/* HTTP Request Handling Copyright (C) 1999-2006, 2008, Joe Orton 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) ne_attribute((nonnull)); /* 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) ne_attribute((nonnull)); /* 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) ne_attribute((nonnull)); /* "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) ne_attribute((nonnull (1))); /* 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 */