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/*
* net/tipc/bcast.c: TIPC broadcast code
*
* Copyright (c) 2004-2006, 2014-2017, Ericsson AB
* Copyright (c) 2004, Intel Corporation.
* 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 <linux/tipc_config.h>
#include "socket.h"
#include "msg.h"
#include "bcast.h"
#include "link.h"
#include "name_table.h"
#define BCLINK_WIN_DEFAULT 50 /* bcast link window size (default) */
#define BCLINK_WIN_MIN 32 /* bcast minimum link window size */
const char tipc_bclink_name[] = "broadcast-link";
/**
* struct tipc_bc_base - base structure for keeping broadcast send state
* @link: broadcast send link structure
* @inputq: data input queue; will only carry SOCK_WAKEUP messages
* @dest: array keeping number of reachable destinations per bearer
* @primary_bearer: a bearer having links to all broadcast destinations, if any
* @bcast_support: indicates if primary bearer, if any, supports broadcast
* @rcast_support: indicates if all peer nodes support replicast
* @rc_ratio: dest count as percentage of cluster size where send method changes
* @bc_threshold: calculated drom rc_ratio; if dests > threshold use broadcast
*/
struct tipc_bc_base {
struct tipc_link *link;
struct sk_buff_head inputq;
int dests[MAX_BEARERS];
int primary_bearer;
bool bcast_support;
bool rcast_support;
int rc_ratio;
int bc_threshold;
};
static struct tipc_bc_base *tipc_bc_base(struct net *net)
{
return tipc_net(net)->bcbase;
}
/* tipc_bcast_get_mtu(): -get the MTU currently used by broadcast link
* Note: the MTU is decremented to give room for a tunnel header, in
* case the message needs to be sent as replicast
*/
int tipc_bcast_get_mtu(struct net *net)
{
return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE;
}
void tipc_bcast_disable_rcast(struct net *net)
{
tipc_bc_base(net)->rcast_support = false;
}
static void tipc_bcbase_calc_bc_threshold(struct net *net)
{
struct tipc_bc_base *bb = tipc_bc_base(net);
int cluster_size = tipc_link_bc_peers(tipc_bc_sndlink(net));
bb->bc_threshold = 1 + (cluster_size * bb->rc_ratio / 100);
}
/* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
* if any, and make it primary bearer
*/
static void tipc_bcbase_select_primary(struct net *net)
{
struct tipc_bc_base *bb = tipc_bc_base(net);
int all_dests = tipc_link_bc_peers(bb->link);
int i, mtu, prim;
bb->primary_bearer = INVALID_BEARER_ID;
bb->bcast_support = true;
if (!all_dests)
return;
for (i = 0; i < MAX_BEARERS; i++) {
if (!bb->dests[i])
continue;
mtu = tipc_bearer_mtu(net, i);
if (mtu < tipc_link_mtu(bb->link))
tipc_link_set_mtu(bb->link, mtu);
bb->bcast_support &= tipc_bearer_bcast_support(net, i);
if (bb->dests[i] < all_dests)
continue;
bb->primary_bearer = i;
/* Reduce risk that all nodes select same primary */
if ((i ^ tipc_own_addr(net)) & 1)
break;
}
prim = bb->primary_bearer;
if (prim != INVALID_BEARER_ID)
bb->bcast_support = tipc_bearer_bcast_support(net, prim);
}
void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
{
struct tipc_bc_base *bb = tipc_bc_base(net);
tipc_bcast_lock(net);
bb->dests[bearer_id]++;
tipc_bcbase_select_primary(net);
tipc_bcast_unlock(net);
}
void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
{
struct tipc_bc_base *bb = tipc_bc_base(net);
tipc_bcast_lock(net);
bb->dests[bearer_id]--;
tipc_bcbase_select_primary(net);
tipc_bcast_unlock(net);
}
/* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
*
* Note that number of reachable destinations, as indicated in the dests[]
* array, may transitionally differ from the number of destinations indicated
* in each sent buffer. We can sustain this. Excess destination nodes will
* drop and never acknowledge the unexpected packets, and missing destinations
* will either require retransmission (if they are just about to be added to
* the bearer), or be removed from the buffer's 'ackers' counter (if they
* just went down)
*/
static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
{
int bearer_id;
struct tipc_bc_base *bb = tipc_bc_base(net);
struct sk_buff *skb, *_skb;
struct sk_buff_head _xmitq;
if (skb_queue_empty(xmitq))
return;
/* The typical case: at least one bearer has links to all nodes */
bearer_id = bb->primary_bearer;
if (bearer_id >= 0) {
tipc_bearer_bc_xmit(net, bearer_id, xmitq);
return;
}
/* We have to transmit across all bearers */
skb_queue_head_init(&_xmitq);
for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
if (!bb->dests[bearer_id])
continue;
skb_queue_walk(xmitq, skb) {
_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
if (!_skb)
break;
__skb_queue_tail(&_xmitq, _skb);
}
tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
}
__skb_queue_purge(xmitq);
__skb_queue_purge(&_xmitq);
}
static void tipc_bcast_select_xmit_method(struct net *net, int dests,
struct tipc_mc_method *method)
{
struct tipc_bc_base *bb = tipc_bc_base(net);
unsigned long exp = method->expires;
/* Broadcast supported by used bearer/bearers? */
if (!bb->bcast_support) {
method->rcast = true;
return;
}
/* Any destinations which don't support replicast ? */
if (!bb->rcast_support) {
method->rcast = false;
return;
}
/* Can current method be changed ? */
method->expires = jiffies + TIPC_METHOD_EXPIRE;
if (method->mandatory || time_before(jiffies, exp))
return;
/* Determine method to use now */
method->rcast = dests <= bb->bc_threshold;
}
/* tipc_bcast_xmit - broadcast the buffer chain to all external nodes
* @net: the applicable net namespace
* @pkts: chain of buffers containing message
* @cong_link_cnt: set to 1 if broadcast link is congested, otherwise 0
* Consumes the buffer chain.
* Returns 0 if success, otherwise errno: -EHOSTUNREACH,-EMSGSIZE
*/
static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
u16 *cong_link_cnt)
{
struct tipc_link *l = tipc_bc_sndlink(net);
struct sk_buff_head xmitq;
int rc = 0;
skb_queue_head_init(&xmitq);
tipc_bcast_lock(net);
if (tipc_link_bc_peers(l))
rc = tipc_link_xmit(l, pkts, &xmitq);
tipc_bcast_unlock(net);
tipc_bcbase_xmit(net, &xmitq);
__skb_queue_purge(pkts);
if (rc == -ELINKCONG) {
*cong_link_cnt = 1;
rc = 0;
}
return rc;
}
/* tipc_rcast_xmit - replicate and send a message to given destination nodes
* @net: the applicable net namespace
* @pkts: chain of buffers containing message
* @dests: list of destination nodes
* @cong_link_cnt: returns number of congested links
* @cong_links: returns identities of congested links
* Returns 0 if success, otherwise errno
*/
static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts,
struct tipc_nlist *dests, u16 *cong_link_
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