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 <linux/if_tunnel.h>
  16 #include <sys/types.h>
  17 #include <sys/socket.h>
  18 #include <arpa/inet.h>
  19
  20 #include "rt_names.h"
  21 #include "utils.h"
  22 #include "ip_common.h"
  23 #include "tunnel.h"
  24
  25 static void usage(void) __attribute__((noreturn));
  26 static void usage(void)
  27 {
  28         fprintf(stderr, "Usage: ip link { add | set | change | replace | del } NAME\n");
  29         fprintf(stderr, "          type { gre | gretap } [ remote ADDR ] [ local ADDR ]\n");
  30         fprintf(stderr, "          [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
  31         fprintf(stderr, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
  32         fprintf(stderr, "\n");
  33         fprintf(stderr, "Where: NAME := STRING\n");
  34         fprintf(stderr, "       ADDR := { IP_ADDRESS | any }\n");
  35         fprintf(stderr, "       TOS  := { NUMBER | inherit }\n");
  36         fprintf(stderr, "       TTL  := { 1..255 | inherit }\n");
  37         fprintf(stderr, "       KEY  := { DOTTED_QUAD | NUMBER }\n");
  38         exit(-1);
  39 }
  40
  41 static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
  42                          struct nlmsghdr *n)
  43 {
  44         __u16 iflags = 0;
  45         __u16 oflags = 0;
  46         unsigned ikey = 0;
  47         unsigned okey = 0;
  48         unsigned saddr = 0;
  49         unsigned daddr = 0;
  50
  51         while (argc > 0) {
  52                 if (!matches(*argv, "key")) {
  53                         unsigned uval;
  54
  55                         NEXT_ARG();
  56                         iflags |= GRE_KEY;
  57                         oflags |= GRE_KEY;
  58                         if (strchr(*argv, '.'))
  59                                 uval = get_addr32(*argv);
  60                         else {
  61                                 if (get_unsigned(&uval, *argv, 0) < 0) {
  62                                         fprintf(stderr,
  63                                                 "Invalid value for \"key\"\n");
  64                                         exit(-1);
  65                                 }
  66                                 uval = htonl(uval);
  67                         }
  68
  69                         ikey = okey = uval;
  70                 } else if (!matches(*argv, "ikey")) {
  71                         unsigned uval;
  72
  73                         NEXT_ARG();
  74                         iflags |= GRE_KEY;
  75                         if (strchr(*argv, '.'))
  76                                 uval = get_addr32(*argv);
  77                         else {
  78                                 if (get_unsigned(&uval, *argv, 0)<0) {
  79                                         fprintf(stderr, "invalid value of \"ikey\"\n");
  80                                         exit(-1);
  81                                 }
  82                                 uval = htonl(uval);
  83                         }
  84                         ikey = uval;
  85                 } else if (!matches(*argv, "okey")) {
  86                         unsigned uval;
  87
  88                         NEXT_ARG();
  89                         oflags |= GRE_KEY;
  90                         if (strchr(*argv, '.'))
