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linux/net/ipv4/udplite.c
Herbert Xu 759e5d0064 [UDP]: Clean up UDP-Lite receive checksum
This patch eliminates some duplicate code for the verification of
receive checksums between UDP-Lite and UDP.  It does this by
introducing __skb_checksum_complete_head which is identical to
__skb_checksum_complete_head apart from the fact that it takes
a length parameter rather than computing the first skb->len bytes.

As a result UDP-Lite will be able to use hardware checksum offload
for packets which do not use partial coverage checksums.  It also
means that UDP-Lite loopback no longer does unnecessary checksum
verification.

If any NICs start support UDP-Lite this would also start working
automatically.

This patch removes the assumption that msg_flags has MSG_TRUNC clear
upon entry in recvmsg.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:51 -07:00

120 lines
3.2 KiB
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;
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 int udplite_v4_get_port(struct sock *sk, unsigned short snum)
{
return udplite_get_port(sk, snum, ipv4_rcv_saddr_equal);
}
static int udplite_rcv(struct sk_buff *skb)
{
return __udp4_lib_rcv(skb, udplite_hash, IPPROTO_UDPLITE);
}
static 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);