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_find(struct genl_info *info)
  52 {
  53         u32 tunnel_id;
  54         u32 session_id;
  55         char *ifname;
  56         struct l2tp_tunnel *tunnel;
  57         struct l2tp_session *session = NULL;
  58         struct net *net = genl_info_net(info);
  59
  60         if (info->attrs[L2TP_ATTR_IFNAME]) {
  61                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  62                 session = l2tp_session_find_by_ifname(net, ifname);
  63         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  64                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  65                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  66                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  67                 tunnel = l2tp_tunnel_find(net, tunnel_id);
  68                 if (tunnel)
  69                         session = l2tp_session_find(net, tunnel, session_id);
  70         }
  71
  72         return session;
  73 }
  74
  75 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  76 {
  77         struct sk_buff *msg;
  78         void *hdr;
  79         int ret = -ENOBUFS;
  80
  81         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  82         if (!msg) {
  83                 ret = -ENOMEM;
  84                 goto out;
  85         }
  86
  87         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  88                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  89         if (!hdr) {
  90                 ret = -EMSGSIZE;
  91                 goto err_out;
  92         }
  93
  94         genlmsg_end(msg, hdr);
  95
  96         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
  97
  98 err_out:
  99         nlmsg_free(msg);
 100
 101 out:
 102         return ret;
 103 }
 104
 105 static int l2tp_tunnel_notify(struct genl_family *family,
 106                               struct genl_info *info,
 107                               struct l2tp_tunnel *tunnel,
 108                               u8 cmd)
 109 {
 110         struct sk_buff *msg;
 111         int ret;
 112
 113         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 114         if (!msg)
 115                 return -ENOMEM;
 116
 117         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 118                                   NLM_F_ACK, tunnel, cmd);
 119
 120         if (ret >= 0) {
 121                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 122                 /* We don't care if no one is listening */
 123                 if (ret == -ESRCH)
 124                         ret = 0;
 125                 return ret;
 126         }
 127
 128         nlmsg_free(msg);
 129
 130         return ret;
 131 }
 132
 133 static int l2tp_session_notify(struct genl_family *family,
 134                                struct genl_info *info,
 135                                struct l2tp_session *session,
 136                                u8 cmd)
 137 {
 138         struct sk_buff *msg;
 139         int ret;
 140
 141         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 142         if (!msg)
 143                 return -ENOMEM;
 144
 145         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 146                                    NLM_F_ACK, session, cmd);
 147
 148         if (ret >= 0) {
 149                 ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 150                 /* We don't care if no one is listening */
 151                 if (ret == -ESRCH)
 152                         ret = 0;
 153                 return ret;
 154         }
 155
 156         nlmsg_free(msg);
 157
 158         return ret;
 159 }
 160
 161 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 162 {
 163         u32 tunnel_id;
 164         u32 peer_tunnel_id;
 165         int proto_version;
 166         int fd;
 167         int ret = 0;
 168         struct l2tp_tunnel_cfg cfg = { 0, };
 169         struct l2tp_tunnel *tunnel;
 170         struct net *net = genl_info_net(info);
 171
 172         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 173                 ret = -EINVAL;
 174                 goto out;
 175         }
 176         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 177
 178         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 179                 ret = -EINVAL;
 180                 goto out;
 181         }
 182         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 183
 184         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 185                 ret = -EINVAL;
 186                 goto out;
 187         }
 188         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 189
 190         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 191                 ret = -EINVAL;
 192                 goto out;
 193         }
 194         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 195
 196         fd = -1;
 197         if (info->attrs[L2TP_ATTR_FD]) {
 198                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 199         } else {
 200 #if IS_ENABLED(CONFIG_IPV6)
 201                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 202                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 203                         cfg.local_ip6 = nla_data(
 204                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 205                         cfg.peer_ip6 = nla_data(
 206                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 207                 } else
 208 #endif
 209                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 210                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 211                         cfg.local_ip.s_addr = nla_get_in_addr(
 212                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 213                         cfg.peer_ip.s_addr = nla_get_in_addr(
 214                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 215                 } else {
 216                         ret = -EINVAL;
 217                         goto out;
