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 };
  41
  42 /* Accessed under genl lock */
  43 static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
  44
  45 static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info)
  46 {
  47         u32 tunnel_id;
  48         u32 session_id;
  49         char *ifname;
  50         struct l2tp_tunnel *tunnel;
  51         struct l2tp_session *session = NULL;
  52         struct net *net = genl_info_net(info);
  53
  54         if (info->attrs[L2TP_ATTR_IFNAME]) {
  55                 ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
  56                 session = l2tp_session_find_by_ifname(net, ifname);
  57         } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) &&
  58                    (info->attrs[L2TP_ATTR_CONN_ID])) {
  59                 tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
  60                 session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
  61                 tunnel = l2tp_tunnel_find(net, tunnel_id);
  62                 if (tunnel)
  63                         session = l2tp_session_find(net, tunnel, session_id);
  64         }
  65
  66         return session;
  67 }
  68
  69 static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  70 {
  71         struct sk_buff *msg;
  72         void *hdr;
  73         int ret = -ENOBUFS;
  74
  75         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  76         if (!msg) {
  77                 ret = -ENOMEM;
  78                 goto out;
  79         }
  80
  81         hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq,
  82                           &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  83         if (IS_ERR(hdr)) {
  84                 ret = PTR_ERR(hdr);
  85                 goto err_out;
  86         }
  87
  88         genlmsg_end(msg, hdr);
  89
  90         return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
  91
  92 err_out:
  93         nlmsg_free(msg);
  94
  95 out:
  96         return ret;
  97 }
  98
  99 static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 100 {
 101         u32 tunnel_id;
 102         u32 peer_tunnel_id;
 103         int proto_version;
 104         int fd;
 105         int ret = 0;
 106         struct l2tp_tunnel_cfg cfg = { 0, };
 107         struct l2tp_tunnel *tunnel;
 108         struct net *net = genl_info_net(info);
 109
 110         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 111                 ret = -EINVAL;
 112                 goto out;
 113         }
 114         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 115
 116         if (!info->attrs[L2TP_ATTR_PEER_CONN_ID]) {
 117                 ret = -EINVAL;
 118                 goto out;
 119         }
 120         peer_tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_CONN_ID]);
 121
 122         if (!info->attrs[L2TP_ATTR_PROTO_VERSION]) {
 123                 ret = -EINVAL;
 124                 goto out;
 125         }
 126         proto_version = nla_get_u8(info->attrs[L2TP_ATTR_PROTO_VERSION]);
 127
 128         if (!info->attrs[L2TP_ATTR_ENCAP_TYPE]) {
 129                 ret = -EINVAL;
 130                 goto out;
 131         }
 132         cfg.encap = nla_get_u16(info->attrs[L2TP_ATTR_ENCAP_TYPE]);
 133
 134         fd = -1;
 135         if (info->attrs[L2TP_ATTR_FD]) {
 136                 fd = nla_get_u32(info->attrs[L2TP_ATTR_FD]);
 137         } else {
 138 #if IS_ENABLED(CONFIG_IPV6)
 139                 if (info->attrs[L2TP_ATTR_IP6_SADDR] &&
 140                     info->attrs[L2TP_ATTR_IP6_DADDR]) {
 141                         cfg.local_ip6 = nla_data(
 142                                 info->attrs[L2TP_ATTR_IP6_SADDR]);
 143                         cfg.peer_ip6 = nla_data(
 144                                 info->attrs[L2TP_ATTR_IP6_DADDR]);
 145                 } else
 146 #endif
 147                 if (info->attrs[L2TP_ATTR_IP_SADDR] &&
 148                     info->attrs[L2TP_ATTR_IP_DADDR]) {
 149                         cfg.local_ip.s_addr = nla_get_be32(
 150                                 info->attrs[L2TP_ATTR_IP_SADDR]);
 151                         cfg.peer_ip.s_addr = nla_get_be32(
 152                                 info->attrs[L2TP_ATTR_IP_DADDR]);
 153                 } else {
 154                         ret = -EINVAL;
 155                         goto out;
 156                 }
 157                 if (info->attrs[L2TP_ATTR_UDP_SPORT])
 158                         cfg.local_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_SPORT]);
 159                 if (info->attrs[L2TP_ATTR_UDP_DPORT])
 160                         cfg.peer_udp_port = nla_get_u16(info->attrs[L2TP_ATTR_UDP_DPORT]);
 161                 if (info->attrs[L2TP_ATTR_UDP_CSUM])
 162                         cfg.use_udp_checksums = nla_get_flag(info->attrs[L2TP_ATTR_UDP_CSUM]);
