src/server/public/webdav.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2020 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.
 */

#ifndef WS_WEBDAV_H
#define	WS_WEBDAV_H

#include "nsapi.h"
#include "vfs.h"

#include <sys/file.h>
#include <sys/stat.h>
#include <inttypes.h>

#ifdef	__cplusplus
extern "C" {
#endif

typedef struct WebdavBackend          WebdavBackend;
    
typedef struct WebdavProperty         WebdavProperty;
typedef struct WebdavPList            WebdavPList;
typedef struct WebdavNSList           WebdavNSList;

typedef struct WebdavPListIterator    WebdavPListIterator;

typedef enum   WebdavLockScope        WebdavLockScope;
typedef enum   WebdavLockType         WebdavLockType;

typedef enum   WebdavValueType        WebdavValueType;

typedef struct WebdavPropfindRequest  WebdavPropfindRequest;
typedef struct WebdavProppatchRequest WebdavProppatchRequest;
typedef struct WebdavLockRequest      WebdavLockRequest;

typedef struct WebdavVFSRequest       WebdavVFSRequest;

typedef struct WebdavResponse         WebdavResponse;
typedef struct WebdavResource         WebdavResource;

typedef struct WebdavVFSProperties    WebdavVFSProperties;

typedef struct WebdavOperation        WebdavOperation;

typedef struct WSXmlData              WSXmlData;
typedef struct WSText                 WSText;

typedef struct _xmlNs   WSNamespace;
typedef struct _xmlNode WSXmlNode;

#define WS_NODE_ELEMENT        1
#define WS_NODE_TEXT           3
#define WS_NODE_CDATA          4
#define WS_NODE_ENTITY_REF     5

typedef int(*wsxml_func)(WSXmlNode *, void *);

/* propfind settings */

/*
 * Use the vfs to stat files or read the directory children
 */
#define WS_WEBDAV_PROPFIND_USE_VFS     0x01

/*
 * Use the vfs to open a file for proppatch
 */
#define WS_WEBDAV_PROPPATCH_USE_VFS   0x02


typedef WebdavBackend*(*webdav_create_func)(Session *sn, Request *rq, pblock *pb);

enum WebdavValueType {
    WS_VALUE_NO_TYPE = 0,
    WS_VALUE_XML_NODE,
    WS_VALUE_XML_DATA,
    WS_VALUE_TEXT
};

struct WSText {
    char   *str;
    size_t length;
};

struct WebdavProperty {
    WSNamespace *namespace;
    
    const char *name;
    
    char *lang;
    
    union {
        WSXmlNode *node;
        WSXmlData *data;
        WSText    text;
    } value;
    WebdavValueType vtype;
};

struct WSXmlData {
    WebdavNSList *namespaces;
    char         *data;
    size_t       length;
};

struct WebdavPList {
    WebdavProperty *property;
    WebdavPList *prev;
    WebdavPList *next;
};

struct WebdavNSList {
    WSNamespace  *namespace;
    WebdavNSList *prev;
    WebdavNSList *next;
};

struct WebdavPListIterator {
    WebdavPList **list;
    WebdavPList *cur;
    WebdavPList *next;
    size_t      index;
};

enum WebdavLockScope {
    WEBDAV_LOCK_EXCLUSIVE = 0,
    WEBDAV_LOCK_SHARED,
    WEBDAV_LOCK_SCOPE_UNKNOWN
};

enum WebdavLockType {
    WEBDAV_LOCK_WRITE = 0,
    WEBDAV_LOCK_TYPE_UNKNOWN
};

struct WebdavPropfindRequest {
    Session *sn;
    Request *rq;
    
    WebdavBackend *dav;

    void *doc;
      
    /*
     * list of requested properties
     */
    WebdavPList *properties;
    
    /*
     * number of properties
     */
    size_t propcount;
    
    WSBool allprop;
    WSBool propname;
    WSBool deadproperties;
    
    int depth;
    
    /*
     * custom userdata for the backend
     */
    void *userdata;
};

struct WebdavProppatchRequest {
    Session *sn;
    Request *rq;
    
