Adding upstream version 2.4.38.upstream/2.4.38

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1125 insertions, 0 deletions

diff --git a/modules/dav/main/props.c b/modules/dav/main/props.c
new file mode 100644
index 0000000..f64878e
--- /dev/null
+++ b/modules/dav/main/props.c
@@ -0,0 +1,1125 @@
+/* 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 extension module for Apache 2.0.*
+**  - Property database handling (repository-independent)
+**
+** NOTES:
+**
+**   PROPERTY DATABASE
+**
+**   This version assumes that there is a per-resource database provider
+**   to record properties. The database provider decides how and where to
+**   store these databases.
+**
+**   The DBM keys for the properties have the following form:
+**
+**     namespace ":" propname
+**
+**   For example: 5:author
+**
+**   The namespace provides an integer index into the namespace table
+**   (see below). propname is simply the property name, without a namespace
+**   prefix.
+**
+**   A special case exists for properties that had a prefix starting with
+**   "xml". The XML Specification reserves these for future use. mod_dav
+**   stores and retrieves them unchanged. The keys for these properties
+**   have the form:
+**
+**     ":" propname
+**
+**   The propname will contain the prefix and the property name. For
+**   example, a key might be ":xmlfoo:name"
+**
+**   The ":name" style will also be used for properties that do not
+**   exist within a namespace.
+**
+**   The DBM values consist of two null-terminated strings, appended
+**   together (the null-terms are retained and stored in the database).
+**   The first string is the xml:lang value for the property. An empty
+**   string signifies that a lang value was not in context for the value.
+**   The second string is the property value itself.
+**
+**
+**   NAMESPACE TABLE
+**
+**   The namespace table is an array that lists each of the namespaces
+**   that are in use by the properties in the given propdb. Each entry
+**   in the array is a simple URI.
+**
+**   For example: http://www.foo.bar/standards/props/
+**
+**   The prefix used for the property is stripped and the URI for it
+**   is entered into the namespace table. Also, any namespaces used
+**   within the property value will be entered into the table (and
+**   stripped from the child elements).
+**
+**   The namespaces are stored in the DBM database under the "METADATA" key.
+**
+**
+**   STRIPPING NAMESPACES
+**
+**   Within the property values, the namespace declarations (xmlns...)
+**   are stripped. Each element and attribute will have its prefix removed
+**   and a new prefix inserted.
+**
+**   This must be done so that we can return multiple properties in a
+**   PROPFIND which may have (originally) used conflicting prefixes. For
+**   that case, we must bind all property value elements to new namespace
+**   values.
+**
+**   This implies that clients must NOT be sensitive to the namespace
+**   prefix used for their properties. It WILL change when the properties
+**   are returned (we return them as "ns<index>", e.g. "ns5"). Also, the
+**   property value can contain ONLY XML elements and CDATA. PI and comment
+**   elements will be stripped. CDATA whitespace will be preserved, but
+**   whitespace within element tags will be altered. Attribute ordering
+**   may be altered. Element and CDATA ordering will be preserved.
+**
+**
+**   ATTRIBUTES ON PROPERTY NAME ELEMENTS
+**
+**   When getting/setting properties, the XML used looks like:
+**
+**     <prop>
+**       <propname1>value</propname1>
+**       <propname2>value</propname1>
+**     </prop>
+**
+**   This implementation (mod_dav) DOES NOT save any attributes that are
+**   associated with the <propname1> element. The property value is deemed
+**   to be only the contents ("value" in the above example).
+**
+**   We do store the xml:lang value (if any) that applies to the context
+**   of the <propname1> element. Whether the xml:lang attribute is on
+**   <propname1> itself, or from a higher level element, we will store it
+**   with the property value.
+**
+**
+**   VERSIONING
+**
+**   The DBM db contains a key named "METADATA" that holds database-level
+**   information, such as the namespace table. The record also contains the
+**   db's version number as the very first 16-bit value. This first number
+**   is actually stored as two single bytes: the first byte is a "major"
+**   version number. The second byte is a "minor" number.
+**
+**   If the major number is not what mod_dav expects, then the db is closed
+**   immediately and an error is returned. A minor number change is
+**   acceptable -- it is presumed that old/new dav_props.c can deal with
+**   the database format. For example, a newer dav_props might update the
+**   minor value and append information to the end of the metadata record
+**   (which would be ignored by previous versions).
+**
+**
+** ISSUES:
+**
+**   At the moment, for the dav_get_allprops() and dav_get_props() functions,
+**   we must return a set of xmlns: declarations for ALL known namespaces
+**   in the file. There isn't a way to filter this because we don't know
+**   which are going to be used or not. Examining property names is not
+**   sufficient because the property values could use entirely different
+**   namespaces.
+**
+**   ==> we must devise a scheme where we can "garbage collect" the namespace
+**       entries from the property database.
