apreq_parser.h revision 6ac28b74a504006c016d4df3fb84d2cd2e373942
/*
** 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.
*/
#ifndef APREQ_PARSERS_H
#define APREQ_PARSERS_H
/* These structs are defined below */
#include "apreq_param.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @file apreq_parser.h
* @brief Request body parser API
* @ingroup libapreq2
*/
/**
* A hook is called by the parser whenever data arrives in a file
* upload parameter of the request body. You may associate any number
* of hooks with a parser instance with apreq_parser_add_hook().
*/
typedef struct apreq_hook_t apreq_hook_t;
/**
* A request body parser instance.
*/
typedef struct apreq_parser_t apreq_parser_t;
/** Parser arguments. */
#define APREQ_PARSER_ARGS apreq_parser_t *parser, \
apr_table_t *t, \
apr_bucket_brigade *bb
/** Hook arguments */
#define APREQ_HOOK_ARGS apreq_hook_t *hook, \
apreq_param_t *param, \
apr_bucket_brigade *bb
/**
* The callback function implementing a request body parser.
*/
typedef apr_status_t (*apreq_parser_function_t)(APREQ_PARSER_ARGS);
/**
* The callback function of a hook. See apreq_hook_t.
*/
typedef apr_status_t (*apreq_hook_function_t)(APREQ_HOOK_ARGS);
/**
* Declares a API parser.
*/
#define APREQ_DECLARE_PARSER(f) APREQ_DECLARE_NONSTD(apr_status_t) \
(f) (APREQ_PARSER_ARGS)
/**
* Declares an API hook.
*/
#define APREQ_DECLARE_HOOK(f) APREQ_DECLARE_NONSTD(apr_status_t) \
(f) (APREQ_HOOK_ARGS)
/**
* A hook is called by the parser whenever data arrives in a file
* upload parameter of the request body. You may associate any number
* of hooks with a parser instance with apreq_parser_add_hook().
*/
struct apreq_hook_t {
apreq_hook_function_t hook; /**< the hook function */
apreq_hook_t *next; /**< next item in the linked list */
apr_pool_t *pool; /**< pool which allocated this hook */
void *ctx; /**< a user defined pointer passed to the hook function */
};
/**
* A request body parser instance.
*/
struct apreq_parser_t {
/** the function which parses chunks of body data */
apreq_parser_function_t parser;
/** the Content-Type request header */
const char *content_type;
/** a pool which outlasts the bucket_alloc. */
apr_pool_t *pool;
/** bucket allocator used to create bucket brigades */
apr_bucket_alloc_t *bucket_alloc;
/** the maximum in-memory bytes a brigade may use */
apr_size_t brigade_limit;
/** the directory for generating temporary files */
const char *temp_dir;
/** linked list of hooks */
apreq_hook_t *hook;
/** internal context pointer used by the parser function */
void *ctx;
};
/**
* Parse the incoming brigade into a table. Parsers normally
* consume all the buckets of the brigade during parsing. However
* parsers may leave "rejected" data in the brigade, even during a
* successful parse, so callers may need to clean up the brigade
* themselves (in particular, rejected buckets should not be
* passed back to the parser again).
* @remark bb == NULL is valid: the parser should return its
* public status: APR_INCOMPLETE, APR_SUCCESS, or an error code.
*/
static APR_INLINE
apr_status_t apreq_parser_run(struct apreq_parser_t *psr, apr_table_t *t,
apr_bucket_brigade *bb)
{
return psr->parser(psr, t, bb);
}
/**
* Run the hook with the current parameter and the incoming
* bucket brigade. The hook may modify the brigade if necessary.
* Once all hooks have completed, the contents of the brigade will
* be added to the parameter's bb attribute.
* @return APR_SUCCESS on success. All other values represent errors.
*/
static APR_INLINE
apr_status_t apreq_hook_run(struct apreq_hook_t *h, apreq_param_t *param,
apr_bucket_brigade *bb)
{
return h->hook(h, param, bb);
}
/**
* RFC 822 Header parser. It will reject all data
* after the first CRLF CRLF sequence (an empty line).
* See apreq_parser_run() for more info on rejected data.
*/
APREQ_DECLARE_PARSER(apreq_parse_headers);
/**
* RFC 2396 application/x-www-form-urlencoded parser.
*/
APREQ_DECLARE_PARSER(apreq_parse_urlencoded);
/**
* RFC 2388 multipart/form-data (and XForms 1.0 multipart/related)
* parser. It will reject any buckets representing preamble and
* postamble text (this is normal behavior, not an error condition).
