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         .id             = GENL_ID_GENERATE,
  36         .name           = L2TP_GENL_NAME,
  37         .version        = L2TP_GENL_VERSION,
  38         .hdrsize        = 0,
  39         .maxattr        = L2TP_ATTR_MAX,
  40         .netnsok        = true,
  41 };
  42
  43 static const struct genl_multicast_group l2tp_multicast_group[] = {
  44         {
  45                 .name = L2TP_GENL_MCGROUP,
  46         },
  47 };
  48
  49 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
  50                                int flags, struct l2tp_tunnel *tunnel, u8 cmd);
  51 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
  52                                 int flags, struct l2tp_session *session,
  53                                 u8 cmd);
  54
  55 /* Accessed under genl lock */
  56 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
  57
  58 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
  59 {
  60         u32 tunnel_id;
  61         u32 session_id;
  62         char *ifname;
  63         struct l2tp_tunnel *tunnel;
  64         struct l2tp_session *session = NULL;
  65         struct net *net = genl_info_net(info);
  66
  67         if (info->attrs[L2TP_ATTR_IFNAME]) {
  68                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  69                 session = l2tp_session_find_by_ifname(net, ifname);
  70         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  71                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  72                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  73                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  74                 tunnel = l2tp_tunnel_find(net, tunnel_id);
  75                 if (tunnel)
  76                         session = l2tp_session_find(net, tunnel, session_id);
  77         }
  78
  79         return session;
  80 }
  81
  82 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  83 {
  84         struct sk_buff *msg;
  85         void *hdr;
  86         int ret = -ENOBUFS;
  87
  88         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  89         if (!msg) {
  90                 ret = -ENOMEM;
  91                 goto out;
  92         }
  93
  94         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  95                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  96         if (!hdr) {
  97                 ret = -EMSGSIZE;
  98                 goto err_out;
  99         }
 100
 101         genlmsg_end(msg, hdr);
 102
 103         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 104
 105 err_out:
 106         nlmsg_free(msg);
 107
 108 out:
 109         return ret;
 110 }
 111
 112 static int l2tp_tunnel_notify(struct genl_family *family,
 113                               struct genl_info *info,
 114                               struct l2tp_tunnel *tunnel,
 115                               u8 cmd)
 116 {
 117         struct sk_buff *msg;
 118         int ret;
 119
 120         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 121         if (!msg)
 122                 return -ENOMEM;
 123
 124         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 125                                   NLM_F_ACK, tunnel, cmd);
 126
 127         if (ret >= 0) {
 128                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 129                 /* We don't care if no one is listening */
 130                 if (ret == -ESRCH)
 131                         ret = 0;
 132                 return ret;
 133         }
 134
 135         nlmsg_free(msg);
 136
 137         return ret;
 138 }
 139
 140 static int l2tp_session_notify(struct genl_family *family,
 141                                struct genl_info *info,
 142                                struct l2tp_session *session,
 143                                u8 cmd)
 144 {
 145         struct sk_buff *msg;
 146         int ret;
 147
 148         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 149         if (!msg)
 150                 return -ENOMEM;
 151
 152         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 153                                    NLM_F_ACK, session, cmd);
 154
 155         if (ret >= 0) {
 156                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 157                 /* We don't care if no one is listening */
 158                 if (ret == -ESRCH)
 159                         ret = 0;
 160                 return ret;
 161         }
 162
 163         nlmsg_free(msg);
 164
 165         return ret;
 166 }
 167
 168 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 169 {
 170         u32 tunnel_id;
 171         u32 peer_tunnel_id;
 172         int proto_version;
 173         int fd;
 174         int ret = 0;
 175         struct l2tp_tunnel_cfg cfg = { 0, };
 176         struct l2tp_tunnel *tunnel;
 177         struct net *net = genl_info_net(info);
 178
 179         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 180                 ret = -EINVAL;
 181                 goto out;
 182         }
 183         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 184
 185         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 186                 ret = -EINVAL;
 187                 goto out;
 188         }
 189         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 190
 191         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 192                 ret = -EINVAL;
 193                 goto out;
 194         }
 195         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 196
 197         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 198                 ret = -EINVAL;
 199                 goto out;
 200         }
 201         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 202
 203         fd = -1;
 204         if (info->attrs[L2TP_ATTR_FD]) {
 205                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 206         } else {
 207 #if IS_ENABLED(CONFIG_IPV6)
 208                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 209                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 210                         cfg.local_ip6 = nla_data(
 211                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 212                         cfg.peer_ip6 = nla_data(
 213                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 214                 } else
 215 #endif
