[linux-block.git] / net / netfilter / nft_socket.c

/* 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;
	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;
}
#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:
		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 = 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_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_CGROUPS
	case NFT_SOCKET_CGROUPV2: {
		unsigned int level;

		if (!tb[NFTA_SOCKET_LEVEL])
			return -EINVAL;

		level = ntohl(nla_get_be32(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_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)))
		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 int nft_socket_validate(const struct nft_ctx *ctx,
			       const struct nft_expr *expr,
			       const struct nft_data **data)
{
	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,
	.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");
Commit	Line	Data
554ced0a ME	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#include <linux/module.h>
	3	#include <linux/netfilter/nf_tables.h>
	4	#include <net/netfilter/nf_tables.h>
	5	#include <net/netfilter/nf_tables_core.h>
	6	#include <net/netfilter/nf_socket.h>
	7	#include <net/inet_sock.h>
8d6e5557	8	#include <net/tcp.h>
554ced0a ME	9
	10	struct nft_socket {
	11	enum nft_socket_keys key:8;
e0bb96db	12	u8 level;
d77a721d	13	u8 len;
554ced0a	14	union {
345023b0	15	u8 dreg;
554ced0a ME	16	};
	17	};
	18
67407a40 BS	19	static void nft_socket_wildcard(const struct nft_pktinfo *pkt,
	20	struct nft_regs regs, struct sock sk,
	21	u32 *dest)
	22	{
	23	switch (nft_pf(pkt)) {
	24	case NFPROTO_IPV4:
	25	nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0);
	26	break;
	27	#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
	28	case NFPROTO_IPV6:
	29	nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr));
	30	break;
	31	#endif
	32	default:
	33	regs->verdict.code = NFT_BREAK;
	34	return;
	35	}
	36	}
	37
7acc0bb4	38	#ifdef CONFIG_SOCK_CGROUP_DATA
e0bb96db	39	static noinline bool
05ae2fba	40	nft_sock_get_eval_cgroupv2(u32 dest, struct sock sk, const struct nft_pktinfo *pkt, u32 level)
e0bb96db	41	{
e0bb96db	42	struct cgroup *cgrp;
7f203bc8	43	u64 cgid;
e0bb96db	44
05ae2fba	45	if (!sk_fullsock(sk))
e0bb96db PNA	46	return false;
e0bb96db PNA	47
7f203bc8 TH	48	cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level);
7f203bc8 TH	49	if (!cgrp)
e0bb96db PNA	50	return false;
e0bb96db PNA	51
7f203bc8 TH	52	cgid = cgroup_id(cgrp);
7f203bc8 TH	53	memcpy(dest, &cgid, sizeof(u64));
e0bb96db PNA	54	return true;
	55	}
	56	#endif
	57
743b83f1 FW	58	static struct sock nft_socket_do_lookup(const struct nft_pktinfo pkt)
	59	{
	60	const struct net_device *indev = nft_in(pkt);
	61	const struct sk_buff *skb = pkt->skb;
	62	struct sock *sk = NULL;
	63
	64	if (!indev)
	65	return NULL;
	66
	67	switch (nft_pf(pkt)) {
	68	case NFPROTO_IPV4:
	69	sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev);
	70	break;
	71	#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
	72	case NFPROTO_IPV6:
	73	sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev);
	74	break;
	75	#endif
	76	default:
	77	WARN_ON_ONCE(1);
	78	break;
	79	}
	80
	81	return sk;
	82	}
	83
554ced0a ME	84	static void nft_socket_eval(const struct nft_expr *expr,
	85	struct nft_regs *regs,
	86	const struct nft_pktinfo *pkt)
	87	{
	88	const struct nft_socket *priv = nft_expr_priv(expr);
	89	struct sk_buff *skb = pkt->skb;
	90	struct sock *sk = skb->sk;
	91	u32 *dest = &regs->data[priv->dreg];
	92
f5646501 FL	93	if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
	94	sk = NULL;
	95
554ced0a	96	if (!sk)
743b83f1	97	sk = nft_socket_do_lookup(pkt);
554ced0a	98
f5646501	99	if (!sk) {
365b5a36	100	regs->verdict.code = NFT_BREAK;
554ced0a ME	101	return;
	102	}
	103
554ced0a ME	104	switch(priv->key) {
554ced0a ME	105	case NFT_SOCKET_TRANSPARENT:
8d6e5557	106	nft_reg_store8(dest, inet_sk_transparent(sk));
554ced0a	107	break;
7d25f885 ME	108	case NFT_SOCKET_MARK:
	109	if (sk_fullsock(sk)) {
	110	*dest = sk->sk_mark;
	111	} else {
	112	regs->verdict.code = NFT_BREAK;
	113	return;
	114	}
	115	break;
67407a40 BS	116	case NFT_SOCKET_WILDCARD:
	117	if (!sk_fullsock(sk)) {
	118	regs->verdict.code = NFT_BREAK;
	119	return;
	120	}
	121	nft_socket_wildcard(pkt, regs, sk, dest);
	122	break;
7acc0bb4	123	#ifdef CONFIG_SOCK_CGROUP_DATA
e0bb96db	124	case NFT_SOCKET_CGROUPV2:
05ae2fba	125	if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) {
e0bb96db PNA	126	regs->verdict.code = NFT_BREAK;
	127	return;
	128	}
	129	break;
	130	#endif
554ced0a ME	131	default:
	132	WARN_ON(1);
	133	regs->verdict.code = NFT_BREAK;
