* [PATCH 1/3] netfilter: ipv4: propagate routing errors from ip_route_me_harder()
2013-04-05 16:41 [PATCH 0/3] netfilter: propagate routing and XFRM errors Patrick McHardy
@ 2013-04-05 16:41 ` Patrick McHardy
2013-04-05 16:41 ` [PATCH 2/3] netfilter: ipv6: propagate routing errors from ip6_route_me_harder() Patrick McHardy
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Patrick McHardy @ 2013-04-05 16:41 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
Propagate routing errors from ip_route_me_harder() when dropping a packet
using NF_DROP_ERR(). This makes userspace get the proper error instead of
EPERM for everything.
Example:
# ip r a unreachable default table 100
# ip ru add fwmark 0x1 lookup 100
# iptables -t mangle -A OUTPUT -d 8.8.8.8 -j MARK --set-mark 0x1
Current behaviour:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
New behaviour:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
net/ipv4/netfilter.c | 8 ++++----
net/ipv4/netfilter/iptable_mangle.c | 9 ++++++---
net/ipv4/netfilter/iptable_nat.c | 6 ++++--
3 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 4c0cf63..8b201e8 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -40,14 +40,14 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned int addr_type)
fl4.flowi4_flags = flags;
rt = ip_route_output_key(net, &fl4);
if (IS_ERR(rt))
- return -1;
+ return PTR_ERR(rt);
/* Drop old route. */
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
if (skb_dst(skb)->error)
- return -1;
+ return skb_dst(skb)->error;
#ifdef CONFIG_XFRM
if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
@@ -56,7 +56,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned int addr_type)
skb_dst_set(skb, NULL);
dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), skb->sk, 0);
if (IS_ERR(dst))
- return -1;
+ return PTR_ERR(dst);;
skb_dst_set(skb, dst);
}
#endif
@@ -66,7 +66,7 @@ int ip_route_me_harder(struct sk_buff *skb, unsigned int addr_type)
if (skb_headroom(skb) < hh_len &&
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
0, GFP_ATOMIC))
- return -1;
+ return -ENOMEM;
return 0;
}
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 85d88f2..cba5658 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -44,6 +44,7 @@ ipt_mangle_out(struct sk_buff *skb, const struct net_device *out)
u_int8_t tos;
__be32 saddr, daddr;
u_int32_t mark;
+ int err;
/* root is playing with raw sockets. */
if (skb->len < sizeof(struct iphdr) ||
@@ -66,9 +67,11 @@ ipt_mangle_out(struct sk_buff *skb, const struct net_device *out)
if (iph->saddr != saddr ||
iph->daddr != daddr ||
skb->mark != mark ||
- iph->tos != tos)
- if (ip_route_me_harder(skb, RTN_UNSPEC))
- ret = NF_DROP;
+ iph->tos != tos) {
+ err = ip_route_me_harder(skb, RTN_UNSPEC);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
}
return ret;
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index eeaff7e..c2937c8 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -213,6 +213,7 @@ nf_nat_ipv4_local_fn(unsigned int hooknum,
const struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
unsigned int ret;
+ int err;
/* root is playing with raw sockets. */
if (skb->len < sizeof(struct iphdr) ||
@@ -226,8 +227,9 @@ nf_nat_ipv4_local_fn(unsigned int hooknum,
if (ct->tuplehash[dir].tuple.dst.u3.ip !=
ct->tuplehash[!dir].tuple.src.u3.ip) {
- if (ip_route_me_harder(skb, RTN_UNSPEC))
- ret = NF_DROP;
+ err = ip_route_me_harder(skb, RTN_UNSPEC);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
}
#ifdef CONFIG_XFRM
else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
--
1.8.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] netfilter: ipv6: propagate routing errors from ip6_route_me_harder()
2013-04-05 16:41 [PATCH 0/3] netfilter: propagate routing and XFRM errors Patrick McHardy
2013-04-05 16:41 ` [PATCH 1/3] netfilter: ipv4: propagate routing errors from ip_route_me_harder() Patrick McHardy
@ 2013-04-05 16:41 ` Patrick McHardy
2013-04-05 16:41 ` [PATCH 3/3] netfilter: nat: propagate errors from xfrm_me_harder() Patrick McHardy
2013-04-06 12:02 ` [PATCH 0/3] netfilter: propagate routing and XFRM errors Pablo Neira Ayuso
3 siblings, 0 replies; 5+ messages in thread
From: Patrick McHardy @ 2013-04-05 16:41 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
Propagate routing errors from ip_route_me_harder() when dropping a packet
using NF_DROP_ERR(). This makes userspace get the proper error instead of
EPERM for everything.