 216                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 217                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 218                         cfg.local_ip.s_addr = nla_get_in_addr(
 219                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 220                         cfg.peer_ip.s_addr = nla_get_in_addr(
 221                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 222                 } else {
 223                         ret = -EINVAL;
 224                         goto out;
 225                 }
 226                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 227                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 228                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 229                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 230                 if (info->attrs[L2TP_ATTR_UDP_CSUM])
 231                         cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
 232
 233 #if IS_ENABLED(CONFIG_IPV6)
 234                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
 235                         cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 236                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
 237                         cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 238 #endif
 239         }
 240
 241         if (info->attrs[L2TP_ATTR_DEBUG])
 242                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 243
 244         tunnel = l2tp_tunnel_find(net, tunnel_id);
 245         if (tunnel != NULL) {
 246                 ret = -EEXIST;
 247                 goto out;
 248         }
 249
 250         ret = -EINVAL;
 251         switch (cfg.encap) {
 252         case L2TP_ENCAPTYPE_UDP:
 253         case L2TP_ENCAPTYPE_IP:
 254                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 255                                          peer_tunnel_id, &cfg, &tunnel);
 256                 break;
 257         }
 258
 259         if (ret >= 0)
 260                 ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 261                                          tunnel, L2TP_CMD_TUNNEL_CREATE);
 262 out:
 263         return ret;
 264 }
 265
 266 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 267 {
 268         struct l2tp_tunnel *tunnel;
 269         u32 tunnel_id;
 270         int ret = 0;
 271         struct net *net = genl_info_net(info);
 272
 273         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 274                 ret = -EINVAL;
 275                 goto out;
 276         }
 277         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 278
 279         tunnel = l2tp_tunnel_find(net, tunnel_id);
 280         if (tunnel == NULL) {
 281                 ret = -ENODEV;
 282                 goto out;
 283         }
 284
 285         l2tp_tunnel_notify(&l2tp_nl_family, info,
 286                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 287
 288         (void) l2tp_tunnel_delete(tunnel);
 289
 290 out:
 291         return ret;
 292 }
 293
 294 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 295 {
 296         struct l2tp_tunnel *tunnel;
 297         u32 tunnel_id;
 298         int ret = 0;
 299         struct net *net = genl_info_net(info);
 300
 301         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 302                 ret = -EINVAL;
 303                 goto out;
 304         }
 305         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 306
 307         tunnel = l2tp_tunnel_find(net, tunnel_id);
 308         if (tunnel == NULL) {
 309                 ret = -ENODEV;
 310                 goto out;
 311         }
 312
 313         if (info->attrs[L2TP_ATTR_DEBUG])
 314                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 315
 316         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 317                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 318
 319 out:
 320         return ret;
 321 }
 322
 323 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 324                                struct l2tp_tunnel *tunnel, u8 cmd)
 325 {
 326         void *hdr;
 327         struct nlattr *nest;
 328         struct sock *sk = NULL;
 329         struct inet_sock *inet;
 330 #if IS_ENABLED(CONFIG_IPV6)
 331         struct ipv6_pinfo *np = NULL;
 332 #endif
 333
 334         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 335         if (!hdr)
 336                 return -EMSGSIZE;
 337
 338         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 339             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 340             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 341             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 342             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 343                 goto nla_put_failure;
 344
 345         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 346         if (nest == NULL)
 347                 goto nla_put_failure;
 348
 349         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 350                               atomic_long_read(&tunnel->stats.tx_packets),
 351                               L2TP_ATTR_STATS_PAD) ||
 352             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 353                               atomic_long_read(&tunnel->stats.tx_bytes),
 354                               L2TP_ATTR_STATS_PAD) ||
 355             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 356                               atomic_long_read(&tunnel->stats.tx_errors),
 357                               L2TP_ATTR_STATS_PAD) ||
 358             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 359                               atomic_long_read(&tunnel->stats.rx_packets),
 360                               L2TP_ATTR_STATS_PAD) ||
 361             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 362                               atomic_long_read(&tunnel->stats.rx_bytes),
 363                               L2TP_ATTR_STATS_PAD) ||
 364             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 365                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 366                               L2TP_ATTR_STATS_PAD) ||
 367             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 368                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 369                               L2TP_ATTR_STATS_PAD) ||
