1 /*
2 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
3 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 #ifndef _EVENT2_HTTP_H_
28 #define _EVENT2_HTTP_H_
29
30 /* For int types. */
31 #include <event2/util.h>
32
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36
37 /* In case we haven't included the right headers yet. */
38 struct evbuffer;
39 struct event_base;
40
41 /** @file event2/http.h
42 *
43 * Basic support for HTTP serving.
44 *
45 * As Libevent is a library for dealing with event notification and most
46 * interesting applications are networked today, I have often found the
47 * need to write HTTP code. The following prototypes and definitions provide
48 * an application with a minimal interface for making HTTP requests and for
49 * creating a very simple HTTP server.
50 */
51
52 /* Response codes */
53 #define HTTP_OK 200 /**< request completed ok */
54 #define HTTP_NOCONTENT 204 /**< request does not have content */
55 #define HTTP_MOVEPERM 301 /**< the uri moved permanently */
56 #define HTTP_MOVETEMP 302 /**< the uri moved temporarily */
57 #define HTTP_NOTMODIFIED 304 /**< page was not modified from last */
58 #define HTTP_BADREQUEST 400 /**< invalid http request was made */
59 #define HTTP_NOTFOUND 404 /**< could not find content for uri */
60 #define HTTP_BADMETHOD 405 /**< method not allowed for this uri */
61 #define HTTP_ENTITYTOOLARGE 413 /**< */
62 #define HTTP_EXPECTATIONFAILED 417 /**< we can't handle this expectation */
63 #define HTTP_INTERNAL 500 /**< internal error */
64 #define HTTP_NOTIMPLEMENTED 501 /**< not implemented */
65 #define HTTP_SERVUNAVAIL 503 /**< the server is not available */
66
67 struct evhttp;
68 struct evhttp_request;
69 struct evkeyvalq;
70 struct evhttp_bound_socket;
71 struct evconnlistener;
72
73 /**
74 * Create a new HTTP server.
75 *
76 * @param base (optional) the event base to receive the HTTP events
77 * @return a pointer to a newly initialized evhttp server structure
78 * @see evhttp_free()
79 */
80 struct evhttp *evhttp_new(struct event_base *base);
81
82 /**
83 * Binds an HTTP server on the specified address and port.
84 *
85 * Can be called multiple times to bind the same http server
86 * to multiple different ports.
87 *
88 * @param http a pointer to an evhttp object
89 * @param address a string containing the IP address to listen(2) on
90 * @param port the port number to listen on
91 * @return 0 on success, -1 on failure.
92 * @see evhttp_accept_socket()
93 */
94 int evhttp_bind_socket(struct evhttp *http, const char *address, ev_uint16_t port);
95
96 /**
97 * Like evhttp_bind_socket(), but returns a handle for referencing the socket.
98 *
99 * The returned pointer is not valid after \a http is freed.
100 *
101 * @param http a pointer to an evhttp object
102 * @param address a string containing the IP address to listen(2) on
103 * @param port the port number to listen on
104 * @return Handle for the socket on success, NULL on failure.
105 * @see evhttp_bind_socket(), evhttp_del_accept_socket()
106 */
107 struct evhttp_bound_socket *evhttp_bind_socket_with_handle(struct evhttp *http, const char *address, ev_uint16_t port);
108
109 /**
110 * Makes an HTTP server accept connections on the specified socket.
111 *
112 * This may be useful to create a socket and then fork multiple instances
113 * of an http server, or when a socket has been communicated via file
114 * descriptor passing in situations where an http servers does not have
115 * permissions to bind to a low-numbered port.
116 *
117 * Can be called multiple times to have the http server listen to
118 * multiple different sockets.
119 *
120 * @param http a pointer to an evhttp object
121 * @param fd a socket fd that is ready for accepting connections
122 * @return 0 on success, -1 on failure.
123 * @see evhttp_bind_socket()
124 */
125 int evhttp_accept_socket(struct evhttp *http, evutil_socket_t fd);
126
127 /**
128 * Like evhttp_accept_socket(), but returns a handle for referencing the socket.
129 *
130 * The returned pointer is not valid after \a http is freed.
