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                                                 bool do_ref)
  53 {
  54         u32 tunnel_id;
  55         u32 session_id;
  56         char *ifname;
  57         struct l2tp_tunnel *tunnel;
  58         struct l2tp_session *session = NULL;
  59         struct net *net = genl_info_net(info);
  60
  61         if (info->attrs[L2TP_ATTR_IFNAME]) {
  62                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  63                 session = l2tp_session_get_by_ifname(net, ifname, do_ref);
  64         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  65                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  66                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  67                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  68                 tunnel = l2tp_tunnel_find(net, tunnel_id);
  69                 if (tunnel)
  70                         session = l2tp_session_get(net, tunnel, session_id,
  71                                                    do_ref);
  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_find(net, tunnel_id);
 275         if (tunnel == NULL) {
 276                 ret = -ENODEV;
 277                 goto out;
 278         }
 279
 280         l2tp_tunnel_notify(&l2tp_nl_family, info,
 281                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 282
 283         (void) l2tp_tunnel_delete(tunnel);
 284
 285 out:
 286         return ret;
 287 }
 288
 289 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 290 {
 291         struct l2tp_tunnel *tunnel;
 292         u32 tunnel_id;
 293         int ret = 0;
 294         struct net *net = genl_info_net(info);
 295
 296         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 297                 ret = -EINVAL;
 298                 goto out;
 299         }
 300         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 301
 302         tunnel = l2tp_tunnel_find(net, tunnel_id);
 303         if (tunnel == NULL) {
 304                 ret = -ENODEV;
 305                 goto out;
 306         }
 307
 308         if (info->attrs[L2TP_ATTR_DEBUG])
 309                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 310
 311         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 312                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 313
 314 out:
 315         return ret;
 316 }
 317
 318 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 319                                struct l2tp_tunnel *tunnel, u8 cmd)
 320 {
 321         void *hdr;
 322         struct nlattr *nest;
 323         struct sock *sk = NULL;
 324         struct inet_sock *inet;
 325 #if IS_ENABLED(CONFIG_IPV6)
 326         struct ipv6_pinfo *np = NULL;
 327 #endif
 328
 329         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 330         if (!hdr)
 331                 return -EMSGSIZE;
 332
 333         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 334             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 335             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 336             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 337             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 338                 goto nla_put_failure;
 339
 340         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 341         if (nest == NULL)
 342                 goto nla_put_failure;
 343
 344         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 345                               atomic_long_read(&tunnel->stats.tx_packets),
 346                               L2TP_ATTR_STATS_PAD) ||
 347             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 348                               atomic_long_read(&tunnel->stats.tx_bytes),
 349                               L2TP_ATTR_STATS_PAD) ||
 350             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 351                               atomic_long_read(&tunnel->stats.tx_errors),
 352                               L2TP_ATTR_STATS_PAD) ||
 353             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 354                               atomic_long_read(&tunnel->stats.rx_packets),
 355                               L2TP_ATTR_STATS_PAD) ||
 356             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 357                               atomic_long_read(&tunnel->stats.rx_bytes),
 358                               L2TP_ATTR_STATS_PAD) ||
 359             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 360                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 361                               L2TP_ATTR_STATS_PAD) ||
 362             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 363                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 364                               L2TP_ATTR_STATS_PAD) ||
 365             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 366                               atomic_long_read(&tunnel->stats.rx_errors),
 367                               L2TP_ATTR_STATS_PAD))
 368                 goto nla_put_failure;
 369         nla_nest_end(skb, nest);
 370
 371         sk = tunnel->sock;
 372         if (!sk)
 373                 goto out;
 374
 375 #if IS_ENABLED(CONFIG_IPV6)
 376         if (sk->sk_family == AF_INET6)
 377                 np = inet6_sk(sk);
 378 #endif
 379
 380         inet = inet_sk(sk);
 381
 382         switch (tunnel->encap) {
 383         case L2TP_ENCAPTYPE_UDP:
 384                 switch (sk->sk_family) {
 385                 case AF_INET:
 386                         if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 387                                 goto nla_put_failure;
 388                         break;
 389 #if IS_ENABLED(CONFIG_IPV6)
 390                 case AF_INET6:
 391                         if (udp_get_no_check6_tx(sk) &&
 392                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
 393                                 goto nla_put_failure;
 394                         if (udp_get_no_check6_rx(sk) &&
 395                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
 396                                 goto nla_put_failure;
 397                         break;
 398 #endif
 399                 }
 400                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 401                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 402                         goto nla_put_failure;
