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 /* Accessed under genl lock */
  44 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
  45
  46 static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info,
  47                                                 bool do_ref)
  48 {
  49         u32 tunnel_id;
  50         u32 session_id;
  51         char *ifname;
  52         struct l2tp_tunnel *tunnel;
  53         struct l2tp_session *session = NULL;
  54         struct net *net = genl_info_net(info);
  55
  56         if (info->attrs[L2TP_ATTR_IFNAME]) {
  57                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  58                 session = l2tp_session_get_by_ifname(net, ifname, do_ref);
  59         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  60                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  61                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  62                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  63                 tunnel = l2tp_tunnel_get(net, tunnel_id);
  64                 if (tunnel) {
  65                         session = l2tp_session_get(net, tunnel, session_id,
  66                                                    do_ref);
  67                         l2tp_tunnel_dec_refcount(tunnel);
  68                 }
  69         }
  70
  71         return session;
  72 }
  73
  74 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  75 {
  76         struct sk_buff *msg;
  77         void *hdr;
  78         int ret = -ENOBUFS;
  79
  80         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  81         if (!msg) {
  82                 ret = -ENOMEM;
  83                 goto out;
  84         }
  85
  86         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  87                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  88         if (!hdr) {
  89                 ret = -EMSGSIZE;
  90                 goto err_out;
  91         }
  92
  93         genlmsg_end(msg, hdr);
  94
  95         return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
  96
  97 err_out:
  98         nlmsg_free(msg);
  99
 100 out:
 101         return ret;
 102 }
 103
 104 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 105 {
 106         u32 tunnel_id;
 107         u32 peer_tunnel_id;
 108         int proto_version;
 109         int fd;
 110         int ret = 0;
 111         struct l2tp_tunnel_cfg cfg = { 0, };
 112         struct l2tp_tunnel *tunnel;
 113         struct net *net = genl_info_net(info);
 114
 115         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 116                 ret = -EINVAL;
 117                 goto out;
 118         }
 119         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 120
 121         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 122                 ret = -EINVAL;
 123                 goto out;
 124         }
 125         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 126
 127         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 128                 ret = -EINVAL;
 129                 goto out;
 130         }
 131         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 132
 133         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 134                 ret = -EINVAL;
 135                 goto out;
 136         }
 137         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 138
 139         fd = -1;
 140         if (info->attrs[L2TP_ATTR_FD]) {
 141                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 142         } else {
 143 #if IS_ENABLED(CONFIG_IPV6)
 144                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 145                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 146                         cfg.local_ip6 = nla_data(
 147                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 148                         cfg.peer_ip6 = nla_data(
 149                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 150                 } else
 151 #endif
 152                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 153                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 154                         cfg.local_ip.s_addr = nla_get_be32(
 155                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 156                         cfg.peer_ip.s_addr = nla_get_be32(
 157                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 158                 } else {
 159                         ret = -EINVAL;
 160                         goto out;
 161                 }
 162                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 163                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 164                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 165                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 166                 if (info->attrs[L2TP_ATTR_UDP_CSUM])
 167                         cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
 168
 169 #if IS_ENABLED(CONFIG_IPV6)
 170                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX])
 171                         cfg.udp6_zero_tx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 172                 if (info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX])
 173                         cfg.udp6_zero_rx_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 174 #endif
 175         }
 176
 177         if (info->attrs[L2TP_ATTR_DEBUG])
 178                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 179
 180         tunnel = l2tp_tunnel_find(net, tunnel_id);
 181         if (tunnel != NULL) {
 182                 ret = -EEXIST;
