net/l2tp/l2tp_netlink.c

   1 /*
   2  * L2TP netlink layer, for management
   3  *
   4  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
   5  *
   6  * Partly based on the IrDA nelink implementation
   7  * (see net/irda/irnetlink.c) which is:
   8  * Copyright (c) 2007 Samuel Ortiz <samuel@sortiz.org>
   9  * which is in turn partly based on the wireless netlink code:
  10  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <net/sock.h>
  20 #include <net/genetlink.h>
  21 #include <net/udp.h>
  22 #include <linux/in.h>
  23 #include <linux/udp.h>
  24 #include <linux/socket.h>
  25 #include <linux/module.h>
  26 #include <linux/list.h>
  27 #include <net/net_namespace.h>
  28
  29 #include <linux/l2tp.h>
  30
  31 #include "l2tp_core.h"
  32
  33
  34 static struct genl_family l2tp_nl_family;
  35
  36 static const struct genl_multicast_group l2tp_multicast_group[] = {
  37         {
  38                 .name = L2TP_GENL_MCGROUP,
  39         },
  40 };
  41
  42 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
  43                                int flags, struct l2tp_tunnel *tunnel, u8 cmd);
  44 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
  45                                 int flags, struct l2tp_session *session,
  46                                 u8 cmd);
  47
  48 /* Accessed under genl lock */
  49 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
  50
  51 static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info)
  52 {
  53         u32 tunnel_id;
  54         u32 session_id;
  55         char *ifname;
  56         struct l2tp_tunnel *tunnel;
  57         struct l2tp_session *session = NULL;
  58         struct net *net = genl_info_net(info);
  59
  60         if (info->attrs[L2TP_ATTR_IFNAME]) {
  61                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  62                 session = l2tp_session_get_by_ifname(net, ifname);
  63         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  64                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  65                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  66                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  67                 tunnel = l2tp_tunnel_get(net, tunnel_id);
  68                 if (tunnel) {
  69                         session = l2tp_session_get(net, tunnel, session_id);
  70                         l2tp_tunnel_dec_refcount(tunnel);
  71                 }
  72         }
  73
  74         return session;
  75 }
  76
  77 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  78 {
  79         struct sk_buff *msg;
  80         void *hdr;
  81         int ret = -ENOBUFS;
  82
  83         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  84         if (!msg) {
  85                 ret = -ENOMEM;
  86                 goto out;
  87         }
  88
  89         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  90                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  91         if (!hdr) {
  92                 ret = -EMSGSIZE;
  93                 goto err_out;
  94         }
  95
  96         genlmsg_end(msg, hdr);
  97
  98         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
  99
 100 err_out:
 101         nlmsg_free(msg);
 102
 103 out:
 104         return ret;
 105 }
 106
 107 static int l2tp_tunnel_notify(struct genl_family *family,
 108                               struct genl_info *info,
 109                               struct l2tp_tunnel *tunnel,
 110                               u8 cmd)
 111 {
 112         struct sk_buff *msg;
 113         int ret;
 114
 115         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 116         if (!msg)
 117                 return -ENOMEM;
 118
 119         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 120                                   NLM_F_ACK, tunnel, cmd);
 121
 122         if (ret >= 0) {
 123                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 124                 /* We don't care if no one is listening */
 125                 if (ret == -ESRCH)
 126                         ret = 0;
 127                 return ret;
 128         }
 129
 130         nlmsg_free(msg);
 131
 132         return ret;
 133 }
 134
 135 static int l2tp_session_notify(struct genl_family *family,
 136                                struct genl_info *info,
 137                                struct l2tp_session *session,
 138                                u8 cmd)
 139 {
 140         struct sk_buff *msg;
 141         int ret;
 142
 143         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 144         if (!msg)
 145                 return -ENOMEM;
 146
 147         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 148                                    NLM_F_ACK, session, cmd);
 149
 150         if (ret >= 0) {
 151                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 152                 /* We don't care if no one is listening */
 153                 if (ret == -ESRCH)
 154                         ret = 0;
 155                 return ret;
 156         }
 157
 158         nlmsg_free(msg);
 159
 160         return ret;
 161 }
 162
 163 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 164 {
 165         u32 tunnel_id;
 166         u32 peer_tunnel_id;
 167         int proto_version;
 168         int fd;
 169         int ret = 0;
 170         struct l2tp_tunnel_cfg cfg = { 0, };
 171         struct l2tp_tunnel *tunnel;
 172         struct net *net = genl_info_net(info);
 173
 174         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 175                 ret = -EINVAL;
 176                 goto out;
 177         }
 178         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 179
 180         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 181                 ret = -EINVAL;
