mod_autoindex.c

/* 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.
 */

/*
 * mod_autoindex.c: Handles the on-the-fly html index generation
 *
 * Rob McCool
 * 3/23/93
 *
 * Adapted to Apache by rst.
 *
 * Version sort added by Martin Pool <mbp@humbug.org.au>.
 */

#include "apr_strings.h"
#include "apr_fnmatch.h"
#include "apr_strings.h"
#include "apr_lib.h"

#define APR_WANT_STRFUNC
#include "apr_want.h"

#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_request.h"
#include "http_protocol.h"
#include "http_log.h"
#include "http_main.h"
#include "util_script.h"

#include "mod_core.h"

module AP_MODULE_DECLARE_DATA autoindex_module;

/****************************************************************
 *
 * Handling configuration directives...
 */

#define NO_OPTIONS          (1 <<  0)  /* Indexing options */
#define ICONS_ARE_LINKS     (1 <<  1)
#define SCAN_HTML_TITLES    (1 <<  2)
#define SUPPRESS_ICON       (1 <<  3)
#define SUPPRESS_LAST_MOD   (1 <<  4)
#define SUPPRESS_SIZE       (1 <<  5)
#define SUPPRESS_DESC       (1 <<  6)
#define SUPPRESS_PREAMBLE   (1 <<  7)
#define SUPPRESS_COLSORT    (1 <<  8)
#define SUPPRESS_RULES      (1 <<  9)
#define FOLDERS_FIRST       (1 << 10)
#define VERSION_SORT        (1 << 11)
#define TRACK_MODIFIED      (1 << 12)
#define FANCY_INDEXING      (1 << 13)
#define TABLE_INDEXING      (1 << 14)
#define IGNORE_CLIENT       (1 << 15)
#define IGNORE_CASE         (1 << 16)
#define EMIT_XHTML          (1 << 17)
#define SHOW_FORBIDDEN      (1 << 18)
#define ADDALTCLASS         (1 << 19)
#define OPTION_UNSET        (1 << 20)

#define K_NOADJUST 0
#define K_ADJUST 1
#define K_UNSET 2

/*
 * Define keys for sorting.
 */
#define K_NAME 'N'              /* Sort by file name (default) */
#define K_LAST_MOD 'M'          /* Last modification date */
#define K_SIZE 'S'              /* Size (absolute, not as displayed) */
#define K_DESC 'D'              /* Description */
#define K_VALID "NMSD"          /* String containing _all_ valid K_ opts */

#define D_ASCENDING 'A'
#define D_DESCENDING 'D'
#define D_VALID "AD"            /* String containing _all_ valid D_ opts */

/*
 * These are the dimensions of the default icons supplied with Apache.
 */
#define DEFAULT_ICON_WIDTH 20
#define DEFAULT_ICON_HEIGHT 22

/*
 * Other default dimensions.
 */
#define DEFAULT_NAME_WIDTH 23
#define DEFAULT_DESC_WIDTH 23

struct item {
    char *type;
    char *apply_to;
    char *apply_path;
    char *data;
};

typedef struct ai_desc_t {
    char *pattern;
    char *description;
    int full_path;
    int wildcards;
} ai_desc_t;

typedef struct autoindex_config_struct {

    char *default_icon;
    char *style_sheet;
    char *head_insert;
    char *header;
    char *readme;
    apr_int32_t opts;
    apr_int32_t incremented_opts;
    apr_int32_t decremented_opts;
    int name_width;
    int name_adjust;
    int desc_width;
    int desc_adjust;
    int icon_width;
    int icon_height;
    char default_keyid;
    char default_direction;

    apr_array_header_t *icon_list;
    apr_array_header_t *alt_list;
    apr_array_header_t *desc_list;
    apr_array_header_t *ign_list;
    int ign_noinherit;

    char *ctype;
    char *charset;
    char *datetime_format;
} autoindex_config_rec;

static char c_by_encoding, c_by_type, c_by_path;

#define BY_ENCODING &c_by_encoding
#define BY_TYPE &c_by_type
#define BY_PATH &c_by_path

static APR_INLINE int response_is_html(request_rec *r)
{
    char *ctype = ap_field_noparam(r->pool, r->content_type);

    return !ap_cstr_casecmp(ctype, "text/html")
        || !ap_cstr_casecmp(ctype, "application/xhtml+xml");
}

