Commit 9a599ad0 authored by Stefan Fritsch's avatar Stefan Fritsch
Browse files

Add some features to ap_expr for use by mod_include: 

 * a restricted mode that does not allow to bypass request access restrictions
 * new variables DOCUMENT_URI (alias for REQUEST_URI), LAST_MODIFIED
 * -A as an alias for -U
 * an additional data entry in ap_expr_eval_ctx_t for use by the consumer
 * an extensible ap_expr_exec_ctx() API that allows to use that data entry


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1128564 13f79535-47bb-0310-9956-ffa450edef68
parent b6f6f867

CHANGES

+7 −0
Changes for CHANGES: 7 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -2,6 +2,13 @@ 


Changes with Apache 2.3.13



  *) core: Add some features to ap_expr for use by mod_include: a restricted

     mode that does not allow to bypass request access restrictions; new

     variables DOCUMENT_URI (alias for REQUEST_URI), LAST_MODIFIED; -A as an

     alias for -U; an additional data entry in ap_expr_eval_ctx_t for use by

     the consumer; an extensible ap_expr_exec_ctx() API that allows to use that

     data entry. [Stefan Fritsch]



  *) mod_include: Merge directory configs instead of one SSI* config directive

     causing all other per-directory SSI* config directives to be reset.

     [Stefan Fritsch]

docs/manual/expr.xml

+9 −0
Changes for docs/manual/expr.xml: 9 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -158,6 +158,8 @@ listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>" 
        <td>The scheme part of the request's URI</td></tr>

    <tr><td><code>REQUEST_URI</code></td>

        <td>The URI of the request</td></tr>

    <tr><td><code>DOCUMENT_URI</code></td>

        <td>Same as REQUEST_URI</td></tr>

    <tr><td><code>REQUEST_FILENAME</code></td>

        <td>The full local filesystem path to the file or script matching the

            request, if this has already been determined by the server at the
@@ -166,6 +168,11 @@ listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>" 
            <code>REQUEST_URI</code> </td></tr>

    <tr><td><code>SCRIPT_FILENAME</code></td>

        <td>Same as <code>REQUEST_FILENAME</code></td></tr>

    <tr><td><code>LAST_MODIFIED</code></td>

        <td>The date and time of last modification of the file in the format

            <code>20101231235959</code>, if this has already been determined by

            the server at the time <code>LAST_MODIFIED</code> is referenced.

            </td></tr>

    <tr><td><code>SCRIPT_USER</code></td>

        <td>The user name of the owner of the script.</td></tr>

    <tr><td><code>SCRIPT_GROUP</code></td>
@@ -374,6 +381,8 @@ listfunction ::= listfuncname "<strong>(</strong>" word "<strong>)</strong>" 
            currently-configured access controls for that path. This uses an

            internal subrequest to do the check, so use it with care - it can

            impact your server's performance!</td></tr>

    <tr><td><code>-A</code></td>

        <td>Alias for <code>-U</code></td></tr>

    <tr><td><code>-n</code></td>

        <td>True if string is not empty</td></tr>

    <tr><td><code>-z</code></td>

include/ap_expr.h

+17 −0
Changes for include/ap_expr.h: 17 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -59,6 +59,11 @@ typedef struct { 
#define AP_EXPR_FLAGS_SSL_EXPR_COMPAT       1

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

#define AP_EXPR_FLAGS_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





/**
@@ -119,8 +124,20 @@ typedef struct { 
     * interested in this information.

     */

    const char **vary_this;

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

    void *data;

} ap_expr_eval_ctx_t;



/**

 * Evaluate a parse tree, full featured version

 * @param ctx The evaluation context with all data filled in

 * @return > 0 if expression evaluates to true, == 0 if false, < 0 on error

 * @note *ctx->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 if ctx->vary_this is set.

 */

AP_DECLARE(int) ap_expr_exec_ctx(ap_expr_eval_ctx_t *ctx);



/**

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

include/ap_mmn.h

+3 −1
Changes for include/ap_mmn.h: 3 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -323,6 +323,8 @@ 
 * 20110329.3 (2.3.12-dev) Add format field to ap_errorlog_info.

 * 20110329.4 (2.3.13-dev) bgrowth and max_balancers to proxy_server_conf.