131 *
132 * @param http a pointer to an evhttp object
133 * @param fd a socket fd that is ready for accepting connections
134 * @return Handle for the socket on success, NULL on failure.
135 * @see evhttp_accept_socket(), evhttp_del_accept_socket()
136 */
137 struct evhttp_bound_socket *evhttp_accept_socket_with_handle(struct evhttp *http, evutil_socket_t fd);
138
139 /**
140 * The most low-level evhttp_bind/accept method: takes an evconnlistener, and
141 * returns an evhttp_bound_socket. The listener will be freed when the bound
142 * socket is freed.
143 */
144 struct evhttp_bound_socket *evhttp_bind_listener(struct evhttp *http, struct evconnlistener *listener);
145
146 /**
147 * Return the listener used to implement a bound socket.
148 */
149 struct evconnlistener *evhttp_bound_socket_get_listener(struct evhttp_bound_socket *bound);
150
151 /**
152 * Makes an HTTP server stop accepting connections on the specified socket
153 *
154 * This may be useful when a socket has been sent via file descriptor passing
155 * and is no longer needed by the current process.
156 *
157 * If you created this bound socket with evhttp_bind_socket_with_handle or
158 * evhttp_accept_socket_with_handle, this function closes the fd you provided.
159 * If you created this bound socket with evhttp_bind_listener, this function
160 * frees the listener you provided.
161 *
162 * \a bound_socket is an invalid pointer after this call returns.
163 *
164 * @param http a pointer to an evhttp object
165 * @param bound_socket a handle returned by evhttp_{bind,accept}_socket_with_handle
166 * @see evhttp_bind_socket_with_handle(), evhttp_accept_socket_with_handle()
167 */
168 void evhttp_del_accept_socket(struct evhttp *http, struct evhttp_bound_socket *bound_socket);
169
170 /**
171 * Get the raw file descriptor referenced by an evhttp_bound_socket.
172 *
173 * @param bound_socket a handle returned by evhttp_{bind,accept}_socket_with_handle
174 * @return the file descriptor used by the bound socket
175 * @see evhttp_bind_socket_with_handle(), evhttp_accept_socket_with_handle()
176 */
177 evutil_socket_t evhttp_bound_socket_get_fd(struct evhttp_bound_socket *bound_socket);
178
179 /**
180 * Free the previously created HTTP server.
181 *
182 * Works only if no requests are currently being served.
183 *
184 * @param http the evhttp server object to be freed
185 * @see evhttp_start()
186 */
187 void evhttp_free(struct evhttp* http);
188
189 /** XXX Document. */
190 void evhttp_set_max_headers_size(struct evhttp* http, ev_ssize_t max_headers_size);
191 /** XXX Document. */
192 void evhttp_set_max_body_size(struct evhttp* http, ev_ssize_t max_body_size);
193
194 /**
195 Sets the what HTTP methods are supported in requests accepted by this
196 server, and passed to user callbacks.
197
198 If not supported they will generate a "405 Method not allowed" response.
199
200 By default this includes the following methods: GET, POST, HEAD, PUT, DELETE
201
202 @param http the http server on which to set the methods
203 @param methods bit mask constructed from evhttp_cmd_type values
204 */
205 void evhttp_set_allowed_methods(struct evhttp* http, ev_uint16_t methods);
206
207 /**
208 Set a callback for a specified URI
209
210 @param http the http sever on which to set the callback
211 @param path the path for which to invoke the callback
212 @param cb the callback function that gets invoked on requesting path
213 @param cb_arg an additional context argument for the callback
214 @return 0 on success, -1 if the callback existed already, -2 on failure
215 */
216 int evhttp_set_cb(struct evhttp *http, const char *path,
217 void (*cb)(struct evhttp_request *, void *), void *cb_arg);
218
219 /** Removes the callback for a specified URI */
220 int evhttp_del_cb(struct evhttp *, const char *);
221
222 /**
223 Set a callback for all requests that are not caught by specific callbacks
224
225 Invokes the specified callback for all requests that do not match any of
226 the previously specified request paths. This is catchall for requests not
227 specifically configured with evhttp_set_cb().
