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gerrit-public.fairphone.software / kernel / msm-4.9 / 089bc8e95ae07b1ada14069935c30fd88204c21c / . / net / tipc / link.c
blob: 0cc3d9015c5d5bb6a1629251d7a636f41239db6f [file] [log] [blame]
/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "link.h"
#include "port.h"
#include "name_distr.h"
#include "discover.h"
#include "config.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 ";
/*
* Out-of-range value for link session numbers
*/
#define INVALID_SESSION 0x10000
/*
* Link state events:
*/
#define STARTING_EVT 856384768 /* link processing trigger */
#define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
#define TIMEOUT_EVT 560817u /* link timer expired */
/*
* The following two 'message types' is really just implementation
* data conveniently stored in the message header.
* They must not be considered part of the protocol
*/
#define OPEN_MSG 0
#define CLOSED_MSG 1
/*
* State value stored in 'exp_msg_count'
*/
#define START_CHANGEOVER 100000u
/**
* struct tipc_link_name - deconstructed link name
* @addr_local: network address of node at this end
* @if_local: name of interface at this end
* @addr_peer: network address of node at far end
* @if_peer: name of interface at far end
*/
struct tipc_link_name {
u32 addr_local;
char if_local[TIPC_MAX_IF_NAME];
u32 addr_peer;
char if_peer[TIPC_MAX_IF_NAME];
};
static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
struct sk_buff *buf);
static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
static int link_recv_changeover_msg(struct tipc_link **l_ptr,
struct sk_buff **buf);
static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
static int link_send_sections_long(struct tipc_port *sender,
struct iovec const *msg_sect,
u32 num_sect, unsigned int total_len,
u32 destnode);
static void link_state_event(struct tipc_link *l_ptr, u32 event);
static void link_reset_statistics(struct tipc_link *l_ptr);
static void link_print(struct tipc_link *l_ptr, const char *str);
static void link_start(struct tipc_link *l_ptr);
static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
static void tipc_link_send_sync(struct tipc_link *l);
static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf);
/*
* Simple link routines
*/
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
static void link_init_max_pkt(struct tipc_link *l_ptr)
{
u32 max_pkt;
max_pkt = (l_ptr->b_ptr->mtu & ~3);
if (max_pkt > MAX_MSG_SIZE)
max_pkt = MAX_MSG_SIZE;
l_ptr->max_pkt_target = max_pkt;
if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
l_ptr->max_pkt = l_ptr->max_pkt_target;
else
l_ptr->max_pkt = MAX_PKT_DEFAULT;
l_ptr->max_pkt_probes = 0;
}
static u32 link_next_sent(struct tipc_link *l_ptr)
{
if (l_ptr->next_out)
return buf_seqno(l_ptr->next_out);
return mod(l_ptr->next_out_no);
}
static u32 link_last_sent(struct tipc_link *l_ptr)
{
return mod(link_next_sent(l_ptr) - 1);
}
/*
* Simple non-static link routines (i.e. referenced outside this file)
*/
int tipc_link_is_up(struct tipc_link *l_ptr)
{
if (!l_ptr)
return 0;
return link_working_working(l_ptr) || link_working_unknown(l_ptr);
}
int tipc_link_is_active(struct tipc_link *l_ptr)
{
return (l_ptr->owner->active_links[0] == l_ptr) ||
(l_ptr->owner->active_links[1] == l_ptr);
}
/**
* link_name_validate - validate & (optionally) deconstruct tipc_link name
* @name: ptr to link name string
* @name_parts: ptr to area for link name components (or NULL if not needed)
*
* Returns 1 if link name is valid, otherwise 0.
*/
static int link_name_validate(const char *name,
struct tipc_link_name *name_parts)
{
char name_copy[TIPC_MAX_LINK_NAME];
char *addr_local;
char *if_local;
char *addr_peer;
char *if_peer;
char dummy;
u32 z_local, c_local, n_local;
u32 z_peer, c_peer, n_peer;
u32 if_local_len;
u32 if_peer_len;
/* copy link name & ensure length is OK */
name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
/* need above in case non-Posix strncpy() doesn't pad with nulls */
strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
return 0;
/* ensure all component parts of link name are present */
addr_local = name_copy;
if_local = strchr(addr_local, ':');
if (if_local == NULL)
return 0;
*(if_local++) = 0;
addr_peer = strchr(if_local, '-');
if (addr_peer == NULL)
return 0;
*(addr_peer++) = 0;
if_local_len = addr_peer - if_local;
if_peer = strchr(addr_peer, ':');
if (if_peer == NULL)
return 0;
*(if_peer++) = 0;
if_peer_len = strlen(if_peer) + 1;
/* validate component parts of link name */
if ((sscanf(addr_local, "%u.%u.%u%c",
&z_local, &c_local, &n_local, &dummy) != 3) ||
(sscanf(addr_peer, "%u.%u.%u%c",
&z_peer, &c_peer, &n_peer, &dummy) != 3) ||
(z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
(z_peer > 255) || (c_peer > 4095) || (n_peer > 4095) ||
(if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
(if_peer_len <= 1) || (if_peer_len > TIPC_MAX_IF_NAME))
return 0;
/* return link name components, if necessary */
if (name_parts) {
name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
strcpy(name_parts->if_local, if_local);
name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
strcpy(name_parts->if_peer, if_peer);
}
return 1;
}
/**
* link_timeout - handle expiration of link timer
* @l_ptr: pointer to link
*
* This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
* with tipc_link_delete(). (There is no risk that the node will be deleted by
* another thread because tipc_link_delete() always cancels the link timer before
* tipc_node_delete() is called.)
*/
static void link_timeout(struct tipc_link *l_ptr)
{
tipc_node_lock(l_ptr->owner);
/* update counters used in statistical profiling of send traffic */
l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
l_ptr->stats.queue_sz_counts++;
if (l_ptr->first_out) {
struct tipc_msg *msg = buf_msg(l_ptr->first_out);
u32 length = msg_size(msg);
if ((msg_user(msg) == MSG_FRAGMENTER) &&
(msg_type(msg) == FIRST_FRAGMENT)) {
length = msg_size(msg_get_wrapped(msg));
}
if (length) {
l_ptr->stats.msg_lengths_total += length;
l_ptr->stats.msg_length_counts++;
if (length <= 64)
l_ptr->stats.msg_length_profile[0]++;
else if (length <= 256)
l_ptr->stats.msg_length_profile[1]++;
else if (length <= 1024)
l_ptr->stats.msg_length_profile[2]++;
else if (length <= 4096)
l_ptr->stats.msg_length_profile[3]++;
else if (length <= 16384)
l_ptr->stats.msg_length_profile[4]++;
else if (length <= 32768)
l_ptr->stats.msg_length_profile[5]++;
else
l_ptr->stats.msg_length_profile[6]++;
}
}
/* do all other link processing performed on a periodic basis */
link_state_event(l_ptr, TIMEOUT_EVT);
if (l_ptr->next_out)
tipc_link_push_queue(l_ptr);
tipc_node_unlock(l_ptr->owner);
}
static void link_set_timer(struct tipc_link *l_ptr, u32 time)
{
k_start_timer(&l_ptr->timer, time);
}
/**
* tipc_link_create - create a new link
* @n_ptr: pointer to associated node
* @b_ptr: pointer to associated bearer
* @media_addr: media address to use when sending messages over link
*
* Returns pointer to link.
*/
struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
struct tipc_bearer *b_ptr,
const struct tipc_media_addr *media_addr)
{
struct tipc_link *l_ptr;
struct tipc_msg *msg;
char *if_name;
char addr_string[16];
u32 peer = n_ptr->addr;
if (n_ptr->link_cnt >= 2) {
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_err("Attempt to establish third link to %s\n", addr_string);
return NULL;
}
if (n_ptr->links[b_ptr->identity]) {
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_err("Attempt to establish second link on <%s> to %s\n",
b_ptr->name, addr_string);
return NULL;
}
l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
if (!l_ptr) {
pr_warn("Link creation failed, no memory\n");
return NULL;
}
l_ptr->addr = peer;
if_name = strchr(b_ptr->name, ':') + 1;
sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
tipc_node(tipc_own_addr),
if_name,
tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
/* note: peer i/f name is updated by reset/activate message */
memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
l_ptr->owner = n_ptr;
l_ptr->checkpoint = 1;
l_ptr->peer_session = INVALID_SESSION;
l_ptr->b_ptr = b_ptr;
link_set_supervision_props(l_ptr, b_ptr->tolerance);
l_ptr->state = RESET_UNKNOWN;
l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
msg = l_ptr->pmsg;
tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
msg_set_size(msg, sizeof(l_ptr->proto_msg));
msg_set_session(msg, (tipc_random & 0xffff));
msg_set_bearer_id(msg, b_ptr->identity);
strcpy((char *)msg_data(msg), if_name);
l_ptr->priority = b_ptr->priority;
tipc_link_set_queue_limits(l_ptr, b_ptr->window);
link_init_max_pkt(l_ptr);
l_ptr->next_out_no = 1;
INIT_LIST_HEAD(&l_ptr->waiting_ports);
link_reset_statistics(l_ptr);
tipc_node_attach_link(n_ptr, l_ptr);
k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
list_add_tail(&l_ptr->link_list, &b_ptr->links);
tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
return l_ptr;
}
/**
* tipc_link_delete - delete a link
* @l_ptr: pointer to link
*
* Note: 'tipc_net_lock' is write_locked, bearer is locked.
* This routine must not grab the node lock until after link timer cancellation
* to avoid a potential deadlock situation.
