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_get(struct genl_info *info,
  59                                                 bool do_ref)
  60 {
  61         u32 tunnel_id;
  62         u32 session_id;
  63         char *ifname;
  64         struct l2tp_tunnel *tunnel;
  65         struct l2tp_session *session = NULL;
  66         struct net *net = genl_info_net(info);
  67
  68         if (info->attrs[L2TP_ATTR_IFNAME]) {
  69                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  70                 session = l2tp_session_get_by_ifname(net, ifname, do_ref);
  71         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  72                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  73                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  74                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  75                 tunnel = l2tp_tunnel_get(net, tunnel_id);
  76                 if (tunnel) {
  77                         session = l2tp_session_get(net, tunnel, session_id,
  78                                                    do_ref);
  79                         l2tp_tunnel_dec_refcount(tunnel);
  80                 }
  81         }
  82
  83         return session;
  84 }
  85
  86 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  87 {
  88         struct sk_buff *msg;
  89         void *hdr;
  90         int ret = -ENOBUFS;
  91
  92         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  93         if (!msg) {
  94                 ret = -ENOMEM;
  95                 goto out;
  96         }
  97
  98         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  99                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
 100         if (!hdr) {
 101                 ret = -EMSGSIZE;
 102                 goto err_out;
 103         }
 104
 105         genlmsg_end(msg, hdr);
 106
 107         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 108
 109 err_out:
 110         nlmsg_free(msg);
 111
 112 out:
 113         return ret;
 114 }
 115
 116 static int l2tp_tunnel_notify(struct genl_family *family,
 117                               struct genl_info *info,
 118                               struct l2tp_tunnel *tunnel,
 119                               u8 cmd)
 120 {
 121         struct sk_buff *msg;
 122         int ret;
 123
 124         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 125         if (!msg)
 126                 return -ENOMEM;
 127
 128         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 129                                   NLM_F_ACK, tunnel, cmd);
 130
 131         if (ret >= 0) {
 132                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 133                 /* We don't care if no one is listening */
 134                 if (ret == -ESRCH)
 135                         ret = 0;
 136                 return ret;
 137         }
 138
 139         nlmsg_free(msg);
 140
 141         return ret;
 142 }
 143
 144 static int l2tp_session_notify(struct genl_family *family,
 145                                struct genl_info *info,
 146                                struct l2tp_session *session,
 147                                u8 cmd)
 148 {
 149         struct sk_buff *msg;
 150         int ret;
 151
 152         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 153         if (!msg)
 154                 return -ENOMEM;
 155
 156         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 157                                    NLM_F_ACK, session, cmd);
 158
 159         if (ret >= 0) {
 160                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 161                 /* We don't care if no one is listening */
 162                 if (ret == -ESRCH)
 163                         ret = 0;
 164                 return ret;
 165         }
 166
 167         nlmsg_free(msg);
 168
 169         return ret;
 170 }
 171
 172 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 173 {
 174         u32 tunnel_id;
 175         u32 peer_tunnel_id;
 176         int proto_version;
 177         int fd;
 178         int ret = 0;
 179         struct l2tp_tunnel_cfg cfg = { 0, };
 180         struct l2tp_tunnel *tunnel;
 181         struct net *net = genl_info_net(info);
 182
 183         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 184                 ret = -EINVAL;
 185                 goto out;
 186         }
 187         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 188
 189         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 190                 ret = -EINVAL;
 191                 goto out;
 192         }
 193         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 194
 195         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 196                 ret = -EINVAL;
 197                 goto out;
 198         }
 199         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 200
 201         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 202                 ret = -EINVAL;
 203                 goto out;
 204         }
 205         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 206
 207         fd = -1;
 208         if (info->attrs[L2TP_ATTR_FD]) {
 209                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 210         } else {
 211 #if IS_ENABLED(CONFIG_IPV6)
 212                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 213                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 214                         cfg.local_ip6 = nla_data(
