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netfilter: nf_tables: add compatibility layer for x_tables

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This patch adds the x_tables compatibility layer. This allows you
to use existing x_tables matches and targets from nf_tables.

This compatibility later allows us to use existing matches/targets
for features that are still missing in nf_tables. We can progressively
replace them with native nf_tables extensions. It also provides the
userspace compatibility software that allows you to express the
rule-set using the iptables syntax but using the nf_tables kernel
components.

In order to get this compatibility layer working, I've done the
following things:

* add NFNL_SUBSYS_NFT_COMPAT: this new nfnetlink subsystem is used
to query the x_tables match/target revision, so we don't need to
use the native x_table getsockopt interface.

* emulate xt structures: this required extending the struct nft_pktinfo
to include the fragment offset, which is already obtained from
ip[6]_tables and that is used by some matches/targets.

* add support for default policy to base chains, required to emulate
  x_tables.

* add NFTA_CHAIN_USE attribute to obtain the number of references to
  chains, required by x_tables emulation.

* add chain packet/byte counters using per-cpu.

* support 32-64 bits compat.

For historical reasons, this patch includes the following patches
that were posted in the netfilter-devel mailing list.

From Pablo Neira Ayuso:
* nf_tables: add default policy to base chains
* netfilter: nf_tables: add NFTA_CHAIN_USE attribute
* nf_tables: nft_compat: private data of target and matches in contiguous area
* nf_tables: validate hooks for compat match/target
* nf_tables: nft_compat: release cached matches/targets
* nf_tables: x_tables support as a compile time option
* nf_tables: fix alias for xtables over nftables module
* nf_tables: add packet and byte counters per chain
* nf_tables: fix per-chain counter stats if no counters are passed
* nf_tables: don't bump chain stats
* nf_tables: add protocol and flags for xtables over nf_tables
* nf_tables: add ip[6]t_entry emulation
* nf_tables: move specific layer 3 compat code to nf_tables_ipv[4|6]
* nf_tables: support 32bits-64bits x_tables compat
* nf_tables: fix compilation if CONFIG_COMPAT is disabled

From Patrick McHardy:
* nf_tables: move policy to struct nft_base_chain
* nf_tables: send notifications for base chain policy changes

From Alexander Primak:
* nf_tables: remove the duplicate NF_INET_LOCAL_OUT

From Nicolas Dichtel:
* nf_tables: fix compilation when nf-netlink is a module

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2013-10-14 00:06:06 +02:00
parent 9370761c56
commit 0ca743a559
20 changed files with 1241 additions and 78 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

44
include/net/netfilter/nf_tables.h
View file

@ -3,6 +3,7 @@
#include <linux/list.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netlink.h>
@ -15,8 +16,23 @@ struct nft_pktinfo {
u8 hooknum;
u8 nhoff;
u8 thoff;
/* for x_tables compatibility */
struct xt_action_param xt;
};
static inline void nft_set_pktinfo(struct nft_pktinfo *pkt,
const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out)
{
pkt->skb = skb;
pkt->in = pkt->xt.in = in;
pkt->out = pkt->xt.out = out;
pkt->hooknum = pkt->xt.hooknum = ops->hooknum;
pkt->xt.family = ops->pf;
}
struct nft_data {
union {
u32 data[4];
@ -57,6 +73,7 @@ static inline void nft_data_debug(const struct nft_data *data)
* @afi: address family info
* @table: the table the chain is contained in
* @chain: the chain the rule is contained in
* @nla: netlink attributes
*/
struct nft_ctx {
const struct sk_buff *skb;
@ -64,6 +81,7 @@ struct nft_ctx {
const struct nft_af_info *afi;
const struct nft_table *table;
const struct nft_chain *chain;
const struct nlattr * const *nla;
};
struct nft_data_desc {
@ -235,7 +253,8 @@ extern void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
* @maxattr: highest netlink attribute number
*/
struct nft_expr_type {
const struct nft_expr_ops *(*select_ops)(const struct nlattr * const tb[]);
const struct nft_expr_ops *(*select_ops)(const struct nft_ctx *,
const struct nlattr * const tb[]);
const struct nft_expr_ops *ops;
struct list_head list;
const char *name;
@ -253,6 +272,8 @@ struct nft_expr_type {
* @destroy: destruction function
* @dump: function to dump parameters
* @type: expression type
* @validate: validate expression, called during loop detection
* @data: extra data to attach to this expression operation
*/
struct nft_expr;
struct nft_expr_ops {
@ -267,8 +288,11 @@ struct nft_expr_ops {
void (*destroy)(const struct nft_expr *expr);
int (*dump)(struct sk_buff *skb,
const struct nft_expr *expr);
const struct nft_data * (*get_verdict)(const struct nft_expr *expr);
int (*validate)(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data);
const struct nft_expr_type *type;
void *data;
};
#define NFT_EXPR_MAXATTR 16
@ -368,16 +392,25 @@ enum nft_chain_type {
NFT_CHAIN_T_MAX
};
struct nft_stats {
u64 bytes;
u64 pkts;
};
/**
* struct nft_base_chain - nf_tables base chain
*
* @ops: netfilter hook ops
* @type: chain type
* @policy: default policy
* @stats: per-cpu chain stats
* @chain: the chain
*/
struct nft_base_chain {
struct nf_hook_ops ops;
enum nft_chain_type type;
u8 policy;
struct nft_stats __percpu *stats;
struct nft_chain chain;
};
@ -386,11 +419,8 @@ static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chai
return container_of(chain, struct nft_base_chain, chain);
}
extern unsigned int nft_do_chain(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *));
extern unsigned int nft_do_chain_pktinfo(struct nft_pktinfo *pkt,
const struct nf_hook_ops *ops);
/**
* struct nft_table - nf_tables table

23
include/net/netfilter/nf_tables_ipv4.h Normal file
View file

@ -0,0 +1,23 @@
#ifndef _NF_TABLES_IPV4_H_
#define _NF_TABLES_IPV4_H_
#include <net/netfilter/nf_tables.h>
#include <net/ip.h>
static inline void
nft_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out)
{
struct iphdr *ip;
nft_set_pktinfo(pkt, ops, skb, in, out);
pkt->xt.thoff = ip_hdrlen(pkt->skb);
ip = ip_hdr(pkt->skb);
pkt->xt.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
}
#endif

30
include/net/netfilter/nf_tables_ipv6.h Normal file
View file

@ -0,0 +1,30 @@
#ifndef _NF_TABLES_IPV6_H_
#define _NF_TABLES_IPV6_H_
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/ipv6.h>
static inline int
nft_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out)
{
int protohdr, thoff = 0;
unsigned short frag_off;
nft_set_pktinfo(pkt, ops, skb, in, out);
protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL);
/* If malformed, drop it */
if (protohdr < 0)
return -1;
pkt->xt.thoff = thoff;
pkt->xt.fragoff = frag_off;
return 0;
}
#endif

