ape: add inet_aton()

1 files changed, 57 insertions, 0 deletions

diff --git a/sys/src/ape/lib/bsd/inet_aton.c b/sys/src/ape/lib/bsd/inet_aton.c
new file mode 100644
index 000000000..8af377862
--- /dev/null
+++ b/sys/src/ape/lib/bsd/inet_aton.c
@@ -0,0 +1,57 @@
+/* posix */
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* bsd extensions */
+#include <sys/uio.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#define CLASS(x)	(x[0]>>6)
+
+int
+inet_aton(char *from, struct in_addr *in)
+{
+	unsigned char *to;
+	unsigned long x;
+	char *p;
+	int i;
+
+	in->s_addr = 0;
+	to = (unsigned char*)&in->s_addr;
+	if(*from == 0)
+		return 0;
+	for(i = 0; i < 4 && *from; i++, from = p){
+		x = strtoul(from, &p, 0);
+		if(x != (unsigned char)x || p == from)
+			return 0;	/* parse error */
+		to[i] = x;
+		if(*p == '.')
+			p++;
+		else if(*p != 0)
+			return 0;	/* parse error */
+	}
+
+	switch(CLASS(to)){
+	case 0:	/* class A - 1 byte 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 byte net */
+		if(i == 3){
+			to[3] = to[2];
+			to[2] = 0;
+		}
+		break;
+	}
+	return 1;
+}