bc_rcvlink; snd_l->ackers++; rcv_l->acked = snd_l->snd_nxt - 1; snd_l->state = LINK_ESTABLISHED; tipc_link_build_bc_init_msg(uc_l, xmitq); } void tipc_link_remove_bc_peer(struct tipc_link *snd_l, struct tipc_link *rcv_l, struct sk_buff_head *xmitq) { u16 ack = snd_l->snd_nxt - 1; snd_l->ackers--; rcv_l->bc_peer_is_up = true; rcv_l->state = LINK_ESTABLISHED; tipc_link_bc_ack_rcv(rcv_l, ack, xmitq); tipc_link_reset(rcv_l); rcv_l->state = LINK_RESET; if (!snd_l->ackers) { tipc_link_reset(snd_l); snd_l->state = LINK_RESET; __skb_queue_purge(xmitq); } } int tipc_link_bc_peers(struct tipc_link *l) { return l->ackers; } static u16 link_bc_rcv_gap(struct tipc_link *l) { struct sk_buff *skb = skb_peek(&l->deferdq); u16 gap = 0; if (more(l->snd_nxt, l->rcv_nxt)) gap = l->snd_nxt - l->rcv_nxt; if (skb) gap = buf_seqno(skb) - l->rcv_nxt; return gap; } void tipc_link_set_mtu(struct tipc_link *l, int mtu) { l->mtu = mtu; } int tipc_link_mtu(struct tipc_link *l) { return l->mtu; } u16 tipc_link_rcv_nxt(struct tipc_link *l) { return l->rcv_nxt; } u16 tipc_link_acked(struct tipc_link *l) { return l->acked; } char *tipc_link_name(struct tipc_link *l) { return l->name; } u32 tipc_link_state(struct tipc_link *l) { return l->state; } /** * tipc_link_create - create a new link * @n: pointer to associated node * @if_name: associated interface name * @bearer_id: id (index) of associated bearer * @tolerance: link tolerance to be used by link * @net_plane: network plane (A,B,c..) this link belongs to * @mtu: mtu to be advertised by link * @priority: priority to be used by link * @window: send window to be used by link * @session: session to be used by link * @ownnode: identity of own node * @peer: node id of peer node * @peer_caps: bitmap describing peer node capabilities * @bc_sndlink: the namespace global link used for broadcast sending * @bc_rcvlink: the peer specific link used for broadcast reception * @inputq: queue to put messages ready for delivery * @namedq: queue to put binding table update messages ready for delivery * @link: return value, pointer to put the created link * * Returns true if link was created, otherwise false */ bool tipc_link_create(struct net *net, char *if_name, int bearer_id, int tolerance, char net_plane, u32 mtu, int priority, int window, u32 session, u32 self, u32 peer, u8 *peer_id, u16 peer_caps, struct tipc_link *bc_sndlink, struct tipc_link *bc_rcvlink, struct sk_buff_head *inputq, struct sk_buff_head *namedq, struct tipc_link **link) { char peer_str[NODE_ID_STR_LEN] = {0,}; char self_str[NODE_ID_STR_LEN] = {0,}; struct tipc_link *l; l = kzalloc(sizeof(*l), GFP_ATOMIC); if (!l) return false; *link = l; l->session = session; /* Set link name for unicast links only */ if (peer_id) { tipc_nodeid2string(self_str, tipc_own_id(net)); if (strlen(self_str) > 16) sprintf(self_str, "%x", self); tipc_nodeid2string(peer_str, peer_id); if (strlen(peer_str) > 16) sprintf(peer_str, "%x", peer); } /* Peer i/f name will be completed by reset/activate message */ snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown", self_str, if_name, peer_str); strcpy(l->if_name, if_name); l->addr = peer; l->peer_caps = peer_caps; l->net = net; l->in_session = false; l->bearer_id = bearer_id; l->tolerance = tolerance; if (bc_rcvlink) bc_rcvlink->tolerance = tolerance; l->net_plane = net_plane; l->advertised_mtu = mtu; l->mtu = mtu; l->priority = priority; tipc_link_set_queue_limits(l, window); l->ackers = 1; l->bc_sndlink = bc_sndlink; l->bc_rcvlink = bc_rcvlink; l->inputq = inputq; l->namedq = namedq; l->state = LINK_RESETTING; __skb_queue_head_init(&l->transmq); __skb_queue_head_init(&l->backlogq); __skb_queue_head_init(&l->deferdq); skb_queue_head_init(&l->wakeupq); skb_queue_head_init(l->inputq); return true; } /** * tipc_link_bc_create - create new link to be used for broadcast * @n: pointer to associated node * @mtu: mtu to be used initially if no peers * @window: send window to be used * @inputq: queue to put messages ready for delivery * @namedq: queue to put binding table update messages ready for delivery * @link: return value, pointer to put the created link * * Returns true if link was created, otherwise false */ bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, int mtu, int window, u16 peer_caps, struct sk_buff_head *inputq, struct sk_buff_head *namedq, struct tipc_link *bc_sndlink, struct tipc_link **link) { struct tipc_link *l; if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window, 0, ownnode, peer, NULL, peer_caps, bc_sndlink, NULL, inputq, namedq, link)) return false; l = *link; strcpy(l->name, tipc_bclink_name); tipc_link_reset(l); l->state = LINK_RESET; l->ackers = 0; l->bc_rcvlink = l; /* Broadcast send link is always up */ if (link_is_bc_sndlink(l)) l->state = LINK_ESTABLISHED; /* Disable replicast if even a single peer doesn't support it */ if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST)) tipc_bcast_disable_rcast(net); return true; } /** * tipc_link_fsm_evt - link finite state machine * @l: pointer to link * @evt: state machine event to be processed */ int tipc_link_fsm_evt(struct tipc_link *l, int evt) { int rc = 0; switch (l->state) { case LINK_RESETTING: switch (evt) { case LINK_PEER_RESET_EVT: l->state = LINK_PEER_RESET; break; case LINK_RESET_EVT: l->state = LINK_RESET; break; case LINK_FAILURE_EVT: case LINK_FAILOVER_BEGIN_EVT: case LINK_ESTABLISH_EVT: case LINK_FAILOVER_END_EVT: case LINK_SYNCH_BEGIN_EVT: case LINK_SYNCH_END_EVT: default: goto illegal_evt; } break; case LINK_RESET: switch (evt) { case LINK_PEER_RESET_EVT: l->state = LINK_ESTABLISHING; break; case LINK_FAILOVER_BEGIN_EVT: l->state = LINK_FAILINGOVER; case LINK_FAILURE_EVT: case LINK_RESET_EVT: case LINK_ESTABLISH_EVT: case LINK_FAILOVER_END_EVT: break; case LINK_SYNCH_BEGIN_EVT: case LINK_SYNCH_END_EVT: default: goto illegal_evt; } break; case LINK_PEER_RESET: switch (evt) { case LINK_RESET_EVT: l->state = LINK_ESTABLISHING; break; case LINK_PEER_RESET_EVT: case LINK_ESTABLISH_EVT: case LINK_FAILURE_EVT: break; case