/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * @file http_protocol.h * @brief HTTP protocol handling * * @defgroup APACHE_CORE_PROTO HTTP Protocol Handling * @ingroup APACHE_CORE * @{ */ #ifndef APACHE_HTTP_PROTOCOL_H #define APACHE_HTTP_PROTOCOL_H #include "httpd.h" #include "apr_portable.h" #include "apr_mmap.h" #include "apr_buckets.h" #include "util_filter.h" #ifdef __cplusplus extern "C" { #endif /** * This hook allows modules to insert filters for the current error response * @param r the current request * @ingroup hooks */ AP_DECLARE_HOOK(void,insert_error_filter,(request_rec *r)) /** This is an optimization. We keep a record of the filter_rec that * stores the old_write filter, so that we can avoid strcmp's later. */ AP_DECLARE_DATA extern ap_filter_rec_t *ap_old_write_func; /* * Prototypes for routines which either talk directly back to the user, * or control the ones that eventually do. */ /** * Read an empty request and set reasonable defaults. * @param c The current connection * @return The new request_rec */ AP_DECLARE(request_rec *) ap_create_request(conn_rec *c); /** * Read a request and fill in the fields. * @param c The current connection * @return The new request_rec */ request_rec *ap_read_request(conn_rec *c); /** * Parse and validate the request line. * @param r The current request * @return 1 on success, 0 on failure */ AP_DECLARE(int) ap_parse_request_line(request_rec *r); /** * Validate the request header and select vhost. * @param r The current request * @return 1 on success, 0 on failure */ AP_DECLARE(int) ap_check_request_header(request_rec *r); /** * Read the mime-encoded headers. * @param r The current request */ AP_DECLARE(void) ap_get_mime_headers(request_rec *r); /** * Optimized version of ap_get_mime_headers() that requires a * temporary brigade to work with * @param r The current request * @param bb temp brigade */ AP_DECLARE(void) ap_get_mime_headers_core(request_rec *r, apr_bucket_brigade *bb); /** * Run post_read_request hook and validate. * @param r The current request * @return OK or HTTP_... */ AP_DECLARE(int) ap_post_read_request(request_rec *r); /* Finish up stuff after a request */ /** * Called at completion of sending the response. It sends the terminating * protocol information. * @param r The current request */ AP_DECLARE(void) ap_finalize_request_protocol(request_rec *r); /** * Send error back to client. * @param r The current request * @param recursive_error last arg indicates error status in case we get * an error in the process of trying to deal with an ErrorDocument * to handle some other error. In that case, we print the default * report for the first thing that went wrong, and more briefly report * on the problem with the ErrorDocument. */ AP_DECLARE(void) ap_send_error_response(request_rec *r, int recursive_error); /* Set last modified header line from the lastmod date of the associated file. * Also, set content length. * * May return an error status, typically HTTP_NOT_MODIFIED (that when the * permit_cache argument is set to one). */ /** * Set the content length for this request * @param r The current request * @param length The new content length */ AP_DECLARE(void) ap_set_content_length(request_rec *r, apr_off_t length); /** * Set the keepalive status for this request * @param r The current request * @return 1 if keepalive can be set, 0 otherwise */ AP_DECLARE(int) ap_set_keepalive(request_rec *r); /** * Return the latest rational time from a request/mtime pair. Mtime is * returned unless it's in the future, in which case we return the current time. * @param r The current request * @param mtime The last modified time * @return the latest rational time. */ AP_DECLARE(apr_time_t) ap_rationalize_mtime(request_rec *r, apr_time_t mtime); /** * Build the content-type that should be sent to the client from the * content-type specified. The following rules are followed: * - if type is NULL or "", return NULL (do not set content-type). * - if charset adding is disabled, stop processing and return type. * - then, if there are no parameters on type, add the default charset * - return type * @param r The current request * @param type The content type * @return The content-type */ AP_DECLARE(const char *) ap_make_content_type(request_rec *r, const char *type); /** * Precompile metadata structures used by ap_make_content_type() * @param pool The pool to use for allocations */ AP_DECLARE(void) ap_setup_make_content_type(apr_pool_t *pool); /** A structure with the ingredients for a file based etag */ typedef struct etag_rec etag_rec; /** * @brief