 218                 }
 219                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 220                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 221                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 222                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 223                 cfg.use_udp_checksums = nla_get_flag(
 224                         info->attrs[L2TP_ATTR_UDP_CSUM]);
 225
 226 #if IS_ENABLED(CONFIG_IPV6)
 227                 cfg.udp6_zero_tx_checksums = nla_get_flag(
 228                         info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 229                 cfg.udp6_zero_rx_checksums = nla_get_flag(
 230                         info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 231 #endif
 232         }
 233
 234         if (info->attrs[L2TP_ATTR_DEBUG])
 235                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 236
 237         tunnel = l2tp_tunnel_find(net, tunnel_id);
 238         if (tunnel != NULL) {
 239                 ret = -EEXIST;
 240                 goto out;
 241         }
 242
 243         ret = -EINVAL;
 244         switch (cfg.encap) {
 245         case L2TP_ENCAPTYPE_UDP:
 246         case L2TP_ENCAPTYPE_IP:
 247                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 248                                          peer_tunnel_id, &cfg, &tunnel);
 249                 break;
 250         }
 251
 252         if (ret >= 0)
 253                 ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 254                                          tunnel, L2TP_CMD_TUNNEL_CREATE);
 255 out:
 256         return ret;
 257 }
 258
 259 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 260 {
 261         struct l2tp_tunnel *tunnel;
 262         u32 tunnel_id;
 263         int ret = 0;
 264         struct net *net = genl_info_net(info);
 265
 266         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 267                 ret = -EINVAL;
 268                 goto out;
 269         }
 270         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 271
 272         tunnel = l2tp_tunnel_find(net, tunnel_id);
 273         if (tunnel == NULL) {
 274                 ret = -ENODEV;
 275                 goto out;
 276         }
 277
 278         l2tp_tunnel_notify(&l2tp_nl_family, info,
 279                            tunnel, L2TP_CMD_TUNNEL_DELETE);
 280
 281         (void) l2tp_tunnel_delete(tunnel);
 282
 283 out:
 284         return ret;
 285 }
 286
 287 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 288 {
 289         struct l2tp_tunnel *tunnel;
 290         u32 tunnel_id;
 291         int ret = 0;
 292         struct net *net = genl_info_net(info);
 293
 294         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 295                 ret = -EINVAL;
 296                 goto out;
 297         }
 298         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 299
 300         tunnel = l2tp_tunnel_find(net, tunnel_id);
 301         if (tunnel == NULL) {
 302                 ret = -ENODEV;
 303                 goto out;
 304         }
 305
 306         if (info->attrs[L2TP_ATTR_DEBUG])
 307                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 308
 309         ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 310                                  tunnel, L2TP_CMD_TUNNEL_MODIFY);
 311
 312 out:
 313         return ret;
 314 }
 315
 316 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 317                                struct l2tp_tunnel *tunnel, u8 cmd)
 318 {
 319         void *hdr;
 320         struct nlattr *nest;
 321         struct sock *sk = NULL;
 322         struct inet_sock *inet;
 323 #if IS_ENABLED(CONFIG_IPV6)
 324         struct ipv6_pinfo *np = NULL;
 325 #endif
 326
 327         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 328         if (!hdr)
 329                 return -EMSGSIZE;
 330
 331         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 332             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 333             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 334             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 335             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 336                 goto nla_put_failure;
 337
 338         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 339         if (nest == NULL)
 340                 goto nla_put_failure;
 341
 342         if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 343                               atomic_long_read(&tunnel->stats.tx_packets),
 344                               L2TP_ATTR_STATS_PAD) ||
 345             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 346                               atomic_long_read(&tunnel->stats.tx_bytes),
 347                               L2TP_ATTR_STATS_PAD) ||
 348             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 349                               atomic_long_read(&tunnel->stats.tx_errors),
 350                               L2TP_ATTR_STATS_PAD) ||
 351             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 352                               atomic_long_read(&tunnel->stats.rx_packets),
 353                               L2TP_ATTR_STATS_PAD) ||
 354             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 355                               atomic_long_read(&tunnel->stats.rx_bytes),
 356                               L2TP_ATTR_STATS_PAD) ||
 357             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 358                               atomic_long_read(&tunnel->stats.rx_seq_discards),
 359                               L2TP_ATTR_STATS_PAD) ||
 360             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 361                               atomic_long_read(&tunnel->stats.rx_oos_packets),
 362                               L2TP_ATTR_STATS_PAD) ||
 363             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 364                               atomic_long_read(&tunnel->stats.rx_errors),
