alistair23-linux/net/netfilter/nft_meta.c
wenxu 0fb4d21956 netfilter: nft_meta: Add NFT_META_I/OIFKIND meta type
In the ip_rcv the skb goes through the PREROUTING hook first, then kicks
in vrf device and go through the same hook again. When conntrack dnat
works with vrf, there will be some conflict with rules because the
packet goes through the hook twice with different nf status.

ip link add user1 type vrf table 1
ip link add user2 type vrf table 2
ip l set dev tun1 master user1
ip l set dev tun2 master user2

nft add table firewall
nft add chain firewall zones { type filter hook prerouting  priority - 300 \; }
nft add rule firewall zones counter ct zone set iif map { "tun1" : 1, "tun2" : 2 }
nft add chain firewall rule-1000-ingress
nft add rule firewall rule-1000-ingress ct zone 1 tcp dport 22 ct state new counter accept
nft add rule firewall rule-1000-ingress counter drop
nft add chain firewall rule-1000-egress
nft add rule firewall rule-1000-egress tcp dport 22 ct state new counter drop
nft add rule firewall rule-1000-egress counter accept

nft add chain firewall rules-all { type filter hook prerouting priority - 150 \; }
nft add rule firewall rules-all ip daddr vmap { "2.2.2.11" : jump rule-1000-ingress }
nft add rule firewall rules-all ct zone vmap { 1 : jump rule-1000-egress }

nft add rule firewall dnat-all ct zone vmap { 1 : jump dnat-1000 }
nft add rule firewall dnat-1000 ip daddr 2.2.2.11 counter dnat to 10.0.0.7

For a package with ip daddr 2.2.2.11 and tcp dport 22, first time accept in the
rule-1000-ingress and dnat to 10.0.0.7. Then second time the packet goto the wrong
chain rule-1000-egress which leads the packet drop

With this patch, userspace can add the 'don't re-do entire ruleset for
vrf' policy itself via:

