ip/link_iptnl.c

   1 /*
   2  * link_iptnl.c ipip and sit driver module
   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:     Nicolas Dichtel <nicolas.dichtel@6wind.com>
  10  *
  11  */
  12
  13 #include <string.h>
  14 #include <net/if.h>
  15 #include <sys/types.h>
  16 #include <sys/socket.h>
  17 #include <arpa/inet.h>
  18
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <linux/if_tunnel.h>
  22 #include "rt_names.h"
  23 #include "utils.h"
  24 #include "ip_common.h"
  25 #include "tunnel.h"
  26
  27 static void print_usage(FILE *f, int sit)
  28 {
  29         const char *type = sit ? "sit " : "ipip";
  30
  31         fprintf(f,
  32                 "Usage: ... %s [ remote ADDR ]\n"
  33                 "                [ local ADDR ]\n"
  34                 "                [ ttl TTL ]\n"
  35                 "                [ tos TOS ]\n"
  36                 "                [ [no]pmtudisc ]\n"
  37                 "                [ dev PHYS_DEV ]\n"
  38                 "                [ 6rd-prefix ADDR ]\n"
  39                 "                [ 6rd-relay_prefix ADDR ]\n"
  40                 "                [ 6rd-reset ]\n"
  41                 "                [ noencap ]\n"
  42                 "                [ encap { fou | gue | none } ]\n"
  43                 "                [ encap-sport PORT ]\n"
  44                 "                [ encap-dport PORT ]\n"
  45                 "                [ [no]encap-csum ]\n"
  46                 "                [ [no]encap-csum6 ]\n"
  47                 "                [ [no]encap-remcsum ]\n",
  48                 type
  49         );
  50         if (sit) {
  51                 fprintf(f, "          [ mode { ip6ip | ipip | mplsip | any } ]\n");
  52                 fprintf(f, "          [ isatap ]\n");
  53         } else {
  54                 fprintf(f, "          [ mode { ipip | mplsip | any } ]\n");
  55         }
  56         fprintf(f, "                [ external ]\n");
  57         fprintf(f, "                [ fwmark MARK ]\n");
  58         fprintf(f, "\n");
  59         fprintf(f, "Where: ADDR := { IP_ADDRESS | any }\n");
  60         fprintf(f, "       TOS  := { NUMBER | inherit }\n");
  61         fprintf(f, "       TTL  := { 1..255 | inherit }\n");
  62         fprintf(f, "       MARK := { 0x0..0xffffffff }\n");
  63 }
  64
  65 static void usage(int sit) __attribute__((noreturn));
  66 static void usage(int sit)
  67 {
  68         print_usage(stderr, sit);
  69         exit(-1);
  70 }
  71
  72 static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
  73                               struct nlmsghdr *n)
  74 {
  75         struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
  76         struct {
  77                 struct nlmsghdr n;
  78                 struct ifinfomsg i;
  79         } req = {
  80                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi)),
  81                 .n.nlmsg_flags = NLM_F_REQUEST,
  82                 .n.nlmsg_type = RTM_GETLINK,
  83                 .i.ifi_family = preferred_family,
  84                 .i.ifi_index = ifi->ifi_index,
  85         };
  86         struct nlmsghdr *answer;
  87         struct rtattr *tb[IFLA_MAX + 1];
  88         struct rtattr *linkinfo[IFLA_INFO_MAX+1];
  89         struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];
  90         int len;
  91         __u32 link = 0;
  92         __u32 laddr = 0;
  93         __u32 raddr = 0;
  94         __u8 ttl = 0;
  95         __u8 tos = 0;
  96         __u8 pmtudisc = 1;
  97         __u16 iflags = 0;
  98         __u8 proto = 0;
  99         struct in6_addr ip6rdprefix = {};
 100         __u16 ip6rdprefixlen = 0;
 101         __u32 ip6rdrelayprefix = 0;
 102         __u16 ip6rdrelayprefixlen = 0;
 103         __u16 encaptype = 0;
 104         __u16 encapflags = 0;
 105         __u16 encapsport = 0;
 106         __u16 encapdport = 0;
 107         __u8 metadata = 0;
 108         __u32 fwmark = 0;
 109
 110         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
 111                 if (rtnl_talk(&rth, &req.n, &answer) < 0) {
 112 get_failed:
 113                         fprintf(stderr,
 114                                 "Failed to get existing tunnel info.\n");
 115                         return -1;
 116                 }
 117
 118                 len = answer->nlmsg_len;
 119                 len -= NLMSG_LENGTH(sizeof(*ifi));
 120                 if (len < 0)
 121                         goto get_failed;
 122