*/
void tipc_link_delete(struct tipc_link *l_ptr)
{
if (!l_ptr) {
pr_err("Attempt to delete non-existent link\n");
return;
}
k_cancel_timer(&l_ptr->timer);
tipc_node_lock(l_ptr->owner);
tipc_link_reset(l_ptr);
tipc_node_detach_link(l_ptr->owner, l_ptr);
tipc_link_stop(l_ptr);
list_del_init(&l_ptr->link_list);
tipc_node_unlock(l_ptr->owner);
k_term_timer(&l_ptr->timer);
kfree(l_ptr);
}
static void link_start(struct tipc_link *l_ptr)
{
tipc_node_lock(l_ptr->owner);
link_state_event(l_ptr, STARTING_EVT);
tipc_node_unlock(l_ptr->owner);
}
/**
* link_schedule_port - schedule port for deferred sending
* @l_ptr: pointer to link
* @origport: reference to sending port
* @sz: amount of data to be sent
*
* Schedules port for renewed sending of messages after link congestion
* has abated.
*/
static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
{
struct tipc_port *p_ptr;
spin_lock_bh(&tipc_port_list_lock);
p_ptr = tipc_port_lock(origport);
if (p_ptr) {
if (!p_ptr->wakeup)
goto exit;
if (!list_empty(&p_ptr->wait_list))
goto exit;
p_ptr->congested = 1;
p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
l_ptr->stats.link_congs++;
exit:
tipc_port_unlock(p_ptr);
}
spin_unlock_bh(&tipc_port_list_lock);
return -ELINKCONG;
}
void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
{
struct tipc_port *p_ptr;
struct tipc_port *temp_p_ptr;
int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
if (all)
win = 100000;
if (win <= 0)
return;
if (!spin_trylock_bh(&tipc_port_list_lock))
return;
if (link_congested(l_ptr))
goto exit;
list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
wait_list) {
if (win <= 0)
break;
list_del_init(&p_ptr->wait_list);
spin_lock_bh(p_ptr->lock);
p_ptr->congested = 0;
p_ptr->wakeup(p_ptr);
win -= p_ptr->waiting_pkts;
spin_unlock_bh(p_ptr->lock);
}
exit:
spin_unlock_bh(&tipc_port_list_lock);
}
/**
* link_release_outqueue - purge link's outbound message queue
* @l_ptr: pointer to link
*/
static void link_release_outqueue(struct tipc_link *l_ptr)
{
struct sk_buff *buf = l_ptr->first_out;
struct sk_buff *next;
while (buf) {
next = buf->next;
kfree_skb(buf);
buf = next;
}
l_ptr->first_out = NULL;
l_ptr->out_queue_size = 0;
}
/**
* tipc_link_reset_fragments - purge link's inbound message fragments queue
* @l_ptr: pointer to link
*/
void tipc_link_reset_fragments(struct tipc_link *l_ptr)
{
struct sk_buff *buf = l_ptr->defragm_buf;
struct sk_buff *next;
while (buf) {
next = buf->next;
kfree_skb(buf);
buf = next;
}
l_ptr->defragm_buf = NULL;
}
/**
* tipc_link_stop - purge all inbound and outbound messages associated with link
* @l_ptr: pointer to link
*/
void tipc_link_stop(struct tipc_link *l_ptr)
{
struct sk_buff *buf;
struct sk_buff *next;
buf = l_ptr->oldest_deferred_in;
while (buf) {
next = buf->next;
kfree_skb(buf);
buf = next;
}
buf = l_ptr->first_out;
while (buf) {
next = buf->next;
kfree_skb(buf);
buf = next;
}
tipc_link_reset_fragments(l_ptr);
kfree_skb(l_ptr->proto_msg_queue);
l_ptr->proto_msg_queue = NULL;
}
void tipc_link_reset(struct tipc_link *l_ptr)
{
struct sk_buff *buf;
u32 prev_state = l_ptr->state;
u32 checkpoint = l_ptr->next_in_no;
int was_active_link = tipc_link_is_active(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 = INVALID_SESSION;
/* Prepare for max packet size negotiation */
link_init_max_pkt(l_ptr);
l_ptr->state = RESET_UNKNOWN;
if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
return;
tipc_node_link_down(l_ptr->owner, l_ptr);
tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
if (was_active_link && tipc_node_active_links(l_ptr->owner) &&
l_ptr->owner->permit_changeover) {
l_ptr->reset_checkpoint = checkpoint;
l_ptr->exp_msg_count = START_CHANGEOVER;
}
/* Clean up all queues: */
link_release_outqueue(l_ptr);
kfree_skb(l_ptr->proto_msg_queue);
l_ptr->proto_msg_queue = NULL;
buf = l_ptr->oldest_deferred_in;
while (buf) {
struct sk_buff *next = buf->next;
kfree_skb(buf);
buf = next;
}
if (!list_empty(&l_ptr->waiting_ports))
tipc_link_wakeup_ports(l_ptr, 1);
l_ptr->retransm_queue_head = 0;
l_ptr->retransm_queue_size = 0;
l_ptr->last_out = NULL;
l_ptr->first_out = NULL;
l_ptr->next_out = NULL;
l_ptr->unacked_window = 0;
l_ptr->checkpoint = 1;
l_ptr->next_out_no = 1;
l_ptr->deferred_inqueue_sz = 0;
l_ptr->oldest_deferred_in = NULL;
l_ptr->newest_deferred_in = NULL;
l_ptr->fsm_msg_cnt = 0;
l_ptr->stale_count = 0;
link_reset_statistics(l_ptr);
}
static void link_activate(struct tipc_link *l_ptr)
{
l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
tipc_node_link_up(l_ptr->owner, l_ptr);
tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
}
/**
* link_state_event - link finite state machine
* @l_ptr: pointer to link
* @event: state machine event to process
*/
static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
{
struct tipc_link *other;
u32 cont_intv = l_ptr->continuity_interval;
if (!l_ptr->started && (event != STARTING_EVT))
return; /* Not yet. */
if (link_blocked(l_ptr)) {
if (event == TIMEOUT_EVT)
link_set_timer(l_ptr, cont_intv);
return; /* Changeover going on */
}
switch (l_ptr->state) {
case WORKING_WORKING:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
break;
case TIMEOUT_EVT:
if (l_ptr->next_in_no != l_ptr->checkpoint) {
l_ptr->checkpoint = l_ptr->next_in_no;
if (tipc_bclink_acks_missing(l_ptr->owner)) {
tipc_link_send_proto_msg(l_ptr, STATE_MSG,
0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
} else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
tipc_link_send_proto_msg(l_ptr, STATE_MSG,
1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
}
link_set_timer(l_ptr, cont_intv);
break;
}
l_ptr->state = WORKING_UNKNOWN;
l_ptr->fsm_msg_cnt = 0;
tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv / 4);
break;
case RESET_MSG:
pr_info("%s<%s>, requested by peer\n", link_rst_msg,
l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_err("%s%u in WW state\n", link_unk_evt, event);
}
break;
case WORKING_UNKNOWN:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
pr_info("%s<%s>, requested by peer while probing\n",
link_rst_msg, l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
case TIMEOUT_EVT:
if (l_ptr->next_in_no != l_ptr->checkpoint) {
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
l_ptr->checkpoint = l_ptr->next_in_no;
if (tipc_bclink_acks_missing(l_ptr->owner)) {
tipc_link_send_proto_msg(l_ptr, STATE_MSG,
0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
}
link_set_timer(l_ptr, cont_intv);
} else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
tipc_link_send_proto_msg(l_ptr, STATE_MSG,
1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv / 4);
} else { /* Link has failed */
pr_warn("%s<%s>, peer not responding\n",
link_rst_msg, l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_UNKNOWN;
l_ptr->fsm_msg_cnt = 0;
tipc_link_send_proto_msg(l_ptr, RESET_MSG,
0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
}
break;
default:
pr_err("%s%u in WU state\n", link_unk_evt, event);
}
break;
case RESET_UNKNOWN:
switch (event) {
case TRAFFIC_MSG_EVT:
break;
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other))
break;
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_activate(l_ptr);
tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
if (l_ptr->owner->working_links == 1)
tipc_link_send_sync(l_ptr);
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
case STARTING_EVT:
l_ptr->started = 1;
/* fall through */
case TIMEOUT_EVT:
tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_err("%s%u in RU state\n", link_unk_evt, event);
}
break;
case RESET_RESET:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other))
break;
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_activate(l_ptr);
tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
if (l_ptr->owner->working_links == 1)
tipc_link_send_sync(l_ptr);
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
break;
case TIMEOUT_EVT:
tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_err("%s%u in RR state\n", link_unk_evt, event);
}
break;
default:
pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
}
}
/*
* link_bundle_buf(): Append contents of a buffer to
* the tail of an existing one.
