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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 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 */
45
46
47/**
48 * struct tipc_link_req - information about an ongoing link setup request
49 * @bearer: bearer issuing requests
50 * @dest: destination address for request messages
51 * @domain: network domain to which links can be established
52 * @num_nodes: number of nodes currently discovered (i.e. with an active link)
53 * @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 tipc_link_req {
58 struct tipc_bearer *bearer;
59 struct tipc_media_addr dest;
60 u32 domain;
61 int num_nodes;
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 */
73static struct sk_buff *tipc_disc_init_msg(u32 type,
74 u32 dest_domain,
75 struct tipc_bearer *b_ptr)
76{
77 struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE);
78 struct tipc_msg *msg;
79
80 if (buf) {
81 msg = buf_msg(buf);
82 tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
83 msg_set_non_seq(msg, 1);
84 msg_set_node_sig(msg, tipc_random);
85 msg_set_dest_domain(msg, dest_domain);
86 msg_set_bc_netid(msg, tipc_net_id);
87 b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg));
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 */
98static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
99 struct tipc_media_addr *media_addr)
100{
101 char node_addr_str[16];
102 char media_addr_str[64];
103 struct print_buf pb;
104
105 tipc_addr_string_fill(node_addr_str, node_addr);
106 tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
107 tipc_media_addr_printf(&pb, media_addr);
108 tipc_printbuf_validate(&pb);
109 warn("Duplicate %s using %s seen on <%s>\n",
110 node_addr_str, media_addr_str, b_ptr->name);
111}
112
113/**
114 * tipc_disc_recv_msg - handle incoming link setup message (request or response)
115 * @buf: buffer containing message
116 * @b_ptr: bearer that message arrived on
117 */
118void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
119{
120 struct tipc_node *n_ptr;
121 struct tipc_link *link;
122 struct tipc_media_addr media_addr;
123 struct sk_buff *rbuf;
124 struct tipc_msg *msg = buf_msg(buf);
125 u32 dest = msg_dest_domain(msg);
126 u32 orig = msg_prevnode(msg);
127 u32 net_id = msg_bc_netid(msg);
128 u32 type = msg_type(msg);
129 u32 signature = msg_node_sig(msg);
130 int addr_mismatch;
131 int link_fully_up;
132
133 media_addr.broadcast = 1;
134 b_ptr->media->msg2addr(&media_addr, msg_media_addr(msg));
135 kfree_skb(buf);
136
137 /* Ensure message from node is valid and communication is permitted */
138 if (net_id != tipc_net_id)
139 return;
140 if (media_addr.broadcast)
141 return;
142 if (!tipc_addr_domain_valid(dest))
143 return;
144 if (!tipc_addr_node_valid(orig))
145 return;
146 if (orig == tipc_own_addr) {
147 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
148 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
149 return;
150 }
151 if (!tipc_in_scope(dest, tipc_own_addr))
152 return;
153 if (!tipc_in_scope(b_ptr->link_req->domain, orig))
154 return;
155
156 /* Locate structure corresponding to requesting node */
157 n_ptr = tipc_node_find(orig);
158 if (!n_ptr) {
159 n_ptr = tipc_node_create(orig);
160 if (!n_ptr)
161 return;
162 }
163 tipc_node_lock(n_ptr);
164
165 /* Prepare to validate requesting node's signature and media address */
166 link = n_ptr->links[b_ptr->identity];
167 addr_mismatch = (link != NULL) &&
168 memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
169
170 /*
171 * Ensure discovery message's signature is correct
172 *
173 * If signature is incorrect and there is no working link to the node,
174 * accept the new signature but invalidate all existing links to the
175 * node so they won't re-activate without a new discovery message.
176 *
177 * If signature is incorrect and the requested link to the node is
178 * working, accept the new signature. (This is an instance of delayed
179 * rediscovery, where a link endpoint was able to re-establish contact
180 * with its peer endpoint on a node that rebooted before receiving a
181 * discovery message from that node.)
