Root/net/tipc/discover.c

1/*
2 * net/tipc/discover.c
3 *
4 * Copyright (c) 2003-2006, Ericsson AB
5 * Copyright (c) 2005-2006, 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 "dbg.h"
39#include "link.h"
40#include "zone.h"
41#include "discover.h"
42#include "port.h"
43#include "name_table.h"
44
45#define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
46#define TIPC_LINK_REQ_FAST 2000 /* normal delay if bearer has no links */
47#define TIPC_LINK_REQ_SLOW 600000 /* normal delay if bearer has links */
48
49#if 0
50#define GET_NODE_INFO 300
51#define GET_NODE_INFO_RESULT 301
52#define FORWARD_LINK_PROBE 302
53#define LINK_REQUEST_REJECTED 303
54#define LINK_REQUEST_ACCEPTED 304
55#define DROP_LINK_REQUEST 305
56#define CHECK_LINK_COUNT 306
57#endif
58
59/*
60 * TODO: Most of the inter-cluster setup stuff should be
61 * rewritten, and be made conformant with specification.
62 */
63
64
65/**
66 * struct link_req - information about an ongoing link setup request
67 * @bearer: bearer issuing requests
68 * @dest: destination address for request messages
69 * @buf: request message to be (repeatedly) sent
70 * @timer: timer governing period between requests
71 * @timer_intv: current interval between requests (in ms)
72 */
73struct link_req {
74    struct bearer *bearer;
75    struct tipc_media_addr dest;
76    struct sk_buff *buf;
77    struct timer_list timer;
78    unsigned int timer_intv;
79};
80
81
82#if 0
83int disc_create_link(const struct tipc_link_create *argv)
84{
85    /*
86     * Code for inter cluster link setup here
87     */
88    return TIPC_OK;
89}
90#endif
91
92/*
93 * disc_lost_link(): A link has lost contact
94 */
95
96void tipc_disc_link_event(u32 addr, char *name, int up)
97{
98    if (in_own_cluster(addr))
99        return;
100    /*
101     * Code for inter cluster link setup here
102     */
103}
104
105/**
106 * tipc_disc_init_msg - initialize a link setup message
107 * @type: message type (request or response)
108 * @req_links: number of links associated with message
109 * @dest_domain: network domain of node(s) which should respond to message
110 * @b_ptr: ptr to bearer issuing message
111 */
112
113static struct sk_buff *tipc_disc_init_msg(u32 type,
114                      u32 req_links,
115                      u32 dest_domain,
116                      struct bearer *b_ptr)
117{
118    struct sk_buff *buf = buf_acquire(DSC_H_SIZE);
119    struct tipc_msg *msg;
120
121    if (buf) {
122        msg = buf_msg(buf);
123        msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain);
124        msg_set_non_seq(msg, 1);
125        msg_set_req_links(msg, req_links);
126        msg_set_dest_domain(msg, dest_domain);
127        msg_set_bc_netid(msg, tipc_net_id);
128        msg_set_media_addr(msg, &b_ptr->publ.addr);
129    }
130    return buf;
131}
132
133/**
134 * disc_dupl_alert - issue node address duplication alert
135 * @b_ptr: pointer to bearer detecting duplication
136 * @node_addr: duplicated node address
137 * @media_addr: media address advertised by duplicated node
138 */
139
140static void disc_dupl_alert(struct bearer *b_ptr, u32 node_addr,
141                struct tipc_media_addr *media_addr)
142{
143    char node_addr_str[16];
144    char media_addr_str[64];
145    struct print_buf pb;
146
147    addr_string_fill(node_addr_str, node_addr);
148    tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
149    tipc_media_addr_printf(&pb, media_addr);
150    tipc_printbuf_validate(&pb);
151    warn("Duplicate %s using %s seen on <%s>\n",
152         node_addr_str, media_addr_str, b_ptr->publ.name);
153}
154
155/**
156 * tipc_disc_recv_msg - handle incoming link setup message (request or response)
157 * @buf: buffer containing message
158 * @b_ptr: bearer that message arrived on
159 */
160
161void tipc_disc_recv_msg(struct sk_buff *buf, struct bearer *b_ptr)
162{
163    struct link *link;
164    struct tipc_media_addr media_addr;
165    struct tipc_msg *msg = buf_msg(buf);
166    u32 dest = msg_dest_domain(msg);
167    u32 orig = msg_prevnode(msg);
168    u32 net_id = msg_bc_netid(msg);
169    u32 type = msg_type(msg);
170
171    msg_get_media_addr(msg,&media_addr);
172    msg_dbg(msg, "RECV:");
173    buf_discard(buf);
174
175    if (net_id != tipc_net_id)
176        return;
177    if (!tipc_addr_domain_valid(dest))
178        return;
179    if (!tipc_addr_node_valid(orig))
180        return;
181    if (orig == tipc_own_addr) {
182        if (memcmp(&media_addr, &b_ptr->publ.addr, sizeof(media_addr)))
183            disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
184        return;
185    }
186    if (!in_scope(dest, tipc_own_addr))
187        return;
188    if (is_slave(tipc_own_addr) && is_slave(orig))
189        return;
190    if (is_slave(orig) && !in_own_cluster(orig))
191        return;
192    if (in_own_cluster(orig)) {
193        /* Always accept link here */
194        struct sk_buff *rbuf;
195        struct tipc_media_addr *addr;
