http_core.h

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/* 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 APACHE_HTTP_CORE_H
#define APACHE_HTTP_CORE_H

#include "apr.h"
#include "apr_hash.h"
#include "apr_optional.h"
#include "util_filter.h"
#include "ap_expr.h"
#include "apr_tables.h"

#include "http_config.h"

#if APR_HAVE_STRUCT_RLIMIT
#include <sys/time.h>
#include <sys/resource.h>
#endif


#ifdef __cplusplus
extern "C" {
#endif

/* ****************************************************************
 *
 * The most basic server code is encapsulated in a single module
 * known as the core, which is just *barely* functional enough to
 * serve documents, though not terribly well.
 *
 * Largely for NCSA back-compatibility reasons, the core needs to
 * make pieces of its config structures available to other modules.
 * The accessors are declared here, along with the interpretation
 * of one of them (allow_options).
 */

#define OPT_NONE 0

#define OPT_INDEXES 1

#define OPT_INCLUDES 2

#define OPT_SYM_LINKS 4

#define OPT_EXECCGI 8

#define OPT_UNSET 16

#define OPT_INC_WITH_EXEC 32

#define OPT_SYM_OWNER 64

#define OPT_MULTI 128

#define OPT_ALL (OPT_INDEXES|OPT_INCLUDES|OPT_INC_WITH_EXEC|OPT_SYM_LINKS|OPT_EXECCGI)

#define REMOTE_HOST (0)

#define REMOTE_NAME (1)

#define REMOTE_NOLOOKUP (2)

#define REMOTE_DOUBLE_REV (3)

#define SATISFY_ALL 0

#define SATISFY_ANY 1

#define SATISFY_NOSPEC 2

#define AP_MIN_BYTES_TO_WRITE  8000

# define AP_DEFAULT_MAX_INTERNAL_REDIRECTS 10

# define AP_DEFAULT_MAX_SUBREQ_DEPTH 10

AP_DECLARE(int) ap_allow_options(request_rec *r);

AP_DECLARE(int) ap_allow_overrides(request_rec *r);

AP_DECLARE(const char *) ap_document_root(request_rec *r);

AP_DECLARE(const char *) ap_get_useragent_host(request_rec *req, int type,
                                               int *str_is_ip);

AP_DECLARE(const char *) ap_get_remote_host(conn_rec *conn, void *dir_config, int type, int *str_is_ip);

AP_DECLARE(const char *) ap_get_remote_logname(request_rec *r);

/* Used for constructing self-referencing URLs, and things like SERVER_PORT,
 * and SERVER_NAME.
 */
AP_DECLARE(char *) ap_construct_url(apr_pool_t *p, const char *uri, request_rec *r);

AP_DECLARE(const char *) ap_get_server_name(request_rec *r);

AP_DECLARE(const char *) ap_get_server_name_for_url(request_rec *r);

AP_DECLARE(apr_port_t) ap_get_server_port(const request_rec *r);

AP_DECLARE(apr_size_t) ap_get_read_buf_size(const request_rec *r);

AP_DECLARE(apr_off_t) ap_get_limit_req_body(const request_rec *r);

AP_DECLARE(apr_size_t) ap_get_limit_xml_body(const request_rec *r);

AP_DECLARE(void) ap_custom_response(request_rec *r, int status, const char *string);

AP_DECLARE(int) ap_is_recursion_limit_exceeded(const request_rec *r);

AP_DECLARE(int) ap_exists_config_define(const char *name);
/* FIXME! See STATUS about how */
AP_DECLARE_NONSTD(int) ap_core_translate(request_rec *r);

/* Authentication stuff.  This is one of the places where compatibility
 * with the old config files *really* hurts; they don't discriminate at
 * all between different authentication schemes, meaning that we need
 * to maintain common state for all of them in the core, and make it
 * available to the other modules through interfaces.
 */

typedef struct require_line require_line;

struct require_line {
    apr_int64_t method_mask;
    char *requirement;
};

AP_DECLARE(const char *) ap_auth_type(request_rec *r);

