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