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DEFINITIONS
This source file includes following definitions.
- dav_dbm_get_statefiles
- dav_fs_dbm_error
- dav_fs_ensure_state_dir
- dav_dbm_open_direct
- dav_dbm_open
- dav_dbm_close
- dav_dbm_fetch
- dav_dbm_store
- dav_dbm_delete
- dav_dbm_exists
- dav_dbm_firstkey
- dav_dbm_nextkey
- dav_dbm_freedatum
- dav_build_key
- dav_append_prop
- dav_propdb_open
- dav_propdb_close
- dav_propdb_define_namespaces
- dav_propdb_output_value
- dav_propdb_map_namespaces
- dav_propdb_store
- dav_propdb_remove
- dav_propdb_exists
- dav_get_ns_table_uri
- dav_set_name
- dav_propdb_next_name
- dav_propdb_first_name
- dav_propdb_get_rollback
- dav_propdb_apply_rollback
/* 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.*
** - Database support using DBM-style databases,
** part of the filesystem repository implementation
*/
/*
** This implementation uses a SDBM database per file and directory to
** record the properties. These databases are kept in a subdirectory (of
** the directory in question or the directory that holds the file in
** question) named by the macro DAV_FS_STATE_DIR (.DAV). The filename of the
** database is equivalent to the target filename, and is
** DAV_FS_STATE_FILE_FOR_DIR (.state_for_dir) for the directory itself.
*/
#include "apr_strings.h"
#include "apr_file_io.h"
#include "apr_dbm.h"
#define APR_WANT_BYTEFUNC
#include "apr_want.h" /* for ntohs and htons */
#include "mod_dav.h"
#include "repos.h"
struct dav_db {
apr_pool_t *pool;
apr_dbm_t *file;
/* when used as a property database: */
int version; /* *minor* version of this db */
dav_buffer ns_table; /* table of namespace URIs */
short ns_count; /* number of entries in table */
int ns_table_dirty; /* ns_table was modified */
apr_hash_t *uri_index; /* map URIs to (1-based) table indices */
dav_buffer wb_key; /* work buffer for dav_gdbm_key */
apr_datum_t iter; /* iteration key */
};
/* -------------------------------------------------------------------------
*
* GENERIC DBM ACCESS
*
* For the most part, this just uses the APR DBM functions. They are wrapped
* a bit with some error handling (using the mod_dav error functions).
*/
void dav_dbm_get_statefiles(apr_pool_t *p, const char *fname,
const char **state1, const char **state2)
{
if (fname == NULL)
fname = DAV_FS_STATE_FILE_FOR_DIR;
apr_dbm_get_usednames(p, fname, state1, state2);
}
static dav_error * dav_fs_dbm_error(dav_db *db, apr_pool_t *p,
apr_status_t status)
{
int save_errno = errno;
int errcode;
const char *errstr;
dav_error *err;
char errbuf[200];
if (status == APR_SUCCESS)
return NULL;
p = db ? db->pool : p;
/* There might not be a <db> if we had problems creating it. */
if (db == NULL) {
errcode = 1;
errstr = "Could not open property database.";
}
else {
(void) apr_dbm_geterror(db->file, &errcode, errbuf, sizeof(errbuf));
errstr = apr_pstrdup(p, errbuf);
}
err = dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, errcode, errstr);
err->save_errno = save_errno;
return err;
}
/* ensure that our state subdirectory is present */
/* ### does this belong here or in dav_fs_repos.c ?? */
void dav_fs_ensure_state_dir(apr_pool_t * p, const char *dirname)
{
const char *pathname = apr_pstrcat(p, dirname, "/" DAV_FS_STATE_DIR, NULL);
/* ### do we need to deal with the umask? */
/* just try to make it, ignoring any resulting errors */
(void) apr_dir_make(pathname, APR_OS_DEFAULT, p);
}
/* dav_dbm_open_direct: Opens a *dbm database specified by path.
* ro = boolean read-only flag.
