[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>

5 files changed, 36 insertions, 13 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 19880b086e71..efe3832c4ad8 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -632,5 +632,15 @@ config TCP_MD5SIG
 
           If unsure, say N.
 
+config IP_UDPLITE
+        bool "IP: UDP-Lite Protocol (RFC 3828)"
+        default n
+        ---help---
+          UDP-Lite (RFC 3828) is a UDP-like protocol with variable-length
+          checksum.  Read <file:Documentation/networking/udplite.txt> for
+          details.
+
+          If unsure, say N.
+
 source "net/ipv4/ipvs/Kconfig"
 
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index ad40ef3f9ebc..e88cebdf3e30 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -8,7 +8,7 @@ obj-y     := route.o inetpeer.o protocol.o \
              inet_timewait_sock.o inet_connection_sock.o \
              tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
              tcp_minisocks.o tcp_cong.o \
-             datagram.o raw.o udp.o udplite.o \
+             datagram.o raw.o udp.o \
              arp.o icmp.o devinet.o af_inet.o  igmp.o \
              fib_frontend.o fib_semantics.o \
              inet_fragment.o
@@ -49,6 +49,7 @@ obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
 obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
 obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
 obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
+obj-$(CONFIG_IP_UDPLITE) += udplite.o
 obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
 
 obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 4f539bd48718..67260c0eaaa8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1317,15 +1317,18 @@ static int __init init_ipv4_mibs(void)
         if (snmp_mib_init((void **)udp_statistics,
                           sizeof(struct udp_mib)) < 0)
                 goto err_udp_mib;
+#ifdef CONFIG_IP_UDPLITE
         if (snmp_mib_init((void **)udplite_statistics,
                           sizeof(struct udp_mib)) < 0)
                 goto err_udplite_mib;
-
+#endif
         tcp_mib_init();
 
         return 0;
 
+#ifdef CONFIG_IP_UDPLITE
 err_udplite_mib:
+#endif
         snmp_mib_free((void **)udp_statistics);
 err_udp_mib:
         snmp_mib_free((void **)tcp_statistics);
@@ -1423,8 +1426,10 @@ static int __init inet_init(void)
         /* Setup UDP memory threshold */
         udp_init();
 
+#ifdef CONFIG_IP_UDPLITE
         /* Add UDP-Lite (RFC 3828) */
         udplite4_register();
+#endif
 
         /*
          *      Set the ICMP layer up
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index d63474c6b400..d75ddb7fa4b8 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -59,7 +59,9 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
                    atomic_read(&tcp_memory_allocated));
         seq_printf(seq, "UDP: inuse %d mem %d\n", sock_prot_inuse_get(&udp_prot),
                    atomic_read(&udp_memory_allocated));
+#ifdef CONFIG_IP_UDPLITE
         seq_printf(seq, "UDPLITE: inuse %d\n", sock_prot_inuse_get(&udplite_prot));
+#endif
         seq_printf(seq, "RAW: inuse %d\n", sock_prot_inuse_get(&raw_prot));
         seq_printf(seq,  "FRAG: inuse %d memory %d\n",
                         ip_frag_nqueues(&init_net), ip_frag_mem(&init_net));
@@ -349,6 +351,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
                            snmp_fold_field((void **)udp_statistics,
                                            snmp4_udp_list[i].entry));
 
+#ifdef CONFIG_IP_UDPLITE
         /* the UDP and UDP-Lite MIBs are the same */
         seq_puts(seq, "\nUdpLite:");
         for (i = 0; snmp4_udp_list[i].name != NULL; i++)
@@ -359,7 +362,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
                 seq_printf(seq, " %lu",
                            snmp_fold_field((void **)udplite_statistics,
                                            snmp4_udp_list[i].entry));
-
+#endif
         seq_putc(seq, '\n');
         return 0;
 }
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7ea1b67b6de1..acc353aa89eb 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1127,7 +1127,7 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
         UDP_SKB_CB(skb)->partial_cov = 0;
         UDP_SKB_CB(skb)->cscov = skb->len;
 
-        if (proto == IPPROTO_UDPLITE) {
+        if (IS_PROTO_UDPLITE(proto)) {
                 err = udplite_checksum_init(skb, uh);
                 if (err)
                         return err;
@@ -1175,7 +1175,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
         if (ulen > skb->len)
                 goto short_packet;
 
-        if (proto == IPPROTO_UDP) {
+        if (IS_PROTO_UDPLITE(proto)) {
                 /* UDP validates ulen. */
                 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
                         goto short_packet;
@@ -1217,7 +1217,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
         if (udp_lib_checksum_complete(skb))
                 goto csum_error;
 
-        UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
+        UDP_INC_STATS_BH(UDP_MIB_NOPORTS, IS_PROTO_UDPLITE(proto));
         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
         /*
@@ -1229,7 +1229,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
 
 short_packet:
         LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
-                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
+                       IS_PROTO_UDPLITE(proto) ? "-Lite" : "",
                        NIPQUAD(saddr),
                        ntohs(uh->source),
                        ulen,
@@ -1244,14 +1244,14 @@ csum_error:
          * the network is concerned, anyway) as per 4.1.3.4 (MUST).
          */
         LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
-                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
+                       IS_PROTO_UDPLITE(proto) ? "-Lite" : "",
                        NIPQUAD(saddr),
                        ntohs(uh->source),
                        NIPQUAD(daddr),
                        ntohs(uh->dest),
                        ulen);
 drop:
-        UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
+        UDP_INC_STATS_BH(UDP_MIB_INERRORS, IS_PROTO_UDPLITE(proto));
         kfree_skb(skb);
         return 0;
 }
@@ -1279,7 +1279,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
         struct udp_sock *up = udp_sk(sk);
         int val;
         int err = 0;
+#ifdef CONFIG_IP_UDPLITE
         int is_udplite = IS_UDPLITE(sk);
+#endif
 
         if (optlen<sizeof(int))
                 return -EINVAL;
@@ -1315,6 +1317,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
                 }
                 break;
 
+#ifdef CONFIG_IP_UDPLITE
         /*
          *      UDP-Lite's partial checksum coverage (RFC 3828).
          */
@@ -1340,6 +1343,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
                 up->pcrlen = val;
                 up->pcflag |= UDPLITE_RECV_CC;
                 break;
+#endif
 
         default:
                 err = -ENOPROTOOPT;
@@ -1352,7 +1356,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 int udp_setsockopt(struct sock *sk, int level, int optname,
                    char __user *optval, int optlen)
 {
-        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+        if (IS_SOL_UDPFAMILY(level))
                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
                                           udp_push_pending_frames);
         return ip_setsockopt(sk, level, optname, optval, optlen);
@@ -1362,7 +1366,7 @@ int udp_setsockopt(struct sock *sk, int level, int optname,
 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
                           char __user *optval, int optlen)
 {
-        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+        if (IS_SOL_UDPFAMILY(level))
                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
                                           udp_push_pending_frames);
         return compat_ip_setsockopt(sk, level, optname, optval, optlen);
@@ -1416,7 +1420,7 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
 int udp_getsockopt(struct sock *sk, int level, int optname,
                    char __user *optval, int __user *optlen)
 {
-        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+        if (IS_SOL_UDPFAMILY(level))
                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
         return ip_getsockopt(sk, level, optname, optval, optlen);
 }
@@ -1425,7 +1429,7 @@ int udp_getsockopt(struct sock *sk, int level, int optname,
 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
                                  char __user *optval, int __user *optlen)
 {
-        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+        if (IS_SOL_UDPFAMILY(level))
                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
         return compat_ip_getsockopt(sk, level, optname, optval, optlen);
 }