net/tipc/discover.c

   1 /*
   2  * net/tipc/discover.c
   3  *
   4  * Copyright (c) 2003-2006, Ericsson AB
   5  * Copyright (c) 2005-2006, 2010-2011, 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
  41 #define TIPC_LINK_REQ_INIT      125     /* min delay during bearer start up */
  42 #define TIPC_LINK_REQ_FAST      2000    /* normal delay if bearer has no links */
  43 #define TIPC_LINK_REQ_SLOW      600000  /* normal delay if bearer has links */
  44
  45 /*
  46  * TODO: Most of the inter-cluster setup stuff should be
  47  * rewritten, and be made conformant with specification.
  48  */
  49
  50
  51 /**
  52  * struct link_req - information about an ongoing link setup request
  53  * @bearer: bearer issuing requests
  54  * @dest: destination address for request messages
  55  * @buf: request message to be (repeatedly) sent
  56  * @timer: timer governing period between requests
  57  * @timer_intv: current interval between requests (in ms)
  58  */
  59 struct link_req {
  60         struct tipc_bearer *bearer;
  61         struct tipc_media_addr dest;
  62         struct sk_buff *buf;
  63         struct timer_list timer;
  64         unsigned int timer_intv;
  65 };
  66
  67 /**
  68  * tipc_disc_init_msg - initialize a link setup message
  69  * @type: message type (request or response)
  70  * @dest_domain: network domain of node(s) which should respond to message
  71  * @b_ptr: ptr to bearer issuing message
  72  */
  73
  74 static struct sk_buff *tipc_disc_init_msg(u32 type,
  75                                           u32 dest_domain,
  76                                           struct tipc_bearer *b_ptr)
  77 {
  78         struct sk_buff *buf = tipc_buf_acquire(DSC_H_SIZE);
  79         struct tipc_msg *msg;
  80
  81         if (buf) {
  82                 msg = buf_msg(buf);
  83                 tipc_msg_init(msg, LINK_CONFIG, type, DSC_H_SIZE, dest_domain);
  84                 msg_set_non_seq(msg, 1);
  85                 msg_set_dest_domain(msg, dest_domain);
  86                 msg_set_bc_netid(msg, tipc_net_id);
  87                 msg_set_media_addr(msg, &b_ptr->addr);
  88         }
  89         return buf;
  90 }
  91
  92 /**
  93  * disc_dupl_alert - issue node address duplication alert
  94  * @b_ptr: pointer to bearer detecting duplication
  95  * @node_addr: duplicated node address
  96  * @media_addr: media address advertised by duplicated node
  97  */
  98
  99 static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
 100                             struct tipc_media_addr *media_addr)
 101 {
 102         char node_addr_str[16];
 103         char media_addr_str[64];
 104         struct print_buf pb;
 105
 106         tipc_addr_string_fill(node_addr_str, node_addr);
 107         tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str));
 108         tipc_media_addr_printf(&pb, media_addr);
 109         tipc_printbuf_validate(&pb);
 110         warn("Duplicate %s using %s seen on <%s>\n",
 111              node_addr_str, media_addr_str, b_ptr->name);
 112 }
 113
 114 /**
 115  * tipc_disc_recv_msg - handle incoming link setup message (request or response)
 116  * @buf: buffer containing message
 117  * @b_ptr: bearer that message arrived on
 118  */
 119
 120 void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 121 {
 122         struct link *link;
 123         struct tipc_media_addr media_addr;
 124         struct tipc_msg *msg = buf_msg(buf);
 125         u32 dest = msg_dest_domain(msg);
 126         u32 orig = msg_prevnode(msg);
 127         u32 net_id = msg_bc_netid(msg);
 128         u32 type = msg_type(msg);
 129
 130         msg_get_media_addr(msg, &media_addr);
 131         buf_discard(buf);
 132
 133         if (net_id != tipc_net_id)
 134                 return;
 135         if (!tipc_addr_domain_valid(dest))
 136                 return;
 137         if (!tipc_addr_node_valid(orig))
 138                 return;
 139         if (orig == tipc_own_addr) {
 140                 if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
 141                         disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
 142                 return;
 143         }
 144         if (!tipc_in_scope(dest, tipc_own_addr))
 145                 return;
 146         if (in_own_cluster(orig)) {
 147                 /* Always accept link here */
 148                 struct sk_buff *rbuf;
 149                 struct tipc_media_addr *addr;
 150                 struct tipc_node *n_ptr = tipc_node_find(orig);
 151                 int link_fully_up;
 152
 153                 if (n_ptr == NULL) {
 154                         n_ptr = tipc_node_create(orig);
 155                         if (!n_ptr)
 156                                 return;
 157                 }
 158                 spin_lock_bh(&n_ptr->lock);
 159
 160                 /* Don't talk to neighbor during cleanup after last session */
 161
 162                 if (n_ptr->cleanup_required) {
 163                         spin_unlock_bh(&n_ptr->lock);
 164                         return;
 165                 }
 166
 167                 link = n_ptr->links[b_ptr->identity];
 168                 if (!link) {
