blob: 05837ba7b68c48eed2c627eac0366d0ed12b8e87 [file] [log] [blame]
/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012-2015, 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 <linux/pkt_sched.h>
/*
* 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 ";
static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
[TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC },
[TIPC_NLA_LINK_NAME] = {
.type = NLA_STRING,
.len = TIPC_MAX_LINK_NAME
},
[TIPC_NLA_LINK_MTU] = { .type = NLA_U32 },
[TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_UP] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_ACTIVE] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_PROP] = { .type = NLA_NESTED },
[TIPC_NLA_LINK_STATS] = { .type = NLA_NESTED },
[TIPC_NLA_LINK_RX] = { .type = NLA_U32 },
[TIPC_NLA_LINK_TX] = { .type = NLA_U32 }
};
/* Properties valid for media, bearar and link */
static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
[TIPC_NLA_PROP_UNSPEC] = { .type = NLA_UNSPEC },
[TIPC_NLA_PROP_PRIO] = { .type = NLA_U32 },
[TIPC_NLA_PROP_TOL] = { .type = NLA_U32 },
[TIPC_NLA_PROP_WIN] = { .type = NLA_U32 }
};
/*
* Interval between NACKs when packets arrive out of order
*/
#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
/*
* Out-of-range value for link session numbers
*/
#define WILDCARD_SESSION 0x10000
/* State value stored in 'failover_pkts'
*/
#define FIRST_FAILOVER 0xffffu
/* Link FSM states and events:
*/
enum {
TIPC_LINK_WORKING,
TIPC_LINK_PROBING,
TIPC_LINK_RESETTING,
TIPC_LINK_ESTABLISHING
};
enum {
PEER_RESET_EVT = RESET_MSG,
ACTIVATE_EVT = ACTIVATE_MSG,
TRAFFIC_EVT, /* Any other valid msg from peer */
SILENCE_EVT /* Peer was silent during last timer interval*/
};
/* Link FSM state checking routines
*/
static int link_working(struct tipc_link *l)
{
return l->state == TIPC_LINK_WORKING;
}
static int link_probing(struct tipc_link *l)
{
return l->state == TIPC_LINK_PROBING;
}
static int link_resetting(struct tipc_link *l)
{
return l->state == TIPC_LINK_RESETTING;
}
static int link_establishing(struct tipc_link *l)
{
return l->state == TIPC_LINK_ESTABLISHING;
}
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,
u16 rcvgap, int tolerance, int priority,
struct sk_buff_head *xmitq);
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_build_bcast_sync_msg(struct tipc_link *l,
struct sk_buff_head *xmitq);
static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
/*
* Simple link routines
*/
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
{
struct tipc_node *n = l->owner;
if (node_active_link(n, 0) != l)
return node_active_link(n, 0);
return node_active_link(n, 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(l_ptr) || link_probing(l_ptr);
}
int tipc_link_is_active(struct tipc_link *l)
{
struct tipc_node *n = l->owner;
return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
}
/**
* 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 sk_buff_head *inputq,
struct sk_buff_head *namedq)
{
struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
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("Cannot 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].link) {
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(tn->own_addr), tipc_cluster(tn->own_addr),
tipc_node(tn->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->peer_session = WILDCARD_SESSION;
l_ptr->bearer_id = b_ptr->identity;
l_ptr->tolerance = b_ptr->tolerance;
l_ptr->snd_nxt = 1;
l_ptr->rcv_nxt = 1;
l_ptr->state = TIPC_LINK_RESETTING;
l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
msg = l_ptr->pmsg;
tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
l_ptr->addr);
msg_set_size(msg, sizeof(l_ptr->proto_msg));
msg_set_session(msg, (tn->random & 0xffff));
msg_set_bearer_id(msg, b_ptr->identity);
strcpy((char *)msg_data(msg), if_name);
l_ptr->net_plane = b_ptr->net_plane;
l_ptr->advertised_mtu = b_ptr->mtu;
l_ptr->mtu = l_ptr->advertised_mtu;
l_ptr->priority = b_ptr->priority;
tipc_link_set_queue_limits(l_ptr, b_ptr->window);
l_ptr->snd_nxt = 1;
__skb_queue_head_init(&l_ptr->transmq);
__skb_queue_head_init(&l_ptr->backlogq);
__skb_queue_head_init(&l_ptr->deferdq);
skb_queue_head_init(&l_ptr->wakeupq);
l_ptr->inputq = inputq;
l_ptr->namedq = namedq;
skb_queue_head_init(l_ptr->inputq);
link_reset_statistics(l_ptr);
tipc_node_attach_link(n_ptr, l_ptr);
return l_ptr;
}
/**
* tipc_link_delete - Delete a link
* @l: link to be deleted
*/
void tipc_link_delete(struct tipc_link *l)
{
tipc_link_reset(l);
tipc_link_reset_fragments(l);
tipc_node_detach_link(l->owner, l);
}
void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_link *link;
struct tipc_node *node;