AP_DECLARE(const char *) ap_auth_name(request_rec *r);

AP_DECLARE(int) ap_satisfies(request_rec *r);

AP_DECLARE_DATA extern module core_module;

AP_DECLARE(void *) ap_get_core_module_config(const ap_conf_vector_t *cv);

AP_DECLARE(void) ap_set_core_module_config(ap_conf_vector_t *cv, void *val);

AP_DECLARE(apr_socket_t *) ap_get_conn_socket(conn_rec *c);

#ifndef AP_DEBUG
#define AP_CORE_MODULE_INDEX  0
#define ap_get_core_module_config(v) \
    (((void **)(v))[AP_CORE_MODULE_INDEX])
#define ap_set_core_module_config(v, val) \
    ((((void **)(v))[AP_CORE_MODULE_INDEX]) = (val))
#else
#define AP_CORE_MODULE_INDEX  (AP_DEBUG_ASSERT(core_module.module_index == 0), 0)
#endif

typedef struct {
    struct apr_bucket_brigade *bb;

    void **notes;

    char **response_code_strings; /* from ap_custom_response(), not from
                                   * ErrorDocument
                                   */

    const char *document_root;

    /*
     * more fine-grained context information which is set by modules like
     * mod_alias and mod_userdir
     */
    const char *context_document_root;
    const char *context_prefix;

    int deliver_script;

    int suppress_charset;
} core_request_config;

/* Standard entries that are guaranteed to be accessible via
 * ap_get_request_note() for each request (additional entries
 * can be added with ap_register_request_note())
 */
#define AP_NOTE_DIRECTORY_WALK 0
#define AP_NOTE_LOCATION_WALK  1
#define AP_NOTE_FILE_WALK      2
#define AP_NOTE_IF_WALK        3
#define AP_NUM_STD_NOTES       4

AP_DECLARE(apr_size_t) ap_register_request_note(void);

AP_DECLARE(void **) ap_get_request_note(request_rec *r, apr_size_t note_num);


typedef unsigned char allow_options_t;
typedef unsigned int overrides_t;

/*
 * Bits of info that go into making an ETag for a file
 * document.  Why a long?  Because char historically
 * proved too short for Options, and int can be different
 * sizes on different platforms.
 */
typedef unsigned long etag_components_t;

#define ETAG_UNSET 0
#define ETAG_NONE  (1 << 0)
#define ETAG_MTIME (1 << 1)
#define ETAG_INODE (1 << 2)
#define ETAG_SIZE  (1 << 3)
#define ETAG_ALL   (ETAG_MTIME | ETAG_INODE | ETAG_SIZE)
/* This is the default value used */
#define ETAG_BACKWARD (ETAG_MTIME | ETAG_SIZE)

/* Generic ON/OFF/UNSET for unsigned int foo :2 */
#define AP_CORE_CONFIG_OFF   (0)
#define AP_CORE_CONFIG_ON    (1)
#define AP_CORE_CONFIG_UNSET (2)

/* Generic merge of flag */
#define AP_CORE_MERGE_FLAG(field, to, base, over) to->field = \
               over->field != AP_CORE_CONFIG_UNSET            \
               ? over->field                                  \
               : base->field                                   

typedef enum {
    srv_sig_unset,
    srv_sig_off,
    srv_sig_on,
    srv_sig_withmail
} server_signature_e;

typedef struct {
    char *d;
    unsigned d_components;

    allow_options_t opts;
    allow_options_t opts_add;
    allow_options_t opts_remove;
    overrides_t override;
    allow_options_t override_opts;

    /* Used to be the custom response config. No longer used. */
    char **response_code_strings; /* from ErrorDocument, not from
                                   * ap_custom_response() */

