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freebsd-dev/sys/netinet/tcp_lro.c
Lawrence Stewart 4b7b743c16 Pass the number of segments coalesced by LRO up the stack by repurposing the 
tso_segsz pkthdr field during RX processing, and use the information in TCP for
more correct accounting and as a congestion control input. This is only a start,
and an audit of other uses for the data is left as future work.

Reviewed by:	gallatin, rrs
Sponsored by:	Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D7564
2016-08-25 13:33:32 +00:00

981 lines
22 KiB
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/*-
* Copyright (c) 2007, Myricom Inc.
* Copyright (c) 2008, Intel Corporation.
* Copyright (c) 2012 The FreeBSD Foundation
* Copyright (c) 2016 Mellanox Technologies.
* All rights reserved.
*
* Portions of this software were developed by Bjoern Zeeb
* under sponsorship from the FreeBSD Foundation.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <net/vnet.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_lro.h>
#include <netinet/tcp_var.h>
#include <netinet6/ip6_var.h>
#include <machine/in_cksum.h>
static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
#define TCP_LRO_UPDATE_CSUM 1
#ifndef TCP_LRO_UPDATE_CSUM
#define TCP_LRO_INVALID_CSUM 0x0000
#endif
static void tcp_lro_rx_done(struct lro_ctrl *lc);
static int tcp_lro_rx2(struct lro_ctrl *lc, struct mbuf *m,
uint32_t csum, int use_hash);
SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TCP LRO");
static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
"default number of LRO entries");
static __inline void
tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
struct lro_entry *le)
{
LIST_INSERT_HEAD(&lc->lro_active, le, next);
LIST_INSERT_HEAD(bucket, le, hash_next);
}
static __inline void
tcp_lro_active_remove(struct lro_entry *le)
{
LIST_REMOVE(le, next); /* active list */
LIST_REMOVE(le, hash_next); /* hash bucket */
}
int
tcp_lro_init(struct lro_ctrl *lc)
{
return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
}
int
tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
unsigned lro_entries, unsigned lro_mbufs)
{
struct lro_entry *le;
size_t size;
unsigned i, elements;
lc->lro_bad_csum = 0;
lc->lro_queued = 0;
lc->lro_flushed = 0;
lc->lro_cnt = 0;
lc->lro_mbuf_count = 0;
lc->lro_mbuf_max = lro_mbufs;
lc->lro_cnt = lro_entries;
lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
lc->ifp = ifp;
LIST_INIT(&lc->lro_free);
LIST_INIT(&lc->lro_active);
/* create hash table to accelerate entry lookup */
if (lro_entries > lro_mbufs)
elements = lro_entries;
else
elements = lro_mbufs;
lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
HASH_NOWAIT);
if (lc->lro_hash == NULL) {
memset(lc, 0, sizeof(*lc));
return (ENOMEM);
}
/* compute size to allocate */
size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
(lro_entries * sizeof(*le));
lc->lro_mbuf_data = (struct lro_mbuf_sort *)
malloc(size, M_LRO, M_NOWAIT | M_ZERO);
/* check for out of memory */
if (lc->lro_mbuf_data == NULL) {
memset(lc, 0, sizeof(*lc));
return (ENOMEM);
}
/* compute offset for LRO entries */
le = (struct lro_entry *)
(lc->lro_mbuf_data + lro_mbufs);
/* setup linked list */
for (i = 0; i != lro_entries; i++)
LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
return (0);
}
void
tcp_lro_free(struct lro_ctrl *lc)
{
struct lro_entry *le;
