160734399f
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
133 lines
3.7 KiB
C
133 lines
3.7 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 udp_table udplite_table;
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/* Slow-path computation of checksum. Socket is locked. */
|
|
static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
const struct udp_sock *up = udp_sk(skb->sk);
|
|
int cscov = up->len;
|
|
__wsum csum = 0;
|
|
|
|
if (up->pcflag & UDPLITE_SEND_CC) {
|
|
/*
|
|
* Sender has set `partial coverage' option on UDP-Lite socket.
|
|
* The special case "up->pcslen == 0" signifies full coverage.
|
|
*/
|
|
if (up->pcslen < up->len) {
|
|
if (0 < up->pcslen)
|
|
cscov = up->pcslen;
|
|
udp_hdr(skb)->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.
|
|
*/
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* Fast-path computation of checksum. Socket may not be locked. */
|
|
static inline __wsum udplite_csum(struct sk_buff *skb)
|
|
{
|
|
const struct udp_sock *up = udp_sk(skb->sk);
|
|
const int off = skb_transport_offset(skb);
|
|
int len = skb->len - off;
|
|
|
|
if ((up->pcflag & UDPLITE_SEND_CC) && up->pcslen < len) {
|
|
if (0 < up->pcslen)
|
|
len = up->pcslen;
|
|
udp_hdr(skb)->len = htons(up->pcslen);
|
|
}
|
|
skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
|
|
|
|
return skb_checksum(skb, off, len, 0);
|
|
}
|
|
|
|
void udplite4_register(void);
|
|
int udplite_get_port(struct sock *sk, unsigned short snum,
|
|
int (*scmp)(const struct sock *, const struct sock *));
|
|
#endif /* _UDPLITE_H */
|