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