unsigned x;
/* reset LRO free list */
LIST_INIT(&lc->lro_free);
/* free active mbufs, if any */
while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
tcp_lro_active_remove(le);
m_freem(le->m_head);
}
/* free hash table */
if (lc->lro_hash != NULL) {
free(lc->lro_hash, M_LRO);
lc->lro_hash = NULL;
}
lc->lro_hashsz = 0;
/* free mbuf array, if any */
for (x = 0; x != lc->lro_mbuf_count; x++)
m_freem(lc->lro_mbuf_data[x].mb);
lc->lro_mbuf_count = 0;
/* free allocated memory, if any */
free(lc->lro_mbuf_data, M_LRO);
lc->lro_mbuf_data = NULL;
}
#ifdef TCP_LRO_UPDATE_CSUM
static uint16_t
tcp_lro_csum_th(struct tcphdr *th)
{
uint32_t ch;
uint16_t *p, l;
ch = th->th_sum = 0x0000;
l = th->th_off;
p = (uint16_t *)th;
while (l > 0) {
ch += *p;
p++;
ch += *p;
p++;
l--;
}
while (ch > 0xffff)
ch = (ch >> 16) + (ch & 0xffff);
return (ch & 0xffff);
}
static uint16_t
tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th,
uint16_t tcp_data_len, uint16_t csum)
{
uint32_t c;
uint16_t cs;
c = csum;
/* Remove length from checksum. */
switch (le->eh_type) {
#ifdef INET6
case ETHERTYPE_IPV6:
{
struct ip6_hdr *ip6;
ip6 = (struct ip6_hdr *)l3hdr;
if (le->append_cnt == 0)
cs = ip6->ip6_plen;
else {
uint32_t cx;
cx = ntohs(ip6->ip6_plen);
cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0);
}
break;
}
#endif
#ifdef INET
case ETHERTYPE_IP:
{
struct ip *ip4;
ip4 = (struct ip *)l3hdr;
if (le->append_cnt == 0)
cs = ip4->ip_len;
else {
cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4),
IPPROTO_TCP);
cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr,
htons(cs));
}
break;
}
#endif
default:
cs = 0; /* Keep compiler happy. */
}
cs = ~cs;
c += cs;
/* Remove TCP header csum. */
cs = ~tcp_lro_csum_th(th);
c += cs;
while (c > 0xffff)
c = (c >> 16) + (c & 0xffff);
return (c & 0xffff);
}
#endif
static void
tcp_lro_rx_done(struct lro_ctrl *lc)
{
struct lro_entry *le;
while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
}
}
void
tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
{
struct lro_entry *le, *le_tmp;
struct timeval tv;
if (LIST_EMPTY(&lc->lro_active))
return;
getmicrotime(&tv);
timevalsub(&tv, timeout);
LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
if (timevalcmp(&tv, &le->mtime, >=)) {
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
}
}
}
void
tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
{
if (le->append_cnt > 0) {
struct tcphdr *th;
uint16_t p_len;
p_len = htons(le->p_len);
switch (le->eh_type) {
#ifdef INET6
case ETHERTYPE_IPV6:
{
struct ip6_hdr *ip6;
ip6 = le->le_ip6;
ip6->ip6_plen = p_len;
th = (struct tcphdr *)(ip6 + 1);
le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
CSUM_PSEUDO_HDR;
le->p_len += ETHER_HDR_LEN + sizeof(*ip6);
break;
}
#endif
#ifdef INET
case ETHERTYPE_IP:
{
struct ip *ip4;
#ifdef TCP_LRO_UPDATE_CSUM
uint32_t cl;
uint16_t c;
#endif
ip4 = le->le_ip4;
#ifdef TCP_LRO_UPDATE_CSUM
/* Fix IP header checksum for new length. */
c = ~ip4->ip_sum;
cl = c;
c = ~ip4->ip_len;
cl += c + p_len;
while (cl > 0xffff)
cl = (cl >> 16) + (cl & 0xffff);
c = cl;
ip4->ip_sum = ~c;
#else
ip4->ip_sum = TCP_LRO_INVALID_CSUM;
#endif
ip4->ip_len = p_len;
th = (struct tcphdr *)(ip4 + 1);
le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
le->p_len += ETHER_HDR_LEN;
break;
}
#endif
default:
th = NULL; /* Keep compiler happy. */
}
