- (dtucker) [defines.h] Bug #336: Add CMSG_DATA and CMSG_FIRSTHDR macros if

   not already defined (eg Linux with some versions of libc5), based on those
   from OpenBSD.

1 files changed, 19 insertions, 1 deletions

diff --git a/defines.h b/defines.h
index ec610d0db..3679ea549 100644
--- a/defines.h
+++ b/defines.h
@@ -25,7 +25,7 @@
 #ifndef _DEFINES_H
 #define _DEFINES_H
 
-/* $Id: defines.h,v 1.99 2003/06/11 12:51:32 djm Exp $ */
+/* $Id: defines.h,v 1.100 2003/08/07 05:58:28 dtucker Exp $ */
 
 
 /* Constants */
@@ -577,4 +577,22 @@ struct winsize {
 
 /** end of login recorder definitions */
 
+#ifndef CMSG_DATA
+/* given pointer to struct cmsghdr, return pointer to data */
+#define CMSG_DATA(cmsg) \
+        ((u_char *)(cmsg) +  (((u_int)(sizeof(struct cmsghdr)) \
+         (sizeof(int) - 1)) &~ (sizeof(int) - 1)))
+#endif /* CMSG_DATA */
+
+#ifndef CMSG_FIRSTHDR
+/*
+ * RFC 2292 requires to check msg_controllen, in case that the kernel returns
+ * an empty list for some reasons.
+ */
+# define CMSG_FIRSTHDR(mhdr) \
+        ((mhdr)->msg_controllen >= sizeof(struct cmsghdr) ? \
+         (struct cmsghdr *)(mhdr)->msg_control : \
+         (struct cmsghdr *)NULL)
+#endif /* CMSG_FIRSTHDR */
+
 #endif /* _DEFINES_H */