    /* Hostname resolution etc */
#define HOSTNAME_LOOKUP_OFF     0
#define HOSTNAME_LOOKUP_ON      1
#define HOSTNAME_LOOKUP_DOUBLE  2
#define HOSTNAME_LOOKUP_UNSET   3
    unsigned int hostname_lookups : 4;

    unsigned int content_md5 : 2;  /* calculate Content-MD5? */

#define USE_CANONICAL_NAME_OFF   (0)
#define USE_CANONICAL_NAME_ON    (1)
#define USE_CANONICAL_NAME_DNS   (2)
#define USE_CANONICAL_NAME_UNSET (3)
    unsigned use_canonical_name : 2;

    /* since is_fnmatch(conf->d) was being called so frequently in
     * directory_walk() and its relatives, this field was created and
     * is set to the result of that call.
     */
    unsigned d_is_fnmatch : 1;

    /* should we force a charset on any outgoing parameterless content-type?
     * if so, which charset?
     */
#define ADD_DEFAULT_CHARSET_OFF   (0)
#define ADD_DEFAULT_CHARSET_ON    (1)
#define ADD_DEFAULT_CHARSET_UNSET (2)
    unsigned add_default_charset : 2;
    const char *add_default_charset_name;

    /* System Resource Control */
#ifdef RLIMIT_CPU
    struct rlimit *limit_cpu;
#endif
#if defined (RLIMIT_DATA) || defined (RLIMIT_VMEM) || defined(RLIMIT_AS)
    struct rlimit *limit_mem;
#endif
#ifdef RLIMIT_NPROC
    struct rlimit *limit_nproc;
#endif
    apr_off_t limit_req_body;      /* limit on bytes in request msg body */
    long limit_xml_body;           /* limit on bytes in XML request msg body */

    /* logging options */

    server_signature_e server_signature;

    /* Access control */
    apr_array_header_t *sec_file;
    apr_array_header_t *sec_if;
    ap_regex_t *r;

    const char *mime_type;       /* forced with ForceType  */
    const char *handler;         /* forced by something other than SetHandler */
    const char *output_filters;  /* forced with SetOutputFilters */
    const char *input_filters;   /* forced with SetInputFilters */
    int accept_path_info;        /* forced with AcceptPathInfo */

    /*
     * What attributes/data should be included in ETag generation?
     */
    etag_components_t etag_bits;
    etag_components_t etag_add;
    etag_components_t etag_remove;

    /*
     * Run-time performance tuning
     */
#define ENABLE_MMAP_OFF    (0)
#define ENABLE_MMAP_ON     (1)
#define ENABLE_MMAP_UNSET  (2)
    unsigned int enable_mmap : 2;  /* whether files in this dir can be mmap'ed */

#define ENABLE_SENDFILE_OFF    (0)
#define ENABLE_SENDFILE_ON     (1)
#define ENABLE_SENDFILE_UNSET  (2)
    unsigned int enable_sendfile : 2;  /* files in this dir can be sendfile'ed */

#define USE_CANONICAL_PHYS_PORT_OFF   (0)
#define USE_CANONICAL_PHYS_PORT_ON    (1)
#define USE_CANONICAL_PHYS_PORT_UNSET (2)
    unsigned int use_canonical_phys_port : 2;

    unsigned int allow_encoded_slashes : 1; /* URLs may contain %2f w/o being
                                             * pitched indiscriminately */
    unsigned int decode_encoded_slashes : 1; /* whether to decode encoded slashes in URLs */

#define AP_CONDITION_IF        1
#define AP_CONDITION_ELSE      2
#define AP_CONDITION_ELSEIF    (AP_CONDITION_ELSE|AP_CONDITION_IF)
    unsigned int condition_ifelse : 2; /* is this an <If>, <ElseIf>, or <Else> */

    ap_expr_info_t *condition;   /* Conditionally merge <If> sections */

    struct ap_logconf *log;

    apr_table_t *override_list;

#define AP_MAXRANGES_UNSET     -1
#define AP_MAXRANGES_DEFAULT   -2
#define AP_MAXRANGES_UNLIMITED -3
#define AP_MAXRANGES_NORANGES   0

    int max_ranges;
    int max_overlaps;
    int max_reversals;

    unsigned int allow_encoded_slashes_set : 1;
    unsigned int decode_encoded_slashes_set : 1;

    apr_array_header_t *refs;

