datapath: ip6_gre: Split up ip6gre_tnl_link_config()

commit a483373ead61e6079bc8ebe27e2dfdb2e3c1559f
Author: Petr Machata <petrm@mellanox.com>
Date:   Thu May 17 16:36:27 2018 +0200

    net: ip6_gre: Split up ip6gre_tnl_link_config()

    The function ip6gre_tnl_link_config() is used for setting up
    configuration of both ip6gretap and ip6erspan tunnels. Split the
    function into the common part and the route-lookup part. The latter then
    takes the calculated header length as an argument. This split will allow
    the patches down the line to sneak in a custom header length computation
    for the ERSPAN tunnel.

    Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support")
    Signed-off-by: Petr Machata <petrm@mellanox.com>
    Acked-by: William Tu <u9012063@gmail.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Tested-by: Greg Rose <gvrose8192@gmail.com>

diff --git a/datapath/linux/compat/ip6_gre.c b/datapath/linux/compat/ip6_gre.c
index 90dddece61c4dcd9bec4cc9d265319bf1b5cc0d5..c55ca56ed4b5d83cf214a085671056ce4243775c 100644 (file)
--- a/datapath/linux/compat/ip6_gre.c
+++ b/datapath/linux/compat/ip6_gre.c
@@ -1183,12 +1183,11 @@ static netdev_tx_t __ip6erspan_tunnel_xmit(struct sk_buff *skb)
        return ip6erspan_tunnel_xmit(skb, skb->dev);
 }
 
-static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
+static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
 {
        struct net_device *dev = t->dev;
        struct __ip6_tnl_parm *p = &t->parms;
        struct flowi6 *fl6 = &t->fl.u.ip6;
-       int t_hlen;
 
        if (dev->type != ARPHRD_ETHER) {
                memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
@@ -1215,12 +1214,13 @@ static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
                dev->flags |= IFF_POINTOPOINT;
        else
                dev->flags &= ~IFF_POINTOPOINT;
+}
 
-       t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
-
-       t->hlen = t->encap_hlen + t->tun_hlen;
-
-       t_hlen = t->hlen + sizeof(struct ipv6hdr);
+static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
+                                        int t_hlen)
+{
+       const struct __ip6_tnl_parm *p = &t->parms;
+       struct net_device *dev = t->dev;
 
        if (p->flags & IP6_TNL_F_CAP_XMIT) {
                int strict = (ipv6_addr_type(&p->raddr) &
@@ -1252,6 +1252,24 @@ static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
        }
 }
 
+static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
+{
+       int t_hlen;
+
+       tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+       tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
+
+       t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
+       tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+       return t_hlen;
+}
+
+static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
+{
+       ip6gre_tnl_link_config_common(t);
+       ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
+}
+
 static int ip6gre_tnl_change(struct ip6_tnl *t,
        const struct __ip6_tnl_parm *p, int set_mtu)
 {
@@ -1553,11 +1571,7 @@ static int ip6gre_tunnel_init_common(struct net_device *dev)
                return ret;
        }
 
-       tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
-       tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
-       t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
-
-       dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+       t_hlen = ip6gre_calc_hlen(tunnel);
        dev->mtu = ETH_DATA_LEN - t_hlen;
        if (dev->type == ARPHRD_ETHER)
                dev->mtu -= ETH_HLEN;