ip/link_ip6tnl.c

   1 /*
   2  * link_ip6tnl.c        ip6tnl 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 <linux/ip6_tunnel.h>
  22 #include "rt_names.h"
  23 #include "utils.h"
  24 #include "ip_common.h"
  25 #include "tunnel.h"
  26
  27 #define IP6_FLOWINFO_TCLASS     htonl(0x0FF00000)
  28 #define IP6_FLOWINFO_FLOWLABEL  htonl(0x000FFFFF)
  29
  30 #define DEFAULT_TNL_HOP_LIMIT   (64)
  31
  32 static void print_usage(FILE *f)
  33 {
  34         fprintf(f, "Usage: ip link { add | set | change | replace | del } NAME\n");
  35         fprintf(f, "          [ mode { ip6ip6 | ipip6 | any } ]\n");
  36         fprintf(f, "          type ip6tnl [ remote ADDR ] [ local ADDR ]\n");
  37         fprintf(f, "          [ dev PHYS_DEV ] [ encaplimit ELIM ]\n");
  38         fprintf(f, "          [ hoplimit HLIM ] [ tclass TCLASS ] [ flowlabel FLOWLABEL ]\n");
  39         fprintf(f, "          [ dscp inherit ] [ fwmark inherit ]\n");
  40         fprintf(f, "\n");
  41         fprintf(f, "Where: NAME      := STRING\n");
  42         fprintf(f, "       ADDR      := IPV6_ADDRESS\n");
  43         fprintf(f, "       ELIM      := { none | 0..255 }(default=%d)\n",
  44                 IPV6_DEFAULT_TNL_ENCAP_LIMIT);
  45         fprintf(f, "       HLIM      := 0..255 (default=%d)\n",
  46                 DEFAULT_TNL_HOP_LIMIT);
  47         fprintf(f, "       TCLASS    := { 0x0..0xff | inherit }\n");
  48         fprintf(f, "       FLOWLABEL := { 0x0..0xfffff | inherit }\n");
  49 }
  50
  51 static void usage(void) __attribute__((noreturn));
  52 static void usage(void)
  53 {
  54         print_usage(stderr);
  55         exit(-1);
  56 }
  57
  58 static int ip6tunnel_parse_opt(struct link_util *lu, int argc, char **argv,
  59                                struct nlmsghdr *n)
  60 {
  61         struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
  62         struct {
  63                 struct nlmsghdr n;
  64                 struct ifinfomsg i;
  65                 char buf[2048];
  66         } req = {
  67                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi)),
  68                 .n.nlmsg_flags = NLM_F_REQUEST,
  69                 .n.nlmsg_type = RTM_GETLINK,
  70                 .i.ifi_family = preferred_family,
  71                 .i.ifi_index = ifi->ifi_index,
  72         };
  73         struct rtattr *tb[IFLA_MAX + 1];
  74         struct rtattr *linkinfo[IFLA_INFO_MAX+1];
  75         struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];
  76         int len;
  77         struct in6_addr laddr = {};
  78         struct in6_addr raddr = {};
  79         __u8 hop_limit = DEFAULT_TNL_HOP_LIMIT;
  80         __u8 encap_limit = IPV6_DEFAULT_TNL_ENCAP_LIMIT;
  81         __u32 flowinfo = 0;
  82         __u32 flags = 0;
  83         __u32 link = 0;
  84         __u8 proto = 0;
  85
  86         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
  87                 if (rtnl_talk(&rth, &req.n, &req.n, sizeof(req)) < 0) {
  88 get_failed:
  89                         fprintf(stderr,
  90                                 "Failed to get existing tunnel info.\n");
  91                         return -1;
  92                 }
  93
  94                 len = req.n.nlmsg_len;
  95                 len -= NLMSG_LENGTH(sizeof(*ifi));
  96                 if (len < 0)
  97                         goto get_failed;
  98
  99                 parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);
 100
 101                 if (!tb[IFLA_LINKINFO])
 102                         goto get_failed;
 103
 104                 parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
 105
 106                 if (!linkinfo[IFLA_INFO_DATA])
 107                         goto get_failed;
 108