/*
 * This routine puts the standard HTML header at the top of the index page.
 * We include the DOCTYPE because we may be using features therefrom (i.e.,
 * HEIGHT and WIDTH attributes on the icons if we're FancyIndexing).
 */
static void emit_preamble(request_rec *r, int xhtml, const char *title)
{
    autoindex_config_rec *d;

    d = (autoindex_config_rec *) ap_get_module_config(r->per_dir_config,
                                                      &autoindex_module);

    if (xhtml) {
        ap_rvputs(r, DOCTYPE_XHTML_1_0T,
                  "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n"
                  " <head>\n  <title>Index of ", title,
                  "</title>\n", NULL);
    } else {
        ap_rvputs(r, DOCTYPE_HTML_3_2,
                  "<html>\n <head>\n"
                  "  <title>Index of ", title,
                  "</title>\n", NULL);
    }

    if (d->style_sheet != NULL) {
        ap_rvputs(r, "  <link rel=\"stylesheet\" href=\"", d->style_sheet,
                "\" type=\"text/css\"", xhtml ? " />\n" : ">\n", NULL);
    }
    if (d->head_insert != NULL) {
        ap_rputs(d->head_insert, r);
    }
    ap_rputs(" </head>\n <body>\n", r);
}

static void push_item(apr_array_header_t *arr, char *type, const char *to,
                      const char *path, const char *data)
{
    struct item *p = (struct item *) apr_array_push(arr);

    if (!to) {
        to = "";
    }
    if (!path) {
        path = "";
    }

    p->type = type;
    p->data = apr_pstrdup(arr->pool, data);
    p->apply_path = apr_pstrcat(arr->pool, path, "*", NULL);

    if ((type == BY_PATH) && (!ap_is_matchexp(to))) {
        p->apply_to = apr_pstrcat(arr->pool, "*", to, NULL);
    }
    else {
        p->apply_to = apr_pstrdup(arr->pool, to);
    }
}

static const char *add_alt(cmd_parms *cmd, void *d, const char *alt,
                           const char *to)
{
    if (cmd->info == BY_PATH) {
        if (!strcmp(to, "**DIRECTORY**")) {
            to = "^^DIRECTORY^^";
        }
    }
    if (cmd->info == BY_ENCODING) {
        char *tmp = apr_pstrdup(cmd->temp_pool, to);
        ap_str_tolower(tmp);
        to = tmp;
    }

    push_item(((autoindex_config_rec *) d)->alt_list, cmd->info, to,
              cmd->path, alt);
    return NULL;
}

static const char *add_icon(cmd_parms *cmd, void *d, const char *icon,
                            const char *to)
{
    char *iconbak = apr_pstrdup(cmd->temp_pool, icon);

    if (icon[0] == '(') {
        char *alt;
        char *cl = strchr(iconbak, ')');

        if (cl == NULL) {
            return "missing closing paren";
        }
        alt = ap_getword_nc(cmd->temp_pool, &iconbak, ',');
        *cl = '\0';                             /* Lose closing paren */
        add_alt(cmd, d, &alt[1], to);
    }
    if (cmd->info == BY_PATH) {
        if (!strcmp(to, "**DIRECTORY**")) {
            to = "^^DIRECTORY^^";
        }
    }
    if (cmd->info == BY_ENCODING) {
        char *tmp = apr_pstrdup(cmd->temp_pool, to);
        ap_str_tolower(tmp);
        to = tmp;
    }

    push_item(((autoindex_config_rec *) d)->icon_list, cmd->info, to,
              cmd->path, iconbak);
    return NULL;
}

/*
 * Add description text for a filename pattern.  If the pattern has
 * wildcards already (or we need to add them), add leading and
 * trailing wildcards to it to ensure substring processing.  If the
 * pattern contains a '/' anywhere, force wildcard matching mode,
 * add a slash to the prefix so that "bar/bletch" won't be matched
 * by "foobar/bletch", and make a note that there's a delimiter;
 * the matching routine simplifies to just the actual filename
 * whenever it can.  This allows definitions in parent directories
 * to be made for files in subordinate ones using relative paths.
 */

