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link.c
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/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, Ericsson AB
* Copyright (c) 2004-2007, 2010-2011, 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"
/*
* 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 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 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 link *l_ptr,
struct sk_buff *buf);
static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
static int link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
static int link_send_sections_long(struct tipc_port *sender,
struct iovec const *msg_sect,
u32 num_sect, u32 destnode);
static void link_check_defragm_bufs(struct link *l_ptr);
static void link_state_event(struct link *l_ptr, u32 event);
static void link_reset_statistics(struct link *l_ptr);
static void link_print(struct link *l_ptr, const char *str);
static void link_start(struct link *l_ptr);
static int link_send_long_buf(struct link *l_ptr, 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 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 link *l_ptr)
{
if (l_ptr->next_out)
return msg_seqno(buf_msg(l_ptr->next_out));
return mod(l_ptr->next_out_no);
}
static u32 link_last_sent(struct 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 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 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 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 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) ||
(strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
(strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
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 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_check_defragm_bufs(l_ptr);
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 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 link *tipc_link_create(struct tipc_node *n_ptr,
struct tipc_bearer *b_ptr,
const struct tipc_media_addr *media_addr)
{
struct 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);
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);
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) {
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:",
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 is appended to link name by reset/activate */
memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
l_ptr->owner = n_ptr;
l_ptr->checkpoint = 1;
l_ptr->b_ptr = b_ptr;
link_set_supervision_props(l_ptr, b_ptr->media->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->media->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 link *l_ptr)
{
if (!l_ptr) {
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 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 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 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 link *l_ptr)
{
struct sk_buff *buf = l_ptr->first_out;
struct sk_buff *next;
while (buf) {
next = buf->next;
buf_discard(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 link *l_ptr)
{
struct sk_buff *buf = l_ptr->defragm_buf;
struct sk_buff *next;
while (buf) {
next = buf->next;
buf_discard(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 link *l_ptr)
{
struct sk_buff *buf;
struct sk_buff *next;
buf = l_ptr->oldest_deferred_in;
while (buf) {
next = buf->next;
buf_discard(buf);
buf = next;
}
buf = l_ptr->first_out;
while (buf) {
next = buf->next;
buf_discard(buf);
buf = next;
}
tipc_link_reset_fragments(l_ptr);
buf_discard(l_ptr->proto_msg_queue);
l_ptr->proto_msg_queue = NULL;
}
/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
#define link_send_event(fcn, l_ptr, up) do { } while (0)
void tipc_link_reset(struct 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);
buf_discard(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;
buf_discard(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);
link_send_event(tipc_cfg_link_event, l_ptr, 0);
if (!in_own_cluster(l_ptr->addr))
link_send_event(tipc_disc_link_event, l_ptr, 0);
}
static void link_activate(struct 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_send_event(tipc_cfg_link_event, l_ptr, 1);
if (!in_own_cluster(l_ptr->addr))
link_send_event(tipc_disc_link_event, l_ptr, 1);
}
/**
* link_state_event - link finite state machine
* @l_ptr: pointer to link
* @event: state machine event to process
*/
static void link_state_event(struct link *l_ptr, unsigned event)
{
struct 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:
info("Resetting link <%s>, requested by peer\n",
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:
err("Unknown link event %u in WW state\n", 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:
info("Resetting link <%s>, requested by peer "
"while probing\n", 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 */
warn("Resetting link <%s>, peer not responding\n",
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:
err("Unknown link event %u in WU state\n", 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++;
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:
err("Unknown link event %u in RU state\n", 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++;
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:
err("Unknown link event %u in RR state\n", event);
}
break;
default:
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 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);
buf_discard(buf);
l_ptr->stats.sent_bundled++;
return 1;
}
static void link_add_to_outqueue(struct 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;
}
/*
* 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 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;
msg_set_prevnode(msg, tipc_own_addr); /* If routed message */
/* Match msg importance against queue limits: */
if (unlikely(queue_size >= queue_limit)) {
if (imp <= TIPC_CRITICAL_IMPORTANCE) {
return link_schedule_port(l_ptr, msg_origport(msg),
size);
}
buf_discard(buf);
if (imp > CONN_MANAGER) {
warn("Resetting link <%s>, send queue full", 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_congested(l_ptr->b_ptr, l_ptr) &&
!link_congested(l_ptr))) {
link_add_to_outqueue(l_ptr, buf, msg);
if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
l_ptr->unacked_window = 0;
} else {
tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
l_ptr->stats.bearer_congs++;
l_ptr->next_out = buf;
}
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)) {
tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
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);
tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
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 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
buf_discard(buf);
tipc_node_unlock(n_ptr);
} else {
buf_discard(buf);
}
read_unlock_bh(&tipc_net_lock);
return res;
}
/*
* 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 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(list_empty(&l_ptr->b_ptr->cong_links))) {
link_add_to_outqueue(l_ptr, buf, msg);
if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
&l_ptr->media_addr))) {
l_ptr->unacked_window = 0;
return res;
}
tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
l_ptr->stats.bearer_congs++;
l_ptr->next_out = buf;
return res;
}
} else
*used_max_pkt = l_ptr->max_pkt;
}
return tipc_link_send_buf(l_ptr, buf); /* All other cases */
}
/*
* tipc_send_buf_fast: Entry for data messages where the