le->m_head->m_pkthdr.csum_data = 0xffff;
le->m_head->m_pkthdr.len = le->p_len;
/* Incorporate the latest ACK into the TCP header. */
th->th_ack = le->ack_seq;
th->th_win = le->window;
/* Incorporate latest timestamp into the TCP header. */
if (le->timestamp != 0) {
uint32_t *ts_ptr;
ts_ptr = (uint32_t *)(th + 1);
ts_ptr[1] = htonl(le->tsval);
ts_ptr[2] = le->tsecr;
}
#ifdef TCP_LRO_UPDATE_CSUM
/* Update the TCP header checksum. */
le->ulp_csum += p_len;
le->ulp_csum += tcp_lro_csum_th(th);
while (le->ulp_csum > 0xffff)
le->ulp_csum = (le->ulp_csum >> 16) +
(le->ulp_csum & 0xffff);
th->th_sum = (le->ulp_csum & 0xffff);
th->th_sum = ~th->th_sum;
#else
th->th_sum = TCP_LRO_INVALID_CSUM;
#endif
}
le->m_head->m_pkthdr.lro_nsegs = le->append_cnt + 1;
(*lc->ifp->if_input)(lc->ifp, le->m_head);
lc->lro_queued += le->append_cnt + 1;
lc->lro_flushed++;
bzero(le, sizeof(*le));
LIST_INSERT_HEAD(&lc->lro_free, le, next);
}
#ifdef HAVE_INLINE_FLSLL
#define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
#else
static inline uint64_t
tcp_lro_msb_64(uint64_t x)
{
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
x |= (x >> 32);
return (x & ~(x >> 1));
}
#endif
/*
* The tcp_lro_sort() routine is comparable to qsort(), except it has
* a worst case complexity limit of O(MIN(N,64)*N), where N is the
* number of elements to sort and 64 is the number of sequence bits
* available. The algorithm is bit-slicing the 64-bit sequence number,
* sorting one bit at a time from the most significant bit until the
* least significant one, skipping the constant bits. This is
* typically called a radix sort.
*/
static void
tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
{
struct lro_mbuf_sort temp;
uint64_t ones;
uint64_t zeros;
uint32_t x;
uint32_t y;
repeat:
/* for small arrays insertion sort is faster */
if (size <= 12) {
for (x = 1; x < size; x++) {
temp = parray[x];
for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
parray[y] = parray[y - 1];
parray[y] = temp;
}
return;
}
/* compute sequence bits which are constant */
ones = 0;
zeros = 0;
for (x = 0; x != size; x++) {
ones |= parray[x].seq;
zeros |= ~parray[x].seq;
}
/* compute bits which are not constant into "ones" */
ones &= zeros;
if (ones == 0)
return;
/* pick the most significant bit which is not constant */
ones = tcp_lro_msb_64(ones);
/*
* Move entries having cleared sequence bits to the beginning
* of the array:
*/
for (x = y = 0; y != size; y++) {
/* skip set bits */
if (parray[y].seq & ones)
continue;
/* swap entries */
temp = parray[x];
parray[x] = parray[y];
parray[y] = temp;
x++;
}
KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
/* sort zeros */
tcp_lro_sort(parray, x);
/* sort ones */
parray += x;
size -= x;
goto repeat;
}
void
tcp_lro_flush_all(struct lro_ctrl *lc)
{
uint64_t seq;
uint64_t nseq;
unsigned x;
/* check if no mbufs to flush */
if (lc->lro_mbuf_count == 0)
goto done;
/* sort all mbufs according to stream */
tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
/* input data into LRO engine, stream by stream */
seq = 0;
for (x = 0; x != lc->lro_mbuf_count; x++) {
struct mbuf *mb;
/* get mbuf */
mb = lc->lro_mbuf_data[x].mb;
/* get sequence number, masking away the packet index */
nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
/* check for new stream */
if (seq != nseq) {
seq = nseq;
/* flush active streams */