*/
static int link_bundle_buf(struct tipc_link *l_ptr, struct sk_buff *bundler,
struct sk_buff *buf)
{
struct tipc_msg *bundler_msg = buf_msg(bundler);
struct tipc_msg *msg = buf_msg(buf);
u32 size = msg_size(msg);
u32 bundle_size = msg_size(bundler_msg);
u32 to_pos = align(bundle_size);
u32 pad = to_pos - bundle_size;
if (msg_user(bundler_msg) != MSG_BUNDLER)
return 0;
if (msg_type(bundler_msg) != OPEN_MSG)
return 0;
if (skb_tailroom(bundler) < (pad + size))
return 0;
if (l_ptr->max_pkt < (to_pos + size))
return 0;
skb_put(bundler, pad + size);
skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
msg_set_size(bundler_msg, to_pos + size);
msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
kfree_skb(buf);
l_ptr->stats.sent_bundled++;
return 1;
}
static void link_add_to_outqueue(struct tipc_link *l_ptr,
struct sk_buff *buf,
struct tipc_msg *msg)
{
u32 ack = mod(l_ptr->next_in_no - 1);
u32 seqno = mod(l_ptr->next_out_no++);
msg_set_word(msg, 2, ((ack << 16) | seqno));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
buf->next = NULL;
if (l_ptr->first_out) {
l_ptr->last_out->next = buf;
l_ptr->last_out = buf;
} else
l_ptr->first_out = l_ptr->last_out = buf;
l_ptr->out_queue_size++;
if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
}
static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
struct sk_buff *buf_chain,
u32 long_msgno)
{
struct sk_buff *buf;
struct tipc_msg *msg;
if (!l_ptr->next_out)
l_ptr->next_out = buf_chain;
while (buf_chain) {
buf = buf_chain;
buf_chain = buf_chain->next;
msg = buf_msg(buf);
msg_set_long_msgno(msg, long_msgno);
link_add_to_outqueue(l_ptr, buf, msg);
}
}
/*
* tipc_link_send_buf() is the 'full path' for messages, called from
* inside TIPC when the 'fast path' in tipc_send_buf
* has failed, and from link_send()
*/
int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
u32 size = msg_size(msg);
u32 dsz = msg_data_sz(msg);
u32 queue_size = l_ptr->out_queue_size;
u32 imp = tipc_msg_tot_importance(msg);
u32 queue_limit = l_ptr->queue_limit[imp];
u32 max_packet = l_ptr->max_pkt;
/* Match msg importance against queue limits: */
if (unlikely(queue_size >= queue_limit)) {
if (imp <= TIPC_CRITICAL_IMPORTANCE) {
link_schedule_port(l_ptr, msg_origport(msg), size);
kfree_skb(buf);
return -ELINKCONG;
}
kfree_skb(buf);
if (imp > CONN_MANAGER) {
pr_warn("%s<%s>, send queue full", link_rst_msg,
l_ptr->name);
tipc_link_reset(l_ptr);
}
return dsz;
}
/* Fragmentation needed ? */
if (size > max_packet)
return link_send_long_buf(l_ptr, buf);
/* Packet can be queued or sent. */
if (likely(!tipc_bearer_blocked(l_ptr->b_ptr) &&
!link_congested(l_ptr))) {
link_add_to_outqueue(l_ptr, buf, msg);
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
l_ptr->unacked_window = 0;
return dsz;
}
/* Congestion: can message be bundled ? */
if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
(msg_user(msg) != MSG_FRAGMENTER)) {
/* Try adding message to an existing bundle */
if (l_ptr->next_out &&
link_bundle_buf(l_ptr, l_ptr->last_out, buf))
return dsz;
/* Try creating a new bundle */
if (size <= max_packet * 2 / 3) {
struct sk_buff *bundler = tipc_buf_acquire(max_packet);
struct tipc_msg bundler_hdr;
if (bundler) {
tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
INT_H_SIZE, l_ptr->addr);
skb_copy_to_linear_data(bundler, &bundler_hdr,
INT_H_SIZE);
skb_trim(bundler, INT_H_SIZE);
link_bundle_buf(l_ptr, bundler, buf);
buf = bundler;
msg = buf_msg(buf);
l_ptr->stats.sent_bundles++;
}
}
}
if (!l_ptr->next_out)
l_ptr->next_out = buf;
link_add_to_outqueue(l_ptr, buf, msg);
return dsz;
}
/*
* tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
* not been selected yet, and the the owner node is not locked
* Called by TIPC internal users, e.g. the name distributor
*/
int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
{
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
int res = -ELINKCONG;
read_lock_bh(&tipc_net_lock);
n_ptr = tipc_node_find(dest);
if (n_ptr) {
tipc_node_lock(n_ptr);
l_ptr = n_ptr->active_links[selector & 1];
if (l_ptr)
res = tipc_link_send_buf(l_ptr, buf);
else
kfree_skb(buf);
tipc_node_unlock(n_ptr);
} else {
kfree_skb(buf);
}
read_unlock_bh(&tipc_net_lock);
return res;
}
/*
* tipc_link_send_sync - synchronize broadcast link endpoints.
*
* Give a newly added peer node the sequence number where it should
* start receiving and acking broadcast packets.
*
* Called with node locked
*/
static void tipc_link_send_sync(struct tipc_link *l)
{
struct sk_buff *buf;
struct tipc_msg *msg;
buf = tipc_buf_acquire(INT_H_SIZE);
if (!buf)
return;
msg = buf_msg(buf);
tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, l->addr);
msg_set_last_bcast(msg, l->owner->bclink.acked);
link_add_chain_to_outqueue(l, buf, 0);
tipc_link_push_queue(l);
}
/*
* tipc_link_recv_sync - 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_recv_sync(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_send_names - send name table entries to new neighbor
*
* Send routine for bulk delivery of name table messages when contact
* with a new neighbor occurs. No link congestion checking is performed
* because name table messages *must* be delivered. The messages must be
* small enough not to require fragmentation.
* Called without any locks held.
*/
void tipc_link_send_names(struct list_head *message_list, u32 dest)
{
struct tipc_node *n_ptr;
struct tipc_link *l_ptr;
struct sk_buff *buf;
struct sk_buff *temp_buf;
if (list_empty(message_list))
return;
read_lock_bh(&tipc_net_lock);
n_ptr = tipc_node_find(dest);
if (n_ptr) {
tipc_node_lock(n_ptr);
l_ptr = n_ptr->active_links[0];
if (l_ptr) {
/* convert circular list to linear list */
((struct sk_buff *)message_list->prev)->next = NULL;
link_add_chain_to_outqueue(l_ptr,
(struct sk_buff *)message_list->next, 0);
tipc_link_push_queue(l_ptr);
INIT_LIST_HEAD(message_list);
}
tipc_node_unlock(n_ptr);
}
read_unlock_bh(&tipc_net_lock);
/* discard the messages if they couldn't be sent */
list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
list_del((struct list_head *)buf);
kfree_skb(buf);
}
}
/*
* link_send_buf_fast: Entry for data messages where the
* destination link is known and the header is complete,
* inclusive total message length. Very time critical.
* Link is locked. Returns user data length.
*/
static int link_send_buf_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
u32 *used_max_pkt)
{
struct tipc_msg *msg = buf_msg(buf);
int res = msg_data_sz(msg);
if (likely(!link_congested(l_ptr))) {
if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
if (likely(!tipc_bearer_blocked(l_ptr->b_ptr))) {
link_add_to_outqueue(l_ptr, buf, msg);
tipc_bearer_send(l_ptr->b_ptr, buf,
&l_ptr->media_addr);
l_ptr->unacked_window = 0;
return res;
}
} else
*used_max_pkt = l_ptr->max_pkt;
}
return tipc_link_send_buf(l_ptr, buf); /* All other cases */
}
/*
* tipc_link_send_sections_fast: Entry for messages where the
* destination processor is known and the header is complete,
* except for total message length.
* Returns user data length or errno.
*/
int tipc_link_send_sections_fast(struct tipc_port *sender,
struct iovec const *msg_sect,
const u32 num_sect, unsigned int total_len,
u32 destaddr)
{
struct tipc_msg *hdr = &sender->phdr;
struct tipc_link *l_ptr;
struct sk_buff *buf;
struct tipc_node *node;
int res;
u32 selector = msg_origport(hdr) & 1;
again:
/*
* Try building message using port's max_pkt hint.
* (Must not hold any locks while building message.)
*/
res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
sender->max_pkt, &buf);
/* Exit if build request was invalid */
if (unlikely(res < 0))
return res;
read_lock_bh(&tipc_net_lock);
node = tipc_node_find(destaddr);
if (likely(node)) {
tipc_node_lock(node);
l_ptr = node->active_links[selector];
if (likely(l_ptr)) {
if (likely(buf)) {
res = link_send_buf_fast(l_ptr, buf,
&sender->max_pkt);
exit:
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
return res;
}
/* Exit if link (or bearer) is congested */
if (link_congested(l_ptr) ||
tipc_bearer_blocked(l_ptr->b_ptr)) {
res = link_schedule_port(l_ptr,
sender->ref, res);
goto exit;
}
/*
* Message size exceeds max_pkt hint; update hint,
* then re-try fast path or fragment the message
*/
sender->max_pkt = l_ptr->max_pkt;
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
goto again;
return link_send_sections_long(sender, msg_sect,
num_sect, total_len,
destaddr);
}
tipc_node_unlock(node);
}
read_unlock_bh(&tipc_net_lock);
/* Couldn't find a link to the destination node */
if (buf)
return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
if (res >= 0)
return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
total_len, TIPC_ERR_NO_NODE);
return res;
}
/*
* link_send_sections_long(): Entry for long messages where the
* destination node is known and the header is complete,
* inclusive total message length.
* Link and bearer congestion status have been checked to be ok,
* and are ignored if they change.
*
* Note that fragments do not use the full link MTU so that they won't have
* to undergo refragmentation if link changeover causes them to be sent
* over another link with an additional tunnel header added as prefix.
* (Refragmentation will still occur if the other link has a smaller MTU.)
*
* Returns user data length or errno.