228
229 @param http the evhttp server object for which to set the callback
230 @param cb the callback to invoke for any unmatched requests
231 @param arg an context argument for the callback
232 */
233 void evhttp_set_gencb(struct evhttp *http,
234 void (*cb)(struct evhttp_request *, void *), void *arg);
235
236 /**
237 Adds a virtual host to the http server.
238
239 A virtual host is a newly initialized evhttp object that has request
240 callbacks set on it via evhttp_set_cb() or evhttp_set_gencb(). It
241 most not have any listing sockets associated with it.
242
243 If the virtual host has not been removed by the time that evhttp_free()
244 is called on the main http server, it will be automatically freed, too.
245
246 It is possible to have hierarchical vhosts. For example: A vhost
247 with the pattern *.example.com may have other vhosts with patterns
248 foo.example.com and bar.example.com associated with it.
249
250 @param http the evhttp object to which to add a virtual host
251 @param pattern the glob pattern against which the hostname is matched.
252 The match is case insensitive and follows otherwise regular shell
253 matching.
254 @param vhost the virtual host to add the regular http server.
255 @return 0 on success, -1 on failure
256 @see evhttp_remove_virtual_host()
257 */
258 int evhttp_add_virtual_host(struct evhttp* http, const char *pattern,
259 struct evhttp* vhost);
260
261 /**
262 Removes a virtual host from the http server.
263
264 @param http the evhttp object from which to remove the virtual host
265 @param vhost the virtual host to remove from the regular http server.
266 @return 0 on success, -1 on failure
267 @see evhttp_add_virtual_host()
268 */
269 int evhttp_remove_virtual_host(struct evhttp* http, struct evhttp* vhost);
270
271 /**
272 Add a server alias to an http object. The http object can be a virtual
273 host or the main server.
274
275 @param http the evhttp object
276 @param alias the alias to add
277 @see evhttp_add_remove_alias()
278 */
279 int evhttp_add_server_alias(struct evhttp *http, const char *alias);
280
281 /**
282 Remove a server alias from an http object.
283
284 @param http the evhttp object
285 @param alias the alias to remove
286 @see evhttp_add_server_alias()
287 */
288 int evhttp_remove_server_alias(struct evhttp *http, const char *alias);
289
290 /**
291 * Set the timeout for an HTTP request.
292 *
293 * @param http an evhttp object
294 * @param timeout_in_secs the timeout, in seconds
295 */
296 void evhttp_set_timeout(struct evhttp *http, int timeout_in_secs);
297
298 /* Request/Response functionality */
299
300 /**
301 * Send an HTML error message to the client.
302 *
303 * @param req a request object
304 * @param error the HTTP error code
305 * @param reason a brief explanation of the error. If this is NULL, we'll
306 * just use the standard meaning of the error code.
307 */
308 void evhttp_send_error(struct evhttp_request *req, int error,
309 const char *reason);
310
311 /**
312 * Send an HTML reply to the client.
313 *
314 * The body of the reply consists of the data in databuf. After calling
315 * evhttp_send_reply() databuf will be empty, but the buffer is still
316 * owned by the caller and needs to be deallocated by the caller if
317 * necessary.
318 *
319 * @param req a request object
320 * @param code the HTTP response code to send
321 * @param reason a brief message to send with the response code
322 * @param databuf the body of the response
323 */
324 void evhttp_send_reply(struct evhttp_request *req, int code,
325 const char *reason, struct evbuffer *databuf);
326
327 /* Low-level response interface, for streaming/chunked replies */
328
329 /**
330 Initiate a reply that uses Transfer-Encoding chunked.
331
332 This allows the caller to stream the reply back to the client and is
333 useful when either not all of the reply data is immediately available
334 or when sending very large replies.
335
336 The caller needs to supply data chunks with evhttp_send_reply_chunk()
337 and complete the reply by calling evhttp_send_reply_end().
338
339 @param req a request object
340 @param code the HTTP response code to send
341 @param reason a brief message to send with the response code
342 */
343 void evhttp_send_reply_start(struct evhttp_request *req, int code,
344 const char *reason);
345
346 /**
347 Send another data chunk as part of an ongoing chunked reply.
348
349 The reply chunk consists of the data in databuf. After calling
350 evhttp_send_reply_chunk() databuf will be empty, but the buffer is
351 still owned by the caller and needs to be deallocated by the caller
352 if necessary.