  91                                 uval = get_addr32(*argv);
  92                         else {
  93                                 if (get_unsigned(&uval, *argv, 0)<0) {
  94                                         fprintf(stderr, "invalid value of \"okey\"\n");
  95                                         exit(-1);
  96                                 }
  97                                 uval = htonl(uval);
  98                         }
  99                         okey = uval;
 100                 } else if (!matches(*argv, "seq")) {
 101                         iflags |= GRE_SEQ;
 102                         oflags |= GRE_SEQ;
 103                 } else if (!matches(*argv, "iseq")) {
 104                         iflags |= GRE_SEQ;
 105                 } else if (!matches(*argv, "oseq")) {
 106                         oflags |= GRE_SEQ;
 107                 } else if (!matches(*argv, "csum")) {
 108                         iflags |= GRE_CSUM;
 109                         oflags |= GRE_CSUM;
 110                 } else if (!matches(*argv, "icsum")) {
 111                         iflags |= GRE_CSUM;
 112                 } else if (!matches(*argv, "ocsum")) {
 113                         oflags |= GRE_CSUM;
 114                 } else if (!matches(*argv, "nopmtudisc")) {
 115                         __u8 val = 0;
 116
 117                         addattr_l(n, 1024, IFLA_GRE_PMTUDISC, &val, 1);
 118                 } else if (!matches(*argv, "pmtudisc")) {
 119                         __u8 val = 1;
 120
 121                         addattr_l(n, 1024, IFLA_GRE_PMTUDISC, &val, 1);
 122                 } else if (!matches(*argv, "remote")) {
 123                         NEXT_ARG();
 124                         if (strcmp(*argv, "any"))
 125                                 daddr = get_addr32(*argv);
 126                 } else if (!matches(*argv, "local")) {
 127                         NEXT_ARG();
 128                         if (strcmp(*argv, "any"))
 129                                 saddr = get_addr32(*argv);
 130                 } else if (!matches(*argv, "dev")) {
 131                         unsigned link;
 132
 133                         NEXT_ARG();
 134                         link = tnl_ioctl_get_ifindex(*argv);
 135                         if (link == 0)
 136                                 exit(-1);
 137
 138                         addattr32(n, 1024, IFLA_GRE_LINK, link);
 139                 } else if (!matches(*argv, "ttl") ||
 140                            !matches(*argv, "hoplimit")) {
 141                         unsigned uval;
 142                         __u8 ttl;
 143
 144                         NEXT_ARG();
 145                         if (strcmp(*argv, "inherit") != 0) {
 146                                 if (get_unsigned(&uval, *argv, 0))
 147                                         invarg("invalid TTL\n", *argv);
 148                                 if (uval > 255)
 149                                         invarg("TTL must be <= 255\n", *argv);
 150                                 ttl = uval;
 151                                 addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);
 152                         }
 153                 } else if (!matches(*argv, "tos") ||
 154                            !matches(*argv, "tclass") ||
 155                            !matches(*argv, "dsfield")) {
 156                         __u32 uval;
 157                         __u8 tos;
 158
 159                         NEXT_ARG();
 160                         if (strcmp(*argv, "inherit") != 0) {
 161                                 if (rtnl_dsfield_a2n(&uval, *argv))
 162                                         invarg("bad TOS value", *argv);
 163                                 tos = uval;
 164                         } else
 165                                 tos = 1;
 166                         addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);
 167                 } else
 168                         usage();
 169                 argc--; argv++;
 170         }
 171
 172         if (!ikey && IN_MULTICAST(ntohl(daddr))) {
 173                 ikey = daddr;
 174                 iflags |= GRE_KEY;
 175         }
 176         if (!okey && IN_MULTICAST(ntohl(daddr))) {
 177                 okey = daddr;
