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/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, int sit)
  27 {
  28         fprintf(f, "Usage: ip link { add | set | change | replace | del } NAME\n");
  29         fprintf(f, "          type { ipip | sit } [ remote ADDR ] [ local ADDR ]\n");
  30         fprintf(f, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
  31         fprintf(f, "          [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n");
  32         fprintf(f, "          [ noencap ] [ encap { fou | gue | none } ]\n");
  33         fprintf(f, "          [ encap-sport PORT ] [ encap-dport PORT ]\n");
  34         fprintf(f, "          [ [no]encap-csum ] [ [no]encap-csum6 ] [ [no]encap-remcsum ]\n");
  35         if (sit) {
  36                 fprintf(f, "          [ mode { ip6ip | ipip | any } ]\n");
  37                 fprintf(f, "          [ isatap ]\n");
  38         }
  39         fprintf(f, "\n");
  40         fprintf(f, "Where: NAME := STRING\n");
  41         fprintf(f, "       ADDR := { IP_ADDRESS | any }\n");
  42         fprintf(f, "       TOS  := { NUMBER | inherit }\n");
  43         fprintf(f, "       TTL  := { 1..255 | inherit }\n");
  44 }
  45
  46 static void usage(int sit) __attribute__((noreturn));
  47 static void usage(int sit)
  48 {
  49         print_usage(stderr, sit);
  50         exit(-1);
  51 }
  52
  53 static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
  54                               struct nlmsghdr *n)
  55 {
  56         struct {
  57                 struct nlmsghdr n;
  58                 struct ifinfomsg i;
  59                 char buf[2048];
  60         } req;
  61         struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
  62         struct rtattr *tb[IFLA_MAX + 1];
  63         struct rtattr *linkinfo[IFLA_INFO_MAX+1];
  64         struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];
  65         int len;
  66         __u32 link = 0;
  67         __u32 laddr = 0;
  68         __u32 raddr = 0;
  69         __u8 ttl = 0;
  70         __u8 tos = 0;
  71         __u8 pmtudisc = 1;
  72         __u16 iflags = 0;
  73         __u8 proto = 0;
  74         struct in6_addr ip6rdprefix;
  75         __u16 ip6rdprefixlen = 0;
  76         __u32 ip6rdrelayprefix = 0;
  77         __u16 ip6rdrelayprefixlen = 0;
  78         __u16 encaptype = 0;
  79         __u16 encapflags = 0;
  80         __u16 encapsport = 0;
  81         __u16 encapdport = 0;
  82
  83         memset(&ip6rdprefix, 0, sizeof(ip6rdprefix));
  84
  85         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
  86                 memset(&req, 0, sizeof(req));
  87
  88                 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
  89                 req.n.nlmsg_flags = NLM_F_REQUEST;
  90                 req.n.nlmsg_type = RTM_GETLINK;
  91                 req.i.ifi_family = preferred_family;
  92                 req.i.ifi_index = ifi->ifi_index;
  93
  94                 if (rtnl_talk(&rth, &req.n, &req.n, sizeof(req)) < 0) {
  95 get_failed:
  96                         fprintf(stderr,
  97                                 "Failed to get existing tunnel info.\n");
  98                         return -1;
  99                 }
 100
 101                 len = req.n.nlmsg_len;
 102                 len -= NLMSG_LENGTH(sizeof(*ifi));
 103                 if (len < 0)
 104                         goto get_failed;
 105
 106                 parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);
 107
 108                 if (!tb[IFLA_LINKINFO])
 109                         goto get_failed;
 110
 111                 parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
 112
 113                 if (!linkinfo[IFLA_INFO_DATA])
 114                         goto get_failed;
 115
 116                 parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,
 117                                     linkinfo[IFLA_INFO_DATA]);
 118
 119                 if (iptuninfo[IFLA_IPTUN_LOCAL])
 120                         laddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LOCAL]);
 121
 122                 if (iptuninfo[IFLA_IPTUN_REMOTE])
 123                         raddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_REMOTE]);
 124