1
include/uapi/linux/netfilter/Kbuild
View file

@ -6,6 +6,7 @@ header-y += nf_conntrack_sctp.h
header-y += nf_conntrack_tcp.h
header-y += nf_conntrack_tuple_common.h
header-y += nf_tables.h
header-y += nf_tables_compat.h
header-y += nf_nat.h
header-y += nfnetlink.h
header-y += nfnetlink_acct.h

32
include/uapi/linux/netfilter/nf_tables.h
View file

@ -115,7 +115,10 @@ enum nft_table_attributes {
* @NFTA_CHAIN_HANDLE: numeric handle of the chain (NLA_U64)
* @NFTA_CHAIN_NAME: name of the chain (NLA_STRING)
* @NFTA_CHAIN_HOOK: hook specification for basechains (NLA_NESTED: nft_hook_attributes)
* @NFTA_CHAIN_POLICY: numeric policy of the chain (NLA_U32)
* @NFTA_CHAIN_USE: number of references to this chain (NLA_U32)
* @NFTA_CHAIN_TYPE: type name of the string (NLA_NUL_STRING)
* @NFTA_CHAIN_COUNTERS: counter specification of the chain (NLA_NESTED: nft_counter_attributes)
*/
enum nft_chain_attributes {
NFTA_CHAIN_UNSPEC,
@ -123,7 +126,10 @@ enum nft_chain_attributes {
NFTA_CHAIN_HANDLE,
NFTA_CHAIN_NAME,
NFTA_CHAIN_HOOK,
NFTA_CHAIN_POLICY,
NFTA_CHAIN_USE,
NFTA_CHAIN_TYPE,
NFTA_CHAIN_COUNTERS,
__NFTA_CHAIN_MAX
};
#define NFTA_CHAIN_MAX (__NFTA_CHAIN_MAX - 1)
@ -135,6 +141,7 @@ enum nft_chain_attributes {
* @NFTA_RULE_CHAIN: name of the chain containing the rule (NLA_STRING)
* @NFTA_RULE_HANDLE: numeric handle of the rule (NLA_U64)
* @NFTA_RULE_EXPRESSIONS: list of expressions (NLA_NESTED: nft_expr_attributes)
* @NFTA_RULE_COMPAT: compatibility specifications of the rule (NLA_NESTED: nft_rule_compat_attributes)
*/
enum nft_rule_attributes {
NFTA_RULE_UNSPEC,
@ -142,10 +149,35 @@ enum nft_rule_attributes {
NFTA_RULE_CHAIN,
NFTA_RULE_HANDLE,
NFTA_RULE_EXPRESSIONS,
NFTA_RULE_COMPAT,
__NFTA_RULE_MAX
};
#define NFTA_RULE_MAX (__NFTA_RULE_MAX - 1)
/**
* enum nft_rule_compat_flags - nf_tables rule compat flags
*
* @NFT_RULE_COMPAT_F_INV: invert the check result
*/
enum nft_rule_compat_flags {
NFT_RULE_COMPAT_F_INV = (1 << 1),
NFT_RULE_COMPAT_F_MASK = NFT_RULE_COMPAT_F_INV,
};
/**
* enum nft_rule_compat_attributes - nf_tables rule compat attributes
*
* @NFTA_RULE_COMPAT_PROTO: numerice value of handled protocol (NLA_U32)
* @NFTA_RULE_COMPAT_FLAGS: bitmask of enum nft_rule_compat_flags (NLA_U32)
*/
enum nft_rule_compat_attributes {
NFTA_RULE_COMPAT_UNSPEC,
NFTA_RULE_COMPAT_PROTO,
NFTA_RULE_COMPAT_FLAGS,
__NFTA_RULE_COMPAT_MAX
};
#define NFTA_RULE_COMPAT_MAX (__NFTA_RULE_COMPAT_MAX - 1)
/**
* enum nft_set_flags - nf_tables set flags
*

38
include/uapi/linux/netfilter/nf_tables_compat.h Normal file
View file

@ -0,0 +1,38 @@
#ifndef _NFT_COMPAT_NFNETLINK_H_
#define _NFT_COMPAT_NFNETLINK_H_
enum nft_target_attributes {
NFTA_TARGET_UNSPEC,
NFTA_TARGET_NAME,
NFTA_TARGET_REV,
NFTA_TARGET_INFO,
__NFTA_TARGET_MAX
};
#define NFTA_TARGET_MAX (__NFTA_TARGET_MAX - 1)
enum nft_match_attributes {
NFTA_MATCH_UNSPEC,
NFTA_MATCH_NAME,
NFTA_MATCH_REV,
NFTA_MATCH_INFO,
__NFTA_MATCH_MAX
};
#define NFTA_MATCH_MAX (__NFTA_MATCH_MAX - 1)
#define NFT_COMPAT_NAME_MAX 32
enum {
NFNL_MSG_COMPAT_GET,
NFNL_MSG_COMPAT_MAX
};
enum {
NFTA_COMPAT_UNSPEC = 0,
NFTA_COMPAT_NAME,
NFTA_COMPAT_REV,
NFTA_COMPAT_TYPE,
__NFTA_COMPAT_MAX,
};
#define NFTA_COMPAT_MAX (__NFTA_COMPAT_MAX - 1)
#endif

3
include/uapi/linux/netfilter/nfnetlink.h
View file

@ -54,6 +54,7 @@ struct nfgenmsg {
#define NFNL_SUBSYS_CTNETLINK_TIMEOUT 8
#define NFNL_SUBSYS_CTHELPER 9
#define NFNL_SUBSYS_NFTABLES 10
#define NFNL_SUBSYS_COUNT 11
#define NFNL_SUBSYS_NFT_COMPAT 11
#define NFNL_SUBSYS_COUNT 12
#endif /* _UAPI_NFNETLINK_H */

32
net/ipv4/netfilter/nf_tables_ipv4.c
View file

@ -15,6 +15,8 @@
#include <linux/netfilter_ipv4.h>
#include <net/netfilter/nf_tables.h>
#include <net/ip.h>
#include <net/net_namespace.h>
#include <net/netfilter/nf_tables_ipv4.h>
static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
struct sk_buff *skb,
@ -22,6 +24,8 @@ static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct nft_pktinfo pkt;
if (unlikely(skb->len < sizeof(struct iphdr) ||
ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
if (net_ratelimit())
@ -29,8 +33,9 @@ static unsigned int nft_ipv4_output(const struct nf_hook_ops *ops,
"packet\n");
return NF_ACCEPT;
}
nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
return nft_do_chain(ops, skb, in, out, okfn);
return nft_do_chain_pktinfo(&pkt, ops);
}
static struct nft_af_info nft_af_ipv4 __read_mostly = {
@ -42,6 +47,21 @@ static struct nft_af_info nft_af_ipv4 __read_mostly = {
},
};
static unsigned int
nft_do_chain_ipv4(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct nft_pktinfo pkt;
nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
return nft_do_chain_pktinfo(&pkt, ops);
}
static struct nf_chain_type filter_ipv4 = {
.family = NFPROTO_IPV4,
.name = "filter",
@ -52,11 +72,11 @@ static struct nf_chain_type filter_ipv4 = {
(1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_POST_ROUTING),
.fn = {
[NF_INET_LOCAL_IN] = nft_do_chain,
[NF_INET_LOCAL_OUT] = nft_do_chain,
[NF_INET_FORWARD] = nft_do_chain,
[NF_INET_PRE_ROUTING] = nft_do_chain,
[NF_INET_POST_ROUTING] = nft_do_chain,
[NF_INET_LOCAL_IN] = nft_do_chain_ipv4,
[NF_INET_LOCAL_OUT] = nft_ipv4_output,
[NF_INET_FORWARD] = nft_do_chain_ipv4,
[NF_INET_PRE_ROUTING] = nft_do_chain_ipv4,
[NF_INET_POST_ROUTING] = nft_do_chain_ipv4,
},
};

