https://github.com/torvalds/linux
Tip revision: a99cde438de0c4c0cecc1d1af1a55a75b10bfdef authored by Linus Torvalds on 04 July 2016, 06:01:00 UTC
Linux 4.7-rc6
Linux 4.7-rc6
Tip revision: a99cde4
name_distr.c
/*
* net/tipc/name_distr.c: TIPC name distribution code
*
* Copyright (c) 2000-2006, 2014, Ericsson AB
* Copyright (c) 2005, 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 "link.h"
#include "name_distr.h"
int sysctl_tipc_named_timeout __read_mostly = 2000;
struct distr_queue_item {
struct distr_item i;
u32 dtype;
u32 node;
unsigned long expires;
struct list_head next;
};
/**
* 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);
}
/**
* named_prepare_buf - allocate & initialize a publication message
*/
static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
u32 dest)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
struct tipc_msg *msg;
if (buf != NULL) {
msg = buf_msg(buf);
tipc_msg_init(tn->own_addr, msg, NAME_DISTRIBUTOR, type,
INT_H_SIZE, dest);
msg_set_size(msg, INT_H_SIZE + size);
}
return buf;
}
/**
* tipc_named_publish - tell other nodes about a new publication by this node
*/
struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct sk_buff *buf;
struct distr_item *item;
list_add_tail_rcu(&publ->local_list,
&tn->nametbl->publ_list[publ->scope]);
if (publ->scope == TIPC_NODE_SCOPE)
return NULL;
buf = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
if (!buf) {
pr_warn("Publication distribution failure\n");
return NULL;
}
item = (struct distr_item *)msg_data(buf_msg(buf));
publ_to_item(item, publ);
return buf;
}
/**
* tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
*/
struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
{
struct sk_buff *buf;
struct distr_item *item;
list_del(&publ->local_list);
if (publ->scope == TIPC_NODE_SCOPE)
return NULL;
buf = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
if (!buf) {
pr_warn("Withdrawal distribution failure\n");
return NULL;
}
item = (struct distr_item *)msg_data(buf_msg(buf));
publ_to_item(item, publ);
return buf;
}
/**
* named_distribute - prepare name info for bulk distribution to another node
* @list: list of messages (buffers) to be returned from this function
* @dnode: node to be updated
* @pls: linked list of publication items to be packed into buffer chain
*/
static void named_distribute(struct net *net, struct sk_buff_head *list,
u32 dnode, struct list_head *pls)
{
struct publication *publ;
struct sk_buff *skb = NULL;
struct distr_item *item = NULL;
uint msg_dsz = (tipc_node_get_mtu(net, dnode, 0) / ITEM_SIZE) *
ITEM_SIZE;
uint msg_rem = msg_dsz;
list_for_each_entry(publ, pls, local_list) {
/* Prepare next buffer: */
if (!skb) {
skb = named_prepare_buf(net, PUBLICATION, msg_rem,
dnode);
if (!skb) {
pr_warn("Bulk publication failure\n");
return;
}
item = (struct distr_item *)msg_data(buf_msg(skb));
}
/* Pack publication into message: */
publ_to_item(item, publ);
item++;
msg_rem -= ITEM_SIZE;
/* Append full buffer to list: */
if (!msg_rem) {
__skb_queue_tail(list, skb);
skb = NULL;
msg_rem = msg_dsz;
}
}
if (skb) {
msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
__skb_queue_tail(list, skb);
}
}
/**
* tipc_named_node_up - tell specified node about all publications by this node
*/
void tipc_named_node_up(struct net *net, u32 dnode)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct sk_buff_head head;
__skb_queue_head_init(&head);
rcu_read_lock();
named_distribute(net, &head, dnode,
&tn->nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
named_distribute(net, &head, dnode,
&tn->nametbl->publ_list[TIPC_ZONE_SCOPE]);
rcu_read_unlock();
tipc_node_xmit(net, &head, dnode, 0);
}
/**
* tipc_publ_purge - 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.