#define AP_CGI_PASS_AUTH_OFF     (0)
#define AP_CGI_PASS_AUTH_ON      (1)
#define AP_CGI_PASS_AUTH_UNSET   (2)

    unsigned int cgi_pass_auth : 2;

    apr_hash_t *response_code_exprs;

    unsigned int qualify_redirect_url :2;
    ap_expr_info_t  *expr_handler;         /* forced with SetHandler */

    apr_hash_t *cgi_var_rules;

    apr_size_t read_buf_size;
} core_dir_config;

/* macro to implement off by default behaviour */
#define AP_SENDFILE_ENABLED(x) \
    ((x) == ENABLE_SENDFILE_ON ? APR_SENDFILE_ENABLED : 0)

/* Per-server core configuration */

typedef struct {

    char *gprof_dir;

    /* Name translations --- we want the core to be able to do *something*
     * so it's at least a minimally functional web server on its own (and
     * can be tested that way).  But let's keep it to the bare minimum:
     */
    const char *ap_document_root;

    /* Access control */

    char *access_name;
    apr_array_header_t *sec_dir;
    apr_array_header_t *sec_url;

    /* recursion backstopper */
    int redirect_limit; /* maximum number of internal redirects */
    int subreq_limit;   /* maximum nesting level of subrequests */

    const char *protocol;
    apr_table_t *accf_map;

    /* array of ap_errorlog_format_item for error log format string */
    apr_array_header_t *error_log_format;
    /*
     * two arrays of arrays of ap_errorlog_format_item for additional information
     * logged to the error log once per connection/request
     */
    apr_array_header_t *error_log_conn;
    apr_array_header_t *error_log_req;

    /* TRACE control */
#define AP_TRACE_UNSET    -1
#define AP_TRACE_DISABLE   0
#define AP_TRACE_ENABLE    1
#define AP_TRACE_EXTENDED  2
    int trace_enable;
#define AP_MERGE_TRAILERS_UNSET    0
#define AP_MERGE_TRAILERS_ENABLE   1
#define AP_MERGE_TRAILERS_DISABLE  2
    int merge_trailers;

    apr_array_header_t *conn_log_level;

#define AP_HTTP09_UNSET   0
#define AP_HTTP09_ENABLE  1
#define AP_HTTP09_DISABLE 2
    char http09_enable;

#define AP_HTTP_CONFORMANCE_UNSET     0
#define AP_HTTP_CONFORMANCE_UNSAFE    1
#define AP_HTTP_CONFORMANCE_STRICT    2
    char http_conformance;

#define AP_HTTP_METHODS_UNSET         0
#define AP_HTTP_METHODS_LENIENT       1
#define AP_HTTP_METHODS_REGISTERED    2
    char http_methods;

#define AP_HTTP_CL_HEAD_ZERO_UNSET    0
#define AP_HTTP_CL_HEAD_ZERO_ENABLE   1
#define AP_HTTP_CL_HEAD_ZERO_DISABLE  2
    int http_cl_head_zero;

#define AP_HTTP_EXPECT_STRICT_UNSET    0
#define AP_HTTP_EXPECT_STRICT_ENABLE   1
#define AP_HTTP_EXPECT_STRICT_DISABLE  2
    int http_expect_strict;

    apr_array_header_t *protocols;
    int protocols_honor_order;
    int async_filter;
    unsigned int async_filter_set:1;
 
    apr_size_t   flush_max_threshold;
    apr_int32_t  flush_max_pipelined;
    unsigned int strict_host_check;
} core_server_config;

/* for AddOutputFiltersByType in core.c */
void ap_add_output_filters_by_type(request_rec *r);

/* for http_config.c */
void ap_core_reorder_directories(apr_pool_t *, server_rec *);