 182                 goto out;
 183         }
 184         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 185
 186         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 187                 ret = -EINVAL;
 188                 goto out;
 189         }
 190         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 191
 192         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 193                 ret = -EINVAL;
 194                 goto out;
 195         }
 196         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 197
 198         fd = -1;
 199         if (info->attrs[L2TP_ATTR_FD]) {
 200                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 201         } else {
 202 #if IS_ENABLED(CONFIG_IPV6)
 203                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 204                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 205                         cfg.local_ip6 = nla_data(
 206                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 207                         cfg.peer_ip6 = nla_data(
 208                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 209                 } else
 210 #endif
 211                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 212                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 213                         cfg.local_ip.s_addr = nla_get_in_addr(
 214                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 215                         cfg.peer_ip.s_addr = nla_get_in_addr(
 216                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 217                 } else {
 218                         ret = -EINVAL;
 219                         goto out;
 220                 }
 221                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 222                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 223                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 224                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 225                 cfg.use_udp_checksums = nla_get_flag(
 226                         info->attrs[L2TP_ATTR_UDP_CSUM]);
 227
 228 #if IS_ENABLED(CONFIG_IPV6)
 229                 cfg.udp6_zero_tx_checksums = nla_get_flag(
 230                         info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 231                 cfg.udp6_zero_rx_checksums = nla_get_flag(
 232                         info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 233 #endif
 234         }
 235
 236         if (info->attrs[L2TP_ATTR_DEBUG])
 237                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 238
 239         ret = -EINVAL;
 240         switch (cfg.encap) {
 241         case L2TP_ENCAPTYPE_UDP:
 242         case L2TP_ENCAPTYPE_IP:
 243                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 244                                          peer_tunnel_id, &cfg, &tunnel);
 245                 break;
 246         }
 247
 248         if (ret < 0)
 249                 goto out;
 250
 251         l2tp_tunnel_inc_refcount(tunnel);
 252         ret = l2tp_tunnel_register(tunnel, net, &cfg);
 253         if (ret < 0) {
 254                 kfree(tunnel);
 255                 goto out;
 256         }
 257         ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
 258                                  L2TP_CMD_TUNNEL_CREATE);
 259         l2tp_tunnel_dec_refcount(tunnel);
 260
 261 out:
 262         return ret;
 263 }
 264
 265 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 266 {
 267         struct l2tp_tunnel *tunnel;
 268         u32 tunnel_id;
 269         int ret = 0;
 270         struct net *net = genl_info_net(info);
 271
 272         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 273                 ret = -EINVAL;
 274                 goto out;
 275         }
 276         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 277
 278         tunnel = l2tp_tunnel_get(net, tunnel_id);
 279         if (!tunnel) {
 280                 ret = -ENODEV;
 281                 goto out;
 282         }
 283
 284         l2tp_tunnel_notify(&l2tp_nl_family, info,
 285                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 286
 287         l2tp_tunnel_delete(tunnel);
 288
 289         l2tp_tunnel_dec_refcount(tunnel);
 290
 291 out:
 292         return ret;
 293 }
 294
 295 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 296 {
 297         struct l2tp_tunnel *tunnel;
 298         u32 tunnel_id;
 299         int ret = 0;
 300         struct net *net = genl_info_net(info);
 301
 302         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 303                 ret = -EINVAL;
 304                 goto out;
 305         }
 306         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 307
 308         tunnel = l2tp_tunnel_get(net, tunnel_id);
 309         if (!tunnel) {
 310                 ret = -ENODEV;
 311                 goto out;
 312         }
 313
 314         if (info->attrs[L2TP_ATTR_DEBUG])
 315                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 316
 317         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 318                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 319
 320         l2tp_tunnel_dec_refcount(tunnel);
 321
 322 out:
 323         return ret;
 324 }
 325
 326 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 327                                struct l2tp_tunnel *tunnel, u8 cmd)
 328 {
 329         void *hdr;
 330         struct nlattr *nest;
 331         struct sock *sk = NULL;
 332         struct inet_sock *inet;
 333 #if IS_ENABLED(CONFIG_IPV6)
 334         struct ipv6_pinfo *np = NULL;
 335 #endif
 336
 337         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 338         if (!hdr)