*/
dav_error * dav_dbm_open_direct(apr_pool_t *p, const char *pathname, int ro,
dav_db **pdb)
{
apr_status_t status;
apr_dbm_t *file;
*pdb = NULL;
if ((status = apr_dbm_open(&file, pathname,
ro ? APR_DBM_READONLY : APR_DBM_RWCREATE,
APR_OS_DEFAULT, p))
!= APR_SUCCESS
&& !ro) {
/* ### do something with 'status' */
/* we can't continue if we couldn't open the file
and we need to write */
return dav_fs_dbm_error(NULL, p, status);
}
/* may be NULL if we tried to open a non-existent db as read-only */
if (file != NULL) {
/* we have an open database... return it */
*pdb = apr_pcalloc(p, sizeof(**pdb));
(*pdb)->pool = p;
(*pdb)->file = file;
}
return NULL;
}
static dav_error * dav_dbm_open(apr_pool_t * p, const dav_resource *resource,
int ro, dav_db **pdb)
{
const char *dirpath;
const char *fname;
const char *pathname;
/* Get directory and filename for resource */
/* ### should test this result value... */
(void) dav_fs_dir_file_name(resource, &dirpath, &fname);
/* If not opening read-only, ensure the state dir exists */
if (!ro) {
/* ### what are the perf implications of always checking this? */
dav_fs_ensure_state_dir(p, dirpath);
}
pathname = apr_pstrcat(p, dirpath, "/" DAV_FS_STATE_DIR "/",
fname ? fname : DAV_FS_STATE_FILE_FOR_DIR,
NULL);
/* ### readers cannot open while a writer has this open; we should
### perform a few retries with random pauses. */
/* ### do we need to deal with the umask? */
return dav_dbm_open_direct(p, pathname, ro, pdb);
}
void dav_dbm_close(dav_db *db)
{
apr_dbm_close(db->file);
}
dav_error * dav_dbm_fetch(dav_db *db, apr_datum_t key, apr_datum_t *pvalue)
{
apr_status_t status = apr_dbm_fetch(db->file, key, pvalue);
return dav_fs_dbm_error(db, NULL, status);
}
dav_error * dav_dbm_store(dav_db *db, apr_datum_t key, apr_datum_t value)
{
apr_status_t status = apr_dbm_store(db->file, key, value);
return dav_fs_dbm_error(db, NULL, status);
}
dav_error * dav_dbm_delete(dav_db *db, apr_datum_t key)
{
apr_status_t status = apr_dbm_delete(db->file, key);
return dav_fs_dbm_error(db, NULL, status);
}
int dav_dbm_exists(dav_db *db, apr_datum_t key)
{
return apr_dbm_exists(db->file, key);
}
static dav_error * dav_dbm_firstkey(dav_db *db, apr_datum_t *pkey)
{
apr_status_t status = apr_dbm_firstkey(db->file, pkey);
return dav_fs_dbm_error(db, NULL, status);
}
static dav_error * dav_dbm_nextkey(dav_db *db, apr_datum_t *pkey)
{
apr_status_t status = apr_dbm_nextkey(db->file, pkey);
return dav_fs_dbm_error(db, NULL, status);
}
void dav_dbm_freedatum(dav_db *db, apr_datum_t data)
{
apr_dbm_freedatum(db->file, data);
}
/* -------------------------------------------------------------------------
*
* PROPERTY DATABASE FUNCTIONS
*/
#define DAV_GDBM_NS_KEY "METADATA"
#define DAV_GDBM_NS_KEY_LEN 8
typedef struct {
unsigned char major;
#define DAV_DBVSN_MAJOR 4
/*
** V4 -- 0.9.9 ..
** Prior versions could have keys or values with invalid
** namespace prefixes as a result of the xmlns="" form not
** resetting the default namespace to be "no namespace". The
** namespace would be set to "" which is invalid; it should
** be set to "no namespace".
**
** V3 -- 0.9.8
** Prior versions could have values with invalid namespace
** prefixes due to an incorrect mapping of input to propdb
** namespace indices. Version bumped to obsolete the old
** values.
**
** V2 -- 0.9.7
** This introduced the xml:lang value into the property value's
** record in the propdb.
**
** V1 -- .. 0.9.6
** Initial version.
*/
unsigned char minor;
#define DAV_DBVSN_MINOR 0
short ns_count;
} dav_propdb_metadata;
struct dav_deadprop_rollback {
apr_datum_t key;
apr_datum_t value;
};
struct dav_namespace_map {
int *ns_map;
};
/*
** Internal function to build a key
**
** WARNING: returns a pointer to a "static" buffer holding the key. The
** value must be copied or no longer used if this function is
** called again.
*/
static apr_datum_t dav_build_key(dav_db *db, const dav_prop_name *name)
{
char nsbuf[20];
apr_size_t l_ns, l_name = strlen(name->name);
apr_datum_t key = { 0 };
/*
* Convert namespace ID to a string. "no namespace" is an empty string,
* so the keys will have the form ":name". Otherwise, the keys will
* have the form "#:name".