*/
static int link_send_sections_long(struct tipc_port *sender,
struct iovec const *msg_sect,
u32 num_sect, unsigned int total_len,
u32 destaddr)
{
struct tipc_link *l_ptr;
struct tipc_node *node;
struct tipc_msg *hdr = &sender->phdr;
u32 dsz = total_len;
u32 max_pkt, fragm_sz, rest;
struct tipc_msg fragm_hdr;
struct sk_buff *buf, *buf_chain, *prev;
u32 fragm_crs, fragm_rest, hsz, sect_rest;
const unchar *sect_crs;
int curr_sect;
u32 fragm_no;
int res = 0;
again:
fragm_no = 1;
max_pkt = sender->max_pkt - INT_H_SIZE;
/* leave room for tunnel header in case of link changeover */
fragm_sz = max_pkt - INT_H_SIZE;
/* leave room for fragmentation header in each fragment */
rest = dsz;
fragm_crs = 0;
fragm_rest = 0;
sect_rest = 0;
sect_crs = NULL;
curr_sect = -1;
/* Prepare reusable fragment header */
tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
INT_H_SIZE, msg_destnode(hdr));
msg_set_size(&fragm_hdr, max_pkt);
msg_set_fragm_no(&fragm_hdr, 1);
/* Prepare header of first fragment */
buf_chain = buf = tipc_buf_acquire(max_pkt);
if (!buf)
return -ENOMEM;
buf->next = NULL;
skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
hsz = msg_hdr_sz(hdr);
skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
/* Chop up message */
fragm_crs = INT_H_SIZE + hsz;
fragm_rest = fragm_sz - hsz;
do { /* For all sections */
u32 sz;
if (!sect_rest) {
sect_rest = msg_sect[++curr_sect].iov_len;
sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
}
if (sect_rest < fragm_rest)
sz = sect_rest;
else
sz = fragm_rest;
if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
res = -EFAULT;
error:
for (; buf_chain; buf_chain = buf) {
buf = buf_chain->next;
kfree_skb(buf_chain);
}
return res;
}
sect_crs += sz;
sect_rest -= sz;
fragm_crs += sz;
fragm_rest -= sz;
rest -= sz;
if (!fragm_rest && rest) {
/* Initiate new fragment: */
if (rest <= fragm_sz) {
fragm_sz = rest;
msg_set_type(&fragm_hdr, LAST_FRAGMENT);
} else {
msg_set_type(&fragm_hdr, FRAGMENT);
}
msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
msg_set_fragm_no(&fragm_hdr, ++fragm_no);
prev = buf;
buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
if (!buf) {
res = -ENOMEM;
goto error;
}
buf->next = NULL;
prev->next = buf;
skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
fragm_crs = INT_H_SIZE;
fragm_rest = fragm_sz;
}
} while (rest > 0);
/*
* Now we have a buffer chain. Select a link and check
* that packet size is still OK
*/
node = tipc_node_find(destaddr);
if (likely(node)) {
tipc_node_lock(node);
l_ptr = node->active_links[sender->ref & 1];
if (!l_ptr) {
tipc_node_unlock(node);
goto reject;
}
if (l_ptr->max_pkt < max_pkt) {
sender->max_pkt = l_ptr->max_pkt;
tipc_node_unlock(node);
for (; buf_chain; buf_chain = buf) {
buf = buf_chain->next;
kfree_skb(buf_chain);
}
goto again;
}
} else {
reject:
for (; buf_chain; buf_chain = buf) {
buf = buf_chain->next;
kfree_skb(buf_chain);
}
return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
total_len, TIPC_ERR_NO_NODE);
}
/* Append chain of fragments to send queue & send them */
l_ptr->long_msg_seq_no++;
link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
l_ptr->stats.sent_fragments += fragm_no;
l_ptr->stats.sent_fragmented++;
tipc_link_push_queue(l_ptr);
tipc_node_unlock(node);
return dsz;
}
/*
* tipc_link_push_packet: Push one unsent packet to the media
*/
u32 tipc_link_push_packet(struct tipc_link *l_ptr)
{
struct sk_buff *buf = l_ptr->first_out;
u32 r_q_size = l_ptr->retransm_queue_size;
u32 r_q_head = l_ptr->retransm_queue_head;
/* Step to position where retransmission failed, if any, */
/* consider that buffers may have been released in meantime */
if (r_q_size && buf) {
u32 last = lesser(mod(r_q_head + r_q_size),
link_last_sent(l_ptr));
u32 first = buf_seqno(buf);
while (buf && less(first, r_q_head)) {
first = mod(first + 1);
buf = buf->next;
}
l_ptr->retransm_queue_head = r_q_head = first;
l_ptr->retransm_queue_size = r_q_size = mod(last - first);
}
/* Continue retransmission now, if there is anything: */
if (r_q_size && buf) {
msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
l_ptr->retransm_queue_head = mod(++r_q_head);
l_ptr->retransm_queue_size = --r_q_size;
l_ptr->stats.retransmitted++;
return 0;
}
/* Send deferred protocol message, if any: */
buf = l_ptr->proto_msg_queue;
if (buf) {
msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
l_ptr->unacked_window = 0;
kfree_skb(buf);
l_ptr->proto_msg_queue = NULL;
return 0;
}
/* Send one deferred data message, if send window not full: */
buf = l_ptr->next_out;
if (buf) {
struct tipc_msg *msg = buf_msg(buf);
u32 next = msg_seqno(msg);
u32 first = buf_seqno(l_ptr->first_out);
if (mod(next - first) < l_ptr->queue_limit[0]) {
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
if (msg_user(msg) == MSG_BUNDLER)
msg_set_type(msg, CLOSED_MSG);
l_ptr->next_out = buf->next;
return 0;
}
}
return 1;
}
/*
* push_queue(): push out the unsent messages of a link where
* congestion has abated. Node is locked
*/
void tipc_link_push_queue(struct tipc_link *l_ptr)
{
u32 res;
if (tipc_bearer_blocked(l_ptr->b_ptr))
return;
do {
res = tipc_link_push_packet(l_ptr);
} while (!res);
}
static void link_reset_all(unsigned long addr)
{
struct tipc_node *n_ptr;
char addr_string[16];
u32 i;
read_lock_bh(&tipc_net_lock);
n_ptr = tipc_node_find((u32)addr);
if (!n_ptr) {
read_unlock_bh(&tipc_net_lock);
return; /* node no longer exists */
}
tipc_node_lock(n_ptr);
pr_warn("Resetting all links to %s\n",
tipc_addr_string_fill(addr_string, n_ptr->addr));
for (i = 0; i < MAX_BEARERS; i++) {
if (n_ptr->links[i]) {
link_print(n_ptr->links[i], "Resetting link\n");
tipc_link_reset(n_ptr->links[i]);
}
}
tipc_node_unlock(n_ptr);
read_unlock_bh(&tipc_net_lock);
}
static void link_retransmit_failure(struct tipc_link *l_ptr,
struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
if (l_ptr->addr) {
/* Handle failure on standard link */
link_print(l_ptr, "Resetting link\n");
tipc_link_reset(l_ptr);
} else {
/* Handle failure on broadcast link */
struct tipc_node *n_ptr;
char addr_string[16];
pr_info("Msg seq number: %u, ", msg_seqno(msg));
pr_cont("Outstanding acks: %lu\n",
(unsigned long) TIPC_SKB_CB(buf)->handle);
n_ptr = tipc_bclink_retransmit_to();
tipc_node_lock(n_ptr);
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_info("Broadcast link info for %s\n", addr_string);
pr_info("Reception permitted: %d, Acked: %u\n",
n_ptr->bclink.recv_permitted,
n_ptr->bclink.acked);
pr_info("Last in: %u, Oos state: %u, Last sent: %u\n",
n_ptr->bclink.last_in,
n_ptr->bclink.oos_state,
n_ptr->bclink.last_sent);
tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
tipc_node_unlock(n_ptr);
l_ptr->stale_count = 0;
}
}
void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
u32 retransmits)
{
struct tipc_msg *msg;
if (!buf)
return;
msg = buf_msg(buf);
if (tipc_bearer_blocked(l_ptr->b_ptr)) {
if (l_ptr->retransm_queue_size == 0) {
l_ptr->retransm_queue_head = msg_seqno(msg);
l_ptr->retransm_queue_size = retransmits;
} else {
pr_err("Unexpected retransmit on link %s (qsize=%d)\n",
l_ptr->name, l_ptr->retransm_queue_size);
}
return;
} else {
/* Detect repeated retransmit failures on unblocked bearer */
if (l_ptr->last_retransmitted == msg_seqno(msg)) {
if (++l_ptr->stale_count > 100) {
link_retransmit_failure(l_ptr, buf);
return;
}
} else {
l_ptr->last_retransmitted = msg_seqno(msg);
l_ptr->stale_count = 1;
}
}
while (retransmits && (buf != l_ptr->next_out) && buf) {
msg = buf_msg(buf);
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
buf = buf->next;
retransmits--;
l_ptr->stats.retransmitted++;
}
l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
}
/**
* link_insert_deferred_queue - insert deferred messages back into receive chain
*/
static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
struct sk_buff *buf)
{
u32 seq_no;
if (l_ptr->oldest_deferred_in == NULL)
return buf;
seq_no = buf_seqno(l_ptr->oldest_deferred_in);
if (seq_no == mod(l_ptr->next_in_no)) {
l_ptr->newest_deferred_in->next = buf;
buf = l_ptr->oldest_deferred_in;
l_ptr->oldest_deferred_in = NULL;
l_ptr->deferred_inqueue_sz = 0;
}
return buf;
}
/**
* link_recv_buf_validate - validate basic format of received message
*
* This routine ensures a TIPC message has an acceptable header, and at least
* as much data as the header indicates it should. The routine also ensures
* that the entire message header is stored in the main fragment of the message
* buffer, to simplify future access to message header fields.
*
* Note: Having extra info present in the message header or data areas is OK.
* TIPC will ignore the excess, under the assumption that it is optional info
* introduced by a later release of the protocol.
