/* 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.
*/
/*
** DAV repository-independent lock functions
*/
#include "apr.h"
#include "apr_strings.h"
#include "mod_dav.h"
#include "http_log.h"
#include "http_config.h"
#include "http_protocol.h"
#include "http_core.h"
APLOG_USE_MODULE(dav);
/* ---------------------------------------------------------------
**
** Property-related lock functions
**
*/
/*
** dav_lock_get_activelock: Returns a <lockdiscovery> containing
** an activelock element for every item in the lock_discovery tree
*/
DAV_DECLARE(
const char *) dav_lock_get_activelock(request_rec *r,
dav_lock *lock,
dav_buffer *pbuf)
{
dav_lock *lock_scan;
const dav_hooks_locks *hooks = DAV_GET_HOOKS_LOCKS(r);
int count = 0;
dav_buffer work_buf = { 0 };
apr_pool_t *p = r->pool;
/* If no locks or no lock provider, there are no locks */
if (lock == NULL || hooks == NULL) {
/*
** Since resourcediscovery is defined with (activelock)*,
** <D:activelock/> shouldn't be necessary for an empty lock.
*/
return "";
}
/*
** Note: it could be interesting to sum the lengths of the owners
** and locktokens during this loop. However, the buffer
** mechanism provides some rough padding so that we don't
** really need to have an exact size. Further, constructing
** locktoken strings could be relatively expensive.
*/
for (lock_scan = lock; lock_scan != NULL; lock_scan = lock_scan->next)
count++;
/* if a buffer was not provided, then use an internal buffer */
if (pbuf == NULL)
pbuf = &work_buf;
/* reset the length before we start appending stuff */
pbuf->cur_len = 0;
/* prep the buffer with a "good" size */
dav_check_bufsize(p, pbuf, count * 300);
for (; lock != NULL; lock = lock->next) {
char tmp[100];
#if DAV_DEBUG
if (lock->rectype == DAV_LOCKREC_INDIRECT_PARTIAL) {
/* ### crap. design error */
dav_buffer_append(p, pbuf,
"DESIGN ERROR: attempted to product an "
"activelock element from a partial, indirect "
"lock record. Creating an XML parsing error "
"to ease detection of this situation: <");
}
#endif
dav_buffer_append(p, pbuf,
"" DEBUG_CR
"");
switch (lock->type) {
case DAV_LOCKTYPE_WRITE:
dav_buffer_append(p, pbuf,
"");
break;
default:
/* ### internal error. log something? */
break;
}
dav_buffer_append(p, pbuf,
"" DEBUG_CR
"");
switch (lock->scope) {
case DAV_LOCKSCOPE_EXCLUSIVE:
dav_buffer_append(p, pbuf,
"");
break;
case DAV_LOCKSCOPE_SHARED:
dav_buffer_append(p, pbuf,
"");
break;
default:
/* ### internal error. log something? */
break;
}
dav_buffer_append(p, pbuf,
"" DEBUG_CR);
apr_snprintf(tmp,
sizeof(tmp),
"%s" DEBUG_CR,
lock->depth == DAV_INFINITY ?
"infinity" :
"0");
dav_buffer_append(p, pbuf, tmp);
if (lock->owner) {
/*
** This contains a complete, self-contained <DAV:owner> element,
** with namespace declarations and xml:lang handling. Just drop
** it in.
*/
dav_buffer_append(p, pbuf, lock->owner);
}
dav_buffer_append(p, pbuf,
"");
if (lock->timeout == DAV_TIMEOUT_INFINITE) {
dav_buffer_append(p, pbuf,
"Infinite");
}
else {
time_t now = time(NULL);
