LXR linux/net/tipc/net.c

   1/*
   2 * net/tipc/net.c: TIPC network routing code
   3 *
   4 * Copyright (c) 1995-2006, 2014, Ericsson AB
   5 * Copyright (c) 2005, 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 "net.h"
  39#include "name_distr.h"
  40#include "subscr.h"
  41#include "socket.h"
  42#include "node.h"
  43#include "bcast.h"
  44#include "netlink.h"
  45#include "monitor.h"
  46
  47/*
  48 * The TIPC locking policy is designed to ensure a very fine locking
  49 * granularity, permitting complete parallel access to individual
  50 * port and node/link instances. The code consists of four major
  51 * locking domains, each protected with their own disjunct set of locks.
  52 *
  53 * 1: The bearer level.
  54 *    RTNL lock is used to serialize the process of configuring bearer
  55 *    on update side, and RCU lock is applied on read side to make
  56 *    bearer instance valid on both paths of message transmission and
  57 *    reception.
  58 *
  59 * 2: The node and link level.
  60 *    All node instances are saved into two tipc_node_list and node_htable
  61 *    lists. The two lists are protected by node_list_lock on write side,
  62 *    and they are guarded with RCU lock on read side. Especially node
  63 *    instance is destroyed only when TIPC module is removed, and we can
  64 *    confirm that there has no any user who is accessing the node at the
  65 *    moment. Therefore, Except for iterating the two lists within RCU
  66 *    protection, it's no needed to hold RCU that we access node instance
  67 *    in other places.
  68 *
  69 *    In addition, all members in node structure including link instances
  70 *    are protected by node spin lock.
  71 *
  72 * 3: The transport level of the protocol.
  73 *    This consists of the structures port, (and its user level
  74 *    representations, such as user_port and tipc_sock), reference and
  75 *    tipc_user (port.c, reg.c, socket.c).
  76 *
  77 *    This layer has four different locks:
  78 *     - The tipc_port spin_lock. This is protecting each port instance
  79 *       from parallel data access and removal. Since we can not place
  80 *       this lock in the port itself, it has been placed in the
  81 *       corresponding reference table entry, which has the same life
  82 *       cycle as the module. This entry is difficult to access from
  83 *       outside the TIPC core, however, so a pointer to the lock has
  84 *       been added in the port instance, -to be used for unlocking
  85 *       only.
  86 *     - A read/write lock to protect the reference table itself (teg.c).
  87 *       (Nobody is using read-only access to this, so it can just as
  88 *       well be changed to a spin_lock)
  89 *     - A spin lock to protect the registry of kernel/driver users (reg.c)
  90 *     - A global spin_lock (tipc_port_lock), which only task is to ensure
  91 *       consistency where more than one port is involved in an operation,
  92 *       i.e., whe a port is part of a linked list of ports.
  93 *       There are two such lists; 'port_list', which is used for management,
  94 *       and 'wait_list', which is used to queue ports during congestion.
  95 *
  96 *  4: The name table (name_table.c, name_distr.c, subscription.c)
  97 *     - There is one big read/write-lock (tipc_nametbl_lock) protecting the
  98 *       overall name table structure. Nothing must be added/removed to
  99 *       this structure without holding write access to it.
 100 *     - There is one local spin_lock per sub_sequence, which can be seen
 101 *       as a sub-domain to the tipc_nametbl_lock domain. It is used only
 102 *       for translation operations, and is needed because a translation
 103 *       steps the root of the 'publication' linked list between each lookup.
 104 *       This is always used within the scope of a tipc_nametbl_lock(read).
 105 *     - A local spin_lock protecting the queue of subscriber events.
 106*/
 107
 108struct tipc_net_work {
 109        struct work_struct work;
 110        struct net *net;
 111        u32 addr;
 112};
 113
 114static void tipc_net_finalize(struct net *net, u32 addr);
 115
 116int tipc_net_init(struct net *net, u8 *node_id, u32 addr)
 117{
 118        if (tipc_own_id(net)) {
 119                pr_info("Cannot configure node identity twice\n");
 120                return -1;
 121        }
 122        pr_info("Started in network mode\n");
 123
 124        if (node_id)
 125                tipc_set_node_id(net, node_id);
 126        if (addr)
 127                tipc_net_finalize(net, addr);
 128        return 0;
 129}
 130
 131static void tipc_net_finalize(struct net *net, u32 addr)
 132{
 133        struct tipc_net *tn = tipc_net(net);
 134
 135        if (cmpxchg(&tn->node_addr, 0, addr))
 136                return;
 137        tipc_set_node_addr(net, addr);
 138        tipc_named_reinit(net);
 139        tipc_sk_reinit(net);
 140        tipc_mon_reinit_self(net);
 141        tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr,
 142                             TIPC_CLUSTER_SCOPE, 0, addr);
 143}
 144
 145static void tipc_net_finalize_work(struct work_struct *work)
 146{
 147        struct tipc_net_work *fwork;
 148
 149        fwork = container_of(work, struct tipc_net_work, work);
 150        tipc_net_finalize(fwork->net, fwork->addr);
 151        kfree(fwork);
 152}
 153
 154void tipc_sched_net_finalize(struct net *net, u32 addr)
 155{
 156        struct tipc_net_work *fwork = kzalloc(sizeof(*fwork), GFP_ATOMIC);
 157
 158        if (!fwork)
 159                return;
 160        INIT_WORK(&fwork->work, tipc_net_finalize_work);
 161        fwork->net = net;
 162        fwork->addr = addr;
 163        schedule_work(&fwork->work);
 164}
 165
 166void tipc_net_stop(struct net *net)
 167{
 168        if (!tipc_own_id(net))
 169                return;
 170
 171        rtnl_lock();
