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(skb, L2TP_ATTR_TX_PACKETS,
 358                     atomic_long_read(&tunnel->stats.tx_packets)) ||
 359             nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
 360                     atomic_long_read(&tunnel->stats.tx_bytes)) ||
 361             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
 362                     atomic_long_read(&tunnel->stats.tx_errors)) ||
 363             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
 364                     atomic_long_read(&tunnel->stats.rx_packets)) ||
 365             nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
 366                     atomic_long_read(&tunnel->stats.rx_bytes)) ||
 367             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 368                     atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
 369             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 370                     atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
 371             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
 372                     atomic_long_read(&tunnel->stats.rx_errors)))
 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 err;
 432         }
 433
 434         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 435
 436         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 437         if (!msg) {
 438                 ret = -ENOMEM;
 439                 goto err;
 440         }
 441
 442         tunnel = l2tp_tunnel_get(net, tunnel_id);
 443         if (!tunnel) {
 444                 ret = -ENODEV;
 445                 goto err_nlmsg;
 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_nlmsg_tunnel;
 452
 453         l2tp_tunnel_dec_refcount(tunnel);
 454
 455         return genlmsg_unicast(net, msg, info->snd_portid);
 456
 457 err_nlmsg_tunnel:
 458         l2tp_tunnel_dec_refcount(tunnel);
 459 err_nlmsg:
 460         nlmsg_free(msg);
 461 err:
 462         return ret;
 463 }
 464
 465 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 466 {
 467         int ti = cb->args[0];
 468         struct l2tp_tunnel *tunnel;
 469         struct net *net = sock_net(skb->sk);
 470
 471         for (;;) {
 472                 tunnel = l2tp_tunnel_find_nth(net, ti);
 473                 if (tunnel == NULL)
 474                         goto out;
 475
 476                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 477                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 478                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 479                         goto out;
 480
 481                 ti++;
 482         }
 483
 484 out:
 485         cb->args[0] = ti;
 486
 487         return skb->len;
 488 }
 489
 490 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 491 {
 492         u32 tunnel_id = 0;
 493         u32 session_id;
 494         u32 peer_session_id;
 495         int ret = 0;
 496         struct l2tp_tunnel *tunnel;
 497         struct l2tp_session *session;
 498         struct l2tp_session_cfg cfg = { 0, };
 499         struct net *net = genl_info_net(info);
 500
 501         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 502                 ret = -EINVAL;
 503                 goto out;
 504         }
 505
 506         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 507         tunnel = l2tp_tunnel_get(net, tunnel_id);
 508         if (!tunnel) {
 509                 ret = -ENODEV;
 510                 goto out;
 511         }
 512
 513         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 514                 ret = -EINVAL;
 515                 goto out_tunnel;
 516         }
 517         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 518
 519         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 520                 ret = -EINVAL;
 521                 goto out_tunnel;
 522         }
 523         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 524
 525         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 526                 ret = -EINVAL;
 527                 goto out_tunnel;
 528         }
 529         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 530         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 531                 ret = -EINVAL;
 532                 goto out_tunnel;
 533         }
 534
 535         if (tunnel->version > 2) {
 536                 if (info->attrs[L2TP_ATTR_OFFSET])
 537                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 538
 539                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 540                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 541
 542                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 543                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 544                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 545
 546                 cfg.l2specific_len = 4;
 547                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 548                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 549
 550                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 551                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 552                         if (len > 8) {
 553                                 ret = -EINVAL;
 554                                 goto out_tunnel;
 555                         }
 556                         cfg.cookie_len = len;
 557                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 558                 }
 559                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 560                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 561                         if (len > 8) {
 562                                 ret = -EINVAL;
 563                                 goto out_tunnel;
 564                         }
 565                         cfg.peer_cookie_len = len;
 566                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 567                 }
 568                 if (info->attrs[L2TP_ATTR_IFNAME])
 569                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 570
 571                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 572                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 573         }
 574
 575         if (info->attrs[L2TP_ATTR_DEBUG])
 576                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 577
 578         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 579                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 580
 581         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 582                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 583
 584         if (info->attrs[L2TP_ATTR_LNS_MODE])
 585                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 586
 587         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 588                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 589
 590         if (info->attrs[L2TP_ATTR_MTU])
 591                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 592
 593         if (info->attrs[L2TP_ATTR_MRU])
 594                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 595
 596 #ifdef CONFIG_MODULES
 597         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 598                 genl_unlock();
 599                 request_module("net-l2tp-type-%u", cfg.pw_type);
 600                 genl_lock();
 601         }
 602 #endif
 603         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 604             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 605                 ret = -EPROTONOSUPPORT;
 606                 goto out_tunnel;
 607         }
 608
 609         /* Check that pseudowire-specific params are present */
 610         switch (cfg.pw_type) {
 611         case L2TP_PWTYPE_NONE:
 612                 break;
 613         case L2TP_PWTYPE_ETH_VLAN:
 614                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 615                         ret = -EINVAL;
 616                         goto out_tunnel;
 617                 }
 618                 break;
 619         case L2TP_PWTYPE_ETH:
 620                 break;
 621         case L2TP_PWTYPE_PPP:
 622         case L2TP_PWTYPE_PPP_AC:
 623                 break;
 624         case L2TP_PWTYPE_IP:
 625         default:
 626                 ret = -EPROTONOSUPPORT;
 627                 break;
 628         }
 629
 630         ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 631                                                            session_id,