 403                 /* NOBREAK */
 404         case L2TP_ENCAPTYPE_IP:
 405 #if IS_ENABLED(CONFIG_IPV6)
 406                 if (np) {
 407                         if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
 408                                              &np->saddr) ||
 409                             nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
 410                                              &sk->sk_v6_daddr))
 411                                 goto nla_put_failure;
 412                 } else
 413 #endif
 414                 if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
 415                                     inet->inet_saddr) ||
 416                     nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
 417                                     inet->inet_daddr))
 418                         goto nla_put_failure;
 419                 break;
 420         }
 421
 422 out:
 423         genlmsg_end(skb, hdr);
 424         return 0;
 425
 426 nla_put_failure:
 427         genlmsg_cancel(skb, hdr);
 428         return -1;
 429 }
 430
 431 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 432 {
 433         struct l2tp_tunnel *tunnel;
 434         struct sk_buff *msg;
 435         u32 tunnel_id;
 436         int ret = -ENOBUFS;
 437         struct net *net = genl_info_net(info);
 438
 439         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 440                 ret = -EINVAL;
 441                 goto out;
 442         }
 443
 444         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 445
 446         tunnel = l2tp_tunnel_find(net, tunnel_id);
 447         if (tunnel == NULL) {
 448                 ret = -ENODEV;
 449                 goto out;
 450         }
 451
 452         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 453         if (!msg) {
 454                 ret = -ENOMEM;
 455                 goto out;
 456         }
 457
 458         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 459                                   NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 460         if (ret < 0)
 461                 goto err_out;
 462
 463         return genlmsg_unicast(net, msg, info->snd_portid);
 464
 465 err_out:
 466         nlmsg_free(msg);
 467
 468 out:
 469         return ret;
 470 }
 471
 472 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 473 {
 474         int ti = cb->args[0];
 475         struct l2tp_tunnel *tunnel;
 476         struct net *net = sock_net(skb->sk);
 477
 478         for (;;) {
 479                 tunnel = l2tp_tunnel_find_nth(net, ti);
 480                 if (tunnel == NULL)
 481                         goto out;
 482
 483                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 484                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 485                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 486                         goto out;
 487
 488                 ti++;
 489         }
 490
 491 out:
 492         cb->args[0] = ti;
 493
 494         return skb->len;
 495 }
 496
 497 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 498 {
 499         u32 tunnel_id = 0;
 500         u32 session_id;
 501         u32 peer_session_id;
 502         int ret = 0;
 503         struct l2tp_tunnel *tunnel;
 504         struct l2tp_session *session;
 505         struct l2tp_session_cfg cfg = { 0, };
 506         struct net *net = genl_info_net(info);
 507
 508         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 509                 ret = -EINVAL;
 510                 goto out;
 511         }
 512         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 513         tunnel = l2tp_tunnel_find(net, tunnel_id);
 514         if (!tunnel) {
 515                 ret = -ENODEV;
 516                 goto out;
 517         }
 518
 519         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 520                 ret = -EINVAL;
 521                 goto out;
 522         }
 523         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 524         session = l2tp_session_find(net, tunnel, session_id);
 525         if (session) {
 526                 ret = -EEXIST;
 527                 goto out;
 528         }
 529
 530         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 531                 ret = -EINVAL;
 532                 goto out;
 533         }
 534         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 535
 536         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 537                 ret = -EINVAL;
 538                 goto out;
 539         }
 540         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 541         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 542                 ret = -EINVAL;
 543                 goto out;
 544         }
 545
 546         if (tunnel->version > 2) {
 547                 if (info->attrs[L2TP_ATTR_OFFSET])
 548                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 549
 550                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 551                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 552
 553                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 554                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 555                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 556
 557                 cfg.l2specific_len = 4;
 558                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 559                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 560
 561                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 562                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 563                         if (len > 8) {
 564                                 ret = -EINVAL;
 565                                 goto out;
 566                         }
 567                         cfg.cookie_len = len;
 568                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 569                 }
 570                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 571                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 572                         if (len > 8) {
 573                                 ret = -EINVAL;
 574                                 goto out;
 575                         }
 576                         cfg.peer_cookie_len = len;