LINK_SYNCH_BEGIN_EVT: case LINK_SYNCH_END_EVT: case LINK_FAILOVER_BEGIN_EVT: case LINK_FAILOVER_END_EVT: default: goto illegal_evt; } break; case LINK_FAILINGOVER: switch (evt) { case LINK_FAILOVER_END_EVT: l->state = LINK_RESET; break; case LINK_PEER_RESET_EVT: case LINK_RESET_EVT: case LINK_ESTABLISH_EVT: case LINK_FAILURE_EVT: break; case LINK_FAILOVER_BEGIN_EVT: case LINK_SYNCH_BEGIN_EVT: case LINK_SYNCH_END_EVT: default: goto illegal_evt; } break; case LINK_ESTABLISHING: switch (evt) { case LINK_ESTABLISH_EVT: l->state = LINK_ESTABLISHED; break; case LINK_FAILOVER_BEGIN_EVT: l->state = LINK_FAILINGOVER; break; case LINK_RESET_EVT: l->state = LINK_RESET; break; case LINK_FAILURE_EVT: case LINK_PEER_RESET_EVT: case LINK_SYNCH_BEGIN_EVT: case LINK_FAILOVER_END_EVT: break; case LINK_SYNCH_END_EVT: default: goto illegal_evt; } break; case LINK_ESTABLISHED: switch (evt) { case LINK_PEER_RESET_EVT: l->state = LINK_PEER_RESET; rc |= TIPC_LINK_DOWN_EVT; break; case LINK_FAILURE_EVT: l->state = LINK_RESETTING; rc |= TIPC_LINK_DOWN_EVT; break; case LINK_RESET_EVT: l->state = LINK_RESET; break; case LINK_ESTABLISH_EVT: case LINK_SYNCH_END_EVT: break; case LINK_SYNCH_BEGIN_EVT: l->state = LINK_SYNCHING; break; case LINK_FAILOVER_BEGIN_EVT: case LINK_FAILOVER_END_EVT: default: goto illegal_evt; } break; case LINK_SYNCHING: switch (evt) { case LINK_PEER_RESET_EVT: l->state = LINK_PEER_RESET; rc |= TIPC_LINK_DOWN_EVT; break; case LINK_FAILURE_EVT: l->state = LINK_RESETTING; rc |= TIPC_LINK_DOWN_EVT; break; case LINK_RESET_EVT: l->state = LINK_RESET; break; case LINK_ESTABLISH_EVT: case LINK_SYNCH_BEGIN_EVT: break; case LINK_SYNCH_END_EVT: l->state = LINK_ESTABLISHED; break; case LINK_FAILOVER_BEGIN_EVT: case LINK_FAILOVER_END_EVT: default: goto illegal_evt; } break; default: pr_err("Unknown FSM state %x in %s\n", l->state, l->name); } return rc; illegal_evt: pr_err("Illegal FSM event %x in state %x on link %s\n", evt, l->state, l->name); return rc; } /* link_profile_stats - update statistical profiling of traffic */ static void link_profile_stats(struct tipc_link *l) { struct sk_buff *skb; struct tipc_msg *msg; int length; /* Update counters used in statistical profiling of send traffic */ l->stats.accu_queue_sz += skb_queue_len(&l->transmq); l->stats.queue_sz_counts++; skb = skb_peek(&l->transmq); if (!skb) return; msg = buf_msg(skb); length = msg_size(msg); if (msg_user(msg) == MSG_FRAGMENTER) { if (msg_type(msg) != FIRST_FRAGMENT) return; length = msg_size(msg_get_wrapped(msg)); } l->stats.msg_lengths_total += length; l->stats.msg_length_counts++; if (length <= 64) l->stats.msg_length_profile[0]++; else if (length <= 256) l->stats.msg_length_profile[1]++; else if (length <= 1024) l->stats.msg_length_profile[2]++; else if (length <= 4096) l->stats.msg_length_profile[3]++; else if (length <= 16384) l->stats.msg_length_profile[4]++; else if (length <= 32768) l->stats.msg_length_profile[5]++; else l->stats.msg_length_profile[6]++; } /* tipc_link_timeout - perform periodic task as instructed from node timeout */ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq) { int mtyp = 0; int rc = 0; bool state = false; bool probe = false; bool setup = false; u16 bc_snt = l->bc_sndlink->snd_nxt - 1; u16 bc_acked = l->bc_rcvlink->acked; struct tipc_mon_state *mstate = &l->mon_state; switch (l->state) { case LINK_ESTABLISHED: case LINK_SYNCHING: mtyp = STATE_MSG; link_profile_stats(l); tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id); if (mstate->reset || (l->silent_intv_cnt > l->abort_limit)) return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); state = bc_acked != bc_snt; state |= l->bc_rcvlink->rcv_unacked; state |= l->rcv_unacked; state |= !skb_queue_empty(&l->transmq); state |= !skb_queue_empty(&l->deferdq); probe = mstate->probing; probe |= l->silent_intv_cnt; if (probe || mstate->monitoring) l->silent_intv_cnt++; break; case LINK_RESET: setup = l->rst_cnt++ <= 4; setup |= !(l->rst_cnt % 16); mtyp = RESET_MSG; break; case LINK_ESTABLISHING: setup = true; mtyp = ACTIVATE_MSG; break; case LINK_PEER_RESET: case LINK_RESETTING: case LINK_FAILINGOVER: break; default: break; } if (state || probe || setup) tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq); return rc; } /** * link_schedule_user - schedule a message sender for wakeup after congestion * @l: congested link * @hdr: header of message that is being sent * Create pseudo msg to send back to user when congestion abates */ static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr) { u32 dnode = tipc_own_addr(l->net); u32 dport = msg_origport(hdr); struct sk_buff *skb; /* Create and schedule wakeup pseudo message */ skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, dnode, l->addr, dport, 0, 0); if (!skb) return -ENOBUFS; msg_set_dest_droppable(buf_msg(skb), true); TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr); skb_queue_tail(&l->wakeupq, skb); l->stats.link_congs++; return -ELINKCONG; } /** * link_prepare_wakeup - prepare users for wakeup after congestion * @l: congested link * Wake up a number of waiting users, as permitted by available space * in the send queue */ static void link_prepare_wakeup(struct tipc_link *l) { struct sk_buff *skb, *tmp; int imp, i = 0; skb_queue_walk_safe(&l->wakeupq, skb, tmp) { imp = TIPC_SKB_CB(skb)->chain_imp; if (l->backlog[imp].len < l->backlog[imp].limit) { skb_unlink(skb, &l->wakeupq); skb_queue_tail(l->inputq, skb); } else if (i++ > 10) { break; } } } void tipc_link_reset(struct tipc_link *l) { struct sk_buff_head list; __skb_queue_head_init(&list); l->in_session = false; l->session++; l->mtu = l->advertised_mtu; spin_lock_bh(&l->wakeupq.lock); skb_queue_splice_init(&l->wakeupq, &list); spin_unlock_bh(&l->wakeupq.lock); spin_lock_bh(&l->inputq->lock); skb_queue_splice_init(&list, l->inputq); spin_unlock_bh(&l->inputq->lock); __skb_queue_purge(&l->transmq); __skb_queue_purge(&l->deferdq); __skb_queue_purge(&l->backlogq); l->backlog[TIPC_LOW_IMPORTANCE].len = 