[http] Rewrite HTTP core to support content encodings

Rewrite the HTTP core to allow for the addition of arbitrary content
encoding mechanisms, such as PeerDist and gzip.

The core now exposes http_open() which can be used to create requests
with an explicitly selected HTTP method, an optional requested content
range, and an optional request body.  A simple wrapper provides the
preexisting behaviour of creating either a GET request or an
application/x-www-form-urlencoded POST request (if the URI includes
parameters).

The HTTP SAN interface is now implemented using the generic block
device translator.  Individual blocks are requested using http_open()
to create a range request.

Server connections are now managed via a connection pool; this allows
for multiple requests to the same server (e.g. for SAN blocks) to be
completely unaware of each other.  Repeated HTTPS connections to the
same server can reuse a pooled connection, avoiding the per-connection
overhead of establishing a TLS session (which can take several seconds
if using a client certificate).

Support for HTTP SAN booting and for the Basic and Digest
authentication schemes is now optional and can be controlled via the
SANBOOT_PROTO_HTTP, HTTP_AUTH_BASIC, and HTTP_AUTH_DIGEST build
configuration options in config/general.h.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 483 insertions, 5 deletions

diff --git a/src/include/ipxe/http.h b/src/include/ipxe/http.h
index 421598b54..a0dff7d00 100644
--- a/src/include/ipxe/http.h
+++ b/src/include/ipxe/http.h
@@ -9,16 +9,494 @@
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
+#include <stdint.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/interface.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/process.h>
+#include <ipxe/retry.h>
+#include <ipxe/linebuf.h>
+#include <ipxe/pool.h>
+#include <ipxe/tables.h>
+
+struct http_transaction;
+
+/******************************************************************************
+ *
+ * HTTP URI schemes
+ *
+ ******************************************************************************
+ */
+
 /** HTTP default port */
 #define HTTP_PORT 80
 
