4 * Copyright (c) 2003-2006, 2014-2015, Ericsson AB
5 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
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.
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.
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.
41 /* min delay during bearer start up */
42 #define TIPC_LINK_REQ_INIT msecs_to_jiffies(125)
43 /* max delay if bearer has no links */
44 #define TIPC_LINK_REQ_FAST msecs_to_jiffies(1000)
45 /* max delay if bearer has links */
46 #define TIPC_LINK_REQ_SLOW msecs_to_jiffies(60000)
47 /* indicates no timer in use */
48 #define TIPC_LINK_REQ_INACTIVE 0xffffffff
51 * struct tipc_link_req - 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 * @buf: request message to be (repeatedly) sent
59 * @timer: timer governing period between requests
60 * @timer_intv: current interval between requests (in ms)
62 struct tipc_link_req {
64 struct tipc_media_addr dest;
70 struct timer_list timer;
71 unsigned long timer_intv;
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: ptr to bearer issuing message
80 static void tipc_disc_init_msg(struct net *net, struct sk_buff *buf, u32 type,
81 struct tipc_bearer *b_ptr)
83 struct tipc_net *tn = net_generic(net, tipc_net_id);
85 u32 dest_domain = b_ptr->domain;
88 tipc_msg_init(tn->own_addr, msg, LINK_CONFIG, type,
89 INT_H_SIZE, dest_domain);
90 msg_set_non_seq(msg, 1);
91 msg_set_node_sig(msg, tn->random);
92 msg_set_dest_domain(msg, dest_domain);
93 msg_set_bc_netid(msg, tn->net_id);
94 b_ptr->media->addr2msg(msg_media_addr(msg), &b_ptr->addr);
98 * disc_dupl_alert - issue node address duplication alert
99 * @b_ptr: pointer to bearer detecting duplication
100 * @node_addr: duplicated node address
101 * @media_addr: media address advertised by duplicated node
103 static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
104 struct tipc_media_addr *media_addr)
106 char node_addr_str[16];
107 char media_addr_str[64];
109 tipc_addr_string_fill(node_addr_str, node_addr);
110 tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
112 pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str,
113 media_addr_str, b_ptr->name);
117 * tipc_disc_rcv - handle incoming discovery message (request or response)
118 * @net: the applicable net namespace
119 * @buf: buffer containing message
120 * @bearer: bearer that message arrived on
122 void tipc_disc_rcv(struct net *net, struct sk_buff *buf,
123 struct tipc_bearer *bearer)
125 struct tipc_net *tn = net_generic(net, tipc_net_id);
126 struct tipc_node *node;
127 struct tipc_link *link;
128 struct tipc_media_addr maddr;
129 struct sk_buff *rbuf;
130 struct tipc_msg *msg = buf_msg(buf);
131 u32 ddom = msg_dest_domain(msg);
132 u32 onode = msg_prevnode(msg);
133 u32 net_id = msg_bc_netid(msg);
134 u32 mtyp = msg_type(msg);
135 u32 signature = msg_node_sig(msg);
136 bool addr_match = false;
137 bool sign_match = false;
138 bool link_up = false;
139 bool accept_addr = false;
140 bool accept_sign = false;
141 bool respond = false;
143 bearer->media->msg2addr(bearer, &maddr, msg_media_addr(msg));
146 /* Ensure message from node is valid and communication is permitted */
147 if (net_id != tn->net_id)
151 if (!tipc_addr_domain_valid(ddom))
153 if (!tipc_addr_node_valid(onode))
156 if (in_own_node(net, onode)) {
157 if (memcmp(&maddr, &bearer->addr, sizeof(maddr)))
158 disc_dupl_alert(bearer, tn->own_addr, &maddr);
161 if (!tipc_in_scope(ddom, tn->own_addr))
163 if (!tipc_in_scope(bearer->domain, onode))
166 node = tipc_node_create(net, onode);
169 tipc_node_lock(node);
170 link = node->links[bearer->identity];
172 /* Prepare to validate requesting node's signature and media address */
173 sign_match = (signature == node->signature);
174 addr_match = link && !memcmp(&link->media_addr, &maddr, sizeof(maddr));
175 link_up = link && tipc_link_is_up(link);
178 /* These three flags give us eight permutations: */
180 if (sign_match && addr_match && link_up) {
181 /* All is fine. Do nothing. */
182 } else if (sign_match && addr_match && !link_up) {
183 /* Respond. The link will come up in due time */
185 } else if (sign_match && !addr_match && link_up) {
186 /* Peer has changed i/f address without rebooting.
187 * If so, the link will reset soon, and the next
188 * discovery will be accepted. So we can ignore it.
189 * It may also be an cloned or malicious peer having
190 * chosen the same node address and signature as an
192 * Ignore requests until the link goes down, if ever.
194 disc_dupl_alert(bearer, onode, &maddr);
195 } else if (sign_match && !addr_match && !link_up) {
196 /* Peer link has changed i/f address without rebooting.
197 * It may also be a cloned or malicious peer; we can't
198 * distinguish between the two.
199 * The signature is correct, so we must accept.
203 } else if (!sign_match && addr_match && link_up) {
204 /* Peer node rebooted. Two possibilities:
205 * - Delayed re-discovery; this link endpoint has already
206 * reset and re-established contact with the peer, before
207 * receiving a discovery message from that node.
208 * (The peer happened to receive one from this node first).
209 * - The peer came back so fast that our side has not
210 * discovered it yet. Probing from this side will soon
211 * reset the link, since there can be no working link
212 * endpoint at the peer end, and the link will re-establish.
213 * Accept the signature, since it comes from a known peer.