 365                               L2TP_ATTR_STATS_PAD))
 366                 goto nla_put_failure;
 367         nla_nest_end(skb, nest);
 368
 369         sk = tunnel->sock;
 370         if (!sk)
 371                 goto out;
 372
 373 #if IS_ENABLED(CONFIG_IPV6)
 374         if (sk->sk_family == AF_INET6)
 375                 np = inet6_sk(sk);
 376 #endif
 377
 378         inet = inet_sk(sk);
 379
 380         switch (tunnel->encap) {
 381         case L2TP_ENCAPTYPE_UDP:
 382                 switch (sk->sk_family) {
 383                 case AF_INET:
 384                         if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 385                                 goto nla_put_failure;
 386                         break;
 387 #if IS_ENABLED(CONFIG_IPV6)
 388                 case AF_INET6:
 389                         if (udp_get_no_check6_tx(sk) &&
 390                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
 391                                 goto nla_put_failure;
 392                         if (udp_get_no_check6_rx(sk) &&
 393                             nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
 394                                 goto nla_put_failure;
 395                         break;
 396 #endif
 397                 }
 398                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 399                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 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 out;
 440         }
 441
 442         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 443
 444         tunnel = l2tp_tunnel_find(net, tunnel_id);
 445         if (tunnel == NULL) {
 446                 ret = -ENODEV;
 447                 goto out;
 448         }
 449
 450         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 451         if (!msg) {
 452                 ret = -ENOMEM;
 453                 goto out;
 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_out;
 460
 461         return genlmsg_unicast(net, msg, info->snd_portid);
 462
 463 err_out:
 464         nlmsg_free(msg);
 465
 466 out:
 467         return ret;
 468 }
 469
 470 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 471 {
 472         int ti = cb->args[0];
 473         struct l2tp_tunnel *tunnel;
 474         struct net *net = sock_net(skb->sk);
 475
 476         for (;;) {
 477                 tunnel = l2tp_tunnel_find_nth(net, ti);
 478                 if (tunnel == NULL)
 479                         goto out;
 480
 481                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 482                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 483                                         tunnel, L2TP_CMD_TUNNEL_GET) < 0)
 484                         goto out;
 485
 486                 ti++;
 487         }
 488
 489 out:
 490         cb->args[0] = ti;
 491
 492         return skb->len;
 493 }
 494
 495 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 496 {
 497         u32 tunnel_id = 0;
 498         u32 session_id;
 499         u32 peer_session_id;
 500         int ret = 0;
 501         struct l2tp_tunnel *tunnel;
 502         struct l2tp_session *session;
 503         struct l2tp_session_cfg cfg = { 0, };
 504         struct net *net = genl_info_net(info);
 505
 506         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 507                 ret = -EINVAL;
 508                 goto out;
 509         }
 510         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 511         tunnel = l2tp_tunnel_find(net, tunnel_id);
 512         if (!tunnel) {
 513                 ret = -ENODEV;
 514                 goto out;
 515         }
 516
 517         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 518                 ret = -EINVAL;
 519                 goto out;
 520         }
 521         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 522         session = l2tp_session_find(net, tunnel, session_id);
 523         if (session) {
 524                 ret = -EEXIST;
 525                 goto out;
 526         }
 527
 528         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 529                 ret = -EINVAL;
 530                 goto out;
 531         }
 532         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 533
 534         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 535                 ret = -EINVAL;
 536                 goto out;
 537         }
 538         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 539         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 540                 ret = -EINVAL;
 541                 goto out;
 542         }
 543
 544         if (tunnel->version > 2) {
 545                 if (info->attrs[L2TP_ATTR_OFFSET])
 546                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 547
 548                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 549                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 550
 551                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 552                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 553                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 554
 555                 cfg.l2specific_len = 4;
 556                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 557                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 558
 559                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 560                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 561                         if (len > 8) {
 562                                 ret = -EINVAL;
 563                                 goto out;
 564                         }
 565                         cfg.cookie_len = len;
 566                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 567                 }
 568                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 569                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 570                         if (len > 8) {
 571                                 ret = -EINVAL;
