New API calls iso_local_get_lfa_flags(), iso_local_set_lfa_flags(), iso_node_get_lfa_flags(), iso_node_set_lfa_flags(), iso_util_decode_lfa_flags(), iso_util_encode_lfa_flags()

Makefile.am

@@ -1,6 +1,6 @@
 
 # Copyright (c) 2007 Vreixo Formoso
-# Copyright (c) 2009 - 2019 Thomas Schmitt
+# Copyright (c) 2009 - 2024 Thomas Schmitt
 # Provided under the terms of the GNU General Public License version 2 or later.
 
 # ts A90315 : LIBBURNIA_PKGCONFDIR is defined OS specific in acinclude.m4
@@ -22,11 +22,12 @@ ACLOCAL_AMFLAGS = -I ./
 libisofs_libisofs_la_LDFLAGS = \
 	-version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE) $(LIBLDFLAGS)
 
-# Eventually enabling system adapters for ACL and EA.
+# Enabling system adapters for ACL and EA.
-# ts A90409: Eventually enabling use of zlib.
+# ts A90409: Enabling use of zlib.
-# ts B00927: Eventually enabling use of libjte (Jigdo Template Extraction)
+# ts B00927: Enabling use of libjte (Jigdo Template Extraction)
-libisofs_libisofs_la_CFLAGS = $(LIBACL_DEF) $(XATTR_DEF) $(ZLIB_DEF) \
+# ts C40713: Enabling system adapter for Linux chattr(1) flags
-                              $(LIBJTE_DEF)
+libisofs_libisofs_la_CFLAGS = $(LIBACL_DEF) $(XATTR_DEF) $(LFA_DEF) \
+                              $(ZLIB_DEF) $(LIBJTE_DEF)
 
 # ts A90114 : added aaip_0_2.*
 

configure.ac

@@ -207,7 +207,7 @@ AC_ARG_ENABLE(xattr,
               [  --enable-xattr          Enable use of extended file attributes by libisofs, default=yes],
               , enable_xattr=yes)
 AC_ARG_ENABLE(xattr_h_pref_attr,
-              [  --enable-xattr-h-pref-attr   Prefer include file attr/xattr.h over sys/xattr.h, default=no],
+              [  --enable-xattr-h-pref-attr  Prefer include file attr/xattr.h over sys/xattr.h, default=no],
               , enable_xattr_h_pref_attr=no)
 
 XATTR_DEF=
@@ -286,6 +286,21 @@ XATTR_DEF="$XATTR_DEF $XATTR_ADDON_DEF"
 
 AC_SUBST(XATTR_DEF)
 
+dnl ts C40713
+LFA_DEF=
+AC_ARG_ENABLE(linux-attr-flags,
+[  --enable-linux-attr-flags   Enable processing of Linux chattr(1) flags, default=yes],
+               , linux_attr_flags=yes)
+if test x"$linux_attr_flags" = xyes; then
+    AC_CHECK_HEADER(linux/fs.h, LFA_DEF="-DLibisofs_with_aaip_lfa_flagS",
+                    LFA_DEF=)
+fi
+if test x"$LFA_DEF" = x; then
+    echo "disabled Linux chattr(1) flags"
+else
+    echo "enabled  Linux chattr(1) flags"
+fi
+AC_SUBST(LFA_DEF)
 
 dnl ts A90409
 AC_ARG_ENABLE(zlib,
@@ -306,7 +321,7 @@ AC_SUBST(ZLIB_DEF)
 
 dnl ts B00927
 AC_ARG_ENABLE(libjte,
-[  --enable-libjte           Enable use of libjte >= 2.0 by libisofs, default=yes],
+[  --enable-libjte         Enable use of libjte >= 2.0 by libisofs, default=yes],
                , enable_libjte=yes)
 if test "x$enable_libjte" = xyes; then
     LIBJTE_DEF="-DLibisofs_with_libjtE"

doc/susp_aaip_isofs_names.txt

@@ -126,6 +126,57 @@ Registered:
 
 -------------------------------------------------------------------------------
 
+Name:
+      isofs.fa
+
+Purpose:
+      Records the file attribute flags as of Linux program chattr(1) and
+      ioctl(FS_IOC_GETFLAGS) in <linux/fs.h> as bits in a byte string.
+      Known from Debian GNU/Linux 8 to 12 are:
+      bit0=  FS_SECRM_FL        's' zero blocks on deletion
+      bit1=  FS_UNRM_FL         'u' on delete prepare for undelete
+      bit2=  FS_COMPR_FL        'c' compress
+      bit3=  FS_SYNC_FL         'S' synchronous write
+      bit4=  FS_IMMUTABLE_FL    'i' immutable
+      bit5=  FS_APPEND_FL       'a' appending write only
+      bit6=  FS_NODUMP_FL       'd' dump(8) shall ignore this file
+      bit7=  FS_NOATIME_FL      'A' do not update atime
+      bit8=  FS_DIRTY_FL        'Z' compressed dirty file
+      bit9=  FS_COMPRBLK_FL     (? one or more compressed clusters) 
+      bit10= FS_NOCOMP_FL       'm' do not compress
+      bit11= FS_ECOMPR_FL       'E' compression error (old)
+             FS_ENCRYPT_FL      'E' encrypted file (new)
+      bit12= FS_BTREE_FL        (? btree format dir)
+             FS_INDEX_FL        'I' hash-indexed directory ?
+      bit13= FS_IMAGIC_FL       (? AFS directory)
+      bit14= FS_JOURNAL_DATA_FL 'j' data journalling
+      bit15= FS_NOTAIL_FL       't' no tail-merging
+      bit16= FS_DIRSYNC_FL      'D' synchronous directory updates
+      bit17= FS_TOPDIR_FL       'T' top of directory hierarchy
+      bit18= FS_HUGE_FILE_FL    ('h' huge file ? 'h' old, FS_HUGE_FILE_FL new)
+      bit19= FS_EXTENT_FL       'e' using extents
+      bit20= FS_DIRECTIO_FL     (? use direct i/o) (old)
+             FS_VERITY_FL       'V' fs-verity enabled (new)
+      bit21= FS_EA_INODE_FL     (? Inode used for large EA)
+      bit22= FS_EOFBLOCKS_FL    (? reserved for ext4)
+      bit23= FS_NOCOW_FL        'C' no copy on write
+      bit25= FS_DAX_FL          'x' direct access
+      bit28= FS_INLINE_DATA_FL  'N' data stored in inode
+      bit29= FS_PROJINHERIT_FL  'P' project hierarchy
+      bit30= FS_CASEFOLD_FL     'F' case-insensitive directory lookups
+      bit31= FS_RESERVED_FL     (? reserved for ext2 lib)
+
+Format of Value:
+      A byte string which begins with the most significant byte.
+
+Example:
+      (FS_SECRM_FL|FS_APPEND_FL|FS_NOCOMP_FL) = 0x421
+      {   4 ,  33 }
+Registered:
+      12 Jul 2024 by Thomas Schmitt for libisofs.
+
+-------------------------------------------------------------------------------
+
 Name:
       isofs.hb
 