rcu_read_lock();
list_for_each_entry_rcu(node, &tn->node_list, list) {
tipc_node_lock(node);
link = node->links[bearer_id].link;
if (link)
tipc_link_delete(link);
tipc_node_unlock(node);
}
rcu_read_unlock();
}
/* tipc_link_build_bcast_sync_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_bcast_sync_msg(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
struct sk_buff *skb;
struct sk_buff_head list;
u16 last_sent;
skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
0, l->addr, link_own_addr(l), 0, 0, 0);
if (!skb)
return;
last_sent = tipc_bclink_get_last_sent(l->owner->net);
msg_set_last_bcast(buf_msg(skb), last_sent);
__skb_queue_head_init(&list);
__skb_queue_tail(&list, skb);
tipc_link_xmit(l, &list, xmitq);
}
/**
* tipc_link_fsm_evt - link finite state machine
* @l: pointer to link
* @evt: state machine event to be processed
* @xmitq: queue to prepend created protocol message, if any
*/
static int tipc_link_fsm_evt(struct tipc_link *l, int evt,
struct sk_buff_head *xmitq)
{
int mtyp = 0, rc = 0;
struct tipc_link *pl;
enum {
LINK_RESET = 1,
LINK_ACTIVATE = (1 << 1),
SND_PROBE = (1 << 2),
SND_STATE = (1 << 3),
SND_RESET = (1 << 4),
SND_ACTIVATE = (1 << 5),
SND_BCAST_SYNC = (1 << 6)
} actions = 0;
if (l->exec_mode == TIPC_LINK_BLOCKED)
return rc;
switch (l->state) {
case TIPC_LINK_WORKING:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
break;
case SILENCE_EVT:
l->state = TIPC_LINK_PROBING;
actions |= SND_PROBE;
break;
case PEER_RESET_EVT:
actions |= LINK_RESET | SND_ACTIVATE;
break;
default:
pr_debug("%s%u WORKING\n", link_unk_evt, evt);
}
break;
case TIPC_LINK_PROBING:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
l->state = TIPC_LINK_WORKING;
break;
case PEER_RESET_EVT:
actions |= LINK_RESET | SND_ACTIVATE;
break;
case SILENCE_EVT:
if (l->silent_intv_cnt <= l->abort_limit) {
actions |= SND_PROBE;
break;
}
actions |= LINK_RESET | SND_RESET;
break;
default:
pr_err("%s%u PROBING\n", link_unk_evt, evt);
}
break;
case TIPC_LINK_RESETTING:
switch (evt) {
case TRAFFIC_EVT:
break;
case ACTIVATE_EVT:
pl = node_active_link(l->owner, 0);
if (pl && link_probing(pl))
break;
l->state = TIPC_LINK_WORKING;
actions |= LINK_ACTIVATE;
if (!l->owner->working_links)
actions |= SND_BCAST_SYNC;
break;
case PEER_RESET_EVT:
l->state = TIPC_LINK_ESTABLISHING;
actions |= SND_ACTIVATE;
break;
case SILENCE_EVT:
actions |= SND_RESET;
break;
default:
pr_err("%s%u in RESETTING\n", link_unk_evt, evt);
}
break;
case TIPC_LINK_ESTABLISHING:
switch (evt) {
case TRAFFIC_EVT:
case ACTIVATE_EVT:
pl = node_active_link(l->owner, 0);
if (pl && link_probing(pl))
break;
l->state = TIPC_LINK_WORKING;
actions |= LINK_ACTIVATE;
if (!l->owner->working_links)
actions |= SND_BCAST_SYNC;
break;
case PEER_RESET_EVT:
break;
case SILENCE_EVT:
actions |= SND_ACTIVATE;
break;
default:
pr_err("%s%u ESTABLISHING\n", link_unk_evt, evt);
}
break;
default:
pr_err("Unknown link state %u/%u\n", l->state, evt);
}
/* Perform actions as decided by FSM */
if (actions & LINK_RESET) {
l->exec_mode = TIPC_LINK_BLOCKED;
rc |= TIPC_LINK_DOWN_EVT;
}
if (actions & LINK_ACTIVATE) {
l->exec_mode = TIPC_LINK_OPEN;
rc |= TIPC_LINK_UP_EVT;
}
if (actions & (SND_STATE | SND_PROBE))
mtyp = STATE_MSG;
if (actions & SND_RESET)
mtyp = RESET_MSG;
if (actions & SND_ACTIVATE)
mtyp = ACTIVATE_MSG;
if (actions & (SND_PROBE | SND_STATE | SND_RESET | SND_ACTIVATE))
tipc_link_build_proto_msg(l, mtyp, actions & SND_PROBE,
0, 0, 0, xmitq);
if (actions & SND_BCAST_SYNC)
tipc_link_build_bcast_sync_msg(l, xmitq);
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 rc = 0;
link_profile_stats(l);
if (l->silent_intv_cnt)
rc = tipc_link_fsm_evt(l, SILENCE_EVT, xmitq);
else if (link_working(l) && tipc_bclink_acks_missing(l->owner))
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
l->silent_intv_cnt++;
return rc;
}
/**
* link_schedule_user - schedule a message sender for wakeup after congestion
* @link: congested link
* @list: message that was attempted sent
* Create pseudo msg to send back to user when congestion abates
* Does not consume buffer list
*/
static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
{
struct tipc_msg *msg = buf_msg(skb_peek(list));
int imp = msg_importance(msg);
u32 oport = msg_origport(msg);
u32 addr = link_own_addr(link);
struct sk_buff *skb;
/* This really cannot happen... */
if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
return -ENOBUFS;
}
/* Non-blocking sender: */
if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
return -ELINKCONG;
/* Create and schedule wakeup pseudo message */
skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
addr, addr, oport, 0, 0);
if (!skb)
