Current File : //usr/include/apache2/http_protocol.h
/* 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: <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 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 */
/** @} */
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