linux/net/tipc/bearer.c

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/*
* net/tipc/bearer.c: TIPC bearer code
*
* Copyright (c) 2003-2006, Ericsson AB
* Copyright (c) 2004-2005, 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 "dbg.h"
#include "bearer.h"
#include "link.h"
#include "port.h"
#include "discover.h"
#include "bcast.h"
#define MAX_ADDR_STR 32
static struct media *media_list = 0;
static u32 media_count = 0;
struct bearer *bearers = 0;
/**
* 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);
}
/**
* media_find - locates specified media object by name
*/
static struct media *media_find(const char *name)
{
struct media *m_ptr;
u32 i;
for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
if (!strcmp(m_ptr->name, name))
return m_ptr;
}
return 0;
}
/**
* tipc_register_media - register a media type
*
* Bearers for this media type must be activated separately at a later stage.
*/
int tipc_register_media(u32 media_type,
char *name,
int (*enable)(struct tipc_bearer *),
void (*disable)(struct tipc_bearer *),
int (*send_msg)(struct sk_buff *,
struct tipc_bearer *,
struct tipc_media_addr *),
char *(*addr2str)(struct tipc_media_addr *a,
char *str_buf, int str_size),
struct tipc_media_addr *bcast_addr,
const u32 bearer_priority,
const u32 link_tolerance, /* [ms] */
const u32 send_window_limit)
{
struct media *m_ptr;
u32 media_id;
u32 i;
int res = -EINVAL;
write_lock_bh(&net_lock);
if (!media_list)
goto exit;
if (!media_name_valid(name)) {
warn("Media registration error: illegal name <%s>\n", name);
goto exit;
}
if (!bcast_addr) {
warn("Media registration error: no broadcast address supplied\n");
goto exit;
}
if (bearer_priority >= TIPC_NUM_LINK_PRI) {
warn("Media registration error: priority %u\n", bearer_priority);
goto exit;
}
if ((link_tolerance < TIPC_MIN_LINK_TOL) ||
(link_tolerance > TIPC_MAX_LINK_TOL)) {
warn("Media registration error: tolerance %u\n", link_tolerance);
goto exit;
}
media_id = media_count++;
if (media_id >= MAX_MEDIA) {
warn("Attempt to register more than %u media\n", MAX_MEDIA);
media_count--;
goto exit;
}
for (i = 0; i < media_id; i++) {
if (media_list[i].type_id == media_type) {
warn("Attempt to register second media with type %u\n",
media_type);
media_count--;
goto exit;
}
if (!strcmp(name, media_list[i].name)) {
warn("Attempt to re-register media name <%s>\n", name);
media_count--;
goto exit;
}
}
m_ptr = &media_list[media_id];
m_ptr->type_id = media_type;
m_ptr->send_msg = send_msg;
m_ptr->enable_bearer = enable;
m_ptr->disable_bearer = disable;
m_ptr->addr2str = addr2str;
memcpy(&m_ptr->bcast_addr, bcast_addr, sizeof(*bcast_addr));
m_ptr->bcast = 1;
strcpy(m_ptr->name, name);
m_ptr->priority = bearer_priority;
m_ptr->tolerance = link_tolerance;
m_ptr->window = send_window_limit;
dbg("Media <%s> registered\n", name);
res = 0;
exit:
write_unlock_bh(&net_lock);
return res;
}
/**
* media_addr_printf - record media address in print buffer
*/
void media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a)
{
struct media *m_ptr;
u32 media_type;
u32 i;
media_type = ntohl(a->type);
for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
if (m_ptr->type_id == media_type)
break;
}
if ((i < media_count) && (m_ptr->addr2str != NULL)) {
char addr_str[MAX_ADDR_STR];
tipc_printf(pb, "%s(%s) ", m_ptr->name,
m_ptr->addr2str(a, addr_str, sizeof(addr_str)));
} else {
unchar *addr = (unchar *)&a->dev_addr;
tipc_printf(pb, "UNKNOWN(%u):", media_type);
for (i = 0; i < (sizeof(*a) - sizeof(a->type)); i++) {
tipc_printf(pb, "%02x ", addr[i]);
}
}
}
/**
* media_get_names - record names of registered media in buffer
*/
struct sk_buff *media_get_names(void)
{
struct sk_buff *buf;
struct media *m_ptr;
int i;
buf = cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
if (!buf)
return NULL;
read_lock_bh(&net_lock);
for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, m_ptr->name,
strlen(m_ptr->name) + 1);
}
read_unlock_bh(&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 bearer_name *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 ((if_name = strchr(media_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;
