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linux/net/tipc/link.c
Jon Paul Maloy e099e86c9e tipc: add node_lock protection to link lookup function 
In an earlier commit, ("tipc: remove links list from bearer struct")
we described three issues that need to be pre-emptively resolved before
we can remove tipc_net_lock. Here we resolve issue a) described in that
commit:

"a) In access method #2, we access the link before taking the
    protecting node_lock. This will not work once net_lock is gone,
    so we will have to change the access order. We will deal with
    this in a later commit in this series."

Here, we change that access order, by ensuring that the function
link_find_link() returns only a safe reference for finding
the link, i.e., a node pointer and an index into its 'links' array,
not the link pointer itself. We also change all callers of this
function to first take the node lock before they can check if there
still is a valid link pointer at the returned index. Since the
function now returns a node pointer rather than a link pointer,
we rename it to the more appropriate 'tipc_link_find_owner().

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:57:07 -05:00

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/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012-2014, 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
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 tipc_link_tunnel_rcv(struct tipc_node *n_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,
unsigned int 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 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_timeout - handle expiration of link timer
* @l_ptr: pointer to link
*/
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);
link_state_event(l_ptr, STARTING_EVT);
return l_ptr;
}
void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
{
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
list_for_each_entry(n_ptr, &tipc_node_list, list) {
spin_lock_bh(&n_ptr->lock);
l_ptr = n_ptr->links[bearer_id];
if (l_ptr) {
tipc_link_reset(l_ptr);
if (shutting_down || !tipc_node_is_up(n_ptr)) {
tipc_node_detach_link(l_ptr->owner, l_ptr);
tipc_link_reset_fragments(l_ptr);
spin_unlock_bh(&n_ptr->lock);
/* Nobody else can access this link now: */
del_timer_sync(&l_ptr->timer);
kfree(l_ptr);
} else {
/* Detach/delete when failover is finished: */
l_ptr->flags |= LINK_STOPPED;
spin_unlock_bh(&n_ptr->lock);
del_timer_sync(&l_ptr->timer);
}
continue;
}
spin_unlock_bh(&n_ptr->lock);
}
}
/**
* 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)
{
kfree_skb_list(l_ptr->first_out);
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)
{
kfree_skb(l_ptr->reasm_head);
l_ptr->reasm_head = NULL;
l_ptr->reasm_tail = NULL;
}
/**
* tipc_link_purge_queues - purge all pkt queues associated with link
* @l_ptr: pointer to link
*/
void tipc_link_purge_queues(struct tipc_link *l_ptr)
{
kfree_skb_list(l_ptr->oldest_deferred_in);
kfree_skb_list(l_ptr->first_out);
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)
{
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->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;
kfree_skb_list(l_ptr->oldest_deferred_in);
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);
}
void tipc_link_reset_list(unsigned int bearer_id)
{
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
list_for_each_entry(n_ptr, &tipc_node_list, list) {
spin_lock_bh(&n_ptr->lock);
l_ptr = n_ptr->links[bearer_id];
if (l_ptr)
tipc_link_reset(l_ptr);
spin_unlock_bh(&n_ptr->lock);
}
}
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->flags & LINK_STOPPED)
return;
if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
return; /* Not yet. */
/* Check whether changeover is going on */
if (l_ptr->exp_msg_count) {
if (event == TIMEOUT_EVT)
link_set_timer(l_ptr, cont_intv);
return;
}
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->flags |= LINK_STARTED;
/* 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(!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)) {
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,
unsigned int 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, 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)) {
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, 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,
