/*
* net/tipc/node.c: TIPC node management routines
*
* Copyright (c) 2000-2006, Ericsson AB
* Copyright (c) 2005-2006, 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 "node.h"
#include "name_distr.h"
static void node_lost_contact(struct tipc_node *n_ptr);
static void node_established_contact(struct tipc_node *n_ptr);
static DEFINE_SPINLOCK(node_create_lock);
u32 tipc_own_tag;
/**
* tipc_node_create - create neighboring node
*
* Currently, this routine is called by neighbor discovery code, which holds
* net_lock for reading only. We must take node_create_lock to ensure a node
* isn't created twice if two different bearers discover the node at the same
* time. (It would be preferable to switch to holding net_lock in write mode,
* but this is a non-trivial change.)
*/
struct tipc_node *tipc_node_create(u32 addr)
{
struct tipc_node *n_ptr;
u32 n_num;
spin_lock_bh(&node_create_lock);
n_ptr = tipc_node_find(addr);
if (n_ptr) {
spin_unlock_bh(&node_create_lock);
return n_ptr;
}
n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
if (!n_ptr) {
spin_unlock_bh(&node_create_lock);
warn("Node creation failed, no memory\n");
return NULL;
}
n_ptr->addr = addr;
spin_lock_init(&n_ptr->lock);
INIT_LIST_HEAD(&n_ptr->nsub);
n_num = tipc_node(addr);
tipc_net.nodes[n_num] = n_ptr;
if (n_num > tipc_net.highest_node)
tipc_net.highest_node = n_num;
spin_unlock_bh(&node_create_lock);
return n_ptr;
}
void tipc_node_delete(struct tipc_node *n_ptr)
{
u32 n_num;
if (!n_ptr)
return;
n_num = tipc_node(n_ptr->addr);
tipc_net.nodes[n_num] = NULL;
kfree(n_ptr);
while (!tipc_net.nodes[tipc_net.highest_node])
if (--tipc_net.highest_node == 0)
break;
}
/**
* tipc_node_link_up - handle addition of link
*
* Link becomes active (alone or shared) or standby, depending on its priority.
*/
void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr)
{
struct link **active = &n_ptr->active_links[0];
n_ptr->working_links++;
info("Established link <%s> on network plane %c\n",
l_ptr->name, l_ptr->b_ptr->net_plane);
if (!active[0]) {
active[0] = active[1] = l_ptr;
node_established_contact(n_ptr);
return;
}
if (l_ptr->priority < active[0]->priority) {
info("New link <%s> becomes standby\n", l_ptr->name);
return;
}
tipc_link_send_duplicate(active[0], l_ptr);
if (l_ptr->priority == active[0]->priority) {
active[0] = l_ptr;
return;
}
info("Old link <%s> becomes standby\n", active[0]->name);
if (active[1] != active[0])
info("Old link <%s> becomes standby\n", active[1]->name);
active[0] = active[1] = l_ptr;
}
/**
* node_select_active_links - select active link
*/
static void node_select_active_links(struct tipc_node *n_ptr)
{
struct link **active = &n_ptr->active_links[0];
u32 i;
u32 highest_prio = 0;
active[0] = active[1] = NULL;
for (i = 0; i < MAX_BEARERS; i++) {
struct link *l_ptr = n_ptr->links[i];
if (!l_ptr || !tipc_link_is_up(l_ptr) ||
(l_ptr->priority < highest_prio))
continue;
if (l_ptr->priority > highest_prio) {
highest_prio = l_ptr->priority;
active[0] = active[1] = l_ptr;
} else {
active[1] = l_ptr;
}
}
}
/**
* tipc_node_link_down - handle loss of link
*/
void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr)
{
struct link **active;
n_ptr->working_links--;
if (!tipc_link_is_active(l_ptr)) {
info("Lost standby link <%s> on network plane %c\n",
l_ptr->name, l_ptr->b_ptr->net_plane);
return;
}
info("Lost link <%s> on network plane %c\n",
l_ptr->name, l_ptr->b_ptr->net_plane);
active = &n_ptr->active_links[0];
if (active[0] == l_ptr)
active[0] = active[1];
if (active[1] == l_ptr)
active[1] = active[0];
if (active[0] == l_ptr)
node_select_active_links(n_ptr);
if (tipc_node_is_up(n_ptr))
tipc_link_changeover(l_ptr);
else
node_lost_contact(n_ptr);
}
int tipc_node_has_active_links(struct tipc_node *n_ptr)
{
return n_ptr->active_links[0] != NULL;
}