}
/**
* bearer_find - locates bearer object with matching bearer name
*/
static struct bearer *bearer_find(const char *name)
{
struct bearer *b_ptr;
u32 i;
for (i = 0, b_ptr = bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (b_ptr->active && (!strcmp(b_ptr->publ.name, name)))
return b_ptr;
}
return 0;
}
/**
* bearer_find - locates bearer object with matching interface name
*/
struct bearer *bearer_find_interface(const char *if_name)
{
struct bearer *b_ptr;
char *b_if_name;
u32 i;
for (i = 0, b_ptr = bearers; i < MAX_BEARERS; i++, b_ptr++) {
if (!b_ptr->active)
continue;
b_if_name = strchr(b_ptr->publ.name, ':') + 1;
if (!strcmp(b_if_name, if_name))
return b_ptr;
}
return 0;
}
/**
* bearer_get_names - record names of bearers in buffer
*/
struct sk_buff *bearer_get_names(void)
{
struct sk_buff *buf;
struct media *m_ptr;
struct bearer *b_ptr;
int i, j;
buf = cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
if (!buf)
return NULL;
read_lock_bh(&net_lock);
for (i = 0, m_ptr = media_list; i < media_count; i++, m_ptr++) {
for (j = 0; j < MAX_BEARERS; j++) {
b_ptr = &bearers[j];
if (b_ptr->active && (b_ptr->media == m_ptr)) {
cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
b_ptr->publ.name,
strlen(b_ptr->publ.name) + 1);
}
}
}
read_unlock_bh(&net_lock);
return buf;
}
void bearer_add_dest(struct bearer *b_ptr, u32 dest)
{
nmap_add(&b_ptr->nodes, dest);
disc_update_link_req(b_ptr->link_req);
bcbearer_sort();
}
void bearer_remove_dest(struct bearer *b_ptr, u32 dest)
{
nmap_remove(&b_ptr->nodes, dest);
disc_update_link_req(b_ptr->link_req);
bcbearer_sort();
}
/*
* 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.
* '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 bearer *b_ptr)
{
u32 res = TIPC_OK;
struct link *ln, *tln;
if (b_ptr->publ.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 = 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 bearer_lock_push(struct bearer *b_ptr)
{
int res;
spin_lock_bh(&b_ptr->publ.lock);
res = bearer_push(b_ptr);
spin_unlock_bh(&b_ptr->publ.lock);
if (res)
bcbearer_push();
}
/*
* Interrupt enabling new requests after bearer congestion or blocking:
* See bearer_send().
*/
void tipc_continue(struct tipc_bearer *tb_ptr)
{
struct bearer *b_ptr = (struct bearer *)tb_ptr;
spin_lock_bh(&b_ptr->publ.lock);
b_ptr->continue_count++;
if (!list_empty(&b_ptr->cong_links))
k_signal((Handler)bearer_lock_push, (unsigned long)b_ptr);
b_ptr->publ.blocked = 0;
spin_unlock_bh(&b_ptr->publ.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. 'net_lock' is in read_lock here
* bearer.lock is busy
*/
static void bearer_schedule_unlocked(struct bearer *b_ptr, struct 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. 'net_lock' is in read_lock here,
* bearer.lock is free
*/
void bearer_schedule(struct bearer *b_ptr, struct link *l_ptr)
{
spin_lock_bh(&b_ptr->publ.lock);
bearer_schedule_unlocked(b_ptr, l_ptr);
spin_unlock_bh(&b_ptr->publ.lock);
}
/*
* bearer_resolve_congestion(): Check if there is bearer congestion,
* and if there is, try to resolve it before returning.
* 'net_lock' is read_locked when this function is called
*/
int bearer_resolve_congestion(struct bearer *b_ptr, struct link *l_ptr)
{
int res = 1;
if (list_empty(&b_ptr->cong_links))
return 1;
spin_lock_bh(&b_ptr->publ.lock);
if (!bearer_push(b_ptr)) {
bearer_schedule_unlocked(b_ptr, l_ptr);
res = 0;
}
spin_unlock_bh(&b_ptr->publ.lock);
return res;
}
/**
* tipc_enable_bearer - enable bearer with the given name
*/
int tipc_enable_bearer(const char *name, u32 bcast_scope, u32 priority)
{
struct bearer *b_ptr;
struct media *m_ptr;
struct bearer_name b_name;
char addr_string[16];
u32 bearer_id;
u32 with_this_prio;
u32 i;
int res = -EINVAL;
if (tipc_mode != TIPC_NET_MODE)
return -ENOPROTOOPT;
if (!bearer_name_validate(name, &b_name) ||
!addr_domain_valid(bcast_scope) ||
!in_scope(bcast_scope, tipc_own_addr) ||
(priority > TIPC_NUM_LINK_PRI))
return -EINVAL;
write_lock_bh(&net_lock);
if (!bearers)
goto failed;
m_ptr = media_find(b_name.media_name);
if (!m_ptr) {