196        struct tipc_node *n_ptr = tipc_node_find(orig);
197        int link_fully_up;
198
199        dbg(" in own cluster\n");
200        if (n_ptr == NULL) {
201            n_ptr = tipc_node_create(orig);
202            if (!n_ptr)
203                return;
204        }
205        spin_lock_bh(&n_ptr->lock);
206        link = n_ptr->links[b_ptr->identity];
207        if (!link) {
208            dbg("creating link\n");
209            link = tipc_link_create(b_ptr, orig, &media_addr);
210            if (!link) {
211                spin_unlock_bh(&n_ptr->lock);
212                return;
213            }
214        }
215        addr = &link->media_addr;
216        if (memcmp(addr, &media_addr, sizeof(*addr))) {
217            if (tipc_link_is_up(link) || (!link->started)) {
218                disc_dupl_alert(b_ptr, orig, &media_addr);
219                spin_unlock_bh(&n_ptr->lock);
220                return;
221            }
222            warn("Resetting link <%s>, peer interface address changed\n",
223                 link->name);
224            memcpy(addr, &media_addr, sizeof(*addr));
225            tipc_link_reset(link);
226        }
227        link_fully_up = (link->state == WORKING_WORKING);
228        spin_unlock_bh(&n_ptr->lock);
229        if ((type == DSC_RESP_MSG) || link_fully_up)
230            return;
231        rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
232        if (rbuf != NULL) {
233            msg_dbg(buf_msg(rbuf),"SEND:");
234            b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr);
235            buf_discard(rbuf);
236        }
237    }
238}
239
240/**
241 * tipc_disc_stop_link_req - stop sending periodic link setup requests
242 * @req: ptr to link request structure
243 */
244
245void tipc_disc_stop_link_req(struct link_req *req)
246{
247    if (!req)
248        return;
249
250    k_cancel_timer(&req->timer);
251    k_term_timer(&req->timer);
252    buf_discard(req->buf);
253    kfree(req);
254}
255
256/**
257 * tipc_disc_update_link_req - update frequency of periodic link setup requests
258 * @req: ptr to link request structure
259 */
260
261void tipc_disc_update_link_req(struct link_req *req)
262{
263    if (!req)
264        return;
265
266    if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
267        if (!req->bearer->nodes.count) {
268            req->timer_intv = TIPC_LINK_REQ_FAST;
269            k_start_timer(&req->timer, req->timer_intv);
270        }
271    } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
272        if (req->bearer->nodes.count) {
273            req->timer_intv = TIPC_LINK_REQ_SLOW;
274            k_start_timer(&req->timer, req->timer_intv);
275        }
276    } else {
277        /* leave timer "as is" if haven't yet reached a "normal" rate */
278    }
279}
280
281/**
282 * disc_timeout - send a periodic link setup request
283 * @req: ptr to link request structure
284 *
285 * Called whenever a link setup request timer associated with a bearer expires.
286 */
287
288static void disc_timeout(struct link_req *req)
289{
290    spin_lock_bh(&req->bearer->publ.lock);
291
292    req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest);
293
294    if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
295        (req->timer_intv == TIPC_LINK_REQ_FAST)) {
296        /* leave timer interval "as is" if already at a "normal" rate */
297    } else {
298        req->timer_intv *= 2;
299        if (req->timer_intv > TIPC_LINK_REQ_FAST)
300            req->timer_intv = TIPC_LINK_REQ_FAST;
301        if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
302            (req->bearer->nodes.count))
303            req->timer_intv = TIPC_LINK_REQ_SLOW;
304    }
305    k_start_timer(&req->timer, req->timer_intv);
306
307    spin_unlock_bh(&req->bearer->publ.lock);
308}
309
310/**
311 * tipc_disc_init_link_req - start sending periodic link setup requests
312 * @b_ptr: ptr to bearer issuing requests
313 * @dest: destination address for request messages
314 * @dest_domain: network domain of node(s) which should respond to message
315 * @req_links: max number of desired links
316 *
317 * Returns pointer to link request structure, or NULL if unable to create.
318 */
319
320struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr,
321                     const struct tipc_media_addr *dest,
322                     u32 dest_domain,
323                     u32 req_links)
324{
325    struct link_req *req;
326
327    req = kmalloc(sizeof(*req), GFP_ATOMIC);
328    if (!req)
329        return NULL;
330
331    req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
332    if (!req->buf) {
333        kfree(req);
334        return NULL;
335    }
336
337    memcpy(&req->dest, dest, sizeof(*dest));
338    req->bearer = b_ptr;
339    req->timer_intv = TIPC_LINK_REQ_INIT;
340    k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
341    k_start_timer(&req->timer, req->timer_intv);
342    return req;
343}
344
345

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