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

   1 /* darkstat 3
   2  * copyright (c) 2001-2012 Emil Mikulic.
   3  *
   4  * localip.c: determine local IPs of an interface
   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 #include "bsd.h" /* for strlcpy */
  12 #include "config.h" /* for HAVE_IFADDRS_H */
  13 #include "conv.h"
  14 #include "err.h"
  15 #include "localip.h"
  16 #include "now.h"
  17
  18 #include <sys/socket.h>
  19 #include <net/if.h>
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <time.h>
  25 #include <unistd.h>
  26
  27 #ifdef HAVE_IFADDRS_H
  28 # include <ifaddrs.h>
  29 #else
  30 # ifdef HAVE_SYS_SOCKIO_H
  31 #  include <sys/sockio.h> /* for SIOCGIFADDR, especially on Solaris */
  32 # endif
  33 # include <sys/ioctl.h>
  34 #endif
  35
  36 void localip_init(struct local_ips *ips) {
  37    ips->is_valid = 0;
  38    ips->last_update_mono = 0;
  39    ips->num_addrs = 0;
  40    ips->addrs = NULL;
  41 }
  42
  43 void localip_free(struct local_ips *ips) {
  44    if (ips->addrs != NULL)
  45       free(ips->addrs);
  46 }
  47
  48 static void add_ip(const char *iface,
  49                    struct local_ips *ips,
  50                    int *idx,
  51                    struct addr *a) {
  52    if (ips->num_addrs <= *idx) {
  53       /* Grow. */
  54       ips->addrs = xrealloc(ips->addrs, sizeof(*(ips->addrs)) * (*idx + 1));
  55       ips->num_addrs++;
  56       assert(ips->num_addrs > *idx);
  57       verbosef("interface '%s' gained new address %s", iface, addr_to_str(a));
  58    } else {
  59       /* Warn about changed address. */
  60       if (!addr_equal(ips->addrs + *idx, a)) {
  61          static char before[INET6_ADDRSTRLEN];
  62          strncpy(before, addr_to_str(ips->addrs + *idx), INET6_ADDRSTRLEN);
  63          verbosef("interface '%s' address %d/%d changed from %s to %s",
  64             iface, *idx+1, ips->num_addrs, before, addr_to_str(a));
  65       }
  66    }
  67    ips->addrs[*idx] = *a;
  68    (*idx)++;
  69 }
  70
  71 /* Returns 0 on failure. */
  72 void localip_update(const char *iface, struct local_ips *ips) {
  73    struct addr a;
  74    int new_addrs = 0;
  75
  76    if (iface == NULL) {
  77       /* reading from capfile */
  78       ips->is_valid = 0;
  79       return;
  80    }
  81
  82    if (ips->last_update_mono == now_mono()) {
  83       /* Too soon, bail out. */
  84       return;
  85    }
  86    ips->last_update_mono = now_mono();
  87
  88 #ifdef HAVE_IFADDRS_H
  89    {
  90       struct ifaddrs *ifas, *ifa;
  91
  92       if (getifaddrs(&ifas) < 0)
  93          err(1, "getifaddrs() failed");
  94
  95       for (ifa=ifas; ifa; ifa=ifa->ifa_next) {
  96          if (strncmp(ifa->ifa_name, iface, IFNAMSIZ))
  97             continue;   /* Wrong interface. */
  98
  99          if (!ifa->ifa_addr)
 100             continue;   /* This can be NULL, e.g. for ppp0. */
 101
 102          if (ifa->ifa_addr->sa_family == AF_INET) {
 103             a.family = IPv4;
 104             a.ip.v4 = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
 105             add_ip(iface, ips, &new_addrs, &a);
 106          }
 107          if (ifa->ifa_addr->sa_family == AF_INET6) {
 108             struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 109 # if 0
 110             if ( IN6_IS_ADDR_LINKLOCAL(&(sa6->sin6_addr))
 111                  || IN6_IS_ADDR_SITELOCAL(&(sa6->sin6_addr)) )
 112                continue;
 113 # endif
 114             a.family = IPv6;
 115             memcpy(&(a.ip.v6), &sa6->sin6_addr, sizeof(a.ip.v6));
 116             add_ip(iface, ips, &new_addrs, &a);
 117          }
 118       }
 119       freeifaddrs(ifas);
 120    }
 121 #else /* don't HAVE_IFADDRS_H */
 122    {
 123       int tmp = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
 124       struct ifreq ifr;
 125       struct sockaddr sa;
 126
 127       strlcpy(ifr.ifr_name, iface, IFNAMSIZ);
 128       ifr.ifr_addr.sa_family = AF_INET;
 129       if (ioctl(tmp, SIOCGIFADDR, &ifr) != -1) {
 130          sa = ifr.ifr_addr;
 131          a.family = IPv4;
 132          a.ip.v4 = ((struct sockaddr_in*)(&ifr.ifr_addr))->sin_addr.s_addr;
 133          add_ip(iface, ips, &new_addrs, &a);
 134       }
 135       close(tmp);
 136    }
 137 #endif
 138    if (new_addrs == 0) {
 139       if (ips->is_valid)
 140          verbosef("interface '%s' no longer has any addresses", iface);
 141       ips->is_valid = 0;
 142    } else {
 143       if (!ips->is_valid)
 144          verbosef("interface '%s' now has addresses", iface);
 145       ips->is_valid = 1;
 146       if (ips->num_addrs != new_addrs)
 147          verbosef("interface '%s' number of addresses decreased from %d to %d",
 148             iface, ips->num_addrs, new_addrs);
 149       ips->num_addrs = new_addrs;
 150    }
 151 }
 152
 153 int is_localip(const struct addr * const a,
 154                const struct local_ips * const ips) {
 155    int i;
 156
 157    for (i=0; i<ips->num_addrs; i++) {
 158       if (addr_equal(a, ips->addrs+i))
 159          return 1;
 160    }
 161    return 0;
 162 }
 163
 164 /* vim:set ts=3 sw=3 tw=80 et: */