mod_dav.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

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 * The Apache Software License, Version 1.1
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 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/*
** DAV extension module for Apache 2.0.*
**
** This module is repository-independent. It depends on hooks provided by a
** repository implementation.
**
** APACHE ISSUES:
**   - within a DAV hierarchy, if an unknown method is used and we default
**     to Apache's implementation, it sends back an OPTIONS with the wrong
**     set of methods -- there is NO HOOK for us.
**     therefore: we need to manually handle the HTTP_METHOD_NOT_ALLOWED
**       and HTTP_NOT_IMPLEMENTED responses (not ap_send_error_response).
**   - process_mkcol_body() had to dup code from ap_setup_client_block().
**   - it would be nice to get status lines from Apache for arbitrary
**     status codes
**   - it would be nice to be able to extend Apache's set of response
**     codes so that it doesn't return 500 when an unknown code is placed
**     into r->status.
**   - http_vhost functions should apply "const" to their params
**
** DESIGN NOTES:
**   - For PROPFIND, we batch up the entire response in memory before
**     sending it. We may want to reorganize around sending the information
**     as we suck it in from the propdb. Alternatively, we should at least
**     generate a total Content-Length if we're going to buffer in memory
**     so that we can keep the connection open.
*/

#include "apr_strings.h"
#include "apr_lib.h"            /* for apr_is* */

#define APR_WANT_STRFUNC
#include "apr_want.h"

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

#include "mod_dav.h"


/* ### what is the best way to set this? */
#define DAV_DEFAULT_PROVIDER    "filesystem"

enum {
    DAV_ENABLED_UNSET = 0,
    DAV_ENABLED_OFF,
    DAV_ENABLED_ON
};

/* per-dir configuration */
typedef struct {
    const char *provider_name;
    const dav_provider *provider;
    const char *dir;
    int locktimeout;
    int allow_depthinfinity;

    apr_table_t *d_params;	/* per-directory DAV config parameters */

} dav_dir_conf;

/* per-server configuration */
typedef struct {
    int unused;

} dav_server_conf;

#define DAV_INHERIT_VALUE(parent, child, field) \
		((child)->field ? (child)->field : (parent)->field)


/* forward-declare for use in configuration lookup */
extern module DAV_DECLARE_DATA dav_module;

static void dav_init_handler(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp,
                             server_rec *s)
{
    /* DBG0("dav_init_handler"); */

    ap_add_version_component(p, "DAV/2");
}

static void *dav_create_server_config(apr_pool_t *p, server_rec *s)
{
    dav_server_conf *newconf;

    newconf = (dav_server_conf *) apr_pcalloc(p, sizeof(*newconf));

    /* ### this isn't used at the moment... */

    return newconf;
}

static void *dav_merge_server_config(apr_pool_t *p, void *base, void *overrides)
{
#if 0
    dav_server_conf *child = overrides;
#endif
    dav_server_conf *newconf;

    newconf = (dav_server_conf *) apr_pcalloc(p, sizeof(*newconf));

    /* ### nothing to merge right now... */

    return newconf;
}

static void *dav_create_dir_config(apr_pool_t *p, char *dir)
{
    /* NOTE: dir==NULL creates the default per-dir config */

    dav_dir_conf *conf;

    conf = (dav_dir_conf *) apr_pcalloc(p, sizeof(*conf));

    /* clean up the directory to remove any trailing slash */
    if (dir != NULL) {
        char *d;
        apr_size_t l;

        d = apr_pstrdup(p, dir);
        l = strlen(d);
        if (l > 1 && d[l - 1] == '/')
            d[l - 1] = '\0';
        conf->dir = d;
    }

    conf->d_params = apr_table_make(p, 1);

    return conf;
}

static void *dav_merge_dir_config(apr_pool_t *p, void *base, void *overrides)
{
    dav_dir_conf *parent = base;
    dav_dir_conf *child = overrides;
    dav_dir_conf *newconf = (dav_dir_conf *) apr_pcalloc(p, sizeof(*newconf));

    /* DBG3("dav_merge_dir_config: new=%08lx  base=%08lx  overrides=%08lx",
       (long)newconf, (long)base, (long)overrides); */

    newconf->provider_name = DAV_INHERIT_VALUE(parent, child, provider_name);
    newconf->provider = DAV_INHERIT_VALUE(parent, child, provider);
    if (parent->provider_name != NULL) {
        if (child->provider_name == NULL) {
            ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, NULL,
                         "\"DAV Off\" cannot be used to turn off a subtree "
                         "of a DAV-enabled location.");
        }
        else if (strcasecmp(child->provider_name,
                            parent->provider_name) != 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, NULL,
                         "A subtree cannot specify a different DAV provider "
                         "than its parent.");
        }
    }

    newconf->locktimeout = DAV_INHERIT_VALUE(parent, child, locktimeout);
    newconf->dir = DAV_INHERIT_VALUE(parent, child, dir);
    newconf->allow_depthinfinity = DAV_INHERIT_VALUE(parent, child,
                                                     allow_depthinfinity);

    newconf->d_params = apr_table_copy(p, parent->d_params);
    apr_table_overlap(newconf->d_params, child->d_params,
		      APR_OVERLAP_TABLES_SET);

    return newconf;
}

apr_table_t *dav_get_dir_params(const request_rec *r)
{
    dav_dir_conf *conf;

    conf = ap_get_module_config(r->per_dir_config, &dav_module);
    return conf->d_params;
}

static const dav_provider * dav_get_provider(request_rec *r)
{
    dav_dir_conf *conf;

    conf = ap_get_module_config(r->per_dir_config, &dav_module);
    /* assert: conf->provider_name != NULL
       (otherwise, DAV is disabled, and we wouldn't be here) */