 123                 parse_rtattr(tb, IFLA_MAX, IFLA_RTA(NLMSG_DATA(answer)), len);
 124
 125                 if (!tb[IFLA_LINKINFO])
 126                         goto get_failed;
 127
 128                 parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
 129
 130                 if (!linkinfo[IFLA_INFO_DATA])
 131                         goto get_failed;
 132
 133                 parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,
 134                                     linkinfo[IFLA_INFO_DATA]);
 135
 136                 if (iptuninfo[IFLA_IPTUN_LOCAL])
 137                         laddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LOCAL]);
 138
 139                 if (iptuninfo[IFLA_IPTUN_REMOTE])
 140                         raddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_REMOTE]);
 141
 142                 if (iptuninfo[IFLA_IPTUN_TTL])
 143                         ttl = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);
 144
 145                 if (iptuninfo[IFLA_IPTUN_TOS])
 146                         tos = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TOS]);
 147
 148                 if (iptuninfo[IFLA_IPTUN_PMTUDISC])
 149                         pmtudisc =
 150                                 rta_getattr_u8(iptuninfo[IFLA_IPTUN_PMTUDISC]);
 151
 152                 if (iptuninfo[IFLA_IPTUN_FLAGS])
 153                         iflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_FLAGS]);
 154
 155                 if (iptuninfo[IFLA_IPTUN_LINK])
 156                         link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);
 157
 158                 if (iptuninfo[IFLA_IPTUN_PROTO])
 159                         proto = rta_getattr_u8(iptuninfo[IFLA_IPTUN_PROTO]);
 160
 161                 if (iptuninfo[IFLA_IPTUN_ENCAP_TYPE])
 162                         encaptype = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_TYPE]);
 163                 if (iptuninfo[IFLA_IPTUN_ENCAP_FLAGS])
 164                         encapflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_FLAGS]);
 165                 if (iptuninfo[IFLA_IPTUN_ENCAP_SPORT])
 166                         encapsport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_SPORT]);
 167                 if (iptuninfo[IFLA_IPTUN_ENCAP_DPORT])
 168                         encapdport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_DPORT]);
 169                 if (iptuninfo[IFLA_IPTUN_6RD_PREFIX])
 170                         memcpy(&ip6rdprefix,
 171                                RTA_DATA(iptuninfo[IFLA_IPTUN_6RD_PREFIX]),
 172                                sizeof(laddr));
 173
 174                 if (iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN])
 175                         ip6rdprefixlen =
 176                                 rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN]);
 177
 178                 if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX])
 179                         ip6rdrelayprefix =
 180                                 rta_getattr_u32(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX]);
 181
 182                 if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN])
 183                         ip6rdrelayprefixlen =
 184                                 rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
 185                 if (iptuninfo[IFLA_IPTUN_COLLECT_METADATA])
 186                         metadata = 1;
 187
 188                 if (iptuninfo[IFLA_IPTUN_FWMARK])
 189                         fwmark = rta_getattr_u32(iptuninfo[IFLA_IPTUN_FWMARK]);
 190
 191                 free(answer);
 192         }
 193
 194         while (argc > 0) {
 195                 if (strcmp(*argv, "remote") == 0) {
 196                         NEXT_ARG();
 197                         raddr = get_addr32(*argv);
 198                 } else if (strcmp(*argv, "local") == 0) {
 199                         NEXT_ARG();
 200                         laddr = get_addr32(*argv);
 201                 } else if (matches(*argv, "dev") == 0) {
 202                         NEXT_ARG();
 203                         link = if_nametoindex(*argv);
 204                         if (link == 0)
 205                                 invarg("\"dev\" is invalid", *argv);
 206                 } else if (strcmp(*argv, "ttl") == 0 ||
 207                            strcmp(*argv, "hoplimit") == 0) {
 208                         NEXT_ARG();
 209                         if (strcmp(*argv, "inherit") != 0) {
 210                                 if (get_u8(&ttl, *argv, 0))