@@ -224,7 +275,7 @@ Registered:
 -------------------------------------------------------------------------------
 
 This text is under
-Copyright (c) 2009 - 2015 Thomas Schmitt <scdbackup@gmx.net>
+Copyright (c) 2009 - 2024 Thomas Schmitt <scdbackup@gmx.net>
 It shall only be modified in sync with libisofs and other software which
 makes use of AAIP. Please mail change requests to mailing list
 <bug-xorriso@gnu.org> or to the copyright holder in private.

libisofs/aaip-os-dummy.c

@@ -11,7 +11,7 @@
 
  To be included by aaip_0_2.c
 
- Copyright (c) 2009 - 2011 Thomas Schmitt
+ Copyright (c) 2009 - 2024 Thomas Schmitt
 
  This file is part of the libisofs project; you can redistribute it and/or
  modify it under the terms of the GNU General Public License version 2
@@ -82,6 +82,19 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
 }
 
 
+/* Obtain the file attribute flags of the given file as bit array in uint64_t.
+   The bit numbers are compatible to the FS_*_FL definitions in Linux.
+*/
+int aaip_get_lfa_flags(char *path, uint64_t *lfa_flags, int *max_bit,
+                       int *os_errno, int flag)
+{
+ *lfa_flags= 0;
+ *max_bit= -1;
+ *os_errno= 0;
+ return(0);
+}
+
+
 /* ------------------------------ Setters --------------------------------- */
 
 
@@ -134,3 +147,11 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
 }
 
 
+int aaip_set_lfa_flags(char *path, uint64_t lfa_flags, int max_bit,
+                       int *os_errno, int flag)
+{
+ *os_errno= 0;
+ return(0);
+}
+
+

libisofs/aaip-os-freebsd.c

@@ -7,7 +7,7 @@
 
  To be included by aaip_0_2.c for FreeBSD, NetBSD, and OpenBSD
 
- Copyright (c) 2009 - 2016 Thomas Schmitt
+ Copyright (c) 2009 - 2024 Thomas Schmitt
 
  This file is part of the libisofs project; you can redistribute it and/or
  modify it under the terms of the GNU General Public License version 2
@@ -388,6 +388,9 @@ static int get_single_attr(char *path, char *name, size_t *value_length,
                                by "user."
                         bit4=  do not return trivial ACL that matches st_mode
                         bit5=  in case of symbolic link: inquire link target
+                        bit6=  do not obtain Linux style file attribute flags
+                               (chattr).
+                               This obtaining is not implemented here anyways.
                         bit15= free memory of names, value_lengths, values
    @return              1   ok
                         2   ok, no permission to inspect non-user namespaces
@@ -601,6 +604,10 @@ ex:;
                                I.e. those which are not from name space
                                EXTATTR_NAMESPACE_USER
                         bit4=  do not return trivial ACL that matches st_mode
+                        bit5=  in case of symbolic link: inquire link target
+                        bit6=  do not obtain Linux style file attribute flags
+                               (chattr).
+                               This obtaining is not implemented here anyways.
                         bit15= free memory of names, value_lengths, values
    @return              >0  ok
                         <=0 error
@@ -705,6 +712,19 @@ ex:;
 #endif /* Libisofs_old_freebsd_acl_adapteR */
 
 
+/* Obtain the file attribute flags of the given file as bit array in uint64_t.
+   The bit numbers are compatible to the FS_*_FL definitions in Linux.
+*/
+int aaip_get_lfa_flags(char *path, uint64_t *lfa_flags, int *max_bit,
+                       int *os_errno, int flag)
+{
+ *lfa_flags= 0;
+ *max_bit= -1;
+ *os_errno= 0;
+ return(0);
+}
+
+
 /* ------------------------------ Setters --------------------------------- */
 
 
@@ -1094,3 +1114,12 @@ ex:;
 
 #endif /* Libisofs_old_freebsd_acl_adapteR */
 
+
+int aaip_set_lfa_flags(char *path, uint64_t lfa_flags, int max_bit,
+                       int *os_errno, int flag)
+{
+ *os_errno= 0;
+ return(0);
+}
+
+

libisofs/aaip-os-linux.c

@@ -7,7 +7,7 @@
 
  To be included by aaip_0_2.c for Linux
 
- Copyright (c) 2009 - 2022 Thomas Schmitt
+ Copyright (c) 2009 - 2024 Thomas Schmitt
 
  This file is part of the libisofs project; you can redistribute it and/or
  modify it under the terms of the GNU General Public License version 2
@@ -42,6 +42,11 @@
 #endif
 #endif
 
+#ifdef Libisofs_with_aaip_lfa_flagS
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+#endif
+ 
 
 /* ------------------------------ Inquiry --------------------------------- */
 
@@ -50,14 +55,16 @@
         Bitfield for control purposes
              bit0= inquire availability of ACL
              bit1= inquire availability of xattr
-             bit2 - bit7= Reserved for future types.
+             bit2= inquire availability of Linux-like file attribute flags
+             bit3 - bit7= Reserved for future types.
                           It is permissibile to set them to 1 already now.
              bit8 and higher: reserved, submit 0
    @return
         Bitfield corresponding to flag. If bits are set, th
              bit0= ACL adapter is enabled
              bit1= xattr adapter is enabled
-             bit2 - bit7= Reserved for future types.
+             bit2= Linux-like file attribute flags adapter is enabled
+             bit3 - bit7= Reserved for future types.
              bit8 and higher: reserved, do not interpret these
 */
 int aaip_local_attr_support(int flag)
@@ -68,11 +75,21 @@ int aaip_local_attr_support(int flag)
  if(flag & 1)
    ret|= 1;
 #endif
+
 #ifdef Libisofs_with_aaip_xattR
  if(flag & 2)
    ret|= 2;
 #endif
 
+#ifdef Libisofs_with_aaip_lfa_flagS
+#ifdef FS_IOC_GETFLAGS
+#ifdef FS_IOC_SETFLAGS
+ if(flag & 4)
+   ret|= 4;
+#endif
+#endif
+#endif
+
  return(ret);
 }
 
