[UDP]: Allow users to configure UDP-Lite.

Let's give users an option for disabling UDP-Lite (~4K).

old:
|    text	   data	    bss	    dec	    hex	filename
|  286498	  12432	   6072	 305002	  4a76a	net/ipv4/built-in.o
|  193830	   8192	   3204	 205226	  321aa	net/ipv6/ipv6.o

new (without UDP-Lite):
|    text	   data	    bss	    dec	    hex	filename
|  284086	  12136	   5432	 301654	  49a56	net/ipv4/built-in.o
|  191835	   7832	   3076	 202743	  317f7	net/ipv6/ipv6.o

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 8ec703f462da..4144664d69d9 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -70,8 +70,10 @@ struct udp_sock {
 #define UDPLITE_BIT      0x1            /* set by udplite proto init function */
 #define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
 #define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
+#ifdef CONFIG_IP_UDPLITE
         __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
         __u8             unused[3];
+#endif
         /*
          * For encapsulation sockets.
          */
@@ -82,7 +84,16 @@ static inline struct udp_sock *udp_sk(const struct sock *sk)
 {
         return (struct udp_sock *)sk;
 }
+
+#ifdef CONFIG_IP_UDPLITE
 #define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
+#define IS_PROTO_UDPLITE(__proto) ((__proto) == IPPROTO_UDPLITE)
+#define IS_SOL_UDPFAMILY(level) ((level) == SOL_UDP || (level) == SOL_UDPLITE)
+#else
+#define IS_UDPLITE(__sk) 0
+#define IS_PROTO_UDPLITE(__proto) 0
+#define IS_SOL_UDPFAMILY(level) ((level) == SOL_UDP)
+#endif
 
 #endif