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ena: properly handle IPv6 L4 checksum offload

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ena_tx_csum function did not check if IPv6 checksum offload was
requested it only checked checksum offloading flags for IPv4 packets.
Because of that, when encountering CSUM_IP6_* flags, the function simply
returned without actually setting checksum offloading in ena_ctx.
Check CUSM_IP6_* flags to enable IPv6 checksum offload.

Additionally, only IPv4 header was being parsed regardless of EtherType
field, because of that, value of L4 protocol read when actually trying
to send IPv6 packets was wrong. Use ip6_lasthdr function to get length
of all IPv6 headers and payload protocol.

Set the DF flag to 1 in order to allow the device to offload the IPv6
checksum calculation and achieve optimal performance.

Add CSUM6_OFFLOAD and CSUM_OFFLOAD definitions into ena_datapath.h.

Submitted by: Dawid Gorecki <dgr@semihalf.com>
Obtained from: Semihalf
MFC after: 2 weeks
Sponsored by: Amazon, Inc.
This commit is contained in:
Dawid Gorecki 2022-01-03 14:49:58 +01:00 committed by Marcin Wojtas
parent eb4c4f4a2e
commit 2bbef9d95d
2 changed files with 30 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
sys/dev/ena/ena_datapath.c
View File

@ -40,6 +40,8 @@ __FBSDID("$FreeBSD$");
#include <net/rss_config.h>
#endif /* RSS */
#include <netinet6/ip6_var.h>
/*********************************************************************
* Static functions prototypes
*********************************************************************/
@ -712,6 +714,7 @@ ena_tx_csum(struct ena_com_tx_ctx *ena_tx_ctx, struct mbuf *mbuf,
uint16_t etype;
int ehdrlen;
struct ip *ip;
int ipproto;
int iphlen;
struct tcphdr *th;
int offset;
@ -729,6 +732,9 @@ ena_tx_csum(struct ena_com_tx_ctx *ena_tx_ctx, struct mbuf *mbuf,
if ((mbuf->m_pkthdr.csum_flags & CSUM_OFFLOAD) != 0)
offload = true;
if ((mbuf->m_pkthdr.csum_flags & CSUM6_OFFLOAD) != 0)
offload = true;
if (!offload) {
if (disable_meta_caching) {
memset(ena_meta, 0, sizeof(*ena_meta));
@ -750,8 +756,27 @@ ena_tx_csum(struct ena_com_tx_ctx *ena_tx_ctx, struct mbuf *mbuf,
}
mbuf_next = m_getptr(mbuf, ehdrlen, &offset);
ip = (struct ip *)(mtodo(mbuf_next, offset));
iphlen = ip->ip_hl << 2;
switch (etype) {
case ETHERTYPE_IP:
ip = (struct ip *)(mtodo(mbuf_next, offset));
iphlen = ip->ip_hl << 2;
ipproto = ip->ip_p;
ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV4;
if ((ip->ip_off & htons(IP_DF)) != 0)
ena_tx_ctx->df = 1;
break;
case ETHERTYPE_IPV6:
ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV6;
iphlen = ip6_lasthdr(mbuf, ehdrlen, IPPROTO_IPV6, &ipproto);
iphlen -= ehdrlen;
ena_tx_ctx->df = 1;
break;
default:
iphlen = 0;
ipproto = 0;
break;
}
mbuf_next = m_getptr(mbuf, iphlen + ehdrlen, &offset);
th = (struct tcphdr *)(mtodo(mbuf_next, offset));
@ -764,27 +789,14 @@ ena_tx_csum(struct ena_com_tx_ctx *ena_tx_ctx, struct mbuf *mbuf,
ena_meta->l4_hdr_len = (th->th_off);
}
switch (etype) {
case ETHERTYPE_IP:
ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV4;
if ((ip->ip_off & htons(IP_DF)) != 0)
ena_tx_ctx->df = 1;
break;
case ETHERTYPE_IPV6:
ena_tx_ctx->l3_proto = ENA_ETH_IO_L3_PROTO_IPV6;
default:
break;
}
if (ip->ip_p == IPPROTO_TCP) {
if (ipproto == IPPROTO_TCP) {
ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_TCP;
if ((mbuf->m_pkthdr.csum_flags &
(CSUM_IP_TCP | CSUM_IP6_TCP)) != 0)
ena_tx_ctx->l4_csum_enable = 1;
else
ena_tx_ctx->l4_csum_enable = 0;
} else if (ip->ip_p == IPPROTO_UDP) {
} else if (ipproto == IPPROTO_UDP) {
ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_UDP;
if ((mbuf->m_pkthdr.csum_flags &
(CSUM_IP_UDP | CSUM_IP6_UDP)) != 0)

1
sys/dev/ena/ena_datapath.h
View File

@ -40,5 +40,6 @@ int ena_mq_start(if_t ifp, struct mbuf *m);
void ena_deferred_mq_start(void *arg, int pending);
#define CSUM_OFFLOAD (CSUM_IP|CSUM_TCP|CSUM_UDP)
#define CSUM6_OFFLOAD (CSUM_IP6_UDP|CSUM_IP6_TCP)
#endif /* ENA_TXRX_H */