linux/net/l2tp/l2tp_netlink.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   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
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <net/sock.h>
  16#include <net/genetlink.h>
  17#include <net/udp.h>
  18#include <linux/in.h>
  19#include <linux/udp.h>
  20#include <linux/socket.h>
  21#include <linux/module.h>
  22#include <linux/list.h>
  23#include <net/net_namespace.h>
  24
  25#include <linux/l2tp.h>
  26
  27#include "l2tp_core.h"
  28
  29static struct genl_family l2tp_nl_family;
  30
  31static const struct genl_multicast_group l2tp_multicast_group[] = {
  32        {
  33                .name = L2TP_GENL_MCGROUP,
  34        },
  35};
  36
  37static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq,
  38                               int flags, struct l2tp_tunnel *tunnel, u8 cmd);
  39static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq,
  40                                int flags, struct l2tp_session *session,
  41                                u8 cmd);
  42
  43/* Accessed under genl lock */
  44static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX];
  45
  46static struct l2tp_session *l2tp_nl_session_get(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_get_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_get(net, tunnel_id);
  63                if (tunnel) {
  64                        session = l2tp_tunnel_get_session(tunnel, session_id);
  65                        l2tp_tunnel_dec_refcount(tunnel);
  66                }
  67        }
  68
  69        return session;
  70}
  71
  72static int l2tp_nl_cmd_noop(struct sk_buff *skb, struct genl_info *info)
  73{
  74        struct sk_buff *msg;
  75        void *hdr;
  76        int ret = -ENOBUFS;
  77
  78        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  79        if (!msg) {
  80                ret = -ENOMEM;
  81                goto out;
  82        }
  83
  84        hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
  85                          &l2tp_nl_family, 0, L2TP_CMD_NOOP);
  86        if (!hdr) {
  87                ret = -EMSGSIZE;
  88                goto err_out;
  89        }
  90
  91        genlmsg_end(msg, hdr);
  92
  93        return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
  94
  95err_out:
  96        nlmsg_free(msg);
  97
  98out:
  99        return ret;
 100}
 101
 102static int l2tp_tunnel_notify(struct genl_family *family,
 103                              struct genl_info *info,
 104                              struct l2tp_tunnel *tunnel,
 105                              u8 cmd)
 106{
 107        struct sk_buff *msg;
 108        int ret;
 109
 110        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 111        if (!msg)
 112                return -ENOMEM;
 113
 114        ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 115                                  NLM_F_ACK, tunnel, cmd);
 116
 117        if (ret >= 0) {
 118                ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 119                /* We don't care if no one is listening */
 120                if (ret == -ESRCH)
 121                        ret = 0;
 122                return ret;
 123        }
 124
 125        nlmsg_free(msg);
 126
 127        return ret;
 128}
 129
 130static int l2tp_session_notify(struct genl_family *family,
 131                               struct genl_info *info,
 132                               struct l2tp_session *session,
 133                               u8 cmd)
 134{
 135        struct sk_buff *msg;
 136        int ret;
 137
 138        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 139        if (!msg)
 140                return -ENOMEM;
 141
 142        ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 143                                   NLM_F_ACK, session, cmd);
 144
 145        if (ret >= 0) {
 146                ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
 147                /* We don't care if no one is listening */
 148                if (ret == -ESRCH)
 149                        ret = 0;
 150                return ret;
 151        }
 152
 153        nlmsg_free(msg);
 154
 155        return ret;
 156}
 157
 158static int l2tp_nl_cmd_tunnel_create_get_addr(struct nlattr **attrs, struct l2tp_tunnel_cfg *cfg)
 159{
 160        if (attrs[L2TP_ATTR_UDP_SPORT])
 161                cfg->local_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_SPORT]);
 162        if (attrs[L2TP_ATTR_UDP_DPORT])
 163                cfg->peer_udp_port = nla_get_u16(attrs[L2TP_ATTR_UDP_DPORT]);
 164        cfg->use_udp_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_CSUM]);
 165
 166        /* Must have either AF_INET or AF_INET6 address for source and destination */
 167#if IS_ENABLED(CONFIG_IPV6)
 168        if (attrs[L2TP_ATTR_IP6_SADDR] && attrs[L2TP_ATTR_IP6_DADDR]) {