 183                 goto out;
 184         }
 185
 186         ret = -EINVAL;
 187         switch (cfg.encap) {
 188         case L2TP_ENCAPTYPE_UDP:
 189         case L2TP_ENCAPTYPE_IP:
 190                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 191                                          peer_tunnel_id, &cfg, &tunnel);
 192                 break;
 193         }
 194
 195 out:
 196         return ret;
 197 }
 198
 199 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 200 {
 201         struct l2tp_tunnel *tunnel;
 202         u32 tunnel_id;
 203         int ret = 0;
 204         struct net *net = genl_info_net(info);
 205
 206         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 207                 ret = -EINVAL;
 208                 goto out;
 209         }
 210         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 211
 212         tunnel = l2tp_tunnel_get(net, tunnel_id);
 213         if (!tunnel) {
 214                 ret = -ENODEV;
 215                 goto out;
 216         }
 217
 218         (void) l2tp_tunnel_delete(tunnel);
 219
 220         l2tp_tunnel_dec_refcount(tunnel);
 221
 222 out:
 223         return ret;
 224 }
 225
 226 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 227 {
 228         struct l2tp_tunnel *tunnel;
 229         u32 tunnel_id;
 230         int ret = 0;
 231         struct net *net = genl_info_net(info);
 232
 233         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 234                 ret = -EINVAL;
 235                 goto out;
 236         }
 237         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 238
 239         tunnel = l2tp_tunnel_get(net, tunnel_id);
 240         if (!tunnel) {
 241                 ret = -ENODEV;
 242                 goto out;
 243         }
 244
 245         if (info->attrs[L2TP_ATTR_DEBUG])
 246                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 247
 248         l2tp_tunnel_dec_refcount(tunnel);
 249
 250 out:
 251         return ret;
 252 }
 253
 254 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 255                                struct l2tp_tunnel *tunnel)
 256 {
 257         void *hdr;
 258         struct nlattr *nest;
 259         struct sock *sk = NULL;
 260         struct inet_sock *inet;
 261 #if IS_ENABLED(CONFIG_IPV6)
 262         struct ipv6_pinfo *np = NULL;
 263 #endif
 264
 265         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags,
 266                           L2TP_CMD_TUNNEL_GET);
 267         if (!hdr)
 268                 return -EMSGSIZE;
 269
 270         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 271             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 272             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 273             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 274             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 275                 goto nla_put_failure;
 276
 277         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 278         if (nest == NULL)
 279                 goto nla_put_failure;
 280
 281         if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
 282                     atomic_long_read(&tunnel->stats.tx_packets)) ||
 283             nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
 284                     atomic_long_read(&tunnel->stats.tx_bytes)) ||
 285             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
 286                     atomic_long_read(&tunnel->stats.tx_errors)) ||
 287             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
 288                     atomic_long_read(&tunnel->stats.rx_packets)) ||
 289             nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
 290                     atomic_long_read(&tunnel->stats.rx_bytes)) ||
 291             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 292                     atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
 293             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 294                     atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
 295             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
 296                     atomic_long_read(&tunnel->stats.rx_errors)))
 297                 goto nla_put_failure;
 298         nla_nest_end(skb, nest);
 299
 300         sk = tunnel->sock;
 301         if (!sk)
 302                 goto out;
 303
 304 #if IS_ENABLED(CONFIG_IPV6)
 305         if (sk->sk_family == AF_INET6)
 306                 np = inet6_sk(sk);
 307 #endif
 308
 309         inet = inet_sk(sk);
 310
 311         switch (tunnel->encap) {
 312         case L2TP_ENCAPTYPE_UDP:
 313                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 314                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
 315                     nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
 316                         goto nla_put_failure;
 317                 /* NOBREAK */
 318         case L2TP_ENCAPTYPE_IP:
 319 #if IS_ENABLED(CONFIG_IPV6)
 320                 if (np) {
 321                         if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
 322                                     &np->saddr) ||
 323                             nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(sk->sk_v6_daddr),
 324                                     &sk->sk_v6_daddr))
 325                                 goto nla_put_failure;
 326                 } else
 327 #endif
 328                 if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
 329                     nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
 330                         goto nla_put_failure;
 331                 break;