 370             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 371                               atomic_long_read(&tunnel->stats.rx_errors),
 372                               L2TP_ATTR_STATS_PAD))
 373                 goto nla_put_failure;
 374         nla_nest_end(skb, nest);
 375
 376         sk = tunnel->sock;
 377         if (!sk)
 378                 goto out;
 379
 380 #if IS_ENABLED(CONFIG_IPV6)
 381         if (sk->sk_family == AF_INET6)
 382                 np = inet6_sk(sk);
 383 #endif
 384
 385         inet = inet_sk(sk);
 386
 387         switch (tunnel->encap) {
 388         case L2TP_ENCAPTYPE_UDP:
 389                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 390                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
 391                     nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 392                         goto nla_put_failure;
 393                 /* NOBREAK */
 394         case L2TP_ENCAPTYPE_IP:
 395 #if IS_ENABLED(CONFIG_IPV6)
 396                 if (np) {
 397                         if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
 398                                              &np->saddr) ||
 399                             nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
 400                                              &sk->sk_v6_daddr))
 401                                 goto nla_put_failure;
 402                 } else
 403 #endif
 404                 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
 405                                     inet->inet_saddr) ||
 406                     nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
 407                                     inet->inet_daddr))
 408                         goto nla_put_failure;
 409                 break;
 410         }
 411
 412 out:
 413         genlmsg_end(skb, hdr);
 414         return 0;
 415
 416 nla_put_failure:
 417         genlmsg_cancel(skb, hdr);
 418         return -1;
 419 }
 420
 421 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 422 {
 423         struct l2tp_tunnel *tunnel;
 424         struct sk_buff *msg;
 425         u32 tunnel_id;
 426         int ret = -ENOBUFS;
 427         struct net *net = genl_info_net(info);
 428
 429         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 430                 ret = -EINVAL;
 431                 goto out;
 432         }
 433
 434         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 435
 436         tunnel = l2tp_tunnel_find(net, tunnel_id);
 437         if (tunnel == NULL) {
 438                 ret = -ENODEV;
 439                 goto out;
 440         }
 441
 442         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 443         if (!msg) {
 444                 ret = -ENOMEM;
 445                 goto out;
 446         }
 447
 448         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 449                                   NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 450         if (ret < 0)
 451                 goto err_out;
 452
 453         return genlmsg_unicast(net, msg, info->snd_portid);
 454
 455 err_out:
 456         nlmsg_free(msg);
 457
 458 out:
 459         return ret;
 460 }
 461
 462 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 463 {
 464         int ti = cb->args[0];
 465         struct l2tp_tunnel *tunnel;
 466         struct net *net = sock_net(skb->sk);
 467
 468         for (;;) {
 469                 tunnel = l2tp_tunnel_find_nth(net, ti);
 470                 if (tunnel == NULL)
 471                         goto out;
 472
 473                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 474                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 475                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 476                         goto out;
 477
 478                 ti++;
 479         }
 480
 481 out:
 482         cb->args[0] = ti;
 483
 484         return skb->len;
 485 }
 486
 487 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 488 {
 489         u32 tunnel_id = 0;
 490         u32 session_id;
 491         u32 peer_session_id;
 492         int ret = 0;
 493         struct l2tp_tunnel *tunnel;
 494         struct l2tp_session *session;
 495         struct l2tp_session_cfg cfg = { 0, };
 496         struct net *net = genl_info_net(info);
 497
 498         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 499                 ret = -EINVAL;
 500                 goto out;
 501         }
 502         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 503         tunnel = l2tp_tunnel_find(net, tunnel_id);
 504         if (!tunnel) {
 505                 ret = -ENODEV;
 506                 goto out;
 507         }
 508
 509         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 510                 ret = -EINVAL;
 511                 goto out;
 512         }
 513         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 514         session = l2tp_session_find(net, tunnel, session_id);
 515         if (session) {
 516                 ret = -EEXIST;
 517                 goto out;
 518         }
 519
 520         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 521                 ret = -EINVAL;
 522                 goto out;
 523         }
 524         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 525
 526         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 527                 ret = -EINVAL;
 528                 goto out;
 529         }
 530         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 531         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 532                 ret = -EINVAL;
 533                 goto out;
 534         }
 535
 536         if (tunnel->version > 2) {
 537                 if (info->attrs[L2TP_ATTR_OFFSET])
 538                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 539
 540                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 541                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 542
 543                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 544                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 545                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 546
 547                 cfg.l2specific_len = 4;
 548                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 549                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 550
