aboutsummaryrefslogtreecommitdiff
path: root/net/tipc/discover.c
blob: fa026bd91a68e88f7e8e1125dd232cf27e628316 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
/*
 * net/tipc/discover.c
 *
 * Copyright (c) 2003-2006, Ericsson AB
 * Copyright (c) 2005-2006, 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 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 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->publ.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 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->publ.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 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->publ.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->publ, &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->publ.lock);

	req->bearer->media->send_msg(req->buf, &req->bearer->publ, &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->publ.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 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;
}