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 = ASSERT_PTR(userdata);
 485         const char *p = ASSERT_PTR(rvalue);
 486         union in_addr_union a;
 487         int r, f;
 488
 489         assert(filename);
 490         assert(lvalue);
 491
 492         if (isempty(rvalue)) {
 493                 t->local_ifname = mfree(t->local_ifname);
 494                 t->local_address_type = NETDEV_L2TP_LOCAL_ADDRESS_AUTO;
 495                 t->local = IN_ADDR_NULL;
 496
 497                 if (!in_addr_is_set(t->family, &t->remote))
 498                         /* If Remote= is not specified yet, then also clear family. */
 499                         t->family = AF_UNSPEC;
 500
 501                 return 0;
 502         }
 503
 504         r = extract_first_word(&p, &addr_or_type, "@", 0);
 505         if (r < 0)
 506                 return log_oom();
 507         if (r == 0) {
 508                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 509                            "Invalid L2TP Tunnel address specified in %s=, ignoring assignment: %s", lvalue, rvalue);
 510                 return 0;
 511         }
 512
 513         if (!isempty(p)) {
 514                 if (!ifname_valid_full(p, IFNAME_VALID_ALTERNATIVE)) {
 515                         log_syntax(unit, LOG_WARNING, filename, line, 0,
 516                                    "Invalid interface name specified in %s=, ignoring assignment: %s", lvalue, rvalue);
 517                         return 0;
 518                 }
 519
 520                 ifname = strdup(p);
 521                 if (!ifname)
 522                         return log_oom();
 523         }
 524
 525         type = l2tp_local_address_type_from_string(rvalue);
 526         if (type >= 0) {
 527                 free_and_replace(t->local_ifname, ifname);
 528                 t->local_address_type = type;
 529                 t->local = IN_ADDR_NULL;
 530
 531                 if (!in_addr_is_set(t->family, &t->remote))
 532                         /* If Remote= is not specified yet, then also clear family. */
 533                         t->family = AF_UNSPEC;
 534
 535                 return 0;
 536         }
 537
 538         r = in_addr_from_string_auto(rvalue, &f, &a);
 539         if (r < 0) {
 540                 log_syntax(unit, LOG_WARNING, filename, line, r,
 541                            "Invalid L2TP Tunnel local address specified, ignoring assignment: %s", rvalue);
 542                 return 0;
 543         }
 544
 545         if (in_addr_is_null(f, &a)) {
 546                 log_syntax(unit, LOG_WARNING, filename, line, r,
 547                            "L2TP Tunnel local address cannot be null, ignoring assignment: %s", rvalue);
 548                 return 0;
 549         }
 550
 551         if (t->family != AF_UNSPEC && t->family != f) {
 552                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 553                            "Address family does not match the previous assignment, ignoring assignment: %s", rvalue);
 554                 return 0;
 555         }
 556
 557         t->family = f;
 558         t->local = a;
 559         free_and_replace(t->local_ifname, ifname);
 560         t->local_address_type = _NETDEV_L2TP_LOCAL_ADDRESS_INVALID;
 561         return 0;
 562 }
 563
 564 int config_parse_l2tp_tunnel_remote_address(
 565                 const char *unit,
 566                 const char *filename,
 567                 unsigned line,
 568                 const char *section,
 569                 unsigned section_line,
 570                 const char *lvalue,
 571                 int ltype,
 572                 const char *rvalue,
 573                 void *data,
 574                 void *userdata) {
 575
 576         L2tpTunnel *t = ASSERT_PTR(userdata);
 577         union in_addr_union a;
 578         int r, f;
 579
 580         assert(filename);
 581         assert(lvalue);
 582         assert(rvalue);
 583
 584         if (isempty(rvalue)) {
 585                 t->remote = IN_ADDR_NULL;
 586
 587                 if (!in_addr_is_set(t->family, &t->local))
 588                         /* If Local= is not specified yet, then also clear family. */
 589                         t->family = AF_UNSPEC;
 590
 591                 return 0;
 592         }
 593
 594         r = in_addr_from_string_auto(rvalue, &f, &a);
 595         if (r < 0) {
 596                 log_syntax(unit, LOG_WARNING, filename, line, r,
 597                            "Invalid L2TP Tunnel remote address specified, ignoring assignment: %s", rvalue);
 598                 return 0;
 599         }
 600
 601         if (in_addr_is_null(f, &a)) {
 602                 log_syntax(unit, LOG_WARNING, filename, line, r,
 603                            "L2TP Tunnel remote address cannot be null, ignoring assignment: %s", rvalue);