 125                 if (iptuninfo[IFLA_IPTUN_TTL])
 126                         ttl = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);
 127
 128                 if (iptuninfo[IFLA_IPTUN_TOS])
 129                         tos = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TOS]);
 130
 131                 if (iptuninfo[IFLA_IPTUN_PMTUDISC])
 132                         pmtudisc =
 133                                 rta_getattr_u8(iptuninfo[IFLA_IPTUN_PMTUDISC]);
 134
 135                 if (iptuninfo[IFLA_IPTUN_FLAGS])
 136                         iflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_FLAGS]);
 137
 138                 if (iptuninfo[IFLA_IPTUN_LINK])
 139                         link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);
 140
 141                 if (iptuninfo[IFLA_IPTUN_PROTO])
 142                         proto = rta_getattr_u8(iptuninfo[IFLA_IPTUN_PROTO]);
 143
 144                 if (iptuninfo[IFLA_IPTUN_ENCAP_TYPE])
 145                         encaptype = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_TYPE]);
 146                 if (iptuninfo[IFLA_IPTUN_ENCAP_FLAGS])
 147                         encapflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_FLAGS]);
 148                 if (iptuninfo[IFLA_IPTUN_ENCAP_SPORT])
 149                         encapsport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_SPORT]);
 150                 if (iptuninfo[IFLA_IPTUN_ENCAP_DPORT])
 151                         encapdport = rta_getattr_u16(iptuninfo[IFLA_IPTUN_ENCAP_DPORT]);
 152                 if (iptuninfo[IFLA_IPTUN_6RD_PREFIX])
 153                         memcpy(&ip6rdprefix,
 154                                RTA_DATA(iptuninfo[IFLA_IPTUN_6RD_PREFIX]),
 155                                sizeof(laddr));
 156
 157                 if (iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN])
 158                         ip6rdprefixlen =
 159                                 rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN]);
 160
 161                 if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX])
 162                         ip6rdrelayprefix =
 163                                 rta_getattr_u32(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX]);
 164
 165                 if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN])
 166                         ip6rdrelayprefixlen =
 167                                 rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
 168         }
 169
 170         while (argc > 0) {
 171                 if (strcmp(*argv, "remote") == 0) {
 172                         NEXT_ARG();
 173                         if (strcmp(*argv, "any"))
 174                                 raddr = get_addr32(*argv);
 175                         else
 176                                 raddr = 0;
 177                 } else if (strcmp(*argv, "local") == 0) {
 178                         NEXT_ARG();
 179                         if (strcmp(*argv, "any"))
 180                                 laddr = get_addr32(*argv);
 181                         else
 182                                 laddr = 0;
 183                 } else if (matches(*argv, "dev") == 0) {
 184                         NEXT_ARG();
 185                         link = if_nametoindex(*argv);
 186                         if (link == 0)
 187                                 invarg("\"dev\" is invalid", *argv);
 188                 } else if (strcmp(*argv, "ttl") == 0 ||
 189                            strcmp(*argv, "hoplimit") == 0) {
 190                         NEXT_ARG();
 191                         if (strcmp(*argv, "inherit") != 0) {
 192                                 if (get_u8(&ttl, *argv, 0))
 193                                         invarg("invalid TTL\n", *argv);
 194                         } else
 195                                 ttl = 0;
 196                 } else if (strcmp(*argv, "tos") == 0 ||
 197                            strcmp(*argv, "tclass") == 0 ||
 198                            matches(*argv, "dsfield") == 0) {
 199                         __u32 uval;
 200
 201                         NEXT_ARG();
 202                         if (strcmp(*argv, "inherit") != 0) {
 203                                 if (rtnl_dsfield_a2n(&uval, *argv))
