Support for POSIX ACLs

[chaz/tar] / src / xheader.c

diff --git a/src/xheader.c b/src/xheader.c
index 114a4994d5e84f82d468876ea7cdf8405784bf60..6141748a7228dc01d4f1272147f340fb5857b358 100644 (file)
--- a/src/xheader.c
+++ b/src/xheader.c
@@ -1,10 +1,11 @@
-/* This file is part of GNU Tar
+/* POSIX extended headers for tar.

 
 

-   Copyright (C) 2003 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2012
+   Free Software Foundation, Inc.

 
    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
 
    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, or (at your option) any later
+   Free Software Foundation; either version 3, or (at your option) any later

    version.
 
    This program is distributed in the hope that it will be useful, but
    version.
 
    This program is distributed in the hope that it will be useful, but


@@ -14,282 +15,1705 @@
 
    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
 
    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,

-   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

 
 

-#include "system.h"
+#include <system.h>

 
 

-#include <grp.h>
+#include <fnmatch.h>

 #include <hash.h>
 #include <hash.h>

-#include <pwd.h>
+#include <inttostr.h>

 #include <quotearg.h>
 
 #include "common.h"
 
 #include <quotearg.h>
 
 #include "common.h"
 

-/* Forward declarations */
-static void dummy_handler (struct tar_stat_info *st, char *keyword, char *arg);
+static void xheader_init (struct xheader *xhdr);
+static bool xheader_protected_pattern_p (char const *pattern);
+static bool xheader_protected_keyword_p (char const *keyword);
+static void xheader_set_single_keyword (char *) __attribute__ ((noreturn));

 
 

-static void atime_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void atime_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+/* Used by xheader_finish() */
+static void code_string (char const *string, char const *keyword,
+                        struct xheader *xhdr);

 
 

-static void gid_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void gid_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+/* Number of global headers written so far. */
+static size_t global_header_count;
+/* FIXME: Possibly it should be reset after changing the volume.
+   POSIX %n specification says that it is expanded to the sequence
+   number of current global header in *the* archive. However, for
+   multi-volume archives this will yield duplicate header names
+   in different volumes, which I'd like to avoid. The best way
+   to solve this would be to use per-archive header count as required
+   by POSIX *and* set globexthdr.name to, say,
+   $TMPDIR/GlobalHead.%p.$NUMVOLUME.%n.

 
 

-static void gname_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void gname_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+   However it should wait until buffer.c is finally rewritten */

 
 

-static void linkpath_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void linkpath_decoder (struct tar_stat_info *st, char *keyword, char *arg);  
+\f
+/* Interface functions to obstacks */
+
+static void
+x_obstack_grow (struct xheader *xhdr, const char *ptr, size_t length)
+{
+  obstack_grow (xhdr->stk, ptr, length);
+  xhdr->size += length;
+}
+
+static void
+x_obstack_1grow (struct xheader *xhdr, char c)
+{
+  obstack_1grow (xhdr->stk, c);
+  xhdr->size++;
+}
+
+static void
+x_obstack_blank (struct xheader *xhdr, size_t length)
+{
+  obstack_blank (xhdr->stk, length);
+  xhdr->size += length;
+}
+
+\f
+/* Keyword options */
+
+struct keyword_list
+{
+  struct keyword_list *next;
+  char *pattern;
+  char *value;
+};
+
+
+/* List of keyword patterns set by delete= option */
+static struct keyword_list *keyword_pattern_list;
+
+/* List of keyword/value pairs set by 'keyword=value' option */
+static struct keyword_list *keyword_global_override_list;
+
+/* List of keyword/value pairs set by 'keyword:=value' option */
+static struct keyword_list *keyword_override_list;
+
+/* List of keyword/value pairs decoded from the last 'g' type header */
+static struct keyword_list *global_header_override_list;
+
+/* Template for the name field of an 'x' type header */
+static char *exthdr_name;
+
+static char *exthdr_mtime_option;
+static time_t exthdr_mtime;
+
+/* Template for the name field of a 'g' type header */
+static char *globexthdr_name;
+
+static char *globexthdr_mtime_option;
+static time_t globexthdr_mtime;
+
+bool
+xheader_keyword_deleted_p (const char *kw)
+{
+  struct keyword_list *kp;
+
+  for (kp = keyword_pattern_list; kp; kp = kp->next)
+    if (fnmatch (kp->pattern, kw, 0) == 0)
+      return true;
+  return false;
+}
+
+static bool
+xheader_keyword_override_p (const char *keyword)
+{
+  struct keyword_list *kp;
+
+  for (kp = keyword_override_list; kp; kp = kp->next)
+    if (strcmp (kp->pattern, keyword) == 0)
+      return true;
+  return false;
+}
+
+static void
+xheader_list_append (struct keyword_list **root, char const *kw,
+                    char const *value)
+{
+  struct keyword_list *kp = xmalloc (sizeof *kp);
+  kp->pattern = xstrdup (kw);
+  kp->value = value ? xstrdup (value) : NULL;
+  kp->next = *root;
+  *root = kp;
+}
+
+static void
+xheader_list_destroy (struct keyword_list **root)
+{
+  if (root)
+    {
+      struct keyword_list *kw = *root;
+      while (kw)
+       {
+         struct keyword_list *next = kw->next;
+         free (kw->pattern);
+         free (kw->value);
+         free (kw);
+         kw = next;
+       }
+      *root = NULL;
+    }
+}
+
+static void
+xheader_set_single_keyword (char *kw)
+{
+  USAGE_ERROR ((0, 0, _("Keyword %s is unknown or not yet implemented"), kw));
+}
+
+static void
+assign_time_option (char **sval, time_t *tval, const char *input)
+{
+  uintmax_t u;
+  char *p;
+  time_t t = u = strtoumax (input, &p, 10);
+  if (t != u || *p || errno == ERANGE)
+    ERROR ((0, 0, _("Time stamp is out of allowed range")));
+  else
+    {
+      *tval = t;
+      assign_string (sval, input);
+    }
+}
+
+static void
+xheader_set_keyword_equal (char *kw, char *eq)
+{
+  bool global = true;
+  char *p = eq;
+
+  if (eq[-1] == ':')
+    {
+      p--;
+      global = false;
+    }

 
 

-static void mtime_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void mtime_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+  while (p > kw && isspace ((unsigned char) *p))
+    p--;

 
 

-static void ctime_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void ctime_decoder (struct tar_stat_info *st, char *keyword, char *arg);
-     
-static void path_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void path_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+  *p = 0;

 
 

-static void size_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void size_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+  for (p = eq + 1; *p && isspace ((unsigned char) *p); p++)
+    ;

 
 

