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                 msg_init(msg, LINK_CONFIG, type, TIPC_OK, DSC_H_SIZE,
 124                          dest_domain);
 125                 msg_set_non_seq(msg);
 126                 msg_set_req_links(msg, req_links);
 127                 msg_set_dest_domain(msg, dest_domain);
 128                 msg_set_bc_netid(msg, tipc_net_id);
 129                 msg_set_media_addr(msg, &b_ptr->publ.addr);
 130         }
 131         return buf;
 132 }
 133
 134 /**
 135  * tipc_disc_recv_msg - handle incoming link setup message (request or response)
 136  * @buf: buffer containing message
 137  */
 138
 139 void tipc_disc_recv_msg(struct sk_buff *buf)
 140 {
 141         struct bearer *b_ptr = (struct bearer *)TIPC_SKB_CB(buf)->handle;
 142         struct link *link;
 143         struct tipc_media_addr media_addr;
 144         struct tipc_msg *msg = buf_msg(buf);
 145         u32 dest = msg_dest_domain(msg);
 146         u32 orig = msg_prevnode(msg);
 147         u32 net_id = msg_bc_netid(msg);
 148         u32 type = msg_type(msg);
 149
 150         msg_get_media_addr(msg,&media_addr);
 151         msg_dbg(msg, "RECV:");
 152         buf_discard(buf);
 153
 154         if (net_id != tipc_net_id)
 155                 return;
 156         if (!tipc_addr_domain_valid(dest))
 157                 return;
 158         if (!tipc_addr_node_valid(orig))
 159                 return;
 160         if (orig == tipc_own_addr)
 161                 return;
 162         if (!in_scope(dest, tipc_own_addr))
 163                 return;
 164         if (is_slave(tipc_own_addr) && is_slave(orig))
 165                 return;
 166         if (is_slave(orig) && !in_own_cluster(orig))
 167                 return;
 168         if (in_own_cluster(orig)) {
 169                 /* Always accept link here */
 170                 struct sk_buff *rbuf;
 171                 struct tipc_media_addr *addr;
 172                 struct node *n_ptr = tipc_node_find(orig);
 173                 int link_up;
 174                 dbg(" in own cluster\n");
 175                 if (n_ptr == NULL) {
 176                         n_ptr = tipc_node_create(orig);
 177                 }
 178                 if (n_ptr == NULL) {
 179                         return;
 180                 }
 181                 spin_lock_bh(&n_ptr->lock);
 182                 link = n_ptr->links[b_ptr->identity];
 183                 if (!link) {
 184                         dbg("creating link\n");
 185                         link = tipc_link_create(b_ptr, orig, &media_addr);
 186                         if (!link) {
 187                                 spin_unlock_bh(&n_ptr->lock);
 188                                 return;
 189                         }
 190                 }
 191                 addr = &link->media_addr;
 192                 if (memcmp(addr, &media_addr, sizeof(*addr))) {
 193                         warn("Resetting link <%s>, peer interface address changed\n",
 194                              link->name);
 195                         memcpy(addr, &media_addr, sizeof(*addr));
 196                         tipc_link_reset(link);
 197                 }
 198                 link_up = tipc_link_is_up(link);
 199                 spin_unlock_bh(&n_ptr->lock);
 200                 if ((type == DSC_RESP_MSG) || link_up)
 201                         return;
 202                 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
 203                 if (rbuf != NULL) {
 204                         msg_dbg(buf_msg(rbuf),"SEND:");
 205                         b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr);
 206                         buf_discard(rbuf);
 207                 }
 208         }
 209 }
 210
 211 /**
 212  * tipc_disc_stop_link_req - stop sending periodic link setup requests
 213  * @req: ptr to link request structure
 214  */
 215
 216 void tipc_disc_stop_link_req(struct link_req *req)
 217 {
 218         if (!req)
 219                 return;
 220
 221         k_cancel_timer(&req->timer);
 222         k_term_timer(&req->timer);
 223         buf_discard(req->buf);
 224         kfree(req);
 225 }
 226
 227 /**
 228  * tipc_disc_update_link_req - update frequency of periodic link setup requests
 229  * @req: ptr to link request structure
 230  */
 231
 232 void tipc_disc_update_link_req(struct link_req *req)
 233 {
 234         if (!req)
 235                 return;
 236
 237         if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
 238                 if (!req->bearer->nodes.count) {
 239                         req->timer_intv = TIPC_LINK_REQ_FAST;
 240                         k_start_timer(&req->timer, req->timer_intv);
 241                 }
 242         } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
 243                 if (req->bearer->nodes.count) {
 244                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 245                         k_start_timer(&req->timer, req->timer_intv);
 246                 }
 247         } else {
 248                 /* leave timer "as is" if haven't yet reached a "normal" rate */
 249         }
 250 }
 251
 252 /**
 253  * disc_timeout - send a periodic link setup request
 254  * @req: ptr to link request structure
 255  *
 256  * Called whenever a link setup request timer associated with a bearer expires.
 257  */
 258
 259 static void disc_timeout(struct link_req *req)
 260 {
 261         spin_lock_bh(&req->bearer->publ.lock);
 262
 263         req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest);
 264
 265         if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
 266             (req->timer_intv == TIPC_LINK_REQ_FAST)) {
 267                 /* leave timer interval "as is" if already at a "normal" rate */
 268         } else {
 269                 req->timer_intv *= 2;
 270                 if (req->timer_intv > TIPC_LINK_REQ_FAST)
 271                         req->timer_intv = TIPC_LINK_REQ_FAST;
 272                 if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
 273                     (req->bearer->nodes.count))
 274                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 275         }
 276         k_start_timer(&req->timer, req->timer_intv);
 277
 278         spin_unlock_bh(&req->bearer->publ.lock);
 279 }
 280
 281 /**
 282  * tipc_disc_init_link_req - start sending periodic link setup requests
 283  * @b_ptr: ptr to bearer issuing requests
 284  * @dest: destination address for request messages
 285  * @dest_domain: network domain of node(s) which should respond to message
 286  * @req_links: max number of desired links
 287  *
 288  * Returns pointer to link request structure, or NULL if unable to create.
 289  */
 290
 291 struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr,
 292                                          const struct tipc_media_addr *dest,
 293                                          u32 dest_domain,
 294                                          u32 req_links)
 295 {
 296         struct link_req *req;
 297
 298         req = kmalloc(sizeof(*req), GFP_ATOMIC);
 299         if (!req)
 300                 return NULL;
 301
 302         req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
 303         if (!req->buf) {
 304                 kfree(req);
 305                 return NULL;
 306         }
 307
 308         memcpy(&req->dest, dest, sizeof(*dest));
 309         req->bearer = b_ptr;
 310         req->timer_intv = TIPC_LINK_REQ_INIT;
 311         k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
 312         k_start_timer(&req->timer, req->timer_intv);
 313         return req;
 314 }
 315