src/network/netdev/l2tp-tunnel.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <netinet/in.h>
   4 #include <linux/l2tp.h>
   5 #include <linux/genetlink.h>
   6
   7 #include "conf-parser.h"
   8 #include "hashmap.h"
   9 #include "l2tp-tunnel.h"
  10 #include "netlink-util.h"
  11 #include "networkd-address.h"
  12 #include "networkd-manager.h"
  13 #include "networkd-route-util.h"
  14 #include "parse-util.h"
  15 #include "socket-util.h"
  16 #include "string-table.h"
  17 #include "string-util.h"
  18 #include "util.h"
  19
  20 static const char* const l2tp_l2spec_type_table[_NETDEV_L2TP_L2SPECTYPE_MAX] = {
  21         [NETDEV_L2TP_L2SPECTYPE_NONE]    = "none",
  22         [NETDEV_L2TP_L2SPECTYPE_DEFAULT] = "default",
  23 };
  24
  25 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_l2spec_type, L2tpL2specType);
  26
  27 static const char* const l2tp_encap_type_table[_NETDEV_L2TP_ENCAPTYPE_MAX] = {
  28         [NETDEV_L2TP_ENCAPTYPE_UDP] = "udp",
  29         [NETDEV_L2TP_ENCAPTYPE_IP]  = "ip",
  30 };
  31
  32 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_encap_type, L2tpEncapType);
  33 DEFINE_CONFIG_PARSE_ENUM(config_parse_l2tp_encap_type, l2tp_encap_type, L2tpEncapType, "Failed to parse L2TP Encapsulation Type");
  34
  35 static const char* const l2tp_local_address_type_table[_NETDEV_L2TP_LOCAL_ADDRESS_MAX] = {
  36          [NETDEV_L2TP_LOCAL_ADDRESS_AUTO]    = "auto",
  37          [NETDEV_L2TP_LOCAL_ADDRESS_STATIC]  = "static",
  38          [NETDEV_L2TP_LOCAL_ADDRESS_DYNAMIC] = "dynamic",
  39 };
  40
  41 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_local_address_type, L2tpLocalAddressType);
  42
  43 static L2tpSession* l2tp_session_free(L2tpSession *s) {
  44         if (!s)
  45                 return NULL;
  46
  47         if (s->tunnel && s->section)
  48                 ordered_hashmap_remove(s->tunnel->sessions_by_section, s->section);
  49
  50         config_section_free(s->section);
  51         free(s->name);
  52         return mfree(s);
  53 }
  54
  55 DEFINE_SECTION_CLEANUP_FUNCTIONS(L2tpSession, l2tp_session_free);
  56
  57 static int l2tp_session_new_static(L2tpTunnel *t, const char *filename, unsigned section_line, L2tpSession **ret) {
  58         _cleanup_(config_section_freep) ConfigSection *n = NULL;
  59         _cleanup_(l2tp_session_freep) L2tpSession *s = NULL;
  60         int r;
  61
  62         assert(t);
  63         assert(ret);
  64         assert(filename);
  65         assert(section_line > 0);
  66
  67         r = config_section_new(filename, section_line, &n);
  68         if (r < 0)
  69                 return r;
  70
  71         s = ordered_hashmap_get(t->sessions_by_section, n);
  72         if (s) {
  73                 *ret = TAKE_PTR(s);
  74                 return 0;
  75         }
  76
  77         s = new(L2tpSession, 1);
  78         if (!s)
  79                 return -ENOMEM;
  80
  81         *s = (L2tpSession) {
  82                 .l2tp_l2spec_type = NETDEV_L2TP_L2SPECTYPE_DEFAULT,
  83                 .tunnel = t,
  84                 .section = TAKE_PTR(n),
  85         };
  86
  87         r = ordered_hashmap_ensure_put(&t->sessions_by_section, &config_section_hash_ops, s->section, s);
  88         if (r < 0)
  89                 return r;
  90
  91         *ret = TAKE_PTR(s);
  92         return 0;
  93 }
  94
  95 static int netdev_l2tp_create_message_tunnel(NetDev *netdev, union in_addr_union *local_address, sd_netlink_message **ret) {
  96         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
  97         uint16_t encap_type;
  98         L2tpTunnel *t;
  99         int r;
 100
 101         assert(netdev);
 102         assert(local_address);
 103         assert_se(t = L2TP(netdev));
 104
 105         r = sd_genl_message_new(netdev->manager->genl, L2TP_GENL_NAME, L2TP_CMD_TUNNEL_CREATE, &m);
 106         if (r < 0)
 107                 return r;
 108
 109         r = sd_netlink_message_append_u32(m, L2TP_ATTR_CONN_ID, t->tunnel_id);
 110         if (r < 0)
 111                 return r;
 112