 169                cfg->local_ip6 = nla_data(attrs[L2TP_ATTR_IP6_SADDR]);
 170                cfg->peer_ip6 = nla_data(attrs[L2TP_ATTR_IP6_DADDR]);
 171                cfg->udp6_zero_tx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX]);
 172                cfg->udp6_zero_rx_checksums = nla_get_flag(attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX]);
 173                return 0;
 174        }
 175#endif
 176        if (attrs[L2TP_ATTR_IP_SADDR] && attrs[L2TP_ATTR_IP_DADDR]) {
 177                cfg->local_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_SADDR]);
 178                cfg->peer_ip.s_addr = nla_get_in_addr(attrs[L2TP_ATTR_IP_DADDR]);
 179                return 0;
 180        }
 181        return -EINVAL;
 182}
 183
 184static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info)
 185{
 186        u32 tunnel_id;
 187        u32 peer_tunnel_id;
 188        int proto_version;
 189        int fd = -1;
 190        int ret = 0;
 191        struct l2tp_tunnel_cfg cfg = { 0, };
 192        struct l2tp_tunnel *tunnel;
 193        struct net *net = genl_info_net(info);
 194        struct nlattr **attrs = info->attrs;
 195
 196        if (!attrs[L2TP_ATTR_CONN_ID]) {
 197                ret = -EINVAL;
 198                goto out;
 199        }
 200        tunnel_id = nla_get_u32(attrs[L2TP_ATTR_CONN_ID]);
 201
 202        if (!attrs[L2TP_ATTR_PEER_CONN_ID]) {
 203                ret = -EINVAL;
 204                goto out;
 205        }
 206        peer_tunnel_id = nla_get_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
 207
 208        if (!attrs[L2TP_ATTR_PROTO_VERSION]) {
 209                ret = -EINVAL;
 210                goto out;
 211        }
 212        proto_version = nla_get_u8(attrs[L2TP_ATTR_PROTO_VERSION]);
 213
 214        if (!attrs[L2TP_ATTR_ENCAP_TYPE]) {
 215                ret = -EINVAL;
 216                goto out;
 217        }
 218        cfg.encap = nla_get_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
 219
 220        /* Managed tunnels take the tunnel socket from userspace.
 221         * Unmanaged tunnels must call out the source and destination addresses
 222         * for the kernel to create the tunnel socket itself.
 223         */
 224        if (attrs[L2TP_ATTR_FD]) {
 225                fd = nla_get_u32(attrs[L2TP_ATTR_FD]);
 226        } else {
 227                ret = l2tp_nl_cmd_tunnel_create_get_addr(attrs, &cfg);
 228                if (ret < 0)
 229                        goto out;
 230        }
 231
 232        ret = -EINVAL;
 233        switch (cfg.encap) {
 234        case L2TP_ENCAPTYPE_UDP:
 235        case L2TP_ENCAPTYPE_IP:
 236                ret = l2tp_tunnel_create(fd, proto_version, tunnel_id,
 237                                         peer_tunnel_id, &cfg, &tunnel);
 238                break;
 239        }
 240
 241        if (ret < 0)
 242                goto out;
 243
 244        l2tp_tunnel_inc_refcount(tunnel);
 245        ret = l2tp_tunnel_register(tunnel, net, &cfg);
 246        if (ret < 0) {
 247                kfree(tunnel);
 248                goto out;
 249        }
 250        ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
 251                                 L2TP_CMD_TUNNEL_CREATE);
 252        l2tp_tunnel_dec_refcount(tunnel);
 253
 254out:
 255        return ret;
 256}
 257
 258static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info)
 259{
 260        struct l2tp_tunnel *tunnel;
 261        u32 tunnel_id;
 262        int ret = 0;
 263        struct net *net = genl_info_net(info);
 264
 265        if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 266                ret = -EINVAL;
 267                goto out;
 268        }
 269        tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 270
 271        tunnel = l2tp_tunnel_get(net, tunnel_id);
 272        if (!tunnel) {
 273                ret = -ENODEV;
 274                goto out;
 275        }
 276
 277        l2tp_tunnel_notify(&l2tp_nl_family, info,
 278                           tunnel, L2TP_CMD_TUNNEL_DELETE);
 279
 280        l2tp_tunnel_delete(tunnel);
 281
 282        l2tp_tunnel_dec_refcount(tunnel);
 283
 284out:
 285        return ret;
 286}
 287
 288static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info)
 289{
 290        struct l2tp_tunnel *tunnel;
 291        u32 tunnel_id;
 292        int ret = 0;
 293        struct net *net = genl_info_net(info);
 294
 295        if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 296                ret = -EINVAL;
 297                goto out;
 298        }
 299        tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 300
 301        tunnel = l2tp_tunnel_get(net, tunnel_id);
 302        if (!tunnel) {
 303                ret = -ENODEV;
 304                goto out;
 305        }
 306
