2.5-18.1

sysdeps/unix/sysv/linux/renameat.c

@@ -0,0 +1,184 @@
+/* Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <kernel-features.h>
+#include <sysdep.h>
+
+
+#ifndef __ASSUME_ATFCTS
+void
+attribute_hidden
+__atfct_seterrno_2 (int errval, int fd1, const char *buf1, int fd2,
+		    const char *buf2)
+{
+  if (buf1 != NULL || buf2 != NULL)
+    {
+      struct stat64 st;
+
+      if (errval == ENOTDIR)
+	{
+	  /* This can mean either the file descriptor is invalid or
+	     /proc is not mounted.  */
+	  if (buf1 != NULL)
+	    {
+	      if (__fxstat64 (_STAT_VER, fd1, &st) != 0)
+		/* errno is already set correctly.  */
+		return;
+
+	      /* If /proc is not mounted there is nothing we can do.  */
+	      if (S_ISDIR (st.st_mode)
+		  && (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0
+		      || !S_ISDIR (st.st_mode)))
+		{
+		  errval = ENOSYS;
+		  goto out;
+		}
+	    }
+
+	  if (buf2 != NULL)
+	    {
+	      if (__fxstat64 (_STAT_VER, fd2, &st) != 0)
+		/* errno is already set correctly.  */
+		return;
+
+	      /* If /proc is not mounted there is nothing we can do.  */
+	      if (S_ISDIR (st.st_mode)
+		  && (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0
+		      || !S_ISDIR (st.st_mode)))
+		errval = ENOSYS;
+	    }
+	}
+      else if (errval == ENOENT)
+	{
+	  /* This could mean the file descriptor is not valid.  We
+	     reuse BUF for the stat call.  Find the slash after the
+	     file descriptor number.  */
+	  if (buf1 != NULL)
+	    {
+	      *(char *) strchr (buf1 + sizeof "/proc/self/fd", '/') = '\0';
+
+	      int e = __lxstat64 (_STAT_VER, buf1, &st);
+	      if ((e == -1 && errno == ENOENT)
+		  ||(e == 0 && !S_ISLNK (st.st_mode)))
+		{
+		  errval = EBADF;
+		  goto out;
+		}
+	    }
+
+	  if (buf2 != NULL)
+	    {
+	      *(char *) strchr (buf2 + sizeof "/proc/self/fd", '/') = '\0';
+
+	      int e = __lxstat64 (_STAT_VER, buf2, &st);
+	      if ((e == -1 && errno == ENOENT)
+		  ||(e == 0 && !S_ISLNK (st.st_mode)))
+		errval = EBADF;
+	    }
+	}
+    }
+
+ out:
+  __set_errno (errval);
+}
+#endif
+
+
+/* Rename the file OLD relative to OLDFD to NEW relative to NEWFD.  */
+int
+renameat (oldfd, old, newfd, new)
+     int oldfd;
+     const char *old;
+     int newfd;
+     const char *new;
+{
+  int result;
+
+#ifdef __NR_renameat
+# ifndef __ASSUME_ATFCTS
+  if (__have_atfcts >= 0)
+# endif
+    {
+      result = INLINE_SYSCALL (renameat, 4, oldfd, old, newfd, new);
+# ifndef __ASSUME_ATFCTS
+      if (result == -1 && errno == ENOSYS)
+	__have_atfcts = -1;
+      else
+# endif
+	return result;
+    }
+#endif
+
+#ifndef __ASSUME_ATFCTS
+  static const char procfd[] = "/proc/self/fd/%d/%s";
+  char *bufold = NULL;
+
+  if (oldfd != AT_FDCWD && old[0] != '/')
+    {
+      size_t filelen = strlen (old);
+      /* Buffer for the path name we are going to use.  It consists of
+	 - the string /proc/self/fd/
+	 - the file descriptor number
+	 - the file name provided.
+	 The final NUL is included in the sizeof.   A bit of overhead
+	 due to the format elements compensates for possible negative
+	 numbers.  */
+      size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
+      bufold = alloca (buflen);
+
+      __snprintf (bufold, buflen, procfd, oldfd, old);
+      old = bufold;
+    }
+
+  char *bufnew = NULL;
+
+  if (newfd != AT_FDCWD && new[0] != '/')
+    {
+      size_t filelen = strlen (new);
+      /* Buffer for the path name we are going to use.  It consists of
+	 - the string /proc/self/fd/
+	 - the file descriptor number
+	 - the file name provided.
+	 The final NUL is included in the sizeof.   A bit of overhead
+	 due to the format elements compensates for possible negative
+	 numbers.  */
+      size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
+      bufnew = alloca (buflen);
+
+      __snprintf (bufnew, buflen, procfd, newfd, new);
+      new = bufnew;
+    }
+
+  INTERNAL_SYSCALL_DECL (err);
+
+  result = INTERNAL_SYSCALL (rename, err, 2, old,  new);
+
+  if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0))
+    {
+      __atfct_seterrno_2 (INTERNAL_SYSCALL_ERRNO (result, err), newfd, bufnew,
+			  oldfd, bufold);
+      result = -1;
+    }
+
+  return result;
+#endif
+}