* See apreq_parser_run() for more info on rejected data.
*/
APREQ_DECLARE_PARSER(apreq_parse_multipart);
/**
* Generic parser. No table entries will be added to
* the req->body table by this parser. The parser creates
* a dummy apreq_param_t to pass to any configured hooks. If
* no hooks are configured, the dummy param's bb slot will
* contain a copy of the request body. It can be retrieved
* by casting the parser's ctx pointer to (apreq_param_t **).
*/
APREQ_DECLARE_PARSER(apreq_parse_generic);
/**
* apr_xml_parser hook. It will parse until EOS appears.
* The parsed document isn't available until parsing has
* completed successfully. The hook's ctx pointer may
* be cast as (apr_xml_doc **) to retrieve the
* parsed document.
*/
APREQ_DECLARE_HOOK(apreq_hook_apr_xml_parser);
/**
* Construct a parser.
*
* @param pool Pool used to allocate the parser.
* @param ba bucket allocator used to create bucket brigades
* @param content_type Content-type that this parser can deal with.
* @param pfn The parser function.
* @param brigade_limit the maximum in-memory bytes a brigade may use
* @param temp_dir the directory used by the parser for temporary files
* @param hook Hooks to associate this parser with.
* @param ctx Parser's internal scratch pad.
* @return New parser.
*/
APREQ_DECLARE(apreq_parser_t *) apreq_parser_make(apr_pool_t *pool,
apr_bucket_alloc_t *ba,
const char *content_type,
apreq_parser_function_t pfn,
apr_size_t brigade_limit,
const char *temp_dir,
apreq_hook_t *hook,
void *ctx);
/**
* Construct a hook.
*
* @param pool used to allocate the hook.
* @param hook The hook function.
* @param next List of other hooks for this hook to call on.
* @param ctx Hook's internal scratch pad.
* @return New hook.
*/
APREQ_DECLARE(apreq_hook_t *) apreq_hook_make(apr_pool_t *pool,
apreq_hook_function_t hook,
apreq_hook_t *next,
void *ctx);
/**
* Add a new hook to the end of the parser's hook list.
*
* @param p Parser.
* @param h Hook to append.
*/
APREQ_DECLARE(apr_status_t) apreq_parser_add_hook(apreq_parser_t *p,
apreq_hook_t *h);
/**
* Fetch the default parser function associated with the given MIME type.
* @param enctype The desired enctype (can also be a full "Content-Type"
* header).
* @return The parser function, or NULL if the enctype is unrecognized.
*/
APREQ_DECLARE(apreq_parser_function_t)apreq_parser(const char *enctype);
/**
* Register a new parsing function with a MIME enctype.
* Registered parsers are added to apreq_parser()'s
* internal lookup table.
*
* @param enctype The MIME type.
* @param pfn The function to use during parsing. Setting
* parser == NULL will remove an existing parser.
*
* @return APR_SUCCESS or error.
*/
APREQ_DECLARE(apr_status_t) apreq_register_parser(const char *enctype,
apreq_parser_function_t pfn);
/**
* Returns APREQ_ERROR_GENERAL. Effectively disables mfd parser
* if a file-upload field is present.
*
*/
APREQ_DECLARE_HOOK(apreq_hook_disable_uploads);
/**
* Calls apr_brigade_cleanup on the incoming brigade
* after passing the brigade to any subsequent hooks.
*/
APREQ_DECLARE_HOOK(apreq_hook_discard_brigade);
/**
* Context struct for the apreq_hook_find_param hook.
*/
typedef struct apreq_hook_find_param_ctx_t {
const char *name;
apreq_param_t *param;
apreq_hook_t *prev;
} apreq_hook_find_param_ctx_t;
/**
* Special purpose utility for locating a parameter
* during parsing. The hook's ctx shoud be initialized
* to an apreq_hook_find_param_ctx_t *, with the name
* attribute set to the sought parameter name, the param
* attribute set to NULL, and the prev attribute set to
* the address of the previous hook. The param attribute
* will be reassigned to the first param found, and once
* that happens this hook is immediately removed from the chain.
*
* @remarks When used, this should always be the first hook
* invoked, so add it manually with ctx->prev = &parser->hook
* instead of using apreq_parser_add_hook.
*/
APREQ_DECLARE_HOOK(apreq_hook_find_param);
#ifdef __cplusplus
}
#endif
#endif /* APREQ_PARSERS_H */