/*
HTTP Request Handling
Copyright (C) 1999-2006, 2008, Joe Orton <joe@manyfish.co.uk>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/
#ifndef NE_REQUEST_H
#define NE_REQUEST_H
#include "ne_utils.h" /* For ne_status */
#include "ne_string.h" /* For ne_buffer */
#include "ne_session.h"
NE_BEGIN_DECLS
#define NE_OK (0) /* Success */
#define NE_ERROR (1) /* Generic error; use ne_get_error(session) for message */
#define NE_LOOKUP (2) /* Server or proxy hostname lookup failed */
#define NE_AUTH (3) /* User authentication failed on server */
#define NE_PROXYAUTH (4) /* User authentication failed on proxy */
#define NE_CONNECT (5) /* Could not connect to server */
#define NE_TIMEOUT (6) /* Connection timed out */
#define NE_FAILED (7) /* The precondition failed */
#define NE_RETRY (8) /* Retry request (ne_end_request ONLY) */
#define NE_REDIRECT (9) /* See ne_redirect.h */
/* Opaque object representing a single HTTP request. */
typedef struct ne_request_s ne_request;
/***** Request Handling *****/
/* Create a request in session 'sess', with given method and path.
* 'path' must conform to the 'abs_path' grammar in RFC2396, with an
* optional "? query" part, and MUST be URI-escaped by the caller. */
ne_request *ne_request_create(ne_session *sess,
const char *method, const char *path);
/* The request body will be taken from 'size' bytes of 'buffer'. */
void ne_set_request_body_buffer(ne_request *req, const char *buffer,
size_t size);
/* The request body will be taken from 'length' bytes read from the
* file descriptor 'fd', starting from file offset 'offset'. */
void ne_set_request_body_fd(ne_request *req, int fd,
ne_off_t offset, ne_off_t length);
/* "Pull"-based request body provider: a callback which is invoked to
* provide blocks of request body on demand.
*
* Before each time the body is provided, the callback will be called
* once with buflen == 0. The body may have to be provided >1 time
* per request (for authentication retries etc.).
*
* For a call with buflen == 0, the callback must return zero on success
* or non-zero on error; the session error string must be set on error.
* For a call with buflen > 0, the callback must return:
* <0 : error, abort request; session error string must be set.
* 0 : ignore 'buffer' contents, end of body.
* 0 < x <= buflen : buffer contains x bytes of body data. */
typedef ssize_t (*ne_provide_body)(void *userdata,
char *buffer, size_t buflen);
/* Install a callback which is invoked as needed to provide the
* request body, a block at a time. The total size of the request
* body is 'length'; the callback must ensure that it returns no more
* than 'length' bytes in total. If 'length' is set to -1, then the
* total size of the request is unknown by the caller and chunked
* tranfer will be used. */
void ne_set_request_body_provider(ne_request *req, ne_off_t length,
ne_provide_body provider, void *userdata);
/* Handling response bodies; two callbacks must be provided:
*
* 1) 'acceptance' callback: determines whether you want to handle the
* response body given the response-status information, e.g., if you
* only want 2xx responses, say so here.
*
* 2) 'reader' callback: passed blocks of the response-body as they
* arrive, if the acceptance callback returned non-zero. */
/* 'acceptance' callback type. Return non-zero to accept the response,
* else zero to ignore it. */
typedef int (*ne_accept_response)(void *userdata, ne_request *req,
const ne_status *st);
/* An 'acceptance' callback which only accepts 2xx-class responses.
* Ignores userdata. */
int ne_accept_2xx(void *userdata, ne_request *req, const ne_status *st);
/* An acceptance callback which accepts all responses. Ignores
* userdata. */
int ne_accept_always(void *userdata, ne_request *req, const ne_status *st);
/* Callback for reading a block of data. Returns zero on success, or
* non-zero on error. If returning an error, the response will be
* aborted and the callback will not be invoked again. The request
* dispatch (or ne_read_response_block call) will fail with NE_ERROR;
* the session error string should have been set by the callback. */
typedef int (*ne_block_reader)(void *userdata, const char *buf, size_t len);
/* Add a response reader for the given request, with the given
* acceptance function. userdata is passed as the first argument to
* the acceptance + reader callbacks.
