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linux_old1/net/tipc/link.c

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/*
* 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 tunneling error, ";
static const char *link_rst_msg = "Resetting link ";
static const char tipc_bclink_name[] = "broadcast-link";
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 }
};
/* Send states for broadcast NACKs
*/
enum {
BC_NACK_SND_CONDITIONAL,
BC_NACK_SND_UNCONDITIONAL,
BC_NACK_SND_SUPPRESS,
};
/*
* 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
/* 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,
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_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);
}
bool link_is_bc_sndlink(struct tipc_link *l)
{
return !l->bc_sndlink;
}
bool link_is_bc_rcvlink(struct tipc_link *l)
{
return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
}
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);
}
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;
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--;
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);
__skb_queue_purge(xmitq);
}
}
int tipc_link_bc_peers(struct tipc_link *l)
{
return l->ackers;
}
static u32 link_own_addr(struct tipc_link *l)
{
return msg_prevnode(l->pmsg);
}
/**
* 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
* @maddr: media address to be used
* @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 tipc_node *n, char *if_name, int bearer_id,
int tolerance, char net_plane, u32 mtu, int priority,
int window, u32 session, u32 ownnode, u32 peer,
u16 peer_caps,
struct tipc_media_addr *maddr,
struct tipc_link *bc_sndlink,
struct tipc_link *bc_rcvlink,
struct sk_buff_head *inputq,
struct sk_buff_head *namedq,
struct tipc_link **link)
{
struct tipc_link *l;
struct tipc_msg *hdr;
l = kzalloc(sizeof(*l), GFP_ATOMIC);
if (!l)
return false;
*link = l;
l->pmsg = (struct tipc_msg *)&l->proto_msg;
hdr = l->pmsg;
tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
msg_set_size(hdr, sizeof(l->proto_msg));
msg_set_session(hdr, session);
msg_set_bearer_id(hdr, l->bearer_id);
/* Note: peer i/f name is completed by reset/activate message */
sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
strcpy((char *)msg_data(hdr), if_name);
l->addr = peer;
l->peer_caps = peer_caps;
l->media_addr = maddr;
l->owner = n;
l->peer_session = WILDCARD_SESSION;
l->bearer_id = bearer_id;
l->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
* @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 tipc_node *n, 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(n, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
0, ownnode, peer, peer_caps, NULL, 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;
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
*/
/* 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;
int mtyp = STATE_MSG;
bool xmit = false;
bool prb = false;
u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
u16 bc_acked = l->bc_rcvlink->acked;
bool bc_up = link_is_up(l->bc_rcvlink);
link_profile_stats(l);
switch (l->state) {
case LINK_ESTABLISHED:
case LINK_SYNCHING:
if (!l->silent_intv_cnt) {
if (bc_up && (bc_acked != bc_snt))
xmit = true;
} else if (l->silent_intv_cnt <= l->abort_limit) {
xmit = true;
prb = true;
} else {
rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
l->silent_intv_cnt++;
break;
case LINK_RESET:
xmit = true;
mtyp = RESET_MSG;
break;
case LINK_ESTABLISHING:
xmit = true;
mtyp = ACTIVATE_MSG;
break;
case LINK_PEER_RESET:
case LINK_RESETTING:
case LINK_FAILINGOVER:
break;
default:
break;
}
if (xmit)
tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
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);
}
}
/**
* 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)
{
/* Link is down, accept any session */
l->peer_session = WILDCARD_SESSION;
/* If peer is up, it only accepts an incremented session number */
msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
/* Prepare for renewed mtu size negotiation */
l->mtu = l->advertised_mtu;
/* Clean up all queues: */
__skb_queue_purge(&l->transmq);
__skb_queue_purge(&l->deferdq);
skb_queue_splice_init(&l->wakeupq, l->inputq);
tipc_link_purge_backlog(l);
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->acked = 0;
l->silent_intv_cnt = 0;
l->stats.recv_info = 0;
l->stale_count = 0;
l->bc_peer_is_up = false;
link_reset_statistics(l);
}
/**
* __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_ack = link->bc_rcvlink->rcv_nxt - 1;
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_ack);
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_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;
/* 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_ack);
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);
TIPC_SKB_CB(skb)->ackers = l->ackers;
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;
}
/*
* 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;
TIPC_SKB_CB(skb)->ackers = link->ackers;
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;
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;
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, "Resetting 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));
}
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++;
}
}
int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
struct sk_buff_head *xmitq)
{
struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
struct tipc_msg *hdr;
u16 ack = l->rcv_nxt - 1;
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
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_fsm_evt(l, LINK_FAILURE_EVT);
