ip/link_gre.c

   1 /*
   2  * link_gre.c   gre 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:     Herbert Xu <herbert@gondor.apana.org.au>
  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/ip.h>
  20 #include <linux/if_tunnel.h>
  21 #include "rt_names.h"
  22 #include "utils.h"
  23 #include "ip_common.h"
  24 #include "tunnel.h"
  25
  26 static void print_usage(FILE *f)
  27 {
  28         fprintf(f,
  29                 "Usage: ... { gre | gretap | erspan } [ remote ADDR ]\n"
  30                 "                            [ local ADDR ]\n"
  31                 "                            [ [i|o]seq ]\n"
  32                 "                            [ [i|o]key KEY ]\n"
  33                 "                            [ [i|o]csum ]\n"
  34                 "                            [ ttl TTL ]\n"
  35                 "                            [ tos TOS ]\n"
  36                 "                            [ [no]pmtudisc ]\n"
  37                 "                            [ [no]ignore-df ]\n"
  38                 "                            [ dev PHYS_DEV ]\n"
  39                 "                            [ noencap ]\n"
  40                 "                            [ encap { fou | gue | none } ]\n"
  41                 "                            [ encap-sport PORT ]\n"
  42                 "                            [ encap-dport PORT ]\n"
  43                 "                            [ [no]encap-csum ]\n"
  44                 "                            [ [no]encap-csum6 ]\n"
  45                 "                            [ [no]encap-remcsum ]\n"
  46                 "                            [ external ]\n"
  47                 "                            [ fwmark MARK ]\n"
  48                 "                            [ erspan IDX ]\n"
  49                 "\n"
  50                 "Where: ADDR := { IP_ADDRESS | any }\n"
  51                 "       TOS  := { NUMBER | inherit }\n"
  52                 "       TTL  := { 1..255 | inherit }\n"
  53                 "       KEY  := { DOTTED_QUAD | NUMBER }\n"
  54                 "       MARK := { 0x0..0xffffffff }\n"
  55         );
  56 }
  57
  58 static void usage(void) __attribute__((noreturn));
  59 static void usage(void)
  60 {
  61         print_usage(stderr);
  62         exit(-1);
  63 }
  64
  65 static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
  66                          struct nlmsghdr *n)
  67 {
  68         struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
  69         struct {
  70                 struct nlmsghdr n;
  71                 struct ifinfomsg i;
  72         } req = {
  73                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi)),
  74                 .n.nlmsg_flags = NLM_F_REQUEST,
  75                 .n.nlmsg_type = RTM_GETLINK,
  76                 .i.ifi_family = preferred_family,
  77                 .i.ifi_index = ifi->ifi_index,
  78         };
  79         struct nlmsghdr *answer;
  80         struct rtattr *tb[IFLA_MAX + 1];
  81         struct rtattr *linkinfo[IFLA_INFO_MAX+1];
  82         struct rtattr *greinfo[IFLA_GRE_MAX + 1];
  83         __u16 iflags = 0;
  84         __u16 oflags = 0;
  85         __be32 ikey = 0;
  86         __be32 okey = 0;
  87         unsigned int saddr = 0;
  88         unsigned int daddr = 0;
  89         unsigned int link = 0;
  90         __u8 pmtudisc = 1;
  91         __u8 ttl = 0;
  92         __u8 tos = 0;
  93         int len;
  94         __u16 encaptype = 0;
  95         __u16 encapflags = 0;
  96         __u16 encapsport = 0;
  97         __u16 encapdport = 0;
  98         __u8 metadata = 0;
  99         __u8 ignore_df = 0;
 100         __u32 fwmark = 0;
 101         __u32 erspan_idx = 0;
 102
 103         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
 104                 if (rtnl_talk(&rth, &req.n, &answer) < 0) {
 105 get_failed:
 106                         fprintf(stderr,
 107                                 "Failed to get existing tunnel info.\n");
 108                         return -1;
 109                 }
 110
 111                 len = answer->nlmsg_len;
 112                 len -= NLMSG_LENGTH(sizeof(*ifi));
 113                 if (len < 0)
 114                         goto get_failed;
 115