int tipc_node_has_redundant_links(struct tipc_node *n_ptr)
{
return n_ptr->working_links > 1;
}
int tipc_node_is_up(struct tipc_node *n_ptr)
{
return tipc_node_has_active_links(n_ptr);
}
struct tipc_node *tipc_node_attach_link(struct link *l_ptr)
{
struct tipc_node *n_ptr = tipc_node_find(l_ptr->addr);
if (!n_ptr)
n_ptr = tipc_node_create(l_ptr->addr);
if (n_ptr) {
u32 bearer_id = l_ptr->b_ptr->identity;
char addr_string[16];
if (n_ptr->link_cnt >= 2) {
err("Attempt to create third link to %s\n",
tipc_addr_string_fill(addr_string, n_ptr->addr));
return NULL;
}
if (!n_ptr->links[bearer_id]) {
n_ptr->links[bearer_id] = l_ptr;
tipc_net.links++;
n_ptr->link_cnt++;
return n_ptr;
}
err("Attempt to establish second link on <%s> to %s\n",
l_ptr->b_ptr->name,
tipc_addr_string_fill(addr_string, l_ptr->addr));
}
return NULL;
}
void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr)
{
n_ptr->links[l_ptr->b_ptr->identity] = NULL;
tipc_net.links--;
n_ptr->link_cnt--;
}
/*
* Routing table management - five cases to handle:
*
* 1: A link towards a zone/cluster external node comes up.
* => Send a multicast message updating routing tables of all
* system nodes within own cluster that the new destination
* can be reached via this node.
* (node.establishedContact()=>cluster.multicastNewRoute())
*
* 2: A link towards a slave node comes up.
* => Send a multicast message updating routing tables of all
* system nodes within own cluster that the new destination
* can be reached via this node.
* (node.establishedContact()=>cluster.multicastNewRoute())
* => Send a message to the slave node about existence
* of all system nodes within cluster:
* (node.establishedContact()=>cluster.sendLocalRoutes())
*
* 3: A new cluster local system node becomes available.
* => Send message(s) to this particular node containing
* information about all cluster external and slave
* nodes which can be reached via this node.
* (node.establishedContact()==>network.sendExternalRoutes())
* (node.establishedContact()==>network.sendSlaveRoutes())
* => Send messages to all directly connected slave nodes
* containing information about the existence of the new node
* (node.establishedContact()=>cluster.multicastNewRoute())
*
* 4: The link towards a zone/cluster external node or slave
* node goes down.
* => Send a multcast message updating routing tables of all
* nodes within cluster that the new destination can not any
* longer be reached via this node.
* (node.lostAllLinks()=>cluster.bcastLostRoute())
*
* 5: A cluster local system node becomes unavailable.
* => Remove all references to this node from the local
* routing tables. Note: This is a completely node
* local operation.
* (node.lostAllLinks()=>network.removeAsRouter())
* => Send messages to all directly connected slave nodes
* containing information about loss of the node
* (node.establishedContact()=>cluster.multicastLostRoute())
*
*/
static void node_established_contact(struct tipc_node *n_ptr)
{
tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
/* Syncronize broadcast acks */
n_ptr->bclink.acked = tipc_bclink_get_last_sent();
if (n_ptr->bclink.supported) {
tipc_nmap_add(&tipc_bcast_nmap, n_ptr->addr);
if (n_ptr->addr < tipc_own_addr)
tipc_own_tag++;
}
}
static void node_cleanup_finished(unsigned long node_addr)
{
struct tipc_node *n_ptr;
read_lock_bh(&tipc_net_lock);
n_ptr = tipc_node_find(node_addr);
if (n_ptr) {
tipc_node_lock(n_ptr);
n_ptr->cleanup_required = 0;
tipc_node_unlock(n_ptr);
}
read_unlock_bh(&tipc_net_lock);
}
static void node_lost_contact(struct tipc_node *n_ptr)
{
struct tipc_node_subscr *ns, *tns;
char addr_string[16];
u32 i;
/* Clean up broadcast reception remains */
n_ptr->bclink.gap_after = n_ptr->bclink.gap_to = 0;
while (n_ptr->bclink.deferred_head) {
struct sk_buff *buf = n_ptr->bclink.deferred_head;
