ip/iplink_vxlan.c

   1 /*
   2  * iplink_vxlan.c       VXLAN device support
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Stephen Hemminger <shemminger@vyatta.com
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <net/if.h>
  16 #include <linux/ip.h>
  17 #include <linux/if_link.h>
  18 #include <arpa/inet.h>
  19
  20 #include "rt_names.h"
  21 #include "utils.h"
  22 #include "ip_common.h"
  23
  24 static void print_explain(FILE *f)
  25 {
  26         fprintf(f, "Usage: ... vxlan id VNI [ { group | remote } IP_ADDRESS ] [ local ADDR ]\n");
  27         fprintf(f, "                 [ ttl TTL ] [ tos TOS ] [ flowlabel LABEL ] [ dev PHYS_DEV ]\n");
  28         fprintf(f, "                 [ dstport PORT ] [ srcport MIN MAX ]\n");
  29         fprintf(f, "                 [ [no]learning ] [ [no]proxy ] [ [no]rsc ]\n");
  30         fprintf(f, "                 [ [no]l2miss ] [ [no]l3miss ]\n");
  31         fprintf(f, "                 [ ageing SECONDS ] [ maxaddress NUMBER ]\n");
  32         fprintf(f, "                 [ [no]udpcsum ] [ [no]udp6zerocsumtx ] [ [no]udp6zerocsumrx ]\n");
  33         fprintf(f, "                 [ [no]remcsumtx ] [ [no]remcsumrx ]\n");
  34         fprintf(f, "                 [ [no]external ] [ gbp ] [ gpe ]\n");
  35         fprintf(f, "\n");
  36         fprintf(f, "Where: VNI   := 0-16777215\n");
  37         fprintf(f, "       ADDR  := { IP_ADDRESS | any }\n");
  38         fprintf(f, "       TOS   := { NUMBER | inherit }\n");
  39         fprintf(f, "       TTL   := { 1..255 | inherit }\n");
  40         fprintf(f, "       LABEL := 0-1048575\n");
  41 }
  42
  43 static void explain(void)
  44 {
  45         print_explain(stderr);
  46 }
  47
  48 static int vxlan_parse_opt(struct link_util *lu, int argc, char **argv,
  49                           struct nlmsghdr *n)
  50 {
  51         __u32 vni = 0;
  52         int vni_set = 0;
  53         __u32 saddr = 0;
  54         __u32 gaddr = 0;
  55         __u32 daddr = 0;
  56         struct in6_addr saddr6 = IN6ADDR_ANY_INIT;
  57         struct in6_addr gaddr6 = IN6ADDR_ANY_INIT;
  58         struct in6_addr daddr6 = IN6ADDR_ANY_INIT;
  59         unsigned int link = 0;
  60         __u8 tos = 0;
  61         __u8 ttl = 0;
  62         __u32 label = 0;
  63         __u8 learning = 1;
  64         __u8 proxy = 0;
  65         __u8 rsc = 0;
  66         __u8 l2miss = 0;
  67         __u8 l3miss = 0;
  68         __u8 noage = 0;
  69         __u32 age = 0;
  70         __u32 maxaddr = 0;
  71         __u16 dstport = 0;
  72         __u8 udpcsum = 0;
  73         bool udpcsum_set = false;
  74         __u8 udp6zerocsumtx = 0;
  75         bool udp6zerocsumtx_set = false;
  76         __u8 udp6zerocsumrx = 0;
  77         bool udp6zerocsumrx_set = false;
  78         __u8 remcsumtx = 0;
  79         __u8 remcsumrx = 0;
  80         __u8 metadata = 0;
  81         __u8 gbp = 0;
  82         __u8 gpe = 0;
  83         int dst_port_set = 0;
  84         struct ifla_vxlan_port_range range = { 0, 0 };
  85
  86         while (argc > 0) {
  87                 if (!matches(*argv, "id") ||
  88                     !matches(*argv, "vni")) {
  89                         NEXT_ARG();
  90                         if (get_u32(&vni, *argv, 0) ||
  91                             vni >= 1u << 24)
  92                                 invarg("invalid id", *argv);
  93                         vni_set = 1;
  94                 } else if (!matches(*argv, "group")) {
  95                         NEXT_ARG();
  96                         if (!inet_get_addr(*argv, &gaddr, &gaddr6)) {
  97                                 fprintf(stderr, "Invalid address \"%s\"\n", *argv);
  98                                 return -1;
  99                         }
 100                         if (!IN6_IS_ADDR_MULTICAST(&gaddr6) && !IN_MULTICAST(ntohl(gaddr)))