353
354 @param req a request object
355 @param databuf the data chunk to send as part of the reply.
356 */
357 void evhttp_send_reply_chunk(struct evhttp_request *req,
358 struct evbuffer *databuf);
359 /**
360 Complete a chunked reply, freeing the request as appropriate.
361
362 @param req a request object
363 */
364 void evhttp_send_reply_end(struct evhttp_request *req);
365
366 /*
367 * Interfaces for making requests
368 */
369
370 /** The different request types supported by evhttp. These are as specified
371 * in RFC2616, except for PATCH which is specified by RFC5789.
372 *
373 * By default, only some of these methods are accepted and passed to user
374 * callbacks; use evhttp_set_allowed_methods() to change which methods
375 * are allowed.
376 */
377 enum evhttp_cmd_type {
378 EVHTTP_REQ_GET = 1 << 0,
379 EVHTTP_REQ_POST = 1 << 1,
380 EVHTTP_REQ_HEAD = 1 << 2,
381 EVHTTP_REQ_PUT = 1 << 3,
382 EVHTTP_REQ_DELETE = 1 << 4,
383 EVHTTP_REQ_OPTIONS = 1 << 5,
384 EVHTTP_REQ_TRACE = 1 << 6,
385 EVHTTP_REQ_CONNECT = 1 << 7,
386 EVHTTP_REQ_PATCH = 1 << 8
387 };
388
389 /** a request object can represent either a request or a reply */
390 enum evhttp_request_kind { EVHTTP_REQUEST, EVHTTP_RESPONSE };
391
392 /**
393 * Creates a new request object that needs to be filled in with the request
394 * parameters. The callback is executed when the request completed or an
395 * error occurred.
396 */
397 struct evhttp_request *evhttp_request_new(
398 void (*cb)(struct evhttp_request *, void *), void *arg);
399
400 /**
401 * Enable delivery of chunks to requestor.
402 * @param cb will be called after every read of data with the same argument
403 * as the completion callback. Will never be called on an empty
404 * response. May drain the input buffer; it will be drained
405 * automatically on return.
406 */
407 void evhttp_request_set_chunked_cb(struct evhttp_request *,
408 void (*cb)(struct evhttp_request *, void *));
409
410 /** Frees the request object and removes associated events. */
411 void evhttp_request_free(struct evhttp_request *req);
412
413 struct evdns_base;
414
415 /**
416 * A connection object that can be used to for making HTTP requests. The
417 * connection object tries to resolve address and establish the connection
418 * when it is given an http request object.
419 *
420 * @param base the event_base to use for handling the connection
421 * @param dnsbase the dns_base to use for resolving host names; if not
422 * specified host name resolution will block.
423 * @param address the address to which to connect
424 * @param port the port to connect to
425 * @return an evhttp_connection object that can be used for making requests
426 */
427 struct evhttp_connection *evhttp_connection_base_new(
428 struct event_base *base, struct evdns_base *dnsbase,
429 const char *address, unsigned short port);
430
431 /**
432 * Return the bufferevent that an evhttp_connection is using.
433 */
434 struct bufferevent *evhttp_connection_get_bufferevent(
435 struct evhttp_connection *evcon);
436
437 /** Takes ownership of the request object
438 *
439 * Can be used in a request callback to keep onto the request until
440 * evhttp_request_free() is explicitly called by the user.
441 */
442 void evhttp_request_own(struct evhttp_request *req);
443
444 /** Returns 1 if the request is owned by the user */
445 int evhttp_request_is_owned(struct evhttp_request *req);
446
447 /**
448 * Returns the connection object associated with the request or NULL
449 *
450 * The user needs to either free the request explicitly or call
451 * evhttp_send_reply_end().