0; l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0; l->backlog[TIPC_HIGH_IMPORTANCE].len = 0; l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0; l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0; kfree_skb(l->reasm_buf); kfree_skb(l->failover_reasm_skb); l->reasm_buf = NULL; l->failover_reasm_skb = NULL; l->rcv_unacked = 0; l->snd_nxt = 1; l->rcv_nxt = 1; l->snd_nxt_state = 1; l->rcv_nxt_state = 1; l->acked = 0; l->silent_intv_cnt = 0; l->rst_cnt = 0; l->stale_cnt = 0; l->bc_peer_is_up = false; memset(&l->mon_state, 0, sizeof(l->mon_state)); tipc_link_reset_stats(l); } /** * tipc_link_xmit(): enqueue buffer list according to queue situation * @link: link to use * @list: chain of buffers containing message * @xmitq: returned list of packets to be sent by caller * * Consumes the buffer chain. * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted */ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, struct sk_buff_head *xmitq) { struct tipc_msg *hdr = buf_msg(skb_peek(list)); unsigned int maxwin = l->window; int imp = msg_importance(hdr); unsigned int mtu = l->mtu; u16 ack = l->rcv_nxt - 1; u16 seqno = l->snd_nxt; u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; struct sk_buff_head *transmq = &l->transmq; struct sk_buff_head *backlogq = &l->backlogq; struct sk_buff *skb, *_skb, *bskb; int pkt_cnt = skb_queue_len(list); int rc = 0; if (unlikely(msg_size(hdr) > mtu)) { skb_queue_purge(list); return -EMSGSIZE; } /* Allow oversubscription of one data msg per source at congestion */ if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) { if (imp == TIPC_SYSTEM_IMPORTANCE) { pr_warn("%s<%s>, link overflow", link_rst_msg, l->name); return -ENOBUFS; } rc = link_schedule_user(l, hdr); } if (pkt_cnt > 1) { l->stats.sent_fragmented++; l->stats.sent_fragments += pkt_cnt; } /* Prepare each packet for sending, and add to relevant queue: */ while (skb_queue_len(list)) { skb = skb_peek(list); hdr = buf_msg(skb); msg_set_seqno(hdr, seqno); msg_set_ack(hdr, ack); msg_set_bcast_ack(hdr, bc_ack); if (likely(skb_queue_len(transmq) < maxwin)) { _skb = skb_clone(skb, GFP_ATOMIC); if (!_skb) { skb_queue_purge(list); return -ENOBUFS; } __skb_dequeue(list); __skb_queue_tail(transmq, skb); __skb_queue_tail(xmitq, _skb); TIPC_SKB_CB(skb)->ackers = l->ackers; l->rcv_unacked = 0; l->stats.sent_pkts++; seqno++; continue; } if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) { kfree_skb(__skb_dequeue(list)); l->stats.sent_bundled++; continue; } if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) { kfree_skb(__skb_dequeue(list)); __skb_queue_tail(backlogq, bskb); l->backlog[msg_importance(buf_msg(bskb))].len++; l->stats.sent_bundled++; l->stats.sent_bundles++; continue; } l->backlog[imp].len += skb_queue_len(list); skb_queue_splice_tail_init(list, backlogq); } l->snd_nxt = seqno; return rc; } static void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq) { struct sk_buff *skb, *_skb; struct tipc_msg *hdr; u16 seqno = l->snd_nxt; u16 ack = l->rcv_nxt - 1; u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; while (skb_queue_len(&l->transmq) < l->window) { skb = skb_peek(&l->backlogq); if (!skb) break; _skb = skb_clone(skb, GFP_ATOMIC); if (!_skb) break; __skb_dequeue(&l->backlogq); hdr = buf_msg(skb); l->backlog[msg_importance(hdr)].len--; __skb_queue_tail(&l->transmq, skb); __skb_queue_tail(xmitq, _skb); TIPC_SKB_CB(skb)->ackers = l->ackers; msg_set_seqno(hdr, seqno); msg_set_ack(hdr, ack); msg_set_bcast_ack(hdr, bc_ack); l->rcv_unacked = 0; l->stats.sent_pkts++; seqno++; } l->snd_nxt = seqno; } static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb) { struct tipc_msg *hdr = buf_msg(skb); pr_warn("Retransmission failure on link <%s>\n", l->name); link_print(l, "State of link "); pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n", msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr)); pr_info("sqno %u, prev: %x, src: %x\n", msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr)); } /* tipc_link_retrans() - retransmit one or more packets * @l: the link to transmit on * @r: the receiving link ordering the retransmit. Same as l if unicast * @from: retransmit from (inclusive) this sequence number * @to: retransmit to (inclusive) this sequence number * xmitq: queue for accumulating the retransmitted packets */ static int tipc_link_retrans(struct tipc_link *l, struct tipc_link *r, u16 from, u16 to, struct sk_buff_head *xmitq) { struct sk_buff *_skb, *skb = skb_peek(&l->transmq); u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; u16 ack = l->rcv_nxt - 1; struct tipc_msg *hdr; if (!skb) return 0; /* Detect repeated retransmit failures on same packet */ if (r->last_retransm != buf_seqno(skb)) { r->last_retransm = buf_seqno(skb); r->stale_limit = jiffies + msecs_to_jiffies(r->tolerance); r->stale_cnt = 0; } else if (++r->stale_cnt > 99 && time_after(jiffies, r->stale_limit)) { link_retransmit_failure(l, skb); if (link_is_bc_sndlink(l)) return TIPC_LINK_DOWN_EVT; return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); } skb_queue_walk(&l->transmq, skb) { hdr = buf_msg(skb); if (less(msg_seqno(hdr), from)) continue; if (more(msg_seqno(hdr), to)) break; _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC); if (!