net/tipc/name_distr.c

   1 /*
   2  * net/tipc/name_distr.c: TIPC name distribution code
   3  *
   4  * Copyright (c) 2000-2006, 2014-2019, Ericsson AB
   5  * Copyright (c) 2005, 2010-2011, Wind River Systems
   6  * Copyright (c) 2020-2021, Red Hat Inc
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the names of the copyright holders nor the names of its
  18  *    contributors may be used to endorse or promote products derived from
  19  *    this software without specific prior written permission.
  20  *
  21  * Alternatively, this software may be distributed under the terms of the
  22  * GNU General Public License ("GPL") version 2 as published by the Free
  23  * Software Foundation.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "core.h"
  39 #include "link.h"
  40 #include "name_distr.h"
  41
  42 int sysctl_tipc_named_timeout __read_mostly = 2000;
  43
  44 /**
  45  * publ_to_item - add publication info to a publication message
  46  * @p: publication info
  47  * @i: location of item in the message
  48  */
  49 static void publ_to_item(struct distr_item *i, struct publication *p)
  50 {
  51         i->type = htonl(p->sr.type);
  52         i->lower = htonl(p->sr.lower);
  53         i->upper = htonl(p->sr.upper);
  54         i->port = htonl(p->sk.ref);
  55         i->key = htonl(p->key);
  56 }
  57
  58 /**
  59  * named_prepare_buf - allocate & initialize a publication message
  60  * @net: the associated network namespace
  61  * @type: message type
  62  * @size: payload size
  63  * @dest: destination node
  64  *
  65  * The buffer returned is of size INT_H_SIZE + payload size
  66  */
  67 static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
  68                                          u32 dest)
  69 {
  70         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
  71         u32 self = tipc_own_addr(net);
  72         struct tipc_msg *msg;
  73
  74         if (buf != NULL) {
  75                 msg = buf_msg(buf);
  76                 tipc_msg_init(self, msg, NAME_DISTRIBUTOR,
  77                               type, INT_H_SIZE, dest);
  78                 msg_set_size(msg, INT_H_SIZE + size);
  79         }
  80         return buf;
  81 }
  82
  83 /**
  84  * tipc_named_publish - tell other nodes about a new publication by this node
  85  * @net: the associated network namespace
  86  * @p: the new publication
  87  */
  88 struct sk_buff *tipc_named_publish(struct net *net, struct publication *p)
  89 {
  90         struct name_table *nt = tipc_name_table(net);
  91         struct distr_item *item;
  92         struct sk_buff *skb;
  93
  94         if (p->scope == TIPC_NODE_SCOPE) {
  95                 list_add_tail_rcu(&p->binding_node, &nt->node_scope);
  96                 return NULL;
  97         }
  98         write_lock_bh(&nt->cluster_scope_lock);
  99         list_add_tail(&p->binding_node, &nt->cluster_scope);
 100         write_unlock_bh(&nt->cluster_scope_lock);
 101         skb = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 102         if (!skb) {
 103                 pr_warn("Publication distribution failure\n");
 104                 return NULL;
 105         }
 106         msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
 107         msg_set_non_legacy(buf_msg(skb));
 108         item = (struct distr_item *)msg_data(buf_msg(skb));
 109         publ_to_item(item, p);
 110         return skb;
 111 }
 112
 113 /**
 114  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 115  * @net: the associated network namespace
 116  * @p: the withdrawn publication
 117  */
 118 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *p)
 119 {
 120         struct name_table *nt = tipc_name_table(net);
 121         struct distr_item *item;
 122         struct sk_buff *skb;
 123
 124         write_lock_bh(&nt->cluster_scope_lock);
 125         list_del(&p->binding_node);
 126         write_unlock_bh(&nt->cluster_scope_lock);
 127         if (p->scope == TIPC_NODE_SCOPE)
 128                 return NULL;
 129
 130         skb = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
 131         if (!skb) {
 132                 pr_warn("Withdrawal distribution failure\n");
 133                 return NULL;
 134         }
 135         msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
 136         msg_set_non_legacy(buf_msg(skb));
 137         item = (struct distr_item *)msg_data(buf_msg(skb));
 138         publ_to_item(item, p);
 139         return skb;
 140 }
 141
 142 /**
 143  * named_distribute - prepare name info for bulk distribution to another node
 144  * @net: the associated network namespace
 145  * @list: list of messages (buffers) to be returned from this function
 146  * @dnode: node to be updated
 147  * @pls: linked list of publication items to be packed into buffer chain
 148  * @seqno: sequence number for this message
 149  */
 150 static void named_distribute(struct net *net, struct sk_buff_head *list,
 151                              u32 dnode, struct list_head *pls, u16 seqno)
 152 {
