#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 {
__cacheline_group_begin(netkit_fastpath);
struct net_device __rcu *peer;
struct bpf_mprog_entry __rcu *active;
enum netkit_action policy;
enum netkit_scrub scrub;
struct bpf_mprog_bundle bundle;
__cacheline_group_end(netkit_fastpath);
__cacheline_group_begin(netkit_slowpath);
enum netkit_mode mode;
bool primary;
u32 headroom;
__cacheline_group_end(netkit_slowpath);
};
struct netkit_link {
struct bpf_link link;
struct net_device *dev;
};
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_xnet(struct sk_buff *skb)
{
skb->priority = 0;
skb->mark = 0;
}
static void netkit_prep_forward(struct sk_buff *skb,
bool xnet, bool xnet_scrub)
{
skb_scrub_packet(skb, false);
nf_skip_egress(skb, true);
skb_reset_mac_header(skb);
if (!xnet)
return;
skb_clear_tstamp(skb);
if (xnet_scrub)
netkit_xnet(skb);
}
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 bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
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;
bpf_net_ctx = bpf_net_ctx_set(&__bpf_net_ctx);
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)),
nk->scrub);
eth_skb_pkt_type(skb, 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:
eth_skb_pull_mac(skb);
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();
bpf_net_ctx_clear(bpf_net_ctx);
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 = READ_ONCE(peer->ifindex);
rcu_read_unlock();
return iflink;
}
static void netkit_set_multicast(struct net_device *dev)
{
}
static int netkit_set_macaddr(struct net_device *dev, void *sa)
{
struct netkit *nk = netkit_priv(dev);
if (nk->mode != NETKIT_L2)
return -EOPNOTSUPP;
return eth_mac_addr(dev, sa);
}
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_set_mac_address = netkit_set_macaddr,
.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->priv_flags |= IFF_DISABLE_NETPOLL;
dev->lltx = true;
dev->ethtool_ops = &netkit_ethtool_ops;
dev->netdev_ops = &netkit_netdev_ops;
dev->features |= netkit_features;
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_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct nlattr *attr = tb[IFLA_ADDRESS];
if (!attr)
return 0;
if (nla_len(attr) != ETH_ALEN)
return -EINVAL;
if (!is_valid_ether_addr(nla_data(attr)))
return -EADDRNOTAVAIL;
return 0;
}
static struct rtnl_link_ops netkit_link_ops;
static int netkit_new_link(struct net_device *dev,
struct rtnl_newlink_params *params,
struct netlink_ext_ack *extack)
{
struct net *peer_net = rtnl_newlink_peer_net(params);
enum netkit_scrub scrub_prim = NETKIT_SCRUB_DEFAULT;
enum netkit_scrub scrub_peer = NETKIT_SCRUB_DEFAULT;
struct nlattr *peer_tb[IFLA_MAX + 1], **tbp, *attr;
enum netkit_action policy_prim = NETKIT_PASS;
enum netkit_action policy_peer = NETKIT_PASS;
struct nlattr **data = params->data;
enum netkit_mode mode = NETKIT_L3;
unsigned char ifname_assign_type;
struct nlattr **tb = params->tb;
u16 headroom = 0, tailroom = 0;
struct ifinfomsg *ifmp = NULL;
struct net_device *peer;
char ifname[IFNAMSIZ];
struct netkit *nk;
int err;
tbp = tb;
if (data) {
if (data[IFLA_NETKIT_MODE])
mode = nla_get_u32(data[IFLA_NETKIT_MODE]);
if (data[IFLA_NETKIT_PEER_INFO]) {
attr = data[IFLA_NETKIT_PEER_INFO];
ifmp = nla_data(attr);
rtnl_nla_parse_ifinfomsg(peer_tb, attr, extack);
tbp = peer_tb;
}
if (data[IFLA_NETKIT_SCRUB])
scrub_prim = nla_get_u32(data[IFLA_NETKIT_SCRUB]);
if (data[IFLA_NETKIT_PEER_SCRUB])
scrub_peer = nla_get_u32(data[IFLA_NETKIT_PEER_SCRUB]);
if (data[IFLA_NETKIT_POLICY]) {
attr = data[IFLA_NETKIT_POLICY];
policy_prim = nla_get_u32(attr);
err = netkit_check_policy(policy_prim, attr, extack);
if (err < 0)
