4 * Copyright (c) 2003-2006, 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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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"
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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: bearer issuing requests
50 * @dest: destination address for request messages
51 * @num_nodes: number of nodes currently discovered (i.e. with an active link)
52 * @lock: spinlock for controlling access to requests
53 * @buf: request message to be (repeatedly) sent
54 * @timer: timer governing period between requests
55 * @timer_intv: current interval between requests (in ms)
57 struct tipc_link_req
{
58 struct tipc_bearer
*bearer
;
59 struct tipc_media_addr dest
;
63 struct timer_list timer
;
64 unsigned int timer_intv
;
68 * tipc_disc_init_msg - initialize a link setup message
69 * @type: message type (request or response)
70 * @b_ptr: ptr to bearer issuing message
72 static struct sk_buff
*tipc_disc_init_msg(u32 type
, struct tipc_bearer
*b_ptr
)
74 struct sk_buff
*buf
= tipc_buf_acquire(INT_H_SIZE
);
76 u32 dest_domain
= b_ptr
->domain
;
80 tipc_msg_init(msg
, LINK_CONFIG
, type
, INT_H_SIZE
, dest_domain
);
81 msg_set_non_seq(msg
, 1);
82 msg_set_node_sig(msg
, tipc_random
);
83 msg_set_dest_domain(msg
, dest_domain
);
84 msg_set_bc_netid(msg
, tipc_net_id
);
85 b_ptr
->media
->addr2msg(&b_ptr
->addr
, msg_media_addr(msg
));
91 * disc_dupl_alert - issue node address duplication alert
92 * @b_ptr: pointer to bearer detecting duplication
93 * @node_addr: duplicated node address
94 * @media_addr: media address advertised by duplicated node
96 static void disc_dupl_alert(struct tipc_bearer
*b_ptr
, u32 node_addr
,
97 struct tipc_media_addr
*media_addr
)
99 char node_addr_str
[16];
100 char media_addr_str
[64];
102 tipc_addr_string_fill(node_addr_str
, node_addr
);
103 tipc_media_addr_printf(media_addr_str
, sizeof(media_addr_str
),
105 pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str
,
106 media_addr_str
, b_ptr
->name
);
110 * tipc_disc_rcv - handle incoming link setup message (request or response)
111 * @buf: buffer containing message
112 * @b_ptr: bearer that message arrived on
114 void tipc_disc_rcv(struct sk_buff
*buf
, struct tipc_bearer
*b_ptr
)
116 struct tipc_node
*n_ptr
;
117 struct tipc_link
*link
;
118 struct tipc_media_addr media_addr
;
119 struct sk_buff
*rbuf
;
120 struct tipc_msg
*msg
= buf_msg(buf
);
121 u32 dest
= msg_dest_domain(msg
);
122 u32 orig
= msg_prevnode(msg
);
123 u32 net_id
= msg_bc_netid(msg
);
124 u32 type
= msg_type(msg
);
125 u32 signature
= msg_node_sig(msg
);
129 media_addr
.broadcast
= 1;
130 b_ptr
->media
->msg2addr(b_ptr
, &media_addr
, msg_media_addr(msg
));
133 /* Ensure message from node is valid and communication is permitted */
134 if (net_id
!= tipc_net_id
)
136 if (media_addr
.broadcast
)
138 if (!tipc_addr_domain_valid(dest
))
140 if (!tipc_addr_node_valid(orig
))
142 if (orig
== tipc_own_addr
) {
143 if (memcmp(&media_addr
, &b_ptr
->addr
, sizeof(media_addr
)))
144 disc_dupl_alert(b_ptr
, tipc_own_addr
, &media_addr
);
147 if (!tipc_in_scope(dest
, tipc_own_addr
))
149 if (!tipc_in_scope(b_ptr
->domain
, orig
))
152 /* Locate structure corresponding to requesting node */
153 n_ptr
= tipc_node_find(orig
);
155 n_ptr
= tipc_node_create(orig
);
159 tipc_node_lock(n_ptr
);
161 /* Prepare to validate requesting node's signature and media address */
162 link
= n_ptr
->links
[b_ptr
->identity
];
163 addr_mismatch
= (link
!= NULL
) &&
164 memcmp(&link
->media_addr
, &media_addr
, sizeof(media_addr
));
167 * Ensure discovery message's signature is correct
169 * If signature is incorrect and there is no working link to the node,
170 * accept the new signature but invalidate all existing links to the
171 * node so they won't re-activate without a new discovery message.
173 * If signature is incorrect and the requested link to the node is
174 * working, accept the new signature. (This is an instance of delayed
175 * rediscovery, where a link endpoint was able to re-establish contact
176 * with its peer endpoint on a node that rebooted before receiving a
177 * discovery message from that node.)
179 * If signature is incorrect and there is a working link to the node
180 * that is not the requested link, reject the request (must be from
183 if (signature
!= n_ptr
->signature
) {
184 if (n_ptr
->working_links
== 0) {
185 struct tipc_link
*curr_link
;
188 for (i
= 0; i
< MAX_BEARERS
; i
++) {
189 curr_link
= n_ptr
->links
[i
];
191 memset(&curr_link
->media_addr
, 0,
193 tipc_link_reset(curr_link
);
196 addr_mismatch
= (link
!= NULL
);
197 } else if (tipc_link_is_up(link
) && !addr_mismatch
) {
198 /* delayed rediscovery */
200 disc_dupl_alert(b_ptr
, orig
, &media_addr
);
201 tipc_node_unlock(n_ptr
);
204 n_ptr
->signature
= signature
;
208 * Ensure requesting node's media address is correct
210 * If media address doesn't match and the link is working, reject the
211 * request (must be from a duplicate node).