 113         r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_CONN_ID, t->peer_tunnel_id);
 114         if (r < 0)
 115                 return r;
 116
 117         r = sd_netlink_message_append_u8(m, L2TP_ATTR_PROTO_VERSION, 3);
 118         if (r < 0)
 119                 return r;
 120
 121         switch (t->l2tp_encap_type) {
 122         case NETDEV_L2TP_ENCAPTYPE_IP:
 123                 encap_type = L2TP_ENCAPTYPE_IP;
 124                 break;
 125         case NETDEV_L2TP_ENCAPTYPE_UDP:
 126         default:
 127                 encap_type = L2TP_ENCAPTYPE_UDP;
 128                 break;
 129         }
 130
 131         r = sd_netlink_message_append_u16(m, L2TP_ATTR_ENCAP_TYPE, encap_type);
 132         if (r < 0)
 133                 return r;
 134
 135         if (t->family == AF_INET) {
 136                 r = sd_netlink_message_append_in_addr(m, L2TP_ATTR_IP_SADDR, &local_address->in);
 137                 if (r < 0)
 138                         return r;
 139
 140                 r = sd_netlink_message_append_in_addr(m, L2TP_ATTR_IP_DADDR, &t->remote.in);
 141                 if (r < 0)
 142                         return r;
 143         } else {
 144                 r = sd_netlink_message_append_in6_addr(m, L2TP_ATTR_IP6_SADDR, &local_address->in6);
 145                 if (r < 0)
 146                         return r;
 147
 148                 r = sd_netlink_message_append_in6_addr(m, L2TP_ATTR_IP6_DADDR, &t->remote.in6);
 149                 if (r < 0)
 150                         return r;
 151         }
 152
 153         if (encap_type == L2TP_ENCAPTYPE_UDP) {
 154                 r = sd_netlink_message_append_u16(m, L2TP_ATTR_UDP_SPORT, t->l2tp_udp_sport);
 155                 if (r < 0)
 156                         return r;
 157
 158                 r = sd_netlink_message_append_u16(m, L2TP_ATTR_UDP_DPORT, t->l2tp_udp_dport);
 159                 if (r < 0)
 160                         return r;
 161
 162                 if (t->udp_csum) {
 163                         r = sd_netlink_message_append_u8(m, L2TP_ATTR_UDP_CSUM, t->udp_csum);
 164                         if (r < 0)
 165                                 return r;
 166                 }
 167
 168                 if (t->udp6_csum_tx) {
 169                         r = sd_netlink_message_append_flag(m, L2TP_ATTR_UDP_ZERO_CSUM6_TX);
 170                         if (r < 0)
 171                                 return r;
 172                 }
 173
 174                 if (t->udp6_csum_rx) {
 175                         r = sd_netlink_message_append_flag(m, L2TP_ATTR_UDP_ZERO_CSUM6_RX);
 176                         if (r < 0)
 177                                 return r;
 178                 }
 179         }
 180
 181         *ret = TAKE_PTR(m);
 182
 183         return 0;
 184 }
 185
 186 static int netdev_l2tp_create_message_session(NetDev *netdev, L2tpSession *session, sd_netlink_message **ret) {
 187         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 188         uint16_t l2_spec_len;
 189         uint8_t l2_spec_type;
 190         int r;
 191
 192         assert(netdev);
 193         assert(session);
 194         assert(session->tunnel);
 195
 196         r = sd_genl_message_new(netdev->manager->genl, L2TP_GENL_NAME, L2TP_CMD_SESSION_CREATE, &m);
 197         if (r < 0)
 198                 return r;
 199
 200         r = sd_netlink_message_append_u32(m, L2TP_ATTR_CONN_ID, session->tunnel->tunnel_id);
 201         if (r < 0)
 202                 return r;
 203
 204         r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_CONN_ID, session->tunnel->peer_tunnel_id);
 205         if (r < 0)
 206                 return r;
 207
 208         r = sd_netlink_message_append_u32(m, L2TP_ATTR_SESSION_ID, session->session_id);
 209         if (r < 0)
 210                 return r;
 211
 212         r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id);
 213         if (r < 0)
 214                 return r;
 215
 216         r = sd_netlink_message_append_u16(m, L2TP_ATTR_PW_TYPE, L2TP_PWTYPE_ETH);
 217         if (r < 0)
