ip/ipprefix.c

   1 /*
   2  * Copyright (C)2005 USAGI/WIDE Project
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses>.
  16  */
  17 /*
  18  * based on ip.c, iproute.c
  19  */
  20 /*
  21  * Authors:
  22  *      Masahide NAKAMURA @USAGI
  23  */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/socket.h>
  29 #include <netinet/icmp6.h>
  30
  31 #include "utils.h"
  32 #include "ip_common.h"
  33
  34 /* prefix flags; see kernel's net/ipv6/addrconf.c and include/net/if_inet6.h */
  35 #define IF_PREFIX_ONLINK        0x01
  36 #define IF_PREFIX_AUTOCONF      0x02
  37
  38 int print_prefix(struct nlmsghdr *n, void *arg)
  39 {
  40         FILE *fp = (FILE *)arg;
  41         struct prefixmsg *prefix = NLMSG_DATA(n);
  42         int len = n->nlmsg_len;
  43         struct rtattr *tb[RTA_MAX+1];
  44         int family = preferred_family;
  45
  46         if (n->nlmsg_type != RTM_NEWPREFIX) {
  47                 fprintf(stderr, "Not a prefix: %08x %08x %08x\n",
  48                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
  49                 return 0;
  50         }
  51
  52         len -= NLMSG_LENGTH(sizeof(*prefix));
  53         if (len < 0) {
  54                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
  55                 return -1;
  56         }
  57
  58         if (family == AF_UNSPEC)
  59                 family = AF_INET6;
  60         if (family != AF_INET6)
  61                 return 0;
  62
  63         if (prefix->prefix_family != AF_INET6) {
  64                 fprintf(stderr, "incorrect protocol family: %d\n", prefix->prefix_family);
  65                 return 0;
  66         }
  67         if (prefix->prefix_type != ND_OPT_PREFIX_INFORMATION) {
  68                 fprintf(stderr, "wrong ND type %d\n", prefix->prefix_type);
  69                 return 0;
  70         }
  71
  72         parse_rtattr(tb, RTA_MAX, RTM_RTA(prefix), len);
  73
  74         if (tb[PREFIX_ADDRESS]) {
  75                 fprintf(fp, "prefix %s/%u",
  76                         rt_addr_n2a_rta(family, tb[PREFIX_ADDRESS]),
  77                         prefix->prefix_len);
  78         }
  79         fprintf(fp, "dev %s ", ll_index_to_name(prefix->prefix_ifindex));
  80
  81         if (prefix->prefix_flags & IF_PREFIX_ONLINK)
  82                 fprintf(fp, "onlink ");
  83         if (prefix->prefix_flags & IF_PREFIX_AUTOCONF)
  84                 fprintf(fp, "autoconf ");
  85
  86         if (tb[PREFIX_CACHEINFO]) {
  87                 const struct prefix_cacheinfo *pc
  88                          = RTA_DATA(tb[PREFIX_CACHEINFO]);
  89
  90                 fprintf(fp, "valid %u ", pc->valid_time);
  91                 fprintf(fp, "preferred %u ", pc->preferred_time);
  92         }
  93
  94         fprintf(fp, "\n");
  95         fflush(fp);
  96
  97         return 0;
  98 }