 632                                                            peer_session_id,
 633                                                            &cfg);
 634
 635         if (ret >= 0) {
 636                 session = l2tp_session_get(net, tunnel, session_id, false);
 637                 if (session) {
 638                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 639                                                   L2TP_CMD_SESSION_CREATE);
 640                         l2tp_session_dec_refcount(session);
 641                 }
 642         }
 643
 644 out_tunnel:
 645         l2tp_tunnel_dec_refcount(tunnel);
 646 out:
 647         return ret;
 648 }
 649
 650 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 651 {
 652         int ret = 0;
 653         struct l2tp_session *session;
 654         u16 pw_type;
 655
 656         session = l2tp_nl_session_get(info, true);
 657         if (session == NULL) {
 658                 ret = -ENODEV;
 659                 goto out;
 660         }
 661
 662         l2tp_session_notify(&l2tp_nl_family, info,
 663                             session, L2TP_CMD_SESSION_DELETE);
 664
 665         pw_type = session->pwtype;
 666         if (pw_type < __L2TP_PWTYPE_MAX)
 667                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 668                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 669
 670         if (session->deref)
 671                 session->deref(session);
 672         l2tp_session_dec_refcount(session);
 673
 674 out:
 675         return ret;
 676 }
 677
 678 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 679 {
 680         int ret = 0;
 681         struct l2tp_session *session;
 682
 683         session = l2tp_nl_session_get(info, false);
 684         if (session == NULL) {
 685                 ret = -ENODEV;
 686                 goto out;
 687         }
 688
 689         if (info->attrs[L2TP_ATTR_DEBUG])
 690                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 691
 692         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 693                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 694
 695         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 696                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 697
 698         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 699                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 700                 l2tp_session_set_header_len(session, session->tunnel->version);
 701         }
 702
 703         if (info->attrs[L2TP_ATTR_LNS_MODE])
 704                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 705
 706         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 707                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 708
 709         if (info->attrs[L2TP_ATTR_MTU])
 710                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 711
 712         if (info->attrs[L2TP_ATTR_MRU])
 713                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 714
 715         ret = l2tp_session_notify(&l2tp_nl_family, info,
 716                                   session, L2TP_CMD_SESSION_MODIFY);
 717
 718         l2tp_session_dec_refcount(session);
 719
 720 out:
 721         return ret;
 722 }
 723
 724 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 725                                 struct l2tp_session *session, u8 cmd)
 726 {
 727         void *hdr;
 728         struct nlattr *nest;
 729         struct l2tp_tunnel *tunnel = session->tunnel;
 730         struct sock *sk = NULL;
 731
 732         sk = tunnel->sock;
 733
 734         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 735         if (!hdr)
 736                 return -EMSGSIZE;
 737
 738         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 739             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 740             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 741             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 742                         session->peer_session_id) ||
 743             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 744             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 745             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 746             (session->mru &&
 747              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 748                 goto nla_put_failure;
 749
 750         if ((session->ifname[0] &&
 751              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 752             (session->cookie_len &&
 753              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 754                      &session->cookie[0])) ||
 755             (session->peer_cookie_len &&
 756              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 757                      &session->peer_cookie[0])) ||
 758             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 759             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 760             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 761 #ifdef CONFIG_XFRM
 762             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 763              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 764 #endif
 765             (session->reorder_timeout &&
 766              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
 767                 goto nla_put_failure;
 768
 769         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 770         if (nest == NULL)
 771                 goto nla_put_failure;
 772
 773         if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
 774                 atomic_long_read(&session->stats.tx_packets)) ||
 775             nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
 776                 atomic_long_read(&session->stats.tx_bytes)) ||
 777             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
 778                 atomic_long_read(&session->stats.tx_errors)) ||
 779             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
 780                 atomic_long_read(&session->stats.rx_packets)) ||
 781             nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
 782                 atomic_long_read(&session->stats.rx_bytes)) ||
 783             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 784                 atomic_long_read(&session->stats.rx_seq_discards)) ||
 785             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 786                 atomic_long_read(&session->stats.rx_oos_packets)) ||
 787             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
 788                 atomic_long_read(&session->stats.rx_errors)))
 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, false);
 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, false);
 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 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 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 989 {
 990         int ret;
 991
 992         ret = -EINVAL;
 993         if (pw_type >= __L2TP_PWTYPE_MAX)
 994                 goto err;
 995
 996         genl_lock();
 997         ret = -EBUSY;
 998         if (l2tp_nl_cmd_ops[pw_type])
 999                 goto out;
1000
1001         l2tp_nl_cmd_ops[pw_type] = ops;
1002         ret = 0;
1003
1004 out:
1005         genl_unlock();
1006 err:
1007         return ret;
1008 }
1009 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1010
1011 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1012 {
1013         if (pw_type < __L2TP_PWTYPE_MAX) {
1014                 genl_lock();
1015                 l2tp_nl_cmd_ops[pw_type] = NULL;
1016                 genl_unlock();
1017         }
1018 }
1019 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1020
1021 static int l2tp_nl_init(void)
1022 {
1023         pr_info("L2TP netlink interface\n");
1024         return genl_register_family_with_ops_groups(&l2tp_nl_family,
1025                                                     l2tp_nl_ops,
1026                                                     l2tp_multicast_group);
1027 }
1028
1029 static void l2tp_nl_cleanup(void)
1030 {
1031         genl_unregister_family(&l2tp_nl_family);
1032 }
1033
1034 module_init(l2tp_nl_init);
1035 module_exit(l2tp_nl_cleanup);
1036
1037 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1038 MODULE_DESCRIPTION("L2TP netlink");
1039 MODULE_LICENSE("GPL");
1040 MODULE_VERSION("1.0");
1041 MODULE_ALIAS_GENL_FAMILY("l2tp");