 204                                         invarg("bad TOS value", *argv);
 205                                 tos = uval;
 206                         } else
 207                                 tos = 1;
 208                 } else if (strcmp(*argv, "nopmtudisc") == 0) {
 209                         pmtudisc = 0;
 210                 } else if (strcmp(*argv, "pmtudisc") == 0) {
 211                         pmtudisc = 1;
 212                 } else if (strcmp(lu->id, "sit") == 0 &&
 213                            strcmp(*argv, "isatap") == 0) {
 214                         iflags |= SIT_ISATAP;
 215                 } else if (strcmp(lu->id, "sit") == 0 &&
 216                            strcmp(*argv, "mode") == 0) {
 217                         NEXT_ARG();
 218                         if (strcmp(*argv, "ipv6/ipv4") == 0 ||
 219                             strcmp(*argv, "ip6ip") == 0)
 220                                 proto = IPPROTO_IPV6;
 221                         else if (strcmp(*argv, "ipv4/ipv4") == 0 ||
 222                                  strcmp(*argv, "ipip") == 0 ||
 223                                  strcmp(*argv, "ip4ip4") == 0)
 224                                 proto = IPPROTO_IPIP;
 225                         else if (strcmp(*argv, "any/ipv4") == 0 ||
 226                                  strcmp(*argv, "any") == 0)
 227                                 proto = 0;
 228                         else
 229                                 invarg("Cannot guess tunnel mode.", *argv);
 230                 } else if (strcmp(*argv, "noencap") == 0) {
 231                         encaptype = TUNNEL_ENCAP_NONE;
 232                 } else if (strcmp(*argv, "encap") == 0) {
 233                         NEXT_ARG();
 234                         if (strcmp(*argv, "fou") == 0)
 235                                 encaptype = TUNNEL_ENCAP_FOU;
 236                         else if (strcmp(*argv, "gue") == 0)
 237                                 encaptype = TUNNEL_ENCAP_GUE;
 238                         else if (strcmp(*argv, "none") == 0)
 239                                 encaptype = TUNNEL_ENCAP_NONE;
 240                         else
 241                                 invarg("Invalid encap type.", *argv);
 242                 } else if (strcmp(*argv, "encap-sport") == 0) {
 243                         NEXT_ARG();
 244                         if (strcmp(*argv, "auto") == 0)
 245                                 encapsport = 0;
 246                         else if (get_u16(&encapsport, *argv, 0))
 247                                 invarg("Invalid source port.", *argv);
 248                 } else if (strcmp(*argv, "encap-dport") == 0) {
 249                         NEXT_ARG();
 250                         if (get_u16(&encapdport, *argv, 0))
 251                                 invarg("Invalid destination port.", *argv);
 252                 } else if (strcmp(*argv, "encap-csum") == 0) {
 253                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM;
 254                 } else if (strcmp(*argv, "noencap-csum") == 0) {
 255                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;
 256                 } else if (strcmp(*argv, "encap-udp6-csum") == 0) {
 257                         encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;
 258                 } else if (strcmp(*argv, "noencap-udp6-csum") == 0) {
 259                         encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM6;
 260                 } else if (strcmp(*argv, "encap-remcsum") == 0) {
 261                         encapflags |= TUNNEL_ENCAP_FLAG_REMCSUM;
 262                 } else if (strcmp(*argv, "noencap-remcsum") == 0) {
 263                         encapflags &= ~TUNNEL_ENCAP_FLAG_REMCSUM;
 264                 } else if (strcmp(*argv, "6rd-prefix") == 0) {
 265                         inet_prefix prefix;
 266
 267                         NEXT_ARG();
 268                         if (get_prefix(&prefix, *argv, AF_INET6))
 269                                 invarg("invalid 6rd_prefix\n", *argv);
 270                         memcpy(&ip6rdprefix, prefix.data, 16);
 271                         ip6rdprefixlen = prefix.bitlen;
 272                 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
