release/src-rt-6.x.4708/linux/linux-2.6.36/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 /*
  51  * TODO: Most of the inter-cluster setup stuff should be
  52  * rewritten, and be made conformant with specification.
  53  */
  54
  55
  56 /**
  57  * struct link_req - information about an ongoing link setup request
  58  * @bearer: bearer issuing requests
  59  * @dest: destination address for request messages
  60  * @buf: request message to be (repeatedly) sent
  61  * @timer: timer governing period between requests
  62  * @timer_intv: current interval between requests (in ms)
  63  */
  64 struct link_req {
  65         struct bearer *bearer;
  66         struct tipc_media_addr dest;
  67         struct sk_buff *buf;
  68         struct timer_list timer;
  69         unsigned int timer_intv;
  70 };
  71
  72
  73
  74 /*
  75  * disc_lost_link(): A link has lost contact
  76  */
  77
  78 void tipc_disc_link_event(u32 addr, char *name, int up)
  79 {
  80         if (in_own_cluster(addr))
  81                 return;
  82         /*
  83          * Code for inter cluster link setup here
  84          */
  85 }
  86
  87 /**
  88  * tipc_disc_init_msg - initialize a link setup message
  89  * @type: message type (request or response)
  90  * @req_links: number of links associated with message
  91  * @dest_domain: network domain of node(s) which should respond to message
  92  * @b_ptr: ptr to bearer issuing message
  93  */
  94
  95 static struct sk_buff *tipc_disc_init_msg(u32 type,
  96                                           u32 req_links,
  97                                           u32 dest_domain,
  98                                           struct bearer *b_ptr)
  99 {
 100         struct sk_buff *buf = buf_acquire(DSC_H_SIZE);
 101         struct tipc_msg *msg;
 102
 103         if (buf) {
 104                 msg = buf_msg(buf);
 105                 tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain);
 106                 msg_set_non_seq(msg, 1);
 107                 msg_set_req_links(msg, req_links);
 108                 msg_set_dest_domain(msg, dest_domain);
 109                 msg_set_bc_netid(msg, tipc_net_id);
 110                 msg_set_media_addr(msg, &b_ptr->publ.addr);
 111         }
 112         return buf;
 113 }
 114
 115 /**
 116  * disc_dupl_alert - issue node address duplication alert
 117  * @b_ptr: pointer to bearer detecting duplication
 118  * @node_addr: duplicated node address
 119  * @media_addr: media address advertised by duplicated node
 120  */
 121
 122 static void disc_dupl_alert(struct bearer *b_ptr, u32 node_addr,
 123                             struct tipc_media_addr *media_addr)
 124 {
 125         char node_addr_str[16];
 126         char media_addr_str[64];
 127         struct print_buf pb;
 128
 129         tipc_addr_string_fill(node_addr_str, node_addr);
 130         tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
 131         tipc_media_addr_printf(&pb, media_addr);
 132         tipc_printbuf_validate(&pb);
 133         warn("Duplicate %s using %s seen on <%s>\n",
 134              node_addr_str, media_addr_str, b_ptr->publ.name);
 135 }
 136
 137 /**
 138  * tipc_disc_recv_msg - handle incoming link setup message (request or response)
 139  * @buf: buffer containing message
 140  * @b_ptr: bearer that message arrived on
 141  */
 142
 143 void tipc_disc_recv_msg(struct sk_buff *buf, struct bearer *b_ptr)
 144 {
 145         struct link *link;
 146         struct tipc_media_addr media_addr;
 147         struct tipc_msg *msg = buf_msg(buf);
 148         u32 dest = msg_dest_domain(msg);
 149         u32 orig = msg_prevnode(msg);
 150         u32 net_id = msg_bc_netid(msg);
 151         u32 type = msg_type(msg);
 152
 153         msg_get_media_addr(msg,&media_addr);
 154         msg_dbg(msg, "RECV:");
 155         buf_discard(buf);
 156
 157         if (net_id != tipc_net_id)
 158                 return;
 159         if (!tipc_addr_domain_valid(dest))
 160                 return;
 161         if (!tipc_addr_node_valid(orig))
 162                 return;
 163         if (orig == tipc_own_addr) {
 164                 if (memcmp(&media_addr, &b_ptr->publ.addr, sizeof(media_addr)))
 165                         disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
 166                 return;
 167         }
 168         if (!tipc_in_scope(dest, tipc_own_addr))
 169                 return;
 170         if (is_slave(tipc_own_addr) && is_slave(orig))
 171                 return;
 172         if (is_slave(orig) && !in_own_cluster(orig))
 173                 return;
 174         if (in_own_cluster(orig)) {
 175                 /* Always accept link here */
 176                 struct sk_buff *rbuf;
 177                 struct tipc_media_addr *addr;
 178                 struct tipc_node *n_ptr = tipc_node_find(orig);
 179                 int link_fully_up;
 180
 181                 dbg(" in own cluster\n");
 182                 if (n_ptr == NULL) {
 183                         n_ptr = tipc_node_create(orig);
 184                         if (!n_ptr)
 185                                 return;
 186                 }
 187                 spin_lock_bh(&n_ptr->lock);
 188                 link = n_ptr->links[b_ptr->identity];
 189                 if (!link) {
 190                         dbg("creating link\n");
 191                         link = tipc_link_create(b_ptr, orig, &media_addr);
