4 * Copyright (c) 2003-2006, 2014, Ericsson AB
5 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
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9 * modification, are permitted provided that the following conditions are met:
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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"
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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34 * POSSIBILITY OF SUCH DAMAGE.
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 */
48 * struct tipc_link_req - information about an ongoing link setup request
49 * @bearer_id: identity of 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 * @lock: spinlock for controlling access to requests
54 * @buf: request message to be (repeatedly) sent
55 * @timer: timer governing period between requests
56 * @timer_intv: current interval between requests (in ms)
58 struct tipc_link_req
{
60 struct tipc_media_addr dest
;
65 struct timer_list timer
;
66 unsigned int timer_intv
;
70 * tipc_disc_init_msg - initialize a link setup message
71 * @type: message type (request or response)
72 * @b_ptr: ptr to bearer issuing message
74 static void tipc_disc_init_msg(struct sk_buff
*buf
, u32 type
,
75 struct tipc_bearer
*b_ptr
)
78 u32 dest_domain
= b_ptr
->domain
;
81 tipc_msg_init(msg
, LINK_CONFIG
, type
, INT_H_SIZE
, dest_domain
);
82 msg_set_non_seq(msg
, 1);
83 msg_set_node_sig(msg
, tipc_random
);
84 msg_set_dest_domain(msg
, dest_domain
);
85 msg_set_bc_netid(msg
, tipc_net_id
);
86 b_ptr
->media
->addr2msg(msg_media_addr(msg
), &b_ptr
->addr
);
90 * disc_dupl_alert - issue node address duplication alert
91 * @b_ptr: pointer to bearer detecting duplication
92 * @node_addr: duplicated node address
93 * @media_addr: media address advertised by duplicated node
95 static void disc_dupl_alert(struct tipc_bearer
*b_ptr
, u32 node_addr
,
96 struct tipc_media_addr
*media_addr
)
98 char node_addr_str
[16];
99 char media_addr_str
[64];
101 tipc_addr_string_fill(node_addr_str
, node_addr
);
102 tipc_media_addr_printf(media_addr_str
, sizeof(media_addr_str
),
104 pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str
,
105 media_addr_str
, b_ptr
->name
);
109 * tipc_disc_rcv - handle incoming discovery message (request or response)
110 * @buf: buffer containing message
111 * @bearer: bearer that message arrived on
113 void tipc_disc_rcv(struct sk_buff
*buf
, struct tipc_bearer
*bearer
)
115 struct tipc_node
*node
;
116 struct tipc_link
*link
;
117 struct tipc_media_addr maddr
;
118 struct sk_buff
*rbuf
;
119 struct tipc_msg
*msg
= buf_msg(buf
);
120 u32 ddom
= msg_dest_domain(msg
);
121 u32 onode
= msg_prevnode(msg
);
122 u32 net_id
= msg_bc_netid(msg
);
123 u32 mtyp
= msg_type(msg
);
124 u32 signature
= msg_node_sig(msg
);
125 bool addr_match
= false;
126 bool sign_match
= false;
127 bool link_up
= false;
128 bool accept_addr
= false;
129 bool accept_sign
= false;
130 bool respond
= false;
132 bearer
->media
->msg2addr(bearer
, &maddr
, msg_media_addr(msg
));
135 /* Ensure message from node is valid and communication is permitted */
136 if (net_id
!= tipc_net_id
)
140 if (!tipc_addr_domain_valid(ddom
))
142 if (!tipc_addr_node_valid(onode
))
145 if (in_own_node(onode
)) {
146 if (memcmp(&maddr
, &bearer
->addr
, sizeof(maddr
)))
147 disc_dupl_alert(bearer
, tipc_own_addr
, &maddr
);
150 if (!tipc_in_scope(ddom
, tipc_own_addr
))
152 if (!tipc_in_scope(bearer
->domain
, onode
))
155 /* Locate, or if necessary, create, node: */
156 node
= tipc_node_find(onode
);
158 node
= tipc_node_create(onode
);
162 tipc_node_lock(node
);
163 link
= node
->links
[bearer
->identity
];
165 /* Prepare to validate requesting node's signature and media address */
166 sign_match
= (signature
== node
->signature
);
167 addr_match
= link
&& !memcmp(&link
->media_addr
, &maddr
, sizeof(maddr
));
168 link_up
= link
&& tipc_link_is_up(link
);
171 /* These three flags give us eight permutations: */
173 if (sign_match
&& addr_match
&& link_up
) {
174 /* All is fine. Do nothing. */
175 } else if (sign_match
&& addr_match
&& !link_up
) {
176 /* Respond. The link will come up in due time */
178 } else if (sign_match
&& !addr_match
&& link_up
) {
179 /* Peer has changed i/f address without rebooting.
