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Per Lidenb97bf3f2006-01-02 19:04:38 +01001/*
2 * net/tipc/discover.c
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +09003 *
Per Liden9da1c8b2006-01-11 18:40:41 +01004 * Copyright (c) 2003-2006, Ericsson AB
Allan Stephens2d627b92011-01-07 13:00:11 -05005 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
Per Lidenb97bf3f2006-01-02 19:04:38 +01006 * All rights reserved.
7 *
Per Liden9ea1fd32006-01-11 13:30:43 +01008 * Redistribution and use in source and binary forms, with or without
Per Lidenb97bf3f2006-01-02 19:04:38 +01009 * modification, are permitted provided that the following conditions are met:
10 *
Per Liden9ea1fd32006-01-11 13:30:43 +010011 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
Per Lidenb97bf3f2006-01-02 19:04:38 +010019 *
Per Liden9ea1fd32006-01-11 13:30:43 +010020 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
Per Lidenb97bf3f2006-01-02 19:04:38 +010034 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include "core.h"
Per Lidenb97bf3f2006-01-02 19:04:38 +010038#include "link.h"
Per Lidenb97bf3f2006-01-02 19:04:38 +010039#include "discover.h"
Per Lidenb97bf3f2006-01-02 19:04:38 +010040
41#define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
Allan Stephens972a77f2011-04-21 20:34:03 -050042#define TIPC_LINK_REQ_FAST 1000 /* max delay if bearer has no links */
43#define TIPC_LINK_REQ_SLOW 60000 /* max delay if bearer has links */
44#define TIPC_LINK_REQ_INACTIVE 0xffffffff /* indicates no timer in use */
Per Lidenb97bf3f2006-01-02 19:04:38 +010045
46
47/**
48 * struct link_req - information about an ongoing link setup request
49 * @bearer: bearer issuing requests
50 * @dest: destination address for request messages
Allan Stephens66e019a2011-04-20 16:24:07 -050051 * @domain: network domain to which links can be established
Allan Stephens12099662011-04-21 19:05:25 -050052 * @num_nodes: number of nodes currently discovered (i.e. with an active link)
Per Lidenb97bf3f2006-01-02 19:04:38 +010053 * @buf: request message to be (repeatedly) sent
54 * @timer: timer governing period between requests
55 * @timer_intv: current interval between requests (in ms)
56 */
57struct link_req {
Allan Stephens2d627b92011-01-07 13:00:11 -050058 struct tipc_bearer *bearer;
Per Lidenb97bf3f2006-01-02 19:04:38 +010059 struct tipc_media_addr dest;
Allan Stephens66e019a2011-04-20 16:24:07 -050060 u32 domain;
Allan Stephens12099662011-04-21 19:05:25 -050061 int num_nodes;
Per Lidenb97bf3f2006-01-02 19:04:38 +010062 struct sk_buff *buf;
63 struct timer_list timer;
64 unsigned int timer_intv;
65};
66
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +090067/**
Per Liden4323add2006-01-18 00:38:21 +010068 * tipc_disc_init_msg - initialize a link setup message
Per Lidenb97bf3f2006-01-02 19:04:38 +010069 * @type: message type (request or response)
Per Lidenb97bf3f2006-01-02 19:04:38 +010070 * @dest_domain: network domain of node(s) which should respond to message
71 * @b_ptr: ptr to bearer issuing message
72 */
73
Adrian Bunk988f0882006-03-20 22:37:52 -080074static struct sk_buff *tipc_disc_init_msg(u32 type,
Adrian Bunk988f0882006-03-20 22:37:52 -080075 u32 dest_domain,
Allan Stephens2d627b92011-01-07 13:00:11 -050076 struct tipc_bearer *b_ptr)
Per Lidenb97bf3f2006-01-02 19:04:38 +010077{
Allan Stephensd901a422011-02-28 16:02:30 -050078 struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE);
Per Lidenb97bf3f2006-01-02 19:04:38 +010079 struct tipc_msg *msg;
80
81 if (buf) {
82 msg = buf_msg(buf);
Allan Stephensd901a422011-02-28 16:02:30 -050083 tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
Allan Stephens40aecb12008-06-04 17:54:48 -070084 msg_set_non_seq(msg, 1);
Per Lidenb97bf3f2006-01-02 19:04:38 +010085 msg_set_dest_domain(msg, dest_domain);
86 msg_set_bc_netid(msg, tipc_net_id);
Allan Stephens2d627b92011-01-07 13:00:11 -050087 msg_set_media_addr(msg, &b_ptr->addr);
Per Lidenb97bf3f2006-01-02 19:04:38 +010088 }
89 return buf;
90}
91
92/**
Allan Stephense91ed0b2006-10-16 21:44:59 -070093 * disc_dupl_alert - issue node address duplication alert
94 * @b_ptr: pointer to bearer detecting duplication
95 * @node_addr: duplicated node address
96 * @media_addr: media address advertised by duplicated node
97 */
98
Allan Stephens2d627b92011-01-07 13:00:11 -050099static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
Allan Stephense91ed0b2006-10-16 21:44:59 -0700100 struct tipc_media_addr *media_addr)