 307        ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 308                                 tunnel, L2TP_CMD_TUNNEL_MODIFY);
 309
 310        l2tp_tunnel_dec_refcount(tunnel);
 311
 312out:
 313        return ret;
 314}
 315
 316#if IS_ENABLED(CONFIG_IPV6)
 317static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk,
 318                                     enum l2tp_encap_type encap)
 319{
 320        struct inet_sock *inet = inet_sk(sk);
 321        struct ipv6_pinfo *np = inet6_sk(sk);
 322
 323        switch (encap) {
 324        case L2TP_ENCAPTYPE_UDP:
 325                if (udp_get_no_check6_tx(sk) &&
 326                    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
 327                        return -1;
 328                if (udp_get_no_check6_rx(sk) &&
 329                    nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
 330                        return -1;
 331                if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 332                    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 333                        return -1;
 334                fallthrough;
 335        case L2TP_ENCAPTYPE_IP:
 336                if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) ||
 337                    nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr))
 338                        return -1;
 339                break;
 340        }
 341        return 0;
 342}
 343#endif
 344
 345static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk,
 346                                     enum l2tp_encap_type encap)
 347{
 348        struct inet_sock *inet = inet_sk(sk);
 349
 350        switch (encap) {
 351        case L2TP_ENCAPTYPE_UDP:
 352                if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) ||
 353                    nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
 354                    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
 355                        return -1;
 356                fallthrough;
 357        case L2TP_ENCAPTYPE_IP:
 358                if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) ||
 359                    nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr))
 360                        return -1;
 361                break;
 362        }
 363
 364        return 0;
 365}
 366
 367/* Append attributes for the tunnel address, handling the different attribute types
 368 * used for different tunnel encapsulation and AF_INET v.s. AF_INET6.
 369 */
 370static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel)
 371{
 372        struct sock *sk = tunnel->sock;
 373
 374        if (!sk)
 375                return 0;
 376
 377#if IS_ENABLED(CONFIG_IPV6)
 378        if (sk->sk_family == AF_INET6)
 379                return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap);
 380#endif
 381        return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap);
 382}
 383
 384static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 385                               struct l2tp_tunnel *tunnel, u8 cmd)
 386{
 387        void *hdr;
 388        struct nlattr *nest;
 389
 390        hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 391        if (!hdr)
 392                return -EMSGSIZE;
 393
 394        if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 395            nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 396            nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 397            nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
 398            nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 399                goto nla_put_failure;
 400
 401        nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
 402        if (!nest)
 403                goto nla_put_failure;
 404
 405        if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 406                              atomic_long_read(&tunnel->stats.tx_packets),
 407                              L2TP_ATTR_STATS_PAD) ||
 408            nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 409                              atomic_long_read(&tunnel->stats.tx_bytes),
 410                              L2TP_ATTR_STATS_PAD) ||
 411            nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 412                              atomic_long_read(&tunnel->stats.tx_errors),
 413                              L2TP_ATTR_STATS_PAD) ||
 414            nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 415                              atomic_long_read(&tunnel->stats.rx_packets),
 416                              L2TP_ATTR_STATS_PAD) ||
 417            nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 418                              atomic_long_read(&tunnel->stats.rx_bytes),
 419                              L2TP_ATTR_STATS_PAD) ||
 420            nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 421                              atomic_long_read(&tunnel->stats.rx_seq_discards),
