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link.c
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link.c
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/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2006, Ericsson AB
* Copyright (c) 2004-2006, 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 "dbg.h"
#include "link.h"
#include "net.h"
#include "node.h"
#include "port.h"
#include "addr.h"
#include "node_subscr.h"
#include "name_distr.h"
#include "bearer.h"
#include "name_table.h"
#include "discover.h"
#include "config.h"
#include "bcast.h"
/*
* Limit for deferred reception queue:
*/
#define DEF_QUEUE_LIMIT 256u
/*
* 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];
};
#if 0
/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
/**
* struct link_event - link up/down event notification
*/
struct link_event {
u32 addr;
int up;
void (*fcn)(u32, char *, int);
char name[TIPC_MAX_LINK_NAME];
};
#endif
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 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, struct print_buf *buf,
const char *str);
/*
* Debugging code used by link routines only
*
* When debugging link problems on a system that has multiple links,
* the standard TIPC debugging routines may not be useful since they
* allow the output from multiple links to be intermixed. For this reason
* routines of the form "dbg_link_XXX()" have been created that will capture
* debug info into a link's personal print buffer, which can then be dumped
* into the TIPC system log (LOG) upon request.
*
* To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
* of the print buffer used by each link. If LINK_LOG_BUF_SIZE is set to 0,
* the dbg_link_XXX() routines simply send their output to the standard
* debug print buffer (DBG_OUTPUT), if it has been defined; this can be useful
* when there is only a single link in the system being debugged.
*
* Notes:
* - When enabled, LINK_LOG_BUF_SIZE should be set to at least 1000 (bytes)
* - "l_ptr" must be valid when using dbg_link_XXX() macros
*/
#define LINK_LOG_BUF_SIZE 0
#define dbg_link(fmt, arg...) do {if (LINK_LOG_BUF_SIZE) tipc_printf(&l_ptr->print_buf, fmt, ## arg); } while(0)
#define dbg_link_msg(msg, txt) do {if (LINK_LOG_BUF_SIZE) tipc_msg_print(&l_ptr->print_buf, msg, txt); } while(0)
#define dbg_link_state(txt) do {if (LINK_LOG_BUF_SIZE) link_print(l_ptr, &l_ptr->print_buf, txt); } while(0)
#define dbg_link_dump() do { \
if (LINK_LOG_BUF_SIZE) { \
tipc_printf(LOG, "\n\nDumping link <%s>:\n", l_ptr->name); \
tipc_printbuf_move(LOG, &l_ptr->print_buf); \
} \
} while (0)
static void dbg_print_link(struct link *l_ptr, const char *str)
{
if (DBG_OUTPUT)
link_print(l_ptr, DBG_OUTPUT, str);
}
static void dbg_print_buf_chain(struct sk_buff *root_buf)
{
if (DBG_OUTPUT) {
struct sk_buff *buf = root_buf;
while (buf) {
msg_dbg(buf_msg(buf), "In chain: ");
buf = buf->next;
}
}
}
/*
* Simple link routines
*/
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
static int link_working_working(struct link *l_ptr)
{
return (l_ptr->state == WORKING_WORKING);
}
static int link_working_unknown(struct link *l_ptr)
{
return (l_ptr->state == WORKING_UNKNOWN);
}
static int link_reset_unknown(struct link *l_ptr)
{
return (l_ptr->state == RESET_UNKNOWN);
}
static int link_reset_reset(struct link *l_ptr)
{
return (l_ptr->state == RESET_RESET);
}
static int link_blocked(struct link *l_ptr)
{
return (l_ptr->exp_msg_count || l_ptr->blocked);
}
static int link_congested(struct link *l_ptr)
{
return (l_ptr->out_queue_size >= l_ptr->queue_limit[0]);
}
static u32 link_max_pkt(struct link *l_ptr)
{
return l_ptr->max_pkt;
}
static void link_init_max_pkt(struct link *l_ptr)
{
u32 max_pkt;
max_pkt = (l_ptr->b_ptr->publ.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 ((if_local = strchr(addr_local, ':')) == NULL)
return 0;
*(if_local++) = 0;
if ((addr_peer = strchr(if_local, '-')) == NULL)
return 0;
*(addr_peer++) = 0;
if_local_len = addr_peer - if_local;
if ((if_peer = strchr(addr_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->out_queue_size > l_ptr->stats.max_queue_sz)
l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
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
* @b_ptr: pointer to associated bearer
* @peer: network address of node at other end of link
* @media_addr: media address to use when sending messages over link
*
* Returns pointer to link.