 339                 return -EMSGSIZE;
 340
 341         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 342             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 343             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 344             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 345             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 346                 goto nla_put_failure;
 347
 348         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 349         if (nest == NULL)
 350                 goto nla_put_failure;
 351
 352         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 353                               atomic_long_read(&tunnel->stats.tx_packets),
 354                               L2TP_ATTR_STATS_PAD) ||
 355             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 356                               atomic_long_read(&tunnel->stats.tx_bytes),
 357                               L2TP_ATTR_STATS_PAD) ||
 358             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 359                               atomic_long_read(&tunnel->stats.tx_errors),
 360                               L2TP_ATTR_STATS_PAD) ||
 361             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 362                               atomic_long_read(&tunnel->stats.rx_packets),
 363                               L2TP_ATTR_STATS_PAD) ||
 364             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 365                               atomic_long_read(&tunnel->stats.rx_bytes),
 366                               L2TP_ATTR_STATS_PAD) ||
 367             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 368                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 369                               L2TP_ATTR_STATS_PAD) ||
 370             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 371                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 372                               L2TP_ATTR_STATS_PAD) ||
 373             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 374                               atomic_long_read(&tunnel->stats.rx_errors),
 375                               L2TP_ATTR_STATS_PAD))
 376                 goto nla_put_failure;
 377         nla_nest_end(skb, nest);
 378
 379         sk = tunnel->sock;
 380         if (!sk)
 381                 goto out;
 382
 383 #if IS_ENABLED(CONFIG_IPV6)
 384         if (sk->sk_family == AF_INET6)
 385                 np = inet6_sk(sk);
 386 #endif
 387
 388         inet = inet_sk(sk);
 389
 390         switch (tunnel->encap) {
 391         case L2TP_ENCAPTYPE_UDP:
 392                 switch (sk->sk_family) {
 393                 case AF_INET:
 394                         if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 395                                 goto nla_put_failure;
 396                         break;
 397 #if IS_ENABLED(CONFIG_IPV6)
 398                 case AF_INET6:
 399                         if (udp_get_no_check6_tx(sk) &&
 400                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
 401                                 goto nla_put_failure;
 402                         if (udp_get_no_check6_rx(sk) &&
 403                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
 404                                 goto nla_put_failure;
 405                         break;
 406 #endif
 407                 }
 408                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 409                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 410                         goto nla_put_failure;
 411                 /* fall through  */
 412         case L2TP_ENCAPTYPE_IP:
 413 #if IS_ENABLED(CONFIG_IPV6)
 414                 if (np) {
 415                         if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
 416                                              &np->saddr) ||
 417                             nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
 418                                              &sk->sk_v6_daddr))
 419                                 goto nla_put_failure;
 420                 } else
 421 #endif
 422                 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
 423                                     inet->inet_saddr) ||
 424                     nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
 425                                     inet->inet_daddr))
 426                         goto nla_put_failure;
 427                 break;
 428         }
 429
 430 out:
 431         genlmsg_end(skb, hdr);
 432         return 0;
 433
 434 nla_put_failure:
 435         genlmsg_cancel(skb, hdr);
 436         return -1;
 437 }
 438
 439 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 440 {
 441         struct l2tp_tunnel *tunnel;
 442         struct sk_buff *msg;
 443         u32 tunnel_id;
 444         int ret = -ENOBUFS;
 445         struct net *net = genl_info_net(info);
 446
 447         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 448                 ret = -EINVAL;
 449                 goto err;
 450         }
 451
 452         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 453
 454         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 455         if (!msg) {
 456                 ret = -ENOMEM;
 457                 goto err;
 458         }
 459
 460         tunnel = l2tp_tunnel_get(net, tunnel_id);
 461         if (!tunnel) {
 462                 ret = -ENODEV;
 463                 goto err_nlmsg;
 464         }
 465
 466         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 467                                   NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 468         if (ret < 0)
 469                 goto err_nlmsg_tunnel;
 470
 471         l2tp_tunnel_dec_refcount(tunnel);