 332         }
 333
 334 out:
 335         return genlmsg_end(skb, hdr);
 336
 337 nla_put_failure:
 338         genlmsg_cancel(skb, hdr);
 339         return -1;
 340 }
 341
 342 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 343 {
 344         struct l2tp_tunnel *tunnel;
 345         struct sk_buff *msg;
 346         u32 tunnel_id;
 347         int ret = -ENOBUFS;
 348         struct net *net = genl_info_net(info);
 349
 350         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 351                 ret = -EINVAL;
 352                 goto err;
 353         }
 354
 355         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 356
 357         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 358         if (!msg) {
 359                 ret = -ENOMEM;
 360                 goto err;
 361         }
 362
 363         tunnel = l2tp_tunnel_get(net, tunnel_id);
 364         if (!tunnel) {
 365                 ret = -ENODEV;
 366                 goto err_nlmsg;
 367         }
 368
 369         ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 370                                   NLM_F_ACK, tunnel);
 371         if (ret < 0)
 372                 goto err_nlmsg_tunnel;
 373
 374         l2tp_tunnel_dec_refcount(tunnel);
 375
 376         return genlmsg_unicast(net, msg, info->snd_portid);
 377
 378 err_nlmsg_tunnel:
 379         l2tp_tunnel_dec_refcount(tunnel);
 380 err_nlmsg:
 381         nlmsg_free(msg);
 382 err:
 383         return ret;
 384 }
 385
 386 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 387 {
 388         int ti = cb->args[0];
 389         struct l2tp_tunnel *tunnel;
 390         struct net *net = sock_net(skb->sk);
 391
 392         for (;;) {
 393                 tunnel = l2tp_tunnel_find_nth(net, ti);
 394                 if (tunnel == NULL)
 395                         goto out;
 396
 397                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 398                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 399                                         tunnel) <= 0)
 400                         goto out;
 401
 402                 ti++;
 403         }
 404
 405 out:
 406         cb->args[0] = ti;
 407
 408         return skb->len;
 409 }
 410
 411 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 412 {
 413         u32 tunnel_id = 0;
 414         u32 session_id;
 415         u32 peer_session_id;
 416         int ret = 0;
 417         struct l2tp_tunnel *tunnel;
 418         struct l2tp_session_cfg cfg = { 0, };
 419         struct net *net = genl_info_net(info);
 420
 421         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 422                 ret = -EINVAL;
 423                 goto out;
 424         }
 425
 426         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 427         tunnel = l2tp_tunnel_get(net, tunnel_id);
 428         if (!tunnel) {
 429                 ret = -ENODEV;
 430                 goto out;
 431         }
 432
 433         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 434                 ret = -EINVAL;
 435                 goto out_tunnel;
 436         }
 437         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 438
 439         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 440                 ret = -EINVAL;
 441                 goto out_tunnel;
 442         }
 443         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 444
 445         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 446                 ret = -EINVAL;
 447                 goto out_tunnel;
 448         }
 449         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 450         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 451                 ret = -EINVAL;
 452                 goto out_tunnel;
 453         }
 454
 455         if (tunnel->version > 2) {
 456                 if (info->attrs[L2TP_ATTR_OFFSET])
 457                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 458
 459                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 460                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 461
 462                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 463                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 464                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 465
 466                 cfg.l2specific_len = 4;
 467                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 468                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 469
 470                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 471                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 472                         if (len > 8) {
 473                                 ret = -EINVAL;
 474                                 goto out_tunnel;
 475                         }
 476                         cfg.cookie_len = len;
 477                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 478                 }
 479                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 480                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 481                         if (len > 8) {
 482                                 ret = -EINVAL;
 483                                 goto out_tunnel;
 484                         }
 485                         cfg.peer_cookie_len = len;
 486                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 487                 }
 488                 if (info->attrs[L2TP_ATTR_IFNAME])
 489                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 490
 491                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 492                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 493         }
