From 8bce6d7d0d1ede22af334ee241841e9278365278 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Mon, 29 Sep 2014 20:22:29 -0700 Subject: [PATCH] udp: Generalize skb_udp_segment skb_udp_segment is the function called from udp4_ufo_fragment to segment a UDP tunnel packet. This function currently assumes segmentation is transparent Ethernet bridging (i.e. VXLAN encapsulation). This patch generalizes the function to operate on either Ethertype or IP protocol. The inner_protocol field must be set to the protocol of the inner header. This can now be either an Ethertype or an IP protocol (in a union). A new flag in the skbuff indicates which type is effective. skb_set_inner_protocol and skb_set_inner_ipproto helper functions were added to set the inner_protocol. These functions are called from the point where the tunnel encapsulation is occuring. When skb_udp_tunnel_segment is called, the function to segment the inner packet is selected based on the inner IP or Ethertype. In the case of an IP protocol encapsulation, the function is derived from inet[6]_offloads. In the case of Ethertype, skb->protocol is set to the inner_protocol and skb_mac_gso_segment is called. (GRE currently does this, but it might be possible to lookup the protocol in offload_base and call the appropriate segmenation function directly). Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/skbuff.h | 26 +++++++++++++++++++-- include/net/udp.h | 3 ++- net/ipv4/udp_offload.c | 51 +++++++++++++++++++++++++++++++++++++----- net/ipv6/udp_offload.c | 2 +- 4 files changed, 73 insertions(+), 9 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d8f7d74d5a4d..7c5036d11feb 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -596,7 +596,8 @@ struct sk_buff { __u8 ndisc_nodetype:2; #endif __u8 ipvs_property:1; - /* 5 or 7 bit hole */ + __u8 inner_protocol_type:1; + /* 4 or 6 bit hole */ #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ @@ -632,7 +633,11 @@ struct sk_buff { __u32 reserved_tailroom; }; - __be16 inner_protocol; + union { + __be16 inner_protocol; + __u8 inner_ipproto; + }; + __u16 inner_transport_header; __u16 inner_network_header; __u16 inner_mac_header; @@ -1762,6 +1767,23 @@ static inline void skb_reserve(struct sk_buff *skb, int len) skb->tail += len; } +#define ENCAP_TYPE_ETHER 0 +#define ENCAP_TYPE_IPPROTO 1 + +static inline void skb_set_inner_protocol(struct sk_buff *skb, + __be16 protocol) +{ + skb->inner_protocol = protocol; + skb->inner_protocol_type = ENCAP_TYPE_ETHER; +} + +static inline void skb_set_inner_ipproto(struct sk_buff *skb, + __u8 ipproto) +{ + skb->inner_ipproto = ipproto; + skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; +} + static inline void skb_reset_inner_headers(struct sk_buff *skb) { skb->inner_mac_header = skb->mac_header; diff --git a/include/net/udp.h b/include/net/udp.h index 16f4e80f0519..07f9b70962f6 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -239,7 +239,8 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); int udp_disconnect(struct sock *sk, int flags); unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait); struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, - netdev_features_t features); + netdev_features_t features, + bool is_ipv6); int udp_lib_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); int udp_lib_setsockopt(struct sock *sk, int level, int optname, diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 19ebe6a39ddc..8c35f2c939ee 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -25,8 +25,11 @@ struct udp_offload_priv { struct udp_offload_priv __rcu *next; }; -struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, - netdev_features_t features) +static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, + netdev_features_t features, + struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, + netdev_features_t features), + __be16 new_protocol) { struct sk_buff *segs = ERR_PTR(-EINVAL); u16 mac_offset = skb->mac_header; @@ -48,7 +51,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, skb_reset_mac_header(skb); skb_set_network_header(skb, skb_inner_network_offset(skb)); skb->mac_len = skb_inner_network_offset(skb); - skb->protocol = htons(ETH_P_TEB); + skb->protocol = new_protocol; need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); if (need_csum) @@ -56,7 +59,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, /* segment inner packet. */ enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); - segs = skb_mac_gso_segment(skb, enc_features); + segs = gso_inner_segment(skb, enc_features); if (IS_ERR_OR_NULL(segs)) { skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, mac_len); @@ -101,6 +104,44 @@ out: return segs; } +struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, + netdev_features_t features, + bool is_ipv6) +{ + __be16 protocol = skb->protocol; + const struct net_offload **offloads; + const struct net_offload *ops; + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, + netdev_features_t features); + + rcu_read_lock(); + + switch (skb->inner_protocol_type) { + case ENCAP_TYPE_ETHER: + protocol = skb->inner_protocol; + gso_inner_segment = skb_mac_gso_segment; + break; + case ENCAP_TYPE_IPPROTO: + offloads = is_ipv6 ? inet6_offloads : inet_offloads; + ops = rcu_dereference(offloads[skb->inner_ipproto]); + if (!ops || !ops->callbacks.gso_segment) + goto out_unlock; + gso_inner_segment = ops->callbacks.gso_segment; + break; + default: + goto out_unlock; + } + + segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, + protocol); + +out_unlock: + rcu_read_unlock(); + + return segs; +} + static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, netdev_features_t features) { @@ -113,7 +154,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, if (skb->encapsulation && (skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { - segs = skb_udp_tunnel_segment(skb, features); + segs = skb_udp_tunnel_segment(skb, features, false); goto out; } diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index 212ebfc7973f..8f96988c1db2 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -58,7 +58,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, if (skb->encapsulation && skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) - segs = skb_udp_tunnel_segment(skb, features); + segs = skb_udp_tunnel_segment(skb, features, true); else { const struct ipv6hdr *ipv6h; struct udphdr *uh;