src/server/webdav/xattrbackend.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2023 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */


#include "xattrbackend.h"

#include "../util/util.h"
#include "../util/libxattr.h"


static WebdavBackend webdav_xattr_backend = {
    webdav_xattr_propfind_init,
    webdav_xattr_propfind_do,
    webdav_xattr_propfind_finish,
    webdav_xattr_proppatch_do,
    webdav_xattr_proppatch_finish,
    NULL, // opt_mkcol
    NULL, // opt_mkcol_finish
    NULL, // opt_delete
    NULL, // opt_delete_finish
    WS_WEBDAV_PROPFIND_USE_VFS | WS_WEBDAV_PROPPATCH_USE_VFS, // settings
    NULL, // instance
    NULL  // next
};

int webdav_init_xattr_backend(void) {
    
    
    if(webdav_register_backend("xattr", webdav_xattr_init, webdav_xattr_create)) {
        return 1;
    }
    return 0;
}

void* webdav_xattr_init(ServerConfiguration *cfg, pool_handle_t *pool, WSConfigNode *config) {
    WebdavXAttrRepository *repo = pool_malloc(pool, sizeof(WebdavXAttrRepository));
    if(!repo) {
        return NULL;
    }
    
    // TODO: config
    repo->xattr_name = "webdav_properties";
    
    return repo;
}

WebdavBackend* webdav_xattr_create(Session *sn, Request *rq, pblock *pb, void *initData) {
    WebdavBackend *dav = pool_malloc(sn->pool, sizeof(WebdavBackend));
    if(!dav) {
        return NULL;
    }
    
    WebdavXAttrBackend *instance = pool_malloc(sn->pool, sizeof(WebdavXAttrBackend));
    if(!instance) {
        return NULL;
    }
    instance->repo = initData;
    
    *dav = webdav_xattr_backend;
    dav->instance = instance;
    
    return dav; 
}


/* -------------------- webdav backend imlementation ----------------------*/

int webdav_xattr_propfind_init(
        WebdavPropfindRequest *rq,
        const char *path,
        const char *href,
        WebdavPList **outplist)
{
    // make sure the sys vfs is used, because currently only
    // native sysfs xattr is supported
    if(rq->rq->vfs) {
        log_ereport(LOG_FAILURE, "webdav-propfind: xattr backend unsupported with non-native VFS");
        return 1;
    }
    
    XAttrPropfind *xprop = pool_malloc(rq->sn->pool, sizeof(XAttrPropfind));
    if(!xprop) {
        return 1;
    }
    rq->userdata = xprop;
    
    xprop->base_href = href;
    xprop->base_path = path;
    
    return 0;
}

int webdav_xattr_propfind_do(
        WebdavPropfindRequest *request,
        WebdavResponse *response,
        VFS_DIR parent,
        WebdavResource *resource,
        struct stat *s)
{
    Session *sn = request->sn;
    Request *rq = request->rq;
    
    WebdavXAttrBackend *xdav = request->dav->instance;
    WebdavXAttrRepository *repo = xdav->repo;
    XAttrPropfind *xprop = request->userdata;
    
    const char *path;
    char *path_dp = NULL;
    if(!parent) {
        // use base path
        path = xprop->base_path;
    } else {
        size_t base_href_len = strlen(xprop->base_href);
        size_t base_path_len = strlen(xprop->base_path);
        char *res_path = resource->href + base_href_len;
        size_t res_path_len = strlen(res_path);
        
        path_dp = pool_malloc(sn->pool, base_path_len + res_path_len + 2);
        memcpy(path_dp, xprop->base_path, base_path_len);
        int s = 0;
        if(path_dp[base_path_len-1] != '/' && res_path[0] != '/') {
            path_dp[base_path_len] = '/';
            s = 1;
        }
        memcpy(path_dp + base_path_len + s, res_path, res_path_len);
        path_dp[base_path_len + s + res_path_len] = 0;
        
        path = path_dp;
    }
    
    ssize_t xattr_data_len = 0;
    char *xattr_data = xattr_get_alloc(
            sn->pool,
            (libxattr_malloc_func)pool_malloc,
            (libxattr_free_func)pool_free,
            path,
            repo->xattr_name,
            &xattr_data_len);
    
    
    return 0;
}

int webdav_xattr_propfind_finish(WebdavPropfindRequest *rq) {
    return 0;
}

int webdav_xattr_proppatch_do(
            WebdavProppatchRequest *request,
            WebdavResource *response,
            VFSFile *file,
            WebdavPList **setInOut,
            WebdavPList **removeInOut)
{
    return 0;
}

int webdav_xattr_proppatch_finish(
            WebdavProppatchRequest *request,
            WebdavResource *response,
            VFSFile *file,
            WSBool commit)
{
    return 0;
}