 422                              L2TP_ATTR_STATS_PAD) ||
 423            nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
 424                              atomic_long_read(&tunnel->stats.rx_cookie_discards),
 425                              L2TP_ATTR_STATS_PAD) ||
 426            nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 427                              atomic_long_read(&tunnel->stats.rx_oos_packets),
 428                              L2TP_ATTR_STATS_PAD) ||
 429            nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 430                              atomic_long_read(&tunnel->stats.rx_errors),
 431                              L2TP_ATTR_STATS_PAD))
 432                goto nla_put_failure;
 433        nla_nest_end(skb, nest);
 434
 435        if (l2tp_nl_tunnel_send_addr(skb, tunnel))
 436                goto nla_put_failure;
 437
 438        genlmsg_end(skb, hdr);
 439        return 0;
 440
 441nla_put_failure:
 442        genlmsg_cancel(skb, hdr);
 443        return -1;
 444}
 445
 446static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info)
 447{
 448        struct l2tp_tunnel *tunnel;
 449        struct sk_buff *msg;
 450        u32 tunnel_id;
 451        int ret = -ENOBUFS;
 452        struct net *net = genl_info_net(info);
 453
 454        if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 455                ret = -EINVAL;
 456                goto err;
 457        }
 458
 459        tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 460
 461        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 462        if (!msg) {
 463                ret = -ENOMEM;
 464                goto err;
 465        }
 466
 467        tunnel = l2tp_tunnel_get(net, tunnel_id);
 468        if (!tunnel) {
 469                ret = -ENODEV;
 470                goto err_nlmsg;
 471        }
 472
 473        ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
 474                                  NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET);
 475        if (ret < 0)
 476                goto err_nlmsg_tunnel;
 477
 478        l2tp_tunnel_dec_refcount(tunnel);
 479
 480        return genlmsg_unicast(net, msg, info->snd_portid);
 481
 482err_nlmsg_tunnel:
 483        l2tp_tunnel_dec_refcount(tunnel);
 484err_nlmsg:
 485        nlmsg_free(msg);
 486err:
 487        return ret;
 488}
 489
 490static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback *cb)
 491{
 492        int ti = cb->args[0];
 493        struct l2tp_tunnel *tunnel;
 494        struct net *net = sock_net(skb->sk);
 495
 496        for (;;) {
 497                tunnel = l2tp_tunnel_get_nth(net, ti);
 498                if (!tunnel)
 499                        goto out;
 500
 501                if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid,
 502                                        cb->nlh->nlmsg_seq, NLM_F_MULTI,
 503                                        tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
 504                        l2tp_tunnel_dec_refcount(tunnel);
 505                        goto out;
 506                }
 507                l2tp_tunnel_dec_refcount(tunnel);
 508
 509                ti++;
 510        }
 511
 512out:
 513        cb->args[0] = ti;
 514
 515        return skb->len;
 516}
 517
 518static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *info)
 519{
 520        u32 tunnel_id = 0;
 521        u32 session_id;
 522        u32 peer_session_id;
 523        int ret = 0;
 524        struct l2tp_tunnel *tunnel;
 525        struct l2tp_session *session;
 526        struct l2tp_session_cfg cfg = { 0, };
 527        struct net *net = genl_info_net(info);
 528
 529        if (!info->attrs[L2TP_ATTR_CONN_ID]) {
 530                ret = -EINVAL;
 531                goto out;
 532        }
 533
 534        tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]);
 535        tunnel = l2tp_tunnel_get(net, tunnel_id);
 536        if (!tunnel) {
 537                ret = -ENODEV;
 538                goto out;
 539        }
 540
 541        if (!info->attrs[L2TP_ATTR_SESSION_ID]) {
 542                ret = -EINVAL;
 543                goto out_tunnel;
 544        }
 545        session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]);
 546
 547        if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) {
 548                ret = -EINVAL;
 549                goto out_tunnel;
 550        }
 551        peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]);
 552
 553        if (!info->attrs[L2TP_ATTR_PW_TYPE]) {
 554                ret = -EINVAL;
 555                goto out_tunnel;
 556        }
 557        cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]);
 558        if (cfg.pw_type >= __L2TP_PWTYPE_MAX) {
 559                ret = -EINVAL;
 560                goto out_tunnel;
