X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=src%2Fxheader.c;h=e88934e85ec82823e8b6ee1ebcf55338b3feba46;hb=d659cbaccdc1f3279c49107cf15f15a639738529;hp=1f1b190d0cc5eca9b47fb3c57b8c9f138e619b81;hpb=f3875c4a269a88121e5c1e72d3dc1a1fe545d2e8;p=chaz%2Ftar

diff --git a/src/xheader.c b/src/xheader.c
index 1f1b190..e88934e 100644
--- a/src/xheader.c
+++ b/src/xheader.c
@@ -1,6 +1,6 @@
-/* POSIX extended and STAR headers.
+/* POSIX extended headers for tar.
 
-   Copyright (C) 2003 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005 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
@@ -14,31 +14,413 @@
 
    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 <pwd.h>
+#include <inttostr.h>
 #include <quotearg.h>
+#include <stpcpy.h>
 
 #include "common.h"
 
-#define obstack_chunk_alloc xmalloc
-#define obstack_chunk_free free
-#include <obstack.h>
+#include <fnmatch.h>
 
+#if !HAVE_DECL_STRTOIMAX && !defined strtoimax
+intmax_t strtoimax ();
+#endif
+#if !HAVE_DECL_STRTOUMAX && !defined strtoumax
+uintmax_t strtoumax ();
+#endif
+
+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));
+
+/* Used by xheader_finish() */
+static void code_string (char const *string, char const *keyword,
+			 struct xheader *xhdr);
+static void extended_header_init (void);
+
+/* 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.
+
+   However it should wait until buffer.c is finally rewritten */
+
+enum { BILLION = 1000000000, LOG10_BILLION = 9 };
+
+
+/* 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;
+
+/* Template for the name field of a 'g' type header */
+static char *globexthdr_name;
+
+static 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 imlemented"), kw));
+}
+
+static void
+xheader_set_keyword_equal (char *kw, char *eq)
+{
+  bool global = true;
+  char *p = eq;
+
+  if (eq[-1] == ':')
+    {
+      p--;
+      global = false;
+    }
+
+  while (p > kw && isspace (*p))
+    p--;
+
+  *p = 0;
+
+  for (p = eq + 1; *p && isspace (*p); p++)
+    ;
+
+  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 (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.
+     %%                       A '%' character. */
+
+static char *
+xheader_format_name (struct tar_stat_info *st, const char *fmt, bool allow_n)
+{
+  char *buf;
+  size_t len = strlen (fmt);
+  char *q;
+  const char *p;
+  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;
+
+	case 'd':
+	  if (st)
+	    {
+	      dir = safer_name_suffix (dir_name (st->orig_file_name),
+	                               false, absolute_names_option);
+	      len += strlen (dir) - 1;
+	    }
+	  break;
+
+	case 'f':
+	  if (st)
+	    {
+	      base = base_name (st->orig_file_name);
+	      len += strlen (base) - 1;
+	    }
+	  break;
+
+	case 'p':
+	  pptr = umaxtostr (getpid (), pidbuf);
+	  len += pidbuf + sizeof pidbuf - 1 - pptr - 1;
+	  break;
+
+	case 'n':
+	  if (allow_n)
+	    {
+	      nptr = umaxtostr (global_header_count + 1, nbuf);
+	      len += nbuf + sizeof nbuf - 1 - nptr - 1;
+	    }
+	  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;
+		}
+	      /* else fall through */
+
+	    default:
+	      *q++ = *p++;
+	      if (*p)
+		*q++ = *p++;
+	    }
+	}
+      else
+	*q++ = *p++;
+    }
+
+  /* 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, false);
+}
+
+#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, true);
+}
+
+void
+xheader_write (char type, char *name, struct xheader *xhdr)
+{
+  union block *header;
+  size_t size;
+  char *p;
+
+  size = xhdr->size;
+  header = start_private_header (name, size);
+  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);
+}
+
+void
+xheader_write_global (void)
+{
+  char *name;
+  struct keyword_list *kp;
+
+  if (!keyword_global_override_list)
+    return;
+
+  extended_header_init ();
+  for (kp = keyword_global_override_list; kp; kp = kp->next)
+    code_string (kp->value, kp->pattern, &extended_header);
+  xheader_finish (&extended_header);
+  xheader_write (XGLTYPE, name = xheader_ghdr_name (),
+		 &extended_header);
+  free (name);
+  global_header_count++;
+}
+
+
 /* General Interface */
 
 struct xhdr_tab
 {
   char const *keyword;
-  void (*coder) (struct tar_stat_info const *, char const *, struct xheader *);
+  void (*coder) (struct tar_stat_info const *, char const *,
+		 struct xheader *, void *data);
   void (*decoder) (struct tar_stat_info *, char const *);
+  bool protect;
 };
 
-static struct xhdr_tab const xhdr_tab[];
+/* 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 const *
 locate_handler (char const *keyword)
@@ -51,72 +433,170 @@ locate_handler (char const *keyword)
   return NULL;
 }
 
-/* Decodes a single extended header record. Advances P to the next
-   record.
-   Returns true on success, false otherwise. */
 static bool
-decode_record (char **p, struct tar_stat_info *st)
+xheader_protected_pattern_p (const char *pattern)
+{
+  struct xhdr_tab const *p;
+
+  for (p = xhdr_tab; p->keyword; p++)
+    if (p->protect && 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->protect && 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 (char **ptr,
+	       void (*handler) (void *, char const *, char const *),
+	       void *data)
 {
-  size_t len;
+  char *start = *ptr;
+  char *p = start;
+  unsigned long int len;
+  char *len_lim;
   char const *keyword;
-  char *eqp;
-  char *start = *p;
-  struct xhdr_tab const *t;
+  char *nextp;
+  size_t len_max = extended_header.buffer + extended_header.size - start;
 
-  if (**p == 0)
-    return false;
+  while (*p == ' ' || *p == '\t')
+    p++;
 
-  len = strtoul (*p, p, 10);
-  if (**p != ' ')
+  if (! ISDIGIT (*p))
     {
-      ERROR ((0, 0, _("Malformed extended header: missing whitespace after the length")));
+      if (*p)
+	ERROR ((0, 0, _("Malformed extended header: missing length")));
       return false;
     }
 
-  keyword = ++*p;
-  for (;*p < start + len; ++*p)
-    if (**p == '=')
-      break;
+  errno = 0;
+  len = strtoul (p, &len_lim, 10);
 
-  if (**p != '=')
+  if (len_max < len)
     {
-      ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
+      int len_len = len_lim - p;
+      ERROR ((0, 0, _("Extended header length %*s is out of range"),
+	      len_len, p));
       return false;
     }
 
-  eqp = *p;
-  **p = 0;
-  t = locate_handler (keyword);
-  if (t)
+  nextp = start + len;
+
+  for (p = len_lim; *p == ' ' || *p == '\t'; p++)
+    continue;
+  if (p == len_lim)
     {
-      char endc;
-      char *value;
+      ERROR ((0, 0,
+	      _("Malformed extended header: missing blank after length")));
+      return false;
+    }
 
-      value = ++*p;
+  keyword = p;
+  p = strchr (p, '=');
+  if (! (p && p < nextp))
+    {
+      ERROR ((0, 0, _("Malformed extended header: missing equal sign")));
+      return false;
+    }
 
-      endc = start[len-1];
-      start[len-1] = 0;
-      t->decoder (st, value);
-      start[len-1] = endc;
+  if (nextp[-1] != '\n')
+    {
+      ERROR ((0, 0, _("Malformed extended header: missing newline")));
+      return false;
     }
-  *eqp = '=';
-  *p = &start[len];
+
+  *p = nextp[-1] = '\0';
+  handler (data, keyword, p + 1);
+  *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, kp->value);
+    }
+}
+
+static void
+decx (void *data, char const *keyword, char const *value)
+{
+  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->decoder (st, value);
+}
+
 void
 xheader_decode (struct tar_stat_info *st)
 {
-  char *p = extended_header.buffer + BLOCKSIZE;
-  char *endp = &extended_header.buffer[extended_header.size-1];
+  run_override_list (keyword_global_override_list, st);
+  run_override_list (global_header_override_list, st);
 
-  while (p < endp)
-    if (!decode_record (&p, st))
-      break;
+  if (extended_header.size)
+    {
+      char *p = extended_header.buffer + BLOCKSIZE;
+      while (decode_record (&p, decx, st))
+	continue;
+    }
+  run_override_list (keyword_override_list, st);
+}
+
+static void
+decg (void *data, char const *keyword, char const *value)
+{
+  struct keyword_list **kwl = data;
+  xheader_list_append (kwl, keyword, value);
 }
 
 void
-xheader_store (char const *keyword, struct tar_stat_info const *st)
+xheader_decode_global (void)
+{
+  if (extended_header.size)
+    {
+      char *p = extended_header.buffer + BLOCKSIZE;
+
+      xheader_list_destroy (&global_header_override_list);
+      while (decode_record (&p, decg, &global_header_override_list))
+	continue;
+    }
+}
+
+static void
+extended_header_init (void)
+{
+  if (!extended_header.stk)
+    {
+      extended_header.stk = xmalloc (sizeof *extended_header.stk);
+      obstack_init (extended_header.stk);
+    }
+}
+
+void
+xheader_store (char const *keyword, struct tar_stat_info const *st, void *data)
 {
   struct xhdr_tab const *t;
 
@@ -125,12 +605,11 @@ xheader_store (char const *keyword, struct tar_stat_info const *st)
   t = locate_handler (keyword);
   if (!t)
     return;
-  if (!extended_header.stk)
-    {
-      extended_header.stk = xmalloc (sizeof *extended_header.stk);
-      obstack_init (extended_header.stk);
-    }
-  t->coder (st, keyword, &extended_header);
+  if (xheader_keyword_deleted_p (keyword)
+      || xheader_keyword_override_p (keyword))
+    return;
+  extended_header_init ();
+  t->coder (st, keyword, &extended_header, data);
 }
 
 void
@@ -144,6 +623,7 @@ xheader_read (union block *p, size_t size)
   extended_header.size = size;
   nblocks = (size + BLOCKSIZE - 1) / BLOCKSIZE;
   extended_header.buffer = xmalloc (size + 1);
+  extended_header.buffer[size] = '\0';
 
   do
     {
@@ -151,7 +631,7 @@ xheader_read (union block *p, size_t size)
 
       if (len > BLOCKSIZE)
 	len = BLOCKSIZE;
-      
+
       memcpy (&extended_header.buffer[j], p->buffer, len);
       set_next_block_after (p);
 
@@ -163,48 +643,24 @@ xheader_read (union block *p, size_t size)
   while (size > 0);
 }
 
-static size_t
-format_uintmax (uintmax_t val, char *buf, size_t s)
-{
-  if (!buf)
-    {
-      s = 0;
-      do
-	s++;
-      while ((val /= 10) != 0);
-    }
-  else
-    {
-      char *p = buf + s - 1;
-
-      do
-	{
-	  *p-- = val % 10 + '0';
-	}
-      while ((val /= 10) != 0);
-
-      while (p >= buf)
-	*p-- = '0';
-    }
-  return s;
-}
-
 static void
 xheader_print (struct xheader *xhdr, char const *keyword, char const *value)
 {
   size_t len = strlen (keyword) + strlen (value) + 3; /* ' ' + '=' + '\n' */
-  size_t p, n = 0;
-  char nbuf[100];
+  size_t p;
+  size_t n = 0;
+  char nbuf[UINTMAX_STRSIZE_BOUND];
+  char const *np;
 
   do
     {
       p = n;
-      n = format_uintmax (len + p, NULL, 0);
+      np = umaxtostr (len + p, nbuf);
+      n = nbuf + sizeof nbuf - 1 - np;
     }
   while (n != p);
 
-  format_uintmax (len + n, nbuf, n);
-  obstack_grow (xhdr->stk, nbuf, n);
+  obstack_grow (xhdr->stk, np, n);
   obstack_1grow (xhdr->stk, ' ');
   obstack_grow (xhdr->stk, keyword, strlen (keyword));
   obstack_1grow (xhdr->stk, '=');
@@ -215,6 +671,11 @@ xheader_print (struct xheader *xhdr, char const *keyword, char const *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);
+
   obstack_1grow (xhdr->stk, 0);
   xhdr->buffer = obstack_finish (xhdr->stk);
   xhdr->size = strlen (xhdr->buffer);
@@ -237,61 +698,222 @@ xheader_destroy (struct xheader *xhdr)
 
 
 /* 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)
 {
-  xheader_print (xhdr, keyword, string);
+  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 (time_t t, char const *keyword, struct xheader *xhdr)
+code_time (struct timespec t, char const *keyword, struct xheader *xhdr)
+{
+  time_t s = t.tv_sec;
+  int ns = t.tv_nsec;
+  char sbuf[1/*"-"*/ + UINTMAX_STRSIZE_BOUND + 1/*"."*/ + LOG10_BILLION];
+  char *np;
+  bool negative = s < 0;
+
+  if (negative && ns != 0)
+    {
+      s++;
+      ns = BILLION - ns;
+    }
+
+  np = umaxtostr (negative ? - (uintmax_t) s : (uintmax_t) s, sbuf + 1);
+  if (negative)
+    *--np = '-';
+  code_ns_fraction (ns, sbuf + UINTMAX_STRSIZE_BOUND);
+  xheader_print (xhdr, keyword, np);
+}
+
+static bool
+decode_time (struct timespec *ts, char const *arg, char const *keyword)
 {
-  char sbuf[100];
-  size_t s = format_uintmax (t, NULL, 0);
-  format_uintmax (t, sbuf, s);
-  sbuf[s++] = '.';
-  format_uintmax (0, sbuf + s, 9);
-  sbuf[s+9] = 0;
-  xheader_print (xhdr, keyword, sbuf);
+  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)
+	    goto out_of_range;
+	  s = i;
+	}
+      else
+	{
+	  uintmax_t i = strtoumax (arg, &arg_lim, 10);
+	  if (TYPE_MAXIMUM (time_t) < i)
+	    goto out_of_range;
+	  s = i;
+	}
+
+      p = arg_lim;
+
+      if (errno == ERANGE)
+	goto out_of_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))
+		    goto out_of_range;
+		  s--;
+		  ns = BILLION - ns;
+		}
+	    }
+	}
+
+      if (! *p)
+	{
+	  ts->tv_sec = s;
+	  ts->tv_nsec = ns;
+	  return true;
+	}
+    }
+
+  ERROR ((0, 0, _("Malformed extended header: invalid %s=%s"),
+	  keyword, arg));
+  return false;
+
+ out_of_range:
+  out_of_range_header (keyword, arg, - (uintmax_t) TYPE_MINIMUM (time_t),
+		       TYPE_MAXIMUM (time_t));
+  return false;
 }
 
 static void
 code_num (uintmax_t value, char const *keyword, struct xheader *xhdr)
 {
-  char sbuf[100];
-  size_t s = format_uintmax (value, NULL, 0);
-  format_uintmax (value, sbuf, s);
-  sbuf[s] = 0;
-  xheader_print (xhdr, keyword, sbuf);
+  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, char const *keyword,
-	     struct xheader *xhdr)
+dummy_coder (struct tar_stat_info const *st __attribute__ ((unused)),
+	     char const *keyword __attribute__ ((unused)),
+	     struct xheader *xhdr __attribute__ ((unused)),
+	     void *data __attribute__ ((unused)))
 {
 }
 
 static void
-dummy_decoder (struct tar_stat_info *st, char const *arg)
+dummy_decoder (struct tar_stat_info *st __attribute__ ((unused)),
+	       char const *arg __attribute__ ((unused)))
 {
 }
 
 static void
 atime_coder (struct tar_stat_info const *st, char const *keyword,
-	     struct xheader *xhdr)
+	     struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
-  code_time (st->stat.st_atime, keyword, xhdr);
+  code_time (get_stat_atime (&st->stat), keyword, xhdr);
 }
 
 static void
 atime_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_atime = strtoul (arg, NULL, 0);
+  struct timespec ts;
+  if (decode_time (&ts, arg, "atime"))
+    set_stat_atime (&st->stat, ts);
 }
 
 static void
 gid_coder (struct tar_stat_info const *st, char const *keyword,
-	   struct xheader *xhdr)
+	   struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_num (st->stat.st_gid, keyword, xhdr);
 }
@@ -299,12 +921,14 @@ gid_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 gid_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_gid = strtoul (arg, NULL, 0);
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (gid_t), "gid"))
+    st->stat.st_gid = u;
 }
 
 static void
 gname_coder (struct tar_stat_info const *st, char const *keyword,
-	     struct xheader *xhdr)
+	     struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_string (st->gname, keyword, xhdr);
 }
@@ -312,12 +936,12 @@ gname_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 gname_decoder (struct tar_stat_info *st, char const *arg)
 {
-  assign_string (&st->gname, arg);
+  decode_string (&st->gname, arg);
 }
 
 static void
 linkpath_coder (struct tar_stat_info const *st, char const *keyword,
-		struct xheader *xhdr)
+		struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_string (st->link_name, keyword, xhdr);
 }
@@ -325,38 +949,42 @@ linkpath_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 linkpath_decoder (struct tar_stat_info *st, char const *arg)
 {
-  assign_string (&st->link_name, arg);
+  decode_string (&st->link_name, arg);
 }
 
 static void
 ctime_coder (struct tar_stat_info const *st, char const *keyword,
-	     struct xheader *xhdr)
+	     struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
-  code_time (st->stat.st_ctime, keyword, xhdr);
+  code_time (get_stat_ctime (&st->stat), keyword, xhdr);
 }
 
 static void
 ctime_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_ctime = strtoul (arg, NULL, 0);
+  struct timespec ts;
+  if (decode_time (&ts, arg, "ctime"))
+    set_stat_ctime (&st->stat, ts);
 }
 
 static void
 mtime_coder (struct tar_stat_info const *st, char const *keyword,
-	     struct xheader *xhdr)
+	     struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
-  code_time (st->stat.st_mtime, keyword, xhdr);
+  code_time (get_stat_mtime (&st->stat), keyword, xhdr);
 }
 
 static void
 mtime_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_mtime = strtoul (arg, NULL, 0);
+  struct timespec ts;
+  if (decode_time (&ts, arg, "mtime"))
+    set_stat_mtime (&st->stat, ts);
 }
 
 static void
 path_coder (struct tar_stat_info const *st, char const *keyword,
-	    struct xheader *xhdr)
+	    struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_string (st->file_name, keyword, xhdr);
 }
@@ -364,14 +992,14 @@ path_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 path_decoder (struct tar_stat_info *st, char const *arg)
 {
-  assign_string (&st->orig_file_name, arg);
-  assign_string (&st->file_name, arg);
+  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
 size_coder (struct tar_stat_info const *st, char const *keyword,
-	    struct xheader *xhdr)
+	    struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_num (st->stat.st_size, keyword, xhdr);
 }
@@ -379,12 +1007,14 @@ size_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 size_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_size = strtoul (arg, NULL, 0);
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "size"))
+    st->archive_file_size = st->stat.st_size = u;
 }
 
 static void
 uid_coder (struct tar_stat_info const *st, char const *keyword,
-	   struct xheader *xhdr)
+	   struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_num (st->stat.st_uid, keyword, xhdr);
 }
@@ -392,12 +1022,14 @@ uid_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 uid_decoder (struct tar_stat_info *st, char const *arg)
 {
-  st->stat.st_uid = strtoul (arg, NULL, 0);
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (uid_t), "uid"))
+    st->stat.st_uid = u;
 }
 
 static void
 uname_coder (struct tar_stat_info const *st, char const *keyword,
-	     struct xheader *xhdr)
+	     struct xheader *xhdr, void *data __attribute__ ((unused)))
 {
   code_string (st->uname, keyword, xhdr);
 }
@@ -405,36 +1037,116 @@ uname_coder (struct tar_stat_info const *st, char const *keyword,
 static void
 uname_decoder (struct tar_stat_info *st, char const *arg)
 {
-  assign_string (&st->uname, arg);
+  decode_string (&st->uname, arg);
 }
 
-static struct xhdr_tab const xhdr_tab[] = {
-  { "atime",	atime_coder,	atime_decoder	},
-  { "comment",	dummy_coder,	dummy_decoder	},
-  { "charset",	dummy_coder,	dummy_decoder	},
-  { "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	},
+static void
+sparse_size_coder (struct tar_stat_info const *st, char const *keyword,
+	     struct xheader *xhdr, void *data)
+{
+  size_coder (st, keyword, xhdr, data);
+}
+
+static void
+sparse_size_decoder (struct tar_stat_info *st, char const *arg)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "GNU.sparse.size"))
+    st->stat.st_size = u;
+}
+
+static void
+sparse_numblocks_coder (struct tar_stat_info const *st, char const *keyword,
+			struct xheader *xhdr,
+			void *data __attribute__ ((unused)))
+{
+  code_num (st->sparse_map_avail, keyword, xhdr);
+}
+
+static void
+sparse_numblocks_decoder (struct tar_stat_info *st, char const *arg)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, SIZE_MAX, "GNU.sparse.numblocks"))
+    {
+      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 *data)
+{
+  size_t i = *(size_t*)data;
+  code_num (st->sparse_map[i].offset, keyword, xhdr);
+}
+
+static void
+sparse_offset_decoder (struct tar_stat_info *st, char const *arg)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "GNU.sparse.offset"))
+    st->sparse_map[st->sparse_map_avail].offset = u;
+}
+
+static void
+sparse_numbytes_coder (struct tar_stat_info const *st, char const *keyword,
+		     struct xheader *xhdr, void *data)
+{
+  size_t i = *(size_t*)data;
+  code_num (st->sparse_map[i].numbytes, keyword, xhdr);
+}
+
+static void
+sparse_numbytes_decoder (struct tar_stat_info *st, char const *arg)
+{
+  uintmax_t u;
+  if (decode_num (&u, arg, SIZE_MAX, "GNU.sparse.numbytes"))
+    {
+      if (st->sparse_map_avail == st->sparse_map_size)
+	st->sparse_map = x2nrealloc (st->sparse_map,
+				     &st->sparse_map_size,
+				     sizeof st->sparse_map[0]);
+      st->sparse_map[st->sparse_map_avail++].numbytes = u;
+    }
+}
+
+struct xhdr_tab const xhdr_tab[] = {
+  { "atime",	atime_coder,	atime_decoder,	  false },
+  { "comment",	dummy_coder,	dummy_decoder,	  false },
+  { "charset",	dummy_coder,	dummy_decoder,	  false },
+  { "ctime",	ctime_coder,	ctime_decoder,	  false },
+  { "gid",	gid_coder,	gid_decoder,	  false },
+  { "gname",	gname_coder,	gname_decoder,	  false },
+  { "linkpath", linkpath_coder, linkpath_decoder, false },
+  { "mtime",	mtime_coder,	mtime_decoder,	  false },
+  { "path",	path_coder,	path_decoder,	  false },
+  { "size",	size_coder,	size_decoder,	  false },
+  { "uid",	uid_coder,	uid_decoder,	  false },
+  { "uname",	uname_coder,	uname_decoder,	  false },
 
-#if 0 /* GNU private keywords (not yet implemented) */
   /* Sparse file handling */
-  { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder },
-  { "GNU.sparse.numbytes",   sparse_numbytes_coder, sparse_numbytes_decoder },
+  { "GNU.sparse.size",       sparse_size_coder, sparse_size_decoder, true },
+  { "GNU.sparse.numblocks",  sparse_numblocks_coder, sparse_numblocks_decoder,
+    true },
+  { "GNU.sparse.offset",     sparse_offset_coder, sparse_offset_decoder,
+    true },
+  { "GNU.sparse.numbytes",   sparse_numbytes_coder, sparse_numbytes_decoder,
+    true },
+
+#if 0 /* GNU private keywords (not yet implemented) */
 
   /* The next directory entry actually contains the names of files
      that were in the directory at the time the dump was made.
      Supersedes GNUTYPE_DUMPDIR header type.  */
-  { "GNU.dumpdir",  dumpdir_coder, dumpdir_decoder },
+  { "GNU.dump.name",  dump_name_coder, dump_name_decoder, false },
+  { "GNU.dump.status", dump_status_coder, dump_status_decoder, false },
 
   /* Keeps the tape/volume header. May be present only in the global headers.
      Equivalent to GNUTYPE_VOLHDR.  */
-  { "GNU.volume.header", volume_header_coder, volume_header_decoder },
+  { "GNU.volume.header", volume_header_coder, volume_header_decoder, false },
 
   /* These may be present in a first global header of the archive.
      They provide the same functionality as GNUTYPE_MULTIVOL header.
@@ -442,9 +1154,9 @@ static struct xhdr_tab const xhdr_tab[] = {
      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.size", volume_size_coder, volume_size_decoder },
-  { "GNU.volume.offset", volume_offset_coder, volume_offset_decoder },
+  { "GNU.volume.size", volume_size_coder, volume_size_decoder, false },
+  { "GNU.volume.offset", volume_offset_coder, volume_offset_decoder, false },
 #endif
 
-  { NULL, NULL, NULL }
+  { NULL, NULL, NULL, false }
 };