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,
unsigned int len, u32 destaddr)
{
struct tipc_link *l_ptr;
struct tipc_node *node;
struct tipc_msg *hdr = &sender->phdr;
u32 dsz = 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 __user *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 = 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:
kfree_skb_list(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);
kfree_skb_list(buf_chain);
goto again;
}
} else {
reject:
kfree_skb_list(buf_chain);
return tipc_port_reject_sections(sender, hdr, msg_sect,
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
*/
static 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;
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);
/* Detect repeated retransmit failures */
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_rcv - process TIPC packets/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_rcv(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;
head = head->next;
buf->next = NULL;
/* Ensure bearer is still enabled */
if (unlikely(!b_ptr->active))
goto discard;
/* Ensure message is well-formed */
if (unlikely(!link_recv_buf_validate(buf)))
goto discard;
/* Ensure message data is a single contiguous unit */
if (unlikely(skb_linearize(buf)))
goto discard;
/* 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 discard;
/* Locate neighboring node that sent message */
n_ptr = tipc_node_find(msg_prevnode(msg));
if (unlikely(!n_ptr))
goto discard;
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))
goto unlock_discard;
/* 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)
goto unlock_discard;
/* 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);
}
/* Process the incoming packet */
if (unlikely(!link_working_working(l_ptr))) {
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;
}
goto unlock_discard;
}
/* Link is now in state WORKING_WORKING */
if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
link_handle_out_of_seq_msg(l_ptr, buf);
head = link_insert_deferred_queue(l_ptr, head);
tipc_node_unlock(n_ptr);
continue;
}
l_ptr->next_in_no++;
if (unlikely(l_ptr->oldest_deferred_in))
head = link_insert_deferred_queue(l_ptr, head);
/* Deliver packet/message to correct user: */
if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL)) {
if (!tipc_link_tunnel_rcv(n_ptr, &buf)) {
tipc_node_unlock(n_ptr);
continue;
}
msg = buf_msg(buf);
} else if (msg_user(msg) == MSG_FRAGMENTER) {
int rc;
l_ptr->stats.recv_fragments++;
rc = tipc_link_frag_rcv(&l_ptr->reasm_head,
&l_ptr->reasm_tail,
&buf);
if (rc == LINK_REASM_COMPLETE) {
l_ptr->stats.recv_fragmented++;
msg = buf_msg(buf);
} else {
if (rc == LINK_REASM_ERROR)
tipc_link_reset(l_ptr);
tipc_node_unlock(n_ptr);
continue;
}
}
switch (msg_user(msg)) {
case TIPC_LOW_IMPORTANCE:
case TIPC_MEDIUM_IMPORTANCE:
case TIPC_HIGH_IMPORTANCE:
case TIPC_CRITICAL_IMPORTANCE:
tipc_node_unlock(n_ptr);
tipc_port_recv_msg(buf);
continue;
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 CONN_MANAGER:
tipc_node_unlock(n_ptr);
tipc_port_recv_proto_msg(buf);
continue;
case BCAST_PROTOCOL:
tipc_link_recv_sync(n_ptr, buf);
break;
default:
kfree_skb(buf);
break;
}
tipc_node_unlock(n_ptr);
continue;
unlock_discard:
tipc_node_unlock(n_ptr);
discard:
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;
}
/* Don't send protocol message during link changeover */
if (l_ptr->exp_msg_count)
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;
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);
/* Discard protocol message during link changeover */
if (l_ptr->exp_msg_count)
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);
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_xmit(): Tunnel one packet via a link belonging to
* a different bearer. Owner node is locked.
*/
static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
struct tipc_msg *tunnel_hdr,
struct tipc_msg *msg,
u32 selector)
{
struct tipc_link *tunnel;
struct sk_buff *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);
}
/* tipc_link_failover_send_queue(): A link has gone down, but a second
* link is still active. We can do failover. Tunnel the failing link's
* whole send queue via the remaining link. This way, we don't lose
* any packets, and sequence order is preserved for subsequent traffic
* sent over the remaining link. Owner node is locked.
