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Message-ID: <20150403150744.GE31348@tuxdriver.com>
Date: Fri, 3 Apr 2015 11:07:44 -0400
From: "John W. Linville" <linville@...driver.com>
To: Jiri Pirko <jiri@...nulli.us>
Cc: netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>,
Jesse Gross <jesse@...ira.com>, Andy Zhou <azhou@...ira.com>,
Stephen Hemminger <stephen@...workplumber.org>,
Alexander Duyck <alexander.h.duyck@...hat.com>
Subject: Re: [RFC PATCH 5/5] geneve: add initial netdev driver for GENEVE
tunnels
On Fri, Apr 03, 2015 at 10:57:12AM -0400, John W. Linville wrote:
> On Thu, Apr 02, 2015 at 10:20:02PM +0200, Jiri Pirko wrote:
> > Thu, Apr 02, 2015 at 09:17:06PM CEST, linville@...driver.com wrote:
> > >This is an initial implementation of a netdev driver for GENEVE
> > >tunnels. This implementation uses a fixed UDP port, and only supports
> > >a single tunnel (and therefore only a single VNI) per net namespace.
> > >Only IPv4 links are supported at this time.
> >
> >
> > Thanks for doing this John!
> >
> >
> > >
> > >Signed-off-by: John W. Linville <linville@...driver.com>
> > >---
> > > drivers/net/Kconfig | 14 ++
> > > drivers/net/Makefile | 1 +
> > > drivers/net/geneve.c | 451 +++++++++++++++++++++++++++++++++++++++++++
> > > include/uapi/linux/if_link.h | 9 +
> > > 4 files changed, 475 insertions(+)
> > > create mode 100644 drivers/net/geneve.c
> > >
> >
> > ...
> >
> > >+/* Initialize the device structure. */
> > >+static void geneve_setup(struct net_device *dev)
> > >+{
> > >+ struct geneve_dev *geneve = netdev_priv(dev);
> > >+
> > >+ ether_setup(dev);
> > >+
> > >+ dev->netdev_ops = &geneve_netdev_ops;
> > >+ dev->destructor = free_netdev;
> > >+ SET_NETDEV_DEVTYPE(dev, &geneve_type);
> > >+
> > >+ INIT_WORK(&geneve->sock_work, geneve_sock_work);
> >
> > I would push work initialization into geneve_newlink. Seems odd to have
> > it here in setup.
>
> Yes, that will probably work a lot better for multiple tunnels on a
> host... :-)
Ignore that comment -- I was thinking...something else...need coffee... ;-)
What makes newlink better for INIT_WORK than setup?
>
> > >+
> > >+ dev->tx_queue_len = 0;
> > >+ dev->features = 0;
> > >+
> > >+ dev->vlan_features = dev->features;
> > >+ dev->hw_features = 0;
> > >+
> > >+ geneve->dev = dev;
> > >+}
> > >+
> > >+static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
> > >+ [IFLA_GENEVE_ID] = { .type = NLA_U32 },
> > >+ [IFLA_GENEVE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
> > >+};
> > >+
> > >+static int geneve_validate(struct nlattr *tb[], struct nlattr *data[])
> > >+{
> > >+ if (tb[IFLA_ADDRESS]) {
> > >+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
> > >+ return -EINVAL;
> > >+
> > >+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
> > >+ return -EADDRNOTAVAIL;
> > >+ }
> > >+
> > >+ if (!data)
> > >+ return -EINVAL;
> > >+
> > >+ if (data[IFLA_GENEVE_ID]) {
> > >+ __u32 vni = nla_get_u32(data[IFLA_GENEVE_ID]);
> >
> > missing newline
>
> Sure.
>
> > >+ if (vni >= GENEVE_VID_MASK)
> > >+ return -ERANGE;
> > >+ }
> > >+
> > >+ return 0;
> > >+}
> > >+
> > >+static void geneve_get_drvinfo(struct net_device *dev,
> > >+ struct ethtool_drvinfo *drvinfo)
> > >+{
> > >+ strlcpy(drvinfo->version, GENEVE_NETDEV_VER, sizeof(drvinfo->version));
> > >+ strlcpy(drvinfo->driver, "geneve", sizeof(drvinfo->driver));
> > >+}
> > >+
> > >+static const struct ethtool_ops geneve_ethtool_ops = {
> > >+ .get_drvinfo = geneve_get_drvinfo,
> > >+ .get_link = ethtool_op_get_link,
> > >+};
> > >+
> > >+static int geneve_newlink(struct net *net, struct net_device *dev,
> > >+ struct nlattr *tb[], struct nlattr *data[])
> > >+{
> > >+ struct geneve_net *gn = net_generic(net, geneve_net_id);
> > >+ struct geneve_dev *geneve = netdev_priv(dev);
> > >+ __u32 vni;
> >
> > why not "u32" ?
>
> I think I copied that from vxlan.c. In fact, I'm not really sure I
> understand why both exist?
>
> > >+ int err;
> > >+
> > >+ /* TODO: need to support multiple tunnels in a namespace */
> > >+ if (!list_empty(&gn->geneve_list))
> > >+ return -EBUSY;
> >
> > Interesting limitation :)
>
> That should disappear, of course. :-)
>
> > ...
> >
> > >+static void __net_exit geneve_exit_net(struct net *net)
> > >+{
> > >+ struct geneve_net *gn = net_generic(net, geneve_net_id);
> > >+ struct geneve_dev *geneve, *next;
> > >+ struct net_device *dev, *aux;
> > >+ LIST_HEAD(list);
> > >+
> > >+ rtnl_lock();
> > >+ for_each_netdev_safe(net, dev, aux)
> > >+ if (dev->rtnl_link_ops == &geneve_link_ops)
> > >+ unregister_netdevice_queue(dev, &list);
> > >+
> > >+ list_for_each_entry_safe(geneve, next, &gn->geneve_list, next) {
> > >+ /* If geneve->dev is in the same netns, it was already added
> > >+ * to the list by the previous loop.
> > >+ */
> > >+ if (!net_eq(dev_net(geneve->dev), net))
> > >+ unregister_netdevice_queue(dev, &list);
> > >+ }
> >
> > I know this is c&p of vxlan, but I do not understand why the first loop
> > is there. The second loop will take care of all since all devs are
> > listed in ->geneve_list, right?
> >
> > Also you do not need _safe variant since you traverse through
> > ->geneve_list, which is not modified.
>
> Yes, it is boilerplate from vxlan. Maybe Stephen can explain it?
>
> Maybe it relates to the the ordering of the unregister queue?
> I'll try to figure it out...
>
> > >+
> > >+ unregister_netdevice_many(&list);
> > >+ rtnl_unlock();
> > >+}
>
> Thanks for the review and suggestions!
>
> John
>
> --
> John W. Linville Someday the world will need a hero, and you
> linville@...driver.com might be all we have. Be ready.
> --
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>
--
John W. Linville Someday the world will need a hero, and you
linville@...driver.com might be all we have. Be ready.
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