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         tunnel = l2tp_tunnel_find(net, tunnel_id);
 240         if (tunnel != NULL) {
 241                 ret = -EEXIST;
 242                 goto out;
 243         }
 244
 245         ret = -EINVAL;
 246         switch (cfg.encap) {
 247         case L2TP_ENCAPTYPE_UDP:
 248         case L2TP_ENCAPTYPE_IP:
 249                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 250                                          peer_tunnel_id, &cfg, &tunnel);
 251                 break;
 252         }
 253
 254         if (ret >= 0)
 255                 ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 256                                          tunnel, L2TP_CMD_TUNNEL_CREATE);
 257 out:
 258         return ret;
 259 }
 260
 261 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 262 {
 263         struct l2tp_tunnel *tunnel;
 264         u32 tunnel_id;
 265         int ret = 0;
 266         struct net *net = genl_info_net(info);
 267
 268         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 269                 ret = -EINVAL;
 270                 goto out;
 271         }
 272         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 273
 274         tunnel = l2tp_tunnel_get(net, tunnel_id);
 275         if (!tunnel) {
 276                 ret = -ENODEV;
 277                 goto out;
 278         }
 279
 280         l2tp_tunnel_notify(&l2tp_nl_family, info,
 281                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 282
 283         l2tp_tunnel_delete(tunnel);
 284
 285         l2tp_tunnel_dec_refcount(tunnel);
 286
 287 out:
 288         return ret;
 289 }
 290
 291 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 292 {
 293         struct l2tp_tunnel *tunnel;
 294         u32 tunnel_id;
 295         int ret = 0;
 296         struct net *net = genl_info_net(info);
 297
 298         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 299                 ret = -EINVAL;
 300                 goto out;
 301         }
 302         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 303
 304         tunnel = l2tp_tunnel_get(net, tunnel_id);
 305         if (!tunnel) {
 306                 ret = -ENODEV;
 307                 goto out;
 308         }
 309
 310         if (info->attrs[L2TP_ATTR_DEBUG])
 311                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 312
 313         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 314                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 315
 316         l2tp_tunnel_dec_refcount(tunnel);
 317
 318 out:
 319         return ret;
 320 }
 321
 322 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 323                                struct l2tp_tunnel *tunnel, u8 cmd)
 324 {
 325         void *hdr;
 326         struct nlattr *nest;
 327         struct sock *sk = NULL;
 328         struct inet_sock *inet;
 329 #if IS_ENABLED(CONFIG_IPV6)
 330         struct ipv6_pinfo *np = NULL;
 331 #endif
 332
 333         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 334         if (!hdr)
 335                 return -EMSGSIZE;
 336
 337         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 338             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 339             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 340             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 341             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 342                 goto nla_put_failure;
 343
 344         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 345         if (nest == NULL)
 346                 goto nla_put_failure;
 347
 348         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 349                               atomic_long_read(&tunnel->stats.tx_packets),
 350                               L2TP_ATTR_STATS_PAD) ||
 351             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 352                               atomic_long_read(&tunnel->stats.tx_bytes),
 353                               L2TP_ATTR_STATS_PAD) ||
 354             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 355                               atomic_long_read(&tunnel->stats.tx_errors),
 356                               L2TP_ATTR_STATS_PAD) ||
 357             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 358                               atomic_long_read(&tunnel->stats.rx_packets),
 359                               L2TP_ATTR_STATS_PAD) ||
 360             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 361                               atomic_long_read(&tunnel->stats.rx_bytes),
 362                               L2TP_ATTR_STATS_PAD) ||
 363             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 364                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 365                               L2TP_ATTR_STATS_PAD) ||
 366             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 367                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 368                               L2TP_ATTR_STATS_PAD) ||
 369             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 370                               atomic_long_read(&tunnel->stats.rx_errors),
 371                               L2TP_ATTR_STATS_PAD))
 372                 goto nla_put_failure;
 373         nla_nest_end(skb, nest);
 374
 375         sk = tunnel->sock;
 376         if (!sk)