 218                 return r;
 219
 220         switch (session->l2tp_l2spec_type) {
 221         case NETDEV_L2TP_L2SPECTYPE_NONE:
 222                 l2_spec_type = L2TP_L2SPECTYPE_NONE;
 223                 l2_spec_len = 0;
 224                 break;
 225         case NETDEV_L2TP_L2SPECTYPE_DEFAULT:
 226         default:
 227                 l2_spec_type = L2TP_L2SPECTYPE_DEFAULT;
 228                 l2_spec_len = 4;
 229                 break;
 230         }
 231
 232         r = sd_netlink_message_append_u8(m, L2TP_ATTR_L2SPEC_TYPE, l2_spec_type);
 233         if (r < 0)
 234                 return r;
 235
 236         r = sd_netlink_message_append_u8(m, L2TP_ATTR_L2SPEC_LEN, l2_spec_len);
 237         if (r < 0)
 238                 return r;
 239
 240         r = sd_netlink_message_append_string(m, L2TP_ATTR_IFNAME, session->name);
 241         if (r < 0)
 242                 return r;
 243
 244         *ret = TAKE_PTR(m);
 245
 246         return 0;
 247 }
 248
 249 static int link_get_l2tp_local_address(Link *link, L2tpTunnel *t, union in_addr_union *ret) {
 250         Address *a;
 251
 252         assert(link);
 253         assert(t);
 254
 255         SET_FOREACH(a, link->addresses) {
 256                 if (!address_is_ready(a))
 257                         continue;
 258
 259                 if (a->family != t->family)
 260                         continue;
 261
 262                 if (in_addr_is_set(a->family, &a->in_addr_peer))
 263                         continue;
 264
 265                 if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_STATIC &&
 266                     !FLAGS_SET(a->flags, IFA_F_PERMANENT))
 267                         continue;
 268
 269                 if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_DYNAMIC &&
 270                     FLAGS_SET(a->flags, IFA_F_PERMANENT))
 271                         continue;
 272
 273                 if (ret)
 274                         *ret = a->in_addr;
 275         }
 276
 277         return -ENOENT;
 278 }
 279
 280 static int l2tp_get_local_address(NetDev *netdev, union in_addr_union *ret) {
 281         Link *link = NULL;
 282         L2tpTunnel *t;
 283         Address *a = NULL;
 284         int r;
 285
 286         assert(netdev);
 287         assert(netdev->manager);
 288         assert_se(t = L2TP(netdev));
 289
 290         if (t->local_ifname) {
 291                 r = link_get_by_name(netdev->manager, t->local_ifname, &link);
 292                 if (r < 0)
 293                         return r;
 294
 295                 if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false))
 296                         return -EBUSY;
 297         }
 298
 299         if (netdev->manager->manage_foreign_routes) {
 300                 /* First, check if the remote address is accessible. */
 301                 if (link)
 302                         r = link_address_is_reachable(link, t->family, &t->remote, &t->local, &a);
 303                 else
 304                         r = manager_address_is_reachable(netdev->manager, t->family, &t->remote, &t->local, &a);
 305                 if (r < 0)
 306                         return r;
 307         }
 308
 309         if (in_addr_is_set(t->family, &t->local)) {
 310                 /* local address is explicitly specified. */
 311
 312                 if (!a) {
 313                         if (link)
 314                                 r = link_get_address(link, t->family, &t->local, 0, &a);
 315                         else
 316                                 r = manager_get_address(netdev->manager, t->family, &t->local, 0, &a);
 317                         if (r < 0)
 318                                 return r;
 319
 320                         if (!address_is_ready(a))
 321                                 return -EBUSY;
 322                 }
 323
 324                 if (ret)
 325                         *ret = a->in_addr;
 326
 327                 return 0;
 328         }
 329
 330         if (a) {
 331                 if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_STATIC &&