182 *
183 * If signature is incorrect and there is a working link to the node
184 * that is not the requested link, reject the request (must be from
185 * a duplicate node).
186 */
187 if (signature != n_ptr->signature) {
188 if (n_ptr->working_links == 0) {
189 struct tipc_link *curr_link;
190 int i;
191
192 for (i = 0; i < MAX_BEARERS; i++) {
193 curr_link = n_ptr->links[i];
194 if (curr_link) {
195 memset(&curr_link->media_addr, 0,
196 sizeof(media_addr));
197 tipc_link_reset(curr_link);
198 }
199 }
200 addr_mismatch = (link != NULL);
201 } else if (tipc_link_is_up(link) && !addr_mismatch) {
202 /* delayed rediscovery */
203 } else {
204 disc_dupl_alert(b_ptr, orig, &media_addr);
205 tipc_node_unlock(n_ptr);
206 return;
207 }
208 n_ptr->signature = signature;
209 }
210
211 /*
212 * Ensure requesting node's media address is correct
213 *
214 * If media address doesn't match and the link is working, reject the
215 * request (must be from a duplicate node).
216 *
217 * If media address doesn't match and the link is not working, accept
218 * the new media address and reset the link to ensure it starts up
219 * cleanly.
220 */
221 if (addr_mismatch) {
222 if (tipc_link_is_up(link)) {
223 disc_dupl_alert(b_ptr, orig, &media_addr);
224 tipc_node_unlock(n_ptr);
225 return;
226 } else {
227 memcpy(&link->media_addr, &media_addr,
228 sizeof(media_addr));
229 tipc_link_reset(link);
230 }
231 }
232
233 /* Create a link endpoint for this bearer, if necessary */
234 if (!link) {
235 link = tipc_link_create(n_ptr, b_ptr, &media_addr);
236 if (!link) {
237 tipc_node_unlock(n_ptr);
238 return;
239 }
240 }
241
242 /* Accept discovery message & send response, if necessary */
243 link_fully_up = link_working_working(link);
244
245 if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) {
246 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
247 if (rbuf) {
248 b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
249 kfree_skb(rbuf);
250 }
251 }
252
253 tipc_node_unlock(n_ptr);
254}
255
256/**
257 * disc_update - update frequency of periodic link setup requests
258 * @req: ptr to link request structure
259 *
260 * Reinitiates discovery process if discovery object has no associated nodes
261 * and is either not currently searching or is searching at a slow rate
262 */
263static void disc_update(struct tipc_link_req *req)
264{
265 if (!req->num_nodes) {
266 if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) ||
267 (req->timer_intv > TIPC_LINK_REQ_FAST)) {
268 req->timer_intv = TIPC_LINK_REQ_INIT;
269 k_start_timer(&req->timer, req->timer_intv);
270 }
271 }
272}
273
274/**
275 * tipc_disc_add_dest - increment set of discovered nodes
276 * @req: ptr to link request structure
277 */
278void tipc_disc_add_dest(struct tipc_link_req *req)
279{
280 req->num_nodes++;
281}
282
283/**
284 * tipc_disc_remove_dest - decrement set of discovered nodes
285 * @req: ptr to link request structure
286 */
287void tipc_disc_remove_dest(struct tipc_link_req *req)
288{
289 req->num_nodes--;
290 disc_update(req);
291}
292
293/**
294 * disc_send_msg - send link setup request message
295 * @req: ptr to link request structure
296 */
297static void disc_send_msg(struct tipc_link_req *req)
298{
299 if (!req->bearer->blocked)
300 tipc_bearer_send(req->bearer, req->buf, &req->dest);
301}
302
303/**
304 * disc_timeout - send a periodic link setup request
305 * @req: ptr to link request structure
306 *
307 * Called whenever a link setup request timer associated with a bearer expires.