# ip -6 r a unreachable default table 100
# ip -6 ru add fwmark 0x1 lookup 100
# ip6tables -t mangle -A OUTPUT -d 2001:4860:4860::8888 -j MARK --set-mark 0x1
Old behaviour:
PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
New behaviour:
PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
net/ipv6/netfilter.c | 6 +++---
net/ipv6/netfilter/ip6table_mangle.c | 9 ++++++---
net/ipv6/netfilter/ip6table_nat.c | 6 ++++--
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 429089c..fc5fbd7 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -29,7 +29,7 @@ int ip6_route_me_harder(struct sk_buff *skb)
IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
dst_release(dst);
- return -EINVAL;
+ return dst->error;
}
/* Drop old route. */
@@ -43,7 +43,7 @@ int ip6_route_me_harder(struct sk_buff *skb)
skb_dst_set(skb, NULL);
dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
if (IS_ERR(dst))
- return -1;
+ return PTR_ERR(dst);
skb_dst_set(skb, dst);
}
#endif
@@ -53,7 +53,7 @@ int ip6_route_me_harder(struct sk_buff *skb)
if (skb_headroom(skb) < hh_len &&
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
0, GFP_ATOMIC))
- return -1;
+ return -ENOMEM;
return 0;
}
diff --git a/net/ipv6/netfilter/ip6table_mangle.c b/net/ipv6/netfilter/ip6table_mangle.c
index 6134a1e..e075399 100644
--- a/net/ipv6/netfilter/ip6table_mangle.c
+++ b/net/ipv6/netfilter/ip6table_mangle.c
@@ -38,7 +38,7 @@ ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out)
struct in6_addr saddr, daddr;
u_int8_t hop_limit;
u_int32_t flowlabel, mark;
-
+ int err;
#if 0
/* root is playing with raw sockets. */
if (skb->len < sizeof(struct iphdr) ||
@@ -65,8 +65,11 @@ ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out)
!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) ||
skb->mark != mark ||
ipv6_hdr(skb)->hop_limit != hop_limit ||
- flowlabel != *((u_int32_t *)ipv6_hdr(skb))))
- return ip6_route_me_harder(skb) == 0 ? ret : NF_DROP;
+ flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) {
+ err = ip6_route_me_harder(skb);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
return ret;
}
diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
index e0e788d..97e2edd 100644
--- a/net/ipv6/netfilter/ip6table_nat.c
+++ b/net/ipv6/netfilter/ip6table_nat.c
@@ -215,6 +215,7 @@ nf_nat_ipv6_local_fn(unsigned int hooknum,
const struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
unsigned int ret;
+ int err;
/* root is playing with raw sockets. */
if (skb->len < sizeof(struct ipv6hdr))
@@ -227,8 +228,9 @@ nf_nat_ipv6_local_fn(unsigned int hooknum,
if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3,
&ct->tuplehash[!dir].tuple.src.u3)) {
- if (ip6_route_me_harder(skb))
- ret = NF_DROP;
+ err = ip6_route_me_harder(skb);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
}
#ifdef CONFIG_XFRM
else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
--
1.8.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] netfilter: nat: propagate errors from xfrm_me_harder()
2013-04-05 16:41 [PATCH 0/3] netfilter: propagate routing and XFRM errors Patrick McHardy
2013-04-05 16:41 ` [PATCH 1/3] netfilter: ipv4: propagate routing errors from ip_route_me_harder() Patrick McHardy
2013-04-05 16:41 ` [PATCH 2/3] netfilter: ipv6: propagate routing errors from ip6_route_me_harder() Patrick McHardy
@ 2013-04-05 16:41 ` Patrick McHardy
2013-04-06 12:02 ` [PATCH 0/3] netfilter: propagate routing and XFRM errors Pablo Neira Ayuso
3 siblings, 0 replies; 5+ messages in thread
From: Patrick McHardy @ 2013-04-05 16:41 UTC (permalink / raw)
To: pablo; +Cc: netfilter-devel, netdev
Propagate errors from ip_xfrm_me_harder() instead of returning EPERM in
all cases.
