add uh_addr_rfc1918()

3 files changed, 25 insertions, 9 deletions

diff --git a/uhttpd.h b/uhttpd.h
index cb56fcd..f47c743 100644
--- a/uhttpd.h
+++ b/uhttpd.h
@@ -136,15 +136,6 @@ struct dispatch_handler {
 	void (*handle_request)(struct client *cl, const char *url, struct path_info *pi);
 };
 
-struct uh_addr {
-	uint8_t family;
-	uint16_t port;
-	union {
-		struct in_addr in;
-		struct in6_addr in6;
-	};
-};
-
 struct client {
 	struct list_head list;
 	int id;
diff --git a/utils.c b/utils.c
index d2ad296..742e280 100644
--- a/utils.c
+++ b/utils.c
@@ -217,3 +217,18 @@ char *uh_split_header(char *str)
 
 	return val;
 }
+
+bool uh_addr_rfc1918(struct uh_addr *addr)
+{
+	uint32_t a;
+
+	if (addr->family != AF_INET)
+		return false;
+
+	a = htonl(addr->in.s_addr);
+	return ((a >= 0x0A000000) && (a <= 0x0AFFFFFF)) ||
+	       ((a >= 0xAC100000) && (a <= 0xAC1FFFFF)) ||
+	       ((a >= 0xC0A80000) && (a <= 0xC0A8FFFF));
+
+	return 0;
+}
diff --git a/utils.h b/utils.h
index 8f67823..a53c256 100644
--- a/utils.h
+++ b/utils.h
@@ -29,6 +29,15 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+struct uh_addr {
+	uint8_t family;
+	uint16_t port;
+	union {
+		struct in_addr in;
+		struct in6_addr in6;
+	};
+};
+
 #define min(x, y) (((x) < (y)) ? (x) : (y))
 #define max(x, y) (((x) > (y)) ? (x) : (y))
 
@@ -57,5 +66,6 @@ int uh_urlencode(char *buf, int blen, const char *src, int slen);
 int uh_b64decode(char *buf, int blen, const void *src, int slen);
 bool uh_path_match(const char *prefix, const char *url);
 char *uh_split_header(char *str);
+bool uh_addr_rfc1918(struct uh_addr *addr);
 
 #endif