A structure with the ingredients for a file based etag */ struct etag_rec { /** Optional vary list validator */ const char *vlist_validator; /** Time when the request started */ apr_time_t request_time; /** finfo.protection (st_mode) set to zero if no such file */ apr_finfo_t *finfo; /** File pathname used when generating a digest */ const char *pathname; /** File descriptor used when generating a digest */ apr_file_t *fd; /** Force a non-digest etag to be weak */ int force_weak; }; /** * Construct an entity tag from the resource information. If it's a real * file, build in some of the file characteristics. * @param r The current request * @param force_weak Force the entity tag to be weak - it could be modified * again in as short an interval. * @return The entity tag */ AP_DECLARE(char *) ap_make_etag(request_rec *r, int force_weak); /** * Construct an entity tag from information provided in the etag_rec * structure. * @param r The current request * @param er The etag record, containing ingredients for the etag. */ AP_DECLARE(char *) ap_make_etag_ex(request_rec *r, etag_rec *er); /** * Set the E-tag outgoing header * @param r The current request */ AP_DECLARE(void) ap_set_etag(request_rec *r); /** * Set the E-tag outgoing header, with the option of forcing a strong ETag. * @param r The current request * @param fd The file descriptor */ AP_DECLARE(void) ap_set_etag_fd(request_rec *r, apr_file_t *fd); /** * Set the last modified time for the file being sent * @param r The current request */ AP_DECLARE(void) ap_set_last_modified(request_rec *r); typedef enum { AP_CONDITION_NONE, AP_CONDITION_NOMATCH, AP_CONDITION_WEAK, AP_CONDITION_STRONG } ap_condition_e; /** * Tests conditional request rules for the If-Match header. * @param r The current request * @param headers The response headers to check against * @return AP_CONDITION_NONE if the header is missing, AP_CONDITION_NOMATCH * if the header does not match, AP_CONDITION_STRONG for a strong * match. Weak matches are not permitted for the If-Match header. */ AP_DECLARE(ap_condition_e) ap_condition_if_match(request_rec *r, apr_table_t *headers); /** * Tests conditional request rules for the If-Unmodified-Since header. * @param r The current request * @param headers The response headers to check against * @return AP_CONDITION_NONE if the header is missing, AP_CONDITION_NOMATCH * if the header does not match, AP_CONDITION_WEAK if a weak match * was present and allowed by RFC2616, AP_CONDITION_STRONG for a * strong match. */ AP_DECLARE(ap_condition_e) ap_condition_if_unmodified_since(request_rec *r, apr_table_t *headers); /** * Tests conditional request rules for the If-None-Match header. * @param r The current request * @param headers The response headers to check against * @return AP_CONDITION_NONE if the header is missing, AP_CONDITION_NOMATCH * if the header does not match, AP_CONDITION_WEAK if a weak match * was present and allowed by RFC2616, AP_CONDITION_STRONG for a * strong match. */ AP_DECLARE(ap_condition_e) ap_condition_if_none_match(request_rec *r, apr_table_t *headers); /** * Tests conditional request rules for the If-Modified-Since header. * @param r The current request * @param headers The response headers to check against * @return AP_CONDITION_NONE if the header is missing, AP_CONDITION_NOMATCH * if the header does not match, AP_CONDITION_WEAK if a weak match * was present and allowed by RFC2616, AP_CONDITION_STRONG for a * strong match. */ AP_DECLARE(ap_condition_e) ap_condition_if_modified_since(request_rec *r, apr_table_t *headers); /** * Tests conditional request rules for the If-Range header. * @param r The current request * @param headers The response headers to check against * @return AP_CONDITION_NONE if either the If-Range or Range header is * missing, AP_CONDITION_NOMATCH if the header does not match, * AP_CONDITION_STRONG for a strong match. Weak matches are not * permitted for the If-Range header. */ AP_DECLARE(ap_condition_e) ap_condition_if_range(request_rec *r, apr_table_t *headers); /** * Implements condition GET rules for HTTP/1.1 specification. This function * inspects the client headers and determines if the response fulfills * the requirements specified. * @param r The current request * @return OK if the response fulfills the condition GET rules, some * other status code otherwise */ AP_DECLARE(int) ap_meets_conditions(request_rec *r); /* Other ways to send stuff at the client. All of these keep track * of bytes_sent automatically. This indirection is intended to make * it a little more painless to slide