 /** HTTPS default port */
 #define HTTPS_PORT 443
 
-extern int http_open_filter ( struct interface *xfer, struct uri *uri,
-			      unsigned int default_port,
-			      int ( * filter ) ( struct interface *,
-						 const char *,
-						 struct interface ** ) );
+/** An HTTP URI scheme */
+struct http_scheme {
+	/** Scheme name (e.g. "http" or "https") */
+	const char *name;
+	/** Default port */
+	unsigned int port;
+	/** Transport-layer filter (if any)
+	 *
+	 * @v xfer		Data transfer interface
+	 * @v name		Host name
+	 * @v next		Next interface
+	 * @ret rc		Return status code
+	 */
+	int ( * filter ) ( struct interface *xfer, const char *name,
+			   struct interface **next );
+};
+
+/** HTTP scheme table */
+#define HTTP_SCHEMES __table ( struct http_scheme, "http_schemes" )
+
+/** Declare an HTTP scheme */
+#define __http_scheme __table_entry ( HTTP_SCHEMES, 01 )
+
+/******************************************************************************
+ *
+ * Connections
+ *
+ ******************************************************************************
+ */
+
+/** An HTTP connection
+ *
+ * This represents a potentially reusable connection to an HTTP
+ * server.
+ */
+struct http_connection {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Connection URI
+	 *
+	 * This encapsulates the server (and protocol) used for the
+	 * connection.  This may be the origin server or a proxy
+	 * server.
+	 */
+	struct uri *uri;
+	/** HTTP scheme */
+	struct http_scheme *scheme;
+	/** Transport layer interface */
+	struct interface socket;
+	/** Data transfer interface */
+	struct interface xfer;
+	/** Pooled connection */
+	struct pooled_connection pool;
+};
+
+/******************************************************************************
+ *
+ * HTTP methods
+ *
+ ******************************************************************************
+ */
+
+/** An HTTP method */
+struct http_method {
+	/** Method name (e.g. "GET" or "POST") */
+	const char *name;
+};
+
+extern struct http_method http_head;
+extern struct http_method http_get;
+extern struct http_method http_post;
+
+/******************************************************************************
+ *
+ * Requests
+ *
+ ******************************************************************************
+ */
+
+/** HTTP Digest authentication client nonce count
+ *
+ * We choose to generate a new client nonce each time.
+ */
+#define HTTP_DIGEST_NC "00000001"
+
+/** HTTP Digest authentication client nonce length
+ *
+ * We choose to use a 32-bit hex client nonce.
+ */
+#define HTTP_DIGEST_CNONCE_LEN 8
+
+/** HTTP Digest authentication response length
+ *
+ * The Digest authentication response is a Base16-encoded 16-byte MD5
+ * checksum.
+ */
+#define HTTP_DIGEST_RESPONSE_LEN 32
+
+/** HTTP request range descriptor */
+struct http_request_range {
+	/** Range start */
+	size_t start;
+	/** Range length, or zero for no range request */
+	size_t len;
+};
+
+/** HTTP request content descriptor */
+struct http_request_content {
+	/** Content type (if any) */
+	const char *type;
+	/** Content data (if any) */
+	const void *data;
+	/** Content length */
+	size_t len;
+};
+
+/** HTTP request authentication descriptor */
+struct http_request_auth {
+	/** Authentication scheme (if any) */
+	struct http_authentication *auth;
+	/** Username */
+	const char *username;
+	/** Password */
+	const char *password;
+	/** Quality of protection */
+	const char *qop;
+	/** Algorithm */
+	const char *algorithm;
+	/** Client nonce */
+	char cnonce[ HTTP_DIGEST_CNONCE_LEN + 1 /* NUL */ ];
+	/** Response */
+	char response[ HTTP_DIGEST_RESPONSE_LEN + 1 /* NUL */ ];
+};
+
+/** An HTTP request
+ *
+ * This represents a single request to be sent to a server, including
+ * the values required to construct all headers.
+ *
+ * Pointers within this structure must point to storage which is
+ * guaranteed to remain valid for the lifetime of the containing HTTP
+ * transaction.
+ */
+struct http_request {
+	/** Method */
+	struct http_method *method;
+	/** Request URI string */
+	const char *uri;
+	/** Server host name */
+	const char *host;
+	/** Range descriptor */
+	struct http_request_range range;
+	/** Content descriptor */
+	struct http_request_content content;
+	/** Authentication descriptor */
+	struct http_request_auth auth;
+};
+
+/** An HTTP request header */
+struct http_request_header {
+	/** Header name (e.g. "User-Agent") */
+	const char *name;
+	/** Construct remaining header line
+	 *
+	 * @v http		HTTP transaction
+	 * @v buf		Buffer
+	 * @v len		Length of buffer
+	 * @ret len		Header length if present, or negative error
+	 */
+	int ( * format ) ( struct http_transaction *http, char *buf,
+			   size_t len );
+};
+
+/** HTTP request header table */
+#define HTTP_REQUEST_HEADERS \
+	__table ( struct http_request_header, "http_request_headers" )
+
+/** Declare an HTTP request header */
+#define __http_request_header __table_entry ( HTTP_REQUEST_HEADERS, 01 )
+
+/******************************************************************************
+ *
+ * Responses
+ *
+ ******************************************************************************
+ */
+
+/** HTTP response transfer descriptor */
+struct http_response_transfer {
+	/** Transfer encoding */
+	struct http_transfer_encoding *encoding;
+};
+
+/** HTTP response content descriptor */
+struct http_response_content {
+	/** Content length (may be zero) */
+	size_t len;
+	/** Content encoding */
+	struct http_content_encoding *encoding;
+};
+
+/** HTTP response authorization descriptor */
+struct http_response_auth {
+	/** Authentication scheme (if any) */
+	struct http_authentication *auth;
+	/** Realm */
+	const char *realm;
+	/** Quality of protection */
+	const char *qop;
+	/** Algorithm */
+	const char *algorithm;
+	/** Nonce */
+	const char *nonce;
+	/** Opaque */
+	const char *opaque;
+};
+
+/** An HTTP response
+ *
+ * This represents a single response received from the server,
+ * including all values parsed from headers.
+ *
+ * Pointers within this structure may point into the raw response
+ * buffer, and so should be invalidated when the response buffer is
+ * modified or discarded.
+ */
+struct http_response {
+	/** Raw response header lines
+	 *
+	 * This is the raw response data received from the server, up
+	 * to and including the terminating empty line.  String
+	 * pointers within the response may point into this data
+	 * buffer; NUL terminators will be added (overwriting the
+	 * original terminating characters) as needed.
