[PATCH 4.9 06/16] net/mlx4_en: dont set CHECKSUM_COMPLETE on SCTP packets

Greg Kroah-Hartman
2017-08-11T22:11:02Z

From: Davide Caratti <dcaratti@redhat.com>

[ Upstream commit e718fe450e616227b74d27a233cdf37b4df0c82b ]

if the NIC fails to validate the checksum on TCP/UDP, and validation of IP
checksum is successful, the driver subtracts the pseudo-header checksum
from the value obtained by the hardware and sets CHECKSUM_COMPLETE. Don't
do that if protocol is IPPROTO_SCTP, otherwise CRC32c validation fails.

V2: don't test MLX4_CQE_STATUS_IPV6 if MLX4_CQE_STATUS_IPV4 is set

Reported-by: Shuang Li <shuali@redhat.com>
Fixes: f8c6455bb04b ("net/mlx4_en: Extend checksum offloading by CHECKSUM COMPLETE")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -724,16 +724,21 @@ static inline __wsum get_fixed_vlan_csum
* header, the HW adds it. To address that, we are subtracting the pseudo
* header checksum from the checksum value provided by the HW.
*/
-static void get_fixed_ipv4_csum(__wsum hw_checksum, struct sk_buff *skb,
- struct iphdr *iph)
+static int get_fixed_ipv4_csum(__wsum hw_checksum, struct sk_buff *skb,
+ struct iphdr *iph)
{
__u16 length_for_csum = 0;
__wsum csum_pseudo_header = 0;
+ __u8 ipproto = iph->protocol;
+
+ if (unlikely(ipproto == IPPROTO_SCTP))
+ return -1;

length_for_csum = (be16_to_cpu(iph->tot_len) - (iph->ihl << 2));
csum_pseudo_header = csum_tcpudp_nofold(iph->saddr, iph->daddr,
- length_for_csum, iph->protocol, 0);
+ length_for_csum, ipproto, 0);
skb->csum = csum_sub(hw_checksum, csum_pseudo_header);
+ return 0;
}

#if IS_ENABLED(CONFIG_IPV6)
@@ -744,17 +749,20 @@ static void get_fixed_ipv4_csum(__wsum h
static int get_fixed_ipv6_csum(__wsum hw_checksum, struct sk_buff *skb,
struct ipv6hdr *ipv6h)
{
+ __u8 nexthdr = ipv6h->nexthdr;
__wsum csum_pseudo_hdr = 0;

- if (unlikely(ipv6h->nexthdr == IPPROTO_FRAGMENT ||
- ipv6h->nexthdr == IPPROTO_HOPOPTS))
+ if (unlikely(nexthdr == IPPROTO_FRAGMENT ||
+ nexthdr == IPPROTO_HOPOPTS ||
+ nexthdr == IPPROTO_SCTP))
return -1;
- hw_checksum = csum_add(hw_checksum, (__force __wsum)htons(ipv6h->nexthdr));
+ hw_checksum = csum_add(hw_checksum, (__force __wsum)htons(nexthdr));

csum_pseudo_hdr = csum_partial(&ipv6h->saddr,
sizeof(ipv6h->saddr) + sizeof(ipv6h->daddr), 0);
csum_pseudo_hdr = csum_add(csum_pseudo_hdr, (__force __wsum)ipv6h->payload_len);
- csum_pseudo_hdr = csum_add(csum_pseudo_hdr, (__force __wsum)ntohs(ipv6h->nexthdr));
+ csum_pseudo_hdr = csum_add(csum_pseudo_hdr,
+ (__force __wsum)htons(nexthdr));

skb->csum = csum_sub(hw_checksum, csum_pseudo_hdr);
skb->csum = csum_add(skb->csum, csum_partial(ipv6h, sizeof(struct ipv6hdr), 0));
@@ -777,11 +785,10 @@ static int check_csum(struct mlx4_cqe *c
}

if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4))
- get_fixed_ipv4_csum(hw_checksum, skb, hdr);
+ return get_fixed_ipv4_csum(hw_checksum, skb, hdr);
#if IS_ENABLED(CONFIG_IPV6)
- else if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
- if (unlikely(get_fixed_ipv6_csum(hw_checksum, skb, hdr)))
- return -1;
+ if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
+ return get_fixed_ipv6_csum(hw_checksum, skb, hdr);
#endif
return 0;
}