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