| /* Return point to next ancillary data entry in message header. |
| Copyright (C) 1997-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <stddef.h> |
| #include <sys/socket.h> |
| |
| |
| struct cmsghdr * |
| __cmsg_nxthdr (struct msghdr *mhdr, struct cmsghdr *cmsg) |
| { |
| if ((size_t) cmsg->cmsg_len < sizeof (struct cmsghdr)) |
| /* The kernel header does this so there may be a reason. */ |
| return NULL; |
| |
| cmsg = (struct cmsghdr *) ((unsigned char *) cmsg |
| + CMSG_ALIGN (cmsg->cmsg_len)); |
| if ((unsigned char *) (cmsg + 1) > ((unsigned char *) mhdr->msg_control |
| + mhdr->msg_controllen) |
| || ((unsigned char *) cmsg + CMSG_ALIGN (cmsg->cmsg_len) |
| > ((unsigned char *) mhdr->msg_control + mhdr->msg_controllen))) |
| /* No more entries. */ |
| return NULL; |
| return cmsg; |
| } |
| libc_hidden_def (__cmsg_nxthdr) |