 163         }
 164
 165         if (info->attrs[L2TP_ATTR_DEBUG])
 166                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 167
 168         tunnel = l2tp_tunnel_find(net, tunnel_id);
 169         if (tunnel != NULL) {
 170                 ret = -EEXIST;
 171                 goto out;
 172         }
 173
 174         ret = -EINVAL;
 175         switch (cfg.encap) {
 176         case L2TP_ENCAPTYPE_UDP:
 177         case L2TP_ENCAPTYPE_IP:
 178                 ret = l2tp_tunnel_create(net, fd, proto_version, tunnel_id,
 179                                          peer_tunnel_id, &cfg, &tunnel);
 180                 break;
 181         }
 182
 183 out:
 184         return ret;
 185 }
 186
 187 static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 188 {
 189         struct l2tp_tunnel *tunnel;
 190         u32 tunnel_id;
 191         int ret = 0;
 192         struct net *net = genl_info_net(info);
 193
 194         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 195                 ret = -EINVAL;
 196                 goto out;
 197         }
 198         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 199
 200         tunnel = l2tp_tunnel_find(net, tunnel_id);
 201         if (tunnel == NULL) {
 202                 ret = -ENODEV;
 203                 goto out;
 204         }
 205
 206         (void) l2tp_tunnel_delete(tunnel);
 207
 208 out:
 209         return ret;
 210 }
 211
 212 static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 213 {
 214         struct l2tp_tunnel *tunnel;
 215         u32 tunnel_id;
 216         int ret = 0;
 217         struct net *net = genl_info_net(info);
 218
 219         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 220                 ret = -EINVAL;
 221                 goto out;
 222         }
 223         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 224
 225         tunnel = l2tp_tunnel_find(net, tunnel_id);
 226         if (tunnel == NULL) {
 227                 ret = -ENODEV;
 228                 goto out;
 229         }
 230
 231         if (info->attrs[L2TP_ATTR_DEBUG])
 232                 tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 233
 234 out:
 235         return ret;
 236 }
 237
 238 static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
 239                                struct l2tp_tunnel *tunnel)
 240 {
 241         void *hdr;
 242         struct nlattr *nest;
 243         struct sock *sk = NULL;
 244         struct inet_sock *inet;
 245 #if IS_ENABLED(CONFIG_IPV6)
 246         struct ipv6_pinfo *np = NULL;
 247 #endif
 248         struct l2tp_stats stats;
 249         unsigned int start;
 250
 251         hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags,
 252                           L2TP_CMD_TUNNEL_GET);
 253         if (IS_ERR(hdr))
 254                 return PTR_ERR(hdr);
 255
 256         if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 257             nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 258             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 259             nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
 260             nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 261                 goto nla_put_failure;
 262
 263         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 264         if (nest == NULL)
 265                 goto nla_put_failure;
 266
 267         do {
 268                 start = u64_stats_fetch_begin(&tunnel->stats.syncp);
 269                 stats.tx_packets = tunnel->stats.tx_packets;
 270                 stats.tx_bytes = tunnel->stats.tx_bytes;
 271                 stats.tx_errors = tunnel->stats.tx_errors;
 272                 stats.rx_packets = tunnel->stats.rx_packets;
 273                 stats.rx_bytes = tunnel->stats.rx_bytes;
 274                 stats.rx_errors = tunnel->stats.rx_errors;
 275                 stats.rx_seq_discards = tunnel->stats.rx_seq_discards;
 276                 stats.rx_oos_packets = tunnel->stats.rx_oos_packets;
 277         } while (u64_stats_fetch_retry(&tunnel->stats.syncp, start));
 278
 279         if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
 280             nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
 281             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
 282             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
 283             nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
 284             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 285                         stats.rx_seq_discards) ||
 286             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 287                         stats.rx_oos_packets) ||
 288             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
 289                 goto nla_put_failure;
 290         nla_nest_end(skb, nest);
 291
 292         sk = tunnel->sock;