	134	}
039b1f4f FFM	135
	136	if (sk != skb->sk)
	137	sock_gen_put(sk);
554ced0a ME	138	}
	139
	140	static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
	141	[NFTA_SOCKET_KEY] = { .type = NLA_U32 },
	142	[NFTA_SOCKET_DREG] = { .type = NLA_U32 },
e0bb96db	143	[NFTA_SOCKET_LEVEL] = { .type = NLA_U32 },
554ced0a ME	144	};
	145
	146	static int nft_socket_init(const struct nft_ctx *ctx,
	147	const struct nft_expr *expr,
	148	const struct nlattr * const tb[])
	149	{
	150	struct nft_socket *priv = nft_expr_priv(expr);
8a7363f8	151	unsigned int len;
554ced0a ME	152
	153	if (!tb[NFTA_SOCKET_DREG] \|\| !tb[NFTA_SOCKET_KEY])
	154	return -EINVAL;
	155
	156	switch(ctx->family) {
	157	case NFPROTO_IPV4:
5d400a49	158	#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
554ced0a ME	159	case NFPROTO_IPV6:
	160	#endif
	161	case NFPROTO_INET:
	162	break;
	163	default:
	164	return -EOPNOTSUPP;
	165	}
	166
d86473bf	167	priv->key = ntohl(nla_get_be32(tb[NFTA_SOCKET_KEY]));
554ced0a ME	168	switch(priv->key) {
554ced0a ME	169	case NFT_SOCKET_TRANSPARENT:
67407a40	170	case NFT_SOCKET_WILDCARD:
554ced0a ME	171	len = sizeof(u8);
554ced0a ME	172	break;
7d25f885 ME	173	case NFT_SOCKET_MARK:
	174	len = sizeof(u32);
	175	break;
e0bb96db	176	#ifdef CONFIG_CGROUPS
8a7363f8 AB	177	case NFT_SOCKET_CGROUPV2: {
	178	unsigned int level;
	179
e0bb96db PNA	180	if (!tb[NFTA_SOCKET_LEVEL])
	181	return -EINVAL;
	182
d86473bf	183	level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL]));
e0bb96db PNA	184	if (level > 255)
	185	return -EOPNOTSUPP;
	186
	187	priv->level = level;
	188	len = sizeof(u64);
	189	break;
8a7363f8	190	}
e0bb96db	191	#endif
554ced0a ME	192	default:
	193	return -EOPNOTSUPP;
	194	}
	195
d77a721d	196	priv->len = len;
345023b0 PNA	197	return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg,
345023b0 PNA	198	NULL, NFT_DATA_VALUE, len);
554ced0a ME	199	}
	200
	201	static int nft_socket_dump(struct sk_buff *skb,
	202	const struct nft_expr *expr)
	203	{
	204	const struct nft_socket *priv = nft_expr_priv(expr);
	205
d86473bf	206	if (nla_put_be32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
554ced0a ME	207	return -1;
	208	if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
	209	return -1;
e0bb96db	210	if (priv->key == NFT_SOCKET_CGROUPV2 &&
d86473bf	211	nla_put_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level)))
e0bb96db	212	return -1;
554ced0a ME	213	return 0;
	214	}
	215
d77a721d PNA	216	static bool nft_socket_reduce(struct nft_regs_track *track,
	217	const struct nft_expr *expr)
	218	{
	219	const struct nft_socket *priv = nft_expr_priv(expr);
	220	const struct nft_socket *socket;
	221
	222	if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
	223	nft_reg_track_update(track, expr, priv->dreg, priv->len);
	224	return false;
	225	}
	226
	227	socket = nft_expr_priv(track->regs[priv->dreg].selector);
	228	if (priv->key != socket->key \|\|
	229	priv->dreg != socket->dreg \|\|
	230	priv->level != socket->level) {
	231	nft_reg_track_update(track, expr, priv->dreg, priv->len);
	232	return false;
	233	}
	234
	235	if (!track->regs[priv->dreg].bitwise)
	236	return true;
	237
	238	return nft_expr_reduce_bitwise(track, expr);
	239	}
	240
743b83f1 FW	241	static int nft_socket_validate(const struct nft_ctx *ctx,
	242	const struct nft_expr *expr,
	243	const struct nft_data **data)
	244	{
	245	return nft_chain_validate_hooks(ctx->chain,
	246	(1 << NF_INET_PRE_ROUTING) \|
	247	(1 << NF_INET_LOCAL_IN) \|
	248	(1 << NF_INET_LOCAL_OUT));
	249	}
	250
554ced0a ME	251	static struct nft_expr_type nft_socket_type;
	252	static const struct nft_expr_ops nft_socket_ops = {
	253	.type = &nft_socket_type,
	254	.size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
	255	.eval = nft_socket_eval,
	256	.init = nft_socket_init,
	257	.dump = nft_socket_dump,
743b83f1	258	.validate = nft_socket_validate,
d77a721d	259	.reduce = nft_socket_reduce,
554ced0a ME	260	};
	261
	262	static struct nft_expr_type nft_socket_type __read_mostly = {
	263	.name = "socket",
	264	.ops = &nft_socket_ops,
	265	.policy = nft_socket_policy,
	266	.maxattr = NFTA_SOCKET_MAX,
	267	.owner = THIS_MODULE,
	268	};
	269
	270	static int __init nft_socket_module_init(void)
	271	{
	272	return nft_register_expr(&nft_socket_type);
	273	}
	274
	275	static void __exit nft_socket_module_exit(void)
	276	{
	277	nft_unregister_expr(&nft_socket_type);
	278	}
	279
	280	module_init(nft_socket_module_init);
	281	module_exit(nft_socket_module_exit);
	282
	283	MODULE_LICENSE("GPL");
	284	MODULE_AUTHOR("Máté Eckl");
	285	MODULE_DESCRIPTION("nf_tables socket match module");
3fb61eca	286	MODULE_ALIAS_NFT_EXPR("socket");