bcast.c

linux 内核源代码

#if (TIPC_BCAST_LOSS_RATE)
	static int rx_count = 0;
#endif
	struct tipc_msg *msg = buf_msg(buf);
	struct node* node = tipc_node_find(msg_prevnode(msg));
	u32 next_in;
	u32 seqno;
	struct sk_buff *deferred;

	msg_dbg(msg, "<BC<<<");

	if (unlikely(!node || !tipc_node_is_up(node) || !node->bclink.supported ||
		     (msg_mc_netid(msg) != tipc_net_id))) {
		buf_discard(buf);
		return;
	}

	if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
		msg_dbg(msg, "<BCNACK<<<");
		if (msg_destnode(msg) == tipc_own_addr) {
			tipc_node_lock(node);
			tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
			tipc_node_unlock(node);
			spin_lock_bh(&bc_lock);
			bcl->stats.recv_nacks++;
			bcl->owner->next = node;   /* remember requestor */
			bclink_retransmit_pkt(msg_bcgap_after(msg),
					      msg_bcgap_to(msg));
			bcl->owner->next = NULL;
			spin_unlock_bh(&bc_lock);
		} else {
			tipc_bclink_peek_nack(msg_destnode(msg),
					      msg_bcast_tag(msg),
					      msg_bcgap_after(msg),
					      msg_bcgap_to(msg));
		}
		buf_discard(buf);
		return;
	}

#if (TIPC_BCAST_LOSS_RATE)
	if (++rx_count == TIPC_BCAST_LOSS_RATE) {
		rx_count = 0;
		buf_discard(buf);
		return;
	}
#endif

	tipc_node_lock(node);
receive:
	deferred = node->bclink.deferred_head;
	next_in = mod(node->bclink.last_in + 1);
	seqno = msg_seqno(msg);

	if (likely(seqno == next_in)) {
		bcl->stats.recv_info++;
		node->bclink.last_in++;
		bclink_set_gap(node);
		if (unlikely(bclink_ack_allowed(seqno))) {
			bclink_send_ack(node);
			bcl->stats.sent_acks++;
		}
		if (likely(msg_isdata(msg))) {
			tipc_node_unlock(node);
			tipc_port_recv_mcast(buf, NULL);
		} else if (msg_user(msg) == MSG_BUNDLER) {
			bcl->stats.recv_bundles++;
			bcl->stats.recv_bundled += msg_msgcnt(msg);
			tipc_node_unlock(node);
			tipc_link_recv_bundle(buf);
		} else if (msg_user(msg) == MSG_FRAGMENTER) {
			bcl->stats.recv_fragments++;
			if (tipc_link_recv_fragment(&node->bclink.defragm,
						    &buf, &msg))
				bcl->stats.recv_fragmented++;
			tipc_node_unlock(node);
			tipc_net_route_msg(buf);
		} else {
			tipc_node_unlock(node);
			tipc_net_route_msg(buf);
		}
		if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
			tipc_node_lock(node);
			buf = deferred;
			msg = buf_msg(buf);
			node->bclink.deferred_head = deferred->next;
			goto receive;
		}
		return;
	} else if (less(next_in, seqno)) {
		u32 gap_after = node->bclink.gap_after;
		u32 gap_to = node->bclink.gap_to;

		if (tipc_link_defer_pkt(&node->bclink.deferred_head,
					&node->bclink.deferred_tail,
					buf)) {
			node->bclink.nack_sync++;
			bcl->stats.deferred_recv++;
			if (seqno == mod(gap_after + 1))
				node->bclink.gap_after = seqno;
			else if (less(gap_after, seqno) && less(seqno, gap_to))
				node->bclink.gap_to = seqno;
		}
		if (bclink_ack_allowed(node->bclink.nack_sync)) {
			if (gap_to != gap_after)
				bclink_send_nack(node);
			bclink_set_gap(node);
		}
	} else {
		bcl->stats.duplicates++;
		buf_discard(buf);
	}
	tipc_node_unlock(node);
}

u32 tipc_bclink_get_last_sent(void)
{
	u32 last_sent = mod(bcl->next_out_no - 1);

	if (bcl->next_out)
		last_sent = mod(buf_seqno(bcl->next_out) - 1);
	return last_sent;
}

u32 tipc_bclink_acks_missing(struct node *n_ptr)
{
	return (n_ptr->bclink.supported &&
		(tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
}