 494
 495         if (info->attrs[L2TP_ATTR_DEBUG])
 496                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 497
 498         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 499                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 500
 501         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 502                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 503
 504         if (info->attrs[L2TP_ATTR_LNS_MODE])
 505                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 506
 507         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 508                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 509
 510         if (info->attrs[L2TP_ATTR_MTU])
 511                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 512
 513         if (info->attrs[L2TP_ATTR_MRU])
 514                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 515
 516         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 517             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 518                 ret = -EPROTONOSUPPORT;
 519                 goto out_tunnel;
 520         }
 521
 522         /* Check that pseudowire-specific params are present */
 523         switch (cfg.pw_type) {
 524         case L2TP_PWTYPE_NONE:
 525                 break;
 526         case L2TP_PWTYPE_ETH_VLAN:
 527                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 528                         ret = -EINVAL;
 529                         goto out_tunnel;
 530                 }
 531                 break;
 532         case L2TP_PWTYPE_ETH:
 533                 break;
 534         case L2TP_PWTYPE_PPP:
 535         case L2TP_PWTYPE_PPP_AC:
 536                 break;
 537         case L2TP_PWTYPE_IP:
 538         default:
 539                 ret = -EPROTONOSUPPORT;
 540                 break;
 541         }
 542
 543         ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 544                                                            session_id,
 545                                                            peer_session_id,
 546                                                            &cfg);
 547
 548 out_tunnel:
 549         l2tp_tunnel_dec_refcount(tunnel);
 550 out:
 551         return ret;
 552 }
 553
 554 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 555 {
 556         int ret = 0;
 557         struct l2tp_session *session;
 558         u16 pw_type;
 559
 560         session = l2tp_nl_session_get(info, true);
 561         if (session == NULL) {
 562                 ret = -ENODEV;
 563                 goto out;
 564         }
 565
 566         pw_type = session->pwtype;
 567         if (pw_type < __L2TP_PWTYPE_MAX)
 568                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 569                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 570
 571         if (session->deref)
 572                 session->deref(session);
 573         l2tp_session_dec_refcount(session);
 574
 575 out:
 576         return ret;
 577 }
 578
 579 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 580 {
 581         int ret = 0;
 582         struct l2tp_session *session;
 583
 584         session = l2tp_nl_session_get(info, false);
 585         if (session == NULL) {
 586                 ret = -ENODEV;
 587                 goto out;
 588         }
 589
 590         if (info->attrs[L2TP_ATTR_DEBUG])
 591                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 592
 593         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 594                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 595
 596         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 597                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 598
 599         if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 600                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 601                 l2tp_session_set_header_len(session, session->tunnel->version);
 602         }
 603
 604         if (info->attrs[L2TP_ATTR_LNS_MODE])
 605                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 606
 607         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 608                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 609
 610         if (info->attrs[L2TP_ATTR_MTU])
 611                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 612
 613         if (info->attrs[L2TP_ATTR_MRU])
 614                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 615
 616         l2tp_session_dec_refcount(session);
 617
 618 out:
 619         return ret;
 620 }
 621
 622 static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 623                                 struct l2tp_session *session)
 624 {
 625         void *hdr;
 626         struct nlattr *nest;
 627         struct l2tp_tunnel *tunnel = session->tunnel;
 628         struct sock *sk = NULL;
 629
 630         sk = tunnel->sock;
 631
 632         hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
 633         if (!hdr)
 634                 return -EMSGSIZE;
 635
 636         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 637             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 638             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 639             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 640                         session->peer_session_id) ||
 641             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 642             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 643             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 644             (session->mru &&
