On Thu, May 25, 2023 at 10:40:51PM +0200, Jan Klemkow wrote:
> On Wed, May 24, 2023 at 05:28:58PM +0200, Alexander Bluhm wrote:
> > On Tue, May 23, 2023 at 02:14:57PM +0200, Jan Klemkow wrote:
> > > This diff sets needed offloading flags and the calculated mss to LRO
> > > mbufs in ix(4). Thus, we can forward this packets and process them via
> > > tcp_if_output_tso(). This diff also uses tcp_if_output_tso() in
> > > ip6_forward().
After lot of testing by Hrvoje and fixing corner cases with Jan,
this is the diff we currently have. There a no more known problems
with TCP large receive offloading.
ok?
bluhm
Index: dev/pci/if_ix.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/dev/pci/if_ix.c,v
retrieving revision 1.196
diff -u -p -r1.196 if_ix.c
--- dev/pci/if_ix.c 23 May 2023 09:16:16 -0000 1.196
+++ dev/pci/if_ix.c 31 May 2023 13:48:25 -0000
@@ -3245,6 +3245,8 @@ ixgbe_rxeof(struct rx_ring *rxr)
sendmp = NULL;
mp->m_next = nxbuf->buf;
} else { /* Sending this frame? */
+ uint16_t pkts;
+
ixgbe_rx_checksum(staterr, sendmp);
if (hashtype != IXGBE_RXDADV_RSSTYPE_NONE) {
@@ -3252,19 +3254,45 @@ ixgbe_rxeof(struct rx_ring *rxr)
SET(sendmp->m_pkthdr.csum_flags, M_FLOWID);
}
- if (sendmp->m_pkthdr.ph_mss == 1)
- sendmp->m_pkthdr.ph_mss = 0;
+ pkts = sendmp->m_pkthdr.ph_mss;
+ sendmp->m_pkthdr.ph_mss = 0;
- if (sendmp->m_pkthdr.ph_mss > 0) {
+ if (pkts > 1) {
struct ether_extracted ext;
- uint16_t pkts = sendmp->m_pkthdr.ph_mss;
+ uint32_t hdrlen, paylen;
+ /* Calculate header size. */
ether_extract_headers(sendmp, &ext);
- if (ext.tcp)
+ hdrlen = sizeof(*ext.eh);
+ if (ext.ip4)
+ hdrlen += ext.ip4->ip_hl << 2;
+ if (ext.ip6)
+ hdrlen += sizeof(*ext.ip6);
+ if (ext.tcp) {
+ hdrlen += ext.tcp->th_off << 2;
tcpstat_inc(tcps_inhwlro);
- else
+ tcpstat_add(tcps_inpktlro, pkts);
+ } else {
tcpstat_inc(tcps_inbadlro);
- tcpstat_add(tcps_inpktlro, pkts);
+ }
+
+ /*
+ * If we gonna forward this packet, we have to
+ * mark it as TSO, set a correct mss,
+ * and recalculate the TCP checksum.
+ */
+ paylen = sendmp->m_pkthdr.len - hdrlen;
+ if (ext.tcp && paylen >= pkts) {
+ SET(sendmp->m_pkthdr.csum_flags,
+ M_TCP_TSO);
+ sendmp->m_pkthdr.ph_mss = paylen / pkts;
+ }
+ if (ext.tcp &&
+ ISSET(sendmp->m_pkthdr.csum_flags,
+ M_TCP_CSUM_IN_OK)) {
+ SET(sendmp->m_pkthdr.csum_flags,
+ M_TCP_CSUM_OUT);
+ }
}
ml_enqueue(&ml, sendmp);
Index: netinet6/ip6_forward.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/ip6_forward.c,v
retrieving revision 1.109
diff -u -p -r1.109 ip6_forward.c
--- netinet6/ip6_forward.c 5 Apr 2023 13:56:31 -0000 1.109
+++ netinet6/ip6_forward.c 31 May 2023 13:48:25 -0000
@@ -63,8 +63,10 @@
#include <netinet/ip_ah.h>
#include <netinet/ip_esp.h>
#include <netinet/udp.h>
-#include <netinet/tcp.h>
#endif
+#include <netinet/tcp.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
/*
* Forward a packet. If some error occurs return the sender
@@ -316,7 +318,11 @@ reroute:
goto reroute;
}
#endif
- in6_proto_cksum_out(m, ifp);
+
+ error = tcp_if_output_tso(ifp, &m, sin6tosa(sin6), rt, IFCAP_TSOv6,
+ ifp->if_mtu);
+ if (error || m == NULL)
+ goto freecopy;
/* Check the size after pf_test to give pf a chance to refragment. */
if (m->m_pkthdr.len > ifp->if_mtu) {
@@ -327,6 +333,7 @@ reroute:
goto out;
}
+ in6_proto_cksum_out(m, ifp);
error = ifp->if_output(ifp, m, sin6tosa(sin6), rt);
if (error) {
ip6stat_inc(ip6s_cantforward);