6
net/ipv4/netfilter/nft_chain_nat_ipv4.c
View file

@ -23,6 +23,7 @@
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_ipv4.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/ip.h>
@ -181,6 +182,7 @@ static unsigned int nf_nat_fn(const struct nf_hook_ops *ops,
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
struct nf_conn_nat *nat;
enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum);
struct nft_pktinfo pkt;
unsigned int ret;
if (ct == NULL || nf_ct_is_untracked(ct))
@ -213,7 +215,9 @@ static unsigned int nf_nat_fn(const struct nf_hook_ops *ops,
if (nf_nat_initialized(ct, maniptype))
break;
ret = nft_do_chain(ops, skb, in, out, okfn);
nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
ret = nft_do_chain_pktinfo(&pkt, ops);
if (ret != NF_ACCEPT)
return ret;
if (!nf_nat_initialized(ct, maniptype)) {

6
net/ipv4/netfilter/nft_chain_route_ipv4.c
View file

@ -17,6 +17,7 @@
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_ipv4.h>
#include <net/route.h>
#include <net/ip.h>
@ -27,6 +28,7 @@ static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops,
int (*okfn)(struct sk_buff *))
{
unsigned int ret;
struct nft_pktinfo pkt;
u32 mark;
__be32 saddr, daddr;
u_int8_t tos;
@ -37,13 +39,15 @@ static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops,
ip_hdrlen(skb) < sizeof(struct iphdr))
return NF_ACCEPT;
nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out);
mark = skb->mark;
iph = ip_hdr(skb);
saddr = iph->saddr;
daddr = iph->daddr;
tos = iph->tos;
ret = nft_do_chain(ops, skb, in, out, okfn);
ret = nft_do_chain_pktinfo(&pkt, ops);
if (ret != NF_DROP && ret != NF_QUEUE) {
iph = ip_hdr(skb);

33
net/ipv6/netfilter/nf_tables_ipv6.c
View file

@ -14,6 +14,7 @@
#include <linux/ipv6.h>
#include <linux/netfilter_ipv6.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_ipv6.h>
static unsigned int nft_ipv6_output(const struct nf_hook_ops *ops,
struct sk_buff *skb,
@ -21,14 +22,18 @@ static unsigned int nft_ipv6_output(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct nft_pktinfo pkt;
if (unlikely(skb->len < sizeof(struct ipv6hdr))) {
if (net_ratelimit())
pr_info("nf_tables_ipv6: ignoring short SOCK_RAW "
"packet\n");
return NF_ACCEPT;
}
if (nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out) < 0)
return NF_DROP;
return nft_do_chain(ops, skb, in, out, okfn);
return nft_do_chain_pktinfo(&pkt, ops);
}
static struct nft_af_info nft_af_ipv6 __read_mostly = {
@ -40,6 +45,22 @@ static struct nft_af_info nft_af_ipv6 __read_mostly = {
},
};
static unsigned int
nft_do_chain_ipv6(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct nft_pktinfo pkt;
/* malformed packet, drop it */
if (nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out) < 0)
return NF_DROP;
return nft_do_chain_pktinfo(&pkt, ops);
}
static struct nf_chain_type filter_ipv6 = {
.family = NFPROTO_IPV6,
.name = "filter",
@ -50,11 +71,11 @@ static struct nf_chain_type filter_ipv6 = {
(1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_POST_ROUTING),
.fn = {
[NF_INET_LOCAL_IN] = nft_do_chain,
[NF_INET_LOCAL_OUT] = nft_do_chain,
[NF_INET_FORWARD] = nft_do_chain,
[NF_INET_PRE_ROUTING] = nft_do_chain,
[NF_INET_POST_ROUTING] = nft_do_chain,
[NF_INET_LOCAL_IN] = nft_do_chain_ipv6,
[NF_INET_LOCAL_OUT] = nft_ipv6_output,
[NF_INET_FORWARD] = nft_do_chain_ipv6,
[NF_INET_PRE_ROUTING] = nft_do_chain_ipv6,
[NF_INET_POST_ROUTING] = nft_do_chain_ipv6,
},
};

8
net/ipv6/netfilter/nft_chain_route_ipv6.c
View file

@ -19,6 +19,7 @@
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_ipv6.h>
#include <net/route.h>
static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops,
@ -28,10 +29,15 @@ static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops,
int (*okfn)(struct sk_buff *))
{
unsigned int ret;
struct nft_pktinfo pkt;
struct in6_addr saddr, daddr;
u_int8_t hop_limit;
u32 mark, flowlabel;
/* malformed packet, drop it */
if (nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out) < 0)
return NF_DROP;
/* save source/dest address, mark, hoplimit, flowlabel, priority */
memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr));
memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr));
@ -41,7 +47,7 @@ static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops,
/* flowlabel and prio (includes version, which shouldn't change either */
flowlabel = *((u32 *)ipv6_hdr(skb));
ret = nft_do_chain(ops, skb, in, out, okfn);
ret = nft_do_chain_pktinfo(&pkt, ops);
if (ret != NF_DROP && ret != NF_QUEUE &&
(memcmp(&ipv6_hdr(skb)->saddr, &saddr, sizeof(saddr)) ||
memcmp(&ipv6_hdr(skb)->daddr, &daddr, sizeof(daddr)) ||

9
net/netfilter/Kconfig
View file

@ -450,6 +450,15 @@ config NFT_LIMIT
depends on NF_TABLES
tristate "Netfilter nf_tables limit module"
config NFT_COMPAT
depends on NF_TABLES
depends on NETFILTER_XTABLES
tristate "Netfilter x_tables over nf_tables module"
help
This is required if you intend to use any of existing
x_tables match/target extensions over the nf_tables
framework.
config NETFILTER_XTABLES
tristate "Netfilter Xtables support (required for ip_tables)"
default m if NETFILTER_ADVANCED=n