tcp_lro_rx_done(lc);
}
/* add packet to LRO engine */
if (tcp_lro_rx2(lc, mb, 0, 0) != 0) {
/* input packet to network layer */
(*lc->ifp->if_input)(lc->ifp, mb);
lc->lro_queued++;
lc->lro_flushed++;
}
}
done:
/* flush active streams */
tcp_lro_rx_done(lc);
lc->lro_mbuf_count = 0;
}
#ifdef INET6
static int
tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6,
struct tcphdr **th)
{
/* XXX-BZ we should check the flow-label. */
/* XXX-BZ We do not yet support ext. hdrs. */
if (ip6->ip6_nxt != IPPROTO_TCP)
return (TCP_LRO_NOT_SUPPORTED);
/* Find the TCP header. */
*th = (struct tcphdr *)(ip6 + 1);
return (0);
}
#endif
#ifdef INET
static int
tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4,
struct tcphdr **th)
{
int csum_flags;
uint16_t csum;
if (ip4->ip_p != IPPROTO_TCP)
return (TCP_LRO_NOT_SUPPORTED);
/* Ensure there are no options. */
if ((ip4->ip_hl << 2) != sizeof (*ip4))
return (TCP_LRO_CANNOT);
/* .. and the packet is not fragmented. */
if (ip4->ip_off & htons(IP_MF|IP_OFFMASK))
return (TCP_LRO_CANNOT);
/* Legacy IP has a header checksum that needs to be correct. */
csum_flags = m->m_pkthdr.csum_flags;
if (csum_flags & CSUM_IP_CHECKED) {
if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) {
lc->lro_bad_csum++;
return (TCP_LRO_CANNOT);
}
} else {
csum = in_cksum_hdr(ip4);
if (__predict_false((csum) != 0)) {
lc->lro_bad_csum++;
return (TCP_LRO_CANNOT);
}
}
/* Find the TCP header (we assured there are no IP options). */
*th = (struct tcphdr *)(ip4 + 1);
return (0);
}
#endif
static int
tcp_lro_rx2(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, int use_hash)
{
struct lro_entry *le;
struct ether_header *eh;
#ifdef INET6
struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */
#endif
#ifdef INET
struct ip *ip4 = NULL; /* Keep compiler happy. */
#endif
struct tcphdr *th;
void *l3hdr = NULL; /* Keep compiler happy. */
uint32_t *ts_ptr;
tcp_seq seq;
int error, ip_len, l;
uint16_t eh_type, tcp_data_len;
struct lro_head *bucket;
int force_flush = 0;
/* We expect a contiguous header [eh, ip, tcp]. */
eh = mtod(m, struct ether_header *);
eh_type = ntohs(eh->ether_type);
switch (eh_type) {
#ifdef INET6
case ETHERTYPE_IPV6:
{
CURVNET_SET(lc->ifp->if_vnet);
if (V_ip6_forwarding != 0) {
/* XXX-BZ stats but changing lro_ctrl is a problem. */
CURVNET_RESTORE();
return (TCP_LRO_CANNOT);
}
CURVNET_RESTORE();
l3hdr = ip6 = (struct ip6_hdr *)(eh + 1);
error = tcp_lro_rx_ipv6(lc, m, ip6, &th);
if (error != 0)
return (error);
tcp_data_len = ntohs(ip6->ip6_plen);
ip_len = sizeof(*ip6) + tcp_data_len;
break;
}
#endif
#ifdef INET
case ETHERTYPE_IP:
{
CURVNET_SET(lc->ifp->if_vnet);
if (V_ipforwarding != 0) {
/* XXX-BZ stats but changing lro_ctrl is a problem. */
CURVNET_RESTORE();
return (TCP_LRO_CANNOT);
}
CURVNET_RESTORE();
l3hdr = ip4 = (struct ip *)(eh + 1);
error = tcp_lro_rx_ipv4(lc, m, ip4, &th);
if (error != 0)
return (error);
ip_len = ntohs(ip4->ip_len);
tcp_data_len = ip_len - sizeof(*ip4);
break;
}
#endif
/* XXX-BZ what happens in case of VLAN(s)? */
default:
return (TCP_LRO_NOT_SUPPORTED);
}
/*
* If the frame is padded beyond the end of the IP packet, then we must
* trim the extra bytes off.
*/
l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len);
if (l != 0) {
if (l < 0)
/* Truncated packet. */
return (TCP_LRO_CANNOT);
m_adj(m, -l);
}
/*
* Check TCP header constraints.