nft add rule firewall rules-all meta iifkind "vrf" counter accept

Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18 15:58:20 +01:00

674 lines
15 KiB
C

/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
* Copyright (c) 2014 Intel Corporation
* Author: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#include <linux/kernel.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/smp.h>
#include <linux/static_key.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/tcp_states.h> /* for TCP_TIME_WAIT */
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */
struct nft_meta {
enum nft_meta_keys key:8;
union {
enum nft_registers dreg:8;
enum nft_registers sreg:8;
};
};
static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);
#ifdef CONFIG_NF_TABLES_BRIDGE
#include "../bridge/br_private.h"
#endif
void nft_meta_get_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_meta *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;
const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
struct sock *sk;
u32 *dest = &regs->data[priv->dreg];
#ifdef CONFIG_NF_TABLES_BRIDGE
const struct net_bridge_port *p;
#endif
switch (priv->key) {
case NFT_META_LEN:
*dest = skb->len;
break;
case NFT_META_PROTOCOL:
nft_reg_store16(dest, (__force u16)skb->protocol);
break;
case NFT_META_NFPROTO:
nft_reg_store8(dest, nft_pf(pkt));
break;
case NFT_META_L4PROTO:
if (!pkt->tprot_set)
goto err;
nft_reg_store8(dest, pkt->tprot);
break;
case NFT_META_PRIORITY:
*dest = skb->priority;
break;
case NFT_META_MARK:
*dest = skb->mark;
break;
case NFT_META_IIF:
if (in == NULL)
goto err;
*dest = in->ifindex;
break;
case NFT_META_OIF:
if (out == NULL)
goto err;
*dest = out->ifindex;
break;
case NFT_META_IIFNAME:
if (in == NULL)
goto err;
strncpy((char *)dest, in->name, IFNAMSIZ);
break;
case NFT_META_OIFNAME:
if (out == NULL)
goto err;
strncpy((char *)dest, out->name, IFNAMSIZ);
break;
case NFT_META_IIFTYPE:
if (in == NULL)
goto err;
nft_reg_store16(dest, in->type);
break;
case NFT_META_OIFTYPE:
if (out == NULL)
goto err;
nft_reg_store16(dest, out->type);
break;
case NFT_META_SKUID:
sk = skb_to_full_sk(skb);
if (!sk || !sk_fullsock(sk) ||
!net_eq(nft_net(pkt), sock_net(sk)))
goto err;
read_lock_bh(&sk->sk_callback_lock);
if (sk->sk_socket == NULL ||
sk->sk_socket->file == NULL) {
read_unlock_bh(&sk->sk_callback_lock);
goto err;
}
*dest = from_kuid_munged(&init_user_ns,
sk->sk_socket->file->f_cred->fsuid);
read_unlock_bh(&sk->sk_callback_lock);
break;
case NFT_META_SKGID:
sk = skb_to_full_sk(skb);
if (!sk || !sk_fullsock(sk) ||
!net_eq(nft_net(pkt), sock_net(sk)))
goto err;
read_lock_bh(&sk->sk_callback_lock);
if (sk->sk_socket == NULL ||
sk->sk_socket->file == NULL) {
read_unlock_bh(&sk->sk_callback_lock);
goto err;
}
*dest = from_kgid_munged(&init_user_ns,
sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&sk->sk_callback_lock);
break;
#ifdef CONFIG_IP_ROUTE_CLASSID
case NFT_META_RTCLASSID: {
const struct dst_entry *dst = skb_dst(skb);
if (dst == NULL)
goto err;
*dest = dst->tclassid;
break;
}
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
*dest = skb->secmark;
break;
#endif
case NFT_META_PKTTYPE:
if (skb->pkt_type != PACKET_LOOPBACK) {
nft_reg_store8(dest, skb->pkt_type);
break;
}
switch (nft_pf(pkt)) {
case NFPROTO_IPV4:
if (ipv4_is_multicast(ip_hdr(skb)->daddr))
nft_reg_store8(dest, PACKET_MULTICAST);
else
nft_reg_store8(dest, PACKET_BROADCAST);
break;
case NFPROTO_IPV6:
nft_reg_store8(dest, PACKET_MULTICAST);
break;
case NFPROTO_NETDEV:
switch (skb->protocol) {
case htons(ETH_P_IP): {
int noff = skb_network_offset(skb);
struct iphdr *iph, _iph;
iph = skb_header_pointer(skb, noff,
sizeof(_iph), &_iph);
if (!iph)
goto err;
if (ipv4_is_multicast(iph->daddr))
nft_reg_store8(dest, PACKET_MULTICAST);
else
nft_reg_store8(dest, PACKET_BROADCAST);
break;
}
case htons(ETH_P_IPV6):
nft_reg_store8(dest, PACKET_MULTICAST);
break;
default:
WARN_ON_ONCE(1);
goto err;
}
break;
default:
WARN_ON_ONCE(1);
goto err;
}
break;
case NFT_META_CPU:
*dest = raw_smp_processor_id();
break;
case NFT_META_IIFGROUP:
if (in == NULL)
goto err;
*dest = in->group;
break;
case NFT_META_OIFGROUP:
if (out == NULL)
goto err;
*dest = out->group;
break;
#ifdef CONFIG_CGROUP_NET_CLASSID
case NFT_META_CGROUP:
sk = skb_to_full_sk(skb);
if (!sk || !sk_fullsock(sk) ||
!net_eq(nft_net(pkt), sock_net(sk)))
