Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following large patchset contains Netfilter updates for your
net-next tree. My initial intention was to send you this in two goes but
when I looked back twice I already had this burden on top of me.

Several updates for IPVS from Marco Angaroni:

1) Allow SIP connections originating from real-servers to be load
   balanced by the SIP persistence engine as is already implemented
   in the other direction.

2) Release connections immediately for One-packet-scheduling (OPS)
   in IPVS, instead of making it via timer and rcu callback.

3) Skip deleting conntracks for each one packet in OPS, and don't call
   nf_conntrack_alter_reply() since no reply is expected.

4) Enable drop on exhaustion for OPS + SIP persistence.

Miscelaneous conntrack updates from Florian Westphal, including fix for
hash resize:

5) Move conntrack generation counter out of conntrack pernet structure
   since this is only used by the init_ns to allow hash resizing.

6) Use get_random_once() from packet path to collect hash random seed
    instead of our compound.

7) Don't disable BH from ____nf_conntrack_find() for statistics,
   use NF_CT_STAT_INC_ATOMIC() instead.

8) Fix lookup race during conntrack hash resizing.

9) Introduce clash resolution on conntrack insertion for connectionless
   protocol.

Then, Florian's netns rework to get rid of per-netns conntrack table,
thus we use one single table for them all. There was consensus on this
change during the NFWS 2015 and, on top of that, it has recently been
pointed as a source of multiple problems from unpriviledged netns:

11) Use a single conntrack hashtable for all namespaces. Include netns
    in object comparisons and make it part of the hash calculation.
    Adapt early_drop() to consider netns.

12) Use single expectation and NAT hashtable for all namespaces.

13) Use a single slab cache for all namespaces for conntrack objects.

14) Skip full table scanning from nf_ct_iterate_cleanup() if the pernet
    conntrack counter tells us the table is empty (ie. equals zero).

Fixes for nf_tables interval set element handling, support to set
conntrack connlabels and allow set names up to 32 bytes.

15) Parse element flags from element deletion path and pass it up to the
    backend set implementation.

16) Allow adjacent intervals in the rbtree set type for dynamic interval
    updates.

17) Add support to set connlabel from nf_tables, from Florian Westphal.

18) Allow set names up to 32 bytes in nf_tables.

Several x_tables fixes and updates:

19) Fix incorrect use of IS_ERR_VALUE() in x_tables, original patch
    from Andrzej Hajda.

And finally, miscelaneous netfilter updates such as:

20) Disable automatic helper assignment by default. Note this proc knob
    was introduced by a9006892643a ("netfilter: nf_ct_helper: allow to
    disable automatic helper assignment") 4 years ago to start moving
    towards explicit conntrack helper configuration via iptables CT
    target.

21) Get rid of obsolete and inconsistent debugging instrumentation
    in x_tables.

22) Remove unnecessary check for null after ip6_route_output().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 269 insertions, 9 deletions

diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 85ca189bdc3d..2cb3c626cd43 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -104,6 +104,7 @@ static inline void ct_write_unlock_bh(unsigned int key)
 	spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 }
 
+static void ip_vs_conn_expire(unsigned long data);
 
 /*
  *	Returns hash value for IPVS connection entry
@@ -453,10 +454,16 @@ ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
 }
 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 
+static void __ip_vs_conn_put_notimer(struct ip_vs_conn *cp)
+{
+	__ip_vs_conn_put(cp);
+	ip_vs_conn_expire((unsigned long)cp);
+}
+
 /*
  *      Put back the conn and restart its timer with its timeout
  */
-void ip_vs_conn_put(struct ip_vs_conn *cp)
+static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
 {
 	unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 		0 : cp->timeout;
@@ -465,6 +472,16 @@ void ip_vs_conn_put(struct ip_vs_conn *cp)
 	__ip_vs_conn_put(cp);
 }
 
+void ip_vs_conn_put(struct ip_vs_conn *cp)
+{
+	if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
+	    (atomic_read(&cp->refcnt) == 1) &&
+	    !timer_pending(&cp->timer))
+		/* expire connection immediately */
+		__ip_vs_conn_put_notimer(cp);
+	else
+		__ip_vs_conn_put_timer(cp);
+}
 
 /*
  *	Fill a no_client_port connection with a client port number
@@ -819,7 +836,8 @@ static void ip_vs_conn_expire(unsigned long data)
 		if (cp->control)
 			ip_vs_control_del(cp);
 