 551                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 552                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 553                         if (len > 8) {
 554                                 ret = -EINVAL;
 555                                 goto out;
 556                         }
 557                         cfg.cookie_len = len;
 558                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 559                 }
 560                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 561                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 562                         if (len > 8) {
 563                                 ret = -EINVAL;
 564                                 goto out;
 565                         }
 566                         cfg.peer_cookie_len = len;
 567                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 568                 }
 569                 if (info->attrs[L2TP_ATTR_IFNAME])
 570                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 571
 572                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 573                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 574         }
 575
 576         if (info->attrs[L2TP_ATTR_DEBUG])
 577                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 578
 579         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 580                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 581
 582         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 583                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 584
 585         if (info->attrs[L2TP_ATTR_LNS_MODE])
 586                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 587
 588         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 589                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 590
 591         if (info->attrs[L2TP_ATTR_MTU])
 592                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 593
 594         if (info->attrs[L2TP_ATTR_MRU])
 595                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 596
 597 #ifdef CONFIG_MODULES
 598         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 599                 genl_unlock();
 600                 request_module("net-l2tp-type-%u", cfg.pw_type);
 601                 genl_lock();
 602         }
 603 #endif
 604         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 605             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 606                 ret = -EPROTONOSUPPORT;
 607                 goto out;
 608         }
 609
 610         /* Check that pseudowire-specific params are present */
 611         switch (cfg.pw_type) {
 612         case L2TP_PWTYPE_NONE:
 613                 break;
 614         case L2TP_PWTYPE_ETH_VLAN:
 615                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 616                         ret = -EINVAL;
 617                         goto out;
 618                 }
 619                 break;
 620         case L2TP_PWTYPE_ETH:
 621                 break;
 622         case L2TP_PWTYPE_PPP:
 623         case L2TP_PWTYPE_PPP_AC:
 624                 break;
 625         case L2TP_PWTYPE_IP:
 626         default:
 627                 ret = -EPROTONOSUPPORT;
 628                 break;
 629         }
 630
 631         ret = -EPROTONOSUPPORT;
 632         if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
 633                 ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
 634                         session_id, peer_session_id, &cfg);
 635
 636         if (ret >= 0) {
 637                 session = l2tp_session_find(net, tunnel, session_id);
 638                 if (session)
 639                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 640                                                   L2TP_CMD_SESSION_CREATE);
 641         }
 642
 643 out:
 644         return ret;
 645 }
 646
 647 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 648 {
 649         int ret = 0;
 650         struct l2tp_session *session;
 651         u16 pw_type;
 652
 653         session = l2tp_nl_session_find(info);
 654         if (session == NULL) {
 655                 ret = -ENODEV;
 656                 goto out;
 657         }
 658
 659         l2tp_session_notify(&l2tp_nl_family, info,
 660                             session, L2TP_CMD_SESSION_DELETE);
 661
 662         pw_type = session->pwtype;
 663         if (pw_type < __L2TP_PWTYPE_MAX)
 664                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 665                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 666
 667 out:
 668         return ret;
 669 }
 670
 671 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 672 {
 673         int ret = 0;
 674         struct l2tp_session *session;
 675
 676         session = l2tp_nl_session_find(info);
 677         if (session == NULL) {
 678                 ret = -ENODEV;
 679                 goto out;
 680         }
 681
 682         if (info->attrs[L2TP_ATTR_DEBUG])
 683                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 684
 685         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 686                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 687
 688         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 689                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 690
 691         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 692                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 693                 l2tp_session_set_header_len(session, session->tunnel->version);
 694         }
 695
 696         if (info->attrs[L2TP_ATTR_LNS_MODE])
 697                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 698
 699         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 700                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 701
 702         if (info->attrs[L2TP_ATTR_MTU])
 703                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 704
 705         if (info->attrs[L2TP_ATTR_MRU])
 706                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 707
 708         ret = l2tp_session_notify(&l2tp_nl_family, info,
 709                                   session, L2TP_CMD_SESSION_MODIFY);
 710
 711 out:
 712         return ret;
 713 }
 714
