Now ip_gre is using ip_tunnel_changelink to update it's properties, but
ip_tunnel_changelink in ip_tunnel doesn't update i/o_flags as a common
function.
o_flags updates would cause that tunnel->tun_hlen / hlen and dev->mtu /
needed_headroom need to be recalculated, and dev->(hw_)features need to
be updated as well.
Therefore, we can't just add the update into ip_tunnel_update called
in ip_tunnel_changelink, and it's also better not to touch ip_tunnel
codes.
This patch updates i/o_flags and calls ipgre_link_update to recalculate
these gre properties after ip_tunnel_changelink does the common update.
Note that since ipgre_link_update doesn't know the lower dev, it will
update gre->hlen, dev->mtu and dev->needed_headroom with the value of
'new tun_hlen - old tun_hlen'. In this way, we can avoid many redundant
codes, unlike ip6_gre.
Reported-by: Jianlin Shi <ji...@redhat.com>
Signed-off-by: Xin Long <lucien....@gmail.com>
---
net/ipv4/ip_gre.c | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index c105a31..81e1e20 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -773,6 +773,30 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
return NETDEV_TX_OK;
}
+static void ipgre_link_update(struct net_device *dev, bool set_mtu)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ int len;
+
+ len = tunnel->tun_hlen;
+ tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+ len = tunnel->tun_hlen - len;
+ tunnel->hlen = tunnel->hlen + len;
+
+ dev->needed_headroom = dev->needed_headroom + len;
+ if (set_mtu)
+ dev->mtu = max_t(int, dev->mtu - len, 68);
+
+ if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
+ if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
+ tunnel->encap.type == TUNNEL_ENCAP_NONE) {
+ dev->features |= NETIF_F_GSO_SOFTWARE;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+ }
+ dev->features |= NETIF_F_LLTX;
+ }
+}
+
static int ipgre_tunnel_ioctl(struct net_device *dev,
struct ifreq *ifr, int cmd)
{
@@ -1307,9 +1331,9 @@ static int ipgre_changelink(struct net_device *dev,
struct nlattr *tb[],
struct netlink_ext_ack *extack)
{
struct ip_tunnel *t = netdev_priv(dev);
- struct ip_tunnel_parm p;
struct ip_tunnel_encap ipencap;
__u32 fwmark = t->fwmark;
+ struct ip_tunnel_parm p;
int err;
if (ipgre_netlink_encap_parms(data, &ipencap)) {
@@ -1322,7 +1346,18 @@ static int ipgre_changelink(struct net_device *dev,
struct nlattr *tb[],
err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
if (err < 0)
return err;
- return ip_tunnel_changelink(dev, tb, &p, fwmark);
+
+ err = ip_tunnel_changelink(dev, tb, &p, fwmark);
+ if (err < 0)
+ return err;
+
+ t->parms.i_flags = p.i_flags;
+ t->parms.o_flags = p.o_flags;
+
+ if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
+ ipgre_link_update(dev, !tb[IFLA_MTU]);
+
+ return 0;
}
static size_t ipgre_get_size(const struct net_device *dev)
--
2.1.0
