4 * Copyright (c) 2003-2006, Ericsson AB
5 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems
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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(&b_ptr->addr, msg_media_addr(msg));
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 link setup message (request or response)
110 * @buf: buffer containing message
111 * @b_ptr: bearer that message arrived on
113 void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *b_ptr)
115 struct tipc_node *n_ptr;
116 struct tipc_link *link;
117 struct tipc_media_addr media_addr;
118 struct sk_buff *rbuf;
119 struct tipc_msg *msg = buf_msg(buf);
120 u32 dest = msg_dest_domain(msg);
121 u32 orig = msg_prevnode(msg);
122 u32 net_id = msg_bc_netid(msg);
123 u32 type = msg_type(msg);
124 u32 signature = msg_node_sig(msg);
128 media_addr.broadcast = 1;
129 b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg));
132 /* Ensure message from node is valid and communication is permitted */
133 if (net_id != tipc_net_id)
135 if (media_addr.broadcast)
137 if (!tipc_addr_domain_valid(dest))
139 if (!tipc_addr_node_valid(orig))
141 if (orig == tipc_own_addr) {
142 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
143 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
146 if (!tipc_in_scope(dest, tipc_own_addr))
148 if (!tipc_in_scope(b_ptr->domain, orig))
151 /* Locate structure corresponding to requesting node */
152 n_ptr = tipc_node_find(orig);
154 n_ptr = tipc_node_create(orig);
158 tipc_node_lock(n_ptr);
160 /* Prepare to validate requesting node's signature and media address */
161 link = n_ptr->links[b_ptr->identity];
162 addr_mismatch = (link != NULL) &&
163 memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
166 * Ensure discovery message's signature is correct
168 * If signature is incorrect and there is no working link to the node,
169 * accept the new signature but invalidate all existing links to the
170 * node so they won't re-activate without a new discovery message.
172 * If signature is incorrect and the requested link to the node is
173 * working, accept the new signature. (This is an instance of delayed
174 * rediscovery, where a link endpoint was able to re-establish contact
175 * with its peer endpoint on a node that rebooted before receiving a
176 * discovery message from that node.)
178 * If signature is incorrect and there is a working link to the node
179 * that is not the requested link, reject the request (must be from
182 if (signature != n_ptr->signature) {
183 if (n_ptr->working_links == 0) {
184 struct tipc_link *curr_link;
187 for (i = 0; i < MAX_BEARERS; i++) {
188 curr_link = n_ptr->links[i];
190 memset(&curr_link->media_addr, 0,
192 tipc_link_reset(curr_link);
195 addr_mismatch = (link != NULL);
196 } else if (tipc_link_is_up(link) && !addr_mismatch) {
197 /* delayed rediscovery */
199 disc_dupl_alert(b_ptr, orig, &media_addr);
200 tipc_node_unlock(n_ptr);
203 n_ptr->signature = signature;
207 * Ensure requesting node's media address is correct
209 * If media address doesn't match and the link is working, reject the
210 * request (must be from a duplicate node).
212 * If media address doesn't match and the link is not working, accept
213 * the new media address and reset the link to ensure it starts up
217 if (tipc_link_is_up(link)) {
218 disc_dupl_alert(b_ptr, orig, &media_addr);
219 tipc_node_unlock(n_ptr);
222 memcpy(&link->media_addr, &media_addr,
224 tipc_link_reset(link);
228 /* Create a link endpoint for this bearer, if necessary */
230 link = tipc_link_create(n_ptr, b_ptr, &media_addr);
232 tipc_node_unlock(n_ptr);
237 /* Accept discovery message & send response, if necessary */
238 link_fully_up = link_working_working(link);
240 if ((type == DSC_REQ_MSG) && !link_fully_up) {
241 rbuf = tipc_buf_acquire(INT_H_SIZE);
243 tipc_disc_init_msg(rbuf, DSC_RESP_MSG, b_ptr);
244 tipc_bearer_send(b_ptr->identity, 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->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_id, 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_buf_acquire(INT_H_SIZE);
356 tipc_disc_init_msg(req->buf, DSC_REQ_MSG, b_ptr);
357 memcpy(&req->dest, dest, sizeof(*dest));
358 req->bearer_id = b_ptr->identity;
359 req->domain = b_ptr->domain;
361 req->timer_intv = TIPC_LINK_REQ_INIT;
362 spin_lock_init(&req->lock);
363 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
364 k_start_timer(&req->timer, req->timer_intv);
365 b_ptr->link_req = req;
366 tipc_bearer_send(req->bearer_id, req->buf, &req->dest);
371 * tipc_disc_delete - destroy object sending periodic link setup requests
372 * @req: ptr to link request structure
374 void tipc_disc_delete(struct tipc_link_req *req)
376 k_cancel_timer(&req->timer);
377 k_term_timer(&req->timer);
383 * tipc_disc_reset - reset object to send periodic link setup requests
384 * @b_ptr: ptr to bearer issuing requests
385 * @dest_domain: network domain to which links can be established
387 void tipc_disc_reset(struct tipc_bearer *b_ptr)
389 struct tipc_link_req *req = b_ptr->link_req;
391 spin_lock_bh(&req->lock);
392 tipc_disc_init_msg(req->buf, DSC_REQ_MSG, b_ptr);
393 req->bearer_id = b_ptr->identity;
394 req->domain = b_ptr->domain;
396 req->timer_intv = TIPC_LINK_REQ_INIT;
397 k_start_timer(&req->timer, req->timer_intv);
398 tipc_bearer_send(req->bearer_id, req->buf, &req->dest);
399 spin_unlock_bh(&req->lock);