 116                 parse_rtattr(tb, IFLA_MAX, IFLA_RTA(NLMSG_DATA(answer)), len);
 117
 118                 if (!tb[IFLA_LINKINFO])
 119                         goto get_failed;
 120
 121                 parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
 122
 123                 if (!linkinfo[IFLA_INFO_DATA])
 124                         goto get_failed;
 125
 126                 parse_rtattr_nested(greinfo, IFLA_GRE_MAX,
 127                                     linkinfo[IFLA_INFO_DATA]);
 128
 129                 if (greinfo[IFLA_GRE_IKEY])
 130                         ikey = rta_getattr_u32(greinfo[IFLA_GRE_IKEY]);
 131
 132                 if (greinfo[IFLA_GRE_OKEY])
 133                         okey = rta_getattr_u32(greinfo[IFLA_GRE_OKEY]);
 134
 135                 if (greinfo[IFLA_GRE_IFLAGS])
 136                         iflags = rta_getattr_u16(greinfo[IFLA_GRE_IFLAGS]);
 137
 138                 if (greinfo[IFLA_GRE_OFLAGS])
 139                         oflags = rta_getattr_u16(greinfo[IFLA_GRE_OFLAGS]);
 140
 141                 if (greinfo[IFLA_GRE_LOCAL])
 142                         saddr = rta_getattr_u32(greinfo[IFLA_GRE_LOCAL]);
 143
 144                 if (greinfo[IFLA_GRE_REMOTE])
 145                         daddr = rta_getattr_u32(greinfo[IFLA_GRE_REMOTE]);
 146
 147                 if (greinfo[IFLA_GRE_PMTUDISC])
 148                         pmtudisc = rta_getattr_u8(
 149                                 greinfo[IFLA_GRE_PMTUDISC]);
 150
 151                 if (greinfo[IFLA_GRE_TTL])
 152                         ttl = rta_getattr_u8(greinfo[IFLA_GRE_TTL]);
 153
 154                 if (greinfo[IFLA_GRE_TOS])
 155                         tos = rta_getattr_u8(greinfo[IFLA_GRE_TOS]);
 156
 157                 if (greinfo[IFLA_GRE_LINK])
 158                         link = rta_getattr_u32(greinfo[IFLA_GRE_LINK]);
 159
 160                 if (greinfo[IFLA_GRE_ENCAP_TYPE])
 161                         encaptype = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_TYPE]);
 162                 if (greinfo[IFLA_GRE_ENCAP_FLAGS])
 163                         encapflags = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_FLAGS]);
 164                 if (greinfo[IFLA_GRE_ENCAP_SPORT])
 165                         encapsport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_SPORT]);
 166                 if (greinfo[IFLA_GRE_ENCAP_DPORT])
 167                         encapdport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_DPORT]);
 168
 169                 if (greinfo[IFLA_GRE_COLLECT_METADATA])
 170                         metadata = 1;
 171
 172                 if (greinfo[IFLA_GRE_IGNORE_DF])
 173                         ignore_df =
 174                                 !!rta_getattr_u8(greinfo[IFLA_GRE_IGNORE_DF]);
 175
 176                 if (greinfo[IFLA_GRE_FWMARK])
 177                         fwmark = rta_getattr_u32(greinfo[IFLA_GRE_FWMARK]);
 178
 179                 if (greinfo[IFLA_GRE_ERSPAN_INDEX])
 180                         erspan_idx = rta_getattr_u32(greinfo[IFLA_GRE_ERSPAN_INDEX]);
 181
 182                 free(answer);
 183         }
 184
 185         while (argc > 0) {
 186                 if (!matches(*argv, "key")) {
 187                         NEXT_ARG();
 188                         iflags |= GRE_KEY;
 189                         oflags |= GRE_KEY;
 190                         ikey = okey = tnl_parse_key("key", *argv);
 191                 } else if (!matches(*argv, "ikey")) {
 192                         NEXT_ARG();
 193                         iflags |= GRE_KEY;
 194                         ikey = tnl_parse_key("ikey", *argv);
 195                 } else if (!matches(*argv, "okey")) {
 196                         NEXT_ARG();
 197                         oflags |= GRE_KEY;
 198                         okey = tnl_parse_key("okey", *argv);
 199                 } else if (!matches(*argv, "seq")) {
 200                         iflags |= GRE_SEQ;
 201                         oflags |= GRE_SEQ;
 202                 } else if (!matches(*argv, "iseq")) {
 203                         iflags |= GRE_SEQ;
 204                 } else if (!matches(*argv, "oseq")) {
 205                         oflags |= GRE_SEQ;
 206                 } else if (!matches(*argv, "csum")) {
