Some/most devices implementing gso_partial need to disable the GSO partial features when the IP ID can't be mangled; to that extend each of them implements something alike the following: if (skb->encapsulation && !(features & NETIF_F_TSO_MANGLEID)) features &= ~NETIF_F_TSO; in the ndo_features_check() op, which leads to a bit of duplicate code. Later patch in the series will implement GSO partial support for virtual device, and the current status quo will require more duplicate code and a new indirect call in the TX path for such devices. Introduce the mangleid_features mask, allowing the core to disable NIC features based on/requiring MANGLEID, without any further intervention from the driver. The same functionality could be alternatively implemented adding a single boolean flag to the struct net_device, but would require an additional checks in ndo_features_check(). Also note that the above mentioned action is incorrect if the NIC additionally implements NETIF_F_GSO_UDP_L4, mangleid_features transparently handle even such a case. Signed-off-by: Paolo Abeni --- include/linux/netdevice.h | 5 ++++- net/core/dev.c | 4 +++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d99b0fbc1942..23a698b70de1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1830,7 +1830,9 @@ enum netdev_reg_state { * and drivers will need to set them appropriately. * * @mpls_features: Mask of features inheritable by MPLS - * @gso_partial_features: value(s) from NETIF_F_GSO\* + * @gso_partial_features: value(s) from NETIF_F_GSO + * @mangleid_features: Mask of features requiring MANGLEID, will be + * disabled together with the latter. * * @ifindex: interface index * @group: The group the device belongs to @@ -2219,6 +2221,7 @@ struct net_device { netdev_features_t vlan_features; netdev_features_t hw_enc_features; netdev_features_t mpls_features; + netdev_features_t mangleid_features; unsigned int min_mtu; unsigned int max_mtu; diff --git a/net/core/dev.c b/net/core/dev.c index c711da335510..6154f306ed76 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3788,8 +3788,10 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb, struct iphdr *iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); - if (!(iph->frag_off & htons(IP_DF))) + if (!(iph->frag_off & htons(IP_DF))) { features &= ~NETIF_F_TSO_MANGLEID; + features &= ~dev->mangleid_features; + } } /* NETIF_F_IPV6_CSUM does not support IPv6 extension headers, -- 2.52.0