lock.c

linux网络服务器工具

        "<D:lockscope><D:shared/></D:lockscope>" DEBUG_CR
        "<D:locktype><D:write/></D:locktype>" DEBUG_CR
        "</D:lockentry>" DEBUG_CR;

    return supported;
}

/* ---------------------------------------------------------------
**
** General lock functions
**
*/

/* ---------------------------------------------------------------
**
** Functions dealing with lock-null resources
**
*/

/*
** dav_fs_load_locknull_list:  Returns a dav_buffer dump of the locknull file
**    for the given directory.
*/
static dav_error * dav_fs_load_locknull_list(apr_pool_t *p, const char *dirpath,
                                             dav_buffer *pbuf)
{
    apr_finfo_t finfo;
    apr_file_t *file = NULL;
    dav_error *err = NULL;
    apr_size_t amt;
    apr_status_t rv;

    dav_buffer_init(p, pbuf, dirpath);

    if (pbuf->buf[pbuf->cur_len - 1] == '/')
        pbuf->buf[--pbuf->cur_len] = '\0';

    dav_buffer_place(p, pbuf, "/" DAV_FS_STATE_DIR "/" DAV_FS_LOCK_NULL_FILE);

    /* reset this in case we leave w/o reading into the buffer */
    pbuf->cur_len = 0;

    if (apr_file_open(&file, pbuf->buf, APR_READ | APR_BINARY, APR_OS_DEFAULT,
                p) != APR_SUCCESS) {
        return NULL;
    }

    rv = apr_file_info_get(&finfo, APR_FINFO_SIZE, file);
    if (rv != APR_SUCCESS) {
        err = dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                            apr_psprintf(p,
                                        "Opened but could not stat file %s",
                                        pbuf->buf));
        goto loaderror;
    }

    if (finfo.size != (apr_size_t)finfo.size) {
        err = dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                            apr_psprintf(p,
                                        "Opened but rejected huge file %s",
                                        pbuf->buf));
        goto loaderror;
    }

    amt = (apr_size_t)finfo.size;
    dav_set_bufsize(p, pbuf, amt);
    if (apr_file_read(file, pbuf->buf, &amt) != APR_SUCCESS
        || amt != finfo.size) {
        err = dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                            apr_psprintf(p,
                                        "Failure reading locknull file "
                                        "for %s", dirpath));

        /* just in case the caller disregards the returned error */
        pbuf->cur_len = 0;
        goto loaderror;
    }

  loaderror:
    apr_file_close(file);
    return err;
}

/*
** dav_fs_save_locknull_list:  Saves contents of pbuf into the
**    locknull file for dirpath.
*/
static dav_error * dav_fs_save_locknull_list(apr_pool_t *p, const char *dirpath,
                                             dav_buffer *pbuf)
{
    const char *pathname;
    apr_file_t *file = NULL;
    dav_error *err = NULL;
    apr_size_t amt;

    if (pbuf->buf == NULL)
        return NULL;

    dav_fs_ensure_state_dir(p, dirpath);
    pathname = apr_pstrcat(p,
                          dirpath,
                          dirpath[strlen(dirpath) - 1] == '/' ? "" : "/",
                          DAV_FS_STATE_DIR "/" DAV_FS_LOCK_NULL_FILE,
                          NULL);

    if (pbuf->cur_len == 0) {
        /* delete the file if cur_len == 0 */
        if (apr_file_remove(pathname, p) != 0) {
            return dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                                 apr_psprintf(p,
                                             "Error removing %s", pathname));
        }
        return NULL;
    }

    if (apr_file_open(&file, pathname,
                APR_WRITE | APR_CREATE | APR_TRUNCATE | APR_BINARY,
                APR_OS_DEFAULT, p) != APR_SUCCESS) {
        return dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                             apr_psprintf(p,
                                         "Error opening %s for writing",
                                         pathname));
    }