/*
 * Absent a strcasestr() function, we have to force wildcards on
 * systems for which "AAA" and "aaa" mean the same file.
 */
#ifdef CASE_BLIND_FILESYSTEM
#define WILDCARDS_REQUIRED 1
#else
#define WILDCARDS_REQUIRED 0
#endif

static const char *add_desc(cmd_parms *cmd, void *d, const char *desc,
                            const char *to)
{
    autoindex_config_rec *dcfg = (autoindex_config_rec *) d;
    ai_desc_t *desc_entry;
    char *prefix = "";

    desc_entry = (ai_desc_t *) apr_array_push(dcfg->desc_list);
    desc_entry->full_path = (ap_strchr_c(to, '/') == NULL) ? 0 : 1;
    desc_entry->wildcards = (WILDCARDS_REQUIRED
                             || desc_entry->full_path
                             || apr_fnmatch_test(to));
    if (desc_entry->wildcards) {
        prefix = desc_entry->full_path ? "*/" : "*";
        desc_entry->pattern = apr_pstrcat(dcfg->desc_list->pool,
                                          prefix, to, "*", NULL);
    }
    else {
        desc_entry->pattern = apr_pstrdup(dcfg->desc_list->pool, to);
    }
    desc_entry->description = apr_pstrdup(dcfg->desc_list->pool, desc);
    return NULL;
}

static const char *add_ignore(cmd_parms *cmd, void *d, const char *ext)
{
    push_item(((autoindex_config_rec *) d)->ign_list, 0, ext, cmd->path, NULL);
    return NULL;
}

static const char *add_opts(cmd_parms *cmd, void *d, int argc, char *const argv[])
{
    int i;
    char *w;
    apr_int32_t opts;
    apr_int32_t opts_add;
    apr_int32_t opts_remove;
    char action;
    autoindex_config_rec *d_cfg = (autoindex_config_rec *) d;

    opts = d_cfg->opts;
    opts_add = d_cfg->incremented_opts;
    opts_remove = d_cfg->decremented_opts;

    for (i = 0; i < argc; i++) {
        int option = 0;
        w = argv[i];

        if ((*w == '+') || (*w == '-')) {
            action = *(w++);
        }
        else {
            action = '\0';
        }
        if (!strcasecmp(w, "FancyIndexing")) {
            option = FANCY_INDEXING;
        }
        else if (!strcasecmp(w, "FoldersFirst")) {
            option = FOLDERS_FIRST;
        }
        else if (!strcasecmp(w, "HTMLTable")) {
            option = TABLE_INDEXING;
        }
        else if (!strcasecmp(w, "IconsAreLinks")) {
            option = ICONS_ARE_LINKS;
        }
        else if (!strcasecmp(w, "IgnoreCase")) {
            option = IGNORE_CASE;
        }
        else if (!strcasecmp(w, "IgnoreClient")) {
            option = IGNORE_CLIENT;
        }
        else if (!strcasecmp(w, "ScanHTMLTitles")) {
            option = SCAN_HTML_TITLES;
        }
        else if (!strcasecmp(w, "SuppressColumnSorting")) {
            option = SUPPRESS_COLSORT;
        }
        else if (!strcasecmp(w, "SuppressDescription")) {
            option = SUPPRESS_DESC;
        }
        else if (!strcasecmp(w, "SuppressHTMLPreamble")) {
            option = SUPPRESS_PREAMBLE;
        }
        else if (!strcasecmp(w, "SuppressIcon")) {
            option = SUPPRESS_ICON;
        }
        else if (!strcasecmp(w, "SuppressLastModified")) {
            option = SUPPRESS_LAST_MOD;
        }
        else if (!strcasecmp(w, "SuppressSize")) {
            option = SUPPRESS_SIZE;
        }
        else if (!strcasecmp(w, "SuppressRules")) {
            option = SUPPRESS_RULES;
        }
        else if (!strcasecmp(w, "TrackModified")) {
            option = TRACK_MODIFIED;
        }
        else if (!strcasecmp(w, "VersionSort")) {
            option = VERSION_SORT;
        }
        else if (!strcasecmp(w, "XHTML")) {
            option = EMIT_XHTML;
        }
        else if (!strcasecmp(w, "ShowForbidden")) {
            option = SHOW_FORBIDDEN;
        }
        else if (!strcasecmp(w, "AddAltClass")) {
            option = ADDALTCLASS;
        }
        else if (!strcasecmp(w, "None")) {
            if (action != '\0') {
                return "Cannot combine '+' or '-' with 'None' keyword";
            }
            opts = NO_OPTIONS;
            opts_add = 0;
            opts_remove = 0;
        }
        else if (!strcasecmp(w, "IconWidth")) {
            if (action != '-') {
                d_cfg->icon_width = DEFAULT_ICON_WIDTH;
            }
            else {
                d_cfg->icon_width = 0;
            }
        }
        else if (!strncasecmp(w, "IconWidth=", 10)) {
            if (action == '-') {
                return "Cannot combine '-' with IconWidth=n";
            }
            d_cfg->icon_width = atoi(&w[10]);
        }
        else if (!strcasecmp(w, "IconHeight")) {
            if (action != '-') {
                d_cfg->icon_height = DEFAULT_ICON_HEIGHT;
            }
            else {
                d_cfg->icon_height = 0;
            }
        }
        else if (!strncasecmp(w, "IconHeight=", 11)) {
            if (action == '-') {
                return "Cannot combine '-' with IconHeight=n";
            }
            d_cfg->icon_height = atoi(&w[11]);
        }
        else if (!strcasecmp(w, "NameWidth")) {
            if (action != '-') {
                return "NameWidth with no value may only appear as "
                       "'-NameWidth'";
            }
            d_cfg->name_width = DEFAULT_NAME_WIDTH;
            d_cfg->name_adjust = K_NOADJUST;
        }
        else if (!strncasecmp(w, "NameWidth=", 10)) {
            if (action == '-') {
                return "Cannot combine '-' with NameWidth=n";
            }
            if (w[10] == '*') {
                d_cfg->name_adjust = K_ADJUST;
            }
            else {
                int width = atoi(&w[10]);

