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1 /*
2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 FILE_LICENCE ( GPL2_OR_LATER );
20 
21 /**
22  * @file
23  *
24  * Hyper Text Transfer Protocol (HTTP)
25  *
26  */
27 
28 #include <stdint.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <strings.h>
33 #include <byteswap.h>
34 #include <errno.h>
35 #include <assert.h>
36 #include <gpxe/uri.h>
37 #include <gpxe/refcnt.h>
38 #include <gpxe/iobuf.h>
39 #include <gpxe/xfer.h>
40 #include <gpxe/open.h>
41 #include <gpxe/socket.h>
42 #include <gpxe/tcpip.h>
43 #include <gpxe/process.h>
44 #include <gpxe/linebuf.h>
45 #include <gpxe/features.h>
46 #include <gpxe/base64.h>
47 #include <gpxe/http.h>
48 
49 FEATURE ( FEATURE_PROTOCOL, "HTTP", DHCP_EB_FEATURE_HTTP, 1 );
50 
51 /** HTTP receive state */
52 enum http_rx_state {
53 	HTTP_RX_RESPONSE = 0,
54 	HTTP_RX_HEADER,
55 	HTTP_RX_DATA,
56 	HTTP_RX_DEAD,
57 };
58 
59 /**
60  * An HTTP request
61  *
62  */
63 struct http_request {
64 	/** Reference count */
65 	struct refcnt refcnt;
66 	/** Data transfer interface */
67 	struct xfer_interface xfer;
68 
69 	/** URI being fetched */
70 	struct uri *uri;
71 	/** Transport layer interface */
72 	struct xfer_interface socket;
73 
74 	/** TX process */
75 	struct process process;
76 
77 	/** HTTP response code */
78 	unsigned int response;
79 	/** HTTP Content-Length */
80 	size_t content_length;
81 	/** Received length */
82 	size_t rx_len;
83 	/** RX state */
84 	enum http_rx_state rx_state;
85 	/** Line buffer for received header lines */
86 	struct line_buffer linebuf;
87 };
88 
89 /**
90  * Free HTTP request
91  *
92  * @v refcnt		Reference counter
93  */
http_free(struct refcnt * refcnt)94 static void http_free ( struct refcnt *refcnt ) {
95 	struct http_request *http =
96 		container_of ( refcnt, struct http_request, refcnt );
97 
98 	uri_put ( http->uri );
99 	empty_line_buffer ( &http->linebuf );
100 	free ( http );
101 };
102 
103 /**
104  * Mark HTTP request as complete
105  *
106  * @v http		HTTP request
107  * @v rc		Return status code
108  */
http_done(struct http_request * http,int rc)109 static void http_done ( struct http_request *http, int rc ) {
110 
111 	/* Prevent further processing of any current packet */
112 	http->rx_state = HTTP_RX_DEAD;
113 
114 	/* If we had a Content-Length, and the received content length
115 	 * isn't correct, flag an error
116 	 */
117 	if ( http->content_length &&
118 	     ( http->content_length != http->rx_len ) ) {
119 		DBGC ( http, "HTTP %p incorrect length %zd, should be %zd\n",
120 		       http, http->rx_len, http->content_length );
121 		rc = -EIO;
122 	}
123 
124 	/* Remove process */
125 	process_del ( &http->process );
126 
127 	/* Close all data transfer interfaces */
128 	xfer_nullify ( &http->socket );
129 	xfer_close ( &http->socket, rc );
130 	xfer_nullify ( &http->xfer );
131 	xfer_close ( &http->xfer, rc );
132 }
133 
134 /**
135  * Convert HTTP response code to return status code
136  *
137  * @v response		HTTP response code
