[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>

include/linux/in.h

@@ -45,6 +45,7 @@ enum {
 
   IPPROTO_COMP   = 108,                /* Compression Header protocol */
   IPPROTO_SCTP   = 132,		/* Stream Control Transport Protocol	*/
+  IPPROTO_UDPLITE = 136,	/* UDP-Lite (RFC 3828)			*/
 
   IPPROTO_RAW	 = 255,		/* Raw IP packets			*/
   IPPROTO_MAX

include/linux/socket.h

@@ -264,6 +264,7 @@ struct ucred {
 #define SOL_IPV6	41
 #define SOL_ICMPV6	58
 #define SOL_SCTP	132
+#define SOL_UDPLITE	136     /* UDP-Lite (RFC 3828) */
 #define SOL_RAW		255
 #define SOL_IPX		256
 #define SOL_AX25	257

include/linux/udp.h

@@ -38,6 +38,7 @@ struct udphdr {
 #include <linux/types.h>
 
 #include <net/inet_sock.h>
+#define UDP_HTABLE_SIZE		128
 
 struct udp_sock {
 	/* inet_sock has to be the first member */
@@ -50,12 +51,23 @@ struct udp_sock {
 	 * when the socket is uncorked.
 	 */
 	__u16		 len;		/* total length of pending frames */
+	/*
+	 * Fields specific to UDP-Lite.
+	 */
+	__u16		 pcslen;
+	__u16		 pcrlen;
+/* indicator bits used by pcflag: */
+#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        */
+	__u8		 pcflag;        /* marks socket as UDP-Lite if > 0    */
 };
 
 static inline struct udp_sock *udp_sk(const struct sock *sk)
 {
 	return (struct udp_sock *)sk;
 }
+#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
 
 #endif
 

include/net/ipv6.h

@@ -158,9 +158,13 @@ DECLARE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics);
 	SNMP_INC_STATS_OFFSET_BH(icmpv6_statistics, field, _offset);    	\
 })
 DECLARE_SNMP_STAT(struct udp_mib, udp_stats_in6);
-#define UDP6_INC_STATS(field)		SNMP_INC_STATS(udp_stats_in6, field)
-#define UDP6_INC_STATS_BH(field)	SNMP_INC_STATS_BH(udp_stats_in6, field)
-#define UDP6_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(udp_stats_in6, field)
+DECLARE_SNMP_STAT(struct udp_mib, udplite_stats_in6);
+#define UDP6_INC_STATS_BH(field, is_udplite) 			      do  {  \
+	if (is_udplite) SNMP_INC_STATS_BH(udplite_stats_in6, field);         \
+	else		SNMP_INC_STATS_BH(udp_stats_in6, field);    } while(0)
+#define UDP6_INC_STATS_USER(field, is_udplite)			       do {    \
+	if (is_udplite) SNMP_INC_STATS_USER(udplite_stats_in6, field);         \
+	else		SNMP_INC_STATS_USER(udp_stats_in6, field);    } while(0)
 
 int snmp6_register_dev(struct inet6_dev *idev);
 int snmp6_unregister_dev(struct inet6_dev *idev);
@@ -604,6 +608,8 @@ extern int  tcp6_proc_init(void);
 extern void tcp6_proc_exit(void);
 extern int  udp6_proc_init(void);
 extern void udp6_proc_exit(void);
+extern int  udplite6_proc_init(void);
+extern void udplite6_proc_exit(void);
 extern int  ipv6_misc_proc_init(void);
 extern void ipv6_misc_proc_exit(void);
 

include/net/transp_v6.h

@@ -11,6 +11,7 @@
 
 extern struct proto rawv6_prot;
 extern struct proto udpv6_prot;
+extern struct proto udplitev6_prot;
 extern struct proto tcpv6_prot;
 
 struct flowi;
@@ -24,6 +25,7 @@ extern void				ipv6_destopt_init(void);
 /* transport protocols */
 extern void				rawv6_init(void);
 extern void				udpv6_init(void);
+extern void 				udplitev6_init(void);
 extern void				tcpv6_init(void);
 
 extern int				udpv6_connect(struct sock *sk,

include/net/udp.h

@@ -26,9 +26,28 @@
 #include <net/inet_sock.h>
 #include <net/sock.h>
 #include <net/snmp.h>
+#include <net/ip.h>
+#include <linux/ipv6.h>
 #include <linux/seq_file.h>
 
-#define UDP_HTABLE_SIZE		128
+/**
+ *	struct udp_skb_cb  -  UDP(-Lite) private variables
+ *
+ *	@header:      private variables used by IPv4/IPv6
+ *	@cscov:       checksum coverage length (UDP-Lite only)
+ *	@partial_cov: if set indicates partial csum coverage
+ */
+struct udp_skb_cb {
+	union {
+		struct inet_skb_parm	h4;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+		struct inet6_skb_parm	h6;
+#endif
+	} header;
+	__u16		cscov;
+	__u8		partial_cov;
+};
+#define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb))
 
 extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
 extern rwlock_t udp_hash_lock;
@@ -47,6 +66,62 @@ extern struct proto udp_prot;
 
 struct sk_buff;
 