 332                     !FLAGS_SET(a->flags, IFA_F_PERMANENT))
 333                         return -EINVAL;
 334
 335                 if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_DYNAMIC &&
 336                     FLAGS_SET(a->flags, IFA_F_PERMANENT))
 337                         return -EINVAL;
 338
 339                 if (ret)
 340                         *ret = a->in_addr;
 341
 342                 return 0;
 343         }
 344
 345         if (link)
 346                 return link_get_l2tp_local_address(link, t, ret);
 347
 348         HASHMAP_FOREACH(link, netdev->manager->links_by_index) {
 349                 if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false))
 350                         continue;
 351
 352                 if (link_get_l2tp_local_address(link, t, ret) >= 0)
 353                         return 0;
 354         }
 355
 356         return -ENOENT;
 357 }
 358
 359 static void l2tp_session_destroy_callback(L2tpSession *session) {
 360         if (!session)
 361                 return;
 362
 363         netdev_unref(NETDEV(session->tunnel));
 364 }
 365
 366 static int l2tp_create_session_handler(sd_netlink *rtnl, sd_netlink_message *m, L2tpSession *session) {
 367         NetDev *netdev;
 368         int r;
 369
 370         assert(session);
 371         assert(session->tunnel);
 372
 373         netdev = NETDEV(session->tunnel);
 374
 375         r = sd_netlink_message_get_errno(m);
 376         if (r == -EEXIST)
 377                 log_netdev_info(netdev, "L2TP session %s exists, using existing without changing its parameters",
 378                                 session->name);
 379         else if (r < 0) {
 380                 log_netdev_warning_errno(netdev, r, "L2TP session %s could not be created: %m", session->name);
 381                 return 1;
 382         }
 383
 384         log_netdev_debug(netdev, "L2TP session %s created", session->name);
 385         return 1;
 386 }
 387
 388 static int l2tp_create_session(NetDev *netdev, L2tpSession *session) {
 389         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *n = NULL;
 390         int r;
 391
 392         r = netdev_l2tp_create_message_session(netdev, session, &n);
 393         if (r < 0)
 394                 return log_netdev_error_errno(netdev, r, "Failed to create netlink message: %m");
 395
 396         r = netlink_call_async(netdev->manager->genl, NULL, n, l2tp_create_session_handler,
 397                                l2tp_session_destroy_callback, session);
 398         if (r < 0)
 399                 return log_netdev_error_errno(netdev, r, "Failed to create L2TP session %s: %m", session->name);
 400
 401         netdev_ref(netdev);
 402         return 0;
 403 }
 404
 405 static int l2tp_create_tunnel_handler(sd_netlink *rtnl, sd_netlink_message *m, NetDev *netdev) {
 406         L2tpSession *session;
 407         L2tpTunnel *t;
 408         int r;
 409
 410         assert(netdev);
 411         assert(netdev->state != _NETDEV_STATE_INVALID);
 412
 413         t = L2TP(netdev);
 414
 415         assert(t);
 416
 417         r = sd_netlink_message_get_errno(m);
 418         if (r == -EEXIST)
 419                 log_netdev_info(netdev, "netdev exists, using existing without changing its parameters");
 420         else if (r < 0) {
 421                 log_netdev_warning_errno(netdev, r, "netdev could not be created: %m");
 422                 netdev_enter_failed(netdev);
 423
 424                 return 1;
 425         }
 426
 427         log_netdev_debug(netdev, "L2TP tunnel is created");
 428
 429         ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
 430                 (void) l2tp_create_session(netdev, session);
 431
 432         return 1;
 433 }
 434
 435 static int l2tp_create_tunnel(NetDev *netdev) {
 436         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 437         union in_addr_union local_address;
 438         L2tpTunnel *t;
 439         int r;
 440
 441         assert(netdev);
 442         assert_se(t = L2TP(netdev));