@@ -260,6 +277,8 @@ static int get_single_attr(char *path, char *name, size_t *value_length,
                                by "user."
                         bit4=  do not return trivial ACL that matches st_mode
                         bit5=  in case of symbolic link: inquire link target
+                        bit6=  do not obtain Linux style file attribute flags
+                               (chattr)
                         bit15= free memory of names, value_lengths, values
    @return              1  ok
                         (reserved for FreeBSD: 2 ok, no permission to inspect
@@ -288,6 +307,11 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
 #ifdef Libisofs_aaip_get_attr_activE
  ssize_t i, num_names= 0;
 #endif
+#ifdef Libisofs_with_aaip_lfa_flagS
+ uint64_t lfa_flags;
+ int max_bit, os_errno, lfa_length;
+ unsigned char lfa_value[8];
+#endif
 
  if(flag & (1 << 15)) { /* Free memory */
    {ret= 1; goto ex;}
@@ -349,6 +373,13 @@ ex:;
  if(flag & 1)
    num_names++;
 
+#endif
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+
+ if(!(flag & 64))
+   num_names++;
+
 #endif
 
  if(num_names == 0)
@@ -397,7 +428,7 @@ ex:;
    aaip_get_acl_text(path, &a_acl_text, flag & (16 | 32));
    aaip_get_acl_text(path, &d_acl_text, 1 | (flag & 32));
    if(a_acl_text == NULL && d_acl_text == NULL)
-     {ret= 1; goto ex;}
+     goto try_lfa_flags;
    ret= aaip_encode_both_acl(a_acl_text, d_acl_text, (mode_t) 0,
                              &acl_len, &acl, (flag & 2));
    if(ret <= 0)
@@ -415,6 +446,30 @@ ex:;
 
 #endif /* Libisofs_with_aaip_acL */
 
+try_lfa_flags:;
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+
+ if(!(flag & 64)) {
+   ret= aaip_get_lfa_flags(path, &lfa_flags, &max_bit, &os_errno, 0);
+   if(ret > 0) {
+     ret= aaip_encode_lfa_flags(lfa_flags, lfa_value, &lfa_length, 0);
+     if(ret > 0) {
+       (*names)[*num_attrs]= strdup("isofs.fa");
+       if((*names)[*num_attrs] == NULL)
+         {ret= -1; goto ex;}
+       (*values)[*num_attrs]= calloc(lfa_length, 1);
+       if((*values)[*num_attrs] == NULL)
+         {ret= -1; goto ex;}
+       memcpy((*values)[*num_attrs], (char *) lfa_value, lfa_length);
+       (*value_lengths)[*num_attrs]= lfa_length;
+       (*num_attrs)++;
+     }
+   }
+ }
+
+#endif /* Libisofs_with_aaip_lfa_flagS */
+
  ret= 1;
 ex:;
 #ifdef Libisofs_with_aaip_acL
@@ -455,6 +510,69 @@ ex:;
 }
 
 
+/* Obtain the file attribute flags of the given file as bit array in uint64_t.
+   The bit numbers are compatible to the FS_*_FL definitions in Linux
+   include file <linux/fs.h>. A (possibly outdated) copy of them is in
+   doc/susp_aaip_isofs_names.txt, name isofs.fa .
+   The attribute flags of other systems may or may not be mappable to these
+   flags.
+   @param path          Path to the file
+   @param lfa_flags     Will get filled with the FS_*_FL
+   @param max_bit       Will tell the highest bit that is possibly set
+                        (-1 = surely no bit is valid)
+   @param flag          Bitfield for control purposes. Submit 0.
+   @return              1= ok, all local attribute flags are in lfa_flags
+                        2= ok, but some local flags could not be mapped to
+                           the FS_*_FL bits
+                        0= local flag retrieval not enabled at compile time
+                        <0 error with system calls
+*/
+int aaip_get_lfa_flags(char *path, uint64_t *lfa_flags, int *max_bit,
+                       int *os_errno, int flag)
+{
+ int ret= 0;
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+ int fd;
+ long ioctl_result= 0;
+#endif
+
+ *lfa_flags= 0;
+ *max_bit= -1;
+ *os_errno= 0;
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+#ifdef FS_IOC_GETFLAGS
+ fd= open(path, O_RDONLY | O_NDELAY);
+ if(fd == -1) {
+   aaip_local_error("open", path, errno, 0);
+   *os_errno= errno;
+   return(-1);
+ }
+ ret= ioctl(fd, FS_IOC_GETFLAGS, &ioctl_result);
+ close(fd);
+ if(ret == -1) {
+   aaip_local_error("ioctl(FS_IOC_GETFLAGS)", path, errno, 0);
+   *os_errno= errno;
+   return(-1);
+ }
+ *lfa_flags= ioctl_result;
+ if(*lfa_flags < 1 << 24)
+   *max_bit= 23;
+ else if(*lfa_flags < (uint64_t) 1 << 32)
+   *max_bit= 31;
+ else
+   *max_bit= sizeof(long) * 8 - 1;
+
+ ret= 1;
+   
+#endif /* FS_IOC_GETFLAGS */
+#endif /* Libisofs_with_aaip_lfa_flagS */
+
+ return(ret);
+}
+
+
 /* ------------------------------ Setters --------------------------------- */
 
 
@@ -749,3 +867,49 @@ ex:;
 }
 
 
+int aaip_set_lfa_flags(char *path, uint64_t lfa_flags, int max_bit,
+                       int *os_errno, int flag)
+{
+ int ret= 0;
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+ int fd;
+ long ioctl_arg;
+#endif
+
+ *os_errno= 0;
+
+#ifdef Libisofs_with_aaip_lfa_flagS
+#ifdef FS_IOC_GETFLAGS
+
+ if(max_bit > (int) sizeof(long) * 8 - 1) {
+   aaip_local_error("ioctl(FS_IOC_SETFLAGS) with too many bits", path, 0, 0);
+   return(-1);
+ }
+   
+ fd= open(path, O_RDONLY | O_NDELAY);
+ if(fd == -1) {
+   aaip_local_error("open", path, errno, 0);
+   *os_errno= errno;
+   return(-1);
+ }
+ if(max_bit < 0)
+   ioctl_arg= 0;
+ else
+   ioctl_arg= lfa_flags;
+ ret= ioctl(fd, FS_IOC_SETFLAGS, ioctl_arg);
+ close(fd);
+ if(ret == -1) {
+   aaip_local_error("ioctl(FS_IOC_SETFLAGS)", path, errno, 0);
+   *os_errno= errno;
+   return(-1);
+ }
+ ret= 1;
+   
+#endif /* FS_IOC_GETFLAGS */
+#endif /* Libisofs_with_aaip_lfa_flagS */
+
+ return(ret);
+}
+
+

libisofs/aaip_0_2.c

@@ -900,6 +900,26 @@ int aaip_add_acl_st_mode(char *acl_text, mode_t st_mode, int flag)
 }
 