/*
** Check if the timeout is not, for any reason, already elapsed.
** (e.g., because of a large collection, or disk under heavy load...)
*/
if (now >= lock->timeout) {
dav_buffer_append(p, pbuf,
"Second-0");
}
else {
apr_snprintf(tmp,
sizeof(tmp),
"Second-%lu", (
long unsigned int)(lock->timeout - now));
dav_buffer_append(p, pbuf, tmp);
}
}
dav_buffer_append(p, pbuf,
"" DEBUG_CR
"" DEBUG_CR
"");
dav_buffer_append(p, pbuf,
(*hooks->format_locktoken)(p, lock->locktoken));
dav_buffer_append(p, pbuf,
"" DEBUG_CR
"" DEBUG_CR
"" DEBUG_CR);
}
return pbuf->buf;
}
/*
** dav_lock_parse_lockinfo: Validates the given xml_doc to contain a
** lockinfo XML element, then populates a dav_lock structure
** with its contents.
*/
DAV_DECLARE(dav_error *) dav_lock_parse_lockinfo(request_rec *r,
const dav_resource *resource,
dav_lockdb *lockdb,
const apr_xml_doc *doc,
dav_lock **lock_request)
{
apr_pool_t *p = r->pool;
dav_error *err;
apr_xml_elem *child;
dav_lock *lock;
if (!dav_validate_root(doc,
"lockinfo")) {
return dav_new_error(p, HTTP_BAD_REQUEST, 0, 0,
"The request body contains an unexpected "
"XML root element.");
}
if ((err = (*lockdb->hooks->create_lock)(lockdb, resource,
&lock)) != NULL) {
return dav_push_error(p, err->status, 0,
"Could not parse the lockinfo due to an "
"internal problem creating a lock structure.",
err);
}
lock->depth = dav_get_depth(r, DAV_INFINITY);
if (lock->depth == -1) {
return dav_new_error(p, HTTP_BAD_REQUEST, 0, 0,
"An invalid Depth header was specified.");
}
lock->timeout = dav_get_timeout(r);
/* Parse elements in the XML body */
for (child = doc->root->first_child; child; child = child->next) {
if (strcmp(child->name,
"locktype") == 0
&& child->first_child
&& lock->type == DAV_LOCKTYPE_UNKNOWN) {
if (strcmp(child->first_child->name,
"write") == 0) {
lock->type = DAV_LOCKTYPE_WRITE;
continue;
}
}
if (strcmp(child->name,
"lockscope") == 0
&& child->first_child
&& lock->scope == DAV_LOCKSCOPE_UNKNOWN) {
if (strcmp(child->first_child->name,
"exclusive") == 0)
lock->scope = DAV_LOCKSCOPE_EXCLUSIVE;
else if (strcmp(child->first_child->name,
"shared") == 0)
lock->scope = DAV_LOCKSCOPE_SHARED;
if (lock->scope != DAV_LOCKSCOPE_UNKNOWN)
continue;
}
if (strcmp(child->name,
"owner") == 0 && lock->owner == NULL) {
const char *text;
/* quote all the values in the <DAV:owner> element */
apr_xml_quote_elem(p, child);
/*
** Store a full <DAV:owner> element with namespace definitions
** and an xml:lang definition, if applicable.
*/
apr_xml_to_text(p, child, APR_XML_X2T_FULL_NS_LANG, doc->namespaces,
NULL, &text, NULL);
lock->owner = text;
continue;
}
return dav_new_error(p, HTTP_PRECONDITION_FAILED, 0, 0,
apr_psprintf(p,
"The server cannot satisfy the "
"LOCK request due to an unknown XML "
"element (\"%s\
") within the "
"DAV:lockinfo element.",
child->name));
}
*lock_request = lock;
return NULL;
}
/* ---------------------------------------------------------------
**
** General lock functions
**
*/
/* dav_lock_walker: Walker callback function to record indirect locks */
static dav_error * dav_lock_walker(dav_walk_resource *wres,
int calltype)
{
dav_walker_ctx *ctx = wres->walk_ctx;
dav_error *err;
/* We don't want to set indirects on the target */
if ((*wres->resource->hooks->is_same_resource)(wres->resource,
ctx->w.root))
return NULL;
if ((err = (*ctx->w.lockdb->hooks->append_locks)(ctx->w.lockdb,
wres->resource, 1,
ctx->lock)) != NULL) {
if (ap_is_HTTP_SERVER_ERROR(err->status)) {
/* ### add a higher-level description? */
return err;
}
/* add to the multistatus response */
dav_add_response(wres, err->status, NULL);
