- 根目录:
- net
- tipc
- bearer.c
/*
* net/tipc/bearer.c: TIPC bearer code
*
* Copyright (c) 1996-2006, Ericsson AB
* Copyright (c) 2004-2006, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "config.h"
#include "bearer.h"
#include "discover.h"
#define MAX_ADDR_STR 32
static struct tipc_media *media_list[MAX_MEDIA];
static u32 media_count;
struct tipc_bearer tipc_bearers[MAX_BEARERS];
static void bearer_disable(struct tipc_bearer *b_ptr);
/**
* media_name_valid - validate media name
*
* Returns 1 if media name is valid, otherwise 0.
*/
static int media_name_valid(const char *name)
{
u32 len;
len = strlen(name);
if ((len + 1) > TIPC_MAX_MEDIA_NAME)
return 0;
return strspn(name, tipc_alphabet) == len;
}
/**
* tipc_media_find - locates specified media object by name
*/
struct tipc_media *tipc_media_find(const char *name)
{
u32 i;
for (i = 0; i < media_count; i++) {
if (!strcmp(media_list[i]->name, name))
return media_list[i];
}
return NULL;
}
/**
* media_find_id - locates specified media object by type identifier
*/
static struct tipc_media *media_find_id(u8 type)
{
u32 i;
for (i = 0; i < media_count; i++) {
if (media_list[i]->type_id == type)
return media_list[i];
}
return NULL;
}
/**
* tipc_register_media - register a media type
*
* Bearers for this media type must be activated separately at a later stage.
*/
int tipc_register_media(struct tipc_media *m_ptr)
{
int res = -EINVAL;
write_lock_bh(&tipc_net_lock);
if (!media_name_valid(m_ptr->name))
goto exit;
if ((m_ptr->bcast_addr.media_id != m_ptr->type_id) ||
!m_ptr->bcast_addr.broadcast)
goto exit;
if (m_ptr->priority > TIPC_MAX_LINK_PRI)
goto exit;
if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) ||
(m_ptr->tolerance > TIPC_MAX_LINK_TOL))
goto exit;
if (media_count >= MAX_MEDIA)
goto exit;
if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id))
goto exit;
media_list[media_count] = m_ptr;
media_count++;
res = 0;
exit:
write_unlock_bh(&tipc_net_lock);
if (res)
warn("Media <%s> registration error\n", m_ptr->name);
return res;
}
/**
* tipc_media_addr_printf - record media address in print buffer
*/
void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a)
{
char addr_str[MAX_ADDR_STR];
struct tipc_media *m_ptr;
m_ptr = media_find_id(a->media_id);
if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
tipc_printf(pb, "%s(%s)", m_ptr->name, addr_str);
else {
u32 i;
tipc_printf(pb, "UNKNOWN(%u)", a->media_id);
for (i = 0; i < sizeof(a->value); i++)
tipc_printf(pb, "-%02x", a->value[i]);
}
}
/**
* tipc_media_get_names - record names of registered media in buffer
*/
struct sk_buff *tipc_media_get_names(void)
{
struct sk_buff *buf;
int i;
buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
if (!buf)
return NULL;
read_lock_bh(&tipc_net_lock);
for (i = 0; i < media_count; i++) {
tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
media_list[i]->name,
strlen(media_list[i]->name) + 1);
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
/**
* bearer_name_validate - validate & (optionally) deconstruct bearer name
* @name - ptr to bearer name string
* @name_parts - ptr to area for bearer name components (or NULL if not needed)
*
* Returns 1 if bearer name is valid, otherwise 0.
