diff options
Diffstat (limited to 'drivers/net/netkit.c')
| -rw-r--r-- | drivers/net/netkit.c | 960 |
1 files changed, 960 insertions, 0 deletions
diff --git a/drivers/net/netkit.c b/drivers/net/netkit.c new file mode 100644 index 0000000000..39171380cc --- /dev/null +++ b/drivers/net/netkit.c @@ -0,0 +1,960 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2023 Isovalent */ + +#include <linux/netdevice.h> +#include <linux/ethtool.h> +#include <linux/etherdevice.h> +#include <linux/filter.h> +#include <linux/netfilter_netdev.h> +#include <linux/bpf_mprog.h> +#include <linux/indirect_call_wrapper.h> + +#include <net/netkit.h> +#include <net/dst.h> +#include <net/tcx.h> + +#define DRV_NAME "netkit" + +struct netkit { + /* Needed in fast-path */ + struct net_device __rcu *peer; + struct bpf_mprog_entry __rcu *active; + enum netkit_action policy; + struct bpf_mprog_bundle bundle; + + /* Needed in slow-path */ + enum netkit_mode mode; + bool primary; + u32 headroom; +}; + +struct netkit_link { + struct bpf_link link; + struct net_device *dev; + u32 location; +}; + +static __always_inline int +netkit_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb, + enum netkit_action ret) +{ + const struct bpf_mprog_fp *fp; + const struct bpf_prog *prog; + + bpf_mprog_foreach_prog(entry, fp, prog) { + bpf_compute_data_pointers(skb); + ret = bpf_prog_run(prog, skb); + if (ret != NETKIT_NEXT) + break; + } + return ret; +} + +static void netkit_prep_forward(struct sk_buff *skb, bool xnet) +{ + skb_scrub_packet(skb, xnet); + skb->priority = 0; + nf_skip_egress(skb, true); +} + +static struct netkit *netkit_priv(const struct net_device *dev) +{ + return netdev_priv(dev); +} + +static netdev_tx_t netkit_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + enum netkit_action ret = READ_ONCE(nk->policy); + netdev_tx_t ret_dev = NET_XMIT_SUCCESS; + const struct bpf_mprog_entry *entry; + struct net_device *peer; + int len = skb->len; + + rcu_read_lock(); + peer = rcu_dereference(nk->peer); + if (unlikely(!peer || !(peer->flags & IFF_UP) || + !pskb_may_pull(skb, ETH_HLEN) || + skb_orphan_frags(skb, GFP_ATOMIC))) + goto drop; + netkit_prep_forward(skb, !net_eq(dev_net(dev), dev_net(peer))); + skb->dev = peer; + entry = rcu_dereference(nk->active); + if (entry) + ret = netkit_run(entry, skb, ret); + switch (ret) { + case NETKIT_NEXT: + case NETKIT_PASS: + skb->protocol = eth_type_trans(skb, skb->dev); + skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); + if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) { + dev_sw_netstats_tx_add(dev, 1, len); + dev_sw_netstats_rx_add(peer, len); + } else { + goto drop_stats; + } + break; + case NETKIT_REDIRECT: + dev_sw_netstats_tx_add(dev, 1, len); + skb_do_redirect(skb); + break; + case NETKIT_DROP: + default: +drop: + kfree_skb(skb); +drop_stats: + dev_core_stats_tx_dropped_inc(dev); + ret_dev = NET_XMIT_DROP; + break; + } + rcu_read_unlock(); + return ret_dev; +} + +static int netkit_open(struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + + if (!peer) + return -ENOTCONN; + if (peer->flags & IFF_UP) { + netif_carrier_on(dev); + netif_carrier_on(peer); + } + return 0; +} + +static int netkit_close(struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + + netif_carrier_off(dev); + if (peer) + netif_carrier_off(peer); + return 0; +} + +static int netkit_get_iflink(const struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer; + int iflink = 0; + + rcu_read_lock(); + peer = rcu_dereference(nk->peer); + if (peer) + iflink = peer->ifindex; + rcu_read_unlock(); + return iflink; +} + +static void netkit_set_multicast(struct net_device *dev) +{ + /* Nothing to do, we receive whatever gets pushed to us! */ +} + +static void netkit_set_headroom(struct net_device *dev, int headroom) +{ + struct netkit *nk = netkit_priv(dev), *nk2; + struct net_device *peer; + + if (headroom < 0) + headroom = NET_SKB_PAD; + + rcu_read_lock(); + peer = rcu_dereference(nk->peer); + if (unlikely(!peer)) + goto out; + + nk2 = netkit_priv(peer); + nk->headroom = headroom; + headroom = max(nk->headroom, nk2->headroom); + + peer->needed_headroom = headroom; + dev->needed_headroom = headroom; +out: + rcu_read_unlock(); +} + +INDIRECT_CALLABLE_SCOPE struct net_device *netkit_peer_dev(struct net_device *dev) +{ + return rcu_dereference(netkit_priv(dev)->peer); +} + +static void netkit_get_stats(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + dev_fetch_sw_netstats(stats, dev->tstats); + stats->tx_dropped = DEV_STATS_READ(dev, tx_dropped); +} + +static void netkit_uninit(struct net_device *dev); + +static const struct net_device_ops netkit_netdev_ops = { + .ndo_open = netkit_open, + .ndo_stop = netkit_close, + .ndo_start_xmit = netkit_xmit, + .ndo_set_rx_mode = netkit_set_multicast, + .ndo_set_rx_headroom = netkit_set_headroom, + .ndo_get_iflink = netkit_get_iflink, + .ndo_get_peer_dev = netkit_peer_dev, + .ndo_get_stats64 = netkit_get_stats, + .ndo_uninit = netkit_uninit, + .ndo_features_check = passthru_features_check, +}; + +static void netkit_get_drvinfo(struct net_device *dev, + struct ethtool_drvinfo *info) +{ + strscpy(info->driver, DRV_NAME, sizeof(info->driver)); +} + +static const struct ethtool_ops netkit_ethtool_ops = { + .get_drvinfo = netkit_get_drvinfo, +}; + +static void netkit_setup(struct net_device *dev) +{ + static const netdev_features_t netkit_features_hw_vlan = + NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_CTAG_RX | + NETIF_F_HW_VLAN_STAG_TX | + NETIF_F_HW_VLAN_STAG_RX; + static const netdev_features_t netkit_features = + netkit_features_hw_vlan | + NETIF_F_SG | + NETIF_F_FRAGLIST | + NETIF_F_HW_CSUM | + NETIF_F_RXCSUM | + NETIF_F_SCTP_CRC | + NETIF_F_HIGHDMA | + NETIF_F_GSO_SOFTWARE | + NETIF_F_GSO_ENCAP_ALL; + + ether_setup(dev); + dev->max_mtu = ETH_MAX_MTU; + dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; + + dev->flags |= IFF_NOARP; + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + dev->priv_flags |= IFF_PHONY_HEADROOM; + dev->priv_flags |= IFF_NO_QUEUE; + + dev->ethtool_ops = &netkit_ethtool_ops; + dev->netdev_ops = &netkit_netdev_ops; + + dev->features |= netkit_features | NETIF_F_LLTX; + dev->hw_features = netkit_features; + dev->hw_enc_features = netkit_features; + dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE; + dev->vlan_features = dev->features & ~netkit_features_hw_vlan; + + dev->needs_free_netdev = true; + + netif_set_tso_max_size(dev, GSO_MAX_SIZE); +} + +static struct net *netkit_get_link_net(const struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + + return peer ? dev_net(peer) : dev_net(dev); +} + +static int netkit_check_policy(int policy, struct nlattr *tb, + struct netlink_ext_ack *extack) +{ + switch (policy) { + case NETKIT_PASS: + case NETKIT_DROP: + return 0; + default: + NL_SET_ERR_MSG_ATTR(extack, tb, + "Provided default xmit policy not supported"); + return -EINVAL; + } +} + +static int netkit_check_mode(int mode, struct nlattr *tb, + struct netlink_ext_ack *extack) +{ + switch (mode) { + case NETKIT_L2: + case NETKIT_L3: + return 0; + default: + NL_SET_ERR_MSG_ATTR(extack, tb, + "Provided device mode can only be L2 or L3"); + return -EINVAL; + } +} + +static int netkit_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct nlattr *attr = tb[IFLA_ADDRESS]; + + if (!attr) + return 0; + NL_SET_ERR_MSG_ATTR(extack, attr, + "Setting Ethernet address is not supported"); + return -EOPNOTSUPP; +} + +static struct rtnl_link_ops netkit_link_ops; + +static int netkit_new_link(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct nlattr *peer_tb[IFLA_MAX + 1], **tbp = tb, *attr; + enum netkit_action default_prim = NETKIT_PASS; + enum netkit_action default_peer = NETKIT_PASS; + enum netkit_mode mode = NETKIT_L3; + unsigned char ifname_assign_type; + struct ifinfomsg *ifmp = NULL; + struct net_device *peer; + char ifname[IFNAMSIZ]; + struct netkit *nk; + struct net *net; + int err; + + if (data) { + if (data[IFLA_NETKIT_MODE]) { + attr = data[IFLA_NETKIT_MODE]; + mode = nla_get_u32(attr); + err = netkit_check_mode(mode, attr, extack); + if (err < 0) + return err; + } + if (data[IFLA_NETKIT_PEER_INFO]) { + attr = data[IFLA_NETKIT_PEER_INFO]; + ifmp = nla_data(attr); + err = rtnl_nla_parse_ifinfomsg(peer_tb, attr, extack); + if (err < 0) + return err; + err = netkit_validate(peer_tb, NULL, extack); + if (err < 0) + return err; + tbp = peer_tb; + } + if (data[IFLA_NETKIT_POLICY]) { + attr = data[IFLA_NETKIT_POLICY]; + default_prim = nla_get_u32(attr); + err = netkit_check_policy(default_prim, attr, extack); + if (err < 0) + return err; + } + if (data[IFLA_NETKIT_PEER_POLICY]) { + attr = data[IFLA_NETKIT_PEER_POLICY]; + default_peer = nla_get_u32(attr); + err = netkit_check_policy(default_peer, attr, extack); + if (err < 0) + return err; + } + } + + if (ifmp && tbp[IFLA_IFNAME]) { + nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); + ifname_assign_type = NET_NAME_USER; + } else { + strscpy(ifname, "nk%d", IFNAMSIZ); + ifname_assign_type = NET_NAME_ENUM; + } + + net = rtnl_link_get_net(src_net, tbp); + if (IS_ERR(net)) + return PTR_ERR(net); + + peer = rtnl_create_link(net, ifname, ifname_assign_type, + &netkit_link_ops, tbp, extack); + if (IS_ERR(peer)) { + put_net(net); + return PTR_ERR(peer); + } + + netif_inherit_tso_max(peer, dev); + + if (mode == NETKIT_L2) + eth_hw_addr_random(peer); + if (ifmp && dev->ifindex) + peer->ifindex = ifmp->ifi_index; + + nk = netkit_priv(peer); + nk->primary = false; + nk->policy = default_peer; + nk->mode = mode; + bpf_mprog_bundle_init(&nk->bundle); + + err = register_netdevice(peer); + put_net(net); + if (err < 0) + goto err_register_peer; + netif_carrier_off(peer); + if (mode == NETKIT_L2) + dev_change_flags(peer, peer->flags & ~IFF_NOARP, NULL); + + err = rtnl_configure_link(peer, NULL, 0, NULL); + if (err < 0) + goto err_configure_peer; + + if (mode == NETKIT_L2) + eth_hw_addr_random(dev); + if (tb[IFLA_IFNAME]) + nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); + else + strscpy(dev->name, "nk%d", IFNAMSIZ); + + nk = netkit_priv(dev); + nk->primary = true; + nk->policy = default_prim; + nk->mode = mode; + bpf_mprog_bundle_init(&nk->bundle); + + err = register_netdevice(dev); + if (err < 0) + goto err_configure_peer; + netif_carrier_off(dev); + if (mode == NETKIT_L2) + dev_change_flags(dev, dev->flags & ~IFF_NOARP, NULL); + + rcu_assign_pointer(netkit_priv(dev)->peer, peer); + rcu_assign_pointer(netkit_priv(peer)->peer, dev); + return 0; +err_configure_peer: + unregister_netdevice(peer); + return err; +err_register_peer: + free_netdev(peer); + return err; +} + +static struct bpf_mprog_entry *netkit_entry_fetch(struct net_device *dev, + bool bundle_fallback) +{ + struct netkit *nk = netkit_priv(dev); + struct bpf_mprog_entry *entry; + + ASSERT_RTNL(); + entry = rcu_dereference_rtnl(nk->active); + if (entry) + return entry; + if (bundle_fallback) + return &nk->bundle.a; + return NULL; +} + +static void netkit_entry_update(struct net_device *dev, + struct bpf_mprog_entry *entry) +{ + struct netkit *nk = netkit_priv(dev); + + ASSERT_RTNL(); + rcu_assign_pointer(nk->active, entry); +} + +static void netkit_entry_sync(void) +{ + synchronize_rcu(); +} + +static struct net_device *netkit_dev_fetch(struct net *net, u32 ifindex, u32 which) +{ + struct net_device *dev; + struct netkit *nk; + + ASSERT_RTNL(); + + switch (which) { + case BPF_NETKIT_PRIMARY: + case BPF_NETKIT_PEER: + break; + default: + return ERR_PTR(-EINVAL); + } + + dev = __dev_get_by_index(net, ifindex); + if (!dev) + return ERR_PTR(-ENODEV); + if (dev->netdev_ops != &netkit_netdev_ops) + return ERR_PTR(-ENXIO); + + nk = netkit_priv(dev); + if (!nk->primary) + return ERR_PTR(-EACCES); + if (which == BPF_NETKIT_PEER) { + dev = rcu_dereference_rtnl(nk->peer); + if (!dev) + return ERR_PTR(-ENODEV); + } + return dev; +} + +int netkit_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_mprog_entry *entry, *entry_new; + struct bpf_prog *replace_prog = NULL; + struct net_device *dev; + int ret; + + rtnl_lock(); + dev = netkit_dev_fetch(current->nsproxy->net_ns, attr->target_ifindex, + attr->attach_type); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto out; + } + entry = netkit_entry_fetch(dev, true); + if (attr->attach_flags & BPF_F_REPLACE) { + replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, + prog->type); + if (IS_ERR(replace_prog)) { + ret = PTR_ERR(replace_prog); + replace_prog = NULL; + goto out; + } + } + ret = bpf_mprog_attach(entry, &entry_new, prog, NULL, replace_prog, + attr->attach_flags, attr->relative_fd, + attr->expected_revision); + if (!ret) { + if (entry != entry_new) { + netkit_entry_update(dev, entry_new); + netkit_entry_sync(); + } + bpf_mprog_commit(entry); + } +out: + if (replace_prog) + bpf_prog_put(replace_prog); + rtnl_unlock(); + return ret; +} + +int netkit_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_mprog_entry *entry, *entry_new; + struct net_device *dev; + int ret; + + rtnl_lock(); + dev = netkit_dev_fetch(current->nsproxy->net_ns, attr->target_ifindex, + attr->attach_type); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto out; + } + entry = netkit_entry_fetch(dev, false); + if (!entry) { + ret = -ENOENT; + goto out; + } + ret = bpf_mprog_detach(entry, &entry_new, prog, NULL, attr->attach_flags, + attr->relative_fd, attr->expected_revision); + if (!ret) { + if (!bpf_mprog_total(entry_new)) + entry_new = NULL; + netkit_entry_update(dev, entry_new); + netkit_entry_sync(); + bpf_mprog_commit(entry); + } +out: + rtnl_unlock(); + return ret; +} + +int netkit_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) +{ + struct net_device *dev; + int ret; + + rtnl_lock(); + dev = netkit_dev_fetch(current->nsproxy->net_ns, + attr->query.target_ifindex, + attr->query.attach_type); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto out; + } + ret = bpf_mprog_query(attr, uattr, netkit_entry_fetch(dev, false)); +out: + rtnl_unlock(); + return ret; +} + +static struct netkit_link *netkit_link(const struct bpf_link *link) +{ + return container_of(link, struct netkit_link, link); +} + +static int netkit_link_prog_attach(struct bpf_link *link, u32 flags, + u32 id_or_fd, u64 revision) +{ + struct netkit_link *nkl = netkit_link(link); + struct bpf_mprog_entry *entry, *entry_new; + struct net_device *dev = nkl->dev; + int ret; + + ASSERT_RTNL(); + entry = netkit_entry_fetch(dev, true); + ret = bpf_mprog_attach(entry, &entry_new, link->prog, link, NULL, flags, + id_or_fd, revision); + if (!ret) { + if (entry != entry_new) { + netkit_entry_update(dev, entry_new); + netkit_entry_sync(); + } + bpf_mprog_commit(entry); + } + return ret; +} + +static void netkit_link_release(struct bpf_link *link) +{ + struct netkit_link *nkl = netkit_link(link); + struct bpf_mprog_entry *entry, *entry_new; + struct net_device *dev; + int ret = 0; + + rtnl_lock(); + dev = nkl->dev; + if (!dev) + goto out; + entry = netkit_entry_fetch(dev, false); + if (!entry) { + ret = -ENOENT; + goto out; + } + ret = bpf_mprog_detach(entry, &entry_new, link->prog, link, 0, 0, 0); + if (!ret) { + if (!bpf_mprog_total(entry_new)) + entry_new = NULL; + netkit_entry_update(dev, entry_new); + netkit_entry_sync(); + bpf_mprog_commit(entry); + nkl->dev = NULL; + } +out: + WARN_ON_ONCE(ret); + rtnl_unlock(); +} + +static int netkit_link_update(struct bpf_link *link, struct bpf_prog *nprog, + struct bpf_prog *oprog) +{ + struct netkit_link *nkl = netkit_link(link); + struct bpf_mprog_entry *entry, *entry_new; + struct net_device *dev; + int ret = 0; + + rtnl_lock(); + dev = nkl->dev; + if (!dev) { + ret = -ENOLINK; + goto out; + } + if (oprog && link->prog != oprog) { + ret = -EPERM; + goto out; + } + oprog = link->prog; + if (oprog == nprog) { + bpf_prog_put(nprog); + goto out; + } + entry = netkit_entry_fetch(dev, false); + if (!entry) { + ret = -ENOENT; + goto out; + } + ret = bpf_mprog_attach(entry, &entry_new, nprog, link, oprog, + BPF_F_REPLACE | BPF_F_ID, + link->prog->aux->id, 0); + if (!ret) { + WARN_ON_ONCE(entry != entry_new); + oprog = xchg(&link->prog, nprog); + bpf_prog_put(oprog); + bpf_mprog_commit(entry); + } +out: + rtnl_unlock(); + return ret; +} + +static void netkit_link_dealloc(struct bpf_link *link) +{ + kfree(netkit_link(link)); +} + +static void netkit_link_fdinfo(const struct bpf_link *link, struct seq_file *seq) +{ + const struct netkit_link *nkl = netkit_link(link); + u32 ifindex = 0; + + rtnl_lock(); + if (nkl->dev) + ifindex = nkl->dev->ifindex; + rtnl_unlock(); + + seq_printf(seq, "ifindex:\t%u\n", ifindex); + seq_printf(seq, "attach_type:\t%u (%s)\n", + nkl->location, + nkl->location == BPF_NETKIT_PRIMARY ? "primary" : "peer"); +} + +static int netkit_link_fill_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + const struct netkit_link *nkl = netkit_link(link); + u32 ifindex = 0; + + rtnl_lock(); + if (nkl->dev) + ifindex = nkl->dev->ifindex; + rtnl_unlock(); + + info->netkit.ifindex = ifindex; + info->netkit.attach_type = nkl->location; + return 0; +} + +static int netkit_link_detach(struct bpf_link *link) +{ + netkit_link_release(link); + return 0; +} + +static const struct bpf_link_ops netkit_link_lops = { + .release = netkit_link_release, + .detach = netkit_link_detach, + .dealloc = netkit_link_dealloc, + .update_prog = netkit_link_update, + .show_fdinfo = netkit_link_fdinfo, + .fill_link_info = netkit_link_fill_info, +}; + +static int netkit_link_init(struct netkit_link *nkl, + struct bpf_link_primer *link_primer, + const union bpf_attr *attr, + struct net_device *dev, + struct bpf_prog *prog) +{ + bpf_link_init(&nkl->link, BPF_LINK_TYPE_NETKIT, + &netkit_link_lops, prog); + nkl->location = attr->link_create.attach_type; + nkl->dev = dev; + return bpf_link_prime(&nkl->link, link_primer); +} + +int netkit_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_link_primer link_primer; + struct netkit_link *nkl; + struct net_device *dev; + int ret; + + rtnl_lock(); + dev = netkit_dev_fetch(current->nsproxy->net_ns, + attr->link_create.target_ifindex, + attr->link_create.attach_type); + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + goto out; + } + nkl = kzalloc(sizeof(*nkl), GFP_KERNEL_ACCOUNT); + if (!nkl) { + ret = -ENOMEM; + goto out; + } + ret = netkit_link_init(nkl, &link_primer, attr, dev, prog); + if (ret) { + kfree(nkl); + goto out; + } + ret = netkit_link_prog_attach(&nkl->link, + attr->link_create.flags, + attr->link_create.netkit.relative_fd, + attr->link_create.netkit.expected_revision); + if (ret) { + nkl->dev = NULL; + bpf_link_cleanup(&link_primer); + goto out; + } + ret = bpf_link_settle(&link_primer); +out: + rtnl_unlock(); + return ret; +} + +static void netkit_release_all(struct net_device *dev) +{ + struct bpf_mprog_entry *entry; + struct bpf_tuple tuple = {}; + struct bpf_mprog_fp *fp; + struct bpf_mprog_cp *cp; + + entry = netkit_entry_fetch(dev, false); + if (!entry) + return; + netkit_entry_update(dev, NULL); + netkit_entry_sync(); + bpf_mprog_foreach_tuple(entry, fp, cp, tuple) { + if (tuple.link) + netkit_link(tuple.link)->dev = NULL; + else + bpf_prog_put(tuple.prog); + } +} + +static void netkit_uninit(struct net_device *dev) +{ + netkit_release_all(dev); +} + +static void netkit_del_link(struct net_device *dev, struct list_head *head) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + + RCU_INIT_POINTER(nk->peer, NULL); + unregister_netdevice_queue(dev, head); + if (peer) { + nk = netkit_priv(peer); + RCU_INIT_POINTER(nk->peer, NULL); + unregister_netdevice_queue(peer, head); + } +} + +static int netkit_change_link(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + enum netkit_action policy; + struct nlattr *attr; + int err; + + if (!nk->primary) { + NL_SET_ERR_MSG(extack, + "netkit