+/*
+ *	Generic checksumming routines for UDP(-Lite) v4 and v6
+ */
+static inline u16  __udp_lib_checksum_complete(struct sk_buff *skb)
+{
+	if (! UDP_SKB_CB(skb)->partial_cov)
+		return __skb_checksum_complete(skb);
+	return  csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov,
+			  skb->csum));
+}
+
+static __inline__ int udp_lib_checksum_complete(struct sk_buff *skb)
+{
+	return skb->ip_summed != CHECKSUM_UNNECESSARY &&
+		__udp_lib_checksum_complete(skb);
+}
+
+/**
+ * 	udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
+ * 	@sk: 	socket we are writing to
+ * 	@skb: 	sk_buff containing the filled-in UDP header
+ * 	        (checksum field must be zeroed out)
+ */
+static inline u32 udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
+{
+	u32 csum = csum_partial(skb->h.raw, sizeof(struct udphdr), 0);
+
+	skb_queue_walk(&sk->sk_write_queue, skb) {
+		csum = csum_add(csum, skb->csum);
+	}
+	return csum;
+}
+
+/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
+static inline void udp_lib_hash(struct sock *sk)
+{
+	BUG();
+}
+
+static inline void udp_lib_unhash(struct sock *sk)
+{
+	write_lock_bh(&udp_hash_lock);
+	if (sk_del_node_init(sk)) {
+		inet_sk(sk)->num = 0;
+		sock_prot_dec_use(sk->sk_prot);
+	}
+	write_unlock_bh(&udp_hash_lock);
+}
+
+static inline void udp_lib_close(struct sock *sk, long timeout)
+{
+	sk_common_release(sk);
+}
+
+
+/* net/ipv4/udp.c */
 extern int	udp_get_port(struct sock *sk, unsigned short snum,
 			     int (*saddr_cmp)(const struct sock *, const struct sock *));
 extern void	udp_err(struct sk_buff *, u32);
@@ -61,21 +136,29 @@ extern unsigned int udp_poll(struct file *file, struct socket *sock,
 			     poll_table *wait);
 
 DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
-#define UDP_INC_STATS(field)		SNMP_INC_STATS(udp_statistics, field)
-#define UDP_INC_STATS_BH(field)		SNMP_INC_STATS_BH(udp_statistics, field)
-#define UDP_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(udp_statistics, field)
+/*
+ * 	SNMP statistics for UDP and UDP-Lite
+ */
+#define UDP_INC_STATS_USER(field, is_udplite)			       do {   \
+	if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field);       \
+	else		SNMP_INC_STATS_USER(udp_statistics, field);  }  while(0)
+#define UDP_INC_STATS_BH(field, is_udplite) 			       do  {  \
+	if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field);         \
+	else		SNMP_INC_STATS_BH(udp_statistics, field);    }  while(0)
 
 /* /proc */
 struct udp_seq_afinfo {
 	struct module		*owner;
 	char			*name;
 	sa_family_t		family;
+	struct hlist_head	*hashtable;
 	int 			(*seq_show) (struct seq_file *m, void *v);
 	struct file_operations	*seq_fops;
 };
 
 struct udp_iter_state {
 	sa_family_t		family;
+	struct hlist_head	*hashtable;
 	int			bucket;
 	struct seq_operations	seq_ops;
 };