308 */
309static void disc_timeout(struct tipc_link_req *req)
310{
311 int max_delay;
312
313 spin_lock_bh(&req->bearer->lock);
314
315 /* Stop searching if only desired node has been found */
316 if (tipc_node(req->domain) && req->num_nodes) {
317 req->timer_intv = TIPC_LINK_REQ_INACTIVE;
318 goto exit;
319 }
320
321 /*
322 * Send discovery message, then update discovery timer
323 *
324 * Keep doubling time between requests until limit is reached;
325 * hold at fast polling rate if don't have any associated nodes,
326 * otherwise hold at slow polling rate
327 */
328 disc_send_msg(req);
329
330 req->timer_intv *= 2;
331 if (req->num_nodes)
332 max_delay = TIPC_LINK_REQ_SLOW;
333 else
334 max_delay = TIPC_LINK_REQ_FAST;
335 if (req->timer_intv > max_delay)
336 req->timer_intv = max_delay;
337
338 k_start_timer(&req->timer, req->timer_intv);
339exit:
340 spin_unlock_bh(&req->bearer->lock);
341}
342
343/**
344 * tipc_disc_create - create object to send periodic link setup requests
345 * @b_ptr: ptr to bearer issuing requests
346 * @dest: destination address for request messages
347 * @dest_domain: network domain to which links can be established
348 *
349 * Returns 0 if successful, otherwise -errno.
350 */
351int tipc_disc_create(struct tipc_bearer *b_ptr,
352 struct tipc_media_addr *dest, u32 dest_domain)
353{
354 struct tipc_link_req *req;
355
356 req = kmalloc(sizeof(*req), GFP_ATOMIC);
357 if (!req)
358 return -ENOMEM;
359
360 req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr);
361 if (!req->buf) {
362 kfree(req);
363 return -ENOMSG;
364 }
365
366 memcpy(&req->dest, dest, sizeof(*dest));
367 req->bearer = b_ptr;
368 req->domain = dest_domain;
369 req->num_nodes = 0;
370 req->timer_intv = TIPC_LINK_REQ_INIT;
371 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
372 k_start_timer(&req->timer, req->timer_intv);
373 b_ptr->link_req = req;
374 disc_send_msg(req);
375 return 0;
376}
377
378/**
379 * tipc_disc_delete - destroy object sending periodic link setup requests
380 * @req: ptr to link request structure
381 */
382void tipc_disc_delete(struct tipc_link_req *req)
383{
384 k_cancel_timer(&req->timer);
385 k_term_timer(&req->timer);
386 kfree_skb(req->buf);
387 kfree(req);
388}
1/*
2 * net/tipc/discover.c
3 *
4 * Copyright (c) 2003-2006, 2014-2018, 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 "node.h"
39#include "discover.h"
40
41/* min delay during bearer start up */
42#define TIPC_DISC_INIT msecs_to_jiffies(125)
43/* max delay if bearer has no links */
44#define TIPC_DISC_FAST msecs_to_jiffies(1000)
45/* max delay if bearer has links */
46#define TIPC_DISC_SLOW msecs_to_jiffies(60000)
47/* indicates no timer in use */
48#define TIPC_DISC_INACTIVE 0xffffffff
49
50/**
51 * struct tipc_discoverer - information about an ongoing link setup request
52 * @bearer_id: identity of bearer issuing requests
53 * @net: network namespace instance
54 * @dest: destination address for request messages
55 * @domain: network domain to which links can be established
56 * @num_nodes: number of nodes currently discovered (i.e. with an active link)
57 * @lock: spinlock for controlling access to requests
58 * @skb: request message to be (repeatedly) sent
59 * @timer: timer governing period between requests
60 * @timer_intv: current interval between requests (in ms)