link settings can be changed only through the primary device"); + return -EACCES; + } + + if (data[IFLA_NETKIT_MODE]) { + NL_SET_ERR_MSG_ATTR(extack, data[IFLA_NETKIT_MODE], + "netkit link operating mode cannot be changed after device creation"); + return -EACCES; + } + + if (data[IFLA_NETKIT_PEER_INFO]) { + NL_SET_ERR_MSG_ATTR(extack, data[IFLA_NETKIT_PEER_INFO], + "netkit peer info cannot be changed after device creation"); + return -EINVAL; + } + + if (data[IFLA_NETKIT_POLICY]) { + attr = data[IFLA_NETKIT_POLICY]; + policy = nla_get_u32(attr); + err = netkit_check_policy(policy, attr, extack); + if (err) + return err; + WRITE_ONCE(nk->policy, policy); + } + + if (data[IFLA_NETKIT_PEER_POLICY]) { + err = -EOPNOTSUPP; + attr = data[IFLA_NETKIT_PEER_POLICY]; + policy = nla_get_u32(attr); + if (peer) + err = netkit_check_policy(policy, attr, extack); + if (err) + return err; + nk = netkit_priv(peer); + WRITE_ONCE(nk->policy, policy); + } + + return 0; +} + +static size_t netkit_get_size(const struct net_device *dev) +{ + return nla_total_size(sizeof(u32)) + /* IFLA_NETKIT_POLICY */ + nla_total_size(sizeof(u32)) + /* IFLA_NETKIT_PEER_POLICY */ + nla_total_size(sizeof(u8)) + /* IFLA_NETKIT_PRIMARY */ + nla_total_size(sizeof(u32)) + /* IFLA_NETKIT_MODE */ + 0; +} + +static int netkit_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct netkit *nk = netkit_priv(dev); + struct net_device *peer = rtnl_dereference(nk->peer); + + if (nla_put_u8(skb, IFLA_NETKIT_PRIMARY, nk->primary)) + return -EMSGSIZE; + if (nla_put_u32(skb, IFLA_NETKIT_POLICY, nk->policy)) + return -EMSGSIZE; + if (nla_put_u32(skb, IFLA_NETKIT_MODE, nk->mode)) + return -EMSGSIZE; + + if (peer) { + nk = netkit_priv(peer); + if (nla_put_u32(skb, IFLA_NETKIT_PEER_POLICY, nk->policy)) + return -EMSGSIZE; + } + + return 0; +} + +static const struct nla_policy netkit_policy[IFLA_NETKIT_MAX + 1] = { + [IFLA_NETKIT_PEER_INFO] = { .len = sizeof(struct ifinfomsg) }, + [IFLA_NETKIT_POLICY] = { .type = NLA_U32 }, + [IFLA_NETKIT_MODE] = { .type = NLA_U32 }, + [IFLA_NETKIT_PEER_POLICY] = { .type = NLA_U32 }, + [IFLA_NETKIT_PRIMARY] = { .type = NLA_REJECT, + .reject_message = "Primary attribute is read-only" }, +}; + +static struct rtnl_link_ops netkit_link_ops = { + .kind = DRV_NAME, + .priv_size = sizeof(struct netkit), + .setup = netkit_setup, + .newlink = netkit_new_link, + .dellink = netkit_del_link, + .changelink = netkit_change_link, + .get_link_net = netkit_get_link_net, + .get_size = netkit_get_size, + .fill_info = netkit_fill_info, + .policy = netkit_policy, + .validate = netkit_validate, + .maxtype = IFLA_NETKIT_MAX, +}; + +static __init int netkit_init(void) +{ + BUILD_BUG_ON((int)NETKIT_NEXT != (int)TCX_NEXT || + (int)NETKIT_PASS != (int)TCX_PASS || + (int)NETKIT_DROP != (int)TCX_DROP || + (int)NETKIT_REDIRECT != (int)TCX_REDIRECT); + + return rtnl_link_register(&netkit_link_ops); +} + +static __exit void netkit_exit(void) +{ + rtnl_link_unregister(&netkit_link_ops); +} + +module_init(netkit_init); +module_exit(netkit_exit); + +MODULE_DESCRIPTION("BPF-programmable network device"); +MODULE_AUTHOR("Daniel Borkmann <daniel@iogearbox.net>"); +MODULE_AUTHOR("Nikolay Aleksandrov <razor@blackwall.org>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK(DRV_NAME); |