/* 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;		/* cgroupv2 level to extract */	u8				level_user;	/* cgroupv2 level provided by userspace */	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_DATAstatic noinline boolnft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level){	struct cgroup *cgrp;	u64 cgid; 	if (!sk_fullsock(sk))		return false; 	cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level);	if (!cgrp)		return false; 	cgid = cgroup_id(cgrp);	memcpy(dest, &cgid, sizeof(u64));	return true;} /* process context only, uses current->nsproxy. */static noinline int nft_socket_cgroup_subtree_level(void){	struct cgroup *cgrp = cgroup_get_from_path("/");	int level; 	if (IS_ERR(cgrp))		return PTR_ERR(cgrp); 	level = cgrp->level; 	cgroup_put(cgrp); 	if (level > 255)		return -ERANGE; 	if (unlikely(level < 0)) {		DEBUG_NET_WARN_ON_ONCE(1);		return -EINVAL;	} 	return level;}#endif static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt){	const struct net_device *indev = nft_in(pkt);	const struct sk_buff *skb = pkt->skb;	struct sock *sk = NULL; 	if (!indev)		return NULL; 	switch (nft_pf(pkt)) {	case NFPROTO_IPV4:		sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev);		break;#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)	case NFPROTO_IPV6:		sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev);		break;#endif	default:		DEBUG_NET_WARN_ON_ONCE(1);		break;	} 	return sk;} 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 = &regs->data[priv->dreg]; 	if (sk && !net_eq(nft_net(pkt), sock_net(sk)))		sk = NULL; 	if (!sk)		sk = nft_socket_do_lookup(pkt); 	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 = READ_ONCE(sk->sk_mark);		} else {			regs->verdict.code = NFT_BREAK;			goto out_put_sk;		}		break;	case NFT_SOCKET_WILDCARD:		if (!sk_fullsock(sk)) {			regs->verdict.code = NFT_BREAK;			goto out_put_sk;		}		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;			goto out_put_sk;		}		break;#endif	default:		DEBUG_NET_WARN_ON_ONCE(1);		regs->verdict.code = NFT_BREAK;	} out_put_sk:	if (sk != skb->sk)		sock_gen_put(sk);} static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {	[NFTA_SOCKET_KEY]		= NLA_POLICY_MAX(NLA_BE32, 255),	[NFTA_SOCKET_DREG]		= NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),	[NFTA_SOCKET_LEVEL]		= NLA_POLICY_MAX(NLA_BE32, 255),}; 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_be32(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_SOCK_CGROUP_DATA	case NFT_SOCKET_CGROUPV2: {		unsigned int level;		int err; 		if (!tb[NFTA_SOCKET_LEVEL])			return -EINVAL; 		level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL]));		if (level > 255)			return -EOPNOTSUPP; 		err = nft_socket_cgroup_subtree_level();		if (err < 0)			return err; 		priv->level_user = level; 		level += err;		/* Implies a giant cgroup tree */		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, bool reset){	const struct nft_socket *priv = nft_expr_priv(expr); 	if (nla_put_be32(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_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level_user)))		return -1;	return 0;} static int nft_socket_validate(const struct nft_ctx *ctx,			       const struct nft_expr *expr){	if (ctx->family != NFPROTO_IPV4 &&	    ctx->family != NFPROTO_IPV6 &&	    ctx->family != NFPROTO_INET)		return -EOPNOTSUPP; 	return nft_chain_validate_hooks(ctx->chain,					(1 << NF_INET_PRE_ROUTING) |					(1 << NF_INET_LOCAL_IN) |					(1 << NF_INET_LOCAL_OUT));} 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,	.validate	= nft_socket_validate,}; 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");