[NET]: Supporting UDP-Lite (RFC 3828) in Linux

This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:

	* UDP and UDP-Lite now use separate object files
	* source file dependencies resolved via header files
	  net/ipv{4,6}/udp_impl.h
	* order of inclusion files in udp.c/udplite.c adapted
	  accordingly

[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)

This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
        * generic routines are all located in net/ipv4/udp.c
        * UDP-Lite specific routines are in net/ipv4/udplite.c
        * MIB/statistics support in /proc/net/snmp and /proc/net/udplite
        * shared API with extensions for partial checksum coverage

[NET/IPv6]: Extension for UDP-Lite over IPv6

It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
        * UDPv6 generic and shared code is in net/ipv6/udp.c
        * UDP-Litev6 specific extensions are in net/ipv6/udplite.c
        * MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
        * support for IPV6_ADDRFORM
        * aligned the coding style of protocol initialisation with af_inet6.c
        * made the error handling in udpv6_queue_rcv_skb consistent;
          to return `-1' on error on all error cases
        * consolidation of shared code

[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support

The UDP-Lite patch further provides
        * API documentation for UDP-Lite
        * basic xfrm support
        * basic netfilter support for IPv4 and IPv6 (LOG target)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 2 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index de6b91981b30..1eafcfc95e81 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -51,6 +51,7 @@
 #include <net/inet_common.h>
 #include <net/tcp.h>
 #include <net/udp.h>
+#include <net/udplite.h>
 #include <net/xfrm.h>
 
 #include <asm/uaccess.h>
@@ -239,6 +240,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
                         struct sk_buff *pktopt;
 
                         if (sk->sk_protocol != IPPROTO_UDP &&
+                            sk->sk_protocol != IPPROTO_UDPLITE &&
                             sk->sk_protocol != IPPROTO_TCP)
                                 break;
 
@@ -276,11 +278,15 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
                                 sk->sk_family = PF_INET;
                                 tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                         } else {
+                                struct proto *prot = &udp_prot;
+
+                                if (sk->sk_protocol == IPPROTO_UDPLITE)
+                                        prot = &udplite_prot;
                                 local_bh_disable();
                                 sock_prot_dec_use(sk->sk_prot);
-                                sock_prot_inc_use(&udp_prot);
+                                sock_prot_inc_use(prot);
                                 local_bh_enable();
-                                sk->sk_prot = &udp_prot;
+                                sk->sk_prot = prot;
                                 sk->sk_socket->ops = &inet_dgram_ops;
                                 sk->sk_family = PF_INET;
                         }
@@ -813,6 +819,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
         switch (optname) {
         case IPV6_ADDRFORM:
                 if (sk->sk_protocol != IPPROTO_UDP &&
+                    sk->sk_protocol != IPPROTO_UDPLITE &&
                     sk->sk_protocol != IPPROTO_TCP)
                         return -EINVAL;
                 if (sk->sk_state != TCP_ESTABLISHED)