netfilter: nft_masq: support port range

Complete masquerading support by allowing port range selection.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2016-03-01 19:55:14 +01:00
parent af4610c395
commit 8a6bf5da1a
5 changed files with 58 additions and 13 deletions

View file

@ -2,7 +2,9 @@
#define _NFT_MASQ_H_
struct nft_masq {
u32 flags;
u32 flags;
enum nft_registers sreg_proto_min:8;
enum nft_registers sreg_proto_max:8;
};
extern const struct nla_policy nft_masq_policy[];

View file

@ -951,10 +951,14 @@ enum nft_nat_attributes {
* enum nft_masq_attributes - nf_tables masquerade expression attributes
*
* @NFTA_MASQ_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)
* @NFTA_MASQ_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
* @NFTA_MASQ_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
*/
enum nft_masq_attributes {
NFTA_MASQ_UNSPEC,
NFTA_MASQ_FLAGS,
NFTA_MASQ_REG_PROTO_MIN,
NFTA_MASQ_REG_PROTO_MAX,
__NFTA_MASQ_MAX
};
#define NFTA_MASQ_MAX (__NFTA_MASQ_MAX - 1)

View file

@ -25,7 +25,12 @@ static void nft_masq_ipv4_eval(const struct nft_expr *expr,
memset(&range, 0, sizeof(range));
range.flags = priv->flags;
if (priv->sreg_proto_min) {
range.min_proto.all =
*(__be16 *)&regs->data[priv->sreg_proto_min];
range.max_proto.all =
*(__be16 *)&regs->data[priv->sreg_proto_max];
}
regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, pkt->hook,
&range, pkt->out);
}

View file

@ -26,7 +26,12 @@ static void nft_masq_ipv6_eval(const struct nft_expr *expr,
memset(&range, 0, sizeof(range));
range.flags = priv->flags;
if (priv->sreg_proto_min) {
range.min_proto.all =
*(__be16 *)&regs->data[priv->sreg_proto_min];
range.max_proto.all =
*(__be16 *)&regs->data[priv->sreg_proto_max];
}
regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range, pkt->out);
}

View file

@ -17,7 +17,9 @@
#include <net/netfilter/nft_masq.h>
const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
[NFTA_MASQ_FLAGS] = { .type = NLA_U32 },
[NFTA_MASQ_FLAGS] = { .type = NLA_U32 },
[NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 },
[NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 },
};
EXPORT_SYMBOL_GPL(nft_masq_policy);
@ -40,6 +42,7 @@ int nft_masq_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
u32 plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
struct nft_masq *priv = nft_expr_priv(expr);
int err;
@ -47,12 +50,32 @@ int nft_masq_init(const struct nft_ctx *ctx,
if (err)
return err;
if (tb[NFTA_MASQ_FLAGS] == NULL)
return 0;
if (tb[NFTA_MASQ_FLAGS]) {
priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
if (priv->flags & ~NF_NAT_RANGE_MASK)
return -EINVAL;
}
priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
if (priv->flags & ~NF_NAT_RANGE_MASK)
return -EINVAL;
if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
priv->sreg_proto_min =
nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MIN]);
err = nft_validate_register_load(priv->sreg_proto_min, plen);
if (err < 0)
return err;
if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
priv->sreg_proto_max =
nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MAX]);
err = nft_validate_register_load(priv->sreg_proto_max,
plen);
if (err < 0)
return err;
} else {
priv->sreg_proto_max = priv->sreg_proto_min;
}
}
return 0;
}
@ -62,12 +85,18 @@ int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_masq *priv = nft_expr_priv(expr);
if (priv->flags == 0)
return 0;
if (nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
if (priv->flags != 0 &&
nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
goto nla_put_failure;
if (priv->sreg_proto_min) {
if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
priv->sreg_proto_min) ||
nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX,
priv->sreg_proto_max))
goto nla_put_failure;
}
return 0;
nla_put_failure: