Fri, Aug 09, 2019 at 06:11:30AM CEST, ro...@cumulusnetworks.com wrote:
>On Fri, Jul 19, 2019 at 4:00 AM Jiri Pirko <j...@resnulli.us> wrote:
>>
>> From: Jiri Pirko <j...@mellanox.com>
>>
>> Add two commands to add and delete alternative ifnames for net device.
>> Each net device can have multiple alternative names.
>>
>> Signed-off-by: Jiri Pirko <j...@mellanox.com>
>> ---
>> include/linux/netdevice.h | 4 ++
>> include/uapi/linux/if.h | 1 +
>> include/uapi/linux/if_link.h | 1 +
>> include/uapi/linux/rtnetlink.h | 7 +++
>> net/core/dev.c | 58 ++++++++++++++++++-
>> net/core/rtnetlink.c | 102 +++++++++++++++++++++++++++++++++
>> security/selinux/nlmsgtab.c | 4 +-
>> 7 files changed, 175 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>> index 74f99f127b0e..6922fdb483ca 100644
>> --- a/include/linux/netdevice.h
>> +++ b/include/linux/netdevice.h
>> @@ -920,10 +920,14 @@ struct tlsdev_ops;
>>
>> struct netdev_name_node {
>> struct hlist_node hlist;
>> + struct list_head list;
>> struct net_device *dev;
>> char *name;
>> };
>>
>> +int netdev_name_node_alt_create(struct net_device *dev, char *name);
>> +int netdev_name_node_alt_destroy(struct net_device *dev, char *name);
>> +
>> /*
>> * This structure defines the management hooks for network devices.
>> * The following hooks can be defined; unless noted otherwise, they are
>> diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
>> index 7fea0fd7d6f5..4bf33344aab1 100644
>> --- a/include/uapi/linux/if.h
>> +++ b/include/uapi/linux/if.h
>> @@ -33,6 +33,7 @@
>> #define IFNAMSIZ 16
>> #endif /* __UAPI_DEF_IF_IFNAMSIZ */
>> #define IFALIASZ 256
>> +#define ALTIFNAMSIZ 128
>> #include <linux/hdlc/ioctl.h>
>>
>> /* For glibc compatibility. An empty enum does not compile. */
>> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
>> index 4a8c02cafa9a..92268946e04a 100644
>> --- a/include/uapi/linux/if_link.h
>> +++ b/include/uapi/linux/if_link.h
>> @@ -167,6 +167,7 @@ enum {
>> IFLA_NEW_IFINDEX,
>> IFLA_MIN_MTU,
>> IFLA_MAX_MTU,
>> + IFLA_ALT_IFNAME_MOD, /* Alternative ifname to add/delete */
>> __IFLA_MAX
>> };
>>
>> diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
>> index ce2a623abb75..b36cfd83eb76 100644
>> --- a/include/uapi/linux/rtnetlink.h
>> +++ b/include/uapi/linux/rtnetlink.h
>> @@ -164,6 +164,13 @@ enum {
>> RTM_GETNEXTHOP,
>> #define RTM_GETNEXTHOP RTM_GETNEXTHOP
>>
>> + RTM_NEWALTIFNAME = 108,
>> +#define RTM_NEWALTIFNAME RTM_NEWALTIFNAME
>> + RTM_DELALTIFNAME,
>> +#define RTM_DELALTIFNAME RTM_DELALTIFNAME
>> + RTM_GETALTIFNAME,
>> +#define RTM_GETALTIFNAME RTM_GETALTIFNAME
>> +
>
>I might have missed the prior discussion, why do we need new commands
>?. can't this simply be part of RTM_*LINK and we use RTM_SETLINK to
>set alternate names ?
How? This is to add/remove. How do you suggest to to add/remove by
setlink?
