ip: IP cmsg cleanup

Move the IP_CMSG_* constants from ip_sockglue.c to inet_sock.h so that
they can be referenced in other source files.

Restructure ip_cmsg_recv to not go through flags using shift, check
for flags by 'and'. This eliminates both the shift and a conditional
per flag check.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 37 insertions, 27 deletions

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 8a89c738b7a3..80f78565b41b 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -45,14 +45,6 @@
 #include <linux/errqueue.h>
 #include <asm/uaccess.h>
 
-#define IP_CMSG_PKTINFO         1
-#define IP_CMSG_TTL             2
-#define IP_CMSG_TOS             4
-#define IP_CMSG_RECVOPTS        8
-#define IP_CMSG_RETOPTS         16
-#define IP_CMSG_PASSSEC         32
-#define IP_CMSG_ORIGDSTADDR     64
-
 /*
  *      SOL_IP control messages.
  */
@@ -150,37 +142,55 @@ void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
         unsigned int flags = inet->cmsg_flags;
 
         /* Ordered by supposed usage frequency */
-        if (flags & 1)
+        if (flags & IP_CMSG_PKTINFO) {
                 ip_cmsg_recv_pktinfo(msg, skb);
-        if ((flags >>= 1) == 0)
-                return;
 
-        if (flags & 1)
+                flags &= ~IP_CMSG_PKTINFO;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_TTL) {
                 ip_cmsg_recv_ttl(msg, skb);
-        if ((flags >>= 1) == 0)
-                return;
 
-        if (flags & 1)
+                flags &= ~IP_CMSG_TTL;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_TOS) {
                 ip_cmsg_recv_tos(msg, skb);
-        if ((flags >>= 1) == 0)
-                return;
 
-        if (flags & 1)
+                flags &= ~IP_CMSG_TOS;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_RECVOPTS) {
                 ip_cmsg_recv_opts(msg, skb);
-        if ((flags >>= 1) == 0)
-                return;
 
-        if (flags & 1)
+                flags &= ~IP_CMSG_RECVOPTS;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_RETOPTS) {
                 ip_cmsg_recv_retopts(msg, skb);
-        if ((flags >>= 1) == 0)
-                return;
 
-        if (flags & 1)
+                flags &= ~IP_CMSG_RETOPTS;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_PASSSEC) {
                 ip_cmsg_recv_security(msg, skb);
 
-        if ((flags >>= 1) == 0)
-                return;
-        if (flags & 1)
+                flags &= ~IP_CMSG_PASSSEC;
+                if (!flags)
+                        return;
+        }
+
+        if (flags & IP_CMSG_ORIGDSTADDR)
                 ip_cmsg_recv_dstaddr(msg, skb);
 
 }