 577                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 578                 }
 579                 if (info->attrs[L2TP_ATTR_IFNAME])
 580                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 581
 582                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 583                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 584         }
 585
 586         if (info->attrs[L2TP_ATTR_DEBUG])
 587                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 588
 589         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 590                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 591
 592         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 593                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 594
 595         if (info->attrs[L2TP_ATTR_LNS_MODE])
 596                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 597
 598         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 599                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 600
 601         if (info->attrs[L2TP_ATTR_MTU])
 602                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 603
 604         if (info->attrs[L2TP_ATTR_MRU])
 605                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 606
 607 #ifdef CONFIG_MODULES
 608         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 609                 genl_unlock();
 610                 request_module("net-l2tp-type-%u", cfg.pw_type);
 611                 genl_lock();
 612         }
 613 #endif
 614         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 615             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 616                 ret = -EPROTONOSUPPORT;
 617                 goto out;
 618         }
 619
 620         /* Check that pseudowire-specific params are present */
 621         switch (cfg.pw_type) {
 622         case L2TP_PWTYPE_NONE:
 623                 break;
 624         case L2TP_PWTYPE_ETH_VLAN:
 625                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 626                         ret = -EINVAL;
 627                         goto out;
 628                 }
 629                 break;
 630         case L2TP_PWTYPE_ETH:
 631                 break;
 632         case L2TP_PWTYPE_PPP:
 633         case L2TP_PWTYPE_PPP_AC:
 634                 break;
 635         case L2TP_PWTYPE_IP:
 636         default:
 637                 ret = -EPROTONOSUPPORT;
 638                 break;
 639         }
 640
 641         ret = -EPROTONOSUPPORT;
 642         if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
 643                 ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
 644                         session_id, peer_session_id, &cfg);
 645
 646         if (ret >= 0) {
 647                 session = l2tp_session_get(net, tunnel, session_id, false);
 648                 if (session) {
 649                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 650                                                   L2TP_CMD_SESSION_CREATE);
 651                         l2tp_session_dec_refcount(session);
 652                 }
 653         }
 654
 655 out:
 656         return ret;
 657 }
 658
 659 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 660 {
 661         int ret = 0;
 662         struct l2tp_session *session;
 663         u16 pw_type;
 664
 665         session = l2tp_nl_session_get(info, true);
 666         if (session == NULL) {
 667                 ret = -ENODEV;
 668                 goto out;
 669         }
 670
 671         l2tp_session_notify(&l2tp_nl_family, info,
 672                             session, L2TP_CMD_SESSION_DELETE);
 673
 674         pw_type = session->pwtype;
 675         if (pw_type < __L2TP_PWTYPE_MAX)
 676                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 677                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 678
 679         if (session->deref)
 680                 session->deref(session);
 681         l2tp_session_dec_refcount(session);
 682
 683 out:
 684         return ret;
 685 }
 686
 687 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 688 {
 689         int ret = 0;
 690         struct l2tp_session *session;
 691
 692         session = l2tp_nl_session_get(info, false);
 693         if (session == NULL) {
 694                 ret = -ENODEV;
 695                 goto out;
 696         }
 697
 698         if (info->attrs[L2TP_ATTR_DEBUG])
 699                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 700
 701         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 702                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 703
 704         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 705                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 706
 707         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 708                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 709                 l2tp_session_set_header_len(session, session->tunnel->version);
 710         }
 711
 712         if (info->attrs[L2TP_ATTR_LNS_MODE])
 713                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 714
 715         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 716                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 717
 718         if (info->attrs[L2TP_ATTR_MTU])
 719                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 720
 721         if (info->attrs[L2TP_ATTR_MRU])
 722                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 723
 724         ret = l2tp_session_notify(&l2tp_nl_family, info,
 725                                   session, L2TP_CMD_SESSION_MODIFY);
 726
 727         l2tp_session_dec_refcount(session);
 728
 729 out:
 730         return ret;
 731 }
 732
 733 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 734                                 struct l2tp_session *session, u8 cmd)
 735 {
 736         void *hdr;
 737         struct nlattr *nest;
 738         struct l2tp_tunnel *tunnel = session->tunnel;
 739         struct sock *sk = NULL;
 740
 741         sk = tunnel->sock;
 742
 743         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 744         if (!hdr)
 745                 return -EMSGSIZE;
 746
