On Sun, Mar 01, 2015 at 07:06:13PM +0100, Markus Kötter wrote:
[...]
> None of this works with current kernels, as changes to the netlink
> logging infrastructure in v3.17 prevent TRACE messages from being
> relayed to netlink.
> I filed a report here:
> http://bugzilla.netfilter.org/show_bug.cgi?id=1003
>
> Using NULL as nf_loginfo works for me (messages end up in group 0 as
> before) [...]
It seems we cannot pass NULL since it will default on log level 5
instead of 4, and I think there may be users relying on that too.
I'm attaching a patch to address this problem.
Thanks for reporting.
>From adab0dd4789936495bb2f0d6892ad26437ebb31e Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date: Mon, 2 Mar 2015 01:04:55 +0100
Subject: [PATCH] netfilter: restore rule tracing via nfnetlink_log
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Since fab4085 ("netfilter: log: nf_log_packet() as real unified
interface"), the loginfo structure that is passed to nf_log_packet()
is used to explicitly indicate the logger type you want to use.
This is a problem for people tracing rules through nfnetlink_log since
packets are always routed to the NF_LOG_TYPE logger after the
aforementioned patch.
We can fix this by removing the trace loginfo structures, but that still
changes the log level from 4 to 5 for tracing messages and there may be
someone relying on this outthere. So let's just introduce some compat
code to restore the former behaviour.
Reported-by: Markus Kötter <koetter@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_log.h | 10 ++++++++++
net/ipv4/netfilter/ip_tables.c | 2 +-
net/ipv6/netfilter/ip6_tables.c | 2 +-
net/netfilter/nf_log.c | 25 +++++++++++++++++++++++++
net/netfilter/nf_tables_core.c | 2 +-
5 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h
index 534e1f2..b11f2a0 100644
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h
@@ -79,6 +79,16 @@ void nf_log_packet(struct net *net,
const struct nf_loginfo *li,
const char *fmt, ...);
+__printf(8, 9)
+void nf_log_compat(struct net *net,
+ u_int8_t pf,
+ unsigned int hooknum,
+ const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct nf_loginfo *li,
+ const char *fmt, ...);
+
struct nf_log_buf;
struct nf_log_buf *nf_log_buf_open(void);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 99e810f..b438ab5 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -272,7 +272,7 @@ static void trace_packet(const struct sk_buff *skb,
&chainname, &comment, &rulenum) != 0)
break;
- nf_log_packet(net, AF_INET, hook, skb, in, out, &trace_loginfo,
+ nf_log_compat(net, AF_INET, hook, skb, in, out, &trace_loginfo,
"TRACE: %s:%s:%s:%u ",
tablename, chainname, comment, rulenum);
}
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index e080fbb..fdfe86b 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -298,7 +298,7 @@ static void trace_packet(const struct sk_buff *skb,
&chainname, &comment, &rulenum) != 0)
break;
- nf_log_packet(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
+ nf_log_compat(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
"TRACE: %s:%s:%s:%u ",
tablename, chainname, comment, rulenum);
}
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 0d8448f..d6d2254 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -212,6 +212,31 @@ void nf_log_packet(struct net *net,
}
EXPORT_SYMBOL(nf_log_packet);
+void nf_log_compat(struct net *net,
+ u_int8_t pf,
+ unsigned int hooknum,
+ const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct nf_loginfo *loginfo, const char *fmt, ...)
+{
+ va_list args;
+ char prefix[NF_LOG_PREFIXLEN];
+ const struct nf_logger *logger;
+
+ rcu_read_lock();
+ logger = rcu_dereference(net->nf.nf_loggers[pf]);
+
+ if (logger) {
+ va_start(args, fmt);
+ vsnprintf(prefix, sizeof(prefix), fmt, args);
+ va_end(args);
+ logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(nf_log_compat);
+
#define S_SIZE (1024 - (sizeof(unsigned int) + 1))
struct nf_log_buf {
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 3b90eb2..7c9f3ec 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -94,7 +94,7 @@ static void nft_trace_packet(const struct nft_pktinfo *pkt,
{
struct net *net = dev_net(pkt->in ? pkt->in : pkt->out);
- nf_log_packet(net, pkt->xt.family, pkt->ops->hooknum, pkt->skb, pkt->in,
+ nf_log_compat(net, pkt->xt.family, pkt->ops->hooknum, pkt->skb, pkt->in,
pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
chain->table->name, chain->name, comments[type],
rulenum);
--
1.7.10.4