 561        }
 562
 563        /* L2TPv2 only accepts PPP pseudo-wires */
 564        if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) {
 565                ret = -EPROTONOSUPPORT;
 566                goto out_tunnel;
 567        }
 568
 569        if (tunnel->version > 2) {
 570                if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
 571                        cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
 572                        if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
 573                            cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
 574                                ret = -EINVAL;
 575                                goto out_tunnel;
 576                        }
 577                } else {
 578                        cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
 579                }
 580
 581                if (info->attrs[L2TP_ATTR_COOKIE]) {
 582                        u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]);
 583
 584                        if (len > 8) {
 585                                ret = -EINVAL;
 586                                goto out_tunnel;
 587                        }
 588                        cfg.cookie_len = len;
 589                        memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len);
 590                }
 591                if (info->attrs[L2TP_ATTR_PEER_COOKIE]) {
 592                        u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]);
 593
 594                        if (len > 8) {
 595                                ret = -EINVAL;
 596                                goto out_tunnel;
 597                        }
 598                        cfg.peer_cookie_len = len;
 599                        memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len);
 600                }
 601                if (info->attrs[L2TP_ATTR_IFNAME])
 602                        cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 603        }
 604
 605        if (info->attrs[L2TP_ATTR_RECV_SEQ])
 606                cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 607
 608        if (info->attrs[L2TP_ATTR_SEND_SEQ])
 609                cfg.send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 610
 611        if (info->attrs[L2TP_ATTR_LNS_MODE])
 612                cfg.lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 613
 614        if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 615                cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 616
 617#ifdef CONFIG_MODULES
 618        if (!l2tp_nl_cmd_ops[cfg.pw_type]) {
 619                genl_unlock();
 620                request_module("net-l2tp-type-%u", cfg.pw_type);
 621                genl_lock();
 622        }
 623#endif
 624        if (!l2tp_nl_cmd_ops[cfg.pw_type] || !l2tp_nl_cmd_ops[cfg.pw_type]->session_create) {
 625                ret = -EPROTONOSUPPORT;
 626                goto out_tunnel;
 627        }
 628
 629        ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel,
 630                                                           session_id,
 631                                                           peer_session_id,
 632                                                           &cfg);
 633
 634        if (ret >= 0) {
 635                session = l2tp_tunnel_get_session(tunnel, session_id);
 636                if (session) {
 637                        ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 638                                                  L2TP_CMD_SESSION_CREATE);
 639                        l2tp_session_dec_refcount(session);
 640                }
 641        }
 642
 643out_tunnel:
 644        l2tp_tunnel_dec_refcount(tunnel);
 645out:
 646        return ret;
 647}
 648
 649static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *info)
 650{
 651        int ret = 0;
 652        struct l2tp_session *session;
 653        u16 pw_type;
 654
 655        session = l2tp_nl_session_get(info);
 656        if (!session) {
 657                ret = -ENODEV;
 658                goto out;
 659        }
 660
 661        l2tp_session_notify(&l2tp_nl_family, info,
 662                            session, L2TP_CMD_SESSION_DELETE);
 663
 664        pw_type = session->pwtype;
 665        if (pw_type < __L2TP_PWTYPE_MAX)
 666                if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete)
 667                        l2tp_nl_cmd_ops[pw_type]->session_delete(session);
 668
 669        l2tp_session_dec_refcount(session);
 670
 671out:
 672        return ret;
 673}
 674
 675static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *info)
 676{
 677        int ret = 0;
 678        struct l2tp_session *session;
 679
 680        session = l2tp_nl_session_get(info);
 681        if (!session) {
 682                ret = -ENODEV;
 683                goto out;