 604                 return 0;
 605         }
 606
 607         if (t->family != AF_UNSPEC && t->family != f) {
 608                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 609                            "Address family does not match the previous assignment, ignoring assignment: %s", rvalue);
 610                 return 0;
 611         }
 612
 613         t->family = f;
 614         t->remote = a;
 615         return 0;
 616 }
 617
 618 int config_parse_l2tp_tunnel_id(
 619                 const char *unit,
 620                 const char *filename,
 621                 unsigned line,
 622                 const char *section,
 623                 unsigned section_line,
 624                 const char *lvalue,
 625                 int ltype,
 626                 const char *rvalue,
 627                 void *data,
 628                 void *userdata) {
 629
 630         uint32_t *id = data, k;
 631         int r;
 632
 633         assert(filename);
 634         assert(lvalue);
 635         assert(rvalue);
 636         assert(data);
 637
 638         r = safe_atou32(rvalue, &k);
 639         if (r < 0) {
 640                 log_syntax(unit, LOG_WARNING, filename, line, r,
 641                            "Failed to parse L2TP tunnel id. Ignoring assignment: %s", rvalue);
 642                 return 0;
 643         }
 644
 645         if (k == 0) {
 646                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 647                            "Invalid L2TP tunnel id. Ignoring assignment: %s", rvalue);
 648                 return 0;
 649         }
 650
 651         *id = k;
 652
 653         return 0;
 654 }
 655
 656 int config_parse_l2tp_session_id(
 657                 const char *unit,
 658                 const char *filename,
 659                 unsigned line,
 660                 const char *section,
 661                 unsigned section_line,
 662                 const char *lvalue,
 663                 int ltype,
 664                 const char *rvalue,
 665                 void *data,
 666                 void *userdata) {
 667
 668         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 669         L2tpTunnel *t = userdata;
 670         uint32_t k;
 671         int r;
 672
 673         assert(filename);
 674         assert(section);
 675         assert(lvalue);
 676         assert(rvalue);
 677         assert(data);
 678
 679         r = l2tp_session_new_static(t, filename, section_line, &session);
 680         if (r < 0)
 681                 return log_oom();
 682
 683         r = safe_atou32(rvalue, &k);
 684         if (r < 0) {
 685                 log_syntax(unit, LOG_WARNING, filename, line, r,
 686                            "Failed to parse L2TP session id. Ignoring assignment: %s", rvalue);
 687                 return 0;
 688         }
 689
 690         if (k == 0) {
 691                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 692                            "Invalid L2TP session id. Ignoring assignment: %s", rvalue);
 693                 return 0;
 694         }
 695
 696         if (streq(lvalue, "SessionId"))
 697                 session->session_id = k;
 698         else
 699                 session->peer_session_id = k;
 700
 701         session = NULL;
 702         return 0;
 703 }
 704
 705 int config_parse_l2tp_session_l2spec(
 706                 const char *unit,
 707                 const char *filename,
 708                 unsigned line,
 709                 const char *section,
 710                 unsigned section_line,
 711                 const char *lvalue,
 712                 int ltype,
 713                 const char *rvalue,
 714                 void *data,
 715                 void *userdata) {
 716
 717         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 718         L2tpTunnel *t = userdata;
 719         L2tpL2specType spec;
 720         int r;
 721
 722         assert(filename);
 723         assert(section);
 724         assert(lvalue);
 725         assert(rvalue);
 726         assert(data);
 727
 728         r = l2tp_session_new_static(t, filename, section_line, &session);
 729         if (r < 0)
 730                 return log_oom();
 731
 732         spec = l2tp_l2spec_type_from_string(rvalue);
 733         if (spec < 0) {
 734                 log_syntax(unit, LOG_WARNING, filename, line, spec,
 735                            "Failed to parse layer2 specific header type. Ignoring assignment: %s", rvalue);
 736                 return 0;
 737         }
 738
 739         session->l2tp_l2spec_type = spec;
 740
 741         session = NULL;
 742         return 0;
 743 }
 744
 745 int config_parse_l2tp_session_name(
 746                 const char *unit,
 747                 const char *filename,
 748                 unsigned line,
 749                 const char *section,
 750                 unsigned section_line,