 715 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 716                                 struct l2tp_session *session, u8 cmd)
 717 {
 718         void *hdr;
 719         struct nlattr *nest;
 720         struct l2tp_tunnel *tunnel = session->tunnel;
 721         struct sock *sk = NULL;
 722
 723         sk = tunnel->sock;
 724
 725         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 726         if (!hdr)
 727                 return -EMSGSIZE;
 728
 729         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 730             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 731             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 732             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 733                         session->peer_session_id) ||
 734             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 735             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 736             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 737             (session->mru &&
 738              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 739                 goto nla_put_failure;
 740
 741         if ((session->ifname[0] &&
 742              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 743             (session->cookie_len &&
 744              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 745                      &session->cookie[0])) ||
 746             (session->peer_cookie_len &&
 747              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 748                      &session->peer_cookie[0])) ||
 749             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 750             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 751             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 752 #ifdef CONFIG_XFRM
 753             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 754              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 755 #endif
 756             (session->reorder_timeout &&
 757              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 758                            session->reorder_timeout, L2TP_ATTR_PAD)))
 759                 goto nla_put_failure;
 760
 761         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 762         if (nest == NULL)
 763                 goto nla_put_failure;
 764
 765         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 766                               atomic_long_read(&session->stats.tx_packets),
 767                               L2TP_ATTR_STATS_PAD) ||
 768             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 769                               atomic_long_read(&session->stats.tx_bytes),
 770                               L2TP_ATTR_STATS_PAD) ||
 771             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 772                               atomic_long_read(&session->stats.tx_errors),
 773                               L2TP_ATTR_STATS_PAD) ||
 774             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 775                               atomic_long_read(&session->stats.rx_packets),
 776                               L2TP_ATTR_STATS_PAD) ||
 777             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 778                               atomic_long_read(&session->stats.rx_bytes),
 779                               L2TP_ATTR_STATS_PAD) ||
 780             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 781                               atomic_long_read(&session->stats.rx_seq_discards),
 782                               L2TP_ATTR_STATS_PAD) ||
 783             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 784                               atomic_long_read(&session->stats.rx_oos_packets),
 785                               L2TP_ATTR_STATS_PAD) ||
 786             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 787                               atomic_long_read(&session->stats.rx_errors),
 788                               L2TP_ATTR_STATS_PAD))
 789                 goto nla_put_failure;
 790         nla_nest_end(skb, nest);
 791
 792         genlmsg_end(skb, hdr);
 793         return 0;
 794
 795  nla_put_failure:
 796         genlmsg_cancel(skb, hdr);
 797         return -1;
 798 }
 799
 800 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 801 {
 802         struct l2tp_session *session;
 803         struct sk_buff *msg;
 804         int ret;
 805
 806         session = l2tp_nl_session_find(info);
 807         if (session == NULL) {
 808                 ret = -ENODEV;
 809                 goto out;
 810         }
 811
 812         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 813         if (!msg) {
 814                 ret = -ENOMEM;
 815                 goto out;
 816         }
 817
 818         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 819                                    0, session, L2TP_CMD_SESSION_GET);
 820         if (ret < 0)
 821                 goto err_out;
 822
 823         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 824
 825 err_out:
 826         nlmsg_free(msg);
 827
 828 out:
 829         return ret;
 830 }
 831
 832 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 833 {
 834         struct net *net = sock_net(skb->sk);
 835         struct l2tp_session *session;
 836         struct l2tp_tunnel *tunnel = NULL;
 837         int ti = cb->args[0];
 838         int si = cb->args[1];
 839
 840         for (;;) {
 841                 if (tunnel == NULL) {
 842                         tunnel = l2tp_tunnel_find_nth(net, ti);
 843                         if (tunnel == NULL)
 844                                 goto out;
 845                 }
 846
 847                 session = l2tp_session_find_nth(tunnel, si);
 848                 if (session == NULL) {
 849                         ti++;
 850                         tunnel = NULL;
 851                         si = 0;
 852                         continue;
 853                 }
 854
 855                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 856                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 857                                          session, L2TP_CMD_SESSION_GET) < 0)
 858                         break;
 859
 860                 si++;
 861         }
 862
 863 out:
 864         cb->args[0] = ti;
 865         cb->args[1] = si;
 866
 867         return skb->len;
 868 }
 869