 153         struct publication *publ;
 154         struct sk_buff *skb = NULL;
 155         struct distr_item *item = NULL;
 156         u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0, false) - INT_H_SIZE) /
 157                         ITEM_SIZE) * ITEM_SIZE;
 158         u32 msg_rem = msg_dsz;
 159         struct tipc_msg *hdr;
 160
 161         list_for_each_entry(publ, pls, binding_node) {
 162                 /* Prepare next buffer: */
 163                 if (!skb) {
 164                         skb = named_prepare_buf(net, PUBLICATION, msg_rem,
 165                                                 dnode);
 166                         if (!skb) {
 167                                 pr_warn("Bulk publication failure\n");
 168                                 return;
 169                         }
 170                         hdr = buf_msg(skb);
 171                         msg_set_bc_ack_invalid(hdr, true);
 172                         msg_set_bulk(hdr);
 173                         msg_set_non_legacy(hdr);
 174                         item = (struct distr_item *)msg_data(hdr);
 175                 }
 176
 177                 /* Pack publication into message: */
 178                 publ_to_item(item, publ);
 179                 item++;
 180                 msg_rem -= ITEM_SIZE;
 181
 182                 /* Append full buffer to list: */
 183                 if (!msg_rem) {
 184                         __skb_queue_tail(list, skb);
 185                         skb = NULL;
 186                         msg_rem = msg_dsz;
 187                 }
 188         }
 189         if (skb) {
 190                 hdr = buf_msg(skb);
 191                 msg_set_size(hdr, INT_H_SIZE + (msg_dsz - msg_rem));
 192                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 193                 __skb_queue_tail(list, skb);
 194         }
 195         hdr = buf_msg(skb_peek_tail(list));
 196         msg_set_last_bulk(hdr);
 197         msg_set_named_seqno(hdr, seqno);
 198 }
 199
 200 /**
 201  * tipc_named_node_up - tell specified node about all publications by this node
 202  * @net: the associated network namespace
 203  * @dnode: destination node
 204  * @capabilities: peer node's capabilities
 205  */
 206 void tipc_named_node_up(struct net *net, u32 dnode, u16 capabilities)
 207 {
 208         struct name_table *nt = tipc_name_table(net);
 209         struct tipc_net *tn = tipc_net(net);
 210         struct sk_buff_head head;
 211         u16 seqno;
 212
 213         __skb_queue_head_init(&head);
 214         spin_lock_bh(&tn->nametbl_lock);
 215         if (!(capabilities & TIPC_NAMED_BCAST))
 216                 nt->rc_dests++;
 217         seqno = nt->snd_nxt;
 218         spin_unlock_bh(&tn->nametbl_lock);
 219
 220         read_lock_bh(&nt->cluster_scope_lock);
 221         named_distribute(net, &head, dnode, &nt->cluster_scope, seqno);
 222         tipc_node_xmit(net, &head, dnode, 0);
 223         read_unlock_bh(&nt->cluster_scope_lock);
 224 }
 225
 226 /**
 227  * tipc_publ_purge - remove publication associated with a failed node
 228  * @net: the associated network namespace
 229  * @p: the publication to remove
 230  * @addr: failed node's address
 231  *
 232  * Invoked for each publication issued by a newly failed node.
 233  * Removes publication structure from name table & deletes it.
 234  */
 235 static void tipc_publ_purge(struct net *net, struct publication *p, u32 addr)
 236 {
 237         struct tipc_net *tn = tipc_net(net);
 238         struct publication *_p;
 239         struct tipc_uaddr ua;
 240
 241         tipc_uaddr(&ua, TIPC_SERVICE_RANGE, p->scope, p->sr.type,
 242                    p->sr.lower, p->sr.upper);
 243         spin_lock_bh(&tn->nametbl_lock);
 244         _p = tipc_nametbl_remove_publ(net, &ua, &p->sk, p->key);
 245         if (_p)
 246                 tipc_node_unsubscribe(net, &_p->binding_node, addr);
 247         spin_unlock_bh(&tn->nametbl_lock);
 248         if (_p)
 249                 kfree_rcu(_p, rcu);
 250 }
 251
 252 void tipc_publ_notify(struct net *net, struct list_head *nsub_list,
 253                       u32 addr, u16 capabilities)
 254 {
 255         struct name_table *nt = tipc_name_table(net);
 256         struct tipc_net *tn = tipc_net(net);
 257
 258         struct publication *publ, *tmp;
 259
 260         list_for_each_entry_safe(publ, tmp, nsub_list, binding_node)
 261                 tipc_publ_purge(net, publ, addr);
 262         spin_lock_bh(&tn->nametbl_lock);
 263         if (!(capabilities & TIPC_NAMED_BCAST))
 264                 nt->rc_dests--;
 265         spin_unlock_bh(&tn->nametbl_lock);
 266 }
 267
 268 /**
 269  * tipc_update_nametbl - try to process a nametable update and notify
 270  *                       subscribers
 271  * @net: the associated network namespace
 272  * @i: location of item in the message
 273  * @node: node address
 274  * @dtype: name distributor message type
 275  *
 276  * tipc_nametbl_lock must be held.
 277  * Return: the publication item if successful, otherwise NULL.
