net/tipc/discover.c

   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 "dbg.h"
  39 #include "link.h"
  40 #include "zone.h"
  41 #include "discover.h"
  42 #include "port.h"
  43 #include "name_table.h"
  44
  45 #define TIPC_LINK_REQ_INIT      125     /* min delay during bearer start up */
  46 #define TIPC_LINK_REQ_FAST      2000    /* normal delay if bearer has no links */
  47 #define TIPC_LINK_REQ_SLOW      600000  /* normal delay if bearer has links */
  48
  49 #if 0
  50 #define  GET_NODE_INFO         300
  51 #define  GET_NODE_INFO_RESULT  301
  52 #define  FORWARD_LINK_PROBE    302
  53 #define  LINK_REQUEST_REJECTED 303
  54 #define  LINK_REQUEST_ACCEPTED 304
  55 #define  DROP_LINK_REQUEST     305
  56 #define  CHECK_LINK_COUNT      306
  57 #endif
  58
  59 /*
  60  * TODO: Most of the inter-cluster setup stuff should be
  61  * rewritten, and be made conformant with specification.
  62  */
  63
  64
  65 /**
  66  * struct link_req - information about an ongoing link setup request
  67  * @bearer: bearer issuing requests
  68  * @dest: destination address for request messages
  69  * @buf: request message to be (repeatedly) sent
  70  * @timer: timer governing period between requests
  71  * @timer_intv: current interval between requests (in ms)
  72  */
  73 struct link_req {
  74         struct bearer *bearer;
  75         struct tipc_media_addr dest;
  76         struct sk_buff *buf;
  77         struct timer_list timer;
  78         unsigned int timer_intv;
  79 };
  80
  81
  82 #if 0
  83 int disc_create_link(const struct tipc_link_create *argv)
  84 {
  85         /*
  86          * Code for inter cluster link setup here
  87          */
  88         return TIPC_OK;
  89 }
  90 #endif
  91
  92 /*
  93  * disc_lost_link(): A link has lost contact
  94  */
  95
  96 void tipc_disc_link_event(u32 addr, char *name, int up)
  97 {
  98         if (in_own_cluster(addr))
  99                 return;
 100         /*
 101          * Code for inter cluster link setup here
 102          */
 103 }
 104
 105 /**
 106  * tipc_disc_init_msg - initialize a link setup message
 107  * @type: message type (request or response)
 108  * @req_links: number of links associated with message
 109  * @dest_domain: network domain of node(s) which should respond to message
 110  * @b_ptr: ptr to bearer issuing message
 111  */
 112
 113 static struct sk_buff *tipc_disc_init_msg(u32 type,
 114                                           u32 req_links,
 115                                           u32 dest_domain,
 116                                           struct bearer *b_ptr)
 117 {
 118         struct sk_buff *buf = buf_acquire(DSC_H_SIZE);
 119         struct tipc_msg *msg;
 120
 121         if (buf) {
 122                 msg = buf_msg(buf);
 123                 tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain);
 124                 msg_set_non_seq(msg, 1);
 125                 msg_set_req_links(msg, req_links);
 126                 msg_set_dest_domain(msg, dest_domain);
 127                 msg_set_bc_netid(msg, tipc_net_id);
 128                 msg_set_media_addr(msg, &b_ptr->publ.addr);
 129         }
 130         return buf;
 131 }
 132
 133 /**
 134  * disc_dupl_alert - issue node address duplication alert
 135  * @b_ptr: pointer to bearer detecting duplication
 136  * @node_addr: duplicated node address
 137  * @media_addr: media address advertised by duplicated node
 138  */
 139
 140 static void disc_dupl_alert(struct bearer *b_ptr, u32 node_addr,
 141                             struct tipc_media_addr *media_addr)
 142 {
 143         char node_addr_str[16];
 144         char media_addr_str[64];
 145         struct print_buf pb;
 146
 147         tipc_addr_string_fill(node_addr_str, node_addr);
 148         tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
 149         tipc_media_addr_printf(&pb, media_addr);
 150         tipc_printbuf_validate(&pb);
 151         warn("Duplicate %s using %s seen on <%s>\n",
 152              node_addr_str, media_addr_str, b_ptr->publ.name);
 153 }
 154
 155 /**
 156  * tipc_disc_recv_msg - handle incoming link setup message (request or response)
 157  * @buf: buffer containing message
 158  * @b_ptr: bearer that message arrived on
 159  */
 160
 161 void tipc_disc_recv_msg(struct sk_buff *buf, struct bearer *b_ptr)
 162 {
 163         struct link *link;
 164         struct tipc_media_addr media_addr;
 165         struct tipc_msg *msg = buf_msg(buf);
 166         u32 dest = msg_dest_domain(msg);
 167         u32 orig = msg_prevnode(msg);
 168         u32 net_id = msg_bc_netid(msg);
 169         u32 type = msg_type(msg);
 170
 171         msg_get_media_addr(msg,&media_addr);
 172         msg_dbg(msg, "RECV:");
 173         buf_discard(buf);
 174
 175         if (net_id != tipc_net_id)
 176                 return;
 177         if (!tipc_addr_domain_valid(dest))
 178                 return;
 179         if (!tipc_addr_node_valid(orig))
 180                 return;
 181         if (orig == tipc_own_addr) {
 182                 if (memcmp(&media_addr, &b_ptr->publ.addr, sizeof(media_addr)))
 183                         disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
 184                 return;
 185         }
 186         if (!tipc_in_scope(dest, tipc_own_addr))
 187                 return;
 188         if (is_slave(tipc_own_addr) && is_slave(orig))
 189                 return;
 190         if (is_slave(orig) && !in_own_cluster(orig))
 191                 return;
 192         if (in_own_cluster(orig)) {
 193                 /* Always accept link here */
 194                 struct sk_buff *rbuf;
 195                 struct tipc_media_addr *addr;
 196                 struct tipc_node *n_ptr = tipc_node_find(orig);
 197                 int link_fully_up;
 198
 199                 dbg(" in own cluster\n");