_skb) return 0; hdr = buf_msg(_skb); msg_set_ack(hdr, ack); msg_set_bcast_ack(hdr, bc_ack); _skb->priority = TC_PRIO_CONTROL; __skb_queue_tail(xmitq, _skb); l->stats.retransmitted++; } return 0; } /* tipc_data_input - deliver data and name distr msgs to upper layer * * Consumes buffer if message is of right type * Node lock must be held */ static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *inputq) { struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq; struct tipc_msg *hdr = buf_msg(skb); switch (msg_user(hdr)) { case TIPC_LOW_IMPORTANCE: case TIPC_MEDIUM_IMPORTANCE: case TIPC_HIGH_IMPORTANCE: case TIPC_CRITICAL_IMPORTANCE: if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) { skb_queue_tail(mc_inputq, skb); return true; } /* else: fall through */ case CONN_MANAGER: skb_queue_tail(inputq, skb); return true; case GROUP_PROTOCOL: skb_queue_tail(mc_inputq, skb); return true; case NAME_DISTRIBUTOR: l->bc_rcvlink->state = LINK_ESTABLISHED; skb_queue_tail(l->namedq, skb); return true; case MSG_BUNDLER: case TUNNEL_PROTOCOL: case MSG_FRAGMENTER: case BCAST_PROTOCOL: return false; default: pr_warn("Dropping received illegal msg type\n"); kfree_skb(skb); return false; }; } /* tipc_link_input - process packet that has passed link protocol check * * Consumes buffer */ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *inputq) { struct tipc_msg *hdr = buf_msg(skb); struct sk_buff **reasm_skb = &l->reasm_buf; struct sk_buff *iskb; struct sk_buff_head tmpq; int usr = msg_user(hdr); int rc = 0; int pos = 0; int ipos = 0; if (unlikely(usr == TUNNEL_PROTOCOL)) { if (msg_type(hdr) == SYNCH_MSG) { __skb_queue_purge(&l->deferdq); goto drop; } if (!tipc_msg_extract(skb, &iskb, &ipos)) return rc; kfree_skb(skb); skb = iskb; hdr = buf_msg(skb); if (less(msg_seqno(hdr), l->drop_point)) goto drop; if (tipc_data_input(l, skb, inputq)) return rc; usr = msg_user(hdr); reasm_skb = &l->failover_reasm_skb; } if (usr == MSG_BUNDLER) { skb_queue_head_init(&tmpq); l->stats.recv_bundles++; l->stats.recv_bundled += msg_msgcnt(hdr); while (tipc_msg_extract(skb, &iskb, &pos)) tipc_data_input(l, iskb, &tmpq); tipc_skb_queue_splice_tail(&tmpq, inputq); return 0; } else if (usr == MSG_FRAGMENTER) { l->stats.recv_fragments++; if (tipc_buf_append(reasm_skb, &skb)) { l->stats.recv_fragmented++; tipc_data_input(l, skb, inputq); } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) { pr_warn_ratelimited("Unable to build fragment list\n"); return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); } return 0; } else if (usr == BCAST_PROTOCOL) { tipc_bcast_lock(l->net); tipc_link_bc_init_rcv(l->bc_rcvlink, hdr); tipc_bcast_unlock(l->net); } drop: kfree_skb(skb); return 0; } static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked) { bool released = false; struct sk_buff *skb, *tmp; skb_queue_walk_safe(&l->transmq, skb, tmp) { if (more(buf_seqno(skb), acked)) break; __skb_unlink(skb, &l->transmq); kfree_skb(skb); released = true; } return released; } /* tipc_link_build_state_msg: prepare link state message for transmission * * Note that sending of broadcast ack is coordinated among nodes, to reduce * risk of ack storms towards the sender */ int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq) { if (!l) return 0; /* Broadcast ACK must be sent via a unicast link => defer to caller */ if (link_is_bc_rcvlink(l)) { if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf) return 0; l->rcv_unacked = 0; /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */ l->snd_nxt = l->rcv_nxt; return TIPC_LINK_SND_STATE; } /* Unicast ACK */ l->rcv_unacked = 0; l->stats.sent_acks++; tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq); return 0; } /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message */ void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq) { int mtyp = RESET_MSG; struct sk_buff *skb; if (l->state == LINK_ESTABLISHING) mtyp = ACTIVATE_MSG; tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq); /* Inform peer that this endpoint is going down if applicable */ skb = skb_peek_tail(xmitq); if (skb && (l->state == LINK_RESET)) msg_set_peer_stopping(buf_msg(skb), 1); } /* tipc_link_build_nack_msg: prepare link nack message for transmission * Note that sending of broadcast NACK is coordinated among nodes, to * reduce the risk of NACK storms towards the sender */ static int tipc_link_build_nack_msg(struct tipc_link *l, struct sk_buff_head *xmitq) { u32 def_cnt = ++l->stats.deferred_recv; int match1, match2; if (link_is_bc_rcvlink(l)) { match1 = def_cnt & 0xf; match2 = tipc_own_addr(l->net) & 0xf; if (match1 == match2) return TIPC_LINK_SND_STATE; return 0; } if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV)) tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq); return 0; } /* tipc_link_rcv - process TIPC packets/messages arriving from off-node * @l: the link that should handle the message * @skb: TIPC packet * @xmitq: queue to place packets to be sent after this call */ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq) { struct sk_buff_head *defq = &l->deferdq; struct tipc_msg *hdr; u16 seqno, rcv_nxt, win_lim; int rc = 0; do { hdr = buf_msg(skb); seqno = msg_seqno(hdr); rcv_nxt = l->rcv_nxt; win_lim = rcv_nxt + TIPC_MAX_LINK_WIN; /* Verify and update link state */ if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) return tipc_link_proto_rcv(l, skb, xmitq); if (unlikely(!link_is_up(l))) { if (l->state == LINK_ESTABLISHING) rc = TIPC_LINK_UP_EVT; goto drop; } /* Don't send probe at next timeout expiration */ l->silent_intv_cnt = 0; /* Drop if outside receive window */ if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) { l->stats.duplicates++; goto drop; } /* Forward queues and wake up waiting users */ if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) { l->stale_cnt = 0; tipc_link_advance_backlog(l, xmitq); if (unlikely(!skb_queue_empty(&l->wakeupq))) link_prepare_wakeup(l); } /* Defer delivery if sequence gap */ if (unlikely(seqno != rcv_nxt)) { __tipc_skb_queue_sorted(defq, seqno, skb); rc |= tipc_link_build_nack_msg(l, xmitq); break; } /* Deliver packet */ l->rcv_nxt++; l->stats.recv_pkts++; if (!tipc_data_input(l, skb, l->inputq)) rc |= tipc_link_input(l, skb, l->inputq); if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) rc |= tipc_link_build_state_msg(l, xmitq); if (unlikely(rc & ~TIPC_LINK_SND_STATE)) break; } while ((skb = __skb_dequeue(defq))); return rc; drop: kfree_skb(skb); return rc; } static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, bool probe_reply, u16 rcvgap, int tolerance, int priority, struct sk_buff_head *xmitq) { struct tipc_link *bcl = l->bc_rcvlink; struct sk_buff *skb; struct tipc_msg *hdr; struct sk_buff_head *dfq = &l->deferdq; bool node_up = link_is_up(bcl); struct tipc_mon_state *mstate = &l->mon_state; int dlen = 0; void *data; /* Don't