 215                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 216                         cfg.peer_ip6 = nla_data(
 217                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 218                 } else
 219 #endif
 220                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 221                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 222                         cfg.local_ip.s_addr = nla_get_in_addr(
 223                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 224                         cfg.peer_ip.s_addr = nla_get_in_addr(
 225                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 226                 } else {
 227                         ret = -EINVAL;
 228                         goto out;
 229                 }
 230                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 231                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 232                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 233                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 234                 if (info->attrs[L2TP_ATTR_UDP_CSUM])
 235                         cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
 236
 237 #if IS_ENABLED(CONFIG_IPV6)
 238                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
 239                         cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 240                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
 241                         cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 242 #endif
 243         }
 244
 245         if (info->attrs[L2TP_ATTR_DEBUG])
 246                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 247
 248         tunnel = l2tp_tunnel_find(net, tunnel_id);
 249         if (tunnel != NULL) {
 250                 ret = -EEXIST;
 251                 goto out;
 252         }
 253
 254         ret = -EINVAL;
 255         switch (cfg.encap) {
 256         case L2TP_ENCAPTYPE_UDP:
 257         case L2TP_ENCAPTYPE_IP:
 258                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 259                                          peer_tunnel_id, &cfg, &tunnel);
 260                 break;
 261         }
 262
 263         if (ret >= 0)
 264                 ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 265                                          tunnel, L2TP_CMD_TUNNEL_CREATE);
 266 out:
 267         return ret;
 268 }
 269
 270 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 271 {
 272         struct l2tp_tunnel *tunnel;
 273         u32 tunnel_id;
 274         int ret = 0;
 275         struct net *net = genl_info_net(info);
 276
 277         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 278                 ret = -EINVAL;
 279                 goto out;
 280         }
 281         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 282
 283         tunnel = l2tp_tunnel_get(net, tunnel_id);
 284         if (!tunnel) {
 285                 ret = -ENODEV;
 286                 goto out;
 287         }
 288
 289         l2tp_tunnel_notify(&l2tp_nl_family, info,
 290                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 291
 292         l2tp_tunnel_delete(tunnel);
 293
 294         l2tp_tunnel_dec_refcount(tunnel);
 295
 296 out:
 297         return ret;
 298 }
 299
 300 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 301 {
 302         struct l2tp_tunnel *tunnel;
 303         u32 tunnel_id;
 304         int ret = 0;
 305         struct net *net = genl_info_net(info);
 306
 307         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 308                 ret = -EINVAL;
 309                 goto out;
 310         }
 311         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 312
 313         tunnel = l2tp_tunnel_get(net, tunnel_id);
 314         if (!tunnel) {
 315                 ret = -ENODEV;
 316                 goto out;
 317         }
 318
 319         if (info->attrs[L2TP_ATTR_DEBUG])
 320                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 321
 322         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 323                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 324
 325         l2tp_tunnel_dec_refcount(tunnel);
 326
 327 out:
 328         return ret;
 329 }
 330
 331 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 332                                struct l2tp_tunnel *tunnel, u8 cmd)
 333 {
 334         void *hdr;
 335         struct nlattr *nest;
 336         struct sock *sk = NULL;
 337         struct inet_sock *inet;
 338 #if IS_ENABLED(CONFIG_IPV6)
 339         struct ipv6_pinfo *np = NULL;
 340 #endif
 341
 342         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 343         if (!hdr)
 344                 return -EMSGSIZE;
 345
 346         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 347             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 348             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 349             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 350             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 351                 goto nla_put_failure;
 352
 353         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 354         if (nest == NULL)
 355                 goto nla_put_failure;
 356
 357         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 358                               atomic_long_read(&tunnel->stats.tx_packets),