1
net/netfilter/Makefile
View file

@ -70,6 +70,7 @@ nf_tables-objs += nft_immediate.o nft_cmp.o nft_lookup.o
nf_tables-objs += nft_bitwise.o nft_byteorder.o nft_payload.o
obj-$(CONFIG_NF_TABLES) += nf_tables.o
obj-$(CONFIG_NFT_COMPAT) += nft_compat.o
obj-$(CONFIG_NFT_EXTHDR) += nft_exthdr.o
obj-$(CONFIG_NFT_META) += nft_meta.o
obj-$(CONFIG_NFT_CT) += nft_ct.o

220
net/netfilter/nf_tables_api.c
View file

@ -438,7 +438,9 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = {
[NFTA_CHAIN_NAME] = { .type = NLA_STRING,
.len = NFT_CHAIN_MAXNAMELEN - 1 },
[NFTA_CHAIN_HOOK] = { .type = NLA_NESTED },
[NFTA_CHAIN_POLICY] = { .type = NLA_U32 },
[NFTA_CHAIN_TYPE] = { .type = NLA_NUL_STRING },
[NFTA_CHAIN_COUNTERS] = { .type = NLA_NESTED },
};
static const struct nla_policy nft_hook_policy[NFTA_HOOK_MAX + 1] = {
@ -446,6 +448,33 @@ static const struct nla_policy nft_hook_policy[NFTA_HOOK_MAX + 1] = {
[NFTA_HOOK_PRIORITY] = { .type = NLA_U32 },
};
static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats)
{
struct nft_stats *cpu_stats, total;
struct nlattr *nest;
int cpu;
memset(&total, 0, sizeof(total));
for_each_possible_cpu(cpu) {
cpu_stats = per_cpu_ptr(stats, cpu);
total.pkts += cpu_stats->pkts;
total.bytes += cpu_stats->bytes;
}
nest = nla_nest_start(skb, NFTA_CHAIN_COUNTERS);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.pkts)) ||
nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes)))
goto nla_put_failure;
nla_nest_end(skb, nest);
return 0;
nla_put_failure:
return -ENOSPC;
}
static int nf_tables_fill_chain_info(struct sk_buff *skb, u32 portid, u32 seq,
int event, u32 flags, int family,
const struct nft_table *table,
@ -472,8 +501,11 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, u32 portid, u32 seq,
goto nla_put_failure;
if (chain->flags & NFT_BASE_CHAIN) {
const struct nf_hook_ops *ops = &nft_base_chain(chain)->ops;
struct nlattr *nest = nla_nest_start(skb, NFTA_CHAIN_HOOK);
const struct nft_base_chain *basechain = nft_base_chain(chain);
const struct nf_hook_ops *ops = &basechain->ops;
struct nlattr *nest;
nest = nla_nest_start(skb, NFTA_CHAIN_HOOK);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_HOOK_HOOKNUM, htonl(ops->hooknum)))
@ -482,11 +514,21 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, u32 portid, u32 seq,
goto nla_put_failure;
nla_nest_end(skb, nest);
if (nla_put_be32(skb, NFTA_CHAIN_POLICY,
htonl(basechain->policy)))
goto nla_put_failure;
if (nla_put_string(skb, NFTA_CHAIN_TYPE,
chain_type[ops->pf][nft_base_chain(chain)->type]->name))
goto nla_put_failure;
if (nft_dump_stats(skb, nft_base_chain(chain)->stats))
goto nla_put_failure;
}
if (nla_put_be32(skb, NFTA_CHAIN_USE, htonl(chain->use)))
goto nla_put_failure;
return nlmsg_end(skb, nlh);
nla_put_failure:
@ -617,6 +659,67 @@ static int nf_tables_getchain(struct sock *nlsk, struct sk_buff *skb,
return err;
}
static int
nf_tables_chain_policy(struct nft_base_chain *chain, const struct nlattr *attr)
{
switch (ntohl(nla_get_be32(attr))) {
case NF_DROP:
chain->policy = NF_DROP;
break;
case NF_ACCEPT:
chain->policy = NF_ACCEPT;
break;
default:
return -EINVAL;
}
return 0;
}
static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
[NFTA_COUNTER_PACKETS] = { .type = NLA_U64 },
[NFTA_COUNTER_BYTES] = { .type = NLA_U64 },
};
static int
nf_tables_counters(struct nft_base_chain *chain, const struct nlattr *attr)
{
struct nlattr *tb[NFTA_COUNTER_MAX+1];
struct nft_stats __percpu *newstats;
struct nft_stats *stats;
int err;
err = nla_parse_nested(tb, NFTA_COUNTER_MAX, attr, nft_counter_policy);
if (err < 0)
return err;
if (!tb[NFTA_COUNTER_BYTES] || !tb[NFTA_COUNTER_PACKETS])
return -EINVAL;
newstats = alloc_percpu(struct nft_stats);
if (newstats == NULL)
return -ENOMEM;
/* Restore old counters on this cpu, no problem. Per-cpu statistics
* are not exposed to userspace.
*/
stats = this_cpu_ptr(newstats);
stats->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
stats->pkts = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
if (chain->stats) {
/* nfnl_lock is held, add some nfnl function for this, later */
struct nft_stats __percpu *oldstats =
rcu_dereference_protected(chain->stats, 1);
rcu_assign_pointer(chain->stats, newstats);
synchronize_rcu();
free_percpu(oldstats);
} else
rcu_assign_pointer(chain->stats, newstats);
return 0;
}
static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const nla[])
@ -626,7 +729,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
const struct nft_af_info *afi;
struct nft_table *table;
struct nft_chain *chain;
struct nft_base_chain *basechain;
struct nft_base_chain *basechain = NULL;
struct nlattr *ha[NFTA_HOOK_MAX + 1];
int family = nfmsg->nfgen_family;
u64 handle = 0;
@ -673,6 +776,26 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
!IS_ERR(nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME])))
return -EEXIST;
if (nla[NFTA_CHAIN_POLICY]) {
if (!(chain->flags & NFT_BASE_CHAIN))
return -EOPNOTSUPP;
err = nf_tables_chain_policy(nft_base_chain(chain),
nla[NFTA_CHAIN_POLICY]);
if (err < 0)
return err;
}
if (nla[NFTA_CHAIN_COUNTERS]) {
if (!(chain->flags & NFT_BASE_CHAIN))
return -EOPNOTSUPP;
err = nf_tables_counters(nft_base_chain(chain),
nla[NFTA_CHAIN_COUNTERS]);
if (err < 0)
return err;
}
if (nla[NFTA_CHAIN_HANDLE] && name)
nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN);
@ -727,6 +850,36 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
ops->hook = afi->hooks[ops->hooknum];
chain->flags |= NFT_BASE_CHAIN;
if (nla[NFTA_CHAIN_POLICY]) {
err = nf_tables_chain_policy(basechain,