 * 20110329.5 (2.3.13-dev) Add ap_regexec_len()

 * 20110329.6 (2.3.13-dev) Add AP_EXPR_FLAGS_RESTRICTED, ap_expr_eval_ctx_t->data,

 *                         ap_expr_exec_ctx()

 */



#define MODULE_MAGIC_COOKIE 0x41503234UL /* "AP24" */
@@ -330,7 +332,7 @@ 
#ifndef MODULE_MAGIC_NUMBER_MAJOR

#define MODULE_MAGIC_NUMBER_MAJOR 20110329

#endif

#define MODULE_MAGIC_NUMBER_MINOR 5                    /* 0...n */

#define MODULE_MAGIC_NUMBER_MINOR 6                    /* 0...n */



/**

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

server/util_expr_eval.c

+107 −68
Changes for server/util_expr_eval.c: 107 added lines, 68 removed lines.
Original line number Diff line number Diff line
@@ -384,7 +384,7 @@ static ap_expr_t *ap_expr_info_make(int type, const char *name, 
    ap_expr_t *info = apr_palloc(ctx->pool, sizeof(ap_expr_t));

    ap_expr_lookup_parms parms;

    parms.type  = type;

    parms.flags = 0;

    parms.flags = ctx->flags;

    parms.pool  = ctx->pool;

    parms.ptemp = ctx->ptemp;

    parms.name  = name;
@@ -691,12 +691,47 @@ AP_DECLARE(int) ap_expr_exec(request_rec *r, const ap_expr_info_t *info, 
    return ap_expr_exec_re(r, info, 0, NULL, NULL, err);

}



AP_DECLARE(int) ap_expr_exec_ctx(ap_expr_eval_ctx_t *ctx)

{

    int rc;



    AP_DEBUG_ASSERT(ctx->p != NULL);

    /* XXX: allow r, c == NULL */

    AP_DEBUG_ASSERT(ctx->r != NULL);

    AP_DEBUG_ASSERT(ctx->c != NULL);

    AP_DEBUG_ASSERT(ctx->s != NULL);

    AP_DEBUG_ASSERT(ctx->err != NULL);

    AP_DEBUG_ASSERT(ctx->info != NULL);

    if (ctx->re_pmatch) {

        AP_DEBUG_ASSERT(ctx->re_source != NULL);

        AP_DEBUG_ASSERT(ctx->re_nmatch > 0);

    }



    *ctx->err = NULL;

    rc = ap_expr_eval(ctx, ctx->info->root_node);

    if (*ctx->err != NULL) {

        ap_log_rerror(LOG_MARK(ctx->info), APLOG_ERR, 0, ctx->r,

                      "Evaluation of expression from %s:%d failed: %s",

                      ctx->info->filename, ctx->info->line_number, *ctx->err);

        return -1;

    } else {

        rc = rc ? 1 : 0;

        ap_log_rerror(LOG_MARK(ctx->info), APLOG_TRACE4, 0, ctx->r,

                      "Evaluation of expression from %s:%d gave: %d",

                      ctx->info->filename, ctx->info->line_number, rc);



        if (ctx->vary_this)

            apr_table_merge(ctx->r->headers_out, "Vary", *ctx->vary_this);



        return rc;

    }

}



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

                                apr_size_t nmatch, ap_regmatch_t *pmatch,

                                const char **source, const char **err)

{

    ap_expr_eval_ctx_t ctx;

    int rc;

    int dont_vary = (info->flags & AP_EXPR_FLAGS_DONT_VARY);

    const char *tmp_source = NULL, *vary_this = NULL;

    ap_regmatch_t tmp_pmatch[10];
@@ -711,35 +746,15 @@ AP_DECLARE(int) ap_expr_exec_re(request_rec *r, const ap_expr_info_t *info, 
    ctx.re_pmatch = pmatch;

    ctx.re_source = source;

    ctx.vary_this = dont_vary ? NULL : &vary_this;

    ctx.data = NULL;



    if (!pmatch) {

        ctx.re_nmatch = 10;

        ctx.re_pmatch = tmp_pmatch;

        ctx.re_source = &tmp_source;

    }

    else {

        AP_DEBUG_ASSERT(source != NULL);

        AP_DEBUG_ASSERT(nmatch > 0);

    }



    *err = NULL;

    rc = ap_expr_eval(&ctx, info->root_node);

    if (*err != NULL) {

        ap_log_rerror(LOG_MARK(info), APLOG_ERR, 0, r,

                      "Evaluation of expression from %s:%d failed: %s",

                      info->filename, info->line_number, *err);

        return -1;

    } else {

        rc = rc ? 1 : 0;

        ap_log_rerror(LOG_MARK(info), APLOG_TRACE4, 0, r,

                      "Evaluation of expression from %s:%d gave: %d",

                      info->filename, info->line_number, rc);



        if (vary_this)

            apr_table_merge(r->headers_out, "Vary", vary_this);



        return rc;

    }

    return ap_expr_exec_ctx(&ctx);

