unix4lyfe git - darkstat-debian/blob - addr.c

   1 /* darkstat 3
   2  * copyright (c) 2011 Emil Mikulic.
   3  *
   4  * addr.c: compound IPv4/IPv6 address
   5  *
   6  * You may use, modify and redistribute this file under the terms of the
   7  * GNU General Public License version 2. (see COPYING.GPL)
   8  */
   9
  10 #include "addr.h"
  11
  12 #include <arpa/inet.h> /* for inet_ntop */
  13 #include <assert.h>
  14 #include <string.h> /* for memcmp */
  15 #include <netdb.h> /* for getaddrinfo */
  16
  17 int addr_equal(const struct addr * const a, const struct addr * const b)
  18 {
  19    if (a->family != b->family)
  20       return 0;
  21    if (a->family == IPv4)
  22       return (a->ip.v4 == b->ip.v4);
  23    else {
  24       assert(a->family == IPv6);
  25       return (memcmp(&(a->ip.v6), &(b->ip.v6), sizeof(a->ip.v6)) == 0);
  26    }
  27 }
  28
  29 static char _addrstrbuf[INET6_ADDRSTRLEN];
  30 const char *addr_to_str(const struct addr * const a)
  31 {
  32    if (a->family == IPv4) {
  33       struct in_addr in;
  34       in.s_addr = a->ip.v4;
  35       return (inet_ntoa(in));
  36    } else {
  37       assert(a->family == IPv6);
  38       inet_ntop(AF_INET6, &(a->ip.v6), _addrstrbuf, sizeof(_addrstrbuf));
  39       return (_addrstrbuf);
  40    }
  41 }
  42
  43 int str_to_addr(const char *s, struct addr *a)
  44 {
  45    struct addrinfo hints, *ai;
  46    int ret;
  47
  48    memset(&hints, 0, sizeof(hints));
  49    hints.ai_family = AF_UNSPEC;
  50    hints.ai_flags = AI_NUMERICHOST;
  51
  52    if ((ret = getaddrinfo(s, NULL, &hints, &ai)) != 0)
  53       return (ret);
  54
  55    if (ai->ai_family == AF_INET) {
  56       a->family = IPv4;
  57       a->ip.v4 = ((const struct sockaddr_in *)ai->ai_addr)->sin_addr.s_addr;
  58    } else if (ai->ai_family == AF_INET6) {
  59       a->family = IPv6;
  60       memcpy(&(a->ip.v6),
  61              ((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr.s6_addr,
  62              sizeof(a->ip.v6));
  63    } else {
  64       ret = EAI_FAMILY;
  65    }
  66
  67    freeaddrinfo(ai);
  68    return (ret);
  69 }
  70
  71 void addr_mask(struct addr *a, const struct addr * const mask)
  72 {
  73    assert(a->family == mask->family);
  74    if (a->family == IPv4)
  75       a->ip.v4 &= mask->ip.v4;
  76    else {
  77       size_t i;
  78
  79       assert(a->family == IPv6);
  80       for (i=0; i<sizeof(a->ip.v6.s6_addr); i++)
  81          a->ip.v6.s6_addr[i] &= mask->ip.v6.s6_addr[i];
  82    }
  83 }
  84
  85 int addr_inside(const struct addr * const a,
  86    const struct addr * const net, const struct addr * const mask)
  87 {
  88    struct addr masked;
  89
  90    assert(a->family == net->family);
  91    assert(a->family == mask->family);
  92
  93    masked = *a;
  94    addr_mask(&masked, mask);
  95    return (addr_equal(&masked, net));
  96 }
  97
  98 /* vim:set ts=3 sw=3 tw=78 et: */