 178                 oflags |= GRE_KEY;
 179         }
 180         if (IN_MULTICAST(ntohl(daddr)) && !saddr) {
 181                 fprintf(stderr, "Broadcast tunnel requires a source address.\n");
 182                 return -1;
 183         }
 184
 185         addattr32(n, 1024, IFLA_GRE_IKEY, ikey);
 186         addattr32(n, 1024, IFLA_GRE_OKEY, okey);
 187         addattr_l(n, 1024, IFLA_GRE_IFLAGS, &iflags, 2);
 188         addattr_l(n, 1024, IFLA_GRE_OFLAGS, &oflags, 2);
 189         addattr_l(n, 1024, IFLA_GRE_LOCAL, &saddr, 4);
 190         addattr_l(n, 1024, IFLA_GRE_REMOTE, &daddr, 4);
 191
 192         return 0;
 193 }
 194
 195 static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 196 {
 197         char s1[1024];
 198         char s2[64];
 199         const char *local = "any";
 200         const char *remote = "any";
 201         unsigned iflags = 0;
 202         unsigned oflags = 0;
 203
 204         if (!tb)
 205                 return;
 206
 207         if (tb[IFLA_GRE_REMOTE]) {
 208                 unsigned addr = *(__u32 *)RTA_DATA(tb[IFLA_GRE_REMOTE]);
 209
 210                 if (addr)
 211                         remote = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
 212         }
 213
 214         fprintf(f, "remote %s ", remote);
 215
 216         if (tb[IFLA_GRE_LOCAL]) {
 217                 unsigned addr = *(__u32 *)RTA_DATA(tb[IFLA_GRE_LOCAL]);
 218
 219                 if (addr)
 220                         local = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
 221         }
 222
 223         fprintf(f, "local %s ", local);
 224
 225         if (tb[IFLA_GRE_LINK] && *(__u32 *)RTA_DATA(tb[IFLA_GRE_LINK])) {
 226                 unsigned link = *(__u32 *)RTA_DATA(tb[IFLA_GRE_LINK]);
 227                 char *n = tnl_ioctl_get_ifname(link);
 228
 229                 if (n)
 230                         fprintf(f, "dev %s ", n);
 231                 else
 232                         fprintf(f, "dev %u ", link);
 233         }
 234
 235         if (tb[IFLA_GRE_TTL] && *(__u8 *)RTA_DATA(tb[IFLA_GRE_TTL]))
 236                 fprintf(f, "ttl %d ", *(__u8 *)RTA_DATA(tb[IFLA_GRE_TTL]));
 237         else
 238                 fprintf(f, "ttl inherit ");
 239
 240         if (tb[IFLA_GRE_TOS] && *(__u8 *)RTA_DATA(tb[IFLA_GRE_TOS])) {
 241                 int tos = *(__u8 *)RTA_DATA(tb[IFLA_GRE_TOS]);
 242
 243                 fputs("tos ", f);
 244                 if (tos == 1)
 245                         fputs("inherit ", f);
 246                 else
 247                         fprintf(f, "0x%x ", tos);
 248         }
 249
 250         if (tb[IFLA_GRE_PMTUDISC] &&
 251             !*(__u8 *)RTA_DATA(tb[IFLA_GRE_PMTUDISC]))
 252                 fputs("nopmtudisc ", f);
 253
 254         if (tb[IFLA_GRE_IFLAGS])
 255                 iflags = *(__u16 *)RTA_DATA(tb[IFLA_GRE_IFLAGS]);
 256
 257         if (tb[IFLA_GRE_OFLAGS])
 258                 oflags = *(__u16 *)RTA_DATA(tb[IFLA_GRE_OFLAGS]);
 259
 260         if (iflags & GRE_KEY && tb[IFLA_GRE_IKEY] &&
 261             *(__u32 *)RTA_DATA(tb[IFLA_GRE_IKEY])) {
 262                 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_IKEY]), s2, sizeof(s2));
 263                 fprintf(f, "ikey %s ", s2);
 264         }
 265
 266         if (oflags & GRE_KEY && tb[IFLA_GRE_OKEY] &&
 267             *(__u32 *)RTA_DATA(tb[IFLA_GRE_OKEY])) {
 268                 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_OKEY]), s2, sizeof(s2));
 269                 fprintf(f, "ikey %s ", s2);
 270         }
 271
 272         if (iflags & GRE_SEQ)
 273                 fputs("iseq ", f);
 274         if (oflags & GRE_SEQ)
 275                 fputs("oseq ", f);
 276         if (iflags & GRE_CSUM)
 277                 fputs("icsum ", f);
 278         if (oflags & GRE_CSUM)
 279                 fputs("ocsum ", f);
 280 }
 281
 282 struct link_util gre_link_util = {
 283         .id = "gre",
 284         .maxattr = IFLA_GRE_MAX,
 285         .parse_opt = gre_parse_opt,
 286         .print_opt = gre_print_opt,
 287 };
 288
 289 struct link_util gretap_link_util = {
 290         .id = "gretap",
 291         .maxattr = IFLA_GRE_MAX,
 292         .parse_opt = gre_parse_opt,
 293         .print_opt = gre_print_opt,
 294 };