 359                               L2TP_ATTR_STATS_PAD) ||
 360             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 361                               atomic_long_read(&tunnel->stats.tx_bytes),
 362                               L2TP_ATTR_STATS_PAD) ||
 363             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 364                               atomic_long_read(&tunnel->stats.tx_errors),
 365                               L2TP_ATTR_STATS_PAD) ||
 366             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 367                               atomic_long_read(&tunnel->stats.rx_packets),
 368                               L2TP_ATTR_STATS_PAD) ||
 369             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 370                               atomic_long_read(&tunnel->stats.rx_bytes),
 371                               L2TP_ATTR_STATS_PAD) ||
 372             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 373                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 374                               L2TP_ATTR_STATS_PAD) ||
 375             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 376                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 377                               L2TP_ATTR_STATS_PAD) ||
 378             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 379                               atomic_long_read(&tunnel->stats.rx_errors),
 380                               L2TP_ATTR_STATS_PAD))
 381                 goto nla_put_failure;
 382         nla_nest_end(skb, nest);
 383
 384         sk = tunnel->sock;
 385         if (!sk)
 386                 goto out;
 387
 388 #if IS_ENABLED(CONFIG_IPV6)
 389         if (sk->sk_family == AF_INET6)
 390                 np = inet6_sk(sk);
 391 #endif
 392
 393         inet = inet_sk(sk);
 394
 395         switch (tunnel->encap) {
 396         case L2TP_ENCAPTYPE_UDP:
 397                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 398                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
 399                     nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 400                         goto nla_put_failure;
 401                 /* NOBREAK */
 402         case L2TP_ENCAPTYPE_IP:
 403 #if IS_ENABLED(CONFIG_IPV6)
 404                 if (np) {
 405                         if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
 406                                              &np->saddr) ||
 407                             nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
 408                                              &sk->sk_v6_daddr))
 409                                 goto nla_put_failure;
 410                 } else
 411 #endif
 412                 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
 413                                     inet->inet_saddr) ||
 414                     nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
 415                                     inet->inet_daddr))
 416                         goto nla_put_failure;
 417                 break;
 418         }
 419
 420 out:
 421         genlmsg_end(skb, hdr);
 422         return 0;
 423
 424 nla_put_failure:
 425         genlmsg_cancel(skb, hdr);
 426         return -1;
 427 }
 428
 429 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 430 {
 431         struct l2tp_tunnel *tunnel;
 432         struct sk_buff *msg;
 433         u32 tunnel_id;
 434         int ret = -ENOBUFS;
 435         struct net *net = genl_info_net(info);
 436
 437         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 438                 ret = -EINVAL;
 439                 goto err;
 440         }
 441
 442         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 443
 444         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 445         if (!msg) {
 446                 ret = -ENOMEM;
 447                 goto err;
 448         }
 449
 450         tunnel = l2tp_tunnel_get(net, tunnel_id);
 451         if (!tunnel) {
 452                 ret = -ENODEV;
 453                 goto err_nlmsg;
 454         }
 455
 456         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 457                                   NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 458         if (ret < 0)
 459                 goto err_nlmsg_tunnel;
 460
 461         l2tp_tunnel_dec_refcount(tunnel);
 462
 463         return genlmsg_unicast(net, msg, info->snd_portid);
 464
 465 err_nlmsg_tunnel:
 466         l2tp_tunnel_dec_refcount(tunnel);
 467 err_nlmsg:
 468         nlmsg_free(msg);
 469 err:
 470         return ret;
 471 }
 472
 473 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 474 {
 475         int ti = cb->args[0];
 476         struct l2tp_tunnel *tunnel;
 477         struct net *net = sock_net(skb->sk);
 478
 479         for (;;) {
 480                 tunnel = l2tp_tunnel_find_nth(net, ti);
 481                 if (tunnel == NULL)
 482                         goto out;
 483
 484                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 485                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 486                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 487                         goto out;
 488
 489                 ti++;
 490         }
 491
 492 out:
 493         cb->args[0] = ti;
 494
 495         return skb->len;
 496 }
 497
 498 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 499 {
 500         u32 tunnel_id = 0;
 501         u32 session_id;
 502         u32 peer_session_id;