138  * @ret rc		Return status code
139  */
http_response_to_rc(unsigned int response)140 static int http_response_to_rc ( unsigned int response ) {
141 	switch ( response ) {
142 	case 200:
143 	case 301:
144 	case 302:
145 		return 0;
146 	case 404:
147 		return -ENOENT;
148 	case 403:
149 		return -EPERM;
150 	case 401:
151 		return -EACCES;
152 	default:
153 		return -EIO;
154 	}
155 }
156 
157 /**
158  * Handle HTTP response
159  *
160  * @v http		HTTP request
161  * @v response		HTTP response
162  * @ret rc		Return status code
163  */
http_rx_response(struct http_request * http,char * response)164 static int http_rx_response ( struct http_request *http, char *response ) {
165 	char *spc;
166 	int rc;
167 
168 	DBGC ( http, "HTTP %p response \"%s\"\n", http, response );
169 
170 	/* Check response starts with "HTTP/" */
171 	if ( strncmp ( response, "HTTP/", 5 ) != 0 )
172 		return -EIO;
173 
174 	/* Locate and check response code */
175 	spc = strchr ( response, ' ' );
176 	if ( ! spc )
177 		return -EIO;
178 	http->response = strtoul ( spc, NULL, 10 );
179 	if ( ( rc = http_response_to_rc ( http->response ) ) != 0 )
180 		return rc;
181 
182 	/* Move to received headers */
183 	http->rx_state = HTTP_RX_HEADER;
184 	return 0;
185 }
186 
187 /**
188  * Handle HTTP Location header
189  *
190  * @v http		HTTP request
191  * @v value		HTTP header value
192  * @ret rc		Return status code
193  */
http_rx_location(struct http_request * http,const char * value)194 static int http_rx_location ( struct http_request *http, const char *value ) {
195 	int rc;
196 
197 	/* Redirect to new location */
198 	DBGC ( http, "HTTP %p redirecting to %s\n", http, value );
199 	if ( ( rc = xfer_redirect ( &http->xfer, LOCATION_URI_STRING,
200 				    value ) ) != 0 ) {
201 		DBGC ( http, "HTTP %p could not redirect: %s\n",
202 		       http, strerror ( rc ) );
203 		return rc;
204 	}
205 
206 	return 0;
207 }
208 
209 /**
210  * Handle HTTP Content-Length header
211  *
212  * @v http		HTTP request
213  * @v value		HTTP header value
214  * @ret rc		Return status code
215  */
http_rx_content_length(struct http_request * http,const char * value)216 static int http_rx_content_length ( struct http_request *http,
217 				    const char *value ) {
218 	char *endp;
219 
220 	http->content_length = strtoul ( value, &endp, 10 );
221 	if ( *endp != '\0' ) {
222 		DBGC ( http, "HTTP %p invalid Content-Length \"%s\"\n",
223 		       http, value );
224 		return -EIO;
225 	}
226 
227 	/* Use seek() to notify recipient of filesize */
228 	xfer_seek ( &http->xfer, http->content_length, SEEK_SET );
229 	xfer_seek ( &http->xfer, 0, SEEK_SET );
230 
231 	return 0;
232 }
233 
234 /** An HTTP header handler */
235 struct http_header_handler {
236 	/** Name (e.g. "Content-Length") */
237 	const char *header;
238 	/** Handle received header
239 	 *
240 	 * @v http	HTTP request
241 	 * @v value	HTTP header value
242 	 * @ret rc	Return status code
243 	 *
244 	 * If an error is returned, the download will be aborted.