 870 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 871         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 872         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 873         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 874         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 875         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 876         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 877         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 878         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 879         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 880         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 881         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 882         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 883         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 884         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 885         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 886         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 887         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 888         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 889         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 890         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 891         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 892         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 893         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 894         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 895         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 896         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 897         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 898         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 899         [L2TP_ATTR_IP6_SADDR] = {
 900                 .type = NLA_BINARY,
 901                 .len = sizeof(struct in6_addr),
 902         },
 903         [L2TP_ATTR_IP6_DADDR] = {
 904                 .type = NLA_BINARY,
 905                 .len = sizeof(struct in6_addr),
 906         },
 907         [L2TP_ATTR_IFNAME] = {
 908                 .type = NLA_NUL_STRING,
 909                 .len = IFNAMSIZ - 1,
 910         },
 911         [L2TP_ATTR_COOKIE] = {
 912                 .type = NLA_BINARY,
 913                 .len = 8,
 914         },
 915         [L2TP_ATTR_PEER_COOKIE] = {
 916                 .type = NLA_BINARY,
 917                 .len = 8,
 918         },
 919 };
 920
 921 static const struct genl_ops l2tp_nl_ops[] = {
 922         {
 923                 .cmd = L2TP_CMD_NOOP,
 924                 .doit = l2tp_nl_cmd_noop,
 925                 .policy = l2tp_nl_policy,
 926                 /* can be retrieved by unprivileged users */
 927         },
 928         {
 929                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 930                 .doit = l2tp_nl_cmd_tunnel_create,
 931                 .policy = l2tp_nl_policy,
 932                 .flags = GENL_ADMIN_PERM,
 933         },
 934         {
 935                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 936                 .doit = l2tp_nl_cmd_tunnel_delete,
 937                 .policy = l2tp_nl_policy,
 938                 .flags = GENL_ADMIN_PERM,
 939         },
 940         {
 941                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 942                 .doit = l2tp_nl_cmd_tunnel_modify,
 943                 .policy = l2tp_nl_policy,
 944                 .flags = GENL_ADMIN_PERM,
 945         },
 946         {
 947                 .cmd = L2TP_CMD_TUNNEL_GET,
 948                 .doit = l2tp_nl_cmd_tunnel_get,
 949                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 950                 .policy = l2tp_nl_policy,
 951                 .flags = GENL_ADMIN_PERM,
 952         },
 953         {
 954                 .cmd = L2TP_CMD_SESSION_CREATE,
 955                 .doit = l2tp_nl_cmd_session_create,
 956                 .policy = l2tp_nl_policy,
 957                 .flags = GENL_ADMIN_PERM,
 958         },
 959         {
 960                 .cmd = L2TP_CMD_SESSION_DELETE,
 961                 .doit = l2tp_nl_cmd_session_delete,
 962                 .policy = l2tp_nl_policy,
 963                 .flags = GENL_ADMIN_PERM,
 964         },
 965         {
 966                 .cmd = L2TP_CMD_SESSION_MODIFY,
 967                 .doit = l2tp_nl_cmd_session_modify,
 968                 .policy = l2tp_nl_policy,
 969                 .flags = GENL_ADMIN_PERM,
 970         },
 971         {
 972                 .cmd = L2TP_CMD_SESSION_GET,
 973                 .doit = l2tp_nl_cmd_session_get,
 974                 .dumpit = l2tp_nl_cmd_session_dump,
 975                 .policy = l2tp_nl_policy,
 976                 .flags = GENL_ADMIN_PERM,
 977         },
 978 };
 979
 980 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 981 {
 982         int ret;
 983
 984         ret = -EINVAL;
 985         if (pw_type >= __L2TP_PWTYPE_MAX)
 986                 goto err;
 987
 988         genl_lock();
 989         ret = -EBUSY;
 990         if (l2tp_nl_cmd_ops[pw_type])
 991                 goto out;
 992
 993         l2tp_nl_cmd_ops[pw_type] = ops;
 994         ret = 0;
 995
 996 out:
 997         genl_unlock();
 998 err:
 999         return ret;
1000 }
1001 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1002
1003 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1004 {
1005         if (pw_type < __L2TP_PWTYPE_MAX) {
1006                 genl_lock();
1007                 l2tp_nl_cmd_ops[pw_type] = NULL;
1008                 genl_unlock();
1009         }
1010 }
1011 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1012
1013 static int l2tp_nl_init(void)
1014 {
1015         pr_info("L2TP netlink interface\n");
1016         return genl_register_family_with_ops_groups(&l2tp_nl_family,
1017                                                     l2tp_nl_ops,
1018                                                     l2tp_multicast_group);
1019 }
1020
1021 static void l2tp_nl_cleanup(void)
1022 {
1023         genl_unregister_family(&l2tp_nl_family);
1024 }
1025
1026 module_init(l2tp_nl_init);
1027 module_exit(l2tp_nl_cleanup);
1028
1029 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1030 MODULE_DESCRIPTION("L2TP netlink");
1031 MODULE_LICENSE("GPL");
1032 MODULE_VERSION("1.0");
1033 MODULE_ALIAS_GENL_FAMILY("l2tp");