61 */
62struct tipc_discoverer {
63 u32 bearer_id;
64 struct tipc_media_addr dest;
65 struct net *net;
66 u32 domain;
67 int num_nodes;
68 spinlock_t lock;
69 struct sk_buff *skb;
70 struct timer_list timer;
71 unsigned long timer_intv;
72};
73
74/**
75 * tipc_disc_init_msg - initialize a link setup message
76 * @net: the applicable net namespace
77 * @type: message type (request or response)
78 * @b: ptr to bearer issuing message
79 */
80static void tipc_disc_init_msg(struct net *net, struct sk_buff *skb,
81 u32 mtyp, struct tipc_bearer *b)
82{
83 struct tipc_net *tn = tipc_net(net);
84 u32 dest_domain = b->domain;
85 struct tipc_msg *hdr;
86
87 hdr = buf_msg(skb);
88 tipc_msg_init(tn->trial_addr, hdr, LINK_CONFIG, mtyp,
89 MAX_H_SIZE, dest_domain);
90 msg_set_size(hdr, MAX_H_SIZE + NODE_ID_LEN);
91 msg_set_non_seq(hdr, 1);
92 msg_set_node_sig(hdr, tn->random);
93 msg_set_node_capabilities(hdr, TIPC_NODE_CAPABILITIES);
94 msg_set_dest_domain(hdr, dest_domain);
95 msg_set_bc_netid(hdr, tn->net_id);
96 b->media->addr2msg(msg_media_addr(hdr), &b->addr);
97 msg_set_node_id(hdr, tipc_own_id(net));
98}
99
100static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst,
101 u32 src, u32 sugg_addr,
102 struct tipc_media_addr *maddr,
103 struct tipc_bearer *b)
104{
105 struct tipc_msg *hdr;
106 struct sk_buff *skb;
107
108 skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
109 if (!skb)
110 return;
111 hdr = buf_msg(skb);
112 tipc_disc_init_msg(net, skb, mtyp, b);
113 msg_set_sugg_node_addr(hdr, sugg_addr);
114 msg_set_dest_domain(hdr, dst);
115 tipc_bearer_xmit_skb(net, b->identity, skb, maddr);
116}
117
118/**
119 * disc_dupl_alert - issue node address duplication alert
120 * @b: pointer to bearer detecting duplication
121 * @node_addr: duplicated node address
122 * @media_addr: media address advertised by duplicated node
123 */
124static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr,
125 struct tipc_media_addr *media_addr)
126{
127 char media_addr_str[64];
128
129 tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
130 media_addr);
131 pr_warn("Duplicate %x using %s seen on <%s>\n", node_addr,
132 media_addr_str, b->name);
133}
134
135/* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer
136 * Returns true if message should be dropped by caller, i.e., if it is a
137 * trial message or we are inside trial period. Otherwise false.
138 */
139static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d,
140 struct tipc_media_addr *maddr,
141 struct tipc_bearer *b,
142 u32 dst, u32 src,
143 u32 sugg_addr,
144 u8 *peer_id,
145 int mtyp)
146{
147 struct net *net = d->net;
148 struct tipc_net *tn = tipc_net(net);
149 bool trial = time_before(jiffies, tn->addr_trial_end);
150 u32 self = tipc_own_addr(net);
151
152 if (mtyp == DSC_TRIAL_FAIL_MSG) {
153 if (!trial)
154 return true;
155
156 /* Ignore if somebody else already gave new suggestion */
157 if (dst != tn->trial_addr)
158 return true;
159
160 /* Otherwise update trial address and restart trial period */
161 tn->trial_addr = sugg_addr;
162 msg_set_prevnode(buf_msg(d->skb), sugg_addr);
163 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
164 return true;
165 }
166
167 /* Apply trial address if we just left trial period */
168 if (!trial && !self) {
169 tipc_sched_net_finalize(net, tn->trial_addr);