 684        }
 685
 686        if (info->attrs[L2TP_ATTR_RECV_SEQ])
 687                session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 688
 689        if (info->attrs[L2TP_ATTR_SEND_SEQ]) {
 690                session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]);
 691                l2tp_session_set_header_len(session, session->tunnel->version);
 692        }
 693
 694        if (info->attrs[L2TP_ATTR_LNS_MODE])
 695                session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]);
 696
 697        if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 698                session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 699
 700        ret = l2tp_session_notify(&l2tp_nl_family, info,
 701                                  session, L2TP_CMD_SESSION_MODIFY);
 702
 703        l2tp_session_dec_refcount(session);
 704
 705out:
 706        return ret;
 707}
 708
 709static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
 710                                struct l2tp_session *session, u8 cmd)
 711{
 712        void *hdr;
 713        struct nlattr *nest;
 714        struct l2tp_tunnel *tunnel = session->tunnel;
 715
 716        hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
 717        if (!hdr)
 718                return -EMSGSIZE;
 719
 720        if (nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 721            nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 722            nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 723            nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
 724            nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
 725            nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
 726                goto nla_put_failure;
 727
 728        if ((session->ifname[0] &&
 729             nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) ||
 730            (session->cookie_len &&
 731             nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, session->cookie)) ||
 732            (session->peer_cookie_len &&
 733             nla_put(skb, L2TP_ATTR_PEER_COOKIE, session->peer_cookie_len, session->peer_cookie)) ||
 734            nla_put_u8(skb, L2TP_ATTR_RECV_SEQ, session->recv_seq) ||
 735            nla_put_u8(skb, L2TP_ATTR_SEND_SEQ, session->send_seq) ||
 736            nla_put_u8(skb, L2TP_ATTR_LNS_MODE, session->lns_mode) ||
 737            (l2tp_tunnel_uses_xfrm(tunnel) &&
 738             nla_put_u8(skb, L2TP_ATTR_USING_IPSEC, 1)) ||
 739            (session->reorder_timeout &&
 740             nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT,
 741                           session->reorder_timeout, L2TP_ATTR_PAD)))
 742                goto nla_put_failure;
 743
 744        nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
 745        if (!nest)
 746                goto nla_put_failure;
 747
 748        if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
 749                              atomic_long_read(&session->stats.tx_packets),
 750                              L2TP_ATTR_STATS_PAD) ||
 751            nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
 752                              atomic_long_read(&session->stats.tx_bytes),
 753                              L2TP_ATTR_STATS_PAD) ||
 754            nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
 755                              atomic_long_read(&session->stats.tx_errors),
 756                              L2TP_ATTR_STATS_PAD) ||
 757            nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
 758                              atomic_long_read(&session->stats.rx_packets),
 759                              L2TP_ATTR_STATS_PAD) ||
 760            nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
 761                              atomic_long_read(&session->stats.rx_bytes),
 762                              L2TP_ATTR_STATS_PAD) ||
 763            nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
 764                              atomic_long_read(&session->stats.rx_seq_discards),
 765                              L2TP_ATTR_STATS_PAD) ||
 766            nla_put_u64_64bit(skb, L2TP_ATTR_RX_COOKIE_DISCARDS,
 767                              atomic_long_read(&session->stats.rx_cookie_discards),
 768                              L2TP_ATTR_STATS_PAD) ||
 769            nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
 770                              atomic_long_read(&session->stats.rx_oos_packets),
 771                              L2TP_ATTR_STATS_PAD) ||
 772            nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
 773                              atomic_long_read(&session->stats.rx_errors),
 774                              L2TP_ATTR_STATS_PAD))
 775                goto nla_put_failure;
 776        nla_nest_end(skb, nest);
 777
 778        genlmsg_end(skb, hdr);