101{
102 char node_addr_str[16];
103 char media_addr_str[64];
104 struct print_buf pb;
105
Allan Stephensc68ca7b2010-05-11 14:30:12 +0000106 tipc_addr_string_fill(node_addr_str, node_addr);
Allan Stephense91ed0b2006-10-16 21:44:59 -0700107 tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
108 tipc_media_addr_printf(&pb, media_addr);
109 tipc_printbuf_validate(&pb);
110 warn("Duplicate %s using %s seen on <%s>\n",
Allan Stephens2d627b92011-01-07 13:00:11 -0500111 node_addr_str, media_addr_str, b_ptr->name);
Allan Stephense91ed0b2006-10-16 21:44:59 -0700112}
113
114/**
Per Liden4323add2006-01-18 00:38:21 +0100115 * tipc_disc_recv_msg - handle incoming link setup message (request or response)
Per Lidenb97bf3f2006-01-02 19:04:38 +0100116 * @buf: buffer containing message
Allan Stephens1265a022008-06-04 17:32:35 -0700117 * @b_ptr: bearer that message arrived on
Per Lidenb97bf3f2006-01-02 19:04:38 +0100118 */
119
Allan Stephens2d627b92011-01-07 13:00:11 -0500120void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
Per Lidenb97bf3f2006-01-02 19:04:38 +0100121{
Allan Stephensa7287502011-02-28 10:03:05 -0500122 struct tipc_node *n_ptr;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100123 struct link *link;
Allan Stephensa7287502011-02-28 10:03:05 -0500124 struct tipc_media_addr media_addr, *addr;
125 struct sk_buff *rbuf;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100126 struct tipc_msg *msg = buf_msg(buf);
127 u32 dest = msg_dest_domain(msg);
128 u32 orig = msg_prevnode(msg);
129 u32 net_id = msg_bc_netid(msg);
130 u32 type = msg_type(msg);
Allan Stephensa7287502011-02-28 10:03:05 -0500131 int link_fully_up;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100132
Allan Stephens0e659672010-12-31 18:59:32 +0000133 msg_get_media_addr(msg, &media_addr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100134 buf_discard(buf);
135
Allan Stephensa7287502011-02-28 10:03:05 -0500136 /* Validate discovery message from requesting node */
Per Lidenb97bf3f2006-01-02 19:04:38 +0100137 if (net_id != tipc_net_id)
138 return;
Per Liden4323add2006-01-18 00:38:21 +0100139 if (!tipc_addr_domain_valid(dest))
Per Lidenb97bf3f2006-01-02 19:04:38 +0100140 return;
Per Liden4323add2006-01-18 00:38:21 +0100141 if (!tipc_addr_node_valid(orig))
Per Lidenb97bf3f2006-01-02 19:04:38 +0100142 return;
Allan Stephense91ed0b2006-10-16 21:44:59 -0700143 if (orig == tipc_own_addr) {
Allan Stephens2d627b92011-01-07 13:00:11 -0500144 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
Allan Stephense91ed0b2006-10-16 21:44:59 -0700145 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100146 return;
Allan Stephense91ed0b2006-10-16 21:44:59 -0700147 }
Allan Stephensc68ca7b2010-05-11 14:30:12 +0000148 if (!tipc_in_scope(dest, tipc_own_addr))
Per Lidenb97bf3f2006-01-02 19:04:38 +0100149 return;
Allan Stephens66e019a2011-04-20 16:24:07 -0500150 if (!tipc_in_scope(b_ptr->link_req->domain, orig))
Allan Stephensa7287502011-02-28 10:03:05 -0500151 return;
Allan Stephens2de07f62006-10-16 21:57:13 -0700152
Allan Stephensa7287502011-02-28 10:03:05 -0500153 /* Locate structure corresponding to requesting node */
154 n_ptr = tipc_node_find(orig);
155 if (!n_ptr) {
156 n_ptr = tipc_node_create(orig);
157 if (!n_ptr)
Allan Stephens5a68d5ee2010-08-17 11:00:16 +0000158 return;
Allan Stephensa7287502011-02-28 10:03:05 -0500159 }
160 tipc_node_lock(n_ptr);
Allan Stephens5a68d5ee2010-08-17 11:00:16 +0000161
Allan Stephensa7287502011-02-28 10:03:05 -0500162 /* Don't talk to neighbor during cleanup after last session */
163 if (n_ptr->cleanup_required) {
164 tipc_node_unlock(n_ptr);
165 return;
166 }
167
168 link = n_ptr->links[b_ptr->identity];
169
170 /* Create a link endpoint for this bearer, if necessary */
171 if (!link) {
Allan Stephens37b9c082011-02-28 11:32:27 -0500172 link = tipc_link_create(n_ptr, b_ptr, &media_addr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100173 if (!link) {
Allan Stephensa7287502011-02-28 10:03:05 -0500174 tipc_node_unlock(n_ptr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100175 return;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100176 }
177 }
Allan Stephensa7287502011-02-28 10:03:05 -0500178
179 /*
180 * Ensure requesting node's media address is correct
181 *
182 * If media address doesn't match and the link is working, reject the
183 * request (must be from a duplicate node).