 572                                 goto out;
 573                         }
 574                         cfg.peer_cookie_len = len;
 575                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 576                 }
 577                 if (info->attrs[L2TP_ATTR_IFNAME])
 578                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 579
 580                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 581                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 582         }
 583
 584         if (info->attrs[L2TP_ATTR_DEBUG])
 585                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 586
 587         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 588                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 589
 590         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 591                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 592
 593         if (info->attrs[L2TP_ATTR_LNS_MODE])
 594                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 595
 596         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 597                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 598
 599         if (info->attrs[L2TP_ATTR_MTU])
 600                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 601
 602         if (info->attrs[L2TP_ATTR_MRU])
 603                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 604
 605 #ifdef CONFIG_MODULES
 606         if (l2tp_nl_cmd_ops[cfg.pw_type] == NULL) {
 607                 genl_unlock();
 608                 request_module("net-l2tp-type-%u", cfg.pw_type);
 609                 genl_lock();
 610         }
 611 #endif
 612         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 613             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 614                 ret = -EPROTONOSUPPORT;
 615                 goto out;
 616         }
 617
 618         /* Check that pseudowire-specific params are present */
 619         switch (cfg.pw_type) {
 620         case L2TP_PWTYPE_NONE:
 621                 break;
 622         case L2TP_PWTYPE_ETH_VLAN:
 623                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 624                         ret = -EINVAL;
 625                         goto out;
 626                 }
 627                 break;
 628         case L2TP_PWTYPE_ETH:
 629                 break;
 630         case L2TP_PWTYPE_PPP:
 631         case L2TP_PWTYPE_PPP_AC:
 632                 break;
 633         case L2TP_PWTYPE_IP:
 634         default:
 635                 ret = -EPROTONOSUPPORT;
 636                 break;
 637         }
 638
 639         ret = -EPROTONOSUPPORT;
 640         if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
 641                 ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
 642                         session_id, peer_session_id, &cfg);
 643
 644         if (ret >= 0) {
 645                 session = l2tp_session_find(net, tunnel, session_id);
 646                 if (session)
 647                         ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 648                                                   L2TP_CMD_SESSION_CREATE);
 649         }
 650
 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_find(info);
 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 out:
 676         return ret;
 677 }
 678
 679 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 680 {
 681         int ret = 0;
 682         struct l2tp_session *session;
 683
 684         session = l2tp_nl_session_find(info);
 685         if (session == NULL) {
 686                 ret = -ENODEV;
 687                 goto out;
 688         }
 689
 690         if (info->attrs[L2TP_ATTR_DEBUG])
 691                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 692
 693         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 694                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 695
 696         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 697                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 698
 699         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 700                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 701                 l2tp_session_set_header_len(session, session->tunnel->version);
 702         }
 703
 704         if (info->attrs[L2TP_ATTR_LNS_MODE])
 705                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 706
 707         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 708                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 709
 710         if (info->attrs[L2TP_ATTR_MTU])
 711                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 712
 713         if (info->attrs[L2TP_ATTR_MRU])
 714                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 715
 716         ret = l2tp_session_notify(&l2tp_nl_family, info,
 717                                   session, L2TP_CMD_SESSION_MODIFY);
 718
 719 out:
 720         return ret;
 721 }
 722
 723 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 724                                 struct l2tp_session *session, u8 cmd)
 725 {
 726         void *hdr;
 727         struct nlattr *nest;
 728         struct l2tp_tunnel *tunnel = session->tunnel;
 729         struct sock *sk = NULL;
 730
 731         sk = tunnel->sock;
 732
 733         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 734         if (!hdr)
 735                 return -EMSGSIZE;
 736
 737         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 738             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 739             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 740             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 741                         session->peer_session_id) ||
 742             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 743             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 744             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 745             (session->mru &&
