diff options
| author | Mahesh Bandewar <maheshb@google.com> | 2017-01-10 02:05:54 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-11 04:47:12 +0300 |
| commit | da36e13cf653541e385a8d2ec2637fff6ea3461a (patch) | |
| tree | 3d86b8c8337e679806f77b875ee6564ebf6712dc /drivers/net/ipvlan | |
| parent | de28c99d71d91251713b67c545fa05b2b5e0d232 (diff) | |
| download | linux-da36e13cf653541e385a8d2ec2637fff6ea3461a.tar.xz | |
ipvlan: improvise dev_id generation logic in IPvlan
The patch 009146d117b ("ipvlan: assign unique dev-id for each slave
device.") used ida_simple_get() to generate dev_ids assigned to the
slave devices. However (Eric has pointed out that) there is a shortcoming
with that approach as it always uses the first available ID. This
becomes a problem when a slave gets deleted and a new slave gets added.
The ID gets reassigned causing the new slave to get the same link-local
address. This side-effect is undesirable.
This patch adds a per-port variable that keeps track of the IDs
assigned and used as the stat-base for the IDR api. This base will be
wrapped around when it reaches the MAX (0xFFFE) value possibly on a
busy system where slaves are added and deleted routinely.
Fixes: 009146d117b ("ipvlan: assign unique dev-id for each slave device.")
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: Eric Dumazet <edumazet@google.com>
CC: David Miller <davem@davemloft.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ipvlan')
| -rw-r--r-- | drivers/net/ipvlan/ipvlan.h | 1 | ||||
| -rw-r--r-- | drivers/net/ipvlan/ipvlan_main.c | 13 |
2 files changed, 13 insertions, 1 deletions
diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h index 0a9068fdee0f..406ae4ff0ae8 100644 --- a/drivers/net/ipvlan/ipvlan.h +++ b/drivers/net/ipvlan/ipvlan.h @@ -94,6 +94,7 @@ struct ipvl_port { struct hlist_head hlhead[IPVLAN_HASH_SIZE]; struct list_head ipvlans; u16 mode; + u16 dev_id_start; struct work_struct wq; struct sk_buff_head backlog; int count; diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index 1cdb8c5ec403..92b221a03350 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -120,6 +120,7 @@ static int ipvlan_port_create(struct net_device *dev) skb_queue_head_init(&port->backlog); INIT_WORK(&port->wq, ipvlan_process_multicast); ida_init(&port->ida); + port->dev_id_start = 1; err = netdev_rx_handler_register(dev, ipvlan_handle_frame, port); if (err) @@ -534,15 +535,25 @@ static int ipvlan_link_new(struct net *src_net, struct net_device *dev, ipvlan_adjust_mtu(ipvlan, phy_dev); INIT_LIST_HEAD(&ipvlan->addrs); + /* If the port-id base is at the MAX value, then wrap it around and + * begin from 0x1 again. This may be due to a busy system where lots + * of slaves are getting created and deleted. + */ + if (port->dev_id_start == 0xFFFE) + port->dev_id_start = 0x1; + /* Since L2 address is shared among all IPvlan slaves including * master, use unique 16 bit dev-ids to diffentiate among them. * Assign IDs between 0x1 and 0xFFFE (used by the master) to each * slave link [see addrconf_ifid_eui48()]. */ - err = ida_simple_get(&port->ida, 1, 0xFFFE, GFP_KERNEL); + err = ida_simple_get(&port->ida, port->dev_id_start, 0xFFFE, + GFP_KERNEL); if (err < 0) goto destroy_ipvlan_port; dev->dev_id = err; + /* Increment id-base to the next slot for the future assignment */ + port->dev_id_start = err + 1; /* TODO Probably put random address here to be presented to the * world but keep using the physical-dev address for the outgoing |