-static void uid_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void uid_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+  if (strcmp (kw, "delete") == 0)
+    {
+      if (xheader_protected_pattern_p (p))
+       USAGE_ERROR ((0, 0, _("Pattern %s cannot be used"), quote (p)));
+      xheader_list_append (&keyword_pattern_list, p, NULL);
+    }
+  else if (strcmp (kw, "exthdr.name") == 0)
+    assign_string (&exthdr_name, p);
+  else if (strcmp (kw, "globexthdr.name") == 0)
+    assign_string (&globexthdr_name, p);
+  else if (strcmp (kw, "exthdr.mtime") == 0)
+    assign_time_option (&exthdr_mtime_option, &exthdr_mtime, p);
+  else if (strcmp (kw, "globexthdr.mtime") == 0)
+    assign_time_option (&globexthdr_mtime_option, &globexthdr_mtime, p);
+  else
+    {
+      if (xheader_protected_keyword_p (kw))
+       USAGE_ERROR ((0, 0, _("Keyword %s cannot be overridden"), kw));
+      if (global)
+       xheader_list_append (&keyword_global_override_list, kw, p);
+      else
+       xheader_list_append (&keyword_override_list, kw, p);
+    }
+}
+
+void
+xheader_set_option (char *string)
+{
+  char *token;
+  for (token = strtok (string, ","); token; token = strtok (NULL, ","))
+    {
+      char *p = strchr (token, '=');
+      if (!p)
+       xheader_set_single_keyword (token);
+      else
+       xheader_set_keyword_equal (token, p);
+    }
+}
+
+/*
+    string Includes:          Replaced By:
+     %d                       The directory name of the file,
+                              equivalent to the result of the
+                              dirname utility on the translated
+                              file name.
+     %f                       The filename of the file, equivalent
+                              to the result of the basename
+                              utility on the translated file name.
+     %p                       The process ID of the pax process.
+     %n                       The value of the 3rd argument.
+     %%                       A '%' character. */
+
+char *
+xheader_format_name (struct tar_stat_info *st, const char *fmt, size_t n)
+{
+  char *buf;
+  size_t len = strlen (fmt);
+  char *q;
+  const char *p;
+  char *dirp = NULL;
+  char *dir = NULL;
+  char *base = NULL;
+  char pidbuf[UINTMAX_STRSIZE_BOUND];
+  char const *pptr;
+  char nbuf[UINTMAX_STRSIZE_BOUND];
+  char const *nptr = NULL;
+
+  for (p = fmt; *p && (p = strchr (p, '%')); )
+    {
+      switch (p[1])
+       {
+       case '%':
+         len--;
+         break;

 
 

-static void uname_coder (struct tar_stat_info *st, char *keyword, char *arg); 
-static void uname_decoder (struct tar_stat_info *st, char *keyword, char *arg);
+       case 'd':
+         if (st)
+           {
+             if (!dirp)
+               dirp = dir_name (st->orig_file_name);
+             dir = safer_name_suffix (dirp, false, absolute_names_option);
+             len += strlen (dir) - 2;
+           }
+         break;
+
+       case 'f':
+         if (st)
+           {
+             base = last_component (st->orig_file_name);
+             len += strlen (base) - 2;
+           }
+         break;
+
+       case 'p':
+         pptr = umaxtostr (getpid (), pidbuf);
+         len += pidbuf + sizeof pidbuf - 1 - pptr - 2;
+         break;
+
+       case 'n':
+         nptr = umaxtostr (n, nbuf);
+         len += nbuf + sizeof nbuf - 1 - nptr - 2;
+         break;
+       }
+      p++;
+    }
+
+  buf = xmalloc (len + 1);
+  for (q = buf, p = fmt; *p; )
+    {
+      if (*p == '%')
+       {
+         switch (p[1])
+           {
+           case '%':
+             *q++ = *p++;
+             p++;
+             break;
+
+           case 'd':
+             if (dir)
+               q = stpcpy (q, dir);
+             p += 2;
+             break;
+
+           case 'f':
+             if (base)
+               q = stpcpy (q, base);
+             p += 2;
+             break;
+
+           case 'p':
+             q = stpcpy (q, pptr);
+             p += 2;
+             break;
+
+           case 'n':
+             if (nptr)
+               {
+                 q = stpcpy (q, nptr);
+                 p += 2;
+                 break;
+               }
+             /* else fall through */
+
+           default:
+             *q++ = *p++;
+             if (*p)
+               *q++ = *p++;
+           }
+       }
+      else
+       *q++ = *p++;
+    }
+
+  free (dirp);
+
+  /* Do not allow it to end in a slash */
+  while (q > buf && ISSLASH (q[-1]))
+    q--;
+  *q = 0;
+  return buf;
+}

 
 

+char *
+xheader_xhdr_name (struct tar_stat_info *st)
+{
+  if (!exthdr_name)
+    assign_string (&exthdr_name, "%d/PaxHeaders.%p/%f");
+  return xheader_format_name (st, exthdr_name, 0);
+}
+
+#define GLOBAL_HEADER_TEMPLATE "/GlobalHead.%p.%n"
+
+char *
+xheader_ghdr_name (void)
+{
+  if (!globexthdr_name)
+    {
+      size_t len;
+      const char *tmp = getenv ("TMPDIR");
+      if (!tmp)
+       tmp = "/tmp";
+      len = strlen (tmp) + sizeof (GLOBAL_HEADER_TEMPLATE); /* Includes nul */
+      globexthdr_name = xmalloc (len);
+      strcpy(globexthdr_name, tmp);
+      strcat(globexthdr_name, GLOBAL_HEADER_TEMPLATE);
+    }
+
+  return xheader_format_name (NULL, globexthdr_name, global_header_count + 1);
+}
+
+void
+xheader_write (char type, char *name, time_t t, struct xheader *xhdr)
+{
+  union block *header;
+  size_t size;
+  char *p;
+
+  size = xhdr->size;
+  switch (type)
+    {
+    case XGLTYPE:
+      if (globexthdr_mtime_option)
+       t = globexthdr_mtime;
+      break;
+
+    case XHDTYPE:
+      if (exthdr_mtime_option)
+       t = exthdr_mtime;
+      break;
+    }
+  header = start_private_header (name, size, t);
+  header->header.typeflag = type;
+
+  simple_finish_header (header);
+
+  p = xhdr->buffer;
+
+  do
+    {
+      size_t len;
+
+      header = find_next_block ();
+      len = BLOCKSIZE;
+      if (len > size)
+       len = size;
+      memcpy (header->buffer, p, len);
+      if (len < BLOCKSIZE)
+       memset (header->buffer + len, 0, BLOCKSIZE - len);
+      p += len;
+      size -= len;
+      set_next_block_after (header);
+    }
+  while (size > 0);
+  xheader_destroy (xhdr);
+
+  if (type == XGLTYPE)
+    global_header_count++;
+}
+
+void
+xheader_write_global (struct xheader *xhdr)
+{
+  if (keyword_global_override_list)
+    {
+      struct keyword_list *kp;
+
+      xheader_init (xhdr);
+      for (kp = keyword_global_override_list; kp; kp = kp->next)
+       code_string (kp->value, kp->pattern, xhdr);
+    }
+  if (xhdr->stk)
+    {
+      char *name;
+
+      xheader_finish (xhdr);
+      xheader_write (XGLTYPE, name = xheader_ghdr_name (), time (NULL), xhdr);
+      free (name);
+    }
+}
+
+void xheader_xattr_init (struct tar_stat_info *st)
+{
+  st->xattr_map = NULL;
+  st->xattr_map_size = 0;
+
+  st->acls_a_ptr = NULL;
+  st->acls_a_len = 0;
+  st->acls_d_ptr = NULL;
+  st->acls_d_len = 0;
+}
+
+void xheader_xattr_free (struct xattr_array *xattr_map, size_t xattr_map_size)
+{
+  size_t scan = 0;
+
+  while (scan < xattr_map_size)
+    {
+      free (xattr_map[scan].xkey);
+      free (xattr_map[scan].xval_ptr);
+
+      ++scan;
+    }
+  free (xattr_map);
+}
+
+static void xheader_xattr__add (struct xattr_array **xattr_map,
+                                size_t *xattr_map_size,
+                                const char *key, const char *val, size_t len)
+{
+  size_t pos = (*xattr_map_size)++;
+
+  *xattr_map = xrealloc (*xattr_map,
+                         *xattr_map_size * sizeof(struct xattr_array));
+  (*xattr_map)[pos].xkey = xstrdup (key);
+  (*xattr_map)[pos].xval_ptr = xmemdup (val, len + 1);
+  (*xattr_map)[pos].xval_len = len;
+}
+
+void xheader_xattr_add(struct tar_stat_info *st,
+                       const char *key, const char *val, size_t len)
+{
+  size_t klen = strlen (key);
+  char *xkey = xmalloc (strlen("SCHILY.xattr.") + klen + 1);
+  char *tmp = xkey;
+
+  tmp = stpcpy (tmp, "SCHILY.xattr.");
+  stpcpy (tmp, key);
+
+  xheader_xattr__add (&st->xattr_map, &st->xattr_map_size, xkey, val, len);
+
+  free (xkey);
+}
+
+void xheader_xattr_copy(const struct tar_stat_info *st,
+                        struct xattr_array **xattr_map, size_t *xattr_map_size)
+{
+  size_t scan = 0;
+
+  *xattr_map = NULL;
+  *xattr_map_size = 0;
+
+  while (scan < st->xattr_map_size)
+    {
+      char  *key = st->xattr_map[scan].xkey;
+      char  *val = st->xattr_map[scan].xval_ptr;
+      size_t len = st->xattr_map[scan].xval_len;
+
+      xheader_xattr__add(xattr_map, xattr_map_size, key, val, len);
+
+      ++scan;
+    }
+}
+
+\f