+*/
+
+#include "apr.h"
+#include "apr_strings.h"
+
+#define APR_WANT_STDIO
+#define APR_WANT_BYTEFUNC
+#include "apr_want.h"
+
+#include "mod_dav.h"
+
+#include "http_log.h"
+#include "http_request.h"
+
+/*
+** There is some rough support for writable DAV:getcontenttype and
+** DAV:getcontentlanguage properties. If this #define is (1), then
+** this support is disabled.
+**
+** We are disabling it because of a lack of support in GET and PUT
+** operations. For GET, it would be "expensive" to look for a propdb,
+** open it, and attempt to extract the Content-Type and Content-Language
+** values for the response.
+** (Handling the PUT would not be difficult, though)
+*/
+#define DAV_DISABLE_WRITABLE_PROPS     1
+
+#define DAV_EMPTY_VALUE                "\0"    /* TWO null terms */
+
+struct dav_propdb {
+    apr_pool_t *p;                /* the pool we should use */
+    request_rec *r;               /* the request record */
+
+    const dav_resource *resource; /* the target resource */
+
+    int deferred;                 /* open of db has been deferred */
+    dav_db *db;                   /* underlying database containing props */
+
+    apr_array_header_t *ns_xlate; /* translation of an elem->ns to URI */
+    dav_namespace_map *mapping;   /* namespace mapping */
+
+    dav_lockdb *lockdb;           /* the lock database */
+
+    dav_buffer wb_lock;           /* work buffer for lockdiscovery property */
+
+    /* if we ever run a GET subreq, it will be stored here */
+    request_rec *subreq;
+
+    /* hooks we should use for processing (based on the target resource) */
+    const dav_hooks_db *db_hooks;
+};
+
+/* NOTE: dav_core_props[] and the following enum must stay in sync. */
+/* ### move these into a "core" liveprop provider? */
+static const char * const dav_core_props[] =
+{
+    "getcontenttype",
+    "getcontentlanguage",
+    "lockdiscovery",
+    "supportedlock",
+
+    NULL        /* sentinel */
+};
+enum {
+    DAV_PROPID_CORE_getcontenttype = DAV_PROPID_CORE,
+    DAV_PROPID_CORE_getcontentlanguage,
+    DAV_PROPID_CORE_lockdiscovery,
+    DAV_PROPID_CORE_supportedlock,
+
+    DAV_PROPID_CORE_UNKNOWN
+};
+
+/*
+** This structure is used to track information needed for a rollback.
+*/
+typedef struct dav_rollback_item {
+    /* select one of the two rollback context structures based on the
+       value of dav_prop_ctx.is_liveprop */
+    dav_deadprop_rollback *deadprop;
+    dav_liveprop_rollback *liveprop;
+
+} dav_rollback_item;
+
+
+static int dav_find_liveprop_provider(dav_propdb *propdb,
+                                      const char *ns_uri,
+                                      const char *propname,
+                                      const dav_hooks_liveprop **provider)
+{
+    int propid;
+
+    *provider = NULL;
+
+    if (ns_uri == NULL) {
+        /* policy: liveprop providers cannot define no-namespace properties */
+        return DAV_PROPID_CORE_UNKNOWN;
+    }
+
+    /* check liveprop providers first, so they can define core properties */
+    propid = dav_run_find_liveprop(propdb->resource, ns_uri, propname,
+                                   provider);
+    if (propid != 0) {
+        return propid;
+    }
+
+    /* check for core property */
+    if (strcmp(ns_uri, "DAV:") == 0) {
+        const char * const *p = dav_core_props;
+
+        for (propid = DAV_PROPID_CORE; *p != NULL; ++p, ++propid)
+            if (strcmp(propname, *p) == 0) {
+                return propid;
+            }
+    }
+
+    /* no provider for this property */
+    return DAV_PROPID_CORE_UNKNOWN;
+}
+
+static void dav_find_liveprop(dav_propdb *propdb, apr_xml_elem *elem)
+{
+    const char *ns_uri;
+    dav_elem_private *priv = elem->priv;
+    const dav_hooks_liveprop *hooks;
+
+
+    if (elem->ns == APR_XML_NS_NONE)
+        ns_uri = NULL;
+    else if (elem->ns == APR_XML_NS_DAV_ID)
+        ns_uri = "DAV:";
+    else
+        ns_uri = APR_XML_GET_URI_ITEM(propdb->ns_xlate, elem->ns);
+
+    priv->propid = dav_find_liveprop_provider(propdb, ns_uri, elem->name,
+                                              &hooks);
+
+    /* ### this test seems redundant... */
+    if (priv->propid != DAV_PROPID_CORE_UNKNOWN) {
+        priv->provider = hooks;
+    }
+}
+
+/* is the live property read/write? */
+static int dav_rw_liveprop(dav_propdb *propdb, dav_elem_private *priv)
+{
+    int propid = priv->propid;
+
+    /*
+    ** Check the liveprop provider (if this is a provider-defined prop)
+    */
+    if (priv->provider != NULL) {
+        return (*priv->provider->is_writable)(propdb->resource, propid);
+    }
+
+    /* these are defined as read-only */
+    if (propid == DAV_PROPID_CORE_lockdiscovery
+#if DAV_DISABLE_WRITABLE_PROPS
+        || propid == DAV_PROPID_CORE_getcontenttype
+        || propid == DAV_PROPID_CORE_getcontentlanguage
+#endif
+        || propid == DAV_PROPID_CORE_supportedlock
+        ) {
+
+        return 0;
+    }
+
+    /* these are defined as read/write */
+    if (propid == DAV_PROPID_CORE_getcontenttype
+        || propid == DAV_PROPID_CORE_getcontentlanguage