 377                 goto out;
 378
 379 #if IS_ENABLED(CONFIG_IPV6)
 380         if (sk->sk_family == AF_INET6)
 381                 np = inet6_sk(sk);
 382 #endif
 383
 384         inet = inet_sk(sk);
 385
 386         switch (tunnel->encap) {
 387         case L2TP_ENCAPTYPE_UDP:
 388                 switch (sk->sk_family) {
 389                 case AF_INET:
 390                         if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 391                                 goto nla_put_failure;
 392                         break;
 393 #if IS_ENABLED(CONFIG_IPV6)
 394                 case AF_INET6:
 395                         if (udp_get_no_check6_tx(sk) &&
 396                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
 397                                 goto nla_put_failure;
 398                         if (udp_get_no_check6_rx(sk) &&
 399                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
 400                                 goto nla_put_failure;
 401                         break;
 402 #endif
 403                 }
 404                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 405                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 406                         goto nla_put_failure;
 407                 /* fall through  */
 408         case L2TP_ENCAPTYPE_IP:
 409 #if IS_ENABLED(CONFIG_IPV6)
 410                 if (np) {
 411                         if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
 412                                              &np->saddr) ||
 413                             nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
 414                                              &sk->sk_v6_daddr))
 415                                 goto nla_put_failure;
 416                 } else
 417 #endif
 418                 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
 419                                     inet->inet_saddr) ||
 420                     nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
 421                                     inet->inet_daddr))
 422                         goto nla_put_failure;
 423                 break;
 424         }
 425
 426 out:
 427         genlmsg_end(skb, hdr);
 428         return 0;
 429
 430 nla_put_failure:
 431         genlmsg_cancel(skb, hdr);
 432         return -1;
 433 }
 434
 435 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 436 {
 437         struct l2tp_tunnel *tunnel;
 438         struct sk_buff *msg;
 439         u32 tunnel_id;
 440         int ret = -ENOBUFS;
 441         struct net *net = genl_info_net(info);
 442
 443         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 444                 ret = -EINVAL;
 445                 goto err;
 446         }
 447
 448         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 449
 450         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 451         if (!msg) {
 452                 ret = -ENOMEM;
 453                 goto err;
 454         }
 455
 456         tunnel = l2tp_tunnel_get(net, tunnel_id);
 457         if (!tunnel) {
 458                 ret = -ENODEV;
 459                 goto err_nlmsg;
 460         }
 461
 462         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 463                                   NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 464         if (ret < 0)
 465                 goto err_nlmsg_tunnel;
 466
 467         l2tp_tunnel_dec_refcount(tunnel);
 468
 469         return genlmsg_unicast(net, msg, info->snd_portid);
 470
 471 err_nlmsg_tunnel:
 472         l2tp_tunnel_dec_refcount(tunnel);
 473 err_nlmsg:
 474         nlmsg_free(msg);
 475 err:
 476         return ret;
 477 }
 478
 479 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 480 {
 481         int ti = cb->args[0];
 482         struct l2tp_tunnel *tunnel;
 483         struct net *net = sock_net(skb->sk);
 484
 485         for (;;) {
 486                 tunnel = l2tp_tunnel_find_nth(net, ti);
 487                 if (tunnel == NULL)
 488                         goto out;
 489
 490                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 491                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 492                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 493                         goto out;
 494
 495                 ti++;
 496         }
 497
 498 out:
 499         cb->args[0] = ti;
 500
 501         return skb->len;
 502 }
 503
 504 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 505 {
 506         u32 tunnel_id = 0;
 507         u32 session_id;
 508         u32 peer_session_id;
 509         int ret = 0;
 510         struct l2tp_tunnel *tunnel;
 511         struct l2tp_session *session;
 512         struct l2tp_session_cfg cfg = { 0, };
 513         struct net *net = genl_info_net(info);
 514
 515         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 516                 ret = -EINVAL;
 517                 goto out;
 518         }
 519
 520         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 521         tunnel = l2tp_tunnel_get(net, tunnel_id);
 522         if (!tunnel) {
 523                 ret = -ENODEV;
 524                 goto out;
 525         }
 526
 527         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 528                 ret = -EINVAL;
 529                 goto out_tunnel;
 530         }
 531         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 532