    amt = pbuf->cur_len;
    if (apr_file_write(file, pbuf->buf, &amt) != APR_SUCCESS
        || amt != pbuf->cur_len) {
        err = dav_new_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                            apr_psprintf(p,
                                        "Error writing %" APR_SIZE_T_FMT
                                        " bytes to %s",
                                        pbuf->cur_len, pathname));
    }

    apr_file_close(file);
    return err;
}

/*
** dav_fs_remove_locknull_member:  Removes filename from the locknull list
**    for directory path.
*/
static dav_error * dav_fs_remove_locknull_member(apr_pool_t *p,
                                                 const char *filename,
                                                 dav_buffer *pbuf)
{
    dav_error *err;
    apr_size_t len;
    apr_size_t scanlen;
    char *scan;
    const char *scanend;
    char *dirpath = apr_pstrdup(p, filename);
    char *fname = strrchr(dirpath, '/');
    int dirty = 0;

    if (fname != NULL)
        *fname++ = '\0';
    else
        fname = dirpath;
    len = strlen(fname) + 1;

    if ((err = dav_fs_load_locknull_list(p, dirpath, pbuf)) != NULL) {
        /* ### add a higher level description? */
        return err;
    }

    for (scan = pbuf->buf, scanend = scan + pbuf->cur_len;
         scan < scanend;
         scan += scanlen) {
        scanlen = strlen(scan) + 1;
        if (len == scanlen && memcmp(fname, scan, scanlen) == 0) {
            pbuf->cur_len -= scanlen;
            memmove(scan, scan + scanlen, scanend - (scan + scanlen));
            dirty = 1;
            break;
        }
    }

    if (dirty) {
        if ((err = dav_fs_save_locknull_list(p, dirpath, pbuf)) != NULL) {
            /* ### add a higher level description? */
            return err;
        }
    }

    return NULL;
}

/* Note: used by dav_fs_repos.c */
dav_error * dav_fs_get_locknull_members(
    const dav_resource *resource,
    dav_buffer *pbuf)
{
    const char *dirpath;

    /* ### should test this result value... */
    (void) dav_fs_dir_file_name(resource, &dirpath, NULL);
    return dav_fs_load_locknull_list(dav_fs_pool(resource), dirpath, pbuf);
}

/* ### fold into append_lock? */
/* ### take an optional buf parameter? */
static dav_error * dav_fs_add_locknull_state(
    dav_lockdb *lockdb,
    const dav_resource *resource)
{
    dav_buffer buf = { 0 };
    apr_pool_t *p = lockdb->info->pool;
    const char *dirpath;
    const char *fname;
    dav_error *err;

    /* ### should test this result value... */
    (void) dav_fs_dir_file_name(resource, &dirpath, &fname);

    if ((err = dav_fs_load_locknull_list(p, dirpath, &buf)) != NULL) {
        return dav_push_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                              "Could not load .locknull file.", err);
    }

    dav_buffer_append(p, &buf, fname);
    buf.cur_len++;   /* we want the null-term here */

    if ((err = dav_fs_save_locknull_list(p, dirpath, &buf)) != NULL) {
        return dav_push_error(p, HTTP_INTERNAL_SERVER_ERROR, 0,
                              "Could not save .locknull file.", err);
    }

    return NULL;
}

/*
** dav_fs_remove_locknull_state:  Given a request, check to see if r->filename
**    is/was a lock-null resource.  If so, return it to an existant state.
**
**    ### this function is broken... it doesn't check!
**
**    In this implementation, this involves two things:
**    (a) remove it from the list in the appropriate .DAV/locknull file
**    (b) on *nix, convert the key from a filename to an inode.
*/
static dav_error * dav_fs_remove_locknull_state(
    dav_lockdb *lockdb,
    const dav_resource *resource)
{
    dav_buffer buf = { 0 };
    dav_error *err;
    apr_pool_t *p = lockdb->info->pool;
    const char *pathname = dav_fs_pathname(resource);

    if ((err = dav_fs_remove_locknull_member(p, pathname, &buf)) != NULL) {
        /* ### add a higher-level description? */
        return err;
    }