*/
if (*name->ns == '\0') {
nsbuf[0] = '\0';
l_ns = 0;
}
else {
long ns_id = (long)apr_hash_get(db->uri_index, name->ns,
APR_HASH_KEY_STRING);
if (ns_id == 0) {
/* the namespace was not found(!) */
return key; /* zeroed */
}
l_ns = sprintf(nsbuf, "%ld", ns_id - 1);
}
/* assemble: #:name */
dav_set_bufsize(db->pool, &db->wb_key, l_ns + 1 + l_name + 1);
memcpy(db->wb_key.buf, nsbuf, l_ns);
db->wb_key.buf[l_ns] = ':';
memcpy(&db->wb_key.buf[l_ns + 1], name->name, l_name + 1);
/* build the database key */
key.dsize = l_ns + 1 + l_name + 1;
key.dptr = db->wb_key.buf;
return key;
}
static void dav_append_prop(apr_pool_t *pool,
const char *name, const char *value,
apr_text_header *phdr)
{
const char *s;
const char *lang = value;
/* skip past the xml:lang value */
value += strlen(lang) + 1;
if (*value == '\0') {
/* the property is an empty value */
if (*name == ':') {
/* "no namespace" case */
s = apr_psprintf(pool, "<%s/>" DEBUG_CR, name+1);
}
else {
s = apr_psprintf(pool, "<ns%s/>" DEBUG_CR, name);
}
}
else if (*lang != '\0') {
if (*name == ':') {
/* "no namespace" case */
s = apr_psprintf(pool, "<%s xml:lang=\"%s\">%s</%s>" DEBUG_CR,
name+1, lang, value, name+1);
}
else {
s = apr_psprintf(pool, "<ns%s xml:lang=\"%s\">%s</ns%s>" DEBUG_CR,
name, lang, value, name);
}
}
else if (*name == ':') {
/* "no namespace" case */
s = apr_psprintf(pool, "<%s>%s</%s>" DEBUG_CR, name+1, value, name+1);
}
else {
s = apr_psprintf(pool, "<ns%s>%s</ns%s>" DEBUG_CR, name, value, name);
}
apr_text_append(pool, phdr, s);
}
static dav_error * dav_propdb_open(apr_pool_t *pool,
const dav_resource *resource, int ro,
dav_db **pdb)
{
dav_db *db;
dav_error *err;
apr_datum_t key;
apr_datum_t value = { 0 };
*pdb = NULL;
/*
** Return if an error occurred, or there is no database.
**
** NOTE: 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.
*/
if ((err = dav_dbm_open(pool, resource, ro, &db)) != NULL
|| db == NULL)
return err;
db->uri_index = apr_hash_make(pool);
key.dptr = DAV_GDBM_NS_KEY;
key.dsize = DAV_GDBM_NS_KEY_LEN;
if ((err = dav_dbm_fetch(db, key, &value)) != NULL) {
/* ### push a higher-level description? */
return err;
}
if (value.dptr == NULL) {
dav_propdb_metadata m = {
DAV_DBVSN_MAJOR, DAV_DBVSN_MINOR, 0
};