                if (width && (width < 5)) {
                    return "NameWidth value must be greater than 5";
                }
                d_cfg->name_width = width;
                d_cfg->name_adjust = K_NOADJUST;
            }
        }
        else if (!strcasecmp(w, "DescriptionWidth")) {
            if (action != '-') {
                return "DescriptionWidth with no value may only appear as "
                       "'-DescriptionWidth'";
            }
            d_cfg->desc_width = DEFAULT_DESC_WIDTH;
            d_cfg->desc_adjust = K_NOADJUST;
        }
        else if (!strncasecmp(w, "DescriptionWidth=", 17)) {
            if (action == '-') {
                return "Cannot combine '-' with DescriptionWidth=n";
            }
            if (w[17] == '*') {
                d_cfg->desc_adjust = K_ADJUST;
            }
            else {
                int width = atoi(&w[17]);

                if (width && (width < 12)) {
                    return "DescriptionWidth value must be greater than 12";
                }
                d_cfg->desc_width = width;
                d_cfg->desc_adjust = K_NOADJUST;
            }
        }
        else if (!strncasecmp(w, "Type=", 5)) {
            d_cfg->ctype = apr_pstrdup(cmd->pool, &w[5]);
        }
        else if (!strncasecmp(w, "Charset=", 8)) {
            d_cfg->charset = apr_pstrdup(cmd->pool, &w[8]);
        }
        else if (!strcasecmp(w, "UseOldDateFormat")) {
            d_cfg->datetime_format = "%d-%b-%Y %H:%M";
        }
        else {
            return "Invalid directory indexing option";
        }
        if (action == '\0') {
            opts |= option;
            opts_add = 0;
            opts_remove = 0;
        }
        else if (action == '+') {
            opts_add |= option;
            opts_remove &= ~option;
        }
        else {
            opts_remove |= option;
            opts_add &= ~option;
        }
    }
    if ((opts & NO_OPTIONS) && (opts & ~NO_OPTIONS)) {
        return "Cannot combine other IndexOptions keywords with 'None'";
    }
    d_cfg->incremented_opts = opts_add;
    d_cfg->decremented_opts = opts_remove;
    d_cfg->opts = opts;
    return NULL;
}

static const char *set_default_order(cmd_parms *cmd, void *m,
                                     const char *direction, const char *key)
{
    autoindex_config_rec *d_cfg = (autoindex_config_rec *) m;

