/* * Copyright (c) 2000-2004 Niels Provos * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef _EVHTTP_H_ #define _EVHTTP_H_ #include #ifdef __cplusplus extern "C" { #endif #ifdef WIN32 #define WIN32_LEAN_AND_MEAN #include #include #undef WIN32_LEAN_AND_MEAN #endif /** @file evhttp.h * * Basic support for HTTP serving. * * As libevent is a library for dealing with event notification and most * interesting applications are networked today, I have often found the * need to write HTTP code. The following prototypes and definitions provide * an application with a minimal interface for making HTTP requests and for * creating a very simple HTTP server. */ /* Response codes */ #define HTTP_OK 200 #define HTTP_NOCONTENT 204 #define HTTP_MOVEPERM 301 #define HTTP_MOVETEMP 302 #define HTTP_NOTMODIFIED 304 #define HTTP_BADREQUEST 400 #define HTTP_NOTFOUND 404 #define HTTP_SERVUNAVAIL 503 struct evhttp; struct evhttp_request; struct evkeyvalq; struct evhttp_connection; /** Create a new HTTP server * * @param base (optional) the event base to receive the HTTP events * @return a pointer to a newly initialized evhttp server structure */ struct evhttp *evhttp_new(struct event_base *base); /** * Binds an HTTP server on the specified address and port. * * Can be called multiple times to bind the same http server * to multiple different ports. * * @param http a pointer to an evhttp object * @param address a string containing the IP address to listen(2) on * @param port the port number to listen on * @return a newly allocated evhttp struct * @see evhttp_free() */ int evhttp_bind_socket(struct evhttp *http, const char *address, u_short port); /** * Makes an HTTP server accept connections on the specified socket * * This may be useful to create a socket and then fork multiple instances * of an http server, or when a socket has been communicated via file * descriptor passing in situations where an http servers does not have * permissions to bind to a low-numbered port. * * Can be called multiple times to have the http server listen to * multiple different sockets. * * @param http a pointer to an evhttp object * @param fd a socket fd that is ready for accepting connections * @return 0 on success, -1 on failure. * @see evhttp_free(), evhttp_bind_socket() */ int evhttp_accept_socket(struct evhttp *http, int fd); /** * Free the previously created HTTP server. * * Works only if no requests are currently being served. * * @param http the evhttp server object to be freed * @see evhttp_start() */ void evhttp_free(struct evhttp* http); /** Set a callback for a specified URI */ void evhttp_set_cb(struct evhttp *, const char *, void (*)(struct evhttp_request *, void *), void *); /** Removes the callback for a specified URI */ int evhttp_del_cb(struct evhttp *, const char *); /** Set a callback for all requests that are not caught by specific callbacks */ void evhttp_set_gencb(struct evhttp *, void (*)(struct evhttp_request *, void *), void *); /** * Set the timeout for an HTTP request. * * @param http an evhttp object * @param timeout_in_secs the timeout, in seconds */ void evhttp_set_timeout(struct evhttp *, int timeout_in_secs); /* Request/Response functionality */ /** * Send an HTML error message to the client. * * @param req a request object * @param error the HTTP error code * @param reason a brief explanation of the error */ void evhttp_send_error(struct evhttp_request *req, int error, const char *reason); /** * Send an HTML reply to the client. * * @param req a request object * @param code the HTTP response code to send * @param reason a brief message to send with the response code * @param databuf the body of the response */ void evhttp_send_reply(struct evhttp_request *req, int code, const char *reason, struct evbuffer *databuf); /* Low-level response interface, for streaming/chunked replies */ void evhttp_send_reply_start(struct evhttp_request *, int, const char *); void evhttp_send_reply_chunk_with_cb(struct evhttp_request *, struct evbuffer *, void (*cb)(struct evhttp_connection *, void *), void *arg); void evhttp_send_reply_chunk(struct evhttp_request *, struct evbuffer *); void evhttp_send_reply_end(struct evhttp_request *); /** * Start an HTTP server on the specified address and port * * DEPRECATED: it does not allow an event base to be specified * * @param address the address to which the HTTP server should be bound * @param port the port number on which the HTTP server should listen * @return an struct evhttp object */ struct evhttp *evhttp_start(const char *address, u_short port); /* * Interfaces for making requests */ enum evhttp_cmd_type { EVHTTP_REQ_GET, EVHTTP_REQ_POST, EVHTTP_REQ_HEAD }; enum evhttp_request_kind { EVHTTP_REQUEST, EVHTTP_RESPONSE }; /** * the request structure that a server receives. * WARNING: expect this structure to change. I will try to provide * reasonable accessors. */ struct evhttp_request { #if defined(TAILQ_ENTRY) TAILQ_ENTRY(evhttp_request) next; #else struct { struct evhttp_request *tqe_next; struct