From 5de36cf449053fb25a40a18141f0a18bf5b52444 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Fri, 1 Jul 2016 18:24:00 +0200
Subject: [PATCH] Add inet_pton(3).

---
 libc/Makefile              |  2 +-
 libc/arpa/inet/inet_pton.c | 87 +++++++++++++++++++++++++++++++++-----
 2 files changed, 77 insertions(+), 12 deletions(-)

diff --git a/libc/Makefile b/libc/Makefile
index 2176bae7..04f8f34f 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -17,6 +17,7 @@ ASFLAGS=
 
 FREEOBJS=\
 arpa/inet/inet_ntop.o \
+arpa/inet/inet_pton.o \
 assert/__assert.o \
 c++/c++.o \
 c++/op-new.o \
@@ -317,7 +318,6 @@ wctype/wctype.o \
 HOSTEDOBJS=\
 arpa/inet/inet_addr.o \
 arpa/inet/inet_ntoa.o \
-arpa/inet/inet_pton.o \
 blf/blowfish.o \
 $(CPUDIR)/fork.o \
 $(CPUDIR)/setjmp.o \
diff --git a/libc/arpa/inet/inet_pton.c b/libc/arpa/inet/inet_pton.c
index 9daa0aa6..1751af0f 100644
--- a/libc/arpa/inet/inet_pton.c
+++ b/libc/arpa/inet/inet_pton.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2016 Jonas 'Sortie' Termansen.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -14,21 +14,86 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * arpa/inet/inet_pton.c
- * Internet address manipulation routines.
+ * Convert string to network address.
  */
 
 #include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
 
-#include <stdio.h>
-#include <stdlib.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <string.h>
 
 int inet_pton(int af, const char* restrict src, void* restrict dst)
 {
-	(void) af;
-	(void) src;
-	(void) dst;
-	fprintf(stderr, "%s is not implemented yet, aborting.\n", __func__);
-	abort();
+	if ( af == AF_INET )
+	{
+		unsigned char ip[4];
+		size_t index = 0;
+		for ( int i = 0; i < 4; i++ )
+		{
+			if ( i && src[index++] != '.' )
+				return 0;
+			if ( src[index] < '0' || '9' < src[index] )
+				return 0;
+			int num = src[index++] - '0';
+			if ( num )
+			{
+				if ( '0' <= src[index] && src[index] <= '9' )
+				{
+					num = 10 * num + src[index++] - '0';
+					if ( '0' <= src[index] && src[index] <= '9' )
+					{
+						num = 10 * num + src[index++] - '0';
+						if ( 256 <= num )
+							return 0;
+					}
+				}
+			}
+			ip[i] = num;
+		}
+		if ( src[index] )
+			return 0;
+		memcpy(dst, ip, sizeof(ip));
+		return 1;
+	}
+	else if ( af == AF_INET6 )
+	{
+		unsigned char ip[16];
+		size_t index = 0;
+		// TODO: Support for :: syntax.
+		// TODO: Support for x:x:x:x:x:x:d.d.d.d syntax.
+		for ( int i = 0; i < 8; i++ )
+		{
+			if ( i && src[index++] != ':' )
+				return 0;
+			int num = 0;
+			for ( int j = 0; j < 4; j++ )
+			{
+				int dgt;
+				if ( '0' <= src[index] && src[index] <= '9' )
+					dgt = src[index] - '0';
+				else if ( 'a' <= src[index] && src[index] <= 'f' )
+					dgt = src[index] - 'a' + 10;
+				else if ( 'A' <= src[index] && src[index] <= 'F' )
+					dgt = src[index] - 'A' + 10;
+				else
+				{
+					if ( j == 0 )
+						return 0;
+					break;
+				}
+				num = num << 4 | dgt;
+				index++;
+			}
+			ip[2 * i + 0] = num >> 8 & 0xFF;
+			ip[2 * i + 1] = num >> 0 & 0xFF;
+		}
+		if ( src[index] )
+			return 0;
+		memcpy(dst, ip, sizeof(ip));
+		return 1;
+	}
+	else
+		return errno = EAFNOSUPPORT, -1;
 }