blob: e860d8fe0e5e2fd8fe1684032a06cee1ac63c9c6 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/nf_tables.h>
#include <net/ip.h> /* for ipv4 options. */
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_flow_table.h>
struct nft_flow_offload {
struct nft_flowtable *flowtable;
};
static enum flow_offload_xmit_type nft_xmit_type(struct dst_entry *dst)
{
if (dst_xfrm(dst))
return FLOW_OFFLOAD_XMIT_XFRM;
return FLOW_OFFLOAD_XMIT_NEIGH;
}
static void nft_default_forward_path(struct nf_flow_route *route,
struct dst_entry *dst_cache,
enum ip_conntrack_dir dir)
{
route->tuple[!dir].in.ifindex = dst_cache->dev->ifindex;
route->tuple[dir].dst = dst_cache;
route->tuple[dir].xmit_type = nft_xmit_type(dst_cache);
}
static bool nft_is_valid_ether_device(const struct net_device *dev)
{
if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
return false;
return true;
}
static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
const struct dst_entry *dst_cache,
const struct nf_conn *ct,
enum ip_conntrack_dir dir, u8 *ha,
struct net_device_path_stack *stack)
{
const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
struct net_device *dev = dst_cache->dev;
struct neighbour *n;
u8 nud_state;
if (!nft_is_valid_ether_device(dev))
goto out;
n = dst_neigh_lookup(dst_cache, daddr);
if (!n)
return -1;
read_lock_bh(&n->lock);
nud_state = n->nud_state;
ether_addr_copy(ha, n->ha);
read_unlock_bh(&n->lock);
neigh_release(n);
if (!(nud_state & NUD_VALID))
return -1;
out:
return dev_fill_forward_path(dev, ha, stack);
}
struct nft_forward_info {
const struct net_device *indev;
const struct net_device *outdev;
const struct net_device *hw_outdev;
struct id {
__u16 id;
__be16 proto;
} encap[NF_FLOW_TABLE_ENCAP_MAX];
u8 num_encaps;
u8 ingress_vlans;
u8 h_source[ETH_ALEN];
u8 h_dest[ETH_ALEN];
enum flow_offload_xmit_type xmit_type;
};
static void nft_dev_path_info(const struct net_device_path_stack *stack,
struct nft_forward_info *info,
unsigned char *ha, struct nf_flowtable *flowtable)
{
const struct net_device_path *path;
int i;
memcpy(info->h_dest, ha, ETH_ALEN);
for (i = 0; i < stack->num_paths; i++) {
path = &stack->path[i];
switch (path->type) {
case DEV_PATH_ETHERNET:
case DEV_PATH_DSA:
case DEV_PATH_VLAN:
case DEV_PATH_PPPOE:
info->indev = path->dev;
if (is_zero_ether_addr(info->h_source))
memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
if (path->type == DEV_PATH_ETHERNET)
break;
if (path->type == DEV_PATH_DSA) {
i = stack->num_paths;
break;
}
/* DEV_PATH_VLAN and DEV_PATH_PPPOE */
if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
info->indev = NULL;
break;
}
if (!info->outdev)
info->outdev = path->dev;
info->encap[info->num_encaps].id = path->encap.id;
info->encap[info->num_encaps].proto = path->encap.proto;
info->num_encaps++;
if (path->type == DEV_PATH_PPPOE)
memcpy(info->h_dest, path->encap.h_dest, ETH_ALEN);
break;
case DEV_PATH_BRIDGE:
if (is_zero_ether_addr(info->h_source))
memcpy(info->h_source, path->dev->dev_addr, ETH_ALEN);
switch (path->bridge.vlan_mode) {
case DEV_PATH_BR_VLAN_UNTAG_HW:
info->ingress_vlans |= BIT(info->num_encaps - 1);
break;
case DEV_PATH_BR_VLAN_TAG:
info->encap[info->num_encaps].id = path->bridge.vlan_id;
info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
info->num_encaps++;
break;
case DEV_PATH_BR_VLAN_UNTAG:
info->num_encaps--;
break;
case DEV_PATH_BR_VLAN_KEEP:
break;
}
info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
break;
default:
info->indev = NULL;
break;
}
}
if (!info->outdev)
info->outdev = info->indev;
info->hw_outdev = info->indev;
if (nf_flowtable_hw_offload(flowtable) &&
nft_is_valid_ether_device(info->indev))
info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
}
static bool nft_flowtable_find_dev(const struct net_device *dev,
struct nft_flowtable *ft)
{
struct nft_hook *hook;
bool found = false;
list_for_each_entry_rcu(hook, &ft->hook_list, list) {
if (hook->ops.dev != dev)
continue;
found = true;
break;
}
return found;
}
static void nft_dev_forward_path(struct nf_flow_route *route,