+        || propid == DAV_PROPID_CORE_UNKNOWN) {
+
+        return 1;
+    }
+
+    /*
+    ** We don't recognize the property, so it must be dead (and writable)
+    */
+    return 1;
+}
+
+/* do a sub-request to fetch properties for the target resource's URI. */
+static void dav_do_prop_subreq(dav_propdb *propdb)
+{
+    /* need to escape the uri that's in the resource struct because during
+     * the property walker it's not encoded. */
+    const char *e_uri = ap_escape_uri(propdb->resource->pool,
+                                      propdb->resource->uri);
+
+    /* perform a "GET" on the resource's URI (note that the resource
+       may not correspond to the current request!). */
+    propdb->subreq = ap_sub_req_lookup_uri(e_uri, propdb->r, NULL);
+}
+
+static dav_error * dav_insert_coreprop(dav_propdb *propdb,
+                                       int propid, const char *name,
+                                       dav_prop_insert what,
+                                       apr_text_header *phdr,
+                                       dav_prop_insert *inserted)
+{
+    const char *value = NULL;
+    dav_error *err;
+
+    *inserted = DAV_PROP_INSERT_NOTDEF;
+
+    /* fast-path the common case */
+    if (propid == DAV_PROPID_CORE_UNKNOWN)
+        return NULL;
+
+    switch (propid) {
+
+    case DAV_PROPID_CORE_lockdiscovery:
+        if (propdb->lockdb != NULL) {
+            dav_lock *locks;
+
+            if ((err = dav_lock_query(propdb->lockdb, propdb->resource,
+                                      &locks)) != NULL) {
+                return dav_push_error(propdb->p, err->status, 0,
+                                      "DAV:lockdiscovery could not be "
+                                      "determined due to a problem fetching "
+                                      "the locks for this resource.",
+                                      err);
+            }
+
+            /* fast-path the no-locks case */
+            if (locks == NULL) {
+                value = "";
+            }
+            else {
+                /*
+                ** This may modify the buffer. value may point to
+                ** wb_lock.pbuf or a string constant.
+                */
+                value = dav_lock_get_activelock(propdb->r, locks,
+                                                &propdb->wb_lock);
+
+                /* make a copy to isolate it from changes to wb_lock */
+                value = apr_pstrdup(propdb->p, propdb->wb_lock.buf);
+            }
+        }
+        break;
+
+    case DAV_PROPID_CORE_supportedlock:
+        if (propdb->lockdb != NULL) {
+            value = (*propdb->lockdb->hooks->get_supportedlock)(propdb->resource);
+        }
+        break;
+
+    case DAV_PROPID_CORE_getcontenttype:
+        if (propdb->subreq == NULL) {
+            dav_do_prop_subreq(propdb);
+        }
+        if (propdb->subreq->content_type != NULL) {
+            value = propdb->subreq->content_type;
+        }
+        break;
+
+    case DAV_PROPID_CORE_getcontentlanguage:
+    {
+        const char *lang;
+
+        if (propdb->subreq == NULL) {
+            dav_do_prop_subreq(propdb);
+        }
+        if ((lang = apr_table_get(propdb->subreq->headers_out,
+                                 "Content-Language")) != NULL) {
+            value = lang;
+        }
+        break;
+    }
+
+    default:
+        /* fall through to interpret as a dead property */
+        break;
+    }
+
+    /* if something was supplied, then insert it */
+    if (value != NULL) {
+        const char *s;
+
+        if (what == DAV_PROP_INSERT_SUPPORTED) {
+            /* use D: prefix to refer to the DAV: namespace URI,
+             * and let the namespace attribute default to "DAV:"
+             */
+            s = apr_psprintf(propdb->p,
+                            "<D:supported-live-property D:name=\"%s\"/>" DEBUG_CR,
+                            name);
+        }
+        else if (what == DAV_PROP_INSERT_VALUE && *value != '\0') {
+            /* use D: prefix to refer to the DAV: namespace URI */
+            s = apr_psprintf(propdb->p, "<D:%s>%s</D:%s>" DEBUG_CR,
+                            name, value, name);
+        }
+        else {
+            /* use D: prefix to refer to the DAV: namespace URI */
+            s = apr_psprintf(propdb->p, "<D:%s/>" DEBUG_CR, name);
+        }
+        apr_text_append(propdb->p, phdr, s);
+
+        *inserted = what;
+    }
+
+    return NULL;
+}
+
+static dav_error * dav_insert_liveprop(dav_propdb *propdb,
+                                       const apr_xml_elem *elem,
+                                       dav_prop_insert what,
+                                       apr_text_header *phdr,
+                                       dav_prop_insert *inserted)
+{
+    dav_elem_private *priv = elem->priv;
+
+    *inserted = DAV_PROP_INSERT_NOTDEF;
+
+    if (priv->provider == NULL) {
+        /* this is a "core" property that we define */
+        return dav_insert_coreprop(propdb, priv->propid, elem->name,
+                                   what, phdr, inserted);
+    }
+