>
>
>
>> __RTM_MAX,
>> #define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
>> };
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index ad0d42fbdeee..2a3be2b279d3 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -244,7 +244,13 @@ static struct netdev_name_node
>> *netdev_name_node_alloc(struct net_device *dev,
>> static struct netdev_name_node *
>> netdev_name_node_head_alloc(struct net_device *dev)
>> {
>> - return netdev_name_node_alloc(dev, dev->name);
>> + struct netdev_name_node *name_node;
>> +
>> + name_node = netdev_name_node_alloc(dev, dev->name);
>> + if (!name_node)
>> + return NULL;
>> + INIT_LIST_HEAD(&name_node->list);
>> + return name_node;
>> }
>>
>> static void netdev_name_node_free(struct netdev_name_node *name_node)
>> @@ -288,6 +294,55 @@ static struct netdev_name_node
>> *netdev_name_node_lookup_rcu(struct net *net,
>> return NULL;
>> }
>>
>> +int netdev_name_node_alt_create(struct net_device *dev, char *name)
>> +{
>> + struct netdev_name_node *name_node;
>> + struct net *net = dev_net(dev);
>> +
>> + name_node = netdev_name_node_lookup(net, name);
>> + if (name_node)
>> + return -EEXIST;
>> + name_node = netdev_name_node_alloc(dev, name);
>> + if (!name_node)
>> + return -ENOMEM;
>> + netdev_name_node_add(net, name_node);
>> + /* The node that holds dev->name acts as a head of per-device list.
>> */
>> + list_add_tail(&name_node->list, &dev->name_node->list);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(netdev_name_node_alt_create);
>> +
>> +static void __netdev_name_node_alt_destroy(struct netdev_name_node
>> *name_node)
>> +{
>> + list_del(&name_node->list);
>> + netdev_name_node_del(name_node);
>> + kfree(name_node->name);
>> + netdev_name_node_free(name_node);
>> +}
>> +
>> +int netdev_name_node_alt_destroy(struct net_device *dev, char *name)
>> +{
>> + struct netdev_name_node *name_node;
>> + struct net *net = dev_net(dev);
>> +
>> + name_node = netdev_name_node_lookup(net, name);
>> + if (!name_node)
>> + return -ENOENT;
>> + __netdev_name_node_alt_destroy(name_node);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(netdev_name_node_alt_destroy);
>> +
>> +static void netdev_name_node_alt_flush(struct net_device *dev)
>> +{
>> + struct netdev_name_node *name_node, *tmp;
>> +
>> + list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
>> + __netdev_name_node_alt_destroy(name_node);
>> +}
>> +
>> /* Device list insertion */
>> static void list_netdevice(struct net_device *dev)
>> {
>> @@ -8258,6 +8313,7 @@ static void rollback_registered_many(struct list_head
>> *head)
>> dev_uc_flush(dev);
>> dev_mc_flush(dev);
>>
>> + netdev_name_node_alt_flush(dev);
>> netdev_name_node_free(dev->name_node);
>>
>> if (dev->netdev_ops->ndo_uninit)
>> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
>> index 1ee6460f8275..7a2010b16e10 100644
>> --- a/net/core/rtnetlink.c
>> +++ b/net/core/rtnetlink.c
>> @@ -1750,6 +1750,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1]
>> = {
>> [IFLA_CARRIER_DOWN_COUNT] = { .type = NLA_U32 },
>> [IFLA_MIN_MTU] = { .type = NLA_U32 },
>> [IFLA_MAX_MTU] = { .type = NLA_U32 },
>> + [IFLA_ALT_IFNAME_MOD] = { .type = NLA_STRING,
>> + .len = ALTIFNAMSIZ - 1 },
>> };
>>
>> static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
>> @@ -3373,6 +3375,103 @@ static int rtnl_getlink(struct sk_buff *skb, struct
>> nlmsghdr *nlh,
>> return err;
>> }
>>
>> +static int rtnl_newaltifname(struct sk_buff *skb, struct nlmsghdr *nlh,
>> + struct netlink_ext_ack *extack)
>> +{
>> + struct net *net = sock_net(skb->sk);
>> + struct nlattr *tb[IFLA_MAX + 1];
>> + struct net_device *dev;
>> + struct ifinfomsg *ifm;
>> + char *new_alt_ifname;
>> + int err;
>> +
>> + err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
>> extack);
>> + if (err)
>> + return err;
>> +