452 */
453 struct evhttp_connection *evhttp_request_get_connection(struct evhttp_request *req);
454
455 /**
456 * Returns the underlying event_base for this connection
457 */
458 struct event_base *evhttp_connection_get_base(struct evhttp_connection *req);
459
460 void evhttp_connection_set_max_headers_size(struct evhttp_connection *evcon,
461 ev_ssize_t new_max_headers_size);
462
463 void evhttp_connection_set_max_body_size(struct evhttp_connection* evcon,
464 ev_ssize_t new_max_body_size);
465
466 /** Frees an http connection */
467 void evhttp_connection_free(struct evhttp_connection *evcon);
468
469 /** sets the ip address from which http connections are made */
470 void evhttp_connection_set_local_address(struct evhttp_connection *evcon,
471 const char *address);
472
473 /** sets the local port from which http connections are made */
474 void evhttp_connection_set_local_port(struct evhttp_connection *evcon,
475 ev_uint16_t port);
476
477 /** Sets the timeout for events related to this connection */
478 void evhttp_connection_set_timeout(struct evhttp_connection *evcon,
479 int timeout_in_secs);
480
481 /** Sets the retry limit for this connection - -1 repeats indefinitely */
482 void evhttp_connection_set_retries(struct evhttp_connection *evcon,
483 int retry_max);
484
485 /** Set a callback for connection close. */
486 void evhttp_connection_set_closecb(struct evhttp_connection *evcon,
487 void (*)(struct evhttp_connection *, void *), void *);
488
489 /** Get the remote address and port associated with this connection. */
490 void evhttp_connection_get_peer(struct evhttp_connection *evcon,
491 char **address, ev_uint16_t *port);
492
493 /**
494 Make an HTTP request over the specified connection.
495
496 The connection gets ownership of the request. On failure, the
497 request object is no longer valid as it has been freed.
498
499 @param evcon the evhttp_connection object over which to send the request
500 @param req the previously created and configured request object
501 @param type the request type EVHTTP_REQ_GET, EVHTTP_REQ_POST, etc.
502 @param uri the URI associated with the request
503 @return 0 on success, -1 on failure
504 @see evhttp_cancel_request()
505 */
506 int evhttp_make_request(struct evhttp_connection *evcon,
507 struct evhttp_request *req,
508 enum evhttp_cmd_type type, const char *uri);
509
510 /**
511 Cancels a pending HTTP request.
512
513 Cancels an ongoing HTTP request. The callback associated with this request
514 is not executed and the request object is freed. If the request is
515 currently being processed, e.g. it is ongoing, the corresponding
516 evhttp_connection object is going to get reset.
517
518 A request cannot be canceled if its callback has executed already. A request
519 may be canceled reentrantly from its chunked callback.
520
521 @param req the evhttp_request to cancel; req becomes invalid after this call.
522 */
523 void evhttp_cancel_request(struct evhttp_request *req);
524
525 /**
526 * A structure to hold a parsed URI or Relative-Ref conforming to RFC3986.
527 */
528 struct evhttp_uri;
529
530 /** Returns the request URI */
531 const char *evhttp_request_get_uri(const struct evhttp_request *req);
532 /** Returns the request URI (parsed) */
533 const struct evhttp_uri *evhttp_request_get_evhttp_uri(const struct evhttp_request *req);
534 /** Returns the request command */
535 enum evhttp_cmd_type evhttp_request_get_command(const struct evhttp_request *req);
536
537 int evhttp_request_get_response_code(const struct evhttp_request *req);
538
539 /** Returns the input headers */
540 struct evkeyvalq *evhttp_request_get_input_headers(struct evhttp_request *req);
541 /** Returns the output headers */
542 struct evkeyvalq *evhttp_request_get_output_headers(struct evhttp_request *req);
543 /** Returns the input buffer */
544 struct evbuffer *evhttp_request_get_input_buffer(struct evhttp_request *req);
545 /** Returns the output buffer */
546 struct evbuffer *evhttp_request_get_output_buffer(struct evhttp_request *req);
547 /** Returns the host associated with the request. If a client sends an absolute
548 URI, the host part of that is preferred. Otherwise, the input headers are
549 searched for a Host: header. NULL is returned if no absolute URI or Host:
550 header is provided. */
551 const char *evhttp_request_get_host(struct evhttp_request *req);
552
553 /* Interfaces for dealing with HTTP headers */
554
555 /**
556 Finds the value belonging to a header.
557
558 @param headers the evkeyvalq object in which to find the header
559 @param key the name of the header to find
560 @returns a pointer to the value for the header or NULL if the header
561 count not be found.