184 *
185 * If media address doesn't match and the link is not working, accept
186 * the new media address and reset the link to ensure it starts up
187 * cleanly.
188 */
189 addr = &link->media_addr;
190 if (memcmp(addr, &media_addr, sizeof(*addr))) {
191 if (tipc_link_is_up(link) || (!link->started)) {
192 disc_dupl_alert(b_ptr, orig, &media_addr);
193 tipc_node_unlock(n_ptr);
194 return;
195 }
196 warn("Resetting link <%s>, peer interface address changed\n",
197 link->name);
198 memcpy(addr, &media_addr, sizeof(*addr));
199 tipc_link_reset(link);
200 }
201
202 /* Accept discovery message & send response, if necessary */
203 link_fully_up = link_working_working(link);
Allan Stephensfa2bae22011-02-28 10:56:23 -0500204
Allan Stephensf9107eb2011-02-28 11:04:08 -0500205 if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) {
Allan Stephensfa2bae22011-02-28 10:56:23 -0500206 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
207 if (rbuf) {
208 b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
209 buf_discard(rbuf);
210 }
Allan Stephensa7287502011-02-28 10:03:05 -0500211 }
Allan Stephensfa2bae22011-02-28 10:56:23 -0500212
213 tipc_node_unlock(n_ptr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100214}
215
216/**
Allan Stephens12099662011-04-21 19:05:25 -0500217 * disc_update - update frequency of periodic link setup requests
Per Lidenb97bf3f2006-01-02 19:04:38 +0100218 * @req: ptr to link request structure
Allan Stephens972a77f2011-04-21 20:34:03 -0500219 *
220 * Reinitiates discovery process if discovery object has no associated nodes
221 * and is either not currently searching or is searching at a slow rate
Per Lidenb97bf3f2006-01-02 19:04:38 +0100222 */
223
Allan Stephens12099662011-04-21 19:05:25 -0500224static void disc_update(struct link_req *req)
Per Lidenb97bf3f2006-01-02 19:04:38 +0100225{
Allan Stephens972a77f2011-04-21 20:34:03 -0500226 if (!req->num_nodes) {
227 if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) ||
228 (req->timer_intv > TIPC_LINK_REQ_FAST)) {
229 req->timer_intv = TIPC_LINK_REQ_INIT;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100230 k_start_timer(&req->timer, req->timer_intv);
231 }
Per Lidenb97bf3f2006-01-02 19:04:38 +0100232 }
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +0900233}
Per Lidenb97bf3f2006-01-02 19:04:38 +0100234
235/**
Allan Stephens12099662011-04-21 19:05:25 -0500236 * tipc_disc_add_dest - increment set of discovered nodes
237 * @req: ptr to link request structure
238 */
239
240void tipc_disc_add_dest(struct link_req *req)
241{
242 req->num_nodes++;
Allan Stephens12099662011-04-21 19:05:25 -0500243}
244
245/**
246 * tipc_disc_remove_dest - decrement set of discovered nodes
247 * @req: ptr to link request structure
248 */
249
250void tipc_disc_remove_dest(struct link_req *req)
251{
252 req->num_nodes--;
253 disc_update(req);
254}
255
256/**
Allan Stephens691a6202011-04-21 16:28:02 -0500257 * disc_send_msg - send link setup request message
258 * @req: ptr to link request structure
259 */
260
261static void disc_send_msg(struct link_req *req)
262{
263 if (!req->bearer->blocked)
264 tipc_bearer_send(req->bearer, req->buf, &req->dest);
265}
266
267/**
Per Lidenb97bf3f2006-01-02 19:04:38 +0100268 * disc_timeout - send a periodic link setup request
269 * @req: ptr to link request structure
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +0900270 *
Per Lidenb97bf3f2006-01-02 19:04:38 +0100271 * Called whenever a link setup request timer associated with a bearer expires.