+    /* ask the provider (that defined this prop) to insert the prop */
+    *inserted = (*priv->provider->insert_prop)(propdb->resource, priv->propid,
+                                               what, phdr);
+
+    return NULL;
+}
+
+static void dav_output_prop_name(apr_pool_t *pool,
+                                 const dav_prop_name *name,
+                                 dav_xmlns_info *xi,
+                                 apr_text_header *phdr)
+{
+    const char *s;
+
+    if (*name->ns == '\0')
+        s = apr_psprintf(pool, "<%s/>" DEBUG_CR, name->name);
+    else {
+        const char *prefix = dav_xmlns_add_uri(xi, name->ns);
+
+        s = apr_psprintf(pool, "<%s:%s/>" DEBUG_CR, prefix, name->name);
+    }
+
+    apr_text_append(pool, phdr, s);
+}
+
+static void dav_insert_xmlns(apr_pool_t *p, const char *pre_prefix, long ns,
+                             const char *ns_uri, apr_text_header *phdr)
+{
+    const char *s;
+
+    s = apr_psprintf(p, " xmlns:%s%ld=\"%s\"", pre_prefix, ns, ns_uri);
+    apr_text_append(p, phdr, s);
+}
+
+static dav_error *dav_really_open_db(dav_propdb *propdb, int ro)
+{
+    dav_error *err;
+
+    /* we're trying to open the db; turn off the 'deferred' flag */
+    propdb->deferred = 0;
+
+    /* ask the DB provider to open the thing */
+    err = (*propdb->db_hooks->open)(propdb->p, propdb->resource, ro,
+                                    &propdb->db);
+    if (err != NULL) {
+        return dav_push_error(propdb->p, HTTP_INTERNAL_SERVER_ERROR,
+                              DAV_ERR_PROP_OPENING,
+                              "Could not open the property database.",
+                              err);
+    }
+
+    /*
+    ** NOTE: propdb->db could be NULL if we attempted to open a readonly
+    **       database that doesn't exist. If we require read/write
+    **       access, then a database was created and opened.
+    */
+
+    return NULL;
+}
+
+DAV_DECLARE(dav_error *)dav_open_propdb(request_rec *r, dav_lockdb *lockdb,
+                                        const dav_resource *resource,
+                                        int ro,
+                                        apr_array_header_t * ns_xlate,
+                                        dav_propdb **p_propdb)
+{
+    dav_propdb *propdb = apr_pcalloc(r->pool, sizeof(*propdb));
+
+    *p_propdb = NULL;
+
+#if DAV_DEBUG
+    if (resource->uri == NULL) {
+        return dav_new_error(r->pool, HTTP_INTERNAL_SERVER_ERROR, 0, 0,
+                             "INTERNAL DESIGN ERROR: resource must define "
+                             "its URI.");
+    }
+#endif
+
+    propdb->r = r;
+    apr_pool_create(&propdb->p, r->pool);
+    propdb->resource = resource;
+    propdb->ns_xlate = ns_xlate;
+
+    propdb->db_hooks = DAV_GET_HOOKS_PROPDB(r);
+
+    propdb->lockdb = lockdb;
+
+    /* always defer actual open, to avoid expense of accessing db
+     * when only live properties are involved
+     */
+    propdb->deferred = 1;
+
+    /* ### what to do about closing the propdb on server failure? */
+
+    *p_propdb = propdb;
+    return NULL;
+}
+
+DAV_DECLARE(void) dav_close_propdb(dav_propdb *propdb)
+{
+    if (propdb->db != NULL) {
+        (*propdb->db_hooks->close)(propdb->db);
+    }
+
+    /* Currently, mod_dav's pool usage doesn't allow clearing this pool. */
+#if 0
+    apr_pool_destroy(propdb->p);
+#endif
+}
+
+DAV_DECLARE(dav_get_props_result) dav_get_allprops(dav_propdb *propdb,
+                                                   dav_prop_insert what)
+{
+    const dav_hooks_db *db_hooks = propdb->db_hooks;
+    apr_text_header hdr = { 0 };
+    apr_text_header hdr_ns = { 0 };
+    dav_get_props_result result = { 0 };
+    int found_contenttype = 0;
+    int found_contentlang = 0;
+    dav_prop_insert unused_inserted;
+
+    /* if not just getting supported live properties,
+     * scan all properties in the dead prop database
+     */
+    if (what != DAV_PROP_INSERT_SUPPORTED) {
+        if (propdb->deferred) {
+            /* ### what to do with db open error? */
+            (void) dav_really_open_db(propdb, 1 /*ro*/);
+        }
+
+        /* initialize the result with some start tags... */
+        apr_text_append(propdb->p, &hdr,
+                        "<D:propstat>" DEBUG_CR
+                        "<D:prop>" DEBUG_CR);
+
+        /* if there ARE properties, then scan them */
+        if (propdb->db != NULL) {
+            dav_xmlns_info *xi = dav_xmlns_create(propdb->p);
+            dav_prop_name name;
+            dav_error *err;
+
+            /* define (up front) any namespaces the db might need */
+            (void) (*db_hooks->define_namespaces)(propdb->db, xi);
+
+            /* get the first property name, beginning the scan */
+            err = (*db_hooks->first_name)(propdb->db, &name);
+            while (!err && name.ns) {
+
+                /*
+                ** We also look for <DAV:getcontenttype> and
+                ** <DAV:getcontentlanguage>. If they are not stored as dead
+                ** properties, then we need to perform a subrequest to get
+                ** their values (if any).