562 @see evhttp_add_header(), evhttp_remove_header()
563 */
564 const char *evhttp_find_header(const struct evkeyvalq *headers,
565 const char *key);
566
567 /**
568 Removes a header from a list of existing headers.
569
570 @param headers the evkeyvalq object from which to remove a header
571 @param key the name of the header to remove
572 @returns 0 if the header was removed, -1 otherwise.
573 @see evhttp_find_header(), evhttp_add_header()
574 */
575 int evhttp_remove_header(struct evkeyvalq *headers, const char *key);
576
577 /**
578 Adds a header to a list of existing headers.
579
580 @param headers the evkeyvalq object to which to add a header
581 @param key the name of the header
582 @param value the value belonging to the header
583 @returns 0 on success, -1 otherwise.
584 @see evhttp_find_header(), evhttp_clear_headers()
585 */
586 int evhttp_add_header(struct evkeyvalq *headers, const char *key, const char *value);
587
588 /**
589 Removes all headers from the header list.
590
591 @param headers the evkeyvalq object from which to remove all headers
592 */
593 void evhttp_clear_headers(struct evkeyvalq *headers);
594
595 /* Miscellaneous utility functions */
596
597
598 /**
599 Helper function to encode a string for inclusion in a URI. All
600 characters are replaced by their hex-escaped (%22) equivalents,
601 except for characters explicitly unreserved by RFC3986 -- that is,
602 ASCII alphanumeric characters, hyphen, dot, underscore, and tilde.
603
604 The returned string must be freed by the caller.
605
606 @param str an unencoded string
607 @return a newly allocated URI-encoded string or NULL on failure
608 */
609 char *evhttp_encode_uri(const char *str);
610
611 /**
612 As evhttp_encode_uri, but if 'size' is nonnegative, treat the string
613 as being 'size' bytes long. This allows you to encode strings that
614 may contain 0-valued bytes.
615
616 The returned string must be freed by the caller.
617
618 @param str an unencoded string
619 @param size the length of the string to encode, or -1 if the string
620 is NUL-terminated
621 @param space_to_plus if true, space characters in 'str' are encoded
622 as +, not %20.
623 @return a newly allocate URI-encoded string, or NULL on failure.
624 */
625 char *evhttp_uriencode(const char *str, ev_ssize_t size, int space_to_plus);
626
627 /**
628 Helper function to sort of decode a URI-encoded string. Unlike
629 evhttp_get_decoded_uri, it decodes all plus characters that appear
630 _after_ the first question mark character, but no plusses that occur
631 before. This is not a good way to decode URIs in whole or in part.
632
633 The returned string must be freed by the caller
634
635 @deprecated This function is deprecated; you probably want to use
636 evhttp_get_decoded_uri instead.
637
638 @param uri an encoded URI
639 @return a newly allocated unencoded URI or NULL on failure
640 */
641 char *evhttp_decode_uri(const char *uri);
642
643 /**
644 Helper function to decode a URI-escaped string or HTTP parameter.
645
646 If 'decode_plus' is 1, then we decode the string as an HTTP parameter
647 value, and convert all plus ('+') characters to spaces. If
648 'decode_plus' is 0, we leave all plus characters unchanged.
649
650 The returned string must be freed by the caller.
651
652 @param uri a URI-encode encoded URI
653 @param decode_plus determines whether we convert '+' to sapce.
654 @param size_out if size_out is not NULL, *size_out is set to the size of the
655 returned string
656 @return a newly allocated unencoded URI or NULL on failure
657 */
658 char *evhttp_uridecode(const char *uri, int decode_plus,
659 size_t *size_out);
660
661 /**
662 Helper function to parse out arguments in a query.
663
664 Parsing a URI like
665
666 http://foo.com/?q=test&s=some+thing
667
668 will result in two entries in the key value queue.
669
670 The first entry is: key="q", value="test"
671 The second entry is: key="s", value="some thing"
672
673 @deprecated This function is deprecated as of Libevent 2.0.9. Use
674 evhttp_uri_parse and evhttp_parse_query_str instead.
