linux/net/tipc/bearer.c
Ying Xue 3c294cb374 tipc: remove the bearer congestion mechanism
Currently at the TIPC bearer layer there is the following congestion
mechanism:

Once sending packets has failed via that bearer, the bearer will be
flagged as being in congested state at once. During bearer congestion,
all packets arriving at link will be queued on the link's outgoing
buffer.  When we detect that the state of bearer congestion has
relaxed (e.g. some packets are received from the bearer) we will try
our best to push all packets in the link's outgoing buffer until the
buffer is empty, or until the bearer is congested again.

However, in fact the TIPC bearer never receives any feedback from the
device layer whether a send was successful or not, so it must always
assume it was successful. Therefore, the bearer congestion mechanism
as it exists currently is of no value.

But the bearer blocking state is still useful for us. For example,
when the physical media goes down/up, we need to change the state of
the links bound to the bearer.  So the code maintaing the state
information is not removed.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-21 20:07:25 -05:00

509 lines
13 KiB
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);
/**
* 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 ((strlen(m_ptr->name) + 1) > TIPC_MAX_MEDIA_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)
pr_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(char *buf, int len, struct tipc_media_addr *a)
{
char addr_str[MAX_ADDR_STR];
struct tipc_media *m_ptr;
int ret;
m_ptr = media_find_id(a->media_id);
if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
else {
u32 i;
ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
for (i = 0; i < sizeof(a->value); i++)
ret += tipc_snprintf(buf - ret, len + ret,
"-%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))
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);
}
/*
* Interrupt enabling new requests after bearer blocking:
* See bearer_send().
*/
void tipc_continue(struct tipc_bearer *b)
{
spin_lock_bh(&b->lock);
b->blocked = 0;
spin_unlock_bh(&b->lock);
}
/*
* tipc_bearer_blocked - determines if bearer is currently blocked
*/
int tipc_bearer_blocked(struct tipc_bearer *b)
{
int res;
spin_lock_bh(&b->lock);
res = b->blocked;
spin_unlock_bh(&b->lock);
return res;
}
/**
* 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) {
pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
name);
return -ENOPROTOOPT;
}
if (!bearer_name_validate(name, &b_names)) {
pr_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_exact(disc_domain))
res = 0; /* accept specified node in own cluster */
}
if (res) {
pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
name);
return -EINVAL;
}
if ((priority > TIPC_MAX_LINK_PRI) &&
(priority != TIPC_MEDIA_LINK_PRI)) {
pr_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) {
pr_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)) {
pr_warn("Bearer <%s> rejected, already enabled\n",
name);
goto exit;
}
if ((tipc_bearers[i].priority == priority) &&
(++with_this_prio > 2)) {
if (priority-- == 0) {
pr_warn("Bearer <%s> rejected, duplicate priority\n",
name);
goto exit;
}
pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
name, priority + 1, priority);
goto restart;
}
}
if (bearer_id >= MAX_BEARERS) {
pr_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) {
pr_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->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);
pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
name);
goto exit;
}
pr_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) {
pr_warn("Attempt to block unknown bearer <%s>\n", name);
read_unlock_bh(&tipc_net_lock);
return -EINVAL;
}
pr_info("Blocking bearer <%s>\n", name);
spin_lock_bh(&b_ptr->lock);
b_ptr->blocked = 1;
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;
pr_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_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) {
pr_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;
}