things like HTTP-NG packetization * underneath the main body of the code later. In the meantime, it lets * us centralize a bit of accounting (bytes_sent). * * These also return the number of bytes written by the call. * They should only be called with a timeout registered, for obvious reaasons. * (Ditto the send_header stuff). */ /** * Send an entire file to the client, using sendfile if supported by the * current platform * @param fd The file to send. * @param r The current request * @param offset Offset into the file to start sending. * @param length Amount of data to send * @param nbytes Amount of data actually sent */ AP_DECLARE(apr_status_t) ap_send_fd(apr_file_t *fd, request_rec *r, apr_off_t offset, apr_size_t length, apr_size_t *nbytes); #if APR_HAS_MMAP /** * Send an MMAP'ed file to the client * @param mm The MMAP'ed file to send * @param r The current request * @param offset The offset into the MMAP to start sending * @param length The amount of data to send * @return The number of bytes sent */ AP_DECLARE(apr_size_t) ap_send_mmap(apr_mmap_t *mm, request_rec *r, apr_size_t offset, apr_size_t length); #endif /** * Register a new request method, and return the offset that will be * associated with that method. * * @param p The pool to create registered method numbers from. * @param methname The name of the new method to register. * @return An int value representing an offset into a bitmask. */ AP_DECLARE(int) ap_method_register(apr_pool_t *p, const char *methname); /** * Initialize the method_registry and allocate memory for it. * * @param p Pool to allocate memory for the registry from. */ AP_DECLARE(void) ap_method_registry_init(apr_pool_t *p); /** * This is a convenience macro to ease with checking a mask * against a method name. */ #define AP_METHOD_CHECK_ALLOWED(mask, methname) \ ((mask) & (AP_METHOD_BIT << ap_method_number_of((methname)))) /** * Create a new method list with the specified number of preallocated * slots for extension methods. * * @param p Pointer to a pool in which the structure should be * allocated. * @param nelts Number of preallocated extension slots * @return Pointer to the newly created structure. */ AP_DECLARE(ap_method_list_t *) ap_make_method_list(apr_pool_t *p, int nelts); /** * Copy a method list * * @param dest List to copy to * @param src List to copy from */ AP_DECLARE(void) ap_copy_method_list(ap_method_list_t *dest, ap_method_list_t *src); /** * Search for an HTTP method name in an ap_method_list_t structure, and * return true if found. * * @param method String containing the name of the method to check. * @param l Pointer to a method list, such as r->allowed_methods. * @return 1 if method is in the list, otherwise 0 */ AP_DECLARE(int) ap_method_in_list(ap_method_list_t *l, const char *method); /** * Add an HTTP method name to an ap_method_list_t structure if it isn't * already listed. * * @param method String containing the name of the method to check. * @param l Pointer to a method list, such as r->allowed_methods. * @return None. */ AP_DECLARE(void) ap_method_list_add(ap_method_list_t *l, const char *method); /** * Remove an HTTP method name from an ap_method_list_t structure. * * @param l Pointer to a method list, such as r->allowed_methods. * @param method String containing the name of the method to remove. * @return None. */ AP_DECLARE(void) ap_method_list_remove(ap_method_list_t *l, const char *method); /** * Reset a method list to be completely empty. * * @param l Pointer to a method list, such as r->allowed_methods. * @return None. */ AP_DECLARE(void) ap_clear_method_list(ap_method_list_t *l); /** * Set the content type for this request (r->content_type). * @param r The current request * @param ct The new content type * @warning This function must be called to set r->content_type in order * for the AddOutputFilterByType directive to work correctly. */ AP_DECLARE(void) ap_set_content_type(request_rec *r, const char *ct); /** * Set the content type for this request (r->content_type). * @param r The current request * @param ct The new content type * @param trusted If non-zero, The content-type should come from a * trusted source such as server configuration rather * than application output. * for the AddOutputFilterByType directive to work correctly. */ AP_DECLARE(void) ap_set_content_type_ex(request_rec *r, const char *ct, int trusted); /** * Set the Accept-Ranges header for this response * @param r The current request */ AP_DECLARE(void) ap_set_accept_ranges(request_rec *r); /* Hmmm... could macrofy these for now, and maybe forever, though