return -ENOBUFS;
TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
TIPC_SKB_CB(skb)->chain_imp = imp;
skb_queue_tail(&link->wakeupq, skb);
link->stats.link_congs++;
return -ELINKCONG;
}
/**
* 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
*/
void link_prepare_wakeup(struct tipc_link *l)
{
int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
int imp, lim;
struct sk_buff *skb, *tmp;
skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
imp = TIPC_SKB_CB(skb)->chain_imp;
lim = l->window + l->backlog[imp].limit;
pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
if ((pnd[imp] + l->backlog[imp].len) >= lim)
break;
skb_unlink(skb, &l->wakeupq);
skb_queue_tail(l->inputq, skb);
l->owner->inputq = l->inputq;
l->owner->action_flags |= TIPC_MSG_EVT;
}
}
/**
* 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;
}
void tipc_link_purge_backlog(struct tipc_link *l)
{
__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;
}
/**
* 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)
{
__skb_queue_purge(&l_ptr->deferdq);
__skb_queue_purge(&l_ptr->transmq);
tipc_link_purge_backlog(l_ptr);
tipc_link_reset_fragments(l_ptr);
}
void tipc_link_reset(struct tipc_link *l_ptr)
{
u32 prev_state = l_ptr->state;
int was_active_link = tipc_link_is_active(l_ptr);
struct tipc_node *owner = l_ptr->owner;
struct tipc_link *pl = tipc_parallel_link(l_ptr);
msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
/* Link is down, accept any session */
l_ptr->peer_session = WILDCARD_SESSION;
/* Prepare for renewed mtu size negotiation */
l_ptr->mtu = l_ptr->advertised_mtu;
l_ptr->state = TIPC_LINK_RESETTING;
if ((prev_state == TIPC_LINK_RESETTING) ||
(prev_state == TIPC_LINK_ESTABLISHING))
return;
tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
l_ptr->exec_mode = TIPC_LINK_BLOCKED;
l_ptr->failover_checkpt = l_ptr->rcv_nxt;
pl->failover_pkts = FIRST_FAILOVER;
pl->failover_checkpt = l_ptr->rcv_nxt;
pl->failover_skb = l_ptr->reasm_buf;
} else {
kfree_skb(l_ptr->reasm_buf);
}
/* Clean up all queues, except inputq: */
__skb_queue_purge(&l_ptr->transmq);
__skb_queue_purge(&l_ptr->deferdq);
if (!owner->inputq)
owner->inputq = l_ptr->inputq;
skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
if (!skb_queue_empty(owner->inputq))
owner->action_flags |= TIPC_MSG_EVT;
tipc_link_purge_backlog(l_ptr);
l_ptr->reasm_buf = NULL;
l_ptr->rcv_unacked = 0;
l_ptr->snd_nxt = 1;
l_ptr->rcv_nxt = 1;
l_ptr->silent_intv_cnt = 0;
l_ptr->stats.recv_info = 0;
l_ptr->stale_count = 0;
link_reset_statistics(l_ptr);
}
/**
* __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
* @link: link to use
* @list: chain of buffers containing message
*
* Consumes the buffer chain, except when returning an error code,
* Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
* Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
*/
int __tipc_link_xmit(struct net *net, struct tipc_link *link,
struct sk_buff_head *list)
{
struct tipc_msg *msg = buf_msg(skb_peek(list));
unsigned int maxwin = link->window;
unsigned int i, imp = msg_importance(msg);
uint mtu = link->mtu;
u16 ack = mod(link->rcv_nxt - 1);
u16 seqno = link->snd_nxt;
u16 bc_last_in = link->owner->bclink.last_in;
struct tipc_media_addr *addr = &link->media_addr;
struct sk_buff_head *transmq = &link->transmq;
struct sk_buff_head *backlogq = &link->backlogq;
struct sk_buff *skb, *bskb;
/* Match msg importance against this and all higher backlog limits: */
for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
return link_schedule_user(link, list);
}
if (unlikely(msg_size(msg) > mtu))
return -EMSGSIZE;
/* Prepare each packet for sending, and add to relevant queue: */
while (skb_queue_len(list)) {
skb = skb_peek(list);
msg = buf_msg(skb);
msg_set_seqno(msg, seqno);
msg_set_ack(msg, ack);
msg_set_bcast_ack(msg, bc_last_in);
if (likely(skb_queue_len(transmq) < maxwin)) {
__skb_dequeue(list);
__skb_queue_tail(transmq, skb);
tipc_bearer_send(net, link->bearer_id, skb, addr);
link->rcv_unacked = 0;
seqno++;
continue;
}
if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
kfree_skb(__skb_dequeue(list));
link->stats.sent_bundled++;
continue;
}
if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
kfree_skb(__skb_dequeue(list));
__skb_queue_tail(backlogq, bskb);
link->backlog[msg_importance(buf_msg(bskb))].len++;
link->stats.sent_bundled++;
link->stats.sent_bundles++;
continue;
}
link->backlog[imp].len += skb_queue_len(list);
skb_queue_splice_tail_init(list, backlogq);
}
link->snd_nxt = seqno;
return 0;
}
/**
* 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, except when returning -ELINKCONG,
* since the caller then may want to make more send attempts.