 211                                         invarg("invalid TTL\n", *argv);
 212                         } else
 213                                 ttl = 0;
 214                 } else if (strcmp(*argv, "tos") == 0 ||
 215                            strcmp(*argv, "tclass") == 0 ||
 216                            matches(*argv, "dsfield") == 0) {
 217                         __u32 uval;
 218
 219                         NEXT_ARG();
 220                         if (strcmp(*argv, "inherit") != 0) {
 221                                 if (rtnl_dsfield_a2n(&uval, *argv))
 222                                         invarg("bad TOS value", *argv);
 223                                 tos = uval;
 224                         } else
 225                                 tos = 1;
 226                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 227                         pmtudisc = 0;
 228                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 229                         pmtudisc = 1;
 230                 } else if (strcmp(lu->id, "sit") == 0 &&
 231                            strcmp(*argv, "isatap") == 0) {
 232                         iflags |= SIT_ISATAP;
 233                 } else if (strcmp(*argv, "mode") == 0) {
 234                         NEXT_ARG();
 235                         if (strcmp(lu->id, "sit") == 0 &&
 236                             (strcmp(*argv, "ipv6/ipv4") == 0 ||
 237                              strcmp(*argv, "ip6ip") == 0))
 238                                 proto = IPPROTO_IPV6;
 239                         else if (strcmp(*argv, "ipv4/ipv4") == 0 ||
 240                                  strcmp(*argv, "ipip") == 0 ||
 241                                  strcmp(*argv, "ip4ip4") == 0)
 242                                 proto = IPPROTO_IPIP;
 243                         else if (strcmp(*argv, "mpls/ipv4") == 0 ||
 244                                    strcmp(*argv, "mplsip") == 0)
 245                                 proto = IPPROTO_MPLS;
 246                         else if (strcmp(*argv, "any/ipv4") == 0 ||
 247                                  strcmp(*argv, "any") == 0)
 248                                 proto = 0;
 249                         else
 250                                 invarg("Cannot guess tunnel mode.", *argv);
 251                 } else if (strcmp(*argv, "noencap") == 0) {
 252                         encaptype = TUNNEL_ENCAP_NONE;
 253                 } else if (strcmp(*argv, "encap") == 0) {
 254                         NEXT_ARG();
 255                         if (strcmp(*argv, "fou") == 0)
 256                                 encaptype = TUNNEL_ENCAP_FOU;
 257                         else if (strcmp(*argv, "gue") == 0)
 258                                 encaptype = TUNNEL_ENCAP_GUE;
 259                         else if (strcmp(*argv, "none") == 0)
 260                                 encaptype = TUNNEL_ENCAP_NONE;
 261                         else
 262                                 invarg("Invalid encap type.", *argv);
 263                 } else if (strcmp(*argv, "encap-sport") == 0) {
 264                         NEXT_ARG();
 265                         if (strcmp(*argv, "auto") == 0)
 266                                 encapsport = 0;
 267                         else if (get_u16(&encapsport, *argv, 0))
 268                                 invarg("Invalid source port.", *argv);
 269                 } else if (strcmp(*argv, "encap-dport") == 0) {
 270                         NEXT_ARG();
 271                         if (get_u16(&encapdport, *argv, 0))
 272                                 invarg("Invalid destination port.", *argv);
 273                 } else if (strcmp(*argv, "encap-csum") == 0) {
 274                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM;
 275                 } else if (strcmp(*argv, "noencap-csum") == 0) {
 276                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;
 277                 } else if (strcmp(*argv, "encap-udp6-csum") == 0) {
 278                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;
 279                 } else if (strcmp(*argv, "noencap-udp6-csum") == 0) {
 280                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM6;
 281                 } else if (strcmp(*argv, "encap-remcsum") == 0) {
 282                         encapflags |= TUNNEL_ENCAP_FLAG_REMCSUM;
 283                 } else if (strcmp(*argv, "noencap-remcsum") == 0) {
 284                         encapflags &= ~TUNNEL_ENCAP_FLAG_REMCSUM;
