1 files changed, 101 insertions, 0 deletions
diff --git a/src/ip4_bit.c b/src/ip4_bit.c
new file mode 100644
index 0000000..02dbf7a
--- /dev/null
+++ b/src/ip4_bit.c
@@ -0,0 +1,101 @@
+/***
+  @file ip4_bit.c
+  @author Jens Wehrenbrecht, feh
+  @funcs ip4_bitstring, bitstring_ip4
+*/
+#include "ip.h"
+#include "byte.h"
+#include "scan.h"
+#include "str.h"
+#include "fmt.h"
+#include "ip_bit.h"
+
+#define BITSUBSTITUTION
+
+static char strnum[FMT_ULONG];
+
+/***
+  /fn ip4_bitstring
+  /brief This function converts a IPv4 address into its binary representation with given prefix len
+  /param out: ip4string    0-terminated destination address.
+  /param in:  ip4address   The source address.
+  /param in:  prefix       The net prefix bits (maximum 32 bits for IPv4).
+  /return -1: lack of memory;  1: non valid IP address; 0: successful converted.
+*/
+
+int ip4_bitstring(stralloc *ip4string, char *ip, unsigned int prefix)
+{
+  int i, j;
+  char ip4[4];
+  int count = 0;
+  unsigned char number;
+#ifdef BITSUBSTITUTION
+  const char *letterarray = "abcdefghijklmnopqrstuvwxyz123456";
+#endif
+
+  if (!stralloc_copys(ip4string,"")) return -1;
+  if (!stralloc_readyplus(ip4string,32)) return -1;
+  ip4_scan(ip,ip4);
+
+  for (i = 0; i < 4; i++) {
+    number = (unsigned char) ip4[i];
+    for (j = 7; j >= 0; j--) {
+      if (number & (1<<j)) {
+#ifdef BITSUBSTITUTION
+        if (!stralloc_catb(ip4string,letterarray + count,1)) return -1;
+#else
+        if (!stralloc_cats(ip4string,"1")) return -1;
+#endif
+      } else {
+        if (!stralloc_cats(ip4string,"0")) return -1;
+      }
+      count++;
+      prefix--;
+      if (prefix == 0) return 0;
+    }
+  }
+
+  return 1;
+}
+
+/***
+  /fn bitstring_ip4
+  /brief This function takes an IPv4 bitstring and translates it to an IPv4 address + prefix
+  /param in:  ip4string    The source address  (with '_' start token).
+  /param out: ip4addr      0-terminated estination IPv4 address + net prefix (eg. 127.0.0.0/16).
+  /return -1: lack of memory;  1: non valid IPv4 address; 0: successful converted.
+*/
+
+int bitstring_ip4(stralloc *ip4addr, stralloc *ip4string)
+{
+  int j;
+  int num = 0;
+  int value = 256;
+  int prefix; 
+
+  if (!stralloc_copys(ip4addr,"")) return -1;
+  prefix = ip4string->len - 1;
+
+  if (prefix <= 0) return 1;
+  if (prefix <= 1 || prefix > 32) return 1;
+
+  for (j = 1; j <= prefix; j++) {
+   if (ip4string->s[j] != '0') {
+      num += (value/2); 
+      value /= 2;
+    } else 
+      value /= 2; 
+    if (j % 8 == 0 || j == prefix) {
+      if (!stralloc_catb(ip4addr,strnum,fmt_ulong(strnum,num))) return -1;
+      if (j < 32) if (!stralloc_cats(ip4addr,".")) return -1;
+      num = 0;
+      value = 256;
+    }
+  }
+  
+  if (!stralloc_cats(ip4addr,"/")) return -1;
+  if (!stralloc_catb(ip4addr,strnum,fmt_ulong(strnum,prefix))) return -1;
+  if (!stralloc_0(ip4addr)) return -1;
+
+  return 0;
+}