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 usage(void) __attribute__((noreturn));
  33 static void usage(void)
  34 {
  35         fprintf(stderr, "Usage: ip link { add | set | change | replace | del } NAME\n");
  36         fprintf(stderr, "          [ mode { ip6ip6 | ipip6 | any } ]\n");
  37         fprintf(stderr, "          type ip6tnl [ remote ADDR ] [ local ADDR ]\n");
  38         fprintf(stderr, "          [ dev PHYS_DEV ] [ encaplimit ELIM ]\n");
  39         fprintf(stderr ,"          [ hoplimit HLIM ] [ tclass TCLASS ] [ flowlabel FLOWLABEL ]\n");
  40         fprintf(stderr, "          [ dscp inherit ] [ fwmark inherit ]\n");
  41         fprintf(stderr, "\n");
  42         fprintf(stderr, "Where: NAME      := STRING\n");
  43         fprintf(stderr, "       ADDR      := IPV6_ADDRESS\n");
  44         fprintf(stderr, "       ELIM      := { none | 0..255 }(default=%d)\n",
  45                 IPV6_DEFAULT_TNL_ENCAP_LIMIT);
  46         fprintf(stderr, "       HLIM      := 0..255 (default=%d)\n",
  47                 DEFAULT_TNL_HOP_LIMIT);
  48         fprintf(stderr, "       TCLASS    := { 0x0..0xff | inherit }\n");
  49         fprintf(stderr, "       FLOWLABEL := { 0x0..0xfffff | inherit }\n");
  50         exit(-1);
  51 }
  52
  53 static int ip6tunnel_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         struct in6_addr laddr;
  67         struct in6_addr raddr;
  68         __u8 hop_limit = DEFAULT_TNL_HOP_LIMIT;
  69         __u8 encap_limit = IPV6_DEFAULT_TNL_ENCAP_LIMIT;
  70         __u32 flowinfo = 0;
  71         __u32 flags = 0;
  72         __u32 link = 0;
  73         __u8 proto = 0;
  74
  75         memset(&laddr, 0, sizeof(laddr));
  76         memset(&raddr, 0, sizeof(raddr));
  77
  78         if (!(n->nlmsg_flags & NLM_F_CREATE)) {
  79                 memset(&req, 0, sizeof(req));
  80
  81                 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
  82                 req.n.nlmsg_flags = NLM_F_REQUEST;
  83                 req.n.nlmsg_type = RTM_GETLINK;
  84                 req.i.ifi_family = preferred_family;
  85                 req.i.ifi_index = ifi->ifi_index;
  86
  87                 if (rtnl_talk(&rth, &req.n, 0, 0, &req.n) < 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                         NEXT_ARG();
 158                         get_prefix(&addr, *argv, preferred_family);
 159                         if (addr.family == AF_UNSPEC)
 160                                 invarg("\"remote\" address family is AF_UNSPEC", *argv);
 161                         memcpy(&raddr, addr.data, addr.bytelen);
 162                 } else if (strcmp(*argv, "local") == 0) {
 163                         inet_prefix addr;
 164                         NEXT_ARG();
 165                         get_prefix(&addr, *argv, preferred_family);
 166                         if (addr.family == AF_UNSPEC)
 167                                 invarg("\"local\" address family is AF_UNSPEC", *argv);
 168                         memcpy(&laddr, addr.data, addr.bytelen);
 169                 } else if (matches(*argv, "dev") == 0) {
 170                         NEXT_ARG();
 171                         link = if_nametoindex(*argv);
 172                         if (link == 0)
 173                                 invarg("\"dev\" is invalid", *argv);
 174                 } else if (strcmp(*argv, "hoplimit") == 0 ||
 175                            strcmp(*argv, "ttl") == 0 ||
 176                            strcmp(*argv, "hlim") == 0) {
 177                         __u8 uval;
 178                         NEXT_ARG();
 179                         if (get_u8(&uval, *argv, 0))
 180                                 invarg("invalid HLIM", *argv);
