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