the * definitions of the macros would get a whole lot hairier. */ /** * Output one character for this request * @param c the character to output * @param r the current request * @return The number of bytes sent */ AP_DECLARE(int) ap_rputc(int c, request_rec *r); /** * Write a buffer for the current request * @param buf The buffer to write * @param nbyte The number of bytes to send from the buffer * @param r The current request * @return The number of bytes sent */ AP_DECLARE(int) ap_rwrite(const void *buf, int nbyte, request_rec *r); /** * Output a string for the current request * @param str The string to output * @param r The current request * @return The number of bytes sent * @note ap_rputs may be implemented as macro or inline function */ static APR_INLINE int ap_rputs(const char *str, request_rec *r) { apr_size_t len; len = strlen(str); for (;;) { if (len <= INT_MAX) { return ap_rwrite(str, (int)len, r); } else { int rc; rc = ap_rwrite(str, INT_MAX, r); if (rc < 0) { return rc; } else { str += INT_MAX; len -= INT_MAX; } } } } /** * Write an unspecified number of strings to the request * @param r The current request * @param ... The strings to write * @return The number of bytes sent */ AP_DECLARE_NONSTD(int) ap_rvputs(request_rec *r,...) AP_FN_ATTR_SENTINEL; /** * Output data to the client in a printf format * @param r The current request * @param fmt The format string * @param vlist The arguments to use to fill out the format string * @return The number of bytes sent */ AP_DECLARE(int) ap_vrprintf(request_rec *r, const char *fmt, va_list vlist); /** * Output data to the client in a printf format * @param r The current request * @param fmt The format string * @param ... The arguments to use to fill out the format string * @return The number of bytes sent */ AP_DECLARE_NONSTD(int) ap_rprintf(request_rec *r, const char *fmt,...) __attribute__((format(printf,2,3))); /** * Flush all of the data for the current request to the client * @param r The current request * @return 0 on success, -1 if an error occurred */ AP_DECLARE(int) ap_rflush(request_rec *r); /** * Index used in custom_responses array for a specific error code * (only use outside protocol.c is in getting them configured). * @param status HTTP status code * @return The index of the response */ AP_DECLARE(int) ap_index_of_response(int status); /** * Return the Status-Line for a given status code (excluding the * HTTP-Version field). If an invalid or unknown status code is * passed, "500 Internal Server Error" will be returned. * @param status The HTTP status code * @return The Status-Line */ AP_DECLARE(const char *) ap_get_status_line(int status); /** * Return the Status-Line for a given status code (excluding the * HTTP-Version field). If an invalid status code is passed, * "500 Internal Server Error" will be returned, whereas an unknown * status will be returned like "xxx Status xxx". * @param p The pool to allocate from when status is unknown * @param status The HTTP status code * @return The Status-Line */ AP_DECLARE(const char *) ap_get_status_line_ex(apr_pool_t *p, int status); /* Reading a block of data from the client connection (e.g., POST arg) */ /** * Setup the client to allow Apache to read the request body. * @param r The current request * @param read_policy How the server should interpret a chunked * transfer-encoding. One of: 
 *    REQUEST_NO_BODY          Send 413 error if message has any body
 *    REQUEST_CHUNKED_ERROR    Send 411 error if body without Content-Length
 *    REQUEST_CHUNKED_DECHUNK  If chunked, remove the chunks for me.
 *
* @return either OK or an error code */ AP_DECLARE(int) ap_setup_client_block(request_rec *r, int read_policy); /** * Determine if the client has sent any data. This also sends a * 100 Continue response to HTTP/1.1 clients, so modules should not be called * until the module is ready to read content. * @warning Never call this function more than once. * @param r The current request * @return 0 if there is no message to read, 1 otherwise */ AP_DECLARE(int) ap_should_client_block(request_rec *r); /** * Call this in a loop. It will put data into a buffer and return the length * of the input block * @param r The current request * @param buffer The buffer in which to store the data * @param bufsiz The size of the buffer * @return Number of bytes inserted into the buffer. When done reading, 0 * if EOF, or -1 if there was an error */ AP_DECLARE(long) ap_get_client_block(request_rec *r, char *buffer, apr_size_t bufsiz); /** * Map specific APR codes returned by the filter stack to HTTP