linux/net/tipc/discover.c
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   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 */
  73struct 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
  83int 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
  96void 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
 113static 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, DSC_H_SIZE, dest_domain);
 124                msg_set_non_seq(msg, 1);
 125                msg_set_req_links(msg, req_links);
 126                msg_set_dest_domain(msg, dest_domain);
 127                msg_set_bc_netid(msg, tipc_net_id);
 128                msg_set_media_addr(msg, &b_ptr->publ.addr);
 129        }
 130        return buf;
 131}
 132
 133/**
 134 * disc_dupl_alert - issue node address duplication alert
 135 * @b_ptr: pointer to bearer detecting duplication
 136 * @node_addr: duplicated node address
 137 * @media_addr: media address advertised by duplicated node
 138 */
 139
 140static void disc_dupl_alert(struct bearer *b_ptr, u32 node_addr,
 141                            struct tipc_media_addr *media_addr)
 142{
 143        char node_addr_str[16];
 144        char media_addr_str[64];
 145        struct print_buf pb;
 146
 147        addr_string_fill(node_addr_str, node_addr);
 148        tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
 149        tipc_media_addr_printf(&pb, media_addr);
 150        tipc_printbuf_validate(&pb);
 151        warn("Duplicate %s using %s seen on <%s>\n",
 152             node_addr_str, media_addr_str, b_ptr->publ.name);
 153}
 154
 155/**
 156 * tipc_disc_recv_msg - handle incoming link setup message (request or response)
 157 * @buf: buffer containing message
 158 * @b_ptr: bearer that message arrived on
 159 */
 160
 161void tipc_disc_recv_msg(struct sk_buff *buf, struct bearer *b_ptr)
 162{
 163        struct link *link;
 164        struct tipc_media_addr media_addr;
 165        struct tipc_msg *msg = buf_msg(buf);
 166        u32 dest = msg_dest_domain(msg);
 167        u32 orig = msg_prevnode(msg);
 168        u32 net_id = msg_bc_netid(msg);
 169        u32 type = msg_type(msg);
 170
 171        msg_get_media_addr(msg,&media_addr);
 172        msg_dbg(msg, "RECV:");
 173        buf_discard(buf);
 174
 175        if (net_id != tipc_net_id)
 176                return;
 177        if (!tipc_addr_domain_valid(dest))
 178                return;
 179        if (!tipc_addr_node_valid(orig))
 180                return;
 181        if (orig == tipc_own_addr) {
 182                if (memcmp(&media_addr, &b_ptr->publ.addr, sizeof(media_addr)))
 183                        disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
 184                return;
 185        }
 186        if (!in_scope(dest, tipc_own_addr))
 187                return;
 188        if (is_slave(tipc_own_addr) && is_slave(orig))
 189                return;
 190        if (is_slave(orig) && !in_own_cluster(orig))
 191                return;
 192        if (in_own_cluster(orig)) {
 193                /* Always accept link here */
 194                struct sk_buff *rbuf;
 195                struct tipc_media_addr *addr;
 196                struct tipc_node *n_ptr = tipc_node_find(orig);
 197                int link_fully_up;
 198
 199                dbg(" in own cluster\n");
 200                if (n_ptr == NULL) {
 201                        n_ptr = tipc_node_create(orig);
 202                        if (!n_ptr)
 203                                return;
 204                }
 205                spin_lock_bh(&n_ptr->lock);
 206                link = n_ptr->links[b_ptr->identity];
 207                if (!link) {
 208                        dbg("creating link\n");
 209                        link = tipc_link_create(b_ptr, orig, &media_addr);
 210                        if (!link) {
 211                                spin_unlock_bh(&n_ptr->lock);
 212                                return;
 213                        }
 214                }
 215                addr = &link->media_addr;
 216                if (memcmp(addr, &media_addr, sizeof(*addr))) {
 217                        if (tipc_link_is_up(link) || (!link->started)) {
 218                                disc_dupl_alert(b_ptr, orig, &media_addr);
 219                                spin_unlock_bh(&n_ptr->lock);
 220                                return;
 221                        }
 222                        warn("Resetting link <%s>, peer interface address changed\n",
 223                             link->name);