 443
 444         r = l2tp_get_local_address(netdev, &local_address);
 445         if (r < 0)
 446                 return log_netdev_error_errno(netdev, r, "Could not find local address.");
 447
 448         if (t->local_address_type >= 0 && DEBUG_LOGGING)
 449                 log_netdev_debug(netdev, "Local address %s acquired.",
 450                                  IN_ADDR_TO_STRING(t->family, &local_address));
 451
 452         r = netdev_l2tp_create_message_tunnel(netdev, &local_address, &m);
 453         if (r < 0)
 454                 return log_netdev_error_errno(netdev, r, "Failed to create netlink message: %m");
 455
 456         r = netlink_call_async(netdev->manager->genl, NULL, m, l2tp_create_tunnel_handler,
 457                                netdev_destroy_callback, netdev);
 458         if (r < 0)
 459                 return log_netdev_error_errno(netdev, r, "Failed to create L2TP tunnel: %m");
 460
 461         netdev_ref(netdev);
 462
 463         return 0;
 464 }
 465
 466 static int netdev_l2tp_is_ready_to_create(NetDev *netdev, Link *link) {
 467         return l2tp_get_local_address(netdev, NULL) >= 0;
 468 }
 469
 470 int config_parse_l2tp_tunnel_local_address(
 471                 const char *unit,
 472                 const char *filename,
 473                 unsigned line,
 474                 const char *section,
 475                 unsigned section_line,
 476                 const char *lvalue,
 477                 int ltype,
 478                 const char *rvalue,
 479                 void *data,
 480                 void *userdata) {
 481
 482         _cleanup_free_ char *addr_or_type = NULL, *ifname = NULL;
 483         L2tpLocalAddressType type;
 484         L2tpTunnel *t = userdata;
 485         const char *p = rvalue;
 486         union in_addr_union a;
 487         int r, f;
 488
 489         assert(filename);
 490         assert(lvalue);
 491         assert(rvalue);
 492         assert(t);
 493
 494         if (isempty(rvalue)) {
 495                 t->local_ifname = mfree(t->local_ifname);
 496                 t->local_address_type = NETDEV_L2TP_LOCAL_ADDRESS_AUTO;
 497                 t->local = IN_ADDR_NULL;
 498
 499                 if (!in_addr_is_set(t->family, &t->remote))
 500                         /* If Remote= is not specified yet, then also clear family. */
 501                         t->family = AF_UNSPEC;
 502
 503                 return 0;
 504         }
 505
 506         r = extract_first_word(&p, &addr_or_type, "@", 0);
 507         if (r < 0)
 508                 return log_oom();
 509         if (r == 0) {
 510                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 511                            "Invalid L2TP Tunnel address specified in %s=, ignoring assignment: %s", lvalue, rvalue);
 512                 return 0;
 513         }
 514
 515         if (!isempty(p)) {
 516                 if (!ifname_valid_full(p, IFNAME_VALID_ALTERNATIVE)) {
 517                         log_syntax(unit, LOG_WARNING, filename, line, 0,
 518                                    "Invalid interface name specified in %s=, ignoring assignment: %s", lvalue, rvalue);
 519                         return 0;
 520                 }
 521
 522                 ifname = strdup(p);
 523                 if (!ifname)
 524                         return log_oom();
 525         }
 526
 527         type = l2tp_local_address_type_from_string(rvalue);
 528         if (type >= 0) {
 529                 free_and_replace(t->local_ifname, ifname);
 530                 t->local_address_type = type;
 531                 t->local = IN_ADDR_NULL;
 532
 533                 if (!in_addr_is_set(t->family, &t->remote))
 534                         /* If Remote= is not specified yet, then also clear family. */
 535                         t->family = AF_UNSPEC;
 536
 537                 return 0;
 538         }
 539
 540         r = in_addr_from_string_auto(rvalue, &f, &a);
 541         if (r < 0) {
 542                 log_syntax(unit, LOG_WARNING, filename, line, r,