 181                         hop_limit = uval;
 182                 } else if (matches(*argv, "encaplimit") == 0) {
 183                         NEXT_ARG();
 184                         if (strcmp(*argv, "none") == 0) {
 185                                 flags |= IP6_TNL_F_IGN_ENCAP_LIMIT;
 186                         } else {
 187                                 __u8 uval;
 188                                 if (get_u8(&uval, *argv, 0) < -1)
 189                                         invarg("invalid ELIM", *argv);
 190                                 encap_limit = uval;
 191                                 flags &= ~IP6_TNL_F_IGN_ENCAP_LIMIT;
 192                         }
 193                 } else if (strcmp(*argv, "tclass") == 0 ||
 194                            strcmp(*argv, "tc") == 0 ||
 195                            strcmp(*argv, "tos") == 0 ||
 196                            matches(*argv, "dsfield") == 0) {
 197                         __u8 uval;
 198                         NEXT_ARG();
 199                         flowinfo &= ~IP6_FLOWINFO_TCLASS;
 200                         if (strcmp(*argv, "inherit") == 0)
 201                                 flags |= IP6_TNL_F_USE_ORIG_TCLASS;
 202                         else {
 203                                 if (get_u8(&uval, *argv, 16))
 204                                         invarg("invalid TClass", *argv);
 205                                 flowinfo |= htonl((__u32)uval << 20) & IP6_FLOWINFO_TCLASS;
 206                                 flags &= ~IP6_TNL_F_USE_ORIG_TCLASS;
 207                         }
 208                 } else if (strcmp(*argv, "flowlabel") == 0 ||
 209                            strcmp(*argv, "fl") == 0) {
 210                         __u32 uval;
 211                         NEXT_ARG();
 212                         flowinfo &= ~IP6_FLOWINFO_FLOWLABEL;
 213                         if (strcmp(*argv, "inherit") == 0)
 214                                 flags |= IP6_TNL_F_USE_ORIG_FLOWLABEL;
 215                         else {
 216                                 if (get_u32(&uval, *argv, 16))
 217                                         invarg("invalid Flowlabel", *argv);
 218                                 if (uval > 0xFFFFF)
 219                                         invarg("invalid Flowlabel", *argv);
 220                                 flowinfo |= htonl(uval) & IP6_FLOWINFO_FLOWLABEL;
 221                                 flags &= ~IP6_TNL_F_USE_ORIG_FLOWLABEL;
 222                         }
 223                 } else if (strcmp(*argv, "dscp") == 0) {
 224                         NEXT_ARG();
 225                         if (strcmp(*argv, "inherit") != 0)
 226                                 invarg("not inherit", *argv);
 227                         flags |= IP6_TNL_F_RCV_DSCP_COPY;
 228                 } else if (strcmp(*argv, "fwmark") == 0) {
 229                         NEXT_ARG();
 230                         if (strcmp(*argv, "inherit") != 0)
 231                                 invarg("not inherit", *argv);
 232                         flags |= IP6_TNL_F_USE_ORIG_FWMARK;
 233                 } else
 234                         usage();
 235                 argc--, argv++;
 236         }
 237
 238         addattr8(n, 1024, IFLA_IPTUN_PROTO, proto);
 239         addattr_l(n, 1024, IFLA_IPTUN_LOCAL, &laddr, sizeof(laddr));
 240         addattr_l(n, 1024, IFLA_IPTUN_REMOTE, &raddr, sizeof(raddr));
 241         addattr8(n, 1024, IFLA_IPTUN_TTL, hop_limit);
 242         addattr8(n, 1024, IFLA_IPTUN_ENCAP_LIMIT, encap_limit);
 243         addattr32(n, 1024, IFLA_IPTUN_FLOWINFO, flowinfo);
 244         addattr32(n, 1024, IFLA_IPTUN_FLAGS, flags);
 245         addattr32(n, 1024, IFLA_IPTUN_LINK, link);