 746              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 747                 goto nla_put_failure;
 748
 749         if ((session->ifname[0] &&
 750              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 751             (session->cookie_len &&
 752              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 753                      &session->cookie[0])) ||
 754             (session->peer_cookie_len &&
 755              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 756                      &session->peer_cookie[0])) ||
 757             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 758             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 759             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 760 #ifdef CONFIG_XFRM
 761             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 762              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 763 #endif
 764             (session->reorder_timeout &&
 765              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 766                            session->reorder_timeout, L2TP_ATTR_PAD)))
 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_64bit(skb, L2TP_ATTR_TX_PACKETS,
 774                               atomic_long_read(&session->stats.tx_packets),
 775                               L2TP_ATTR_STATS_PAD) ||
 776             nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 777                               atomic_long_read(&session->stats.tx_bytes),
 778                               L2TP_ATTR_STATS_PAD) ||
 779             nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 780                               atomic_long_read(&session->stats.tx_errors),
 781                               L2TP_ATTR_STATS_PAD) ||
 782             nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 783                               atomic_long_read(&session->stats.rx_packets),
 784                               L2TP_ATTR_STATS_PAD) ||
 785             nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 786                               atomic_long_read(&session->stats.rx_bytes),
 787                               L2TP_ATTR_STATS_PAD) ||
 788             nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 789                               atomic_long_read(&session->stats.rx_seq_discards),
 790                               L2TP_ATTR_STATS_PAD) ||
 791             nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 792                               atomic_long_read(&session->stats.rx_oos_packets),
 793                               L2TP_ATTR_STATS_PAD) ||
 794             nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 795                               atomic_long_read(&session->stats.rx_errors),
 796                               L2TP_ATTR_STATS_PAD))
 797                 goto nla_put_failure;
 798         nla_nest_end(skb, nest);
 799
 800         genlmsg_end(skb, hdr);
 801         return 0;
 802
 803  nla_put_failure:
 804         genlmsg_cancel(skb, hdr);
 805         return -1;
 806 }
 807
 808 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 809 {
 810         struct l2tp_session *session;
 811         struct sk_buff *msg;
 812         int ret;
 813
 814         session = l2tp_nl_session_find(info);
 815         if (session == NULL) {
 816                 ret = -ENODEV;
 817                 goto out;
 818         }
 819
 820         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 821         if (!msg) {
 822                 ret = -ENOMEM;
 823                 goto out;
 824         }
 825
 826         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 827                                    0, session, L2TP_CMD_SESSION_GET);
 828         if (ret < 0)
 829                 goto err_out;
 830
 831         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 832
 833 err_out:
 834         nlmsg_free(msg);
 835
 836 out:
 837         return ret;
 838 }
 839
 840 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 841 {
 842         struct net *net = sock_net(skb->sk);
 843         struct l2tp_session *session;
 844         struct l2tp_tunnel *tunnel = NULL;
 845         int ti = cb->args[0];
 846         int si = cb->args[1];
 847
 848         for (;;) {
 849                 if (tunnel == NULL) {
 850                         tunnel = l2tp_tunnel_find_nth(net, ti);
 851                         if (tunnel == NULL)
 852                                 goto out;
 853                 }
 854
 855                 session = l2tp_session_find_nth(tunnel, si);
 856                 if (session == NULL) {
 857                         ti++;
 858                         tunnel = NULL;
 859                         si = 0;
 860                         continue;
 861                 }
 862
 863                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 864                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 865                                          session, L2TP_CMD_SESSION_GET) < 0)
 866                         break;
 867
 868                 si++;
 869         }
 870
 871 out:
 872         cb->args[0] = ti;
 873         cb->args[1] = si;
 874
 875         return skb->len;
 876 }
 877