* 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;
unsigned int i, imp = msg_importance(hdr);
unsigned int mtu = l->mtu;
u16 ack = l->rcv_nxt - 1;
u16 seqno = l->snd_nxt;
u16 bc_last_in = l->owner->bclink.last_in;
struct sk_buff_head *transmq = &l->transmq;
struct sk_buff_head *backlogq = &l->backlogq;
struct sk_buff *skb, *_skb, *bskb;
/* Match msg importance against this and all higher backlog limits: */
for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
return link_schedule_user(l, list);
}
if (unlikely(msg_size(hdr) > mtu))
return -EMSGSIZE;
/* 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_last_in);
if (likely(skb_queue_len(transmq) < maxwin)) {
_skb = skb_clone(skb, GFP_ATOMIC);
if (!_skb)
return -ENOBUFS;
__skb_dequeue(list);
__skb_queue_tail(transmq, skb);
__skb_queue_tail(xmitq, _skb);
l->rcv_unacked = 0;
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 0;
}
static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
{
skb_queue_head_init(list);
__skb_queue_tail(list, skb);
}
static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
{
struct sk_buff_head head;
skb2list(skb, &head);
return __tipc_link_xmit(link->owner->net, link, &head);
}
/*
* 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_packets - push unsent packets to bearer
*
* Push out the unsent messages of a link where congestion
* has abated. Node is locked.
*
* Called with node locked
*/
void tipc_link_push_packets(struct tipc_link *link)
{
struct sk_buff *skb;
struct tipc_msg *msg;
u16 seqno = link->snd_nxt;
u16 ack = mod(link->rcv_nxt - 1);
while (skb_queue_len(&link->transmq) < link->window) {
skb = __skb_dequeue(&link->backlogq);
if (!skb)
break;
msg = buf_msg(skb);
link->backlog[msg_importance(msg)].len--;
msg_set_ack(msg, ack);
msg_set_seqno(msg, seqno);
seqno = mod(seqno + 1);
msg_set_bcast_ack(msg, link->owner->bclink.last_in);
link->rcv_unacked = 0;
__skb_queue_tail(&link->transmq, skb);
tipc_bearer_send(link->owner->net, link->bearer_id,
skb, &link->media_addr);
}
link->snd_nxt = seqno;
}
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;
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);
msg_set_ack(hdr, ack);
msg_set_seqno(hdr, seqno);
msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
l->rcv_unacked = 0;
seqno++;
}
l->snd_nxt = seqno;
}
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) {
link_print(node->links[i].link, "Resetting link\n");
tipc_link_reset(node->links[i].link);
}
}
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);
struct net *net = l_ptr->owner->net;
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 ");
pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
msg_user(msg), msg_type(msg), msg_size(msg),
msg_errcode(msg));
pr_info("sqno %u, prev: %x, src: %x\n",
msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
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(net);
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);
n_ptr->action_flags |= TIPC_BCAST_RESET;
l_ptr->stale_count = 0;
}
}
void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
u32 retransmits)
{
struct tipc_msg *msg;
if (!skb)
return;
msg = buf_msg(skb);
/* Detect repeated retransmit failures */
if (l_ptr->last_retransm == msg_seqno(msg)) {
if (++l_ptr->stale_count > 100) {
link_retransmit_failure(l_ptr, skb);
return;
}
} else {
l_ptr->last_retransm = msg_seqno(msg);
l_ptr->stale_count = 1;
}
skb_queue_walk_from(&l_ptr->transmq, skb) {
if (!retransmits)
break;
msg = buf_msg(skb);
msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
&l_ptr->media_addr);
retransmits--;
l_ptr->stats.retransmitted++;
}
}
static int tipc_link_retransm(struct tipc_link *l, int retransm,
struct sk_buff_head *xmitq)
{
struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
struct tipc_msg *hdr;
if (!skb)
return 0;
/* Detect repeated retransmit failures on same packet */
if (likely(l->last_retransm != buf_seqno(skb))) {
l->last_retransm = buf_seqno(skb);
l->stale_count = 1;
} else if (++l->stale_count > 100) {
link_retransmit_failure(l, skb);
return TIPC_LINK_DOWN_EVT;
}
skb_queue_walk(&l->transmq, skb) {
if (!retransm)
return 0;
hdr = buf_msg(skb);
_skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
if (!_skb)
return 0;
hdr = buf_msg(_skb);
msg_set_ack(hdr, l->rcv_nxt - 1);
msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
_skb->priority = TC_PRIO_CONTROL;
__skb_queue_tail(xmitq, _skb);
retransm--;
l->stats.retransmitted++;
}
return 0;
}
/* link_synch(): check if all packets arrived before the synch
* point have been consumed
* Returns true if the parallel links are synched, otherwise false
*/
static bool link_synch(struct tipc_link *l)
{
unsigned int post_synch;
struct tipc_link *pl;
