| // 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 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; |
| |
| 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; |
| |
| 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 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 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; |
| } |
| 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.flowi4_oif = nft_in(pkt)->ifindex; |
| break; |
| case NFPROTO_IPV6: |
| fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6; |
| fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex; |
| 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)) |
| goto out; |
| break; |
| case IPPROTO_UDP: |
| break; |
| 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) |
| { |
| 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, |
| }; |
| |
| 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"); |