216 } else if (!sign_match && addr_match && !link_up) {
217 /* The peer node has rebooted.
218 * Accept signature, since it is a known peer.
222 } else if (!sign_match && !addr_match && link_up) {
223 /* Peer rebooted with new address, or a new/duplicate peer.
224 * Ignore until the link goes down, if ever.
226 disc_dupl_alert(bearer, onode, &maddr);
227 } else if (!sign_match && !addr_match && !link_up) {
228 /* Peer rebooted with new address, or it is a new peer.
229 * Accept signature and address.
237 node->signature = signature;
241 link = tipc_link_create(node, bearer, &maddr);
243 memcpy(&link->media_addr, &maddr, sizeof(maddr));
244 tipc_link_reset(link);
250 /* Send response, if necessary */
251 if (respond && (mtyp == DSC_REQ_MSG)) {
252 rbuf = tipc_buf_acquire(INT_H_SIZE);
254 tipc_disc_init_msg(net, rbuf, DSC_RESP_MSG, bearer);
255 tipc_bearer_send(net, bearer->identity, rbuf, &maddr);
259 tipc_node_unlock(node);
263 * disc_update - update frequency of periodic link setup requests
264 * @req: ptr to link request structure
266 * Reinitiates discovery process if discovery object has no associated nodes
267 * and is either not currently searching or is searching at a slow rate
269 static void disc_update(struct tipc_link_req *req)
271 if (!req->num_nodes) {
272 if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) ||
273 (req->timer_intv > TIPC_LINK_REQ_FAST)) {
274 req->timer_intv = TIPC_LINK_REQ_INIT;
275 mod_timer(&req->timer, jiffies + req->timer_intv);
281 * tipc_disc_add_dest - increment set of discovered nodes
282 * @req: ptr to link request structure
284 void tipc_disc_add_dest(struct tipc_link_req *req)
286 spin_lock_bh(&req->lock);
288 spin_unlock_bh(&req->lock);
292 * tipc_disc_remove_dest - decrement set of discovered nodes
293 * @req: ptr to link request structure
295 void tipc_disc_remove_dest(struct tipc_link_req *req)
297 spin_lock_bh(&req->lock);
300 spin_unlock_bh(&req->lock);
304 * disc_timeout - send a periodic link setup request
305 * @data: ptr to link request structure
307 * Called whenever a link setup request timer associated with a bearer expires.
309 static void disc_timeout(unsigned long data)
311 struct tipc_link_req *req = (struct tipc_link_req *)data;
314 spin_lock_bh(&req->lock);
316 /* Stop searching if only desired node has been found */
317 if (tipc_node(req->domain) && req->num_nodes) {
318 req->timer_intv = TIPC_LINK_REQ_INACTIVE;
323 * Send discovery message, then update discovery timer
325 * Keep doubling time between requests until limit is reached;
326 * hold at fast polling rate if don't have any associated nodes,
327 * otherwise hold at slow polling rate
329 tipc_bearer_send(req->net, req->bearer_id, req->buf, &req->dest);
332 req->timer_intv *= 2;
334 max_delay = TIPC_LINK_REQ_SLOW;
336 max_delay = TIPC_LINK_REQ_FAST;
337 if (req->timer_intv > max_delay)
338 req->timer_intv = max_delay;
340 mod_timer(&req->timer, jiffies + req->timer_intv);
342 spin_unlock_bh(&req->lock);
346 * tipc_disc_create - create object to send periodic link setup requests
347 * @net: the applicable net namespace
348 * @b_ptr: ptr to bearer issuing requests
349 * @dest: destination address for request messages
350 * @dest_domain: network domain to which links can be established
352 * Returns 0 if successful, otherwise -errno.
354 int tipc_disc_create(struct net *net, struct tipc_bearer *b_ptr,
355 struct tipc_media_addr *dest)
357 struct tipc_link_req *req;
359 req = kmalloc(sizeof(*req), GFP_ATOMIC);
363 req->buf = tipc_buf_acquire(INT_H_SIZE);
369 tipc_disc_init_msg(net, req->buf, DSC_REQ_MSG, b_ptr);
370 memcpy(&req->dest, dest, sizeof(*dest));
372 req->bearer_id = b_ptr->identity;
373 req->domain = b_ptr->domain;
375 req->timer_intv = TIPC_LINK_REQ_INIT;
376 spin_lock_init(&req->lock);
377 setup_timer(&req->timer, disc_timeout, (unsigned long)req);
378 mod_timer(&req->timer, jiffies + req->timer_intv);
379 b_ptr->link_req = req;
380 tipc_bearer_send(net, req->bearer_id, req->buf, &req->dest);
385 * tipc_disc_delete - destroy object sending periodic link setup requests
386 * @req: ptr to link request structure
388 void tipc_disc_delete(struct tipc_link_req *req)
390 del_timer_sync(&req->timer);
396 * tipc_disc_reset - reset object to send periodic link setup requests
397 * @net: the applicable net namespace
398 * @b_ptr: ptr to bearer issuing requests
399 * @dest_domain: network domain to which links can be established
401 void tipc_disc_reset(struct net *net, struct tipc_bearer *b_ptr)
403 struct tipc_link_req *req = b_ptr->link_req;
405 spin_lock_bh(&req->lock);
406 tipc_disc_init_msg(net, req->buf, DSC_REQ_MSG, b_ptr);
408 req->bearer_id = b_ptr->identity;
409 req->domain = b_ptr->domain;
411 req->timer_intv = TIPC_LINK_REQ_INIT;
412 mod_timer(&req->timer, jiffies + req->timer_intv);
413 tipc_bearer_send(net, req->bearer_id, req->buf, &req->dest);
414 spin_unlock_bh(&req->lock);