nla[NFTA_CHAIN_POLICY]);
if (err < 0) {
free_percpu(basechain->stats);
kfree(basechain);
return err;
}
} else
basechain->policy = NF_ACCEPT;
if (nla[NFTA_CHAIN_COUNTERS]) {
err = nf_tables_counters(basechain,
nla[NFTA_CHAIN_COUNTERS]);
if (err < 0) {
free_percpu(basechain->stats);
kfree(basechain);
return err;
}
} else {
struct nft_stats __percpu *newstats;
newstats = alloc_percpu(struct nft_stats);
if (newstats == NULL)
return -ENOMEM;
rcu_assign_pointer(nft_base_chain(chain)->stats,
newstats);
}
} else {
chain = kzalloc(sizeof(*chain), GFP_KERNEL);
if (chain == NULL)
@ -739,6 +892,15 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
list_add_tail(&chain->list, &table->chains);
table->use++;
if (chain->flags & NFT_BASE_CHAIN) {
err = nf_register_hook(&nft_base_chain(chain)->ops);
if (err < 0) {
free_percpu(basechain->stats);
kfree(basechain);
return err;
}
}
notify:
nf_tables_chain_notify(skb, nlh, table, chain, NFT_MSG_NEWCHAIN,
family);
@ -751,9 +913,10 @@ static void nf_tables_rcu_chain_destroy(struct rcu_head *head)
BUG_ON(chain->use > 0);
if (chain->flags & NFT_BASE_CHAIN)
if (chain->flags & NFT_BASE_CHAIN) {
free_percpu(nft_base_chain(chain)->stats);
kfree(nft_base_chain(chain));
else
} else
kfree(chain);
}
@ -801,13 +964,15 @@ static void nft_ctx_init(struct nft_ctx *ctx,
const struct nlmsghdr *nlh,
const struct nft_af_info *afi,
const struct nft_table *table,
const struct nft_chain *chain)
const struct nft_chain *chain,
const struct nlattr * const *nla)
{
ctx->skb = skb;
ctx->nlh = nlh;
ctx->afi = afi;
ctx->table = table;
ctx->chain = chain;
ctx->nla = nla;
}
/*
@ -910,7 +1075,8 @@ struct nft_expr_info {
struct nlattr *tb[NFT_EXPR_MAXATTR + 1];
};
static int nf_tables_expr_parse(const struct nlattr *nla,
static int nf_tables_expr_parse(const struct nft_ctx *ctx,
const struct nlattr *nla,
struct nft_expr_info *info)
{
const struct nft_expr_type *type;
@ -935,7 +1101,8 @@ static int nf_tables_expr_parse(const struct nlattr *nla,
memset(info->tb, 0, sizeof(info->tb[0]) * (type->maxattr + 1));
if (type->select_ops != NULL) {
ops = type->select_ops((const struct nlattr * const *)info->tb);
ops = type->select_ops(ctx,
(const struct nlattr * const *)info->tb);
if (IS_ERR(ops)) {
err = PTR_ERR(ops);
goto err1;
@ -1012,6 +1179,7 @@ static const struct nla_policy nft_rule_policy[NFTA_RULE_MAX + 1] = {
.len = NFT_CHAIN_MAXNAMELEN - 1 },
[NFTA_RULE_HANDLE] = { .type = NLA_U64 },
[NFTA_RULE_EXPRESSIONS] = { .type = NLA_NESTED },
[NFTA_RULE_COMPAT] = { .type = NLA_NESTED },
};
static int nf_tables_fill_rule_info(struct sk_buff *skb, u32 portid, u32 seq,
@ -1269,6 +1437,8 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
handle = nf_tables_alloc_handle(table);
}
nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
n = 0;
size = 0;
if (nla[NFTA_RULE_EXPRESSIONS]) {
@ -1278,7 +1448,7 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
goto err1;
if (n == NFT_RULE_MAXEXPRS)
goto err1;
err = nf_tables_expr_parse(tmp, &info[n]);
err = nf_tables_expr_parse(&ctx, tmp, &info[n]);
if (err < 0)
goto err1;
size += info[n].ops->size;
@ -1294,7 +1464,6 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
rule->handle = handle;
rule->dlen = size;
nft_ctx_init(&ctx, skb, nlh, afi, table, chain);
expr = nft_expr_first(rule);
for (i = 0; i < n; i++) {
err = nf_tables_newexpr(&ctx, &info[i], expr);
@ -1304,13 +1473,6 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
expr = nft_expr_next(expr);
}
/* Register hook when first rule is inserted into a base chain */
if (list_empty(&chain->rules) && chain->flags & NFT_BASE_CHAIN) {
err = nf_register_hook(&nft_base_chain(chain)->ops);
if (err < 0)
goto err2;
}
if (nlh->nlmsg_flags & NLM_F_REPLACE) {
list_replace_rcu(&old_rule->list, &rule->list);
nf_tables_rule_destroy(old_rule);
@ -1379,10 +1541,6 @@ static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
}
}
/* Unregister hook when last rule from base chain is deleted */
if (list_empty(&chain->rules) && chain->flags & NFT_BASE_CHAIN)
nf_unregister_hook(&nft_base_chain(chain)->ops);
return 0;
}
@ -1470,7 +1628,7 @@ static int nft_ctx_init_from_setattr(struct nft_ctx *ctx,
return PTR_ERR(table);
}
nft_ctx_init(ctx, skb, nlh, afi, table, NULL);
nft_ctx_init(ctx, skb, nlh, afi, table, NULL, nla);
return 0;
}
@ -1799,7 +1957,7 @@ static int nf_tables_newset(struct sock *nlsk, struct sk_buff *skb,
if (IS_ERR(table))
return PTR_ERR(table);
nft_ctx_init(&ctx, skb, nlh, afi, table, NULL);
nft_ctx_init(&ctx, skb, nlh, afi, table, NULL, nla);
set = nf_tables_set_lookup(table, nla[NFTA_SET_NAME]);
if (IS_ERR(set)) {
@ -1987,7 +2145,7 @@ static int nft_ctx_init_from_elemattr(struct nft_ctx *ctx,
if (IS_ERR(table))
return PTR_ERR(table);
nft_ctx_init(ctx, skb, nlh, afi, table, NULL);
nft_ctx_init(ctx, skb, nlh, afi, table, NULL, nla);
return 0;
}
@ -2435,23 +2593,27 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx,
{
const struct nft_rule *rule;
const struct nft_expr *expr, *last;
const struct nft_data *data;
const struct nft_set *set;
struct nft_set_binding *binding;
struct nft_set_iter iter;
int err;
if (ctx->chain == chain)
return -ELOOP;
list_for_each_entry(rule, &chain->rules, list) {
nft_rule_for_each_expr(expr, last, rule) {
if (!expr->ops->get_verdict)
const struct nft_data *data = NULL;
int err;
if (!expr->ops->validate)
continue;
data = expr->ops->get_verdict(expr);
err = expr->ops->validate(ctx, expr, &data);
if (err < 0)
return err;
if (data == NULL)
break;
continue;
switch (data->verdict) {
case NFT_JUMP:

46
net/netfilter/nf_tables_core.c
View file

@ -60,27 +60,34 @@ static bool nft_payload_fast_eval(const struct nft_expr *expr,
return true;
}
unsigned int nft_do_chain(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
struct nft_jumpstack {
const struct nft_chain *chain;
const struct nft_rule *rule;
};
static inline void
nft_chain_stats(const struct nft_chain *this, const struct nft_pktinfo *pkt,
struct nft_jumpstack *jumpstack, unsigned int stackptr)
{
struct nft_stats __percpu *stats;
const struct nft_chain *chain = stackptr ? jumpstack[0].chain : this;
rcu_read_lock_bh();
stats = rcu_dereference(nft_base_chain(chain)->stats);
__this_cpu_inc(stats->pkts);
__this_cpu_add(stats->bytes, pkt->skb->len);
rcu_read_unlock_bh();
}
unsigned int
nft_do_chain_pktinfo(struct nft_pktinfo *pkt, const struct nf_hook_ops *ops)
{
const struct nft_chain *chain = ops->priv;
const struct nft_rule *rule;
const struct nft_expr *expr, *last;
struct nft_data data[NFT_REG_MAX + 1];
const struct nft_pktinfo pkt = {
.skb = skb,
.in = in,
.out = out,
.hooknum = ops->hooknum,
};
unsigned int stackptr = 0;
struct {
const struct nft_chain *chain;
const struct nft_rule *rule;
} jumpstack[NFT_JUMP_STACK_SIZE];
struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
do_chain:
rule = list_entry(&chain->rules, struct nft_rule, list);
@ -91,8 +98,8 @@ unsigned int nft_do_chain(const struct nf_hook_ops *ops,
if (expr->ops == &nft_cmp_fast_ops)
nft_cmp_fast_eval(expr, data);
else if (expr->ops != &nft_payload_fast_ops ||
!nft_payload_fast_eval(expr, data, &pkt))
expr->ops->eval(expr, data, &pkt);
!nft_payload_fast_eval(expr, data, pkt))
expr->ops->eval(expr, data, pkt);
if (data[NFT_REG_VERDICT].verdict != NFT_CONTINUE)
break;
@ -135,10 +142,11 @@ unsigned int nft_do_chain(const struct nf_hook_ops *ops,
rule = jumpstack[stackptr].rule;
goto next_rule;
}
nft_chain_stats(chain, pkt, jumpstack, stackptr);
return NF_ACCEPT;
return nft_base_chain(chain)->policy;
}
EXPORT_SYMBOL_GPL(nft_do_chain);
EXPORT_SYMBOL_GPL(nft_do_chain_pktinfo);
int __init nf_tables_core_module_init(void)
{

3
net/netfilter/nft_cmp.c
View file

@ -162,7 +162,8 @@ const struct nft_expr_ops nft_cmp_fast_ops = {
.dump = nft_cmp_fast_dump,
};
static const struct nft_expr_ops *nft_cmp_select_ops(const struct nlattr * const tb[])
static const struct nft_expr_ops *
nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
{
struct nft_data_desc desc;
struct nft_data data;

