/* $NetBSD: ether_sw_offload.c,v 1.6 2018/12/15 07:38:58 rin Exp $ */
/*
* Copyright (c) 2018 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Rin Okuyama.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef _KERNEL_OPT
#include "opt_inet.h"
#endif
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ether_sw_offload.c,v 1.6 2018/12/15 07:38:58 rin Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/if_ether.h>
#include <net/ether_sw_offload.h>
#include <netinet/in.h>
#include <netinet/in_offload.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6.h>
#include <netinet6/in6_offload.h>
#endif
/*
* Limit error messages at most once per 10 seconds.
*/
static const struct timeval eso_err_interval = {
.tv_sec = 10,
.tv_usec = 0,
};
static struct timeval eso_err_lasttime;
/*
* Handle TX offload in software. For TSO, split the packet into
* chanks with payloads of size MSS. For chekcsum offload, update
* required checksum fields. The results are more than one packet
* in general. Return a mbuf queue consists of them.
*/
struct mbuf *
ether_sw_offload_tx(struct ifnet *ifp, struct mbuf *m)
{
struct ether_header *ep;
int flags, ehlen;
uint16_t type;
#ifdef INET6
bool v6;
#else
bool v6 __diagused;
#endif
KASSERT(m->m_flags & M_PKTHDR);
flags = m->m_pkthdr.csum_flags;
if (flags == 0)
goto done;
/* Sanity check */
if (!TX_OFFLOAD_SUPPORTED(ifp->if_csum_flags_tx, flags))
goto quit;
KASSERT(m->m_pkthdr.len >= sizeof(*ep));
if (m->m_len < sizeof(*ep)) {
m = m_pullup(m, sizeof(*ep));
if (m == NULL)
return NULL;
}
ep = mtod(m, struct ether_header *);
switch (type = ntohs(ep->ether_type)) {
case ETHERTYPE_IP:
case ETHERTYPE_IPV6:
ehlen = ETHER_HDR_LEN;
break;
case ETHERTYPE_VLAN:
ehlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
break;
default:
if (ratecheck(&eso_err_lasttime, &eso_err_interval))
log(LOG_ERR, "%s: %s: dropping invalid frame "
"type 0x%04hx csum_flags 0x%08x\n",
__func__, ifp->if_xname, type, flags);
goto quit;
}
KASSERT(m->m_pkthdr.len >= ehlen);
v6 = flags & (M_CSUM_TSOv6 | M_CSUM_TCPv6 | M_CSUM_UDPv6);
#ifndef INET6
KASSERT(!v6);
#endif
if (flags & (M_CSUM_TSOv4 | M_CSUM_TSOv6)) {
/*
* tcp[46]_segment() assume that size of payloads is
* a multiple of MSS. Further, tcp6_segment() assumes
* no extention headers.
*
* XXX Do we need some KASSERT's?
*/
#ifdef INET6
if (v6)
return tcp6_segment(m, ehlen);
else
#endif
return tcp4_segment(m, ehlen);
}
#ifdef INET6
if (v6)
in6_undefer_cksum(m, ehlen, flags);
else
#endif
in_undefer_cksum(m, ehlen, flags);
done:
m->m_pkthdr.csum_flags = 0;
m->m_nextpkt = NULL;
return m;
quit:
m_freem(m);
return NULL;
}
/*
* Handle RX offload in software.
*
* XXX Fragmented packets or packets with IPv6 extension headers
* are not currently supported.
