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 a new
nf_log_trace() function that restores the former behaviour.
Reported-by: Markus Kötter <koetter@rrzn.uni-hannover.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
                   const struct nf_loginfo *li,
                   const char *fmt, ...);
 
+__printf(8, 9)
+void nf_log_trace(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);
 
                    &chainname, &comment, &rulenum) != 0)
                        break;
 
-       nf_log_packet(net, AF_INET, hook, skb, in, out, &trace_loginfo,
-                     "TRACE: %s:%s:%s:%u ",
-                     tablename, chainname, comment, rulenum);
+       nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
+                    "TRACE: %s:%s:%s:%u ",
+                    tablename, chainname, comment, rulenum);
 }
 #endif
 
 
                    &chainname, &comment, &rulenum) != 0)
                        break;
 
-       nf_log_packet(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
-                     "TRACE: %s:%s:%s:%u ",
-                     tablename, chainname, comment, rulenum);
+       nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
+                    "TRACE: %s:%s:%s:%u ",
+                    tablename, chainname, comment, rulenum);
 }
 #endif
 
 
 }
 EXPORT_SYMBOL(nf_log_packet);
 
+void nf_log_trace(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_trace);
+
 #define S_SIZE (1024 - (sizeof(unsigned int) + 1))
 
 struct nf_log_buf {
 
 {
        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,
-                     pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
-                     chain->table->name, chain->name, comments[type],
-                     rulenum);
+       nf_log_trace(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);
 }
 
 unsigned int