768
net/netfilter/nft_compat.c Normal file
View file

@ -0,0 +1,768 @@
/*
* (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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.
*
* This software has been sponsored by Sophos Astaro <http://www.sophos.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/netfilter/nf_tables_compat.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <asm/uaccess.h> /* for set_fs */
#include <net/netfilter/nf_tables.h>
union nft_entry {
struct ipt_entry e4;
struct ip6t_entry e6;
};
static inline void
nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
{
par->target = xt;
par->targinfo = xt_info;
par->hotdrop = false;
}
static void nft_target_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
void *info = nft_expr_priv(expr);
struct xt_target *target = expr->ops->data;
struct sk_buff *skb = pkt->skb;
int ret;
nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
ret = target->target(skb, &pkt->xt);
if (pkt->xt.hotdrop)
ret = NF_DROP;
switch(ret) {
case XT_CONTINUE:
data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
break;
default:
data[NFT_REG_VERDICT].verdict = ret;
break;
}
return;
}
static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
[NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
[NFTA_TARGET_REV] = { .type = NLA_U32 },
[NFTA_TARGET_INFO] = { .type = NLA_BINARY },
};
static void
nft_target_set_tgchk_param(struct xt_tgchk_param *par,
const struct nft_ctx *ctx,
struct xt_target *target, void *info,
union nft_entry *entry, u8 proto, bool inv)
{
par->net = &init_net;
par->table = ctx->table->name;
switch (ctx->afi->family) {
case AF_INET:
entry->e4.ip.proto = proto;
entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
break;
case AF_INET6:
entry->e6.ipv6.proto = proto;
entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
break;
}
par->entryinfo = entry;
par->target = target;
par->targinfo = info;
if (ctx->chain->flags & NFT_BASE_CHAIN) {
const struct nft_base_chain *basechain =
nft_base_chain(ctx->chain);
const struct nf_hook_ops *ops = &basechain->ops;
par->hook_mask = 1 << ops->hooknum;
}
par->family = ctx->afi->family;
}
static void target_compat_from_user(struct xt_target *t, void *in, void *out)
{
#ifdef CONFIG_COMPAT
if (t->compat_from_user) {
int pad;
t->compat_from_user(out, in);
pad = XT_ALIGN(t->targetsize) - t->targetsize;
if (pad > 0)
memset(out + t->targetsize, 0, pad);
} else
#endif
memcpy(out, in, XT_ALIGN(t->targetsize));
}
static inline int nft_compat_target_offset(struct xt_target *target)
{
#ifdef CONFIG_COMPAT
return xt_compat_target_offset(target);
#else
return 0;
#endif
}
static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
[NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
[NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
};
static u8 nft_parse_compat(const struct nlattr *attr, bool *inv)
{
struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
u32 flags;
int err;
err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
nft_rule_compat_policy);
if (err < 0)
return err;
if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
return -EINVAL;
flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
if (flags & ~NFT_RULE_COMPAT_F_MASK)
return -EINVAL;
if (flags & NFT_RULE_COMPAT_F_INV)
*inv = true;
return ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
}
static int
nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
void *info = nft_expr_priv(expr);
struct xt_target *target = expr->ops->data;
struct xt_tgchk_param par;
size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
u8 proto = 0;
bool inv = false;
union nft_entry e = {};
int ret;
target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
if (ctx->nla[NFTA_RULE_COMPAT])
proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv);
nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
ret = xt_check_target(&par, size, proto, inv);
if (ret < 0)
goto err;
/* The standard target cannot be used */
if (target->target == NULL) {
ret = -EINVAL;
goto err;
}
return 0;
err:
module_put(target->me);
return ret;
}
static void
nft_target_destroy(const struct nft_expr *expr)
{
struct xt_target *target = expr->ops->data;
module_put(target->me);
}
static int
target_dump_info(struct sk_buff *skb, const struct xt_target *t, const void *in)
{
int ret;
#ifdef CONFIG_COMPAT
if (t->compat_to_user) {
mm_segment_t old_fs;
void *out;
out = kmalloc(XT_ALIGN(t->targetsize), GFP_ATOMIC);
if (out == NULL)
return -ENOMEM;
/* We want to reuse existing compat_to_user */
old_fs = get_fs();
set_fs(KERNEL_DS);
t->compat_to_user(out, in);
set_fs(old_fs);
ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), out);
kfree(out);
} else
#endif
ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), in);
return ret;
}
static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct xt_target *target = expr->ops->data;
void *info = nft_expr_priv(expr);
if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
target_dump_info(skb, target, info))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static int nft_target_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct xt_target *target = expr->ops->data;
unsigned int hook_mask = 0;
if (ctx->chain->flags & NFT_BASE_CHAIN) {
const struct nft_base_chain *basechain =
nft_base_chain(ctx->chain);
const struct nf_hook_ops *ops = &basechain->ops;
hook_mask = 1 << ops->hooknum;
if (hook_mask & target->hooks)
return 0;
/* This target is being called from an invalid chain */
return -EINVAL;
}
return 0;
}
static void nft_match_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
struct sk_buff *skb = pkt->skb;
bool ret;
nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
if (pkt->xt.hotdrop) {
data[NFT_REG_VERDICT].verdict = NF_DROP;
return;
}
switch(ret) {
case true:
data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
break;
case false:
data[NFT_REG_VERDICT].verdict = NFT_BREAK;
break;
}
}
static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
[NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
[NFTA_MATCH_REV] = { .type = NLA_U32 },
[NFTA_MATCH_INFO] = { .type = NLA_BINARY },
};
/* struct xt_mtchk_param and xt_tgchk_param look very similar */
static void
nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
struct xt_match *match, void *info,
union nft_entry *entry, u8 proto, bool inv)
{
par->net = &init_net;
par->table = ctx->table->name;
switch (ctx->afi->family) {
case AF_INET:
entry->e4.ip.proto = proto;
entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
break;
case AF_INET6:
entry->e6.ipv6.proto = proto;
entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
break;
}
par->entryinfo = entry;
par->match = match;
par->matchinfo = info;
if (ctx->chain->flags & NFT_BASE_CHAIN) {
const struct nft_base_chain *basechain =
nft_base_chain(ctx->chain);
const struct nf_hook_ops *ops = &basechain->ops;
par->hook_mask = 1 << ops->hooknum;
}
par->family = ctx->afi->family;
}
static void match_compat_from_user(struct xt_match *m, void *in, void *out)
{
#ifdef CONFIG_COMPAT
if (m->compat_from_user) {
int pad;
m->compat_from_user(out, in);
pad = XT_ALIGN(m->matchsize) - m->matchsize;
if (pad > 0)
memset(out + m->matchsize, 0, pad);
} else
#endif
memcpy(out, in, XT_ALIGN(m->matchsize));
}
static int
nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
struct xt_mtchk_param par;
size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
u8 proto = 0;
bool inv = false;
union nft_entry e = {};
int ret;
match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
if (ctx->nla[NFTA_RULE_COMPAT])
proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv);
nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
ret = xt_check_match(&par, size, proto, inv);
if (ret < 0)
goto err;
return 0;
err:
module_put(match->me);
return ret;
}
static void
nft_match_destroy(const struct nft_expr *expr)
{
struct xt_match *match = expr->ops->data;
module_put(match->me);
}
static int
match_dump_info(struct sk_buff *skb, const struct xt_match *m, const void *in)
{
int ret;
#ifdef CONFIG_COMPAT
if (m->compat_to_user) {
mm_segment_t old_fs;
void *out;
out = kmalloc(XT_ALIGN(m->matchsize), GFP_ATOMIC);
if (out == NULL)
return -ENOMEM;
/* We want to reuse existing compat_to_user */
old_fs = get_fs();
set_fs(KERNEL_DS);
m->compat_to_user(out, in);
set_fs(old_fs);
ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), out);
kfree(out);
} else
#endif
ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), in);
return ret;
}
static inline int nft_compat_match_offset(struct xt_match *match)
{
#ifdef CONFIG_COMPAT
return xt_compat_match_offset(match);
#else
return 0;
#endif
}
static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
void *info = nft_expr_priv(expr);
struct xt_match *match = expr->ops->data;
if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