245 	 */
246 	int ( * rx ) ( struct http_request *http, const char *value );
247 };
248 
249 /** List of HTTP header handlers */
250 static struct http_header_handler http_header_handlers[] = {
251 	{
252 		.header = "Location",
253 		.rx = http_rx_location,
254 	},
255 	{
256 		.header = "Content-Length",
257 		.rx = http_rx_content_length,
258 	},
259 	{ NULL, NULL }
260 };
261 
262 /**
263  * Handle HTTP header
264  *
265  * @v http		HTTP request
266  * @v header		HTTP header
267  * @ret rc		Return status code
268  */
http_rx_header(struct http_request * http,char * header)269 static int http_rx_header ( struct http_request *http, char *header ) {
270 	struct http_header_handler *handler;
271 	char *separator;
272 	char *value;
273 	int rc;
274 
275 	/* An empty header line marks the transition to the data phase */
276 	if ( ! header[0] ) {
277 		DBGC ( http, "HTTP %p start of data\n", http );
278 		empty_line_buffer ( &http->linebuf );
279 		http->rx_state = HTTP_RX_DATA;
280 		return 0;
281 	}
282 
283 	DBGC ( http, "HTTP %p header \"%s\"\n", http, header );
284 
285 	/* Split header at the ": " */
286 	separator = strstr ( header, ": " );
287 	if ( ! separator ) {
288 		DBGC ( http, "HTTP %p malformed header\n", http );
289 		return -EIO;
290 	}
291 	*separator = '\0';
292 	value = ( separator + 2 );
293 
294 	/* Hand off to header handler, if one exists */
295 	for ( handler = http_header_handlers ; handler->header ; handler++ ) {
296 		if ( strcasecmp ( header, handler->header ) == 0 ) {
297 			if ( ( rc = handler->rx ( http, value ) ) != 0 )
298 				return rc;
299 			break;
300 		}
301 	}
302 	return 0;
303 }
304 
305 /** An HTTP line-based data handler */
306 struct http_line_handler {
307 	/** Handle line
308 	 *
309 	 * @v http	HTTP request
310 	 * @v line	Line to handle
311 	 * @ret rc	Return status code
312 	 */
313 	int ( * rx ) ( struct http_request *http, char *line );
314 };
315 
316 /** List of HTTP line-based data handlers */
317 static struct http_line_handler http_line_handlers[] = {
318 	[HTTP_RX_RESPONSE]	= { .rx = http_rx_response },
319 	[HTTP_RX_HEADER]	= { .rx = http_rx_header },
320 };
321 
322 /**
323  * Handle new data arriving via HTTP connection in the data phase
324  *
325  * @v http		HTTP request
326  * @v iobuf		I/O buffer
327  * @ret rc		Return status code
328  */
http_rx_data(struct http_request * http,struct io_buffer * iobuf)329 static int http_rx_data ( struct http_request *http,
330 			  struct io_buffer *iobuf ) {
331 	int rc;
332 
333 	/* Update received length */
334 	http->rx_len += iob_len ( iobuf );
335 
336 	/* Hand off data buffer */
337 	if ( ( rc = xfer_deliver_iob ( &http->xfer, iobuf ) ) != 0 )
338 		return rc;
339 
340 	/* If we have reached the content-length, stop now */
341 	if ( http->content_length &&
342 	     ( http->rx_len >= http->content_length ) ) {
343 		http_done ( http, 0 );
344 	}
345 
346 	return 0;
347 }
348 
349 /**
350  * Handle new data arriving via HTTP connection
351  *
352  * @v socket		Transport layer interface
353  * @v iobuf		I/O buffer
354  * @v meta		Data transfer metadata
355  * @ret rc		Return status code
356  */
http_socket_deliver_iob(struct xfer_interface * socket,struct io_buffer * iobuf,struct xfer_metadata * meta __unused)357 static int http_socket_deliver_iob ( struct xfer_interface *socket,
358 				     struct io_buffer *iobuf,
359 				     struct xfer_metadata *meta __unused ) {
360 	struct http_request *http =
361 		container_of ( socket, struct http_request, socket );
362 	struct http_line_handler *lh;
363 	char *line;
364 	ssize_t len;
365 	int rc = 0;
366 
367 	while ( iob_len ( iobuf ) ) {
368 		switch ( http->rx_state ) {
369 		case HTTP_RX_DEAD:
