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