 779        return 0;
 780
 781 nla_put_failure:
 782        genlmsg_cancel(skb, hdr);
 783        return -1;
 784}
 785
 786static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info)
 787{
 788        struct l2tp_session *session;
 789        struct sk_buff *msg;
 790        int ret;
 791
 792        session = l2tp_nl_session_get(info);
 793        if (!session) {
 794                ret = -ENODEV;
 795                goto err;
 796        }
 797
 798        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 799        if (!msg) {
 800                ret = -ENOMEM;
 801                goto err_ref;
 802        }
 803
 804        ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
 805                                   0, session, L2TP_CMD_SESSION_GET);
 806        if (ret < 0)
 807                goto err_ref_msg;
 808
 809        ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid);
 810
 811        l2tp_session_dec_refcount(session);
 812
 813        return ret;
 814
 815err_ref_msg:
 816        nlmsg_free(msg);
 817err_ref:
 818        l2tp_session_dec_refcount(session);
 819err:
 820        return ret;
 821}
 822
 823static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback *cb)
 824{
 825        struct net *net = sock_net(skb->sk);
 826        struct l2tp_session *session;
 827        struct l2tp_tunnel *tunnel = NULL;
 828        int ti = cb->args[0];
 829        int si = cb->args[1];
 830
 831        for (;;) {
 832                if (!tunnel) {
 833                        tunnel = l2tp_tunnel_get_nth(net, ti);
 834                        if (!tunnel)
 835                                goto out;
 836                }
 837
 838                session = l2tp_session_get_nth(tunnel, si);
 839                if (!session) {
 840                        ti++;
 841                        l2tp_tunnel_dec_refcount(tunnel);
 842                        tunnel = NULL;
 843                        si = 0;
 844                        continue;
 845                }
 846
 847                if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
 848                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 849                                         session, L2TP_CMD_SESSION_GET) < 0) {
 850                        l2tp_session_dec_refcount(session);
 851                        l2tp_tunnel_dec_refcount(tunnel);
 852                        break;
 853                }
 854                l2tp_session_dec_refcount(session);
 855
 856                si++;
 857        }
 858
 859out:
 860        cb->args[0] = ti;
 861        cb->args[1] = si;
 862
 863        return skb->len;
 864}
 865
 866static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = {
 867        [L2TP_ATTR_NONE]                = { .type = NLA_UNSPEC, },
 868        [L2TP_ATTR_PW_TYPE]             = { .type = NLA_U16, },
 869        [L2TP_ATTR_ENCAP_TYPE]          = { .type = NLA_U16, },
 870        [L2TP_ATTR_OFFSET]              = { .type = NLA_U16, },
 871        [L2TP_ATTR_DATA_SEQ]            = { .type = NLA_U8, },
 872        [L2TP_ATTR_L2SPEC_TYPE]         = { .type = NLA_U8, },
 873        [L2TP_ATTR_L2SPEC_LEN]          = { .type = NLA_U8, },
 874        [L2TP_ATTR_PROTO_VERSION]       = { .type = NLA_U8, },
 875        [L2TP_ATTR_CONN_ID]             = { .type = NLA_U32, },
 876        [L2TP_ATTR_PEER_CONN_ID]        = { .type = NLA_U32, },
 877        [L2TP_ATTR_SESSION_ID]          = { .type = NLA_U32, },
 878        [L2TP_ATTR_PEER_SESSION_ID]     = { .type = NLA_U32, },
 879        [L2TP_ATTR_UDP_CSUM]            = { .type = NLA_U8, },
 880        [L2TP_ATTR_VLAN_ID]             = { .type = NLA_U16, },
 881        [L2TP_ATTR_DEBUG]               = { .type = NLA_U32, },
 882        [L2TP_ATTR_RECV_SEQ]            = { .type = NLA_U8, },
 883        [L2TP_ATTR_SEND_SEQ]            = { .type = NLA_U8, },
 884        [L2TP_ATTR_LNS_MODE]            = { .type = NLA_U8, },
 885        [L2TP_ATTR_USING_IPSEC]         = { .type = NLA_U8, },
 886        [L2TP_ATTR_RECV_TIMEOUT]        = { .type = NLA_MSECS, },
 887        [L2TP_ATTR_FD]                  = { .type = NLA_U32, },
 888        [L2TP_ATTR_IP_SADDR]            = { .type = NLA_U32, },
 889        [L2TP_ATTR_IP_DADDR]            = { .type = NLA_U32, },
 890        [L2TP_ATTR_UDP_SPORT]           = { .type = NLA_U16, },
 891        [L2TP_ATTR_UDP_DPORT]           = { .type = NLA_U16, },
 892        [L2TP_ATTR_MTU]                 = { .type = NLA_U16, },
 893        [L2TP_ATTR_MRU]                 = { .type = NLA_U16, },
 894        [L2TP_ATTR_STATS]               = { .type = NLA_NESTED, },
 895        [L2TP_ATTR_IP6_SADDR] = {
 896                .type = NLA_BINARY,
 897                .len = sizeof(struct in6_addr),
 898        },
 899        [L2TP_ATTR_IP6_DADDR] = {
 900                .type = NLA_BINARY,
 901                .len = sizeof(struct in6_addr),