*/
static int bearer_name_validate(const char *name,
struct tipc_bearer_names *name_parts)
{
char name_copy[TIPC_MAX_BEARER_NAME];
char *media_name;
char *if_name;
u32 media_len;
u32 if_len;
/* copy bearer name & ensure length is OK */
name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
/* need above in case non-Posix strncpy() doesn't pad with nulls */
strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
return 0;
/* ensure all component parts of bearer name are present */
media_name = name_copy;
if_name = strchr(media_name, ':');
if (if_name == NULL)
return 0;
*(if_name++) = 0;
media_len = if_name - media_name;
if_len = strlen(if_name) + 1;
/* validate component parts of bearer name */
if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
(if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) ||
(strspn(media_name, tipc_alphabet) != (media_len - 1)) ||
(strspn(if_name, tipc_alphabet) != (if_len - 1)))
return 0;
/* return bearer name components, if necessary */
if (name_parts) {
strcpy(name_parts->media_name, media_name);
strcpy(name_parts->if_name, if_name);
}
return 1;
}
/**
* tipc_bearer_find - locates bearer object with matching bearer name
*/
struct tipc_bearer *tipc_bearer_find(const char *name)
{
struct tipc_bearer *b_ptr;
u32 i;
for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (b_ptr->active && (!strcmp(b_ptr->name, name)))
return b_ptr;
}
return NULL;
}
/**
* tipc_bearer_find_interface - locates bearer object with matching interface name
*/
struct tipc_bearer *tipc_bearer_find_interface(const char *if_name)
{
struct tipc_bearer *b_ptr;
char *b_if_name;
u32 i;
for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (!b_ptr->active)
continue;
b_if_name = strchr(b_ptr->name, ':') + 1;
if (!strcmp(b_if_name, if_name))
return b_ptr;
}
return NULL;
}
/**
* tipc_bearer_get_names - record names of bearers in buffer
*/
struct sk_buff *tipc_bearer_get_names(void)
{
struct sk_buff *buf;
struct tipc_bearer *b_ptr;
int i, j;
buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
if (!buf)
return NULL;
read_lock_bh(&tipc_net_lock);
for (i = 0; i < media_count; i++) {
for (j = 0; j < MAX_BEARERS; j++) {
b_ptr = &tipc_bearers[j];
if (b_ptr->active && (b_ptr->media == media_list[i])) {
tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
b_ptr->name,
strlen(b_ptr->name) + 1);
}
}
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
{
tipc_nmap_add(&b_ptr->nodes, dest);
tipc_bcbearer_sort();
tipc_disc_add_dest(b_ptr->link_req);
}
void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
{
tipc_nmap_remove(&b_ptr->nodes, dest);
tipc_bcbearer_sort();
tipc_disc_remove_dest(b_ptr->link_req);
}
/*
* bearer_push(): Resolve bearer congestion. Force the waiting
* links to push out their unsent packets, one packet per link
* per iteration, until all packets are gone or congestion reoccurs.
* 'tipc_net_lock' is read_locked when this function is called
* bearer.lock must be taken before calling
* Returns binary true(1) ore false(0)
*/
static int bearer_push(struct tipc_bearer *b_ptr)
{
u32 res = 0;
struct tipc_link *ln, *tln;
if (b_ptr->blocked)
return 0;
while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) {
list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) {
res = tipc_link_push_packet(ln);
if (res == PUSH_FAILED)
break;
if (res == PUSH_FINISHED)
list_move_tail(&ln->link_list, &b_ptr->links);
}
}
return list_empty(&b_ptr->cong_links);
}
void tipc_bearer_lock_push(struct tipc_bearer *b_ptr)
{
spin_lock_bh(&b_ptr->lock);
bearer_push(b_ptr);
spin_unlock_bh(&b_ptr->lock);
}
/*
* Interrupt enabling new requests after bearer congestion or blocking:
* See bearer_send().