 200                 if (n_ptr == NULL) {
 201                         n_ptr = tipc_node_create(orig);
 202                         if (!n_ptr)
 203                                 return;
 204                 }
 205                 spin_lock_bh(&n_ptr->lock);
 206                 link = n_ptr->links[b_ptr->identity];
 207                 if (!link) {
 208                         dbg("creating link\n");
 209                         link = tipc_link_create(b_ptr, orig, &media_addr);
 210                         if (!link) {
 211                                 spin_unlock_bh(&n_ptr->lock);
 212                                 return;
 213                         }
 214                 }
 215                 addr = &link->media_addr;
 216                 if (memcmp(addr, &media_addr, sizeof(*addr))) {
 217                         if (tipc_link_is_up(link) || (!link->started)) {
 218                                 disc_dupl_alert(b_ptr, orig, &media_addr);
 219                                 spin_unlock_bh(&n_ptr->lock);
 220                                 return;
 221                         }
 222                         warn("Resetting link <%s>, peer interface address changed\n",
 223                              link->name);
 224                         memcpy(addr, &media_addr, sizeof(*addr));
 225                         tipc_link_reset(link);
 226                 }
 227                 link_fully_up = link_working_working(link);
 228                 spin_unlock_bh(&n_ptr->lock);
 229                 if ((type == DSC_RESP_MSG) || link_fully_up)
 230                         return;
 231                 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
 232                 if (rbuf != NULL) {
 233                         msg_dbg(buf_msg(rbuf),"SEND:");
 234                         b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr);
 235                         buf_discard(rbuf);
 236                 }
 237         }
 238 }
 239
 240 /**
 241  * tipc_disc_stop_link_req - stop sending periodic link setup requests
 242  * @req: ptr to link request structure
 243  */
 244
 245 void tipc_disc_stop_link_req(struct link_req *req)
 246 {
 247         if (!req)
 248                 return;
 249
 250         k_cancel_timer(&req->timer);
 251         k_term_timer(&req->timer);
 252         buf_discard(req->buf);
 253         kfree(req);
 254 }
 255
 256 /**
 257  * tipc_disc_update_link_req - update frequency of periodic link setup requests
 258  * @req: ptr to link request structure
 259  */
 260
 261 void tipc_disc_update_link_req(struct link_req *req)
 262 {
 263         if (!req)
 264                 return;
 265
 266         if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
 267                 if (!req->bearer->nodes.count) {
 268                         req->timer_intv = TIPC_LINK_REQ_FAST;
 269                         k_start_timer(&req->timer, req->timer_intv);
 270                 }
 271         } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
 272                 if (req->bearer->nodes.count) {
 273                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 274                         k_start_timer(&req->timer, req->timer_intv);
 275                 }
 276         } else {
 277                 /* leave timer "as is" if haven't yet reached a "normal" rate */
 278         }
 279 }
 280
 281 /**
 282  * disc_timeout - send a periodic link setup request
 283  * @req: ptr to link request structure
 284  *
 285  * Called whenever a link setup request timer associated with a bearer expires.
 286  */
 287
 288 static void disc_timeout(struct link_req *req)
 289 {
 290         spin_lock_bh(&req->bearer->publ.lock);
 291
 292         req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest);
 293
 294         if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
 295             (req->timer_intv == TIPC_LINK_REQ_FAST)) {
 296                 /* leave timer interval "as is" if already at a "normal" rate */
 297         } else {
 298                 req->timer_intv *= 2;
 299                 if (req->timer_intv > TIPC_LINK_REQ_FAST)
 300                         req->timer_intv = TIPC_LINK_REQ_FAST;
 301                 if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
 302                     (req->bearer->nodes.count))
 303                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 304         }
 305         k_start_timer(&req->timer, req->timer_intv);
 306
 307         spin_unlock_bh(&req->bearer->publ.lock);
 308 }
 309
 310 /**
 311  * tipc_disc_init_link_req - start sending periodic link setup requests
 312  * @b_ptr: ptr to bearer issuing requests
 313  * @dest: destination address for request messages
 314  * @dest_domain: network domain of node(s) which should respond to message
 315  * @req_links: max number of desired links
 316  *
 317  * Returns pointer to link request structure, or NULL if unable to create.
 318  */
 319
 320 struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr,
 321                                          const struct tipc_media_addr *dest,
 322                                          u32 dest_domain,
 323                                          u32 req_links)
 324 {
 325         struct link_req *req;
 326
 327         req = kmalloc(sizeof(*req), GFP_ATOMIC);
 328         if (!req)
 329                 return NULL;
 330
 331         req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
 332         if (!req->buf) {
 333                 kfree(req);
 334                 return NULL;
 335         }
 336
 337         memcpy(&req->dest, dest, sizeof(*dest));
 338         req->bearer = b_ptr;
 339         req->timer_intv = TIPC_LINK_REQ_INIT;
 340         k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
 341         k_start_timer(&req->timer, req->timer_intv);
 342         return req;
 343 }
 344