/* 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

*/

AP_DECLARE(request_rec *) ap_read_request(conn_rec *c);

/**

* Assign the method, uri and protocol (in HTTP/1.x the

* items from the first line) to the request.

* @param r The current request

* @param method the HTTP method

* @param uri the request uri

* @param protocol the request protocol

* @return 1 on success, 0 on failure

*/

AP_DECLARE(int) ap_assign_request_line(request_rec *r,

const char *method, const char *uri,

const char *protocol);

/**

* Parse a HTTP/1.x request line, validate and return the components

* @param r The current request

* @param line the line to parse

* @param pmethod the parsed method on success

* @param puri the parsed uri on success

* @param pprotocol the parsed protocol on success

* @return 1 on success, 0 on failure

*/

AP_DECLARE(int) ap_h1_tokenize_request_line(

request_rec *r, const char *line,

const char **pmethod, const char **puri, const char **pprotocol);

/**

* 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 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, including

* setting r->user (which is supposed to indicate that the user in question has

* been authenticated for the current request).

*

* Modules which call ap_get_basic_auth_pw() during the authentication phase

* MUST either immediately authenticate the user after the call, or else stop

* the request immediately with an error response, to avoid incorrectly

* authenticating the current request. (See CVE-2017-3167.) The replacement

* ap_get_basic_auth_components() API 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 << 0) /* Whether to merge continuation lines */

#define AP_GETLINE_CRLF (1 << 1) /* Whether line ends must be CRLF */

#define AP_GETLINE_NOSPC_EOL (1 << 2) /* Whether to consume up to and including

the end of line on APR_ENOSPC */

#define AP_GETLINE_NONBLOCK (1 << 3) /* Whether to read non-blocking */

/**

* 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 mask of AP_GETLINE_* options

* @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 from an input filter

*

* @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 \p p

* @param n The size of the buffer

* @param read The length of the line.

* @param f Input filter to read from

* @param flags Bit mask of AP_GETLINE_* options

* @param bb Working brigade to use when reading buckets

* @param p The pool to allocate the buffer from (if needed)

* @return APR_SUCCESS, if successful

* APR_ENOSPC, if the line is too big to fit in the buffer

* Other errors where appropriate

*/

AP_DECLARE(apr_status_t) ap_fgetline(char **s, apr_size_t n,

apr_size_t *read, ap_filter_t *f,

int flags, apr_bucket_brigade *bb,

apr_pool_t *p);

/**

* @see ap_fgetline

*

* Note: genuinely calls, ap_fgetline(s, n, read, r->proto_input_filters,

* flags, bb, r->pool)

*/

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);

/**

* 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

*/

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

*/

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

*/

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.

*/

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 client's wishes

* @return The selected protocol or NULL if no protocol could be agreed upon

*/

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

*/

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