 747         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 748             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 749             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 750             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 751                         session->peer_session_id) ||
 752             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 753             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 754             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 755             (session->mru &&
 756              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 757                 goto nla_put_failure;
 758
 759         if ((session->ifname[0] &&
 760              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 761             (session->cookie_len &&
 762              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 763                      &session->cookie[0])) ||
 764             (session->peer_cookie_len &&
 765              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 766                      &session->peer_cookie[0])) ||
 767             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 768             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 769             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 770 #ifdef CONFIG_XFRM
 771             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 772              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 773 #endif
 774             (session->reorder_timeout &&
 775              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 776                            session->reorder_timeout, L2TP_ATTR_PAD)))
 777                 goto nla_put_failure;
 778
 779         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 780         if (nest == NULL)
 781                 goto nla_put_failure;
 782
 783         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 784                               atomic_long_read(&session->stats.tx_packets),
 785                               L2TP_ATTR_STATS_PAD) ||
 786             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 787                               atomic_long_read(&session->stats.tx_bytes),
 788                               L2TP_ATTR_STATS_PAD) ||
 789             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 790                               atomic_long_read(&session->stats.tx_errors),
 791                               L2TP_ATTR_STATS_PAD) ||
 792             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 793                               atomic_long_read(&session->stats.rx_packets),
 794                               L2TP_ATTR_STATS_PAD) ||
 795             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 796                               atomic_long_read(&session->stats.rx_bytes),
 797                               L2TP_ATTR_STATS_PAD) ||
 798             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 799                               atomic_long_read(&session->stats.rx_seq_discards),
 800                               L2TP_ATTR_STATS_PAD) ||
 801             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 802                               atomic_long_read(&session->stats.rx_oos_packets),
 803                               L2TP_ATTR_STATS_PAD) ||
 804             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 805                               atomic_long_read(&session->stats.rx_errors),
 806                               L2TP_ATTR_STATS_PAD))
 807                 goto nla_put_failure;
 808         nla_nest_end(skb, nest);
 809
 810         genlmsg_end(skb, hdr);
 811         return 0;
 812
 813  nla_put_failure:
 814         genlmsg_cancel(skb, hdr);
 815         return -1;
 816 }
 817
 818 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 819 {
 820         struct l2tp_session *session;
 821         struct sk_buff *msg;
 822         int ret;
 823
 824         session = l2tp_nl_session_get(info, false);
 825         if (session == NULL) {
 826                 ret = -ENODEV;
 827                 goto err;
 828         }
 829
 830         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 831         if (!msg) {
 832                 ret = -ENOMEM;
 833                 goto err_ref;
 834         }
 835
 836         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 837                                    0, session, L2TP_CMD_SESSION_GET);
 838         if (ret < 0)
 839                 goto err_ref_msg;
 840
 841         ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 842
 843         l2tp_session_dec_refcount(session);
 844
 845         return ret;
 846
 847 err_ref_msg:
 848         nlmsg_free(msg);
 849 err_ref:
 850         l2tp_session_dec_refcount(session);
 851 err:
 852         return ret;
 853 }
 854
 855 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 856 {
 857         struct net *net = sock_net(skb->sk);
 858         struct l2tp_session *session;
 859         struct l2tp_tunnel *tunnel = NULL;
 860         int ti = cb->args[0];
 861         int si = cb->args[1];
 862
 863         for (;;) {
 864                 if (tunnel == NULL) {
 865                         tunnel = l2tp_tunnel_find_nth(net, ti);
 866                         if (tunnel == NULL)
 867                                 goto out;
 868                 }
 869
 870                 session = l2tp_session_find_nth(tunnel, si);
 871                 if (session == NULL) {
 872                         ti++;
 873                         tunnel = NULL;
 874                         si = 0;
 875                         continue;
 876                 }
 877
 878                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 879                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 880                                          session, L2TP_CMD_SESSION_GET) < 0)
 881                         break;
 882
 883                 si++;
 884         }
 885
 886 out:
 887         cb->args[0] = ti;
 888         cb->args[1] = si;
 889
 890         return skb->len;
 891 }
 892