675
676 @param uri the request URI
677 @param headers the head of the evkeyval queue
678 @return 0 on success, -1 on failure
679 */
680 int evhttp_parse_query(const char *uri, struct evkeyvalq *headers);
681
682 /**
683 Helper function to parse out arguments from the query portion of an
684 HTTP URI.
685
686 Parsing a query string like
687
688 q=test&s=some+thing
689
690 will result in two entries in the key value queue.
691
692 The first entry is: key="q", value="test"
693 The second entry is: key="s", value="some thing"
694
695 @param query_parse the query portion of the URI
696 @param headers the head of the evkeyval queue
697 @return 0 on success, -1 on failure
698 */
699 int evhttp_parse_query_str(const char *uri, struct evkeyvalq *headers);
700
701 /**
702 * Escape HTML character entities in a string.
703 *
704 * Replaces <, >, ", ' and & with <, >, ",
705 * ' and & correspondingly.
706 *
707 * The returned string needs to be freed by the caller.
708 *
709 * @param html an unescaped HTML string
710 * @return an escaped HTML string or NULL on error
711 */
712 char *evhttp_htmlescape(const char *html);
713
714 /**
715 * Return a new empty evhttp_uri with no fields set.
716 */
717 struct evhttp_uri *evhttp_uri_new(void);
718
719 /**
720 * Changes the flags set on a given URI. See EVHTTP_URI_* for
721 * a list of flags.
722 **/
723 void evhttp_uri_set_flags(struct evhttp_uri *uri, unsigned flags);
724
725 /** Return the scheme of an evhttp_uri, or NULL if there is no scheme has
726 * been set and the evhttp_uri contains a Relative-Ref. */
727 const char *evhttp_uri_get_scheme(const struct evhttp_uri *uri);
728 /**
729 * Return the userinfo part of an evhttp_uri, or NULL if it has no userinfo
730 * set.
731 */
732 const char *evhttp_uri_get_userinfo(const struct evhttp_uri *uri);
733 /**
734 * Return the host part of an evhttp_uri, or NULL if it has no host set.
735 * The host may either be a regular hostname (conforming to the RFC 3986
736 * "regname" production), or an IPv4 address, or the empty string, or a
737 * bracketed IPv6 address, or a bracketed 'IP-Future' address.
738 *
739 * Note that having a NULL host means that the URI has no authority
740 * section, but having an empty-string host means that the URI has an
741 * authority section with no host part. For example,
742 * "mailto:user@example.com" has a host of NULL, but "file:///etc/motd"
743 * has a host of "".
744 */
745 const char *evhttp_uri_get_host(const struct evhttp_uri *uri);
746 /** Return the port part of an evhttp_uri, or -1 if there is no port set. */
747 int evhttp_uri_get_port(const struct evhttp_uri *uri);
748 /** Return the path part of an evhttp_uri, or NULL if it has no path set */
749 const char *evhttp_uri_get_path(const struct evhttp_uri *uri);
750 /** Return the query part of an evhttp_uri (excluding the leading "?"), or
751 * NULL if it has no query set */
752 const char *evhttp_uri_get_query(const struct evhttp_uri *uri);
753 /** Return the fragment part of an evhttp_uri (excluding the leading "#"),
754 * or NULL if it has no fragment set */
755 const char *evhttp_uri_get_fragment(const struct evhttp_uri *uri);
756
757 /** Set the scheme of an evhttp_uri, or clear the scheme if scheme==NULL.
758 * Returns 0 on success, -1 if scheme is not well-formed. */
759 int evhttp_uri_set_scheme(struct evhttp_uri *uri, const char *scheme);
760 /** Set the userinfo of an evhttp_uri, or clear the userinfo if userinfo==NULL.
761 * Returns 0 on success, -1 if userinfo is not well-formed. */
762 int evhttp_uri_set_userinfo(struct evhttp_uri *uri, const char *userinfo);
763 /** Set the host of an evhttp_uri, or clear the host if host==NULL.
764 * Returns 0 on success, -1 if host is not well-formed. */
765 int evhttp_uri_set_host(struct evhttp_uri *uri, const char *host);
766 /** Set the port of an evhttp_uri, or clear the port if port==-1.
767 * Returns 0 on success, -1 if port is not well-formed. */
768 int evhttp_uri_set_port(struct evhttp_uri *uri, int port);
769 /** Set the path of an evhttp_uri, or clear the path if path==NULL.
