1 /* 2 * net/tipc/discover.c 3 * 4 * Copyright (c) 2003-2006, Ericsson AB 5 * Copyright (c) 2005-2006, 2010-2011, Wind River Systems 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 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. 19 * 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. 23 * 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. 35 */ 36 37 #include "core.h" 38 #include "link.h" 39 #include "discover.h" 40 41 #define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */ 42 #define TIPC_LINK_REQ_FAST 2000 /* normal delay if bearer has no links */ 43 #define TIPC_LINK_REQ_SLOW 600000 /* normal delay if bearer has links */ 44 45 /* 46 * TODO: Most of the inter-cluster setup stuff should be 47 * rewritten, and be made conformant with specification. 48 */ 49 50 51 /** 52 * struct link_req - information about an ongoing link setup request 53 * @bearer: bearer issuing requests 54 * @dest: destination address for request messages 55 * @buf: request message to be (repeatedly) sent 56 * @timer: timer governing period between requests 57 * @timer_intv: current interval between requests (in ms) 58 */ 59 struct link_req { 60 struct tipc_bearer *bearer; 61 struct tipc_media_addr dest; 62 struct sk_buff *buf; 63 struct timer_list timer; 64 unsigned int timer_intv; 65 }; 66 67 /** 68 * tipc_disc_init_msg - initialize a link setup message 69 * @type: message type (request or response) 70 * @dest_domain: network domain of node(s) which should respond to message 71 * @b_ptr: ptr to bearer issuing message 72 */ 73 74 static struct sk_buff *tipc_disc_init_msg(u32 type, 75 u32 dest_domain, 76 struct tipc_bearer *b_ptr) 77 { 78 struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE); 79 struct tipc_msg *msg; 80 81 if (buf) { 82 msg = buf_msg(buf); 83 tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain); 84 msg_set_non_seq(msg, 1); 85 msg_set_dest_domain(msg, dest_domain); 86 msg_set_bc_netid(msg, tipc_net_id); 87 msg_set_media_addr(msg, &b_ptr->addr); 88 } 89 return buf; 90 } 91 92 /** 93 * disc_dupl_alert - issue node address duplication alert 94 * @b_ptr: pointer to bearer detecting duplication 95 * @node_addr: duplicated node address 96 * @media_addr: media address advertised by duplicated node 97 */ 98 99 static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr, 100 struct tipc_media_addr *media_addr) 101 { 102 char node_addr_str[16]; 103 char media_addr_str[64]; 104 struct print_buf pb; 105 106 tipc_addr_string_fill(node_addr_str, node_addr); 107 tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str)); 108 tipc_media_addr_printf(&pb, media_addr); 109 tipc_printbuf_validate(&pb); 110 warn("Duplicate %s using %s seen on <%s>\n", 111 node_addr_str, media_addr_str, b_ptr->name); 112 } 113 114 /** 115 * tipc_disc_recv_msg - handle incoming link setup message (request or response) 116 * @buf: buffer containing message 117 * @b_ptr: bearer that message arrived on 118 */ 119 120 void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) 121 { 122 struct tipc_node *n_ptr; 123 struct link *link; 124 struct tipc_media_addr media_addr, *addr; 125 struct sk_buff *rbuf; 126 struct tipc_msg *msg = buf_msg(buf); 127 u32 dest = msg_dest_domain(msg); 128 u32 orig = msg_prevnode(msg); 129 u32 net_id = msg_bc_netid(msg); 130 u32 type = msg_type(msg); 131 int link_fully_up; 132 133 msg_get_media_addr(msg, &media_addr); 134 buf_discard(buf); 135 136 /* Validate discovery message from requesting node */ 137 if (net_id != tipc_net_id) 138 return; 139 if (!tipc_addr_domain_valid(dest)) 140 return; 141 if (!tipc_addr_node_valid(orig)) 142 return; 143 if (orig == tipc_own_addr) { 144 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr))) 145 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr); 146 return; 147 } 148 if (!tipc_in_scope(dest, tipc_own_addr)) 149 return; 150 if (!in_own_cluster(orig)) 151 return; 152 153 /* Locate structure corresponding to requesting node */ 154 n_ptr = tipc_node_find(orig); 155 if (!n_ptr) { 156 n_ptr = tipc_node_create(orig); 157 if (!n_ptr) 158 return; 159 } 160 tipc_node_lock(n_ptr); 161 162 /* Don't talk to neighbor during cleanup after last session */ 163 if (n_ptr->cleanup_required) { 164 tipc_node_unlock(n_ptr); 165 return; 166 } 167 168 link = n_ptr->links[b_ptr->identity]; 169 170 /* Create a link endpoint for this bearer, if necessary */ 171 if (!link) { 172 link = tipc_link_create(n_ptr, b_ptr, &media_addr); 173 if (!link) { 174 tipc_node_unlock(n_ptr); 175 return; 176 } 177 } 178 179 /* 180 * Ensure requesting node's media address is correct 181 * 182 * If media address doesn't match and the link is working, reject the 183 * request (must be from a duplicate node). 