 645              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 646                 goto nla_put_failure;
 647
 648         if ((session->ifname[0] &&
 649              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 650             (session->cookie_len &&
 651              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 652                      &session->cookie[0])) ||
 653             (session->peer_cookie_len &&
 654              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 655                      &session->peer_cookie[0])) ||
 656             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 657             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 658             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 659 #ifdef CONFIG_XFRM
 660             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 661              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 662 #endif
 663             (session->reorder_timeout &&
 664              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
 665                 goto nla_put_failure;
 666
 667         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 668         if (nest == NULL)
 669                 goto nla_put_failure;
 670
 671         if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
 672                 atomic_long_read(&session->stats.tx_packets)) ||
 673             nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
 674                 atomic_long_read(&session->stats.tx_bytes)) ||
 675             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
 676                 atomic_long_read(&session->stats.tx_errors)) ||
 677             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
 678                 atomic_long_read(&session->stats.rx_packets)) ||
 679             nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
 680                 atomic_long_read(&session->stats.rx_bytes)) ||
 681             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 682                 atomic_long_read(&session->stats.rx_seq_discards)) ||
 683             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 684                 atomic_long_read(&session->stats.rx_oos_packets)) ||
 685             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
 686                 atomic_long_read(&session->stats.rx_errors)))
 687                 goto nla_put_failure;
 688         nla_nest_end(skb, nest);
 689
 690         return genlmsg_end(skb, hdr);
 691
 692  nla_put_failure:
 693         genlmsg_cancel(skb, hdr);
 694         return -1;
 695 }
 696
 697 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 698 {
 699         struct l2tp_session *session;
 700         struct sk_buff *msg;
 701         int ret;
 702
 703         session = l2tp_nl_session_get(info, false);
 704         if (session == NULL) {
 705                 ret = -ENODEV;
 706                 goto err;
 707         }
 708
 709         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 710         if (!msg) {
 711                 ret = -ENOMEM;
 712                 goto err_ref;
 713         }
 714
 715         ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 716                                    0, session);
 717         if (ret < 0)
 718                 goto err_ref_msg;
 719
 720         ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 721
 722         l2tp_session_dec_refcount(session);
 723
 724         return ret;
 725
 726 err_ref_msg:
 727         nlmsg_free(msg);
 728 err_ref:
 729         l2tp_session_dec_refcount(session);
 730 err:
 731         return ret;
 732 }
 733
 734 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 735 {
 736         struct net *net = sock_net(skb->sk);
 737         struct l2tp_session *session;
 738         struct l2tp_tunnel *tunnel = NULL;
 739         int ti = cb->args[0];
 740         int si = cb->args[1];
 741
 742         for (;;) {
 743                 if (tunnel == NULL) {
 744                         tunnel = l2tp_tunnel_find_nth(net, ti);
 745                         if (tunnel == NULL)
 746                                 goto out;
 747                 }
 748
 749                 session = l2tp_session_get_nth(tunnel, si, false);
 750                 if (session == NULL) {
 751                         ti++;
 752                         tunnel = NULL;
 753                         si = 0;
 754                         continue;
 755                 }
 756
 757                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 758                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 759                                          session) <= 0) {
 760                         l2tp_session_dec_refcount(session);
 761                         break;
 762                 }
 763                 l2tp_session_dec_refcount(session);
 764
 765                 si++;
 766         }
 767
 768 out:
 769         cb->args[0] = ti;
 770         cb->args[1] = si;
 771
 772         return skb->len;
 773 }
 774
