mod_dav.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

                           apr_off_t *range_start, apr_off_t *range_end)
{
    const char *range_c;
    char *range;
    char *dash;
    char *slash;

    range_c = apr_table_get(r->headers_in, "content-range");
    if (range_c == NULL)
        return 0;

    range = apr_pstrdup(r->pool, range_c);
    if (strncasecmp(range, "bytes ", 6) != 0
        || (dash = ap_strchr(range, '-')) == NULL
        || (slash = ap_strchr(range, '/')) == NULL) {
        /* malformed header. ignore it (per S14.16 of RFC2616) */
        return 0;
    }

    *dash = *slash = '\0';

    *range_start = apr_atoi64(range + 6);
    *range_end = apr_atoi64(dash + 1);

    if (*range_end < *range_start
        || (slash[1] != '*' && apr_atoi64(slash + 1) <= *range_end)) {
        /* invalid range. ignore it (per S14.16 of RFC2616) */
        return 0;
    }

    /* we now have a valid range */
    return 1;
}

/* handle the GET method */
static int dav_method_get(request_rec *r)
{
    dav_resource *resource;
    dav_error *err;

    /* This method should only be called when the resource is not
     * visible to Apache. We will fetch the resource from the repository,
     * then create a subrequest for Apache to handle.
     */
    err = dav_get_resource(r, 1 /* label_allowed */, 0 /* use_checked_in */,
                           &resource);
    if (err != NULL)
        return dav_handle_err(r, err, NULL);

    if (!resource->exists) {
        /* Apache will supply a default error for this. */
        return HTTP_NOT_FOUND;
    }

    /* set up the HTTP headers for the response */
    if ((err = (*resource->hooks->set_headers)(r, resource)) != NULL) {
        err = dav_push_error(r->pool, err->status, 0,
                             "Unable to set up HTTP headers.",
                             err);
        return dav_handle_err(r, err, NULL);
    }

    if (r->header_only) {
        return DONE;
    }

    /* okay... time to deliver the content */
    if ((err = (*resource->hooks->deliver)(resource,
                                           r->output_filters)) != NULL) {
        err = dav_push_error(r->pool, err->status, 0,
                             "Unable to deliver content.",
                             err);
        return dav_handle_err(r, err, NULL);
    }

    return DONE;
}

/* validate resource/locks on POST, then pass to the default handler */
static int dav_method_post(request_rec *r)
{
    dav_resource *resource;
    dav_error *err;

    /* Ask repository module to resolve the resource */
    err = dav_get_resource(r, 0 /* label_allowed */, 0 /* use_checked_in */,
                           &resource);
    if (err != NULL)
        return dav_handle_err(r, err, NULL);

    /* Note: depth == 0. Implies no need for a multistatus response. */
    if ((err = dav_validate_request(r, resource, 0, NULL, NULL,
                                    DAV_VALIDATE_RESOURCE, NULL)) != NULL) {
        /* ### add a higher-level description? */
        return dav_handle_err(r, err, NULL);
    }

    return DECLINED;
}

/* handle the PUT method */
static int dav_method_put(request_rec *r)
{
    dav_resource *resource;
    int resource_state;
    dav_auto_version_info av_info;
    const dav_hooks_locks *locks_hooks = DAV_GET_HOOKS_LOCKS(r);
    const char *body;
    dav_error *err;
    dav_error *err2;
    dav_stream_mode mode;
    dav_stream *stream;
    dav_response *multi_response;
    int has_range;
    apr_off_t range_start;
    apr_off_t range_end;

    /* Ask repository module to resolve the resource */
    err = dav_get_resource(r, 0 /* label_allowed */, 0 /* use_checked_in */,
                           &resource);
    if (err != NULL)
        return dav_handle_err(r, err, NULL);

    /* If not a file or collection resource, PUT not allowed */
    if (resource->type != DAV_RESOURCE_TYPE_REGULAR
        && resource->type != DAV_RESOURCE_TYPE_WORKING) {
        body = apr_psprintf(r->pool,
                            "Cannot create resource %s with PUT.",
                            ap_escape_html(r->pool, r->uri));
        return dav_error_response(r, HTTP_CONFLICT, body);
    }