>> + err = rtnl_ensure_unique_netns(tb, extack, true);
>> + if (err)
>> + return err;
>> +
>> + ifm = nlmsg_data(nlh);
>> + if (ifm->ifi_index > 0) {
>> + dev = __dev_get_by_index(net, ifm->ifi_index);
>> + } else if (tb[IFLA_IFNAME]) {
>> + char ifname[IFNAMSIZ];
>> +
>> + nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
>> + dev = __dev_get_by_name(net, ifname);
>> + } else {
>> + return -EINVAL;
>> + }
>> +
>> + if (!dev)
>> + return -ENODEV;
>> +
>> + if (!tb[IFLA_ALT_IFNAME_MOD])
>> + return -EINVAL;
>> +
>> + new_alt_ifname = nla_strdup(tb[IFLA_ALT_IFNAME_MOD], GFP_KERNEL);
>> + if (!new_alt_ifname)
>> + return -ENOMEM;
>> +
>> + err = netdev_name_node_alt_create(dev, new_alt_ifname);
>> + if (err)
>> + goto out_free_new_alt_ifname;
>> +
>> + return 0;
>> +
>> +out_free_new_alt_ifname:
>> + kfree(new_alt_ifname);
>> + return err;
>> +}
>> +
>> +static int rtnl_delaltifname(struct sk_buff *skb, struct nlmsghdr *nlh,
>> + struct netlink_ext_ack *extack)
>> +{
>> + struct net *net = sock_net(skb->sk);
>> + struct nlattr *tb[IFLA_MAX + 1];
>> + struct net_device *dev;
>> + struct ifinfomsg *ifm;
>> + char *del_alt_ifname;
>> + int err;
>> +
>> + err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
>> extack);
>> + if (err)
>> + return err;
>> +
>> + err = rtnl_ensure_unique_netns(tb, extack, true);
>> + if (err)
>> + return err;
>> +
>> + ifm = nlmsg_data(nlh);
>> + if (ifm->ifi_index > 0) {
>> + dev = __dev_get_by_index(net, ifm->ifi_index);
>> + } else if (tb[IFLA_IFNAME]) {
>> + char ifname[IFNAMSIZ];
>> +
>> + nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
>> + dev = __dev_get_by_name(net, ifname);
>> + } else {
>> + return -EINVAL;
>> + }
>> +
>> + if (!dev)
>> + return -ENODEV;
>> +
>> + if (!tb[IFLA_ALT_IFNAME_MOD])
>> + return -EINVAL;
>> +
>> + del_alt_ifname = nla_strdup(tb[IFLA_ALT_IFNAME_MOD], GFP_KERNEL);
>> + if (!del_alt_ifname)
>> + return -ENOMEM;
>> +
>> + err = netdev_name_node_alt_destroy(dev, del_alt_ifname);
>> + kfree(del_alt_ifname);
>> +
>> + return err;
>> +}
>> +
>> static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
>> {
>> struct net *net = sock_net(skb->sk);
>> @@ -5331,6 +5430,9 @@ void __init rtnetlink_init(void)
>> rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all, 0);
>> rtnl_register(PF_UNSPEC, RTM_GETNETCONF, NULL, rtnl_dump_all, 0);
>>
>> + rtnl_register(PF_UNSPEC, RTM_NEWALTIFNAME, rtnl_newaltifname, NULL,
>> 0);
>> + rtnl_register(PF_UNSPEC, RTM_DELALTIFNAME, rtnl_delaltifname, NULL,
>> 0);
>> +
>> rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, rtnl_fdb_add, NULL, 0);
>> rtnl_register(PF_BRIDGE, RTM_DELNEIGH, rtnl_fdb_del, NULL, 0);
>> rtnl_register(PF_BRIDGE, RTM_GETNEIGH, rtnl_fdb_get, rtnl_fdb_dump,
>> 0);
>> diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
>> index 58345ba0528e..a712b54c666c 100644
>> --- a/security/selinux/nlmsgtab.c
>> +++ b/security/selinux/nlmsgtab.c
>> @@ -83,6 +83,8 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
>> { RTM_NEWNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>> { RTM_DELNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>> { RTM_GETNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_READ },
>> + { RTM_NEWALTIFNAME, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>> + { RTM_DELALTIFNAME, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
>> };
>>
>> static const struct nlmsg_perm nlmsg_tcpdiag_perms[] =
>> @@ -166,7 +168,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32
>> *perm)
>> * structures at the top of this file with the new mappings
>> * before updating the BUILD_BUG_ON() macro!
>> */
>> - BUILD_BUG_ON(RTM_MAX != (RTM_NEWNEXTHOP + 3));
>> + BUILD_BUG_ON(RTM_MAX != (RTM_NEWALTIFNAME + 3));
>> err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
>> sizeof(nlmsg_route_perms));
>> break;
>> --
>> 2.21.0
>>