/* for mod_perl */
AP_CORE_DECLARE(void) ap_add_per_dir_conf(server_rec *s, void *dir_config);
AP_CORE_DECLARE(void) ap_add_per_url_conf(server_rec *s, void *url_config);
AP_CORE_DECLARE(void) ap_add_file_conf(apr_pool_t *p, core_dir_config *conf, void *url_config);
AP_CORE_DECLARE(const char *) ap_add_if_conf(apr_pool_t *p, core_dir_config *conf, void *url_config);
AP_CORE_DECLARE_NONSTD(const char *) ap_limit_section(cmd_parms *cmd, void *dummy, const char *arg);

/* Core filters; not exported. */
apr_status_t ap_core_input_filter(ap_filter_t *f, apr_bucket_brigade *b,
                                  ap_input_mode_t mode, apr_read_type_e block,
                                  apr_off_t readbytes);
apr_status_t ap_core_output_filter(ap_filter_t *f, apr_bucket_brigade *b);


AP_DECLARE(const char*) ap_get_server_protocol(server_rec* s);
AP_DECLARE(void) ap_set_server_protocol(server_rec* s, const char* proto);

typedef struct core_output_filter_ctx core_output_filter_ctx_t;
typedef struct core_filter_ctx        core_ctx_t;

typedef struct core_net_rec {
    apr_socket_t *client_socket;

    conn_rec *c;

    core_output_filter_ctx_t *out_ctx;
    core_ctx_t *in_ctx;
} core_net_rec;

AP_DECLARE_HOOK(apr_status_t, insert_network_bucket,
                (conn_rec *c, apr_bucket_brigade *bb, apr_socket_t *socket))

/* ----------------------------------------------------------------------
 *
 * Runtime status/management
 */

typedef enum {
    ap_mgmt_type_string,
    ap_mgmt_type_long,
    ap_mgmt_type_hash
} ap_mgmt_type_e;

typedef union {
    const char *s_value;
    long i_value;
    apr_hash_t *h_value;
} ap_mgmt_value;

typedef struct {
    const char *description;
    const char *name;
    ap_mgmt_type_e vtype;
    ap_mgmt_value v;
} ap_mgmt_item_t;

/* Handles for core filters */
AP_DECLARE_DATA extern ap_filter_rec_t *ap_subreq_core_filter_handle;
AP_DECLARE_DATA extern ap_filter_rec_t *ap_core_output_filter_handle;
AP_DECLARE_DATA extern ap_filter_rec_t *ap_content_length_filter_handle;
AP_DECLARE_DATA extern ap_filter_rec_t *ap_core_input_filter_handle;
AP_DECLARE_DATA extern ap_filter_rec_t *ap_request_core_filter_handle;

AP_DECLARE_HOOK(int, get_mgmt_items,
                (apr_pool_t *p, const char * val, apr_hash_t *ht))

/* ---------------------------------------------------------------------- */

/* ----------------------------------------------------------------------
 *
 * I/O logging with mod_logio
 */

APR_DECLARE_OPTIONAL_FN(void, ap_logio_add_bytes_out,
                        (conn_rec *c, apr_off_t bytes));

APR_DECLARE_OPTIONAL_FN(void, ap_logio_add_bytes_in,
                        (conn_rec *c, apr_off_t bytes));

APR_DECLARE_OPTIONAL_FN(apr_off_t, ap_logio_get_last_bytes, (conn_rec *c));

/* ----------------------------------------------------------------------
 *
 * Error log formats
 */

typedef struct ap_errorlog_info {
    const server_rec *s;

    const conn_rec *c;

    const request_rec *r;
    const request_rec *rmain;

    apr_pool_t *pool;

    const char *file;
    int line;

    int module_index;
    int level;

    apr_status_t status;

    int using_provider;
    int startup;

    const char *format;
} ap_errorlog_info;

#define AP_ERRORLOG_PROVIDER_GROUP "error_log_writer"
#define AP_ERRORLOG_PROVIDER_VERSION "0"
#define AP_ERRORLOG_DEFAULT_PROVIDER "file"