    if (!strcasecmp(direction, "Ascending")) {
        d_cfg->default_direction = D_ASCENDING;
    }
    else if (!strcasecmp(direction, "Descending")) {
        d_cfg->default_direction = D_DESCENDING;
    }
    else {
        return "First keyword must be 'Ascending' or 'Descending'";
    }

    if (!strcasecmp(key, "Name")) {
        d_cfg->default_keyid = K_NAME;
    }
    else if (!strcasecmp(key, "Date")) {
        d_cfg->default_keyid = K_LAST_MOD;
    }
    else if (!strcasecmp(key, "Size")) {
        d_cfg->default_keyid = K_SIZE;
    }
    else if (!strcasecmp(key, "Description")) {
        d_cfg->default_keyid = K_DESC;
    }
    else {
        return "Second keyword must be 'Name', 'Date', 'Size', or "
               "'Description'";
    }

    return NULL;
}

#define DIR_CMD_PERMS OR_INDEXES

static const command_rec autoindex_cmds[] =
{
    AP_INIT_ITERATE2("AddIcon", add_icon, BY_PATH, DIR_CMD_PERMS,
                     "an icon URL followed by one or more filenames"),
    AP_INIT_ITERATE2("AddIconByType", add_icon, BY_TYPE, DIR_CMD_PERMS,
                     "an icon URL followed by one or more MIME types"),
    AP_INIT_ITERATE2("AddIconByEncoding", add_icon, BY_ENCODING, DIR_CMD_PERMS,
                     "an icon URL followed by one or more content encodings"),
    AP_INIT_ITERATE2("AddAlt", add_alt, BY_PATH, DIR_CMD_PERMS,
                     "alternate descriptive text followed by one or more "
                     "filenames"),
    AP_INIT_ITERATE2("AddAltByType", add_alt, BY_TYPE, DIR_CMD_PERMS,
                     "alternate descriptive text followed by one or more MIME "
                     "types"),
    AP_INIT_ITERATE2("AddAltByEncoding", add_alt, BY_ENCODING, DIR_CMD_PERMS,
                     "alternate descriptive text followed by one or more "
                     "content encodings"),
    AP_INIT_TAKE_ARGV("IndexOptions", add_opts, NULL, DIR_CMD_PERMS,
                      "one or more index options [+|-][]"),
    AP_INIT_TAKE2("IndexOrderDefault", set_default_order, NULL, DIR_CMD_PERMS,
                  "{Ascending,Descending} {Name,Size,Description,Date}"),
    AP_INIT_ITERATE("IndexIgnore", add_ignore, NULL, DIR_CMD_PERMS,
                    "one or more file extensions"),
    AP_INIT_FLAG("IndexIgnoreReset", ap_set_flag_slot,
                 (void *)APR_OFFSETOF(autoindex_config_rec, ign_noinherit),
                 DIR_CMD_PERMS,
                 "Reset the inherited list of IndexIgnore filenames"),
    AP_INIT_ITERATE2("AddDescription", add_desc, BY_PATH, DIR_CMD_PERMS,
                     "Descriptive text followed by one or more filenames"),
    AP_INIT_TAKE1("HeaderName", ap_set_string_slot,
                  (void *)APR_OFFSETOF(autoindex_config_rec, header),
                  DIR_CMD_PERMS, "a filename"),
    AP_INIT_TAKE1("ReadmeName", ap_set_string_slot,
                  (void *)APR_OFFSETOF(autoindex_config_rec, readme),
                  DIR_CMD_PERMS, "a filename"),
    AP_INIT_RAW_ARGS("FancyIndexing", ap_set_deprecated, NULL, OR_ALL,
                     "The FancyIndexing directive is no longer supported. "
                     "Use IndexOptions FancyIndexing."),
    AP_INIT_TAKE1("DefaultIcon", ap_set_string_slot,
                  (void *)APR_OFFSETOF(autoindex_config_rec, default_icon),
                  DIR_CMD_PERMS, "an icon URL"),
    AP_INIT_TAKE1("IndexStyleSheet", ap_set_string_slot,
                  (void *)APR_OFFSETOF(autoindex_config_rec, style_sheet),
                  DIR_CMD_PERMS, "URL to style sheet"),
    AP_INIT_TAKE1("IndexHeadInsert", ap_set_string_slot,
                  (void *)APR_OFFSETOF(autoindex_config_rec, head_insert),
                  DIR_CMD_PERMS, "String to insert in HTML HEAD section"),
    {NULL}
};