 101                                 invarg("invalid group address", *argv);
 102                 } else if (!matches(*argv, "remote")) {
 103                         NEXT_ARG();
 104                         if (!inet_get_addr(*argv, &daddr, &daddr6)) {
 105                                 fprintf(stderr, "Invalid address \"%s\"\n", *argv);
 106                                 return -1;
 107                         }
 108                         if (IN6_IS_ADDR_MULTICAST(&daddr6) || IN_MULTICAST(ntohl(daddr)))
 109                                 invarg("invalid remote address", *argv);
 110                 } else if (!matches(*argv, "local")) {
 111                         NEXT_ARG();
 112                         if (strcmp(*argv, "any")) {
 113                                 if (!inet_get_addr(*argv, &saddr, &saddr6)) {
 114                                         fprintf(stderr, "Invalid address \"%s\"\n", *argv);
 115                                         return -1;
 116                                 }
 117                         }
 118
 119                         if (IN_MULTICAST(ntohl(saddr)) || IN6_IS_ADDR_MULTICAST(&saddr6))
 120                                 invarg("invalid local address", *argv);
 121                 } else if (!matches(*argv, "dev")) {
 122                         NEXT_ARG();
 123                         link = if_nametoindex(*argv);
 124                         if (link == 0) {
 125                                 fprintf(stderr, "Cannot find device \"%s\"\n",
 126                                         *argv);
 127                                 exit(-1);
 128                         }
 129                 } else if (!matches(*argv, "ttl") ||
 130                            !matches(*argv, "hoplimit")) {
 131                         unsigned int uval;
 132
 133                         NEXT_ARG();
 134                         if (strcmp(*argv, "inherit") != 0) {
 135                                 if (get_unsigned(&uval, *argv, 0))
 136                                         invarg("invalid TTL", *argv);
 137                                 if (uval > 255)
 138                                         invarg("TTL must be <= 255", *argv);
 139                                 ttl = uval;
 140                         }
 141                 } else if (!matches(*argv, "tos") ||
 142                            !matches(*argv, "dsfield")) {
 143                         __u32 uval;
 144
 145                         NEXT_ARG();
 146                         if (strcmp(*argv, "inherit") != 0) {
 147                                 if (rtnl_dsfield_a2n(&uval, *argv))
 148                                         invarg("bad TOS value", *argv);
 149                                 tos = uval;
 150                         } else
 151                                 tos = 1;
 152                 } else if (!matches(*argv, "label") ||
 153                            !matches(*argv, "flowlabel")) {
 154                         __u32 uval;
 155
 156                         NEXT_ARG();
 157                         if (get_u32(&uval, *argv, 0) ||
 158                             (uval & ~LABEL_MAX_MASK))
 159                                 invarg("invalid flowlabel", *argv);
 160                         label = htonl(uval);
 161                 } else if (!matches(*argv, "ageing")) {
 162                         NEXT_ARG();
 163                         if (strcmp(*argv, "none") == 0)
 164                                 noage = 1;
 165                         else if (get_u32(&age, *argv, 0))
 166                                 invarg("ageing timer", *argv);
 167                 } else if (!matches(*argv, "maxaddress")) {
 168                         NEXT_ARG();
 169                         if (strcmp(*argv, "unlimited") == 0)
 170                                 maxaddr = 0;