 273                         inet_prefix prefix;
 274
 275                         NEXT_ARG();
 276                         if (get_prefix(&prefix, *argv, AF_INET))
 277                                 invarg("invalid 6rd-relay_prefix\n", *argv);
 278                         memcpy(&ip6rdrelayprefix, prefix.data, 4);
 279                         ip6rdrelayprefixlen = prefix.bitlen;
 280                 } else if (strcmp(*argv, "6rd-reset") == 0) {
 281                         inet_prefix prefix;
 282
 283                         get_prefix(&prefix, "2002::", AF_INET6);
 284                         memcpy(&ip6rdprefix, prefix.data, 16);
 285                         ip6rdprefixlen = 16;
 286                         ip6rdrelayprefix = 0;
 287                         ip6rdrelayprefixlen = 0;
 288                 } else
 289                         usage(strcmp(lu->id, "sit") == 0);
 290                 argc--, argv++;
 291         }
 292
 293         if (ttl && pmtudisc == 0) {
 294                 fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
 295                 exit(-1);
 296         }
 297
 298         addattr32(n, 1024, IFLA_IPTUN_LINK, link);
 299         addattr32(n, 1024, IFLA_IPTUN_LOCAL, laddr);
 300         addattr32(n, 1024, IFLA_IPTUN_REMOTE, raddr);
 301         addattr8(n, 1024, IFLA_IPTUN_TTL, ttl);
 302         addattr8(n, 1024, IFLA_IPTUN_TOS, tos);
 303         addattr8(n, 1024, IFLA_IPTUN_PMTUDISC, pmtudisc);
 304
 305         addattr16(n, 1024, IFLA_IPTUN_ENCAP_TYPE, encaptype);
 306         addattr16(n, 1024, IFLA_IPTUN_ENCAP_FLAGS, encapflags);
 307         addattr16(n, 1024, IFLA_IPTUN_ENCAP_SPORT, htons(encapsport));
 308         addattr16(n, 1024, IFLA_IPTUN_ENCAP_DPORT, htons(encapdport));
 309
 310         if (strcmp(lu->id, "sit") == 0) {
 311                 addattr16(n, 1024, IFLA_IPTUN_FLAGS, iflags);
 312                 addattr8(n, 1024, IFLA_IPTUN_PROTO, proto);
 313                 if (ip6rdprefixlen) {
 314                         addattr_l(n, 1024, IFLA_IPTUN_6RD_PREFIX,
 315                                   &ip6rdprefix, sizeof(ip6rdprefix));
 316                         addattr16(n, 1024, IFLA_IPTUN_6RD_PREFIXLEN,
 317                                   ip6rdprefixlen);
 318                         addattr32(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIX,
 319                                   ip6rdrelayprefix);
 320                         addattr16(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
 321                                   ip6rdrelayprefixlen);
 322                 }
 323         }
 324
 325         return 0;
 326 }
 327
 328 static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 329 {
 330         char s1[1024];
 331         char s2[64];
 332         const char *local = "any";
 333         const char *remote = "any";
 334
 335         if (!tb)
 336                 return;
 337
 338         if (tb[IFLA_IPTUN_REMOTE]) {
 339                 unsigned int addr = rta_getattr_u32(tb[IFLA_IPTUN_REMOTE]);
 340
 341                 if (addr)
 342                         remote = format_host(AF_INET, 4, &addr);
 343         }
 344
 345         fprintf(f, "remote %s ", remote);
 346
 347         if (tb[IFLA_IPTUN_LOCAL]) {
 348                 unsigned int addr = rta_getattr_u32(tb[IFLA_IPTUN_LOCAL]);
 349
 350                 if (addr)
 351                         local = format_host(AF_INET, 4, &addr);
 352         }
 353
 354         fprintf(f, "local %s ", local);
 355
 356         if (tb[IFLA_IPTUN_LINK] && rta_getattr_u32(tb[IFLA_IPTUN_LINK])) {
 357                 unsigned int link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
 358                 const char *n = if_indextoname(link, s2);
 359
 360                 if (n)
 361                         fprintf(f, "dev %s ", n);
 362                 else
 363                         fprintf(f, "dev %u ", link);
 364         }
 365
 366         if (tb[IFLA_IPTUN_TTL] && rta_getattr_u8(tb[IFLA_IPTUN_TTL]))
 367                 fprintf(f, "ttl %d ", rta_getattr_u8(tb[IFLA_IPTUN_TTL]));
 368         else
 369                 fprintf(f, "ttl inherit ");
 370
 371         if (tb[IFLA_IPTUN_TOS] && rta_getattr_u8(tb[IFLA_IPTUN_TOS])) {
 372                 int tos = rta_getattr_u8(tb[IFLA_IPTUN_TOS]);