    /* Cannot PUT a collection */
    if (resource->collection) {
        return dav_error_response(r, HTTP_CONFLICT,
                                  "Cannot PUT to a collection.");

    }

    resource_state = dav_get_resource_state(r, resource);

    /*
     * Note: depth == 0 normally requires no multistatus response. However,
     * if we pass DAV_VALIDATE_PARENT, then we could get an error on a URI
     * other than the Request-URI, thereby requiring a multistatus.
     *
     * If the resource does not exist (DAV_RESOURCE_NULL), then we must
     * check the resource *and* its parent. If the resource exists or is
     * a locknull resource, then we check only the resource.
     */
    if ((err = dav_validate_request(r, resource, 0, NULL, &multi_response,
                                    resource_state == DAV_RESOURCE_NULL ?
                                    DAV_VALIDATE_PARENT :
                                    DAV_VALIDATE_RESOURCE, NULL)) != NULL) {
        /* ### add a higher-level description? */
        return dav_handle_err(r, err, multi_response);
    }

    /* make sure the resource can be modified (if versioning repository) */
    if ((err = dav_auto_checkout(r, resource,
                                 0 /* not parent_only */,
                                 &av_info)) != NULL) {
        /* ### add a higher-level description? */
        return dav_handle_err(r, err, NULL);
    }

    /* truncate and rewrite the file unless we see a Content-Range */
    mode = DAV_MODE_WRITE_TRUNC;

    has_range = dav_parse_range(r, &range_start, &range_end);
    if (has_range) {
        mode = DAV_MODE_WRITE_SEEKABLE;
    }

    /* Create the new file in the repository */
    if ((err = (*resource->hooks->open_stream)(resource, mode,
                                               &stream)) != NULL) {
        /* ### assuming FORBIDDEN is probably not quite right... */
        err = dav_push_error(r->pool, HTTP_FORBIDDEN, 0,
                             apr_psprintf(r->pool,
                                          "Unable to PUT new contents for %s.",
                                          ap_escape_html(r->pool, r->uri)),
                             err);
    }

    if (err == NULL && has_range) {
        /* a range was provided. seek to the start */
        err = (*resource->hooks->seek_stream)(stream, range_start);
    }

    if (err == NULL) {
        apr_bucket_brigade *bb;
        apr_bucket *b;
        int seen_eos = 0;

        bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);

        do {
            apr_status_t rc;

            rc = ap_get_brigade(r->input_filters, bb, AP_MODE_READBYTES,
                                APR_BLOCK_READ, DAV_READ_BLOCKSIZE);

            if (rc != APR_SUCCESS) {
                err = dav_new_error(r->pool, HTTP_INTERNAL_SERVER_ERROR, 0,
                                    "Could not get next bucket brigade");
                break;
            }

            for (b = APR_BRIGADE_FIRST(bb);
                 b != APR_BRIGADE_SENTINEL(bb);
                 b = APR_BUCKET_NEXT(b))
            {
                const char *data;
                apr_size_t len;

                if (APR_BUCKET_IS_EOS(b)) {
                    seen_eos = 1;
                    break;
                }

                if (APR_BUCKET_IS_METADATA(b)) {
                    continue;
                }

                rc = apr_bucket_read(b, &data, &len, APR_BLOCK_READ);
                if (rc != APR_SUCCESS) {
                    err = dav_new_error(r->pool, HTTP_BAD_REQUEST, 0,
                                        "An error occurred while reading "
                                        "the request body.");
                    break;
                }

                if (err == NULL) {
                    /* write whatever we read, until we see an error */
                    err = (*resource->hooks->write_stream)(stream, data, len);
                }
            }

            apr_brigade_cleanup(bb);
        } while (!seen_eos);

        apr_brigade_destroy(bb);

        err2 = (*resource->hooks->close_stream)(stream,
                                                err == NULL /* commit */);
        if (err2 != NULL && err == NULL) {
            /* no error during the write, but we hit one at close. use it. */
            err = err2;
        }
    }

