static void bclink_send_nack(struct tipc_node *n_ptr)
{
struct sk_buff *buf;
struct tipc_msg *msg;
if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
return;
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
msg = buf_msg(buf);
tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
INT_H_SIZE, n_ptr->addr);
msg_set_non_seq(msg, 1);
msg_set_mc_netid(msg, tipc_net_id);
msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in));
msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
msg_set_bcast_tag(msg, tipc_own_tag);
tipc_bearer_send(&bcbearer->bearer, buf, NULL);
bcl->stats.sent_nacks++;
buf_discard(buf);
/*
* Ensure we doesn't send another NACK msg to the node
* until 16 more deferred messages arrive from it
* (i.e. helps prevent all nodes from NACK'ing at same time)
*/
n_ptr->bclink.nack_sync = tipc_own_tag;
}
}
/**
* tipc_bclink_update_link_state - update broadcast link state
*
* tipc_net_lock and node lock set
*/
void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
{
struct sk_buff *buf;
/* Ignore "stale" link state info */
if (less_eq(last_sent, n_ptr->bclink.last_in))
return;
/* Update link synchronization state; quit if in sync */
bclink_update_last_sent(n_ptr, last_sent);
if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
return;
/* Update out-of-sync state; quit if loss is still unconfirmed */
if ((++n_ptr->bclink.oos_state) == 1) {
if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
return;
n_ptr->bclink.oos_state++;
}
/* Don't NACK if one has been recently sent (or seen) */
if (n_ptr->bclink.oos_state & 0x1)
return;
/* Send NACK */
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
struct tipc_msg *msg = buf_msg(buf);
tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
INT_H_SIZE, n_ptr->addr);
msg_set_non_seq(msg, 1);
msg_set_mc_netid(msg, tipc_net_id);
msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
? buf_seqno(n_ptr->bclink.deferred_head) - 1
: n_ptr->bclink.last_sent);
spin_lock_bh(&bc_lock);
tipc_bearer_send(&bcbearer->bearer, buf, NULL);
bcl->stats.sent_nacks++;
spin_unlock_bh(&bc_lock);
kfree_skb(buf);
n_ptr->bclink.oos_state++;
}
}
/**
* tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
*
* Send packet over as many bearers as necessary to reach all nodes
* that have joined the broadcast link.
*
* Returns 0 (packet sent successfully) under all circumstances,
* since the broadcast link's pseudo-bearer never blocks
*/
static int tipc_bcbearer_send(struct sk_buff *buf,
struct tipc_bearer *unused1,
struct tipc_media_addr *unused2)
{
int bp_index;
/* Prepare broadcast link message for reliable transmission,
* if first time trying to send it;
* preparation is skipped for broadcast link protocol messages
* since they are sent in an unreliable manner and don't need it
*/
if (likely(!msg_non_seq(buf_msg(buf)))) {
struct tipc_msg *msg;
bcbuf_set_acks(buf, bclink->bcast_nodes.count);
msg = buf_msg(buf);
msg_set_non_seq(msg, 1);
msg_set_mc_netid(msg, tipc_net_id);
bcl->stats.sent_info++;
if (WARN_ON(!bclink->bcast_nodes.count)) {
dump_stack();
return 0;
}
}
/* Send buffer over bearers until all targets reached */
bcbearer->remains = bclink->bcast_nodes;
for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
struct tipc_bearer *b = p;
struct sk_buff *tbuf;
if (!p)
break; /* No more bearers to try */
if (tipc_bearer_blocked(p)) {
if (!s || tipc_bearer_blocked(s))
continue; /* Can't use either bearer */
b = s;
}
tipc_nmap_diff(&bcbearer->remains, &b->nodes,
&bcbearer->remains_new);
if (bcbearer->remains_new.count == bcbearer->remains.count)
continue; /* Nothing added by bearer pair */
if (bp_index == 0) {
/* Use original buffer for first bearer */
tipc_bearer_send(b, buf, &b->bcast_addr);
} else {
/* Avoid concurrent buffer access */
tbuf = pskb_copy(buf, GFP_ATOMIC);
if (!tbuf)
break;
tipc_bearer_send(b, tbuf, &b->bcast_addr);
kfree_skb(tbuf); /* Bearer keeps a clone */
}
/* Swap bearers for next packet */
if (s) {
bcbearer->bpairs[bp_index].primary = s;
bcbearer->bpairs[bp_index].secondary = p;