*/
static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct publication *p;
spin_lock_bh(&tn->nametbl_lock);
p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
publ->node, publ->ref, publ->key);
if (p)
tipc_node_unsubscribe(net, &p->nodesub_list, addr);
spin_unlock_bh(&tn->nametbl_lock);
if (p != publ) {
pr_err("Unable to remove publication from failed node\n"
" (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
publ->type, publ->lower, publ->node, publ->ref,
publ->key);
}
kfree_rcu(p, rcu);
}
/**
* tipc_dist_queue_purge - remove deferred updates from a node that went down
*/
static void tipc_dist_queue_purge(struct net *net, u32 addr)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct distr_queue_item *e, *tmp;
spin_lock_bh(&tn->nametbl_lock);
list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
if (e->node != addr)
continue;
list_del(&e->next);
kfree(e);
}
spin_unlock_bh(&tn->nametbl_lock);
}
void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
{
struct publication *publ, *tmp;
list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
tipc_publ_purge(net, publ, addr);
tipc_dist_queue_purge(net, addr);
}
/**
* tipc_update_nametbl - try to process a nametable update and notify
* subscribers
*
* tipc_nametbl_lock must be held.
* Returns the publication item if successful, otherwise NULL.
*/
static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
u32 node, u32 dtype)
{
struct publication *publ = NULL;
if (dtype == PUBLICATION) {
publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
ntohl(i->lower),
ntohl(i->upper),
TIPC_CLUSTER_SCOPE, node,
ntohl(i->ref), ntohl(i->key));
if (publ) {
tipc_node_subscribe(net, &publ->nodesub_list, node);
return true;
}
} else if (dtype == WITHDRAWAL) {
publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
ntohl(i->lower),
node, ntohl(i->ref),
ntohl(i->key));
if (publ) {
tipc_node_unsubscribe(net, &publ->nodesub_list, node);
kfree_rcu(publ, rcu);
return true;
}
} else {
pr_warn("Unrecognized name table message received\n");
}
return false;
}
/**
* tipc_named_add_backlog - add a failed name table update to the backlog
*
*/
static void tipc_named_add_backlog(struct net *net, struct distr_item *i,
u32 type, u32 node)
{
struct distr_queue_item *e;
struct tipc_net *tn = net_generic(net, tipc_net_id);
unsigned long now = get_jiffies_64();
e = kzalloc(sizeof(*e), GFP_ATOMIC);
if (!e)
return;
e->dtype = type;
e->node = node;
e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
memcpy(e, i, sizeof(*i));
list_add_tail(&e->next, &tn->dist_queue);
}
/**
* tipc_named_process_backlog - try to process any pending name table updates
* from the network.
*/
void tipc_named_process_backlog(struct net *net)
{
struct distr_queue_item *e, *tmp;
struct tipc_net *tn = net_generic(net, tipc_net_id);
char addr[16];
unsigned long now = get_jiffies_64();
list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
if (time_after(e->expires, now)) {
if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
continue;
} else {
tipc_addr_string_fill(addr, e->node);
pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
e->dtype, ntohl(e->i.type),
ntohl(e->i.lower),
ntohl(e->i.upper),
addr, ntohl(e->i.key));
}
list_del(&e->next);
kfree(e);
}
}
/**
* tipc_named_rcv - process name table update messages sent by another node
*/
void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_msg *msg;
struct distr_item *item;
uint count;
u32 node;
struct sk_buff *skb;
int mtype;
spin_lock_bh(&tn->nametbl_lock);
for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
skb_linearize(skb);
msg = buf_msg(skb);
mtype = msg_type(msg);
item = (struct distr_item *)msg_data(msg);
count = msg_data_sz(msg) / ITEM_SIZE;
node = msg_orignode(msg);
while (count--) {
if (!tipc_update_nametbl(net, item, node, mtype))
tipc_named_add_backlog(net, item, mtype, node);
item++;
}
kfree_skb(skb);
tipc_named_process_backlog(net);
}
spin_unlock_bh(&tn->nametbl_lock);
}
/**
* tipc_named_reinit - re-initialize local publications
*
* This routine is called whenever TIPC networking is enabled.
* All name table entries published by this node are updated to reflect
* the node's new network address.
*/
void tipc_named_reinit(struct net *net)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct publication *publ;
int scope;
spin_lock_bh(&tn->nametbl_lock);
for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
list_for_each_entry_rcu(publ, &tn->nametbl->publ_list[scope],
local_list)
publ->node = tn->own_addr;
spin_unlock_bh(&tn->nametbl_lock);
}