 533         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 534                 ret = -EINVAL;
 535                 goto out_tunnel;
 536         }
 537         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 538
 539         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 540                 ret = -EINVAL;
 541                 goto out_tunnel;
 542         }
 543         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 544         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 545                 ret = -EINVAL;
 546                 goto out_tunnel;
 547         }
 548
 549         if (tunnel->version > 2) {
 550                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 551                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 552
 553                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
 554                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 555                         if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
 556                             cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
 557                                 ret = -EINVAL;
 558                                 goto out_tunnel;
 559                         }
 560                 } else {
 561                         cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 562                 }
 563
 564                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 565                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 566                         if (len > 8) {
 567                                 ret = -EINVAL;
 568                                 goto out_tunnel;
 569                         }
 570                         cfg.cookie_len = len;
 571                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 572                 }
 573                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 574                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 575                         if (len > 8) {
 576                                 ret = -EINVAL;
 577                                 goto out_tunnel;
 578                         }
 579                         cfg.peer_cookie_len = len;
 580                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 581                 }
 582                 if (info->attrs[L2TP_ATTR_IFNAME])
 583                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 584
 585                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 586                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 587         }
 588
 589         if (info->attrs[L2TP_ATTR_DEBUG])
 590                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 591
 592         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 593                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 594
 595         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 596                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 597
 598         if (info->attrs[L2TP_ATTR_LNS_MODE])
 599                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 600
 601         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 602                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 603
 604         if (info->attrs[L2TP_ATTR_MTU])
 605                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 606
 607         if (info->attrs[L2TP_ATTR_MRU])
 608                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 609
 610 #ifdef CONFIG_MODULES
 611         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 612                 genl_unlock();
 613                 request_module("net-l2tp-type-%u", cfg.pw_type);
 614                 genl_lock();
 615         }
 616 #endif
 617         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 618             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 619                 ret = -EPROTONOSUPPORT;
 620                 goto out_tunnel;
 621         }
 622
 623         ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 624                                                            session_id,
 625                                                            peer_session_id,
 626                                                            &cfg);
 627
 628         if (ret >= 0) {
 629                 session = l2tp_session_get(net, tunnel, session_id);
 630                 if (session) {
 631                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 632                                                   L2TP_CMD_SESSION_CREATE);
 633                         l2tp_session_dec_refcount(session);
 634                 }
 635         }
 636
 637 out_tunnel:
 638         l2tp_tunnel_dec_refcount(tunnel);
 639 out:
 640         return ret;
 641 }
 642
 643 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 644 {
 645         int ret = 0;
 646         struct l2tp_session *session;
 647         u16 pw_type;
 648
 649         session = l2tp_nl_session_get(info);
 650         if (session == NULL) {
 651                 ret = -ENODEV;
 652                 goto out;
 653         }
 654
 655         l2tp_session_notify(&l2tp_nl_family, info,
 656                             session, L2TP_CMD_SESSION_DELETE);
 657
 658         pw_type = session->pwtype;
 659         if (pw_type < __L2TP_PWTYPE_MAX)