goto err;
*dest = sock_cgroup_classid(&sk->sk_cgrp_data);
break;
#endif
case NFT_META_PRANDOM: {
struct rnd_state *state = this_cpu_ptr(&nft_prandom_state);
*dest = prandom_u32_state(state);
break;
}
#ifdef CONFIG_XFRM
case NFT_META_SECPATH:
nft_reg_store8(dest, secpath_exists(skb));
break;
#endif
#ifdef CONFIG_NF_TABLES_BRIDGE
case NFT_META_BRI_IIFNAME:
if (in == NULL || (p = br_port_get_rcu(in)) == NULL)
goto err;
strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
return;
case NFT_META_BRI_OIFNAME:
if (out == NULL || (p = br_port_get_rcu(out)) == NULL)
goto err;
strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
return;
#endif
case NFT_META_IIFKIND:
if (in == NULL || in->rtnl_link_ops == NULL)
goto err;
strncpy((char *)dest, in->rtnl_link_ops->kind, IFNAMSIZ);
break;
case NFT_META_OIFKIND:
if (out == NULL || out->rtnl_link_ops == NULL)
goto err;
strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ);
break;
default:
WARN_ON(1);
goto err;
}
return;
err:
regs->verdict.code = NFT_BREAK;
}
static void nft_meta_set_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_meta *meta = nft_expr_priv(expr);
struct sk_buff *skb = pkt->skb;
u32 *sreg = &regs->data[meta->sreg];
u32 value = *sreg;
u8 value8;
switch (meta->key) {
case NFT_META_MARK:
skb->mark = value;
break;
case NFT_META_PRIORITY:
skb->priority = value;
break;
case NFT_META_PKTTYPE:
value8 = nft_reg_load8(sreg);
if (skb->pkt_type != value8 &&
skb_pkt_type_ok(value8) &&
skb_pkt_type_ok(skb->pkt_type))
skb->pkt_type = value8;
break;
case NFT_META_NFTRACE:
value8 = nft_reg_load8(sreg);
skb->nf_trace = !!value8;
break;
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
skb->secmark = value;
break;
#endif
default:
WARN_ON(1);
}
}
static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
[NFTA_META_DREG] = { .type = NLA_U32 },
[NFTA_META_KEY] = { .type = NLA_U32 },
[NFTA_META_SREG] = { .type = NLA_U32 },
};
static int nft_meta_get_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_meta *priv = nft_expr_priv(expr);
unsigned int len;
priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
switch (priv->key) {
case NFT_META_PROTOCOL:
case NFT_META_IIFTYPE:
case NFT_META_OIFTYPE:
len = sizeof(u16);
break;
case NFT_META_NFPROTO:
case NFT_META_L4PROTO:
case NFT_META_LEN:
case NFT_META_PRIORITY:
case NFT_META_MARK:
case NFT_META_IIF:
case NFT_META_OIF:
case NFT_META_SKUID:
case NFT_META_SKGID:
#ifdef CONFIG_IP_ROUTE_CLASSID
case NFT_META_RTCLASSID:
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
#endif
case NFT_META_PKTTYPE:
case NFT_META_CPU:
case NFT_META_IIFGROUP:
case NFT_META_OIFGROUP:
#ifdef CONFIG_CGROUP_NET_CLASSID
case NFT_META_CGROUP:
#endif
len = sizeof(u32);
break;
case NFT_META_IIFNAME:
case NFT_META_OIFNAME:
case NFT_META_IIFKIND:
case NFT_META_OIFKIND:
len = IFNAMSIZ;
break;
case NFT_META_PRANDOM:
prandom_init_once(&nft_prandom_state);
len = sizeof(u32);
break;
#ifdef CONFIG_XFRM
case NFT_META_SECPATH:
len = sizeof(u8);
break;
#endif
#ifdef CONFIG_NF_TABLES_BRIDGE
case NFT_META_BRI_IIFNAME:
case NFT_META_BRI_OIFNAME:
if (ctx->family != NFPROTO_BRIDGE)
return -EOPNOTSUPP;
len = IFNAMSIZ;
break;
#endif
default:
return -EOPNOTSUPP;
}
priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
return nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, len);
}
static int nft_meta_get_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
#ifdef CONFIG_XFRM
const struct nft_meta *priv = nft_expr_priv(expr);
unsigned int hooks;
if (priv->key != NFT_META_SECPATH)
return 0;
switch (ctx->family) {
case NFPROTO_NETDEV:
hooks = 1 << NF_NETDEV_INGRESS;
break;
case NFPROTO_IPV4:
case NFPROTO_IPV6:
case NFPROTO_INET:
hooks = (1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_LOCAL_IN) |
(1 << NF_INET_FORWARD);
break;
default:
return -EOPNOTSUPP;
}
return nft_chain_validate_hooks(ctx->chain, hooks);
#else
return 0;
#endif
}
static int nft_meta_set_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct nft_meta *priv = nft_expr_priv(expr);
unsigned int hooks;
if (priv->key != NFT_META_PKTTYPE)
return 0;
switch (ctx->family) {
case NFPROTO_BRIDGE:
hooks = 1 << NF_BR_PRE_ROUTING;
break;
case NFPROTO_NETDEV:
hooks = 1 << NF_NETDEV_INGRESS;
break;
case NFPROTO_IPV4:
case NFPROTO_IPV6:
case NFPROTO_INET:
hooks = 1 << NF_INET_PRE_ROUTING;
break;
default:
return -EOPNOTSUPP;
}