/**
 * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
 *
 * Send through as many bearers as necessary to reach all nodes
 * that support TIPC multicasting.
 *
 * Returns 0 if packet sent successfully, non-zero if not
 */

static int tipc_bcbearer_send(struct sk_buff *buf,
			      struct tipc_bearer *unused1,
			      struct tipc_media_addr *unused2)
{
	static int send_count = 0;

	int bp_index;
	int swap_time;

	/* Prepare buffer for broadcasting (if first time trying to send it) */

	if (likely(!msg_non_seq(buf_msg(buf)))) {
		struct tipc_msg *msg;

		assert(tipc_cltr_bcast_nodes.count != 0);
		bcbuf_set_acks(buf, tipc_cltr_bcast_nodes.count);
		msg = buf_msg(buf);
		msg_set_non_seq(msg);
		msg_set_mc_netid(msg, tipc_net_id);
	}

	/* Determine if bearer pairs should be swapped following this attempt */

	if ((swap_time = (++send_count >= 10)))
		send_count = 0;

	/* Send buffer over bearers until all targets reached */

	bcbearer->remains = tipc_cltr_bcast_nodes;

	for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
		struct bearer *p = bcbearer->bpairs[bp_index].primary;
		struct bearer *s = bcbearer->bpairs[bp_index].secondary;

		if (!p)
			break;	/* no more bearers to try */

		tipc_nmap_diff(&bcbearer->remains, &p->nodes, &bcbearer->remains_new);
		if (bcbearer->remains_new.count == bcbearer->remains.count)
			continue;	/* bearer pair doesn't add anything */

		if (!p->publ.blocked &&
		    !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) {
			if (swap_time && s && !s->publ.blocked)
				goto swap;
			else
				goto update;
		}

		if (!s || s->publ.blocked ||
		    s->media->send_msg(buf, &s->publ, &s->media->bcast_addr))
			continue;	/* unable to send using bearer pair */
swap:
		bcbearer->bpairs[bp_index].primary = s;
		bcbearer->bpairs[bp_index].secondary = p;
update:
		if (bcbearer->remains_new.count == 0)
			return TIPC_OK;

		bcbearer->remains = bcbearer->remains_new;
	}

	/* Unable to reach all targets */

	bcbearer->bearer.publ.blocked = 1;
	bcl->stats.bearer_congs++;
	return ~TIPC_OK;
}

/**
 * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
 */

void tipc_bcbearer_sort(void)
{
	struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
	struct bcbearer_pair *bp_curr;
	int b_index;
	int pri;

	spin_lock_bh(&bc_lock);

	/* Group bearers by priority (can assume max of two per priority) */

	memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));

	for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
		struct bearer *b = &tipc_bearers[b_index];

		if (!b->active || !b->nodes.count)
			continue;

		if (!bp_temp[b->priority].primary)
			bp_temp[b->priority].primary = b;
		else
			bp_temp[b->priority].secondary = b;
	}

	/* Create array of bearer pairs for broadcasting */

	bp_curr = bcbearer->bpairs;
	memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));

	for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {

		if (!bp_temp[pri].primary)
			continue;

		bp_curr->primary = bp_temp[pri].primary;

		if (bp_temp[pri].secondary) {
			if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
					    &bp_temp[pri].secondary->nodes)) {
				bp_curr->secondary = bp_temp[pri].secondary;
			} else {
				bp_curr++;
				bp_curr->primary = bp_temp[pri].secondary;
			}
		}

		bp_curr++;
	}

	spin_unlock_bh(&bc_lock);
}

/**
 * tipc_bcbearer_push - resolve bearer congestion
 *
 * Forces bclink to push out any unsent packets, until all packets are gone
 * or congestion reoccurs.
 * No locks set when function called
 */