 543                            "Invalid L2TP Tunnel local address specified, ignoring assignment: %s", rvalue);
 544                 return 0;
 545         }
 546
 547         if (in_addr_is_null(f, &a)) {
 548                 log_syntax(unit, LOG_WARNING, filename, line, r,
 549                            "L2TP Tunnel local address cannot be null, ignoring assignment: %s", rvalue);
 550                 return 0;
 551         }
 552
 553         if (t->family != AF_UNSPEC && t->family != f) {
 554                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 555                            "Address family does not match the previous assignment, ignoring assignment: %s", rvalue);
 556                 return 0;
 557         }
 558
 559         t->family = f;
 560         t->local = a;
 561         free_and_replace(t->local_ifname, ifname);
 562         t->local_address_type = _NETDEV_L2TP_LOCAL_ADDRESS_INVALID;
 563         return 0;
 564 }
 565
 566 int config_parse_l2tp_tunnel_remote_address(
 567                 const char *unit,
 568                 const char *filename,
 569                 unsigned line,
 570                 const char *section,
 571                 unsigned section_line,
 572                 const char *lvalue,
 573                 int ltype,
 574                 const char *rvalue,
 575                 void *data,
 576                 void *userdata) {
 577
 578         L2tpTunnel *t = userdata;
 579         union in_addr_union a;
 580         int r, f;
 581
 582         assert(filename);
 583         assert(lvalue);
 584         assert(rvalue);
 585         assert(t);
 586
 587         if (isempty(rvalue)) {
 588                 t->remote = IN_ADDR_NULL;
 589
 590                 if (!in_addr_is_set(t->family, &t->local))
 591                         /* If Local= is not specified yet, then also clear family. */
 592                         t->family = AF_UNSPEC;
 593
 594                 return 0;
 595         }
 596
 597         r = in_addr_from_string_auto(rvalue, &f, &a);
 598         if (r < 0) {
 599                 log_syntax(unit, LOG_WARNING, filename, line, r,
 600                            "Invalid L2TP Tunnel remote address specified, ignoring assignment: %s", rvalue);
 601                 return 0;
 602         }
 603
 604         if (in_addr_is_null(f, &a)) {
 605                 log_syntax(unit, LOG_WARNING, filename, line, r,
 606                            "L2TP Tunnel remote address cannot be null, ignoring assignment: %s", rvalue);
 607                 return 0;
 608         }
 609
 610         if (t->family != AF_UNSPEC && t->family != f) {
 611                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 612                            "Address family does not match the previous assignment, ignoring assignment: %s", rvalue);
 613                 return 0;
 614         }
 615
 616         t->family = f;
 617         t->remote = a;
 618         return 0;
 619 }
 620
 621 int config_parse_l2tp_tunnel_id(
 622                 const char *unit,
 623                 const char *filename,
 624                 unsigned line,
 625                 const char *section,
 626                 unsigned section_line,
 627                 const char *lvalue,
 628                 int ltype,
 629                 const char *rvalue,
 630                 void *data,
 631                 void *userdata) {
 632
 633         uint32_t *id = data, k;
 634         int r;
 635
 636         assert(filename);
 637         assert(lvalue);
 638         assert(rvalue);
 639         assert(data);
 640
 641         r = safe_atou32(rvalue, &k);
 642         if (r < 0) {
 643                 log_syntax(unit, LOG_WARNING, filename, line, r,
 644                            "Failed to parse L2TP tunnel id. Ignoring assignment: %s", rvalue);
 645                 return 0;
 646         }
 647
 648         if (k == 0) {
 649                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 650                            "Invalid L2TP tunnel id. Ignoring assignment: %s", rvalue);
 651                 return 0;