/*
** ### actually, this is probably wrong: we want to fail the whole
** ### LOCK process if something goes bad. maybe the caller should
** ### do a dav_unlock() (e.g. a rollback) if any errors occurred.
*/
}
return NULL;
}
/*
** dav_add_lock: Add a direct lock for resource, and indirect locks for
** all children, bounded by depth.
** ### assume request only contains one lock
*/
DAV_DECLARE(dav_error *) dav_add_lock(request_rec *r,
const dav_resource *resource,
dav_lockdb *lockdb, dav_lock *lock,
dav_response **response)
{
dav_error *err;
int depth = lock->depth;
*response = NULL;
/* Requested lock can be:
* Depth: 0 for null resource, existing resource, or existing collection
* Depth: Inf for existing collection
*/
/*
** 2518 9.2 says to ignore depth if target is not a collection (it has
** no internal children); pretend the client gave the correct depth.
*/
if (!resource->collection) {
depth = 0;
}
/* In all cases, first add direct entry in lockdb */
/*
** Append the new (direct) lock to the resource's existing locks.
**
** Note: this also handles locknull resources
*/
if ((err = (*lockdb->hooks->append_locks)(lockdb, resource, 0,
lock)) != NULL) {
/* ### maybe add a higher-level description */
return err;
}
if (depth > 0) {
/* Walk existing collection and set indirect locks */
dav_walker_ctx ctx = { { 0 } };
dav_response *multi_status;
ctx.w.walk_type = DAV_WALKTYPE_NORMAL | DAV_WALKTYPE_AUTH;
ctx.w.func = dav_lock_walker;
ctx.w.walk_ctx = &ctx;
ctx.w.pool = r->pool;
ctx.w.root = resource;
ctx.w.lockdb = lockdb;
ctx.r = r;
ctx.lock = lock;
err = (*resource->hooks->walk)(&ctx.w, DAV_INFINITY, &multi_status);
if (err != NULL) {
/* implies a 5xx status code occurred. screw the multistatus */
return err;
}
if (multi_status != NULL) {
/* manufacture a 207 error for the multistatus response */
*response = multi_status;
return dav_new_error(r->pool, HTTP_MULTI_STATUS, 0, 0,
"Error(s) occurred on resources during the "
"addition of a depth lock.");
}
}
return NULL;
}
/*
** dav_lock_query: Opens the lock database. Returns a linked list of
** dav_lock structures for all direct locks on path.
*/
DAV_DECLARE(dav_error*) dav_lock_query(dav_lockdb *lockdb,
const dav_resource *resource,
dav_lock **locks)
{
/* If no lock database, return empty result */
if (lockdb == NULL) {
*locks = NULL;
return NULL;
}
/* ### insert a higher-level description? */
return (*lockdb->hooks->get_locks)(lockdb, resource,
DAV_GETLOCKS_RESOLVED,
locks);
}
/* dav_unlock_walker: Walker callback function to remove indirect locks */
static dav_error * dav_unlock_walker(dav_walk_resource *wres,
int calltype)
{
dav_walker_ctx *ctx = wres->walk_ctx;
dav_error *err;
/* Before removing the lock, do any auto-checkin required */
if (wres->resource->working) {
/* ### get rid of this typecast */
if ((err = dav_auto_checkin(ctx->r, (dav_resource *) wres->resource,
0
/*undo*/, 1 /*unlock*/, NULL))
!= NULL) {
return err;
}
}
if ((err = (*ctx->w.lockdb->hooks->remove_lock)(ctx->w.lockdb,
wres->resource,
ctx->locktoken)) != NULL) {
/* ### should we stop or return a multistatus? looks like STOP */
/* ### add a higher-level description? */
return err;
}
return NULL;