 751                 const char *lvalue,
 752                 int ltype,
 753                 const char *rvalue,
 754                 void *data,
 755                 void *userdata) {
 756
 757         _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL;
 758         L2tpTunnel *t = userdata;
 759         int r;
 760
 761         assert(filename);
 762         assert(section);
 763         assert(lvalue);
 764         assert(rvalue);
 765         assert(data);
 766
 767         r = l2tp_session_new_static(t, filename, section_line, &session);
 768         if (r < 0)
 769                 return log_oom();
 770
 771         if (!ifname_valid(rvalue)) {
 772                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 773                            "Failed to parse L2TP tunnel session name. Ignoring assignment: %s", rvalue);
 774                 return 0;
 775         }
 776
 777         r = free_and_strdup(&session->name, rvalue);
 778         if (r < 0)
 779                 return log_oom();
 780
 781         session = NULL;
 782         return 0;
 783 }
 784
 785 static void l2tp_tunnel_init(NetDev *netdev) {
 786         L2tpTunnel *t;
 787
 788         assert(netdev);
 789
 790         t = L2TP(netdev);
 791
 792         assert(t);
 793
 794         t->l2tp_encap_type = NETDEV_L2TP_ENCAPTYPE_UDP;
 795         t->udp6_csum_rx = true;
 796         t->udp6_csum_tx = true;
 797 }
 798
 799 static int l2tp_session_verify(L2tpSession *session) {
 800         NetDev *netdev;
 801
 802         assert(session);
 803         assert(session->tunnel);
 804
 805         netdev = NETDEV(session->tunnel);
 806
 807         if (section_is_invalid(session->section))
 808                 return -EINVAL;
 809
 810         if (!session->name)
 811                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 812                                               "%s: L2TP session without name configured. "
 813                                               "Ignoring [L2TPSession] section from line %u",
 814                                               session->section->filename, session->section->line);
 815
 816         if (session->session_id == 0 || session->peer_session_id == 0)
 817                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 818                                               "%s: L2TP session without session IDs configured. "
 819                                               "Ignoring [L2TPSession] section from line %u",
 820                                               session->section->filename, session->section->line);
 821
 822         return 0;
 823 }
 824
 825 static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) {
 826         L2tpTunnel *t;
 827         L2tpSession *session;
 828
 829         assert(netdev);
 830         assert(filename);
 831
 832         t = L2TP(netdev);
 833
 834         assert(t);
 835
 836         if (!IN_SET(t->family, AF_INET, AF_INET6))
 837                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 838                                               "%s: L2TP tunnel with invalid address family configured. Ignoring",
 839                                               filename);
 840
 841         if (!in_addr_is_set(t->family, &t->remote))
 842                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 843                                               "%s: L2TP tunnel without a remote address configured. Ignoring",
 844                                               filename);
 845
 846         if (t->tunnel_id == 0 || t->peer_tunnel_id == 0)
 847                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
 848                                               "%s: L2TP tunnel without tunnel IDs configured. Ignoring",
 849                                               filename);
 850
 851         ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
 852                 if (l2tp_session_verify(session) < 0)
 853                         l2tp_session_free(session);
 854
 855         return 0;
 856 }
 857
 858 static void l2tp_tunnel_done(NetDev *netdev) {
 859         L2tpTunnel *t;
 860
 861         assert(netdev);
 862
 863         t = L2TP(netdev);
 864
 865         assert(t);
 866
 867         ordered_hashmap_free_with_destructor(t->sessions_by_section, l2tp_session_free);
 868         free(t->local_ifname);
 869 }
 870
 871 const NetDevVTable l2tptnl_vtable = {
 872         .object_size = sizeof(L2tpTunnel),
 873         .init = l2tp_tunnel_init,
 874         .sections = NETDEV_COMMON_SECTIONS "L2TP\0L2TPSession\0",
 875         .create = l2tp_create_tunnel,
 876         .done = l2tp_tunnel_done,
 877         .create_type = NETDEV_CREATE_INDEPENDENT,
 878         .is_ready_to_create = netdev_l2tp_is_ready_to_create,
 879         .config_verify = netdev_l2tp_tunnel_verify,
 880 };