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Commit 1cde6436 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by David S. Miller
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[NETFILTER]: ctnetlink: Fix expectaction mask dumping 

The expectation mask has some particularities that requires a different
handling. The protocol number fields can be set to non-valid protocols,
ie. l3num is set to 0xFFFF. Since that protocol does not exist, the mask
tuple will not be dumped. Moreover, this results in a kernel panic when
nf_conntrack accesses the array of protocol handlers, that is PF_MAX (0x1F)
long.

This patch introduces the function ctnetlink_exp_dump_mask, that correctly
dumps the expectation mask. Such function uses the l3num value from the
expectation tuple that is a valid layer 3 protocol number. The value of the
l3num mask isn't dumped since it is meaningless from the userspace side.

Thanks to Yasuyuki Kozakai and Patrick McHardy for the feedback.
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 50b521aa
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Showing with 117 additions and 39 deletions
net/ipv4/netfilter/ip_conntrack_netlink.c
View file @ 1cde6436
......@@ -4,7 +4,7 @@
* (C) 2001 by Jay Schulist <jschlst@samba.org>
* (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
* (C) 2003 by Patrick Mchardy <kaber@trash.net>
* (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
* (C) 2005-2006 by Pablo Neira Ayuso <pablo@eurodev.net>
*
* I've reworked this stuff to use attributes instead of conntrack
* structures. 5.44 am. I need more tea. --pablo 05/07/11.
......@@ -53,20 +53,18 @@ static char __initdata version[] = "0.90";
static inline int
ctnetlink_dump_tuples_proto(struct sk_buff *skb,
const struct ip_conntrack_tuple *tuple)
const struct ip_conntrack_tuple *tuple,
struct ip_conntrack_protocol *proto)
{
struct ip_conntrack_protocol *proto;
int ret = 0;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
/* If no protocol helper is found, this function will return the
* generic protocol helper, so proto won't *ever* be NULL */
proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
if (likely(proto->tuple_to_nfattr))
ret = proto->tuple_to_nfattr(skb, tuple);
ip_conntrack_proto_put(proto);
NFA_NEST_END(skb, nest_parms);
return ret;
......@@ -75,27 +73,40 @@ ctnetlink_dump_tuples_proto(struct sk_buff *skb,
}
static inline int
ctnetlink_dump_tuples(struct sk_buff *skb,
ctnetlink_dump_tuples_ip(struct sk_buff *skb,
const struct ip_conntrack_tuple *tuple)
{
struct nfattr *nest_parms;
int ret;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t), &tuple->src.ip);
NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t), &tuple->dst.ip);
NFA_NEST_END(skb, nest_parms);
nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
ret = ctnetlink_dump_tuples_proto(skb, tuple);
NFA_NEST_END(skb, nest_parms);
return ret;
return 0;
nfattr_failure:
return -1;
}
static inline int
ctnetlink_dump_tuples(struct sk_buff *skb,
const struct ip_conntrack_tuple *tuple)
{
int ret;
struct ip_conntrack_protocol *proto;
ret = ctnetlink_dump_tuples_ip(skb, tuple);
if (unlikely(ret < 0))
return ret;
proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);
ip_conntrack_proto_put(proto);
return ret;
}
static inline int
ctnetlink_dump_status(struct sk_buff *skb, const struct ip_conntrack *ct)
{
......@@ -1134,6 +1145,33 @@ ctnetlink_exp_dump_tuple(struct sk_buff *skb,
return -1;
}
static inline int
ctnetlink_exp_dump_mask(struct sk_buff *skb,
const struct ip_conntrack_tuple *tuple,
const struct ip_conntrack_tuple *mask)
{
int ret;
struct ip_conntrack_protocol *proto;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);
ret = ctnetlink_dump_tuples_ip(skb, mask);
if (unlikely(ret < 0))
goto nfattr_failure;
proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
ret = ctnetlink_dump_tuples_proto(skb, mask, proto);
ip_conntrack_proto_put(proto);
if (unlikely(ret < 0))
goto nfattr_failure;
NFA_NEST_END(skb, nest_parms);
return 0;
nfattr_failure:
return -1;
}