 285                 } else if (strcmp(*argv, "external") == 0) {
 286                         metadata = 1;
 287                 } else if (strcmp(*argv, "6rd-prefix") == 0) {
 288                         inet_prefix prefix;
 289
 290                         NEXT_ARG();
 291                         if (get_prefix(&prefix, *argv, AF_INET6))
 292                                 invarg("invalid 6rd_prefix\n", *argv);
 293                         memcpy(&ip6rdprefix, prefix.data, 16);
 294                         ip6rdprefixlen = prefix.bitlen;
 295                 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
 296                         inet_prefix prefix;
 297
 298                         NEXT_ARG();
 299                         if (get_prefix(&prefix, *argv, AF_INET))
 300                                 invarg("invalid 6rd-relay_prefix\n", *argv);
 301                         memcpy(&ip6rdrelayprefix, prefix.data, 4);
 302                         ip6rdrelayprefixlen = prefix.bitlen;
 303                 } else if (strcmp(*argv, "6rd-reset") == 0) {
 304                         inet_prefix prefix;
 305
 306                         get_prefix(&prefix, "2002::", AF_INET6);
 307                         memcpy(&ip6rdprefix, prefix.data, 16);
 308                         ip6rdprefixlen = 16;
 309                         ip6rdrelayprefix = 0;
 310                         ip6rdrelayprefixlen = 0;
 311                 } else if (strcmp(*argv, "fwmark") == 0) {
 312                         NEXT_ARG();
 313                         if (get_u32(&fwmark, *argv, 0))
 314                                 invarg("invalid fwmark\n", *argv);
 315                 } else
 316                         usage(strcmp(lu->id, "sit") == 0);
 317                 argc--, argv++;
 318         }
 319
 320         if (ttl && pmtudisc == 0) {
 321                 fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
 322                 exit(-1);
 323         }
 324
 325         addattr8(n, 1024, IFLA_IPTUN_PROTO, proto);
 326         if (metadata) {
 327                 addattr_l(n, 1024, IFLA_IPTUN_COLLECT_METADATA, NULL, 0);
 328                 return 0;
 329         }
 330
 331         addattr32(n, 1024, IFLA_IPTUN_LINK, link);
 332         addattr32(n, 1024, IFLA_IPTUN_LOCAL, laddr);
 333         addattr32(n, 1024, IFLA_IPTUN_REMOTE, raddr);
 334         addattr8(n, 1024, IFLA_IPTUN_TTL, ttl);
 335         addattr8(n, 1024, IFLA_IPTUN_TOS, tos);
 336         addattr8(n, 1024, IFLA_IPTUN_PMTUDISC, pmtudisc);
 337         addattr32(n, 1024, IFLA_IPTUN_FWMARK, fwmark);
 338
 339         addattr16(n, 1024, IFLA_IPTUN_ENCAP_TYPE, encaptype);
 340         addattr16(n, 1024, IFLA_IPTUN_ENCAP_FLAGS, encapflags);
 341         addattr16(n, 1024, IFLA_IPTUN_ENCAP_SPORT, htons(encapsport));
 342         addattr16(n, 1024, IFLA_IPTUN_ENCAP_DPORT, htons(encapdport));
 343
 344         if (strcmp(lu->id, "sit") == 0) {
 345                 addattr16(n, 1024, IFLA_IPTUN_FLAGS, iflags);
 346                 if (ip6rdprefixlen) {
 347                         addattr_l(n, 1024, IFLA_IPTUN_6RD_PREFIX,
 348                                   &ip6rdprefix, sizeof(ip6rdprefix));
 349                         addattr16(n, 1024, IFLA_IPTUN_6RD_PREFIXLEN,
 350                                   ip6rdprefixlen);
 351                         addattr32(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIX,
 352                                   ip6rdrelayprefix);
 353                         addattr16(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
 354                                   ip6rdrelayprefixlen);
 355                 }
 356         }
 357
 358         return 0;
 359 }
 360
 361 static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 362 {
 363         char s1[1024];
 364         char s2[64];
 365         const char *local = "any";
 366         const char *remote = "any";
 367         __u16 prefixlen, type;
 368         __u8 ttl = 0;
 369
 370         if (!tb)
 371                 return;
 372
 373         if (tb[IFLA_IPTUN_COLLECT_METADATA])
 374                 print_bool(PRINT_ANY, "external", "external ", true);
 375
 376         if (tb[IFLA_IPTUN_PROTO]) {
 377                 switch (rta_getattr_u8(tb[IFLA_IPTUN_PROTO])) {
 378                 case IPPROTO_IPIP:
 379                         print_string(PRINT_ANY, "proto", "%s ", "ipip");
 380                         break;
 381                 case IPPROTO_IPV6:
 382                         print_string(PRINT_ANY, "proto", "%s ", "ip6ip");
 383                         break;