send protocol message during reset or link failover */ if (tipc_link_is_blocked(l)) return; if (!tipc_link_is_up(l) && (mtyp == STATE_MSG)) return; if (!skb_queue_empty(dfq)) rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt; skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE, tipc_max_domain_size, l->addr, tipc_own_addr(l->net), 0, 0, 0); if (!skb) return; hdr = buf_msg(skb); data = msg_data(hdr); msg_set_session(hdr, l->session); msg_set_bearer_id(hdr, l->bearer_id); msg_set_net_plane(hdr, l->net_plane); msg_set_next_sent(hdr, l->snd_nxt); msg_set_ack(hdr, l->rcv_nxt - 1); msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1); msg_set_bc_ack_invalid(hdr, !node_up); msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1); msg_set_link_tolerance(hdr, tolerance); msg_set_linkprio(hdr, priority); msg_set_redundant_link(hdr, node_up); msg_set_seq_gap(hdr, 0); msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2); if (mtyp == STATE_MSG) { if (l->peer_caps & TIPC_LINK_PROTO_SEQNO) msg_set_seqno(hdr, l->snd_nxt_state++); msg_set_seq_gap(hdr, rcvgap); msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl)); msg_set_probe(hdr, probe); msg_set_is_keepalive(hdr, probe || probe_reply); tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id); msg_set_size(hdr, INT_H_SIZE + dlen); skb_trim(skb, INT_H_SIZE + dlen); l->stats.sent_states++; l->rcv_unacked = 0; } else { /* RESET_MSG or ACTIVATE_MSG */ msg_set_max_pkt(hdr, l->advertised_mtu); strcpy(data, l->if_name); msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME); skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME); } if (probe) l->stats.sent_probes++; if (rcvgap) l->stats.sent_nacks++; skb->priority = TC_PRIO_CONTROL; __skb_queue_tail(xmitq, skb); } void tipc_link_create_dummy_tnl_msg(struct tipc_link *l, struct sk_buff_head *xmitq) { u32 onode = tipc_own_addr(l->net); struct tipc_msg *hdr, *ihdr; struct sk_buff_head tnlq; struct sk_buff *skb; u32 dnode = l->addr; skb_queue_head_init(&tnlq); skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG, INT_H_SIZE, BASIC_H_SIZE, dnode, onode, 0, 0, 0); if (!skb) { pr_warn("%sunable to create tunnel packet\n", link_co_err); return; } hdr = buf_msg(skb); msg_set_msgcnt(hdr, 1); msg_set_bearer_id(hdr, l->peer_bearer_id); ihdr = (struct tipc_msg *)msg_data(hdr); tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG, BASIC_H_SIZE, dnode); msg_set_errcode(ihdr, TIPC_ERR_NO_PORT); __skb_queue_tail(&tnlq, skb); tipc_link_xmit(l, &tnlq, xmitq); } /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets * with contents of the link's transmit and backlog queues. */ void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl, int mtyp, struct sk_buff_head *xmitq) { struct sk_buff *skb, *tnlskb; struct tipc_msg *hdr, tnlhdr; struct sk_buff_head *queue = &l->transmq; struct sk_buff_head tmpxq, tnlq; u16 pktlen, pktcnt, seqno = l->snd_nxt; if (!tnl) return; skb_queue_head_init(&tnlq); skb_queue_head_init(&tmpxq); /* At least one packet required for safe algorithm => add dummy */ skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG, BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net), 0, 0, TIPC_ERR_NO_PORT); if (!skb) { pr_warn("%sunable to create tunnel packet\n", link_co_err); return; } skb_queue_tail(&tnlq, skb); tipc_link_xmit(l, &tnlq, &tmpxq); __skb_queue_purge(&tmpxq); /* Initialize reusable tunnel packet header */ tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL, mtyp, INT_H_SIZE, l->addr); pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq); msg_set_msgcnt(&tnlhdr, pktcnt); msg_set_bearer_id(&tnlhdr, l->peer_bearer_id); tnl: /* Wrap each packet into a tunnel packet */ skb_queue_walk(queue, skb) { hdr = buf_msg(skb); if (queue == &l->backlogq) msg_set_seqno(hdr, seqno++); pktlen = msg_size(hdr); msg_set_size(&tnlhdr, pktlen + INT_H_SIZE); tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC); if (!tnlskb) { pr_warn("%sunable to send packet\n", link_co_err); return; } skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE); skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen); __skb_queue_tail(&tnlq, tnlskb); } if (queue != &l->backlogq) { queue = &l->backlogq; goto tnl; } tipc_link_xmit(tnl, &tnlq, xmitq); if (mtyp == FAILOVER_MSG) { tnl->drop_point = l->rcv_nxt; tnl->failover_reasm_skb = l->reasm_buf; l->reasm_buf = NULL; } } /* tipc_link_validate_msg(): validate message against current link state * Returns true if message should be accepted, otherwise false */ bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr) { u16 curr_session = l->peer_session; u16 session = msg_session(hdr); int mtyp = msg_type(hdr); if (msg_user(hdr) != LINK_PROTOCOL) return true; switch (mtyp) { case RESET_MSG: if (!l->in_session) return true; /* Accept only RESET with new session number */ return more(session, curr_session); case ACTIVATE_MSG: if (!l->in_session) return true; /* Accept only ACTIVATE with new or current session number */ return !less(session, curr_session); case STATE_MSG: /* Accept only STATE with current session number */ if (!l->in_session) return false; if (session != curr_session) return false; /* Extra sanity check */ if (!link_is_up(l) && msg_ack(hdr)) return false; if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO)) return true; /* Accept only STATE with new sequence number */ return !less(msg_seqno(hdr), l->rcv_nxt_state); default: return false; } } /* tipc_link_proto_rcv(): receive link level protocol message : * Note that network plane id propagates through the network, and may * change at any time. The node with lowest numerical id determines * network plane */ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq) { struct tipc_msg *hdr = buf_msg(skb); u16 rcvgap = 0; u16 ack = msg_ack(hdr); u16 gap = msg_seq_gap(hdr); u16 peers_snd_nxt = msg_next_sent(hdr); u16 peers_tol = msg_link_tolerance(hdr); u16 peers_prio = msg_linkprio(hdr); u16 rcv_nxt = l->rcv_nxt; u16 dlen = msg_data_sz(hdr); int mtyp = msg_type(hdr); bool reply = msg_probe(hdr); void *data; char *if_name; int rc = 0; if (tipc_link_is_blocked(l) || !xmitq) goto exit; if (tipc_own_addr(l->net) > msg_prevnode(hdr)) l->net_plane = msg_net_plane(hdr); skb_linearize(skb); hdr = buf_msg(skb); data = msg_data(hdr); if (!tipc_link_validate_msg(l, hdr)) goto exit; switch (mtyp) { case RESET_MSG: case ACTIVATE_MSG: /* Complete own link name with peer's interface name */ if_name = strrchr(l->name, ':') + 1; if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME) break; if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME) break; strncpy(if_name, data, TIPC_MAX_IF_NAME); /* Update own tolerance if peer indicates a non-zero value */ if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) { l->tolerance = peers_tol; l->bc_rcvlink->tolerance = peers_tol; } /* Update own priority if peer's priority is higher */ if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI)) l->priority = peers_prio; /* ACTIVATE_MSG serves as PEER_RESET if link is already down */ if (msg_peer_stopping(hdr)) rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT); else if ((mtyp == RESET_MSG) || !link_is_up(l)) rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT); /* ACTIVATE_MSG takes up link if it was already locally reset */ if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING)) rc = TIPC_LINK_UP_EVT; l->peer_session = msg_session(hdr); l->in_session = true; l->peer_bearer_id = msg_bearer_id(hdr); if (l->mtu > msg_max_pkt(hdr)) l->mtu = msg_max_pkt(hdr); break; case STATE_MSG: l->rcv_nxt_state = msg_seqno(hdr) + 1; /* Update own tolerance if peer indicates a non-zero value */ if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) { l->tolerance = peers_tol; l->bc_rcvlink->tolerance = peers_tol; } /* Update own prio if peer indicates a different value */ if ((peers_prio != l->priority) && in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) { l->priority = peers_prio; rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT); } l->silent_intv_cnt = 0; l->stats.recv_states++; if (msg_probe(hdr)) l->stats.recv_probes++; if (!link_is_up(l)) { if (l->state == LINK_ESTABLISHING) rc = TIPC_LINK_UP_EVT; break; } tipc_mon_rcv(l->net, data, dlen, l->addr, &l->mon_state, l->bearer_id); /* Send NACK if peer has sent pkts we haven't received yet */ if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l)) rcvgap = peers_snd_nxt - l->rcv_nxt; if (rcvgap || reply) tipc_link_build_proto_msg(l, STATE_MSG, 0, reply, rcvgap, 0, 0, xmitq); tipc_link_release_pkts(l, ack); /* If NACK, retransmit will now start at right position */ if (gap) { rc = tipc_link_retrans(l, l, ack + 1, ack + gap, xmitq); l->stats.recv_nacks++; } tipc_link_advance_backlog(l, xmitq); if (unlikely(!skb_queue_empty(&l->wakeupq))) link_prepare_wakeup(l); } exit: kfree_skb(skb); return rc; } /* tipc_link_build_bc_proto_msg() - create broadcast protocol message */ static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast, u16 peers_snd_nxt, struct sk_buff_head *xmitq) { struct sk_buff *skb; struct tipc_msg *hdr; struct sk_buff *dfrd_skb = skb_peek(&l->deferdq); u16 ack = l->rcv_nxt - 1; u16 gap_to = peers_snd_nxt - 1; skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, 0, l->addr, tipc_own_addr(l->net), 0, 0, 0); if (!skb) return false; hdr = buf_msg(skb); msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1); msg_set_bcast_ack(hdr, ack); msg_set_bcgap_after(hdr, ack); if (dfrd_skb) gap_to = buf_seqno(dfrd_skb) - 1; msg_set_bcgap_to(hdr, gap_to); msg_set_non_seq(hdr, bcast); __skb_queue_tail(xmitq, skb); return true; } /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints. * * Give a newly added peer node the sequence number where it should * start receiving and acking broadcast packets. */ static void tipc_link_build_bc_init_msg(struct tipc_link *l, struct sk_buff_head *xmitq) { struct sk_buff_head list; __skb_queue_head_init(&list); if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list)) return; msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true); tipc_link_xmit(l, &list, xmitq); } /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer */ void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr) { int mtyp = msg_type(hdr); u16 peers_snd_nxt = msg_bc_snd_nxt(hdr); if (link_is_up(l)) return; if (msg_user(hdr) == BCAST_PROTOCOL) { l->rcv_nxt = peers_snd_nxt; l->state = LINK_ESTABLISHED; return; } if (l->peer_caps & TIPC_BCAST_SYNCH) return; if (msg_peer_node_is_up(hdr)) return; /* Compatibility: accept older, less safe initial synch data */ if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG)) l->rcv_nxt = peers_snd_nxt; } /* link_bc_retr eval()- check if the indicated range can be retransmitted now * - Adjust permitted range if there is overlap with previous retransmission */ static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to) { unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr); if (less(*to, *from)) return false; /* New retransmission request */ if ((elapsed > TIPC_BC_RETR_LIMIT) || less(*to, l->prev_from) || more(*from, l->prev_to)) { l->prev_from = *from; l->prev_to = *to; l->prev_retr = jiffies; return true; } /* Inside range of previous retransmit */ if (!less(*from, l->prev_from) && !more(*to, l->prev_to)) return false; /* Fully or partially outside previous range => exclude overlap */ if (less(*from, l->prev_from)) { *to = l->prev_from - 1; l->prev_from = *from; } if (more(*to, l->prev_to)) { *from = l->prev_to + 1; l->prev_to = *to; } l->prev_retr = jiffies; return true; } /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state */ int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, struct sk_buff_head *xmitq) { struct tipc_link *snd_l = l->bc_sndlink; u16 peers_snd_nxt = msg_bc_snd_nxt(hdr); u16 from = msg_bcast_ack(hdr) + 1; u16 to = from + msg_bc_gap(hdr) - 1; int rc = 0; if (!link_is_up(l)) return rc; if (!msg_peer_node_is_up(hdr)) return rc; /* Open when peer ackowledges our bcast init msg (pkt #1) */ if (msg_ack(hdr)) l->bc_peer_is_up = true; if (!l->bc_peer_is_up) return