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: 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);