 472
 473         return genlmsg_unicast(net, msg, info->snd_portid);
 474
 475 err_nlmsg_tunnel:
 476         l2tp_tunnel_dec_refcount(tunnel);
 477 err_nlmsg:
 478         nlmsg_free(msg);
 479 err:
 480         return ret;
 481 }
 482
 483 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 484 {
 485         int ti = cb->args[0];
 486         struct l2tp_tunnel *tunnel;
 487         struct net *net = sock_net(skb->sk);
 488
 489         for (;;) {
 490                 tunnel = l2tp_tunnel_get_nth(net, ti);
 491                 if (tunnel == NULL)
 492                         goto out;
 493
 494                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 495                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 496                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
 497                         l2tp_tunnel_dec_refcount(tunnel);
 498                         goto out;
 499                 }
 500                 l2tp_tunnel_dec_refcount(tunnel);
 501
 502                 ti++;
 503         }
 504
 505 out:
 506         cb->args[0] = ti;
 507
 508         return skb->len;
 509 }
 510
 511 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 512 {
 513         u32 tunnel_id = 0;
 514         u32 session_id;
 515         u32 peer_session_id;
 516         int ret = 0;
 517         struct l2tp_tunnel *tunnel;
 518         struct l2tp_session *session;
 519         struct l2tp_session_cfg cfg = { 0, };
 520         struct net *net = genl_info_net(info);
 521
 522         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 523                 ret = -EINVAL;
 524                 goto out;
 525         }
 526
 527         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 528         tunnel = l2tp_tunnel_get(net, tunnel_id);
 529         if (!tunnel) {
 530                 ret = -ENODEV;
 531                 goto out;
 532         }
 533
 534         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 535                 ret = -EINVAL;
 536                 goto out_tunnel;
 537         }
 538         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 539
 540         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 541                 ret = -EINVAL;
 542                 goto out_tunnel;
 543         }
 544         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 545
 546         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 547                 ret = -EINVAL;
 548                 goto out_tunnel;
 549         }
 550         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 551         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 552                 ret = -EINVAL;
 553                 goto out_tunnel;
 554         }
 555
 556         if (tunnel->version > 2) {
 557                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 558                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 559
 560                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
 561                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 562                         if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
 563                             cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
 564                                 ret = -EINVAL;
 565                                 goto out_tunnel;
 566                         }
 567                 } else {
 568                         cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 569                 }
 570
 571                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 572                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 573                         if (len > 8) {
 574                                 ret = -EINVAL;
 575                                 goto out_tunnel;
 576                         }
 577                         cfg.cookie_len = len;
 578                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 579                 }
 580                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 581                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 582                         if (len > 8) {
 583                                 ret = -EINVAL;
 584                                 goto out_tunnel;
 585                         }
 586                         cfg.peer_cookie_len = len;
 587                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 588                 }
 589                 if (info->attrs[L2TP_ATTR_IFNAME])
 590                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 591
 592                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 593                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 594         }
 595
 596         if (info->attrs[L2TP_ATTR_DEBUG])
 597                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 598
 599         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 600                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 601
 602         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 603                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 604
 605         if (info->attrs[L2TP_ATTR_LNS_MODE])
 606                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 607
 608         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 609                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 610
 611         if (info->attrs[L2TP_ATTR_MTU])
 612                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 613
 614         if (info->attrs[L2TP_ATTR_MRU])
 615                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 616
 617 #ifdef CONFIG_MODULES
 618         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 619                 genl_unlock();
