/* * 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 "trace.h" #include "crypto.h" #include <linux/pkt_sched.h> struct tipc_stats { … }; /** * struct tipc_link - TIPC link data structure * @addr: network address of link's peer node * @name: link name character string * @net: pointer to namespace struct * @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 * @priority: current link priority * @net_plane: current link network plane ('A' through 'H') * @mon_state: cookie with information needed by link monitor * @mtu: current maximum packet size for this link * @advertised_mtu: advertised own mtu when link is being established * @backlogq: queue for messages waiting to be sent * @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 * @inputq: buffer queue for messages to be delivered upwards * @namedq: buffer queue for name table messages to be delivered upwards * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate * @reasm_buf: head of partially reassembled inbound message fragments * @stats: collects statistics regarding link activity * @session: session to be used by link * @snd_nxt_state: next send seq number * @rcv_nxt_state: next rcv seq number * @in_session: have received ACTIVATE_MSG from peer * @active: link is active * @if_name: associated interface name * @rst_cnt: link reset counter * @drop_point: seq number for failover handling (FIXME) * @failover_reasm_skb: saved failover msg ptr (FIXME) * @failover_deferdq: deferred message queue for failover processing (FIXME) * @transmq: the link's transmit queue * @backlog: link's backlog by priority (importance) * @snd_nxt: next sequence number to be used * @rcv_unacked: # messages read by user, but not yet acked back to peer * @deferdq: deferred receive queue * @window: sliding window size for congestion handling * @min_win: minimal send window to be used by link * @ssthresh: slow start threshold for congestion handling * @max_win: maximal send window to be used by link * @cong_acks: congestion acks for congestion avoidance (FIXME) * @checkpoint: seq number for congestion window size handling * @reasm_tnlmsg: fragmentation/reassembly area for tunnel protocol message * @last_gap: last gap ack blocks for bcast (FIXME) * @last_ga: ptr to gap ack blocks * @bc_rcvlink: the peer specific link used for broadcast reception * @bc_sndlink: the namespace global link used for broadcast sending * @nack_state: bcast nack state * @bc_peer_is_up: peer has acked the bcast init msg */ struct tipc_link { … }; /* * Error message prefixes */ static const char *link_co_err = …; static const char *link_rst_msg = …; /* Send states for broadcast NACKs */ enum { … }; #define TIPC_BC_RETR_LIM … #define TIPC_UC_RETR_TIME … /* Link FSM states: */ enum { … }; 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 u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga, struct tipc_link *l, u8 start_index); static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr); static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r, u16 acked, u16 gap, struct tipc_gap_ack_blks *ga, struct sk_buff_head *xmitq, bool *retransmitted, int *rc); static void tipc_link_update_cwin(struct tipc_link *l, int released, bool retransmitted); /* * Simple non-static link routines (i.e. referenced outside this file) */ bool tipc_link_is_up(struct tipc_link *l) { … } bool tipc_link_peer_is_down(struct tipc_link *l) { … } bool tipc_link_is_reset(struct tipc_link *l) { … } bool tipc_link_is_establishing(struct tipc_link *l) { … } bool tipc_link_is_synching(struct tipc_link *l) { … } bool tipc_link_is_failingover(struct tipc_link *l) { … } bool tipc_link_is_blocked(struct tipc_link *l) { … } static bool link_is_bc_sndlink(struct tipc_link *l) { … } static bool link_is_bc_rcvlink(struct tipc_link *l) { … } void tipc_link_set_active(struct tipc_link *l, bool active) { … } u32 tipc_link_id(struct tipc_link *l) { … } int tipc_link_min_win(struct tipc_link *l) { … } int tipc_link_max_win(struct tipc_link *l) { … } int tipc_link_prio(struct tipc_link *l) { … } unsigned long tipc_link_tolerance(struct tipc_link *l) { … } struct sk_buff_head *tipc_link_inputq(struct tipc_link *l) { … } char tipc_link_plane(struct tipc_link *l) { … } struct net *tipc_link_net(struct tipc_link *l) { … } void tipc_link_update_caps(struct tipc_link *l, u16 capabilities) { … } void tipc_link_add_bc_peer(struct tipc_link *snd_l, struct tipc_link *uc_l, struct sk_buff_head *xmitq) { … } void tipc_link_remove_bc_peer(struct tipc_link *snd_l, struct tipc_link *rcv_l, struct sk_buff_head *xmitq) { … } int tipc_link_bc_peers(struct tipc_link *l) { … } static u16 link_bc_rcv_gap(struct tipc_link *l) { … } void tipc_link_set_mtu(struct tipc_link *l, int mtu) { … } int tipc_link_mtu(struct tipc_link *l) { … } int tipc_link_mss(struct tipc_link *l) { … } u16 tipc_link_rcv_nxt(struct tipc_link *l) { … } u16 tipc_link_acked(struct tipc_link *l) { … } char *tipc_link_name(struct tipc_link *l) { … } u32 tipc_link_state(struct tipc_link *l) { … } /** * tipc_link_create - create a new link * @net: pointer to associated network namespace * @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 * @min_win: minimal send window to be used by link * @max_win: maximal send window to be used by link * @session: session to be used by link * @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 * @self: local unicast link id * @peer_id: 128-bit ID of peer * * Return: 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, u32 min_win, u32 max_win, 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) { … } /** * tipc_link_bc_create - create new link to be used for broadcast * @net: pointer to associated network namespace * @mtu: mtu to be used initially if no peers * @min_win: minimal send window to be used by link * @max_win: maximal send window to be used by link * @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 * @ownnode: identity of own node * @peer: node id of peer node * @peer_id: 128-bit ID of peer * @peer_caps: bitmap describing peer node capabilities * @bc_sndlink: the namespace global link used for broadcast sending * * Return: true if link was created, otherwise false */ bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id, int mtu, u32 min_win, u32 max_win, u16 peer_caps, struct sk_buff_head *inputq, struct sk_buff_head *namedq, struct tipc_link *bc_sndlink, struct tipc_link **link) { … } /** * 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) { … } /* link_profile_stats - update statistical profiling of traffic */ static void link_profile_stats(struct tipc_link *l) { … } /** * tipc_link_too_silent - check if link is "too silent" * @l: tipc link to be checked * * Return: true if the link 'silent_intv_cnt' is about to reach the * 'abort_limit' value, otherwise false */ bool tipc_link_too_silent(struct tipc_link *l) { … } /* tipc_link_timeout - perform periodic task as instructed from node timeout */ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq) { … } /** * 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) { … } /** * 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) { … } /** * tipc_link_set_skb_retransmit_time - set the time at which retransmission of * the given skb should be next attempted * @skb: skb to set a future retransmission time for * @l: link the skb will be transmitted on */ static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb, struct tipc_link *l) { … } void tipc_link_reset(struct tipc_link *l) { … } /** * tipc_link_xmit(): enqueue buffer list according to queue situation * @l: link to use * @list: chain of buffers containing message * @xmitq: returned list of packets to be sent by caller * * Consumes the buffer chain. * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted * Return: 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS */ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, struct sk_buff_head *xmitq) { … } static void tipc_link_update_cwin(struct tipc_link *l, int released, bool retransmitted) { … } static void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq) { … } /** * link_retransmit_failure() - Detect repeated retransmit failures * @l: tipc link sender * @r: tipc link receiver (= l in case of unicast) * @rc: returned code * * Return: true if the repeated retransmit failures happens, otherwise * false */ static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r, int *rc) { … } /* 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) { … } /* 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 sk_buff **reasm_skb) { … } /* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the * inner message along with the ones in the old link's * deferdq * @l: tunnel link * @skb: TUNNEL_PROTOCOL message * @inputq: queue to put messages ready for delivery */ static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *inputq) { … } /** * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG * @ga: returned pointer to the Gap ACK blocks if any * @l: the tipc link * @hdr: the PROTOCOL/STATE_MSG header * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0) * * Return: the total Gap ACK blocks size */ u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l, struct tipc_msg *hdr, bool uc) { … } static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga, struct tipc_link *l, u8 start_index) { … } /* tipc_build_gap_ack_blks - build Gap ACK blocks * @l: tipc unicast link * @hdr: the tipc message buffer to store the Gap ACK blocks after built * * The function builds Gap ACK blocks for both the unicast & broadcast receiver * links of a certain peer, the buffer after built has the network data format * as found at the struct tipc_gap_ack_blks definition. * * returns the actual allocated memory size */ static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr) { … } /* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing * acked packets, also doing retransmissions if * gaps found * @l: tipc link with transmq queue to be advanced * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast) * @acked: seqno of last packet acked by peer without any gaps before * @gap: # of gap packets * @ga: buffer pointer to Gap ACK blocks from peer * @xmitq: queue for accumulating the retransmitted packets if any * @retransmitted: returned boolean value if a retransmission is really issued * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures * happens (- unlikely case) * * Return: the number of packets released from the link transmq */ static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r, u16 acked, u16 gap, struct tipc_gap_ack_blks *ga, struct sk_buff_head *xmitq, bool *retransmitted, int *rc) { … } /* 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) { … } /* 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) { … } /* 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) { … } /* 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) { … } 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) { … } void tipc_link_create_dummy_tnl_msg(struct tipc_link *l, struct sk_buff_head *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) { … } /** * tipc_link_failover_prepare() - prepare tnl for link failover * * This is a special version of the precursor - tipc_link_tnl_prepare(), * see the tipc_node_link_failover() for details * * @l: failover link * @tnl: tunnel link * @xmitq: queue for messages to be xmited */ void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl, struct sk_buff_head *xmitq) { … } /* 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) { … } /* 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) { … } /* 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) { … } /* 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) { … } /* 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) { … } /* 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) { … } int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap, struct tipc_gap_ack_blks *ga, struct sk_buff_head *xmitq, struct sk_buff_head *retrq) { … } /* 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) { … } void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win) { … } /** * tipc_link_reset_stats - reset link statistics * @l: pointer to link */ void tipc_link_reset_stats(struct tipc_link *l) { … } static void link_print(struct tipc_link *l, const char *str) { … } /* Parse and validate nested (link) properties valid for media, bearer and link */ int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]) { … } static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s) { … } /* 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) { … } static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb, struct tipc_stats *stats) { … } int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg, struct tipc_link *bcl) { … } void tipc_link_set_tolerance(struct tipc_link *l, u32 tol, struct sk_buff_head *xmitq) { … } void tipc_link_set_prio(struct tipc_link *l, u32 prio, struct sk_buff_head *xmitq) { … } void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit) { … } /** * tipc_link_dump - dump TIPC link data * @l: tipc link to be dumped * @dqueues: bitmask to decide if any link queue to be dumped? * - TIPC_DUMP_NONE: don't dump link queues * - TIPC_DUMP_TRANSMQ: dump link transmq queue * - TIPC_DUMP_BACKLOGQ: dump link backlog queue * - TIPC_DUMP_DEFERDQ: dump link deferd queue * - TIPC_DUMP_INPUTQ: dump link input queue * - TIPC_DUMP_WAKEUP: dump link wakeup queue * - TIPC_DUMP_ALL: dump all the link queues above * @buf: returned buffer of dump data in format */ int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf) { … }
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