+                */
+                if (*name.ns == 'D' && strcmp(name.ns, "DAV:") == 0
+                    && *name.name == 'g') {
+                    if (strcmp(name.name, "getcontenttype") == 0) {
+                        found_contenttype = 1;
+                    }
+                    else if (strcmp(name.name, "getcontentlanguage") == 0) {
+                        found_contentlang = 1;
+                    }
+                }
+
+                if (what == DAV_PROP_INSERT_VALUE) {
+                    int found;
+
+                    if ((err = (*db_hooks->output_value)(propdb->db, &name,
+                                                         xi, &hdr,
+                                                         &found)) != NULL) {
+                        /* ### anything better to do? */
+                        /* ### probably should enter a 500 error */
+                        goto next_key;
+                    }
+                    /* assert: found == 1 */
+                }
+                else {
+                    /* the value was not requested, so just add an empty
+                       tag specifying the property name. */
+                    dav_output_prop_name(propdb->p, &name, xi, &hdr);
+                }
+
+              next_key:
+                err = (*db_hooks->next_name)(propdb->db, &name);
+            }
+
+            /* all namespaces have been entered into xi. generate them into
+               the output now. */
+            dav_xmlns_generate(xi, &hdr_ns);
+
+        } /* propdb->db != NULL */
+
+        /* add namespaces for all the liveprop providers */
+        dav_add_all_liveprop_xmlns(propdb->p, &hdr_ns);
+    }
+
+    /* ask the liveprop providers to insert their properties */
+    dav_run_insert_all_liveprops(propdb->r, propdb->resource, what, &hdr);
+
+    /* insert the standard properties */
+    /* ### should be handling the return errors here */
+    (void)dav_insert_coreprop(propdb,
+                              DAV_PROPID_CORE_supportedlock, "supportedlock",
+                              what, &hdr, &unused_inserted);
+    (void)dav_insert_coreprop(propdb,
+                              DAV_PROPID_CORE_lockdiscovery, "lockdiscovery",
+                              what, &hdr, &unused_inserted);
+
+    /* if we didn't find these, then do the whole subreq thing. */
+    if (!found_contenttype) {
+        /* ### should be handling the return error here */
+        (void)dav_insert_coreprop(propdb,
+                                  DAV_PROPID_CORE_getcontenttype,
+                                  "getcontenttype",
+                                  what, &hdr, &unused_inserted);
+    }
+    if (!found_contentlang) {
+        /* ### should be handling the return error here */
+        (void)dav_insert_coreprop(propdb,
+                                  DAV_PROPID_CORE_getcontentlanguage,
+                                  "getcontentlanguage",
+                                  what, &hdr, &unused_inserted);
+    }
+
+    /* if not just reporting on supported live props,
+     * terminate the result */
+    if (what != DAV_PROP_INSERT_SUPPORTED) {
+        apr_text_append(propdb->p, &hdr,
+                        "</D:prop>" DEBUG_CR
+                        "<D:status>HTTP/1.1 200 OK</D:status>" DEBUG_CR
+                        "</D:propstat>" DEBUG_CR);
+    }
+
+    result.propstats = hdr.first;
+    result.xmlns = hdr_ns.first;
+    return result;
+}
+
+DAV_DECLARE(dav_get_props_result) dav_get_props(dav_propdb *propdb,
+                                                apr_xml_doc *doc)
+{
+    const dav_hooks_db *db_hooks = propdb->db_hooks;
+    apr_xml_elem *elem = dav_find_child(doc->root, "prop");
+    apr_text_header hdr_good = { 0 };
+    apr_text_header hdr_bad = { 0 };
+    apr_text_header hdr_ns = { 0 };
+    int have_good = 0;
+    dav_get_props_result result = { 0 };
+    char *marks_liveprop;
+    dav_xmlns_info *xi;
+    int xi_filled = 0;
+
+    /* ### NOTE: we should pass in TWO buffers -- one for keys, one for
+       the marks */
+
+    /* we will ALWAYS provide a "good" result, even if it is EMPTY */
+    apr_text_append(propdb->p, &hdr_good,
+                   "<D:propstat>" DEBUG_CR
+                   "<D:prop>" DEBUG_CR);
+
+    /* ### the marks should be in a buffer! */
+    /* allocate zeroed-memory for the marks. These marks indicate which
+       liveprop namespaces we've generated into the output xmlns buffer */
+
+    /* same for the liveprops */
+    marks_liveprop = apr_pcalloc(propdb->p, dav_get_liveprop_ns_count() + 1);
+
+    xi = dav_xmlns_create(propdb->p);
+
+    for (elem = elem->first_child; elem; elem = elem->next) {
+        dav_elem_private *priv;
+        dav_error *err;
+        dav_prop_insert inserted;
+        dav_prop_name name;
+
+        /*
+        ** First try live property providers; if they don't handle
+        ** the property, then try looking it up in the propdb.
