diff options
Diffstat (limited to 'net/netfilter/nft_fwd_netdev.c')
| -rw-r--r-- | net/netfilter/nft_fwd_netdev.c | 146 |
1 files changed, 145 insertions, 1 deletions
diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c index ce13a50b91893..8abb9891cdf22 100644 --- a/net/netfilter/nft_fwd_netdev.c +++ b/net/netfilter/nft_fwd_netdev.c @@ -12,8 +12,12 @@ #include <linux/netlink.h> #include <linux/netfilter.h> #include <linux/netfilter/nf_tables.h> +#include <linux/ip.h> +#include <linux/ipv6.h> #include <net/netfilter/nf_tables.h> #include <net/netfilter/nf_dup_netdev.h> +#include <net/neighbour.h> +#include <net/ip.h> struct nft_fwd_netdev { enum nft_registers sreg_dev:8; @@ -32,6 +36,8 @@ static void nft_fwd_netdev_eval(const struct nft_expr *expr, static const struct nla_policy nft_fwd_netdev_policy[NFTA_FWD_MAX + 1] = { [NFTA_FWD_SREG_DEV] = { .type = NLA_U32 }, + [NFTA_FWD_SREG_ADDR] = { .type = NLA_U32 }, + [NFTA_FWD_NFPROTO] = { .type = NLA_U32 }, }; static int nft_fwd_netdev_init(const struct nft_ctx *ctx, @@ -62,7 +68,133 @@ nla_put_failure: return -1; } +struct nft_fwd_neigh { + enum nft_registers sreg_dev:8; + enum nft_registers sreg_addr:8; + u8 nfproto; +}; + +static void nft_fwd_neigh_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + void *addr = ®s->data[priv->sreg_addr]; + int oif = regs->data[priv->sreg_dev]; + unsigned int verdict = NF_STOLEN; + struct sk_buff *skb = pkt->skb; + struct net_device *dev; + int neigh_table; + + switch (priv->nfproto) { + case NFPROTO_IPV4: { + struct iphdr *iph; + + if (skb->protocol != htons(ETH_P_IP)) { + verdict = NFT_BREAK; + goto out; + } + if (skb_try_make_writable(skb, sizeof(*iph))) { + verdict = NF_DROP; + goto out; + } + iph = ip_hdr(skb); + ip_decrease_ttl(iph); + neigh_table = NEIGH_ARP_TABLE; + break; + } + case NFPROTO_IPV6: { + struct ipv6hdr *ip6h; + + if (skb->protocol != htons(ETH_P_IPV6)) { + verdict = NFT_BREAK; + goto out; + } + if (skb_try_make_writable(skb, sizeof(*ip6h))) { + verdict = NF_DROP; + goto out; + } + ip6h = ipv6_hdr(skb); + ip6h->hop_limit--; + neigh_table = NEIGH_ND_TABLE; + break; + } + default: + verdict = NFT_BREAK; + goto out; + } + + dev = dev_get_by_index_rcu(nft_net(pkt), oif); + if (dev == NULL) + return; + + skb->dev = dev; + neigh_xmit(neigh_table, dev, addr, skb); +out: + regs->verdict.code = verdict; +} + +static int nft_fwd_neigh_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + unsigned int addr_len; + int err; + + if (!tb[NFTA_FWD_SREG_DEV] || + !tb[NFTA_FWD_SREG_ADDR] || + !tb[NFTA_FWD_NFPROTO]) + return -EINVAL; + + priv->sreg_dev = nft_parse_register(tb[NFTA_FWD_SREG_DEV]); + priv->sreg_addr = nft_parse_register(tb[NFTA_FWD_SREG_ADDR]); + priv->nfproto = ntohl(nla_get_be32(tb[NFTA_FWD_NFPROTO])); + + switch (priv->nfproto) { + case NFPROTO_IPV4: + addr_len = sizeof(struct in_addr); + break; + case NFPROTO_IPV6: + addr_len = sizeof(struct in6_addr); + break; + default: + return -EOPNOTSUPP; + } + + err = nft_validate_register_load(priv->sreg_dev, sizeof(int)); + if (err < 0) + return err; + + return nft_validate_register_load(priv->sreg_addr, addr_len); +} + +static const struct nft_expr_ops nft_fwd_netdev_ingress_ops; + +static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + struct nft_fwd_neigh *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_FWD_SREG_DEV, priv->sreg_dev) || + nft_dump_register(skb, NFTA_FWD_SREG_ADDR, priv->sreg_addr) || + nla_put_be32(skb, NFTA_FWD_NFPROTO, htonl(priv->nfproto))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + static struct nft_expr_type nft_fwd_netdev_type; +static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = { + .type = &nft_fwd_netdev_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_neigh)), + .eval = nft_fwd_neigh_eval, + .init = nft_fwd_neigh_init, + .dump = nft_fwd_neigh_dump, +}; + static const struct nft_expr_ops nft_fwd_netdev_ops = { .type = &nft_fwd_netdev_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_fwd_netdev)), @@ -71,10 +203,22 @@ static const struct nft_expr_ops nft_fwd_netdev_ops = { .dump = nft_fwd_netdev_dump, }; +static const struct nft_expr_ops * +nft_fwd_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_FWD_SREG_ADDR]) + return &nft_fwd_neigh_netdev_ops; + if (tb[NFTA_FWD_SREG_DEV]) + return &nft_fwd_netdev_ops; + + return ERR_PTR(-EOPNOTSUPP); +} + static struct nft_expr_type nft_fwd_netdev_type __read_mostly = { .family = NFPROTO_NETDEV, .name = "fwd", - .ops = &nft_fwd_netdev_ops, + .select_ops = nft_fwd_select_ops, .policy = nft_fwd_netdev_policy, .maxattr = NFTA_FWD_MAX, .owner = THIS_MODULE, |