 373
 374                 fputs("tos ", f);
 375                 if (tos == 1)
 376                         fputs("inherit ", f);
 377                 else
 378                         fprintf(f, "0x%x ", tos);
 379         }
 380
 381         if (tb[IFLA_IPTUN_PMTUDISC] && rta_getattr_u8(tb[IFLA_IPTUN_PMTUDISC]))
 382                 fprintf(f, "pmtudisc ");
 383         else
 384                 fprintf(f, "nopmtudisc ");
 385
 386         if (tb[IFLA_IPTUN_FLAGS]) {
 387                 __u16 iflags = rta_getattr_u16(tb[IFLA_IPTUN_FLAGS]);
 388
 389                 if (iflags & SIT_ISATAP)
 390                         fprintf(f, "isatap ");
 391         }
 392
 393         if (tb[IFLA_IPTUN_6RD_PREFIXLEN] &&
 394             *(__u16 *)RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIXLEN])) {
 395                 __u16 prefixlen = rta_getattr_u16(tb[IFLA_IPTUN_6RD_PREFIXLEN]);
 396                 __u16 relayprefixlen =
 397                         rta_getattr_u16(tb[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
 398                 __u32 relayprefix =
 399                         rta_getattr_u32(tb[IFLA_IPTUN_6RD_RELAY_PREFIX]);
 400
 401                 printf("6rd-prefix %s/%u ",
 402                        inet_ntop(AF_INET6, RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIX]),
 403                                  s1, sizeof(s1)),
 404                        prefixlen);
 405                 if (relayprefix) {
 406                         printf("6rd-relay_prefix %s/%u ",
 407                                format_host(AF_INET, 4, &relayprefix),
 408                                relayprefixlen);
 409                 }
 410         }
 411
 412         if (tb[IFLA_IPTUN_ENCAP_TYPE] &&
 413             *(__u16 *)RTA_DATA(tb[IFLA_IPTUN_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) {
 414                 __u16 type = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_TYPE]);
 415                 __u16 flags = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_FLAGS]);
 416                 __u16 sport = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_SPORT]);
 417                 __u16 dport = rta_getattr_u16(tb[IFLA_IPTUN_ENCAP_DPORT]);
 418
 419                 fputs("encap ", f);
 420                 switch (type) {
 421                 case TUNNEL_ENCAP_FOU:
 422                         fputs("fou ", f);
 423                         break;
 424                 case TUNNEL_ENCAP_GUE:
 425                         fputs("gue ", f);
 426                         break;
 427                 default:
 428                         fputs("unknown ", f);
 429                         break;
 430                 }
 431
 432                 if (sport == 0)
 433                         fputs("encap-sport auto ", f);
 434                 else
 435                         fprintf(f, "encap-sport %u", ntohs(sport));
 436
 437                 fprintf(f, "encap-dport %u ", ntohs(dport));
 438
 439                 if (flags & TUNNEL_ENCAP_FLAG_CSUM)
 440                         fputs("encap-csum ", f);
 441                 else
 442                         fputs("noencap-csum ", f);
 443
 444                 if (flags & TUNNEL_ENCAP_FLAG_CSUM6)
 445                         fputs("encap-csum6 ", f);
 446                 else
 447                         fputs("noencap-csum6 ", f);
 448
 449                 if (flags & TUNNEL_ENCAP_FLAG_REMCSUM)
 450                         fputs("encap-remcsum ", f);
 451                 else
 452                         fputs("noencap-remcsum ", f);
 453         }
 454 }
 455
 456 static void iptunnel_print_help(struct link_util *lu, int argc, char **argv,
 457         FILE *f)
 458 {
 459         print_usage(f, strcmp(lu->id, "sit") == 0);
 460 }
 461
 462 struct link_util ipip_link_util = {
 463         .id = "ipip",
 464         .maxattr = IFLA_IPTUN_MAX,
 465         .parse_opt = iptunnel_parse_opt,
 466         .print_opt = iptunnel_print_opt,
 467         .print_help = iptunnel_print_help,
 468 };
 469
 470 struct link_util sit_link_util = {
 471         .id = "sit",
 472         .maxattr = IFLA_IPTUN_MAX,
 473         .parse_opt = iptunnel_parse_opt,
 474         .print_opt = iptunnel_print_opt,
 475         .print_help = iptunnel_print_help,
 476 };