warn("No media <%s>\n", b_name.media_name);
goto failed;
}
if (priority == TIPC_NUM_LINK_PRI)
priority = m_ptr->priority;
restart:
bearer_id = MAX_BEARERS;
with_this_prio = 1;
for (i = MAX_BEARERS; i-- != 0; ) {
if (!bearers[i].active) {
bearer_id = i;
continue;
}
if (!strcmp(name, bearers[i].publ.name)) {
warn("Bearer <%s> already enabled\n", name);
goto failed;
}
if ((bearers[i].priority == priority) &&
(++with_this_prio > 2)) {
if (priority-- == 0) {
warn("Third bearer <%s> with priority %u, unable to lower to %u\n",
name, priority + 1, priority);
goto failed;
}
warn("Third bearer <%s> with priority %u, lowering to %u\n",
name, priority + 1, priority);
goto restart;
}
}
if (bearer_id >= MAX_BEARERS) {
warn("Attempt to enable more than %d bearers\n", MAX_BEARERS);
goto failed;
}
b_ptr = &bearers[bearer_id];
memset(b_ptr, 0, sizeof(struct bearer));
strcpy(b_ptr->publ.name, name);
res = m_ptr->enable_bearer(&b_ptr->publ);
if (res) {
warn("Failed to enable bearer <%s>\n", name);
goto failed;
}
b_ptr->identity = bearer_id;
b_ptr->media = m_ptr;
b_ptr->net_plane = bearer_id + 'A';
b_ptr->active = 1;
b_ptr->detect_scope = bcast_scope;
b_ptr->priority = priority;
INIT_LIST_HEAD(&b_ptr->cong_links);
INIT_LIST_HEAD(&b_ptr->links);
if (m_ptr->bcast) {
b_ptr->link_req = disc_init_link_req(b_ptr, &m_ptr->bcast_addr,
bcast_scope, 2);
}
b_ptr->publ.lock = SPIN_LOCK_UNLOCKED;
write_unlock_bh(&net_lock);
info("Enabled bearer <%s>, discovery domain %s\n",
name, addr_string_fill(addr_string, bcast_scope));
return 0;
failed:
write_unlock_bh(&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 bearer *b_ptr = 0;
struct link *l_ptr;
struct link *temp_l_ptr;
if (tipc_mode != TIPC_NET_MODE)
return -ENOPROTOOPT;
read_lock_bh(&net_lock);
b_ptr = bearer_find(name);
if (!b_ptr) {
warn("Attempt to block unknown bearer <%s>\n", name);
read_unlock_bh(&net_lock);
return -EINVAL;
}
spin_lock_bh(&b_ptr->publ.lock);
b_ptr->publ.blocked = 1;
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
struct node *n_ptr = l_ptr->owner;
spin_lock_bh(&n_ptr->lock);
link_reset(l_ptr);
spin_unlock_bh(&n_ptr->lock);
}
spin_unlock_bh(&b_ptr->publ.lock);
read_unlock_bh(&net_lock);
info("Blocked bearer <%s>\n", name);
return TIPC_OK;
}
/**
* bearer_disable -
*
* Note: This routine assumes caller holds net_lock.
*/
static int bearer_disable(const char *name)
{
struct bearer *b_ptr;
struct link *l_ptr;
struct link *temp_l_ptr;
if (tipc_mode != TIPC_NET_MODE)
return -ENOPROTOOPT;
b_ptr = bearer_find(name);
if (!b_ptr) {
warn("Attempt to disable unknown bearer <%s>\n", name);
return -EINVAL;
}
disc_stop_link_req(b_ptr->link_req);
spin_lock_bh(&b_ptr->publ.lock);
b_ptr->link_req = NULL;
b_ptr->publ.blocked = 1;
if (b_ptr->media->disable_bearer) {
spin_unlock_bh(&b_ptr->publ.lock);
write_unlock_bh(&net_lock);
b_ptr->media->disable_bearer(&b_ptr->publ);
write_lock_bh(&net_lock);
spin_lock_bh(&b_ptr->publ.lock);
}
list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
link_delete(l_ptr);
}
spin_unlock_bh(&b_ptr->publ.lock);
info("Disabled bearer <%s>\n", name);
memset(b_ptr, 0, sizeof(struct bearer));
return TIPC_OK;
}
int tipc_disable_bearer(const char *name)
{
int res;
write_lock_bh(&net_lock);
res = bearer_disable(name);
write_unlock_bh(&net_lock);
return res;
}
int bearer_init(void)
{
int res;
write_lock_bh(&net_lock);
bearers = kmalloc(MAX_BEARERS * sizeof(struct bearer), GFP_ATOMIC);
media_list = kmalloc(MAX_MEDIA * sizeof(struct media), GFP_ATOMIC);
if (bearers && media_list) {
memset(bearers, 0, MAX_BEARERS * sizeof(struct bearer));
memset(media_list, 0, MAX_MEDIA * sizeof(struct media));
res = TIPC_OK;
} else {
kfree(bearers);
kfree(media_list);
bearers = 0;
media_list = 0;
res = -ENOMEM;
}
write_unlock_bh(&net_lock);
return res;
}
void bearer_stop(void)
{
u32 i;
if (!bearers)
return;
for (i = 0; i < MAX_BEARERS; i++) {
if (bearers[i].active)
bearers[i].publ.blocked = 1;
}
for (i = 0; i < MAX_BEARERS; i++) {
if (bearers[i].active)
bearer_disable(bearers[i].publ.name);
}
kfree(bearers);
kfree(media_list);
bearers = 0;
media_list = 0;
media_count = 0;
}