184 * 185 * If media address doesn't match and the link is not working, accept 186 * the new media address and reset the link to ensure it starts up 187 * cleanly. 188 */ 189 addr = &link->media_addr; 190 if (memcmp(addr, &media_addr, sizeof(*addr))) { 191 if (tipc_link_is_up(link) || (!link->started)) { 192 disc_dupl_alert(b_ptr, orig, &media_addr); 193 tipc_node_unlock(n_ptr); 194 return; 195 } 196 warn("Resetting link <%s>, peer interface address changed\n", 197 link->name); 198 memcpy(addr, &media_addr, sizeof(*addr)); 199 tipc_link_reset(link); 200 } 201 202 /* Accept discovery message & send response, if necessary */ 203 link_fully_up = link_working_working(link); 204 205 if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) { 206 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr); 207 if (rbuf) { 208 b_ptr->media->send_msg(rbuf, b_ptr, &media_addr); 209 buf_discard(rbuf); 210 } 211 } 212 213 tipc_node_unlock(n_ptr); 214 } 215 216 /** 217 * tipc_disc_stop_link_req - stop sending periodic link setup requests 218 * @req: ptr to link request structure 219 */ 220 221 void tipc_disc_stop_link_req(struct link_req *req) 222 { 223 if (!req) 224 return; 225 226 k_cancel_timer(&req->timer); 227 k_term_timer(&req->timer); 228 buf_discard(req->buf); 229 kfree(req); 230 } 231 232 /** 233 * tipc_disc_update_link_req - update frequency of periodic link setup requests 234 * @req: ptr to link request structure 235 */ 236 237 void tipc_disc_update_link_req(struct link_req *req) 238 { 239 if (!req) 240 return; 241 242 if (req->timer_intv == TIPC_LINK_REQ_SLOW) { 243 if (!req->bearer->nodes.count) { 244 req->timer_intv = TIPC_LINK_REQ_FAST; 245 k_start_timer(&req->timer, req->timer_intv); 246 } 247 } else if (req->timer_intv == TIPC_LINK_REQ_FAST) { 248 if (req->bearer->nodes.count) { 249 req->timer_intv = TIPC_LINK_REQ_SLOW; 250 k_start_timer(&req->timer, req->timer_intv); 251 } 252 } else { 253 /* leave timer "as is" if haven't yet reached a "normal" rate */ 254 } 255 } 256 257 /** 258 * disc_timeout - send a periodic link setup request 259 * @req: ptr to link request structure 260 * 261 * Called whenever a link setup request timer associated with a bearer expires. 262 */ 263 264 static void disc_timeout(struct link_req *req) 265 { 266 spin_lock_bh(&req->bearer->lock); 267 268 req->bearer->media->send_msg(req->buf, req->bearer, &req->dest); 269 270 if ((req->timer_intv == TIPC_LINK_REQ_SLOW) || 271 (req->timer_intv == TIPC_LINK_REQ_FAST)) { 272 /* leave timer interval "as is" if already at a "normal" rate */ 273 } else { 274 req->timer_intv *= 2; 275 if (req->timer_intv > TIPC_LINK_REQ_FAST) 276 req->timer_intv = TIPC_LINK_REQ_FAST; 277 if ((req->timer_intv == TIPC_LINK_REQ_FAST) && 278 (req->bearer->nodes.count)) 279 req->timer_intv = TIPC_LINK_REQ_SLOW; 280 } 281 k_start_timer(&req->timer, req->timer_intv); 282 283 spin_unlock_bh(&req->bearer->lock); 284 } 285 286 /** 287 * tipc_disc_init_link_req - start sending periodic link setup requests 288 * @b_ptr: ptr to bearer issuing requests 289 * @dest: destination address for request messages 290 * @dest_domain: network domain of node(s) which should respond to message 291 * 292 * Returns pointer to link request structure, or NULL if unable to create. 293 */ 294 295 struct link_req *tipc_disc_init_link_req(struct tipc_bearer *b_ptr, 296 const struct tipc_media_addr *dest, 297 u32 dest_domain) 298 { 299 struct link_req *req; 300 301 req = kmalloc(sizeof(*req), GFP_ATOMIC); 302 if (!req) 303 return NULL; 304 305 req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr); 306 if (!req->buf) { 307 kfree(req); 308 return NULL; 309 } 310 311 memcpy(&req->dest, dest, sizeof(*dest)); 312 req->bearer = b_ptr; 313 req->timer_intv = TIPC_LINK_REQ_INIT; 314 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req); 315 k_start_timer(&req->timer, req->timer_intv); 316 return req; 317 } 318 319