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Diffstat (limited to 'include/http_protocol.h')
| -rw-r--r-- | include/http_protocol.h | 1023 |
1 files changed, 1023 insertions, 0 deletions
diff --git a/include/http_protocol.h b/include/http_protocol.h new file mode 100644 index 0000000..11c7b2d --- /dev/null +++ b/include/http_protocol.h @@ -0,0 +1,1023 @@ +/* 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 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); + +/** + * 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); + +/* 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); + +/** + * 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); + +/** + * Set the E-tag outgoing header + * @param r The current request + */ +AP_DECLARE(void) ap_set_etag(request_rec *r); + +/** + * 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 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) +{ + return ap_rwrite(str, (int)strlen(str), r); +} + +/** + * 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); + +/* 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: <pre> + * 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. + * </pre> + * @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 choices A list of protocol identifiers, normally the clients whishes + * @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_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 */ +/** @} */ |