+        */
+
+        if (elem->priv == NULL) {
+            elem->priv = apr_pcalloc(propdb->p, sizeof(*priv));
+        }
+        priv = elem->priv;
+
+        /* cache the propid; dav_get_props() could be called many times */
+        if (priv->propid == 0)
+            dav_find_liveprop(propdb, elem);
+
+        if (priv->propid != DAV_PROPID_CORE_UNKNOWN) {
+
+            /* insert the property. returns 1 if an insertion was done. */
+            if ((err = dav_insert_liveprop(propdb, elem, DAV_PROP_INSERT_VALUE,
+                                           &hdr_good, &inserted)) != NULL) {
+                /* ### need to propagate the error to the caller... */
+                /* ### skip it for now, as if nothing was inserted */
+            }
+            if (inserted == DAV_PROP_INSERT_VALUE) {
+                have_good = 1;
+
+                /*
+                ** Add the liveprop's namespace URIs. Note that provider==NULL
+                ** for core properties.
+                */
+                if (priv->provider != NULL) {
+                    const char * const * scan_ns_uri;
+
+                    for (scan_ns_uri = priv->provider->namespace_uris;
+                         *scan_ns_uri != NULL;
+                         ++scan_ns_uri) {
+                        long ns;
+
+                        ns = dav_get_liveprop_ns_index(*scan_ns_uri);
+                        if (marks_liveprop[ns])
+                            continue;
+                        marks_liveprop[ns] = 1;
+
+                        dav_insert_xmlns(propdb->p, "lp", ns, *scan_ns_uri,
+                                         &hdr_ns);
+                    }
+                }
+
+                /* property added. move on to the next property. */
+                continue;
+            }
+            else if (inserted == DAV_PROP_INSERT_NOTDEF) {
+                /* nothing to do. fall thru to allow property to be handled
+                   as a dead property */
+            }
+#if DAV_DEBUG
+            else {
+#if 0
+                /* ### need to change signature to return an error */
+                return dav_new_error(propdb->p, HTTP_INTERNAL_SERVER_ERROR, 0,
+                                     0,
+                                     "INTERNAL DESIGN ERROR: insert_liveprop "
+                                     "did not insert what was asked for.");
+#endif
+            }
+#endif
+        }
+
+        /* The property wasn't a live property, so look in the dead property
+           database. */
+
+        /* make sure propdb is really open */
+        if (propdb->deferred) {
+            /* ### what to do with db open error? */
+            (void) dav_really_open_db(propdb, 1 /*ro*/);
+        }
+
+        if (elem->ns == APR_XML_NS_NONE)
+            name.ns = "";
+        else
+            name.ns = APR_XML_GET_URI_ITEM(propdb->ns_xlate, elem->ns);
+        name.name = elem->name;
+
+        /* only bother to look if a database exists */
+        if (propdb->db != NULL) {
+            int found;
+
+            if ((err = (*db_hooks->output_value)(propdb->db, &name,
+                                                 xi, &hdr_good,
+                                                 &found)) != NULL) {
+                /* ### what to do? continue doesn't seem right... */
+                continue;
+            }
+
+            if (found) {
+                have_good = 1;
+
+                /* if we haven't added the db's namespaces, then do so... */
+                if (!xi_filled) {
+                    (void) (*db_hooks->define_namespaces)(propdb->db, xi);
+                    xi_filled = 1;
+                }
+                continue;
+            }
+        }
+
+        /* not found as a live OR dead property. add a record to the "bad"
+           propstats */
+
+        /* make sure we've started our "bad" propstat */
+        if (hdr_bad.first == NULL) {
+            apr_text_append(propdb->p, &hdr_bad,
+                            "<D:propstat>" DEBUG_CR
+                            "<D:prop>" DEBUG_CR);
+        }
+
+        /* output this property's name (into the bad propstats) */
+        dav_output_prop_name(propdb->p, &name, xi, &hdr_bad);
+    }
+
+    apr_text_append(propdb->p, &hdr_good,
+                    "</D:prop>" DEBUG_CR
+                    "<D:status>HTTP/1.1 200 OK</D:status>" DEBUG_CR
+                    "</D:propstat>" DEBUG_CR);
+
+    /* default to start with the good */
