1 /* 2 * net/tipc/discover.c 3 * 4 * Copyright (c) 2003-2006, Ericsson AB 5 * Copyright (c) 2005-2006, 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 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 * @req_links: number of links associated with message 71 * @dest_domain: network domain of node(s) which should respond to message 72 * @b_ptr: ptr to bearer issuing message 73 */ 74 75 static struct sk_buff *tipc_disc_init_msg(u32 type, 76 u32 req_links, 77 u32 dest_domain, 78 struct bearer *b_ptr) 79 { 80 struct sk_buff *buf = tipc_buf_acquire(DSC_H_SIZE); 81 struct tipc_msg *msg; 82 83 if (buf) { 84 msg = buf_msg(buf); 85 tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain); 86 msg_set_non_seq(msg, 1); 87 msg_set_req_links(msg, req_links); 88 msg_set_dest_domain(msg, dest_domain); 89 msg_set_bc_netid(msg, tipc_net_id); 90 msg_set_media_addr(msg, &b_ptr->publ.addr); 91 } 92 return buf; 93 } 94 95 /** 96 * disc_dupl_alert - issue node address duplication alert 97 * @b_ptr: pointer to bearer detecting duplication 98 * @node_addr: duplicated node address 99 * @media_addr: media address advertised by duplicated node 100 */ 101 102 static void disc_dupl_alert(struct bearer *b_ptr, u32 node_addr, 103 struct tipc_media_addr *media_addr) 104 { 105 char node_addr_str[16]; 106 char media_addr_str[64]; 107 struct print_buf pb; 108 109 tipc_addr_string_fill(node_addr_str, node_addr); 110 tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str)); 111 tipc_media_addr_printf(&pb, media_addr); 112 tipc_printbuf_validate(&pb); 113 warn("Duplicate %s using %s seen on <%s>\n", 114 node_addr_str, media_addr_str, b_ptr->publ.name); 115 } 116 117 /** 118 * tipc_disc_recv_msg - handle incoming link setup message (request or response) 119 * @buf: buffer containing message 120 * @b_ptr: bearer that message arrived on 121 */ 122 123 void tipc_disc_recv_msg(struct sk_buff *buf, struct bearer *b_ptr) 124 { 125 struct link *link; 126 struct tipc_media_addr media_addr; 127 struct tipc_msg *msg = buf_msg(buf); 128 u32 dest = msg_dest_domain(msg); 129 u32 orig = msg_prevnode(msg); 130 u32 net_id = msg_bc_netid(msg); 131 u32 type = msg_type(msg); 132 133 msg_get_media_addr(msg, &media_addr); 134 buf_discard(buf); 135 136 if (net_id != tipc_net_id) 137 return; 138 if (!tipc_addr_domain_valid(dest)) 139 return; 140 if (!tipc_addr_node_valid(orig)) 141 return; 142 if (orig == tipc_own_addr) { 143 if (memcmp(&media_addr, &b_ptr->publ.addr, sizeof(media_addr))) 144 disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr); 145 return; 146 } 147 if (!tipc_in_scope(dest, tipc_own_addr)) 148 return; 149 if (in_own_cluster(orig)) { 150 /* Always accept link here */ 151 struct sk_buff *rbuf; 152 struct tipc_media_addr *addr; 153 struct tipc_node *n_ptr = tipc_node_find(orig); 154 int link_fully_up; 155 156 if (n_ptr == NULL) { 157 n_ptr = tipc_node_create(orig); 158 if (!n_ptr) 159 return; 160 } 161 spin_lock_bh(&n_ptr->lock); 162 163 /* Don't talk to neighbor during cleanup after last session */ 164 165 if (n_ptr->cleanup_required) { 166 spin_unlock_bh(&n_ptr->lock); 167 return; 168 } 169 170 link = n_ptr->links[b_ptr->identity]; 171 if (!link) { 172 link = tipc_link_create(b_ptr, orig, &media_addr); 173 if (!link) { 174 spin_unlock_bh(&n_ptr->lock); 175 return; 176 } 177 } 178 addr = &link->media_addr; 179 if (memcmp(addr, &media_addr, sizeof(*addr))) { 180 if (tipc_link_is_up(link) || (!link->started)) { 181 disc_dupl_alert(b_ptr, orig, &media_addr); 182 spin_unlock_bh(&n_ptr->lock); 