From 36fbf1e52bd3ff8a5cb604955eedfc9350c2e6cc Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 30 Sep 2019 11:48:16 +0200 Subject: [PATCH] net: rtnetlink: add linkprop commands to add and delete alternative ifnames Add two commands to add and delete list of link properties. Implement the first property type along - alternative ifnames. Each net device can have multiple alternative names. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 ++ include/uapi/linux/if.h | 1 + include/uapi/linux/if_link.h | 2 + include/uapi/linux/rtnetlink.h | 7 +++ net/core/dev.c | 58 ++++++++++++++++++- net/core/rtnetlink.c | 103 +++++++++++++++++++++++++++++++++ security/selinux/nlmsgtab.c | 4 +- 7 files changed, 177 insertions(+), 2 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e92bc5467256..48cc71aae466 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -927,10 +927,14 @@ struct tlsdev_ops; struct netdev_name_node { struct hlist_node hlist; + struct list_head list; struct net_device *dev; const char *name; }; +int netdev_name_node_alt_create(struct net_device *dev, const char *name); +int netdev_name_node_alt_destroy(struct net_device *dev, const 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 /* 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..8aec8769d944 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -167,6 +167,8 @@ enum { IFLA_NEW_IFINDEX, IFLA_MIN_MTU, IFLA_MAX_MTU, + IFLA_PROP_LIST, + IFLA_ALT_IFNAME, /* Alternative ifname */ __IFLA_MAX }; diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index ce2a623abb75..1418a8362bb7 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_NEWLINKPROP = 108, +#define RTM_NEWLINKPROP RTM_NEWLINKPROP + RTM_DELLINKPROP, +#define RTM_DELLINKPROP RTM_DELLINKPROP + RTM_GETLINKPROP, +#define RTM_GETLINKPROP RTM_GETLINKPROP + __RTM_MAX, #define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1) }; diff --git a/net/core/dev.c b/net/core/dev.c index d2053d07c94a..7a456c6a7ad8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -245,7 +245,13 @@ 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) @@ -289,6 +295,55 @@ 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, const 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, const 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) { @@ -8317,6 +8372,7 @@ 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..e13646993d82 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1750,6 +1750,9 @@ 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_PROP_LIST] = { .type = NLA_NESTED }, + [IFLA_ALT_IFNAME] = { .type = NLA_STRING, + .len = ALTIFNAMSIZ - 1 }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -3373,6 +3376,103 @@ out: return err; } +static int rtnl_alt_ifname(int cmd, struct net_device *dev, struct nlattr *attr, + bool *changed, struct netlink_ext_ack *extack) +{ + char *alt_ifname; + int err; + + err = nla_validate(attr, attr->nla_len, IFLA_MAX, ifla_policy, extack); + if (err) + return err; + + alt_ifname = nla_data(attr); + if (cmd == RTM_NEWLINKPROP) { + alt_ifname = kstrdup(alt_ifname, GFP_KERNEL); + if (!alt_ifname) + return -ENOMEM; + err = netdev_name_node_alt_create(dev, alt_ifname); + if (err) { + kfree(alt_ifname); + return err; + } + } else if (cmd == RTM_DELLINKPROP) { + err = netdev_name_node_alt_destroy(dev, alt_ifname); + if (err) + return err; + } else { + WARN_ON(1); + return 0; + } + + *changed = true; + return 0; +} + +static int rtnl_linkprop(int cmd, 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; + bool changed = false; + struct nlattr *attr; + int err, rem; + + 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_PROP_LIST]) + return 0; + + nla_for_each_nested(attr, tb[IFLA_PROP_LIST], rem) { + switch (nla_type(attr)) { + case IFLA_ALT_IFNAME: + err = rtnl_alt_ifname(cmd, dev, attr, &changed, extack); + if (err) + return err; + break; + } + } + + if (changed) + netdev_state_change(dev); + return 0; +} + +static int rtnl_newlinkprop(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + return rtnl_linkprop(RTM_NEWLINKPROP, skb, nlh, extack); +} + +static int rtnl_dellinkprop(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + return rtnl_linkprop(RTM_DELLINKPROP, skb, nlh, extack); +} + static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); @@ -5331,6 +5431,9 @@ 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_NEWLINKPROP, rtnl_newlinkprop, NULL, 0); + rtnl_register(PF_UNSPEC, RTM_DELLINKPROP, rtnl_dellinkprop, 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..c97fdae8f71b 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_NEWLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE }, + { RTM_DELLINKPROP, 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_NEWLINKPROP + 3)); err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms, sizeof(nlmsg_route_perms)); break; -- 2.30.2