rc; l->stats.recv_nacks++; /* Ignore if peers_snd_nxt goes beyond receive window */ if (more(peers_snd_nxt, l->rcv_nxt + l->window)) return rc; if (link_bc_retr_eval(snd_l, &from, &to)) rc = tipc_link_retrans(snd_l, l, from, to, xmitq); l->snd_nxt = peers_snd_nxt; if (link_bc_rcv_gap(l)) rc |= TIPC_LINK_SND_STATE; /* Return now if sender supports nack via STATE messages */ if (l->peer_caps & TIPC_BCAST_STATE_NACK) return rc; /* Otherwise, be backwards compatible */ if (!more(peers_snd_nxt, l->rcv_nxt)) { l->nack_state = BC_NACK_SND_CONDITIONAL; return 0; } /* Don't NACK if one was recently sent or peeked */ if (l->nack_state == BC_NACK_SND_SUPPRESS) { l->nack_state = BC_NACK_SND_UNCONDITIONAL; return 0; } /* Conditionally delay NACK sending until next synch rcv */ if (l->nack_state == BC_NACK_SND_CONDITIONAL) { l->nack_state = BC_NACK_SND_UNCONDITIONAL; if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN) return 0; } /* Send NACK now but suppress next one */ tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq); l->nack_state = BC_NACK_SND_SUPPRESS; return 0; } void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked, struct sk_buff_head *xmitq) { struct sk_buff *skb, *tmp; struct tipc_link *snd_l = l->bc_sndlink; if (!link_is_up(l) || !l->bc_peer_is_up) return; if (!more(acked, l->acked)) return; /* Skip over packets peer has already acked */ skb_queue_walk(&snd_l->transmq, skb) { if (more(buf_seqno(skb), l->acked)) break; } /* Update/release the packets peer is acking now */ skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) { if (more(buf_seqno(skb), acked)) break; if (!--TIPC_SKB_CB(skb)->ackers) { __skb_unlink(skb, &snd_l->transmq); kfree_skb(skb); } } l->acked = acked; tipc_link_advance_backlog(snd_l, xmitq); if (unlikely(!skb_queue_empty(&snd_l->wakeupq))) link_prepare_wakeup(snd_l); } /* tipc_link_bc_nack_rcv(): receive broadcast nack message * This function is here for backwards compatibility, since * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5. */ int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq) { struct tipc_msg *hdr = buf_msg(skb); u32 dnode = msg_destnode(hdr); int mtyp = msg_type(hdr); u16 acked = msg_bcast_ack(hdr); u16 from = acked + 1; u16 to = msg_bcgap_to(hdr); u16 peers_snd_nxt = to + 1; int rc = 0; kfree_skb(skb); if (!tipc_link_is_up(l) || !l->bc_peer_is_up) return 0; if (mtyp != STATE_MSG) return 0; if (dnode == tipc_own_addr(l->net)) { tipc_link_bc_ack_rcv(l, acked, xmitq); rc = tipc_link_retrans(l->bc_sndlink, l, from, to, xmitq); l->stats.recv_nacks++; return rc; } /* Msg for other node => suppress own NACK at next sync if applicable */ if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from)) l->nack_state = BC_NACK_SND_SUPPRESS; return 0; } void tipc_link_set_queue_limits(struct tipc_link *l, u32 win) { int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE); l->window = win; l->backlog[TIPC_LOW_IMPORTANCE].limit = max_t(u16, 50, win); l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = max_t(u16, 100, win * 2); l->backlog[TIPC_HIGH_IMPORTANCE].limit = max_t(u16, 150, win * 3); l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4); l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk; } /** * link_reset_stats - reset link statistics * @l: pointer to link */ void tipc_link_reset_stats(struct tipc_link *l) { memset(&l->stats, 0, sizeof(l->stats)); } static void link_print(struct tipc_link *l, const char *str) { struct sk_buff *hskb = skb_peek(&l->transmq); u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1; u16 tail = l->snd_nxt - 1; pr_info("%s Link <%s> state %x\n", str, l->name, l->state); pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n", skb_queue_len(&l->transmq), head, tail, skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt); } /* Parse and validate nested (link) properties valid for media, bearer and link */ int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]) { int err; err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop, tipc_nl_prop_policy, NULL); if (err) return err; if (props[TIPC_NLA_PROP_PRIO]) { u32 prio; prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); if (prio > TIPC_MAX_LINK_PRI) return -EINVAL; } if (props[TIPC_NLA_PROP_TOL]) { u32 tol; tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]); if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL)) return -EINVAL; } if (props[TIPC_NLA_PROP_WIN]) { u32 win; win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN)) return -EINVAL; } return 0; } static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s) { int i; struct nlattr *stats; struct nla_map { u32 key; u32 val; }; struct nla_map map[] = { {TIPC_NLA_STATS_RX_INFO, 0}, {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments}, {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented}, {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles}, {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled}, {TIPC_NLA_STATS_TX_INFO, 0}, {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments}, {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented}, {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles}, {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled}, {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ? s->msg_length_counts : 1}, {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts}, {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total}, {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]}, {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]}, {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]}, {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]}, {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]}, {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]}, {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]}, {TIPC_NLA_STATS_RX_STATES, s->recv_states}, {TIPC_NLA_STATS_RX_PROBES, s->recv_probes}, {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks}, {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv}, {TIPC_NLA_STATS_TX_STATES, s->sent_states}, {TIPC_NLA_STATS_TX_PROBES, s->sent_probes}, {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks}, {TIPC_NLA_STATS_TX_ACKS, s->sent_acks}, {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted}, {TIPC_NLA_STATS_DUPLICATES, s->duplicates}, {TIPC_NLA_STATS_LINK_CONGS, s->link_congs}, {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz}, {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ? (s->accu_queue_sz / s->queue_sz_counts) : 0} }; stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS); if (!stats) return -EMSGSIZE; for (i = 0; i < ARRAY_SIZE(map); i++) if (nla_put_u32(skb, map[i].key, map[i].val)) goto msg_full; nla_nest_end(skb, stats); return 0; msg_full: nla_nest_cancel(skb, stats); return -EMSGSIZE; } /* Caller should hold appropriate locks to protect the link */ int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg, struct tipc_link *link, int nlflags) { u32 self = tipc_own_addr(net); struct nlattr *attrs; struct nlattr *prop; void *hdr; int err; hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, nlflags, TIPC_NL_LINK_GET); if (!hdr) return -EMSGSIZE; attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK); if (!attrs) goto msg_full; if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name)) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self))) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu)) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts)) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts)) goto attr_msg_full; if (tipc_link_is_up(link)) if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP)) goto attr_msg_full; if (link->active) if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE)) goto attr_msg_full; prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP); if (!prop) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) goto prop_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance)) goto prop_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, link->window)) goto prop_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) goto prop_msg_full; nla_nest_end(msg->skb, prop); err = __tipc_nl_add_stats(msg->skb, &link->stats); if (err) goto attr_msg_full; nla_nest_end(msg->skb, attrs); genlmsg_end(msg->skb, hdr); return 0; prop_msg_full: nla_nest_cancel(msg->skb, prop); attr_msg_full: nla_nest_cancel(msg->skb, attrs); msg_full: genlmsg_cancel(msg->skb, hdr); return -EMSGSIZE; } static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb, struct tipc_stats *stats) { int i; struct nlattr *nest; struct nla_map { __u32 key; __u32 val; }; struct nla_map map[] = { {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts}, {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments}, {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented}, {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles}, {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled}, {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts}, {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments}, {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented}, {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles}, {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled}, {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks}, {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv}, {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks}, {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks}, {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted}, {TIPC_NLA_STATS_DUPLICATES, stats->duplicates}, {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs}, {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz}, {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ? (stats->accu_queue_sz / stats->queue_sz_counts) : 0} }; nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS); if (!nest) return -EMSGSIZE; for (i = 0; i < ARRAY_SIZE(map); i++) if (nla_put_u32(skb, map[i].key, map[i].val)) goto msg_full; nla_nest_end(skb, nest); return 0; msg_full: nla_nest_cancel(skb, nest); return -EMSGSIZE; } int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg) { int err; void *hdr; struct nlattr *attrs; struct nlattr *prop; struct tipc_net *tn = net_generic(net, tipc_net_id); struct tipc_link *bcl = tn->bcl; if (!bcl) return 0; tipc_bcast_lock(net); hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, NLM_F_MULTI, TIPC_NL_LINK_GET); if (!hdr) { tipc_bcast_unlock(net); return -EMSGSIZE; } attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK); if (!attrs) goto msg_full; /* The broadcast link is always up */ if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP)) goto attr_msg_full; if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST)) goto attr_msg_full; if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name)) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0)) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0)) goto attr_msg_full; prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP); if (!prop) goto attr_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window)) goto prop_msg_full; nla_nest_end(msg->skb, prop); err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats); if (err) goto attr_msg_full; tipc_bcast_unlock(net); nla_nest_end(msg->skb, attrs); genlmsg_end(msg->skb, hdr); return 0; prop_msg_full: nla_nest_cancel(msg->skb, prop); attr_msg_full: nla_nest_cancel(msg->skb, attrs); msg_full: tipc_bcast_unlock(net); genlmsg_cancel(msg->skb, hdr); return -EMSGSIZE; } void tipc_link_set_tolerance(struct tipc_link *l, u32 tol, struct sk_buff_head *xmitq) { l->tolerance = tol; if (l->bc_rcvlink) l->bc_rcvlink->tolerance = tol; if (link_is_up(l)) tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq); } void tipc_link_set_prio(struct tipc_link *l, u32 prio, struct sk_buff_head *xmitq) { l->priority = prio; tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq); } void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit) { l->abort_limit = limit; }