 293         if (!sk)
 294                 goto out;
 295
 296 #if IS_ENABLED(CONFIG_IPV6)
 297         if (sk->sk_family == AF_INET6)
 298                 np = inet6_sk(sk);
 299 #endif
 300
 301         inet = inet_sk(sk);
 302
 303         switch (tunnel->encap) {
 304         case L2TP_ENCAPTYPE_UDP:
 305                 if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 306                     nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)) ||
 307                     nla_put_u8(skb, L2TP_ATTR_UDP_CSUM,
 308                                (sk->sk_no_check != UDP_CSUM_NOXMIT)))
 309                         goto nla_put_failure;
 310                 /* NOBREAK */
 311         case L2TP_ENCAPTYPE_IP:
 312 #if IS_ENABLED(CONFIG_IPV6)
 313                 if (np) {
 314                         if (nla_put(skb, L2TP_ATTR_IP6_SADDR, sizeof(np->saddr),
 315                                     &np->saddr) ||
 316                             nla_put(skb, L2TP_ATTR_IP6_DADDR, sizeof(np->daddr),
 317                                     &np->daddr))
 318                                 goto nla_put_failure;
 319                 } else
 320 #endif
 321                 if (nla_put_be32(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
 322                     nla_put_be32(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
 323                         goto nla_put_failure;
 324                 break;
 325         }
 326
 327 out:
 328         return genlmsg_end(skb, hdr);
 329
 330 nla_put_failure:
 331         genlmsg_cancel(skb, hdr);
 332         return -1;
 333 }
 334
 335 static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 336 {
 337         struct l2tp_tunnel *tunnel;
 338         struct sk_buff *msg;
 339         u32 tunnel_id;
 340         int ret = -ENOBUFS;
 341         struct net *net = genl_info_net(info);
 342
 343         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 344                 ret = -EINVAL;
 345                 goto out;
 346         }
 347
 348         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 349
 350         tunnel = l2tp_tunnel_find(net, tunnel_id);
 351         if (tunnel == NULL) {
 352                 ret = -ENODEV;
 353                 goto out;
 354         }
 355
 356         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 357         if (!msg) {
 358                 ret = -ENOMEM;
 359                 goto out;
 360         }
 361
 362         ret = l2tp_nl_tunnel_send(msg, info->snd_pid, info->snd_seq,
 363                                   NLM_F_ACK, tunnel);
 364         if (ret < 0)
 365                 goto err_out;
 366
 367         return genlmsg_unicast(net, msg, info->snd_pid);
 368
 369 err_out:
 370         nlmsg_free(msg);
 371
 372 out:
 373         return ret;
 374 }
 375
 376 static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 377 {
 378         int ti = cb->args[0];
 379         struct l2tp_tunnel *tunnel;
 380         struct net *net = sock_net(skb->sk);
 381
 382         for (;;) {
 383                 tunnel = l2tp_tunnel_find_nth(net, ti);
 384                 if (tunnel == NULL)
 385                         goto out;
 386
 387                 if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).pid,
 388                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 389                                         tunnel) <= 0)
 390                         goto out;
 391
 392                 ti++;
 393         }
 394
 395 out:
 396         cb->args[0] = ti;
 397
 398         return skb->len;
 399 }
 400
 401 static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 402 {
 403         u32 tunnel_id = 0;
 404         u32 session_id;
 405         u32 peer_session_id;
 406         int ret = 0;
 407         struct l2tp_tunnel *tunnel;
 408         struct l2tp_session *session;
 409         struct l2tp_session_cfg cfg = { 0, };
 410         struct net *net = genl_info_net(info);
 411
 412         if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 413                 ret = -EINVAL;
 414                 goto out;
 415         }
 416         tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 417         tunnel = l2tp_tunnel_find(net, tunnel_id);
 418         if (!tunnel) {
 419                 ret = -ENODEV;
 420                 goto out;
 421         }
 422
 423         if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 424                 ret = -EINVAL;
 425                 goto out;
 426         }
 427         session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 428         session = l2tp_session_find(net, tunnel, session_id);
 429         if (session) {
 430                 ret = -EEXIST;
 431                 goto out;
 432         }
 433
 434         if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 435                 ret = -EINVAL;
 436                 goto out;
 437         }