include/net/udplite.h

+/*
+ *	Definitions for the UDP-Lite (RFC 3828) code.
+ */
+#ifndef _UDPLITE_H
+#define _UDPLITE_H
+
+/* UDP-Lite socket options */
+#define UDPLITE_SEND_CSCOV   10 /* sender partial coverage (as sent)      */
+#define UDPLITE_RECV_CSCOV   11 /* receiver partial coverage (threshold ) */
+
+extern struct proto 		udplite_prot;
+extern struct hlist_head 	udplite_hash[UDP_HTABLE_SIZE];
+
+/* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */
+DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics);
+
+/*
+ *	Checksum computation is all in software, hence simpler getfrag.
+ */
+static __inline__ int udplite_getfrag(void *from, char *to, int  offset,
+				      int len, int odd, struct sk_buff *skb)
+{
+	return memcpy_fromiovecend(to, (struct iovec *) from, offset, len);
+}
+
+/* Designate sk as UDP-Lite socket */
+static inline int udplite_sk_init(struct sock *sk)
+{
+	udp_sk(sk)->pcflag = UDPLITE_BIT;
+	return 0;
+}
+
+/*
+ * 	Checksumming routines
+ */
+static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+	u16 cscov;
+
+        /* In UDPv4 a zero checksum means that the transmitter generated no
+         * checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
+         * with a zero checksum field are illegal.                            */
+	if (uh->check == 0) {
+		LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n");
+		return 1;
+	}
+
+        UDP_SKB_CB(skb)->partial_cov = 0;
+	cscov = ntohs(uh->len);
+
+	if (cscov == 0)		 /* Indicates that full coverage is required. */
+		cscov = skb->len;
+	else if (cscov < 8  || cscov > skb->len) {
+		/*
+		 * Coverage length violates RFC 3828: log and discard silently.
+		 */
+		LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n",
+			       cscov, skb->len);
+		return 1;
+
+	} else if (cscov < skb->len)
+        	UDP_SKB_CB(skb)->partial_cov = 1;
+
+        UDP_SKB_CB(skb)->cscov = cscov;
+
+	/*
+	 * There is no known NIC manufacturer supporting UDP-Lite yet,
+	 * hence ip_summed is always (re-)set to CHECKSUM_NONE.
+	 */
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 0;
+}
+
+static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+	int rc = udplite_checksum_init(skb, uh);
+
+	if (!rc)
+		skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
+					       skb->nh.iph->daddr,
+					       skb->len, IPPROTO_UDPLITE, 0);
+	return rc;
+}
+
+static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+	int rc = udplite_checksum_init(skb, uh);
+
+	if (!rc)
+		skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr,
+					     &skb->nh.ipv6h->daddr,
+					     skb->len, IPPROTO_UDPLITE, 0);
+	return rc;
+}
+
+static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
+{
+	int cscov = up->len;
+
+	/*
+	 * Sender has set `partial coverage' option on UDP-Lite socket
+	 */
+	if (up->pcflag & UDPLITE_SEND_CC)    {
+		if (up->pcslen < up->len) {
+		/* up->pcslen == 0 means that full coverage is required,
+		 * partial coverage only if  0 < up->pcslen < up->len */
+			if (0 < up->pcslen) {
+			       cscov = up->pcslen;
+			}
+			uh->len = htons(up->pcslen);
+		}
+	/*
+	 * NOTE: Causes for the error case  `up->pcslen > up->len':
+	 *        (i)  Application error (will not be penalized).
+	 *       (ii)  Payload too big for send buffer: data is split
+	 *             into several packets, each with its own header.
+	 *             In this case (e.g. last segment), coverage may
+	 *             exceed packet length.
+	 *       Since packets with coverage length > packet length are
+	 *       illegal, we fall back to the defaults here.
+	 */
+	}
+	return cscov;
+}
+
+static inline u32 udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
+{
+	u32 csum = 0;
+	int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
+
+	skb->ip_summed = CHECKSUM_NONE;     /* no HW support for checksumming */
+
+	skb_queue_walk(&sk->sk_write_queue, skb) {
+		off = skb->h.raw - skb->data;
+		len = skb->len - off;
+
+		csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
+
+		if ((cscov -= len) <= 0)
+			break;
+	}
+	return csum;
+}
+
+extern void	udplite4_register(void);
+extern int 	udplite_get_port(struct sock *sk, unsigned short snum,
+			int (*scmp)(const struct sock *, const struct sock *));
+#endif	/* _UDPLITE_H */

include/net/xfrm.h

@@ -468,6 +468,7 @@ __be16 xfrm_flowi_sport(struct flowi *fl)
 	switch(fl->proto) {
 	case IPPROTO_TCP:
 	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE:
 	case IPPROTO_SCTP:
 		port = fl->fl_ip_sport;
 		break;
@@ -493,6 +494,7 @@ __be16 xfrm_flowi_dport(struct flowi *fl)
 	switch(fl->proto) {
 	case IPPROTO_TCP:
 	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE:
 	case IPPROTO_SCTP:
 		port = fl->fl_ip_dport;
 		break;

net/ipv4/Makefile

@@ -8,7 +8,8 @@ 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 arp.o icmp.o devinet.o af_inet.o igmp.o \
+	     datagram.o raw.o udp.o udplite.o \
+	     arp.o icmp.o devinet.o af_inet.o  igmp.o \
 	     sysctl_net_ipv4.o fib_frontend.o fib_semantics.o
 
 obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o

net/ipv4/af_inet.c

@@ -104,6 +104,7 @@
 #include <net/inet_connection_sock.h>
 #include <net/tcp.h>
 #include <net/udp.h>
+#include <net/udplite.h>
 #include <linux/skbuff.h>
 #include <net/sock.h>
 #include <net/raw.h>
@@ -1223,10 +1224,13 @@ static int __init init_ipv4_mibs(void)
 	tcp_statistics[1] = alloc_percpu(struct tcp_mib);
 	udp_statistics[0] = alloc_percpu(struct udp_mib);
 	udp_statistics[1] = alloc_percpu(struct udp_mib);
+	udplite_statistics[0] = alloc_percpu(struct udp_mib);
+	udplite_statistics[1] = alloc_percpu(struct udp_mib);
 	if (!
 	    (net_statistics[0] && net_statistics[1] && ip_statistics[0]
 	     && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1]
-	     && udp_statistics[0] && udp_statistics[1]))
+	     && udp_statistics[0] && udp_statistics[1]
+	     && udplite_statistics[0] && udplite_statistics[1]             ) )
 		return -ENOMEM;
 