 /* General Interface */
 
 /* General Interface */
 

+#define XHDR_PROTECTED 0x01
+#define XHDR_GLOBAL    0x02
+

 struct xhdr_tab
 {
 struct xhdr_tab
 {

-  char *keyword;
-  void (*coder) (struct tar_stat_info *st, char *keyword, char *arg);
-  void (*decoder) (struct tar_stat_info *st, char *keyword, char *arg);
+  char const *keyword;
+  void (*coder) (struct tar_stat_info const *, char const *,
+                struct xheader *, void const *data);
+  void (*decoder) (struct tar_stat_info *, char const *, char const *, size_t);
+  int flags;
+  bool prefix; /* select handler comparing prefix only */

 };
 
 };
 

-struct xhdr_tab xhdr_tab[] = {
-  { "atime",   atime_coder,    atime_decoder },
-  { "comment", dummy_handler,  dummy_handler },
-  { "charset", dummy_handler,  dummy_handler },
-  { "ctime",   ctime_coder,    ctime_decoder },
-  { "gid",     gid_coder,      gid_decoder },
-  { "gname",   gname_coder,    gname_decoder },
-  { "linkpath",        linkpath_coder, linkpath_decoder },
-  { "mtime",   mtime_coder,    mtime_decoder },
-  { "path",    path_coder,     path_decoder },
-  { "size",    size_coder,     size_decoder },
-  { "uid",     uid_coder,      uid_decoder },
-  { "uname",   uname_coder,    uname_decoder },    
-  { NULL },
-};
+/* This declaration must be extern, because ISO C99 section 6.9.2
+   prohibits a tentative definition that has both internal linkage and
+   incomplete type.  If we made it static, we'd have to declare its
+   size which would be a maintenance pain; if we put its initializer
+   here, we'd need a boatload of forward declarations, which would be
+   even more of a pain.  */
+extern struct xhdr_tab const xhdr_tab[];

 
 

-static struct xhdr_tab *
-locate_handler (char *keyword)
+static struct xhdr_tab const *
+locate_handler (char const *keyword)

 {
 {

-  struct xhdr_tab *p;
+  struct xhdr_tab const *p;

 
   for (p = xhdr_tab; p->keyword; p++)
 
   for (p = xhdr_tab; p->keyword; p++)

-    if (strcmp (p->keyword, keyword) == 0)
-      return p;
+    if (p->prefix)
+      {
+        if (strncmp (p->keyword, keyword, strlen(p->keyword)) == 0)
+          return p;
+      }
+    else
+      {
+        if (strcmp (p->keyword, keyword) == 0)
+          return p;
+      }
+

   return NULL;
 }
 
   return NULL;
 }
 

-static int
-decode_record (char **p, struct tar_stat_info *st)
+static bool
+xheader_protected_pattern_p (const char *pattern)
+{
+  struct xhdr_tab const *p;
+
+  for (p = xhdr_tab; p->keyword; p++)
+    if (!p->prefix && (p->flags & XHDR_PROTECTED)
+        && fnmatch (pattern, p->keyword, 0) == 0)
+      return true;
+  return false;
+}
+
+static bool
+xheader_protected_keyword_p (const char *keyword)

 {
 {

+  struct xhdr_tab const *p;
+
+  for (p = xhdr_tab; p->keyword; p++)
+    if (!p->prefix && (p->flags & XHDR_PROTECTED)
+        && strcmp (p->keyword, keyword) == 0)
+      return true;
+  return false;
+}
+
+/* Decode a single extended header record, advancing *PTR to the next record.
+   Return true on success, false otherwise.  */
+static bool
+decode_record (struct xheader *xhdr,
+              char **ptr,
+              void (*handler) (void *, char const *, char const *, size_t),
+              void *data)
+{
+  char *start = *ptr;
+  char *p = start;
+  uintmax_t u;

   size_t len;
   size_t len;

-  char *keyword, *eqp;
-  char *start = *p;
-  struct xhdr_tab *t;
-
-  if (**p == 0)
-    return 1;
-  
-  len = strtoul (*p, p, 10);
-  if (**p != ' ')
-    {
-      ERROR ((0, 0, _("Malformed extended headed")));
-      return 1;
-    }
-  
-  keyword = ++*p;
-  for (;*p < start + len; ++*p)
-    if (**p == '=')
-      break;
+  char *len_lim;
+  char const *keyword;
+  char *nextp;
+  size_t len_max = xhdr->buffer + xhdr->size - start;

 
 

-  if (**p != '=')
+  while (*p == ' ' || *p == '\t')
+    p++;
+
+  if (! ISDIGIT (*p))

     {
     {

-      ERROR ((0, 0, _("Malformed extended headed")));
-      return 1;
+      if (*p)
+       ERROR ((0, 0, _("Malformed extended header: missing length")));
+      return false;