 278  */
 279 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 280                                 u32 node, u32 dtype)
 281 {
 282         struct publication *p = NULL;
 283         struct tipc_socket_addr sk;
 284         struct tipc_uaddr ua;
 285         u32 key = ntohl(i->key);
 286
 287         tipc_uaddr(&ua, TIPC_SERVICE_RANGE, TIPC_CLUSTER_SCOPE,
 288                    ntohl(i->type), ntohl(i->lower), ntohl(i->upper));
 289         sk.ref = ntohl(i->port);
 290         sk.node = node;
 291
 292         if (dtype == PUBLICATION) {
 293                 p = tipc_nametbl_insert_publ(net, &ua, &sk, key);
 294                 if (p) {
 295                         tipc_node_subscribe(net, &p->binding_node, node);
 296                         return true;
 297                 }
 298         } else if (dtype == WITHDRAWAL) {
 299                 p = tipc_nametbl_remove_publ(net, &ua, &sk, key);
 300                 if (p) {
 301                         tipc_node_unsubscribe(net, &p->binding_node, node);
 302                         kfree_rcu(p, rcu);
 303                         return true;
 304                 }
 305                 pr_warn_ratelimited("Failed to remove binding %u,%u from %u\n",
 306                                     ua.sr.type, ua.sr.lower, node);
 307         } else {
 308                 pr_warn_ratelimited("Unknown name table message received\n");
 309         }
 310         return false;
 311 }
 312
 313 static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
 314                                           u16 *rcv_nxt, bool *open)
 315 {
 316         struct sk_buff *skb, *tmp;
 317         struct tipc_msg *hdr;
 318         u16 seqno;
 319
 320         spin_lock_bh(&namedq->lock);
 321         skb_queue_walk_safe(namedq, skb, tmp) {
 322                 if (unlikely(skb_linearize(skb))) {
 323                         __skb_unlink(skb, namedq);
 324                         kfree_skb(skb);
 325                         continue;
 326                 }
 327                 hdr = buf_msg(skb);
 328                 seqno = msg_named_seqno(hdr);
 329                 if (msg_is_last_bulk(hdr)) {
 330                         *rcv_nxt = seqno;
 331                         *open = true;
 332                 }
 333
 334                 if (msg_is_bulk(hdr) || msg_is_legacy(hdr)) {
 335                         __skb_unlink(skb, namedq);
 336                         spin_unlock_bh(&namedq->lock);
 337                         return skb;
 338                 }
 339
 340                 if (*open && (*rcv_nxt == seqno)) {
 341                         (*rcv_nxt)++;
 342                         __skb_unlink(skb, namedq);
 343                         spin_unlock_bh(&namedq->lock);
 344                         return skb;
 345                 }
 346
 347                 if (less(seqno, *rcv_nxt)) {
 348                         __skb_unlink(skb, namedq);
 349                         kfree_skb(skb);
 350                         continue;
 351                 }
 352         }
 353         spin_unlock_bh(&namedq->lock);
 354         return NULL;
 355 }
 356
 357 /**
 358  * tipc_named_rcv - process name table update messages sent by another node
 359  * @net: the associated network namespace
 360  * @namedq: queue to receive from
 361  * @rcv_nxt: store last received seqno here
 362  * @open: last bulk msg was received (FIXME)
 363  */
 364 void tipc_named_rcv(struct net *net, struct sk_buff_head *namedq,
 365                     u16 *rcv_nxt, bool *open)
 366 {
 367         struct tipc_net *tn = tipc_net(net);
 368         struct distr_item *item;
 369         struct tipc_msg *hdr;
 370         struct sk_buff *skb;
 371         u32 count, node;
 372
 373         spin_lock_bh(&tn->nametbl_lock);
 374         while ((skb = tipc_named_dequeue(namedq, rcv_nxt, open))) {
 375                 hdr = buf_msg(skb);
 376                 node = msg_orignode(hdr);
 377                 item = (struct distr_item *)msg_data(hdr);
 378                 count = msg_data_sz(hdr) / ITEM_SIZE;
 379                 while (count--) {
 380                         tipc_update_nametbl(net, item, node, msg_type(hdr));
 381                         item++;
 382                 }
 383                 kfree_skb(skb);
 384         }
 385         spin_unlock_bh(&tn->nametbl_lock);
 386 }
 387
 388 /**
 389  * tipc_named_reinit - re-initialize local publications
 390  * @net: the associated network namespace
 391  *
 392  * This routine is called whenever TIPC networking is enabled.
 393  * All name table entries published by this node are updated to reflect
 394  * the node's new network address.
 395  */
 396 void tipc_named_reinit(struct net *net)
 397 {
 398         struct name_table *nt = tipc_name_table(net);
 399         struct tipc_net *tn = tipc_net(net);
 400         struct publication *p;
 401         u32 self = tipc_own_addr(net);
 402
 403         spin_lock_bh(&tn->nametbl_lock);
 404
 405         list_for_each_entry_rcu(p, &nt->node_scope, binding_node)
 406                 p->sk.node = self;
 407         list_for_each_entry_rcu(p, &nt->cluster_scope, binding_node)
 408                 p->sk.node = self;
 409         nt->rc_dests = 0;
 410         spin_unlock_bh(&tn->nametbl_lock);
 411 }