770 * Returns 0 on success, -1 if path is not well-formed. */
771 int evhttp_uri_set_path(struct evhttp_uri *uri, const char *path);
772 /** Set the query of an evhttp_uri, or clear the query if query==NULL.
773 * The query should not include a leading "?".
774 * Returns 0 on success, -1 if query is not well-formed. */
775 int evhttp_uri_set_query(struct evhttp_uri *uri, const char *query);
776 /** Set the fragment of an evhttp_uri, or clear the fragment if fragment==NULL.
777 * The fragment should not include a leading "#".
778 * Returns 0 on success, -1 if fragment is not well-formed. */
779 int evhttp_uri_set_fragment(struct evhttp_uri *uri, const char *fragment);
780
781 /**
782 * Helper function to parse a URI-Reference as specified by RFC3986.
783 *
784 * This function matches the URI-Reference production from RFC3986,
785 * which includes both URIs like
786 *
787 * scheme://[[userinfo]@]foo.com[:port]]/[path][?query][#fragment]
788 *
789 * and relative-refs like
790 *
791 * [path][?query][#fragment]
792 *
793 * Any optional elements portions not present in the original URI are
794 * left set to NULL in the resulting evhttp_uri. If no port is
795 * specified, the port is set to -1.
796 *
797 * Note that no decoding is performed on percent-escaped characters in
798 * the string; if you want to parse them, use evhttp_uridecode or
799 * evhttp_parse_query_str as appropriate.
800 *
801 * Note also that most URI schemes will have additional constraints that
802 * this function does not know about, and cannot check. For example,
803 * mailto://www.example.com/cgi-bin/fortune.pl is not a reasonable
804 * mailto url, http://www.example.com:99999/ is not a reasonable HTTP
805 * URL, and ftp:username@example.com is not a reasonable FTP URL.
806 * Nevertheless, all of these URLs conform to RFC3986, and this function
807 * accepts all of them as valid.
808 *
809 * @param source_uri the request URI
810 * @param flags Zero or more EVHTTP_URI_* flags to affect the behavior
811 * of the parser.
812 * @return uri container to hold parsed data, or NULL if there is error
813 * @see evhttp_uri_free()
814 */
815 struct evhttp_uri *evhttp_uri_parse_with_flags(const char *source_uri,
816 unsigned flags);
817
818 /** Tolerate URIs that do not conform to RFC3986.
819 *
820 * Unfortunately, some HTTP clients generate URIs that, according to RFC3986,
821 * are not conformant URIs. If you need to support these URIs, you can
822 * do so by passing this flag to evhttp_uri_parse_with_flags.
823 *
824 * Currently, these changes are:
825 * <ul>
826 * <li> Nonconformant URIs are allowed to contain otherwise unreasonable
827 * characters in their path, query, and fragment components.
828 * </ul>
829 */
830 #define EVHTTP_URI_NONCONFORMANT 0x01
831
832 /** Alias for evhttp_uri_parse_with_flags(source_uri, 0) */
833 struct evhttp_uri *evhttp_uri_parse(const char *source_uri);
834
835 /**
836 * Free all memory allocated for a parsed uri. Only use this for URIs
837 * generated by evhttp_uri_parse.
838 *
839 * @param uri container with parsed data
840 * @see evhttp_uri_parse()
841 */
842 void evhttp_uri_free(struct evhttp_uri *uri);
843
844 /**
845 * Join together the uri parts from parsed data to form a URI-Reference.
846 *
847 * Note that no escaping of reserved characters is done on the members
848 * of the evhttp_uri, so the generated string might not be a valid URI
849 * unless the members of evhttp_uri are themselves valid.
850 *
851 * @param uri container with parsed data
852 * @param buf destination buffer
853 * @param limit destination buffer size
854 * @return an joined uri as string or NULL on error
855 * @see evhttp_uri_parse()
856 */
857 char *evhttp_uri_join(struct evhttp_uri *uri, char *buf, size_t limit);
858
859 #ifdef __cplusplus
860 }
861 #endif
862
863 #endif /* _EVENT2_HTTP_H_ */