 660                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 661                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 662
 663         l2tp_session_dec_refcount(session);
 664
 665 out:
 666         return ret;
 667 }
 668
 669 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 670 {
 671         int ret = 0;
 672         struct l2tp_session *session;
 673
 674         session = l2tp_nl_session_get(info);
 675         if (session == NULL) {
 676                 ret = -ENODEV;
 677                 goto out;
 678         }
 679
 680         if (info->attrs[L2TP_ATTR_DEBUG])
 681                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 682
 683         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 684                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 685
 686         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 687                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 688
 689         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 690                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 691                 l2tp_session_set_header_len(session, session->tunnel->version);
 692         }
 693
 694         if (info->attrs[L2TP_ATTR_LNS_MODE])
 695                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 696
 697         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 698                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 699
 700         if (info->attrs[L2TP_ATTR_MTU])
 701                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 702
 703         if (info->attrs[L2TP_ATTR_MRU])
 704                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 705
 706         ret = l2tp_session_notify(&l2tp_nl_family, info,
 707                                   session, L2TP_CMD_SESSION_MODIFY);
 708
 709         l2tp_session_dec_refcount(session);
 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_get(info);
 807         if (session == NULL) {
 808                 ret = -ENODEV;
 809                 goto err;
 810         }
 811
 812         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 813         if (!msg) {
 814                 ret = -ENOMEM;
 815                 goto err_ref;
 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_ref_msg;
 822
 823         ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 824
 825         l2tp_session_dec_refcount(session);
 826
 827         return ret;
 828
 829 err_ref_msg:
 830         nlmsg_free(msg);
 831 err_ref:
 832         l2tp_session_dec_refcount(session);
 833 err:
 834         return ret;
 835 }
 836
 837 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 838 {
 839         struct net *net = sock_net(skb->sk);
 840         struct l2tp_session *session;
 841         struct l2tp_tunnel *tunnel = NULL;
 842         int ti = cb->args[0];
 843         int si = cb->args[1];
 844
 845         for (;;) {
 846                 if (tunnel == NULL) {
 847                         tunnel = l2tp_tunnel_find_nth(net, ti);
 848                         if (tunnel == NULL)
 849                                 goto out;
 850                 }
 851
 852                 session = l2tp_session_get_nth(tunnel, si);
 853                 if (session == NULL) {
 854                         ti++;
 855                         tunnel = NULL;
 856                         si = 0;
 857                         continue;
 858                 }
 859
 860                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 861                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 862                                          session, L2TP_CMD_SESSION_GET) < 0) {
 863                         l2tp_session_dec_refcount(session);
 864                         break;
 865                 }
 866                 l2tp_session_dec_refcount(session);
 867
 868                 si++;
 869         }
 870
 871 out:
 872         cb->args[0] = ti;
 873         cb->args[1] = si;
 874
 875         return skb->len;
 876 }
 877
 878 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 879         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 880         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 881         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 882         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 883         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 884         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 885         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 886         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 887         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 888         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 889         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 890         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 891         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 892         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 893         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 894         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 895         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 896         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 897         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 898         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 899         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 900         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 901         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 902         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 903         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 904         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 905         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 906         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 907         [L2TP_ATTR_IP6_SADDR] = {
