ip/ipnetconf.c

   1 /*
   2  * ipnetconf.c          "ip netconf".
   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 <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <fcntl.h>
  18 #include <string.h>
  19 #include <sys/time.h>
  20 #include <sys/socket.h>
  21 #include <netinet/in.h>
  22
  23 #include "rt_names.h"
  24 #include "utils.h"
  25 #include "ip_common.h"
  26
  27 static struct
  28 {
  29         int family;
  30         int ifindex;
  31 } filter;
  32
  33 static void usage(void) __attribute__((noreturn));
  34
  35 static void usage(void)
  36 {
  37         fprintf(stderr, "Usage: ip netconf show [ dev STRING ]\n");
  38         exit(-1);
  39 }
  40
  41 #define NETCONF_RTA(r)  ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct netconfmsg))))
  42
  43 int print_netconf(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
  44 {
  45         FILE *fp = (FILE*)arg;
  46         struct netconfmsg *ncm = NLMSG_DATA(n);
  47         int len = n->nlmsg_len;
  48         struct rtattr *tb[NETCONFA_MAX+1];
  49
  50         if (n->nlmsg_type == NLMSG_ERROR)
  51                 return -1;
  52         if (n->nlmsg_type != RTM_NEWNETCONF) {
  53                 fprintf(stderr, "Not RTM_NEWNETCONF: %08x %08x %08x\n",
  54                         n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
  55
  56                 return -1;
  57         }
  58         len -= NLMSG_SPACE(sizeof(*ncm));
  59         if (len < 0) {
  60                 fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
  61                 return -1;
  62         }
  63
  64         if (filter.family && filter.family != ncm->ncm_family)
  65                 return 0;
  66
  67         parse_rtattr(tb, NETCONFA_MAX, NETCONF_RTA(ncm),
  68                      NLMSG_PAYLOAD(n, sizeof(*ncm)));
  69
  70         switch (ncm->ncm_family) {
  71         case AF_INET:
  72                 fprintf(fp, "ipv4 ");
  73                 break;
  74         case AF_INET6:
  75                 fprintf(fp, "ipv6 ");
  76                 break;
  77         default:
  78                 fprintf(fp, "unknown ");
  79                 break;
  80         }
  81
  82         if (tb[NETCONFA_IFINDEX]) {
  83                 int *ifindex = (int *)RTA_DATA(tb[NETCONFA_IFINDEX]);
  84
  85                 switch (*ifindex) {
  86                 case NETCONFA_IFINDEX_ALL:
  87                         fprintf(fp, "all ");
  88                         break;
  89                 case NETCONFA_IFINDEX_DEFAULT:
  90                         fprintf(fp, "default ");
  91                         break;
  92                 default:
  93                         fprintf(fp, "dev %s ", ll_index_to_name(*ifindex));
  94                         break;
  95                 }
  96         }
  97
  98         if (tb[NETCONFA_FORWARDING])
  99                 fprintf(fp, "forwarding %s ",
 100                         *(int *)RTA_DATA(tb[NETCONFA_FORWARDING])?"on":"off");
 101         if (tb[NETCONFA_RP_FILTER]) {
 102                 int rp_filter = *(int *)RTA_DATA(tb[NETCONFA_RP_FILTER]);
 103
 104                 if (rp_filter == 0)
 105                         fprintf(fp, "rp_filter off ");
 106                 else if (rp_filter == 1)
 107                         fprintf(fp, "rp_filter strict ");
 108                 else if (rp_filter == 2)
 109                         fprintf(fp, "rp_filter loose ");
 110                 else
 111                         fprintf(fp, "rp_filter unknown mode ");
 112         }
 113         if (tb[NETCONFA_MC_FORWARDING])
 114                 fprintf(fp, "mc_forwarding %d ",
 115                         *(int *)RTA_DATA(tb[NETCONFA_MC_FORWARDING]));
 116
 117         fprintf(fp, "\n");
 118         fflush(fp);
 119         return 0;
 120 }
 121
 122 static void ipnetconf_reset_filter(void)
 123 {
 124         memset(&filter, 0, sizeof(filter));
 125 }
 126
 127 static int do_show(int argc, char **argv)
 128 {
 129         struct {
 130                 struct nlmsghdr         n;
 131                 struct netconfmsg       ncm;
 132                 char                    buf[1024];
 133         } req;
 134
 135         ipnetconf_reset_filter();
 136         filter.family = preferred_family;
 137         if (filter.family == AF_UNSPEC)
 138                 filter.family = AF_INET;
 139         filter.ifindex = NETCONFA_IFINDEX_ALL;
 140
 141         while (argc > 0) {
 142                 if (strcmp(*argv, "dev") == 0) {
 143                         NEXT_ARG();
 144                         filter.ifindex = ll_name_to_index(*argv);
 145                         if (filter.ifindex <= 0) {
 146                                 fprintf(stderr, "Device \"%s\" does not exist.\n",
 147                                         *argv);
 148                                 return -1;
 149                         }
 150                 }
 151                 argv++; argc--;
 152         }
 153
 154         ll_init_map(&rth);
 155         memset(&req, 0, sizeof(req));
 156         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct netconfmsg));
 157         req.n.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
 158         req.n.nlmsg_type = RTM_GETNETCONF;
 159         req.ncm.ncm_family = filter.family;
 160         addattr_l(&req.n, sizeof(req), NETCONFA_IFINDEX, &filter.ifindex,
 161                   sizeof(filter.ifindex));
 162
 163         rtnl_send(&rth, &req.n, req.n.nlmsg_len);
 164         rtnl_listen(&rth, print_netconf, stdout);
 165
 166         return 0;
 167 }
 168
 169 int do_ipnetconf(int argc, char **argv)
 170 {
 171         if (argc > 0) {
 172                 if (matches(*argv, "show") == 0 ||
 173                     matches(*argv, "lst") == 0 ||
 174                     matches(*argv, "list") == 0)
 175                         return do_show(argc-1, argv+1);
 176                 if (matches(*argv, "help") == 0)
 177                         usage();
 178         } else
 179                 return do_show(0, NULL);
 180
 181         fprintf(stderr, "Command \"%s\" is unknown, try \"ip netconf help\".\n", *argv);
 182         exit(-1);
 183 }