}
/*
** dav_get_direct_resource:
**
** Find a lock on the specified resource, then return the resource the
** lock was applied to (in other words, given a (possibly) indirect lock,
** return the direct lock's corresponding resource).
**
** If the lock is an indirect lock, this usually means traversing up the
** namespace [repository] hierarchy. Note that some lock providers may be
** able to return this information with a traversal.
*/
static dav_error * dav_get_direct_resource(apr_pool_t *p,
dav_lockdb *lockdb,
const dav_locktoken *locktoken,
const dav_resource *resource,
const dav_resource **direct_resource)
{
if (lockdb->hooks->lookup_resource != NULL) {
return (*lockdb->hooks->lookup_resource)(lockdb, locktoken,
resource, direct_resource);
}
*direct_resource = NULL;
/* Find the top of this lock-
* If r->filename's direct locks include locktoken, use r->filename.
* If r->filename's indirect locks include locktoken, retry r->filename/..
* Else fail.
*/
while (resource != NULL) {
dav_error *err;
dav_lock *lock;
dav_resource *parent;
/*
** Find the lock specified by <locktoken> on <resource>. If it is
** an indirect lock, then partial results are okay. We're just
** trying to find the thing and know whether it is a direct or
** an indirect lock.
*/
if ((err = (*lockdb->hooks->find_lock)(lockdb, resource, locktoken,
1, &lock)) != NULL) {
/* ### add a higher-level desc? */
return err;
}
/* not found! that's an error. */
if (lock == NULL) {
return dav_new_error(p, HTTP_BAD_REQUEST, 0, 0,
"The specified locktoken does not correspond "
"to an existing lock on this resource.");
}
if (lock->rectype == DAV_LOCKREC_DIRECT) {
/* we found the direct lock. return this resource. */
*direct_resource = resource;
return NULL;
}
/* the lock was indirect. move up a level in the URL namespace */
if ((err = (*resource->hooks->get_parent_resource)(resource,
&parent)) != NULL) {
/* ### add a higher-level desc? */
return err;
}
resource = parent;
}
return dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0, 0,
"The lock database is corrupt. A direct lock could "
"not be found for the corresponding indirect lock "
"on this resource.");
}
/*
** dav_unlock: Removes all direct and indirect locks for r->filename,
** with given locktoken. If locktoken == null_locktoken, all locks
** are removed. If r->filename represents an indirect lock,
** we must unlock the appropriate direct lock.
** Returns OK or appropriate HTTP_* response and logs any errors.
**
** ### We've already crawled the tree to ensure everything was locked
** by us; there should be no need to incorporate a rollback.
*/
DAV_DECLARE(
int) dav_unlock(request_rec *r,
const dav_resource *resource,
const dav_locktoken *locktoken)
{
int result;
dav_lockdb *lockdb;
const dav_resource *lock_resource = resource;
const dav_hooks_locks *hooks = DAV_GET_HOOKS_LOCKS(r);
const dav_hooks_repository *repos_hooks = resource->hooks;
dav_walker_ctx ctx = { { 0 } };
dav_response *multi_status;
dav_error *err;
/* If no locks provider, then there is nothing to unlock. */
if (hooks == NULL) {
return OK;
}
/* 2518 requires the entire lock to be removed if resource/locktoken
* point to an indirect lock. We need resource of the _direct_
* lock in order to walk down the tree and remove the locks. So,
* If locktoken != null_locktoken,
* Walk up the resource hierarchy until we see a direct lock.
* Or, we could get the direct lock's db/key, pick out the URL
* and do a subrequest. I think walking up is faster and will work
* all the time.
* Else
* Just start removing all locks at and below resource.