    /* assert: conf->provider != NULL
       (checked when conf->provider_name is set) */
    return conf->provider;
}

const dav_hooks_locks *dav_get_lock_hooks(request_rec *r)
{
    return dav_get_provider(r)->locks;
}

const dav_hooks_propdb *dav_get_propdb_hooks(request_rec *r)
{
    return dav_get_provider(r)->propdb;
}

const dav_hooks_vsn *dav_get_vsn_hooks(request_rec *r)
{
    return dav_get_provider(r)->vsn;
}

const dav_hooks_binding *dav_get_binding_hooks(request_rec *r)
{
    return dav_get_provider(r)->binding;
}

/*
 * Command handler for the DAV directive, which is TAKE1.
 */
static const char *dav_cmd_dav(cmd_parms *cmd, void *config, const char *arg1)
{
    dav_dir_conf *conf = (dav_dir_conf *) config;

    if (strcasecmp(arg1, "on") == 0) {
	conf->provider_name = DAV_DEFAULT_PROVIDER;
    }
    else if (strcasecmp(arg1, "off") == 0) {
	conf->provider_name = NULL;
        conf->provider = NULL;
    }
    else {
        conf->provider_name = apr_pstrdup(cmd->pool, arg1);
    }

    if (conf->provider_name != NULL) {
        /* lookup and cache the actual provider now */
        conf->provider = dav_lookup_provider(conf->provider_name);

        if (conf->provider == NULL) {
            /* by the time they use it, the provider should be loaded and
               registered with us. */
            return apr_psprintf(cmd->pool,
                                "Unknown DAV provider: %s",
                                conf->provider_name);
        }
    }

    return NULL;
}

/*
 * Command handler for the DAVDepthInfinity directive, which is FLAG.
 */
static const char *dav_cmd_davdepthinfinity(cmd_parms *cmd, void *config,
                                            int arg)
{
    dav_dir_conf *conf = (dav_dir_conf *) config;

    if (arg)
	conf->allow_depthinfinity = DAV_ENABLED_ON;
    else
	conf->allow_depthinfinity = DAV_ENABLED_OFF;
    return NULL;
}

/*
 * Command handler for DAVMinTimeout directive, which is TAKE1
 */
static const char *dav_cmd_davmintimeout(cmd_parms *cmd, void *config,
                                         const char *arg1)
{
    dav_dir_conf *conf = (dav_dir_conf *) config;

    conf->locktimeout = atoi(arg1);
    if (conf->locktimeout < 0)
        return "DAVMinTimeout requires a non-negative integer.";

    return NULL;
}

/*
 * Command handler for DAVParam directive, which is TAKE2
 */
static const char *dav_cmd_davparam(cmd_parms *cmd, void *config,
                                    const char *arg1, const char *arg2)
{
    dav_dir_conf *conf = (dav_dir_conf *) config;

    apr_table_set(conf->d_params, arg1, arg2);

    return NULL;
}

/*
** dav_error_response()
**
** Send a nice response back to the user. In most cases, Apache doesn't
** allow us to provide details in the body about what happened. This
** function allows us to completely specify the response body.
**
** ### this function is not logging any errors! (e.g. the body)
*/
static int dav_error_response(request_rec *r, int status, const char *body)
{
    r->status = status;
    r->status_line = ap_get_status_line(status);
    r->content_type = "text/html";

    /* since we're returning DONE, ensure the request body is consumed. */
    (void) ap_discard_request_body(r);

    /* begin the response now... */
    ap_rvputs(r,
	      DAV_RESPONSE_BODY_1,
	      r->status_line,
	      DAV_RESPONSE_BODY_2,
	      &r->status_line[4],
	      DAV_RESPONSE_BODY_3,
	      NULL);

    ap_rputs(body, r);

    ap_rputs(ap_psignature("\n<P><HR>\n", r), r);
    ap_rputs(DAV_RESPONSE_BODY_4, r);

    /* the response has been sent. */
    /*
     * ### Use of DONE obviates logging..!
     */
    return DONE;
}

/*
** Apache's URI escaping does not replace '&' since that is a valid character
** in a URI (to form a query section). We must explicitly handle it so that
** we can embed the URI into an XML document.
*/
static const char *dav_xml_escape_uri(apr_pool_t *p, const char *uri)
{
    const char *e_uri = ap_escape_uri(p, uri);

    /* check the easy case... */
    if (ap_strchr_c(e_uri, '&') == NULL)
	return e_uri;

    /* more work needed... sigh. */

    /*
    ** Note: this is a teeny bit of overkill since we know there are no