}
if (bcbearer->remains_new.count == 0)
break; /* All targets reached */
bcbearer->remains = bcbearer->remains_new;
}
return 0;
}
static void disc_send_msg(struct tipc_link_req *req)
{
if (!req->bearer->blocked)
tipc_bearer_send(req->bearer, req->buf, &req->dest);
}
/**
* tipc_disc_recv_msg - handle incoming link setup message (request or response)
* @buf: buffer containing message
* @b_ptr: bearer that message arrived on
*/
void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
{
struct tipc_node *n_ptr;
struct tipc_link *link;
struct tipc_media_addr media_addr;
struct sk_buff *rbuf;
struct tipc_msg *msg = buf_msg(buf);
u32 dest = msg_dest_domain(msg);
u32 orig = msg_prevnode(msg);
u32 net_id = msg_bc_netid(msg);
u32 type = msg_type(msg);
u32 signature = msg_node_sig(msg);
int addr_mismatch;
int link_fully_up;
media_addr.broadcast = 1;
b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg));
kfree_skb(buf);
/* Ensure message from node is valid and communication is permitted */
if (net_id != tipc_net_id)
return;
if (media_addr.broadcast)
return;
if (!tipc_addr_domain_valid(dest))
return;
if (!tipc_addr_node_valid(orig))
return;
if (orig == tipc_own_addr) {
if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
return;
}
if (!tipc_in_scope(dest, tipc_own_addr))
return;
if (!tipc_in_scope(b_ptr->link_req->domain, orig))
return;
/* Locate structure corresponding to requesting node */
n_ptr = tipc_node_find(orig);
if (!n_ptr) {
n_ptr = tipc_node_create(orig);
if (!n_ptr)
return;
}
tipc_node_lock(n_ptr);
/* Prepare to validate requesting node's signature and media address */
link = n_ptr->links[b_ptr->identity];
addr_mismatch = (link != NULL) &&
memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
/*
* Ensure discovery message's signature is correct
*
* If signature is incorrect and there is no working link to the node,
* accept the new signature but invalidate all existing links to the
* node so they won't re-activate without a new discovery message.
*
* If signature is incorrect and the requested link to the node is
* working, accept the new signature. (This is an instance of delayed
* rediscovery, where a link endpoint was able to re-establish contact
* with its peer endpoint on a node that rebooted before receiving a
* discovery message from that node.)
*
* If signature is incorrect and there is a working link to the node
* that is not the requested link, reject the request (must be from
* a duplicate node).
*/
if (signature != n_ptr->signature) {
if (n_ptr->working_links == 0) {
struct tipc_link *curr_link;
int i;
for (i = 0; i < MAX_BEARERS; i++) {
curr_link = n_ptr->links[i];
if (curr_link) {
memset(&curr_link->media_addr, 0,
sizeof(media_addr));
tipc_link_reset(curr_link);
}
}
addr_mismatch = (link != NULL);
} else if (tipc_link_is_up(link) && !addr_mismatch) {
/* delayed rediscovery */
} else {
disc_dupl_alert(b_ptr, orig, &media_addr);
tipc_node_unlock(n_ptr);
return;
}
n_ptr->signature = signature;
}
/*
* Ensure requesting node's media address is correct
*
* If media address doesn't match and the link is working, reject the
* request (must be from a duplicate node).
*
* If media address doesn't match and the link is not working, accept
* the new media address and reset the link to ensure it starts up
* cleanly.
*/
if (addr_mismatch) {
if (tipc_link_is_up(link)) {
disc_dupl_alert(b_ptr, orig, &media_addr);
tipc_node_unlock(n_ptr);
return;
} else {
memcpy(&link->media_addr, &media_addr,
sizeof(media_addr));
tipc_link_reset(link);
}
}
/* Create a link endpoint for this bearer, if necessary */
if (!link) {
link = tipc_link_create(n_ptr, b_ptr, &media_addr);
if (!link) {
tipc_node_unlock(n_ptr);
return;
}
}
/* Accept discovery message & send response, if necessary */
link_fully_up = link_working_working(link);
if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) {
rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
if (rbuf) {
tipc_bearer_send(b_ptr, rbuf, &media_addr);
kfree_skb(rbuf);
}
}
tipc_node_unlock(n_ptr);
}