const struct nf_conn *ct,
enum ip_conntrack_dir dir,
struct nft_flowtable *ft)
{
const struct dst_entry *dst = route->tuple[dir].dst;
struct net_device_path_stack stack;
struct nft_forward_info info = {};
unsigned char ha[ETH_ALEN];
int i;
if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
nft_dev_path_info(&stack, &info, ha, &ft->data);
if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
return;
route->tuple[!dir].in.ifindex = info.indev->ifindex;
for (i = 0; i < info.num_encaps; i++) {
route->tuple[!dir].in.encap[i].id = info.encap[i].id;
route->tuple[!dir].in.encap[i].proto = info.encap[i].proto;
}
route->tuple[!dir].in.num_encaps = info.num_encaps;
route->tuple[!dir].in.ingress_vlans = info.ingress_vlans;
if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
memcpy(route->tuple[dir].out.h_source, info.h_source, ETH_ALEN);
memcpy(route->tuple[dir].out.h_dest, info.h_dest, ETH_ALEN);
route->tuple[dir].out.ifindex = info.outdev->ifindex;
route->tuple[dir].out.hw_ifindex = info.hw_outdev->ifindex;
route->tuple[dir].xmit_type = info.xmit_type;
}
}
static int nft_flow_route(const struct nft_pktinfo *pkt,
const struct nf_conn *ct,
struct nf_flow_route *route,
enum ip_conntrack_dir dir,
struct nft_flowtable *ft)
{
struct dst_entry *this_dst = skb_dst(pkt->skb);
struct dst_entry *other_dst = NULL;
struct flowi fl;
memset(&fl, 0, sizeof(fl));
switch (nft_pf(pkt)) {
case NFPROTO_IPV4:
fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
fl.u.ip4.saddr = ct->tuplehash[!dir].tuple.src.u3.ip;
fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
fl.u.ip4.flowi4_iif = this_dst->dev->ifindex;
fl.u.ip4.flowi4_tos = RT_TOS(ip_hdr(pkt->skb)->tos);
fl.u.ip4.flowi4_mark = pkt->skb->mark;
fl.u.ip4.flowi4_flags = FLOWI_FLAG_ANYSRC;
break;
case NFPROTO_IPV6:
fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
fl.u.ip6.saddr = ct->tuplehash[!dir].tuple.src.u3.in6;
fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
fl.u.ip6.flowi6_iif = this_dst->dev->ifindex;
fl.u.ip6.flowlabel = ip6_flowinfo(ipv6_hdr(pkt->skb));
fl.u.ip6.flowi6_mark = pkt->skb->mark;
fl.u.ip6.flowi6_flags = FLOWI_FLAG_ANYSRC;
break;
}
nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
if (!other_dst)
return -ENOENT;
nft_default_forward_path(route, this_dst, dir);
nft_default_forward_path(route, other_dst, !dir);
if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH &&
route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) {
nft_dev_forward_path(route, ct, dir, ft);
nft_dev_forward_path(route, ct, !dir, ft);
}
return 0;
}
static bool nft_flow_offload_skip(struct sk_buff *skb, int family)
{
if (skb_sec_path(skb))
return true;
if (family == NFPROTO_IPV4) {
const struct ip_options *opt;
opt = &(IPCB(skb)->opt);
if (unlikely(opt->optlen))
return true;
}
return false;
}
static void nft_flow_offload_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_flow_offload *priv = nft_expr_priv(expr);
struct nf_flowtable *flowtable = &priv->flowtable->data;
struct tcphdr _tcph, *tcph = NULL;
struct nf_flow_route route = {};
enum ip_conntrack_info ctinfo;
struct flow_offload *flow;
enum ip_conntrack_dir dir;
struct nf_conn *ct;
int ret;
if (nft_flow_offload_skip(pkt->skb, nft_pf(pkt)))
goto out;
ct = nf_ct_get(pkt->skb, &ctinfo);
if (!ct)
goto out;
switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
case IPPROTO_TCP:
tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt),
sizeof(_tcph), &_tcph);
if (unlikely(!tcph || tcph->fin || tcph->rst ||
!nf_conntrack_tcp_established(ct)))
goto out;
break;
case IPPROTO_UDP:
break;
#ifdef CONFIG_NF_CT_PROTO_GRE
case IPPROTO_GRE: {
struct nf_conntrack_tuple *tuple;
if (ct->status & IPS_NAT_MASK)
goto out;
tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
/* No support for GRE v1 */
if (tuple->src.u.gre.key || tuple->dst.u.gre.key)
goto out;
break;
}
#endif
default:
goto out;
}
if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
ct->status & (IPS_SEQ_ADJUST | IPS_NAT_CLASH))