 878 static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 879         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 880         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 881         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 882         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 883         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 884         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 885         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 886         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 887         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 888         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 889         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 890         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 891         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 892         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 893         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 894         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 895         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 896         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 897         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 898         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 899         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 900         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 901         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 902         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 903         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 904         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 905         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 906         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 907         [L2TP_ATTR_IP6_SADDR] = {
 908                 .type = NLA_BINARY,
 909                 .len = sizeof(struct in6_addr),
 910         },
 911         [L2TP_ATTR_IP6_DADDR] = {
 912                 .type = NLA_BINARY,
 913                 .len = sizeof(struct in6_addr),
 914         },
 915         [L2TP_ATTR_IFNAME] = {
 916                 .type = NLA_NUL_STRING,
 917                 .len = IFNAMSIZ - 1,
 918         },
 919         [L2TP_ATTR_COOKIE] = {
 920                 .type = NLA_BINARY,
 921                 .len = 8,
 922         },
 923         [L2TP_ATTR_PEER_COOKIE] = {
 924                 .type = NLA_BINARY,
 925                 .len = 8,
 926         },
 927 };
 928
 929 static const struct genl_ops l2tp_nl_ops[] = {
 930         {
 931                 .cmd = L2TP_CMD_NOOP,
 932                 .doit = l2tp_nl_cmd_noop,
 933                 .policy = l2tp_nl_policy,
 934                 /* can be retrieved by unprivileged users */
 935         },
 936         {
 937                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 938                 .doit = l2tp_nl_cmd_tunnel_create,
 939                 .policy = l2tp_nl_policy,
 940                 .flags = GENL_ADMIN_PERM,
 941         },
 942         {
 943                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 944                 .doit = l2tp_nl_cmd_tunnel_delete,
 945                 .policy = l2tp_nl_policy,
 946                 .flags = GENL_ADMIN_PERM,
 947         },
 948         {
 949                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 950                 .doit = l2tp_nl_cmd_tunnel_modify,
 951                 .policy = l2tp_nl_policy,
 952                 .flags = GENL_ADMIN_PERM,
 953         },
 954         {
 955                 .cmd = L2TP_CMD_TUNNEL_GET,
 956                 .doit = l2tp_nl_cmd_tunnel_get,
 957                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 958                 .policy = l2tp_nl_policy,
 959                 .flags = GENL_ADMIN_PERM,
 960         },
 961         {
 962                 .cmd = L2TP_CMD_SESSION_CREATE,
 963                 .doit = l2tp_nl_cmd_session_create,
 964                 .policy = l2tp_nl_policy,
 965                 .flags = GENL_ADMIN_PERM,
 966         },
 967         {
 968                 .cmd = L2TP_CMD_SESSION_DELETE,
 969                 .doit = l2tp_nl_cmd_session_delete,
 970                 .policy = l2tp_nl_policy,
 971                 .flags = GENL_ADMIN_PERM,
 972         },
 973         {
 974                 .cmd = L2TP_CMD_SESSION_MODIFY,
 975                 .doit = l2tp_nl_cmd_session_modify,
 976                 .policy = l2tp_nl_policy,
 977                 .flags = GENL_ADMIN_PERM,
 978         },
 979         {
 980                 .cmd = L2TP_CMD_SESSION_GET,
 981                 .doit = l2tp_nl_cmd_session_get,
 982                 .dumpit = l2tp_nl_cmd_session_dump,
 983                 .policy = l2tp_nl_policy,
 984                 .flags = GENL_ADMIN_PERM,
 985         },
 986 };
 987
 988 static struct genl_family l2tp_nl_family __ro_after_init = {
 989         .name           = L2TP_GENL_NAME,
 990         .version        = L2TP_GENL_VERSION,
 991         .hdrsize        = 0,
 992         .maxattr        = L2TP_ATTR_MAX,
 993         .netnsok        = true,
 994         .module         = THIS_MODULE,
 995         .ops            = l2tp_nl_ops,
 996         .n_ops          = ARRAY_SIZE(l2tp_nl_ops),
 997         .mcgrps         = l2tp_multicast_group,
 998         .n_mcgrps       = ARRAY_SIZE(l2tp_multicast_group),
 999 };
1000
1001 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
1002 {
1003         int ret;
1004
1005         ret = -EINVAL;
1006         if (pw_type >= __L2TP_PWTYPE_MAX)
1007                 goto err;
1008
1009         genl_lock();
1010         ret = -EBUSY;
1011         if (l2tp_nl_cmd_ops[pw_type])
1012                 goto out;
1013
1014         l2tp_nl_cmd_ops[pw_type] = ops;
1015         ret = 0;
1016
1017 out:
1018         genl_unlock();
1019 err:
1020         return ret;
1021 }
1022 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1023
1024 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1025 {
1026         if (pw_type < __L2TP_PWTYPE_MAX) {
1027                 genl_lock();
1028                 l2tp_nl_cmd_ops[pw_type] = NULL;
1029                 genl_unlock();
1030         }
1031 }
1032 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1033
1034 static int __init l2tp_nl_init(void)
1035 {
1036         pr_info("L2TP netlink interface\n");
1037         return genl_register_family(&l2tp_nl_family);
1038 }
1039
1040 static void l2tp_nl_cleanup(void)
1041 {
1042         genl_unregister_family(&l2tp_nl_family);
1043 }
1044
1045 module_init(l2tp_nl_init);
1046 module_exit(l2tp_nl_cleanup);
1047
1048 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1049 MODULE_DESCRIPTION("L2TP netlink");
1050 MODULE_LICENSE("GPL");
1051 MODULE_VERSION("1.0");
1052 MODULE_ALIAS_GENL_FAMILY("l2tp");