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/*
* net/tipc/bcast.c: TIPC broadcast code
*
* Copyright (c) 2004-2006, Ericsson AB
* Copyright (c) 2004, Intel Corporation.
* 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 "msg.h"
#include "dbg.h"
#include "link.h"
#include "net.h"
#include "node.h"
#include "port.h"
#include "addr.h"
#include "node_subscr.h"
#include "name_distr.h"
#include "bearer.h"
#include "name_table.h"
#include "bcast.h"
#define MAX_PKT_DEFAULT_MCAST 1500 /* bcast link max packet size (fixed) */
#define BCLINK_WIN_DEFAULT 20 /* bcast link window size (default) */
#define BCLINK_LOG_BUF_SIZE 0
/*
* Loss rate for incoming broadcast frames; used to test retransmission code.
* Set to N to cause every N'th frame to be discarded; 0 => don't discard any.
*/
#define TIPC_BCAST_LOSS_RATE 0
/**
* struct bcbearer_pair - a pair of bearers used by broadcast link
* @primary: pointer to primary bearer
* @secondary: pointer to secondary bearer
*
* Bearers must have same priority and same set of reachable destinations
* to be paired.
*/
struct bcbearer_pair {
struct bearer *primary;
struct bearer *secondary;
};
/**
* struct bcbearer - bearer used by broadcast link
* @bearer: (non-standard) broadcast bearer structure
* @media: (non-standard) broadcast media structure
* @bpairs: array of bearer pairs
* @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort()
* @remains: temporary node map used by tipc_bcbearer_send()
* @remains_new: temporary node map used tipc_bcbearer_send()
*
* Note: The fields labelled "temporary" are incorporated into the bearer
* to avoid consuming potentially limited stack space through the use of
* large local variables within multicast routines. Concurrent access is
* prevented through use of the spinlock "bc_lock".
*/
struct bcbearer {
struct bearer bearer;
struct media media;
struct bcbearer_pair bpairs[MAX_BEARERS];
struct bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
struct tipc_node_map remains;
struct tipc_node_map remains_new;
};
/**
* struct bclink - link used for broadcast messages
* @link: (non-standard) broadcast link structure
* @node: (non-standard) node structure representing b'cast link's peer node
*
* Handles sequence numbering, fragmentation, bundling, etc.
*/
struct bclink {
struct link link;
struct tipc_node node;
};
static struct bcbearer *bcbearer = NULL;
static struct bclink *bclink = NULL;
static struct link *bcl = NULL;
static DEFINE_SPINLOCK(bc_lock);
char tipc_bclink_name[] = "multicast-link";
static u32 buf_seqno(struct sk_buff *buf)
{
return msg_seqno(buf_msg(buf));
}
static u32 bcbuf_acks(struct sk_buff *buf)
{
return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
}
static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
{
TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
}
static void bcbuf_decr_acks(struct sk_buff *buf)
{
bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
}
/**
* bclink_set_gap - set gap according to contents of current deferred pkt queue
*
* Called with 'node' locked, bc_lock unlocked
*/
static void bclink_set_gap(struct tipc_node *n_ptr)
{
struct sk_buff *buf = n_ptr->bclink.deferred_head;
n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
mod(n_ptr->bclink.last_in);
if (unlikely(buf != NULL))
n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
}
/**
* bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
*
* This mechanism endeavours to prevent all nodes in network from trying
* to ACK or NACK at the same time.
*
* Note: TIPC uses a different trigger to distribute ACKs than it does to
* distribute NACKs, but tries to use the same spacing (divide by 16).
*/
static int bclink_ack_allowed(u32 n)
{
return((n % TIPC_MIN_LINK_WIN) == tipc_own_tag);
}
/**
* bclink_retransmit_pkt - retransmit broadcast packets
* @after: sequence number of last packet to *not* retransmit
* @to: sequence number of last packet to retransmit
*
* Called with bc_lock locked
*/
static void bclink_retransmit_pkt(u32 after, u32 to)
{
struct sk_buff *buf;
buf = bcl->first_out;
while (buf && less_eq(buf_seqno(buf), after)) {
buf = buf->next;
}
tipc_link_retransmit(bcl, buf, mod(to - after));
}
/**
* tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
* @n_ptr: node that sent acknowledgement info
* @acked: broadcast sequence # that has been acknowledged
*
* Node is locked, bc_lock unlocked.
*/
void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
{
struct sk_buff *crs;
struct sk_buff *next;
unsigned int released = 0;
if (less_eq(acked, n_ptr->bclink.acked))
return;
spin_lock_bh(&bc_lock);
/* Skip over packets that node has previously acknowledged */
crs = bcl->first_out;
while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) {
crs = crs->next;
}
/* Update packets that node is now acknowledging */
while (crs && less_eq(buf_seqno(crs), acked)) {
next = crs->next;
bcbuf_decr_acks(crs);
if (bcbuf_acks(crs) == 0) {
bcl->first_out = next;
bcl->out_queue_size--;
buf_discard(crs);
released = 1;
}
crs = next;
}
n_ptr->bclink.acked = acked;
/* Try resolving broadcast link congestion, if necessary */
if (unlikely(bcl->next_out))
tipc_link_push_queue(bcl);
if (unlikely(released && !list_empty(&bcl->waiting_ports)))
tipc_link_wakeup_ports(bcl, 0);
spin_unlock_bh(&bc_lock);
}
/**
* bclink_send_ack - unicast an ACK msg
*
* tipc_net_lock and node lock set
*/
static void bclink_send_ack(struct tipc_node *n_ptr)
{
struct link *l_ptr = n_ptr->active_links[n_ptr->addr
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