return err;
}
if (data[IFLA_NETKIT_PEER_POLICY]) {
attr = data[IFLA_NETKIT_PEER_POLICY];
policy_peer = nla_get_u32(attr);
err = netkit_check_policy(policy_peer, attr, extack);
if (err < 0)
return err;
}
if (data[IFLA_NETKIT_HEADROOM])
headroom = nla_get_u16(data[IFLA_NETKIT_HEADROOM]);
if (data[IFLA_NETKIT_TAILROOM])
tailroom = nla_get_u16(data[IFLA_NETKIT_TAILROOM]);
}
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;
}
if (mode != NETKIT_L2 &&
(tb[IFLA_ADDRESS] || tbp[IFLA_ADDRESS]))
return -EOPNOTSUPP;
peer = rtnl_create_link(peer_net, ifname, ifname_assign_type,
&netkit_link_ops, tbp, extack);
if (IS_ERR(peer))
return PTR_ERR(peer);
netif_inherit_tso_max(peer, dev);
if (headroom) {
peer->needed_headroom = headroom;
dev->needed_headroom = headroom;
}
if (tailroom) {
peer->needed_tailroom = tailroom;
dev->needed_tailroom = tailroom;
}
if (mode == NETKIT_L2 && !(ifmp && tbp[IFLA_ADDRESS]))
eth_hw_addr_random(peer);
if (ifmp && dev->ifindex)
peer->ifindex = ifmp->ifi_index;
nk = netkit_priv(peer);
nk->primary = false;
nk->policy = policy_peer;
nk->scrub = scrub_peer;
nk->mode = mode;
nk->headroom = headroom;
bpf_mprog_bundle_init(&nk->bundle);
err = register_netdevice(peer);
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 && !tb[IFLA_ADDRESS])
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 = policy_prim;
nk->scrub = scrub_prim;
nk->mode = mode;
nk->headroom = headroom;
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",
link->attach_type,
link->attach_type == 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 = link->attach_type;
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, 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_obj(*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, i;
static const struct {
u32 attr;
char *name;
} fixed_params[] = {
{ IFLA_NETKIT_MODE, "operating mode" },
{ IFLA_NETKIT_SCRUB, "scrubbing" },
{ IFLA_NETKIT_PEER_SCRUB, "peer scrubbing" },
{ IFLA_NETKIT_PEER_INFO, "peer info" },
{ IFLA_NETKIT_HEADROOM, "headroom" },
{ IFLA_NETKIT_TAILROOM, "tailroom" },
};
if (!nk->primary) {
NL_SET_ERR_MSG(extack,
"netkit link settings can be changed only through the primary device");
return -EACCES;
}
for (i = 0; i < ARRAY_SIZE(fixed_params); i++) {
attr = data[fixed_params[i].attr];
if (attr) {
NL_SET_ERR_MSG_ATTR_FMT(extack, attr,
"netkit link %s cannot be changed after device creation",
fixed_params[i].name);
return -EACCES;
}
}
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)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u8)) +
nla_total_size(sizeof(u16)) +
nla_total_size(sizeof(u16)) +
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 (nla_put_u32(skb, IFLA_NETKIT_SCRUB, nk->scrub))
return -EMSGSIZE;
if (nla_put_u16(skb, IFLA_NETKIT_HEADROOM, dev->needed_headroom))
return -EMSGSIZE;
if (nla_put_u16(skb, IFLA_NETKIT_TAILROOM, dev->needed_tailroom))
return -EMSGSIZE;
if (peer) {
nk = netkit_priv(peer);
if (nla_put_u32(skb, IFLA_NETKIT_PEER_POLICY, nk->policy))
return -EMSGSIZE;
if (nla_put_u32(skb, IFLA_NETKIT_PEER_SCRUB, nk->scrub))
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_MODE] = NLA_POLICY_MAX(NLA_U32, NETKIT_L3),
[IFLA_NETKIT_POLICY] = { .type = NLA_U32 },
[IFLA_NETKIT_PEER_POLICY] = { .type = NLA_U32 },
[IFLA_NETKIT_HEADROOM] = { .type = NLA_U16 },
[IFLA_NETKIT_TAILROOM] = { .type = NLA_U16 },
[IFLA_NETKIT_SCRUB] = NLA_POLICY_MAX(NLA_U32, NETKIT_SCRUB_DEFAULT),
[IFLA_NETKIT_PEER_SCRUB] = NLA_POLICY_MAX(NLA_U32, NETKIT_SCRUB_DEFAULT),
[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,
.peer_type = IFLA_NETKIT_PEER_INFO,
.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);
