add libip

src/libip/parseip.c

@@ -0,0 +1,135 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+
+char*
+v4parseip(uchar *to, char *from)
+{
+	int i;
+	char *p;
+
+	p = from;
+	for(i = 0; i < 4 && *p; i++){
+		to[i] = strtoul(p, &p, 0);
+		if(*p == '.')
+			p++;
+	}
+	switch(CLASS(to)){
+	case 0:	/* class A - 1 uchar net */
+	case 1:
+		if(i == 3){
+			to[3] = to[2];
+			to[2] = to[1];
+			to[1] = 0;
+		} else if (i == 2){
+			to[3] = to[1];
+			to[1] = 0;
+		}
+		break;
+	case 2:	/* class B - 2 uchar net */
+		if(i == 3){
+			to[3] = to[2];
+			to[2] = 0;
+		}
+		break;
+	}
+	return p;
+}
+
+ulong
+parseip(uchar *to, char *from)
+{
+	int i, elipsis = 0, v4 = 1;
+	ulong x;
+	char *p, *op;
+
+	memset(to, 0, IPaddrlen);
+	p = from;
+	for(i = 0; i < 16 && *p; i+=2){
+		op = p;
+		x = strtoul(p, &p, 16);
+		if(*p == '.' || (*p == 0 && i == 0)){
+			p = v4parseip(to+i, op);
+			i += 4;
+			break;
+		}
+		to[i] = x>>8;
+		to[i+1] = x;
+		if(*p == ':'){
+			v4 = 0;
+			if(*++p == ':'){
+				elipsis = i+2;
+				p++;
+			}
+		}
+	}
+	if(i < 16){
+		memmove(&to[elipsis+16-i], &to[elipsis], i-elipsis);
+		memset(&to[elipsis], 0, 16-i);
+	}
+	if(v4){
+		to[10] = to[11] = 0xff;
+		return nhgetl(to+12);
+	} else
+		return 6;
+}
+
+/*
+ *  hack to allow ip v4 masks to be entered in the old
+ *  style
+ */
+ulong
+parseipmask(uchar *to, char *from)
+{
+	ulong x;
+	int i;
+	uchar *p;
+
+	if(*from == '/'){
+		/* as a number of prefix bits */
+		i = atoi(from+1);
+		if(i < 0)
+			i = 0;
+		if(i > 128)
+			i = 128;
+		memset(to, 0, IPaddrlen);
+		for(p = to; i >= 8; i -= 8)
+			*p++ = 0xff;
+		if(i > 0)
+			*p = ~((1<<(8-i))-1);
+		x = nhgetl(to+IPv4off);
+	} else {
+		/* as a straight bit mask */
+		x = parseip(to, from);
+		if(memcmp(to, v4prefix, IPv4off) == 0)
+			memset(to, 0xff, IPv4off);
+	}
+	return x;
+}
+
+/*
+ *  parse a v4 ip address/mask in cidr format
+ */
+char*
+v4parsecidr(uchar *addr, uchar *mask, char *from)
+{
+	int i;
+	char *p;
+	uchar *a;
+
+	p = v4parseip(addr, from);
+
+	if(*p == '/'){
+		/* as a number of prefix bits */
+		i = strtoul(p+1, &p, 0);
+		if(i > 32)
+			i = 32;
+		memset(mask, 0, IPv4addrlen);
+		for(a = mask; i >= 8; i -= 8)
+			*a++ = 0xff;
+		if(i > 0)
+			*a = ~((1<<(8-i))-1);
+	} else 
+		memcpy(mask, defmask(addr), IPv4addrlen);
+	return p;
+}