 893 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 894         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 895         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 896         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 897         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 898         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 899         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 900         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 901         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 902         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 903         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 904         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 905         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 906         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 907         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 908         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 909         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 910         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 911         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 912         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 913         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 914         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 915         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 916         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 917         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 918         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 919         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 920         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 921         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 922         [L2TP_ATTR_IP6_SADDR] = {
 923                 .type = NLA_BINARY,
 924                 .len = sizeof(struct in6_addr),
 925         },
 926         [L2TP_ATTR_IP6_DADDR] = {
 927                 .type = NLA_BINARY,
 928                 .len = sizeof(struct in6_addr),
 929         },
 930         [L2TP_ATTR_IFNAME] = {
 931                 .type = NLA_NUL_STRING,
 932                 .len = IFNAMSIZ - 1,
 933         },
 934         [L2TP_ATTR_COOKIE] = {
 935                 .type = NLA_BINARY,
 936                 .len = 8,
 937         },
 938         [L2TP_ATTR_PEER_COOKIE] = {
 939                 .type = NLA_BINARY,
 940                 .len = 8,
 941         },
 942 };
 943
 944 static const struct genl_ops l2tp_nl_ops[] = {
 945         {
 946                 .cmd = L2TP_CMD_NOOP,
 947                 .doit = l2tp_nl_cmd_noop,
 948                 .policy = l2tp_nl_policy,
 949                 /* can be retrieved by unprivileged users */
 950         },
 951         {
 952                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 953                 .doit = l2tp_nl_cmd_tunnel_create,
 954                 .policy = l2tp_nl_policy,
 955                 .flags = GENL_ADMIN_PERM,
 956         },
 957         {
 958                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 959                 .doit = l2tp_nl_cmd_tunnel_delete,
 960                 .policy = l2tp_nl_policy,
 961                 .flags = GENL_ADMIN_PERM,
 962         },
 963         {
 964                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 965                 .doit = l2tp_nl_cmd_tunnel_modify,
 966                 .policy = l2tp_nl_policy,
 967                 .flags = GENL_ADMIN_PERM,
 968         },
 969         {
 970                 .cmd = L2TP_CMD_TUNNEL_GET,
 971                 .doit = l2tp_nl_cmd_tunnel_get,
 972                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 973                 .policy = l2tp_nl_policy,
 974                 .flags = GENL_ADMIN_PERM,
 975         },
 976         {
 977                 .cmd = L2TP_CMD_SESSION_CREATE,
 978                 .doit = l2tp_nl_cmd_session_create,
 979                 .policy = l2tp_nl_policy,
 980                 .flags = GENL_ADMIN_PERM,
 981         },
 982         {
 983                 .cmd = L2TP_CMD_SESSION_DELETE,
 984                 .doit = l2tp_nl_cmd_session_delete,
 985                 .policy = l2tp_nl_policy,
 986                 .flags = GENL_ADMIN_PERM,
 987         },
 988         {
 989                 .cmd = L2TP_CMD_SESSION_MODIFY,
 990                 .doit = l2tp_nl_cmd_session_modify,
 991                 .policy = l2tp_nl_policy,
 992                 .flags = GENL_ADMIN_PERM,
 993         },
 994         {
 995                 .cmd = L2TP_CMD_SESSION_GET,
 996                 .doit = l2tp_nl_cmd_session_get,
 997                 .dumpit = l2tp_nl_cmd_session_dump,
 998                 .policy = l2tp_nl_policy,
 999                 .flags = GENL_ADMIN_PERM,
1000         },
1001 };
1002
1003 static struct genl_family l2tp_nl_family __ro_after_init = {
1004         .name           = L2TP_GENL_NAME,
1005         .version        = L2TP_GENL_VERSION,
1006         .hdrsize        = 0,
1007         .maxattr        = L2TP_ATTR_MAX,
1008         .netnsok        = true,
1009         .module         = THIS_MODULE,
1010         .ops            = l2tp_nl_ops,
1011         .n_ops          = ARRAY_SIZE(l2tp_nl_ops),
1012         .mcgrps         = l2tp_multicast_group,
1013         .n_mcgrps       = ARRAY_SIZE(l2tp_multicast_group),
1014 };
1015
1016 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1017 {
1018         int ret;
1019
1020         ret = -EINVAL;
1021         if (pw_type >= __L2TP_PWTYPE_MAX)
1022                 goto err;
1023
1024         genl_lock();
1025         ret = -EBUSY;
1026         if (l2tp_nl_cmd_ops[pw_type])
1027                 goto out;
1028
1029         l2tp_nl_cmd_ops[pw_type] = ops;
1030         ret = 0;
1031
1032 out:
1033         genl_unlock();
1034 err:
1035         return ret;
1036 }
1037 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1038
1039 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1040 {
1041         if (pw_type < __L2TP_PWTYPE_MAX) {
1042                 genl_lock();
1043                 l2tp_nl_cmd_ops[pw_type] = NULL;
1044                 genl_unlock();
1045         }
1046 }
1047 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1048
1049 static int __init l2tp_nl_init(void)
1050 {
1051         pr_info("L2TP netlink interface\n");
1052         return genl_register_family(&l2tp_nl_family);
1053 }
1054
1055 static void l2tp_nl_cleanup(void)
1056 {
1057         genl_unregister_family(&l2tp_nl_family);
1058 }
1059
1060 module_init(l2tp_nl_init);
1061 module_exit(l2tp_nl_cleanup);
1062
1063 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1064 MODULE_DESCRIPTION("L2TP netlink");
1065 MODULE_LICENSE("GPL");
1066 MODULE_VERSION("1.0");
1067 MODULE_ALIAS_GENL_FAMILY("l2tp");