 109                 parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,
 110                                     linkinfo[IFLA_INFO_DATA]);
 111
 112                 if (iptuninfo[IFLA_IPTUN_LOCAL])
 113                         memcpy(&laddr, RTA_DATA(iptuninfo[IFLA_IPTUN_LOCAL]),
 114                                sizeof(laddr));
 115
 116                 if (iptuninfo[IFLA_IPTUN_REMOTE])
 117                         memcpy(&raddr, RTA_DATA(iptuninfo[IFLA_IPTUN_REMOTE]),
 118                                sizeof(raddr));
 119
 120                 if (iptuninfo[IFLA_IPTUN_TTL])
 121                         hop_limit = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);
 122
 123                 if (iptuninfo[IFLA_IPTUN_ENCAP_LIMIT])
 124                         encap_limit = rta_getattr_u8(iptuninfo[IFLA_IPTUN_ENCAP_LIMIT]);
 125
 126                 if (iptuninfo[IFLA_IPTUN_FLOWINFO])
 127                         flowinfo = rta_getattr_u32(iptuninfo[IFLA_IPTUN_FLOWINFO]);
 128
 129                 if (iptuninfo[IFLA_IPTUN_FLAGS])
 130                         flags = rta_getattr_u32(iptuninfo[IFLA_IPTUN_FLAGS]);
 131
 132                 if (iptuninfo[IFLA_IPTUN_LINK])
 133                         link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);
 134
 135                 if (iptuninfo[IFLA_IPTUN_PROTO])
 136                         proto = rta_getattr_u8(iptuninfo[IFLA_IPTUN_PROTO]);
 137         }
 138
 139         while (argc > 0) {
 140                 if (matches(*argv, "mode") == 0) {
 141                         NEXT_ARG();
 142                         if (strcmp(*argv, "ipv6/ipv6") == 0 ||
 143                             strcmp(*argv, "ip6ip6") == 0)
 144                                 proto = IPPROTO_IPV6;
 145                         else if (strcmp(*argv, "ip/ipv6") == 0 ||
 146                                  strcmp(*argv, "ipv4/ipv6") == 0 ||
 147                                  strcmp(*argv, "ipip6") == 0 ||
 148                                  strcmp(*argv, "ip4ip6") == 0)
 149                                 proto = IPPROTO_IPIP;
 150                         else if (strcmp(*argv, "any/ipv6") == 0 ||
 151                                  strcmp(*argv, "any") == 0)
 152                                 proto = 0;
 153                         else
 154                                 invarg("Cannot guess tunnel mode.", *argv);
 155                 } else if (strcmp(*argv, "remote") == 0) {
 156                         inet_prefix addr;
 157
 158                         NEXT_ARG();
 159                         get_prefix(&addr, *argv, preferred_family);
 160                         if (addr.family == AF_UNSPEC)
 161                                 invarg("\"remote\" address family is AF_UNSPEC", *argv);
 162                         memcpy(&raddr, addr.data, addr.bytelen);
 163                 } else if (strcmp(*argv, "local") == 0) {
 164                         inet_prefix addr;
 165
 166                         NEXT_ARG();
 167                         get_prefix(&addr, *argv, preferred_family);
 168                         if (addr.family == AF_UNSPEC)
 169                                 invarg("\"local\" address family is AF_UNSPEC", *argv);
 170                         memcpy(&laddr, addr.data, addr.bytelen);
 171                 } else if (matches(*argv, "dev") == 0) {
 172                         NEXT_ARG();
 173                         link = if_nametoindex(*argv);
 174                         if (link == 0)
 175                                 invarg("\"dev\" is invalid", *argv);
 176                 } else if (strcmp(*argv, "hoplimit") == 0 ||
 177                            strcmp(*argv, "ttl") == 0 ||
 178                            strcmp(*argv, "hlim") == 0) {