 503         int ret = 0;
 504         struct l2tp_tunnel *tunnel;
 505         struct l2tp_session *session;
 506         struct l2tp_session_cfg cfg = { 0, };
 507         struct net *net = genl_info_net(info);
 508
 509         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 510                 ret = -EINVAL;
 511                 goto out;
 512         }
 513
 514         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 515         tunnel = l2tp_tunnel_get(net, tunnel_id);
 516         if (!tunnel) {
 517                 ret = -ENODEV;
 518                 goto out;
 519         }
 520
 521         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 522                 ret = -EINVAL;
 523                 goto out_tunnel;
 524         }
 525         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 526
 527         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 528                 ret = -EINVAL;
 529                 goto out_tunnel;
 530         }
 531         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 532
 533         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 534                 ret = -EINVAL;
 535                 goto out_tunnel;
 536         }
 537         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 538         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 539                 ret = -EINVAL;
 540                 goto out_tunnel;
 541         }
 542
 543         if (tunnel->version > 2) {
 544                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 545                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 546
 547                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 548                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 549                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 550
 551                 cfg.l2specific_len = 4;
 552                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 553                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 554
 555                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 556                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 557                         if (len > 8) {
 558                                 ret = -EINVAL;
 559                                 goto out_tunnel;
 560                         }
 561                         cfg.cookie_len = len;
 562                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 563                 }
 564                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 565                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 566                         if (len > 8) {
 567                                 ret = -EINVAL;
 568                                 goto out_tunnel;
 569                         }
 570                         cfg.peer_cookie_len = len;
 571                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 572                 }
 573                 if (info->attrs[L2TP_ATTR_IFNAME])
 574                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 575
 576                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 577                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 578         }
 579
 580         if (info->attrs[L2TP_ATTR_DEBUG])
 581                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 582
 583         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 584                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 585
 586         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 587                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 588
 589         if (info->attrs[L2TP_ATTR_LNS_MODE])
 590                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 591
 592         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 593                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 594
 595         if (info->attrs[L2TP_ATTR_MTU])
 596                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 597
 598         if (info->attrs[L2TP_ATTR_MRU])
 599                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 600
 601 #ifdef CONFIG_MODULES
 602         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 603                 genl_unlock();
 604                 request_module("net-l2tp-type-%u", cfg.pw_type);
 605                 genl_lock();
 606         }
 607 #endif
 608         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 609             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 610                 ret = -EPROTONOSUPPORT;
 611                 goto out_tunnel;
 612         }
 613
 614         /* Check that pseudowire-specific params are present */
 615         switch (cfg.pw_type) {
 616         case L2TP_PWTYPE_NONE:
 617                 break;
 618         case L2TP_PWTYPE_ETH_VLAN:
 619                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 620                         ret = -EINVAL;
 621                         goto out_tunnel;
 622                 }
 623                 break;
 624         case L2TP_PWTYPE_ETH:
 625                 break;
 626         case L2TP_PWTYPE_PPP:
 627         case L2TP_PWTYPE_PPP_AC:
 628                 break;
 629         case L2TP_PWTYPE_IP:
 630         default:
 631                 ret = -EPROTONOSUPPORT;
 632                 break;
 633         }
 634
 635         ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 636                                                            session_id,