 224                        memcpy(addr, &media_addr, sizeof(*addr));
 225                        tipc_link_reset(link);
 226                }
 227                link_fully_up = (link->state == WORKING_WORKING);
 228                spin_unlock_bh(&n_ptr->lock);
 229                if ((type == DSC_RESP_MSG) || link_fully_up)
 230                        return;
 231                rbuf = tipc_disc_init_msg(DSC_RESP_MSG, 1, orig, b_ptr);
 232                if (rbuf != NULL) {
 233                        msg_dbg(buf_msg(rbuf),"SEND:");
 234                        b_ptr->media->send_msg(rbuf, &b_ptr->publ, &media_addr);
 235                        buf_discard(rbuf);
 236                }
 237        }
 238}
 239
 240/**
 241 * tipc_disc_stop_link_req - stop sending periodic link setup requests
 242 * @req: ptr to link request structure
 243 */
 244
 245void tipc_disc_stop_link_req(struct link_req *req)
 246{
 247        if (!req)
 248                return;
 249
 250        k_cancel_timer(&req->timer);
 251        k_term_timer(&req->timer);
 252        buf_discard(req->buf);
 253        kfree(req);
 254}
 255
 256/**
 257 * tipc_disc_update_link_req - update frequency of periodic link setup requests
 258 * @req: ptr to link request structure
 259 */
 260
 261void tipc_disc_update_link_req(struct link_req *req)
 262{
 263        if (!req)
 264                return;
 265
 266        if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
 267                if (!req->bearer->nodes.count) {
 268                        req->timer_intv = TIPC_LINK_REQ_FAST;
 269                        k_start_timer(&req->timer, req->timer_intv);
 270                }
 271        } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
 272                if (req->bearer->nodes.count) {
 273                        req->timer_intv = TIPC_LINK_REQ_SLOW;
 274                        k_start_timer(&req->timer, req->timer_intv);
 275                }
 276        } else {
 277                /* leave timer "as is" if haven't yet reached a "normal" rate */
 278        }
 279}
 280
 281/**
 282 * disc_timeout - send a periodic link setup request
 283 * @req: ptr to link request structure
 284 *
 285 * Called whenever a link setup request timer associated with a bearer expires.
 286 */
 287
 288static void disc_timeout(struct link_req *req)
 289{
 290        spin_lock_bh(&req->bearer->publ.lock);
 291
 292        req->bearer->media->send_msg(req->buf, &req->bearer->publ, &req->dest);
 293
 294        if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
 295            (req->timer_intv == TIPC_LINK_REQ_FAST)) {
 296                /* leave timer interval "as is" if already at a "normal" rate */
 297        } else {
 298                req->timer_intv *= 2;
 299                if (req->timer_intv > TIPC_LINK_REQ_FAST)
 300                        req->timer_intv = TIPC_LINK_REQ_FAST;
 301                if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
 302                    (req->bearer->nodes.count))
 303                        req->timer_intv = TIPC_LINK_REQ_SLOW;
 304        }
 305        k_start_timer(&req->timer, req->timer_intv);
 306
 307        spin_unlock_bh(&req->bearer->publ.lock);
 308}
 309
 310/**
 311 * tipc_disc_init_link_req - start sending periodic link setup requests
 312 * @b_ptr: ptr to bearer issuing requests
 313 * @dest: destination address for request messages
 314 * @dest_domain: network domain of node(s) which should respond to message
 315 * @req_links: max number of desired links
 316 *
 317 * Returns pointer to link request structure, or NULL if unable to create.
 318 */
 319
 320struct link_req *tipc_disc_init_link_req(struct bearer *b_ptr,
 321                                         const struct tipc_media_addr *dest,
 322                                         u32 dest_domain,
 323                                         u32 req_links)
 324{
 325        struct link_req *req;
 326
 327        req = kmalloc(sizeof(*req), GFP_ATOMIC);
 328        if (!req)
 329                return NULL;
 330
 331        req->buf = tipc_disc_init_msg(DSC_REQ_MSG, req_links, dest_domain, b_ptr);
 332        if (!req->buf) {
 333                kfree(req);
 334                return NULL;
 335        }
 336
 337        memcpy(&req->dest, dest, sizeof(*dest));
 338        req->bearer = b_ptr;
 339        req->timer_intv = TIPC_LINK_REQ_INIT;
 340        k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
 341        k_start_timer(&req->timer, req->timer_intv);
 342        return req;
 343}
 344
 345