     }
 
     }
 

-  eqp = *p;
-  **p = 0;
+  errno = 0;
+  len = u = strtoumax (p, &len_lim, 10);
+  if (len != u || errno == ERANGE)
+    {
+      ERROR ((0, 0, _("Extended header length is out of allowed range")));
+      return false;
+    }
+
+  if (len_max < len)
+    {
+      int len_len = len_lim - p;
+      ERROR ((0, 0, _("Extended header length %*s is out of range"),
+             len_len, p));
+      return false;
+    }
+
+  nextp = start + len;
+
+  for (p = len_lim; *p == ' ' || *p == '\t'; p++)
+    continue;
+  if (p == len_lim)
+    {
+      ERROR ((0, 0,
+             _("Malformed extended header: missing blank after length")));
+      return false;
+    }
+
+  keyword = p;
+  p = strchr (p, '=');
+  if (! (p && p < nextp))
+    {
+      ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
+      return false;
+    }
+
+  if (nextp[-1] != '\n')
+    {
+      ERROR ((0, 0, _("Malformed extended header: missing newline")));
+      return false;
+    }
+
+  *p = nextp[-1] = '\0';
+  handler (data, keyword, p + 1, nextp - p - 2); /* '=' + trailing '\n' */
+  *p = '=';
+  nextp[-1] = '\n';
+  *ptr = nextp;
+  return true;
+}
+
+static void
+run_override_list (struct keyword_list *kp, struct tar_stat_info *st)
+{
+  for (; kp; kp = kp->next)
+    {
+      struct xhdr_tab const *t = locate_handler (kp->pattern);
+      if (t)
+       t->decoder (st, t->keyword, kp->value, strlen (kp->value));
+    }
+}
+
+static void
+decx (void *data, char const *keyword, char const *value, size_t size)
+{
+  struct xhdr_tab const *t;
+  struct tar_stat_info *st = data;
+
+  if (xheader_keyword_deleted_p (keyword)
+      || xheader_keyword_override_p (keyword))
+    return;
+

   t = locate_handler (keyword);
   if (t)
   t = locate_handler (keyword);
   if (t)

+    t->decoder (st, keyword, value, size);
+  else
+    WARNOPT (WARN_UNKNOWN_KEYWORD,
+            (0, 0, _("Ignoring unknown extended header keyword '%s'"),
+             keyword));
+}
+
+void
+xheader_decode (struct tar_stat_info *st)
+{
+  run_override_list (keyword_global_override_list, st);
+  run_override_list (global_header_override_list, st);
+
+  if (st->xhdr.size)
+    {
+      char *p = st->xhdr.buffer + BLOCKSIZE;
+      while (decode_record (&st->xhdr, &p, decx, st))
+       continue;
+    }
+  run_override_list (keyword_override_list, st);
+}
+
+static void
+decg (void *data, char const *keyword, char const *value,
+      size_t size __attribute__((unused)))
+{
+  struct keyword_list **kwl = data;
+  struct xhdr_tab const *tab = locate_handler (keyword);
+  if (tab && (tab->flags & XHDR_GLOBAL))
+    tab->decoder (data, keyword, value, size);
+  else
+    xheader_list_append (kwl, keyword, value);
+}
+
+void
+xheader_decode_global (struct xheader *xhdr)
+{
+  if (xhdr->size)

     {
     {

-      char endc;
-      char *value;
+      char *p = xhdr->buffer + BLOCKSIZE;

 
 

-      value = ++*p;
-      
-      endc = start[len-1];
-      start[len-1] = 0;
-      t->decoder (st, keyword, value);
-      start[len-1] = endc;
+      xheader_list_destroy (&global_header_override_list);
+      while (decode_record (xhdr, &p, decg, &global_header_override_list))
+       continue;
+    }
+}
+
+static void
+xheader_init (struct xheader *xhdr)
+{
+  if (!xhdr->stk)
+    {
+      xhdr->stk = xmalloc (sizeof *xhdr->stk);
+      obstack_init (xhdr->stk);

     }
     }

-  *eqp = '=';
-  *p = &start[len];
-  return 0;

 }
 
 void
 }
 
 void

-xheader_decode (struct tar_stat_info *st)
+xheader_store (char const *keyword, struct tar_stat_info *st,
+              void const *data)

 {
 {

-  char *p, *endp;
+  struct xhdr_tab const *t;

 
 

-  p = extended_header.blocks->buffer;
-  endp = &extended_header.blocks[extended_header.nblocks-1].buffer
-                                        [sizeof(extended_header.blocks[0])-1];
-  while (p < endp)
-    if (decode_record (&p, st))
-      break;
+  if (st->xhdr.buffer)
+    return;
+  t = locate_handler (keyword);
+  if (!t || !t->coder)
+    return;
+  if (xheader_keyword_deleted_p (keyword)
+      || xheader_keyword_override_p (keyword))
+    return;
+  xheader_init (&st->xhdr);
+  t->coder (st, keyword, &st->xhdr, data);

 }
 
 void
 }
 
 void

-xheader_read (union block *p, size_t size)
+xheader_read (struct xheader *xhdr, union block *p, size_t size)

 {
 {

-  size_t i;
-  
-  free (extended_header.blocks);
-  extended_header.nblocks = (size + BLOCKSIZE - 1) / BLOCKSIZE;
-  extended_header.blocks = xmalloc (sizeof (extended_header.blocks[0]) *
-                                           extended_header.nblocks);
-  set_next_block_after (p);
-  for (i = 0; i < extended_header.nblocks; i++)
+  size_t j = 0;
+
+  size += BLOCKSIZE;
+  xhdr->size = size;
+  xhdr->buffer = xmalloc (size + 1);
+  xhdr->buffer[size] = '\0';
+
+  do

     {
     {

-      p = find_next_block ();
-      memcpy (&extended_header.blocks[i], p, sizeof (p[0]));
+      size_t len = size;
+
+      if (len > BLOCKSIZE)
+       len = BLOCKSIZE;
+
+      if (!p)
+       FATAL_ERROR ((0, 0, _("Unexpected EOF in archive")));
+
+      memcpy (&xhdr->buffer[j], p->buffer, len);

       set_next_block_after (p);
       set_next_block_after (p);

+
+      p = find_next_block ();
+
+      j += len;
+      size -= len;
+    }
+  while (size > 0);
+}
+
+static void
+xheader_print_n (struct xheader *xhdr, char const *keyword,
+                char const *value, size_t vsize)
+{
+  size_t len = strlen (keyword) + vsize + 3; /* ' ' + '=' + '\n' */
+  size_t p;
+  size_t n = 0;
+  char nbuf[UINTMAX_STRSIZE_BOUND];
+  char const *np;
+
+  do
+    {
+      p = n;
+      np = umaxtostr (len + p, nbuf);
+      n = nbuf + sizeof nbuf - 1 - np;