180 * If so, the link will reset soon, and the next
181 * discovery will be accepted. So we can ignore it.
182 * It may also be an cloned or malicious peer having
183 * chosen the same node address and signature as an
185 * Ignore requests until the link goes down, if ever.
187 disc_dupl_alert(bearer
, onode
, &maddr
);
188 } else if (sign_match
&& !addr_match
&& !link_up
) {
189 /* Peer link has changed i/f address without rebooting.
190 * It may also be a cloned or malicious peer; we can't
191 * distinguish between the two.
192 * The signature is correct, so we must accept.
196 } else if (!sign_match
&& addr_match
&& link_up
) {
197 /* Peer node rebooted. Two possibilities:
198 * - Delayed re-discovery; this link endpoint has already
199 * reset and re-established contact with the peer, before
200 * receiving a discovery message from that node.
201 * (The peer happened to receive one from this node first).
202 * - The peer came back so fast that our side has not
203 * discovered it yet. Probing from this side will soon
204 * reset the link, since there can be no working link
205 * endpoint at the peer end, and the link will re-establish.
206 * Accept the signature, since it comes from a known peer.
209 } else if (!sign_match
&& addr_match
&& !link_up
) {
210 /* The peer node has rebooted.
211 * Accept signature, since it is a known peer.
215 } else if (!sign_match
&& !addr_match
&& link_up
) {
216 /* Peer rebooted with new address, or a new/duplicate peer.
217 * Ignore until the link goes down, if ever.
219 disc_dupl_alert(bearer
, onode
, &maddr
);
220 } else if (!sign_match
&& !addr_match
&& !link_up
) {
221 /* Peer rebooted with new address, or it is a new peer.
222 * Accept signature and address.
230 node
->signature
= signature
;
234 link
= tipc_link_create(node
, bearer
, &maddr
);
236 memcpy(&link
->media_addr
, &maddr
, sizeof(maddr
));
237 tipc_link_reset(link
);
243 /* Send response, if necessary */
244 if (respond
&& (mtyp
== DSC_REQ_MSG
)) {
245 rbuf
= tipc_buf_acquire(INT_H_SIZE
);
247 tipc_disc_init_msg(rbuf
, DSC_RESP_MSG
, bearer
);
248 tipc_bearer_send(bearer
->identity
, rbuf
, &maddr
);
252 tipc_node_unlock(node
);
256 * disc_update - update frequency of periodic link setup requests
257 * @req: ptr to link request structure
259 * Reinitiates discovery process if discovery object has no associated nodes
260 * and is either not currently searching or is searching at a slow rate
262 static void disc_update(struct tipc_link_req
*req
)
264 if (!req
->num_nodes
) {
265 if ((req
->timer_intv
== TIPC_LINK_REQ_INACTIVE
) ||
266 (req
->timer_intv
> TIPC_LINK_REQ_FAST
)) {
267 req
->timer_intv
= TIPC_LINK_REQ_INIT
;
268 k_start_timer(&req
->timer
, req
->timer_intv
);
274 * tipc_disc_add_dest - increment set of discovered nodes
275 * @req: ptr to link request structure
277 void tipc_disc_add_dest(struct tipc_link_req
*req
)
279 spin_lock_bh(&req
->lock
);
281 spin_unlock_bh(&req
->lock
);
285 * tipc_disc_remove_dest - decrement set of discovered nodes
286 * @req: ptr to link request structure
288 void tipc_disc_remove_dest(struct tipc_link_req
*req
)
290 spin_lock_bh(&req
->lock
);
293 spin_unlock_bh(&req
->lock
);
297 * disc_timeout - send a periodic link setup request
298 * @req: ptr to link request structure
300 * Called whenever a link setup request timer associated with a bearer expires.