/*
** If there is no METADATA key, then the database may be
** from versions 0.9.0 .. 0.9.4 (which would be incompatible).
** These can be identified by the presence of an NS_TABLE entry.
*/
key.dptr = "NS_TABLE";
key.dsize = 8;
if (dav_dbm_exists(db, key)) {
dav_dbm_close(db);
/* call it a major version error */
return dav_new_error(pool, HTTP_INTERNAL_SERVER_ERROR,
DAV_ERR_PROP_BAD_MAJOR,
"Prop database has the wrong major "
"version number and cannot be used.");
}
/* initialize a new metadata structure */
dav_set_bufsize(pool, &db->ns_table, sizeof(m));
memcpy(db->ns_table.buf, &m, sizeof(m));
}
else {
dav_propdb_metadata m;
long ns;
const char *uri;
dav_set_bufsize(pool, &db->ns_table, value.dsize);
memcpy(db->ns_table.buf, value.dptr, value.dsize);
memcpy(&m, value.dptr, sizeof(m));
if (m.major != DAV_DBVSN_MAJOR) {
dav_dbm_close(db);
return dav_new_error(pool, HTTP_INTERNAL_SERVER_ERROR,
DAV_ERR_PROP_BAD_MAJOR,
"Prop database has the wrong major "
"version number and cannot be used.");
}
db->version = m.minor;
db->ns_count = ntohs(m.ns_count);
dav_dbm_freedatum(db, value);
/* create db->uri_index */
for (ns = 0, uri = db->ns_table.buf + sizeof(dav_propdb_metadata);
ns++ < db->ns_count;
uri += strlen(uri) + 1) {
/* we must copy the key, in case ns_table.buf moves */
apr_hash_set(db->uri_index,
apr_pstrdup(pool, uri), APR_HASH_KEY_STRING,
(void *)ns);
}
}
*pdb = db;
return NULL;
}
static void dav_propdb_close(dav_db *db)
{
if (db->ns_table_dirty) {
dav_propdb_metadata m;
apr_datum_t key;
apr_datum_t value;
dav_error *err;
key.dptr = DAV_GDBM_NS_KEY;
key.dsize = DAV_GDBM_NS_KEY_LEN;
value.dptr = db->ns_table.buf;
value.dsize = db->ns_table.cur_len;
/* fill in the metadata that we store into the prop db. */
m.major = DAV_DBVSN_MAJOR;
m.minor = db->version; /* ### keep current minor version? */
m.ns_count = htons(db->ns_count);
memcpy(db->ns_table.buf, &m, sizeof(m));
err = dav_dbm_store(db, key, value);
/* ### what to do with the error? */
}
dav_dbm_close(db);
}
static dav_error * dav_propdb_define_namespaces(dav_db *db, dav_xmlns_info *xi)
{
int ns;
const char *uri = db->ns_table.buf + sizeof(dav_propdb_metadata);
/* within the prop values, we use "ns%d" for prefixes... register them */
for (ns = 0; ns < db->ns_count; ++ns, uri += strlen(uri) + 1) {
/* Empty URIs signify the empty namespace. These do not get a
namespace prefix. when we generate the value, we will simply
leave off the prefix, which is defined by mod_dav to be the
empty namespace. */
if (*uri == '\0')
continue;
/* ns_table.buf can move, so copy its value (we want the values to
last as long as the provided dav_xmlns_info). */
dav_xmlns_add(xi,
apr_psprintf(xi->pool, "ns%d", ns),
apr_pstrdup(xi->pool, uri));
}
return NULL;
}
static dav_error * dav_propdb_output_value(dav_db *db,
const dav_prop_name *name,
dav_xmlns_info *xi,
apr_text_header *phdr,
int *found)
{
apr_datum_t key = dav_build_key(db, name);
apr_datum_t value;
dav_error *err;
if ((err = dav_dbm_fetch(db, key, &value)) != NULL)
return err;
if (value.dptr == NULL) {
*found = 0;
return NULL;
}
*found = 1;
dav_append_prop(db->pool, key.dptr, value.dptr, phdr);
dav_dbm_freedatum(db, value);
return NULL;
}
static dav_error * dav_propdb_map_namespaces(
dav_db *db,
const apr_array_header_t *namespaces,
dav_namespace_map **mapping)
{
dav_namespace_map *m = apr_palloc(db->pool, sizeof(*m));
int i;
int *pmap;
const char **puri;