 637                                                            peer_session_id,
 638                                                            &cfg);
 639
 640         if (ret >= 0) {
 641                 session = l2tp_session_get(net, tunnel, session_id, false);
 642                 if (session) {
 643                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 644                                                   L2TP_CMD_SESSION_CREATE);
 645                         l2tp_session_dec_refcount(session);
 646                 }
 647         }
 648
 649 out_tunnel:
 650         l2tp_tunnel_dec_refcount(tunnel);
 651 out:
 652         return ret;
 653 }
 654
 655 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 656 {
 657         int ret = 0;
 658         struct l2tp_session *session;
 659         u16 pw_type;
 660
 661         session = l2tp_nl_session_get(info, true);
 662         if (session == NULL) {
 663                 ret = -ENODEV;
 664                 goto out;
 665         }
 666
 667         l2tp_session_notify(&l2tp_nl_family, info,
 668                             session, L2TP_CMD_SESSION_DELETE);
 669
 670         pw_type = session->pwtype;
 671         if (pw_type < __L2TP_PWTYPE_MAX)
 672                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 673                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 674
 675         if (session->deref)
 676                 session->deref(session);
 677         l2tp_session_dec_refcount(session);
 678
 679 out:
 680         return ret;
 681 }
 682
 683 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 684 {
 685         int ret = 0;
 686         struct l2tp_session *session;
 687
 688         session = l2tp_nl_session_get(info, false);
 689         if (session == NULL) {
 690                 ret = -ENODEV;
 691                 goto out;
 692         }
 693
 694         if (info->attrs[L2TP_ATTR_DEBUG])
 695                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 696
 697         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 698                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 699
 700         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 701                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 702
 703         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 704                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 705                 l2tp_session_set_header_len(session, session->tunnel->version);
 706         }
 707
 708         if (info->attrs[L2TP_ATTR_LNS_MODE])
 709                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 710
 711         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 712                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 713
 714         if (info->attrs[L2TP_ATTR_MTU])
 715                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 716
 717         if (info->attrs[L2TP_ATTR_MRU])
 718                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 719
 720         ret = l2tp_session_notify(&l2tp_nl_family, info,
 721                                   session, L2TP_CMD_SESSION_MODIFY);
 722
 723         l2tp_session_dec_refcount(session);
 724
 725 out:
 726         return ret;
 727 }
 728
 729 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 730                                 struct l2tp_session *session, u8 cmd)
 731 {
 732         void *hdr;
 733         struct nlattr *nest;
 734         struct l2tp_tunnel *tunnel = session->tunnel;
 735         struct sock *sk = NULL;
 736
 737         sk = tunnel->sock;
 738
 739         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 740         if (!hdr)
 741                 return -EMSGSIZE;
 742
 743         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 744             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 745             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 746             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 747                         session->peer_session_id) ||
 748             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 749             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 750             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 751             (session->mru &&
 752              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 753                 goto nla_put_failure;
 754
 755         if ((session->ifname[0] &&
 756              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 757             (session->cookie_len &&
 758              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 759                      &session->cookie[0])) ||
 760             (session->peer_cookie_len &&
 761              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 762                      &session->peer_cookie[0])) ||
 763             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 764             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 765             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 766 #ifdef CONFIG_XFRM
 767             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 768              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 769 #endif
 770             (session->reorder_timeout &&
 771              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 772                            session->reorder_timeout, L2TP_ATTR_PAD)))