 	(void) tcp_mib_init();
@@ -1313,6 +1317,8 @@ static int __init inet_init(void)
 	/* Setup TCP slab cache for open requests. */
 	tcp_init();
 
+	/* Add UDP-Lite (RFC 3828) */
+	udplite4_register();
 
 	/*
 	 *	Set the ICMP layer up

net/ipv4/netfilter/ipt_LOG.c

@@ -171,11 +171,15 @@ static void dump_packet(const struct nf_loginfo *info,
 		}
 		break;
 	}
-	case IPPROTO_UDP: {
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE: {
 		struct udphdr _udph, *uh;
 
-		/* Max length: 10 "PROTO=UDP " */
-		printk("PROTO=UDP ");
+		if (ih->protocol == IPPROTO_UDP)
+			/* Max length: 10 "PROTO=UDP "     */
+			printk("PROTO=UDP " );
+		else	/* Max length: 14 "PROTO=UDPLITE " */
+			printk("PROTO=UDPLITE ");
 
 		if (ntohs(ih->frag_off) & IP_OFFSET)
 			break;
@@ -341,6 +345,7 @@ static void dump_packet(const struct nf_loginfo *info,
 	/* IP:      40+46+6+11+127 = 230 */
 	/* TCP:     10+max(25,20+30+13+9+32+11+127) = 252 */
 	/* UDP:     10+max(25,20) = 35 */
+	/* UDPLITE: 14+max(25,20) = 39 */
 	/* ICMP:    11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
 	/* ESP:     10+max(25)+15 = 50 */
 	/* AH:      9+max(25)+15 = 49 */

net/ipv4/proc.c

@@ -38,6 +38,7 @@
 #include <net/protocol.h>
 #include <net/tcp.h>
 #include <net/udp.h>
+#include <net/udplite.h>
 #include <linux/inetdevice.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
@@ -66,6 +67,7 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 		   tcp_death_row.tw_count, atomic_read(&tcp_sockets_allocated),
 		   atomic_read(&tcp_memory_allocated));
 	seq_printf(seq, "UDP: inuse %d\n", fold_prot_inuse(&udp_prot));
+	seq_printf(seq, "UDPLITE: inuse %d\n", fold_prot_inuse(&udplite_prot));
 	seq_printf(seq, "RAW: inuse %d\n", fold_prot_inuse(&raw_prot));
 	seq_printf(seq,  "FRAG: inuse %d memory %d\n", ip_frag_nqueues,
 		   atomic_read(&ip_frag_mem));
@@ -304,6 +306,17 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 			   fold_field((void **) udp_statistics, 
 				      snmp4_udp_list[i].entry));
 
+	/* the UDP and UDP-Lite MIBs are the same */
+	seq_puts(seq, "\nUdpLite:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_udp_list[i].name);
+
+	seq_puts(seq, "\nUdpLite:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   fold_field((void **) udplite_statistics,
+				      snmp4_udp_list[i].entry)     );
+
 	seq_putc(seq, '\n');
 	return 0;
 }

net/ipv4/udp_impl.h

+#ifndef _UDP4_IMPL_H
+#define _UDP4_IMPL_H
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <net/protocol.h>
+#include <net/inet_common.h>
+
+extern int  	__udp4_lib_rcv(struct sk_buff *, struct hlist_head [], int );
+extern void 	__udp4_lib_err(struct sk_buff *, u32, struct hlist_head []);
+
+extern int	__udp_lib_get_port(struct sock *sk, unsigned short snum,
+				   struct hlist_head udptable[], int *port_rover,
+		       	       	   int (*)(const struct sock*,const struct sock*));
+extern int	ipv4_rcv_saddr_equal(const struct sock *, const struct sock *);
+
+
+extern int	udp_setsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int optlen);
+extern int	udp_getsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int __user *optlen);
+
+#ifdef CONFIG_COMPAT
+extern int	compat_udp_setsockopt(struct sock *sk, int level, int optname,
+				      char __user *optval, int optlen);
+extern int	compat_udp_getsockopt(struct sock *sk, int level, int optname,
+				      char __user *optval, int __user *optlen);
+#endif
+extern int	udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+			    size_t len, int noblock, int flags, int *addr_len);
+extern int	udp_sendpage(struct sock *sk, struct page *page, int offset,
+			     size_t size, int flags);
+extern int	udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb);
+extern int	udp_destroy_sock(struct sock *sk);
+
+#ifdef CONFIG_PROC_FS
+extern int	udp4_seq_show(struct seq_file *seq, void *v);
+#endif
+#endif	/* _UDP4_IMPL_H */