    {
        dav_lock_discovery *ld;
        dav_lock_indirect  *id;
        apr_datum_t key;

        /*
        ** Fetch the lock(s) that made the resource lock-null. Remove
        ** them under the filename key. Obtain the new inode key, and
        ** save the same lock information under it.
        */
        key = dav_fs_build_fname_key(p, pathname);
        if ((err = dav_fs_load_lock_record(lockdb, key, DAV_CREATE_LIST,
                                           &ld, &id)) != NULL) {
            /* ### insert a higher-level error description */
            return err;
        }

        if ((err = dav_fs_save_lock_record(lockdb, key, NULL, NULL)) != NULL) {
            /* ### insert a higher-level error description */
            return err;
        }

        key = dav_fs_build_key(p, resource);
        if ((err = dav_fs_save_lock_record(lockdb, key, ld, id)) != NULL) {
            /* ### insert a higher-level error description */
            return err;
        }
    }

    return NULL;
}

static dav_error * dav_fs_create_lock(dav_lockdb *lockdb,
                                      const dav_resource *resource,
                                      dav_lock **lock)
{
    apr_datum_t key;

    key = dav_fs_build_key(lockdb->info->pool, resource);

    *lock = dav_fs_alloc_lock(lockdb,
                              key,
                              NULL);

    (*lock)->is_locknull = !resource->exists;

    return NULL;
}

static dav_error * dav_fs_get_locks(dav_lockdb *lockdb,
                                    const dav_resource *resource,
                                    int calltype,
                                    dav_lock **locks)
{
    apr_pool_t *p = lockdb->info->pool;
    apr_datum_t key;
    dav_error *err;
    dav_lock *lock = NULL;
    dav_lock *newlock;
    dav_lock_discovery *dp;
    dav_lock_indirect *ip;

#if DAV_DEBUG
    if (calltype == DAV_GETLOCKS_COMPLETE) {
        return dav_new_error(lockdb->info->pool,
                             HTTP_INTERNAL_SERVER_ERROR, 0,
                             "INTERNAL DESIGN ERROR: DAV_GETLOCKS_COMPLETE "
                             "is not yet supported");
    }
#endif

    key = dav_fs_build_key(p, resource);
    if ((err = dav_fs_load_lock_record(lockdb, key, DAV_CREATE_LIST,
                                       &dp, &ip)) != NULL) {
        /* ### push a higher-level desc? */
        return err;
    }

    /* copy all direct locks to the result list */
    for (; dp != NULL; dp = dp->next) {
        newlock = dav_fs_alloc_lock(lockdb, key, dp->locktoken);
        newlock->is_locknull = !resource->exists;
        newlock->scope = dp->f.scope;
        newlock->type = dp->f.type;
        newlock->depth = dp->f.depth;
        newlock->timeout = dp->f.timeout;
        newlock->owner = dp->owner;
        newlock->auth_user = dp->auth_user;

        /* hook into the result list */
        newlock->next = lock;
        lock = newlock;
    }

    /* copy all the indirect locks to the result list. resolve as needed. */
    for (; ip != NULL; ip = ip->next) {
        newlock = dav_fs_alloc_lock(lockdb, ip->key, ip->locktoken);
        newlock->is_locknull = !resource->exists;

        if (calltype == DAV_GETLOCKS_RESOLVED) {
            if ((err = dav_fs_resolve(lockdb, ip, &dp, NULL, NULL)) != NULL) {
                /* ### push a higher-level desc? */
                return err;
            }

            newlock->scope = dp->f.scope;
            newlock->type = dp->f.type;
            newlock->depth = dp->f.depth;
            newlock->timeout = dp->f.timeout;
            newlock->owner = dp->owner;
            newlock->auth_user = dp->auth_user;
        }
        else {
            /* DAV_GETLOCKS_PARTIAL */
            newlock->rectype = DAV_LOCKREC_INDIRECT_PARTIAL;
        }

        /* hook into the result list */
        newlock->next = lock;
        lock = newlock;
    }

    *locks = lock;
    return NULL;