 
+int aaip_encode_lfa_flags(uint64_t lfa_flags, unsigned char value[8],
+                          int *length, int flag)
+{
+ int i, l;
+
+ *length = 1;
+ value[0] = 0;
+
+ /* How many bytes are needed to catch all set bits ? Minimum is 1. */
+ l= 8;
+ for(i= 1; i < l; i++)
+   if(lfa_flags < (uint64_t) 1 << (i * 8))
+ break;
+ *length= i;
+ for(i= 0; i < *length; i++)
+   value[*length - 1 - i]= (lfa_flags >> (8 * i)) & 0xff;
+ return(1);
+}
+
+
 /* --------------------------------- Decoder ---------------------------- */
 
 /* --- private --- */

libisofs/aaip_0_2.h

@@ -9,7 +9,7 @@
 
  test/aaip_0_2.h - Public declarations
 
- Copyright (c) 2009 - 2016 Thomas Schmitt
+ Copyright (c) 2009 - 2024 Thomas Schmitt
 
  This file is part of the libisofs project; you can redistribute it and/or
  modify it under the terms of the GNU General Public License version 2
@@ -155,6 +155,17 @@ int aaip_cleanout_st_mode(char *acl_text, mode_t *st_mode, int flag);
 int aaip_add_acl_st_mode(char *acl_text, mode_t st_mode, int flag);
 
 
+/* Encode a Linux style file attribute flag bits array to a byte string
+   which represents the flags bits in isofs.fa .
+   @param lfa_flags   Bit array as obtained by aaip_get_lfa_flags()
+   @param value       Will be filled with 1 to 8 byte values
+   @param length      Will return the number of filled-in value bytes
+   @return            <0 failure
+*/
+int aaip_encode_lfa_flags(uint64_t lfa_flags, unsigned char value[8],
+                          int *length, int flag);
+
+
 /* ------ OS interface ------ */
 
 /* See also API iso_local_attr_support().
@@ -162,14 +173,17 @@ int aaip_add_acl_st_mode(char *acl_text, mode_t st_mode, int flag);
         Bitfield for control purposes
              bit0= inquire availability of ACL
              bit1= inquire availability of xattr
-             bit2 - bit7= Reserved for future types.
+             bit2= inquire availability of Linux-like file attribute flags
+             bit3 - bit7= Reserved for future types.
                           It is permissibile to set them to 1 already now.
              bit8 and higher: reserved, submit 0
    @return
         Bitfield corresponding to flag. If bits are set, th
              bit0= ACL adapter is enabled
              bit1= xattr adapter is enabled
-             bit2 - bit7= Reserved for future types.
+             bit2= Linux-like file attribute flags adapter is enabled
+             bit3 - bit7= Reserved for future types.
+                          It is permissibile to set them to 1 already now.
              bit8 and higher: reserved, do not interpret these
 */
 int aaip_local_attr_support(int flag);
@@ -210,6 +224,9 @@ int aaip_get_acl_text(char *path, char **text, int flag);
                                I.e. those with a name which does not begin
                                by "user."
                         bit4=  do not return trivial ACL that matches st_mode
+                        bit5=  in case of symbolic link: inquire link target
+                        bit6=  do not obtain Linux style file attribute flags
+                               (chattr)
                         bit15= free memory of names, value_lengths, values
    @return              >0  ok
                         <=0 error
@@ -218,6 +235,28 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
                        size_t **value_lengths, char ***values, int flag);
 
 
+/* Obtain the file attribute flags of the given file as bit array in uint64_t.
+   The bit numbers are compatible to the FS_*_FL definitions in Linux
+   include file <linux/fs.h>. A (possibly outdated) copy of them is in
+   doc/susp_aaip_isofs_names.txt, name isofs.fa .
+   The attribute flags of other systems may or may not be mappable to these
+   flags.
+   @param path          Path to the file
+   @param lfa_flags     Will get filled with the FS_*_FL
+   @param max_bit       Will tell the highest bit that is possibly set
+                        (-1 = surely no bit is valid)
+   @param os_errno      Will get filled with errno if a system call fails
+   @param flag          Bitfield for control purposes. Submit 0.
+   @return              1= ok, all local attribute flags are in lfa_flags
+                        2= ok, but some local flags could not be mapped to
+                           the FS_*_FL bits
+                        0= local flags retrieval not enabled at compile time
+                        <0 error with system calls
+*/
+int aaip_get_lfa_flags(char *path, uint64_t *lfa_flags, int *max_bit,
+                       int *os_errno, int flag);
+
+
 /* --------------------------------- Decoder ---------------------------- */
 
 /*
@@ -515,5 +554,29 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
                        size_t *value_lengths, char **values,
                        int *errnos, int flag);
 
+
+/* Bring the given file attribute flags into effect with the given file.
+   The bit numbers are compatible to the FS_*_FL definitions in Linux
+   include file <linux/fs.h>. A (possibly outdated) copy of them is in
+   doc/susp_aaip_isofs_names.txt, name isofs.fa .
+   The attribute flags of other systems may or may not be mappable to these
+   flags.
+   @param path          Path to the file
+   @param lfa_flags     File attribute flag bits
+   @param max_bit       Gives an upper limit of the highest set flag bit.
+                        (-1 = surely no bit is valid)
+                        On Linux this must be smaller than sizeof(long) * 8.
+   @param os_errno      Will get filled with errno if a system call fails
+   @param flag          Bitfield for control purposes. Submit 0.
+   @return              1= ok, all lfa_flags bits were written
+                        2= ok, but some FS_*_FL bits could not be mapped to
+                           local flags
+                        0= local flags setting not enabled at compile time
+                        <0 error with system calls or with max_bit
+*/
+int aaip_set_lfa_flags(char *path, uint64_t lfa_flags, int max_bit,
+                       int *os_errno, int flag);
+
+
 #endif /* ! Aaip_h_is_includeD */
 

libisofs/builder.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2007 Vreixo Formoso
- * Copyright (c) 2009 - 2015 Thomas Schmitt
+ * Copyright (c) 2009 - 2024 Thomas Schmitt
  * 
  * This file is part of the libisofs project; you can redistribute it and/or 
  * modify it under the terms of the GNU General Public License version 2 
@@ -253,7 +253,8 @@ int default_create_node(IsoNodeBuilder *builder, IsoImage *image,
     ret = iso_file_source_get_aa_string(src, &aa_string,
             1 | (image->builder_ignore_acl << 1) |
                 (image->builder_ignore_ea << 2) |
-                (image->builder_take_all_ea << 3));
+                (image->builder_take_all_ea << 3) |
+                ((!image->builder_ignore_lfa_flags) << 4));
     if(ret == 2)
       image->blind_on_local_get_attrs = 1;
     if (ret > 0 && aa_string != NULL) {

libisofs/fs_local.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2007 Vreixo Formoso
- * Copyright (c) 2009 - 2017 Thomas Schmitt
+ * Copyright (c) 2009 - 2024 Thomas Schmitt
  * 
  * This file is part of the libisofs project; you can redistribute it and/or 
  * modify it under the terms of the GNU General Public License version 2 
@@ -507,12 +507,14 @@ int lfs_get_aa_string(IsoFileSource *src, unsigned char **aa_string, int flag)
 
