1 /* Return point to next ancillary data entry in message header.
2 Copyright (C) 1997, 1998, 2001 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 /* Prevent math.h from defining a colliding inline */
22 #undef __USE_EXTERN_INLINES
23 #include <sys/socket.h>
27 __cmsg_nxthdr (struct msghdr *mhdr, struct cmsghdr *cmsg)
29 if ((size_t) cmsg->cmsg_len < sizeof (struct cmsghdr))
30 /* The kernel header does this so there may be a reason. */
33 cmsg = (struct cmsghdr *) ((unsigned char *) cmsg
34 + CMSG_ALIGN (cmsg->cmsg_len));
35 if ((unsigned char *) (cmsg + 1) > ((unsigned char *) mhdr->msg_control
36 + mhdr->msg_controllen)
37 || ((unsigned char *) cmsg + CMSG_ALIGN (cmsg->cmsg_len)
38 > ((unsigned char *) mhdr->msg_control + mhdr->msg_controllen)))
39 /* No more entries. */
43 libc_hidden_def(__cmsg_nxthdr)