     }
     }

+  while (n != p);
+
+  x_obstack_grow (xhdr, np, n);
+  x_obstack_1grow (xhdr, ' ');
+  x_obstack_grow (xhdr, keyword, strlen (keyword));
+  x_obstack_1grow (xhdr, '=');
+  x_obstack_grow (xhdr, value, vsize);
+  x_obstack_1grow (xhdr, '\n');
+}
+
+static void
+xheader_print (struct xheader *xhdr, char const *keyword, char const *value)
+{
+  xheader_print_n (xhdr, keyword, value, strlen (value));
+}
+
+void
+xheader_finish (struct xheader *xhdr)
+{
+  struct keyword_list *kp;
+
+  for (kp = keyword_override_list; kp; kp = kp->next)
+    code_string (kp->value, kp->pattern, xhdr);
+
+  xhdr->buffer = obstack_finish (xhdr->stk);
+}
+
+void
+xheader_destroy (struct xheader *xhdr)
+{
+  if (xhdr->stk)
+    {
+      obstack_free (xhdr->stk, NULL);
+      free (xhdr->stk);
+      xhdr->stk = NULL;
+    }
+  else
+    free (xhdr->buffer);
+  xhdr->buffer = 0;
+  xhdr->size = 0;
+}
+
+\f
+/* Buildable strings */
+
+void
+xheader_string_begin (struct xheader *xhdr)
+{
+  xhdr->string_length = 0;
+}
+
+void
+xheader_string_add (struct xheader *xhdr, char const *s)
+{
+  if (xhdr->buffer)
+    return;
+  xheader_init (xhdr);
+  xhdr->string_length += strlen (s);
+  x_obstack_grow (xhdr, s, strlen (s));
+}
+
+bool
+xheader_string_end (struct xheader *xhdr, char const *keyword)
+{
+  uintmax_t len;
+  uintmax_t p;
+  uintmax_t n = 0;
+  size_t size;
+  char nbuf[UINTMAX_STRSIZE_BOUND];
+  char const *np;
+  char *cp;
+
+  if (xhdr->buffer)
+    return false;
+  xheader_init (xhdr);
+
+  len = strlen (keyword) + xhdr->string_length + 3; /* ' ' + '=' + '\n' */
+
+  do
+    {
+      p = n;
+      np = umaxtostr (len + p, nbuf);
+      n = nbuf + sizeof nbuf - 1 - np;
+    }
+  while (n != p);
+
+  p = strlen (keyword) + n + 2;
+  size = p;
+  if (size != p)
+    {
+      ERROR ((0, 0,
+        _("Generated keyword/value pair is too long (keyword=%s, length=%s)"),
+             keyword, nbuf));
+      obstack_free (xhdr->stk, obstack_finish (xhdr->stk));
+      return false;
+    }
+  x_obstack_blank (xhdr, p);
+  x_obstack_1grow (xhdr, '\n');
+  cp = obstack_next_free (xhdr->stk) - xhdr->string_length - p - 1;
+  memmove (cp + p, cp, xhdr->string_length);
+  cp = stpcpy (cp, np);
+  *cp++ = ' ';
+  cp = stpcpy (cp, keyword);
+  *cp++ = '=';
+  return true;

 }
 
 \f
 /* Implementations */
 }
 
 \f
 /* Implementations */

+
+static void
+out_of_range_header (char const *keyword, char const *value,
+                    uintmax_t minus_minval, uintmax_t maxval)
+{
+  char minval_buf[UINTMAX_STRSIZE_BOUND + 1];
+  char maxval_buf[UINTMAX_STRSIZE_BOUND];
+  char *minval_string = umaxtostr (minus_minval, minval_buf + 1);
+  char *maxval_string = umaxtostr (maxval, maxval_buf);
+  if (minus_minval)
+    *--minval_string = '-';
+
+  /* TRANSLATORS: The first %s is the pax extended header keyword
+     (atime, gid, etc.).  */
+  ERROR ((0, 0, _("Extended header %s=%s is out of range %s..%s"),
+         keyword, value, minval_string, maxval_string));
+}
+
+static void
+code_string (char const *string, char const *keyword, struct xheader *xhdr)
+{
+  char *outstr;
+  if (!utf8_convert (true, string, &outstr))
+    {
+      /* FIXME: report error */
+      outstr = xstrdup (string);
+    }
+  xheader_print (xhdr, keyword, outstr);
+  free (outstr);
+}
+
+static void
+decode_string (char **string, char const *arg)
+{
+  if (*string)
+    {
+      free (*string);
+      *string = NULL;
+    }
+  if (!utf8_convert (false, arg, string))
+    {
+      /* FIXME: report error and act accordingly to --pax invalid=UTF-8 */
+      assign_string (string, arg);
+    }
+}
+
+static void
+code_time (struct timespec t, char const *keyword, struct xheader *xhdr)
+{
+  char buf[TIMESPEC_STRSIZE_BOUND];
+  xheader_print (xhdr, keyword, code_timespec (t, buf));
+}
+
+enum decode_time_status
+  {
+    decode_time_success,
+    decode_time_range,
+    decode_time_bad_header
+  };
+
+static enum decode_time_status
+_decode_time (struct timespec *ts, char const *arg, char const *keyword)
+{
+  time_t s;
+  unsigned long int ns = 0;
+  char *p;
+  char *arg_lim;
+  bool negative = *arg == '-';
+
+  errno = 0;
+
+  if (ISDIGIT (arg[negative]))
+    {
+      if (negative)
+       {
+         intmax_t i = strtoimax (arg, &arg_lim, 10);
+         if (TYPE_SIGNED (time_t) ? i < TYPE_MINIMUM (time_t) : i < 0)
+           return decode_time_range;
+         s = i;
+       }
+      else
+       {
+         uintmax_t i = strtoumax (arg, &arg_lim, 10);
+         if (TYPE_MAXIMUM (time_t) < i)
+           return decode_time_range;
+         s = i;
+       }
+
+      p = arg_lim;
+
+      if (errno == ERANGE)
+       return decode_time_range;
+
+      if (*p == '.')
+       {
+         int digits = 0;
+         bool trailing_nonzero = false;
+
+         while (ISDIGIT (*++p))
+           if (digits < LOG10_BILLION)
+             {
+               ns = 10 * ns + (*p - '0');
+               digits++;
+             }
+           else
+             trailing_nonzero |= *p != '0';
+
+         while (digits++ < LOG10_BILLION)
+           ns *= 10;
+
+         if (negative)
+           {
+             /* Convert "-1.10000000000001" to s == -2, ns == 89999999.
+                I.e., truncate time stamps towards minus infinity while
+                converting them to internal form.  */
+             ns += trailing_nonzero;
+             if (ns != 0)
+               {
+                 if (s == TYPE_MINIMUM (time_t))
+                   return decode_time_range;
+                 s--;
+                 ns = BILLION - ns;
+               }
+           }
+       }
+
+      if (! *p)
+       {
+         ts->tv_sec = s;
+         ts->tv_nsec = ns;
+         return decode_time_success;
+       }
+    }
+
+  return decode_time_bad_header;
+}
+
+static bool
+decode_time (struct timespec *ts, char const *arg, char const *keyword)
+{
+  switch (_decode_time (ts, arg, keyword))
+    {
+    case decode_time_success:
+      return true;
+    case decode_time_bad_header:
+      ERROR ((0, 0, _("Malformed extended header: invalid %s=%s"),
+             keyword, arg));
+      return false;
+    case decode_time_range:
+      out_of_range_header (keyword, arg, - (uintmax_t) TYPE_MINIMUM (time_t),
+                          TYPE_MAXIMUM (time_t));
+      return false;
+    }
+  return true;
+}
+
+
+