 775 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 776         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 777         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 778         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 779         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 780         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 781         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 782         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 783         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 784         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 785         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 786         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 787         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 788         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 789         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 790         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 791         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 792         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 793         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 794         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 795         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 796         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 797         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 798         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 799         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 800         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 801         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 802         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 803         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 804         [L2TP_ATTR_IP6_SADDR] = {
 805                 .type = NLA_BINARY,
 806                 .len = sizeof(struct in6_addr),
 807         },
 808         [L2TP_ATTR_IP6_DADDR] = {
 809                 .type = NLA_BINARY,
 810                 .len = sizeof(struct in6_addr),
 811         },
 812         [L2TP_ATTR_IFNAME] = {
 813                 .type = NLA_NUL_STRING,
 814                 .len = IFNAMSIZ - 1,
 815         },
 816         [L2TP_ATTR_COOKIE] = {
 817                 .type = NLA_BINARY,
 818                 .len = 8,
 819         },
 820         [L2TP_ATTR_PEER_COOKIE] = {
 821                 .type = NLA_BINARY,
 822                 .len = 8,
 823         },
 824 };
 825
 826 static const struct genl_ops l2tp_nl_ops[] = {
 827         {
 828                 .cmd = L2TP_CMD_NOOP,
 829                 .doit = l2tp_nl_cmd_noop,
 830                 .policy = l2tp_nl_policy,
 831                 /* can be retrieved by unprivileged users */
 832         },
 833         {
 834                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 835                 .doit = l2tp_nl_cmd_tunnel_create,
 836                 .policy = l2tp_nl_policy,
 837                 .flags = GENL_ADMIN_PERM,
 838         },
 839         {
 840                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 841                 .doit = l2tp_nl_cmd_tunnel_delete,
 842                 .policy = l2tp_nl_policy,
 843                 .flags = GENL_ADMIN_PERM,
 844         },
 845         {
 846                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 847                 .doit = l2tp_nl_cmd_tunnel_modify,
 848                 .policy = l2tp_nl_policy,
 849                 .flags = GENL_ADMIN_PERM,
 850         },
 851         {
 852                 .cmd = L2TP_CMD_TUNNEL_GET,
 853                 .doit = l2tp_nl_cmd_tunnel_get,
 854                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 855                 .policy = l2tp_nl_policy,
 856                 .flags = GENL_ADMIN_PERM,
 857         },
 858         {
 859                 .cmd = L2TP_CMD_SESSION_CREATE,
 860                 .doit = l2tp_nl_cmd_session_create,
 861                 .policy = l2tp_nl_policy,
 862                 .flags = GENL_ADMIN_PERM,
 863         },
 864         {
 865                 .cmd = L2TP_CMD_SESSION_DELETE,
 866                 .doit = l2tp_nl_cmd_session_delete,
 867                 .policy = l2tp_nl_policy,
 868                 .flags = GENL_ADMIN_PERM,
 869         },
 870         {
 871                 .cmd = L2TP_CMD_SESSION_MODIFY,
 872                 .doit = l2tp_nl_cmd_session_modify,
 873                 .policy = l2tp_nl_policy,
 874                 .flags = GENL_ADMIN_PERM,
 875         },
 876         {
 877                 .cmd = L2TP_CMD_SESSION_GET,
 878                 .doit = l2tp_nl_cmd_session_get,
 879                 .dumpit = l2tp_nl_cmd_session_dump,
 880                 .policy = l2tp_nl_policy,
 881                 .flags = GENL_ADMIN_PERM,
 882         },
 883 };
 884
 885 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 886 {
 887         int ret;
 888
 889         ret = -EINVAL;
 890         if (pw_type >= __L2TP_PWTYPE_MAX)
 891                 goto err;
 892
 893         genl_lock();
 894         ret = -EBUSY;
 895         if (l2tp_nl_cmd_ops[pw_type])
 896                 goto out;
 897
 898         l2tp_nl_cmd_ops[pw_type] = ops;
 899         ret = 0;
 900
 901 out:
 902         genl_unlock();
 903 err:
 904         return ret;
 905 }
 906 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
 907
 908 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
 909 {
 910         if (pw_type < __L2TP_PWTYPE_MAX) {
 911                 genl_lock();
 912                 l2tp_nl_cmd_ops[pw_type] = NULL;
 913                 genl_unlock();
 914         }
 915 }
 916 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
 917
 918 static int l2tp_nl_init(void)
 919 {
 920         pr_info("L2TP netlink interface\n");
 921         return genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops);
 922 }
 923
 924 static void l2tp_nl_cleanup(void)
 925 {
 926         genl_unregister_family(&l2tp_nl_family);
 927 }
 928
 929 module_init(l2tp_nl_init);
 930 module_exit(l2tp_nl_cleanup);
 931
 932 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 933 MODULE_DESCRIPTION("L2TP netlink");
 934 MODULE_LICENSE("GPL");
 935 MODULE_VERSION("1.0");
 936 MODULE_ALIAS_GENL_FAMILY("l2tp");