-		if (cp->flags & IP_VS_CONN_F_NFCT) {
+		if ((cp->flags & IP_VS_CONN_F_NFCT) &&
+		    !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
 			/* Do not access conntracks during subsys cleanup
 			 * because nf_conntrack_find_get can not be used after
 			 * conntrack cleanup for the net.
@@ -834,7 +852,10 @@ static void ip_vs_conn_expire(unsigned long data)
 		ip_vs_unbind_dest(cp);
 		if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 			atomic_dec(&ip_vs_conn_no_cport_cnt);
-		call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
+		if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
+			ip_vs_conn_rcu_free(&cp->rcu_head);
+		else
+			call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
 		atomic_dec(&ipvs->conn_count);
 		return;
 	}
@@ -850,7 +871,7 @@ static void ip_vs_conn_expire(unsigned long data)
 	if (ipvs->sync_state & IP_VS_STATE_MASTER)
 		ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
 
-	ip_vs_conn_put(cp);
+	__ip_vs_conn_put_timer(cp);
 }
 
 /* Modify timer, so that it expires as soon as possible.
@@ -1240,6 +1261,16 @@ static inline int todrop_entry(struct ip_vs_conn *cp)
 	return 1;
 }
 
+static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
+{
+	struct ip_vs_service *svc;
+
+	if (!cp->dest)
+		return false;
+	svc = rcu_dereference(cp->dest->svc);
+	return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
+}
+
 /* Called from keventd and must protect itself from softirqs */
 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
 {
@@ -1254,11 +1285,16 @@ void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
 		unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
 
 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
-			if (cp->flags & IP_VS_CONN_F_TEMPLATE)
-				/* connection template */
-				continue;
 			if (cp->ipvs != ipvs)
 				continue;
+			if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
+				if (atomic_read(&cp->n_control) ||
+				    !ip_vs_conn_ops_mode(cp))
+					continue;
+				else
+					/* connection template of OPS */
+					goto try_drop;
+			}
 			if (cp->protocol == IPPROTO_TCP) {
 				switch(cp->state) {
 				case IP_VS_TCP_S_SYN_RECV:
@@ -1286,6 +1322,7 @@ void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
 					continue;
 				}
 			} else {
+try_drop:
 				if (!todrop_entry(cp))
 					continue;
 			}
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index b9a4082afa3a..1207f20d24e4 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -68,6 +68,7 @@ EXPORT_SYMBOL(ip_vs_conn_put);
 #ifdef CONFIG_IP_VS_DEBUG
 EXPORT_SYMBOL(ip_vs_get_debug_level);
 #endif
+EXPORT_SYMBOL(ip_vs_new_conn_out);
 
 static int ip_vs_net_id __read_mostly;
 /* netns cnt used for uniqueness */
@@ -611,7 +612,10 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 		ret = cp->packet_xmit(skb, cp, pd->pp, iph);
 		/* do not touch skb anymore */
 
-		atomic_inc(&cp->in_pkts);
+		if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
+			atomic_inc(&cp->control->in_pkts);
+		else
+			atomic_inc(&cp->in_pkts);
 		ip_vs_conn_put(cp);
 		return ret;
 	}
@@ -1100,6 +1104,143 @@ static inline bool is_new_conn_expected(const struct ip_vs_conn *cp,
 	}
 }
 