*/
void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
{
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;
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_xmit(l_ptr, &tunnel_hdr, m,
msg_link_selector(m));
pos += align(msg_size(m));
m = (struct tipc_msg *)pos;
}
} else {
tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
msg_link_selector(msg));
}
crs = crs->next;
}
}
/* tipc_link_dup_send_queue(): A second link has become active. Tunnel a
* duplicate of the first link's send queue via the new link. This way, we
* are guaranteed that currently queued packets from a socket are delivered
* before future traffic from the same socket, even if this is using the
* new link. The last arriving copy of each duplicate packet is dropped at
* the receiving end by the regular protocol check, so packet cardinality
* and sequence order is preserved per sender/receiver socket pair.
* Owner node is locked.
*/
void tipc_link_dup_send_queue(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;
}
/* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
* Owner node is locked.
*/
static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
struct sk_buff *t_buf)
{
struct sk_buff *buf;
if (!tipc_link_is_up(l_ptr))
return;
buf = buf_extract(t_buf, INT_H_SIZE);
if (buf == NULL) {
pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
return;
}
/* Add buffer to deferred queue, if applicable: */
link_handle_out_of_seq_msg(l_ptr, buf);
}
/* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
* Owner node is locked.
*/
static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
struct sk_buff *t_buf)
{
struct tipc_msg *t_msg = buf_msg(t_buf);
struct sk_buff *buf = NULL;
struct tipc_msg *msg;
if (tipc_link_is_up(l_ptr))
tipc_link_reset(l_ptr);
/* First failover packet? */
if (l_ptr->exp_msg_count == START_CHANGEOVER)
l_ptr->exp_msg_count = msg_msgcnt(t_msg);
/* Should there be an inner packet? */
if (l_ptr->exp_msg_count) {
l_ptr->exp_msg_count--;
buf = buf_extract(t_buf, INT_H_SIZE);
if (buf == NULL) {
pr_warn("%sno inner failover pkt\n", link_co_err);
goto exit;
}
msg = buf_msg(buf);
if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
kfree_skb(buf);
buf = NULL;
goto exit;
}
if (msg_user(msg) == MSG_FRAGMENTER) {
l_ptr->stats.recv_fragments++;
tipc_link_frag_rcv(&l_ptr->reasm_head,
&l_ptr->reasm_tail,
&buf);
}
}
exit:
if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
tipc_node_detach_link(l_ptr->owner, l_ptr);
kfree(l_ptr);
}
return buf;
}
/* tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
* via other link as result of a failover (ORIGINAL_MSG) or
* a new active link (DUPLICATE_MSG). Failover packets are
* returned to the active link for delivery upwards.
* Owner node is locked.
*/
static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
struct sk_buff **buf)
{
struct sk_buff *t_buf = *buf;
struct tipc_link *l_ptr;
struct tipc_msg *t_msg = buf_msg(t_buf);
u32 bearer_id = msg_bearer_id(t_msg);
*buf = NULL;
if (bearer_id >= MAX_BEARERS)
goto exit;
l_ptr = n_ptr->links[bearer_id];
if (!l_ptr)
goto exit;
if (msg_type(t_msg) == DUPLICATE_MSG)
tipc_link_dup_rcv(l_ptr, t_buf);
else if (msg_type(t_msg) == ORIGINAL_MSG)
*buf = tipc_link_failover_rcv(l_ptr, t_buf);
else
pr_warn("%sunknown tunnel pkt received\n", link_co_err);
exit:
kfree_skb(t_buf);
return *buf != NULL;
}
/*
* 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);
kfree_skb_list(buf_chain);
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;
}
/* tipc_link_frag_rcv(): Called with node lock on. Returns
* the reassembled buffer if message is complete.