 384                 case IPPROTO_MPLS:
 385                         print_string(PRINT_ANY, "proto", "%s ", "mplsip");
 386                         break;
 387                 case 0:
 388                         print_string(PRINT_ANY, "proto", "%s ", "any");
 389                         break;
 390                 }
 391         }
 392
 393         if (tb[IFLA_IPTUN_REMOTE]) {
 394                 unsigned int addr = rta_getattr_u32(tb[IFLA_IPTUN_REMOTE]);
 395
 396                 if (addr)
 397                         remote = format_host(AF_INET, 4, &addr);
 398         }
 399
 400         print_string(PRINT_ANY, "remote", "remote %s ", remote);
 401
 402         if (tb[IFLA_IPTUN_LOCAL]) {
 403                 unsigned int addr = rta_getattr_u32(tb[IFLA_IPTUN_LOCAL]);
 404
 405                 if (addr)
 406                         local = format_host(AF_INET, 4, &addr);
 407         }
 408
 409         print_string(PRINT_ANY, "local", "local %s ", local);
 410
 411         if (tb[IFLA_IPTUN_LINK]) {
 412                 unsigned int link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
 413
 414                 if (link) {
 415                         print_string(PRINT_ANY, "link", "dev %s ",
 416                                      ll_index_to_name(link));
 417                 }
 418         }
 419
 420         if (tb[IFLA_IPTUN_TTL])
 421                 ttl = rta_getattr_u8(tb[IFLA_IPTUN_TTL]);
 422         if (is_json_context() || ttl)
 423                 print_uint(PRINT_ANY, "ttl", "ttl %u ", ttl);
 424         else
 425                 print_string(PRINT_FP, NULL, "ttl %s ", "inherit");
 426
 427         if (tb[IFLA_IPTUN_TOS]) {
 428                 int tos = rta_getattr_u8(tb[IFLA_IPTUN_TOS]);
 429
 430                 if (tos) {
 431                         if (is_json_context()) {
 432                                 print_0xhex(PRINT_JSON, "tos", "%#x", tos);
 433                         } else {
 434                                 fputs("tos ", f);
 435                                 if (tos == 1)
 436                                         fputs("inherit ", f);
 437                                 else
 438                                         fprintf(f, "0x%x ", tos);
 439                         }
 440                 }
 441         }
 442
 443         if (tb[IFLA_IPTUN_PMTUDISC] && rta_getattr_u8(tb[IFLA_IPTUN_PMTUDISC]))
 444                 print_bool(PRINT_ANY, "pmtudisc", "pmtudisc ", true);
 445         else
 446                 print_bool(PRINT_ANY, "pmtudisc", "nopmtudisc ", false);
 447
 448         if (tb[IFLA_IPTUN_FLAGS]) {
 449                 __u16 iflags = rta_getattr_u16(tb[IFLA_IPTUN_FLAGS]);
 450
 451                 if (iflags & SIT_ISATAP)
 452                         print_bool(PRINT_ANY, "isatap", "isatap ", true);
 453         }
 454
 455         if (tb[IFLA_IPTUN_6RD_PREFIXLEN] &&
 456             (prefixlen = rta_getattr_u16(tb[IFLA_IPTUN_6RD_PREFIXLEN]))) {
 457                 __u16 relayprefixlen =
 458                         rta_getattr_u16(tb[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
 459                 __u32 relayprefix =
 460                         rta_getattr_u32(tb[IFLA_IPTUN_6RD_RELAY_PREFIX]);
 461
 462                 const char *prefix = inet_ntop(AF_INET6,
 463                                                RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIX]),
 464                                                s1, sizeof(s1));
 465
 466                 if (is_json_context()) {
 467                         print_string(PRINT_JSON, "prefix", NULL, prefix);
 468                         print_int(PRINT_JSON, "prefixlen", NULL, prefixlen);
 469                         if (relayprefix) {
 470                                 print_string(PRINT_JSON,
 471                                              "relay_prefix",
 472                                              NULL,
 473                                              format_host(AF_INET,
 474                                                          4,
 475                                                          &relayprefix));
 476                                 print_int(PRINT_JSON,
 477                                           "relay_prefixlen",
 478                                           NULL,
 479                                           relayprefixlen);
 480                         }
 481                 } else {
 482                         printf("6rd-prefix %s/%u ", prefix, prefixlen);
 483                         if (relayprefix) {