*/
void tipc_continue(struct tipc_bearer *b_ptr)
{
spin_lock_bh(&b_ptr->lock);
if (!list_empty(&b_ptr->cong_links))
tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr);
b_ptr->blocked = 0;
spin_unlock_bh(&b_ptr->lock);
}
/*
* Schedule link for sending of messages after the bearer
* has been deblocked by 'continue()'. This method is called
* when somebody tries to send a message via this link while
* the bearer is congested. 'tipc_net_lock' is in read_lock here
* bearer.lock is busy
*/
static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr,
struct tipc_link *l_ptr)
{
list_move_tail(&l_ptr->link_list, &b_ptr->cong_links);
}
/*
* Schedule link for sending of messages after the bearer
* has been deblocked by 'continue()'. This method is called
* when somebody tries to send a message via this link while
* the bearer is congested. 'tipc_net_lock' is in read_lock here,
* bearer.lock is free
*/
void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr)
{
spin_lock_bh(&b_ptr->lock);
tipc_bearer_schedule_unlocked(b_ptr, l_ptr);
spin_unlock_bh(&b_ptr->lock);
}
/*
* tipc_bearer_resolve_congestion(): Check if there is bearer congestion,
* and if there is, try to resolve it before returning.
* 'tipc_net_lock' is read_locked when this function is called
*/
int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr,
struct tipc_link *l_ptr)
{
int res = 1;
if (list_empty(&b_ptr->cong_links))
return 1;
spin_lock_bh(&b_ptr->lock);
if (!bearer_push(b_ptr)) {
tipc_bearer_schedule_unlocked(b_ptr, l_ptr);
res = 0;
}
spin_unlock_bh(&b_ptr->lock);
return res;
}
/**
* tipc_bearer_congested - determines if bearer is currently congested
*/
int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr)
{
if (unlikely(b_ptr->blocked))
return 1;
if (likely(list_empty(&b_ptr->cong_links)))
return 0;
return !tipc_bearer_resolve_congestion(b_ptr, l_ptr);
}
/**
* tipc_enable_bearer - enable bearer with the given name
*/
int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
{
struct tipc_bearer *b_ptr;
struct tipc_media *m_ptr;
struct tipc_bearer_names b_names;
char addr_string[16];
u32 bearer_id;
u32 with_this_prio;
u32 i;
int res = -EINVAL;
if (!tipc_own_addr) {
warn("Bearer <%s> rejected, not supported in standalone mode\n",
name);
return -ENOPROTOOPT;
}
if (!bearer_name_validate(name, &b_names)) {
warn("Bearer <%s> rejected, illegal name\n", name);
return -EINVAL;
}
if (tipc_addr_domain_valid(disc_domain) &&
(disc_domain != tipc_own_addr)) {
if (tipc_in_scope(disc_domain, tipc_own_addr)) {
disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
res = 0; /* accept any node in own cluster */
} else if (in_own_cluster(disc_domain))
res = 0; /* accept specified node in own cluster */
}
if (res) {
warn("Bearer <%s> rejected, illegal discovery domain\n", name);
return -EINVAL;
}
if ((priority > TIPC_MAX_LINK_PRI) &&
(priority != TIPC_MEDIA_LINK_PRI)) {
warn("Bearer <%s> rejected, illegal priority\n", name);
return -EINVAL;
}
write_lock_bh(&tipc_net_lock);
m_ptr = tipc_media_find(b_names.media_name);
if (!m_ptr) {
warn("Bearer <%s> rejected, media <%s> not registered\n", name,
b_names.media_name);
goto exit;
}
if (priority == TIPC_MEDIA_LINK_PRI)
priority = m_ptr->priority;
restart:
bearer_id = MAX_BEARERS;
with_this_prio = 1;
for (i = MAX_BEARERS; i-- != 0; ) {