170 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
171 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
172 }
173
174 /* Accept regular link requests/responses only after trial period */
175 if (mtyp != DSC_TRIAL_MSG)
176 return trial;
177
178 sugg_addr = tipc_node_try_addr(net, peer_id, src);
179 if (sugg_addr)
180 tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, src,
181 self, sugg_addr, maddr, b);
182 return true;
183}
184
185/**
186 * tipc_disc_rcv - handle incoming discovery message (request or response)
187 * @net: applicable net namespace
188 * @skb: buffer containing message
189 * @b: bearer that message arrived on
190 */
191void tipc_disc_rcv(struct net *net, struct sk_buff *skb,
192 struct tipc_bearer *b)
193{
194 struct tipc_net *tn = tipc_net(net);
195 struct tipc_msg *hdr = buf_msg(skb);
196 u16 caps = msg_node_capabilities(hdr);
197 bool legacy = tn->legacy_addr_format;
198 u32 sugg = msg_sugg_node_addr(hdr);
199 u32 signature = msg_node_sig(hdr);
200 u8 peer_id[NODE_ID_LEN] = {0,};
201 u32 dst = msg_dest_domain(hdr);
202 u32 net_id = msg_bc_netid(hdr);
203 struct tipc_media_addr maddr;
204 u32 src = msg_prevnode(hdr);
205 u32 mtyp = msg_type(hdr);
206 bool dupl_addr = false;
207 bool respond = false;
208 u32 self;
209 int err;
210
211 skb_linearize(skb);
212 hdr = buf_msg(skb);
213
214 if (caps & TIPC_NODE_ID128)
215 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN);
216 else
217 sprintf(peer_id, "%x", src);
218
219 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr));
220 kfree_skb(skb);
221 if (err || maddr.broadcast) {
222 pr_warn_ratelimited("Rcv corrupt discovery message\n");
223 return;
224 }
225 /* Ignore discovery messages from own node */
226 if (!memcmp(&maddr, &b->addr, sizeof(maddr)))
227 return;
228 if (net_id != tn->net_id)
229 return;
230 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst,
231 src, sugg, peer_id, mtyp))
232 return;
233 self = tipc_own_addr(net);
234
235 /* Message from somebody using this node's address */
236 if (in_own_node(net, src)) {
237 disc_dupl_alert(b, self, &maddr);
238 return;
239 }
240 if (!tipc_in_scope(legacy, dst, self))
241 return;
242 if (!tipc_in_scope(legacy, b->domain, src))
243 return;
244 tipc_node_check_dest(net, src, peer_id, b, caps, signature,
245 &maddr, &respond, &dupl_addr);
246 if (dupl_addr)
247 disc_dupl_alert(b, src, &maddr);
248 if (!respond)
249 return;
250 if (mtyp != DSC_REQ_MSG)
251 return;
252 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b);
253}
254
255/* tipc_disc_add_dest - increment set of discovered nodes
256 */
257void tipc_disc_add_dest(struct tipc_discoverer *d)
258{
259 spin_lock_bh(&d->lock);
260 d->num_nodes++;
261 spin_unlock_bh(&d->lock);
262}
263
264/* tipc_disc_remove_dest - decrement set of discovered nodes
265 */
266void tipc_disc_remove_dest(struct tipc_discoverer *d)
267{
268 int intv, num;
269
270 spin_lock_bh(&d->lock);
271 d->num_nodes--;
272 num = d->num_nodes;
273 intv = d->timer_intv;
274 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) {
275 d->timer_intv = TIPC_DISC_INIT;
276 mod_timer(&d->timer, jiffies + d->timer_intv);
277 }
278 spin_unlock_bh(&d->lock);
279}
280
281/* tipc_disc_timeout - send a periodic link setup request
282 * Called whenever a link setup request timer associated with a bearer expires.
