net: introduce helper macro for_each_cmsghdr

Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
cmsghdr from msghdr, just cleanup.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 3 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 19f038739087..e171b780b499 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -703,7 +703,7 @@ EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 
 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
 {
-        struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
+        struct cmsghdr *cmsg;
 
         /*
          * Assign an (opaque) qpolicy priority value to skb->priority.
@@ -717,8 +717,7 @@ static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
          */
         skb->priority = 0;
 
-        for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
-
+        for_each_cmsghdr(cmsg, msg) {
                 if (!CMSG_OK(msg, cmsg))
                         return -EINVAL;