#define AP_ERRORLOG_PROVIDER_ADD_EOL_STR       1

typedef struct ap_errorlog_provider ap_errorlog_provider;

struct ap_errorlog_provider {
    void * (*init)(apr_pool_t *p, server_rec *s);

    apr_status_t (*writer)(const ap_errorlog_info *info, void *handle,
                           const char *errstr, apr_size_t len);

    const char * (*parse_errorlog_arg)(cmd_parms *cmd, const char *arg);

    unsigned int flags;
};

typedef int ap_errorlog_handler_fn_t(const ap_errorlog_info *info,
                                     const char *arg, char *buf, int buflen);

AP_DECLARE(void) ap_register_errorlog_handler(apr_pool_t *p, char *tag,
                                              ap_errorlog_handler_fn_t *handler,
                                              int flags);

typedef struct ap_errorlog_handler {
    ap_errorlog_handler_fn_t *func;
    int flags; /* for future extensions */
} ap_errorlog_handler;

#define AP_ERRORLOG_FLAG_FIELD_SEP       1

#define AP_ERRORLOG_FLAG_MESSAGE         2

#define AP_ERRORLOG_FLAG_REQUIRED        4

#define AP_ERRORLOG_FLAG_NULL_AS_HYPHEN  8

typedef struct {
    ap_errorlog_handler_fn_t *func;
    const char *arg;
    unsigned int flags;
    unsigned int min_loglevel;
} ap_errorlog_format_item;

AP_DECLARE_HOOK(void, error_log, (const ap_errorlog_info *info,
                                  const char *errstr))

AP_CORE_DECLARE(void) ap_register_log_hooks(apr_pool_t *p);
AP_CORE_DECLARE(void) ap_register_config_hooks(apr_pool_t *p);

/* ----------------------------------------------------------------------
 *
 * ident lookups with mod_ident
 */

APR_DECLARE_OPTIONAL_FN(const char *, ap_ident_lookup,
                        (request_rec *r));

/* ----------------------------------------------------------------------
 *
 * authorization values with mod_authz_core
 */

APR_DECLARE_OPTIONAL_FN(int, authz_some_auth_required, (request_rec *r));
APR_DECLARE_OPTIONAL_FN(const char *, authn_ap_auth_type, (request_rec *r));
APR_DECLARE_OPTIONAL_FN(const char *, authn_ap_auth_name, (request_rec *r));

/* ----------------------------------------------------------------------
 *
 * authorization values with mod_access_compat
 */

APR_DECLARE_OPTIONAL_FN(int, access_compat_ap_satisfies, (request_rec *r));

/* ---------------------------------------------------------------------- */

AP_DECLARE(int) ap_state_query(int query_code);

/*
 * possible values for query_code in ap_state_query()
 */

#define AP_SQ_MAIN_STATE        0

#define AP_SQ_RUN_MODE          1

#define AP_SQ_CONFIG_GEN        2

/*
 * return values for ap_state_query()
 */

#define AP_SQ_NOT_SUPPORTED       -1

/* values returned for AP_SQ_MAIN_STATE */
#define AP_SQ_MS_INITIAL_STARTUP   1

#define AP_SQ_MS_CREATE_PRE_CONFIG 2

#define AP_SQ_MS_DESTROY_CONFIG    3

#define AP_SQ_MS_CREATE_CONFIG     4

#define AP_SQ_MS_RUN_MPM           5

#define AP_SQ_MS_EXITING           6

/* values returned for AP_SQ_RUN_MODE */
#define AP_SQ_RM_UNKNOWN           1

#define AP_SQ_RM_NORMAL            2

#define AP_SQ_RM_CONFIG_TEST       3

#define AP_SQ_RM_CONFIG_DUMP       4


/* ---------------------------------------------------------------------- */

AP_CORE_DECLARE(conn_rec *) ap_create_slave_connection(conn_rec *c);


#define AP_CORE_DEFAULT(X, Y, Z)    (X ? X->Y : Z)

#ifdef __cplusplus
}
#endif

#endif  /* !APACHE_HTTP_CORE_H */