static void *create_autoindex_config(apr_pool_t *p, char *dummy)
{
    autoindex_config_rec *new =
    (autoindex_config_rec *) apr_pcalloc(p, sizeof(autoindex_config_rec));

    new->icon_width = 0;
    new->icon_height = 0;
    new->name_width = DEFAULT_NAME_WIDTH;
    new->name_adjust = K_UNSET;
    new->desc_width = DEFAULT_DESC_WIDTH;
    new->desc_adjust = K_UNSET;
    new->icon_list = apr_array_make(p, 4, sizeof(struct item));
    new->alt_list = apr_array_make(p, 4, sizeof(struct item));
    new->desc_list = apr_array_make(p, 4, sizeof(ai_desc_t));
    new->ign_list = apr_array_make(p, 4, sizeof(struct item));
    new->opts = OPTION_UNSET;
    new->incremented_opts = 0;
    new->decremented_opts = 0;
    new->default_keyid = '\0';
    new->default_direction = '\0';

    return (void *) new;
}

static void *merge_autoindex_configs(apr_pool_t *p, void *basev, void *addv)
{
    autoindex_config_rec *new;
    autoindex_config_rec *base = (autoindex_config_rec *) basev;
    autoindex_config_rec *add = (autoindex_config_rec *) addv;

    new = (autoindex_config_rec *) apr_pcalloc(p, sizeof(autoindex_config_rec));
    new->default_icon = add->default_icon ? add->default_icon
                                          : base->default_icon;
    new->style_sheet = add->style_sheet ? add->style_sheet
                                          : base->style_sheet;
    new->head_insert = add->head_insert ? add->head_insert
                                          : base->head_insert;
    new->header = add->header ? add->header
                                : base->header;
    new->readme = add->readme ? add->readme
                                : base->readme;
    new->icon_height = add->icon_height ? add->icon_height : base->icon_height;
    new->icon_width = add->icon_width ? add->icon_width : base->icon_width;

    new->ctype = add->ctype ? add->ctype : base->ctype;
    new->charset = add->charset ? add->charset : base->charset;
    new->datetime_format = add->datetime_format ? add->datetime_format : base->datetime_format;

    new->alt_list = apr_array_append(p, add->alt_list, base->alt_list);
    new->desc_list = apr_array_append(p, add->desc_list, base->desc_list);
    new->icon_list = apr_array_append(p, add->icon_list, base->icon_list);
    new->ign_list = add->ign_noinherit ? add->ign_list : apr_array_append(p, add->ign_list, base->ign_list);
    if (add->opts == NO_OPTIONS) {
        /*
         * If the current directory explicitly says 'no options' then we also
         * clear any incremental mods from being inheritable further down.
         */
        new->opts = NO_OPTIONS;
        new->incremented_opts = 0;
        new->decremented_opts = 0;
    }
    else {
        /*
         * If there were any nonincremental options selected for
         * this directory, they dominate and we don't inherit *anything.*
         * Contrariwise, we *do* inherit if the only settings here are
         * incremental ones.
         */
        if (add->opts == OPTION_UNSET) {
            new->incremented_opts = (base->incremented_opts
                                     | add->incremented_opts)
                                    & ~add->decremented_opts;
            new->decremented_opts = (base->decremented_opts
                                     | add->decremented_opts);
            /*
             * We may have incremental settings, so make sure we don't
             * inadvertently inherit an IndexOptions None from above.
             */
            new->opts = (base->opts & ~NO_OPTIONS);
        }
        else {
            /*
             * There are local nonincremental settings, which clear
             * all inheritance from above.  They *are* the new base settings.
             */
            new->opts = add->opts;
        }
        /*
         * We're guaranteed that there'll be no overlap between
         * the add-options and the remove-options.
         */
        new->opts |= new->incremented_opts;
        new->opts &= ~new->decremented_opts;
    }
    /*
     * Inherit the NameWidth settings if there aren't any specific to
     * the new location; otherwise we'll end up using the defaults set in the
     * config-rec creation routine.
     */
    if (add->name_adjust == K_UNSET) {
        new->name_width = base->name_width;
        new->name_adjust = base->name_adjust;
    }
    else {
        new->name_width = add->name_width;
        new->name_adjust = add->name_adjust;
    }

