From dc6ba44ea66c471305908a8053d7de56d705e499 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Sat, 28 Oct 2017 00:03:18 +0200
Subject: [SERVER] Add function to parse x-www-form-urlencoded strings

Use it to properly parse RPC queries. Will also come in handy
when parsing POST body for calls that actually trigger any
actions in the server (reload, alt-servers, ...)
---
 src/server/urldecode.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 src/server/urldecode.c

(limited to 'src/server/urldecode.c')

diff --git a/src/server/urldecode.c b/src/server/urldecode.c
new file mode 100644
index 0000000..4553097
--- /dev/null
+++ b/src/server/urldecode.c
@@ -0,0 +1,61 @@
+#include "urldecode.h"
+#include <stdlib.h>
+#include <ctype.h>
+
+#define hex2int(a) do { \
+			if ( a >= 'a' ) {                           \
+				a = (char)(a - ( 'a' - 'A' - 10 ));      \
+			} else if ( a > 'F' ) {                     \
+				goto normie;                             \
+			} else if ( a >= 'A' ) {                    \
+				a = (char)(a - ( 'A' - 10 ));            \
+			} else if ( a < '0' || a > '9' ) {          \
+				goto normie;                             \
+			} else {                                    \
+				a = (char)(a - '0');                     \
+			}                                           \
+} while (0)
+
+void urldecode(struct string* str, struct field *out, size_t *out_num)
+{
+	char *src = (char*)str->s;
+	char *dst = src;
+	const char * const end = str->s + str->l;
+	char a, b;
+	size_t max_out = *out_num;
+	*out_num = 0;
+	do {
+		if ( *out_num == max_out ) return;
+		out->name.s = dst;
+		while ( src < end && *src != '=' ) {
+			*dst++ = *src++;
+		}
+		if ( src == end ) return;
+		out->name.l = (size_t)( dst - out->name.s );
+		++src;
+		out->value.s = ++dst;
+		while ( src < end && *src != '&' ) {
+			if ( *src == '%' && src + 2 < end ) {
+				if ( src[1] > 'f' || src[2] > 'f' ) goto normie;
+				a = src[1];
+				hex2int(a);
+				b = src[2];
+				hex2int(b);
+				*dst++ = (char)( (16 * a) + b );
+				src += 3;
+			} else if (*src == '+') {
+				*dst++ = (char)' ';
+				++src;
+			} else {
+	normie:;
+				*dst++ = *src++;
+			}
+		}
+		out->value.l = (size_t)( dst - out->value.s );
+		out++;
+		(*out_num)++;
+		if ( src++ >= end ) return;
+		++dst;
+	} while ( 1 );
+}
+
-- 
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