 773                 goto nla_put_failure;
 774
 775         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 776         if (nest == NULL)
 777                 goto nla_put_failure;
 778
 779         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 780                               atomic_long_read(&session->stats.tx_packets),
 781                               L2TP_ATTR_STATS_PAD) ||
 782             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 783                               atomic_long_read(&session->stats.tx_bytes),
 784                               L2TP_ATTR_STATS_PAD) ||
 785             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 786                               atomic_long_read(&session->stats.tx_errors),
 787                               L2TP_ATTR_STATS_PAD) ||
 788             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 789                               atomic_long_read(&session->stats.rx_packets),
 790                               L2TP_ATTR_STATS_PAD) ||
 791             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 792                               atomic_long_read(&session->stats.rx_bytes),
 793                               L2TP_ATTR_STATS_PAD) ||
 794             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 795                               atomic_long_read(&session->stats.rx_seq_discards),
 796                               L2TP_ATTR_STATS_PAD) ||
 797             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 798                               atomic_long_read(&session->stats.rx_oos_packets),
 799                               L2TP_ATTR_STATS_PAD) ||
 800             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 801                               atomic_long_read(&session->stats.rx_errors),
 802                               L2TP_ATTR_STATS_PAD))
 803                 goto nla_put_failure;
 804         nla_nest_end(skb, nest);
 805
 806         genlmsg_end(skb, hdr);
 807         return 0;
 808
 809  nla_put_failure:
 810         genlmsg_cancel(skb, hdr);
 811         return -1;
 812 }
 813
 814 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 815 {
 816         struct l2tp_session *session;
 817         struct sk_buff *msg;
 818         int ret;
 819
 820         session = l2tp_nl_session_get(info, false);
 821         if (session == NULL) {
 822                 ret = -ENODEV;
 823                 goto err;
 824         }
 825
 826         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 827         if (!msg) {
 828                 ret = -ENOMEM;
 829                 goto err_ref;
 830         }
 831
 832         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 833                                    0, session, L2TP_CMD_SESSION_GET);
 834         if (ret < 0)
 835                 goto err_ref_msg;
 836
 837         ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 838
 839         l2tp_session_dec_refcount(session);
 840
 841         return ret;
 842
 843 err_ref_msg:
 844         nlmsg_free(msg);
 845 err_ref:
 846         l2tp_session_dec_refcount(session);
 847 err:
 848         return ret;
 849 }
 850
 851 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 852 {
 853         struct net *net = sock_net(skb->sk);
 854         struct l2tp_session *session;
 855         struct l2tp_tunnel *tunnel = NULL;
 856         int ti = cb->args[0];
 857         int si = cb->args[1];
 858
 859         for (;;) {
 860                 if (tunnel == NULL) {
 861                         tunnel = l2tp_tunnel_find_nth(net, ti);
 862                         if (tunnel == NULL)
 863                                 goto out;
 864                 }
 865
 866                 session = l2tp_session_get_nth(tunnel, si, false);
 867                 if (session == NULL) {
 868                         ti++;
 869                         tunnel = NULL;
 870                         si = 0;
 871                         continue;
 872                 }
 873
 874                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 875                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 876                                          session, L2TP_CMD_SESSION_GET) < 0) {
 877                         l2tp_session_dec_refcount(session);
 878                         break;
 879                 }
 880                 l2tp_session_dec_refcount(session);
 881
 882                 si++;
 883         }
 884
 885 out:
 886         cb->args[0] = ti;
 887         cb->args[1] = si;
 888
 889         return skb->len;
 890 }
 891
 892 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 893         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 894         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 895         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 896         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 897         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 898         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 899         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 900         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 901         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 902         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 903         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 904         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 905         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 906         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 