void tipc_bcbearer_push(void)
{
	struct bearer *b_ptr;

	spin_lock_bh(&bc_lock);
	b_ptr = &bcbearer->bearer;
	if (b_ptr->publ.blocked) {
		b_ptr->publ.blocked = 0;
		tipc_bearer_lock_push(b_ptr);
	}
	spin_unlock_bh(&bc_lock);
}


int tipc_bclink_stats(char *buf, const u32 buf_size)
{
	struct print_buf pb;

	if (!bcl)
		return 0;

	tipc_printbuf_init(&pb, buf, buf_size);

	spin_lock_bh(&bc_lock);

	tipc_printf(&pb, "Link <%s>\n"
			 "  Window:%u packets\n",
		    bcl->name, bcl->queue_limit[0]);
	tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
		    bcl->stats.recv_info,
		    bcl->stats.recv_fragments,
		    bcl->stats.recv_fragmented,
		    bcl->stats.recv_bundles,
		    bcl->stats.recv_bundled);
	tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
		    bcl->stats.sent_info,
		    bcl->stats.sent_fragments,
		    bcl->stats.sent_fragmented,
		    bcl->stats.sent_bundles,
		    bcl->stats.sent_bundled);
	tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n",
		    bcl->stats.recv_nacks,
		    bcl->stats.deferred_recv,
		    bcl->stats.duplicates);
	tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n",
		    bcl->stats.sent_nacks,
		    bcl->stats.sent_acks,
		    bcl->stats.retransmitted);
	tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
		    bcl->stats.bearer_congs,
		    bcl->stats.link_congs,
		    bcl->stats.max_queue_sz,
		    bcl->stats.queue_sz_counts
		    ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
		    : 0);

	spin_unlock_bh(&bc_lock);
	return tipc_printbuf_validate(&pb);
}

int tipc_bclink_reset_stats(void)
{
	if (!bcl)
		return -ENOPROTOOPT;

	spin_lock_bh(&bc_lock);
	memset(&bcl->stats, 0, sizeof(bcl->stats));
	spin_unlock_bh(&bc_lock);
	return TIPC_OK;
}

int tipc_bclink_set_queue_limits(u32 limit)
{
	if (!bcl)
		return -ENOPROTOOPT;
	if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
		return -EINVAL;

	spin_lock_bh(&bc_lock);
	tipc_link_set_queue_limits(bcl, limit);
	spin_unlock_bh(&bc_lock);
	return TIPC_OK;
}

int tipc_bclink_init(void)
{
	bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC);
	bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC);
	if (!bcbearer || !bclink) {
 nomem:
		warn("Multicast link creation failed, no memory\n");
		kfree(bcbearer);
		bcbearer = NULL;
		kfree(bclink);
		bclink = NULL;
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
	bcbearer->bearer.media = &bcbearer->media;
	bcbearer->media.send_msg = tipc_bcbearer_send;
	sprintf(bcbearer->media.name, "tipc-multicast");

	bcl = &bclink->link;
	INIT_LIST_HEAD(&bcl->waiting_ports);
	bcl->next_out_no = 1;
	spin_lock_init(&bclink->node.lock);
	bcl->owner = &bclink->node;
	bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
	tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
	bcl->b_ptr = &bcbearer->bearer;
	bcl->state = WORKING_WORKING;
	sprintf(bcl->name, tipc_bclink_name);

	if (BCLINK_LOG_BUF_SIZE) {
		char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC);

		if (!pb)
			goto nomem;
		tipc_printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE);
	}

	return TIPC_OK;
}

void tipc_bclink_stop(void)
{
	spin_lock_bh(&bc_lock);
	if (bcbearer) {
		tipc_link_stop(bcl);
		if (BCLINK_LOG_BUF_SIZE)
			kfree(bcl->print_buf.buf);
		bcl = NULL;
		kfree(bclink);
		bclink = NULL;
		kfree(bcbearer);
		bcbearer = NULL;
	}
	spin_unlock_bh(&bc_lock);
}