     *aa_string = NULL;
 
-    if ((flag & 6 ) == 6) { /* Neither ACL nor xattr shall be read */
+    if ((flag & (2 | 4 | 16) ) == (2 | 4)) {
+        /* Neither ACL nor xattr shall be read, lfa_flags are not wanted */
         ret = 1;
         goto ex;
     }
     /* Obtain EAs and ACLs ("access" and "default"). ACLs encoded according
        to AAIP ACL representation. Clean out st_mode ACL entries.
+       Obtain Linux style attribute flags.
     */ 
     path = iso_file_source_get_path(src);
     if (path == NULL) {
@@ -521,7 +523,8 @@ int lfs_get_aa_string(IsoFileSource *src, unsigned char **aa_string, int flag)
     }
     ret = aaip_get_attr_list(path, &num_attrs, &names,
                              &value_lengths, &values,
-                             (!(flag & 2)) | 2 | (flag & 4) | (flag & 8) | 16);
+                             (!(flag & 2)) | 2 | (flag & 4) | (flag & 8) | 16 |
+                             ((!(flag & 16)) << 6));
     if (ret <= 0) {
         if (ret == -2)
             ret = ISO_AAIP_NO_GET_LOCAL;
@@ -863,11 +866,13 @@ int iso_local_set_acl_text(char *disk_path, char *text, int flag)
 int iso_local_get_attrs(char *disk_path, size_t *num_attrs, char ***names,
                         size_t **value_lengths, char ***values, int flag)
 {
-    int ret;
+    int ret, lfa;
 
+    lfa = (flag & 64) ^ 64;
     ret = aaip_get_attr_list(disk_path,
                              num_attrs, names, value_lengths, values,
-                             (flag & (1 | 4 | 8 | 32 | (1 << 15))) | 2 | 16);
+                             (flag & (1 | 4 | 8 | 32 | (1 << 15))) |
+                             2 | 16 | lfa);
     if (ret <= 0)
         return ISO_AAIP_NO_GET_LOCAL;
     return 1 + (ret == 2);
@@ -940,3 +945,90 @@ int iso_local_get_perms_wo_acl(char *disk_path, mode_t *st_mode, int flag)
     return 1;
 }
 
+/*
+ * @param flag
+ *      Bitfield for control purposes
+ *      bit5=  in case of symbolic link: inquire link target
+ * @return
+ *      1= ok, lfa_flags is valid
+ *      2= ok, but some local flags could not be mapped to the FS_*_FL bits
+ *      3= ok, symbolic link encountered, flag bit5 not set, lfa_flags set to 0
+ *      0= local flags retrieval not enabled at compile time
+ *     <0= error with system calls
+ */
+int iso_local_get_lfa_flags(char *disk_path, uint64_t *lfa_flags, int *max_bit,
+                            int *os_errno, int flag)
+{
+    int ret;
+    struct stat stbuf;
+
+    *lfa_flags = 0;
+    *max_bit = -1;
+    *os_errno = 0;
+    if (flag & 32)
+        ret = stat(disk_path, &stbuf);
+    else
+        ret = lstat(disk_path, &stbuf);
+    if (ret == -1) {
+        *os_errno = errno;
+        return -1;
+    }
+    if ((stbuf.st_mode & S_IFMT) == S_IFLNK && !(flag & 32))
+        return 3;
+    ret= aaip_get_lfa_flags(disk_path, lfa_flags, max_bit, os_errno, 0);
+    if(ret == 0)
+        return ISO_AAIP_NOT_ENABLED;
+    if (ret < 0)
+        return ISO_AAIP_NO_GET_LOCAL;
+    return ret;
+}
+
+
+/*
+ * @param flag          Bitfield for control purposes
+ *      bit0= do not try to set known superuser flags
+ *      bit1= set only known chattr settable flags
+ *      bit5= in case of symbolic link: inquire link target
+ * @return
+ *      1 = ok, all lfa_flags bits were written
+ *      2 = ok, but some FS_*_FL bits could not be mapped to local flags
+ *      3 = ok, symbolic link encountered, flag bit5 not set, nothing done
+ *     <0 = error
+ */
+int iso_local_set_lfa_flags(char *disk_path, uint64_t lfa_flags, int max_bit,
+                            int *os_errno, int flag)
+{
+    int ret;
+    struct stat stbuf;
+
+    /* chattr letters: User:         sucSdAmtDTCxPF
+                       Superuser:    iaj 
+                       Non-settable: Z(9)EI(13)heV(21)(22)N(31)
+    */
+    static uint64_t known_user_mask = 0x628384cf;
+    static uint64_t known_su_mask =   0x00004030;
+
+    *os_errno = 0;
+    if (flag & 32)
+        ret = stat(disk_path, &stbuf);
+    else
+        ret = lstat(disk_path, &stbuf);
+    if (ret == -1) {
+        *os_errno = errno;
+        return -1;
+    }
+    if ((stbuf.st_mode & S_IFMT) == S_IFLNK && !(flag & 32))
+        return 3;
+    if (flag & 1)
+        lfa_flags &= ~known_su_mask;
+    if (flag & 2)
+        lfa_flags &= known_user_mask | known_su_mask;
+    ret= aaip_set_lfa_flags(disk_path, lfa_flags, max_bit, os_errno, 0);
+    if(ret == 0)
+        return ISO_AAIP_NOT_ENABLED;
+    if(ret < 0)
+        return ISO_AAIP_NO_SET_LOCAL;
+    return ret;
+}
+
+

libisofs/image.c

@@ -200,6 +200,7 @@ int iso_image_new(const char *name, IsoImage **image)
     img->import_src = NULL;
     img->builder_ignore_acl = 1;
     img->builder_ignore_ea = 1;
+    img->builder_ignore_lfa_flags = 1;
     img->truncate_mode = 1;
     img->truncate_length = LIBISOFS_NODE_NAME_MAX;
     img->truncate_buffer[0] = 0;
@@ -629,6 +630,7 @@ void iso_image_set_ignore_aclea(IsoImage *image, int what)
 {
     image->builder_ignore_acl = (what & 1);
     image->builder_ignore_ea = !!(what & 2);
+    image->builder_ignore_lfa_flags= !(what & 4);
     image->builder_take_all_ea = !!(what & 8);
 }
 