183 return; 184 } 185 warn("Resetting link <%s>, peer interface address changed\n", 186 link->name); 187 memcpy(addr, &media_addr, sizeof(*addr)); 188 tipc_link_reset(link); 189 } 190 link_fully_up = link_working_working(link); 191 spin_unlock_bh(&n_ptr->lock); 192 if ((type == DSC_RESP_MSG) || link_fully_up) 193 return; 194 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr); 195 if (rbuf != NULL) { 196 b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr); 197 buf_discard(rbuf); 198 } 199 } 200 } 201 202 /** 203 * tipc_disc_stop_link_req - stop sending periodic link setup requests 204 * @req: ptr to link request structure 205 */ 206 207 void tipc_disc_stop_link_req(struct link_req *req) 208 { 209 if (!req) 210 return; 211 212 k_cancel_timer(&req->timer); 213 k_term_timer(&req->timer); 214 buf_discard(req->buf); 215 kfree(req); 216 } 217 218 /** 219 * tipc_disc_update_link_req - update frequency of periodic link setup requests 220 * @req: ptr to link request structure 221 */ 222 223 void tipc_disc_update_link_req(struct link_req *req) 224 { 225 if (!req) 226 return; 227 228 if (req->timer_intv == TIPC_LINK_REQ_SLOW) { 229 if (!req->bearer->nodes.count) { 230 req->timer_intv = TIPC_LINK_REQ_FAST; 231 k_start_timer(&req->timer, req->timer_intv); 232 } 233 } else if (req->timer_intv == TIPC_LINK_REQ_FAST) { 234 if (req->bearer->nodes.count) { 235 req->timer_intv = TIPC_LINK_REQ_SLOW; 236 k_start_timer(&req->timer, req->timer_intv); 237 } 238 } else { 239 /* leave timer "as is" if haven't yet reached a "normal" rate */ 240 } 241 } 242 243 /** 244 * disc_timeout - send a periodic link setup request 245 * @req: ptr to link request structure 246 * 247 * Called whenever a link setup request timer associated with a bearer expires. 248 */ 249 250 static void disc_timeout(struct link_req *req) 251 { 252 spin_lock_bh(&req->bearer->publ.lock); 253 254 req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest); 255 256 if ((req->timer_intv == TIPC_LINK_REQ_SLOW) || 257 (req->timer_intv == TIPC_LINK_REQ_FAST)) { 258 /* leave timer interval "as is" if already at a "normal" rate */ 259 } else { 260 req->timer_intv *= 2; 261 if (req->timer_intv > TIPC_LINK_REQ_FAST) 262 req->timer_intv = TIPC_LINK_REQ_FAST; 263 if ((req->timer_intv == TIPC_LINK_REQ_FAST) && 264 (req->bearer->nodes.count)) 265 req->timer_intv = TIPC_LINK_REQ_SLOW; 266 } 267 k_start_timer(&req->timer, req->timer_intv); 268 269 spin_unlock_bh(&req->bearer->publ.lock); 270 } 271 272 /** 273 * tipc_disc_init_link_req - start sending periodic link setup requests 274 * @b_ptr: ptr to bearer issuing requests 275 * @dest: destination address for request messages 276 * @dest_domain: network domain of node(s) which should respond to message 277 * @req_links: max number of desired links 278 * 279 * Returns pointer to link request structure, or NULL if unable to create. 280 */ 281 282 struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr, 283 const struct tipc_media_addr *dest, 284 u32 dest_domain, 285 u32 req_links) 286 { 287 struct link_req *req; 288 289 req = kmalloc(sizeof(*req), GFP_ATOMIC); 290 if (!req) 291 return NULL; 292 293 req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr); 294 if (!req->buf) { 295 kfree(req); 296 return NULL; 297 } 298 299 memcpy(&req->dest, dest, sizeof(*dest)); 300 req->bearer = b_ptr; 301 req->timer_intv = TIPC_LINK_REQ_INIT; 302 k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req); 303 k_start_timer(&req->timer, req->timer_intv); 304 return req; 305 } 306 307