213 * If media address doesn't match and the link is not working, accept
214 * the new media address and reset the link to ensure it starts up
218 if (tipc_link_is_up(link
)) {
219 disc_dupl_alert(b_ptr
, orig
, &media_addr
);
220 tipc_node_unlock(n_ptr
);
223 memcpy(&link
->media_addr
, &media_addr
,
225 tipc_link_reset(link
);
229 /* Create a link endpoint for this bearer, if necessary */
231 link
= tipc_link_create(n_ptr
, b_ptr
, &media_addr
);
233 tipc_node_unlock(n_ptr
);
238 /* Accept discovery message & send response, if necessary */
239 link_fully_up
= link_working_working(link
);
241 if ((type
== DSC_REQ_MSG
) && !link_fully_up
) {
242 rbuf
= tipc_disc_init_msg(DSC_RESP_MSG
, b_ptr
);
244 tipc_bearer_send(b_ptr
, rbuf
, &media_addr
);
249 tipc_node_unlock(n_ptr
);
253 * disc_update - update frequency of periodic link setup requests
254 * @req: ptr to link request structure
256 * Reinitiates discovery process if discovery object has no associated nodes
257 * and is either not currently searching or is searching at a slow rate
259 static void disc_update(struct tipc_link_req
*req
)
261 if (!req
->num_nodes
) {
262 if ((req
->timer_intv
== TIPC_LINK_REQ_INACTIVE
) ||
263 (req
->timer_intv
> TIPC_LINK_REQ_FAST
)) {
264 req
->timer_intv
= TIPC_LINK_REQ_INIT
;
265 k_start_timer(&req
->timer
, req
->timer_intv
);
271 * tipc_disc_add_dest - increment set of discovered nodes
272 * @req: ptr to link request structure
274 void tipc_disc_add_dest(struct tipc_link_req
*req
)
276 spin_lock_bh(&req
->lock
);
278 spin_unlock_bh(&req
->lock
);
282 * tipc_disc_remove_dest - decrement set of discovered nodes
283 * @req: ptr to link request structure
285 void tipc_disc_remove_dest(struct tipc_link_req
*req
)
287 spin_lock_bh(&req
->lock
);
290 spin_unlock_bh(&req
->lock
);
294 * disc_timeout - send a periodic link setup request
295 * @req: ptr to link request structure
297 * Called whenever a link setup request timer associated with a bearer expires.
299 static void disc_timeout(struct tipc_link_req
*req
)
303 spin_lock_bh(&req
->lock
);
305 /* Stop searching if only desired node has been found */
306 if (tipc_node(req
->bearer
->domain
) && req
->num_nodes
) {
307 req
->timer_intv
= TIPC_LINK_REQ_INACTIVE
;
312 * Send discovery message, then update discovery timer
314 * Keep doubling time between requests until limit is reached;
315 * hold at fast polling rate if don't have any associated nodes,
316 * otherwise hold at slow polling rate
318 tipc_bearer_send(req
->bearer
, req
->buf
, &req
->dest
);
321 req
->timer_intv
*= 2;
323 max_delay
= TIPC_LINK_REQ_SLOW
;
325 max_delay
= TIPC_LINK_REQ_FAST
;
326 if (req
->timer_intv
> max_delay
)
327 req
->timer_intv
= max_delay
;
329 k_start_timer(&req
->timer
, req
->timer_intv
);
331 spin_unlock_bh(&req
->lock
);
335 * tipc_disc_create - create object to send periodic link setup requests
336 * @b_ptr: ptr to bearer issuing requests
337 * @dest: destination address for request messages
338 * @dest_domain: network domain to which links can be established
340 * Returns 0 if successful, otherwise -errno.
342 int tipc_disc_create(struct tipc_bearer
*b_ptr
, struct tipc_media_addr
*dest
)
344 struct tipc_link_req
*req
;
346 req
= kmalloc(sizeof(*req
), GFP_ATOMIC
);
350 req
->buf
= tipc_disc_init_msg(DSC_REQ_MSG
, b_ptr
);
356 memcpy(&req
->dest
, dest
, sizeof(*dest
));
359 req
->timer_intv
= TIPC_LINK_REQ_INIT
;
360 spin_lock_init(&req
->lock
);
361 k_init_timer(&req
->timer
, (Handler
)disc_timeout
, (unsigned long)req
);
362 k_start_timer(&req
->timer
, req
->timer_intv
);
363 b_ptr
->link_req
= req
;
364 tipc_bearer_send(req
->bearer
, req
->buf
, &req
->dest
);
369 * tipc_disc_delete - destroy object sending periodic link setup requests
370 * @req: ptr to link request structure
372 void tipc_disc_delete(struct tipc_link_req
*req
)
374 k_cancel_timer(&req
->timer
);
375 k_term_timer(&req
->timer
);