6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Dichtel [ Upstream commit 12b6f7069ba5aa160f3332916408b34ae8e0b0f6 ] It could be hard to understand why the netlink command fails. For example, if dev->netns_immutable is set, the error is "Invalid argument". Signed-off-by: Nicolas Dichtel Reviewed-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni Stable-dep-of: debac3a20dec ("net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().") Signed-off-by: Sasha Levin --- include/linux/netdevice.h | 5 +++-- net/core/dev.c | 43 +++++++++++++++++++++++++++++++-------- net/core/rtnetlink.c | 2 +- 3 files changed, 38 insertions(+), 12 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f733b7de0fe0c..61f1a64b72293 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4031,12 +4031,13 @@ int dev_change_flags(struct net_device *dev, unsigned int flags, int dev_set_alias(struct net_device *, const char *, size_t); int dev_get_alias(const struct net_device *, char *, size_t); int __dev_change_net_namespace(struct net_device *dev, struct net *net, - const char *pat, int new_ifindex); + const char *pat, int new_ifindex, + struct netlink_ext_ack *extack); static inline int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat) { - return __dev_change_net_namespace(dev, net, pat, 0); + return __dev_change_net_namespace(dev, net, pat, 0, NULL); } int __dev_set_mtu(struct net_device *, int); int dev_set_mtu(struct net_device *, int); diff --git a/net/core/dev.c b/net/core/dev.c index bad8765c7f13b..cc0335ce38c37 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11309,6 +11309,7 @@ EXPORT_SYMBOL(unregister_netdev); * is already taken in the destination network namespace. * @new_ifindex: If not zero, specifies device index in the target * namespace. + * @extack: netlink extended ack * * This function shuts down a device interface and moves it * to a new network namespace. On success 0 is returned, on @@ -11318,7 +11319,8 @@ EXPORT_SYMBOL(unregister_netdev); */ int __dev_change_net_namespace(struct net_device *dev, struct net *net, - const char *pat, int new_ifindex) + const char *pat, int new_ifindex, + struct netlink_ext_ack *extack) { struct netdev_name_node *name_node; struct net *net_old = dev_net(dev); @@ -11329,12 +11331,16 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, /* Don't allow namespace local devices to be moved. */ err = -EINVAL; - if (dev->features & NETIF_F_NETNS_LOCAL) + if (dev->features & NETIF_F_NETNS_LOCAL) { + NL_SET_ERR_MSG(extack, "The interface netns is immutable"); goto out; + } /* Ensure the device has been registrered */ - if (dev->reg_state != NETREG_REGISTERED) + if (dev->reg_state != NETREG_REGISTERED) { + NL_SET_ERR_MSG(extack, "The interface isn't registered"); goto out; + } /* Get out if there is nothing todo */ err = 0; @@ -11347,30 +11353,49 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, err = -EEXIST; if (netdev_name_in_use(net, dev->name)) { /* We get here if we can't use the current device name */ - if (!pat) + if (!pat) { + NL_SET_ERR_MSG(extack, + "An interface with the same name exists in the target netns"); goto out; + } err = dev_prep_valid_name(net, dev, pat, new_name); - if (err < 0) + if (err < 0) { + NL_SET_ERR_MSG_FMT(extack, + "Unable to use '%s' for the new interface name in the target netns", + pat); goto out; + } } /* Check that none of the altnames conflicts. */ err = -EEXIST; - netdev_for_each_altname(dev, name_node) - if (netdev_name_in_use(net, name_node->name)) + netdev_for_each_altname(dev, name_node) { + if (netdev_name_in_use(net, name_node->name)) { + NL_SET_ERR_MSG_FMT(extack, + "An interface with the altname %s exists in the target netns", + name_node->name); goto out; + } + } /* Check that new_ifindex isn't used yet. */ if (new_ifindex) { err = dev_index_reserve(net, new_ifindex); - if (err < 0) + if (err < 0) { + NL_SET_ERR_MSG_FMT(extack, + "The ifindex %d is not available in the target netns", + new_ifindex); goto out; + } } else { /* If there is an ifindex conflict assign a new one */ err = dev_index_reserve(net, dev->ifindex); if (err == -EBUSY) err = dev_index_reserve(net, 0); - if (err < 0) + if (err < 0) { + NL_SET_ERR_MSG(extack, + "Unable to allocate a new ifindex in the target netns"); goto out; + } new_ifindex = err; } diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 6e4c366ecffc0..5e2df9b8aaf95 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2824,7 +2824,7 @@ static int do_setlink(const struct sk_buff *skb, else new_ifindex = 0; - err = __dev_change_net_namespace(dev, net, pat, new_ifindex); + err = __dev_change_net_namespace(dev, net, pat, new_ifindex, extack); put_net(net); if (err) goto errout; -- 2.53.0