 652         }
 653
 654         *id = k;
 655
 656         return 0;
 657 }
 658
 659 int config_parse_l2tp_session_id(
 660                 const char *unit,
 661                 const char *filename,
 662                 unsigned line,
 663                 const char *section,
 664                 unsigned section_line,
 665                 const char *lvalue,
 666                 int ltype,
 667                 const char *rvalue,
 668                 void *data,
 669                 void *userdata) {
 670
 671         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 672         L2tpTunnel *t = userdata;
 673         uint32_t k;
 674         int r;
 675
 676         assert(filename);
 677         assert(section);
 678         assert(lvalue);
 679         assert(rvalue);
 680         assert(data);
 681
 682         r = l2tp_session_new_static(t, filename, section_line, &session);
 683         if (r < 0)
 684                 return log_oom();
 685
 686         r = safe_atou32(rvalue, &k);
 687         if (r < 0) {
 688                 log_syntax(unit, LOG_WARNING, filename, line, r,
 689                            "Failed to parse L2TP session id. Ignoring assignment: %s", rvalue);
 690                 return 0;
 691         }
 692
 693         if (k == 0) {
 694                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 695                            "Invalid L2TP session id. Ignoring assignment: %s", rvalue);
 696                 return 0;
 697         }
 698
 699         if (streq(lvalue, "SessionId"))
 700                 session->session_id = k;
 701         else
 702                 session->peer_session_id = k;
 703
 704         session = NULL;
 705         return 0;
 706 }
 707
 708 int config_parse_l2tp_session_l2spec(
 709                 const char *unit,
 710                 const char *filename,
 711                 unsigned line,
 712                 const char *section,
 713                 unsigned section_line,
 714                 const char *lvalue,
 715                 int ltype,
 716                 const char *rvalue,
 717                 void *data,
 718                 void *userdata) {
 719
 720         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 721         L2tpTunnel *t = userdata;
 722         L2tpL2specType spec;
 723         int r;
 724
 725         assert(filename);
 726         assert(section);
 727         assert(lvalue);
 728         assert(rvalue);
 729         assert(data);
 730
 731         r = l2tp_session_new_static(t, filename, section_line, &session);
 732         if (r < 0)
 733                 return log_oom();
 734
 735         spec = l2tp_l2spec_type_from_string(rvalue);
 736         if (spec < 0) {
 737                 log_syntax(unit, LOG_WARNING, filename, line, spec,
 738                            "Failed to parse layer2 specific header type. Ignoring assignment: %s", rvalue);
 739                 return 0;
 740         }
 741
 742         session->l2tp_l2spec_type = spec;
 743
 744         session = NULL;
 745         return 0;
 746 }
 747
 748 int config_parse_l2tp_session_name(
 749                 const char *unit,
 750                 const char *filename,
 751                 unsigned line,
 752                 const char *section,
 753                 unsigned section_line,
 754                 const char *lvalue,
 755                 int ltype,
 756                 const char *rvalue,
 757                 void *data,
 758                 void *userdata) {
 759
 760         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 761         L2tpTunnel *t = userdata;
 762         int r;
 763
 764         assert(filename);
 765         assert(section);
 766         assert(lvalue);
 767         assert(rvalue);
 768         assert(data);
 769
 770         r = l2tp_session_new_static(t, filename, section_line, &session);
 771         if (r < 0)
 772                 return log_oom();
 773
 774         if (!ifname_valid(rvalue)) {
 775                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 776                            "Failed to parse L2TP tunnel session name. Ignoring assignment: %s", rvalue);