 171                         else if (get_u32(&maxaddr, *argv, 0))
 172                                 invarg("max addresses", *argv);
 173                 } else if (!matches(*argv, "port") ||
 174                            !matches(*argv, "srcport")) {
 175                         NEXT_ARG();
 176                         if (get_be16(&range.low, *argv, 0))
 177                                 invarg("min port", *argv);
 178                         NEXT_ARG();
 179                         if (get_be16(&range.high, *argv, 0))
 180                                 invarg("max port", *argv);
 181                 } else if (!matches(*argv, "dstport")) {
 182                         NEXT_ARG();
 183                         if (get_u16(&dstport, *argv, 0))
 184                                 invarg("dst port", *argv);
 185                         dst_port_set = 1;
 186                 } else if (!matches(*argv, "nolearning")) {
 187                         learning = 0;
 188                 } else if (!matches(*argv, "learning")) {
 189                         learning = 1;
 190                 } else if (!matches(*argv, "noproxy")) {
 191                         proxy = 0;
 192                 } else if (!matches(*argv, "proxy")) {
 193                         proxy = 1;
 194                 } else if (!matches(*argv, "norsc")) {
 195                         rsc = 0;
 196                 } else if (!matches(*argv, "rsc")) {
 197                         rsc = 1;
 198                 } else if (!matches(*argv, "nol2miss")) {
 199                         l2miss = 0;
 200                 } else if (!matches(*argv, "l2miss")) {
 201                         l2miss = 1;
 202                 } else if (!matches(*argv, "nol3miss")) {
 203                         l3miss = 0;
 204                 } else if (!matches(*argv, "l3miss")) {
 205                         l3miss = 1;
 206                 } else if (!matches(*argv, "udpcsum")) {
 207                         udpcsum = 1;
 208                         udpcsum_set = true;
 209                 } else if (!matches(*argv, "noudpcsum")) {
 210                         udpcsum = 0;
 211                         udpcsum_set = true;
 212                 } else if (!matches(*argv, "udp6zerocsumtx")) {
 213                         udp6zerocsumtx = 1;
 214                         udp6zerocsumtx_set = true;
 215                 } else if (!matches(*argv, "noudp6zerocsumtx")) {
 216                         udp6zerocsumtx = 0;
 217                         udp6zerocsumtx_set = true;
 218                 } else if (!matches(*argv, "udp6zerocsumrx")) {
 219                         udp6zerocsumrx = 1;
 220                         udp6zerocsumrx_set = true;
 221                 } else if (!matches(*argv, "noudp6zerocsumrx")) {
 222                         udp6zerocsumrx = 0;
 223                         udp6zerocsumrx_set = true;
 224                 } else if (!matches(*argv, "remcsumtx")) {
 225                         remcsumtx = 1;
 226                 } else if (!matches(*argv, "noremcsumtx")) {
 227                         remcsumtx = 0;
 228                 } else if (!matches(*argv, "remcsumrx")) {
 229                         remcsumrx = 1;
 230                 } else if (!matches(*argv, "noremcsumrx")) {
 231                         remcsumrx = 0;
 232                 } else if (!matches(*argv, "external")) {
 233                         metadata = 1;
 234                         learning = 0;
 235                 } else if (!matches(*argv, "noexternal")) {
 236                         metadata = 0;
 237                 } else if (!matches(*argv, "gbp")) {
 238                         gbp = 1;
 239                 } else if (!matches(*argv, "gpe")) {
 240                         gpe = 1;
 241                 } else if (matches(*argv, "help") == 0) {