302 static void disc_timeout(struct tipc_link_req
*req
)
306 spin_lock_bh(&req
->lock
);
308 /* Stop searching if only desired node has been found */
309 if (tipc_node(req
->domain
) && req
->num_nodes
) {
310 req
->timer_intv
= TIPC_LINK_REQ_INACTIVE
;
315 * Send discovery message, then update discovery timer
317 * Keep doubling time between requests until limit is reached;
318 * hold at fast polling rate if don't have any associated nodes,
319 * otherwise hold at slow polling rate
321 tipc_bearer_send(req
->bearer_id
, req
->buf
, &req
->dest
);
324 req
->timer_intv
*= 2;
326 max_delay
= TIPC_LINK_REQ_SLOW
;
328 max_delay
= TIPC_LINK_REQ_FAST
;
329 if (req
->timer_intv
> max_delay
)
330 req
->timer_intv
= max_delay
;
332 k_start_timer(&req
->timer
, req
->timer_intv
);
334 spin_unlock_bh(&req
->lock
);
338 * tipc_disc_create - create object to send periodic link setup requests
339 * @b_ptr: ptr to bearer issuing requests
340 * @dest: destination address for request messages
341 * @dest_domain: network domain to which links can be established
343 * Returns 0 if successful, otherwise -errno.
345 int tipc_disc_create(struct tipc_bearer
*b_ptr
, struct tipc_media_addr
*dest
)
347 struct tipc_link_req
*req
;
349 req
= kmalloc(sizeof(*req
), GFP_ATOMIC
);
353 req
->buf
= tipc_buf_acquire(INT_H_SIZE
);
359 tipc_disc_init_msg(req
->buf
, DSC_REQ_MSG
, b_ptr
);
360 memcpy(&req
->dest
, dest
, sizeof(*dest
));
361 req
->bearer_id
= b_ptr
->identity
;
362 req
->domain
= b_ptr
->domain
;
364 req
->timer_intv
= TIPC_LINK_REQ_INIT
;
365 spin_lock_init(&req
->lock
);
366 k_init_timer(&req
->timer
, (Handler
)disc_timeout
, (unsigned long)req
);
367 k_start_timer(&req
->timer
, req
->timer_intv
);
368 b_ptr
->link_req
= req
;
369 tipc_bearer_send(req
->bearer_id
, req
->buf
, &req
->dest
);
374 * tipc_disc_delete - destroy object sending periodic link setup requests
375 * @req: ptr to link request structure
377 void tipc_disc_delete(struct tipc_link_req
*req
)
379 k_cancel_timer(&req
->timer
);
380 k_term_timer(&req
->timer
);
386 * tipc_disc_reset - reset object to send periodic link setup requests
387 * @b_ptr: ptr to bearer issuing requests
388 * @dest_domain: network domain to which links can be established
390 void tipc_disc_reset(struct tipc_bearer
*b_ptr
)
392 struct tipc_link_req
*req
= b_ptr
->link_req
;
394 spin_lock_bh(&req
->lock
);
395 tipc_disc_init_msg(req
->buf
, DSC_REQ_MSG
, b_ptr
);
396 req
->bearer_id
= b_ptr
->identity
;
397 req
->domain
= b_ptr
->domain
;
399 req
->timer_intv
= TIPC_LINK_REQ_INIT
;
400 k_start_timer(&req
->timer
, req
->timer_intv
);
401 tipc_bearer_send(req
->bearer_id
, req
->buf
, &req
->dest
);
402 spin_unlock_bh(&req
->lock
);
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