n_ptr->bclink.deferred_head = buf->next;
buf_discard(buf);
}
if (n_ptr->bclink.defragm) {
buf_discard(n_ptr->bclink.defragm);
n_ptr->bclink.defragm = NULL;
}
if (n_ptr->bclink.supported) {
tipc_bclink_acknowledge(n_ptr,
mod(n_ptr->bclink.acked + 10000));
tipc_nmap_remove(&tipc_bcast_nmap, n_ptr->addr);
if (n_ptr->addr < tipc_own_addr)
tipc_own_tag--;
}
info("Lost contact with %s\n",
tipc_addr_string_fill(addr_string, n_ptr->addr));
/* Abort link changeover */
for (i = 0; i < MAX_BEARERS; i++) {
struct link *l_ptr = n_ptr->links[i];
if (!l_ptr)
continue;
l_ptr->reset_checkpoint = l_ptr->next_in_no;
l_ptr->exp_msg_count = 0;
tipc_link_reset_fragments(l_ptr);
}
/* Notify subscribers */
list_for_each_entry_safe(ns, tns, &n_ptr->nsub, nodesub_list) {
ns->node = NULL;
list_del_init(&ns->nodesub_list);
tipc_k_signal((Handler)ns->handle_node_down,
(unsigned long)ns->usr_handle);
}
/* Prevent re-contact with node until all cleanup is done */
n_ptr->cleanup_required = 1;
tipc_k_signal((Handler)node_cleanup_finished, n_ptr->addr);
}
struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
{
u32 domain;
struct sk_buff *buf;
struct tipc_node *n_ptr;
struct tipc_node_info node_info;
u32 payload_size;
u32 n_num;
if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
if (!tipc_addr_domain_valid(domain))
return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
" (network address)");
read_lock_bh(&tipc_net_lock);
if (!tipc_net.nodes) {
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_none();
}
/* For now, get space for all other nodes */
payload_size = TLV_SPACE(sizeof(node_info)) *
(tipc_net.highest_node - 1);
if (payload_size > 32768u) {
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
" (too many nodes)");
}
buf = tipc_cfg_reply_alloc(payload_size);
if (!buf) {
read_unlock_bh(&tipc_net_lock);
return NULL;
}
/* Add TLVs for all nodes in scope */
for (n_num = 1; n_num <= tipc_net.highest_node; n_num++) {
n_ptr = tipc_net.nodes[n_num];
if (!n_ptr || !tipc_in_scope(domain, n_ptr->addr))
continue;
node_info.addr = htonl(n_ptr->addr);
node_info.up = htonl(tipc_node_is_up(n_ptr));
tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
&node_info, sizeof(node_info));
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
{
u32 domain;
struct sk_buff *buf;
struct tipc_node *n_ptr;
struct tipc_link_info link_info;
u32 payload_size;
u32 n_num;
if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
if (!tipc_addr_domain_valid(domain))
return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
" (network address)");
if (tipc_mode != TIPC_NET_MODE)
return tipc_cfg_reply_none();
read_lock_bh(&tipc_net_lock);
/* Get space for all unicast links + multicast link */
payload_size = TLV_SPACE(sizeof(link_info)) * (tipc_net.links + 1);
if (payload_size > 32768u) {
read_unlock_bh(&tipc_net_lock);
return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
" (too many links)");
}
buf = tipc_cfg_reply_alloc(payload_size);
if (!buf) {
read_unlock_bh(&tipc_net_lock);
return NULL;
}
/* Add TLV for broadcast link */
link_info.dest = htonl(tipc_own_addr & 0xfffff00);
link_info.up = htonl(1);
strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
/* Add TLVs for any other links in scope */
for (n_num = 1; n_num <= tipc_net.highest_node; n_num++) {
u32 i;
n_ptr = tipc_net.nodes[n_num];
if (!n_ptr || !tipc_in_scope(domain, n_ptr->addr))
continue;
tipc_node_lock(n_ptr);
for (i = 0; i < MAX_BEARERS; i++) {
if (!n_ptr->links[i])
continue;
link_info.dest = htonl(n_ptr->addr);
link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
strcpy(link_info.str, n_ptr->links[i]->name);
tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
&link_info, sizeof(link_info));
}
tipc_node_unlock(n_ptr);
}
read_unlock_bh(&tipc_net_lock);
return buf;
}