 static void
 static void

-dummy_handler (struct tar_stat_info *st, char *keyword, char *arg)
+code_num (uintmax_t value, char const *keyword, struct xheader *xhdr)
+{
+  char sbuf[UINTMAX_STRSIZE_BOUND];
+  xheader_print (xhdr, keyword, umaxtostr (value, sbuf));
+}
+
+static bool
+decode_num (uintmax_t *num, char const *arg, uintmax_t maxval,
+           char const *keyword)
+{
+  uintmax_t u;
+  char *arg_lim;
+
+  if (! (ISDIGIT (*arg)
+        && (errno = 0, u = strtoumax (arg, &arg_lim, 10), !*arg_lim)))
+    {
+      ERROR ((0, 0, _("Malformed extended header: invalid %s=%s"),
+             keyword, arg));
+      return false;
+    }
+
+  if (! (u <= maxval && errno != ERANGE))
+    {
+      out_of_range_header (keyword, arg, 0, maxval);
+      return false;
+    }
+
+  *num = u;
+  return true;
+}
+
+static void
+dummy_coder (struct tar_stat_info const *st __attribute__ ((unused)),
+            char const *keyword __attribute__ ((unused)),
+            struct xheader *xhdr __attribute__ ((unused)),
+            void const *data __attribute__ ((unused)))

 {
 }
 
 static void
 {
 }
 
 static void

-atime_coder (struct tar_stat_info *st, char *keyword, char *arg)
+dummy_decoder (struct tar_stat_info *st __attribute__ ((unused)),
+              char const *keyword __attribute__ ((unused)),
+              char const *arg __attribute__ ((unused)),
+              size_t size __attribute__((unused)))

 {
 }
 
 static void
 {
 }
 
 static void

-atime_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+atime_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  st->stat.st_atime = strtoul (arg, NULL, 0);
+  code_time (st->atime, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-gid_coder (struct tar_stat_info *st, char *keyword, char *arg)
+atime_decoder (struct tar_stat_info *st,
+              char const *keyword,
+              char const *arg,
+              size_t size __attribute__((unused)))

 {
 {

+  struct timespec ts;
+  if (decode_time (&ts, arg, keyword))
+    st->atime = ts;

 }
 
 static void
 }
 
 static void

-gid_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+gid_coder (struct tar_stat_info const *st, char const *keyword,
+          struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  st->stat.st_gid = strtoul (arg, NULL, 0);
+  code_num (st->stat.st_gid, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-gname_coder (struct tar_stat_info *st, char *keyword, char *arg)
+gid_decoder (struct tar_stat_info *st,
+            char const *keyword,
+            char const *arg,
+            size_t size __attribute__((unused)))

 {
 {

+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (gid_t), keyword))
+    st->stat.st_gid = u;

 }
 
 static void
 }
 
 static void

-gname_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+gname_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  st->gname = strdup (arg);
+  code_string (st->gname, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-linkpath_coder (struct tar_stat_info *st, char *keyword, char *arg)
+gname_decoder (struct tar_stat_info *st,
+              char const *keyword __attribute__((unused)),
+              char const *arg,
+              size_t size __attribute__((unused)))

 {
 {

+  decode_string (&st->gname, arg);

 }
 
 static void
 }
 
 static void

-linkpath_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+linkpath_coder (struct tar_stat_info const *st, char const *keyword,
+               struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  st->link_name = strdup (arg);
+  code_string (st->link_name, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-ctime_coder (struct tar_stat_info *st, char *keyword, char *arg)
+linkpath_decoder (struct tar_stat_info *st,
+                 char const *keyword __attribute__((unused)),
+                 char const *arg,
+                 size_t size __attribute__((unused)))

 {
 {

+  decode_string (&st->link_name, arg);

 }
 
 static void
 }
 
 static void

-ctime_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+ctime_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  st->stat.st_ctime = strtoul (arg, NULL, 0);
+  code_time (st->ctime, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-mtime_coder (struct tar_stat_info *st, char *keyword, char *arg)
+ctime_decoder (struct tar_stat_info *st,
+              char const *keyword,
+              char const *arg,
+              size_t size __attribute__((unused)))

 {
 {

+  struct timespec ts;
+  if (decode_time (&ts, arg, keyword))
+    st->ctime = ts;

 }
 
 static void
 }
 
 static void

-mtime_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+mtime_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data)

 {
 {

-  st->stat.st_mtime = strtoul (arg, NULL, 0);
+  struct timespec const *mtime = data;
+  code_time (mtime ? *mtime : st->mtime, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-path_coder (struct tar_stat_info *st, char *keyword, char *arg)
+mtime_decoder (struct tar_stat_info *st,
+              char const *keyword,
+              char const *arg,
+              size_t size __attribute__((unused)))

 {
 {

+  struct timespec ts;
+  if (decode_time (&ts, arg, keyword))
+    st->mtime = ts;

 }
 
 static void
 }
 
 static void

-path_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+path_coder (struct tar_stat_info const *st, char const *keyword,
+           struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

-  assign_string (&st->orig_file_name, arg);
-  assign_string (&st->file_name, arg);
+  code_string (st->file_name, keyword, xhdr);
+}
+
+static void
+path_decoder (struct tar_stat_info *st,
+             char const *keyword __attribute__((unused)),
+             char const *arg,
+             size_t size __attribute__((unused)))
+{
+  decode_string (&st->orig_file_name, arg);
+  decode_string (&st->file_name, arg);

   st->had_trailing_slash = strip_trailing_slashes (st->file_name);
 }
 
 static void
   st->had_trailing_slash = strip_trailing_slashes (st->file_name);
 }
 
 static void

-size_coder (struct tar_stat_info *st, char *keyword, char *arg)
+size_coder (struct tar_stat_info const *st, char const *keyword,
+           struct xheader *xhdr, void const *data __attribute__ ((unused)))
+{
+  code_num (st->stat.st_size, keyword, xhdr);
+}
+
+static void
+size_decoder (struct tar_stat_info *st,
+             char const *keyword,
+             char const *arg,
+             size_t size __attribute__((unused)))
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), keyword))
+    st->stat.st_size = u;
+}
+
+static void
+uid_coder (struct tar_stat_info const *st, char const *keyword,
+          struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

+  code_num (st->stat.st_uid, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-size_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+uid_decoder (struct tar_stat_info *st,
+            char const *keyword,
+            char const *arg,
+            size_t size __attribute__((unused)))

 {
 {

-  st->stat.st_size = strtoul (arg, NULL, 0);
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (uid_t), keyword))
+    st->stat.st_uid = u;

 }
 
 static void
 }
 
 static void

-uid_coder (struct tar_stat_info *st, char *keyword, char *arg)
+uname_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data __attribute__ ((unused)))

 {
 {

+  code_string (st->uname, keyword, xhdr);

 }
 
 static void
 }
 
 static void

-uid_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+uname_decoder (struct tar_stat_info *st,
+              char const *keyword __attribute__((unused)),
+              char const *arg,
+              size_t size __attribute__((unused)))

 {
 {

-  st->stat.st_uid = strtoul (arg, NULL, 0);
+  decode_string (&st->uname, arg);

 }
 
 static void
 }
 
 static void

-uname_coder (struct tar_stat_info *st, char *keyword, char *arg)
+sparse_size_coder (struct tar_stat_info const *st, char const *keyword,
+            struct xheader *xhdr, void const *data)

 {
 {

+  size_coder (st, keyword, xhdr, data);

 }
 
 static void
 }
 
 static void

-uname_decoder (struct tar_stat_info *st, char *keyword, char *arg)
+sparse_size_decoder (struct tar_stat_info *st,
+                    char const *keyword,
+                    char const *arg,
+                    size_t size __attribute__((unused)))

 {
 {

-  st->uname = strdup (arg);
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), keyword))
+    st->stat.st_size = u;
+}
+
+static void
+sparse_numblocks_coder (struct tar_stat_info const *st, char const *keyword,
+                       struct xheader *xhdr,
+                       void const *data __attribute__ ((unused)))
+{
+  code_num (st->sparse_map_avail, keyword, xhdr);
+}
+
+static void
+sparse_numblocks_decoder (struct tar_stat_info *st,
+                         char const *keyword,
+                         char const *arg,
+                         size_t size __attribute__((unused)))
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, SIZE_MAX, keyword))
+    {
+      st->sparse_map_size = u;
+      st->sparse_map = xcalloc (u, sizeof st->sparse_map[0]);
+      st->sparse_map_avail = 0;
+    }

 }
 }

-  
+
+static void
+sparse_offset_coder (struct tar_stat_info const *st, char const *keyword,
+                    struct xheader *xhdr, void const *data)
+{
+  size_t const *pi = data;
+  code_num (st->sparse_map[*pi].offset, keyword, xhdr);
+}
+
+static void
+sparse_offset_decoder (struct tar_stat_info *st,
+                      char const *keyword,
+                      char const *arg,
+                      size_t size __attribute__((unused)))
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), keyword))
+    {
+      if (st->sparse_map_avail < st->sparse_map_size)
+       st->sparse_map[st->sparse_map_avail].offset = u;
+      else
+       ERROR ((0, 0, _("Malformed extended header: excess %s=%s"),
+               "GNU.sparse.offset", arg));
+    }
+}
+
+static void
+sparse_numbytes_coder (struct tar_stat_info const *st, char const *keyword,
+                      struct xheader *xhdr, void const *data)
+{
+  size_t const *pi = data;
+  code_num (st->sparse_map[*pi].numbytes, keyword, xhdr);
+}
+
+static void
+sparse_numbytes_decoder (struct tar_stat_info *st,
+                        char const *keyword,
+                        char const *arg,
+                        size_t size __attribute__((unused)))
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), keyword))
+    {
+      if (st->sparse_map_avail < st->sparse_map_size)
+       st->sparse_map[st->sparse_map_avail++].numbytes = u;
+      else
+       ERROR ((0, 0, _("Malformed extended header: excess %s=%s"),
+               keyword, arg));
+    }
+}
+
+static void
+sparse_map_decoder (struct tar_stat_info *st,
+                   char const *keyword,
+                   char const *arg,
+                   size_t size __attribute__((unused)))
+{
+  int offset = 1;
+
+  st->sparse_map_avail = 0;
+  while (1)
+    {
+      uintmax_t u;
+      char *delim;
+      struct sp_array e;
+
+      if (!ISDIGIT (*arg))
+       {
+         ERROR ((0, 0, _("Malformed extended header: invalid %s=%s"),
+                 keyword, arg));
+         return;
+       }
+
+      errno = 0;
+      u = strtoumax (arg, &delim, 10);
+      if (offset)
+       {
+         e.offset = u;
+         if (!(u == e.offset && errno != ERANGE))
+           {
+             out_of_range_header (keyword, arg, 0, TYPE_MAXIMUM (off_t));
+             return;
+           }
+       }
+      else
+       {
+         e.numbytes = u;
+         if (!(u == e.numbytes && errno != ERANGE))
+           {
+             out_of_range_header (keyword, arg, 0, TYPE_MAXIMUM (off_t));
+             return;
+           }
+         if (st->sparse_map_avail < st->sparse_map_size)
+           st->sparse_map[st->sparse_map_avail++] = e;
+         else
+           {
+             ERROR ((0, 0, _("Malformed extended header: excess %s=%s"),
+                     keyword, arg));
+             return;
+           }
+       }
+
+      offset = !offset;
+
+      if (*delim == 0)
+       break;
+      else if (*delim != ',')
+       {
+         ERROR ((0, 0,
+                 _("Malformed extended header: invalid %s: unexpected delimiter %c"),
+                 keyword, *delim));
+         return;
+       }
+
+      arg = delim + 1;
+    }
+
+  if (!offset)
+    ERROR ((0, 0,
+           _("Malformed extended header: invalid %s: odd number of values"),
+           keyword));
+}
+
+static void
+dumpdir_coder (struct tar_stat_info const *st, char const *keyword,
+              struct xheader *xhdr, void const *data)
+{
+  xheader_print_n (xhdr, keyword, data, dumpdir_size (data));
+}
+
+static void
+dumpdir_decoder (struct tar_stat_info *st,
+                char const *keyword __attribute__((unused)),
+                char const *arg,
+                size_t size)
+{
+  st->dumpdir = xmalloc (size);
+  memcpy (st->dumpdir, arg, size);
+}
+
+static void
+volume_label_coder (struct tar_stat_info const *st, char const *keyword,
+                   struct xheader *xhdr, void const *data)
+{
+  code_string (data, keyword, xhdr);
+}
+
+static void
+volume_label_decoder (struct tar_stat_info *st,
+                     char const *keyword __attribute__((unused)),
+                     char const *arg,
+                     size_t size __attribute__((unused)))
+{
+  decode_string (&volume_label, arg);
+}
+
+static void
+volume_size_coder (struct tar_stat_info const *st, char const *keyword,
+                  struct xheader *xhdr, void const *data)
+{
+  off_t const *v = data;
+  code_num (*v, keyword, xhdr);
+}
+
+static void
+volume_size_decoder (struct tar_stat_info *st,
+                    char const *keyword,
+                    char const *arg, size_t size)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (uintmax_t), keyword))
+    continued_file_size = u;
+}
+
+/* FIXME: Merge with volume_size_coder */
+static void
+volume_offset_coder (struct tar_stat_info const *st, char const *keyword,
+                    struct xheader *xhdr, void const *data)
+{
+  off_t const *v = data;
+  code_num (*v, keyword, xhdr);
+}
+
+static void
+volume_offset_decoder (struct tar_stat_info *st,
+                      char const *keyword,
+                      char const *arg, size_t size)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (uintmax_t), keyword))
+    continued_file_offset = u;
+}
+
+static void
+volume_filename_decoder (struct tar_stat_info *st,
+                        char const *keyword __attribute__((unused)),
+                        char const *arg,
+                        size_t size __attribute__((unused)))
+{
+  decode_string (&continued_file_name, arg);
+}
+
+static void
+xattr_acls_a_coder (struct tar_stat_info const *st , char const *keyword,
+                    struct xheader *xhdr, void const *data)
+{
+  xheader_print_n (xhdr, keyword, st->acls_a_ptr, st->acls_a_len);
+}
+
+static void
+xattr_acls_a_decoder (struct tar_stat_info *st,
+                      char const *keyword, char const *arg, size_t size)
+{
+  st->acls_a_ptr = xmemdup (arg, size + 1);
+  st->acls_a_len = size;
+}
+
+static void
+xattr_acls_d_coder (struct tar_stat_info const *st , char const *keyword,
+                    struct xheader *xhdr, void const *data)
+{
+  xheader_print_n (xhdr, keyword, st->acls_d_ptr, st->acls_d_len);
+}
+
+static void
+xattr_acls_d_decoder (struct tar_stat_info *st,
+                      char const *keyword, char const *arg, size_t size)
+{
+  st->acls_d_ptr = xmemdup (arg, size + 1);
+  st->acls_d_len = size;
+}
+
+static void
+xattr_coder (struct tar_stat_info const *st, char const *keyword,
+             struct xheader *xhdr, void const *data)
+{
+  struct xattr_array *xattr_map = st->xattr_map;
+  const size_t *off = data;
+  xheader_print_n (xhdr, keyword,
+                   xattr_map[*off].xval_ptr, xattr_map[*off].xval_len);
+}
+
+static void
+xattr_decoder (struct tar_stat_info *st,
+               char const *keyword, char const *arg, size_t size)
+{
+  char *xstr = NULL;
+
+  xstr = xmemdup(arg, size + 1);
+  xheader_xattr_add(st, keyword + strlen("SCHILY.xattr."), xstr, size);
+  free(xstr);
+}
+
+static void
+sparse_major_coder (struct tar_stat_info const *st, char const *keyword,
+                   struct xheader *xhdr, void const *data)
+{
+  code_num (st->sparse_major, keyword, xhdr);
+}
+
+static void
+sparse_major_decoder (struct tar_stat_info *st,
+                     char const *keyword,
+                     char const *arg,
+                     size_t size)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (unsigned), keyword))
+    st->sparse_major = u;
+}
+
+static void
+sparse_minor_coder (struct tar_stat_info const *st, char const *keyword,
+                     struct xheader *xhdr, void const *data)
+{
+  code_num (st->sparse_minor, keyword, xhdr);
+}
+
+static void
+sparse_minor_decoder (struct tar_stat_info *st,
+                     char const *keyword,
+                     char const *arg,
+                     size_t size)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (unsigned), keyword))
+    st->sparse_minor = u;
+}
+
+struct xhdr_tab const xhdr_tab[] = {
+  { "atime",    atime_coder,    atime_decoder,    0, false },
+  { "comment",  dummy_coder,    dummy_decoder,    0, false },
+  { "charset",  dummy_coder,    dummy_decoder,    0, false },
+  { "ctime",    ctime_coder,    ctime_decoder,    0, false },
+  { "gid",      gid_coder,      gid_decoder,      0, false },
+  { "gname",    gname_coder,    gname_decoder,    0, false },
+  { "linkpath", linkpath_coder, linkpath_decoder, 0, false },
+  { "mtime",    mtime_coder,    mtime_decoder,    0, false },
+  { "path",     path_coder,     path_decoder,     0, false },
+  { "size",     size_coder,     size_decoder,     0, false },
+  { "uid",      uid_coder,      uid_decoder,      0, false },
+  { "uname",    uname_coder,    uname_decoder,    0, false },
+
+  /* Sparse file handling */
+  { "GNU.sparse.name",       path_coder, path_decoder,
+    XHDR_PROTECTED, false },
+  { "GNU.sparse.major",      sparse_major_coder, sparse_major_decoder,
+    XHDR_PROTECTED, false },
+  { "GNU.sparse.minor",      sparse_minor_coder, sparse_minor_decoder,
+    XHDR_PROTECTED, false },
+  { "GNU.sparse.realsize",   sparse_size_coder, sparse_size_decoder,
+    XHDR_PROTECTED, false },
+  { "GNU.sparse.numblocks",  sparse_numblocks_coder, sparse_numblocks_decoder,
+    XHDR_PROTECTED, false },
+
+  /* tar 1.14 - 1.15.90 keywords. */
+  { "GNU.sparse.size",       sparse_size_coder, sparse_size_decoder,
+    XHDR_PROTECTED, false },
+  /* tar 1.14 - 1.15.1 keywords. Multiple instances of these appeared in 'x'
+     headers, and each of them was meaningful. It confilcted with POSIX specs,
+     which requires that "when extended header records conflict, the last one
+     given in the header shall take precedence." */
+  { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder,
+    XHDR_PROTECTED, false },
+  { "GNU.sparse.numbytes",   sparse_numbytes_coder, sparse_numbytes_decoder,
+    XHDR_PROTECTED, false },
+  /* tar 1.15.90 keyword, introduced to remove the above-mentioned conflict. */
+  { "GNU.sparse.map",        NULL /* Unused, see pax_dump_header() */,
+    sparse_map_decoder, 0, false },
+
+  { "GNU.dumpdir",           dumpdir_coder, dumpdir_decoder,
+    XHDR_PROTECTED, false },
+
+  /* Keeps the tape/volume label. May be present only in the global headers.
+     Equivalent to GNUTYPE_VOLHDR.  */
+  { "GNU.volume.label", volume_label_coder, volume_label_decoder,
+    XHDR_PROTECTED | XHDR_GLOBAL, false },
+
+  /* These may be present in a first global header of the archive.
+     They provide the same functionality as GNUTYPE_MULTIVOL header.
+     The GNU.volume.size keeps the real_s_sizeleft value, which is
+     otherwise kept in the size field of a multivolume header.  The
+     GNU.volume.offset keeps the offset of the start of this volume,
+     otherwise kept in oldgnu_header.offset.  */
+  { "GNU.volume.filename", volume_label_coder, volume_filename_decoder,
+    XHDR_PROTECTED | XHDR_GLOBAL, false },
+  { "GNU.volume.size", volume_size_coder, volume_size_decoder,
+    XHDR_PROTECTED | XHDR_GLOBAL, false },
+  { "GNU.volume.offset", volume_offset_coder, volume_offset_decoder,
+    XHDR_PROTECTED | XHDR_GLOBAL, false },
+
+  /* ACLs, use the star format... */
+  { "SCHILY.acl.access",
+    xattr_acls_a_coder, xattr_acls_a_decoder, 0, false },
+
+  { "SCHILY.acl.default",
+    xattr_acls_d_coder, xattr_acls_d_decoder, 0, false },
+
+  /* We are storing all extended attributes using this rule even if some of them
+     were stored by some previous rule (duplicates) -- we just have to make sure
+     they are restored *only once* during extraction later on. */
+  { "SCHILY.xattr", xattr_coder, xattr_decoder, 0, true },
+
+  { NULL, NULL, NULL, 0, false }
+};