*/
struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
const struct tipc_media_addr *media_addr)
{
struct link *l_ptr;
struct tipc_msg *msg;
char *if_name;
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->publ.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));
k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
list_add_tail(&l_ptr->link_list, &b_ptr->links);
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;
msg_init(msg, LINK_PROTOCOL, RESET_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
msg_set_size(msg, sizeof(l_ptr->proto_msg));
msg_set_session(msg, tipc_random);
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);
l_ptr->owner = tipc_node_attach_link(l_ptr);
if (!l_ptr->owner) {
kfree(l_ptr);
return NULL;
}
if (LINK_LOG_BUF_SIZE) {
char *pb = kmalloc(LINK_LOG_BUF_SIZE, GFP_ATOMIC);
if (!pb) {
kfree(l_ptr);
warn("Link creation failed, no memory for print buffer\n");
return NULL;
}
tipc_printbuf_init(&l_ptr->print_buf, pb, LINK_LOG_BUF_SIZE);
}
tipc_k_signal((Handler)tipc_link_start, (unsigned long)l_ptr);
dbg("tipc_link_create(): tolerance = %u,cont intv = %u, abort_limit = %u\n",
l_ptr->tolerance, l_ptr->continuity_interval, l_ptr->abort_limit);
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;
}
dbg("tipc_link_delete()\n");
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);
if (LINK_LOG_BUF_SIZE)
kfree(l_ptr->print_buf.buf);
tipc_node_unlock(l_ptr->owner);
k_term_timer(&l_ptr->timer);
kfree(l_ptr);
}
void tipc_link_start(struct link *l_ptr)
{
dbg("tipc_link_start %x\n", l_ptr);
link_state_event(l_ptr, STARTING_EVT);
}
/**
* 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 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_link = l_ptr;
p_ptr->publ.congested = 1;
p_ptr->waiting_pkts = 1 + ((sz - 1) / link_max_pkt(l_ptr));
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 port *p_ptr;
struct 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);
p_ptr->congested_link = NULL;
spin_lock_bh(p_ptr->publ.lock);
p_ptr->publ.congested = 0;
p_ptr->wakeup(&p_ptr->publ);
win -= p_ptr->waiting_pkts;
spin_unlock_bh(p_ptr->publ.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;
}
#if 0
/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
static void link_recv_event(struct link_event *ev)
{
ev->fcn(ev->addr, ev->name, ev->up);
kfree(ev);
}
static void link_send_event(void (*fcn)(u32 a, char *n, int up),
struct link *l_ptr, int up)
{
struct link_event *ev;
ev = kmalloc(sizeof(*ev), GFP_ATOMIC);
if (!ev) {
warn("Link event allocation failure\n");
return;
}
ev->addr = l_ptr->addr;
ev->up = up;
ev->fcn = fcn;
memcpy(ev->name, l_ptr->name, TIPC_MAX_LINK_NAME);
tipc_k_signal((Handler)link_recv_event, (unsigned long)ev);
}
#else
#define link_send_event(fcn, l_ptr, up) do { } while (0)
#endif
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);
/* Link is down, accept any session: */
l_ptr->peer_session = 0;
/* Prepare for max packet size negotiation */
link_init_max_pkt(l_ptr);
l_ptr->state = RESET_UNKNOWN;
dbg_link_state("Resetting Link\n");
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 0
tipc_printf(TIPC_CONS, "\nReset link <%s>\n", l_ptr->name);
dbg_link_dump();
#endif
if (was_active_link && tipc_node_has_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 */
}
dbg_link("STATE_EV: <%s> ", l_ptr->name);
switch (l_ptr->state) {
case WORKING_WORKING:
dbg_link("WW/");
switch (event) {
case TRAFFIC_MSG_EVT:
dbg_link("TRF-");
/* fall through */
case ACTIVATE_MSG:
dbg_link("ACT\n");
break;
case TIMEOUT_EVT:
dbg_link("TIM ");
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;
}
dbg_link(" -> WU\n");
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:
dbg_link("RES -> RR\n");
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:
dbg_link("WU/");
switch (event) {
case TRAFFIC_MSG_EVT:
dbg_link("TRF-");
case ACTIVATE_MSG:
dbg_link("ACT -> WW\n");
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
dbg_link("RES -> RR\n");
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:
dbg_link("TIM ");
if (l_ptr->next_in_no != l_ptr->checkpoint) {
dbg_link("-> WW \n");
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) {
dbg_link("Probing %u/%u,timer = %u ms)\n",
l_ptr->fsm_msg_cnt, l_ptr->abort_limit,
cont_intv / 4);
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 */
dbg_link("-> RU (%u probes unanswered)\n",
l_ptr->fsm_msg_cnt);
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:
dbg_link("RU/");
switch (event) {
case TRAFFIC_MSG_EVT:
dbg_link("TRF-\n");
break;
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other)) {
dbg_link("ACT\n");
break;
}
dbg_link("ACT -> WW\n");
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:
dbg_link("RES \n");
dbg_link(" -> RR\n");
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:
dbg_link("START-");
l_ptr->started = 1;
/* fall through */
case TIMEOUT_EVT:
dbg_link("TIM \n");
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:
dbg_link("RR/ ");
switch (event) {
case TRAFFIC_MSG_EVT:
dbg_link("TRF-");
/* fall through */
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other)) {
dbg_link("ACT\n");
break;
}
dbg_link("ACT -> WW\n");
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:
dbg_link("RES\n");
break;
case TIMEOUT_EVT:
dbg_link("TIM\n");
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);
dbg_link("fsm_msg_cnt %u\n", l_ptr->fsm_msg_cnt);
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 (link_max_pkt(l_ptr) < (to_pos + size))