goto out;
if (!nf_ct_is_confirmed(ct))
goto out;
if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
goto out;
dir = CTINFO2DIR(ctinfo);
if (nft_flow_route(pkt, ct, &route, dir, priv->flowtable) < 0)
goto err_flow_route;
flow = flow_offload_alloc(ct);
if (!flow)
goto err_flow_alloc;
if (flow_offload_route_init(flow, &route) < 0)
goto err_flow_add;
if (tcph) {
ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
}
ret = flow_offload_add(flowtable, flow);
if (ret < 0)
goto err_flow_add;
dst_release(route.tuple[!dir].dst);
return;
err_flow_add:
flow_offload_free(flow);
err_flow_alloc:
dst_release(route.tuple[!dir].dst);
err_flow_route:
clear_bit(IPS_OFFLOAD_BIT, &ct->status);
out:
regs->verdict.code = NFT_BREAK;
}
static int nft_flow_offload_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
unsigned int hook_mask = (1 << NF_INET_FORWARD);
return nft_chain_validate_hooks(ctx->chain, hook_mask);
}
static const struct nla_policy nft_flow_offload_policy[NFTA_FLOW_MAX + 1] = {
[NFTA_FLOW_TABLE_NAME] = { .type = NLA_STRING,
.len = NFT_NAME_MAXLEN - 1 },
};
static int nft_flow_offload_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_flow_offload *priv = nft_expr_priv(expr);
u8 genmask = nft_genmask_next(ctx->net);
struct nft_flowtable *flowtable;
if (!tb[NFTA_FLOW_TABLE_NAME])
return -EINVAL;
flowtable = nft_flowtable_lookup(ctx->table, tb[NFTA_FLOW_TABLE_NAME],
genmask);
if (IS_ERR(flowtable))
return PTR_ERR(flowtable);
priv->flowtable = flowtable;
flowtable->use++;
return nf_ct_netns_get(ctx->net, ctx->family);
}
static void nft_flow_offload_deactivate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
enum nft_trans_phase phase)
{
struct nft_flow_offload *priv = nft_expr_priv(expr);
nf_tables_deactivate_flowtable(ctx, priv->flowtable, phase);
}
static void nft_flow_offload_activate(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
struct nft_flow_offload *priv = nft_expr_priv(expr);
priv->flowtable->use++;
}
static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
nf_ct_netns_put(ctx->net, ctx->family);
}
static int nft_flow_offload_dump(struct sk_buff *skb,
const struct nft_expr *expr, bool reset)
{
struct nft_flow_offload *priv = nft_expr_priv(expr);
if (nla_put_string(skb, NFTA_FLOW_TABLE_NAME, priv->flowtable->name))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_flow_offload_type;
static const struct nft_expr_ops nft_flow_offload_ops = {
.type = &nft_flow_offload_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_flow_offload)),
.eval = nft_flow_offload_eval,
.init = nft_flow_offload_init,
.activate = nft_flow_offload_activate,
.deactivate = nft_flow_offload_deactivate,
.destroy = nft_flow_offload_destroy,
.validate = nft_flow_offload_validate,
.dump = nft_flow_offload_dump,
.reduce = NFT_REDUCE_READONLY,
};
static struct nft_expr_type nft_flow_offload_type __read_mostly = {
.name = "flow_offload",
.ops = &nft_flow_offload_ops,
.policy = nft_flow_offload_policy,
.maxattr = NFTA_FLOW_MAX,
.owner = THIS_MODULE,
};
static int flow_offload_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (event != NETDEV_DOWN)
return NOTIFY_DONE;
nf_flow_table_cleanup(dev);
return NOTIFY_DONE;
}
static struct notifier_block flow_offload_netdev_notifier = {
.notifier_call = flow_offload_netdev_event,
};
static int __init nft_flow_offload_module_init(void)
{
int err;
err = register_netdevice_notifier(&flow_offload_netdev_notifier);
if (err)
goto err;
err = nft_register_expr(&nft_flow_offload_type);
if (err < 0)
goto register_expr;
return 0;
register_expr:
unregister_netdevice_notifier(&flow_offload_netdev_notifier);
err:
return err;
}
static void __exit nft_flow_offload_module_exit(void)
{
nft_unregister_expr(&nft_flow_offload_type);
unregister_netdevice_notifier(&flow_offload_netdev_notifier);
}
module_init(nft_flow_offload_module_init);
module_exit(nft_flow_offload_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_ALIAS_NFT_EXPR("flow_offload");
MODULE_DESCRIPTION("nftables hardware flow offload module");