 246
 247         return 0;
 248 }
 249
 250 static void ip6tunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 251 {
 252         char s1[256];
 253         char s2[64];
 254         int flags = 0;
 255         __u32 flowinfo = 0;
 256
 257         if (!tb)
 258                 return;
 259
 260         if (tb[IFLA_IPTUN_FLAGS])
 261                 flags = rta_getattr_u32(tb[IFLA_IPTUN_FLAGS]);
 262
 263         if (tb[IFLA_IPTUN_FLOWINFO])
 264                 flowinfo = rta_getattr_u32(tb[IFLA_IPTUN_FLOWINFO]);
 265
 266         if (tb[IFLA_IPTUN_PROTO]) {
 267                 switch (rta_getattr_u8(tb[IFLA_IPTUN_PROTO])) {
 268                 case IPPROTO_IPIP:
 269                         fprintf(f, "ipip6 ");
 270                         break;
 271                 case IPPROTO_IPV6:
 272                         fprintf(f, "ip6ip6 ");
 273                         break;
 274                 case 0:
 275                         fprintf(f, "any ");
 276                         break;
 277                 }
 278         }
 279
 280         if (tb[IFLA_IPTUN_REMOTE]) {
 281                 fprintf(f, "remote %s ",
 282                         rt_addr_n2a(AF_INET6,
 283                                     RTA_PAYLOAD(tb[IFLA_IPTUN_REMOTE]),
 284                                     RTA_DATA(tb[IFLA_IPTUN_REMOTE]),
 285                                     s1, sizeof(s1)));
 286         }
 287
 288         if (tb[IFLA_IPTUN_LOCAL]) {
 289                 fprintf(f, "local %s ",
 290                         rt_addr_n2a(AF_INET6,
 291                                     RTA_PAYLOAD(tb[IFLA_IPTUN_LOCAL]),
 292                                     RTA_DATA(tb[IFLA_IPTUN_LOCAL]),
 293                                     s1, sizeof(s1)));
 294         }
 295
 296         if (tb[IFLA_IPTUN_LINK] && rta_getattr_u32(tb[IFLA_IPTUN_LINK])) {
 297                 unsigned link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
 298                 const char *n = if_indextoname(link, s2);
 299
 300                 if (n)
 301                         fprintf(f, "dev %s ", n);
 302                 else
 303                         fprintf(f, "dev %u ", link);
 304         }
 305
 306         if (flags & IP6_TNL_F_IGN_ENCAP_LIMIT)
 307                 printf("encaplimit none ");
 308         else if (tb[IFLA_IPTUN_ENCAP_LIMIT])
 309                 fprintf(f, "encaplimit %u ",
 310                         rta_getattr_u8(tb[IFLA_IPTUN_ENCAP_LIMIT]));
 311
 312         if (tb[IFLA_IPTUN_TTL])
 313                 fprintf(f, "hoplimit %u ", rta_getattr_u8(tb[IFLA_IPTUN_TTL]));
 314
 315         if (flags & IP6_TNL_F_USE_ORIG_TCLASS)
 316                 printf("tclass inherit ");
 317         else if (tb[IFLA_IPTUN_FLOWINFO]) {
 318                 __u32 val = ntohl(flowinfo & IP6_FLOWINFO_TCLASS);
 319
 320                 printf("tclass 0x%02x ", (__u8)(val >> 20));
 321         }
 322
 323         if (flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
 324                 printf("flowlabel inherit ");
 325         else
 326                 printf("flowlabel 0x%05x ", ntohl(flowinfo & IP6_FLOWINFO_FLOWLABEL));
 327
 328         printf("(flowinfo 0x%08x) ", ntohl(flowinfo));
 329
 330         if (flags & IP6_TNL_F_RCV_DSCP_COPY)
 331                 printf("dscp inherit ");
 332
 333         if (flags & IP6_TNL_F_MIP6_DEV)
 334                 fprintf(f, "mip6 ");
 335
 336         if (flags & IP6_TNL_F_USE_ORIG_FWMARK)
 337                 fprintf(f, "fwmark inherit ");
 338 }
 339
 340 struct link_util ip6tnl_link_util = {
 341         .id = "ip6tnl",
 342         .maxattr = IFLA_IPTUN_MAX,
 343         .parse_opt = ip6tunnel_parse_opt,
 344         .print_opt = ip6tunnel_print_opt,
 345 };