lib/ll_map.c

   1 /*
   2  * ll_map.c
   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:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  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 <sys/socket.h>
  19 #include <netinet/in.h>
  20 #include <net/if.h>
  21 #include <string.h>
  22
  23 #include "libnetlink.h"
  24 #include "ll_map.h"
  25
  26 struct idxmap
  27 {
  28         struct idxmap * next;
  29         unsigned        index;
  30         int             type;
  31         int             alen;
  32         unsigned        flags;
  33         unsigned char   addr[8];
  34         char            name[16];
  35 };
  36
  37 static struct idxmap *idxmap[16];
  38
  39 int ll_remember_index(const struct sockaddr_nl *who,
  40                       struct nlmsghdr *n, void *arg)
  41 {
  42         int h;
  43         struct ifinfomsg *ifi = NLMSG_DATA(n);
  44         struct idxmap *im, **imp;
  45         struct rtattr *tb[IFLA_MAX+1];
  46
  47         if (n->nlmsg_type != RTM_NEWLINK)
  48                 return 0;
  49
  50         if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
  51                 return -1;
  52
  53
  54         memset(tb, 0, sizeof(tb));
  55         parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
  56         if (tb[IFLA_IFNAME] == NULL)
  57                 return 0;
  58
  59         h = ifi->ifi_index&0xF;
  60
  61         for (imp=&idxmap[h]; (im=*imp)!=NULL; imp = &im->next)
  62                 if (im->index == ifi->ifi_index)
  63                         break;
  64
  65         if (im == NULL) {
  66                 im = malloc(sizeof(*im));
  67                 if (im == NULL)
  68                         return 0;
  69                 im->next = *imp;
  70                 im->index = ifi->ifi_index;
  71                 *imp = im;
  72         }
  73
  74         im->type = ifi->ifi_type;
  75         im->flags = ifi->ifi_flags;
  76         if (tb[IFLA_ADDRESS]) {
  77                 int alen;
  78                 im->alen = alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]);
  79                 if (alen > sizeof(im->addr))
  80                         alen = sizeof(im->addr);
  81                 memcpy(im->addr, RTA_DATA(tb[IFLA_ADDRESS]), alen);
  82         } else {
  83                 im->alen = 0;
  84                 memset(im->addr, 0, sizeof(im->addr));
  85         }
  86         strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME]));
  87         return 0;
  88 }
  89
  90 const char *ll_idx_n2a(unsigned idx, char *buf)
  91 {
  92         struct idxmap *im;
  93
  94         if (idx == 0)
  95                 return "*";
  96         for (im = idxmap[idx&0xF]; im; im = im->next)
  97                 if (im->index == idx)
  98                         return im->name;
  99         snprintf(buf, 16, "if%d", idx);
 100         return buf;
 101 }
 102
 103
 104 const char *ll_index_to_name(unsigned idx)
 105 {
 106         static char nbuf[16];
 107
 108         return ll_idx_n2a(idx, nbuf);
 109 }
 110
 111 int ll_index_to_type(unsigned idx)
 112 {
 113         struct idxmap *im;
 114
 115         if (idx == 0)
 116                 return -1;
 117         for (im = idxmap[idx&0xF]; im; im = im->next)
 118                 if (im->index == idx)
 119                         return im->type;
 120         return -1;
 121 }
 122
 123 unsigned ll_index_to_flags(unsigned idx)
 124 {
 125         struct idxmap *im;
 126
 127         if (idx == 0)
 128                 return 0;
 129
 130         for (im = idxmap[idx&0xF]; im; im = im->next)
 131                 if (im->index == idx)
 132                         return im->flags;
 133         return 0;
 134 }
 135
 136 unsigned ll_name_to_index(const char *name)
 137 {
 138         static char ncache[16];
 139         static int icache;
 140         struct idxmap *im;
 141         int i;
 142
 143         if (name == NULL)
 144                 return 0;
 145         if (icache && strcmp(name, ncache) == 0)
 146                 return icache;
 147         for (i=0; i<16; i++) {
 148                 for (im = idxmap[i]; im; im = im->next) {
 149                         if (strcmp(im->name, name) == 0) {
 150                                 icache = im->index;
 151                                 strcpy(ncache, name);
 152                                 return im->index;
 153                         }
 154                 }
 155         }
 156
 157         return if_nametoindex(name);
 158 }
 159
 160 int ll_init_map(struct rtnl_handle *rth)
 161 {
 162         if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
 163                 perror("Cannot send dump request");
 164                 exit(1);
 165         }
 166
 167         if (rtnl_dump_filter(rth, ll_remember_index, &idxmap, NULL, NULL) < 0) {
 168                 fprintf(stderr, "Dump terminated\n");
 169                 exit(1);
 170         }
 171         return 0;
 172 }