evhttp_request **tqe_prev; } next; #endif /* the connection object that this request belongs to */ struct evhttp_connection *evcon; int flags; #define EVHTTP_REQ_OWN_CONNECTION 0x0001 #define EVHTTP_PROXY_REQUEST 0x0002 struct evkeyvalq *input_headers; struct evkeyvalq *output_headers; /* address of the remote host and the port connection came from */ char *remote_host; u_short remote_port; enum evhttp_request_kind kind; enum evhttp_cmd_type type; char *uri; /* uri after HTTP request was parsed */ char major; /* HTTP Major number */ char minor; /* HTTP Minor number */ int response_code; /* HTTP Response code */ char *response_code_line; /* Readable response */ struct evbuffer *input_buffer; /* read data */ ev_int64_t ntoread; int chunked; struct evbuffer *output_buffer; /* outgoing post or data */ /* Callback */ void (*cb)(struct evhttp_request *, void *); void *cb_arg; void (*fail_cb)(struct evhttp_request *, void *); void *fail_cb_arg; /* * Chunked data callback - call for each completed chunk if * specified. If not specified, all the data is delivered via * the regular callback. */ void (*chunk_cb)(struct evhttp_request *, void *); }; /** * Creates a new request object that needs to be filled in with the request * parameters. The callback is executed when the request completed or an * error occurred. */ struct evhttp_request *evhttp_request_new( void (*cb)(struct evhttp_request *, void *), void *arg); /** enable delivery of chunks to requestor */ void evhttp_request_set_chunked_cb(struct evhttp_request *, void (*cb)(struct evhttp_request *, void *)); /** Frees the request object and removes associated events. */ void evhttp_request_free(struct evhttp_request *req); /** * A connection object that can be used to for making HTTP requests. The * connection object tries to establish the connection when it is given an * http request object. */ struct evhttp_connection *evhttp_connection_new( const char *address, unsigned short port); /** Frees an http connection */ void evhttp_connection_free(struct evhttp_connection *evcon); /** sets the ip address from which http connections are made */ void evhttp_connection_set_local_address(struct evhttp_connection *evcon, const char *address); /** sets the local port from which http connections are made */ void evhttp_connection_set_local_port(struct evhttp_connection *evcon, unsigned short port); /** Sets the timeout for events related to this connection */ void evhttp_connection_set_timeout(struct evhttp_connection *evcon, int timeout_in_secs); /** Sets the retry limit for this connection - -1 repeats indefnitely */ void evhttp_connection_set_retries(struct evhttp_connection *evcon, int retry_max); /** Set a callback for connection close. */ void evhttp_connection_set_closecb(struct evhttp_connection *evcon, void (*)(struct evhttp_connection *, void *), void *); /** * Associates an event base with the connection - can only be called * on a freshly created connection object that has not been used yet. */ void evhttp_connection_set_base(struct evhttp_connection *evcon, struct event_base *base); /** Get the remote address and port associated with this connection. */ void evhttp_connection_get_peer(struct evhttp_connection *evcon, char **address, u_short *port); /** The connection gets ownership of the request */ int evhttp_make_request(struct evhttp_connection *evcon, struct evhttp_request *req, enum evhttp_cmd_type type, const char *uri); const char *evhttp_request_uri(struct evhttp_request *req); /* Interfaces for dealing with HTTP headers */ const char *evhttp_find_header(const struct evkeyvalq *, const char *); int evhttp_remove_header(struct evkeyvalq *, const char *); int evhttp_add_header(struct evkeyvalq *, const char *, const char *); void evhttp_clear_headers(struct evkeyvalq *); /* Miscellaneous utility functions */ /** Helper function to encode a URI. The returned string must be freed by the caller. @param uri an unencoded URI @return a newly allocated URI-encoded string */ char *evhttp_encode_uri(const char *uri); /** Helper function to decode a URI. The returned string must be freed by the caller. @param uri an encoded URI @return a newly allocated unencoded URI */ char *evhttp_decode_uri(const char *uri); /** * Helper function to parse out arguments in a query. * * Parsing a uri like * * http://foo.com/?q=test&s=some+thing * * will result in two entries in the key value queue. * The first entry is: key="q", value="test" * The second entry is: key="s", value="some thing" * * @param uri the request URI * @param headers the head of the evkeyval queue */ void evhttp_parse_query(const char *uri, struct evkeyvalq *headers); /** * Escape HTML character entities in a string. * * Replaces <, >, ", ' and & with <, >, ", * ' and & correspondingly. * * The returned string needs to be freed by the caller. * * @param html an unescaped HTML string * @return an escaped HTML string */ char *evhttp_htmlescape(const char *html); #ifdef __cplusplus } #endif #endif /* _EVHTTP_H_ */