 484                                 printf("6rd-relay_prefix %s/%u ",
 485                                        format_host(AF_INET, 4, &relayprefix),
 486                                        relayprefixlen);
 487                         }
 488                 }
 489         }
 490
 491         if (tb[IFLA_IPTUN_ENCAP_TYPE] &&
 492             (type = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_TYPE])) != TUNNEL_ENCAP_NONE) {
 493                 __u16 flags = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_FLAGS]);
 494                 __u16 sport = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_SPORT]);
 495                 __u16 dport = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_DPORT]);
 496
 497                 open_json_object("encap");
 498                 print_string(PRINT_FP, NULL, "encap ", NULL);
 499                 switch (type) {
 500                 case TUNNEL_ENCAP_FOU:
 501                         print_string(PRINT_ANY, "type", "%s ", "fou");
 502                         break;
 503                 case TUNNEL_ENCAP_GUE:
 504                         print_string(PRINT_ANY, "type", "%s ", "gue");
 505                         break;
 506                 default:
 507                         print_null(PRINT_ANY, "type", "unknown ", NULL);
 508                         break;
 509                 }
 510
 511                 if (is_json_context()) {
 512                         print_uint(PRINT_JSON,
 513                                    "sport",
 514                                    NULL,
 515                                    sport ? ntohs(sport) : 0);
 516                         print_uint(PRINT_JSON, "dport", NULL, ntohs(dport));
 517                         print_bool(PRINT_JSON,
 518                                    "csum",
 519                                    NULL,
 520                                    flags & TUNNEL_ENCAP_FLAG_CSUM);
 521                         print_bool(PRINT_JSON,
 522                                    "csum6",
 523                                    NULL,
 524                                    flags & TUNNEL_ENCAP_FLAG_CSUM6);
 525                         print_bool(PRINT_JSON,
 526                                    "remcsum",
 527                                    NULL,
 528                                    flags & TUNNEL_ENCAP_FLAG_REMCSUM);
 529                         close_json_object();
 530                 } else {
 531                         if (sport == 0)
 532                                 fputs("encap-sport auto ", f);
 533                         else
 534                                 fprintf(f, "encap-sport %u", ntohs(sport));
 535
 536                         fprintf(f, "encap-dport %u ", ntohs(dport));
 537
 538                         if (flags & TUNNEL_ENCAP_FLAG_CSUM)
 539                                 fputs("encap-csum ", f);
 540                         else
 541                                 fputs("noencap-csum ", f);
 542
 543                         if (flags & TUNNEL_ENCAP_FLAG_CSUM6)
 544                                 fputs("encap-csum6 ", f);
 545                         else
 546                                 fputs("noencap-csum6 ", f);
 547
 548                         if (flags & TUNNEL_ENCAP_FLAG_REMCSUM)
 549                                 fputs("encap-remcsum ", f);
 550                         else
 551                                 fputs("noencap-remcsum ", f);
 552                 }
 553         }
 554
 555         if (tb[IFLA_IPTUN_FWMARK]) {
 556                 __u32 fwmark = rta_getattr_u32(tb[IFLA_IPTUN_FWMARK]);
 557
 558                 if (fwmark) {
 559                         snprintf(s2, sizeof(s2), "0x%x", fwmark);
 560
 561                         print_string(PRINT_ANY, "fwmark", "fwmark %s ", s2);
 562                 }
 563         }
 564 }
 565
 566 static void iptunnel_print_help(struct link_util *lu, int argc, char **argv,
 567         FILE *f)
 568 {
 569         print_usage(f, strcmp(lu->id, "sit") == 0);
 570 }
 571
 572 struct link_util ipip_link_util = {
 573         .id = "ipip",
 574         .maxattr = IFLA_IPTUN_MAX,
 575         .parse_opt = iptunnel_parse_opt,
 576         .print_opt = iptunnel_print_opt,
 577         .print_help = iptunnel_print_help,
 578 };
 579
 580 struct link_util sit_link_util = {
 581         .id = "sit",
 582         .maxattr = IFLA_IPTUN_MAX,
 583         .parse_opt = iptunnel_parse_opt,
 584         .print_opt = iptunnel_print_opt,
 585         .print_help = iptunnel_print_help,
 586 };