 179                         __u8 uval;
 180
 181                         NEXT_ARG();
 182                         if (get_u8(&uval, *argv, 0))
 183                                 invarg("invalid HLIM", *argv);
 184                         hop_limit = uval;
 185                 } else if (matches(*argv, "encaplimit") == 0) {
 186                         NEXT_ARG();
 187                         if (strcmp(*argv, "none") == 0) {
 188                                 flags |= IP6_TNL_F_IGN_ENCAP_LIMIT;
 189                         } else {
 190                                 __u8 uval;
 191
 192                                 if (get_u8(&uval, *argv, 0) < -1)
 193                                         invarg("invalid ELIM", *argv);
 194                                 encap_limit = uval;
 195                                 flags &= ~IP6_TNL_F_IGN_ENCAP_LIMIT;
 196                         }
 197                 } else if (strcmp(*argv, "tclass") == 0 ||
 198                            strcmp(*argv, "tc") == 0 ||
 199                            strcmp(*argv, "tos") == 0 ||
 200                            matches(*argv, "dsfield") == 0) {
 201                         __u8 uval;
 202
 203                         NEXT_ARG();
 204                         flowinfo &= ~IP6_FLOWINFO_TCLASS;
 205                         if (strcmp(*argv, "inherit") == 0)
 206                                 flags |= IP6_TNL_F_USE_ORIG_TCLASS;
 207                         else {
 208                                 if (get_u8(&uval, *argv, 16))
 209                                         invarg("invalid TClass", *argv);
 210                                 flowinfo |= htonl((__u32)uval << 20) & IP6_FLOWINFO_TCLASS;
 211                                 flags &= ~IP6_TNL_F_USE_ORIG_TCLASS;
 212                         }
 213                 } else if (strcmp(*argv, "flowlabel") == 0 ||
 214                            strcmp(*argv, "fl") == 0) {
 215                         __u32 uval;
 216
 217                         NEXT_ARG();
 218                         flowinfo &= ~IP6_FLOWINFO_FLOWLABEL;
 219                         if (strcmp(*argv, "inherit") == 0)
 220                                 flags |= IP6_TNL_F_USE_ORIG_FLOWLABEL;
 221                         else {
 222                                 if (get_u32(&uval, *argv, 16))
 223                                         invarg("invalid Flowlabel", *argv);
 224                                 if (uval > 0xFFFFF)
 225                                         invarg("invalid Flowlabel", *argv);
 226                                 flowinfo |= htonl(uval) & IP6_FLOWINFO_FLOWLABEL;
 227                                 flags &= ~IP6_TNL_F_USE_ORIG_FLOWLABEL;
 228                         }
 229                 } else if (strcmp(*argv, "dscp") == 0) {
 230                         NEXT_ARG();
 231                         if (strcmp(*argv, "inherit") != 0)
 232                                 invarg("not inherit", *argv);
 233                         flags |= IP6_TNL_F_RCV_DSCP_COPY;
 234                 } else if (strcmp(*argv, "fwmark") == 0) {
 235                         NEXT_ARG();
 236                         if (strcmp(*argv, "inherit") != 0)
 237                                 invarg("not inherit", *argv);
 238                         flags |= IP6_TNL_F_USE_ORIG_FWMARK;
 239                 } else
 240                         usage();
 241                 argc--, argv++;
 242         }
 243
 244         addattr8(n, 1024, IFLA_IPTUN_PROTO, proto);
 245         addattr_l(n, 1024, IFLA_IPTUN_LOCAL, &laddr, sizeof(laddr));
 246         addattr_l(n, 1024, IFLA_IPTUN_REMOTE, &raddr, sizeof(raddr));
 247         addattr8(n, 1024, IFLA_IPTUN_TTL, hop_limit);
 248         addattr8(n, 1024, IFLA_IPTUN_ENCAP_LIMIT, encap_limit);
