[src/trunk]: src/sys/sys cleanup the CMSG* macro mess.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dd50e4b9a636
branches:  trunk
changeset: 335809:dd50e4b9a636
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Jan 24 18:07:54 2015 +0000

description:
cleanup the CMSG* macro mess.

diffstat:

 sys/sys/socket.h |  44 ++++++++++++++++++++++----------------------
 1 files changed, 22 insertions(+), 22 deletions(-)

diffs (92 lines):

diff -r f60c79e89187 -r dd50e4b9a636 sys/sys/socket.h
--- a/sys/sys/socket.h  Sat Jan 24 18:07:37 2015 +0000
+++ b/sys/sys/socket.h  Sat Jan 24 18:07:54 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: socket.h,v 1.114 2015/01/24 17:15:22 christos Exp $    */
+/*     $NetBSD: socket.h,v 1.115 2015/01/24 18:07:54 christos Exp $    */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -470,6 +470,8 @@
 #define        SOMAXCONN       128
 #endif
 
+#include <sys/cdefs.h>
+
 /*
  * Message header for recvmsg and sendmsg calls.
  * Used value-result for recvmsg, value only for sendmsg.
@@ -526,14 +528,6 @@
 /* followed by u_char  cmsg_data[]; */
 };
 
-/* given pointer to struct cmsghdr, return pointer to data */
-#define        CMSG_DATA(cmsg) \
-    ((u_char *)(void *)(cmsg) + \
-    __CMSG_ALIGN(sizeof(struct cmsghdr)))
-#define        CCMSG_DATA(cmsg) \
-    ((const u_char *)(const void *)(cmsg) + \
-    __CMSG_ALIGN(sizeof(struct cmsghdr)))
-
 /*
  * Alignment requirement for CMSG struct manipulation.
  * This basically behaves the same as ALIGN() ARCH/include/param.h.
@@ -544,30 +538,38 @@
  * changes in ALIGNBYTES.
  */
 #define __CMSG_ALIGN(n)        (((n) + __ALIGNBYTES) & ~__ALIGNBYTES)
+
 #ifdef _KERNEL
 #define CMSG_ALIGN(n)  __CMSG_ALIGN(n)
 #endif
 
+#define __CMSG_ASIZE   __CMSG_ALIGN(sizeof(struct cmsghdr))
+#define __CMSG_MSGNEXT(cmsg) \
+    (__CASTV(char *, cmsg) + __CMSG_ALIGN((cmsg)->cmsg_len))
+#define __CMSG_MSGEND(mhdr) \
+    (__CASTV(char *, (mhdr)->msg_control) + (mhdr)->msg_controllen)
+
+/* given pointer to struct cmsghdr, return pointer to data */
+#define        CMSG_DATA(cmsg) (__CASTV(u_char *, cmsg) + __CMSG_ASIZE)
+#define        CCMSG_DATA(cmsg) (__CASTCV(const u_char *, cmsg) + __CMSG_ASIZE)
+
 /* given pointer to struct cmsghdr, return pointer to next cmsghdr */
 #define        CMSG_NXTHDR(mhdr, cmsg) \
-       (((char *)(void *)(cmsg) + __CMSG_ALIGN((cmsg)->cmsg_len) + \
-                           __CMSG_ALIGN(sizeof(struct cmsghdr)) > \
-           (((char *)(void *)(mhdr)->msg_control) + (mhdr)->msg_controllen)) ?\
-           (struct cmsghdr *)0 : \
-           (struct cmsghdr *)(void *)((char *)(void *)(cmsg) + \
-               __CMSG_ALIGN((cmsg)->cmsg_len)))
+    __CASTV(struct cmsghdr *,  \
+       __CMSG_MSGNEXT(cmsg) + __CMSG_ASIZE > __CMSG_MSGEND(mhdr) ? 0 : \
+       __CMSG_MSGNEXT(cmsg))
 
 /*
  * 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 *)(void *)(mhdr)->msg_control : \
-        (struct cmsghdr *)0)
+    __CASTV(struct cmsghdr *, \
+       (mhdr)->msg_controllen < sizeof(struct cmsghdr) ? 0 : \
+       (mhdr)->msg_control)
 
-#define CMSG_SPACE(l)  (__CMSG_ALIGN(sizeof(struct cmsghdr)) + __CMSG_ALIGN(l))
-#define CMSG_LEN(l)    (__CMSG_ALIGN(sizeof(struct cmsghdr)) + (l))
+#define CMSG_SPACE(l)  (__CMSG_ASIZE + __CMSG_ALIGN(l))
+#define CMSG_LEN(l)    (__CMSG_ASIZE + (l))
 
 /* "Socket"-level control message types: */
 #define        SCM_RIGHTS      0x01            /* access rights (array of int) */
@@ -584,8 +586,6 @@
 #define        SHUT_WR         1               /* Disallow further sends. */
 #define        SHUT_RDWR       2               /* Disallow further sends/receives. */
 
-#include <sys/cdefs.h>
-
 #ifdef _KERNEL
 static inline socklen_t
 sockaddr_getlen(const struct sockaddr *sa)