39 lines
1.4 KiB
C
39 lines
1.4 KiB
C
/* Return point to next ancillary data entry in message header.
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Copyright (C) 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <sys/socket.h>
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struct cmsghdr *
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__cmsg_nxthdr (struct msghdr *mhdr, struct cmsghdr *cmsg)
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{
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unsigned char *p;
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if ((size_t) cmsg->cmsg_len < sizeof (struct cmsghdr))
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/* The kernel header does this so there may be a reason. */
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return NULL;
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p = (((unsigned char *) cmsg)
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+ ((cmsg->cmsg_len + sizeof (long int) - 1) & ~sizeof (long int)));
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if (p >= (unsigned char *) mhdr->msg_control + mhdr->msg_controllen)
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/* No more entries. */
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return NULL;
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return (struct cmsghdr *) p;
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}
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