 242                         explain();
 243                         return -1;
 244                 } else {
 245                         fprintf(stderr, "vxlan: unknown command \"%s\"?\n", *argv);
 246                         explain();
 247                         return -1;
 248                 }
 249                 argc--, argv++;
 250         }
 251
 252         if (metadata && vni_set) {
 253                 fprintf(stderr, "vxlan: both 'external' and vni cannot be specified\n");
 254                 return -1;
 255         }
 256
 257         if (!metadata && !vni_set) {
 258                 fprintf(stderr, "vxlan: missing virtual network identifier\n");
 259                 return -1;
 260         }
 261
 262         if ((gaddr && daddr) ||
 263             (!IN6_IS_ADDR_UNSPECIFIED(&gaddr6) &&
 264              !IN6_IS_ADDR_UNSPECIFIED(&daddr6))) {
 265                 fprintf(stderr, "vxlan: both group and remote cannot be specified\n");
 266                 return -1;
 267         }
 268
 269         if ((gaddr || !IN6_IS_ADDR_UNSPECIFIED(&gaddr6)) && !link) {
 270                 fprintf(stderr, "vxlan: 'group' requires 'dev' to be specified\n");
 271                 return -1;
 272         }
 273
 274         if (!dst_port_set && gpe) {
 275                 dstport = 4790;
 276         } else if (!dst_port_set) {
 277                 fprintf(stderr, "vxlan: destination port not specified\n"
 278                         "Will use Linux kernel default (non-standard value)\n");
 279                 fprintf(stderr,
 280                         "Use 'dstport 4789' to get the IANA assigned value\n"
 281                         "Use 'dstport 0' to get default and quiet this message\n");
 282         }
 283
 284         addattr32(n, 1024, IFLA_VXLAN_ID, vni);
 285         if (gaddr)
 286                 addattr_l(n, 1024, IFLA_VXLAN_GROUP, &gaddr, 4);
 287         else if (daddr)
 288                 addattr_l(n, 1024, IFLA_VXLAN_GROUP, &daddr, 4);
 289         else if (!IN6_IS_ADDR_UNSPECIFIED(&gaddr6))
 290                 addattr_l(n, 1024, IFLA_VXLAN_GROUP6, &gaddr6, sizeof(struct in6_addr));
 291         else if (!IN6_IS_ADDR_UNSPECIFIED(&daddr6))
 292                 addattr_l(n, 1024, IFLA_VXLAN_GROUP6, &daddr6, sizeof(struct in6_addr));
 293         else if (preferred_family == AF_INET)
 294                 addattr_l(n, 1024, IFLA_VXLAN_GROUP, &daddr, 4);
 295         else if (preferred_family == AF_INET6)
 296                 addattr_l(n, 1024, IFLA_VXLAN_GROUP6, &daddr6, sizeof(struct in6_addr));
 297
 298         if (saddr)
 299                 addattr_l(n, 1024, IFLA_VXLAN_LOCAL, &saddr, 4);
 300         else if (!IN6_IS_ADDR_UNSPECIFIED(&saddr6))
 301                 addattr_l(n, 1024, IFLA_VXLAN_LOCAL6, &saddr6, sizeof(struct in6_addr));
 302
 303         if (link)
 304                 addattr32(n, 1024, IFLA_VXLAN_LINK, link);
 305         addattr32(n, 1024, IFLA_VXLAN_LABEL, label);
 306         addattr8(n, 1024, IFLA_VXLAN_TTL, ttl);
 307         addattr8(n, 1024, IFLA_VXLAN_TOS, tos);
 308         addattr8(n, 1024, IFLA_VXLAN_LEARNING, learning);
 309         addattr8(n, 1024, IFLA_VXLAN_PROXY, proxy);
 310         addattr8(n, 1024, IFLA_VXLAN_RSC, rsc);
 311         addattr8(n, 1024, IFLA_VXLAN_L2MISS, l2miss);
 312         addattr8(n, 1024, IFLA_VXLAN_L3MISS, l3miss);
 313         addattr8(n, 1024, IFLA_VXLAN_REMCSUM_TX, remcsumtx);
 314         addattr8(n, 1024, IFLA_VXLAN_REMCSUM_RX, remcsumrx);
 315         addattr8(n, 1024, IFLA_VXLAN_COLLECT_METADATA, metadata);
 316
 317         if (udpcsum_set)
 318                 addattr8(n, 1024, IFLA_VXLAN_UDP_CSUM, udpcsum);
 319         if (udp6zerocsumtx_set)
 320                 addattr8(n, 1024, IFLA_VXLAN_UDP_ZERO_CSUM6_TX, udp6zerocsumtx);
 321         if (udp6zerocsumrx_set)
 322                 addattr8(n, 1024, IFLA_VXLAN_UDP_ZERO_CSUM6_RX, udp6zerocsumrx);