match_dump_info(skb, match, info))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static int nft_match_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct xt_match *match = expr->ops->data;
unsigned int hook_mask = 0;
if (ctx->chain->flags & NFT_BASE_CHAIN) {
const struct nft_base_chain *basechain =
nft_base_chain(ctx->chain);
const struct nf_hook_ops *ops = &basechain->ops;
hook_mask = 1 << ops->hooknum;
if (hook_mask & match->hooks)
return 0;
/* This match is being called from an invalid chain */
return -EINVAL;
}
return 0;
}
static int
nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
int event, u16 family, const char *name,
int rev, int target)
{
struct nlmsghdr *nlh;
struct nfgenmsg *nfmsg;
unsigned int flags = portid ? NLM_F_MULTI : 0;
event |= NFNL_SUBSYS_NFT_COMPAT << 8;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
if (nlh == NULL)
goto nlmsg_failure;
nfmsg = nlmsg_data(nlh);
nfmsg->nfgen_family = family;
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = 0;
if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
goto nla_put_failure;
nlmsg_end(skb, nlh);
return skb->len;
nlmsg_failure:
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -1;
}
static int
nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
int ret = 0, target;
struct nfgenmsg *nfmsg;
const char *fmt;
const char *name;
u32 rev;
struct sk_buff *skb2;
if (tb[NFTA_COMPAT_NAME] == NULL ||
tb[NFTA_COMPAT_REV] == NULL ||
tb[NFTA_COMPAT_TYPE] == NULL)
return -EINVAL;
name = nla_data(tb[NFTA_COMPAT_NAME]);
rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
nfmsg = nlmsg_data(nlh);
switch(nfmsg->nfgen_family) {
case AF_INET:
fmt = "ipt_%s";
break;
case AF_INET6:
fmt = "ip6t_%s";
break;
default:
pr_err("nft_compat: unsupported protocol %d\n",
nfmsg->nfgen_family);
return -EINVAL;
}
try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
rev, target, &ret),
fmt, name);
if (ret < 0)
return ret;
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb2 == NULL)
return -ENOMEM;
/* include the best revision for this extension in the message */
if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
nlh->nlmsg_seq,
NFNL_MSG_TYPE(nlh->nlmsg_type),
NFNL_MSG_COMPAT_GET,
nfmsg->nfgen_family,
name, ret, target) <= 0) {
kfree_skb(skb2);
return -ENOSPC;
}
ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret > 0)
ret = 0;
return ret == -EAGAIN ? -ENOBUFS : ret;
}
static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
[NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
.len = NFT_COMPAT_NAME_MAX-1 },
[NFTA_COMPAT_REV] = { .type = NLA_U32 },
[NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
};
static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
[NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
.attr_count = NFTA_COMPAT_MAX,
.policy = nfnl_compat_policy_get },
};
static const struct nfnetlink_subsystem nfnl_compat_subsys = {
.name = "nft-compat",
.subsys_id = NFNL_SUBSYS_NFT_COMPAT,
.cb_count = NFNL_MSG_COMPAT_MAX,
.cb = nfnl_nft_compat_cb,
};
static LIST_HEAD(nft_match_list);
struct nft_xt {
struct list_head head;
struct nft_expr_ops ops;
};
static struct nft_expr_type nft_match_type;
static const struct nft_expr_ops *
nft_match_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_xt *nft_match;
struct xt_match *match;
char *mt_name;
__u32 rev, family;
if (tb[NFTA_MATCH_NAME] == NULL ||
tb[NFTA_MATCH_REV] == NULL ||
tb[NFTA_MATCH_INFO] == NULL)
return ERR_PTR(-EINVAL);
mt_name = nla_data(tb[NFTA_MATCH_NAME]);
rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
family = ctx->afi->family;
/* Re-use the existing match if it's already loaded. */
list_for_each_entry(nft_match, &nft_match_list, head) {
struct xt_match *match = nft_match->ops.data;
if (strcmp(match->name, mt_name) == 0 &&
match->revision == rev && match->family == family)
return &nft_match->ops;
}
match = xt_request_find_match(family, mt_name, rev);
if (IS_ERR(match))
return ERR_PTR(-ENOENT);
/* This is the first time we use this match, allocate operations */
nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
if (nft_match == NULL)
return ERR_PTR(-ENOMEM);
nft_match->ops.type = &nft_match_type;
nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize) +
nft_compat_match_offset(match));
nft_match->ops.eval = nft_match_eval;
nft_match->ops.init = nft_match_init;
nft_match->ops.destroy = nft_match_destroy;
nft_match->ops.dump = nft_match_dump;
nft_match->ops.validate = nft_match_validate;
nft_match->ops.data = match;
list_add(&nft_match->head, &nft_match_list);
return &nft_match->ops;
}
static void nft_match_release(void)
{
struct nft_xt *nft_match;
list_for_each_entry(nft_match, &nft_match_list, head)
kfree(nft_match);
}
static struct nft_expr_type nft_match_type __read_mostly = {
.name = "match",
.select_ops = nft_match_select_ops,
.policy = nft_match_policy,
.maxattr = NFTA_MATCH_MAX,
.owner = THIS_MODULE,
};
static LIST_HEAD(nft_target_list);
static struct nft_expr_type nft_target_type;
static const struct nft_expr_ops *
nft_target_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_xt *nft_target;
struct xt_target *target;
char *tg_name;
__u32 rev, family;
if (tb[NFTA_TARGET_NAME] == NULL ||
tb[NFTA_TARGET_REV] == NULL ||
tb[NFTA_TARGET_INFO] == NULL)
return ERR_PTR(-EINVAL);
tg_name = nla_data(tb[NFTA_TARGET_NAME]);
rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
family = ctx->afi->family;
/* Re-use the existing target if it's already loaded. */
list_for_each_entry(nft_target, &nft_match_list, head) {
struct xt_target *target = nft_target->ops.data;
if (strcmp(target->name, tg_name) == 0 &&
target->revision == rev && target->family == family)
return &nft_target->ops;
}
target = xt_request_find_target(family, tg_name, rev);
if (IS_ERR(target))
return ERR_PTR(-ENOENT);
/* This is the first time we use this target, allocate operations */
nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
if (nft_target == NULL)
return ERR_PTR(-ENOMEM);
nft_target->ops.type = &nft_target_type;
nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize) +
nft_compat_target_offset(target));
nft_target->ops.eval = nft_target_eval;
nft_target->ops.init = nft_target_init;
nft_target->ops.destroy = nft_target_destroy;
nft_target->ops.dump = nft_target_dump;
nft_target->ops.validate = nft_target_validate;
nft_target->ops.data = target;
list_add(&nft_target->head, &nft_target_list);
return &nft_target->ops;
}
static void nft_target_release(void)
{
struct nft_xt *nft_target;
list_for_each_entry(nft_target, &nft_target_list, head)
kfree(nft_target);
}
static struct nft_expr_type nft_target_type __read_mostly = {
.name = "target",
.select_ops = nft_target_select_ops,
.policy = nft_target_policy,
.maxattr = NFTA_TARGET_MAX,
.owner = THIS_MODULE,
};
static int __init nft_compat_module_init(void)
{
int ret;
ret = nft_register_expr(&nft_match_type);
if (ret < 0)
return ret;
ret = nft_register_expr(&nft_target_type);
if (ret < 0)
goto err_match;
ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
if (ret < 0) {
pr_err("nft_compat: cannot register with nfnetlink.\n");
goto err_target;
}
pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
return ret;
err_target:
nft_unregister_expr(&nft_target_type);
err_match:
nft_unregister_expr(&nft_match_type);
return ret;
}
static void __exit nft_compat_module_exit(void)
{
nfnetlink_subsys_unregister(&nfnl_compat_subsys);
nft_unregister_expr(&nft_target_type);
nft_unregister_expr(&nft_match_type);
nft_match_release();
nft_target_release();
}
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
module_init(nft_compat_module_init);
module_exit(nft_compat_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
MODULE_ALIAS_NFT_EXPR("match");
MODULE_ALIAS_NFT_EXPR("target");

12
net/netfilter/nft_immediate.c
View file

@ -90,14 +90,16 @@ static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
return -1;
}
static const struct nft_data *nft_immediate_get_verdict(const struct nft_expr *expr)
static int nft_immediate_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
const struct nft_immediate_expr *priv = nft_expr_priv(expr);
if (priv->dreg == NFT_REG_VERDICT)
return &priv->data;
else
return NULL;
*data = &priv->data;
return 0;
}
static struct nft_expr_type nft_imm_type;
@ -108,7 +110,7 @@ static const struct nft_expr_ops nft_imm_ops = {
.init = nft_immediate_init,
.destroy = nft_immediate_destroy,
.dump = nft_immediate_dump,
.get_verdict = nft_immediate_get_verdict,
.validate = nft_immediate_validate,
};
static struct nft_expr_type nft_imm_type __read_mostly = {

4
net/netfilter/nft_payload.c
View file

@ -107,7 +107,9 @@ const struct nft_expr_ops nft_payload_fast_ops = {
.dump = nft_payload_dump,
};
static const struct nft_expr_ops *nft_payload_select_ops(const struct nlattr * const tb[])
static const struct nft_expr_ops *
nft_payload_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
enum nft_payload_bases base;
unsigned int offset, len;