return nft_chain_validate_hooks(ctx->chain, hooks);
}
static int nft_meta_set_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_meta *priv = nft_expr_priv(expr);
unsigned int len;
int err;
priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
switch (priv->key) {
case NFT_META_MARK:
case NFT_META_PRIORITY:
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
#endif
len = sizeof(u32);
break;
case NFT_META_NFTRACE:
len = sizeof(u8);
break;
case NFT_META_PKTTYPE:
len = sizeof(u8);
break;
default:
return -EOPNOTSUPP;
}
priv->sreg = nft_parse_register(tb[NFTA_META_SREG]);
err = nft_validate_register_load(priv->sreg, len);
if (err < 0)
return err;
if (priv->key == NFT_META_NFTRACE)
static_branch_inc(&nft_trace_enabled);
return 0;
}
static int nft_meta_get_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
goto nla_put_failure;
if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
goto nla_put_failure;
if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static void nft_meta_set_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (priv->key == NFT_META_NFTRACE)
static_branch_dec(&nft_trace_enabled);
}
static const struct nft_expr_ops nft_meta_get_ops = {
.type = &nft_meta_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
.eval = nft_meta_get_eval,
.init = nft_meta_get_init,
.dump = nft_meta_get_dump,
.validate = nft_meta_get_validate,
};
static const struct nft_expr_ops nft_meta_set_ops = {
.type = &nft_meta_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
.eval = nft_meta_set_eval,
.init = nft_meta_set_init,
.destroy = nft_meta_set_destroy,
.dump = nft_meta_set_dump,
.validate = nft_meta_set_validate,
};
static const struct nft_expr_ops *
nft_meta_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
if (tb[NFTA_META_KEY] == NULL)
return ERR_PTR(-EINVAL);
if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
return ERR_PTR(-EINVAL);
if (tb[NFTA_META_DREG])
return &nft_meta_get_ops;
if (tb[NFTA_META_SREG])
return &nft_meta_set_ops;
return ERR_PTR(-EINVAL);
}
struct nft_expr_type nft_meta_type __read_mostly = {
.name = "meta",
.select_ops = nft_meta_select_ops,
.policy = nft_meta_policy,
.maxattr = NFTA_META_MAX,
.owner = THIS_MODULE,
};
#ifdef CONFIG_NETWORK_SECMARK
struct nft_secmark {
u32 secid;
char *ctx;
};
static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
[NFTA_SECMARK_CTX] = { .type = NLA_STRING, .len = NFT_SECMARK_CTX_MAXLEN },
};
static int nft_secmark_compute_secid(struct nft_secmark *priv)
{
u32 tmp_secid = 0;
int err;
err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
if (err)
return err;
if (!tmp_secid)
return -ENOENT;
err = security_secmark_relabel_packet(tmp_secid);
if (err)
return err;
priv->secid = tmp_secid;
return 0;
}
static void nft_secmark_obj_eval(struct nft_object *obj, struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_secmark *priv = nft_obj_data(obj);
struct sk_buff *skb = pkt->skb;
skb->secmark = priv->secid;
}
static int nft_secmark_obj_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[],
struct nft_object *obj)
{
struct nft_secmark *priv = nft_obj_data(obj);
int err;
if (tb[NFTA_SECMARK_CTX] == NULL)
return -EINVAL;
priv->ctx = nla_strdup(tb[NFTA_SECMARK_CTX], GFP_KERNEL);
if (!priv->ctx)
return -ENOMEM;
err = nft_secmark_compute_secid(priv);
if (err) {
kfree(priv->ctx);
return err;
}
security_secmark_refcount_inc();
return 0;
}
static int nft_secmark_obj_dump(struct sk_buff *skb, struct nft_object *obj,
bool reset)
{
struct nft_secmark *priv = nft_obj_data(obj);
int err;
if (nla_put_string(skb, NFTA_SECMARK_CTX, priv->ctx))
return -1;
if (reset) {
err = nft_secmark_compute_secid(priv);
if (err)
return err;
}
return 0;
}
static void nft_secmark_obj_destroy(const struct nft_ctx *ctx, struct nft_object *obj)
{
struct nft_secmark *priv = nft_obj_data(obj);
security_secmark_refcount_dec();
kfree(priv->ctx);
}
static const struct nft_object_ops nft_secmark_obj_ops = {
.type = &nft_secmark_obj_type,
.size = sizeof(struct nft_secmark),
.init = nft_secmark_obj_init,
.eval = nft_secmark_obj_eval,
.dump = nft_secmark_obj_dump,
.destroy = nft_secmark_obj_destroy,
};
struct nft_object_type nft_secmark_obj_type __read_mostly = {
.type = NFT_OBJECT_SECMARK,
.ops = &nft_secmark_obj_ops,
.maxattr = NFTA_SECMARK_MAX,
.policy = nft_secmark_policy,
.owner = THIS_MODULE,
};
#endif /* CONFIG_NETWORK_SECMARK */