 908                 .type = NLA_BINARY,
 909                 .len = sizeof(struct in6_addr),
 910         },
 911         [L2TP_ATTR_IP6_DADDR] = {
 912                 .type = NLA_BINARY,
 913                 .len = sizeof(struct in6_addr),
 914         },
 915         [L2TP_ATTR_IFNAME] = {
 916                 .type = NLA_NUL_STRING,
 917                 .len = IFNAMSIZ - 1,
 918         },
 919         [L2TP_ATTR_COOKIE] = {
 920                 .type = NLA_BINARY,
 921                 .len = 8,
 922         },
 923         [L2TP_ATTR_PEER_COOKIE] = {
 924                 .type = NLA_BINARY,
 925                 .len = 8,
 926         },
 927 };
 928
 929 static const struct genl_ops l2tp_nl_ops[] = {
 930         {
 931                 .cmd = L2TP_CMD_NOOP,
 932                 .doit = l2tp_nl_cmd_noop,
 933                 .policy = l2tp_nl_policy,
 934                 /* can be retrieved by unprivileged users */
 935         },
 936         {
 937                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 938                 .doit = l2tp_nl_cmd_tunnel_create,
 939                 .policy = l2tp_nl_policy,
 940                 .flags = GENL_ADMIN_PERM,
 941         },
 942         {
 943                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 944                 .doit = l2tp_nl_cmd_tunnel_delete,
 945                 .policy = l2tp_nl_policy,
 946                 .flags = GENL_ADMIN_PERM,
 947         },
 948         {
 949                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 950                 .doit = l2tp_nl_cmd_tunnel_modify,
 951                 .policy = l2tp_nl_policy,
 952                 .flags = GENL_ADMIN_PERM,
 953         },
 954         {
 955                 .cmd = L2TP_CMD_TUNNEL_GET,
 956                 .doit = l2tp_nl_cmd_tunnel_get,
 957                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 958                 .policy = l2tp_nl_policy,
 959                 .flags = GENL_ADMIN_PERM,
 960         },
 961         {
 962                 .cmd = L2TP_CMD_SESSION_CREATE,
 963                 .doit = l2tp_nl_cmd_session_create,
 964                 .policy = l2tp_nl_policy,
 965                 .flags = GENL_ADMIN_PERM,
 966         },
 967         {
 968                 .cmd = L2TP_CMD_SESSION_DELETE,
 969                 .doit = l2tp_nl_cmd_session_delete,
 970                 .policy = l2tp_nl_policy,
 971                 .flags = GENL_ADMIN_PERM,
 972         },
 973         {
 974                 .cmd = L2TP_CMD_SESSION_MODIFY,
 975                 .doit = l2tp_nl_cmd_session_modify,
 976                 .policy = l2tp_nl_policy,
 977                 .flags = GENL_ADMIN_PERM,
 978         },
 979         {
 980                 .cmd = L2TP_CMD_SESSION_GET,
 981                 .doit = l2tp_nl_cmd_session_get,
 982                 .dumpit = l2tp_nl_cmd_session_dump,
 983                 .policy = l2tp_nl_policy,
 984                 .flags = GENL_ADMIN_PERM,
 985         },
 986 };
 987
 988 static struct genl_family l2tp_nl_family __ro_after_init = {
 989         .name           = L2TP_GENL_NAME,
 990         .version        = L2TP_GENL_VERSION,
 991         .hdrsize        = 0,
 992         .maxattr        = L2TP_ATTR_MAX,
 993         .netnsok        = true,
 994         .module         = THIS_MODULE,
 995         .ops            = l2tp_nl_ops,
 996         .n_ops          = ARRAY_SIZE(l2tp_nl_ops),
 997         .mcgrps         = l2tp_multicast_group,
 998         .n_mcgrps       = ARRAY_SIZE(l2tp_multicast_group),
 999 };
1000
1001 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1002 {
1003         int ret;
1004
1005         ret = -EINVAL;
1006         if (pw_type >= __L2TP_PWTYPE_MAX)
1007                 goto err;
1008
1009         genl_lock();
1010         ret = -EBUSY;
1011         if (l2tp_nl_cmd_ops[pw_type])
1012                 goto out;
1013
1014         l2tp_nl_cmd_ops[pw_type] = ops;
1015         ret = 0;
1016
1017 out:
1018         genl_unlock();
1019 err:
1020         return ret;
1021 }
1022 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1023
1024 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1025 {
1026         if (pw_type < __L2TP_PWTYPE_MAX) {
1027                 genl_lock();
1028                 l2tp_nl_cmd_ops[pw_type] = NULL;
1029                 genl_unlock();
1030         }
1031 }
1032 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1033
1034 static int __init l2tp_nl_init(void)
1035 {
1036         pr_info("L2TP netlink interface\n");
1037         return genl_register_family(&l2tp_nl_family);
1038 }
1039
1040 static void l2tp_nl_cleanup(void)
1041 {
1042         genl_unregister_family(&l2tp_nl_family);
1043 }
1044
1045 module_init(l2tp_nl_init);
1046 module_exit(l2tp_nl_cleanup);
1047
1048 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1049 MODULE_DESCRIPTION("L2TP netlink");
1050 MODULE_LICENSE("GPL");
1051 MODULE_VERSION("1.0");
1052 MODULE_ALIAS_GENL_FAMILY("l2tp");