pl = tipc_parallel_link(l);
if (pl == l)
goto synched;
/* Was last pre-synch packet added to input queue ? */
if (less_eq(pl->rcv_nxt, l->synch_point))
return false;
/* Is it still in the input queue ? */
post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
if (skb_queue_len(pl->inputq) > post_synch)
return false;
synched:
l->exec_mode = TIPC_LINK_OPEN;
return true;
}
/* 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 *link, struct sk_buff *skb)
{
struct tipc_node *node = link->owner;
struct tipc_msg *msg = buf_msg(skb);
u32 dport = msg_destport(msg);
switch (msg_user(msg)) {
case TIPC_LOW_IMPORTANCE:
case TIPC_MEDIUM_IMPORTANCE:
case TIPC_HIGH_IMPORTANCE:
case TIPC_CRITICAL_IMPORTANCE:
case CONN_MANAGER:
if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
node->inputq = link->inputq;
node->action_flags |= TIPC_MSG_EVT;
}
return true;
case NAME_DISTRIBUTOR:
node->bclink.recv_permitted = true;
node->namedq = link->namedq;
skb_queue_tail(link->namedq, skb);
if (skb_queue_len(link->namedq) == 1)
node->action_flags |= TIPC_NAMED_MSG_EVT;
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
* Node lock must be held
*/
static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
{
struct tipc_node *node = link->owner;
struct tipc_msg *msg = buf_msg(skb);
struct sk_buff *iskb;
int pos = 0;
switch (msg_user(msg)) {
case TUNNEL_PROTOCOL:
if (msg_dup(msg)) {
link->exec_mode = TIPC_LINK_TUNNEL;
link->synch_point = msg_seqno(msg_get_wrapped(msg));
kfree_skb(skb);
break;
}
if (!tipc_link_failover_rcv(link, &skb))
break;
if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
tipc_data_input(link, skb);
break;
}
case MSG_BUNDLER:
link->stats.recv_bundles++;
link->stats.recv_bundled += msg_msgcnt(msg);
while (tipc_msg_extract(skb, &iskb, &pos))
tipc_data_input(link, iskb);
break;
case MSG_FRAGMENTER:
link->stats.recv_fragments++;
if (tipc_buf_append(&link->reasm_buf, &skb)) {
link->stats.recv_fragmented++;
tipc_data_input(link, skb);
} else if (!link->reasm_buf) {
tipc_link_reset(link);
}
break;
case BCAST_PROTOCOL:
tipc_link_sync_rcv(node, skb);
break;
default:
break;
};
}
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_rcv - process TIPC packets/messages arriving from off-node
* @link: 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 *arrvq = &l->deferdq;
struct sk_buff *tmp;
struct tipc_msg *hdr;
u16 seqno, rcv_nxt;
int rc = 0;
if (unlikely(!__tipc_skb_queue_sorted(arrvq, skb))) {
if (!(skb_queue_len(arrvq) % TIPC_NACK_INTV))
tipc_link_build_proto_msg(l, STATE_MSG, 0,
0, 0, 0, xmitq);
return rc;
}
skb_queue_walk_safe(arrvq, skb, tmp) {
hdr = buf_msg(skb);
/* Verify and update link state */
if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) {
__skb_dequeue(arrvq);
rc |= tipc_link_proto_rcv(l, skb, xmitq);
continue;
}
if (unlikely(!link_working(l))) {
rc |= tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
if (!link_working(l)) {
kfree_skb(__skb_dequeue(arrvq));
return rc;
}
}
l->silent_intv_cnt = 0;
/* Forward queues and wake up waiting users */
if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
tipc_link_advance_backlog(l, xmitq);
if (unlikely(!skb_queue_empty(&l->wakeupq)))
link_prepare_wakeup(l);
}
/* Defer reception if there is a gap in the sequence */
seqno = msg_seqno(hdr);
rcv_nxt = l->rcv_nxt;
if (unlikely(less(rcv_nxt, seqno))) {
l->stats.deferred_recv++;
return rc;
}
__skb_dequeue(arrvq);
/* Drop if packet already received */
if (unlikely(more(rcv_nxt, seqno))) {
l->stats.duplicates++;
kfree_skb(skb);
return rc;
}
/* Synchronize with parallel link if applicable */
if (unlikely(l->exec_mode == TIPC_LINK_TUNNEL))
if (!msg_dup(hdr) && !link_synch(l)) {
kfree_skb(skb);
return rc;
}
/* Packet can be delivered */
l->rcv_nxt++;
l->stats.recv_info++;
if (unlikely(!tipc_data_input(l, skb)))
tipc_link_input(l, skb);
/* Ack at regular intervals */
if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
l->rcv_unacked = 0;
l->stats.sent_acks++;
tipc_link_build_proto_msg(l, STATE_MSG,
0, 0, 0, 0, xmitq);
}
}
return rc;
}
/**
* 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 *list, struct sk_buff *skb)
{
struct sk_buff *skb1;
u16 seq_no = buf_seqno(skb);
/* Empty queue ? */
if (skb_queue_empty(list)) {
__skb_queue_tail(list, skb);
return 1;
}
/* Last ? */
if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
__skb_queue_tail(list, skb);
return 1;
}
/* Locate insertion point in queue, then insert; discard if duplicate */
skb_queue_walk(list, skb1) {
u16 curr_seqno = buf_seqno(skb1);
if (seq_no == curr_seqno) {
kfree_skb(skb);
return 0;
}
if (less(seq_no, curr_seqno))
break;
}
__skb_queue_before(list, skb1, skb);
return 1;
}
/*
* Send protocol message to the other endpoint.