if (!tipc_bearers[i].active) {
bearer_id = i;
continue;
}
if (!strcmp(name, tipc_bearers[i].name)) {
warn("Bearer <%s> rejected, already enabled\n", name);
goto exit;
}
if ((tipc_bearers[i].priority == priority) &&
(++with_this_prio > 2)) {
if (priority-- == 0) {
warn("Bearer <%s> rejected, duplicate priority\n",
name);
goto exit;
}
warn("Bearer <%s> priority adjustment required %u->%u\n",
name, priority + 1, priority);
goto restart;
}
}
if (bearer_id >= MAX_BEARERS) {
warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
name, MAX_BEARERS);
goto exit;
}
b_ptr = &tipc_bearers[bearer_id];
strcpy(b_ptr->name, name);
res = m_ptr->enable_bearer(b_ptr);
if (res) {
warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res);
goto exit;
}
b_ptr->identity = bearer_id;
b_ptr->media = m_ptr;
b_ptr->tolerance = m_ptr->tolerance;
b_ptr->window = m_ptr->window;
b_ptr->net_plane = bearer_id + 'A';
b_ptr->active = 1;
b_ptr->priority = priority;
INIT_LIST_HEAD(&b_ptr->cong_links);
INIT_LIST_HEAD(&b_ptr->links);
spin_lock_init(&b_ptr->lock);
res = tipc_disc_create(b_ptr, &m_ptr->bcast_addr, disc_domain);
if (res) {
bearer_disable(b_ptr);
warn("Bearer <%s> rejected, discovery object creation failed\n",
name);
goto exit;
}
info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
name, tipc_addr_string_fill(addr_string, disc_domain), priority);
exit:
write_unlock_bh(&tipc_net_lock);
return res;
}
/**
* tipc_block_bearer(): Block the bearer with the given name,
* and reset all its links
*/
int tipc_block_bearer(const char *name)
{
struct tipc_bearer *b_ptr = NULL;
struct tipc_link *l_ptr;
struct tipc_link *temp_l_ptr;
read_lock_bh(&tipc_net_lock);
b_ptr = tipc_bearer_find(name);
if (!b_ptr) {
warn("Attempt to block unknown bearer <%s>\n", name);
read_unlock_bh(&tipc_net_lock);
return -EINVAL;
}
info("Blocking bearer <%s>\n", name);
spin_lock_bh(&b_ptr->lock);
b_ptr->blocked = 1;
list_splice_init(&b_ptr->cong_links, &b_ptr->links);
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
struct tipc_node *n_ptr = l_ptr->owner;
spin_lock_bh(&n_ptr->lock);
tipc_link_reset(l_ptr);
spin_unlock_bh(&n_ptr->lock);
}
spin_unlock_bh(&b_ptr->lock);
read_unlock_bh(&tipc_net_lock);
return 0;
}
/**
* bearer_disable -
*
* Note: This routine assumes caller holds tipc_net_lock.
*/
static void bearer_disable(struct tipc_bearer *b_ptr)
{
struct tipc_link *l_ptr;
struct tipc_link *temp_l_ptr;
info("Disabling bearer <%s>\n", b_ptr->name);
spin_lock_bh(&b_ptr->lock);
b_ptr->blocked = 1;
b_ptr->media->disable_bearer(b_ptr);
list_splice_init(&b_ptr->cong_links, &b_ptr->links);
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
tipc_link_delete(l_ptr);
}
if (b_ptr->link_req)
tipc_disc_delete(b_ptr->link_req);
spin_unlock_bh(&b_ptr->lock);
memset(b_ptr, 0, sizeof(struct tipc_bearer));
}
int tipc_disable_bearer(const char *name)
{
struct tipc_bearer *b_ptr;
int res;
write_lock_bh(&tipc_net_lock);
b_ptr = tipc_bearer_find(name);
if (b_ptr == NULL) {
warn("Attempt to disable unknown bearer <%s>\n", name);
res = -EINVAL;
} else {
bearer_disable(b_ptr);
res = 0;
}
write_unlock_bh(&tipc_net_lock);
return res;
}
void tipc_bearer_stop(void)
{
u32 i;
for (i = 0; i < MAX_BEARERS; i++) {
if (tipc_bearers[i].active)
bearer_disable(&tipc_bearers[i]);
}
media_count = 0;
}