[linux-2.6-block.git] / net / netfilter / nft_osf.c

#include <net/ip.h>
#include <net/tcp.h>

#include <net/netfilter/nf_tables.h>
#include <linux/netfilter/nfnetlink_osf.h>

struct nft_osf {
	enum nft_registers	dreg:8;
	u8			ttl;
};

static const struct nla_policy nft_osf_policy[NFTA_OSF_MAX + 1] = {
	[NFTA_OSF_DREG]		= { .type = NLA_U32 },
	[NFTA_OSF_TTL]		= { .type = NLA_U8 },
};

static void nft_osf_eval(const struct nft_expr *expr, struct nft_regs *regs,
			 const struct nft_pktinfo *pkt)
{
	struct nft_osf *priv = nft_expr_priv(expr);
	u32 *dest = &regs->data[priv->dreg];
	struct sk_buff *skb = pkt->skb;
	const struct tcphdr *tcp;
	struct tcphdr _tcph;
	const char *os_name;

	tcp = skb_header_pointer(skb, ip_hdrlen(skb),
				 sizeof(struct tcphdr), &_tcph);
	if (!tcp) {
		regs->verdict.code = NFT_BREAK;
		return;
	}
	if (!tcp->syn) {
		regs->verdict.code = NFT_BREAK;
		return;
	}

	os_name = nf_osf_find(skb, nf_osf_fingers, priv->ttl);
	if (!os_name)
		strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN);
	else
		strncpy((char *)dest, os_name, NFT_OSF_MAXGENRELEN);
}

static int nft_osf_init(const struct nft_ctx *ctx,
			const struct nft_expr *expr,
			const struct nlattr * const tb[])
{
	struct nft_osf *priv = nft_expr_priv(expr);
	int err;
	u8 ttl;

	if (tb[NFTA_OSF_TTL]) {
		ttl = nla_get_u8(tb[NFTA_OSF_TTL]);
		if (ttl > 2)
			return -EINVAL;
		priv->ttl = ttl;
	}

	priv->dreg = nft_parse_register(tb[NFTA_OSF_DREG]);
	err = nft_validate_register_store(ctx, priv->dreg, NULL,
					  NFT_DATA_VALUE, NFT_OSF_MAXGENRELEN);
	if (err < 0)
		return err;

	return 0;
}

static int nft_osf_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_osf *priv = nft_expr_priv(expr);

	if (nla_put_u8(skb, NFTA_OSF_TTL, priv->ttl))
		goto nla_put_failure;

	if (nft_dump_register(skb, NFTA_OSF_DREG, priv->dreg))
		goto nla_put_failure;

	return 0;

nla_put_failure:
	return -1;
}

static int nft_osf_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_LOCAL_IN) |
						    (1 << NF_INET_PRE_ROUTING) |
						    (1 << NF_INET_FORWARD));
}

static struct nft_expr_type nft_osf_type;
static const struct nft_expr_ops nft_osf_op = {
	.eval		= nft_osf_eval,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_osf)),
	.init		= nft_osf_init,
	.dump		= nft_osf_dump,
	.type		= &nft_osf_type,
	.validate	= nft_osf_validate,
};

static struct nft_expr_type nft_osf_type __read_mostly = {
	.ops		= &nft_osf_op,
	.name		= "osf",
	.owner		= THIS_MODULE,
	.policy		= nft_osf_policy,
	.maxattr	= NFTA_OSF_MAX,
};

static int __init nft_osf_module_init(void)
{
	return nft_register_expr(&nft_osf_type);
}

static void __exit nft_osf_module_exit(void)
{
	return nft_unregister_expr(&nft_osf_type);
}