 438         peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 439
 440         if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 441                 ret = -EINVAL;
 442                 goto out;
 443         }
 444         cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 445         if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 446                 ret = -EINVAL;
 447                 goto out;
 448         }
 449
 450         if (tunnel->version > 2) {
 451                 if (info->attrs[L2TP_ATTR_OFFSET])
 452                         cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
 453
 454                 if (info->attrs[L2TP_ATTR_DATA_SEQ])
 455                         cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 456
 457                 cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 458                 if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
 459                         cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 460
 461                 cfg.l2specific_len = 4;
 462                 if (info->attrs[L2TP_ATTR_L2SPEC_LEN])
 463                         cfg.l2specific_len = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_LEN]);
 464
 465                 if (info->attrs[L2TP_ATTR_COOKIE]) {
 466                         u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 467                         if (len > 8) {
 468                                 ret = -EINVAL;
 469                                 goto out;
 470                         }
 471                         cfg.cookie_len = len;
 472                         memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 473                 }
 474                 if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 475                         u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 476                         if (len > 8) {
 477                                 ret = -EINVAL;
 478                                 goto out;
 479                         }
 480                         cfg.peer_cookie_len = len;
 481                         memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 482                 }
 483                 if (info->attrs[L2TP_ATTR_IFNAME])
 484                         cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 485
 486                 if (info->attrs[L2TP_ATTR_VLAN_ID])
 487                         cfg.vlan_id = nla_get_u16(info->attrs[L2TP_ATTR_VLAN_ID]);
 488         }
 489
 490         if (info->attrs[L2TP_ATTR_DEBUG])
 491                 cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 492
 493         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 494                 cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 495
 496         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 497                 cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 498
 499         if (info->attrs[L2TP_ATTR_LNS_MODE])
 500                 cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 501
 502         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 503                 cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 504
 505         if (info->attrs[L2TP_ATTR_MTU])
 506                 cfg.mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 507
 508         if (info->attrs[L2TP_ATTR_MRU])
 509                 cfg.mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 510
 511         if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) ||
 512             (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) {
 513                 ret = -EPROTONOSUPPORT;
 514                 goto out;
 515         }
 516
 517         /* Check that pseudowire-specific params are present */
 518         switch (cfg.pw_type) {
 519         case L2TP_PWTYPE_NONE:
 520                 break;
 521         case L2TP_PWTYPE_ETH_VLAN:
 522                 if (!info->attrs[L2TP_ATTR_VLAN_ID]) {
 523                         ret = -EINVAL;
 524                         goto out;
 525                 }
 526                 break;
 527         case L2TP_PWTYPE_ETH:
 528                 break;
 529         case L2TP_PWTYPE_PPP:
 530         case L2TP_PWTYPE_PPP_AC:
 531                 break;
 532         case L2TP_PWTYPE_IP:
 533         default:
 534                 ret = -EPROTONOSUPPORT;
 535                 break;
 536         }
 537
 538         ret = -EPROTONOSUPPORT;
 539         if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create)
 540                 ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id,
 541                         session_id, peer_session_id, &cfg);
 542
 543 out:
 544         return ret;
 545 }
 546
 547 static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 548 {
 549         int ret = 0;
 550         struct l2tp_session *session;
 551         u16 pw_type;
