ea.h

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/*
   Copyright (c) 2009 Frank Lahm <[email protected]>
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
*/
 
#ifndef ATALK_EA_H
#define ATALK_EA_H
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#if HAVE_ATTR_XATTR_H
#include <attr/xattr.h>
#elif HAVE_SYS_XATTR_H
#include <sys/xattr.h>
#endif
 
#ifdef HAVE_SYS_EA_H
#include <sys/ea.h>
#endif
 
#ifdef HAVE_SYS_EXTATTR_H
#include <sys/extattr.h>
#endif
 
#if defined(SOLARIS) && defined(HAVE_SYS_ATTR_H)
#include <sys/attr.h>
#endif
 
#ifndef ENOATTR
#define ENOATTR ENODATA
#endif
 
#include <atalk/vfs.h>
 
/*
 * This seems to be the current limit fo HFS+, we arbitrarily force that
 *  which also safes us from buffer overflows
 */
#define MAX_EA_SIZE 3802
 
/*
 * req_count has space for AFP response bitmap and length as well, so
 * 6 bytes
 */
#define MAX_REPLY_EXTRA_BYTES 6
 
/*
 * Library user must provide a static buffer of size ATTRNAMEBUFSIZ.
 * It's used when listing EAs as intermediate buffer. For afpd it's
 * defined in extattrs.c.
 */
#define ATTRNAMEBUFSIZ 4096
 
enum {
    kXAttrNoFollow = 0x1,
    kXAttrCreate = 0x2,
    kXAttrReplace = 0x4
};
 
#if !defined(HAVE_SETXATTR)
#define XATTR_CREATE  0x1       /* set value, fail if attr already exists */
#define XATTR_REPLACE 0x2       /* set value, fail if attr does not exist */
#endif
 
#if defined(SOLARIS) && defined(HAVE_SYS_ATTR_H)
#define SMB_ATTR_PREFIX "SUNWsmb:"
#define SMB_ATTR_PREFIX_LEN (sizeof(SMB_ATTR_PREFIX) - 1)
#endif
 
/* Names for our Extended Attributes adouble data */
#define AD_EA_META "org.netatalk.Metadata"
#define AD_EA_META_LEN (sizeof(AD_EA_META) - 1)
#ifdef __APPLE__
#define AD_EA_RESO "com.apple.ResourceFork"
#define EA_FINFO "com.apple.FinderInfo"
#define NOT_NETATALK_EA(a) (strcmp((a), AD_EA_META) != 0) && (strcmp((a), AD_EA_RESO) != 0) && (strcmp((a), EA_FINFO) != 0)
#else
#define AD_EA_RESO "org.netatalk.ResourceFork"
#define NOT_NETATALK_EA(a) (strcmp((a), AD_EA_META) != 0) && (strcmp((a), AD_EA_RESO) != 0)
#endif
 
/****************************************************************************************
 * Wrappers for native EA functions taken from Samba
 ****************************************************************************************/
ssize_t sys_getxattr(const char *path, const char *name, void *value,
                     size_t size);
ssize_t sys_lgetxattr(const char *path, const char *name, void *value,
                      size_t size);
ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size);
ssize_t sys_listxattr(const char *path, char *list, size_t size);
ssize_t sys_llistxattr(const char *path, char *list, size_t size);
#if 0
ssize_t sys_flistxattr(int filedes, char *list, size_t size);
#endif
ssize_t sys_flistxattr(int filedes, const char *path, char *list, size_t size);
int sys_removexattr(const char *path, const char *name);
int sys_lremovexattr(const char *path, const char *name);
#if 0
int sys_fremovexattr(int filedes, const char *name);
#endif
int sys_fremovexattr(int filedes, const char *path, const char *name);
int sys_setxattr(const char *path, const char *name, const void *value,
                 size_t size, int flags);
int sys_lsetxattr(const char *path, const char *name, const void *value,
                  size_t size, int flags);
int sys_fsetxattr(int filedes, const char *name, const void *value, size_t size,
                  int flags);
int sys_copyxattr(const char *src, const char *dst);
int sys_getxattrfd(int fd, const char *uname, int oflag, ...);
 
/****************************************************************************************
 * Stuff for our implementation of storing EAs in files in .AppleDouble dirs
 ****************************************************************************************/
 
#define EA_INITED   0xea494e54  /* ea"INT", for interfacing ea_open w. ea_close */
#define EA_MAGIC    0x61644541 /* "adEA" */
#define EA_VERSION1 0x01
#define EA_VERSION  EA_VERSION1
 
typedef enum {
    /* ea_open flags */
    EA_CREATE    = (1 << 1),    /* create if not existing on ea_open */
    EA_RDONLY    = (1 << 2),    /* open read only */
    EA_RDWR      = (1 << 3),    /* open read/write */
    /* ea_open internal flags */
    EA_DIR       = (1 << 4)     /* ea header file is for a dir, ea_open adds it as appropriate */
} eaflags_t;
 