error * codes, or the default status code provided. Use it as follows: * * return ap_map_http_request_error(rv, HTTP_BAD_REQUEST); * * If the filter has already handled the error, AP_FILTER_ERROR will * be returned, which is cleanly passed through. * * These mappings imply that the filter stack is reading from the * downstream client, the proxy will map these codes differently. * @param rv APR status code * @param status Default HTTP code should the APR code not be recognised * @return Mapped HTTP status code */ AP_DECLARE(int) ap_map_http_request_error(apr_status_t rv, int status); /** * In HTTP/1.1, any method can have a body. However, most GET handlers * wouldn't know what to do with a request body if they received one. * This helper routine tests for and reads any message body in the request, * simply discarding whatever it receives. We need to do this because * failing to read the request body would cause it to be interpreted * as the next request on a persistent connection. * @param r The current request * @return error status if request is malformed, OK otherwise */ AP_DECLARE(int) ap_discard_request_body(request_rec *r); /** * Setup the output headers so that the client knows how to authenticate * itself the next time, if an authentication request failed. * @param r The current request */ AP_DECLARE(void) ap_note_auth_failure(request_rec *r); /** * @deprecated @see ap_note_auth_failure */ AP_DECLARE(void) ap_note_basic_auth_failure(request_rec *r); /** * @deprecated @see ap_note_auth_failure */ AP_DECLARE(void) ap_note_digest_auth_failure(request_rec *r); /** * This hook allows modules to add support for a specific auth type to * ap_note_auth_failure * @param r the current request * @param auth_type the configured auth_type * @return OK, DECLINED */ AP_DECLARE_HOOK(int, note_auth_failure, (request_rec *r, const char *auth_type)) /** * Get the password from the request headers. This function has multiple side * effects due to its prior use in the old authentication framework. * ap_get_basic_auth_components() should be preferred. * * @deprecated @see ap_get_basic_auth_components * @param r The current request * @param pw The password as set in the headers * @return 0 (OK) if it set the 'pw' argument (and assured * a correct value in r->user); otherwise it returns * an error code, either HTTP_INTERNAL_SERVER_ERROR if things are * really confused, HTTP_UNAUTHORIZED if no authentication at all * seemed to be in use, or DECLINED if there was authentication but * it wasn't Basic (in which case, the caller should presumably * decline as well). */ AP_DECLARE(int) ap_get_basic_auth_pw(request_rec *r, const char **pw); #define AP_GET_BASIC_AUTH_PW_NOTE "AP_GET_BASIC_AUTH_PW_NOTE" /** * Get the username and/or password from the request's Basic authentication * headers. Unlike ap_get_basic_auth_pw(), calling this function has no side * effects on the passed request_rec. * * @param r The current request * @param username If not NULL, set to the username sent by the client * @param password If not NULL, set to the password sent by the client * @return APR_SUCCESS if the credentials were successfully parsed and returned; * APR_EINVAL if there was no authentication header sent or if the * client was not using the Basic authentication scheme. username and * password are unchanged on failure. */ AP_DECLARE(apr_status_t) ap_get_basic_auth_components(const request_rec *r, const char **username, const char **password); /** * parse_uri: break apart the uri * @warning Side Effects: * @li sets r->args to rest after '?' (or NULL if no '?') * @li sets r->uri to request uri (without r->args part) * @li sets r->hostname (if not set already) from request (scheme://host:port) * @param r The current request * @param uri The uri to break apart */ AP_CORE_DECLARE(void) ap_parse_uri(request_rec *r, const char *uri); #define AP_GETLINE_FOLD 1 /* Whether to merge continuation lines */ #define AP_GETLINE_CRLF 2 /* Whether line ends must be in the form CR LF */ #define AP_GETLINE_NOSPC_EOL 4 /* Whether to consume up to and including the end of line on APR_ENOSPC */ /** * Get the next line of input for the request * @param s The buffer into which to read the line * @param n The size of the buffer * @param r The request * @param flags Bit flag of multiple parsing options * AP_GETLINE_FOLD Whether to merge continuation lines * AP_GETLINE_CRLF Whether line ends must be in the form CR LF * @return The length of the line, if successful * n, if the line is too big to fit in the buffer * -1 for miscellaneous errors */ AP_DECLARE(int) ap_getline(char *s, int n, request_rec *r, int flags); /** * Get the next line of input for the request * * Note: on ASCII boxes, ap_rgetline is a macro which simply calls * ap_rgetline_core to get the line of input. * * on EBCDIC boxes, ap_rgetline is a wrapper function which * translates ASCII protocol lines to the local EBCDIC code page * after getting the line of input. * * @param s Pointer to the pointer to the buffer into which the line * should be read; if *s==NULL, a buffer of the necessary size * to hold the data will be allocated from the request pool * @param n The size of the buffer * @param read The length of the line. * @param r The request * @param flags Bit flag of multiple parsing options * AP_GETLINE_FOLD Whether to merge continuation lines * AP_GETLINE_CRLF Whether line ends must be in the form CR LF * @param bb Working brigade to use when reading buckets * @return APR_SUCCESS, if successful * APR_ENOSPC, if the line is too big to fit in the buffer * Other errors where appropriate */ #if APR_CHARSET_EBCDIC AP_DECLARE(apr_status_t) ap_rgetline(char **s, apr_size_t n, apr_size_t *read, request_rec *r, int flags, apr_bucket_brigade *bb); #else /* ASCII box */ #define ap_rgetline(s, n, read, r, fold, bb) \ ap_rgetline_core((s), (n), (read), (r), (fold), (bb)) #endif /** @see ap_rgetline */ AP_DECLARE(apr_status_t) ap_rgetline_core(char **s, apr_size_t n, apr_size_t *read, request_rec *r, int flags, apr_bucket_brigade *bb); /** * Get the method number associated with the given string, assumed to * contain an HTTP method. Returns M_INVALID if not recognized. * @param method A string containing a valid HTTP method * @return The method number */ AP_DECLARE(int) ap_method_number_of(const char *method); /** * Get the method name associated with the given internal method * number. Returns NULL if not recognized. * @param p A pool to use for temporary allocations. * @param methnum An integer value corresponding to an internal method number * @return The name corresponding to the method number */ AP_DECLARE(const char *) ap_method_name_of(apr_pool_t *p, int methnum); /* Hooks */ /* * pre_read_request --- run right before read_request_line(), * and not run during any subrequests. */ /** * This hook allows modules to affect the request or connection immediately before * the request has been read, and before any other phases have been processes. * @param r The current request of the soon-to-be-read request * @param c The connection * @return None/void */ AP_DECLARE_HOOK(void,pre_read_request,(request_rec *r, conn_rec *c)) /* * post_read_request --- run right after read_request or internal_redirect, * and not run during any subrequests. */ /** * This hook allows modules to affect the request immediately after the request * has been read, and before any other phases have been processes. This allows * modules to make decisions based upon the input header fields * @param r The current request * @return OK or DECLINED */ AP_DECLARE_HOOK(int,post_read_request,(request_rec *r)) /** * This hook allows modules to perform any module-specific logging activities * over and above the normal server things. * @param r The current request * @return OK, DECLINED, or HTTP_... */ AP_DECLARE_HOOK(int,log_transaction,(request_rec *r)) /** * This hook allows modules to retrieve the http scheme for a request. This * allows Apache modules to easily extend the schemes that Apache understands * @param r The current request * @return The http scheme from the request */ AP_DECLARE_HOOK(const char *,http_scheme,(const request_rec *r)) /** * Return the default port from the current request * @param r The current request * @return The current port */ AP_DECLARE_HOOK(apr_port_t,default_port,(const request_rec *r)) #define AP_PROTOCOL_HTTP1 "http/1.1" /** * Determine the list of protocols available for a connection/request. This may * be collected with or without any request sent, in which case the request is * NULL. Or it may be triggered by the request received, e.g. through the * "Upgrade" header. * * This hook will be run whenever protocols are being negotiated (ALPN as * one example). It may also be invoked at other times, e.g. when the server * wants to advertise protocols it is capable of switching to. * * The identifiers for protocols are taken from the TLS extension type ALPN: * https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xml * * If no protocols are added to the proposals, the server not perform any * switch. If the protocol selected from the proposals is the protocol * already in place, also no protocol switch will be invoked. * * The client may already have announced the protocols it is willing to * accept. These will then be listed as offers. This parameter may also * be NULL, indicating that offers from the client are not known and * the hooks should propose all protocols that are valid for the * current connection/request. * * All hooks are run, unless one returns an error. Proposals may contain * duplicates. The order in which proposals are added is usually ignored. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected * @param offers A list of protocol identifiers offered by the client or * NULL to indicated that the hooks are free to propose * @param proposals The list of protocol identifiers proposed by the hooks * @return OK or DECLINED * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE_HOOK(int,protocol_propose,(conn_rec *c, request_rec *r, server_rec *s, const apr_array_header_t *offers, apr_array_header_t *proposals)) /** * Perform a protocol switch on the connection. The exact requirements for * that depend on the protocol in place and the one switched to. The first * protocol module to handle the switch is the last module run. * * For a connection level switch (r == NULL), the handler must on return * leave the conn_rec in a state suitable for processing the switched * protocol, e.g. correct filters in place. * * For a request triggered switch (r != NULL), the protocol switch is done * before the response is sent out. When switching from "http/1.1" via Upgrade * header, the 101 intermediate response will have been sent. The * hook needs then to process the connection until it can be closed. Which * the server will enforce on hook return. * Any error the hook might encounter must already be sent by the hook itself * to the client in whatever form the new protocol requires. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected * @param protocol The protocol identifier we try to switch to * @return OK or DECLINED * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE_HOOK(int,protocol_switch,(conn_rec *c, request_rec *r, server_rec *s, const char *protocol)) /** * Return the protocol used on the connection. Modules implementing * protocol switching must register here and return the correct protocol * identifier for connections they switched. * * To find out the protocol for the current connection, better call * @see ap_get_protocol which internally uses this hook. * * @param c The current connection * @return The identifier of the protocol in place or NULL * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE_HOOK(const char *,protocol_get,(const conn_rec *c)) /** * Get the protocols that the connection and optional request may * upgrade to - besides the protocol currently active on the connection. These * values may be used to announce to a client what choices it has. * * If report_all == 0, only protocols more preferable than the one currently * being used, are reported. Otherwise, all available protocols beside the * current one are being reported. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected or NULL * @param report_all include also protocols less preferred than the current one * @param pupgrades on return, possible protocols to upgrade to in descending order * of preference. Maybe NULL if none are available. * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE(apr_status_t) ap_get_protocol_upgrades(conn_rec *c, request_rec *r, server_rec *s, int report_all, const apr_array_header_t **pupgrades); /** * Select a protocol for the given connection and optional request. Will return * the protocol identifier selected which may be the protocol already in place * on the connection. The selected protocol will be NULL if non of the given * choices could be agreed upon (e.g. no proposal as made). * * A special case is where the choices itself is NULL (instead of empty). In * this case there are no restrictions imposed on protocol selection. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected * @param choices A list of protocol identifiers, normally the clients whishes * @return The selected protocol or NULL if no protocol could be agreed upon * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE(const char *) ap_select_protocol(conn_rec *c, request_rec *r, server_rec *s, const apr_array_header_t *choices); /** * Perform the actual protocol switch. The protocol given must have been * selected before on the very same connection and request pair. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected * @param protocol the protocol to switch to * @return APR_SUCCESS, if caller may continue processing as usual * APR_EOF, if caller needs to stop processing the connection * APR_EINVAL, if the protocol is already in place * APR_NOTIMPL, if no module performed the switch * Other errors where appropriate * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE(apr_status_t) ap_switch_protocol(conn_rec *c, request_rec *r, server_rec *s, const char *protocol); /** * Call the protocol_get hook to determine the protocol currently in use * for the given connection. * * Unless another protocol has been switch to, will default to * @see AP_PROTOCOL_HTTP1 and modules implementing a new protocol must * report a switched connection via the protocol_get hook. * * @param c The connection to determine the protocol for * @return the protocol in use, never NULL * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE(const char *) ap_get_protocol(conn_rec *c); /** * Check if the given protocol is an allowed choice on the given * combination of connection, request and server. * * When server is NULL, it is taken from request_rec, unless * request_rec is NULL. Then it is taken from the connection base * server. * * @param c The current connection * @param r The current request or NULL * @param s The server/virtual host selected or NULL * @param protocol the protocol to switch to * @return != 0 iff protocol is allowed * @bug This API or implementation and order of operations should be considered * experimental and will continue to evolve in future 2.4 releases, with * a corresponding minor module magic number (MMN) bump to indicate the * API revision level. */ AP_DECLARE(int) ap_is_allowed_protocol(conn_rec *c, request_rec *r, server_rec *s, const char *protocol); /** @see ap_bucket_type_error */ typedef struct ap_bucket_error ap_bucket_error; /** * @struct ap_bucket_error * @brief A bucket referring to an HTTP error * * This bucket can be passed down the filter stack to indicate that an * HTTP error occurred while running a filter. In order for this bucket * to be used successfully, it MUST be sent as the first bucket in the * first brigade to be sent from a given filter. */ struct ap_bucket_error { /** Number of buckets using this memory */ apr_bucket_refcount refcount; /** The error code */ int status; /** The error string */ const char *data; }; /** @see ap_bucket_type_error */ AP_DECLARE_DATA extern const apr_bucket_type_t ap_bucket_type_error; /** * Determine if a bucket is an error bucket * @param e The bucket to inspect * @return true or false */ #define AP_BUCKET_IS_ERROR(e) (e->type == &ap_bucket_type_error) /** * Make the bucket passed in an error bucket * @param b The bucket to make into an error bucket * @param error The HTTP error code to put in the bucket. * @param buf An optional error string to put in the bucket. * @param p A pool to allocate out of. * @return The new bucket, or NULL if allocation failed */ AP_DECLARE(apr_bucket *) ap_bucket_error_make(apr_bucket *b, int error, const char *buf, apr_pool_t *p); /** * Create a bucket referring to an HTTP error. * @param error The HTTP error code to put in the bucket. * @param buf An optional error string to put in the bucket. * @param p A pool to allocate the error string out of. * @param list The bucket allocator from which to allocate the bucket * @return The new bucket, or NULL if allocation failed */ AP_DECLARE(apr_bucket *) ap_bucket_error_create(int error, const char *buf, apr_pool_t *p, apr_bucket_alloc_t *list); AP_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f, apr_bucket_brigade *b); AP_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f, apr_bucket_brigade *b); AP_DECLARE_NONSTD(apr_status_t) ap_content_length_filter(ap_filter_t *, apr_bucket_brigade *); AP_DECLARE_NONSTD(apr_status_t) ap_old_write_filter(ap_filter_t *f, apr_bucket_brigade *b); /** * Sett up the protocol fields for subsidiary requests * @param rnew New Sub Request * @param r current request */ AP_DECLARE(void) ap_set_sub_req_protocol(request_rec *rnew, const request_rec *r); /** * A wrapup function to keep the internal accounting straight. * Indicates that there is no more content coming. * @param sub_r Subrequest that is now compete */ AP_DECLARE(void) ap_finalize_sub_req_protocol(request_rec *sub_r); /** * Send an interim (HTTP 1xx) response immediately. * @param r The request * @param send_headers Whether to send&clear headers in r->headers_out */ AP_DECLARE(void) ap_send_interim_response(request_rec *r, int send_headers); #ifdef __cplusplus } #endif #endif /* !APACHE_HTTP_PROTOCOL_H */ /** @} */