}
/* Move forward to where retransmission should start */
skb_queue_walk(&l->transmq, skb) {
if (!less(buf_seqno(skb), from))
break;
}
skb_queue_walk_from(&l->transmq, skb) {
if (more(buf_seqno(skb), to))
break;
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, 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)
{
switch (msg_user(buf_msg(skb))) {
case TIPC_LOW_IMPORTANCE:
case TIPC_MEDIUM_IMPORTANCE:
case TIPC_HIGH_IMPORTANCE:
case TIPC_CRITICAL_IMPORTANCE:
case CONN_MANAGER:
skb_queue_tail(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->owner->net);
tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
tipc_bcast_unlock(l->owner->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_ack_msg: prepare link acknowledge 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_ack_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 ^ link_own_addr(l)) & 0xf) != 0xf)
return 0;
l->rcv_unacked = 0;
return TIPC_LINK_SND_BC_ACK;
}
/* Unicast ACK */
l->rcv_unacked = 0;
l->stats.sent_acks++;
tipc_link_build_proto_msg(l, STATE_MSG, 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;
if (l->state == LINK_ESTABLISHING)
mtyp = ACTIVATE_MSG;
tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
}
/* tipc_link_build_nack_msg: prepare link nack message for transmission
*/
static void tipc_link_build_nack_msg(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
u32 def_cnt = ++l->stats.deferred_recv;
if (link_is_bc_rcvlink(l))
return;
if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 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)
{
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)))) {
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);
tipc_link_build_nack_msg(l, xmitq);
break;
}
/* Deliver packet */
l->rcv_nxt++;
l->stats.recv_info++;
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_ack_msg(l, xmitq);
if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
break;
} while ((skb = __skb_dequeue(defq)));
return rc;
drop:
kfree_skb(skb);
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);
}
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;
bool node_up = link_is_up(l->bc_rcvlink);
/* Don't send protocol message during reset or link failover */
if (tipc_link_is_blocked(l))
return;
msg_set_type(hdr, mtyp);
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, l->bc_rcvlink->rcv_nxt - 1);
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);
/* Compatibility: created msg must not be in sequence with pkt flow */
msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
if (mtyp == STATE_MSG) {
if (!tipc_link_is_up(l))
return;
/* Override rcvgap if there are packets in deferred queue */
if (!skb_queue_empty(&l->deferdq))
rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
if (rcvgap) {
msg_set_seq_gap(hdr, rcvgap);
l->stats.sent_nacks++;
}
msg_set_probe(hdr, probe);
if (probe)
l->stats.sent_probes++;
l->stats.sent_states++;
l->rcv_unacked = 0;
} else {
/* RESET_MSG or ACTIVATE_MSG */
msg_set_max_pkt(hdr, l->advertised_mtu);
msg_set_ack(hdr, l->rcv_nxt - 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_tail(xmitq, skb);
}
/* 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, link_own_addr(l),
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(link_own_addr(l), &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);
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_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;
int mtyp = msg_type(hdr);
char *if_name;
int rc = 0;
if (tipc_link_is_blocked(l) || !xmitq)
goto exit;
if (link_own_addr(l) > msg_prevnode(hdr))
l->net_plane = msg_net_plane(hdr);
switch (mtyp) {
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;
/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
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->peer_bearer_id = msg_bearer_id(hdr);
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++;
if (!link_is_up(l)) {
if (l->state == LINK_ESTABLISHING)
rc = TIPC_LINK_UP_EVT;
break;
}
/* 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 || (msg_probe(hdr)))
tipc_link_build_proto_msg(l, STATE_MSG, 0, 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, 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, link_own_addr(l), 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.
*/
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;
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;
}
/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
*/
void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
struct sk_buff_head *xmitq)
{
u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
if (!link_is_up(l))
return;
if (!msg_peer_node_is_up(hdr))
return;
l->bc_peer_is_up = true;
/* Ignore if peers_snd_nxt goes beyond receive window */
if (more(peers_snd_nxt, l->rcv_nxt + l->window))
return;
if (!more(peers_snd_nxt, l->rcv_nxt)) {
l->nack_state = BC_NACK_SND_CONDITIONAL;
return;
}
/* 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;
}
/* 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;
}
/* 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;
}
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
*/
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 == link_own_addr(l)) {
tipc_link_bc_ack_rcv(l, acked, xmitq);
rc = tipc_link_retrans(l->bc_sndlink, 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_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 - 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);
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;
}
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