*/
if ((err = (*hooks->open_lockdb)(r, 0, 1, &lockdb)) != NULL) {
/* ### return err! maybe add a higher-level desc */
/* ### map result to something nice; log an error */
return HTTP_INTERNAL_SERVER_ERROR;
}
if (locktoken != NULL
&& (err = dav_get_direct_resource(r->pool, lockdb,
locktoken, resource,
&lock_resource)) != NULL) {
/* ### add a higher-level desc? */
/* ### should return err! */
return err->status;
}
/* At this point, lock_resource/locktoken refers to a direct lock (key), ie
* the root of a depth > 0 lock, or locktoken is null.
*/
ctx.w.walk_type = DAV_WALKTYPE_NORMAL | DAV_WALKTYPE_LOCKNULL;
ctx.w.func = dav_unlock_walker;
ctx.w.walk_ctx = &ctx;
ctx.w.pool = r->pool;
ctx.w.root = lock_resource;
ctx.w.lockdb = lockdb;
ctx.r = r;
ctx.locktoken = locktoken;
err = (*repos_hooks->walk)(&ctx.w, DAV_INFINITY, &multi_status);
/* ### fix this! */
/* ### do something with multi_status */
result = err == NULL ? OK : err->status;
(*hooks->close_lockdb)(lockdb);
return result;
}
/* dav_inherit_walker: Walker callback function to inherit locks */
static dav_error * dav_inherit_walker(dav_walk_resource *wres,
int calltype)
{
dav_walker_ctx *ctx = wres->walk_ctx;
if (ctx->skip_root
&& (*wres->resource->hooks->is_same_resource)(wres->resource,
ctx->w.root)) {
return NULL;
}
/* ### maybe add a higher-level desc */
return (*ctx->w.lockdb->hooks->append_locks)(ctx->w.lockdb,
wres->resource, 1,
ctx->lock);
}
/*
** dav_inherit_locks: When a resource or collection is added to a collection,
** locks on the collection should be inherited to the resource/collection.
** (MOVE, MKCOL, etc) Here we propagate any direct or indirect locks from
** parent of resource to resource and below.
*/
static dav_error * dav_inherit_locks(request_rec *r, dav_lockdb *lockdb,
const dav_resource *resource,
int use_parent)
{
dav_error *err;
const dav_resource *which_resource;
dav_lock *locks;
dav_lock *scan;
dav_lock *prev;
dav_walker_ctx ctx = { { 0 } };
const dav_hooks_repository *repos_hooks = resource->hooks;
dav_response *multi_status;
if (use_parent) {
dav_resource *parent;
if ((err = (*repos_hooks->get_parent_resource)(resource,
&parent)) != NULL) {
/* ### add a higher-level desc? */
return err;
}
if (parent == NULL) {
/* ### map result to something nice; log an error */
return dav_new_error(r->pool, HTTP_INTERNAL_SERVER_ERROR, 0, 0,
"Could not fetch parent resource. Unable to "
"inherit locks from the parent and apply "
"them to this resource.");
}
which_resource = parent;
}
else {
which_resource = resource;
}
if ((err = (*lockdb->hooks->get_locks)(lockdb, which_resource,
DAV_GETLOCKS_PARTIAL,
&locks)) != NULL) {
/* ### maybe add a higher-level desc */
return err;
}
if (locks == NULL) {
/* No locks to propagate, just return */
return NULL;
