sit: Setup and TX path for sit/UDP foo-over-udp encapsulation

Added netlink handling of IP tunnel encapulation paramters, properly
adjust MTU for encapsulation. Added ip_tunnel_encap call to
ipip6_tunnel_xmit to actually perform FOU encapsulation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 97 insertions, 10 deletions

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 86e3fa81f85e..db75809ab843 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -822,6 +822,8 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
         int addr_type;
         u8 ttl;
         int err;
+        u8 protocol = IPPROTO_IPV6;
+        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 
         if (skb->protocol != htons(ETH_P_IPV6))
                 goto tx_error;
@@ -911,8 +913,14 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
                 goto tx_error;
         }
 
+        skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
+        if (IS_ERR(skb)) {
+                ip_rt_put(rt);
+                goto out;
+        }
+
         if (df) {
-                mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
+                mtu = dst_mtu(&rt->dst) - t_hlen;
 
                 if (mtu < 68) {
                         dev->stats.collisions++;
@@ -947,7 +955,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
         /*
          * Okay, now see if we can stuff it in the buffer as-is.
          */
-        max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
+        max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 
         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
@@ -969,14 +977,13 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
                 ttl = iph6->hop_limit;
         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 
-        skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
-        if (IS_ERR(skb)) {
+        if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
                 ip_rt_put(rt);
-                goto out;
+                goto tx_error;
         }
 
         err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr,
-                            IPPROTO_IPV6, tos, ttl, df,
+                            protocol, tos, ttl, df,
                             !net_eq(tunnel->net, dev_net(dev)));
         iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
         return NETDEV_TX_OK;
@@ -1059,8 +1066,10 @@ static void ipip6_tunnel_bind_dev(struct net_device *dev)
                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
 
         if (tdev) {
+                int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
-                dev->mtu = tdev->mtu - sizeof(struct iphdr);
+                dev->mtu = tdev->mtu - t_hlen;
                 if (dev->mtu < IPV6_MIN_MTU)
                         dev->mtu = IPV6_MIN_MTU;
         }
@@ -1307,7 +1316,10 @@ done:
 
 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
 {
-        if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
+        struct ip_tunnel *tunnel = netdev_priv(dev);
+        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+        if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - t_hlen)
                 return -EINVAL;
         dev->mtu = new_mtu;
         return 0;
@@ -1338,12 +1350,15 @@ static void ipip6_dev_free(struct net_device *dev)
 
 static void ipip6_tunnel_setup(struct net_device *dev)
 {
+        struct ip_tunnel *tunnel = netdev_priv(dev);
+        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
         dev->netdev_ops         = &ipip6_netdev_ops;
         dev->destructor         = ipip6_dev_free;
 
         dev->type               = ARPHRD_SIT;
-        dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
-        dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
+        dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
+        dev->mtu                = ETH_DATA_LEN - t_hlen;
         dev->flags              = IFF_NOARP;
         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
         dev->iflink             = 0;
@@ -1466,6 +1481,40 @@ static void ipip6_netlink_parms(struct nlattr *data[],
 
 }
 
+/* This function returns true when ENCAP attributes are present in the nl msg */
+static bool ipip6_netlink_encap_parms(struct nlattr *data[],
+                                      struct ip_tunnel_encap *ipencap)
+{
+        bool ret = false;
+
+        memset(ipencap, 0, sizeof(*ipencap));
+
+        if (!data)
+                return ret;
+
+        if (data[IFLA_IPTUN_ENCAP_TYPE]) {
+                ret = true;
+                ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
+        }
+
+        if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
+                ret = true;
+                ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
+        }
+
+        if (data[IFLA_IPTUN_ENCAP_SPORT]) {
+                ret = true;
+                ipencap->sport = nla_get_u16(data[IFLA_IPTUN_ENCAP_SPORT]);
+        }
+
+        if (data[IFLA_IPTUN_ENCAP_DPORT]) {
+                ret = true;
+                ipencap->dport = nla_get_u16(data[IFLA_IPTUN_ENCAP_DPORT]);
+        }
+
+        return ret;
+}
+
 #ifdef CONFIG_IPV6_SIT_6RD
 /* This function returns true when 6RD attributes are present in the nl msg */
 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
@@ -1509,12 +1558,20 @@ static int ipip6_newlink(struct net *src_net, struct net_device *dev,
 {
         struct net *net = dev_net(dev);
         struct ip_tunnel *nt;
+        struct ip_tunnel_encap ipencap;
 #ifdef CONFIG_IPV6_SIT_6RD
         struct ip_tunnel_6rd ip6rd;
 #endif
         int err;
 
         nt = netdev_priv(dev);
+
+        if (ipip6_netlink_encap_parms(data, &ipencap)) {
+                err = ip_tunnel_encap_setup(nt, &ipencap);
+                if (err < 0)
+                        return err;
+        }
+
         ipip6_netlink_parms(data, &nt->parms);
 
         if (ipip6_tunnel_locate(net, &nt->parms, 0))
@@ -1537,15 +1594,23 @@ static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
 {
         struct ip_tunnel *t = netdev_priv(dev);
         struct ip_tunnel_parm p;
+        struct ip_tunnel_encap ipencap;
         struct net *net = t->net;
         struct sit_net *sitn = net_generic(net, sit_net_id);
 #ifdef CONFIG_IPV6_SIT_6RD
         struct ip_tunnel_6rd ip6rd;
 #endif
+        int err;
 
         if (dev == sitn->fb_tunnel_dev)
                 return -EINVAL;
 
+        if (ipip6_netlink_encap_parms(data, &ipencap)) {
+                err = ip_tunnel_encap_setup(t, &ipencap);
+                if (err < 0)
+                        return err;
+        }
+
         ipip6_netlink_parms(data, &p);
 
         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
@@ -1599,6 +1664,14 @@ static size_t ipip6_get_size(const struct net_device *dev)
                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
                 nla_total_size(2) +
 #endif
+                /* IFLA_IPTUN_ENCAP_TYPE */
+                nla_total_size(2) +
+                /* IFLA_IPTUN_ENCAP_FLAGS */
+                nla_total_size(2) +
+                /* IFLA_IPTUN_ENCAP_SPORT */
+                nla_total_size(2) +
+                /* IFLA_IPTUN_ENCAP_DPORT */
+                nla_total_size(2) +
                 0;
 }
 
@@ -1630,6 +1703,16 @@ static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
                 goto nla_put_failure;
 #endif
 
+        if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
+                        tunnel->encap.type) ||
+            nla_put_u16(skb, IFLA_IPTUN_ENCAP_SPORT,
+                        tunnel->encap.sport) ||
+            nla_put_u16(skb, IFLA_IPTUN_ENCAP_DPORT,
+                        tunnel->encap.dport) ||
+            nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
+                        tunnel->encap.dport))
+                goto nla_put_failure;
+
         return 0;
 
 nla_put_failure:
@@ -1651,6 +1734,10 @@ static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
 #endif
+        [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
+        [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
+        [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
+        [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
 };
 
 static void ipip6_dellink(struct net_device *dev, struct list_head *head)