From: Jesse Gross Date: Sat, 19 Mar 2016 16:32:01 +0000 (-0700) Subject: tunnels: Don't apply GRO to multiple layers of encapsulation. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fac8e0f579695a3ecbc4d3cac369139d7f819971;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git tunnels: Don't apply GRO to multiple layers of encapsulation. When drivers express support for TSO of encapsulated packets, they only mean that they can do it for one layer of encapsulation. Supporting additional levels would mean updating, at a minimum, more IP length fields and they are unaware of this. No encapsulation device expresses support for handling offloaded encapsulated packets, so we won't generate these types of frames in the transmit path. However, GRO doesn't have a check for multiple levels of encapsulation and will attempt to build them. UDP tunnel GRO actually does prevent this situation but it only handles multiple UDP tunnels stacked on top of each other. This generalizes that solution to prevent any kind of tunnel stacking that would cause problems. Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack") Signed-off-by: Jesse Gross Signed-off-by: David S. Miller --- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index be693b34662f..f9eebd518545 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2096,8 +2096,8 @@ struct napi_gro_cb { /* This is non-zero if the packet may be of the same flow. */ u8 same_flow:1; - /* Used in udp_gro_receive */ - u8 udp_mark:1; + /* Used in tunnel GRO receive */ + u8 encap_mark:1; /* GRO checksum is valid */ u8 csum_valid:1; diff --git a/net/core/dev.c b/net/core/dev.c index edb7179bc051..43c74cad25bc 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4438,7 +4438,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff NAPI_GRO_CB(skb)->same_flow = 0; NAPI_GRO_CB(skb)->flush = 0; NAPI_GRO_CB(skb)->free = 0; - NAPI_GRO_CB(skb)->udp_mark = 0; + NAPI_GRO_CB(skb)->encap_mark = 0; NAPI_GRO_CB(skb)->gro_remcsum_start = 0; /* Setup for GRO checksum validation */ diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 965923325535..0fefba64ee79 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1380,6 +1380,19 @@ out: return pp; } +static struct sk_buff **ipip_gro_receive(struct sk_buff **head, + struct sk_buff *skb) +{ + if (NAPI_GRO_CB(skb)->encap_mark) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + NAPI_GRO_CB(skb)->encap_mark = 1; + + return inet_gro_receive(head, skb); +} + #define SECONDS_PER_DAY 86400 /* inet_current_timestamp - Return IP network timestamp @@ -1682,7 +1695,7 @@ static struct packet_offload ip_packet_offload __read_mostly = { static const struct net_offload ipip_offload = { .callbacks = { .gso_segment = inet_gso_segment, - .gro_receive = inet_gro_receive, + .gro_receive = ipip_gro_receive, .gro_complete = ipip_gro_complete, }, }; diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c index 540866dbd27d..dd031617160a 100644 --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -126,6 +126,11 @@ static struct sk_buff **gre_gro_receive(struct sk_buff **head, struct packet_offload *ptype; __be16 type; + if (NAPI_GRO_CB(skb)->encap_mark) + goto out; + + NAPI_GRO_CB(skb)->encap_mark = 1; + off = skb_gro_offset(skb); hlen = off + sizeof(*greh); greh = skb_gro_header_fast(skb, off); diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 8a3405a80260..8007f73b8981 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -311,14 +311,14 @@ struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb, unsigned int off = skb_gro_offset(skb); int flush = 1; - if (NAPI_GRO_CB(skb)->udp_mark || + if (NAPI_GRO_CB(skb)->encap_mark || (skb->ip_summed != CHECKSUM_PARTIAL && NAPI_GRO_CB(skb)->csum_cnt == 0 && !NAPI_GRO_CB(skb)->csum_valid)) goto out; - /* mark that this skb passed once through the udp gro layer */ - NAPI_GRO_CB(skb)->udp_mark = 1; + /* mark that this skb passed once through the tunnel gro layer */ + NAPI_GRO_CB(skb)->encap_mark = 1; rcu_read_lock(); uo_priv = rcu_dereference(udp_offload_base); diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index eeca943f12dc..82e9f3076028 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -258,6 +258,19 @@ out: return pp; } +static struct sk_buff **sit_gro_receive(struct sk_buff **head, + struct sk_buff *skb) +{ + if (NAPI_GRO_CB(skb)->encap_mark) { + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + NAPI_GRO_CB(skb)->encap_mark = 1; + + return ipv6_gro_receive(head, skb); +} + static int ipv6_gro_complete(struct sk_buff *skb, int nhoff) { const struct net_offload *ops; @@ -302,7 +315,7 @@ static struct packet_offload ipv6_packet_offload __read_mostly = { static const struct net_offload sit_offload = { .callbacks = { .gso_segment = ipv6_gso_segment, - .gro_receive = ipv6_gro_receive, + .gro_receive = sit_gro_receive, .gro_complete = sit_gro_complete, }, };