    WebdavBackend *dav;
    
    void *doc;
    
    WebdavPList *set;
    size_t setcount;
    
    WebdavPList *remove;
    size_t removecount;
    
    /*
     * custom userdata for the backend
     */
    void *userdata;
};

struct WebdavVFSRequest {
    Session *sn;
    Request *rq;
    
    char *path;
    
    /*
     * custom userdata for the backend
     */
    void *userdata;
};

struct WebdavLockRequest {
    Session *sn;
    Request *rq;
    
    void *doc;
    
    WebdavLockScope scope;
    WebdavLockType type;
    
    WSXmlNode *owner;
};

struct WebdavVFSProperties {
    uint32_t getcontentlength:1;
    uint32_t getlastmodified:1;
    uint32_t getresourcetype:1;
    uint32_t getetag:1;
    uint32_t creationdate:1;
};

struct WebdavResponse {
    WebdavOperation *op;
    
    WebdavResource* (*addresource)(WebdavResponse*, const char*);
};

struct WebdavResource {
    char *href;
    
    WSBool isclosed;
    
    int err;
    
    /*
     * int addprop(WebdavResource *res, WebdavProperty *property, int status);
     * 
     * Adds a property to the resource
     */
    int (*addproperty)(WebdavResource*, WebdavProperty*, int);
    
    /*
     * int close(WebdavResource *res);
     * 
     * Closes a resource object
     */
    int (*close)(WebdavResource*);
};

struct WebdavBackend {
    /*
     * int propfind_init(
     *     WebdavPropfindRequest *rq,
     *     const char *path,
     *     const char *href,
     *     WebdavPList **outplist);
     * 
     * Initializes a propfind request. This is called once for each propfind
     * request and should initialize everything needed for generating the
     * multistatus response.
     * 
     */
    int (*propfind_init)(WebdavPropfindRequest *, const char *, const char *, WebdavPList **);
    
    /*
     * int propfind_do(
     *     WebdavPropfindRequest *rq,
     *     WebdavResponse *response,
     *     VFS_DIR parent,
     *     WebdavResource *resource,
     *     struct stat *s);
     * 
     * This function is called for the requsted resource and for all children
     * if WS_PROPFIND_NO_VFS_CHILDREN is not set.
     */
    int (*propfind_do)(
            WebdavPropfindRequest *,
            WebdavResponse *,
            VFS_DIR,
            WebdavResource *,
            struct stat *);
    
    /*
     * int propfind_finish(WebdavPropfindRequest *rq);
     * 
     * Finishes a propfind request.
     */
    int (*propfind_finish)(WebdavPropfindRequest *);
    
    /*
     * int proppatch_do(
     *     WebdavProppatchRequest *request,
     *     WebdavResource *response,
     *     VFSFile *file,
     *     WebdavPList **out_set,
     *     WebdavPList **out_remove);
     * 
     * Modifies properties of the requsted resource.
     */
    int (*proppatch_do)(
            WebdavProppatchRequest *,
            WebdavResource *,
            VFSFile *,
            WebdavPList **,
            WebdavPList **);
    
    /*
     * int proppatch_finish(
     *     WebdavProppatchRequest *request,
     *     WebdavResource *response,
     *     VFSFile *file,
     *     WSBool commit);
     * 
     * Called after all proppatch_do functions of all backends are executed
     * and should either permanently store the properties (commit == true) or
     * revert all changed (commit == false).
     */
    int (*proppatch_finish)(
            WebdavProppatchRequest *,
            WebdavResource *,
            VFSFile *,
            WSBool);
    
    /*
     * int opt_mkcol(WebdavVFSRequest *request, WSBool *out_created);
     * 
     * Optional mkcol callback that is called before vfs_mkdir. If the function
     * sets out_created to TRUE, vfs_mkdir will not be executed.
     */
    int (*opt_mkcol)(WebdavVFSRequest *, WSBool *);
    
    /*
     * int opt_mkcol_finish(WebdavVFSRequest *request, WSBool success);
     * 
     * Optional callback for finishing a MKCOL request.
     */
    int(*opt_mkcol_finish)(WebdavVFSRequest *, WSBool);
    