*
* The acceptance callback is called once each time the request is
* sent: it may be sent >1 time because of authentication retries etc.
* For each time the acceptance callback is called, if it returns
* non-zero, blocks of the response body will be passed to the reader
* callback as the response is read. After all the response body has
* been read, the callback will be called with a 'len' argument of
* zero. */
void ne_add_response_body_reader(ne_request *req, ne_accept_response accpt,
ne_block_reader reader, void *userdata);
/* Retrieve the value of the response header field with given name;
* returns NULL if no response header with given name was found. The
* return value is valid only until the next call to either
* ne_request_destroy or ne_begin_request for this request. */
const char *ne_get_response_header(ne_request *req, const char *name);
/* Iterator interface for response headers: if passed a NULL cursor,
* returns the first header; if passed a non-NULL cursor pointer,
* returns the next header. The return value is a cursor pointer: if
* it is non-NULL, *name and *value are set to the name and value of
* the header field. If the return value is NULL, no more headers are
* found, *name and *value are undefined.
*
* The order in which response headers is returned is undefined. Both
* the cursor and name/value pointers are valid only until the next
* call to either ne_request_destroy or ne_begin_request for this
* request. */
void *ne_response_header_iterate(ne_request *req, void *cursor,
const char **name, const char **value);
/* Adds a header to the request with given name and value. */
void ne_add_request_header(ne_request *req, const char *name,
const char *value);
/* Adds a header to the request with given name, using printf-like
* format arguments for the value. */
void ne_print_request_header(ne_request *req, const char *name,
const char *format, ...)
ne_attribute((format(printf, 3, 4)));
/* ne_request_dispatch: Sends the given request, and reads the
* response. Returns:
* - NE_OK if the request was sent and response read successfully
* - NE_AUTH, NE_PROXYAUTH for a server or proxy server authentication error
* - NE_CONNECT if connection could not be established
* - NE_TIMEOUT if an timeout occurred sending or reading from the server
* - NE_ERROR for other fatal dispatch errors
* On any error, the session error string is set. On success or
* authentication error, the actual response-status can be retrieved using
* ne_get_status(). */
int ne_request_dispatch(ne_request *req);
/* Returns a pointer to the response status information for the given
* request; pointer is valid until request object is destroyed. */
const ne_status *ne_get_status(const ne_request *req) ne_attribute((const));
/* Returns pointer to session associated with request. */
ne_session *ne_get_session(const ne_request *req) ne_attribute((const));
/* Destroy memory associated with request pointer */
void ne_request_destroy(ne_request *req);
/* "Caller-pulls" request interface. This is an ALTERNATIVE interface
* to ne_request_dispatch: either use that, or do all this yourself:
*
* caller must call:
* 1. ne_begin_request (fail if returns non-NE_OK)
* 2. while(ne_read_response_block(...) > 0) ... loop ...;
* (fail if ne_read_response_block returns <0)
* 3. ne_end_request
*
* ne_end_request and ne_begin_request both return an NE_* code; if
* ne_end_request returns NE_RETRY, you must restart the loop from (1)
* above. */
int ne_begin_request(ne_request *req);
int ne_end_request(ne_request *req);
/* Read a block of the response into the passed buffer of size 'buflen'.
*
* Returns:
* <0 - error, stop reading.
* 0 - end of response
* >0 - number of bytes read into buffer.
*/
ssize_t ne_read_response_block(ne_request *req, char *buffer, size_t buflen);
/* Read response blocks until end of response; exactly equivalent to
* calling ne_read_response_block() until it returns 0. Returns
* non-zero on error. */
int ne_discard_response(ne_request *req);
/* Read response blocks until end of response, writing content to the
* given file descriptor. Returns NE_ERROR on error. */
int ne_read_response_to_fd(ne_request *req, int fd);
/* Defined request flags: */
typedef enum ne_request_flag_e {
NE_REQFLAG_EXPECT100 = 0, /* enable this flag to enable use of the
* "Expect: 100-continue" for the
* request. */
NE_REQFLAG_IDEMPOTENT, /* disable this flag if the request uses a
* non-idempotent method such as POST. */
NE_REQFLAG_LAST /* enum sentinel value */
} ne_request_flag;
/* Set a new value for a particular request flag. */
void ne_set_request_flag(ne_request *req, ne_request_flag flag, int value);
/* Return 0 if the given flag is not set, >0 it is set, or -1 if the
* flag is not supported. */
int ne_get_request_flag(ne_request *req, ne_request_flag flag);
/**** Request hooks handling *****/
typedef void (*ne_free_hooks)(void *cookie);
/* Hook called when a request is created; passed the request method,
* and the string used as the Request-URI (note that this may be a
* absolute URI if a proxy is in use, an absolute path, a "*", etc).