 620                 request_module("net-l2tp-type-%u", cfg.pw_type);
 621                 genl_lock();
 622         }
 623 #endif
 624         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 625             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 626                 ret = -EPROTONOSUPPORT;
 627                 goto out_tunnel;
 628         }
 629
 630         ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 631                                                            session_id,
 632                                                            peer_session_id,
 633                                                            &cfg);
 634
 635         if (ret >= 0) {
 636                 session = l2tp_session_get(net, tunnel, session_id);
 637                 if (session) {
 638                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 639                                                   L2TP_CMD_SESSION_CREATE);
 640                         l2tp_session_dec_refcount(session);
 641                 }
 642         }
 643
 644 out_tunnel:
 645         l2tp_tunnel_dec_refcount(tunnel);
 646 out:
 647         return ret;
 648 }
 649
 650 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 651 {
 652         int ret = 0;
 653         struct l2tp_session *session;
 654         u16 pw_type;
 655
 656         session = l2tp_nl_session_get(info);
 657         if (session == NULL) {
 658                 ret = -ENODEV;
 659                 goto out;
 660         }
 661
 662         l2tp_session_notify(&l2tp_nl_family, info,
 663                             session, L2TP_CMD_SESSION_DELETE);
 664
 665         pw_type = session->pwtype;
 666         if (pw_type < __L2TP_PWTYPE_MAX)
 667                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 668                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 669
 670         l2tp_session_dec_refcount(session);
 671
 672 out:
 673         return ret;
 674 }
 675
 676 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 677 {
 678         int ret = 0;
 679         struct l2tp_session *session;
 680
 681         session = l2tp_nl_session_get(info);
 682         if (session == NULL) {
 683                 ret = -ENODEV;
 684                 goto out;
 685         }
 686
 687         if (info->attrs[L2TP_ATTR_DEBUG])
 688                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 689
 690         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 691                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 692
 693         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 694                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 695
 696         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 697                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 698                 l2tp_session_set_header_len(session, session->tunnel->version);
 699         }
 700
 701         if (info->attrs[L2TP_ATTR_LNS_MODE])
 702                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 703
 704         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 705                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 706
 707         if (info->attrs[L2TP_ATTR_MTU])
 708                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 709
 710         if (info->attrs[L2TP_ATTR_MRU])
 711                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 712
 713         ret = l2tp_session_notify(&l2tp_nl_family, info,
 714                                   session, L2TP_CMD_SESSION_MODIFY);
 715
 716         l2tp_session_dec_refcount(session);
 717
 718 out:
 719         return ret;
 720 }
 721
 722 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 723                                 struct l2tp_session *session, u8 cmd)
 724 {
 725         void *hdr;
 726         struct nlattr *nest;
 727         struct l2tp_tunnel *tunnel = session->tunnel;
 728         struct sock *sk = NULL;
 729
 730         sk = tunnel->sock;
 731
 732         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 733         if (!hdr)
 734                 return -EMSGSIZE;
 735
 736         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 737             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 738             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 739             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 740                         session->peer_session_id) ||
 741             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 742             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 743             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 744             (session->mru &&
 745              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 746                 goto nla_put_failure;
 747
 748         if ((session->ifname[0] &&
 749              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 750             (session->cookie_len &&
 751              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 752                      &session->cookie[0])) ||
 753             (session->peer_cookie_len &&
 754              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 755                      &session->peer_cookie[0])) ||
 756             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 757             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 758             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 759 #ifdef CONFIG_XFRM
 760             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 761              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 762 #endif
 763             (session->reorder_timeout &&
 764              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 765                            session->reorder_timeout, L2TP_ATTR_PAD)))