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
net/ipv4/netfilter/iptable_nat.c | 17 +++++++++++------
net/ipv6/netfilter/ip6table_nat.c | 17 +++++++++++------
net/netfilter/nf_nat_core.c | 9 +++++----
3 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index c2937c8..6383273 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -176,6 +176,7 @@ nf_nat_ipv4_out(unsigned int hooknum,
#ifdef CONFIG_XFRM
const struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
+ int err;
#endif
unsigned int ret;
@@ -195,9 +196,11 @@ nf_nat_ipv4_out(unsigned int hooknum,
ct->tuplehash[!dir].tuple.dst.u3.ip) ||
(ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP &&
ct->tuplehash[dir].tuple.src.u.all !=
- ct->tuplehash[!dir].tuple.dst.u.all))
- if (nf_xfrm_me_harder(skb, AF_INET) < 0)
- ret = NF_DROP;
+ ct->tuplehash[!dir].tuple.dst.u.all)) {
+ err = nf_xfrm_me_harder(skb, AF_INET);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
}
#endif
return ret;
@@ -235,9 +238,11 @@ nf_nat_ipv4_local_fn(unsigned int hooknum,
else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP &&
ct->tuplehash[dir].tuple.dst.u.all !=
- ct->tuplehash[!dir].tuple.src.u.all)
- if (nf_xfrm_me_harder(skb, AF_INET) < 0)
- ret = NF_DROP;
+ ct->tuplehash[!dir].tuple.src.u.all) {
+ err = nf_xfrm_me_harder(skb, AF_INET);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
#endif
}
return ret;
diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
index 97e2edd..6383f90 100644
--- a/net/ipv6/netfilter/ip6table_nat.c
+++ b/net/ipv6/netfilter/ip6table_nat.c
@@ -179,6 +179,7 @@ nf_nat_ipv6_out(unsigned int hooknum,
#ifdef CONFIG_XFRM
const struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
+ int err;
#endif
unsigned int ret;
@@ -197,9 +198,11 @@ nf_nat_ipv6_out(unsigned int hooknum,
&ct->tuplehash[!dir].tuple.dst.u3) ||
(ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 &&
ct->tuplehash[dir].tuple.src.u.all !=
- ct->tuplehash[!dir].tuple.dst.u.all))
- if (nf_xfrm_me_harder(skb, AF_INET6) < 0)
- ret = NF_DROP;
+ ct->tuplehash[!dir].tuple.dst.u.all)) {
+ err = nf_xfrm_me_harder(skb, AF_INET6);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
}
#endif
return ret;
@@ -236,9 +239,11 @@ nf_nat_ipv6_local_fn(unsigned int hooknum,
else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 &&
ct->tuplehash[dir].tuple.dst.u.all !=
- ct->tuplehash[!dir].tuple.src.u.all)
- if (nf_xfrm_me_harder(skb, AF_INET6))
- ret = NF_DROP;
+ ct->tuplehash[!dir].tuple.src.u.all) {
+ err = nf_xfrm_me_harder(skb, AF_INET6);
+ if (err < 0)
+ ret = NF_DROP_ERR(err);
+ }
#endif
}
return ret;
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 8d5769c..346f871 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -87,9 +87,10 @@ int nf_xfrm_me_harder(struct sk_buff *skb, unsigned int family)
struct flowi fl;
unsigned int hh_len;
struct dst_entry *dst;
+ int err;
- if (xfrm_decode_session(skb, &fl, family) < 0)
- return -1;
+ err = xfrm_decode_session(skb, &fl, family);
+ return err;
dst = skb_dst(skb);
if (dst->xfrm)
@@ -98,7 +99,7 @@ int nf_xfrm_me_harder(struct sk_buff *skb, unsigned int family)
dst = xfrm_lookup(dev_net(dst->dev), dst, &fl, skb->sk, 0);
if (IS_ERR(dst))
- return -1;
+ return PTR_ERR(dst);
skb_dst_drop(skb);
skb_dst_set(skb, dst);
@@ -107,7 +108,7 @@ int nf_xfrm_me_harder(struct sk_buff *skb, unsigned int family)
hh_len = skb_dst(skb)->dev->hard_header_len;
if (skb_headroom(skb) < hh_len &&
pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
- return -1;
+ return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(nf_xfrm_me_harder);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] netfilter: propagate routing and XFRM errors
2013-04-05 16:41 [PATCH 0/3] netfilter: propagate routing and XFRM errors Patrick McHardy
` (2 preceding siblings ...)
2013-04-05 16:41 ` [PATCH 3/3] netfilter: nat: propagate errors from xfrm_me_harder() Patrick McHardy
@ 2013-04-06 12:02 ` Pablo Neira Ayuso
3 siblings, 0 replies; 5+ messages in thread
From: Pablo Neira Ayuso @ 2013-04-06 12:02 UTC (permalink / raw)
To: Patrick McHardy; +Cc: netfilter-devel, netdev
On Fri, Apr 05, 2013 at 06:41:09PM +0200, Patrick McHardy wrote:
> These patches fix a long standing annoyance: netfilter will return
> EPERM for all errors during rerouting or XFRM policy lookups.
>
> These patches change {ip,ip6}_route_me_harder() and nf_xfrm_me_harder()
> to return errno codes and use NF_DROP_ERR() to propagate those back
> to userspace.
Applied, thanks Patrick!
^ permalink raw reply [flat|nested] 5+ messages in thread