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