1 files changed, 100 insertions, 0 deletions
diff --git a/ipme.c b/ipme.c
new file mode 100644
index 0000000..3c86127
--- /dev/null
+++ b/ipme.c
@@ -0,0 +1,100 @@
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#ifndef SIOCGIFCONF /* whatever works */
+#include <sys/sockio.h>
+#endif
+#include "hassalen.h"
+#include "byte.h"
+#include "ip.h"
+#include "ipalloc.h"
+#include "stralloc.h"
+#include "ipme.h"
+
+static int ipmeok = 0;
+ipalloc ipme = {0};
+
+int ipme_is(ip)
+struct ip_address *ip;
+{
+  int i;
+  if (ipme_init() != 1) return -1;
+  for (i = 0;i < ipme.len;++i)
+    if (byte_equal(&ipme.ix[i].ip,4,ip))
+      return 1;
+  return 0;
+}
+
+static stralloc buf = {0};
+
+int ipme_init()
+{
+  struct ifconf ifc;
+  char *x;
+  struct ifreq *ifr;
+  struct sockaddr_in *sin;
+  int len;
+  int s;
+  struct ip_mx ix;
+ 
+  if (ipmeok) return 1;
+  if (!ipalloc_readyplus(&ipme,0)) return 0;
+  ipme.len = 0;
+  ix.pref = 0;
+ 
+  /* 0.0.0.0 is a special address which always refers to 
+   * "this host, this network", according to RFC 1122, Sec. 3.2.1.3a.
+  */
+  byte_copy(&ix.ip,4,"\0\0\0\0");
+  if (!ipalloc_append(&ipme,&ix)) { return 0; }
+  if ((s = socket(AF_INET,SOCK_STREAM,0)) == -1) return -1;
+ 
+  len = 256;
+  for (;;) {
+    if (!stralloc_ready(&buf,len)) { close(s); return 0; }
+    buf.len = 0;
+    ifc.ifc_buf = buf.s;
+    ifc.ifc_len = len;
+    if (ioctl(s,SIOCGIFCONF,&ifc) >= 0) /* > is for System V */
+      if (ifc.ifc_len + sizeof(*ifr) + 64 < len) { /* what a stupid interface */
+        buf.len = ifc.ifc_len;
+        break;
+      }
+    if (len > 200000) { close(s); return -1; }
+    len += 100 + (len >> 2);
+  }
+  x = buf.s;
+  while (x < buf.s + buf.len) {
+    ifr = (struct ifreq *) x;
+#ifdef HASSALEN
+    len = sizeof(ifr->ifr_name) + ifr->ifr_addr.sa_len;
+    if (len < sizeof(*ifr))
+      len = sizeof(*ifr);
+    if (ifr->ifr_addr.sa_family == AF_INET) {
+      sin = (struct sockaddr_in *) &ifr->ifr_addr;
+      byte_copy(&ix.ip,4,&sin->sin_addr);
+      if (ioctl(s,SIOCGIFFLAGS,x) == 0)
+        if (ifr->ifr_flags & IFF_UP)
+          if (!ipalloc_append(&ipme,&ix)) { close(s); return 0; }
+    }
+#else
+    len = sizeof(*ifr);
+    if (ioctl(s,SIOCGIFFLAGS,x) == 0)
+      if (ifr->ifr_flags & IFF_UP)
+        if (ioctl(s,SIOCGIFADDR,x) == 0)
+	  if (ifr->ifr_addr.sa_family == AF_INET) {
+	    sin = (struct sockaddr_in *) &ifr->ifr_addr;
+	    byte_copy(&ix.ip,4,&sin->sin_addr);
+	    if (!ipalloc_append(&ipme,&ix)) { close(s); return 0; }
+	  }
+#endif
+    x += len;
+  }
+  close(s);
+  ipmeok = 1;
+  return 1;
+}