 172        tipc_bearer_stop(net);
 173        tipc_node_stop(net);
 174        rtnl_unlock();
 175
 176        pr_info("Left network mode\n");
 177}
 178
 179static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
 180{
 181        struct tipc_net *tn = net_generic(net, tipc_net_id);
 182        u64 *w0 = (u64 *)&tn->node_id[0];
 183        u64 *w1 = (u64 *)&tn->node_id[8];
 184        struct nlattr *attrs;
 185        void *hdr;
 186
 187        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
 188                          NLM_F_MULTI, TIPC_NL_NET_GET);
 189        if (!hdr)
 190                return -EMSGSIZE;
 191
 192        attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NET);
 193        if (!attrs)
 194                goto msg_full;
 195
 196        if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
 197                goto attr_msg_full;
 198        if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID, *w0, 0))
 199                goto attr_msg_full;
 200        if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID_W1, *w1, 0))
 201                goto attr_msg_full;
 202        nla_nest_end(msg->skb, attrs);
 203        genlmsg_end(msg->skb, hdr);
 204
 205        return 0;
 206
 207attr_msg_full:
 208        nla_nest_cancel(msg->skb, attrs);
 209msg_full:
 210        genlmsg_cancel(msg->skb, hdr);
 211
 212        return -EMSGSIZE;
 213}
 214
 215int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
 216{
 217        struct net *net = sock_net(skb->sk);
 218        int err;
 219        int done = cb->args[0];
 220        struct tipc_nl_msg msg;
 221
 222        if (done)
 223                return 0;
 224
 225        msg.skb = skb;
 226        msg.portid = NETLINK_CB(cb->skb).portid;
 227        msg.seq = cb->nlh->nlmsg_seq;
 228
 229        err = __tipc_nl_add_net(net, &msg);
 230        if (err)
 231                goto out;
 232
 233        done = 1;
 234out:
 235        cb->args[0] = done;
 236
 237        return skb->len;
 238}
 239
 240int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
 241{
 242        struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
 243        struct net *net = sock_net(skb->sk);
 244        struct tipc_net *tn = tipc_net(net);
 245        int err;
 246
 247        if (!info->attrs[TIPC_NLA_NET])
 248                return -EINVAL;
 249
 250        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
 251                                          info->attrs[TIPC_NLA_NET],
 252                                          tipc_nl_net_policy, info->extack);
 253
 254        if (err)
 255                return err;
 256
 257        /* Can't change net id once TIPC has joined a network */
 258        if (tipc_own_addr(net))
 259                return -EPERM;
 260
 261        if (attrs[TIPC_NLA_NET_ID]) {
 262                u32 val;
 263
 264                val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
 265                if (val < 1 || val > 9999)
 266                        return -EINVAL;
 267
 268                tn->net_id = val;
 269        }
 270
 271        if (attrs[TIPC_NLA_NET_ADDR]) {
 272                u32 addr;
 273
 274                addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
 275                if (!addr)
 276                        return -EINVAL;
 277                tn->legacy_addr_format = true;
 278                tipc_net_init(net, NULL, addr);
 279        }
 280
 281        if (attrs[TIPC_NLA_NET_NODEID]) {
 282                u8 node_id[NODE_ID_LEN];
 283                u64 *w0 = (u64 *)&node_id[0];
 284                u64 *w1 = (u64 *)&node_id[8];
 285
 286                if (!attrs[TIPC_NLA_NET_NODEID_W1])
 287                        return -EINVAL;
 288                *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
 289                *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
 290                tipc_net_init(net, node_id, 0);
 291        }
 292        return 0;
 293}
 294
 295int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
 296{
 297        int err;
 298
 299        rtnl_lock();
 300        err = __tipc_nl_net_set(skb, info);
 301        rtnl_unlock();
 302
 303        return err;
 304}
 305
 306static int __tipc_nl_addr_legacy_get(struct net *net, struct tipc_nl_msg *msg)
 307{
 308        struct tipc_net *tn = tipc_net(net);
 309        struct nlattr *attrs;
 310        void *hdr;
 311
 312        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
 313                          0, TIPC_NL_ADDR_LEGACY_GET);
 314        if (!hdr)
 315                return -EMSGSIZE;
 316
 317        attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
 318        if (!attrs)
 319                goto msg_full;
 320
 321        if (tn->legacy_addr_format)
 322                if (nla_put_flag(msg->skb, TIPC_NLA_NET_ADDR_LEGACY))
 323                        goto attr_msg_full;
 324
 325        nla_nest_end(msg->skb, attrs);
 326        genlmsg_end(msg->skb, hdr);
 327
 328        return 0;
 329
 330attr_msg_full:
 331        nla_nest_cancel(msg->skb, attrs);
 332msg_full:
 333        genlmsg_cancel(msg->skb, hdr);
 334
 335        return -EMSGSIZE;
 336}
 337
 338int tipc_nl_net_addr_legacy_get(struct sk_buff *skb, struct genl_info *info)
 339{
 340        struct net *net = sock_net(skb->sk);
 341        struct tipc_nl_msg msg;
 342        struct sk_buff *rep;
 343        int err;
 344
 345        rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 346        if (!rep)
 347                return -ENOMEM;
 348
 349        msg.skb = rep;
 350        msg.portid = info->snd_portid;
 351        msg.seq = info->snd_seq;
 352
 353        err = __tipc_nl_addr_legacy_get(net, &msg);
 354        if (err) {
 355                nlmsg_free(msg.skb);
 356                return err;
 357        }
 358
 359        return genlmsg_reply(msg.skb, info);
 360}
 361