283 * - Keep doubling time between sent request until limit is reached;
284 * - Hold at fast polling rate if we don't have any associated nodes
285 * - Otherwise hold at slow polling rate
286 */
287static void tipc_disc_timeout(struct timer_list *t)
288{
289 struct tipc_discoverer *d = from_timer(d, t, timer);
290 struct tipc_net *tn = tipc_net(d->net);
291 struct tipc_media_addr maddr;
292 struct sk_buff *skb = NULL;
293 struct net *net = d->net;
294 u32 bearer_id;
295
296 spin_lock_bh(&d->lock);
297
298 /* Stop searching if only desired node has been found */
299 if (tipc_node(d->domain) && d->num_nodes) {
300 d->timer_intv = TIPC_DISC_INACTIVE;
301 goto exit;
302 }
303
304 /* Did we just leave trial period ? */
305 if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) {
306 mod_timer(&d->timer, jiffies + TIPC_DISC_INIT);
307 spin_unlock_bh(&d->lock);
308 tipc_sched_net_finalize(net, tn->trial_addr);
309 return;
310 }
311
312 /* Adjust timeout interval according to discovery phase */
313 if (time_before(jiffies, tn->addr_trial_end)) {
314 d->timer_intv = TIPC_DISC_INIT;
315 } else {
316 d->timer_intv *= 2;
317 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW)
318 d->timer_intv = TIPC_DISC_SLOW;
319 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST)
320 d->timer_intv = TIPC_DISC_FAST;
321 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
322 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
323 }
324
325 mod_timer(&d->timer, jiffies + d->timer_intv);
326 memcpy(&maddr, &d->dest, sizeof(maddr));
327 skb = skb_clone(d->skb, GFP_ATOMIC);
328 bearer_id = d->bearer_id;
329exit:
330 spin_unlock_bh(&d->lock);
331 if (skb)
332 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr);
333}
334
335/**
336 * tipc_disc_create - create object to send periodic link setup requests
337 * @net: the applicable net namespace
338 * @b: ptr to bearer issuing requests
339 * @dest: destination address for request messages
340 * @dest_domain: network domain to which links can be established
341 *
342 * Returns 0 if successful, otherwise -errno.
343 */
344int tipc_disc_create(struct net *net, struct tipc_bearer *b,
345 struct tipc_media_addr *dest, struct sk_buff **skb)
346{
347 struct tipc_net *tn = tipc_net(net);
348 struct tipc_discoverer *d;
349
350 d = kmalloc(sizeof(*d), GFP_ATOMIC);
351 if (!d)
352 return -ENOMEM;
353 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
354 if (!d->skb) {
355 kfree(d);
356 return -ENOMEM;
357 }
358 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
359
360 /* Do we need an address trial period first ? */
361 if (!tipc_own_addr(net)) {
362 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
363 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
364 }
365 memcpy(&d->dest, dest, sizeof(*dest));
366 d->net = net;
367 d->bearer_id = b->identity;
368 d->domain = b->domain;
369 d->num_nodes = 0;
370 d->timer_intv = TIPC_DISC_INIT;
371 spin_lock_init(&d->lock);
372 timer_setup(&d->timer, tipc_disc_timeout, 0);
373 mod_timer(&d->timer, jiffies + d->timer_intv);
374 b->disc = d;
375 *skb = skb_clone(d->skb, GFP_ATOMIC);
376 return 0;
377}
378
379/**
380 * tipc_disc_delete - destroy object sending periodic link setup requests
381 * @d: ptr to link duest structure
382 */
383void tipc_disc_delete(struct tipc_discoverer *d)
384{
385 del_timer_sync(&d->timer);
386 kfree_skb(d->skb);
387 kfree(d);
388}
389
390/**
391 * tipc_disc_reset - reset object to send periodic link setup requests
392 * @net: the applicable net namespace
393 * @b: ptr to bearer issuing requests
394 * @dest_domain: network domain to which links can be established
395 */
396void tipc_disc_reset(struct net *net, struct tipc_bearer *b)
397{
398 struct tipc_discoverer *d = b->disc;
399 struct tipc_media_addr maddr;
400 struct sk_buff *skb;
401
402 spin_lock_bh(&d->lock);
403 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
404 d->net = net;
405 d->bearer_id = b->identity;
406 d->domain = b->domain;
407 d->num_nodes = 0;
408 d->timer_intv = TIPC_DISC_INIT;
409 memcpy(&maddr, &d->dest, sizeof(maddr));
410 mod_timer(&d->timer, jiffies + d->timer_intv);
411 skb = skb_clone(d->skb, GFP_ATOMIC);
412 spin_unlock_bh(&d->lock);
413 if (skb)
414 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr);
415}