 552
 553         session = l2tp_nl_session_find(info);
 554         if (session == NULL) {
 555                 ret = -ENODEV;
 556                 goto out;
 557         }
 558
 559         pw_type = session->pwtype;
 560         if (pw_type < __L2TP_PWTYPE_MAX)
 561                 if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 562                         ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session);
 563
 564 out:
 565         return ret;
 566 }
 567
 568 static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 569 {
 570         int ret = 0;
 571         struct l2tp_session *session;
 572
 573         session = l2tp_nl_session_find(info);
 574         if (session == NULL) {
 575                 ret = -ENODEV;
 576                 goto out;
 577         }
 578
 579         if (info->attrs[L2TP_ATTR_DEBUG])
 580                 session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
 581
 582         if (info->attrs[L2TP_ATTR_DATA_SEQ])
 583                 session->data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
 584
 585         if (info->attrs[L2TP_ATTR_RECV_SEQ])
 586                 session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 587
 588         if (info->attrs[L2TP_ATTR_SEND_SEQ])
 589                 session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 590
 591         if (info->attrs[L2TP_ATTR_LNS_MODE])
 592                 session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 593
 594         if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 595                 session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 596
 597         if (info->attrs[L2TP_ATTR_MTU])
 598                 session->mtu = nla_get_u16(info->attrs[L2TP_ATTR_MTU]);
 599
 600         if (info->attrs[L2TP_ATTR_MRU])
 601                 session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]);
 602
 603 out:
 604         return ret;
 605 }
 606
 607 static int l2tp_nl_session_send(struct sk_buff *skb, u32 pid, u32 seq, int flags,
 608                                 struct l2tp_session *session)
 609 {
 610         void *hdr;
 611         struct nlattr *nest;
 612         struct l2tp_tunnel *tunnel = session->tunnel;
 613         struct sock *sk = NULL;
 614         struct l2tp_stats stats;
 615         unsigned int start;
 616
 617         sk = tunnel->sock;
 618
 619         hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET);
 620         if (IS_ERR(hdr))
 621                 return PTR_ERR(hdr);
 622
 623         if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 624             nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 625             nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 626             nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID,
 627                         session->peer_session_id) ||
 628             nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
 629             nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype) ||
 630             nla_put_u16(skb, L2TP_ATTR_MTU, session->mtu) ||
 631             (session->mru &&
 632              nla_put_u16(skb, L2TP_ATTR_MRU, session->mru)))
 633                 goto nla_put_failure;
 634
 635         if ((session->ifname && session->ifname[0] &&
 636              nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 637             (session->cookie_len &&
 638              nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len,
 639                      &session->cookie[0])) ||
 640             (session->peer_cookie_len &&
 641              nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len,
 642                      &session->peer_cookie[0])) ||
 643             nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 644             nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 645             nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 646 #ifdef CONFIG_XFRM
 647             (((sk) && (sk->sk_policy[0] || sk->sk_policy[1])) &&
 648              nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 649 #endif
 650             (session->reorder_timeout &&
 651              nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout)))
 652                 goto nla_put_failure;
 653
 654         nest = nla_nest_start(skb, L2TP_ATTR_STATS);
 655         if (nest == NULL)
 656                 goto nla_put_failure;
 657
 658         do {
 659                 start = u64_stats_fetch_begin(&session->stats.syncp);
 660                 stats.tx_packets = session->stats.tx_packets;
 661                 stats.tx_bytes = session->stats.tx_bytes;
 662                 stats.tx_errors = session->stats.tx_errors;
 663                 stats.rx_packets = session->stats.rx_packets;
 664                 stats.rx_bytes = session->stats.rx_bytes;
 665                 stats.rx_errors = session->stats.rx_errors;
