1 /*
2 * net/tipc/discover.c
3 *
4 * Copyright (c) 2003-2006, Ericsson AB
5 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 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.
19 *
20 * 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
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include "core.h"
38 #include "link.h"
39 #include "discover.h"
40
41 #define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
42 #define TIPC_LINK_REQ_FAST 2000 /* normal delay if bearer has no links */
43 #define TIPC_LINK_REQ_SLOW 600000 /* normal delay if bearer has links */
44
45 /*
46 * TODO: Most of the inter-cluster setup stuff should be
47 * rewritten, and be made conformant with specification.
48 */
49
50
51 /**
52 * struct link_req - information about an ongoing link setup request
53 * @bearer: bearer issuing requests
54 * @dest: destination address for request messages
55 * @buf: request message to be (repeatedly) sent
56 * @timer: timer governing period between requests
57 * @timer_intv: current interval between requests (in ms)
58 */
59 struct link_req {
60 struct tipc_bearer *bearer;
61 struct tipc_media_addr dest;
62 struct sk_buff *buf;
63 struct timer_list timer;
64 unsigned int timer_intv;
65 };
66
67 /**
68 * tipc_disc_init_msg - initialize a link setup message
69 * @type: message type (request or response)
70 * @dest_domain: network domain of node(s) which should respond to message
71 * @b_ptr: ptr to bearer issuing message
72 */
73
tipc_disc_init_msg(u32 type,u32 dest_domain,struct tipc_bearer * b_ptr)74 static struct sk_buff *tipc_disc_init_msg(u32 type,
75 u32 dest_domain,
76 struct tipc_bearer *b_ptr)
77 {
78 struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE);
79 struct tipc_msg *msg;
80
81 if (buf) {
82 msg = buf_msg(buf);
83 tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
84 msg_set_non_seq(msg, 1);
85 msg_set_dest_domain(msg, dest_domain);
86 msg_set_bc_netid(msg, tipc_net_id);
87 msg_set_media_addr(msg, &b_ptr->addr);
88 }
89 return buf;
90 }
91
92 /**
93 * 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
disc_dupl_alert(struct tipc_bearer * b_ptr,u32 node_addr,struct tipc_media_addr * media_addr)99 static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
100 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
106 tipc_addr_string_fill(node_addr_str, node_addr);
107 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",
111 node_addr_str, media_addr_str, b_ptr->name);
112 }
113
114 /**
115 * tipc_disc_recv_msg - handle incoming link setup message (request or response)
116 * @buf: buffer containing message
117 * @b_ptr: bearer that message arrived on
118 */
119
tipc_disc_recv_msg(struct sk_buff * buf,struct tipc_bearer * b_ptr)120 void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
121 {
122 struct tipc_node *n_ptr;
123 struct link *link;
124 struct tipc_media_addr media_addr, *addr;
125 struct sk_buff *rbuf;
126 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);
131 int link_fully_up;
132
133 msg_get_media_addr(msg, &media_addr);
134 buf_discard(buf);
135
136 /* Validate discovery message from requesting node */
137 if (net_id != tipc_net_id)
138 return;
139 if (!tipc_addr_domain_valid(dest))
140 return;
141 if (!tipc_addr_node_valid(orig))
142 return;
143 if (orig == tipc_own_addr) {
144 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
145 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
146 return;
147 }
148 if (!tipc_in_scope(dest, tipc_own_addr))
149 return;
150 if (!in_own_cluster(orig))
151 return;
152
153 /* 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)
158 return;
159 }
160 tipc_node_lock(n_ptr);
161
162 /* 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) {
172 link = tipc_link_create(n_ptr, b_ptr, &media_addr);
173 if (!link) {
174 tipc_node_unlock(n_ptr);
175 return;
176 }
177 }
178
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);
204
205 if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) {
206 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 }
211 }
212
213 tipc_node_unlock(n_ptr);
214 }
215
216 /**
217 * tipc_disc_stop_link_req - stop sending periodic link setup requests
218 * @req: ptr to link request structure
219 */
220
tipc_disc_stop_link_req(struct link_req * req)221 void tipc_disc_stop_link_req(struct link_req *req)
222 {
223 if (!req)
224 return;
225
226 k_cancel_timer(&req->timer);
227 k_term_timer(&req->timer);
228 buf_discard(req->buf);
229 kfree(req);
230 }
231
232 /**
233 * tipc_disc_update_link_req - update frequency of periodic link setup requests
234 * @req: ptr to link request structure
235 */
236
tipc_disc_update_link_req(struct link_req * req)237 void tipc_disc_update_link_req(struct link_req *req)
238 {
239 if (!req)
240 return;
241
242 if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
243 if (!req->bearer->nodes.count) {
244 req->timer_intv = TIPC_LINK_REQ_FAST;
245 k_start_timer(&req->timer, req->timer_intv);
246 }
247 } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
248 if (req->bearer->nodes.count) {
249 req->timer_intv = TIPC_LINK_REQ_SLOW;
250 k_start_timer(&req->timer, req->timer_intv);
251 }
252 } else {
253 /* leave timer "as is" if haven't yet reached a "normal" rate */
254 }
255 }
256
257 /**
258 * disc_timeout - send a periodic link setup request
259 * @req: ptr to link request structure
260 *
261 * Called whenever a link setup request timer associated with a bearer expires.
262 */
263
disc_timeout(struct link_req * req)264 static void disc_timeout(struct link_req *req)
265 {
266 spin_lock_bh(&req->bearer->lock);
267
268 req->bearer->media->send_msg(req->buf, req->bearer, &req->dest);
269
270 if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
271 (req->timer_intv == TIPC_LINK_REQ_FAST)) {
272 /* leave timer interval "as is" if already at a "normal" rate */
273 } else {
274 req->timer_intv *= 2;
275 if (req->timer_intv > TIPC_LINK_REQ_FAST)
276 req->timer_intv = TIPC_LINK_REQ_FAST;
277 if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
278 (req->bearer->nodes.count))
279 req->timer_intv = TIPC_LINK_REQ_SLOW;
280 }
281 k_start_timer(&req->timer, req->timer_intv);
282
283 spin_unlock_bh(&req->bearer->lock);
284 }
285
286 /**
287 * tipc_disc_init_link_req - start sending periodic link setup requests
288 * @b_ptr: ptr to bearer issuing requests
289 * @dest: destination address for request messages
290 * @dest_domain: network domain of node(s) which should respond to message
291 *
292 * Returns pointer to link request structure, or NULL if unable to create.
293 */
294
tipc_disc_init_link_req(struct tipc_bearer * b_ptr,const struct tipc_media_addr * dest,u32 dest_domain)295 struct link_req *tipc_disc_init_link_req(struct tipc_bearer *b_ptr,
296 const struct tipc_media_addr *dest,
297 u32 dest_domain)
298 {
299 struct link_req *req;
300
301 req = kmalloc(sizeof(*req), GFP_ATOMIC);
302 if (!req)
303 return NULL;
304
305 req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr);
306 if (!req->buf) {
307 kfree(req);
308 return NULL;
309 }
310
311 memcpy(&req->dest, dest, sizeof(*dest));
312 req->bearer = b_ptr;
313 req->timer_intv = TIPC_LINK_REQ_INIT;
314 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
315 k_start_timer(&req->timer, req->timer_intv);
316 return req;
317 }
318
319