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