 192                         if (!link) {
 193                                 spin_unlock_bh(&n_ptr->lock);
 194                                 return;
 195                         }
 196                 }
 197                 addr = &link->media_addr;
 198                 if (memcmp(addr, &media_addr, sizeof(*addr))) {
 199                         if (tipc_link_is_up(link) || (!link->started)) {
 200                                 disc_dupl_alert(b_ptr, orig, &media_addr);
 201                                 spin_unlock_bh(&n_ptr->lock);
 202                                 return;
 203                         }
 204                         warn("Resetting link <%s>, peer interface address changed\n",
 205                              link->name);
 206                         memcpy(addr, &media_addr, sizeof(*addr));
 207                         tipc_link_reset(link);
 208                 }
 209                 link_fully_up = link_working_working(link);
 210                 spin_unlock_bh(&n_ptr->lock);
 211                 if ((type == DSC_RESP_MSG) || link_fully_up)
 212                         return;
 213                 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
 214                 if (rbuf != NULL) {
 215                         msg_dbg(buf_msg(rbuf),"SEND:");
 216                         b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr);
 217                         buf_discard(rbuf);
 218                 }
 219         }
 220 }
 221
 222 /**
 223  * tipc_disc_stop_link_req - stop sending periodic link setup requests
 224  * @req: ptr to link request structure
 225  */
 226
 227 void tipc_disc_stop_link_req(struct link_req *req)
 228 {
 229         if (!req)
 230                 return;
 231
 232         k_cancel_timer(&req->timer);
 233         k_term_timer(&req->timer);
 234         buf_discard(req->buf);
 235         kfree(req);
 236 }
 237
 238 /**
 239  * tipc_disc_update_link_req - update frequency of periodic link setup requests
 240  * @req: ptr to link request structure
 241  */
 242
 243 void tipc_disc_update_link_req(struct link_req *req)
 244 {
 245         if (!req)
 246                 return;
 247
 248         if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
 249                 if (!req->bearer->nodes.count) {
 250                         req->timer_intv = TIPC_LINK_REQ_FAST;
 251                         k_start_timer(&req->timer, req->timer_intv);
 252                 }
 253         } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
 254                 if (req->bearer->nodes.count) {
 255                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 256                         k_start_timer(&req->timer, req->timer_intv);
 257                 }
 258         } else {
 259                 /* leave timer "as is" if haven't yet reached a "normal" rate */
 260         }
 261 }
 262
 263 /**
 264  * disc_timeout - send a periodic link setup request
 265  * @req: ptr to link request structure
 266  *
 267  * Called whenever a link setup request timer associated with a bearer expires.
 268  */
 269
 270 static void disc_timeout(struct link_req *req)
 271 {
 272         spin_lock_bh(&req->bearer->publ.lock);
 273
 274         req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest);
 275
 276         if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
 277             (req->timer_intv == TIPC_LINK_REQ_FAST)) {
 278                 /* leave timer interval "as is" if already at a "normal" rate */
 279         } else {
 280                 req->timer_intv *= 2;
 281                 if (req->timer_intv > TIPC_LINK_REQ_FAST)
 282                         req->timer_intv = TIPC_LINK_REQ_FAST;
 283                 if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
 284                     (req->bearer->nodes.count))
 285                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 286         }
 287         k_start_timer(&req->timer, req->timer_intv);
 288
 289         spin_unlock_bh(&req->bearer->publ.lock);
 290 }
 291
 292 /**
 293  * tipc_disc_init_link_req - start sending periodic link setup requests
 294  * @b_ptr: ptr to bearer issuing requests
 295  * @dest: destination address for request messages
 296  * @dest_domain: network domain of node(s) which should respond to message
 297  * @req_links: max number of desired links
 298  *
 299  * Returns pointer to link request structure, or NULL if unable to create.
 300  */
 301
 302 struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr,
 303                                          const struct tipc_media_addr *dest,
 304                                          u32 dest_domain,
 305                                          u32 req_links)
 306 {
 307         struct link_req *req;
 308
 309         req = kmalloc(sizeof(*req), GFP_ATOMIC);
 310         if (!req)
 311                 return NULL;
 312
 313         req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
 314         if (!req->buf) {
 315                 kfree(req);
 316                 return NULL;
 317         }
 318
 319         memcpy(&req->dest, dest, sizeof(*dest));
 320         req->bearer = b_ptr;
 321         req->timer_intv = TIPC_LINK_REQ_INIT;
 322         k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
 323         k_start_timer(&req->timer, req->timer_intv);
 324         return req;
 325 }