1 files changed, 79 insertions, 0 deletions
diff --git a/src/bin/iplist2cidr.c b/src/bin/iplist2cidr.c
new file mode 100644
index 0000000..b3cc62c
--- /dev/null
+++ b/src/bin/iplist2cidr.c
@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include <string.h>
+
+struct net {
+ unsigned int ip;
+ unsigned char cidr;
+};
+
+#define min(a,b) ((a)<(b)?(a):(b))
+#define max(a,b) ((a)>(b)?(a):(b))
+
+int main(int argc,char *argv[]) {
+ short in;
+ int maxcidr;
+ int i=0,j=0,len=0;
+ struct net list[65536];//don't do more than a /16!
+ char ips[64];//why not?
+ char *cidrs;
+ while((in=fgetc(stdin)) != -1) {
+  if(in=='\n') {
+   ips[i]=0;
+   if((cidrs=strchr(ips,'/')) != 0) {
+    *cidrs=0;
+    cidrs++;
+   }
+   list[len].ip=htonl(inet_addr(ips));
+   list[len].cidr=cidrs?atoi(cidrs):32;
+   i=0;
+   cidrs=0;
+   len++;
+   continue;
+  }
+  ips[i]=in;
+  i++;
+  if(i>63) {
+   printf("your have a line that is TOOO long. stick to IPv4.\n");
+   return 0;
+  }
+ }
+ //!!!warning!!! inefficient algo ahead!
+ for(i=0;i<len;i++) {
+  for(j=0;j<len;j++) {
+   if(list[i].cidr == list[j].cidr) {
+    if((list[i].ip ^ list[j].ip) >> (32-list[i].cidr) == 1) {
+     list[i].cidr--;
+     list[j].cidr--;
+     list[i].ip &= (0xffffffff << (32-list[i].cidr));
+     list[j].ip &= (0xffffffff << (32-list[j].cidr));
+     i=-1;//start over!
+     j=-1;//start over!
+     continue;
+    }
+   }
+   if(list[i].ip == list[j].ip && list[i].cidr != list[j].cidr) {
+    list[i].cidr = min(list[i].cidr,list[j].cidr);
+    list[j].cidr = min(list[i].cidr,list[j].cidr);
+    i=-1;//start over!
+    j=-1;//start over!
+    continue;
+   }
+   maxcidr=min(list[i].cidr,list[j].cidr);
+   if(list[i].cidr != list[j].cidr) {
+    if(list[i].ip >> (32-maxcidr) == list[j].ip >> (32-maxcidr) ) {
+     list[i].cidr = min(list[i].cidr,list[j].cidr);
+     list[j].cidr = min(list[i].cidr,list[j].cidr);
+     list[i].ip &= (0xffffffff << (32-list[i].cidr));
+     list[j].ip &= (0xffffffff << (32-list[j].cidr));
+     i=-1;//start over!
+     j=-1;//start over!
+     continue;
+    }
+   }
+  }
+ }
+ for(i=0;i<len;i++) {
+  printf("%d.%d.%d.%d/%d\n",list[i].ip>>24&255,list[i].ip>>16&255,list[i].ip>>8&255,list[i].ip&255,list[i].cidr);
+ }
+ return 0;
+}