+    result.propstats = hdr_good.first;
+
+    /* we may not have any "bad" results */
+    if (hdr_bad.first != NULL) {
+        /* "close" the bad propstat */
+        apr_text_append(propdb->p, &hdr_bad,
+                        "</D:prop>" DEBUG_CR
+                        "<D:status>HTTP/1.1 404 Not Found</D:status>" DEBUG_CR
+                        "</D:propstat>" DEBUG_CR);
+
+        /* if there are no good props, then just return the bad */
+        if (!have_good) {
+            result.propstats = hdr_bad.first;
+        }
+        else {
+            /* hook the bad propstat to the end of the good one */
+            hdr_good.last->next = hdr_bad.first;
+        }
+    }
+
+    /* add in all the various namespaces, and return them */
+    dav_xmlns_generate(xi, &hdr_ns);
+    result.xmlns = hdr_ns.first;
+
+    return result;
+}
+
+DAV_DECLARE(void) dav_get_liveprop_supported(dav_propdb *propdb,
+                                             const char *ns_uri,
+                                             const char *propname,
+                                             apr_text_header *body)
+{
+    int propid;
+    const dav_hooks_liveprop *hooks;
+
+    propid = dav_find_liveprop_provider(propdb, ns_uri, propname, &hooks);
+
+    if (propid != DAV_PROPID_CORE_UNKNOWN) {
+        if (hooks == NULL) {
+            /* this is a "core" property that we define */
+            dav_prop_insert unused_inserted;
+            dav_insert_coreprop(propdb, propid, propname,
+                                DAV_PROP_INSERT_SUPPORTED, body, &unused_inserted);
+        }
+        else {
+            (*hooks->insert_prop)(propdb->resource, propid,
+                                  DAV_PROP_INSERT_SUPPORTED, body);
+        }
+    }
+}
+
+DAV_DECLARE_NONSTD(void) dav_prop_validate(dav_prop_ctx *ctx)
+{
+    dav_propdb *propdb = ctx->propdb;
+    apr_xml_elem *prop = ctx->prop;
+    dav_elem_private *priv;
+
+    priv = ctx->prop->priv = apr_pcalloc(propdb->p, sizeof(*priv));
+
+    /*
+    ** Check to see if this is a live property, and fill the fields
+    ** in the XML elem, as appropriate.
+    **
+    ** Verify that the property is read/write. If not, then it cannot
+    ** be SET or DELETEd.
+    */
+    if (priv->propid == 0) {
+        dav_find_liveprop(propdb, prop);
+
+        /* it's a liveprop if a provider was found */
+        /* ### actually the "core" props should really be liveprops, but
+           ### there is no "provider" for those and the r/w props are
+           ### treated as dead props anyhow */
+        ctx->is_liveprop = priv->provider != NULL;
+    }
+
+    if (!dav_rw_liveprop(propdb, priv)) {
+        ctx->err = dav_new_error(propdb->p, HTTP_CONFLICT,
+                                 DAV_ERR_PROP_READONLY, 0,
+                                 "Property is read-only.");
+        return;
+    }
+
+    if (ctx->is_liveprop) {
+        int defer_to_dead = 0;
+
+        ctx->err = (*priv->provider->patch_validate)(propdb->resource,
+                                                     prop, ctx->operation,
+                                                     &ctx->liveprop_ctx,
+                                                     &defer_to_dead);
+        if (ctx->err != NULL || !defer_to_dead)
+            return;
+
+        /* clear is_liveprop -- act as a dead prop now */
+        ctx->is_liveprop = 0;
+    }
+
+    /*
+    ** The property is supposed to be stored into the dead-property
+    ** database. Make sure the thing is truly open (and writable).
+    */
+    if (propdb->deferred
+        && (ctx->err = dav_really_open_db(propdb, 0 /* ro */)) != NULL) {
+        return;
+    }
+
+    /*
+    ** There should be an open, writable database in here!
+    **
+    ** Note: the database would be NULL if it was opened readonly and it
+    **       did not exist.
+    */
+    if (propdb->db == NULL) {
+        ctx->err = dav_new_error(propdb->p, HTTP_INTERNAL_SERVER_ERROR,
+                                 DAV_ERR_PROP_NO_DATABASE, 0,
+                                 "Attempted to set/remove a property "
+                                 "without a valid, open, read/write "
+                                 "property database.");
+        return;
+    }
+
+    if (ctx->operation == DAV_PROP_OP_SET) {
+        /*
+        ** Prep the element => propdb namespace index mapping, inserting
+        ** namespace URIs into the propdb that don't exist.