    /*
     * Likewise for DescriptionWidth.
     */
    if (add->desc_adjust == K_UNSET) {
        new->desc_width = base->desc_width;
        new->desc_adjust = base->desc_adjust;
    }
    else {
        new->desc_width = add->desc_width;
        new->desc_adjust = add->desc_adjust;
    }

    new->default_keyid = add->default_keyid ? add->default_keyid
                                            : base->default_keyid;
    new->default_direction = add->default_direction ? add->default_direction
                                                    : base->default_direction;
    return new;
}

/****************************************************************
 *
 * Looking things up in config entries...
 */

/* Structure used to hold entries when we're actually building an index */

struct ent {
    char *name;
    char *icon;
    char *alt;
    char *desc;
    apr_off_t size;
    apr_time_t lm;
    struct ent *next;
    int ascending, ignore_case, version_sort;
    char key;
    int isdir;
};

static char *find_item(const char *content_type, const char *content_encoding,
                       char *path, apr_array_header_t *list, int path_only)
{
    struct item *items = (struct item *) list->elts;
    int i;

    for (i = 0; i < list->nelts; ++i) {
        struct item *p = &items[i];

        /* Special cased for ^^DIRECTORY^^ and ^^BLANKICON^^ */
        if ((path[0] == '^') || (!ap_strcmp_match(path, p->apply_path))) {
            if (!*(p->apply_to)) {
                return p->data;
            }
            else if (p->type == BY_PATH || path[0] == '^') {
                if (!ap_strcmp_match(path, p->apply_to)) {
                    return p->data;
                }
            }
            else if (!path_only) {
                if (!content_encoding) {
                    if (p->type == BY_TYPE) {
                        if (content_type
                            && !ap_strcasecmp_match(content_type,
                                                    p->apply_to)) {
                            return p->data;
                        }
                    }
                }
                else {
                    if (p->type == BY_ENCODING) {
                        if (!ap_strcasecmp_match(content_encoding,
                                                 p->apply_to)) {
                            return p->data;
                        }
                    }
                }
            }
        }
    }
    return NULL;
}

static char *find_item_by_request(request_rec *r, apr_array_header_t *list, int path_only)
{
    return find_item(ap_field_noparam(r->pool, r->content_type),
                     r->content_encoding, r->filename, list, path_only);
}

#define find_icon(d,p,t) find_item_by_request(p,d->icon_list,t)
#define find_alt(d,p,t) find_item_by_request(p,d->alt_list,t)
#define find_default_icon(d,n) find_item(NULL, NULL, n, d->icon_list, 1)
#define find_default_alt(d,n) find_item(NULL, NULL, n, d->alt_list, 1)

/*
 * Look through the list of pattern/description pairs and return the first one
 * if any) that matches the filename in the request.  If multiple patterns
 * match, only the first one is used; since the order in the array is the
 * same as the order in which directives were processed, earlier matching
 * directives will dominate.
 */

#ifdef CASE_BLIND_FILESYSTEM
#define MATCH_FLAGS APR_FNM_CASE_BLIND
#else
#define MATCH_FLAGS 0
#endif

static char *find_desc(autoindex_config_rec *dcfg, const char *filename_full)
{
    int i;
    ai_desc_t *list = (ai_desc_t *) dcfg->desc_list->elts;
    const char *filename_only;
    const char *filename;

    /*
     * If the filename includes a path, extract just the name itself
     * for the simple matches.
     */
    if ((filename_only = ap_strrchr_c(filename_full, '/')) == NULL) {
        filename_only = filename_full;
    }
    else {
        filename_only++;
    }
    for (i = 0; i < dcfg->desc_list->nelts; ++i) {
        ai_desc_t *tuple = &list[i];
        int found;

