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Message-Id: <c010e9a0dd4fdf31ea8c9308be04e6e93bd30c5c.1526567568.git.petrm@mellanox.com>
Date: Thu, 17 May 2018 16:36:51 +0200
From: Petr Machata <petrm@...lanox.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, kuznet@....inr.ac.ru, yoshfuji@...ux-ipv6.org,
u9012063@...il.com, xeb@...l.ru
Subject: [PATCH net 7/7] net: ip6_gre: Fix ip6erspan hlen calculation
Even though ip6erspan_tap_init() sets up hlen and tun_hlen according to
what ERSPAN needs, it goes ahead to call ip6gre_tnl_link_config() which
overwrites these settings with GRE-specific ones.
Similarly for changelink callbacks, which are handled by
ip6gre_changelink() calls ip6gre_tnl_change() calls
ip6gre_tnl_link_config() as well.
The difference ends up being 12 vs. 20 bytes, and this is generally not
a problem, because a 12-byte request likely ends up allocating more and
the extra 8 bytes are thus available. However correct it is not.
So replace the newlink and changelink callbacks with an ERSPAN-specific
ones, reusing the newly-introduced _common() functions.
Signed-off-by: Petr Machata <petrm@...lanox.com>
---
net/ipv6/ip6_gre.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 65 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index c17e38b..36b1669 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -81,6 +81,7 @@ static int ip6gre_tunnel_init(struct net_device *dev);
static void ip6gre_tunnel_setup(struct net_device *dev);
static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
+static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu);
/* Tunnel hash table */
@@ -1751,6 +1752,19 @@ static const struct net_device_ops ip6gre_tap_netdev_ops = {
.ndo_get_iflink = ip6_tnl_get_iflink,
};
+static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
+{
+ int t_hlen;
+
+ tunnel->tun_hlen = 8;
+ tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
+ erspan_hdr_len(tunnel->parms.erspan_ver);
+
+ t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
+ tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+ return t_hlen;
+}
+
static int ip6erspan_tap_init(struct net_device *dev)
{
struct ip6_tnl *tunnel;
@@ -1774,12 +1788,7 @@ static int ip6erspan_tap_init(struct net_device *dev)
return ret;
}
- tunnel->tun_hlen = 8;
- tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
- erspan_hdr_len(tunnel->parms.erspan_ver);
- t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
-
- dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+ t_hlen = ip6erspan_calc_hlen(tunnel);
dev->mtu = ETH_DATA_LEN - t_hlen;
if (dev->type == ARPHRD_ETHER)
dev->mtu -= ETH_HLEN;
@@ -1787,7 +1796,7 @@ static int ip6erspan_tap_init(struct net_device *dev)
dev->mtu -= 8;
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
- ip6gre_tnl_link_config(tunnel, 1);
+ ip6erspan_tnl_link_config(tunnel, 1);
return 0;
}
@@ -2118,6 +2127,53 @@ static void ip6erspan_tap_setup(struct net_device *dev)
netif_keep_dst(dev);
}
+static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+ struct ip6_tnl *nt = netdev_priv(dev);
+ struct net *net = dev_net(dev);
+
+ if (!err) {
+ ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
+ ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
+ }
+ return err;
+}
+
+static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
+{
+ ip6gre_tnl_link_config_common(t);
+ ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
+}
+
+static int ip6erspan_tnl_change(struct ip6_tnl *t,
+ const struct __ip6_tnl_parm *p, int set_mtu)
+{
+ ip6gre_tnl_copy_tnl_parm(t, p);
+ ip6erspan_tnl_link_config(t, set_mtu);
+ return 0;
+}
+
+static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
+ struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
+ struct __ip6_tnl_parm p;
+ struct ip6_tnl *t;
+
+ t = ip6gre_changelink_common(dev, tb, data, &p, extack);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
+ ip6gre_tunnel_unlink(ign, t);
+ ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
+ ip6gre_tunnel_link(ign, t);
+ return 0;
+}
+
static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
.kind = "ip6gre",
.maxtype = IFLA_GRE_MAX,
@@ -2154,8 +2210,8 @@ static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
.priv_size = sizeof(struct ip6_tnl),
.setup = ip6erspan_tap_setup,
.validate = ip6erspan_tap_validate,
- .newlink = ip6gre_newlink,
- .changelink = ip6gre_changelink,
+ .newlink = ip6erspan_newlink,
+ .changelink = ip6erspan_changelink,
.get_size = ip6gre_get_size,
.fill_info = ip6gre_fill_info,
.get_link_net = ip6_tnl_get_link_net,
--
2.4.11
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