*/
static int link_recv_buf_validate(struct sk_buff *buf)
{
static u32 min_data_hdr_size[8] = {
SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
};
struct tipc_msg *msg;
u32 tipc_hdr[2];
u32 size;
u32 hdr_size;
u32 min_hdr_size;
if (unlikely(buf->len < MIN_H_SIZE))
return 0;
msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
if (msg == NULL)
return 0;
if (unlikely(msg_version(msg) != TIPC_VERSION))
return 0;
size = msg_size(msg);
hdr_size = msg_hdr_sz(msg);
min_hdr_size = msg_isdata(msg) ?
min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
if (unlikely((hdr_size < min_hdr_size) ||
(size < hdr_size) ||
(buf->len < size) ||
(size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
return 0;
return pskb_may_pull(buf, hdr_size);
}
/**
* tipc_recv_msg - process TIPC messages arriving from off-node
* @head: pointer to message buffer chain
* @tb_ptr: pointer to bearer message arrived on
*
* Invoked with no locks held. Bearer pointer must point to a valid bearer
* structure (i.e. cannot be NULL), but bearer can be inactive.
*/
void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
{
read_lock_bh(&tipc_net_lock);
while (head) {
struct tipc_node *n_ptr;
struct tipc_link *l_ptr;
struct sk_buff *crs;
struct sk_buff *buf = head;
struct tipc_msg *msg;
u32 seq_no;
u32 ackd;
u32 released = 0;
int type;
head = head->next;
/* Ensure bearer is still enabled */
if (unlikely(!b_ptr->active))
goto cont;
/* Ensure message is well-formed */
if (unlikely(!link_recv_buf_validate(buf)))
goto cont;
/* Ensure message data is a single contiguous unit */
if (unlikely(skb_linearize(buf)))
goto cont;
/* Handle arrival of a non-unicast link message */
msg = buf_msg(buf);
if (unlikely(msg_non_seq(msg))) {
if (msg_user(msg) == LINK_CONFIG)
tipc_disc_recv_msg(buf, b_ptr);
else
tipc_bclink_recv_pkt(buf);
continue;
}
/* Discard unicast link messages destined for another node */
if (unlikely(!msg_short(msg) &&
(msg_destnode(msg) != tipc_own_addr)))
goto cont;
/* Locate neighboring node that sent message */
n_ptr = tipc_node_find(msg_prevnode(msg));
if (unlikely(!n_ptr))
goto cont;
tipc_node_lock(n_ptr);
/* Locate unicast link endpoint that should handle message */
l_ptr = n_ptr->links[b_ptr->identity];
if (unlikely(!l_ptr)) {
tipc_node_unlock(n_ptr);
goto cont;
}
/* Verify that communication with node is currently allowed */
if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
msg_user(msg) == LINK_PROTOCOL &&
(msg_type(msg) == RESET_MSG ||
msg_type(msg) == ACTIVATE_MSG) &&
!msg_redundant_link(msg))
n_ptr->block_setup &= ~WAIT_PEER_DOWN;
if (n_ptr->block_setup) {
tipc_node_unlock(n_ptr);
goto cont;
}
/* Validate message sequence number info */
seq_no = msg_seqno(msg);
ackd = msg_ack(msg);
/* Release acked messages */
if (n_ptr->bclink.recv_permitted)
tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
crs = l_ptr->first_out;
while ((crs != l_ptr->next_out) &&
less_eq(buf_seqno(crs), ackd)) {
struct sk_buff *next = crs->next;
kfree_skb(crs);
crs = next;
released++;
}
if (released) {
l_ptr->first_out = crs;
l_ptr->out_queue_size -= released;
}
/* Try sending any messages link endpoint has pending */
if (unlikely(l_ptr->next_out))
tipc_link_push_queue(l_ptr);
if (unlikely(!list_empty(&l_ptr->waiting_ports)))
tipc_link_wakeup_ports(l_ptr, 0);
if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
l_ptr->stats.sent_acks++;
tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
}
/* Now (finally!) process the incoming message */
protocol_check:
if (likely(link_working_working(l_ptr))) {
if (likely(seq_no == mod(l_ptr->next_in_no))) {
l_ptr->next_in_no++;
if (unlikely(l_ptr->oldest_deferred_in))
head = link_insert_deferred_queue(l_ptr,
head);
deliver:
if (likely(msg_isdata(msg))) {
tipc_node_unlock(n_ptr);
tipc_port_recv_msg(buf);
continue;
}
switch (msg_user(msg)) {
int ret;
case MSG_BUNDLER:
l_ptr->stats.recv_bundles++;
l_ptr->stats.recv_bundled +=
msg_msgcnt(msg);
tipc_node_unlock(n_ptr);
tipc_link_recv_bundle(buf);
continue;
case NAME_DISTRIBUTOR:
n_ptr->bclink.recv_permitted = true;
tipc_node_unlock(n_ptr);
tipc_named_recv(buf);
continue;
case BCAST_PROTOCOL:
tipc_link_recv_sync(n_ptr, buf);
tipc_node_unlock(n_ptr);
continue;
case CONN_MANAGER:
tipc_node_unlock(n_ptr);
tipc_port_recv_proto_msg(buf);
continue;
case MSG_FRAGMENTER:
l_ptr->stats.recv_fragments++;
ret = tipc_link_recv_fragment(
&l_ptr->defragm_buf,
&buf, &msg);
if (ret == 1) {
l_ptr->stats.recv_fragmented++;
goto deliver;
}
if (ret == -1)
l_ptr->next_in_no--;
break;
case CHANGEOVER_PROTOCOL:
type = msg_type(msg);
if (link_recv_changeover_msg(&l_ptr,
&buf)) {
msg = buf_msg(buf);
seq_no = msg_seqno(msg);
if (type == ORIGINAL_MSG)
goto deliver;
goto protocol_check;
}
break;
default:
kfree_skb(buf);
buf = NULL;
break;
}
tipc_node_unlock(n_ptr);
tipc_net_route_msg(buf);
continue;
}
link_handle_out_of_seq_msg(l_ptr, buf);
head = link_insert_deferred_queue(l_ptr, head);
tipc_node_unlock(n_ptr);
continue;
}
/* Link is not in state WORKING_WORKING */
if (msg_user(msg) == LINK_PROTOCOL) {
link_recv_proto_msg(l_ptr, buf);
head = link_insert_deferred_queue(l_ptr, head);
tipc_node_unlock(n_ptr);
continue;
}
/* Traffic message. Conditionally activate link */
link_state_event(l_ptr, TRAFFIC_MSG_EVT);
if (link_working_working(l_ptr)) {
/* Re-insert buffer in front of queue */
buf->next = head;
head = buf;
tipc_node_unlock(n_ptr);
continue;
}
tipc_node_unlock(n_ptr);
cont:
kfree_skb(buf);
}
read_unlock_bh(&tipc_net_lock);
}
/**
* tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
*
* Returns increase in queue length (i.e. 0 or 1)
*/
u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
struct sk_buff *buf)
{
struct sk_buff *queue_buf;
struct sk_buff **prev;
u32 seq_no = buf_seqno(buf);
buf->next = NULL;
/* Empty queue ? */
if (*head == NULL) {
*head = *tail = buf;
return 1;
}
/* Last ? */
if (less(buf_seqno(*tail), seq_no)) {
(*tail)->next = buf;
*tail = buf;
return 1;
}
/* Locate insertion point in queue, then insert; discard if duplicate */
prev = head;
queue_buf = *head;
for (;;) {
u32 curr_seqno = buf_seqno(queue_buf);
if (seq_no == curr_seqno) {
kfree_skb(buf);
return 0;
}
if (less(seq_no, curr_seqno))
break;
prev = &queue_buf->next;
queue_buf = queue_buf->next;
}
buf->next = queue_buf;
*prev = buf;
return 1;
}
/*
* link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
*/
static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
struct sk_buff *buf)
{
u32 seq_no = buf_seqno(buf);
if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
link_recv_proto_msg(l_ptr, buf);
return;
}
/* Record OOS packet arrival (force mismatch on next timeout) */
l_ptr->checkpoint--;
/*
* Discard packet if a duplicate; otherwise add it to deferred queue
* and notify peer of gap as per protocol specification
*/
if (less(seq_no, mod(l_ptr->next_in_no))) {
l_ptr->stats.duplicates++;
kfree_skb(buf);
return;
}
if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
&l_ptr->newest_deferred_in, buf)) {
l_ptr->deferred_inqueue_sz++;
l_ptr->stats.deferred_recv++;
if ((l_ptr->deferred_inqueue_sz % 16) == 1)
tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
} else
l_ptr->stats.duplicates++;
}
/*
* Send protocol message to the other endpoint.