        /*
         * Only use the full-path filename if the pattern contains '/'s.
         */
        filename = (tuple->full_path) ? filename_full : filename_only;
        /*
         * Make the comparison using the cheapest method; only do
         * wildcard checking if we must.
         */
        if (tuple->wildcards) {
            found = (apr_fnmatch(tuple->pattern, filename, MATCH_FLAGS) == 0);
        }
        else {
            found = (ap_strstr_c(filename, tuple->pattern) != NULL);
        }
        if (found) {
            return tuple->description;
        }
    }
    return NULL;
}

static int ignore_entry(autoindex_config_rec *d, char *path)
{
    apr_array_header_t *list = d->ign_list;
    struct item *items = (struct item *) list->elts;
    char *tt;
    int i;

    if ((tt = strrchr(path, '/')) == NULL) {
        tt = path;
    }
    else {
        tt++;
    }

    for (i = 0; i < list->nelts; ++i) {
        struct item *p = &items[i];
        char *ap;

        if ((ap = strrchr(p->apply_to, '/')) == NULL) {
            ap = p->apply_to;
        }
        else {
            ap++;
        }

#ifndef CASE_BLIND_FILESYSTEM
        if (!ap_strcmp_match(path, p->apply_path)
            && !ap_strcmp_match(tt, ap)) {
            return 1;
        }
#else  /* !CASE_BLIND_FILESYSTEM */
        /*
         * On some platforms, the match must be case-blind.  This is really
         * a factor of the filesystem involved, but we can't detect that
         * reliably - so we have to granularise at the OS level.
         */
        if (!ap_strcasecmp_match(path, p->apply_path)
            && !ap_strcasecmp_match(tt, ap)) {
            return 1;
        }
#endif /* !CASE_BLIND_FILESYSTEM */
    }
    return 0;
}

/*****************************************************************
 *
 * Actually generating output
 */

/*
 * Elements of the emitted document:
 *      Preamble
 *              Emitted unless SUPPRESS_PREAMBLE is set AND ap_run_sub_req
 *              succeeds for the (content_type == text/html) header file.
 *      Header file
 *              Emitted if found (and able).
 *      H1 tag line
 *              Emitted if a header file is NOT emitted.
 *      Directory stuff
 *              Always emitted.
 *      HR
 *              Emitted if FANCY_INDEXING is set.
 *      Readme file
 *              Emitted if found (and able).
 *      ServerSig
 *              Emitted if ServerSignature is not Off AND a readme file
 *              is NOT emitted.
 *      Postamble
 *              Emitted unless SUPPRESS_PREAMBLE is set AND ap_run_sub_req
 *              succeeds for the (content_type == text/html) readme file.
 */


/*
 * emit a plain text file
 */
static void do_emit_plain(request_rec *r, apr_file_t *f)
{
    char buf[AP_IOBUFSIZE + 1];
    int ch;
    apr_size_t i, c, n;
    apr_status_t rv;

    ap_rputs("<pre>\n", r);
    while (!apr_file_eof(f)) {
        do {
            n = sizeof(char) * AP_IOBUFSIZE;
            rv = apr_file_read(f, buf, &n);
        } while (APR_STATUS_IS_EINTR(rv));
        if (n == 0 || rv != APR_SUCCESS) {
            /* ###: better error here? */
            break;
        }
        buf[n] = '\0';
        c = 0;
        while (c < n) {
            for (i = c; i < n; i++) {
                if (buf[i] == '<' || buf[i] == '>' || buf[i] == '&') {
                    break;
                }
            }
            ch = buf[i];
            buf[i] = '\0';
            ap_rputs(&buf[c], r);
            if (ch == '<') {
                ap_rputs("&lt;", r);
            }
            else if (ch == '>') {
                ap_rputs("&gt;", r);
            }
            else if (ch == '&') {
                ap_rputs("&amp;", r);
            }
            c = i + 1;
        }
    }
    ap_rputs("</pre>\n", r);
}

/*
 * Handle the preamble through the H1 tag line, inclusive.  Locate
 * the file with a subrequests.  Process text/html documents by actually
 * running the subrequest; text/xxx documents get copied verbatim,
 * and any other content type is ignored.  This means that a non-text
 * document (such as HEADER.gif) might get multiviewed as the result
 * instead of a text document, meaning nothing will be displayed, but
 * oh well.
 */
static void emit_head(request_rec *r, char *header_fname, int suppress_amble,