 207                         iflags |= GRE_CSUM;
 208                         oflags |= GRE_CSUM;
 209                 } else if (!matches(*argv, "icsum")) {
 210                         iflags |= GRE_CSUM;
 211                 } else if (!matches(*argv, "ocsum")) {
 212                         oflags |= GRE_CSUM;
 213                 } else if (!matches(*argv, "nopmtudisc")) {
 214                         pmtudisc = 0;
 215                 } else if (!matches(*argv, "pmtudisc")) {
 216                         pmtudisc = 1;
 217                 } else if (!matches(*argv, "remote")) {
 218                         NEXT_ARG();
 219                         daddr = get_addr32(*argv);
 220                 } else if (!matches(*argv, "local")) {
 221                         NEXT_ARG();
 222                         saddr = get_addr32(*argv);
 223                 } else if (!matches(*argv, "dev")) {
 224                         NEXT_ARG();
 225                         link = if_nametoindex(*argv);
 226                         if (link == 0) {
 227                                 fprintf(stderr, "Cannot find device \"%s\"\n",
 228                                         *argv);
 229                                 exit(-1);
 230                         }
 231                 } else if (!matches(*argv, "ttl") ||
 232                            !matches(*argv, "hoplimit")) {
 233                         unsigned int uval;
 234
 235                         NEXT_ARG();
 236                         if (strcmp(*argv, "inherit") != 0) {
 237                                 if (get_unsigned(&uval, *argv, 0))
 238                                         invarg("invalid TTL\n", *argv);
 239                                 if (uval > 255)
 240                                         invarg("TTL must be <= 255\n", *argv);
 241                                 ttl = uval;
 242                         } else
 243                                 ttl = 0;
 244                 } else if (!matches(*argv, "tos") ||
 245                            !matches(*argv, "tclass") ||
 246                            !matches(*argv, "dsfield")) {
 247                         __u32 uval;
 248
 249                         NEXT_ARG();
 250                         if (strcmp(*argv, "inherit") != 0) {
 251                                 if (rtnl_dsfield_a2n(&uval, *argv))
 252                                         invarg("bad TOS value", *argv);
 253                                 tos = uval;
 254                         } else
 255                                 tos = 1;
 256                 } else if (strcmp(*argv, "noencap") == 0) {
 257                         encaptype = TUNNEL_ENCAP_NONE;
 258                 } else if (strcmp(*argv, "encap") == 0) {
 259                         NEXT_ARG();
 260                         if (strcmp(*argv, "fou") == 0)
 261                                 encaptype = TUNNEL_ENCAP_FOU;
 262                         else if (strcmp(*argv, "gue") == 0)
 263                                 encaptype = TUNNEL_ENCAP_GUE;
 264                         else if (strcmp(*argv, "none") == 0)
 265                                 encaptype = TUNNEL_ENCAP_NONE;
 266                         else
 267                                 invarg("Invalid encap type.", *argv);
 268                 } else if (strcmp(*argv, "encap-sport") == 0) {
 269                         NEXT_ARG();
 270                         if (strcmp(*argv, "auto") == 0)
 271                                 encapsport = 0;
 272                         else if (get_u16(&encapsport, *argv, 0))
 273                                 invarg("Invalid source port.", *argv);
 274                 } else if (strcmp(*argv, "encap-dport") == 0) {
 275                         NEXT_ARG();
 276                         if (get_u16(&encapdport, *argv, 0))
 277                                 invarg("Invalid destination port.", *argv);
 278                 } else if (strcmp(*argv, "encap-csum") == 0) {
 279                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM;
 280                 } else if (strcmp(*argv, "noencap-csum") == 0) {
 281                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;
 282                 } else if (strcmp(*argv, "encap-udp6-csum") == 0) {