*/
int tipc_link_frag_rcv(struct sk_buff **head, struct sk_buff **tail,
struct sk_buff **fbuf)
{
struct sk_buff *frag = *fbuf;
struct tipc_msg *msg = buf_msg(frag);
u32 fragid = msg_type(msg);
bool headstolen;
int delta;
skb_pull(frag, msg_hdr_sz(msg));
if (fragid == FIRST_FRAGMENT) {
if (*head || skb_unclone(frag, GFP_ATOMIC))
goto out_free;
*head = frag;
skb_frag_list_init(*head);
*fbuf = NULL;
return 0;
} else if (*head &&
skb_try_coalesce(*head, frag, &headstolen, &delta)) {
kfree_skb_partial(frag, headstolen);
} else {
if (!*head)
goto out_free;
if (!skb_has_frag_list(*head))
skb_shinfo(*head)->frag_list = frag;
else
(*tail)->next = frag;
*tail = frag;
(*head)->truesize += frag->truesize;
}
if (fragid == LAST_FRAGMENT) {
*fbuf = *head;
*tail = *head = NULL;
return LINK_REASM_COMPLETE;
}
*fbuf = NULL;
return 0;
out_free:
pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
kfree_skb(*fbuf);
*fbuf = NULL;
return LINK_REASM_ERROR;
}
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;
}
/* tipc_link_find_owner - locate owner node of link by link's name
* @name: pointer to link name string
* @bearer_id: pointer to index in 'node->links' array where the link was found.
* Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
* this also prevents link deletion.
*
* Returns pointer to node owning the link, or 0 if no matching link is found.
*/
static struct tipc_node *tipc_link_find_owner(const char *link_name,
unsigned int *bearer_id)
{
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
struct tipc_node *tmp_n_ptr;
struct tipc_node *found_node = 0;
int i;
*bearer_id = 0;
list_for_each_entry_safe(n_ptr, tmp_n_ptr, &tipc_node_list, list) {
spin_lock(&n_ptr->lock);
for (i = 0; i < MAX_BEARERS; i++) {
l_ptr = n_ptr->links[i];
if (l_ptr && !strcmp(l_ptr->name, link_name)) {
*bearer_id = i;
found_node = n_ptr;
break;
}
}
spin_unlock(&n_ptr->lock);
if (found_node)
break;
}
return found_node;
}
/**
* 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;
int bearer_id;
int res = 0;
node = tipc_link_find_owner(name, &bearer_id);
if (node) {
tipc_node_lock(node);
l_ptr = node->links[bearer_id];
if (l_ptr) {
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;
default:
res = -EINVAL;
break;
}
}
tipc_node_unlock(node);
return res;
}
b_ptr = tipc_bearer_find(name);
if (b_ptr) {
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
b_ptr->tolerance = new_value;
break;
case TIPC_CMD_SET_LINK_PRI:
b_ptr->priority = new_value;
break;
case TIPC_CMD_SET_LINK_WINDOW:
b_ptr->window = new_value;
break;
default:
res = -EINVAL;
break;
}
return res;
}
m_ptr = tipc_media_find(name);
if (!m_ptr)
return -ENODEV;
switch (cmd) {
case TIPC_CMD_SET_LINK_TOL:
m_ptr->tolerance = new_value;
break;
case TIPC_CMD_SET_LINK_PRI:
m_ptr->priority = new_value;
break;
case TIPC_CMD_SET_LINK_WINDOW:
m_ptr->window = new_value;
break;
default:
res = -EINVAL;
break;
}
return res;
}
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;
unsigned int bearer_id;
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);
node = tipc_link_find_owner(link_name, &bearer_id);
if (!node) {
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_error_string("link not found");
}
spin_lock(&node->lock);
l_ptr = node->links[bearer_id];
if (!l_ptr) {
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_error_string("link not found");
}
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;
unsigned int bearer_id;
int ret;
if (!strcmp(name, tipc_bclink_name))
return tipc_bclink_stats(buf, buf_size);
read_lock_bh(&tipc_net_lock);
node = tipc_link_find_owner(name, &bearer_id);
if (!node) {
read_unlock_bh(&tipc_net_lock);
return 0;
}
tipc_node_lock(node);
l = node->links[bearer_id];
if (!l) {
tipc_node_unlock(node);
read_unlock_bh(&tipc_net_lock);
return 0;
}
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");
}
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