From 25537d71e2d007faf42a244a75e5a2bb7c356234 Mon Sep 17 00:00:00 2001 From: Tariq Toukan Date: Thu, 14 Jan 2021 17:12:15 +0200 Subject: [PATCH] net: Allow NETIF_F_HW_TLS_TX if IP_CSUM && IPV6_CSUM Cited patch below blocked the TLS TX device offload unless HW_CSUM is set. This broke devices that use IP_CSUM && IP6_CSUM. Here we fix it. Note that the single HW_TLS_TX feature flag indicates support for both IPv4/6, hence it should still be disabled in case only one of (IP_CSUM | IPV6_CSUM) is set. Fixes: ae0b04b238e2 ("net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled") Signed-off-by: Tariq Toukan Reported-by: Rohit Maheshwari Reviewed-by: Maxim Mikityanskiy Link: https://lore.kernel.org/r/20210114151215.7061-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski --- Documentation/networking/tls-offload.rst | 2 +- net/core/dev.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/tls-offload.rst b/Documentation/networking/tls-offload.rst index 0f55c6d540f97..9af3334d9ad08 100644 --- a/Documentation/networking/tls-offload.rst +++ b/Documentation/networking/tls-offload.rst @@ -530,7 +530,7 @@ TLS device feature flags only control adding of new TLS connection offloads, old connections will remain active after flags are cleared. TLS encryption cannot be offloaded to devices without checksum calculation -offload. Hence, TLS TX device feature flag requires NETIF_F_HW_CSUM being set. +offload. Hence, TLS TX device feature flag requires TX csum offload being set. Disabling the latter implies clearing the former. Disabling TX checksum offload should not affect old connections, and drivers should make sure checksum calculation does not break for them. diff --git a/net/core/dev.c b/net/core/dev.c index 0071a11a6dc3c..c360bb5367e24 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9661,9 +9661,15 @@ static netdev_features_t netdev_fix_features(struct net_device *dev, } } - if ((features & NETIF_F_HW_TLS_TX) && !(features & NETIF_F_HW_CSUM)) { - netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n"); - features &= ~NETIF_F_HW_TLS_TX; + if (features & NETIF_F_HW_TLS_TX) { + bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) == + (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM); + bool hw_csum = features & NETIF_F_HW_CSUM; + + if (!ip_csum && !hw_csum) { + netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n"); + features &= ~NETIF_F_HW_TLS_TX; + } } return features; -- 2.39.5