 777                 return 0;
 778         }
 779
 780         r = free_and_strdup(&session->name, rvalue);
 781         if (r < 0)
 782                 return log_oom();
 783
 784         session = NULL;
 785         return 0;
 786 }
 787
 788 static void l2tp_tunnel_init(NetDev *netdev) {
 789         L2tpTunnel *t;
 790
 791         assert(netdev);
 792
 793         t = L2TP(netdev);
 794
 795         assert(t);
 796
 797         t->l2tp_encap_type = NETDEV_L2TP_ENCAPTYPE_UDP;
 798         t->udp6_csum_rx = true;
 799         t->udp6_csum_tx = true;
 800 }
 801
 802 static int l2tp_session_verify(L2tpSession *session) {
 803         NetDev *netdev;
 804
 805         assert(session);
 806         assert(session->tunnel);
 807
 808         netdev = NETDEV(session->tunnel);
 809
 810         if (section_is_invalid(session->section))
 811                 return -EINVAL;
 812
 813         if (!session->name)
 814                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 815                                               "%s: L2TP session without name configured. "
 816                                               "Ignoring [L2TPSession] section from line %u",
 817                                               session->section->filename, session->section->line);
 818
 819         if (session->session_id == 0 || session->peer_session_id == 0)
 820                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 821                                               "%s: L2TP session without session IDs configured. "
 822                                               "Ignoring [L2TPSession] section from line %u",
 823                                               session->section->filename, session->section->line);
 824
 825         return 0;
 826 }
 827
 828 static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) {
 829         L2tpTunnel *t;
 830         L2tpSession *session;
 831
 832         assert(netdev);
 833         assert(filename);
 834
 835         t = L2TP(netdev);
 836
 837         assert(t);
 838
 839         if (!IN_SET(t->family, AF_INET, AF_INET6))
 840                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 841                                               "%s: L2TP tunnel with invalid address family configured. Ignoring",
 842                                               filename);
 843
 844         if (!in_addr_is_set(t->family, &t->remote))
 845                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 846                                               "%s: L2TP tunnel without a remote address configured. Ignoring",
 847                                               filename);
 848
 849         if (t->tunnel_id == 0 || t->peer_tunnel_id == 0)
 850                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 851                                               "%s: L2TP tunnel without tunnel IDs configured. Ignoring",
 852                                               filename);
 853
 854         ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
 855                 if (l2tp_session_verify(session) < 0)
 856                         l2tp_session_free(session);
 857
 858         return 0;
 859 }
 860
 861 static void l2tp_tunnel_done(NetDev *netdev) {
 862         L2tpTunnel *t;
 863
 864         assert(netdev);
 865
 866         t = L2TP(netdev);
 867
 868         assert(t);
 869
 870         ordered_hashmap_free_with_destructor(t->sessions_by_section, l2tp_session_free);
 871         free(t->local_ifname);
 872 }
 873
 874 const NetDevVTable l2tptnl_vtable = {
 875         .object_size = sizeof(L2tpTunnel),
 876         .init = l2tp_tunnel_init,
 877         .sections = NETDEV_COMMON_SECTIONS "L2TP\0L2TPSession\0",
 878         .create = l2tp_create_tunnel,
 879         .done = l2tp_tunnel_done,
 880         .create_type = NETDEV_CREATE_INDEPENDENT,
 881         .is_ready_to_create = netdev_l2tp_is_ready_to_create,
 882         .config_verify = netdev_l2tp_tunnel_verify,
 883 };