 283                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;
 284                 } else if (strcmp(*argv, "noencap-udp6-csum") == 0) {
 285                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM6;
 286                 } else if (strcmp(*argv, "encap-remcsum") == 0) {
 287                         encapflags |= TUNNEL_ENCAP_FLAG_REMCSUM;
 288                 } else if (strcmp(*argv, "noencap-remcsum") == 0) {
 289                         encapflags &= ~TUNNEL_ENCAP_FLAG_REMCSUM;
 290                 } else if (strcmp(*argv, "external") == 0) {
 291                         metadata = 1;
 292                 } else if (strcmp(*argv, "ignore-df") == 0) {
 293                         ignore_df = 1;
 294                 } else if (strcmp(*argv, "noignore-df") == 0) {
 295                         /*
 296                          *only the lsb is significant, use 2 for presence
 297                          */
 298                         ignore_df = 2;
 299                 } else if (strcmp(*argv, "fwmark") == 0) {
 300                         NEXT_ARG();
 301                         if (get_u32(&fwmark, *argv, 0))
 302                                 invarg("invalid fwmark\n", *argv);
 303                 } else if (strcmp(*argv, "erspan") == 0) {
 304                         NEXT_ARG();
 305                         if (get_u32(&erspan_idx, *argv, 0))
 306                                 invarg("invalid erspan index\n", *argv);
 307                         if (erspan_idx & ~((1<<20) - 1) || erspan_idx == 0)
 308                                 invarg("erspan index must be > 0 and <= 20-bit\n", *argv);
 309                 } else
 310                         usage();
 311                 argc--; argv++;
 312         }
 313
 314         if (!ikey && IN_MULTICAST(ntohl(daddr))) {
 315                 ikey = daddr;
 316                 iflags |= GRE_KEY;
 317         }
 318         if (!okey && IN_MULTICAST(ntohl(daddr))) {
 319                 okey = daddr;
 320                 oflags |= GRE_KEY;
 321         }
 322         if (IN_MULTICAST(ntohl(daddr)) && !saddr) {
 323                 fprintf(stderr, "A broadcast tunnel requires a source address.\n");
 324                 return -1;
 325         }
 326
 327         if (!metadata) {
 328                 addattr32(n, 1024, IFLA_GRE_IKEY, ikey);
 329                 addattr32(n, 1024, IFLA_GRE_OKEY, okey);
 330                 addattr_l(n, 1024, IFLA_GRE_IFLAGS, &iflags, 2);
 331                 addattr_l(n, 1024, IFLA_GRE_OFLAGS, &oflags, 2);
 332                 addattr_l(n, 1024, IFLA_GRE_LOCAL, &saddr, 4);
 333                 addattr_l(n, 1024, IFLA_GRE_REMOTE, &daddr, 4);
 334                 addattr_l(n, 1024, IFLA_GRE_PMTUDISC, &pmtudisc, 1);
 335                 if (link)
 336                         addattr32(n, 1024, IFLA_GRE_LINK, link);
 337                 addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);
 338                 addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);
 339                 addattr32(n, 1024, IFLA_GRE_FWMARK, fwmark);
 340                 if (erspan_idx != 0)
 341                         addattr32(n, 1024, IFLA_GRE_ERSPAN_INDEX, erspan_idx);
 342         } else {
 343                 addattr_l(n, 1024, IFLA_GRE_COLLECT_METADATA, NULL, 0);
 344         }
 345
 346         addattr16(n, 1024, IFLA_GRE_ENCAP_TYPE, encaptype);
 347         addattr16(n, 1024, IFLA_GRE_ENCAP_FLAGS, encapflags);
 348         addattr16(n, 1024, IFLA_GRE_ENCAP_SPORT, htons(encapsport));
 349         addattr16(n, 1024, IFLA_GRE_ENCAP_DPORT, htons(encapdport));
 350
 351         if (ignore_df)
 352                 addattr8(n, 1024, IFLA_GRE_IGNORE_DF, ignore_df & 1);
 353
 354         return 0;
 355 }
 356
 357 static void gre_print_direct_opt(FILE *f, struct rtattr *tb[])
 358 {
 359         char s2[64];
 360         const char *local = "any";
 361         const char *remote = "any";
 362         unsigned int iflags = 0;
 363         unsigned int oflags = 0;
 364
 365         if (tb[IFLA_GRE_REMOTE]) {
 366                 unsigned int addr = rta_getattr_u32(tb[IFLA_GRE_REMOTE]);
 367
 368                 if (addr)
 369                         remote = format_host(AF_INET, 4, &addr);
 370         }
 371
 372         print_string(PRINT_ANY, "remote", "remote %s ", remote);