 766                 goto nla_put_failure;
 767
 768         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 769         if (nest == NULL)
 770                 goto nla_put_failure;
 771
 772         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 773                               atomic_long_read(&session->stats.tx_packets),
 774                               L2TP_ATTR_STATS_PAD) ||
 775             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 776                               atomic_long_read(&session->stats.tx_bytes),
 777                               L2TP_ATTR_STATS_PAD) ||
 778             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 779                               atomic_long_read(&session->stats.tx_errors),
 780                               L2TP_ATTR_STATS_PAD) ||
 781             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 782                               atomic_long_read(&session->stats.rx_packets),
 783                               L2TP_ATTR_STATS_PAD) ||
 784             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 785                               atomic_long_read(&session->stats.rx_bytes),
 786                               L2TP_ATTR_STATS_PAD) ||
 787             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 788                               atomic_long_read(&session->stats.rx_seq_discards),
 789                               L2TP_ATTR_STATS_PAD) ||
 790             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 791                               atomic_long_read(&session->stats.rx_oos_packets),
 792                               L2TP_ATTR_STATS_PAD) ||
 793             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 794                               atomic_long_read(&session->stats.rx_errors),
 795                               L2TP_ATTR_STATS_PAD))
 796                 goto nla_put_failure;
 797         nla_nest_end(skb, nest);
 798
 799         genlmsg_end(skb, hdr);
 800         return 0;
 801
 802  nla_put_failure:
 803         genlmsg_cancel(skb, hdr);
 804         return -1;
 805 }
 806
 807 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 808 {
 809         struct l2tp_session *session;
 810         struct sk_buff *msg;
 811         int ret;
 812
 813         session = l2tp_nl_session_get(info);
 814         if (session == NULL) {
 815                 ret = -ENODEV;
 816                 goto err;
 817         }
 818
 819         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 820         if (!msg) {
 821                 ret = -ENOMEM;
 822                 goto err_ref;
 823         }
 824
 825         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 826                                    0, session, L2TP_CMD_SESSION_GET);
 827         if (ret < 0)
 828                 goto err_ref_msg;
 829
 830         ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 831
 832         l2tp_session_dec_refcount(session);
 833
 834         return ret;
 835
 836 err_ref_msg:
 837         nlmsg_free(msg);
 838 err_ref:
 839         l2tp_session_dec_refcount(session);
 840 err:
 841         return ret;
 842 }
 843
 844 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 845 {
 846         struct net *net = sock_net(skb->sk);
 847         struct l2tp_session *session;
 848         struct l2tp_tunnel *tunnel = NULL;
 849         int ti = cb->args[0];
 850         int si = cb->args[1];
 851
 852         for (;;) {
 853                 if (tunnel == NULL) {
 854                         tunnel = l2tp_tunnel_get_nth(net, ti);
 855                         if (tunnel == NULL)
 856                                 goto out;
 857                 }
 858
 859                 session = l2tp_session_get_nth(tunnel, si);
 860                 if (session == NULL) {
 861                         ti++;
 862                         l2tp_tunnel_dec_refcount(tunnel);
 863                         tunnel = NULL;
 864                         si = 0;
 865                         continue;
 866                 }
 867
 868                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 869                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 870                                          session, L2TP_CMD_SESSION_GET) < 0) {
 871                         l2tp_session_dec_refcount(session);
 872                         l2tp_tunnel_dec_refcount(tunnel);
 873                         break;
 874                 }
 875                 l2tp_session_dec_refcount(session);
 876
 877                 si++;
 878         }
 879
 880 out:
 881         cb->args[0] = ti;
 882         cb->args[1] = si;
 883
 884         return skb->len;
 885 }
 886
 887 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 888         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 889         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 890         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 891         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 892         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 893         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 894         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 895         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 896         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 897         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 898         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 899         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 900         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 901         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 902         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 903         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 904         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 905         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 906         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 907         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 908         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 909         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 910         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 911         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 912         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 913         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 914         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 915         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 916         [L2TP_ATTR_IP6_SADDR] = {