 169                         link = tipc_link_create(b_ptr, orig, &media_addr);
 170                         if (!link) {
 171                                 spin_unlock_bh(&n_ptr->lock);
 172                                 return;
 173                         }
 174                 }
 175                 addr = &link->media_addr;
 176                 if (memcmp(addr, &media_addr, sizeof(*addr))) {
 177                         if (tipc_link_is_up(link) || (!link->started)) {
 178                                 disc_dupl_alert(b_ptr, orig, &media_addr);
 179                                 spin_unlock_bh(&n_ptr->lock);
 180                                 return;
 181                         }
 182                         warn("Resetting link <%s>, peer interface address changed\n",
 183                              link->name);
 184                         memcpy(addr, &media_addr, sizeof(*addr));
 185                         tipc_link_reset(link);
 186                 }
 187                 link_fully_up = link_working_working(link);
 188                 spin_unlock_bh(&n_ptr->lock);
 189                 if ((type == DSC_RESP_MSG) || link_fully_up)
 190                         return;
 191                 rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
 192                 if (rbuf != NULL) {
 193                         b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
 194                         buf_discard(rbuf);
 195                 }
 196         }
 197 }
 198
 199 /**
 200  * tipc_disc_stop_link_req - stop sending periodic link setup requests
 201  * @req: ptr to link request structure
 202  */
 203
 204 void tipc_disc_stop_link_req(struct link_req *req)
 205 {
 206         if (!req)
 207                 return;
 208
 209         k_cancel_timer(&req->timer);
 210         k_term_timer(&req->timer);
 211         buf_discard(req->buf);
 212         kfree(req);
 213 }
 214
 215 /**
 216  * tipc_disc_update_link_req - update frequency of periodic link setup requests
 217  * @req: ptr to link request structure
 218  */
 219
 220 void tipc_disc_update_link_req(struct link_req *req)
 221 {
 222         if (!req)
 223                 return;
 224
 225         if (req->timer_intv == TIPC_LINK_REQ_SLOW) {
 226                 if (!req->bearer->nodes.count) {
 227                         req->timer_intv = TIPC_LINK_REQ_FAST;
 228                         k_start_timer(&req->timer, req->timer_intv);
 229                 }
 230         } else if (req->timer_intv == TIPC_LINK_REQ_FAST) {
 231                 if (req->bearer->nodes.count) {
 232                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 233                         k_start_timer(&req->timer, req->timer_intv);
 234                 }
 235         } else {
 236                 /* leave timer "as is" if haven't yet reached a "normal" rate */
 237         }
 238 }
 239
 240 /**
 241  * disc_timeout - send a periodic link setup request
 242  * @req: ptr to link request structure
 243  *
 244  * Called whenever a link setup request timer associated with a bearer expires.
 245  */
 246
 247 static void disc_timeout(struct link_req *req)
 248 {
 249         spin_lock_bh(&req->bearer->lock);
 250
 251         req->bearer->media->send_msg(req->buf, req->bearer, &req->dest);
 252
 253         if ((req->timer_intv == TIPC_LINK_REQ_SLOW) ||
 254             (req->timer_intv == TIPC_LINK_REQ_FAST)) {
 255                 /* leave timer interval "as is" if already at a "normal" rate */
 256         } else {
 257                 req->timer_intv *= 2;
 258                 if (req->timer_intv > TIPC_LINK_REQ_FAST)
 259                         req->timer_intv = TIPC_LINK_REQ_FAST;
 260                 if ((req->timer_intv == TIPC_LINK_REQ_FAST) &&
 261                     (req->bearer->nodes.count))
 262                         req->timer_intv = TIPC_LINK_REQ_SLOW;
 263         }
 264         k_start_timer(&req->timer, req->timer_intv);
 265
 266         spin_unlock_bh(&req->bearer->lock);
 267 }
 268
 269 /**
 270  * tipc_disc_init_link_req - start sending periodic link setup requests
 271  * @b_ptr: ptr to bearer issuing requests
 272  * @dest: destination address for request messages
 273  * @dest_domain: network domain of node(s) which should respond to message
 274  *
 275  * Returns pointer to link request structure, or NULL if unable to create.
 276  */
 277
 278 struct link_req *tipc_disc_init_link_req(struct tipc_bearer *b_ptr,
 279                                          const struct tipc_media_addr *dest,
 280                                          u32 dest_domain)
 281 {
 282         struct link_req *req;
 283
 284         req = kmalloc(sizeof(*req), GFP_ATOMIC);
 285         if (!req)
 286                 return NULL;
 287
 288         req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr);
 289         if (!req->buf) {
 290                 kfree(req);
 291                 return NULL;
 292         }
 293
 294         memcpy(&req->dest, dest, sizeof(*dest));
 295         req->bearer = b_ptr;
 296         req->timer_intv = TIPC_LINK_REQ_INIT;
 297         k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
 298         k_start_timer(&req->timer, req->timer_intv);
 299         return req;
 300 }
 301