 323         if (noage)
 324                 addattr32(n, 1024, IFLA_VXLAN_AGEING, 0);
 325         else if (age)
 326                 addattr32(n, 1024, IFLA_VXLAN_AGEING, age);
 327         if (maxaddr)
 328                 addattr32(n, 1024, IFLA_VXLAN_LIMIT, maxaddr);
 329         if (range.low || range.high)
 330                 addattr_l(n, 1024, IFLA_VXLAN_PORT_RANGE,
 331                           &range, sizeof(range));
 332         if (dstport)
 333                 addattr16(n, 1024, IFLA_VXLAN_PORT, htons(dstport));
 334
 335         if (gbp)
 336                 addattr_l(n, 1024, IFLA_VXLAN_GBP, NULL, 0);
 337         if (gpe)
 338                 addattr_l(n, 1024, IFLA_VXLAN_GPE, NULL, 0);
 339
 340
 341         return 0;
 342 }
 343
 344 static void vxlan_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 345 {
 346         __u32 vni;
 347         unsigned int link;
 348         __u8 tos;
 349         __u32 maxaddr;
 350         char s2[64];
 351
 352         if (!tb)
 353                 return;
 354
 355         if (!tb[IFLA_VXLAN_ID] ||
 356             RTA_PAYLOAD(tb[IFLA_VXLAN_ID]) < sizeof(__u32))
 357                 return;
 358
 359         vni = rta_getattr_u32(tb[IFLA_VXLAN_ID]);
 360         fprintf(f, "id %u ", vni);
 361
 362         if (tb[IFLA_VXLAN_GROUP]) {
 363                 __be32 addr = rta_getattr_u32(tb[IFLA_VXLAN_GROUP]);
 364
 365                 if (addr) {
 366                         if (IN_MULTICAST(ntohl(addr)))
 367                                 fprintf(f, "group %s ",
 368                                         format_host(AF_INET, 4, &addr));
 369                         else
 370                                 fprintf(f, "remote %s ",
 371                                         format_host(AF_INET, 4, &addr));
 372                 }
 373         } else if (tb[IFLA_VXLAN_GROUP6]) {
 374                 struct in6_addr addr;
 375
 376                 memcpy(&addr, RTA_DATA(tb[IFLA_VXLAN_GROUP6]), sizeof(struct in6_addr));
 377                 if (!IN6_IS_ADDR_UNSPECIFIED(&addr)) {
 378                         if (IN6_IS_ADDR_MULTICAST(&addr))
 379                                 fprintf(f, "group %s ",
 380                                         format_host(AF_INET6, sizeof(struct in6_addr), &addr));
 381                         else
 382                                 fprintf(f, "remote %s ",
 383                                         format_host(AF_INET6, sizeof(struct in6_addr), &addr));
 384                 }
 385         }
 386
 387         if (tb[IFLA_VXLAN_LOCAL]) {
 388                 __be32 addr = rta_getattr_u32(tb[IFLA_VXLAN_LOCAL]);
 389
 390                 if (addr)
 391                         fprintf(f, "local %s ",
 392                                 format_host(AF_INET, 4, &addr));
 393         } else if (tb[IFLA_VXLAN_LOCAL6]) {
 394                 struct in6_addr addr;
 395
 396                 memcpy(&addr, RTA_DATA(tb[IFLA_VXLAN_LOCAL6]), sizeof(struct in6_addr));
 397                 if (!IN6_IS_ADDR_UNSPECIFIED(&addr))
 398                         fprintf(f, "local %s ",
 399                                 format_host(AF_INET6, sizeof(struct in6_addr), &addr));
 400         }
 401
 402         if (tb[IFLA_VXLAN_LINK] &&
 403             (link = rta_getattr_u32(tb[IFLA_VXLAN_LINK]))) {
 404                 const char *n = if_indextoname(link, s2);
 405
 406                 if (n)
 407                         fprintf(f, "dev %s ", n);
 408                 else
 409                         fprintf(f, "dev %u ", link);
 410         }
 411
 412         if (tb[IFLA_VXLAN_PORT_RANGE]) {
 413                 const struct ifla_vxlan_port_range *r
 414                         = RTA_DATA(tb[IFLA_VXLAN_PORT_RANGE]);
 415                 fprintf(f, "srcport %u %u ", ntohs(r->low), ntohs(r->high));