#define EA_MAGIC_OFF   0
#define EA_MAGIC_LEN   4
#define EA_VERSION_OFF (EA_MAGIC_OFF + EA_MAGIC_LEN)
#define EA_VERSION_LEN 2
#define EA_COUNT_OFF   (EA_VERSION_OFF + EA_VERSION_LEN)
#define EA_COUNT_LEN   2
#define EA_HEADER_SIZE (EA_MAGIC_LEN + EA_VERSION_LEN + EA_COUNT_LEN)
 
/*
 * structs describing the layout of the Extended Attributes bookkeeping file.
 * This isn't really an AppleDouble structure, it's just a binary blob that
 * lives in our .AppleDouble directory too.
 */
 
struct ea_entry {
    /* len of ea_name without terminating 0 i.e. strlen(ea_name)*/
    size_t ea_namelen;
    /* size of EA */
    size_t ea_size;
    /* name of the EA */
    char *ea_name;
};
 
/* We read the on-disk data into *ea_data and parse it into this*/
struct ea {
    /* needed for interfacing ea_open w. ea_close */
    uint32_t ea_inited;
    /* vol handle, ea_close needs it */
    const struct vol *vol;
    /* for *at (cf openat) semantics, -1 means ignore */
    int dirfd;
    /* name of file, needed by ea_close too */
    char *filename;
    /* number of EAs in ea_entries array */
    unsigned int ea_count;
    /* malloced and realloced as needed by ea_count*/
    struct ea_entry(*ea_entries)[];
    /* open fd for ea_data */
    int ea_fd;
    /* flags */
    eaflags_t ea_flags;
    /* size of header file = size of ea_data buffer */
    size_t ea_size;
    /* pointer to buffer into that we actually *
     * read the disc file into                 */
    char *ea_data;
};
 
/* On-disk format, just for reference ! */
#if 0
struct ea_entry_ondisk {
    uint32_t ea_size;
    /* zero terminated string */
    char ea_name[];
};
 
struct ea_ondisk {
    uint32_t ea_magic;
    uint16_t ea_version;
    uint16_t ea_count;
    struct ea_entry_ondisk ea_entries[ea_count];
};
#endif /* 0 */
 
/* VFS inderected funcs ... : */
 
/* Default adouble EAs */
extern int get_easize(VFS_FUNC_ARGS_EA_GETSIZE);
extern int get_eacontent(VFS_FUNC_ARGS_EA_GETCONTENT);
extern int list_eas(VFS_FUNC_ARGS_EA_LIST);
extern int set_ea(VFS_FUNC_ARGS_EA_SET);
extern int remove_ea(VFS_FUNC_ARGS_EA_REMOVE);
/* ... EA VFS funcs that deal with file/dir cp/mv/rm */
extern int ea_deletefile(VFS_FUNC_ARGS_DELETEFILE);
extern int ea_renamefile(VFS_FUNC_ARGS_RENAMEFILE);
extern int ea_copyfile(VFS_FUNC_ARGS_COPYFILE);
extern int ea_chown(VFS_FUNC_ARGS_CHOWN);
extern int ea_chmod_file(VFS_FUNC_ARGS_SETFILEMODE);
extern int ea_chmod_dir(VFS_FUNC_ARGS_SETDIRUNIXMODE);
 
/* native EAs */
extern int sys_get_easize(VFS_FUNC_ARGS_EA_GETSIZE);
extern int sys_get_eacontent(VFS_FUNC_ARGS_EA_GETCONTENT);
extern int sys_list_eas(VFS_FUNC_ARGS_EA_LIST);
extern int sys_set_ea(VFS_FUNC_ARGS_EA_SET);
extern int sys_remove_ea(VFS_FUNC_ARGS_EA_REMOVE);
/* native EA VFSfile/dir cp/mv/rm */
extern int sys_ea_copyfile(VFS_FUNC_ARGS_COPYFILE);
 
/* dbd needs access to these */
extern int ea_open(const struct vol *restrict vol,
                   const char *restrict uname,
                   eaflags_t eaflags,
                   struct ea *restrict ea);
extern int ea_openat(const struct vol *restrict vol,
                     int dirfd,
                     const char *restrict uname,
                     eaflags_t eaflags,
                     struct ea *restrict ea);
extern int ea_close(struct ea *restrict ea);
extern char *ea_path(const struct ea *restrict ea,
                     const char *restrict eaname, int macname);
 
#endif /* ATALK_EA_H */