1 files changed, 38 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/cmsg_nxthdr.c b/sysdeps/unix/sysv/linux/cmsg_nxthdr.c
new file mode 100644
index 0000000000..2245db7f25
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/cmsg_nxthdr.c
@@ -0,0 +1,38 @@
+/* Return point to next ancillary data entry in message header.
+   Copyright (C) 1997 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sys/socket.h>
+
+
+struct cmsghdr *
+__cmsg_nxthdr (struct msghdr *mhdr, struct cmsghdr *cmsg)
+{
+  unsigned char *p;
+
+  if ((size_t) cmsg->cmsg_len < sizeof (struct cmsghdr))
+    /* The kernel header does this so there may be a reason.  */
+    return NULL;
+
+  p = (((unsigned char *) cmsg)
+       + ((cmsg->cmsg_len + sizeof (long int) - 1) & ~sizeof (long int)));
+  if (p >= (unsigned char *) mhdr->msg_control + mhdr->msg_controllen)
+    /* No more entries.  */
+    return NULL;
+  return (struct cmsghdr *) p;
+}