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Diffstat (limited to 'sysdeps/unix/sysv/linux/cmsg_nxthdr.c')
-rw-r--r--sysdeps/unix/sysv/linux/cmsg_nxthdr.c38
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;
+}