@@ -637,6 +639,7 @@ int iso_image_get_ignore_aclea(IsoImage *image)
 {
     return image->builder_ignore_acl |
            (image->builder_ignore_ea << 1) |
+           ((!image->builder_ignore_lfa_flags) << 2) |
            (image->builder_take_all_ea << 3);
 }
 

libisofs/image.h

@@ -145,6 +145,13 @@ struct Iso_Image
      */
     unsigned int builder_ignore_ea : 1;
 
+    /**
+     * Whether to ignore Linux style file attribute flags (chattr).
+     * Not in effect with loading a complete ISO image but only with image
+     * manipulation.
+     */
+    unsigned int builder_ignore_lfa_flags : 1;
+
     /**
      * If not builder_ignore_ea : import all xattr namespaces from local
      *                            filesystem, not only "user.

libisofs/libisofs.h

@@ -1307,6 +1307,10 @@ int iso_image_new(const char *name, IsoImage **image);
  *     A bit field which sets the behavior:
  *     bit0= ignore ACLs if the external file object bears some
  *     bit1= ignore xattr if the external file object bears some
+ *     bit2= read Linux-like file attribute flags (chattr)
+ *           if the external file object bears some.
+ *           (I.e. a do-not-ignore, because ignoring was default before)
+ *           @since 1.5.8
  *     bit3= if not bit1: import all xattr namespaces, not only "user."
  *           @since 1.5.0
  *     all other bits are reserved
@@ -7263,6 +7267,9 @@ int iso_file_source_readlink(IsoFileSource *src, char *buf, size_t bufsiz);
  *                   bit3= if not bit2: import all xattr namespaces from
  *                                      local filesystem, not only "user."
  *                         @since 1.5.0
+ *                   bit4= Try to get Linux-like file attribute flags (chattr)
+ *                         as "isofs.fa"
+ *                         @since 1.5.8
  * @return           1 means success (*aa_string == NULL is possible)
  *                  <0 means failure and must b a valid libisofs error code
  *                     (e.g. ISO_FILE_ERROR if no better one can be found).
@@ -7780,6 +7787,53 @@ int iso_node_set_attrs(IsoNode *node, size_t num_attrs, char **names,
                        size_t *value_lengths, char **values, int flag);
 
 
+/**
+ * Obtain the Linux-like file attribute flags (chattr) as bit array.
+ * The bit numbers are compatible to the FS_*_FL definitions in Linux
+ * include file <linux/fs.h>. A (possibly outdated) copy of them is in
+ * doc/susp_aaip_isofs_names.txt, name isofs.fa .
+ * 
+ * @param node
+ *      The node that is to be inquired.
+ * @param lfa_flags
+ *      Will get filled with the FS_*_FL bits
+ * @param max_bit
+ *      Will tell the highest bit that is possibly set
+ *      (-1 = surely no bit is valid)
+ * @param flag
+ *      Bitfield for control purposes. Submit 0.
+ * @return
+ *      1 = ok, lfa_flags and max_bit are valid
+ *      0 = no Linux-like file attributes are associated with the node
+ *    < 0 = error
+ *
+ * @since 1.5.8
+ */
+int iso_node_get_lfa_flags(IsoNode *node, uint64_t *lfa_flags, int *max_bit,
+                           int flag);
+
+/**
+ * Set the Linux-like file attribute flags (chattr) which are associated with
+ * the node.
+ * The bit numbers are compatible to the FS_*_FL definitions in Linux
+ * include file <linux/fs.h>. A (possibly outdated) copy of them is in
+ * doc/susp_aaip_isofs_names.txt, name isofs.fa .
+ *
+ * @param node
+ *      The node that is to be manipulated.
+ * @param lfa_flags
+ *      File attribute flag bits
+ * @param flag
+ *      Bitfield for control purposes. Submit 0.
+ * @return
+ *      1 = ok
+ *    < 0 = error
+ *
+ * @since 1.5.8
+ */
+int iso_node_set_lfa_flags(IsoNode *node, uint64_t lfa_flags, int flag);
+
+
 /* ----- This is an interface to ACL and xattr of the local filesystem ----- */
 
 /**
@@ -7806,7 +7860,10 @@ int iso_node_set_attrs(IsoNode *node, size_t num_attrs, char **names,
  *      Bitfield corresponding to flag.
  *           bit0= ACL adapter is enabled
  *           bit1= xattr adapter is enabled
- *           bit2 - bit7= Reserved for future types.
+ *           bit2= Linux-like file attribute flags (chattr) adapter is enabled
+ *                 @since 1.5.8
+ *           bit3 - bit7= Reserved for future types.
+ *                        It is permissibile to set them to 1 already now.
  *           bit8 and higher: reserved, do not interpret these
  *
  * @since 1.1.6
@@ -7888,7 +7945,8 @@ int iso_local_get_perms_wo_acl(char *disk_path, mode_t *st_mode, int flag);
 
 
 /**
- * Get xattr and non-trivial ACLs of the given file in the local filesystem.
+ * Get xattr, non-trivial ACLs, and possible Linux-like file attribute flags
+ * (chattr) of the given file in the local filesystem.
  * The resulting data has finally to be disposed by a call to this function
  * with flag bit15 set.
  *
@@ -7913,6 +7971,7 @@ int iso_local_get_perms_wo_acl(char *disk_path, mode_t *st_mode, int flag);
  *      bit3=  do not ignore non-user attributes.
  *             I.e. those with a name which does not begin by "user."
  *      bit5=  in case of symbolic link: inquire link target
+ *      bit6=  obtain Linux-like file attribute flags (chattr) as "isofs.fa"
  *      bit15= free memory
  * @return
  *        1 ok
@@ -7978,6 +8037,121 @@ int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,
                         size_t *value_lengths, char **values, int flag);
 