static inline int
ctnetlink_exp_dump_expect(struct sk_buff *skb,
const struct ip_conntrack_expect *exp)
......@@ -1144,7 +1182,7 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
goto nfattr_failure;
if (ctnetlink_exp_dump_tuple(skb, &exp->mask, CTA_EXPECT_MASK) < 0)
if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
goto nfattr_failure;
if (ctnetlink_exp_dump_tuple(skb,
&master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
......
net/netfilter/nf_conntrack_netlink.c
View file @ 1cde6436
......@@ -4,7 +4,7 @@
* (C) 2001 by Jay Schulist <jschlst@samba.org>
* (C) 2002-2006 by Harald Welte <laforge@gnumonks.org>
* (C) 2003 by Patrick Mchardy <kaber@trash.net>
* (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
* (C) 2005-2006 by Pablo Neira Ayuso <pablo@eurodev.net>
*
* I've reworked this stuff to use attributes instead of conntrack
* structures. 5.44 am. I need more tea. --pablo 05/07/11.
......@@ -55,20 +55,18 @@ static char __initdata version[] = "0.93";
static inline int
ctnetlink_dump_tuples_proto(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple)
const struct nf_conntrack_tuple *tuple,
struct nf_conntrack_protocol *proto)
{
struct nf_conntrack_protocol *proto;
int ret = 0;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
/* If no protocol helper is found, this function will return the
* generic protocol helper, so proto won't *ever* be NULL */
proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
if (likely(proto->tuple_to_nfattr))
ret = proto->tuple_to_nfattr(skb, tuple);
nf_ct_proto_put(proto);
NFA_NEST_END(skb, nest_parms);
return ret;
......@@ -77,33 +75,44 @@ ctnetlink_dump_tuples_proto(struct sk_buff *skb,
}
static inline int
ctnetlink_dump_tuples(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple)
ctnetlink_dump_tuples_ip(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple,
struct nf_conntrack_l3proto *l3proto)
{
struct nfattr *nest_parms;
struct nf_conntrack_l3proto *l3proto;
int ret = 0;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
if (likely(l3proto->tuple_to_nfattr))
ret = l3proto->tuple_to_nfattr(skb, tuple);
NFA_NEST_END(skb, nest_parms);
return ret;
nfattr_failure:
return -1;
}
static inline int
ctnetlink_dump_tuples(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple)
{
int ret;
struct nf_conntrack_l3proto *l3proto;
struct nf_conntrack_protocol *proto;
l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);
nf_ct_l3proto_put(l3proto);
if (unlikely(ret < 0))
return ret;
nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
ret = ctnetlink_dump_tuples_proto(skb, tuple);
NFA_NEST_END(skb, nest_parms);
proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);
nf_ct_proto_put(proto);
return ret;
nfattr_failure:
return -1;
}
static inline int
......@@ -1152,6 +1161,37 @@ ctnetlink_exp_dump_tuple(struct sk_buff *skb,
return -1;
}
static inline int
ctnetlink_exp_dump_mask(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_tuple *mask)
{
int ret;
struct nf_conntrack_l3proto *l3proto;
struct nf_conntrack_protocol *proto;
struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);
l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);
ret = ctnetlink_dump_tuples_ip(skb, mask, l3proto);
nf_ct_l3proto_put(l3proto);
if (unlikely(ret < 0))
goto nfattr_failure;
proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);
ret = ctnetlink_dump_tuples_proto(skb, mask, proto);
nf_ct_proto_put(proto);
if (unlikely(ret < 0))
goto nfattr_failure;
NFA_NEST_END(skb, nest_parms);
return 0;
nfattr_failure:
return -1;
}
static inline int
ctnetlink_exp_dump_expect(struct sk_buff *skb,
const struct nf_conntrack_expect *exp)
......@@ -1162,7 +1202,7 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
goto nfattr_failure;
if (ctnetlink_exp_dump_tuple(skb, &exp->mask, CTA_EXPECT_MASK) < 0)
if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
goto nfattr_failure;
if (ctnetlink_exp_dump_tuple(skb,
&master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
......
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