 249         addattr32(n, 1024, IFLA_IPTUN_FLOWINFO, flowinfo);
 250         addattr32(n, 1024, IFLA_IPTUN_FLAGS, flags);
 251         addattr32(n, 1024, IFLA_IPTUN_LINK, link);
 252
 253         return 0;
 254 }
 255
 256 static void ip6tunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 257 {
 258         char s2[64];
 259         int flags = 0;
 260         __u32 flowinfo = 0;
 261
 262         if (!tb)
 263                 return;
 264
 265         if (tb[IFLA_IPTUN_FLAGS])
 266                 flags = rta_getattr_u32(tb[IFLA_IPTUN_FLAGS]);
 267
 268         if (tb[IFLA_IPTUN_FLOWINFO])
 269                 flowinfo = rta_getattr_u32(tb[IFLA_IPTUN_FLOWINFO]);
 270
 271         if (tb[IFLA_IPTUN_PROTO]) {
 272                 switch (rta_getattr_u8(tb[IFLA_IPTUN_PROTO])) {
 273                 case IPPROTO_IPIP:
 274                         fprintf(f, "ipip6 ");
 275                         break;
 276                 case IPPROTO_IPV6:
 277                         fprintf(f, "ip6ip6 ");
 278                         break;
 279                 case 0:
 280                         fprintf(f, "any ");
 281                         break;
 282                 }
 283         }
 284
 285         if (tb[IFLA_IPTUN_REMOTE]) {
 286                 fprintf(f, "remote %s ",
 287                         rt_addr_n2a_rta(AF_INET6, tb[IFLA_IPTUN_REMOTE]));
 288         }
 289
 290         if (tb[IFLA_IPTUN_LOCAL]) {
 291                 fprintf(f, "local %s ",
 292                         rt_addr_n2a_rta(AF_INET6, tb[IFLA_IPTUN_LOCAL]));
 293         }
 294
 295         if (tb[IFLA_IPTUN_LINK] && rta_getattr_u32(tb[IFLA_IPTUN_LINK])) {
 296                 unsigned int link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
 297                 const char *n = if_indextoname(link, s2);
 298
 299                 if (n)
 300                         fprintf(f, "dev %s ", n);
 301                 else
 302                         fprintf(f, "dev %u ", link);
 303         }
 304
 305         if (flags & IP6_TNL_F_IGN_ENCAP_LIMIT)
 306                 printf("encaplimit none ");
 307         else if (tb[IFLA_IPTUN_ENCAP_LIMIT])
 308                 fprintf(f, "encaplimit %u ",
 309                         rta_getattr_u8(tb[IFLA_IPTUN_ENCAP_LIMIT]));
 310
 311         if (tb[IFLA_IPTUN_TTL])
 312                 fprintf(f, "hoplimit %u ", rta_getattr_u8(tb[IFLA_IPTUN_TTL]));
 313
 314         if (flags & IP6_TNL_F_USE_ORIG_TCLASS)
 315                 printf("tclass inherit ");
 316         else if (tb[IFLA_IPTUN_FLOWINFO]) {
 317                 __u32 val = ntohl(flowinfo & IP6_FLOWINFO_TCLASS);
 318
 319                 printf("tclass 0x%02x ", (__u8)(val >> 20));
 320         }
 321
 322         if (flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 323                 printf("flowlabel inherit ");
 324         else
 325                 printf("flowlabel 0x%05x ", ntohl(flowinfo & IP6_FLOWINFO_FLOWLABEL));
 326
 327         printf("(flowinfo 0x%08x) ", ntohl(flowinfo));
 328
 329         if (flags & IP6_TNL_F_RCV_DSCP_COPY)
 330                 printf("dscp inherit ");
 331
 332         if (flags & IP6_TNL_F_MIP6_DEV)
 333                 fprintf(f, "mip6 ");
 334
 335         if (flags & IP6_TNL_F_USE_ORIG_FWMARK)
 336                 fprintf(f, "fwmark inherit ");
 337 }
 338
 339 static void ip6tunnel_print_help(struct link_util *lu, int argc, char **argv,
 340         FILE *f)
 341 {
 342         print_usage(f);
 343 }
 344
 345 struct link_util ip6tnl_link_util = {
 346         .id = "ip6tnl",
 347         .maxattr = IFLA_IPTUN_MAX,
 348         .parse_opt = ip6tunnel_parse_opt,
 349         .print_opt = ip6tunnel_print_opt,
 350         .print_help = ip6tunnel_print_help,
 351 };