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ip_gre: add the support for i/o_flags update via netlink 

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 <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2017-11-07 16:33:08 +08:00 committed by David S. Miller
parent c7947e4339
commit dd9d598c66
1 changed files with 37 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
net/ipv4/ip_gre.c
View File

@ -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)