 666                 stats.rx_seq_discards = session->stats.rx_seq_discards;
 667                 stats.rx_oos_packets = session->stats.rx_oos_packets;
 668         } while (u64_stats_fetch_retry(&session->stats.syncp, start));
 669
 670         if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
 671             nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
 672             nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
 673             nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
 674             nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
 675             nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 676                         stats.rx_seq_discards) ||
 677             nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
 678                         stats.rx_oos_packets) ||
 679             nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
 680                 goto nla_put_failure;
 681         nla_nest_end(skb, nest);
 682
 683         return genlmsg_end(skb, hdr);
 684
 685  nla_put_failure:
 686         genlmsg_cancel(skb, hdr);
 687         return -1;
 688 }
 689
 690 static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 691 {
 692         struct l2tp_session *session;
 693         struct sk_buff *msg;
 694         int ret;
 695
 696         session = l2tp_nl_session_find(info);
 697         if (session == NULL) {
 698                 ret = -ENODEV;
 699                 goto out;
 700         }
 701
 702         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 703         if (!msg) {
 704                 ret = -ENOMEM;
 705                 goto out;
 706         }
 707
 708         ret = l2tp_nl_session_send(msg, info->snd_pid, info->snd_seq,
 709                                    0, session);
 710         if (ret < 0)
 711                 goto err_out;
 712
 713         return genlmsg_unicast(genl_info_net(info), msg, info->snd_pid);
 714
 715 err_out:
 716         nlmsg_free(msg);
 717
 718 out:
 719         return ret;
 720 }
 721
 722 static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 723 {
 724         struct net *net = sock_net(skb->sk);
 725         struct l2tp_session *session;
 726         struct l2tp_tunnel *tunnel = NULL;
 727         int ti = cb->args[0];
 728         int si = cb->args[1];
 729
 730         for (;;) {
 731                 if (tunnel == NULL) {
 732                         tunnel = l2tp_tunnel_find_nth(net, ti);
 733                         if (tunnel == NULL)
 734                                 goto out;
 735                 }
 736
 737                 session = l2tp_session_find_nth(tunnel, si);
 738                 if (session == NULL) {
 739                         ti++;
 740                         tunnel = NULL;
 741                         si = 0;
 742                         continue;
 743                 }
 744
 745                 if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).pid,
 746                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
 747                                          session) <= 0)
 748                         break;
 749
 750                 si++;
 751         }
 752
 753 out:
 754         cb->args[0] = ti;
 755         cb->args[1] = si;
 756
 757         return skb->len;
 758 }
 759
 760 static struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 761         [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 762         [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 763         [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 764         [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 765         [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 766         [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 767         [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 768         [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 769         [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 770         [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 771         [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 772         [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 773         [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 774         [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 775         [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 776         [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 777         [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 778         [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 779         [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 780         [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 781         [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 782         [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 783         [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 784         [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 785         [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 786         [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 787         [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 788         [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 789         [L2TP_ATTR_IP6_SADDR] = {
