First version: far too large (408 bytes!!!)

src/core/url.c

@@ -0,0 +1,144 @@
+#include "stdlib.h"
+#include "string.h"
+#include "proto.h"
+#include "resolv.h"
+#include "url.h"
+
+static struct protocol protocols[0] __protocol_start;
+static struct protocol default_protocols[0] __default_protocol_start;
+static struct protocol protocols_end[0] __protocol_end;
+
+/*
+ * Parse protocol portion of a URL.  Return 0 if no "proto://" is
+ * present.
+ *
+ */
+static inline int parse_protocol ( struct url_info *info, const char **p ) {
+	const char *q = *p;
+
+	info->protocol = q;
+	for ( ; *q ; q++ ) {
+		if ( memcmp ( q, "://", 3 ) == 0 ) {
+			info->protocol_len = q - info->protocol;
+			*p = q + 3;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Parse the host:port portion of a URL.  Also fills in sin_port.
+ *
+ */
+static inline void parse_host_port ( struct url_info *info, const char **p ) {
+	info->host = *p;
+	for ( ; **p && ( **p != '/' ) ; (*p)++ ) {
+		if ( **p == ':' ) {
+			info->host_len = *p - info->host;
+			info->port = ++(*p);
+			info->sin.sin_port = strtoul ( *p, p, 10 );
+			info->port_len = *p - info->port;
+			return;
+		}
+	}
+	/* No ':' separator seen; it's all the host part */
+	info->host_len = *p - info->host;
+}
+
+/*
+ * Identify the protocol
+ *
+ */
+static inline int identify_protocol ( struct url_info *info ) {
+	struct protocol *proto;
+
+	if ( info->protocol_len ) {
+		char *terminator;
+		char temp;
+
+		/* Explcitly specified protocol */
+		terminator = ( char * ) &info->protocol[info->protocol_len];
+		temp = *terminator;
+		*terminator = '\0';
+		for ( proto = protocols ; proto < protocols_end ; proto++ ) {
+			if ( memcmp ( proto->name, info->protocol,
+				      info->protocol_len + 1 ) == 0 ) {
+				info->proto = proto;
+				break;
+			}
+		}
+		*terminator = temp;
+	} else {
+		/* No explicitly specified protocol */
+		if ( default_protocols < protocols_end )
+			info->proto = default_protocols;
+	}
+	return ( ( int ) info->proto ); /* NULL indicates failure */
+}
+
+/*
+ * Resolve the host portion of the URL
+ *
+ */
+static inline int resolve_host ( struct url_info *info ) {
+	char *terminator;
+	char temp;
+	int success;
+
+	if ( ! info->host_len ) {
+		/* No host specified - leave sin.sin_addr empty to
+		 * indicate use of DHCP-supplied next-server
+		 */
+		return 1;
+	}
+
+	terminator = ( char * ) &info->host[info->host_len];
+	temp = *terminator;
+	*terminator = '\0';
+	success = resolv ( &info->sin.sin_addr, info->host );
+	*terminator = temp;
+	return success;
+}
+
+/*
+ * Parse a URL string into its constituent parts.  Perform name
+ * resolution if required (and if resolver code is linked in), and
+ * identify the protocol.
+ *
+ * We accept URLs of the form
+ *
+ *   [protocol://[host][:port]/]path/to/file
+ *
+ * We return true for success, 0 for failure (e.g. unknown protocol).
+ * Note that the "/" before path/to/file *will* be counted as part of
+ * the filename, if it is present.
+ *
+ */
+int parse_url ( struct url_info *info, const char *url ) {
+	const char *p;
+
+	/* Fill in initial values */
+	memset ( info, 0, sizeof ( *info ) );
+	info->url = url;
+	info->protocol = url;
+	info->host = url;
+	info->port = url;
+	info->file = url;
+
+	/* Split the URL into substrings, and fill in sin.sin_port */
+	p = url;
+	if ( parse_protocol ( info, &p ) )
+		parse_host_port ( info, &p );
+	info->file = p;
+
+	/* Identify the protocol */
+	if ( ! identify_protocol ( info ) )
+		return 0;
+
+	/* Resolve the host name to an IP address */
+	if ( ! resolve_host ( info ) )
+		return 0;
+
+	return 1;
+}