| /* SPDX-License-Identifier: GPL-2.0 */ |
| #include <linux/module.h> |
| #include <linux/netfilter/nf_tables.h> |
| #include <net/netfilter/nf_tables.h> |
| #include <net/netfilter/nf_tables_core.h> |
| #include <net/netfilter/nf_socket.h> |
| #include <net/inet_sock.h> |
| #include <net/tcp.h> |
| |
| struct nft_socket { |
| enum nft_socket_keys key:8; |
| u8 level; |
| u8 len; |
| union { |
| u8 dreg; |
| }; |
| }; |
| |
| static void nft_socket_wildcard(const struct nft_pktinfo *pkt, |
| struct nft_regs *regs, struct sock *sk, |
| u32 *dest) |
| { |
| switch (nft_pf(pkt)) { |
| case NFPROTO_IPV4: |
| nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); |
| break; |
| #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) |
| case NFPROTO_IPV6: |
| nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); |
| break; |
| #endif |
| default: |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| } |
| |
| #ifdef CONFIG_SOCK_CGROUP_DATA |
| static noinline bool |
| nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level) |
| { |
| struct cgroup *cgrp; |
| |
| if (!sk_fullsock(sk)) |
| return false; |
| |
| cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); |
| if (level > cgrp->level) |
| return false; |
| |
| memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64)); |
| |
| return true; |
| } |
| #endif |
| |
| static void nft_socket_eval(const struct nft_expr *expr, |
| struct nft_regs *regs, |
| const struct nft_pktinfo *pkt) |
| { |
| const struct nft_socket *priv = nft_expr_priv(expr); |
| struct sk_buff *skb = pkt->skb; |
| struct sock *sk = skb->sk; |
| u32 *dest = ®s->data[priv->dreg]; |
| |
| if (sk && !net_eq(nft_net(pkt), sock_net(sk))) |
| sk = NULL; |
| |
| if (!sk) |
| switch(nft_pf(pkt)) { |
| case NFPROTO_IPV4: |
| sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt)); |
| break; |
| #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) |
| case NFPROTO_IPV6: |
| sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt)); |
| break; |
| #endif |
| default: |
| WARN_ON_ONCE(1); |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| |
| if (!sk) { |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| |
| switch(priv->key) { |
| case NFT_SOCKET_TRANSPARENT: |
| nft_reg_store8(dest, inet_sk_transparent(sk)); |
| break; |
| case NFT_SOCKET_MARK: |
| if (sk_fullsock(sk)) { |
| *dest = sk->sk_mark; |
| } else { |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| break; |
| case NFT_SOCKET_WILDCARD: |
| if (!sk_fullsock(sk)) { |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| nft_socket_wildcard(pkt, regs, sk, dest); |
| break; |
| #ifdef CONFIG_SOCK_CGROUP_DATA |
| case NFT_SOCKET_CGROUPV2: |
| if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) { |
| regs->verdict.code = NFT_BREAK; |
| return; |
| } |
| break; |
| #endif |
| default: |
| WARN_ON(1); |
| regs->verdict.code = NFT_BREAK; |
| } |
| |
| if (sk != skb->sk) |
| sock_gen_put(sk); |
| } |
| |
| static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { |
| [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, |
| [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, |
| [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, |
| }; |
| |
| static int nft_socket_init(const struct nft_ctx *ctx, |
| const struct nft_expr *expr, |
| const struct nlattr * const tb[]) |
| { |
| struct nft_socket *priv = nft_expr_priv(expr); |
| unsigned int len; |
| |
| if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) |
| return -EINVAL; |
| |
| switch(ctx->family) { |
| case NFPROTO_IPV4: |
| #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) |
| case NFPROTO_IPV6: |
| #endif |
| case NFPROTO_INET: |
| break; |
| default: |
| return -EOPNOTSUPP; |
| } |
| |
| priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); |
| switch(priv->key) { |
| case NFT_SOCKET_TRANSPARENT: |
| case NFT_SOCKET_WILDCARD: |
| len = sizeof(u8); |
| break; |
| case NFT_SOCKET_MARK: |
| len = sizeof(u32); |
| break; |
| #ifdef CONFIG_CGROUPS |
| case NFT_SOCKET_CGROUPV2: { |
| unsigned int level; |
| |
| if (!tb[NFTA_SOCKET_LEVEL]) |
| return -EINVAL; |
| |
| level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL])); |
| if (level > 255) |
| return -EOPNOTSUPP; |
| |
| priv->level = level; |
| len = sizeof(u64); |
| break; |
| } |
| #endif |
| default: |
| return -EOPNOTSUPP; |
| } |
| |
| priv->len = len; |
| return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, |
| NULL, NFT_DATA_VALUE, len); |
| } |
| |
| static int nft_socket_dump(struct sk_buff *skb, |
| const struct nft_expr *expr) |
| { |
| const struct nft_socket *priv = nft_expr_priv(expr); |
| |
| if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) |
| return -1; |
| if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) |
| return -1; |
| if (priv->key == NFT_SOCKET_CGROUPV2 && |
| nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) |
| return -1; |
| return 0; |
| } |
| |
| static bool nft_socket_reduce(struct nft_regs_track *track, |
| const struct nft_expr *expr) |
| { |
| const struct nft_socket *priv = nft_expr_priv(expr); |
| const struct nft_socket *socket; |
| |
| if (!nft_reg_track_cmp(track, expr, priv->dreg)) { |
| nft_reg_track_update(track, expr, priv->dreg, priv->len); |
| return false; |
| } |
| |
| socket = nft_expr_priv(track->regs[priv->dreg].selector); |
| if (priv->key != socket->key || |
| priv->dreg != socket->dreg || |
| priv->level != socket->level) { |
| nft_reg_track_update(track, expr, priv->dreg, priv->len); |
| return false; |
| } |
| |
| if (!track->regs[priv->dreg].bitwise) |
| return true; |
| |
| return nft_expr_reduce_bitwise(track, expr); |
| } |
| |
| static struct nft_expr_type nft_socket_type; |
| static const struct nft_expr_ops nft_socket_ops = { |
| .type = &nft_socket_type, |
| .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), |
| .eval = nft_socket_eval, |
| .init = nft_socket_init, |
| .dump = nft_socket_dump, |
| .reduce = nft_socket_reduce, |
| }; |
| |
| static struct nft_expr_type nft_socket_type __read_mostly = { |
| .name = "socket", |
| .ops = &nft_socket_ops, |
| .policy = nft_socket_policy, |
| .maxattr = NFTA_SOCKET_MAX, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init nft_socket_module_init(void) |
| { |
| return nft_register_expr(&nft_socket_type); |
| } |
| |
| static void __exit nft_socket_module_exit(void) |
| { |
| nft_unregister_expr(&nft_socket_type); |
| } |
| |
| module_init(nft_socket_module_init); |
| module_exit(nft_socket_module_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Máté Eckl"); |
| MODULE_DESCRIPTION("nf_tables socket match module"); |
| MODULE_ALIAS_NFT_EXPR("socket"); |