From 56328486539ddd07cbaafec7a542a2c8a3043623 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Wed, 17 Sep 2014 12:25:58 -0700 Subject: [PATCH] net: Changes to ip_tunnel to support foo-over-udp encapsulation This patch changes IP tunnel to support (secondary) encapsulation, Foo-over-UDP. Changes include: 1) Adding tun_hlen as the tunnel header length, encap_hlen as the encapsulation header length, and hlen becomes the grand total of these. 2) Added common netlink define to support FOU encapsulation. 3) Routines to perform FOU encapsulation. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/net/ip_tunnels.h | 19 ++++++- include/uapi/linux/if_tunnel.h | 12 +++++ net/ipv4/ip_tunnel.c | 91 +++++++++++++++++++++++++++++++++- 3 files changed, 120 insertions(+), 2 deletions(-) diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 8dd8cab88b87..7f538ba6e267 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -10,6 +10,7 @@ #include #include #include +#include #include #if IS_ENABLED(CONFIG_IPV6) @@ -31,6 +32,13 @@ struct ip_tunnel_6rd_parm { }; #endif +struct ip_tunnel_encap { + __u16 type; + __u16 flags; + __be16 sport; + __be16 dport; +}; + struct ip_tunnel_prl_entry { struct ip_tunnel_prl_entry __rcu *next; __be32 addr; @@ -56,13 +64,18 @@ struct ip_tunnel { /* These four fields used only by GRE */ __u32 i_seqno; /* The last seen seqno */ __u32 o_seqno; /* The last output seqno */ - int hlen; /* Precalculated header length */ + int tun_hlen; /* Precalculated header length */ int mlink; struct ip_tunnel_dst __percpu *dst_cache; struct ip_tunnel_parm parms; + int encap_hlen; /* Encap header length (FOU,GUE) */ + struct ip_tunnel_encap encap; + + int hlen; /* tun_hlen + encap_hlen */ + /* for SIT */ #ifdef CONFIG_IPV6_SIT_6RD struct ip_tunnel_6rd_parm ip6rd; @@ -114,6 +127,8 @@ void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops); void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params, const u8 protocol); int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd); +int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t, + u8 *protocol, struct flowi4 *fl4); int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu); struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev, @@ -131,6 +146,8 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], struct ip_tunnel_parm *p); void ip_tunnel_setup(struct net_device *dev, int net_id); void ip_tunnel_dst_reset_all(struct ip_tunnel *t); +int ip_tunnel_encap_setup(struct ip_tunnel *t, + struct ip_tunnel_encap *ipencap); /* Extract dsfield from inner protocol */ static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph, diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h index 3bce9e9d9f7c..9fedca7d8dae 100644 --- a/include/uapi/linux/if_tunnel.h +++ b/include/uapi/linux/if_tunnel.h @@ -53,10 +53,22 @@ enum { IFLA_IPTUN_6RD_RELAY_PREFIX, IFLA_IPTUN_6RD_PREFIXLEN, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, + IFLA_IPTUN_ENCAP_TYPE, + IFLA_IPTUN_ENCAP_FLAGS, + IFLA_IPTUN_ENCAP_SPORT, + IFLA_IPTUN_ENCAP_DPORT, __IFLA_IPTUN_MAX, }; #define IFLA_IPTUN_MAX (__IFLA_IPTUN_MAX - 1) +enum tunnel_encap_types { + TUNNEL_ENCAP_NONE, + TUNNEL_ENCAP_FOU, +}; + +#define TUNNEL_ENCAP_FLAG_CSUM (1<<0) +#define TUNNEL_ENCAP_FLAG_CSUM6 (1<<1) + /* SIT-mode i_flags */ #define SIT_ISATAP 0x0001 diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index afed1aac2638..e3a3dc91e49c 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -55,6 +55,7 @@ #include #include #include +#include #if IS_ENABLED(CONFIG_IPV6) #include @@ -487,6 +488,91 @@ drop: } EXPORT_SYMBOL_GPL(ip_tunnel_rcv); +static int ip_encap_hlen(struct ip_tunnel_encap *e) +{ + switch (e->type) { + case TUNNEL_ENCAP_NONE: + return 0; + case TUNNEL_ENCAP_FOU: + return sizeof(struct udphdr); + default: + return -EINVAL; + } +} + +int ip_tunnel_encap_setup(struct ip_tunnel *t, + struct ip_tunnel_encap *ipencap) +{ + int hlen; + + memset(&t->encap, 0, sizeof(t->encap)); + + hlen = ip_encap_hlen(ipencap); + if (hlen < 0) + return hlen; + + t->encap.type = ipencap->type; + t->encap.sport = ipencap->sport; + t->encap.dport = ipencap->dport; + t->encap.flags = ipencap->flags; + + t->encap_hlen = hlen; + t->hlen = t->encap_hlen + t->tun_hlen; + + return 0; +} +EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); + +static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, + size_t hdr_len, u8 *protocol, struct flowi4 *fl4) +{ + struct udphdr *uh; + __be16 sport; + bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM); + int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; + + skb = iptunnel_handle_offloads(skb, csum, type); + + if (IS_ERR(skb)) + return PTR_ERR(skb); + + /* Get length and hash before making space in skb */ + + sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev), + skb, 0, 0, false); + + skb_push(skb, hdr_len); + + skb_reset_transport_header(skb); + uh = udp_hdr(skb); + + uh->dest = e->dport; + uh->source = sport; + uh->len = htons(skb->len); + uh->check = 0; + udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb, + fl4->saddr, fl4->daddr, skb->len); + + *protocol = IPPROTO_UDP; + + return 0; +} + +int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t, + u8 *protocol, struct flowi4 *fl4) +{ + switch (t->encap.type) { + case TUNNEL_ENCAP_NONE: + return 0; + case TUNNEL_ENCAP_FOU: + return fou_build_header(skb, &t->encap, t->encap_hlen, + protocol, fl4); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(ip_tunnel_encap); + static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, struct rtable *rt, __be16 df) { @@ -536,7 +622,7 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, } void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, - const struct iphdr *tnl_params, const u8 protocol) + const struct iphdr *tnl_params, u8 protocol) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *inner_iph; @@ -617,6 +703,9 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr, tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link); + if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) + goto tx_error; + rt = connected ? tunnel_rtable_get(tunnel, 0, &fl4.saddr) : NULL; if (!rt) { -- 2.34.1