*/
void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
int probe_msg, u32 gap, u32 tolerance,
u32 priority, u32 ack_mtu)
{
struct sk_buff *buf = NULL;
struct tipc_msg *msg = l_ptr->pmsg;
u32 msg_size = sizeof(l_ptr->proto_msg);
int r_flag;
/* Discard any previous message that was deferred due to congestion */
if (l_ptr->proto_msg_queue) {
kfree_skb(l_ptr->proto_msg_queue);
l_ptr->proto_msg_queue = NULL;
}
if (link_blocked(l_ptr))
return;
/* Abort non-RESET send if communication with node is prohibited */
if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
return;
/* Create protocol message with "out-of-sequence" sequence number */
msg_set_type(msg, msg_typ);
msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
if (msg_typ == STATE_MSG) {
u32 next_sent = mod(l_ptr->next_out_no);
if (!tipc_link_is_up(l_ptr))
return;
if (l_ptr->next_out)
next_sent = buf_seqno(l_ptr->next_out);
msg_set_next_sent(msg, next_sent);
if (l_ptr->oldest_deferred_in) {
u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
gap = mod(rec - mod(l_ptr->next_in_no));
}
msg_set_seq_gap(msg, gap);
if (gap)
l_ptr->stats.sent_nacks++;
msg_set_link_tolerance(msg, tolerance);
msg_set_linkprio(msg, priority);
msg_set_max_pkt(msg, ack_mtu);
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_probe(msg, probe_msg != 0);
if (probe_msg) {
u32 mtu = l_ptr->max_pkt;
if ((mtu < l_ptr->max_pkt_target) &&
link_working_working(l_ptr) &&
l_ptr->fsm_msg_cnt) {
msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
if (l_ptr->max_pkt_probes == 10) {
l_ptr->max_pkt_target = (msg_size - 4);
l_ptr->max_pkt_probes = 0;
msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
}
l_ptr->max_pkt_probes++;
}
l_ptr->stats.sent_probes++;
}
l_ptr->stats.sent_states++;
} else { /* RESET_MSG or ACTIVATE_MSG */
msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
msg_set_seq_gap(msg, 0);
msg_set_next_sent(msg, 1);
msg_set_probe(msg, 0);
msg_set_link_tolerance(msg, l_ptr->tolerance);
msg_set_linkprio(msg, l_ptr->priority);
msg_set_max_pkt(msg, l_ptr->max_pkt_target);
}
r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
msg_set_redundant_link(msg, r_flag);
msg_set_linkprio(msg, l_ptr->priority);
msg_set_size(msg, msg_size);
msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
buf = tipc_buf_acquire(msg_size);
if (!buf)
return;
skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
buf->priority = TC_PRIO_CONTROL;
/* Defer message if bearer is already blocked */
if (tipc_bearer_blocked(l_ptr->b_ptr)) {
l_ptr->proto_msg_queue = buf;
return;
}
tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
l_ptr->unacked_window = 0;
kfree_skb(buf);
}
/*
* Receive protocol message :
* Note that network plane id propagates through the network, and may
* change at any time. The node with lowest address rules
*/
static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
{
u32 rec_gap = 0;
u32 max_pkt_info;
u32 max_pkt_ack;
u32 msg_tol;
struct tipc_msg *msg = buf_msg(buf);
if (link_blocked(l_ptr))
goto exit;
/* record unnumbered packet arrival (force mismatch on next timeout) */
l_ptr->checkpoint--;
if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
if (tipc_own_addr > msg_prevnode(msg))
l_ptr->b_ptr->net_plane = msg_net_plane(msg);
l_ptr->owner->permit_changeover = msg_redundant_link(msg);
switch (msg_type(msg)) {
case RESET_MSG:
if (!link_working_unknown(l_ptr) &&
(l_ptr->peer_session != INVALID_SESSION)) {
if (less_eq(msg_session(msg), l_ptr->peer_session))
break; /* duplicate or old reset: ignore */
}
if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
link_working_unknown(l_ptr))) {
/*
* peer has lost contact -- don't allow peer's links
* to reactivate before we recognize loss & clean up
*/
l_ptr->owner->block_setup = WAIT_NODE_DOWN;
}
link_state_event(l_ptr, RESET_MSG);
/* fall thru' */
case ACTIVATE_MSG:
/* Update link settings according other endpoint's values */
strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
msg_tol = msg_link_tolerance(msg);
if (msg_tol > l_ptr->tolerance)
link_set_supervision_props(l_ptr, msg_tol);
if (msg_linkprio(msg) > l_ptr->priority)
l_ptr->priority = msg_linkprio(msg);
max_pkt_info = msg_max_pkt(msg);
if (max_pkt_info) {
if (max_pkt_info < l_ptr->max_pkt_target)
l_ptr->max_pkt_target = max_pkt_info;
if (l_ptr->max_pkt > l_ptr->max_pkt_target)
l_ptr->max_pkt = l_ptr->max_pkt_target;
} else {
l_ptr->max_pkt = l_ptr->max_pkt_target;
}
/* Synchronize broadcast link info, if not done previously */
if (!tipc_node_is_up(l_ptr->owner)) {
l_ptr->owner->bclink.last_sent =
l_ptr->owner->bclink.last_in =
msg_last_bcast(msg);
l_ptr->owner->bclink.oos_state = 0;
}
l_ptr->peer_session = msg_session(msg);
l_ptr->peer_bearer_id = msg_bearer_id(msg);
if (msg_type(msg) == ACTIVATE_MSG)
link_state_event(l_ptr, ACTIVATE_MSG);
break;
case STATE_MSG:
msg_tol = msg_link_tolerance(msg);
if (msg_tol)
link_set_supervision_props(l_ptr, msg_tol);
if (msg_linkprio(msg) &&
(msg_linkprio(msg) != l_ptr->priority)) {
pr_warn("%s<%s>, priority change %u->%u\n",
link_rst_msg, l_ptr->name, l_ptr->priority,
msg_linkprio(msg));
l_ptr->priority = msg_linkprio(msg);
tipc_link_reset(l_ptr); /* Enforce change to take effect */
break;
}
link_state_event(l_ptr, TRAFFIC_MSG_EVT);
l_ptr->stats.recv_states++;
if (link_reset_unknown(l_ptr))
break;
if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
rec_gap = mod(msg_next_sent(msg) -
mod(l_ptr->next_in_no));
}
max_pkt_ack = msg_max_pkt(msg);
if (max_pkt_ack > l_ptr->max_pkt) {
l_ptr->max_pkt = max_pkt_ack;
l_ptr->max_pkt_probes = 0;
}
max_pkt_ack = 0;
if (msg_probe(msg)) {
l_ptr->stats.recv_probes++;
if (msg_size(msg) > sizeof(l_ptr->proto_msg))
max_pkt_ack = msg_size(msg);
}
/* Protocol message before retransmits, reduce loss risk */
if (l_ptr->owner->bclink.recv_permitted)
tipc_bclink_update_link_state(l_ptr->owner,
msg_last_bcast(msg));
if (rec_gap || (msg_probe(msg))) {
tipc_link_send_proto_msg(l_ptr, STATE_MSG,
0, rec_gap, 0, 0, max_pkt_ack);
}
if (msg_seq_gap(msg)) {
l_ptr->stats.recv_nacks++;
tipc_link_retransmit(l_ptr, l_ptr->first_out,
msg_seq_gap(msg));
}
break;
}
exit:
kfree_skb(buf);
}
/*
* tipc_link_tunnel(): Send one message via a link belonging to
* another bearer. Owner node is locked.
*/
static void tipc_link_tunnel(struct tipc_link *l_ptr,
struct tipc_msg *tunnel_hdr, struct tipc_msg *msg,
u32 selector)
{
struct tipc_link *tunnel;
struct sk_buff *buf;
u32 length = msg_size(msg);
tunnel = l_ptr->owner->active_links[selector & 1];
if (!tipc_link_is_up(tunnel)) {
pr_warn("%stunnel link no longer available\n", link_co_err);
return;
}
msg_set_size(tunnel_hdr, length + INT_H_SIZE);
buf = tipc_buf_acquire(length + INT_H_SIZE);
if (!buf) {
pr_warn("%sunable to send tunnel msg\n", link_co_err);
return;
}
skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
tipc_link_send_buf(tunnel, buf);
}
/*
* changeover(): Send whole message queue via the remaining link
* Owner node is locked.
*/
void tipc_link_changeover(struct tipc_link *l_ptr)
{
u32 msgcount = l_ptr->out_queue_size;
struct sk_buff *crs = l_ptr->first_out;
struct tipc_link *tunnel = l_ptr->owner->active_links[0];
struct tipc_msg tunnel_hdr;
int split_bundles;
if (!tunnel)
return;
if (!l_ptr->owner->permit_changeover) {
pr_warn("%speer did not permit changeover\n", link_co_err);
return;
}
tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
msg_set_msgcnt(&tunnel_hdr, msgcount);
if (!l_ptr->first_out) {
struct sk_buff *buf;
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
msg_set_size(&tunnel_hdr, INT_H_SIZE);
tipc_link_send_buf(tunnel, buf);
} else {
pr_warn("%sunable to send changeover msg\n",
link_co_err);
}
return;
}
split_bundles = (l_ptr->owner->active_links[0] !=
l_ptr->owner->active_links[1]);
while (crs) {
struct tipc_msg *msg = buf_msg(crs);
if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
struct tipc_msg *m = msg_get_wrapped(msg);
unchar *pos = (unchar *)m;
msgcount = msg_msgcnt(msg);
while (msgcount--) {
msg_set_seqno(m, msg_seqno(msg));
tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
msg_link_selector(m));
pos += align(msg_size(m));
m = (struct tipc_msg *)pos;
}
} else {
tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
msg_link_selector(msg));
}
crs = crs->next;
}
}
void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *tunnel)
{
struct sk_buff *iter;
struct tipc_msg tunnel_hdr;
tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
iter = l_ptr->first_out;
while (iter) {
struct sk_buff *outbuf;
struct tipc_msg *msg = buf_msg(iter);
u32 length = msg_size(msg);
if (msg_user(msg) == MSG_BUNDLER)
msg_set_type(msg, CLOSED_MSG);
msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
outbuf = tipc_buf_acquire(length + INT_H_SIZE);
if (outbuf == NULL) {
pr_warn("%sunable to send duplicate msg\n",
link_co_err);
return;
}
skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
length);
tipc_link_send_buf(tunnel, outbuf);
if (!tipc_link_is_up(l_ptr))
return;
iter = iter->next;
}
}
/**
* buf_extract - extracts embedded TIPC message from another message
* @skb: encapsulating message buffer
* @from_pos: offset to extract from
*
* Returns a new message buffer containing an embedded message. The
* encapsulating message itself is left unchanged.