    /*
     * Ensure that we think the resource exists now.
     * ### eek. if an error occurred during the write and we did not commit,
     * ### then the resource might NOT exist (e.g. dav_fs_repos.c)
     */
    if (err == NULL) {
        resource->exists = 1;
    }

    /* restore modifiability of resources back to what they were */
    err2 = dav_auto_checkin(r, resource, err != NULL /* undo if error */,
                            0 /*unlock*/, &av_info);

    /* check for errors now */
    if (err != NULL) {
        return dav_handle_err(r, err, NULL);
    }

    if (err2 != NULL) {
        /* just log a warning */
        err2 = dav_push_error(r->pool, err2->status, 0,
                              "The PUT was successful, but there "
                              "was a problem automatically checking in "
                              "the resource or its parent collection.",
                              err2);
        dav_log_err(r, err2, APLOG_WARNING);
    }

    /* ### place the Content-Type and Content-Language into the propdb */

    if (locks_hooks != NULL) {
        dav_lockdb *lockdb;

        if ((err = (*locks_hooks->open_lockdb)(r, 0, 0, &lockdb)) != NULL) {
            /* The file creation was successful, but the locking failed. */
            err = dav_push_error(r->pool, err->status, 0,
                                 "The file was PUT successfully, but there "
                                 "was a problem opening the lock database "
                                 "which prevents inheriting locks from the "
                                 "parent resources.",
                                 err);
            return dav_handle_err(r, err, NULL);
        }

        /* notify lock system that we have created/replaced a resource */
        err = dav_notify_created(r, lockdb, resource, resource_state, 0);

        (*locks_hooks->close_lockdb)(lockdb);

        if (err != NULL) {
            /* The file creation was successful, but the locking failed. */
            err = dav_push_error(r->pool, err->status, 0,
                                 "The file was PUT successfully, but there "
                                 "was a problem updating its lock "
                                 "information.",
                                 err);
            return dav_handle_err(r, err, NULL);
        }
    }

    /* NOTE: WebDAV spec, S8.7.1 states properties should be unaffected */

    /* return an appropriate response (HTTP_CREATED or HTTP_NO_CONTENT) */
    return dav_created(r, NULL, "Resource", resource_state == DAV_RESOURCE_EXISTS);
}


/* Use POOL to temporarily construct a dav_response object (from WRES
   STATUS, and PROPSTATS) and stream it via WRES's ctx->brigade. */
static void dav_stream_response(dav_walk_resource *wres,
                                int status,
                                dav_get_props_result *propstats,
                                apr_pool_t *pool)
{
    dav_response resp = { 0 };
    dav_walker_ctx *ctx = wres->walk_ctx;

    resp.href = wres->resource->uri;
    resp.status = status;
    if (propstats) {
        resp.propresult = *propstats;
    }

    dav_send_one_response(&resp, ctx->bb, ctx->r->output_filters, pool);
}


/* ### move this to dav_util? */
DAV_DECLARE(void) dav_add_response(dav_walk_resource *wres,
                                   int status, dav_get_props_result *propstats)
{
    dav_response *resp;

    /* just drop some data into an dav_response */
    resp = apr_pcalloc(wres->pool, sizeof(*resp));
    resp->href = apr_pstrdup(wres->pool, wres->resource->uri);
    resp->status = status;
    if (propstats) {
        resp->propresult = *propstats;
    }

    resp->next = wres->response;
    wres->response = resp;
}


/* handle the DELETE method */
static int dav_method_delete(request_rec *r)
{
    dav_resource *resource;
    dav_auto_version_info av_info;
    dav_error *err;
    dav_error *err2;
    dav_response *multi_response;
    int result;
    int depth;

    /* We don't use the request body right now, so torch it. */
    if ((result = ap_discard_request_body(r)) != OK) {
        return result;
    }

    /* Ask repository module to resolve the resource */
    err = dav_get_resource(r, 0 /* label_allowed */, 0 /* use_checked_in */,
                           &resource);
    if (err != NULL)
        return dav_handle_err(r, err, NULL);
    if (!resource->exists) {
        /* Apache will supply a default error for this. */
        return HTTP_NOT_FOUND;