+/* Generic function to create new connections for outgoing RS packets
+ *
+ * Pre-requisites for successful connection creation:
+ * 1) Virtual Service is NOT fwmark based:
+ *    In fwmark-VS actual vaddr and vport are unknown to IPVS
+ * 2) Real Server and Virtual Service were NOT configured without port:
+ *    This is to allow match of different VS to the same RS ip-addr
+ */
+struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
+				      struct ip_vs_dest *dest,
+				      struct sk_buff *skb,
+				      const struct ip_vs_iphdr *iph,
+				      __be16 dport,
+				      __be16 cport)
+{
+	struct ip_vs_conn_param param;
+	struct ip_vs_conn *ct = NULL, *cp = NULL;
+	const union nf_inet_addr *vaddr, *daddr, *caddr;
+	union nf_inet_addr snet;
+	__be16 vport;
+	unsigned int flags;
+
+	EnterFunction(12);
+	vaddr = &svc->addr;
+	vport = svc->port;
+	daddr = &iph->saddr;
+	caddr = &iph->daddr;
+
+	/* check pre-requisites are satisfied */
+	if (svc->fwmark)
+		return NULL;
+	if (!vport || !dport)
+		return NULL;
+
+	/* for persistent service first create connection template */
+	if (svc->flags & IP_VS_SVC_F_PERSISTENT) {
+		/* apply netmask the same way ingress-side does */
+#ifdef CONFIG_IP_VS_IPV6
+		if (svc->af == AF_INET6)
+			ipv6_addr_prefix(&snet.in6, &caddr->in6,
+					 (__force __u32)svc->netmask);
+		else
+#endif
+			snet.ip = caddr->ip & svc->netmask;
+		/* fill params and create template if not existent */
+		if (ip_vs_conn_fill_param_persist(svc, skb, iph->protocol,
+						  &snet, 0, vaddr,
+						  vport, &param) < 0)
+			return NULL;
+		ct = ip_vs_ct_in_get(&param);
+		if (!ct) {
+			ct = ip_vs_conn_new(&param, dest->af, daddr, dport,
+					    IP_VS_CONN_F_TEMPLATE, dest, 0);
+			if (!ct) {
+				kfree(param.pe_data);
+				return NULL;
+			}
+			ct->timeout = svc->timeout;
+		} else {
+			kfree(param.pe_data);
+		}
+	}
+
+	/* connection flags */
+	flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET) &&
+		 iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;
+	/* create connection */
+	ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
+			      caddr, cport, vaddr, vport, &param);
+	cp = ip_vs_conn_new(&param, dest->af, daddr, dport, flags, dest, 0);
+	if (!cp) {
+		if (ct)
+			ip_vs_conn_put(ct);
+		return NULL;
+	}
+	if (ct) {
+		ip_vs_control_add(cp, ct);
+		ip_vs_conn_put(ct);
+	}
+	ip_vs_conn_stats(cp, svc);
+
+	/* return connection (will be used to handle outgoing packet) */
+	IP_VS_DBG_BUF(6, "New connection RS-initiated:%c c:%s:%u v:%s:%u "
+		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
+		      ip_vs_fwd_tag(cp),
+		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
+		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
+		      IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
+		      cp->flags, atomic_read(&cp->refcnt));
+	LeaveFunction(12);
+	return cp;
+}
+
+/* Handle outgoing packets which are considered requests initiated by
+ * real servers, so that subsequent responses from external client can be
+ * routed to the right real server.
+ * Used also for outgoing responses in OPS mode.
+ *
+ * Connection management is handled by persistent-engine specific callback.
+ */
+static struct ip_vs_conn *__ip_vs_rs_conn_out(unsigned int hooknum,
+					      struct netns_ipvs *ipvs,
+					      int af, struct sk_buff *skb,
+					      const struct ip_vs_iphdr *iph)
+{
+	struct ip_vs_dest *dest;
+	struct ip_vs_conn *cp = NULL;
+	__be16 _ports[2], *pptr;
+
+	if (hooknum == NF_INET_LOCAL_IN)
+		return NULL;
+
+	pptr = frag_safe_skb_hp(skb, iph->len,
+				sizeof(_ports), _ports, iph);
+	if (!pptr)
+		return NULL;
+
+	rcu_read_lock();
+	dest = ip_vs_find_real_service(ipvs, af, iph->protocol,
+				       &iph->saddr, pptr[0]);
+	if (dest) {
+		struct ip_vs_service *svc;
+		struct ip_vs_pe *pe;
+
+		svc = rcu_dereference(dest->svc);
+		if (svc) {
+			pe = rcu_dereference(svc->pe);
+			if (pe && pe->conn_out)
+				cp = pe->conn_out(svc, dest, skb, iph,
+						  pptr[0], pptr[1]);
+		}
+	}
+	rcu_read_unlock();
+
+	return cp;
+}
+
 /* Handle response packets: rewrite addresses and send away...
  */
 static unsigned int
@@ -1245,6 +1386,22 @@ ip_vs_out(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, in
 
 	if (likely(cp))
 		return handle_response(af, skb, pd, cp, &iph, hooknum);
+
+	/* Check for real-server-started requests */
+	if (atomic_read(&ipvs->conn_out_counter)) {
+		/* Currently only for UDP:
+		 * connection oriented protocols typically use
+		 * ephemeral ports for outgoing connections, so
+		 * related incoming responses would not match any VS
+		 */
+		if (pp->protocol == IPPROTO_UDP) {
+			cp = __ip_vs_rs_conn_out(hooknum, ipvs, af, skb, &iph);
+			if (likely(cp))
+				return handle_response(af, skb, pd, cp, &iph,
+						       hooknum);
+		}
+	}
+
 	if (sysctl_nat_icmp_send(ipvs) &&
 	    (pp->protocol == IPPROTO_TCP ||
 	     pp->protocol == IPPROTO_UDP ||
@@ -1837,6 +1994,9 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 
 	if (ipvs->sync_state & IP_VS_STATE_MASTER)
 		ip_vs_sync_conn(ipvs, cp, pkts);
+	else if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
+		/* increment is done inside ip_vs_sync_conn too */
+		atomic_inc(&cp->control->in_pkts);
 
 	ip_vs_conn_put(cp);
 	return ret;
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index f35ebc02fa5c..c3c809b2e712 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -567,6 +567,36 @@ bool ip_vs_has_real_service(struct netns_ipvs *ipvs, int af, __u16 protocol,
 	return false;
 }
 