}
/*
** (1) Copy all indirect locks from our parent;
** (2) Create indirect locks for the depth infinity, direct locks
** in our parent.
**
** The append_locks call in the walker callback will do the indirect
** conversion, but we need to remove any direct locks that are NOT
** depth "infinity".
*/
for (scan = locks, prev = NULL;
scan != NULL;
prev = scan, scan = scan->next) {
if (scan->rectype == DAV_LOCKREC_DIRECT
&& scan->depth != DAV_INFINITY) {
if (prev == NULL)
locks = scan->next;
else
prev->next = scan->next;
}
}
/* <locks> has all our new locks. Walk down and propagate them. */
ctx.w.walk_type = DAV_WALKTYPE_NORMAL | DAV_WALKTYPE_LOCKNULL;
ctx.w.func = dav_inherit_walker;
ctx.w.walk_ctx = &ctx;
ctx.w.pool = r->pool;
ctx.w.root = resource;
ctx.w.lockdb = lockdb;
ctx.r = r;
ctx.lock = locks;
ctx.skip_root = !use_parent;
/* ### do something with multi_status */
return (*repos_hooks->walk)(&ctx.w, DAV_INFINITY, &multi_status);
}
/* ---------------------------------------------------------------
**
** Functions dealing with lock-null resources
**
*/
/*
** dav_get_resource_state: Returns the state of the resource
** r->filename: DAV_RESOURCE_NULL, DAV_RESOURCE_LOCK_NULL,
** or DAV_RESOURCE_EXIST.
**
** Returns DAV_RESOURCE_ERROR if an error occurs.
*/
DAV_DECLARE(
int) dav_get_resource_state(request_rec *r,
const dav_resource *resource)
{
const dav_hooks_locks *hooks = DAV_GET_HOOKS_LOCKS(r);
if (resource->exists)
return DAV_RESOURCE_EXISTS;
if (hooks != NULL) {
dav_error *err;
dav_lockdb *lockdb;
int locks_present;
/*
** A locknull resource has the form:
**
** known-dir "/" locknull-file
**
** It would be nice to look into <resource> to verify this form,
** but it does not have enough information for us. Instead, we
** can look at the path_info. If the form does not match, then
** there is no way we could have a locknull resource -- it must
** be a plain, null resource.
**
** Apache sets r->filename to known-dir/unknown-file and r->path_info
** to "" for the "proper" case. If anything is in path_info, then
** it can't be a locknull resource.
**
** ### I bet this path_info hack doesn't work for repositories.
** ### Need input from repository implementors! What kind of
** ### restructure do we need? New provider APIs?
*/
if (r->path_info != NULL && *r->path_info !=
'\0') {
return DAV_RESOURCE_NULL;
}
if ((err = (*hooks->open_lockdb)(r, 1, 1, &lockdb)) == NULL) {
/* note that we might see some expired locks... *shrug* */
err = (*hooks->has_locks)(lockdb, resource, &locks_present);
(*hooks->close_lockdb)(lockdb);
}
if (err != NULL) {
/* ### don't log an error. return err. add higher-level desc. */
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00623)
"Failed to query lock-null status for %s",
r->filename);
return DAV_RESOURCE_ERROR;
}
if (locks_present)
return DAV_RESOURCE_LOCK_NULL;
}
return DAV_RESOURCE_NULL;
}
DAV_DECLARE(dav_error *) dav_notify_created(request_rec *r,
dav_lockdb *lockdb,
const dav_resource *resource,
int resource_state,
int depth)
{
dav_error *err;
if (resource_state == DAV_RESOURCE_LOCK_NULL) {
/*
** The resource is no longer a locknull resource. This will remove
** the special marker.
**
** Note that a locknull resource has already inherited all of the
** locks from the parent. We do not need to call dav_inherit_locks.
**
** NOTE: some lock providers record locks for locknull resources using
** a different key than for regular resources. this will shift
** the lock information between the two key types.
*/
(
void)(*lockdb->hooks->remove_locknull_state)(lockdb, resource);
/*
** There are resources under this one, which are new. We must
** propagate the locks down to the new resources.
*/
if (depth > 0 &&
(err = dav_inherit_locks(r, lockdb, resource, 0)) != NULL) {
/* ### add a higher level desc? */
return err;
}
}
else if (resource_state == DAV_RESOURCE_NULL) {
/* ### should pass depth to dav_inherit_locks so that it can
** ### optimize for the depth==0 case.
*/
/* this resource should inherit locks from its parent */
if ((err = dav_inherit_locks(r, lockdb, resource, 1)) != NULL) {
err = dav_push_error(r->pool, err->status, 0,
"The resource was created successfully, but "
"there was a problem inheriting locks from "
"the parent resource.",
err);
return err;
}
}
/* else the resource already exists and its locks are correct. */
return NULL;
}