}



static void add_vary(ap_expr_eval_ctx_t *ctx, const char *name)
@@ -911,12 +926,12 @@ static int op_file_min(ap_expr_eval_ctx_t *ctx, const void *data, const char *ar 
    apr_finfo_t sb;

    const char *name = (const char *)data;

    if (apr_stat(&sb, arg, APR_FINFO_MIN, ctx->p) != APR_SUCCESS)

        return 0;

        return FALSE;

    switch (name[0]) {

    case 'd':

        return (sb.filetype == APR_DIR);

    case 'e':

        return 1;

        return TRUE;

    case 'f':

        return (sb.filetype == APR_REG);

    case 's':
@@ -924,7 +939,7 @@ static int op_file_min(ap_expr_eval_ctx_t *ctx, const void *data, const char *ar 
    default:

        ap_assert(0);

    }

    return 0;

    return FALSE;

}



static int op_file_link(ap_expr_eval_ctx_t *ctx, const void *data, const char *arg)
@@ -933,10 +948,10 @@ static int op_file_link(ap_expr_eval_ctx_t *ctx, const void *data, const char *a 
#if !defined(OS2)

    if (apr_stat(&sb, arg, APR_FINFO_MIN | APR_FINFO_LINK, ctx->p) == APR_SUCCESS

        && sb.filetype == APR_LNK) {

        return 1;

        return TRUE;

    }

#endif

    return 0;

    return FALSE;

}



static int op_file_xbit(ap_expr_eval_ctx_t *ctx, const void *data, const char *arg)
@@ -944,24 +959,24 @@ static int op_file_xbit(ap_expr_eval_ctx_t *ctx, const void *data, const char *a 
    apr_finfo_t sb;

    if (apr_stat(&sb, arg, APR_FINFO_PROT| APR_FINFO_LINK, ctx->p) == APR_SUCCESS

        && (sb.protection & (APR_UEXECUTE | APR_GEXECUTE | APR_WEXECUTE))) {

        return 1;

        return TRUE;

    }

    return 0;

    return FALSE;

}



static int op_url_subr(ap_expr_eval_ctx_t *ctx, const void *data, const char *arg)

{

    int rc = 0;

    int rc = FALSE;

    request_rec  *rsub, *r = ctx->r;

    if (!r)

        return 0;

        return FALSE;

    /* avoid some infinite recursions */

    if (r->main && r->main->uri && r->uri && strcmp(r->main->uri, r->uri) == 0)

        return 0;

        return FALSE;



    rsub = ap_sub_req_lookup_uri(arg, r, NULL);

    if (rsub->status < 400) {

            rc = 1;

            rc = TRUE;

    }

    ap_log_rerror(LOG_MARK(ctx->info), APLOG_TRACE5, 0, r,

                  "Subrequest for -U %s at %s:%d gave status: %d",
@@ -973,16 +988,16 @@ static int op_url_subr(ap_expr_eval_ctx_t *ctx, const void *data, const char *ar 


static int op_file_subr(ap_expr_eval_ctx_t *ctx, const void *data, const char *arg)

{

    int rc = 0;

    int rc = FALSE;

    apr_finfo_t sb;

    request_rec *rsub, *r = ctx->r;

    if (!r)

        return 0;

        return FALSE;

    rsub = ap_sub_req_lookup_file(arg, r, NULL);

    if (rsub->status < 300 &&

        /* double-check that file exists since default result is 200 */

        apr_stat(&sb, rsub->filename, APR_FINFO_MIN, ctx->p) == APR_SUCCESS) {

        rc = 1;

        rc = TRUE;

    }

    ap_log_rerror(LOG_MARK(ctx->info), APLOG_TRACE5, 0, r,

                  "Subrequest for -F %s at %s:%d gave status: %d",
@@ -1064,6 +1079,8 @@ static const char *request_var_names[] = { 
    "REQUEST_LOG_ID",           /* 20 */

    "SCRIPT_USER",              /* 21 */

    "SCRIPT_GROUP",             /* 22 */

    "DOCUMENT_URI",             /* 23 */

    "LAST_MODIFIED",            /* 24 */

    NULL

};
@@ -1132,6 +1149,17 @@ static const char *request_var_fn(ap_expr_eval_ctx_t *ctx, const void *data) 
                apr_gid_name_get(&result, r->finfo.group, ctx->p);

            return result;

        }

    case 23:

        return r->uri;

    case 24:

        {

            apr_time_exp_t tm;

            apr_time_exp_lt(&tm, r->mtime);

            return apr_psprintf(ctx->p, "%02d%02d%02d%02d%02d%02d%02d",

                                (tm.tm_year / 100) + 19, (tm.tm_year % 100),

                                tm.tm_mon+1, tm.tm_mday, tm.tm_hour, tm.tm_min,

                                tm.tm_sec);