module_init(nft_osf_module_init);
module_exit(nft_osf_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");
MODULE_ALIAS_NFT_EXPR("osf");
Commit	Line	Data
b96af92d FFM	1	#include <net/ip.h>
	2	#include <net/tcp.h>
	3
	4	#include <net/netfilter/nf_tables.h>
ddba40be	5	#include <linux/netfilter/nfnetlink_osf.h>
b96af92d	6
b96af92d FFM	7	struct nft_osf {
b96af92d FFM	8	enum nft_registers dreg:8;
a218dc82	9	u8 ttl;
b96af92d FFM	10	};
	11
	12	static const struct nla_policy nft_osf_policy[NFTA_OSF_MAX + 1] = {
	13	[NFTA_OSF_DREG] = { .type = NLA_U32 },
a218dc82	14	[NFTA_OSF_TTL] = { .type = NLA_U8 },
b96af92d FFM	15	};
	16
	17	static void nft_osf_eval(const struct nft_expr expr, struct nft_regs regs,
	18	const struct nft_pktinfo *pkt)
	19	{
	20	struct nft_osf *priv = nft_expr_priv(expr);
	21	u32 *dest = &regs->data[priv->dreg];
	22	struct sk_buff *skb = pkt->skb;
	23	const struct tcphdr *tcp;
	24	struct tcphdr _tcph;
	25	const char *os_name;
	26
	27	tcp = skb_header_pointer(skb, ip_hdrlen(skb),
	28	sizeof(struct tcphdr), &_tcph);
	29	if (!tcp) {
	30	regs->verdict.code = NFT_BREAK;
	31	return;
	32	}
	33	if (!tcp->syn) {
	34	regs->verdict.code = NFT_BREAK;
	35	return;
	36	}
	37
a218dc82	38	os_name = nf_osf_find(skb, nf_osf_fingers, priv->ttl);
b96af92d	39	if (!os_name)
35a8a3bd	40	strncpy((char *)dest, "unknown", NFT_OSF_MAXGENRELEN);
b96af92d	41	else
35a8a3bd	42	strncpy((char *)dest, os_name, NFT_OSF_MAXGENRELEN);
b96af92d FFM	43	}
	44
	45	static int nft_osf_init(const struct nft_ctx *ctx,
	46	const struct nft_expr *expr,
	47	const struct nlattr * const tb[])
	48	{
	49	struct nft_osf *priv = nft_expr_priv(expr);
	50	int err;
a218dc82 FFM	51	u8 ttl;
a218dc82 FFM	52
5e91c9d9	53	if (tb[NFTA_OSF_TTL]) {
a218dc82 FFM	54	ttl = nla_get_u8(tb[NFTA_OSF_TTL]);
	55	if (ttl > 2)
	56	return -EINVAL;
	57	priv->ttl = ttl;
	58	}
b96af92d FFM	59
	60	priv->dreg = nft_parse_register(tb[NFTA_OSF_DREG]);
	61	err = nft_validate_register_store(ctx, priv->dreg, NULL,
bab43449	62	NFT_DATA_VALUE, NFT_OSF_MAXGENRELEN);
b96af92d FFM	63	if (err < 0)
	64	return err;
	65
	66	return 0;
	67	}
	68
	69	static int nft_osf_dump(struct sk_buff skb, const struct nft_expr expr)
	70	{
	71	const struct nft_osf *priv = nft_expr_priv(expr);
	72
a218dc82 FFM	73	if (nla_put_u8(skb, NFTA_OSF_TTL, priv->ttl))
	74	goto nla_put_failure;
	75
b96af92d FFM	76	if (nft_dump_register(skb, NFTA_OSF_DREG, priv->dreg))
	77	goto nla_put_failure;
	78
	79	return 0;
	80
	81	nla_put_failure:
	82	return -1;
	83	}
	84
4a3e71b7 FFM	85	static int nft_osf_validate(const struct nft_ctx *ctx,
	86	const struct nft_expr *expr,
	87	const struct nft_data **data)
	88	{
	89	return nft_chain_validate_hooks(ctx->chain, (1 << NF_INET_LOCAL_IN) \|
	90	(1 << NF_INET_PRE_ROUTING) \|
	91	(1 << NF_INET_FORWARD));
	92	}
	93
b96af92d FFM	94	static struct nft_expr_type nft_osf_type;
	95	static const struct nft_expr_ops nft_osf_op = {
	96	.eval = nft_osf_eval,
	97	.size = NFT_EXPR_SIZE(sizeof(struct nft_osf)),
	98	.init = nft_osf_init,
	99	.dump = nft_osf_dump,
	100	.type = &nft_osf_type,
4a3e71b7	101	.validate = nft_osf_validate,
b96af92d FFM	102	};
	103
	104	static struct nft_expr_type nft_osf_type __read_mostly = {
	105	.ops = &nft_osf_op,
	106	.name = "osf",
	107	.owner = THIS_MODULE,
	108	.policy = nft_osf_policy,
	109	.maxattr = NFTA_OSF_MAX,
	110	};
	111
	112	static int __init nft_osf_module_init(void)
	113	{
	114	return nft_register_expr(&nft_osf_type);
	115	}
	116
	117	static void __exit nft_osf_module_exit(void)
	118	{
	119	return nft_unregister_expr(&nft_osf_type);
	120	}
	121
	122	module_init(nft_osf_module_init);
	123	module_exit(nft_osf_module_exit);
	124
	125	MODULE_LICENSE("GPL");
	126	MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");
	127	MODULE_ALIAS_NFT_EXPR("osf");