 917                 .type = NLA_BINARY,
 918                 .len = sizeof(struct in6_addr),
 919         },
 920         [L2TP_ATTR_IP6_DADDR] = {
 921                 .type = NLA_BINARY,
 922                 .len = sizeof(struct in6_addr),
 923         },
 924         [L2TP_ATTR_IFNAME] = {
 925                 .type = NLA_NUL_STRING,
 926                 .len = IFNAMSIZ - 1,
 927         },
 928         [L2TP_ATTR_COOKIE] = {
 929                 .type = NLA_BINARY,
 930                 .len = 8,
 931         },
 932         [L2TP_ATTR_PEER_COOKIE] = {
 933                 .type = NLA_BINARY,
 934                 .len = 8,
 935         },
 936 };
 937
 938 static const struct genl_ops l2tp_nl_ops[] = {
 939         {
 940                 .cmd = L2TP_CMD_NOOP,
 941                 .doit = l2tp_nl_cmd_noop,
 942                 .policy = l2tp_nl_policy,
 943                 /* can be retrieved by unprivileged users */
 944         },
 945         {
 946                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 947                 .doit = l2tp_nl_cmd_tunnel_create,
 948                 .policy = l2tp_nl_policy,
 949                 .flags = GENL_ADMIN_PERM,
 950         },
 951         {
 952                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 953                 .doit = l2tp_nl_cmd_tunnel_delete,
 954                 .policy = l2tp_nl_policy,
 955                 .flags = GENL_ADMIN_PERM,
 956         },
 957         {
 958                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 959                 .doit = l2tp_nl_cmd_tunnel_modify,
 960                 .policy = l2tp_nl_policy,
 961                 .flags = GENL_ADMIN_PERM,
 962         },
 963         {
 964                 .cmd = L2TP_CMD_TUNNEL_GET,
 965                 .doit = l2tp_nl_cmd_tunnel_get,
 966                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 967                 .policy = l2tp_nl_policy,
 968                 .flags = GENL_ADMIN_PERM,
 969         },
 970         {
 971                 .cmd = L2TP_CMD_SESSION_CREATE,
 972                 .doit = l2tp_nl_cmd_session_create,
 973                 .policy = l2tp_nl_policy,
 974                 .flags = GENL_ADMIN_PERM,
 975         },
 976         {
 977                 .cmd = L2TP_CMD_SESSION_DELETE,
 978                 .doit = l2tp_nl_cmd_session_delete,
 979                 .policy = l2tp_nl_policy,
 980                 .flags = GENL_ADMIN_PERM,
 981         },
 982         {
 983                 .cmd = L2TP_CMD_SESSION_MODIFY,
 984                 .doit = l2tp_nl_cmd_session_modify,
 985                 .policy = l2tp_nl_policy,
 986                 .flags = GENL_ADMIN_PERM,
 987         },
 988         {
 989                 .cmd = L2TP_CMD_SESSION_GET,
 990                 .doit = l2tp_nl_cmd_session_get,
 991                 .dumpit = l2tp_nl_cmd_session_dump,
 992                 .policy = l2tp_nl_policy,
 993                 .flags = GENL_ADMIN_PERM,
 994         },
 995 };
 996
 997 static struct genl_family l2tp_nl_family __ro_after_init = {
 998         .name           = L2TP_GENL_NAME,
 999         .version        = L2TP_GENL_VERSION,
1000         .hdrsize        = 0,
1001         .maxattr        = L2TP_ATTR_MAX,
1002         .netnsok        = true,
1003         .module         = THIS_MODULE,
1004         .ops            = l2tp_nl_ops,
1005         .n_ops          = ARRAY_SIZE(l2tp_nl_ops),
1006         .mcgrps         = l2tp_multicast_group,
1007         .n_mcgrps       = ARRAY_SIZE(l2tp_multicast_group),
1008 };
1009
1010 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1011 {
1012         int ret;
1013
1014         ret = -EINVAL;
1015         if (pw_type >= __L2TP_PWTYPE_MAX)
1016                 goto err;
1017
1018         genl_lock();
1019         ret = -EBUSY;
1020         if (l2tp_nl_cmd_ops[pw_type])
1021                 goto out;
1022
1023         l2tp_nl_cmd_ops[pw_type] = ops;
1024         ret = 0;
1025
1026 out:
1027         genl_unlock();
1028 err:
1029         return ret;
1030 }
1031 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1032
1033 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1034 {
1035         if (pw_type < __L2TP_PWTYPE_MAX) {
1036                 genl_lock();
1037                 l2tp_nl_cmd_ops[pw_type] = NULL;
1038                 genl_unlock();
1039         }
1040 }
1041 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1042
1043 static int __init l2tp_nl_init(void)
1044 {
1045         pr_info("L2TP netlink interface\n");
1046         return genl_register_family(&l2tp_nl_family);
1047 }
1048
1049 static void l2tp_nl_cleanup(void)
1050 {
1051         genl_unregister_family(&l2tp_nl_family);
1052 }
1053
1054 module_init(l2tp_nl_init);
1055 module_exit(l2tp_nl_cleanup);
1056
1057 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1058 MODULE_DESCRIPTION("L2TP netlink");
1059 MODULE_LICENSE("GPL");
1060 MODULE_VERSION("1.0");
1061 MODULE_ALIAS_GENL_FAMILY("l2tp");