        }

    default:

        ap_assert(0);

        return NULL;
@@ -1326,6 +1354,7 @@ struct expr_provider_single { 
    const void *func;

    const char *name;

    ap_expr_lookup_fn_t *arg_parsing_func;

    int restricted;

};



struct expr_provider_multi {
@@ -1342,46 +1371,47 @@ static const struct expr_provider_multi var_providers[] = { 
};



static const struct expr_provider_single string_func_providers[] = {

    { osenv_func,           "osenv",          NULL },

    { env_func,             "env",            NULL },

    { req_table_func,       "resp",           NULL },

    { req_table_func,       "req",            NULL },

    { osenv_func,           "osenv",          NULL, 0 },

    { env_func,             "env",            NULL, 0 },

    { req_table_func,       "resp",           NULL, 0 },

    { req_table_func,       "req",            NULL, 0 },

    /* 'http' as alias for 'req' for compatibility with ssl_expr */

    { req_table_func,       "http",           NULL },

    { req_table_func,       "note",           NULL },

    { req_table_func,       "reqenv",         NULL },

    { tolower_func,         "tolower",        NULL },

    { toupper_func,         "toupper",        NULL },

    { escape_func,          "escape",         NULL },

    { unescape_func,        "unescape",       NULL },

    { file_func,            "file",           NULL },

    { filesize_func,        "filesize",       NULL },

    { req_table_func,       "http",           NULL, 0 },

    { req_table_func,       "note",           NULL, 0 },

    { req_table_func,       "reqenv",         NULL, 0 },

    { tolower_func,         "tolower",        NULL, 0 },

    { toupper_func,         "toupper",        NULL, 0 },

    { escape_func,          "escape",         NULL, 0 },

    { unescape_func,        "unescape",       NULL, 0 },

    { file_func,            "file",           NULL, 1 },

    { filesize_func,        "filesize",       NULL, 1 },

    { NULL, NULL, NULL}

};

/* XXX: base64 encode/decode ? */



static const struct expr_provider_single unary_op_providers[] = {

    { op_nz,        "n", NULL },

    { op_nz,        "z", NULL },

    { op_R,         "R", subnet_parse_arg },

    { op_T,         "T", NULL },

    { op_file_min,  "d", NULL },

    { op_file_min,  "e", NULL },

    { op_file_min,  "f", NULL },

    { op_file_min,  "s", NULL },

    { op_file_link, "L", NULL },

    { op_file_link, "h", NULL },

    { op_file_xbit, "x", NULL },

    { op_file_subr, "F", NULL },

    { op_url_subr,  "U", NULL },

    { op_nz,        "n", NULL,             0 },

    { op_nz,        "z", NULL,             0 },

    { op_R,         "R", subnet_parse_arg, 0 },

    { op_T,         "T", NULL,             0 },

    { op_file_min,  "d", NULL,             1 },

    { op_file_min,  "e", NULL,             1 },

    { op_file_min,  "f", NULL,             1 },

    { op_file_min,  "s", NULL,             1 },

    { op_file_link, "L", NULL,             1 },

    { op_file_link, "h", NULL,             1 },

    { op_file_xbit, "x", NULL,             1 },

    { op_file_subr, "F", NULL,             0 },

    { op_url_subr,  "U", NULL,             0 },

    { op_url_subr,  "A", NULL,             0 },

    { NULL, NULL, NULL }

};



static const struct expr_provider_single binary_op_providers[] = {

    { op_ipmatch,   "ipmatch",      subnet_parse_arg },

    { op_fnmatch,   "fnmatch",      NULL },

    { op_strmatch,  "strmatch",     NULL },

    { op_strcmatch, "strcmatch",    NULL },

    { op_ipmatch,   "ipmatch",      subnet_parse_arg, 0 },

    { op_fnmatch,   "fnmatch",      NULL,             0 },

    { op_strmatch,  "strmatch",     NULL,             0 },

    { op_strcmatch, "strcmatch",    NULL,             0 },

    { NULL, NULL, NULL }

};
@@ -1423,6 +1453,15 @@ static int core_expr_lookup(ap_expr_lookup_parms *parms) 
            }

            while (prov->func) {

                if (strcasecmp(prov->name, parms->name) == 0) {

                    if ((parms->flags & AP_EXPR_FLAGS_RESTRICTED)

                        && prov->restricted) {

                        *parms->err =

                            apr_psprintf(parms->ptemp,

                                         "%s%s not available in restricted context",

                                         (parms->type == AP_EXPR_FUNC_STRING) ? "" : "-",

                                         prov->name);

                        return !OK;

                    }

                    *parms->func = prov->func;

                    if (prov->arg_parsing_func) {

                        return prov->arg_parsing_func(parms);