// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> * * Development of this code funded by Astaro AG (http://www.astaro.com/) */ #include <linux/kernel.h>#include <linux/init.h>#include <linux/module.h>#include <linux/netlink.h>#include <linux/netfilter.h>#include <linux/if_arp.h>#include <linux/netfilter/nf_tables.h>#include <net/netfilter/nf_tables_core.h>#include <net/netfilter/nf_tables_offload.h>#include <net/netfilter/nf_tables.h> struct nft_cmp_expr {	struct nft_data		data;	u8			sreg;	u8			len;	enum nft_cmp_ops	op:8;}; void nft_cmp_eval(const struct nft_expr *expr,		  struct nft_regs *regs,		  const struct nft_pktinfo *pkt){	const struct nft_cmp_expr *priv = nft_expr_priv(expr);	int d; 	d = memcmp(&regs->data[priv->sreg], &priv->data, priv->len);	switch (priv->op) {	case NFT_CMP_EQ:		if (d != 0)			goto mismatch;		break;	case NFT_CMP_NEQ:		if (d == 0)			goto mismatch;		break;	case NFT_CMP_LT:		if (d == 0)			goto mismatch;		fallthrough;	case NFT_CMP_LTE:		if (d > 0)			goto mismatch;		break;	case NFT_CMP_GT:		if (d == 0)			goto mismatch;		fallthrough;	case NFT_CMP_GTE:		if (d < 0)			goto mismatch;		break;	}	return; mismatch:	regs->verdict.code = NFT_BREAK;} static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {	[NFTA_CMP_SREG]		= NLA_POLICY_MAX(NLA_BE32, NFT_REG32_MAX),	[NFTA_CMP_OP]		= { .type = NLA_U32 },	[NFTA_CMP_DATA]		= { .type = NLA_NESTED },}; static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,			const struct nlattr * const tb[]){	struct nft_cmp_expr *priv = nft_expr_priv(expr);	struct nft_data_desc desc = {		.type	= NFT_DATA_VALUE,		.size	= sizeof(priv->data),	};	int err; 	err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);	if (err < 0)		return err; 	err = nft_parse_register_load(ctx, tb[NFTA_CMP_SREG], &priv->sreg, desc.len);	if (err < 0)		return err; 	priv->op  = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));	priv->len = desc.len;	return 0;} static int nft_cmp_dump(struct sk_buff *skb,			const struct nft_expr *expr, bool reset){	const struct nft_cmp_expr *priv = nft_expr_priv(expr); 	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))		goto nla_put_failure;	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))		goto nla_put_failure; 	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,			  NFT_DATA_VALUE, priv->len) < 0)		goto nla_put_failure;	return 0; nla_put_failure:	return -1;} union nft_cmp_offload_data {	u16	val16;	u32	val32;	u64	val64;}; static void nft_payload_n2h(union nft_cmp_offload_data *data,			    const u8 *val, u32 len){	switch (len) {	case 2:		data->val16 = ntohs(*((__be16 *)val));		break;	case 4:		data->val32 = ntohl(*((__be32 *)val));		break;	case 8:		data->val64 = be64_to_cpu(*((__be64 *)val));		break;	default:		WARN_ON_ONCE(1);		break;	}} static int __nft_cmp_offload(struct nft_offload_ctx *ctx,			     struct nft_flow_rule *flow,			     const struct nft_cmp_expr *priv){	struct nft_offload_reg *reg = &ctx->regs[priv->sreg];	union nft_cmp_offload_data _data, _datamask;	u8 *mask = (u8 *)&flow->match.mask;	u8 *key = (u8 *)&flow->match.key;	u8 *data, *datamask; 	if (priv->op != NFT_CMP_EQ || priv->len > reg->len)		return -EOPNOTSUPP; 	if (reg->flags & NFT_OFFLOAD_F_NETWORK2HOST) {		nft_payload_n2h(&_data, (u8 *)&priv->data, reg->len);		nft_payload_n2h(&_datamask, (u8 *)&reg->mask, reg->len);		data = (u8 *)&_data;		datamask = (u8 *)&_datamask;	} else {		data = (u8 *)&priv->data;		datamask = (u8 *)&reg->mask;	} 	memcpy(key + reg->offset, data, reg->len);	memcpy(mask + reg->offset, datamask, reg->len); 	flow->match.dissector.used_keys |= BIT_ULL(reg->key);	flow->match.dissector.offset[reg->key] = reg->base_offset; 	if (reg->key == FLOW_DISSECTOR_KEY_META &&	    reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&	    nft_reg_load16(priv->data.data) != ARPHRD_ETHER)		return -EOPNOTSUPP; 	nft_offload_update_dependency(ctx, &priv->data, reg->len); 	return 0;} static int nft_cmp_offload(struct nft_offload_ctx *ctx,			   struct nft_flow_rule *flow,			   const struct nft_expr *expr){	const struct nft_cmp_expr *priv = nft_expr_priv(expr); 	return __nft_cmp_offload(ctx, flow, priv);} static const struct nft_expr_ops nft_cmp_ops = {	.type		= &nft_cmp_type,	.size		= NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),	.eval		= nft_cmp_eval,	.init		= nft_cmp_init,	.dump		= nft_cmp_dump,	.offload	= nft_cmp_offload,}; /* Calculate the mask for the nft_cmp_fast expression. On big endian the * mask needs to include the *upper* bytes when interpreting that data as * something smaller than the full u32, therefore a cpu_to_le32 is done. */static u32 nft_cmp_fast_mask(unsigned int len){	__le32 mask = cpu_to_le32(~0U >> (sizeof_field(struct nft_cmp_fast_expr,					  data) * BITS_PER_BYTE - len)); 	return (__force u32)mask;} static int nft_cmp_fast_init(const struct nft_ctx *ctx,			     const struct nft_expr *expr,			     const struct nlattr * const tb[]){	struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);	struct nft_data data;	struct nft_data_desc desc = {		.type	= NFT_DATA_VALUE,		.size	= sizeof(data),	};	int err; 	err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);	if (err < 0)		return err; 	err = nft_parse_register_load(ctx, tb[NFTA_CMP_SREG], &priv->sreg, desc.len);	if (err < 0)		return err; 	desc.len *= BITS_PER_BYTE; 	priv->mask = nft_cmp_fast_mask(desc.len);	priv->data = data.data[0] & priv->mask;	priv->len  = desc.len;	priv->inv  = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;	return 0;} static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,				struct nft_flow_rule *flow,				const struct nft_expr *expr){	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);	struct nft_cmp_expr cmp = {		.data	= {			.data	= {				[0] = priv->data,			},		},		.sreg	= priv->sreg,		.len	= priv->len / BITS_PER_BYTE,		.op	= priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,	}; 	return __nft_cmp_offload(ctx, flow, &cmp);} static int nft_cmp_fast_dump(struct sk_buff *skb,			     const struct nft_expr *expr, bool reset){	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);	enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;	struct nft_data data; 	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))		goto nla_put_failure;	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))		goto nla_put_failure; 	data.data[0] = priv->data;	if (nft_data_dump(skb, NFTA_CMP_DATA, &data,			  NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)		goto nla_put_failure;	return 0; nla_put_failure:	return -1;} const struct nft_expr_ops nft_cmp_fast_ops = {	.type		= &nft_cmp_type,	.size		= NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),	.eval		= NULL,	/* inlined */	.init		= nft_cmp_fast_init,	.dump		= nft_cmp_fast_dump,	.offload	= nft_cmp_fast_offload,}; static u32 nft_cmp_mask(u32 bitlen){	return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen));} static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen){	int len = bitlen / BITS_PER_BYTE;	int i, words = len / sizeof(u32); 	for (i = 0; i < words; i++) {		data->data[i] = 0xffffffff;		bitlen -= sizeof(u32) * BITS_PER_BYTE;	} 	if (len % sizeof(u32))		data->data[i++] = nft_cmp_mask(bitlen); 	for (; i < 4; i++)		data->data[i] = 0;} static int nft_cmp16_fast_init(const struct nft_ctx *ctx,			       const struct nft_expr *expr,			       const struct nlattr * const tb[]){	struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);	struct nft_data_desc desc = {		.type	= NFT_DATA_VALUE,		.size	= sizeof(priv->data),	};	int err; 	err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);	if (err < 0)		return err; 	err = nft_parse_register_load(ctx, tb[NFTA_CMP_SREG], &priv->sreg, desc.len);	if (err < 0)		return err; 	nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE);	priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;	priv->len = desc.len; 	return 0;} static int nft_cmp16_fast_offload(struct nft_offload_ctx *ctx,				  struct nft_flow_rule *flow,				  const struct nft_expr *expr){	const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);	struct nft_cmp_expr cmp = {		.data	= priv->data,		.sreg	= priv->sreg,		.len	= priv->len,		.op	= priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,	}; 	return __nft_cmp_offload(ctx, flow, &cmp);} static int nft_cmp16_fast_dump(struct sk_buff *skb,			       const struct nft_expr *expr, bool reset){	const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr);	enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; 	if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))		goto nla_put_failure;	if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))		goto nla_put_failure; 	if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,			  NFT_DATA_VALUE, priv->len) < 0)		goto nla_put_failure;	return 0; nla_put_failure:	return -1;}  const struct nft_expr_ops nft_cmp16_fast_ops = {	.type		= &nft_cmp_type,	.size		= NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)),	.eval		= NULL,	/* inlined */	.init		= nft_cmp16_fast_init,	.dump		= nft_cmp16_fast_dump,	.offload	= nft_cmp16_fast_offload,}; static const struct nft_expr_ops *nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]){	struct nft_data data;	struct nft_data_desc desc = {		.type	= NFT_DATA_VALUE,		.size	= sizeof(data),	};	enum nft_cmp_ops op;	u8 sreg;	int err; 	if (tb[NFTA_CMP_SREG] == NULL ||	    tb[NFTA_CMP_OP] == NULL ||	    tb[NFTA_CMP_DATA] == NULL)		return ERR_PTR(-EINVAL); 	op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));	switch (op) {	case NFT_CMP_EQ:	case NFT_CMP_NEQ:	case NFT_CMP_LT:	case NFT_CMP_LTE:	case NFT_CMP_GT:	case NFT_CMP_GTE:		break;	default:		return ERR_PTR(-EINVAL);	} 	err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);	if (err < 0)		return ERR_PTR(err); 	sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); 	if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) {		if (desc.len <= sizeof(u32))			return &nft_cmp_fast_ops;		else if (desc.len <= sizeof(data) &&			 ((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) ||			  (sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0)))			return &nft_cmp16_fast_ops;	}	return &nft_cmp_ops;} struct nft_expr_type nft_cmp_type __read_mostly = {	.name		= "cmp",	.select_ops	= nft_cmp_select_ops,	.policy		= nft_cmp_policy,	.maxattr	= NFTA_CMP_MAX,	.owner		= THIS_MODULE,};