tar: don't crash if getcwd fails

[chaz/tar] / src / misc.c

diff --git a/src/misc.c b/src/misc.c
index a76b24eb6764cc85106c8bc38fbfa94f446f76f0..12b40ac341e50c62aed399d480821bfa372002e0 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -1,7 +1,7 @@
 /* Miscellaneous functions, not really specific to GNU tar.
 
    Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
-   2003, 2004, 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
+   2003, 2004, 2005, 2006, 2007, 2009, 2010 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
@@ -25,7 +25,6 @@
 #include <xgetcwd.h>
 #include <unlinkdir.h>
 #include <utimens.h>
-#include <canonicalize.h>
 
 #if HAVE_STROPTS_H
 # include <stropts.h>
@@ -34,6 +33,10 @@
 # include <sys/filio.h>
 #endif
 
+#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
+# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
+#endif
+
 \f
 /* Handling strings.  */
 
@@ -230,10 +233,54 @@ zap_slashes (char *name)
   return name;
 }
 
+/* Normalize FILE_NAME by removing redundant slashes and "."
+   components, including redundant trailing slashes.  Leave ".."
+   alone, as it may be significant in the presence of symlinks and on
+   platforms where "/.." != "/".  Destructive version: modifies its
+   argument. */
+static void
+normalize_filename_x (char *file_name)
+{
+  char *name = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
+  char *p;
+  char const *q;
+  char c;
+
+  /* Don't squeeze leading "//" to "/", on hosts where they're distinct.  */
+  name += (DOUBLE_SLASH_IS_DISTINCT_ROOT
+          && ISSLASH (*name) && ISSLASH (name[1]) && ! ISSLASH (name[2]));
+
+  /* Omit redundant leading "." components.  */
+  for (q = p = name; (*p = *q) == '.' && ISSLASH (q[1]); p += !*q)
+    for (q += 2; ISSLASH (*q); q++)
+      continue;
+
+  /* Copy components from Q to P, omitting redundant slashes and
+     internal "."  components.  */
+  while ((*p++ = c = *q++) != '\0')
+    if (ISSLASH (c))
+      while (ISSLASH (q[*q == '.']))
+       q += (*q == '.') + 1;
+
+  /* Omit redundant trailing "." component and slash.  */
+  if (2 < p - name)
+    {
+      p -= p[-2] == '.' && ISSLASH (p[-3]);
+      p -= 2 < p - name && ISSLASH (p[-2]);
+      p[-1] = '\0';
+    }
+}
+
+/* Normalize NAME by removing redundant slashes and "." components,
+   including redundant trailing slashes.  Return a normalized
+   newly-allocated copy.  */
+
 char *
 normalize_filename (const char *name)
 {
-  return zap_slashes (canonicalize_filename_mode (name, CAN_MISSING));
+  char *copy = xstrdup (name);
+  normalize_filename_x (copy);
+  return copy;
 }
 
 \f
@@ -298,6 +345,10 @@ code_timespec (struct timespec t, char sbuf[TIMESPEC_STRSIZE_BOUND])
   char *np;
   bool negative = s < 0;
 
+  /* ignore invalid values of ns */
+  if (BILLION <= ns || ns < 0)
+    ns = 0;
+
   if (negative && ns != 0)
     {
       s++;
@@ -656,6 +707,8 @@ chdir_do (int i)
                  close (fd1);
                  prev->saved_cwd.desc = -1;
                  prev->saved_cwd.name = xgetcwd ();
+                 if (! prev->saved_cwd.name)
+                   err = errno;
                }
              else
                err = errno;
@@ -745,6 +798,36 @@ stat_diag (char const *name)
     stat_error (name);
 }
 
+void
+file_removed_diag (const char *name, bool top_level,
+                  void (*diagfn) (char const *name))
+{
+  if (!top_level && errno == ENOENT)
+    {
+      WARNOPT (WARN_FILE_REMOVED,
+              (0, 0, _("%s: File removed before we read it"),
+               quotearg_colon (name)));
+      set_exit_status (TAREXIT_DIFFERS);
+    }
+  else
+    diagfn (name);
+}
+
+void
+dir_removed_diag (const char *name, bool top_level,
+                  void (*diagfn) (char const *name))
+{
+  if (!top_level && errno == ENOENT)
+    {
+      WARNOPT (WARN_FILE_REMOVED,
+              (0, 0, _("%s: Directory removed before we read it"),
+               quotearg_colon (name)));
+      set_exit_status (TAREXIT_DIFFERS);
+    }
+  else
+    diagfn (name);
+}
+
 void
 write_fatal_details (char const *name, ssize_t status, size_t size)
 {
@@ -797,3 +880,41 @@ page_aligned_alloc (void **ptr, size_t size)
   return ptr_align (*ptr, alignment);
 }
 
+\f
+
+struct namebuf
+{
+  char *buffer;                /* directory, `/', and directory member */
+  size_t buffer_size;  /* allocated size of name_buffer */
+  size_t dir_length;   /* length of directory part in buffer */
+};
+
+namebuf_t
+namebuf_create (const char *dir)
+{
+  namebuf_t buf = xmalloc (sizeof (*buf));
+  buf->buffer_size = strlen (dir) + 2;
+  buf->buffer = xmalloc (buf->buffer_size);
+  strcpy (buf->buffer, dir);
+  buf->dir_length = strlen (buf->buffer);
+  if (!ISSLASH (buf->buffer[buf->dir_length - 1]))
+    buf->buffer[buf->dir_length++] = DIRECTORY_SEPARATOR;
+  return buf;
+}
+
+void
+namebuf_free (namebuf_t buf)
+{
+  free (buf->buffer);
+  free (buf);
+}
+
+char *
+namebuf_name (namebuf_t buf, const char *name)
+{
+  size_t len = strlen (name);
+  while (buf->dir_length + len + 1 >= buf->buffer_size)
+    buf->buffer = x2realloc (buf->buffer, &buf->buffer_size);
+  strcpy (buf->buffer + buf->dir_length, name);
+  return buf->buffer;
+}