* A create_request hook is called exactly once per request. */
typedef void (*ne_create_request_fn)(ne_request *req, void *userdata,
const char *method, const char *requri);
void ne_hook_create_request(ne_session *sess,
ne_create_request_fn fn, void *userdata);
/* Hook called before the request is sent. 'header' is the raw HTTP
* header before the trailing CRLF is added; more headers can be added
* here. A pre_send hook may be called >1 time per request if the
* request is retried due to a post_send hook returning NE_RETRY. */
typedef void (*ne_pre_send_fn)(ne_request *req, void *userdata,
ne_buffer *header);
void ne_hook_pre_send(ne_session *sess, ne_pre_send_fn fn, void *userdata);
/* Hook called directly after the response headers have been read, but
* before the resposnse body has been read. 'status' is the response
* status-code. A post_header hook may be called >1 time per request
* if the request is retried due to a post_send hook returning
* NE_RETRY. */
typedef void (*ne_post_headers_fn)(ne_request *req, void *userdata,
const ne_status *status);
void ne_hook_post_headers(ne_session *sess,
ne_post_headers_fn fn, void *userdata);
/* Hook called after the request is dispatched (request sent, and
* the entire response read). If an error occurred reading the response,
* this hook will not run. May return:
* NE_OK everything is okay
* NE_RETRY try sending the request again.
* anything else signifies an error, and the request is failed. The return
* code is passed back the _dispatch caller, so the session error must
* also be set appropriately (ne_set_error).
*/
typedef int (*ne_post_send_fn)(ne_request *req, void *userdata,
const ne_status *status);
void ne_hook_post_send(ne_session *sess, ne_post_send_fn fn, void *userdata);
/* Hook called when the function is destroyed. */
typedef void (*ne_destroy_req_fn)(ne_request *req, void *userdata);
void ne_hook_destroy_request(ne_session *sess,
ne_destroy_req_fn fn, void *userdata);
typedef void (*ne_destroy_sess_fn)(void *userdata);
/* Hook called when the session is about to be destroyed. */
void ne_hook_destroy_session(ne_session *sess,
ne_destroy_sess_fn fn, void *userdata);
typedef void (*ne_close_conn_fn)(void *userdata);
/* Hook called when the connection is closed; note that this hook
* may be called *AFTER* the destroy_session hook. */
void ne_hook_close_conn(ne_session *sess, ne_close_conn_fn fn, void *userdata);
/* The ne_unhook_* functions remove a hook registered with the given
* session. If a hook is found which was registered with a given
* function 'fn', and userdata pointer 'userdata', then it will be
* removed from the hooks list.
*
* It is unsafe to use any of these functions from a hook function to
* unregister itself, except for ne_unhook_destroy_request. */
void ne_unhook_create_request(ne_session *sess,
ne_create_request_fn fn, void *userdata);
void ne_unhook_pre_send(ne_session *sess, ne_pre_send_fn fn, void *userdata);
void ne_unhook_post_headers(ne_session *sess, ne_post_headers_fn fn, void *userdata);
void ne_unhook_post_send(ne_session *sess, ne_post_send_fn fn, void *userdata);
void ne_unhook_destroy_request(ne_session *sess,
ne_destroy_req_fn fn, void *userdata);
void ne_unhook_destroy_session(ne_session *sess,
ne_destroy_sess_fn fn, void *userdata);
void ne_unhook_close_conn(ne_session *sess,
ne_close_conn_fn fn, void *userdata);
/* Store an opaque context for the request, 'priv' is returned by a
* call to ne_request_get_private with the same ID. */
void ne_set_request_private(ne_request *req, const char *id, void *priv);
void *ne_get_request_private(ne_request *req, const char *id);
NE_END_DECLS
#endif /* NE_REQUEST_H */