/*
* net/tipc/name_distr.c: TIPC name distribution code
*
* Copyright (c) 2000-2006, Ericsson AB
* Copyright (c) 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 "cluster.h"
#include "dbg.h"
#include "link.h"
#include "msg.h"
#include "name_distr.h"
#undef DBG_OUTPUT
#define DBG_OUTPUT NULL
#define ITEM_SIZE sizeof(struct distr_item)
/**
* struct distr_item - publication info distributed to other nodes
* @type: name sequence type
* @lower: name sequence lower bound
* @upper: name sequence upper bound
* @ref: publishing port reference
* @key: publication key
*
* ===> All fields are stored in network byte order. <===
*
* First 3 fields identify (name or) name sequence being published.
* Reference field uniquely identifies port that published name sequence.
* Key field uniquely identifies publication, in the event a port has
* multiple publications of the same name sequence.
*
* Note: There is no field that identifies the publishing node because it is
* the same for all items contained within a publication message.
*/
struct distr_item {
u32 type;
u32 lower;
u32 upper;
u32 ref;
u32 key;
};
/**
* List of externally visible publications by this node --
* that is, all publications having scope > TIPC_NODE_SCOPE.
*/
static LIST_HEAD(publ_root);
static u32 publ_cnt = 0;
/**
* publ_to_item - add publication info to a publication message
*/
static void publ_to_item(struct distr_item *i, struct publication *p)
{
i->type = htonl(p->type);
i->lower = htonl(p->lower);
i->upper = htonl(p->upper);
i->ref = htonl(p->ref);
i->key = htonl(p->key);
dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
}
/**
* named_prepare_buf - allocate & initialize a publication message
*/
static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
{
struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
struct tipc_msg *msg;
if (buf != NULL) {
msg = buf_msg(buf);
msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK,
LONG_H_SIZE, dest);
msg_set_size(msg, LONG_H_SIZE + size);
}
return buf;
}
/**
* named_publish - tell other nodes about a new publication by this node
*/
void named_publish(struct publication *publ)
{
struct sk_buff *buf;
struct distr_item *item;
list_add(&publ->local_list, &publ_root);
publ_cnt++;
buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
if (!buf) {
warn("Memory squeeze; failed to distribute publication\n");
return;
}
item = (struct distr_item *)msg_data(buf_msg(buf));
publ_to_item(item, publ);
dbg("named_withdraw: broadcasting publish msg\n");
cluster_broadcast(buf);
}
/**
* named_withdraw - tell other nodes about a withdrawn publication by this node
*/
void named_withdraw(struct publication *publ)
{
struct sk_buff *buf;
struct distr_item *item;
list_del(&publ->local_list);
publ_cnt--;
buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
if (!buf) {
warn("Memory squeeze; failed to distribute withdrawal\n");
return;
}
item = (struct distr_item *)msg_data(buf_msg(buf));
publ_to_item(item, publ);
dbg("named_withdraw: broadcasting withdraw msg\n");
cluster_broadcast(buf);
}
/**
* named_node_up - tell specified node about all publications by this node
*/
void named_node_up(unsigned long node)
{
struct publication *publ;
struct distr_item *item = 0;
struct sk_buff *buf = 0;
u32 left = 0;
u32 rest;
u32 max_item_buf;
assert(in_own_cluster(node));
read_lock_bh(&nametbl_lock);
max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
max_item_buf *= ITEM_SIZE;
rest = publ_cnt * ITEM_SIZE;
list_for_each_entry(publ, &publ_root, local_list) {
if (!buf) {
left = (rest <= max_item_buf) ? rest : max_item_buf;
rest -= left;
buf = named_prepare_buf(PUBLICATION, left, node);
if (buf == NULL) {
warn("Memory Squeeze; could not send publication\n");
goto exit;
}
item = (struct distr_item *)msg_data(buf_msg(buf));
}
publ_to_item(item, publ);
item++;
left -= ITEM_SIZE;
if (!left) {
msg_set_link_selector(buf_msg(buf), node);
dbg("named_node_up: sending publish msg to "
"<%u.%u.%u>\n", tipc_zone(node),
tipc_cluster(node), tipc_node(node));
link_send(buf, node, node);
buf = 0;
}
}
exit:
read_unlock_bh(&nametbl_lock);
}
/**
* node_is_down - remove publication associated with a failed node
*
* Invoked for each publication issued by a newly failed node.
* Removes publication structure from name table & deletes it.
* In rare cases the link may have come back up again when this
* function is called, and we have two items representing the same
* publication. Nudge this item's key to distinguish it from the other.
* (Note: Publication's node subscription is already unsubscribed.)
*/
static void node_is_down(struct publication *publ)
{
struct publication *p;
write_lock_bh(&nametbl_lock);
dbg("node_is_down: withdrawing %u, %u, %u\n",
publ->type, publ->lower, publ->upper);
publ->key += 1222345;
p = nametbl_remove_publ(publ->type, publ->lower,
publ->node, publ->ref, publ->key);
assert(p == publ);
write_unlock_bh(&nametbl_lock);
if (publ)
kfree(publ);
}
/**
* named_recv - process name table update message sent by another node
*/
void named_recv(struct sk_buff *buf)
{
struct publication *publ;
struct tipc_msg *msg = buf_msg(buf);
struct distr_item *item = (struct distr_item *)msg_data(msg);
u32 count = msg_data_sz(msg) / ITEM_SIZE;
write_lock_bh(&nametbl_lock);
while (count--) {
if (msg_type(msg) == PUBLICATION) {
dbg("named_recv: got publication for %u, %u, %u\n",
ntohl(item->type), ntohl(item->lower),
ntohl(item->upper));
publ = nametbl_insert_publ(ntohl(item->type),
ntohl(item->lower),
ntohl(item->upper),
TIPC_CLUSTER_SCOPE,
msg_orignode(msg),
ntohl(item->ref),
ntohl(item->key));
if (publ) {
nodesub_subscribe(&publ->subscr,
msg_orignode(msg),
publ,
(net_ev_handler)node_is_down);
}
} else if (msg_type(msg) == WITHDRAWAL) {
dbg("named_recv: got withdrawl for %u, %u, %u\n",
ntohl(item->type), ntohl(item->lower),
ntohl(item->upper));
publ = nametbl_remove_publ(ntohl(item->type),
ntohl(item->lower),
msg_orignode(msg),
ntohl(item->ref),
ntohl(item->key));
if (publ) {
nodesub_unsubscribe(&publ->subscr);
kfree(publ);
}
} else {
warn("named_recv: unknown msg\n");
}
item++;
}
write_unlock_bh(&nametbl_lock);
buf_discard(buf);
}
/**
* named_reinit - re-initialize local publication list
*
* This routine is called whenever TIPC networking is (re)enabled.
* All existing publications by this node that have "cluster" or "zone" scope
* are updated to reflect the node's current network address.
* (If the node's address is unchanged, the update loop terminates immediately.)
*/
void named_reinit(void)
{
struct publication *publ;
write_lock_bh(&nametbl_lock);
list_for_each_entry(publ, &publ_root, local_list) {
if (publ->node == tipc_own_addr)
break;
publ->node = tipc_own_addr;
}
write_unlock_bh(&nametbl_lock);
}