 416         }
 417
 418         if (tb[IFLA_VXLAN_PORT])
 419                 fprintf(f, "dstport %u ",
 420                         rta_getattr_be16(tb[IFLA_VXLAN_PORT]));
 421
 422         if (tb[IFLA_VXLAN_LEARNING] &&
 423             !rta_getattr_u8(tb[IFLA_VXLAN_LEARNING]))
 424                 fputs("nolearning ", f);
 425
 426         if (tb[IFLA_VXLAN_PROXY] && rta_getattr_u8(tb[IFLA_VXLAN_PROXY]))
 427                 fputs("proxy ", f);
 428
 429         if (tb[IFLA_VXLAN_RSC] && rta_getattr_u8(tb[IFLA_VXLAN_RSC]))
 430                 fputs("rsc ", f);
 431
 432         if (tb[IFLA_VXLAN_L2MISS] && rta_getattr_u8(tb[IFLA_VXLAN_L2MISS]))
 433                 fputs("l2miss ", f);
 434
 435         if (tb[IFLA_VXLAN_L3MISS] && rta_getattr_u8(tb[IFLA_VXLAN_L3MISS]))
 436                 fputs("l3miss ", f);
 437
 438         if (tb[IFLA_VXLAN_TOS] &&
 439             (tos = rta_getattr_u8(tb[IFLA_VXLAN_TOS]))) {
 440                 if (tos == 1)
 441                         fprintf(f, "tos inherit ");
 442                 else
 443                         fprintf(f, "tos %#x ", tos);
 444         }
 445
 446         if (tb[IFLA_VXLAN_TTL]) {
 447                 __u8 ttl = rta_getattr_u8(tb[IFLA_VXLAN_TTL]);
 448
 449                 if (ttl)
 450                         fprintf(f, "ttl %d ", ttl);
 451         }
 452
 453         if (tb[IFLA_VXLAN_LABEL]) {
 454                 __u32 label = rta_getattr_u32(tb[IFLA_VXLAN_LABEL]);
 455
 456                 if (label)
 457                         fprintf(f, "flowlabel %#x ", ntohl(label));
 458         }
 459
 460         if (tb[IFLA_VXLAN_AGEING]) {
 461                 __u32 age = rta_getattr_u32(tb[IFLA_VXLAN_AGEING]);
 462
 463                 if (age == 0)
 464                         fprintf(f, "ageing none ");
 465                 else
 466                         fprintf(f, "ageing %u ", age);
 467         }
 468
 469         if (tb[IFLA_VXLAN_LIMIT] &&
 470             ((maxaddr = rta_getattr_u32(tb[IFLA_VXLAN_LIMIT])) != 0))
 471                     fprintf(f, "maxaddr %u ", maxaddr);
 472
 473         if (tb[IFLA_VXLAN_UDP_CSUM]) {
 474                 if (!rta_getattr_u8(tb[IFLA_VXLAN_UDP_CSUM]))
 475                         fputs("no", f);
 476                 fputs("udpcsum ", f);
 477         }
 478
 479         if (tb[IFLA_VXLAN_UDP_ZERO_CSUM6_TX]) {
 480                 if (!rta_getattr_u8(tb[IFLA_VXLAN_UDP_ZERO_CSUM6_TX]))
 481                         fputs("no", f);
 482                 fputs("udp6zerocsumtx ", f);
 483         }
 484
 485         if (tb[IFLA_VXLAN_UDP_ZERO_CSUM6_RX]) {
 486                 if (!rta_getattr_u8(tb[IFLA_VXLAN_UDP_ZERO_CSUM6_RX]))
 487                         fputs("no", f);
 488                 fputs("udp6zerocsumrx ", f);
 489         }
 490
 491         if (tb[IFLA_VXLAN_REMCSUM_TX] &&
 492             rta_getattr_u8(tb[IFLA_VXLAN_REMCSUM_TX]))
 493                 fputs("remcsumtx ", f);
 494
 495         if (tb[IFLA_VXLAN_REMCSUM_RX] &&
 496             rta_getattr_u8(tb[IFLA_VXLAN_REMCSUM_RX]))
 497                 fputs("remcsumrx ", f);
 498
 499         if (tb[IFLA_VXLAN_COLLECT_METADATA] &&
 500             rta_getattr_u8(tb[IFLA_VXLAN_COLLECT_METADATA]))
 501                 fputs("external ", f);
 502
 503         if (tb[IFLA_VXLAN_GBP])
 504                 fputs("gbp ", f);
 505         if (tb[IFLA_VXLAN_GPE])
 506                 fputs("gpe ", f);
 507 }
 508
 509 static void vxlan_print_help(struct link_util *lu, int argc, char **argv,
 510         FILE *f)
 511 {
 512         print_explain(f);
 513 }
 514
 515 struct link_util vxlan_link_util = {
 516         .id             = "vxlan",
 517         .maxattr        = IFLA_VXLAN_MAX,
 518         .parse_opt      = vxlan_parse_opt,
 519         .print_opt      = vxlan_print_opt,
 520         .print_help     = vxlan_print_help,
 521 };