 
+/**
+ * Obtain the Linux-like file attribute flags (chattr) of the given file as
+ * bit array.
+ * The bit numbers are compatible to the FS_*_FL definitions in Linux
+ * include file <linux/fs.h>. A (possibly outdated) copy of them is in
+ * doc/susp_aaip_isofs_names.txt, name isofs.fa .
+ * The attribute flags of other systems may or may not be mappable to these
+ * flags.
+ * @param disk_path
+ *      Path to the file
+ * @param lfa_flags
+ *      Will get filled with the FS_*_FL bits
+ * @param max_bit
+ *      Will tell the highest bit that is possibly set
+ *      (-1 = surely no bit is valid)
+ * @param os_errno
+ *      Will get filled with errno if a system call fails.
+ *      Else it will be filled with 0.
+ * @param flag
+ *      Bitfield for control purposes
+ *      bit5=  in case of symbolic link: inquire link target
+ * @return
+ *      1 = ok, lfa_flags is valid
+ *      2 = ok, but some local flags could not be mapped to the FS_*_FL bits
+ *      3 = ok, symbolic link encountered, flag bit5 not set,lfa_flags set to 0
+ *     <0 = error
+ *
+ * @since 1.5.8
+ */
+int iso_local_get_lfa_flags(char *disk_path, uint64_t *lfa_flags, int *max_bit,
+                            int *os_errno, int flag);
+
+
+/**
+ * Bring the given Linux-like file attribute flags (chattr) into effect with
+ * the given file.
+ * The bit numbers are compatible to the FS_*_FL definitions in Linux
+ * include file <linux/fs.h>. A (possibly outdated) copy of them is in
+ * doc/susp_aaip_isofs_names.txt, name isofs.fa .
+ * The attribute flags of other systems may or may not be mappable to these
+ * flags.
+ * @param disk_path
+ *      Path to the file
+ * @param lfa_flags
+ *      File attribute flag bits
+ * @param max_bit
+ *      Gives an upper limit of the highest possibly set flag bit.
+ *      (-1 = surely no bit is valid)
+ *      On Linux this must be smaller than sizeof(long) * 8.
+ * @param os_errno
+ *      Will get filled with errno if a system call fails.
+ *      Else it will be filled with 0.
+ * @param flag
+ *      Bitfield for control purposes
+ *      bit0= do not try to set known chattr superuser flags: iaj
+ *      bit1= set only known chattr settable flags: sucSiadAmjtDTCxPF
+ *      bit5= in case of symbolic link: operate on link target
+ * @return
+ *      1 = ok, all lfa_flags bits were written
+ *      2 = ok, but some FS_*_FL bits could not be mapped to local flags
+ *      3 = ok, symbolic link encountered, flag bit5 not set, nothing done
+ *     <0 = error
+ *
+ * @since 1.5.8
+ */
+int iso_local_set_lfa_flags(char *disk_path, uint64_t lfa_flags, int max_bit,
+                            int *os_errno, int flag);
+
+
+/**
+ * Convert the known set bits of the given Linux-like file attribute flags
+ * to a string of flag letters like expected by chattr(1).
+ *
+ * @param lfa_flags
+ *      File attribute flag bits to be converted
+ * @param flags_text
+ *      Will return the string of known set flag letters.
+ *      If it is not returned as NULL, then submit it to free(2) when
+ *      no longer needed.
+ * @param flag
+ *      Bitfield for control purposes.
+ *      bit0= produce lsattr(1) format with '-' and peculiar sequence
+ *            (This might be more prone to ISO_LFA_UNKNOWN_BIT. 
+ *             Some versions of lsattr showed less bits. Maybe newer versions
+ *             will show more bits.)
+ * @return
+ *      >0 = success
+ *      <0 = error
+ *           ISO_LFA_UNKNOWN_BIT indicates a partial result in flags_text
+ *      
+ * @since 1.5.8
+ */
+int iso_util_encode_lfa_flags(uint64_t lfa_flags, char **flags_text, int flag);
+
+
+/** 
+ * Convert the given string of flag letters to a bit array usable by
+ * iso_*_set_lfa_flags(). The letters are as expected by chattr(1) or shown
+ * by lsattr(1).
+ *
+ * @param flags_text
+ *      The string of flag letters to be converted
+ * @param lfa_flags
+ *      Will return the resultig file attribute flag bits
+ * @param flag
+ *      Bitfield for control purposes. Submit 0.
+ * @return
+ *      >0 = success
+ *      <0 = error
+ *      
+ * @since 1.5.8
+ */
+int iso_util_decode_lfa_flags(char *flags_text, uint64_t *lfa_flags, int flag);
+
+
 /* Default in case that the compile environment has no macro PATH_MAX.
 */
 #define Libisofs_default_path_maX 4096
@@ -9460,6 +9634,14 @@ int iso_conv_name_chars(IsoWriteOpts *opts, char *name, size_t name_len,
                                                        (WARNING,HIGH, -429) */
 #define ISO_CE_REMOVING_ATTR        0xD030FE53
 
+/** Unknown Linux-like chattr letter encountered during conversion
+                                                       (WARNING,HIGH, -430) */
+#define ISO_LFA_UNKNOWN_LETTER      0xD030FE52
+
+/** Unknown Linux-like file attribute flag bit encountered during conversion
+                                                       (WARNING,HIGH, -431) */
+#define ISO_LFA_UNKNOWN_BIT         0xD030FE51
+
 
 /* Internal developer note: 
    Place new error codes directly above this comment. 

libisofs/libisofs.ver

@@ -384,3 +384,13 @@ iso_zisofs_set_params;
 serial_id;
 local: *;
 };
+
+LIBISOFS6_1.5.8 {
+iso_local_get_lfa_flags;
+iso_local_set_lfa_flags;
+iso_node_get_lfa_flags;
+iso_node_set_lfa_flags;
+iso_util_decode_lfa_flags;
+iso_util_encode_lfa_flags;
+} LIBISOFS6;
+

libisofs/messages.c

@@ -573,6 +573,10 @@ const char *iso_error_to_msg(int errcode)
         return "Too many CE entries for single file when mounted by Linux";
     case ISO_CE_REMOVING_ATTR:
         return "Too many CE entries for single file, removing attributes";
+    case ISO_LFA_UNKNOWN_LETTER:
+        return "Unknown Linux-like chattr letter encountered during conversion";
+    case ISO_LFA_UNKNOWN_BIT:
+        return "Unknown Linux-like file attribute flag bit encountered during conversion";
     default:
         return "Unknown error";
     }

libisofs/node.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2007 Vreixo Formoso
- * Copyright (c) 2009 - 2023 Thomas Schmitt
+ * Copyright (c) 2009 - 2024 Thomas Schmitt
  *
  * This file is part of the libisofs project; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version 2 
@@ -2057,6 +2057,7 @@ ex:;
 
 /* @param flag
         bit0= delete ACL, too
+        bit1= delete file attribute flags (isofs.fa), too
 */
 int iso_node_remove_fattr(IsoNode *node, int flag)
 {
@@ -2072,7 +2073,8 @@ int iso_node_remove_fattr(IsoNode *node, int flag)
     /* Delete variables of all namespaces except isofs */
     w = 0;
     for (i = 0; i < num_attrs; i++) {
-        if (strncmp(names[i], "isofs.", 6) != 0) {
+        if (strncmp(names[i], "isofs.", 6) != 0 ||
+            ((flag & 2) && strcmp(names[i], "isofs.fa") == 0)) {
             free(names[i]);
             names[i] = NULL;
             free(values[i]);
@@ -2452,6 +2454,53 @@ ex:;
 }
 