*/
static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
{
struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
u32 size = msg_size(msg);
struct sk_buff *eb;
eb = tipc_buf_acquire(size);
if (eb)
skb_copy_to_linear_data(eb, msg, size);
return eb;
}
/*
* link_recv_changeover_msg(): Receive tunneled packet sent
* via other link. Node is locked. Return extracted buffer.
*/
static int link_recv_changeover_msg(struct tipc_link **l_ptr,
struct sk_buff **buf)
{
struct sk_buff *tunnel_buf = *buf;
struct tipc_link *dest_link;
struct tipc_msg *msg;
struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
u32 msg_typ = msg_type(tunnel_msg);
u32 msg_count = msg_msgcnt(tunnel_msg);
u32 bearer_id = msg_bearer_id(tunnel_msg);
if (bearer_id >= MAX_BEARERS)
goto exit;
dest_link = (*l_ptr)->owner->links[bearer_id];
if (!dest_link)
goto exit;
if (dest_link == *l_ptr) {
pr_err("Unexpected changeover message on link <%s>\n",
(*l_ptr)->name);
goto exit;
}
*l_ptr = dest_link;
msg = msg_get_wrapped(tunnel_msg);
if (msg_typ == DUPLICATE_MSG) {
if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
goto exit;
*buf = buf_extract(tunnel_buf, INT_H_SIZE);
if (*buf == NULL) {
pr_warn("%sduplicate msg dropped\n", link_co_err);
goto exit;
}
kfree_skb(tunnel_buf);
return 1;
}
/* First original message ?: */
if (tipc_link_is_up(dest_link)) {
pr_info("%s<%s>, changeover initiated by peer\n", link_rst_msg,
dest_link->name);
tipc_link_reset(dest_link);
dest_link->exp_msg_count = msg_count;
if (!msg_count)
goto exit;
} else if (dest_link->exp_msg_count == START_CHANGEOVER) {
dest_link->exp_msg_count = msg_count;
if (!msg_count)
goto exit;
}
/* Receive original message */
if (dest_link->exp_msg_count == 0) {
pr_warn("%sgot too many tunnelled messages\n", link_co_err);
goto exit;
}
dest_link->exp_msg_count--;
if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
goto exit;
} else {
*buf = buf_extract(tunnel_buf, INT_H_SIZE);
if (*buf != NULL) {
kfree_skb(tunnel_buf);
return 1;
} else {
pr_warn("%soriginal msg dropped\n", link_co_err);
}
}
exit:
*buf = NULL;
kfree_skb(tunnel_buf);
return 0;
}
/*
* Bundler functionality:
*/
void tipc_link_recv_bundle(struct sk_buff *buf)
{
u32 msgcount = msg_msgcnt(buf_msg(buf));
u32 pos = INT_H_SIZE;
struct sk_buff *obuf;
while (msgcount--) {
obuf = buf_extract(buf, pos);
if (obuf == NULL) {
pr_warn("Link unable to unbundle message(s)\n");
break;
}
pos += align(msg_size(buf_msg(obuf)));
tipc_net_route_msg(obuf);
}
kfree_skb(buf);
}
/*
* Fragmentation/defragmentation:
*/
/*
* link_send_long_buf: Entry for buffers needing fragmentation.
* The buffer is complete, inclusive total message length.
* Returns user data length.
*/
static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
{
struct sk_buff *buf_chain = NULL;
struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
struct tipc_msg *inmsg = buf_msg(buf);
struct tipc_msg fragm_hdr;
u32 insize = msg_size(inmsg);
u32 dsz = msg_data_sz(inmsg);
unchar *crs = buf->data;
u32 rest = insize;
u32 pack_sz = l_ptr->max_pkt;
u32 fragm_sz = pack_sz - INT_H_SIZE;
u32 fragm_no = 0;
u32 destaddr;
if (msg_short(inmsg))
destaddr = l_ptr->addr;
else
destaddr = msg_destnode(inmsg);
/* Prepare reusable fragment header: */
tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
INT_H_SIZE, destaddr);
/* Chop up message: */
while (rest > 0) {
struct sk_buff *fragm;
if (rest <= fragm_sz) {
fragm_sz = rest;
msg_set_type(&fragm_hdr, LAST_FRAGMENT);
}
fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
if (fragm == NULL) {
kfree_skb(buf);
while (buf_chain) {
buf = buf_chain;
buf_chain = buf_chain->next;
kfree_skb(buf);
}
return -ENOMEM;
}
msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
fragm_no++;
msg_set_fragm_no(&fragm_hdr, fragm_no);
skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
fragm_sz);
buf_chain_tail->next = fragm;
buf_chain_tail = fragm;
rest -= fragm_sz;
crs += fragm_sz;
msg_set_type(&fragm_hdr, FRAGMENT);
}
kfree_skb(buf);
/* Append chain of fragments to send queue & send them */
l_ptr->long_msg_seq_no++;
link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
l_ptr->stats.sent_fragments += fragm_no;
l_ptr->stats.sent_fragmented++;
tipc_link_push_queue(l_ptr);
return dsz;
}
/*
* A pending message being re-assembled must store certain values
* to handle subsequent fragments correctly. The following functions
* help storing these values in unused, available fields in the
* pending message. This makes dynamic memory allocation unnecessary.
*/
static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
{
msg_set_seqno(buf_msg(buf), seqno);
}
static u32 get_fragm_size(struct sk_buff *buf)
{
return msg_ack(buf_msg(buf));
}
static void set_fragm_size(struct sk_buff *buf, u32 sz)
{
msg_set_ack(buf_msg(buf), sz);
}
static u32 get_expected_frags(struct sk_buff *buf)
{
return msg_bcast_ack(buf_msg(buf));
}
static void set_expected_frags(struct sk_buff *buf, u32 exp)
{
msg_set_bcast_ack(buf_msg(buf), exp);
}
/*
* tipc_link_recv_fragment(): Called with node lock on. Returns
* the reassembled buffer if message is complete.
*/
int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
struct tipc_msg **m)
{
struct sk_buff *prev = NULL;
struct sk_buff *fbuf = *fb;
struct tipc_msg *fragm = buf_msg(fbuf);
struct sk_buff *pbuf = *pending;
u32 long_msg_seq_no = msg_long_msgno(fragm);
*fb = NULL;
/* Is there an incomplete message waiting for this fragment? */
while (pbuf && ((buf_seqno(pbuf) != long_msg_seq_no) ||
(msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
prev = pbuf;
pbuf = pbuf->next;
}
if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
u32 msg_sz = msg_size(imsg);
u32 fragm_sz = msg_data_sz(fragm);
u32 exp_fragm_cnt;
u32 max = TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
if (msg_type(imsg) == TIPC_MCAST_MSG)
max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
if (fragm_sz == 0 || msg_size(imsg) > max) {
kfree_skb(fbuf);
return 0;
}
exp_fragm_cnt = msg_sz / fragm_sz + !!(msg_sz % fragm_sz);
pbuf = tipc_buf_acquire(msg_size(imsg));
if (pbuf != NULL) {
pbuf->next = *pending;
*pending = pbuf;
skb_copy_to_linear_data(pbuf, imsg,
msg_data_sz(fragm));
/* Prepare buffer for subsequent fragments. */
set_long_msg_seqno(pbuf, long_msg_seq_no);
set_fragm_size(pbuf, fragm_sz);
set_expected_frags(pbuf, exp_fragm_cnt - 1);
} else {
pr_debug("Link unable to reassemble fragmented message\n");
kfree_skb(fbuf);
return -1;
}
kfree_skb(fbuf);
return 0;
} else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
u32 dsz = msg_data_sz(fragm);
u32 fsz = get_fragm_size(pbuf);
u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
u32 exp_frags = get_expected_frags(pbuf) - 1;
skb_copy_to_linear_data_offset(pbuf, crs,
msg_data(fragm), dsz);
kfree_skb(fbuf);
/* Is message complete? */
if (exp_frags == 0) {
if (prev)
prev->next = pbuf->next;
else
*pending = pbuf->next;
msg_reset_reroute_cnt(buf_msg(pbuf));
*fb = pbuf;
*m = buf_msg(pbuf);
return 1;
}
set_expected_frags(pbuf, exp_frags);
return 0;
}
kfree_skb(fbuf);
return 0;
}
static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
{
if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
return;
l_ptr->tolerance = tolerance;
l_ptr->continuity_interval =
((tolerance / 4) > 500) ? 500 : tolerance / 4;
l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
}
void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
{
/* Data messages from this node, inclusive FIRST_FRAGM */
l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
/* Transiting data messages,inclusive FIRST_FRAGM */
l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
l_ptr->queue_limit[CONN_MANAGER] = 1200;
l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
/* FRAGMENT and LAST_FRAGMENT packets */
l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
}
/**
* link_find_link - locate link by name
* @name: ptr to link name string
* @node: ptr to area to be filled with ptr to associated node
*
* Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
* this also prevents link deletion.
*
* Returns pointer to link (or 0 if invalid link name).
*/
static struct tipc_link *link_find_link(const char *name,
struct tipc_node **node)
{
struct tipc_link_name link_name_parts;
struct tipc_bearer *b_ptr;
struct tipc_link *l_ptr;
if (!link_name_validate(name, &link_name_parts))
return NULL;
b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
if (!b_ptr)
return NULL;
*node = tipc_node_find(link_name_parts.addr_peer);
if (!*node)
return NULL;
l_ptr = (*node)->links[b_ptr->identity];
if (!l_ptr || strcmp(l_ptr->name, name))
return NULL;
return l_ptr;
}
/**
* link_value_is_valid -- validate proposed link tolerance/priority/window
*
* @cmd: value type (TIPC_CMD_SET_LINK_*)
* @new_value: the new value
*
* Returns 1 if value is within range, 0 if not.