+	 */
+	struct line_buffer headers;
+	/** Status code
+	 *
+	 * This is the raw HTTP numeric status code (e.g. 404).
+	 */
+	unsigned int status;
+	/** Return status code
+	 *
+	 * This is the iPXE return status code corresponding to the
+	 * HTTP status code (e.g. -ENOENT).
+	 */
+	int rc;
+	/** Redirection location */
+	const char *location;
+	/** Transfer descriptor */
+	struct http_response_transfer transfer;
+	/** Content descriptor */
+	struct http_response_content content;
+	/** Authorization descriptor */
+	struct http_response_auth auth;
+	/** Retry delay (in seconds) */
+	unsigned int retry_after;
+	/** Flags */
+	unsigned int flags;
+};
+
+/** HTTP response flags */
+enum http_response_flags {
+	/** Keep connection alive after close */
+	HTTP_RESPONSE_KEEPALIVE = 0x0001,
+	/** Content length specified */
+	HTTP_RESPONSE_CONTENT_LEN = 0x0002,
+	/** Transaction may be retried on failure */
+	HTTP_RESPONSE_RETRY = 0x0004,
+};
+
+/** An HTTP response header */
+struct http_response_header {
+	/** Header name (e.g. "Transfer-Encoding") */
+	const char *name;
+	/** Parse header line
+	 *
+	 * @v http		HTTP transaction
+	 * @v line		Remaining header line
+	 * @ret rc		Return status code
+	 */
+	int ( * parse ) ( struct http_transaction *http, char *line );
+};
+
+/** HTTP response header table */
+#define HTTP_RESPONSE_HEADERS \
+	__table ( struct http_response_header, "http_response_headers" )
+
+/** Declare an HTTP response header */
+#define __http_response_header __table_entry ( HTTP_RESPONSE_HEADERS, 01 )
+
+/******************************************************************************
+ *
+ * Transactions
+ *
+ ******************************************************************************
+ */
+
+/** HTTP transaction state */
+struct http_state {
+	/** Transmit data
+	 *
+	 * @v http		HTTP transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * tx ) ( struct http_transaction *http );
+	/** Receive data
+	 *
+	 * @v http		HTTP transaction
+	 * @v iobuf		I/O buffer (may be claimed)
+	 * @ret rc		Return status code
+	 */
+	int ( * rx ) ( struct http_transaction *http,
+		       struct io_buffer **iobuf );
+	/** Server connection closed
+	 *
+	 * @v http		HTTP transaction
+	 * @v rc		Reason for close
+	 */
+	void ( * close ) ( struct http_transaction *http, int rc );
+};
+
+/** An HTTP transaction */
+struct http_transaction {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Data transfer interface */
+	struct interface xfer;
+	/** Content-decoded interface */
+	struct interface content;
+	/** Transfer-decoded interface */
+	struct interface transfer;
+	/** Server connection */
+	struct interface conn;
+	/** Transmit process */
+	struct process process;
+	/** Reconnection timer */
+	struct retry_timer timer;
+
+	/** Request URI */
+	struct uri *uri;
+	/** Request */
+	struct http_request request;
+	/** Response */
+	struct http_response response;
+	/** Temporary line buffer */
+	struct line_buffer linebuf;
+
+	/** Transaction state */
+	struct http_state *state;
+	/** Accumulated transfer-decoded length */
+	size_t len;
+	/** Chunk length remaining */
+	size_t remaining;
+};
+
+/******************************************************************************
+ *
+ * Transfer encoding
+ *
+ ******************************************************************************
+ */
+
+/** An HTTP transfer encoding */
+struct http_transfer_encoding {
+	/** Name */
+	const char *name;
+	/** Initialise transfer encoding
+	 *
+	 * @v http		HTTP transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * init ) ( struct http_transaction *http );
+	/** Receive data state */
+	struct http_state state;
+};
+
+/** HTTP transfer encoding table */
+#define HTTP_TRANSFER_ENCODINGS \
+	__table ( struct http_transfer_encoding, "http_transfer_encodings" )
+
+/** Declare an HTTP transfer encoding */
+#define __http_transfer_encoding __table_entry ( HTTP_TRANSFER_ENCODINGS, 01 )
+
+/******************************************************************************
+ *
+ * Content encoding
+ *
+ ******************************************************************************
+ */
+
+/** An HTTP content encoding */
+struct http_content_encoding {
+	/** Name */
+	const char *name;
+	/** Check if content encoding is supported for this request
+	 *
+	 * @v http		HTTP transaction
+	 * @ret supported	Content encoding is supported for this request
+	 */
+	int ( * supported ) ( struct http_transaction *http );
+	/** Initialise content encoding
+	 *
+	 * @v http		HTTP transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * init ) ( struct http_transaction *http );
+};
+
+/** HTTP content encoding table */
+#define HTTP_CONTENT_ENCODINGS \
+	__table ( struct http_content_encoding, "http_content_encodings" )
+
+/** Declare an HTTP content encoding */
+#define __http_content_encoding __table_entry ( HTTP_CONTENT_ENCODINGS, 01 )
+
+/******************************************************************************
+ *
+ * Authentication
+ *
+ ******************************************************************************
+ */
+
+/** An HTTP authentication scheme */
+struct http_authentication {
+	/** Name (e.g. "Digest") */
+	const char *name;
+	/** Perform authentication
+	 *
+	 * @v http		HTTP transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * authenticate ) ( struct http_transaction *http );
+	/** Construct remaining "Authorization" header line
+	 *
+	 * @v http		HTTP transaction
+	 * @v buf		Buffer
+	 * @v len		Length of buffer
+	 * @ret len		Header length if present, or negative error
+	 */
+	int ( * format ) ( struct http_transaction *http, char *buf,
+			   size_t len );
+};
+
+/** HTTP authentication scheme table */
+#define HTTP_AUTHENTICATIONS \
+	__table ( struct http_authentication, "http_authentications" )
+
+/** Declare an HTTP authentication scheme */
+#define __http_authentication __table_entry ( HTTP_AUTHENTICATIONS, 01 )
+
+/******************************************************************************
+ *
+ * General
+ *
+ ******************************************************************************
+ */
+
+extern char * http_token ( char **line, char **value );
+extern int http_connect ( struct interface *xfer, struct uri *uri );
+extern int http_open ( struct interface *xfer, struct http_method *method,
+		       struct uri *uri, struct http_request_range *range,
+		       struct http_request_content *content );
+extern int http_open_uri ( struct interface *xfer, struct uri *uri );
 
 #endif /* _IPXE_HTTP_H */