/*
* net/tipc/discover.c
*
* Copyright (c) 2003-2006, Ericsson AB
* Copyright (c) 2005-2006, 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 "discover.h"
#define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
#define TIPC_LINK_REQ_FAST 2000 /* normal delay if bearer has no links */
#define TIPC_LINK_REQ_SLOW 600000 /* normal delay if bearer has links */
/*
* TODO: Most of the inter-cluster setup stuff should be
* rewritten, and be made conformant with specification.
*/
/**
* struct link_req - information about an ongoing link setup request
* @bearer: bearer issuing requests
* @dest: destination address for request messages
* @buf: request message to be (repeatedly) sent
* @timer: timer governing period between requests
* @timer_intv: current interval between requests (in ms)
*/
struct link_req {
struct tipc_bearer *bearer;
struct tipc_media_addr dest;
struct sk_buff *buf;
struct timer_list timer;
unsigned int timer_intv;
};
/**
* tipc_disc_init_msg - initialize a link setup message
* @type: message type (request or response)
* @req_links: number of links associated with message
* @dest_domain: network domain of node(s) which should respond to message
* @b_ptr: ptr to bearer issuing message
*/
static struct sk_buff *tipc_disc_init_msg(u32 type,
u32 req_links,
u32 dest_domain,
struct tipc_bearer *b_ptr)
{
struct sk_buff *buf = tipc_buf_acquire(DSC_H_SIZE);
struct tipc_msg *msg;
if (buf) {
msg = buf_msg(buf);
tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain);
msg_set_non_seq(msg, 1);
msg_set_req_links(msg, req_links);
msg_set_dest_domain(msg, dest_domain);
msg_set_bc_netid(msg, tipc_net_id);
msg_set_media_addr(msg, &b_ptr->addr);
}
return buf;
}
/**
* disc_dupl_alert - issue node address duplication alert
* @b_ptr: pointer to bearer detecting duplication
* @node_addr: duplicated node address
* @media_addr: media address advertised by duplicated node
*/
static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
struct tipc_media_addr *media_addr)
{
char node_addr_str[16];
char media_addr_str[64];
struct print_buf pb;
tipc_addr_string_fill(node_addr_str, node_addr);
tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
tipc_media_addr_printf(&pb, media_addr);
tipc_printbuf_validate(&pb);
warn("Duplicate %s using %s seen on <%s>\n",
node_addr_str, media_addr_str, b_ptr->name);
}
/**
* 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 link *link;
struct tipc_media_addr media_addr;
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);
msg_get_media_addr(msg, &media_addr);
buf_discard(buf);
if (net_id != tipc_net_id)
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 (in_own_cluster(orig)) {
/* Always accept link here */
struct sk_buff *rbuf;
struct tipc_media_addr *addr;
struct tipc_node *n_ptr = tipc_node_find(orig);
int link_fully_up;
if (n_ptr == NULL) {
n_ptr = tipc_node_create(orig);
if (!n_ptr)
return;
}
spin_lock_bh(&n_ptr->lock);
/* Don't talk to neighbor during cleanup after last session */
if (n_ptr->cleanup_required) {
spin_unlock_bh(&n_ptr->lock);
return;
}
link = n_ptr->links[b_ptr->identity];
if (!link) {
link = tipc_link_create(b_ptr, orig, &media_addr);
if (!link) {
spin_unlock_bh(&n_ptr->lock);
return;
}
}
addr = &link->media_addr;
if (memcmp(addr, &media_addr, sizeof(*addr))) {
if (tipc_link_is_up(link) || (!link->started)) {
disc_dupl_alert(b_ptr, orig, &media_addr);
spin_unlock_bh(&n_ptr->lock);
return;
}
warn("Resetting link <%s>, peer interface address changed\n",
link->name);
memcpy(addr, &media_addr, sizeof(*addr));
tipc_link_reset(link);
}
link_fully_up = link_working_working(link);
spin_unlock_bh(&n_ptr->lock);
if ((type == DSC_RESP_MSG) || link_fully_up)
return;
rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
if (rbuf != NULL) {
b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
buf_discard(rbuf);
}
}
}
/**
* tipc_disc_stop_link_req - stop sending periodic link setup requests
* @req: ptr to link request structure
*/
void tipc_disc_stop_link_req(struct link_req *req)
{
if (!req)
return;
k_cancel_timer(&req->timer);
k_term_timer(&req->timer);
buf_discard(req->buf);
kfree(req);
}
/**
* tipc_disc_update_link_req - update frequency of periodic link setup requests
* @req: ptr to link request structure
*/
void tipc_disc_update_link_req(struct link_req *req)
{
if (!req)
return;
if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
if (!req->bearer->nodes.count) {
req->timer_intv = TIPC_LINK_REQ_FAST;
k_start_timer(&req->timer, req->timer_intv);
}
} else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
if (req->bearer->nodes.count) {
req->timer_intv = TIPC_LINK_REQ_SLOW;
k_start_timer(&req->timer, req->timer_intv);
}
} else {
/* leave timer "as is" if haven't yet reached a "normal" rate */
}
}
/**
* disc_timeout - send a periodic link setup request
* @req: ptr to link request structure
*
* Called whenever a link setup request timer associated with a bearer expires.
*/
static void disc_timeout(struct link_req *req)
{
spin_lock_bh(&req->bearer->lock);
req->bearer->media->send_msg(req->buf, req->bearer, &req->dest);
if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
(req->timer_intv == TIPC_LINK_REQ_FAST)) {
/* leave timer interval "as is" if already at a "normal" rate */
} else {
req->timer_intv *= 2;
if (req->timer_intv > TIPC_LINK_REQ_FAST)
req->timer_intv = TIPC_LINK_REQ_FAST;
if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
(req->bearer->nodes.count))
req->timer_intv = TIPC_LINK_REQ_SLOW;
}
k_start_timer(&req->timer, req->timer_intv);
spin_unlock_bh(&req->bearer->lock);
}
/**
* tipc_disc_init_link_req - start sending periodic link setup requests
* @b_ptr: ptr to bearer issuing requests
* @dest: destination address for request messages
* @dest_domain: network domain of node(s) which should respond to message
* @req_links: max number of desired links
*
* Returns pointer to link request structure, or NULL if unable to create.
*/
struct link_req *tipc_disc_init_link_req(struct tipc_bearer *b_ptr,
const struct tipc_media_addr *dest,
u32 dest_domain,
u32 req_links)
{
struct link_req *req;
req = kmalloc(sizeof(*req), GFP_ATOMIC);
if (!req)
return NULL;
req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
if (!req->buf) {
kfree(req);
return NULL;
}
memcpy(&req->dest, dest, sizeof(*dest));
req->bearer = b_ptr;
req->timer_intv = TIPC_LINK_REQ_INIT;
k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
k_start_timer(&req->timer, req->timer_intv);
return req;
}