907         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 908         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 909         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 910         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 911         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 912         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 913         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 914         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 915         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 916         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 917         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 918         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 919         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 920         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 921         [L2TP_ATTR_IP6_SADDR] = {
 922                 .type = NLA_BINARY,
 923                 .len = sizeof(struct in6_addr),
 924         },
 925         [L2TP_ATTR_IP6_DADDR] = {
 926                 .type = NLA_BINARY,
 927                 .len = sizeof(struct in6_addr),
 928         },
 929         [L2TP_ATTR_IFNAME] = {
 930                 .type = NLA_NUL_STRING,
 931                 .len = IFNAMSIZ - 1,
 932         },
 933         [L2TP_ATTR_COOKIE] = {
 934                 .type = NLA_BINARY,
 935                 .len = 8,
 936         },
 937         [L2TP_ATTR_PEER_COOKIE] = {
 938                 .type = NLA_BINARY,
 939                 .len = 8,
 940         },
 941 };
 942
 943 static const struct genl_ops l2tp_nl_ops[] = {
 944         {
 945                 .cmd = L2TP_CMD_NOOP,
 946                 .doit = l2tp_nl_cmd_noop,
 947                 .policy = l2tp_nl_policy,
 948                 /* can be retrieved by unprivileged users */
 949         },
 950         {
 951                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 952                 .doit = l2tp_nl_cmd_tunnel_create,
 953                 .policy = l2tp_nl_policy,
 954                 .flags = GENL_ADMIN_PERM,
 955         },
 956         {
 957                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 958                 .doit = l2tp_nl_cmd_tunnel_delete,
 959                 .policy = l2tp_nl_policy,
 960                 .flags = GENL_ADMIN_PERM,
 961         },
 962         {
 963                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 964                 .doit = l2tp_nl_cmd_tunnel_modify,
 965                 .policy = l2tp_nl_policy,
 966                 .flags = GENL_ADMIN_PERM,
 967         },
 968         {
 969                 .cmd = L2TP_CMD_TUNNEL_GET,
 970                 .doit = l2tp_nl_cmd_tunnel_get,
 971                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 972                 .policy = l2tp_nl_policy,
 973                 .flags = GENL_ADMIN_PERM,
 974         },
 975         {
 976                 .cmd = L2TP_CMD_SESSION_CREATE,
 977                 .doit = l2tp_nl_cmd_session_create,
 978                 .policy = l2tp_nl_policy,
 979                 .flags = GENL_ADMIN_PERM,
 980         },
 981         {
 982                 .cmd = L2TP_CMD_SESSION_DELETE,
 983                 .doit = l2tp_nl_cmd_session_delete,
 984                 .policy = l2tp_nl_policy,
 985                 .flags = GENL_ADMIN_PERM,
 986         },
 987         {
 988                 .cmd = L2TP_CMD_SESSION_MODIFY,
 989                 .doit = l2tp_nl_cmd_session_modify,
 990                 .policy = l2tp_nl_policy,
 991                 .flags = GENL_ADMIN_PERM,
 992         },
 993         {
 994                 .cmd = L2TP_CMD_SESSION_GET,
 995                 .doit = l2tp_nl_cmd_session_get,
 996                 .dumpit = l2tp_nl_cmd_session_dump,
 997                 .policy = l2tp_nl_policy,
 998                 .flags = GENL_ADMIN_PERM,
 999         },
1000 };
1001
1002 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1003 {
1004         int ret;
1005
1006         ret = -EINVAL;
1007         if (pw_type >= __L2TP_PWTYPE_MAX)
1008                 goto err;
1009
1010         genl_lock();
1011         ret = -EBUSY;
1012         if (l2tp_nl_cmd_ops[pw_type])
1013                 goto out;
1014
1015         l2tp_nl_cmd_ops[pw_type] = ops;
1016         ret = 0;
1017
1018 out:
1019         genl_unlock();
1020 err:
1021         return ret;
1022 }
1023 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1024
1025 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1026 {
1027         if (pw_type < __L2TP_PWTYPE_MAX) {
1028                 genl_lock();
1029                 l2tp_nl_cmd_ops[pw_type] = NULL;
1030                 genl_unlock();
1031         }
1032 }
1033 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1034
1035 static int l2tp_nl_init(void)
1036 {
1037         pr_info("L2TP netlink interface\n");
1038         return genl_register_family_with_ops_groups(&l2tp_nl_family,
1039                                                     l2tp_nl_ops,
1040                                                     l2tp_multicast_group);
1041 }
1042
1043 static void l2tp_nl_cleanup(void)
1044 {
1045         genl_unregister_family(&l2tp_nl_family);
1046 }
1047
1048 module_init(l2tp_nl_init);
1049 module_exit(l2tp_nl_cleanup);
1050
1051 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1052 MODULE_DESCRIPTION("L2TP netlink");
1053 MODULE_LICENSE("GPL");
1054 MODULE_VERSION("1.0");
1055 MODULE_ALIAS_GENL_FAMILY("l2tp");