android_kernel_motorola_sm6225/include/net/udplite.h
David S. Miller fc038410b4 [UDP]: Fix AF-specific references in AF-agnostic code.
__udp_lib_port_inuse() cannot make direct references to
inet_sk(sk)->rcv_saddr as that is ipv4 specific state and
this code is used by ipv6 too.

Use an operations vector to solve this, and this also paves
the way for ipv6 support for non-wild saddr hashing in UDP.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-10 23:47:22 -07:00

124 lines
3.5 KiB
C

/*
* 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;
}
cscov = ntohs(uh->len);
if (cscov == 0) /* Indicates that full coverage is required. */
;
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;
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
}
return 0;
}
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 cscov = udplite_sender_cscov(udp_sk(sk), udp_hdr(skb));
__wsum csum = 0;
skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
skb_queue_walk(&sk->sk_write_queue, skb) {
const int off = skb_transport_offset(skb);
const int 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,
const struct udp_get_port_ops *ops);
#endif /* _UDPLITE_H */