 790                 .type = NLA_BINARY,
 791                 .len = sizeof(struct in6_addr),
 792         },
 793         [L2TP_ATTR_IP6_DADDR] = {
 794                 .type = NLA_BINARY,
 795                 .len = sizeof(struct in6_addr),
 796         },
 797         [L2TP_ATTR_IFNAME] = {
 798                 .type = NLA_NUL_STRING,
 799                 .len = IFNAMSIZ - 1,
 800         },
 801         [L2TP_ATTR_COOKIE] = {
 802                 .type = NLA_BINARY,
 803                 .len = 8,
 804         },
 805         [L2TP_ATTR_PEER_COOKIE] = {
 806                 .type = NLA_BINARY,
 807                 .len = 8,
 808         },
 809 };
 810
 811 static struct genl_ops l2tp_nl_ops[] = {
 812         {
 813                 .cmd = L2TP_CMD_NOOP,
 814                 .doit = l2tp_nl_cmd_noop,
 815                 .policy = l2tp_nl_policy,
 816                 /* can be retrieved by unprivileged users */
 817         },
 818         {
 819                 .cmd = L2TP_CMD_TUNNEL_CREATE,
 820                 .doit = l2tp_nl_cmd_tunnel_create,
 821                 .policy = l2tp_nl_policy,
 822                 .flags = GENL_ADMIN_PERM,
 823         },
 824         {
 825                 .cmd = L2TP_CMD_TUNNEL_DELETE,
 826                 .doit = l2tp_nl_cmd_tunnel_delete,
 827                 .policy = l2tp_nl_policy,
 828                 .flags = GENL_ADMIN_PERM,
 829         },
 830         {
 831                 .cmd = L2TP_CMD_TUNNEL_MODIFY,
 832                 .doit = l2tp_nl_cmd_tunnel_modify,
 833                 .policy = l2tp_nl_policy,
 834                 .flags = GENL_ADMIN_PERM,
 835         },
 836         {
 837                 .cmd = L2TP_CMD_TUNNEL_GET,
 838                 .doit = l2tp_nl_cmd_tunnel_get,
 839                 .dumpit = l2tp_nl_cmd_tunnel_dump,
 840                 .policy = l2tp_nl_policy,
 841                 .flags = GENL_ADMIN_PERM,
 842         },
 843         {
 844                 .cmd = L2TP_CMD_SESSION_CREATE,
 845                 .doit = l2tp_nl_cmd_session_create,
 846                 .policy = l2tp_nl_policy,
 847                 .flags = GENL_ADMIN_PERM,
 848         },
 849         {
 850                 .cmd = L2TP_CMD_SESSION_DELETE,
 851                 .doit = l2tp_nl_cmd_session_delete,
 852                 .policy = l2tp_nl_policy,
 853                 .flags = GENL_ADMIN_PERM,
 854         },
 855         {
 856                 .cmd = L2TP_CMD_SESSION_MODIFY,
 857                 .doit = l2tp_nl_cmd_session_modify,
 858                 .policy = l2tp_nl_policy,
 859                 .flags = GENL_ADMIN_PERM,
 860         },
 861         {
 862                 .cmd = L2TP_CMD_SESSION_GET,
 863                 .doit = l2tp_nl_cmd_session_get,
 864                 .dumpit = l2tp_nl_cmd_session_dump,
 865                 .policy = l2tp_nl_policy,
 866                 .flags = GENL_ADMIN_PERM,
 867         },
 868 };
 869
 870 int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 871 {
 872         int ret;
 873
 874         ret = -EINVAL;
 875         if (pw_type >= __L2TP_PWTYPE_MAX)
 876                 goto err;
 877
 878         genl_lock();
 879         ret = -EBUSY;
 880         if (l2tp_nl_cmd_ops[pw_type])
 881                 goto out;
 882
 883         l2tp_nl_cmd_ops[pw_type] = ops;
 884         ret = 0;
 885
 886 out:
 887         genl_unlock();
 888 err:
 889         return ret;
 890 }
 891 EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
 892
 893 void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
 894 {
 895         if (pw_type < __L2TP_PWTYPE_MAX) {
 896                 genl_lock();
 897                 l2tp_nl_cmd_ops[pw_type] = NULL;
 898                 genl_unlock();
 899         }
 900 }
 901 EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
 902
 903 static int l2tp_nl_init(void)
 904 {
 905         int err;
 906
 907         pr_info("L2TP netlink interface\n");
 908         err = genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops,
 909                                             ARRAY_SIZE(l2tp_nl_ops));
 910
 911         return err;
 912 }
 913
 914 static void l2tp_nl_cleanup(void)
 915 {
 916         genl_unregister_family(&l2tp_nl_family);
 917 }
 918
 919 module_init(l2tp_nl_init);
 920 module_exit(l2tp_nl_cleanup);
 921
 922 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 923 MODULE_DESCRIPTION("L2TP netlink");
 924 MODULE_LICENSE("GPL");
 925 MODULE_VERSION("1.0");
 926 MODULE_ALIAS_GENL_FAMILY("l2tp");