networking/libiproute/ll_map.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License
   5  * as published by the Free Software Foundation; either version
   6  * 2 of the License, or (at your option) any later version.
   7  *
   8  * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9  */
  10 #include <net/if.h>  /* struct ifreq and co. */
  11
  12 #include "libbb.h"
  13 #include "libnetlink.h"
  14 #include "ll_map.h"
  15
  16 struct idxmap {
  17         struct idxmap *next;
  18         int            index;
  19         int            type;
  20         int            alen;
  21         unsigned       flags;
  22         unsigned char  addr[8];
  23         char           name[16];
  24 };
  25
  26 static struct idxmap **idxmap; /* treat as *idxmap[16] */
  27
  28 static struct idxmap *find_by_index(int idx)
  29 {
  30         struct idxmap *im;
  31
  32         if (idxmap)
  33                 for (im = idxmap[idx & 0xF]; im; im = im->next)
  34                         if (im->index == idx)
  35                                 return im;
  36         return NULL;
  37 }
  38
  39 int FAST_FUNC ll_remember_index(const struct sockaddr_nl *who UNUSED_PARAM,
  40                 struct nlmsghdr *n,
  41                 void *arg UNUSED_PARAM)
  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         //memset(tb, 0, sizeof(tb)); - parse_rtattr does this
  55         parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
  56         if (tb[IFLA_IFNAME] == NULL)
  57                 return 0;
  58
  59         if (!idxmap)
  60                 idxmap = xzalloc(sizeof(idxmap[0]) * 16);
  61
  62         h = ifi->ifi_index & 0xF;
  63         for (imp = &idxmap[h]; (im = *imp) != NULL; imp = &im->next)
  64                 if (im->index == ifi->ifi_index)
  65                         goto found;
  66
  67         im = xmalloc(sizeof(*im));
  68         im->next = *imp;
  69         im->index = ifi->ifi_index;
  70         *imp = im;
  71  found:
  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 > (int)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 static
  89 const char FAST_FUNC *ll_idx_n2a(int idx/*, char *buf*/)
  90 {
  91         struct idxmap *im;
  92
  93         if (idx == 0)
  94                 return "*";
  95         im = find_by_index(idx);
  96         if (im)
  97                 return im->name;
  98         //snprintf(buf, 16, "if%d", idx);
  99         //return buf;
 100         return auto_string(xasprintf("if%d", idx));
 101 }
 102
 103 const char FAST_FUNC *ll_index_to_name(int idx)
 104 {
 105         //static char nbuf[16];
 106         return ll_idx_n2a(idx/*, nbuf*/);
 107 }
 108
 109 #ifdef UNUSED
 110 int ll_index_to_type(int idx)
 111 {
 112         struct idxmap *im;
 113
 114         if (idx == 0)
 115                 return -1;
 116         im = find_by_index(idx);
 117         if (im)
 118                 return im->type;
 119         return -1;
 120 }
 121 #endif
 122
 123 unsigned FAST_FUNC ll_index_to_flags(int idx)
 124 {
 125         struct idxmap *im;
 126
 127         if (idx == 0)
 128                 return 0;
 129         im = find_by_index(idx);
 130         if (im)
 131                 return im->flags;
 132         return 0;
 133 }
 134
 135 int FAST_FUNC xll_name_to_index(const char *name)
 136 {
 137         int ret = 0;
 138
 139 /* caching is not warranted - no users which repeatedly call it */
 140 #ifdef UNUSED
 141         static char ncache[16];
 142         static int icache;
 143
 144         struct idxmap *im;
 145         int i;
 146
 147         if (name == NULL)
 148                 goto out;
 149         if (icache && strcmp(name, ncache) == 0) {
 150                 ret = icache;
 151                 goto out;
 152         }
 153         if (idxmap) {
 154                 for (i = 0; i < 16; i++) {
 155                         for (im = idxmap[i]; im; im = im->next) {
 156                                 if (strcmp(im->name, name) == 0) {
 157                                         icache = im->index;
 158                                         strcpy(ncache, name);
 159                                         ret = im->index;
 160                                         goto out;
 161                                 }
 162                         }
 163                 }
 164         }
 165 #endif
 166         ret = if_nametoindex(name);
 167 /* out:*/
 168         if (ret <= 0)
 169                 bb_error_msg_and_die("can't find device '%s'", name);
 170         return ret;
 171 }
 172
 173 int FAST_FUNC ll_init_map(struct rtnl_handle *rth)
 174 {
 175         xrtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK);
 176         xrtnl_dump_filter(rth, ll_remember_index, NULL);
 177         return 0;
 178 }