net/ipv4/udplite.c

+/*
+ *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
+ *
+ *  Version:    $Id: udplite.c,v 1.25 2006/10/19 07:22:36 gerrit Exp $
+ *
+ *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
+ *
+ *  Changes:
+ *  Fixes:
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#include "udp_impl.h"
+DEFINE_SNMP_STAT(struct udp_mib, udplite_statistics)	__read_mostly;
+
+struct hlist_head 	udplite_hash[UDP_HTABLE_SIZE];
+static int		udplite_port_rover;
+
+__inline__ int udplite_get_port(struct sock *sk, unsigned short p,
+			int (*c)(const struct sock *, const struct sock *))
+{
+	return  __udp_lib_get_port(sk, p, udplite_hash, &udplite_port_rover, c);
+}
+
+static __inline__ int udplite_v4_get_port(struct sock *sk, unsigned short snum)
+{
+	return udplite_get_port(sk, snum, ipv4_rcv_saddr_equal);
+}
+
+__inline__ int udplite_rcv(struct sk_buff *skb)
+{
+	return __udp4_lib_rcv(skb, udplite_hash, 1);
+}
+
+__inline__ void udplite_err(struct sk_buff *skb, u32 info)
+{
+	return __udp4_lib_err(skb, info, udplite_hash);
+}
+
+static	struct net_protocol udplite_protocol = {
+	.handler	= udplite_rcv,
+	.err_handler	= udplite_err,
+	.no_policy	= 1,
+};
+
+struct proto 	udplite_prot = {
+	.name		   = "UDP-Lite",
+	.owner		   = THIS_MODULE,
+	.close		   = udp_lib_close,
+	.connect	   = ip4_datagram_connect,
+	.disconnect	   = udp_disconnect,
+	.ioctl		   = udp_ioctl,
+	.init		   = udplite_sk_init,
+	.destroy	   = udp_destroy_sock,
+	.setsockopt	   = udp_setsockopt,
+	.getsockopt	   = udp_getsockopt,
+	.sendmsg	   = udp_sendmsg,
+	.recvmsg	   = udp_recvmsg,
+	.sendpage	   = udp_sendpage,
+	.backlog_rcv	   = udp_queue_rcv_skb,
+	.hash		   = udp_lib_hash,
+	.unhash		   = udp_lib_unhash,
+	.get_port	   = udplite_v4_get_port,
+	.obj_size	   = sizeof(struct udp_sock),
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_udp_setsockopt,
+	.compat_getsockopt = compat_udp_getsockopt,
+#endif
+};
+
+static struct inet_protosw udplite4_protosw = {
+	.type		=  SOCK_DGRAM,
+	.protocol	=  IPPROTO_UDPLITE,
+	.prot		=  &udplite_prot,
+	.ops		=  &inet_dgram_ops,
+	.capability	= -1,
+	.no_check	=  0,		/* must checksum (RFC 3828) */
+	.flags		=  INET_PROTOSW_PERMANENT,
+};
+
+#ifdef CONFIG_PROC_FS
+static struct file_operations udplite4_seq_fops;
+static struct udp_seq_afinfo udplite4_seq_afinfo = {
+	.owner		= THIS_MODULE,
+	.name		= "udplite",
+	.family		= AF_INET,
+	.hashtable	= udplite_hash,
+	.seq_show	= udp4_seq_show,
+	.seq_fops	= &udplite4_seq_fops,
+};
+#endif
+
+void __init udplite4_register(void)
+{
+	if (proto_register(&udplite_prot, 1))
+		goto out_register_err;
+
+	if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
+		goto out_unregister_proto;
+
+	inet_register_protosw(&udplite4_protosw);
+
+#ifdef CONFIG_PROC_FS
+	if (udp_proc_register(&udplite4_seq_afinfo)) /* udplite4_proc_init() */
+		printk(KERN_ERR "%s: Cannot register /proc!\n", __FUNCTION__);
+#endif
+	return;
+
+out_unregister_proto:
+	proto_unregister(&udplite_prot);
+out_register_err:
+	printk(KERN_CRIT "%s: Cannot add UDP-Lite protocol.\n", __FUNCTION__);
+}
+
+EXPORT_SYMBOL(udplite_hash);
+EXPORT_SYMBOL(udplite_prot);
+EXPORT_SYMBOL(udplite_get_port);

net/ipv4/xfrm4_policy.c

@@ -199,6 +199,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl)
 	if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
 		switch (iph->protocol) {
 		case IPPROTO_UDP:
+		case IPPROTO_UDPLITE:
 		case IPPROTO_TCP:
 		case IPPROTO_SCTP:
 		case IPPROTO_DCCP:

net/ipv6/Makefile

@@ -5,8 +5,8 @@
 obj-$(CONFIG_IPV6) += ipv6.o
 
 ipv6-objs :=	af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
-		route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o raw.o \
-		protocol.o icmp.o mcast.o reassembly.o tcp_ipv6.o \
+		route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
+		raw.o protocol.o icmp.o mcast.o reassembly.o tcp_ipv6.o \
 		exthdrs.o sysctl_net_ipv6.o datagram.o proc.o \
 		ip6_flowlabel.o ipv6_syms.o inet6_connection_sock.o
 

net/ipv6/af_inet6.c

@@ -49,6 +49,7 @@
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/udp.h>
+#include <net/udplite.h>
 #include <net/tcp.h>
 #include <net/ipip.h>
 #include <net/protocol.h>
@@ -737,8 +738,13 @@ static int __init init_ipv6_mibs(void)
 	if (snmp6_mib_init((void **)udp_stats_in6, sizeof (struct udp_mib),
 			   __alignof__(struct udp_mib)) < 0)
 		goto err_udp_mib;
+	if (snmp6_mib_init((void **)udplite_stats_in6, sizeof (struct udp_mib),
+			   __alignof__(struct udp_mib)) < 0)
+		goto err_udplite_mib;
 	return 0;
 
+err_udplite_mib:
+	snmp6_mib_free((void **)udp_stats_in6);
 err_udp_mib:
 	snmp6_mib_free((void **)icmpv6_statistics);
 err_icmp_mib:
@@ -753,6 +759,7 @@ static void cleanup_ipv6_mibs(void)
 	snmp6_mib_free((void **)ipv6_statistics);
 	snmp6_mib_free((void **)icmpv6_statistics);
 	snmp6_mib_free((void **)udp_stats_in6);
+	snmp6_mib_free((void **)udplite_stats_in6);
 }
 
 static int __init inet6_init(void)
@@ -780,10 +787,14 @@ static int __init inet6_init(void)
 	if (err)
 		goto out_unregister_tcp_proto;
 
-	err = proto_register(&rawv6_prot, 1);
+	err = proto_register(&udplitev6_prot, 1);
 	if (err)
 		goto out_unregister_udp_proto;
 
+	err = proto_register(&rawv6_prot, 1);
+	if (err)
+		goto out_unregister_udplite_proto;
+
 
 	/* Register the socket-side information for inet6_create.  */
 	for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
@@ -837,6 +848,8 @@ static int __init inet6_init(void)
 		goto proc_tcp6_fail;
 	if (udp6_proc_init())
 		goto proc_udp6_fail;
+	if (udplite6_proc_init())
+		goto proc_udplite6_fail;
 	if (ipv6_misc_proc_init())
 		goto proc_misc6_fail;
 
@@ -862,6 +875,7 @@ static int __init inet6_init(void)
 
 	/* Init v6 transport protocols. */
 	udpv6_init();
+	udplitev6_init();
 	tcpv6_init();
 
 	ipv6_packet_init();
@@ -879,6 +893,8 @@ static int __init inet6_init(void)
 proc_anycast6_fail:
 	ipv6_misc_proc_exit();
 proc_misc6_fail:
+	udplite6_proc_exit();
+proc_udplite6_fail:
 	udp6_proc_exit();
 proc_udp6_fail:
 	tcp6_proc_exit();
@@ -902,6 +918,8 @@ static int __init inet6_init(void)
 	sock_unregister(PF_INET6);
 out_unregister_raw_proto:
 	proto_unregister(&rawv6_prot);
+out_unregister_udplite_proto:
+	proto_unregister(&udplitev6_prot);
 out_unregister_udp_proto:
 	proto_unregister(&udpv6_prot);
 out_unregister_tcp_proto:
@@ -919,6 +937,7 @@ static void __exit inet6_exit(void)
 	ac6_proc_exit();
  	ipv6_misc_proc_exit();
  	udp6_proc_exit();
+ 	udplite6_proc_exit();
  	tcp6_proc_exit();
  	raw6_proc_exit();
 #endif

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)

net/ipv6/netfilter/ip6t_LOG.c

@@ -270,11 +270,15 @@ static void dump_packet(const struct nf_loginfo *info,
 		}
 		break;
 	}
-	case IPPROTO_UDP: {
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE: {
 		struct udphdr _udph, *uh;
 
