Commit 3cf1e534 authored by Stefan Fritsch's avatar Stefan Fritsch
Browse files

Add string valued expressions to ap_expr, do some API cleanup 

- add possibility to have expressions that evaluate to a string and not to
  a boolean value
- modify ap_expr_parse_cmd() interface to support this and make it more
  convenient to use in general
- rename AP_EXPR_FLAGS_* to AP_EXPR_FLAG_* for consistency


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1142164 13f79535-47bb-0310-9956-ffa450edef68
parent 2c552ea5

include/ap_expr.h

+64 −11
Original line number Diff line number Diff line
@@ -47,23 +47,25 @@ typedef struct { 
    const char *filename;

    /** The line number where the expression has been defined (for logging). */

    unsigned int line_number;

    /** Flags relevant for the expression, see AP_EXPR_FLAGS_* */

    /** Flags relevant for the expression, see AP_EXPR_FLAG_* */

    unsigned int flags;

    /** The module that is used for loglevel configuration (XXX put into eval_ctx?) */

    /** The module that is used for loglevel configuration */

    int module_index;

} ap_expr_info_t;



/** Use ssl_expr compatibility mode (changes the meaning of the comparison

 * operators)

 */

#define AP_EXPR_FLAGS_SSL_EXPR_COMPAT       1

#define AP_EXPR_FLAG_SSL_EXPR_COMPAT       1

/** Don't add siginificant request headers to the Vary response header */

#define AP_EXPR_FLAGS_DONT_VARY             2

#define AP_EXPR_FLAG_DONT_VARY             2

/** Don't allow functions/vars that bypass the current request's access

 *  restrictions or would otherwise leak confidential information.

 *  Used by e.g. mod_include.

 */

#define AP_EXPR_FLAGS_RESTRICTED            4

#define AP_EXPR_FLAG_RESTRICTED            4

/** Expression evaluates to a string, not to a bool */

#define AP_EXPR_FLAG_STRING_RESULT         8





/**
@@ -74,7 +76,7 @@ typedef struct { 
 * @return > 0 if expression evaluates to true, == 0 if false, < 0 on error

 * @note err will be set to NULL on success, or to an error message on error

 * @note request headers used during evaluation will be added to the Vary:

 *       response header, unless ::AP_EXPR_FLAGS_DONT_VARY is set.

 *       response header, unless ::AP_EXPR_FLAG_DONT_VARY is set.

 */

AP_DECLARE(int) ap_expr_exec(request_rec *r, const ap_expr_info_t *expr,

                             const char **err);
@@ -93,7 +95,7 @@ AP_DECLARE(int) ap_expr_exec(request_rec *r, const ap_expr_info_t *expr, 
 *       available to ap_expr_exec_re and to use ap_expr_exec_re's matches

 *       later on.

 * @note request headers used during evaluation will be added to the Vary:

 *       response header, unless ::AP_EXPR_FLAGS_DONT_VARY is set.

 *       response header, unless ::AP_EXPR_FLAG_DONT_VARY is set.

 */

AP_DECLARE(int) ap_expr_exec_re(request_rec *r, const ap_expr_info_t *expr,

                                apr_size_t nmatch, ap_regmatch_t *pmatch,
@@ -124,6 +126,8 @@ typedef struct { 
     * interested in this information.

     */

    const char **vary_this;

    /** where to store the result string */

    const char **result_string;

    /** Arbitrary context data provided by the caller for custom functions */

    void *data;

} ap_expr_eval_ctx_t;
@@ -139,6 +143,44 @@ typedef struct { 
 */

AP_DECLARE(int) ap_expr_exec_ctx(ap_expr_eval_ctx_t *ctx);



/**

 * Evaluate a parse tree of a string valued expression

 * @param r The current request

 * @param expr The expression to be evaluated

 * @param err Where an error message should be stored

 * @return The result string, NULL on error

 * @note err will be set to NULL on success, or to an error message on error

 * @note request headers used during evaluation will be added to the Vary:

 *       response header, unless ::AP_EXPR_FLAG_DONT_VARY is set.

 */

AP_DECLARE(const char *) ap_expr_str_exec(request_rec *r,

                                          const ap_expr_info_t *expr,

                                          const char **err);



/**

 * Evaluate a parse tree of a string valued expression

 * @param r The current request

 * @param expr The expression to be evaluated

 * @param nmatch size of the regex match vector pmatch

 * @param pmatch information about regex matches

 * @param source the string that pmatch applies to

 * @param err Where an error message should be stored

 * @return The result string, NULL on error

 * @note err will be set to NULL on success, or to an error message on error

 * @note nmatch/pmatch/source can be used both to make previous matches

 *       available to ap_expr_exec_re and to use ap_expr_exec_re's matches

 *       later on.

 * @note request headers used during evaluation will be added to the Vary:

 *       response header, unless ::AP_EXPR_FLAG_DONT_VARY is set.

 */

AP_DECLARE(const char *) ap_expr_str_exec_re(request_rec *r,

                                             const ap_expr_info_t *expr,

                                             apr_size_t nmatch,

                                             ap_regmatch_t *pmatch,

                                             const char **source,

                                             const char **err);





/**

 * The parser can be extended with variable lookup, functions, and

 * and operators.
@@ -274,16 +316,27 @@ AP_DECLARE(const char *) ap_expr_parse(apr_pool_t *pool, apr_pool_t *ptemp, 
 * uses info from cmd_parms to fill in most of it.