*/
void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
u32 gap, u32 tolerance, u32 priority)
{
struct sk_buff *skb = NULL;
struct sk_buff_head xmitq;
__skb_queue_head_init(&xmitq);
tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
tolerance, priority, &xmitq);
skb = __skb_dequeue(&xmitq);
if (!skb)
return;
tipc_bearer_send(l->owner->net, l->bearer_id, skb, &l->media_addr);
l->rcv_unacked = 0;
kfree_skb(skb);
}
/* tipc_link_build_proto_msg: prepare link protocol message for transmission
*/
static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
u16 rcvgap, int tolerance, int priority,
struct sk_buff_head *xmitq)
{
struct sk_buff *skb = NULL;
struct tipc_msg *hdr = l->pmsg;
u16 snd_nxt = l->snd_nxt;
u16 rcv_nxt = l->rcv_nxt;
u16 rcv_last = rcv_nxt - 1;
int node_up = l->owner->bclink.recv_permitted;
/* Don't send protocol message during reset or link failover */
if (l->exec_mode == TIPC_LINK_BLOCKED)
return;
msg_set_type(hdr, mtyp);
msg_set_net_plane(hdr, l->net_plane);
msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
msg_set_link_tolerance(hdr, tolerance);
msg_set_linkprio(hdr, priority);
msg_set_redundant_link(hdr, node_up);
msg_set_seq_gap(hdr, 0);
/* Compatibility: created msg must not be in sequence with pkt flow */
msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
if (mtyp == STATE_MSG) {
if (!tipc_link_is_up(l))
return;
msg_set_next_sent(hdr, snd_nxt);
/* Override rcvgap if there are packets in deferred queue */
if (!skb_queue_empty(&l->deferdq))
rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
if (rcvgap) {
msg_set_seq_gap(hdr, rcvgap);
l->stats.sent_nacks++;
}
msg_set_ack(hdr, rcv_last);
msg_set_probe(hdr, probe);
if (probe)
l->stats.sent_probes++;
l->stats.sent_states++;
} else {
/* RESET_MSG or ACTIVATE_MSG */
msg_set_max_pkt(hdr, l->advertised_mtu);
msg_set_ack(hdr, l->failover_checkpt - 1);
msg_set_next_sent(hdr, 1);
}
skb = tipc_buf_acquire(msg_size(hdr));
if (!skb)
return;
skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
skb->priority = TC_PRIO_CONTROL;
__skb_queue_head(xmitq, skb);
}
/* 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 *skb;
u32 length = msg_size(msg);
tunnel = node_active_link(l_ptr->owner, 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);
skb = tipc_buf_acquire(length + INT_H_SIZE);
if (!skb) {
pr_warn("%sunable to send tunnel msg\n", link_co_err);
return;
}
skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
__tipc_link_xmit_skb(tunnel, skb);
}
/* 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)
{
int msgcount;
struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
struct tipc_msg tunnel_hdr;
struct sk_buff *skb;
int split_bundles;
if (!tunnel)
return;
tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
skb_queue_walk(&l_ptr->backlogq, skb) {
msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
}
skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
tipc_link_purge_backlog(l_ptr);
msgcount = skb_queue_len(&l_ptr->transmq);
msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
msg_set_msgcnt(&tunnel_hdr, msgcount);
if (skb_queue_empty(&l_ptr->transmq)) {
skb = tipc_buf_acquire(INT_H_SIZE);
if (skb) {
skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
msg_set_size(&tunnel_hdr, INT_H_SIZE);
__tipc_link_xmit_skb(tunnel, skb);
} else {
pr_warn("%sunable to send changeover msg\n",
link_co_err);
}
return;
}
split_bundles = (node_active_link(l_ptr->owner, 0) !=
node_active_link(l_ptr->owner, 0));
skb_queue_walk(&l_ptr->transmq, skb) {
struct tipc_msg *msg = buf_msg(skb);
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));
}
}
}
/* 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 *link,
struct tipc_link *tnl)
{
struct sk_buff *skb;
struct tipc_msg tnl_hdr;
struct sk_buff_head *queue = &link->transmq;
int mcnt;
u16 seqno;
tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
SYNCH_MSG, INT_H_SIZE, link->addr);
mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
msg_set_msgcnt(&tnl_hdr, mcnt);
msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
tunnel_queue:
skb_queue_walk(queue, skb) {
struct sk_buff *outskb;
struct tipc_msg *msg = buf_msg(skb);
u32 len = msg_size(msg);
msg_set_ack(msg, mod(link->rcv_nxt - 1));
msg_set_bcast_ack(msg, link->owner->bclink.last_in);
msg_set_size(&tnl_hdr, len + INT_H_SIZE);
outskb = tipc_buf_acquire(len + INT_H_SIZE);
if (outskb == NULL) {
pr_warn("%sunable to send duplicate msg\n",
link_co_err);
return;
}
skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
skb->data, len);
__tipc_link_xmit_skb(tnl, outskb);
if (!tipc_link_is_up(link))
return;
}
if (queue == &link->backlogq)
return;
seqno = link->snd_nxt;
skb_queue_walk(&link->backlogq, skb) {
msg_set_seqno(buf_msg(skb), seqno);
seqno = mod(seqno + 1);
}
queue = &link->backlogq;
goto tunnel_queue;
}
/* tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
* Owner node is locked.