 
+int iso_node_set_lfa_flags(IsoNode *node, uint64_t lfa_flags, int flag)
+{
+    static char *names = "isofs.fa";
+    static size_t value_lengths[1];
+    unsigned char value[8];
+    char *valuept;
+    int ret, l;
+
+    ret = aaip_encode_lfa_flags(lfa_flags, value, &l, 0);
+    if (ret < 0)
+        return ret; 
+    value_lengths[0] = l;
+    valuept= (char *) value;
+    ret = iso_node_set_attrs(node, (size_t) 1,
+                             &names, value_lengths, &valuept, 2 | 8);
+    return ret;
+}
+
+
+int iso_node_get_lfa_flags(IsoNode *node, uint64_t *lfa_flags, int *max_bit,
+                           int flag)
+{
+    int ret, i;
+    size_t value_len;
+    char *value = NULL;
+
+    *lfa_flags = 0;
+    *max_bit = -1;
+
+    ret = iso_node_lookup_attr(node, "isofs.fa", &value_len, &value, 0);
+    if (ret <= 0)
+        return ret;
+    if (value_len <= 0) {
+        *max_bit = 7;
+        return 1;
+    }
+    if (value_len > 8) {
+        value += value_len - 8;
+        value_len = 8;
+    }
+    for (i = 0; i < (int) value_len; i++)
+        *lfa_flags = (*lfa_flags << 8) | ((unsigned char *) value)[i];
+    *max_bit = value_len * 8 - 1;
+    return 1;
+}
+
+
 /* Function to identify and manage ZF parameters.
  * data is supposed to be a pointer to struct zisofs_zf_info
  */

libisofs/rockridge.c

@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2007 Vreixo Formoso
  * Copyright (c) 2007 Mario Danic
- * Copyright (c) 2009 - 2023 Thomas Schmitt
+ * Copyright (c) 2009 - 2024 Thomas Schmitt
  * 
  * This file is part of the libisofs project; you can redistribute it and/or 
  * modify it under the terms of the GNU General Public License version 2 
@@ -1600,10 +1600,10 @@ try_again:
             }
         } else if (retry == 2) {
             if ((t->opts->max_ce_drop_attr & 15) >= 2) {
-                ret = iso_node_remove_fattr(n->node, 1);
+                ret = iso_node_remove_fattr(n->node, 1 | 2);
                 if (ret > 0) {
                     iso_msg_submit(t->image->id, ISO_CE_REMOVING_ATTR, 0,
-                                   "Removed ACL");
+                                   "Removed ACL and attribute flags");
                     goto try_again;
                 }
             }

libisofs/util.c

@@ -2510,3 +2510,103 @@ int iso_nowtime(time_t *now, int flag)
     return 2;
 }
 
+
+/* Bit sequence as of Linux 6.1.0 <linux/fs.h> FS_*_FL .
+   Letters as of e2fsprogs 1.47.1, man chattr and lib/pf.c for lsattr(1).
+*/
+static char lfa_flag_letters[] = { 's', 'u', 'c', 'S', 'i', 'a', 'd', 'A',
+                                   'Z', '-', 'm', 'E', 'I', '-', 'j', 't',
+                                   'D', 'T', 'h', 'e', 'V', '-', '-', 'C',
+                                   '-', 'x', '-', '-', 'N', 'P', 'F', '-' };
+
+/* Sequence and coverage as of e2fsprogs 1.47.1, lib/pf.c for lsattr(1) */
+
+static int lsattr_permutation[] = {  0,  1,  3, 16,  4,  5,  6,  7,
+                                     2, 11, 14, 12, 15, 17, 19, 23,
+                                    25, 30, 28, 29, 20, 10, -1};
+static int num_lsattr_bits = 22;
+static int max_lsattr_bit = 30;
+static int non_lsattr_bits[] = {  8, 9, 13, 18, 21, 22, 24, 26, 27, -1 };
+
+
+/* @param flag bit0= produce lsattr format with '-' and peculiar sequence
+*/
+int iso_util_encode_lfa_flags(uint64_t lfa_flags, char **flags_text, int flag)
+{
+    int i, len = 0, w = 0, was_unknown = 0, pi;
+
+    *flags_text = NULL;
+    if (flag & 1)
+        goto lsattr_format;
+
+    for (i = 0; i < 64; i++)
+      if (lfa_flags & (((uint64_t) 1) << i))
+        len++;
+    *flags_text = calloc(len + 1, 1);
+    if (*flags_text == NULL)
+        return ISO_OUT_OF_MEM;
+
+    for (i = 0; i < 64; i++) {
+        if (!(lfa_flags & (((uint64_t) 1) << i)))
+    continue;
+        if (lfa_flag_letters[i] == '-') {
+            was_unknown = 1;
+        } else {
+            (*flags_text)[w++] = lfa_flag_letters[i];
+        }
+    }
+    flags_text[w] = 0;
+    if (was_unknown)
+        return ISO_LFA_UNKNOWN_BIT;
+    return ISO_SUCCESS;
+
+lsattr_format:;
+
+    *flags_text = calloc(num_lsattr_bits + 1, 1);
+    if (*flags_text == NULL)
+        return ISO_OUT_OF_MEM;
+
+    for (i = 0; i < num_lsattr_bits; i++) {
+        pi = lsattr_permutation[i];
+        if (pi < 0)
+    break;
+        if (lfa_flags & (((uint64_t) 1) << pi)) {
+            (*flags_text)[w++] = lfa_flag_letters[pi];
+        } else {
+            (*flags_text)[w++] = '-';
+        }
+    }
+    (*flags_text)[num_lsattr_bits] = 0;
+
+    for (i = 0; non_lsattr_bits[i] >= 0; i++)
+        if (lfa_flags & (((uint64_t) 1) << non_lsattr_bits[i]))
+            return ISO_LFA_UNKNOWN_BIT;
+    for (i= max_lsattr_bit + 1; i < 63; i++)
+        if (lfa_flags & (((uint64_t) 1) << i))
+            return ISO_LFA_UNKNOWN_BIT;
+    return ISO_SUCCESS;
+}
+
+
+int iso_util_decode_lfa_flags(char *flags_text, uint64_t *lfa_flags, int flag)
+{
+    int i, j, was_unknown = 0;
+
+    *lfa_flags = 0;
+    for (i = 0; flags_text[i] != 0; i++) {
+        if (flags_text[i] == '-')
+    continue;
+        for (j = 0; j < 64; j++)
+            if (lfa_flag_letters[j] == flags_text[i])
+        break;
+        if (j >= 64) {
+            was_unknown = 1;
+    continue;
+        }
+        *lfa_flags |= ((uint64_t) 1) << j;
+    }
+    if (was_unknown)
+        return ISO_LFA_UNKNOWN_LETTER;
+    return 1;
+}
+