Gave asynchronous operations approximate POSIX signal semantics. This

will enable us to cascade async operations, which is necessary in order to
properly support DNS.  (For example, an HTTP request may have to redirect
to a new location and will have to perform a new DNS lookup, so we can't
just rely on doing the name lookup at the time of parsing the initial
URL).

Anything other than HTTP is probably broken right now; I'll fix the others
up asap.

src/net/tcp/http.c

@@ -27,9 +27,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
-#include <vsprintf.h>
+#include <errno.h>
 #include <assert.h>
+#include <vsprintf.h>
 #include <gpxe/async.h>
+#include <gpxe/uri.h>
 #include <gpxe/buffer.h>
 #include <gpxe/http.h>
 
@@ -67,7 +69,7 @@ static void http_done ( struct http_request *http, int rc ) {
 	}
 
 	/* Mark async operation as complete */
-	async_done ( &http->aop, rc );
+	async_done ( &http->async, rc );
 }
 
 /**
@@ -303,12 +305,21 @@ static void http_newdata ( struct tcp_application *app,
 static void http_senddata ( struct tcp_application *app,
 			    void *buf, size_t len ) {
 	struct http_request *http = tcp_to_http ( app );
+	const char *path = http->uri->path;
+	const char *host = http->uri->host;
+
+	if ( ! path )
+		path = "/";
+
+	if ( ! host )
+		host = "";
 
 	len = snprintf ( buf, len,
-			 "GET /%s HTTP/1.1\r\n"
+			 "GET %s HTTP/1.1\r\n"
 			 "User-Agent: gPXE/" VERSION "\r\n"
 			 "Host: %s\r\n"
-			 "\r\n", http->filename, http->hostname );
+			 "\r\n", path, host );
+
 	tcp_send ( app, ( buf + http->tx_offset ), ( len - http->tx_offset ) );
 }
 
@@ -346,17 +357,72 @@ static struct tcp_operations http_tcp_operations = {
 	.senddata	= http_senddata,
 };
 
+/**
+ * Reap asynchronous operation
+ *
+ * @v async		Asynchronous operation
+ */
+static void http_reap ( struct async *async ) {
+	struct http_request *http =
+		container_of ( async, struct http_request, async );
+
+	free_uri ( http->uri );
+	free ( http );
+}
+
+/** HTTP asynchronous operations */
+static struct async_operations http_async_operations = {
+	.reap			= http_reap,
+};
+
+#warning "Quick name resolution hack"
+#include <byteswap.h>
+
 /**
  * Initiate a HTTP connection
  *
- * @v http	a HTTP request
+ * @v uri		Uniform Resource Identifier
+ * @v buffer		Buffer into which to download file
+ * @v parent		Parent asynchronous operation
+ * @ret rc		Return status code
+ *
+ * If it returns success, this function takes ownership of the URI.
  */
-struct async_operation * http_get ( struct http_request *http ) {
+int http_get ( struct uri *uri, struct buffer *buffer, struct async *parent ) {
+	struct http_request *http;
 	int rc;
 
+	/* Allocate and populate HTTP structure */
+	http = malloc ( sizeof ( *http ) );
+	if ( ! http ) {
+		rc = -ENOMEM;
+		goto err;
+	}
+	memset ( http, 0, sizeof ( *http ) );
+	http->uri = uri;
+	http->buffer = buffer;
 	http->tcp.tcp_op = &http_tcp_operations;
-	if ( ( rc = tcp_connect ( &http->tcp, &http->server, 0 ) ) != 0 )
-		async_done ( &http->aop, rc );
 
-	return &http->aop;
+#warning "Quick name resolution hack"
+	union {
+		struct sockaddr_tcpip st;
+		struct sockaddr_in sin;
+	} server;
+	server.sin.sin_port = htons ( HTTP_PORT );
+	server.sin.sin_family = AF_INET;
+	if ( inet_aton ( uri->host, &server.sin.sin_addr ) == 0 ) {
+		rc = -EINVAL;
+		goto err;
+	}
+
+	if ( ( rc = tcp_connect ( &http->tcp, &server.st, 0 ) ) != 0 )
+		goto err;
+
+	async_init ( &http->async, &http_async_operations, parent );
+	return 0;
+
+ err:
+	DBGC ( http, "HTTP %p could not create request: %s\n", 
+	       http, strerror ( rc ) );
+	return rc;
 }