+        */
+        (void) (*propdb->db_hooks->map_namespaces)(propdb->db,
+                                                   propdb->ns_xlate,
+                                                   &propdb->mapping);
+    }
+    else if (ctx->operation == DAV_PROP_OP_DELETE) {
+        /*
+        ** There are no checks to perform here. If a property exists, then
+        ** we will delete it. If it does not exist, then it does not matter
+        ** (see S12.13.1).
+        **
+        ** Note that if a property does not exist, that does not rule out
+        ** that a SET will occur during this PROPPATCH (thusly creating it).
+        */
+    }
+}
+
+DAV_DECLARE_NONSTD(void) dav_prop_exec(dav_prop_ctx *ctx)
+{
+    dav_propdb *propdb = ctx->propdb;
+    dav_error *err = NULL;
+    dav_elem_private *priv = ctx->prop->priv;
+
+    ctx->rollback = apr_pcalloc(propdb->p, sizeof(*ctx->rollback));
+
+    if (ctx->is_liveprop) {
+        err = (*priv->provider->patch_exec)(propdb->resource,
+                                            ctx->prop, ctx->operation,
+                                            ctx->liveprop_ctx,
+                                            &ctx->rollback->liveprop);
+    }
+    else {
+        dav_prop_name name;
+
+        if (ctx->prop->ns == APR_XML_NS_NONE)
+            name.ns = "";
+        else
+            name.ns = APR_XML_GET_URI_ITEM(propdb->ns_xlate, ctx->prop->ns);
+        name.name = ctx->prop->name;
+
+        /* save the old value so that we can do a rollback. */
+        if ((err = (*propdb->db_hooks
+                    ->get_rollback)(propdb->db, &name,
+                                    &ctx->rollback->deadprop)) != NULL)
+            goto error;
+
+        if (ctx->operation == DAV_PROP_OP_SET) {
+
+            /* Note: propdb->mapping was set in dav_prop_validate() */
+            err = (*propdb->db_hooks->store)(propdb->db, &name, ctx->prop,
+                                             propdb->mapping);
+
+            /*
+            ** If an error occurred, then assume that we didn't change the
+            ** value. Remove the rollback item so that we don't try to set
+            ** its value during the rollback.
+            */
+            /* ### euh... where is the removal? */
+        }
+        else if (ctx->operation == DAV_PROP_OP_DELETE) {
+
+            /*
+            ** Delete the property. Ignore errors -- the property is there, or
+            ** we are deleting it for a second time.
+            */
+            /* ### but what about other errors? */
+            (void) (*propdb->db_hooks->remove)(propdb->db, &name);
+        }
+    }
+
+  error:
+    /* push a more specific error here */
+    if (err != NULL) {
+        /*
+        ** Use HTTP_INTERNAL_SERVER_ERROR because we shouldn't have seen
+        ** any errors at this point.
+        */
+        ctx->err = dav_push_error(propdb->p, HTTP_INTERNAL_SERVER_ERROR,
+                                  DAV_ERR_PROP_EXEC,
+                                  "Could not execute PROPPATCH.", err);
+    }
+}
+
+DAV_DECLARE_NONSTD(void) dav_prop_commit(dav_prop_ctx *ctx)
+{
+    dav_elem_private *priv = ctx->prop->priv;
+
+    /*
+    ** Note that a commit implies ctx->err is NULL. The caller should assume
+    ** a status of HTTP_OK for this case.
+    */
+
+    if (ctx->is_liveprop) {
+        (*priv->provider->patch_commit)(ctx->propdb->resource,
+                                        ctx->operation,
+                                        ctx->liveprop_ctx,
+                                        ctx->rollback->liveprop);
+    }
+}
+
+DAV_DECLARE_NONSTD(void) dav_prop_rollback(dav_prop_ctx *ctx)
+{
+    dav_error *err = NULL;
+    dav_elem_private *priv = ctx->prop->priv;
+
+    /* do nothing if there is no rollback information. */
+    if (ctx->rollback == NULL)
+        return;
+
+    /*
+    ** ### if we have an error, and a rollback occurs, then the namespace
+    ** ### mods should not happen at all. Basically, the namespace management
+    ** ### is simply a bitch.
+    */
+
+    if (ctx->is_liveprop) {
+        err = (*priv->provider->patch_rollback)(ctx->propdb->resource,
+                                                ctx->operation,
+                                                ctx->liveprop_ctx,
+                                                ctx->rollback->liveprop);
+    }
+    else {
+        err = (*ctx->propdb->db_hooks
+               ->apply_rollback)(ctx->propdb->db, ctx->rollback->deadprop);
+    }
+
+    if (err != NULL) {
+        if (ctx->err == NULL)
+            ctx->err = err;
+        else {
+            dav_error *scan = err;
+
+            /* hook previous errors at the end of the rollback error */
+            while (scan->prev != NULL)
+                scan = scan->prev;
+            scan->prev = ctx->err;
+            ctx->err = err;
+        }
+    }
+}