 902        },
 903        [L2TP_ATTR_IFNAME] = {
 904                .type = NLA_NUL_STRING,
 905                .len = IFNAMSIZ - 1,
 906        },
 907        [L2TP_ATTR_COOKIE] = {
 908                .type = NLA_BINARY,
 909                .len = 8,
 910        },
 911        [L2TP_ATTR_PEER_COOKIE] = {
 912                .type = NLA_BINARY,
 913                .len = 8,
 914        },
 915};
 916
 917static const struct genl_small_ops l2tp_nl_ops[] = {
 918        {
 919                .cmd = L2TP_CMD_NOOP,
 920                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 921                .doit = l2tp_nl_cmd_noop,
 922                /* can be retrieved by unprivileged users */
 923        },
 924        {
 925                .cmd = L2TP_CMD_TUNNEL_CREATE,
 926                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 927                .doit = l2tp_nl_cmd_tunnel_create,
 928                .flags = GENL_UNS_ADMIN_PERM,
 929        },
 930        {
 931                .cmd = L2TP_CMD_TUNNEL_DELETE,
 932                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 933                .doit = l2tp_nl_cmd_tunnel_delete,
 934                .flags = GENL_UNS_ADMIN_PERM,
 935        },
 936        {
 937                .cmd = L2TP_CMD_TUNNEL_MODIFY,
 938                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 939                .doit = l2tp_nl_cmd_tunnel_modify,
 940                .flags = GENL_UNS_ADMIN_PERM,
 941        },
 942        {
 943                .cmd = L2TP_CMD_TUNNEL_GET,
 944                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 945                .doit = l2tp_nl_cmd_tunnel_get,
 946                .dumpit = l2tp_nl_cmd_tunnel_dump,
 947                .flags = GENL_UNS_ADMIN_PERM,
 948        },
 949        {
 950                .cmd = L2TP_CMD_SESSION_CREATE,
 951                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 952                .doit = l2tp_nl_cmd_session_create,
 953                .flags = GENL_UNS_ADMIN_PERM,
 954        },
 955        {
 956                .cmd = L2TP_CMD_SESSION_DELETE,
 957                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 958                .doit = l2tp_nl_cmd_session_delete,
 959                .flags = GENL_UNS_ADMIN_PERM,
 960        },
 961        {
 962                .cmd = L2TP_CMD_SESSION_MODIFY,
 963                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 964                .doit = l2tp_nl_cmd_session_modify,
 965                .flags = GENL_UNS_ADMIN_PERM,
 966        },
 967        {
 968                .cmd = L2TP_CMD_SESSION_GET,
 969                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 970                .doit = l2tp_nl_cmd_session_get,
 971                .dumpit = l2tp_nl_cmd_session_dump,
 972                .flags = GENL_UNS_ADMIN_PERM,
 973        },
 974};
 975
 976static struct genl_family l2tp_nl_family __ro_after_init = {
 977        .name           = L2TP_GENL_NAME,
 978        .version        = L2TP_GENL_VERSION,
 979        .hdrsize        = 0,
 980        .maxattr        = L2TP_ATTR_MAX,
 981        .policy = l2tp_nl_policy,
 982        .netnsok        = true,
 983        .module         = THIS_MODULE,
 984        .small_ops      = l2tp_nl_ops,
 985        .n_small_ops    = ARRAY_SIZE(l2tp_nl_ops),
 986        .mcgrps         = l2tp_multicast_group,
 987        .n_mcgrps       = ARRAY_SIZE(l2tp_multicast_group),
 988};
 989
 990int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops)
 991{
 992        int ret;
 993
 994        ret = -EINVAL;
 995        if (pw_type >= __L2TP_PWTYPE_MAX)
 996                goto err;
 997
 998        genl_lock();
 999        ret = -EBUSY;
1000        if (l2tp_nl_cmd_ops[pw_type])
1001                goto out;
1002
1003        l2tp_nl_cmd_ops[pw_type] = ops;
1004        ret = 0;
1005
1006out:
1007        genl_unlock();
1008err:
1009        return ret;
1010}
1011EXPORT_SYMBOL_GPL(l2tp_nl_register_ops);
1012
1013void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type)
1014{
1015        if (pw_type < __L2TP_PWTYPE_MAX) {
1016                genl_lock();
1017                l2tp_nl_cmd_ops[pw_type] = NULL;
1018                genl_unlock();
1019        }
1020}
1021EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops);
1022
1023static int __init l2tp_nl_init(void)
1024{
1025        pr_info("L2TP netlink interface\n");
1026        return genl_register_family(&l2tp_nl_family);
1027}
1028
1029static void l2tp_nl_cleanup(void)
1030{
1031        genl_unregister_family(&l2tp_nl_family);
1032}
1033
1034module_init(l2tp_nl_init);
1035module_exit(l2tp_nl_cleanup);
1036
1037MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1038MODULE_DESCRIPTION("L2TP netlink");
1039MODULE_LICENSE("GPL");
1040MODULE_VERSION("1.0");
1041MODULE_ALIAS_GENL_FAMILY("l2tp");
1042