/*
** Iterate over the provided namespaces. If a namespace already appears
** in our internal map of URI -> ns_id, then store that in the map. If
** we don't know the namespace yet, then add it to the map and to our
** table of known namespaces.
*/
m->ns_map = pmap = apr_palloc(db->pool, namespaces->nelts * sizeof(*pmap));
for (i = namespaces->nelts, puri = (const char **)namespaces->elts;
i-- > 0;
++puri, ++pmap) {
const char *uri = *puri;
apr_size_t uri_len = strlen(uri);
long ns_id = (long)apr_hash_get(db->uri_index, uri, uri_len);
if (ns_id == 0) {
dav_check_bufsize(db->pool, &db->ns_table, uri_len + 1);
memcpy(db->ns_table.buf + db->ns_table.cur_len, uri, uri_len + 1);
db->ns_table.cur_len += uri_len + 1;
/* copy the uri in case the passed-in namespaces changes in
some way. */
apr_hash_set(db->uri_index, apr_pstrdup(db->pool, uri), uri_len,
(void *)((long)(db->ns_count + 1)));
db->ns_table_dirty = 1;
*pmap = db->ns_count++;
}
else {
*pmap = ns_id - 1;
}
}
*mapping = m;
return NULL;
}
static dav_error * dav_propdb_store(dav_db *db, const dav_prop_name *name,
const apr_xml_elem *elem,
dav_namespace_map *mapping)
{
apr_datum_t key = dav_build_key(db, name);
apr_datum_t value;
/* Note: mapping->ns_map was set up in dav_propdb_map_namespaces() */
/* ### use a db- subpool for these values? clear on exit? */
/* quote all the values in the element */
/* ### be nice to do this without affecting the element itself */
/* ### of course, the cast indicates Badness is occurring here */
apr_xml_quote_elem(db->pool, (apr_xml_elem *)elem);
/* generate a text blob for the xml:lang plus the contents */
apr_xml_to_text(db->pool, elem, APR_XML_X2T_LANG_INNER, NULL,
mapping->ns_map,
(const char **)&value.dptr, &value.dsize);
return dav_dbm_store(db, key, value);
}
static dav_error * dav_propdb_remove(dav_db *db, const dav_prop_name *name)
{
apr_datum_t key = dav_build_key(db, name);
return dav_dbm_delete(db, key);
}
static int dav_propdb_exists(dav_db *db, const dav_prop_name *name)
{
apr_datum_t key = dav_build_key(db, name);
return dav_dbm_exists(db, key);
}
static const char *dav_get_ns_table_uri(dav_db *db, int ns_id)
{
const char *p = db->ns_table.buf + sizeof(dav_propdb_metadata);
while (ns_id--)
p += strlen(p) + 1;
return p;
}
static void dav_set_name(dav_db *db, dav_prop_name *pname)
{
const char *s = db->iter.dptr;
if (s == NULL) {
pname->ns = pname->name = NULL;
}
else if (*s == ':') {
pname->ns = "";
pname->name = s + 1;
}
else {
int id = atoi(s);
pname->ns = dav_get_ns_table_uri(db, id);
if (s[1] == ':') {
pname->name = s + 2;
}
else {
pname->name = ap_strchr_c(s + 2, ':') + 1;
}
}
}
static dav_error * dav_propdb_next_name(dav_db *db, dav_prop_name *pname)
{
dav_error *err;
/* free the previous key. note: if the loop is aborted, then the DBM
will toss the key (via pool cleanup) */
if (db->iter.dptr != NULL)
dav_dbm_freedatum(db, db->iter);
if ((err = dav_dbm_nextkey(db, &db->iter)) != NULL)
return err;
/* skip past the METADATA key */
if (db->iter.dptr != NULL && *db->iter.dptr == 'M')
return dav_propdb_next_name(db, pname);
dav_set_name(db, pname);
return NULL;
}
static dav_error * dav_propdb_first_name(dav_db *db, dav_prop_name *pname)
{
dav_error *err;
if ((err = dav_dbm_firstkey(db, &db->iter)) != NULL)
return err;
/* skip past the METADATA key */
if (db->iter.dptr != NULL && *db->iter.dptr == 'M')
return dav_propdb_next_name(db, pname);
dav_set_name(db, pname);
return NULL;
}
static dav_error * dav_propdb_get_rollback(dav_db *db,
const dav_prop_name *name,
dav_deadprop_rollback **prollback)
{
dav_deadprop_rollback *rb = apr_pcalloc(db->pool, sizeof(*rb));
apr_datum_t key;
apr_datum_t value;
dav_error *err;
key = dav_build_key(db, name);
rb->key.dptr = apr_pstrdup(db->pool, key.dptr);
rb->key.dsize = key.dsize;
if ((err = dav_dbm_fetch(db, key, &value)) != NULL)
return err;
if (value.dptr != NULL) {
rb->value.dptr = apr_pmemdup(db->pool, value.dptr, value.dsize);
rb->value.dsize = value.dsize;
}
*prollback = rb;
return NULL;
}
static dav_error * dav_propdb_apply_rollback(dav_db *db,
dav_deadprop_rollback *rollback)
{
if (rollback->value.dptr == NULL) {
/* don't fail if the thing isn't really there. */
(void) dav_dbm_delete(db, rollback->key);
return NULL;
}
return dav_dbm_store(db, rollback->key, rollback->value);
}
const dav_hooks_db dav_hooks_db_dbm =
{
dav_propdb_open,
dav_propdb_close,
dav_propdb_define_namespaces,
dav_propdb_output_value,
dav_propdb_map_namespaces,
dav_propdb_store,
dav_propdb_remove,
dav_propdb_exists,
dav_propdb_first_name,
dav_propdb_next_name,
dav_propdb_get_rollback,
dav_propdb_apply_rollback,
NULL /* ctx */
};