*/
/* Ensure no bits set besides ACK or PSH. */
if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
if (th->th_flags & TH_SYN)
return (TCP_LRO_CANNOT);
/*
* Make sure that previously seen segements/ACKs are delivered
* before this segement, e.g. FIN.
*/
force_flush = 1;
}
/* XXX-BZ We lose a ACK|PUSH flag concatenating multiple segments. */
/* XXX-BZ Ideally we'd flush on PUSH? */
/*
* Check for timestamps.
* Since the only option we handle are timestamps, we only have to
* handle the simple case of aligned timestamps.
*/
l = (th->th_off << 2);
tcp_data_len -= l;
l -= sizeof(*th);
ts_ptr = (uint32_t *)(th + 1);
if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) ||
(*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16|
TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) {
/*
* Make sure that previously seen segements/ACKs are delivered
* before this segement.
*/
force_flush = 1;
}
/* If the driver did not pass in the checksum, set it now. */
if (csum == 0x0000)
csum = th->th_sum;
seq = ntohl(th->th_seq);
if (!use_hash) {
bucket = &lc->lro_hash[0];
} else if (M_HASHTYPE_ISHASH(m)) {
bucket = &lc->lro_hash[m->m_pkthdr.flowid % lc->lro_hashsz];
} else {
uint32_t hash;
switch (eh_type) {
#ifdef INET
case ETHERTYPE_IP:
hash = ip4->ip_src.s_addr + ip4->ip_dst.s_addr;
break;
#endif
#ifdef INET6
case ETHERTYPE_IPV6:
hash = ip6->ip6_src.s6_addr32[0] +
ip6->ip6_dst.s6_addr32[0];
hash += ip6->ip6_src.s6_addr32[1] +
ip6->ip6_dst.s6_addr32[1];
hash += ip6->ip6_src.s6_addr32[2] +
ip6->ip6_dst.s6_addr32[2];
hash += ip6->ip6_src.s6_addr32[3] +
ip6->ip6_dst.s6_addr32[3];
break;
#endif
default:
hash = 0;
break;
}
hash += th->th_sport + th->th_dport;
bucket = &lc->lro_hash[hash % lc->lro_hashsz];
}
/* Try to find a matching previous segment. */
LIST_FOREACH(le, bucket, hash_next) {
if (le->eh_type != eh_type)
continue;
if (le->source_port != th->th_sport ||
le->dest_port != th->th_dport)
continue;
switch (eh_type) {
#ifdef INET6
case ETHERTYPE_IPV6:
if (bcmp(&le->source_ip6, &ip6->ip6_src,
sizeof(struct in6_addr)) != 0 ||
bcmp(&le->dest_ip6, &ip6->ip6_dst,
sizeof(struct in6_addr)) != 0)
continue;
break;
#endif
#ifdef INET
case ETHERTYPE_IP:
if (le->source_ip4 != ip4->ip_src.s_addr ||
le->dest_ip4 != ip4->ip_dst.s_addr)
continue;
break;
#endif
}
if (force_flush) {
/* Timestamps mismatch; this is a FIN, etc */
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
return (TCP_LRO_CANNOT);
}
/* Flush now if appending will result in overflow. */
if (le->p_len > (lc->lro_length_lim - tcp_data_len)) {
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
break;
}
/* Try to append the new segment. */
if (__predict_false(seq != le->next_seq ||
(tcp_data_len == 0 && le->ack_seq == th->th_ack))) {
/* Out of order packet or duplicate ACK. */
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
return (TCP_LRO_CANNOT);
}
if (l != 0) {
uint32_t tsval = ntohl(*(ts_ptr + 1));
/* Make sure timestamp values are increasing. */
/* XXX-BZ flip and use TSTMP_GEQ macro for this? */
if (__predict_false(le->tsval > tsval ||
*(ts_ptr + 2) == 0))
return (TCP_LRO_CANNOT);
le->tsval = tsval;
le->tsecr = *(ts_ptr + 2);
}
le->next_seq += tcp_data_len;
le->ack_seq = th->th_ack;
le->window = th->th_win;
le->append_cnt++;
#ifdef TCP_LRO_UPDATE_CSUM
le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th,
tcp_data_len, ~csum);
#endif
if (tcp_data_len == 0) {
m_freem(m);
/*
* Flush this LRO entry, if this ACK should not
* be further delayed.