 373
 374         if (tb[IFLA_GRE_LOCAL]) {
 375                 unsigned int addr = rta_getattr_u32(tb[IFLA_GRE_LOCAL]);
 376
 377                 if (addr)
 378                         local = format_host(AF_INET, 4, &addr);
 379         }
 380
 381         print_string(PRINT_ANY, "local", "local %s ", local);
 382
 383         if (tb[IFLA_GRE_LINK] && rta_getattr_u32(tb[IFLA_GRE_LINK])) {
 384                 unsigned int link = rta_getattr_u32(tb[IFLA_GRE_LINK]);
 385                 const char *n = if_indextoname(link, s2);
 386
 387                 if (n)
 388                         print_string(PRINT_ANY, "link", "dev %s ", n);
 389                 else
 390                         print_uint(PRINT_ANY, "link_index", "dev %u ", link);
 391         }
 392
 393         if (tb[IFLA_GRE_TTL]) {
 394                 __u8 ttl = rta_getattr_u8(tb[IFLA_GRE_TTL]);
 395
 396                 if (ttl)
 397                         print_int(PRINT_ANY, "ttl", "ttl %d ", ttl);
 398                 else
 399                         print_int(PRINT_JSON, "ttl", NULL, ttl);
 400         } else {
 401                 print_string(PRINT_FP, NULL, "ttl %s ", "inherit");
 402         }
 403
 404         if (tb[IFLA_GRE_TOS] && rta_getattr_u8(tb[IFLA_GRE_TOS])) {
 405                 int tos = rta_getattr_u8(tb[IFLA_GRE_TOS]);
 406
 407                 if (is_json_context()) {
 408                         SPRINT_BUF(b1);
 409
 410                         snprintf(b1, sizeof(b1), "0x%x", tos);
 411                         print_string(PRINT_JSON, "tos", NULL, b1);
 412                 } else {
 413                         fputs("tos ", f);
 414                         if (tos == 1)
 415                                 fputs("inherit ", f);
 416                         else
 417                                 fprintf(f, "0x%x ", tos);
 418                 }
 419         }
 420
 421         if (tb[IFLA_GRE_PMTUDISC]) {
 422                 if (!rta_getattr_u8(tb[IFLA_GRE_PMTUDISC]))
 423                         print_bool(PRINT_ANY, "pmtudisc", "nopmtudisc ", false);
 424                 else
 425                         print_bool(PRINT_JSON, "pmtudisc", NULL, true);
 426         }
 427
 428         if (tb[IFLA_GRE_IFLAGS])
 429                 iflags = rta_getattr_u16(tb[IFLA_GRE_IFLAGS]);
 430
 431         if (tb[IFLA_GRE_OFLAGS])
 432                 oflags = rta_getattr_u16(tb[IFLA_GRE_OFLAGS]);
 433
 434         if ((iflags & GRE_KEY) && tb[IFLA_GRE_IKEY]) {
 435                 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_IKEY]), s2, sizeof(s2));
 436                 print_string(PRINT_ANY, "ikey", "ikey %s ", s2);
 437         }
 438
 439         if ((oflags & GRE_KEY) && tb[IFLA_GRE_OKEY]) {
 440                 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_OKEY]), s2, sizeof(s2));
 441                 print_string(PRINT_ANY, "okey", "okey %s ", s2);
 442         }
 443
 444         if (iflags & GRE_SEQ)
 445                 print_bool(PRINT_ANY, "iseq", "iseq ", true);
 446         if (oflags & GRE_SEQ)
 447                 print_bool(PRINT_ANY, "oseq", "oseq ", true);
 448         if (iflags & GRE_CSUM)
 449                 print_bool(PRINT_ANY, "icsum", "icsum ", true);
 450         if (oflags & GRE_CSUM)
 451                 print_bool(PRINT_ANY, "ocsum", "ocsum ", true);
 452
 453         if (tb[IFLA_GRE_FWMARK]) {
 454                 __u32 fwmark = rta_getattr_u32(tb[IFLA_GRE_FWMARK]);
 455
 456                 if (fwmark) {
 457                         snprintf(s2, sizeof(s2), "0x%x", fwmark);
 458
 459                         print_string(PRINT_ANY, "fwmark", "fwmark %s ", s2);
 460                 }
 461         }
 462 }
 463
 464 static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 465 {
 466         if (!tb)
 467                 return;
 468
 469         if (!tb[IFLA_GRE_COLLECT_METADATA])
 470                 gre_print_direct_opt(f, tb);
 471         else
 472                 print_bool(PRINT_ANY, "external", "external ", true);
 473
 474         if (tb[IFLA_GRE_IGNORE_DF] && rta_getattr_u8(tb[IFLA_GRE_IGNORE_DF]))
 475                 print_bool(PRINT_ANY, "ignore_df", "ignore-df ", true);
 476
 477         if (tb[IFLA_GRE_ERSPAN_INDEX]) {
 478                 __u32 erspan_idx = rta_getattr_u32(tb[IFLA_GRE_ERSPAN_INDEX]);