272 */
273
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +0900274static void disc_timeout(struct link_req *req)
Per Lidenb97bf3f2006-01-02 19:04:38 +0100275{
Allan Stephens972a77f2011-04-21 20:34:03 -0500276 int max_delay;
277
Allan Stephens2d627b92011-01-07 13:00:11 -0500278 spin_lock_bh(&req->bearer->lock);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100279
Allan Stephens972a77f2011-04-21 20:34:03 -0500280 /* Stop searching if only desired node has been found */
281
282 if (tipc_node(req->domain) && req->num_nodes) {
283 req->timer_intv = TIPC_LINK_REQ_INACTIVE;
284 goto exit;
285 }
286
287 /*
288 * Send discovery message, then update discovery timer
289 *
290 * Keep doubling time between requests until limit is reached;
291 * hold at fast polling rate if don't have any associated nodes,
292 * otherwise hold at slow polling rate
293 */
294
Allan Stephens691a6202011-04-21 16:28:02 -0500295 disc_send_msg(req);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100296
Allan Stephens972a77f2011-04-21 20:34:03 -0500297 req->timer_intv *= 2;
298 if (req->num_nodes)
299 max_delay = TIPC_LINK_REQ_SLOW;
300 else
301 max_delay = TIPC_LINK_REQ_FAST;
302 if (req->timer_intv > max_delay)
303 req->timer_intv = max_delay;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100304
Allan Stephens972a77f2011-04-21 20:34:03 -0500305 k_start_timer(&req->timer, req->timer_intv);
306exit:
Allan Stephens2d627b92011-01-07 13:00:11 -0500307 spin_unlock_bh(&req->bearer->lock);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100308}
309
310/**
Allan Stephens3a777ff2011-04-21 13:58:26 -0500311 * tipc_disc_create - create object to send periodic link setup requests
Per Lidenb97bf3f2006-01-02 19:04:38 +0100312 * @b_ptr: ptr to bearer issuing requests
313 * @dest: destination address for request messages
Allan Stephens66e019a2011-04-20 16:24:07 -0500314 * @dest_domain: network domain to which links can be established
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +0900315 *
Allan Stephens3a777ff2011-04-21 13:58:26 -0500316 * Returns 0 if successful, otherwise -errno.
Per Lidenb97bf3f2006-01-02 19:04:38 +0100317 */
318
Allan Stephens3a777ff2011-04-21 13:58:26 -0500319int tipc_disc_create(struct tipc_bearer *b_ptr,
320 struct tipc_media_addr *dest, u32 dest_domain)
Per Lidenb97bf3f2006-01-02 19:04:38 +0100321{
322 struct link_req *req;
323
Panagiotis Issaris9df3f3d2006-07-21 15:52:20 -0700324 req = kmalloc(sizeof(*req), GFP_ATOMIC);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100325 if (!req)
Allan Stephens3a777ff2011-04-21 13:58:26 -0500326 return -ENOMEM;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100327
Allan Stephens2e07dda2011-01-25 14:39:59 -0500328 req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100329 if (!req->buf) {
330 kfree(req);
Allan Stephens3a777ff2011-04-21 13:58:26 -0500331 return -ENOMSG;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100332 }
333
334 memcpy(&req->dest, dest, sizeof(*dest));
335 req->bearer = b_ptr;
Allan Stephens66e019a2011-04-20 16:24:07 -0500336 req->domain = dest_domain;
Allan Stephens12099662011-04-21 19:05:25 -0500337 req->num_nodes = 0;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100338 req->timer_intv = TIPC_LINK_REQ_INIT;
339 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
340 k_start_timer(&req->timer, req->timer_intv);
Allan Stephens3a777ff2011-04-21 13:58:26 -0500341 b_ptr->link_req = req;
Allan Stephens691a6202011-04-21 16:28:02 -0500342 disc_send_msg(req);
Allan Stephens3a777ff2011-04-21 13:58:26 -0500343 return 0;
344}
345
346/**
347 * tipc_disc_delete - destroy object sending periodic link setup requests
348 * @req: ptr to link request structure
349 */
350
351void tipc_disc_delete(struct link_req *req)
352{
353 k_cancel_timer(&req->timer);
354 k_term_timer(&req->timer);
355 buf_discard(req->buf);
356 kfree(req);
YOSHIFUJI Hideakic4307282007-02-09 23:25:21 +0900357}
Per Lidenb97bf3f2006-01-02 19:04:38 +0100358