*/
struct mbuf *
ether_sw_offload_rx(struct ifnet *ifp, struct mbuf *m)
{
struct ether_header *eh;
struct ip *ip;
struct tcphdr *th;
struct udphdr *uh;
uint16_t sum, osum;
uint8_t proto;
int flags, enabled, len, ehlen, iphlen, l4offset;
bool v6;
flags = 0;
enabled = ifp->if_csum_flags_rx;
if (!(enabled & (M_CSUM_IPv4 | M_CSUM_TCPv4 | M_CSUM_UDPv4 |
M_CSUM_TCPv6 | M_CSUM_UDPv6)))
goto done;
KASSERT(m->m_flags & M_PKTHDR);
len = m->m_pkthdr.len;
KASSERT(len >= sizeof(*eh));
if (m->m_len < sizeof(*eh)) {
m = m_pullup(m, sizeof(*eh));
if (m == NULL)
return NULL;
}
eh = mtod(m, struct ether_header *);
switch (htons(eh->ether_type)) {
case ETHERTYPE_IP:
case ETHERTYPE_IPV6:
ehlen = ETHER_HDR_LEN;
break;
case ETHERTYPE_VLAN:
ehlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
break;
default:
goto done;
}
KASSERT(len >= ehlen);
len = m->m_pkthdr.len - ehlen;
KASSERT(len >= sizeof(*ip));
if (m->m_len < ehlen + sizeof(*ip)) {
m = m_pullup(m, ehlen + sizeof(*ip));
if (m == NULL)
return NULL;
}
ip = (void *)(mtod(m, char *) + ehlen);
v6 = (ip->ip_v != IPVERSION);
if (v6) {
#ifdef INET6
struct ip6_hdr *ip6;
KASSERT(len >= sizeof(*ip6));
if (m->m_len < ehlen + sizeof(*ip6)) {
m = m_pullup(m, ehlen + sizeof(*ip6));
if (m == NULL)
return NULL;
}
ip6 = (void *)(mtod(m, char *) + ehlen);
KASSERT((ip6->ip6_vfc & IPV6_VERSION_MASK) == IPV6_VERSION);
iphlen = sizeof(*ip6);
len -= iphlen;
proto = ip6->ip6_nxt;
switch (proto) {
case IPPROTO_TCP:
if (!(enabled & M_CSUM_TCPv6))
goto done;
break;
case IPPROTO_UDP:
if (!(enabled & M_CSUM_UDPv6))
goto done;
break;
default:
/* XXX Extension headers are not supported. */
goto done;
}
sum = in6_cksum_phdr(&ip6->ip6_src, &ip6->ip6_dst, htonl(len),
htonl(proto));
#else
goto done;
#endif
} else {
if (enabled & M_CSUM_IPv4)
flags |= M_CSUM_IPv4;
iphlen = ip->ip_hl << 2;
KASSERT(iphlen >= sizeof(*ip));
len -= iphlen;
KASSERT(len >= 0);
if (in4_cksum(m, 0, ehlen, iphlen) != 0) {
if (enabled & M_CSUM_IPv4)
flags |= M_CSUM_IPv4_BAD;
/* Broken. Do not check further. */
goto done;
}
/* Check if fragmented. */
if (ntohs(ip->ip_off) & ~(IP_DF | IP_RF))
goto done;
proto = ip->ip_p;
switch (proto) {
case IPPROTO_TCP:
if (!(enabled & M_CSUM_TCPv4))
goto done;
break;
case IPPROTO_UDP:
if (!(enabled & M_CSUM_UDPv4))
goto done;
break;
default:
goto done;
}
sum = in_cksum_phdr(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htons((uint16_t)len + proto));
}
l4offset = ehlen + iphlen;
switch (proto) {
case IPPROTO_TCP:
KASSERT(len >= sizeof(*th));
if (m->m_len < l4offset + sizeof(*th)) {
m = m_pullup(m, l4offset + sizeof(*th));
if (m == NULL)
return NULL;
}
th = (void *)(mtod(m, char *) + l4offset);
osum = th->th_sum;
th->th_sum = sum;
#ifdef INET6
if (v6) {
flags |= M_CSUM_TCPv6;
sum = in6_cksum(m, 0, l4offset, len);
} else
#endif
{
flags |= M_CSUM_TCPv4;
sum = in4_cksum(m, 0, l4offset, len);
}
if (sum != osum)
flags |= M_CSUM_TCP_UDP_BAD;
th->th_sum = osum;
break;
case IPPROTO_UDP:
KASSERT(len >= sizeof(*uh));
if (m->m_len < l4offset + sizeof(*uh)) {
m = m_pullup(m, l4offset + sizeof(*uh));
if (m == NULL)
return NULL;
}
uh = (void *)(mtod(m, char *) + l4offset);
osum = uh->uh_sum;
if (osum == 0)
break;
uh->uh_sum = sum;
#ifdef INET6
if (v6) {
flags |= M_CSUM_UDPv6;
sum = in6_cksum(m, 0, l4offset, len);
} else
#endif
{
flags |= M_CSUM_UDPv4;
sum = in4_cksum(m, 0, l4offset, len);
}
if (sum == 0)
sum = 0xffff;
if (sum != osum)
flags |= M_CSUM_TCP_UDP_BAD;
uh->uh_sum = osum;
break;
default:
panic("%s: impossible", __func__);
}
done:
m->m_pkthdr.csum_flags = flags;
return m;
}