 479
 480                 fprintf(f, "erspan_index %u ", erspan_idx);
 481         }
 482
 483         if (tb[IFLA_GRE_ENCAP_TYPE] &&
 484             rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) {
 485                 __u16 type = rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]);
 486                 __u16 flags = rta_getattr_u16(tb[IFLA_GRE_ENCAP_FLAGS]);
 487                 __u16 sport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_SPORT]);
 488                 __u16 dport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_DPORT]);
 489
 490
 491                 open_json_object("encap");
 492                 print_string(PRINT_FP, NULL, "encap ", NULL);
 493
 494                 switch (type) {
 495                 case TUNNEL_ENCAP_FOU:
 496                         print_string(PRINT_ANY, "type", "%s ", "fou");
 497                         break;
 498                 case TUNNEL_ENCAP_GUE:
 499                         print_string(PRINT_ANY, "type", "%s ", "gue");
 500                         break;
 501                 default:
 502                         print_null(PRINT_ANY, "type", "%s ", "unknown");
 503                         break;
 504                 }
 505
 506                 if (is_json_context()) {
 507                         print_uint(PRINT_JSON,
 508                                    "sport",
 509                                    NULL,
 510                                    sport ? ntohs(sport) : 0);
 511                         print_uint(PRINT_JSON, "dport", NULL, ntohs(dport));
 512
 513                         print_bool(PRINT_JSON,
 514                                    "csum",
 515                                    NULL,
 516                                    flags & TUNNEL_ENCAP_FLAG_CSUM);
 517
 518                         print_bool(PRINT_JSON,
 519                                    "csum6",
 520                                    NULL,
 521                                    flags & TUNNEL_ENCAP_FLAG_CSUM6);
 522
 523                         print_bool(PRINT_JSON,
 524                                    "remcsum",
 525                                    NULL,
 526                                    flags & TUNNEL_ENCAP_FLAG_REMCSUM);
 527
 528                         close_json_object();
 529                 } else {
 530                         if (sport == 0)
 531                                 fputs("encap-sport auto ", f);
 532                         else
 533                                 fprintf(f, "encap-sport %u", ntohs(sport));
 534
 535                         fprintf(f, "encap-dport %u ", ntohs(dport));
 536
 537                         if (flags & TUNNEL_ENCAP_FLAG_CSUM)
 538                                 fputs("encap-csum ", f);
 539                         else
 540                                 fputs("noencap-csum ", f);
 541
 542                         if (flags & TUNNEL_ENCAP_FLAG_CSUM6)
 543                                 fputs("encap-csum6 ", f);
 544                         else
 545                                 fputs("noencap-csum6 ", f);
 546
 547                         if (flags & TUNNEL_ENCAP_FLAG_REMCSUM)
 548                                 fputs("encap-remcsum ", f);
 549                         else
 550                                 fputs("noencap-remcsum ", f);
 551                 }
 552         }
 553 }
 554
 555 static void gre_print_help(struct link_util *lu, int argc, char **argv,
 556                            FILE *f)
 557 {
 558         print_usage(f);
 559 }
 560
 561 struct link_util gre_link_util = {
 562         .id = "gre",
 563         .maxattr = IFLA_GRE_MAX,
 564         .parse_opt = gre_parse_opt,
 565         .print_opt = gre_print_opt,
 566         .print_help = gre_print_help,
 567 };
 568
 569 struct link_util gretap_link_util = {
 570         .id = "gretap",
 571         .maxattr = IFLA_GRE_MAX,
 572         .parse_opt = gre_parse_opt,
 573         .print_opt = gre_print_opt,
 574         .print_help = gre_print_help,
 575 };
 576
 577 struct link_util erspan_link_util = {
 578         .id = "erspan",
 579         .maxattr = IFLA_GRE_MAX,
 580         .parse_opt = gre_parse_opt,
 581         .print_opt = gre_print_opt,
 582         .print_help = gre_print_help,
 583 };