370 			/* Do no further processing */
371 			goto done;
372 		case HTTP_RX_DATA:
373 			/* Once we're into the data phase, just fill
374 			 * the data buffer
375 			 */
376 			rc = http_rx_data ( http, iob_disown ( iobuf ) );
377 			goto done;
378 		case HTTP_RX_RESPONSE:
379 		case HTTP_RX_HEADER:
380 			/* In the other phases, buffer and process a
381 			 * line at a time
382 			 */
383 			len = line_buffer ( &http->linebuf, iobuf->data,
384 					    iob_len ( iobuf ) );
385 			if ( len < 0 ) {
386 				rc = len;
387 				DBGC ( http, "HTTP %p could not buffer line: "
388 				       "%s\n", http, strerror ( rc ) );
389 				goto done;
390 			}
391 			iob_pull ( iobuf, len );
392 			line = buffered_line ( &http->linebuf );
393 			if ( line ) {
394 				lh = &http_line_handlers[http->rx_state];
395 				if ( ( rc = lh->rx ( http, line ) ) != 0 )
396 					goto done;
397 			}
398 			break;
399 		default:
400 			assert ( 0 );
401 			break;
402 		}
403 	}
404 
405  done:
406 	if ( rc )
407 		http_done ( http, rc );
408 	free_iob ( iobuf );
409 	return rc;
410 }
411 
412 /**
413  * HTTP process
414  *
415  * @v process		Process
416  */
http_step(struct process * process)417 static void http_step ( struct process *process ) {
418 	struct http_request *http =
419 		container_of ( process, struct http_request, process );
420 	const char *host = http->uri->host;
421 	const char *user = http->uri->user;
422 	const char *password =
423 		( http->uri->password ? http->uri->password : "" );
424 	size_t user_pw_len = ( user ? ( strlen ( user ) + 1 /* ":" */ +
425 					strlen ( password ) ) : 0 );
426 	size_t user_pw_base64_len = base64_encoded_len ( user_pw_len );
427 	char user_pw[ user_pw_len + 1 /* NUL */ ];
428 	char user_pw_base64[ user_pw_base64_len + 1 /* NUL */ ];
429 	int rc;
430 	int request_len = unparse_uri ( NULL, 0, http->uri,
431 					URI_PATH_BIT | URI_QUERY_BIT );
432 
433 	if ( xfer_window ( &http->socket ) ) {
434 		char request[request_len + 1];
435 
436 		/* Construct path?query request */
437 		unparse_uri ( request, sizeof ( request ), http->uri,
438 			      URI_PATH_BIT | URI_QUERY_BIT );
439 
440 		/* We want to execute only once */
441 		process_del ( &http->process );
442 
443 		/* Construct authorisation, if applicable */
444 		if ( user ) {
445 			/* Make "user:password" string from decoded fields */
446 			snprintf ( user_pw, sizeof ( user_pw ), "%s:%s",
447 				   user, password );
448 
449 			/* Base64-encode the "user:password" string */
450 			base64_encode ( user_pw, user_pw_base64 );
451 		}
452 
453 		/* Send GET request */
454 		if ( ( rc = xfer_printf ( &http->socket,
455 					  "GET %s%s HTTP/1.0\r\n"
456 					  "User-Agent: gPXE/" VERSION "\r\n"
457 					  "%s%s%s"
458 					  "Host: %s\r\n"
459 					  "\r\n",
460 					  http->uri->path ? "" : "/",
461 					  request,
462 					  ( user ?
463 					    "Authorization: Basic " : "" ),
464 					  ( user ? user_pw_base64 : "" ),
465 					  ( user ? "\r\n" : "" ),
466 					  host ) ) != 0 ) {
467 			http_done ( http, rc );
468 		}
469 	}
470 }
471 
472 /**
473  * HTTP connection closed by network stack
474  *
475  * @v socket		Transport layer interface
476  * @v rc		Reason for close
477  */
http_socket_close(struct xfer_interface * socket,int rc)478 static void http_socket_close ( struct xfer_interface *socket, int rc ) {
479 	struct http_request *http =
480 		container_of ( socket, struct http_request, socket );
481 
482 	DBGC ( http, "HTTP %p socket closed: %s\n",
483 	       http, strerror ( rc ) );
484 
485 	http_done ( http, rc );
486 }
487 
488 /** HTTP socket operations */
489 static struct xfer_interface_operations http_socket_operations = {
490 	.close		= http_socket_close,
491 	.vredirect	= xfer_vreopen,
492 	.window		= unlimited_xfer_window,
493 	.alloc_iob	= default_xfer_alloc_iob,
494 	.deliver_iob	= http_socket_deliver_iob,
495 	.deliver_raw	= xfer_deliver_as_iob,
496 };
497 
498 /**
499  * Close HTTP data transfer interface
500  *
501  * @v xfer		Data transfer interface
502  * @v rc		Reason for close
503  */
http_xfer_close(struct xfer_interface * xfer,int rc)504 static void http_xfer_close ( struct xfer_interface *xfer, int rc ) {
505 	struct http_request *http =
506 		container_of ( xfer, struct http_request, xfer );
507 
508 	DBGC ( http, "HTTP %p interface closed: %s\n",
509 	       http, strerror ( rc ) );
510 
511 	http_done ( http, rc );
512 }
513 
514 /** HTTP data transfer interface operations */
515 static struct xfer_interface_operations http_xfer_operations = {
516 	.close		= http_xfer_close,
517 	.vredirect	= ignore_xfer_vredirect,
518 	.window		= unlimited_xfer_window,
519 	.alloc_iob	= default_xfer_alloc_iob,
520 	.deliver_iob	= xfer_deliver_as_raw,
521 	.deliver_raw	= ignore_xfer_deliver_raw,
522 };
523 
524 /**
525  * Initiate an HTTP connection, with optional filter
526  *
527  * @v xfer		Data transfer interface
528  * @v uri		Uniform Resource Identifier
529  * @v default_port	Default port number
530  * @v filter		Filter to apply to socket, or NULL
531  * @ret rc		Return status code
532  */
http_open_filter(struct xfer_interface * xfer,struct uri * uri,unsigned int default_port,int (* filter)(struct xfer_interface * xfer,struct xfer_interface ** next))533 int http_open_filter ( struct xfer_interface *xfer, struct uri *uri,
534 		       unsigned int default_port,
535 		       int ( * filter ) ( struct xfer_interface *xfer,
536 					  struct xfer_interface **next ) ) {
537 	struct http_request *http;
538 	struct sockaddr_tcpip server;
539 	struct xfer_interface *socket;
540 	int rc;
541 
542 	/* Sanity checks */
543 	if ( ! uri->host )
544 		return -EINVAL;
545 
546 	/* Allocate and populate HTTP structure */
547 	http = zalloc ( sizeof ( *http ) );
548 	if ( ! http )
549 		return -ENOMEM;
550 	http->refcnt.free = http_free;
551 	xfer_init ( &http->xfer, &http_xfer_operations, &http->refcnt );
552        	http->uri = uri_get ( uri );
553 	xfer_init ( &http->socket, &http_socket_operations, &http->refcnt );
554 	process_init ( &http->process, http_step, &http->refcnt );
555 
556 	/* Open socket */
557 	memset ( &server, 0, sizeof ( server ) );
558 	server.st_port = htons ( uri_port ( http->uri, default_port ) );
559 	socket = &http->socket;
560 	if ( filter ) {
561 		if ( ( rc = filter ( socket, &socket ) ) != 0 )
562 			goto err;
563 	}
564 	if ( ( rc = xfer_open_named_socket ( socket, SOCK_STREAM,
565 					     ( struct sockaddr * ) &server,
566 					     uri->host, NULL ) ) != 0 )
567 		goto err;
568 
569 	/* Attach to parent interface, mortalise self, and return */
570 	xfer_plug_plug ( &http->xfer, xfer );
571 	ref_put ( &http->refcnt );
572 	return 0;
573 
574  err:
575 	DBGC ( http, "HTTP %p could not create request: %s\n",
576 	       http, strerror ( rc ) );
577 	http_done ( http, rc );
578 	ref_put ( &http->refcnt );
579 	return rc;
580 }
581 
582 /**
583  * Initiate an HTTP connection
584  *
585  * @v xfer		Data transfer interface
586  * @v uri		Uniform Resource Identifier
587  * @ret rc		Return status code
588  */
http_open(struct xfer_interface * xfer,struct uri * uri)589 static int http_open ( struct xfer_interface *xfer, struct uri *uri ) {
590 	return http_open_filter ( xfer, uri, HTTP_PORT, NULL );
591 }
592 
593 /** HTTP URI opener */
594 struct uri_opener http_uri_opener __uri_opener = {
595 	.scheme	= "http",
596 	.open	= http_open,
597 };
598