*/
static int link_value_is_valid(u16 cmd, u32 new_value)
{
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
return (new_value >= TIPC_MIN_LINK_TOL) &&
(new_value <= TIPC_MAX_LINK_TOL);
case TIPC_CMD_SET_LINK_PRI:
return (new_value <= TIPC_MAX_LINK_PRI);
case TIPC_CMD_SET_LINK_WINDOW:
return (new_value >= TIPC_MIN_LINK_WIN) &&
(new_value <= TIPC_MAX_LINK_WIN);
}
return 0;
}
/**
* link_cmd_set_value - change priority/tolerance/window for link/bearer/media
* @name: ptr to link, bearer, or media name
* @new_value: new value of link, bearer, or media setting
* @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
*
* Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
*
* Returns 0 if value updated and negative value on error.
*/
static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
{
struct tipc_node *node;
struct tipc_link *l_ptr;
struct tipc_bearer *b_ptr;
struct tipc_media *m_ptr;
l_ptr = link_find_link(name, &node);
if (l_ptr) {
/*
* acquire node lock for tipc_link_send_proto_msg().
* see "TIPC locking policy" in net.c.
*/
tipc_node_lock(node);
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
link_set_supervision_props(l_ptr, new_value);
tipc_link_send_proto_msg(l_ptr,
STATE_MSG, 0, 0, new_value, 0, 0);
break;
case TIPC_CMD_SET_LINK_PRI:
l_ptr->priority = new_value;
tipc_link_send_proto_msg(l_ptr,
STATE_MSG, 0, 0, 0, new_value, 0);
break;
case TIPC_CMD_SET_LINK_WINDOW:
tipc_link_set_queue_limits(l_ptr, new_value);
break;
}
tipc_node_unlock(node);
return 0;
}
b_ptr = tipc_bearer_find(name);
if (b_ptr) {
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
b_ptr->tolerance = new_value;
return 0;
case TIPC_CMD_SET_LINK_PRI:
b_ptr->priority = new_value;
return 0;
case TIPC_CMD_SET_LINK_WINDOW:
b_ptr->window = new_value;
return 0;
}
return -EINVAL;
}
m_ptr = tipc_media_find(name);
if (!m_ptr)
return -ENODEV;
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
m_ptr->tolerance = new_value;
return 0;
case TIPC_CMD_SET_LINK_PRI:
m_ptr->priority = new_value;
return 0;
case TIPC_CMD_SET_LINK_WINDOW:
m_ptr->window = new_value;
return 0;
}
return -EINVAL;
}
struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
u16 cmd)
{
struct tipc_link_config *args;
u32 new_value;
int res;
if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
new_value = ntohl(args->value);
if (!link_value_is_valid(cmd, new_value))
return tipc_cfg_reply_error_string(
"cannot change, value invalid");
if (!strcmp(args->name, tipc_bclink_name)) {
if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
(tipc_bclink_set_queue_limits(new_value) == 0))
return tipc_cfg_reply_none();
return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
" (cannot change setting on broadcast link)");
}
read_lock_bh(&tipc_net_lock);
res = link_cmd_set_value(args->name, new_value, cmd);
read_unlock_bh(&tipc_net_lock);
if (res)
return tipc_cfg_reply_error_string("cannot change link setting");
return tipc_cfg_reply_none();
}
/**
* link_reset_statistics - reset link statistics
* @l_ptr: pointer to link
*/
static void link_reset_statistics(struct tipc_link *l_ptr)
{
memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
l_ptr->stats.sent_info = l_ptr->next_out_no;
l_ptr->stats.recv_info = l_ptr->next_in_no;
}
struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
{
char *link_name;
struct tipc_link *l_ptr;
struct tipc_node *node;
if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
link_name = (char *)TLV_DATA(req_tlv_area);
if (!strcmp(link_name, tipc_bclink_name)) {
if (tipc_bclink_reset_stats())
return tipc_cfg_reply_error_string("link not found");
return tipc_cfg_reply_none();
}
read_lock_bh(&tipc_net_lock);
l_ptr = link_find_link(link_name, &node);
if (!l_ptr) {
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_error_string("link not found");
}
tipc_node_lock(node);
link_reset_statistics(l_ptr);
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_none();
}
/**
* percent - convert count to a percentage of total (rounding up or down)
*/
static u32 percent(u32 count, u32 total)
{
return (count * 100 + (total / 2)) / total;
}
/**
* tipc_link_stats - print link statistics
* @name: link name
* @buf: print buffer area
* @buf_size: size of print buffer area
*
* Returns length of print buffer data string (or 0 if error)
*/
static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
{
struct tipc_link *l;
struct tipc_stats *s;
struct tipc_node *node;
char *status;
u32 profile_total = 0;
int ret;
if (!strcmp(name, tipc_bclink_name))
return tipc_bclink_stats(buf, buf_size);
read_lock_bh(&tipc_net_lock);
l = link_find_link(name, &node);
if (!l) {
read_unlock_bh(&tipc_net_lock);
return 0;
}
tipc_node_lock(node);
s = &l->stats;
if (tipc_link_is_active(l))
status = "ACTIVE";
else if (tipc_link_is_up(l))
status = "STANDBY";
else
status = "DEFUNCT";
ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
" %s MTU:%u Priority:%u Tolerance:%u ms"
" Window:%u packets\n",
l->name, status, l->max_pkt, l->priority,
l->tolerance, l->queue_limit[0]);
ret += tipc_snprintf(buf + ret, buf_size - ret,
" RX packets:%u fragments:%u/%u bundles:%u/%u\n",
l->next_in_no - s->recv_info, s->recv_fragments,
s->recv_fragmented, s->recv_bundles,
s->recv_bundled);
ret += tipc_snprintf(buf + ret, buf_size - ret,
" TX packets:%u fragments:%u/%u bundles:%u/%u\n",
l->next_out_no - s->sent_info, s->sent_fragments,
s->sent_fragmented, s->sent_bundles,
s->sent_bundled);
profile_total = s->msg_length_counts;
if (!profile_total)
profile_total = 1;
ret += tipc_snprintf(buf + ret, buf_size - ret,
" TX profile sample:%u packets average:%u octets\n"
" 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
"-16384:%u%% -32768:%u%% -66000:%u%%\n",
s->msg_length_counts,
s->msg_lengths_total / profile_total,
percent(s->msg_length_profile[0], profile_total),
percent(s->msg_length_profile[1], profile_total),
percent(s->msg_length_profile[2], profile_total),
percent(s->msg_length_profile[3], profile_total),
percent(s->msg_length_profile[4], profile_total),
percent(s->msg_length_profile[5], profile_total),
percent(s->msg_length_profile[6], profile_total));
ret += tipc_snprintf(buf + ret, buf_size - ret,
" RX states:%u probes:%u naks:%u defs:%u"
" dups:%u\n", s->recv_states, s->recv_probes,
s->recv_nacks, s->deferred_recv, s->duplicates);
ret += tipc_snprintf(buf + ret, buf_size - ret,
" TX states:%u probes:%u naks:%u acks:%u"
" dups:%u\n", s->sent_states, s->sent_probes,
s->sent_nacks, s->sent_acks, s->retransmitted);
ret += tipc_snprintf(buf + ret, buf_size - ret,
" Congestion link:%u Send queue"
" max:%u avg:%u\n", s->link_congs,
s->max_queue_sz, s->queue_sz_counts ?
(s->accu_queue_sz / s->queue_sz_counts) : 0);
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
return ret;
}
struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
{
struct sk_buff *buf;
struct tlv_desc *rep_tlv;
int str_len;
int pb_len;
char *pb;
if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
if (!buf)
return NULL;
rep_tlv = (struct tlv_desc *)buf->data;
pb = TLV_DATA(rep_tlv);
pb_len = ULTRA_STRING_MAX_LEN;
str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
pb, pb_len);
if (!str_len) {
kfree_skb(buf);
return tipc_cfg_reply_error_string("link not found");
}
str_len += 1; /* for "\0" */
skb_put(buf, TLV_SPACE(str_len));
TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
return buf;
}
/**
* tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
* @dest: network address of destination node
* @selector: used to select from set of active links
*
* If no active link can be found, uses default maximum packet size.
*/
u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
{
struct tipc_node *n_ptr;
struct tipc_link *l_ptr;
u32 res = MAX_PKT_DEFAULT;
if (dest == tipc_own_addr)
return MAX_MSG_SIZE;
read_lock_bh(&tipc_net_lock);
n_ptr = tipc_node_find(dest);
if (n_ptr) {
tipc_node_lock(n_ptr);
l_ptr = n_ptr->active_links[selector & 1];
if (l_ptr)
res = l_ptr->max_pkt;
tipc_node_unlock(n_ptr);
}
read_unlock_bh(&tipc_net_lock);
return res;
}
static void link_print(struct tipc_link *l_ptr, const char *str)
{
pr_info("%s Link %x<%s>:", str, l_ptr->addr, l_ptr->b_ptr->name);
if (link_working_unknown(l_ptr))
pr_cont(":WU\n");
else if (link_reset_reset(l_ptr))
pr_cont(":RR\n");
else if (link_reset_unknown(l_ptr))
pr_cont(":RU\n");
else if (link_working_working(l_ptr))
pr_cont(":WW\n");
else
pr_cont("\n");
}