*/
static bool tipc_link_failover_rcv(struct tipc_link *link,
struct sk_buff **skb)
{
struct tipc_msg *msg = buf_msg(*skb);
struct sk_buff *iskb = NULL;
struct tipc_link *pl = NULL;
int bearer_id = msg_bearer_id(msg);
int pos = 0;
if (msg_type(msg) != FAILOVER_MSG) {
pr_warn("%sunknown tunnel pkt received\n", link_co_err);
goto exit;
}
if (bearer_id >= MAX_BEARERS)
goto exit;
if (bearer_id == link->bearer_id)
goto exit;
pl = link->owner->links[bearer_id].link;
if (pl && tipc_link_is_up(pl))
tipc_link_reset(pl);
if (link->failover_pkts == FIRST_FAILOVER)
link->failover_pkts = msg_msgcnt(msg);
/* Should we expect an inner packet? */
if (!link->failover_pkts)
goto exit;
if (!tipc_msg_extract(*skb, &iskb, &pos)) {
pr_warn("%sno inner failover pkt\n", link_co_err);
*skb = NULL;
goto exit;
}
link->failover_pkts--;
*skb = NULL;
/* Was this packet already delivered? */
if (less(buf_seqno(iskb), link->failover_checkpt)) {
kfree_skb(iskb);
iskb = NULL;
goto exit;
}
if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
link->stats.recv_fragments++;
tipc_buf_append(&link->failover_skb, &iskb);
}
exit:
if (!link->failover_pkts && pl)
pl->exec_mode = TIPC_LINK_OPEN;
kfree_skb(*skb);
*skb = iskb;
return *skb;
}
/* 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 nacked_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);
char *if_name;
int rc = 0;
if (l->exec_mode == TIPC_LINK_BLOCKED)
goto exit;
if (link_own_addr(l) > msg_prevnode(hdr))
l->net_plane = msg_net_plane(hdr);
switch (msg_type(hdr)) {
case RESET_MSG:
/* Ignore duplicate RESET with old session number */
if ((less_eq(msg_session(hdr), l->peer_session)) &&
(l->peer_session != WILDCARD_SESSION))
break;
/* fall thru' */
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, msg_data(hdr), 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;
/* 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;
l->peer_session = msg_session(hdr);
l->peer_bearer_id = msg_bearer_id(hdr);
rc = tipc_link_fsm_evt(l, msg_type(hdr), xmitq);
if (l->mtu > msg_max_pkt(hdr))
l->mtu = msg_max_pkt(hdr);
break;
case STATE_MSG:
/* 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->silent_intv_cnt = 0;
l->stats.recv_states++;
if (msg_probe(hdr))
l->stats.recv_probes++;
rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
if (!tipc_link_is_up(l))
break;
/* Has peer sent packets we haven't received yet ? */
if (more(peers_snd_nxt, l->rcv_nxt))
rcvgap = peers_snd_nxt - l->rcv_nxt;
if (rcvgap || (msg_probe(hdr)))
tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
0, 0, xmitq);
tipc_link_release_pkts(l, msg_ack(hdr));
/* If NACK, retransmit will now start at right position */
if (nacked_gap) {
rc |= tipc_link_retransm(l, nacked_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;
}
void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
{
int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
l->window = win;
l->backlog[TIPC_LOW_IMPORTANCE].limit = win / 2;
l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = win;
l->backlog[TIPC_HIGH_IMPORTANCE].limit = win / 2 * 3;
l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
}
/* tipc_link_find_owner - locate owner node of link by link's name
* @net: the applicable net namespace
* @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(struct net *net,
const char *link_name,
unsigned int *bearer_id)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
struct tipc_node *found_node = NULL;
int i;
*bearer_id = 0;
rcu_read_lock();
list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
tipc_node_lock(n_ptr);
for (i = 0; i < MAX_BEARERS; i++) {
l_ptr = n_ptr->links[i].link;
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_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->snd_nxt;
l_ptr->stats.recv_info = l_ptr->rcv_nxt;
}
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;
u16 tail = l->snd_nxt - 1;
pr_info("%s Link <%s>:", str, l->name);
if (link_probing(l))
pr_cont(":P\n");
else if (link_establishing(l))
pr_cont(":E\n");
else if (link_resetting(l))
pr_cont(":R\n");
else if (link_working(l))
pr_cont(":W\n");
else
pr_cont("\n");
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);
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;
}
int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
{
int err;
int res = 0;
int bearer_id;
char *name;
struct tipc_link *link;
struct tipc_node *node;
struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
struct net *net = sock_net(skb->sk);
if (!info->attrs[TIPC_NLA_LINK])
return -EINVAL;
err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
info->attrs[TIPC_NLA_LINK],
tipc_nl_link_policy);
if (err)
return err;
if (!attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
if (strcmp(name, tipc_bclink_name) == 0)
return tipc_nl_bc_link_set(net, attrs);
node = tipc_link_find_owner(net, name, &bearer_id);
if (!node)