    /*
     * int opt_delete(WebdavVFSRequest *request, WSBool *out_deleted);
     * 
     * Optional delete callback that is called once before any VFS deletions.
     * When the callback sets out_deleted to TRUE, no VFS unlink operations
     * will be done.
     * 
     */
    int (*opt_delete)(WebdavVFSRequest *, WSBool *);
    
    /*
     * int opt_delete_finish(WebdavVFSRequest *request, WSBool success);
     * 
     * Optional callback for finishing a DELETE request.
     */
    int (*opt_delete_finish)(WebdavVFSRequest *, WSBool);
    
    /*
     * See the WS_WEBDAV_* macros for informations about the settings
     */
    uint32_t settings;
    
    /*
     * private instance data
     */
    void *instance;
    
    /*
     * next Backend
     */
    WebdavBackend *next;
};

/*
 * register a webdav backend
 */
int webdav_register_backend(const char *name, webdav_create_func vfsCreate);

/*
 * gets the requested depth
 * 
 * in case of infinity, -1 is returned
 * if no depth is specified, 0 is returned
 */
int webdav_getdepth(Request *rq);

int webdav_plist_add(
        pool_handle_t *pool,
        WebdavPList **begin,
        WebdavPList **end,
        WebdavProperty *prop);

WebdavPList* webdav_plist_clone(pool_handle_t *pool, WebdavPList *list);
WebdavPList* webdav_plist_clone_s(
        pool_handle_t *pool,
        WebdavPList *list,
        size_t *newlen);

size_t webdav_plist_size(WebdavPList *list);

int webdav_nslist_add(
        pool_handle_t *pool,
        WebdavNSList **begin,
        WebdavNSList **end,
        WSNamespace *ns);

WebdavPListIterator webdav_plist_iterator(WebdavPList **list);
int webdav_plist_iterator_next(WebdavPListIterator *i, WebdavPList **cur);
void webdav_plist_iterator_remove_current(WebdavPListIterator *i);

WSNamespace* webdav_dav_namespace(void);
WebdavProperty* webdav_resourcetype_collection(void);
WebdavProperty* webdav_resourcetype_empty(void);
WebdavProperty* webdav_dav_property(
        pool_handle_t *pool,
        const char *name);

int webdav_resource_add_dav_stringproperty(
        WebdavResource *res,
        pool_handle_t pool,
        const char *name,
        const char *str,
        size_t len);
int webdav_resource_add_stringproperty(
        WebdavResource *res,
        pool_handle_t pool,
        const char *xmlns_prefix,
        const char *xmlns_href,
        const char *name,
        const char *str,
        size_t len);

int webdav_property_set_value(
        WebdavProperty *property,
        pool_handle_t *pool,
        char *value);

WebdavVFSProperties webdav_vfs_properties(
        WebdavPList **plistInOut,
        WSBool removefromlist,
        uint32_t flags);

int webdav_add_vfs_properties(
        WebdavResource *res,
        pool_handle_t *pool,
        WebdavVFSProperties properties,
        struct stat *s);

int wsxml_iterator(
        pool_handle_t *pool,
        WSXmlNode *node,
        wsxml_func begincb,
        wsxml_func endcb,
        void *udata);

WebdavNSList* wsxml_get_required_namespaces(
        pool_handle_t *pool,
        WSXmlNode *node,
        int *error);

WSXmlData* wsxml_node2data(
        pool_handle_t *pool,
        WSXmlNode *node);

/*
 * converts a property list to a string
 * 
 * namespaces are separated by a newline character and have the format:
 * <prefix>:<href>
 */
char* wsxml_nslist2string(pool_handle_t *pool, WebdavNSList *nslist);

/*
 * converts a namespace list string (created by wsxml_nslist2string) to
 * a WebdavNSList object
 */
WebdavNSList* wsxml_string2nslist(pool_handle_t *pool, char *nsliststr);

#ifdef	__cplusplus
}
#endif

#endif	/* WS_WEBDAV_H */