-		/* Max length: 10 "PROTO=UDP " */
-		printk("PROTO=UDP ");
+		if (currenthdr == IPPROTO_UDP)
+			/* Max length: 10 "PROTO=UDP "     */
+			printk("PROTO=UDP " );
+		else	/* Max length: 14 "PROTO=UDPLITE " */
+			printk("PROTO=UDPLITE ");
 
 		if (fragment)
 			break;

net/ipv6/proc.c

@@ -49,6 +49,8 @@ static int sockstat6_seq_show(struct seq_file *seq, void *v)
 		       fold_prot_inuse(&tcpv6_prot));
 	seq_printf(seq, "UDP6: inuse %d\n",
 		       fold_prot_inuse(&udpv6_prot));
+	seq_printf(seq, "UDPLITE6: inuse %d\n",
+		        fold_prot_inuse(&udplitev6_prot));
 	seq_printf(seq, "RAW6: inuse %d\n",
 		       fold_prot_inuse(&rawv6_prot));
 	seq_printf(seq, "FRAG6: inuse %d memory %d\n",
@@ -133,6 +135,14 @@ static struct snmp_mib snmp6_udp6_list[] = {
 	SNMP_MIB_SENTINEL
 };
 
+static struct snmp_mib snmp6_udplite6_list[] = {
+	SNMP_MIB_ITEM("UdpLite6InDatagrams", UDP_MIB_INDATAGRAMS),
+	SNMP_MIB_ITEM("UdpLite6NoPorts", UDP_MIB_NOPORTS),
+	SNMP_MIB_ITEM("UdpLite6InErrors", UDP_MIB_INERRORS),
+	SNMP_MIB_ITEM("UdpLite6OutDatagrams", UDP_MIB_OUTDATAGRAMS),
+	SNMP_MIB_SENTINEL
+};
+
 static unsigned long
 fold_field(void *mib[], int offt)
 {
@@ -167,6 +177,7 @@ static int snmp6_seq_show(struct seq_file *seq, void *v)
 		snmp6_seq_show_item(seq, (void **)ipv6_statistics, snmp6_ipstats_list);
 		snmp6_seq_show_item(seq, (void **)icmpv6_statistics, snmp6_icmp6_list);
 		snmp6_seq_show_item(seq, (void **)udp_stats_in6, snmp6_udp6_list);
+		snmp6_seq_show_item(seq, (void **)udplite_stats_in6, snmp6_udplite6_list);
 	}
 	return 0;
 }

net/ipv6/udp_impl.h

+#ifndef _UDP6_IMPL_H
+#define _UDP6_IMPL_H
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <net/protocol.h>
+#include <net/addrconf.h>
+#include <net/inet_common.h>
+
+extern int  	__udp6_lib_rcv(struct sk_buff **, struct hlist_head [], int );
+extern void 	__udp6_lib_err(struct sk_buff *, struct inet6_skb_parm *,
+			       int , int , int , __be32 , struct hlist_head []);
+
+extern int	udpv6_getsockopt(struct sock *sk, int level, int optname,
+		     		 char __user *optval, int __user *optlen);
+extern int	udpv6_setsockopt(struct sock *sk, int level, int optname,
+			  	 char __user *optval, int optlen);
+#ifdef CONFIG_COMPAT
+extern int	compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
+					char __user *optval, int optlen);
+extern int	compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
+				       char __user *optval, int __user *optlen);
+#endif
+extern int	udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
+			      struct msghdr *msg, size_t len);
+extern int	udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
+			      struct msghdr *msg, size_t len,
+		  	      int noblock, int flags, int *addr_len);
+extern int	udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb);
+extern int	udpv6_destroy_sock(struct sock *sk);
+
+#ifdef CONFIG_PROC_FS
+extern int	udp6_seq_show(struct seq_file *seq, void *v);
+#endif
+#endif	/* _UDP6_IMPL_H */

