[net-next-2.6.git] / include / net / udplite.h

/*
 *	Definitions for the UDP-Lite (RFC 3828) code.
 */
#ifndef _UDPLITE_H
#define _UDPLITE_H

#include <net/ip6_checksum.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_unfold(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 __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
{
	int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
	__wsum csum = 0;

	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 */
Commit	Line	Data
ba4e58ec GR	1	/*
	2	* Definitions for the UDP-Lite (RFC 3828) code.
	3	*/
	4	#ifndef _UDPLITE_H
	5	#define _UDPLITE_H
	6
6bb100b9 DM	7	#include <net/ip6_checksum.h>
6bb100b9 DM	8
ba4e58ec GR	9	/* UDP-Lite socket options */
	10	#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
	11	#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
	12
	13	extern struct proto udplite_prot;
	14	extern struct hlist_head udplite_hash[UDP_HTABLE_SIZE];
	15
	16	/* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */
	17	DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics);
	18
	19	/*
	20	* Checksum computation is all in software, hence simpler getfrag.
	21	*/
	22	static __inline__ int udplite_getfrag(void from, char to, int offset,
	23	int len, int odd, struct sk_buff *skb)
	24	{
	25	return memcpy_fromiovecend(to, (struct iovec *) from, offset, len);
	26	}
	27
	28	/* Designate sk as UDP-Lite socket */
	29	static inline int udplite_sk_init(struct sock *sk)
	30	{
	31	udp_sk(sk)->pcflag = UDPLITE_BIT;
	32	return 0;
	33	}
	34
	35	/*
	36	* Checksumming routines
	37	*/
	38	static inline int udplite_checksum_init(struct sk_buff skb, struct udphdr uh)
	39	{
	40	u16 cscov;
	41
	42	/* In UDPv4 a zero checksum means that the transmitter generated no
	43	* checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
	44	* with a zero checksum field are illegal. */
	45	if (uh->check == 0) {
	46	LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n");
	47	return 1;
	48	}
	49
	50	UDP_SKB_CB(skb)->partial_cov = 0;
	51	cscov = ntohs(uh->len);
	52
	53	if (cscov == 0) /* Indicates that full coverage is required. */
	54	cscov = skb->len;
	55	else if (cscov < 8 \|\| cscov > skb->len) {
	56	/*
	57	* Coverage length violates RFC 3828: log and discard silently.
	58	*/
	59	LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n",
	60	cscov, skb->len);
	61	return 1;
	62
	63	} else if (cscov < skb->len)
	64	UDP_SKB_CB(skb)->partial_cov = 1;
	65
	66	UDP_SKB_CB(skb)->cscov = cscov;
	67
	68	/*
	69	* There is no known NIC manufacturer supporting UDP-Lite yet,
	70	* hence ip_summed is always (re-)set to CHECKSUM_NONE.
	71	*/
	72	skb->ip_summed = CHECKSUM_NONE;
73
74	return 0;
75	}
76
77	static __inline__ int udplite4_csum_init(struct sk_buff skb, struct udphdr uh)
78	{
79	int rc = udplite_checksum_init(skb, uh);
80
81	if (!rc)
82	skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
83	skb->nh.iph->daddr,
84	skb->len, IPPROTO_UDPLITE, 0);
85	return rc;
86	}
87
88	static __inline__ int udplite6_csum_init(struct sk_buff skb, struct udphdr uh)
89	{
90	int rc = udplite_checksum_init(skb, uh);
91
92	if (!rc)
8e5200f5	93	skb->csum = ~csum_unfold(csum_ipv6_magic(&skb->nh.ipv6h->saddr,
ba4e58ec	94	&skb->nh.ipv6h->daddr,
8e5200f5	95	skb->len, IPPROTO_UDPLITE, 0));
ba4e58ec GR	96	return rc;
	97	}
	98
	99	static inline int udplite_sender_cscov(struct udp_sock up, struct udphdr uh)
	100	{
	101	int cscov = up->len;
	102
	103	/*
	104	* Sender has set `partial coverage' option on UDP-Lite socket
	105	*/
	106	if (up->pcflag & UDPLITE_SEND_CC) {
	107	if (up->pcslen < up->len) {
	108	/* up->pcslen == 0 means that full coverage is required,
	109	* partial coverage only if 0 < up->pcslen < up->len */
	110	if (0 < up->pcslen) {
	111	cscov = up->pcslen;
	112	}
	113	uh->len = htons(up->pcslen);
	114	}
	115	/*
	116	* NOTE: Causes for the error case `up->pcslen > up->len':
	117	* (i) Application error (will not be penalized).
	118	* (ii) Payload too big for send buffer: data is split
	119	* into several packets, each with its own header.
	120	* In this case (e.g. last segment), coverage may
	121	* exceed packet length.
	122	* Since packets with coverage length > packet length are
	123	* illegal, we fall back to the defaults here.
	124	*/
	125	}
	126	return cscov;
	127	}
	128
868c86bc	129	static inline __wsum udplite_csum_outgoing(struct sock sk, struct sk_buff skb)
ba4e58ec	130	{
ba4e58ec	131	int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
868c86bc	132	__wsum csum = 0;
ba4e58ec GR	133
	134	skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
	135
	136	skb_queue_walk(&sk->sk_write_queue, skb) {
	137	off = skb->h.raw - skb->data;
	138	len = skb->len - off;
	139
	140	csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
	141
	142	if ((cscov -= len) <= 0)
	143	break;
	144	}
	145	return csum;
	146	}
	147
	148	extern void udplite4_register(void);
	149	extern int udplite_get_port(struct sock *sk, unsigned short snum,
	150	int (scmp)(const struct sock , const struct sock *));
	151	#endif /* _UDPLITE_H */