 * @param cmd The cmd_parms struct

 * @param expr The expression string to parse

 * @param flags The flags to use, see AP_EXPR_FLAG_*

 * @param err Set to NULL on success, error message on error

 * @param lookup_fn The lookup function used to lookup vars, functions, and

 *        operators

 * @param module_index The module_index to set for the expression

 * @return The parsed expression

 * @note Usually ap_expr_parse_cmd() should be used

 */

AP_DECLARE(ap_expr_info_t *) ap_expr_parse_cmd(const cmd_parms *cmd,

AP_DECLARE(ap_expr_info_t *) ap_expr_parse_cmd_mi(const cmd_parms *cmd,

                                                  const char *expr,

                                                  unsigned int flags,

                                                  const char **err,

                                               ap_expr_lookup_fn_t *lookup_fn);

                                                  ap_expr_lookup_fn_t *lookup_fn,

                                                  int module_index);



/**

 * Convenience wrapper for ap_expr_parse_cmd_mi() that sets

 * module_index = APLOG_MODULE_INDEX

 */

#define ap_expr_parse_cmd(cmd, expr, flags, err, lookup_fn) \

        ap_expr_parse_cmd_mi(cmd, expr, flags, err, lookup_fn, APLOG_MODULE_INDEX)



 /**

  * Internal initialisation of ap_expr (for httpd internal use)

include/ap_mmn.h

+5 −2
Original line number Diff line number Diff line
@@ -337,14 +337,17 @@ 
 *                         add ap_start_lingering_close(),

 *                         add conn_state_e:CONN_STATE_LINGER_NORMAL and CONN_STATE_LINGER_SHORT

 * 20110619.1 (2.3.13-dev) add ap_str_toupper()

 * 20110702.0 (2.3.13-dev) make ap_expr_parse_cmd() macro wrapper for new

 *                         ap_expr_parse_cmd_mi() function, add ap_expr_str_*() functions,

 *                         rename AP_EXPR_FLAGS_* -> AP_EXPR_FLAG_*

 */



#define MODULE_MAGIC_COOKIE 0x41503234UL /* "AP24" */



#ifndef MODULE_MAGIC_NUMBER_MAJOR

#define MODULE_MAGIC_NUMBER_MAJOR 20110619

#define MODULE_MAGIC_NUMBER_MAJOR 20110702

#endif

#define MODULE_MAGIC_NUMBER_MINOR 1                    /* 0...n */

#define MODULE_MAGIC_NUMBER_MINOR 0                    /* 0...n */



/**

 * Determine if the server's current MODULE_MAGIC_NUMBER is at least a

modules/aaa/mod_authz_core.c

+2 −2
Original line number Diff line number Diff line
@@ -1034,12 +1034,12 @@ static const char *expr_parse_config(cmd_parms *cmd, const char *require_line, 
                                     const void **parsed_require_line)

{

    const char *expr_err = NULL;

    ap_expr_info_t *expr = ap_expr_parse_cmd(cmd, require_line, &expr_err, NULL);

    ap_expr_info_t *expr = ap_expr_parse_cmd(cmd, require_line, 0, &expr_err,

                                             NULL);



    if (expr_err)

        return "Cannot parse expression in require line";



    expr->module_index = APLOG_MODULE_INDEX;

    *parsed_require_line = expr;



    return NULL;

modules/filters/mod_filter.c

+1 −4
Original line number Diff line number Diff line
@@ -427,20 +427,17 @@ static const char *filter_provider(cmd_parms *cmd, void *CFG, 
    if (!provider_frec) {

        return apr_psprintf(cmd->pool, "Unknown filter provider %s", pname);

    }

    node = ap_expr_parse_cmd(cmd, expr, &err, NULL);

    node = ap_expr_parse_cmd(cmd, expr, 0, &err, NULL);

    if (err) {

        return apr_pstrcat(cmd->pool,

                           "Error parsing FilterProvider expression:", err,

                           NULL);

    }

    node->module_index = APLOG_MODULE_INDEX;



    provider = apr_palloc(cmd->pool, sizeof(ap_filter_provider_t));

    provider->expr = node;

    provider->frec = provider_frec;

    provider->next = frec->providers;

    frec->providers = provider;



    return NULL;

}

static const char *filter_chain(cmd_parms *cmd, void *CFG, const char *arg)

modules/filters/mod_include.c

+1 −1
Original line number Diff line number Diff line
@@ -1597,7 +1597,7 @@ static int parse_ap_expr(include_ctx_t *ctx, const char *expr, int *was_error) 
    expr_info.filename = ctx->r->filename;

    expr_info.line_number = 0;

    expr_info.module_index = APLOG_MODULE_INDEX;

    expr_info.flags = AP_EXPR_FLAGS_RESTRICTED;

    expr_info.flags = AP_EXPR_FLAG_RESTRICTED;

    err = ap_expr_parse(ctx->r->pool, ctx->r->pool, &expr_info, expr,

                        include_expr_lookup);

    if (err) {