* [PATCH net-next 2/2] dev: advertise the new ifindex when the netns iface changes
2018-01-25 14:01 [PATCH net-next 0/2] Ease to follow an interface that moves to another netns Nicolas Dichtel
2018-01-25 14:01 ` [PATCH net-next 1/2] dev: always advertise the new nsid when the netns iface changes Nicolas Dichtel
@ 2018-01-25 14:01 ` Nicolas Dichtel
2018-01-25 22:33 ` Jiri Benc
2018-01-29 17:36 ` [PATCH net-next 0/2] Ease to follow an interface that moves to another netns David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Nicolas Dichtel @ 2018-01-25 14:01 UTC (permalink / raw)
To: davem; +Cc: netdev, jbenc, christian.brauner, Nicolas Dichtel
The goal is to let the user follow an interface that moves to another
netns.
CC: Jiri Benc <jbenc@redhat.com>
CC: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
include/linux/rtnetlink.h | 5 +++--
include/uapi/linux/if_link.h | 1 +
net/core/dev.c | 19 ++++++++++++-------
net/core/rtnetlink.c | 31 ++++++++++++++++++++-----------
4 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 62d508b31f56..0514cc36ac34 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -19,10 +19,11 @@ extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags);
void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
- gfp_t flags, int *new_nsid);
+ gfp_t flags, int *new_nsid, int new_ifindex);
struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
unsigned change, u32 event,
- gfp_t flags, int *new_nsid);
+ gfp_t flags, int *new_nsid,
+ int new_ifindex);
void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,
gfp_t flags);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 8616131e2c61..6d9447700e18 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -163,6 +163,7 @@ enum {
IFLA_IF_NETNSID,
IFLA_CARRIER_UP_COUNT,
IFLA_CARRIER_DOWN_COUNT,
+ IFLA_NEW_IFINDEX,
__IFLA_MAX
};
diff --git a/net/core/dev.c b/net/core/dev.c
index 59987eb6511a..858501b12869 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7360,7 +7360,7 @@ static void rollback_registered_many(struct list_head *head)
if (!dev->rtnl_link_ops ||
dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
- GFP_KERNEL, NULL);
+ GFP_KERNEL, NULL, 0);
/*
* Flush the unicast and multicast chains
@@ -8473,7 +8473,7 @@ EXPORT_SYMBOL(unregister_netdev);
int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
{
- int err, new_nsid;
+ int err, new_nsid, new_ifindex;
ASSERT_RTNL();
@@ -8529,8 +8529,16 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
rcu_barrier();
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
+
new_nsid = peernet2id_alloc(dev_net(dev), net);
- rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid);
+ /* If there is an ifindex conflict assign a new one */
+ if (__dev_get_by_index(net, dev->ifindex))
+ new_ifindex = dev_new_index(net);
+ else
+ new_ifindex = dev->ifindex;
+
+ rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
+ new_ifindex);
/*
* Flush the unicast and multicast chains
@@ -8544,10 +8552,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
/* Actually switch the network namespace */
dev_net_set(dev, net);
-
- /* If there is an ifindex conflict assign a new one */
- if (__dev_get_by_index(net, dev->ifindex))
- dev->ifindex = dev_new_index(net);
+ dev->ifindex = new_ifindex;
/* Send a netdev-add uevent to the new namespace */
kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 97874daa1336..cdade82bb363 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -988,6 +988,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
+ rtnl_xdp_size() /* IFLA_XDP */
+ nla_total_size(4) /* IFLA_EVENT */
+ nla_total_size(4) /* IFLA_NEW_NETNSID */
+ + nla_total_size(4) /* IFLA_NEW_IFINDEX */
+ nla_total_size(1) /* IFLA_PROTO_DOWN */
+ nla_total_size(4) /* IFLA_IF_NETNSID */
+ nla_total_size(4) /* IFLA_CARRIER_UP_COUNT */
@@ -1511,7 +1512,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
struct net_device *dev, struct net *src_net,
int type, u32 pid, u32 seq, u32 change,
unsigned int flags, u32 ext_filter_mask,
- u32 event, int *new_nsid, int tgt_netnsid)
+ u32 event, int *new_nsid, int new_ifindex,
+ int tgt_netnsid)
{
struct ifinfomsg *ifm;
struct nlmsghdr *nlh;
@@ -1608,6 +1610,10 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
if (new_nsid &&
nla_put_s32(skb, IFLA_NEW_NETNSID, *new_nsid) < 0)
goto nla_put_failure;
+ if (new_ifindex &&
+ nla_put_s32(skb, IFLA_NEW_IFINDEX, new_ifindex) < 0)
+ goto nla_put_failure;
+
rcu_read_lock();
if (rtnl_fill_link_af(skb, dev, ext_filter_mask))
@@ -1853,7 +1859,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, 0,
flags,
- ext_filter_mask, 0, NULL,
+ ext_filter_mask, 0, NULL, 0,
netnsid);
if (err < 0) {
@@ -3034,7 +3040,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
err = rtnl_fill_ifinfo(nskb, dev, net,
RTM_NEWLINK, NETLINK_CB(skb).portid,
nlh->nlmsg_seq, 0, 0, ext_filter_mask,
- 0, NULL, netnsid);
+ 0, NULL, 0, netnsid);
if (err < 0) {
/* -EMSGSIZE implies BUG in if_nlmsg_size */
WARN_ON(err == -EMSGSIZE);
@@ -3130,7 +3136,8 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
unsigned int change,
- u32 event, gfp_t flags, int *new_nsid)
+ u32 event, gfp_t flags, int *new_nsid,
+ int new_ifindex)
{
struct net *net = dev_net(dev);
struct sk_buff *skb;
@@ -3143,7 +3150,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
err = rtnl_fill_ifinfo(skb, dev, dev_net(dev),
type, 0, 0, change, 0, 0, event,
- new_nsid, -1);
+ new_nsid, new_ifindex, -1);
if (err < 0) {
/* -EMSGSIZE implies BUG in if_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
@@ -3166,14 +3173,15 @@ void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags)
static void rtmsg_ifinfo_event(int type, struct net_device *dev,
unsigned int change, u32 event,
- gfp_t flags, int *new_nsid)
+ gfp_t flags, int *new_nsid, int new_ifindex)
{
struct sk_buff *skb;
if (dev->reg_state != NETREG_REGISTERED)
return;
- skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid);
+ skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid,
+ new_ifindex);
if (skb)
rtmsg_ifinfo_send(skb, dev, flags);
}
@@ -3181,14 +3189,15 @@ static void rtmsg_ifinfo_event(int type, struct net_device *dev,
void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
gfp_t flags)
{
- rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags, NULL);
+ rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
+ NULL, 0);
}
void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
- gfp_t flags, int *new_nsid)
+ gfp_t flags, int *new_nsid, int new_ifindex)
{
rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,
- new_nsid);
+ new_nsid, new_ifindex);
}
static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -4588,7 +4597,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
case NETDEV_CHANGELOWERSTATE:
case NETDEV_CHANGE_TX_QUEUE_LEN:
rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),
- GFP_KERNEL, NULL);
+ GFP_KERNEL, NULL, 0);
break;
default:
break;
--
2.15.1
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