return -EINVAL;
tipc_node_lock(node);
link = node->links[bearer_id].link;
if (!link) {
res = -EINVAL;
goto out;
}
if (attrs[TIPC_NLA_LINK_PROP]) {
struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
props);
if (err) {
res = err;
goto out;
}
if (props[TIPC_NLA_PROP_TOL]) {
u32 tol;
tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
link->tolerance = tol;
tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
}
if (props[TIPC_NLA_PROP_PRIO]) {
u32 prio;
prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
link->priority = prio;
tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
}
if (props[TIPC_NLA_PROP_WIN]) {
u32 win;
win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
tipc_link_set_queue_limits(link, win);
}
}
out:
tipc_node_unlock(node);
return res;
}
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, s->recv_info},
{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, s->sent_info},
{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 */
static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
struct tipc_link *link, int nlflags)
{
int err;
void *hdr;
struct nlattr *attrs;
struct nlattr *prop;
struct tipc_net *tn = net_generic(net, tipc_net_id);
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(tn->own_addr)))
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->rcv_nxt))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
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 (tipc_link_is_active(link))
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;
}
/* Caller should hold node lock */
static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
struct tipc_node *node, u32 *prev_link)
{
u32 i;
int err;
for (i = *prev_link; i < MAX_BEARERS; i++) {
*prev_link = i;
if (!node->links[i].link)
continue;
err = __tipc_nl_add_link(net, msg,
node->links[i].link, NLM_F_MULTI);
if (err)
return err;
}
*prev_link = 0;
return 0;
}
int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *node;
struct tipc_nl_msg msg;
u32 prev_node = cb->args[0];
u32 prev_link = cb->args[1];
int done = cb->args[2];
int err;
if (done)
return 0;
msg.skb = skb;
msg.portid = NETLINK_CB(cb->skb).portid;
msg.seq = cb->nlh->nlmsg_seq;
rcu_read_lock();
if (prev_node) {
node = tipc_node_find(net, prev_node);
if (!node) {
/* We never set seq or call nl_dump_check_consistent()
* this means that setting prev_seq here will cause the
* consistence check to fail in the netlink callback
* handler. Resulting in the last NLMSG_DONE message
* having the NLM_F_DUMP_INTR flag set.
*/
cb->prev_seq = 1;
goto out;
}
tipc_node_put(node);
list_for_each_entry_continue_rcu(node, &tn->node_list,
list) {
tipc_node_lock(node);
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_unlock(node);
if (err)
goto out;
prev_node = node->addr;
}
} else {
err = tipc_nl_add_bc_link(net, &msg);
if (err)
goto out;
list_for_each_entry_rcu(node, &tn->node_list, list) {
tipc_node_lock(node);
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_unlock(node);
if (err)
goto out;
prev_node = node->addr;
}
}
done = 1;
out:
rcu_read_unlock();
cb->args[0] = prev_node;
cb->args[1] = prev_link;
cb->args[2] = done;
return skb->len;
}
int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
struct tipc_nl_msg msg;
char *name;
int err;
msg.portid = info->snd_portid;
msg.seq = info->snd_seq;
if (!info->attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg.skb)
return -ENOMEM;
if (strcmp(name, tipc_bclink_name) == 0) {
err = tipc_nl_add_bc_link(net, &msg);
if (err) {
nlmsg_free(msg.skb);
return err;
}
} else {
int bearer_id;
struct tipc_node *node;
struct tipc_link *link;
node = tipc_link_find_owner(net, name, &bearer_id);
if (!node)
return -EINVAL;
tipc_node_lock(node);
link = node->links[bearer_id].link;
if (!link) {
tipc_node_unlock(node);
nlmsg_free(msg.skb);
return -EINVAL;
}
err = __tipc_nl_add_link(net, &msg, link, 0);
tipc_node_unlock(node);
if (err) {
nlmsg_free(msg.skb);
return err;
}
}
return genlmsg_reply(msg.skb, info);
}
int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
{
int err;
char *link_name;
unsigned int bearer_id;
struct tipc_link *link;
struct tipc_node *node;
struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
struct net *net = sock_net(skb->sk);
if (!info->attrs[TIPC_NLA_LINK])
return -EINVAL;
err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
info->attrs[TIPC_NLA_LINK],
tipc_nl_link_policy);
if (err)
return err;
if (!attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
if (strcmp(link_name, tipc_bclink_name) == 0) {
err = tipc_bclink_reset_stats(net);
if (err)
return err;
return 0;
}
node = tipc_link_find_owner(net, link_name, &bearer_id);
if (!node)
return -EINVAL;
tipc_node_lock(node);
link = node->links[bearer_id].link;
if (!link) {
tipc_node_unlock(node);
return -EINVAL;
}
link_reset_statistics(link);
tipc_node_unlock(node);
return 0;
}