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 <string.h>
  21
  22 #include "libnetlink.h"
  23 #include "ll_map.h"
  24
  25 extern unsigned int if_nametoindex (const char *);
  26
  27 struct idxmap
  28 {
  29         struct idxmap * next;
  30         unsigned        index;
  31         int             type;
  32         int             alen;
  33         unsigned        flags;
  34         unsigned char   addr[8];
  35         char            name[16];
  36 };
  37
  38 static struct idxmap *idxmap[16];
  39
  40 int ll_remember_index(const struct sockaddr_nl *who,
  41                       struct nlmsghdr *n, void *arg)
  42 {
  43         int h;
  44         struct ifinfomsg *ifi = NLMSG_DATA(n);
  45         struct idxmap *im, **imp;
  46         struct rtattr *tb[IFLA_MAX+1];
  47
  48         if (n->nlmsg_type != RTM_NEWLINK)
  49                 return 0;
  50
  51         if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
  52                 return -1;
  53
  54
  55         memset(tb, 0, sizeof(tb));
  56         parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
  57         if (tb[IFLA_IFNAME] == NULL)
  58                 return 0;
  59
  60         h = ifi->ifi_index&0xF;
  61
  62         for (imp=&idxmap[h]; (im=*imp)!=NULL; imp = &im->next)
  63                 if (im->index == ifi->ifi_index)
  64                         break;
  65
  66         if (im == NULL) {
  67                 im = malloc(sizeof(*im));
  68                 if (im == NULL)
  69                         return 0;
  70                 im->next = *imp;
  71                 im->index = ifi->ifi_index;
  72                 *imp = im;
  73         }
  74
  75         im->type = ifi->ifi_type;
  76         im->flags = ifi->ifi_flags;
  77         if (tb[IFLA_ADDRESS]) {
  78                 int alen;
  79                 im->alen = alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]);
  80                 if (alen > sizeof(im->addr))
  81                         alen = sizeof(im->addr);
  82                 memcpy(im->addr, RTA_DATA(tb[IFLA_ADDRESS]), alen);
  83         } else {
  84                 im->alen = 0;
  85                 memset(im->addr, 0, sizeof(im->addr));
  86         }
  87         strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME]));
  88         return 0;
  89 }
  90
  91 const char *ll_idx_n2a(unsigned idx, char *buf)
  92 {
  93         struct idxmap *im;
  94
  95         if (idx == 0)
  96                 return "*";
  97         for (im = idxmap[idx&0xF]; im; im = im->next)
  98                 if (im->index == idx)
  99                         return im->name;
 100         snprintf(buf, 16, "if%d", idx);
 101         return buf;
 102 }
 103
 104
 105 const char *ll_index_to_name(unsigned idx)
 106 {
 107         static char nbuf[16];
 108
 109         return ll_idx_n2a(idx, nbuf);
 110 }
 111
 112 int ll_index_to_type(unsigned idx)
 113 {
 114         struct idxmap *im;
 115
 116         if (idx == 0)
 117                 return -1;
 118         for (im = idxmap[idx&0xF]; im; im = im->next)
 119                 if (im->index == idx)
 120                         return im->type;
 121         return -1;
 122 }
 123
 124 unsigned ll_index_to_flags(unsigned idx)
 125 {
 126         struct idxmap *im;
 127
 128         if (idx == 0)
 129                 return 0;
 130
 131         for (im = idxmap[idx&0xF]; im; im = im->next)
 132                 if (im->index == idx)
 133                         return im->flags;
 134         return 0;
 135 }
 136
 137 unsigned ll_name_to_index(const char *name)
 138 {
 139         static char ncache[16];
 140         static int icache;
 141         struct idxmap *im;
 142         int i;
 143
 144         if (name == NULL)
 145                 return 0;
 146         if (icache && strcmp(name, ncache) == 0)
 147                 return icache;
 148         for (i=0; i<16; i++) {
 149                 for (im = idxmap[i]; im; im = im->next) {
 150                         if (strcmp(im->name, name) == 0) {
 151                                 icache = im->index;
 152                                 strcpy(ncache, name);
 153                                 return im->index;
 154                         }
 155                 }
 156         }
 157
 158         return if_nametoindex(name);
 159 }
 160
 161 int ll_init_map(struct rtnl_handle *rth)
 162 {
 163         if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
 164                 perror("Cannot send dump request");
 165                 exit(1);
 166         }
 167
 168         if (rtnl_dump_filter(rth, ll_remember_index, &idxmap, NULL, NULL) < 0) {
 169                 fprintf(stderr, "Dump terminated\n");
 170                 exit(1);
 171         }
 172         return 0;
 173 }