*/
if (le->append_cnt >= lc->lro_ackcnt_lim) {
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
}
return (0);
}
le->p_len += tcp_data_len;
/*
* Adjust the mbuf so that m_data points to the first byte of
* the ULP payload. Adjust the mbuf to avoid complications and
* append new segment to existing mbuf chain.
*/
m_adj(m, m->m_pkthdr.len - tcp_data_len);
m_demote_pkthdr(m);
le->m_tail->m_next = m;
le->m_tail = m_last(m);
/*
* If a possible next full length packet would cause an
* overflow, pro-actively flush now.
*/
if (le->p_len > (lc->lro_length_lim - lc->ifp->if_mtu)) {
tcp_lro_active_remove(le);
tcp_lro_flush(lc, le);
} else
getmicrotime(&le->mtime);
return (0);
}
if (force_flush) {
/*
* Nothing to flush, but this segment can not be further
* aggregated/delayed.
*/
return (TCP_LRO_CANNOT);
}
/* Try to find an empty slot. */
if (LIST_EMPTY(&lc->lro_free))
return (TCP_LRO_NO_ENTRIES);
/* Start a new segment chain. */
le = LIST_FIRST(&lc->lro_free);
LIST_REMOVE(le, next);
tcp_lro_active_insert(lc, bucket, le);
getmicrotime(&le->mtime);
/* Start filling in details. */
switch (eh_type) {
#ifdef INET6
case ETHERTYPE_IPV6:
le->le_ip6 = ip6;
le->source_ip6 = ip6->ip6_src;
le->dest_ip6 = ip6->ip6_dst;
le->eh_type = eh_type;
le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6);
break;
#endif
#ifdef INET
case ETHERTYPE_IP:
le->le_ip4 = ip4;
le->source_ip4 = ip4->ip_src.s_addr;
le->dest_ip4 = ip4->ip_dst.s_addr;
le->eh_type = eh_type;
le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN;
break;
#endif
}
le->source_port = th->th_sport;
le->dest_port = th->th_dport;
le->next_seq = seq + tcp_data_len;
le->ack_seq = th->th_ack;
le->window = th->th_win;
if (l != 0) {
le->timestamp = 1;
le->tsval = ntohl(*(ts_ptr + 1));
le->tsecr = *(ts_ptr + 2);
}
#ifdef TCP_LRO_UPDATE_CSUM
/*
* Do not touch the csum of the first packet. However save the
* "adjusted" checksum of just the source and destination addresses,
* the next header and the TCP payload. The length and TCP header
* parts may change, so we remove those from the saved checksum and
* re-add with final values on tcp_lro_flush() if needed.
*/
KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n",
__func__, le, le->ulp_csum));
le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len,
~csum);
th->th_sum = csum; /* Restore checksum on first packet. */
#endif
le->m_head = m;
le->m_tail = m_last(m);
return (0);
}
int
tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
{
return tcp_lro_rx2(lc, m, csum, 1);
}
void
tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
{
/* sanity checks */
if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
lc->lro_mbuf_max == 0)) {
/* packet drop */
m_freem(mb);
return;
}
/* check if packet is not LRO capable */
if (__predict_false(mb->m_pkthdr.csum_flags == 0 ||
(lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
lc->lro_flushed++;
lc->lro_queued++;
/* input packet to network layer */
(*lc->ifp->if_input) (lc->ifp, mb);
return;
}
/* check if array is full */
if (__predict_false(lc->lro_mbuf_count == lc->lro_mbuf_max))
tcp_lro_flush_all(lc);
/* create sequence number */
lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
(((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
(((uint64_t)mb->m_pkthdr.flowid) << 24) |
((uint64_t)lc->lro_mbuf_count);
/* enter mbuf */
lc->lro_mbuf_data[lc->lro_mbuf_count++].mb = mb;
}
/* end */
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