net/ipv6/udplite.c

+/*
+ *  UDPLITEv6   An implementation of the UDP-Lite protocol over IPv6.
+ *              See also net/ipv4/udplite.c
+ *
+ *  Version:    $Id: udplite.c,v 1.9 2006/10/19 08:28:10 gerrit Exp $
+ *
+ *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
+ *
+ *  Changes:
+ *  Fixes:
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#include "udp_impl.h"
+
+DEFINE_SNMP_STAT(struct udp_mib, udplite_stats_in6) __read_mostly;
+
+static __inline__ int udplitev6_rcv(struct sk_buff **pskb)
+{
+	return __udp6_lib_rcv(pskb, udplite_hash, 1);
+}
+
+static __inline__ void udplitev6_err(struct sk_buff *skb,
+				     struct inet6_skb_parm *opt,
+				     int type, int code, int offset, __u32 info)
+{
+	return __udp6_lib_err(skb, opt, type, code, offset, info, udplite_hash);
+}
+
+static struct inet6_protocol udplitev6_protocol = {
+	.handler	=	udplitev6_rcv,
+	.err_handler	=	udplitev6_err,
+	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+static __inline__ int udplite_v6_get_port(struct sock *sk, unsigned short snum)
+{
+	return udplite_get_port(sk, snum, ipv6_rcv_saddr_equal);
+}
+
+struct proto udplitev6_prot = {
+	.name		   = "UDPLITEv6",
+	.owner		   = THIS_MODULE,
+	.close		   = udp_lib_close,
+	.connect	   = ip6_datagram_connect,
+	.disconnect	   = udp_disconnect,
+	.ioctl		   = udp_ioctl,
+	.init		   = udplite_sk_init,
+	.destroy	   = udpv6_destroy_sock,
+	.setsockopt	   = udpv6_setsockopt,
+	.getsockopt	   = udpv6_getsockopt,
+	.sendmsg	   = udpv6_sendmsg,
+	.recvmsg	   = udpv6_recvmsg,
+	.backlog_rcv	   = udpv6_queue_rcv_skb,
+	.hash		   = udp_lib_hash,
+	.unhash		   = udp_lib_unhash,
+	.get_port	   = udplite_v6_get_port,
+	.obj_size	   = sizeof(struct udp6_sock),
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_udpv6_setsockopt,
+	.compat_getsockopt = compat_udpv6_getsockopt,
+#endif
+};
+
+static struct inet_protosw udplite6_protosw = {
+	.type		= SOCK_DGRAM,
+	.protocol	= IPPROTO_UDPLITE,
+	.prot		= &udplitev6_prot,
+	.ops		= &inet6_dgram_ops,
+	.capability	= -1,
+	.no_check	= 0,
+	.flags		= INET_PROTOSW_PERMANENT,
+};
+
+void __init udplitev6_init(void)
+{
+	if (inet6_add_protocol(&udplitev6_protocol, IPPROTO_UDPLITE) < 0)
+		printk(KERN_ERR "%s: Could not register.\n", __FUNCTION__);
+
+	inet6_register_protosw(&udplite6_protosw);
+}
+
+#ifdef CONFIG_PROC_FS
+static struct file_operations udplite6_seq_fops;
+static struct udp_seq_afinfo udplite6_seq_afinfo = {
+	.owner		= THIS_MODULE,
+	.name		= "udplite6",
+	.family		= AF_INET6,
+	.hashtable	= udplite_hash,
+	.seq_show	= udp6_seq_show,
+	.seq_fops	= &udplite6_seq_fops,
+};
+
+int __init udplite6_proc_init(void)
+{
+	return udp_proc_register(&udplite6_seq_afinfo);
+}
+
+void udplite6_proc_exit(void)
+{
+	udp_proc_unregister(&udplite6_seq_afinfo);
+}
+#endif

net/ipv6/xfrm6_policy.c

@@ -274,6 +274,7 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl)
 			break;
 
 		case IPPROTO_UDP:
+		case IPPROTO_UDPLITE:
 		case IPPROTO_TCP:
 		case IPPROTO_SCTP:
 		case IPPROTO_DCCP:

net/netfilter/xt_multiport.c

-/* Kernel module to match one of a list of TCP/UDP/SCTP/DCCP ports: ports are in
-   the same place so we can treat them as equal. */
+/* Kernel module to match one of a list of TCP/UDP(-Lite)/SCTP/DCCP ports:
+   ports are in the same place so we can treat them as equal. */
 
 /* (C) 1999-2001 Paul `Rusty' Russell
  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
@@ -162,6 +162,7 @@ check(u_int16_t proto,
 {
 	/* Must specify supported protocol, no unknown flags or bad count */
 	return (proto == IPPROTO_TCP || proto == IPPROTO_UDP
+		|| proto == IPPROTO_UDPLITE
 		|| proto == IPPROTO_SCTP || proto == IPPROTO_DCCP)
 		&& !(ip_invflags & XT_INV_PROTO)
 		&& (match_flags == XT_MULTIPORT_SOURCE

net/netfilter/xt_tcpudp.c

@@ -10,7 +10,7 @@
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter_ipv6/ip6_tables.h>
 
-MODULE_DESCRIPTION("x_tables match for TCP and UDP, supports IPv4 and IPv6");
+MODULE_DESCRIPTION("x_tables match for TCP and UDP(-Lite), supports IPv4 and IPv6");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("xt_tcp");
 MODULE_ALIAS("xt_udp");
@@ -234,6 +234,24 @@ static struct xt_match xt_tcpudp_match[] = {
 		.proto		= IPPROTO_UDP,
 		.me		= THIS_MODULE,
 	},
+	{
+		.name		= "udplite",
+		.family		= AF_INET,
+		.checkentry	= udp_checkentry,
+		.match		= udp_match,
+		.matchsize	= sizeof(struct xt_udp),
+		.proto		= IPPROTO_UDPLITE,
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "udplite",
+		.family		= AF_INET6,
+		.checkentry	= udp_checkentry,
+		.match		= udp_match,
+		.matchsize	= sizeof(struct xt_udp),
+		.proto		= IPPROTO_UDPLITE,
+		.me		= THIS_MODULE,
+	},
 };
 
 static int __init xt_tcpudp_init(void)