+/* Find real service record by <proto,addr,port>.
+ * In case of multiple records with the same <proto,addr,port>, only
+ * the first found record is returned.
+ *
+ * To be called under RCU lock.
+ */
+struct ip_vs_dest *ip_vs_find_real_service(struct netns_ipvs *ipvs, int af,
+					   __u16 protocol,
+					   const union nf_inet_addr *daddr,
+					   __be16 dport)
+{
+	unsigned int hash;
+	struct ip_vs_dest *dest;
+
+	/* Check for "full" addressed entries */
+	hash = ip_vs_rs_hashkey(af, daddr, dport);
+
+	hlist_for_each_entry_rcu(dest, &ipvs->rs_table[hash], d_list) {
+		if (dest->port == dport &&
+		    dest->af == af &&
+		    ip_vs_addr_equal(af, &dest->addr, daddr) &&
+			(dest->protocol == protocol || dest->vfwmark)) {
+			/* HIT */
+			return dest;
+		}
+	}
+
+	return NULL;
+}
+
 /* Lookup destination by {addr,port} in the given service
  * Called under RCU lock.
  */
@@ -1253,6 +1283,8 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
 		atomic_inc(&ipvs->ftpsvc_counter);
 	else if (svc->port == 0)
 		atomic_inc(&ipvs->nullsvc_counter);
+	if (svc->pe && svc->pe->conn_out)
+		atomic_inc(&ipvs->conn_out_counter);
 
 	ip_vs_start_estimator(ipvs, &svc->stats);
 
@@ -1293,6 +1325,7 @@ ip_vs_edit_service(struct ip_vs_service *svc, struct ip_vs_service_user_kern *u)
 	struct ip_vs_scheduler *sched = NULL, *old_sched;
 	struct ip_vs_pe *pe = NULL, *old_pe = NULL;
 	int ret = 0;
+	bool new_pe_conn_out, old_pe_conn_out;
 
 	/*
 	 * Lookup the scheduler, by 'u->sched_name'
@@ -1355,8 +1388,16 @@ ip_vs_edit_service(struct ip_vs_service *svc, struct ip_vs_service_user_kern *u)
 	svc->netmask = u->netmask;
 
 	old_pe = rcu_dereference_protected(svc->pe, 1);
-	if (pe != old_pe)
+	if (pe != old_pe) {
 		rcu_assign_pointer(svc->pe, pe);
+		/* check for optional methods in new pe */
+		new_pe_conn_out = (pe && pe->conn_out) ? true : false;
+		old_pe_conn_out = (old_pe && old_pe->conn_out) ? true : false;
+		if (new_pe_conn_out && !old_pe_conn_out)
+			atomic_inc(&svc->ipvs->conn_out_counter);
+		if (old_pe_conn_out && !new_pe_conn_out)
+			atomic_dec(&svc->ipvs->conn_out_counter);
+	}
 
 out:
 	ip_vs_scheduler_put(old_sched);
@@ -1389,6 +1430,8 @@ static void __ip_vs_del_service(struct ip_vs_service *svc, bool cleanup)
 
 	/* Unbind persistence engine, keep svc->pe */
 	old_pe = rcu_dereference_protected(svc->pe, 1);
+	if (old_pe && old_pe->conn_out)
+		atomic_dec(&ipvs->conn_out_counter);
 	ip_vs_pe_put(old_pe);
 
 	/*
@@ -3969,6 +4012,7 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
 		    (unsigned long) ipvs);
 	atomic_set(&ipvs->ftpsvc_counter, 0);
 	atomic_set(&ipvs->nullsvc_counter, 0);
+	atomic_set(&ipvs->conn_out_counter, 0);
 
 	/* procfs stats */
 	ipvs->tot_stats.cpustats = alloc_percpu(struct ip_vs_cpu_stats);
diff --git a/net/netfilter/ipvs/ip_vs_nfct.c b/net/netfilter/ipvs/ip_vs_nfct.c
index 30434fb133df..f04fd8df210b 100644
--- a/net/netfilter/ipvs/ip_vs_nfct.c
+++ b/net/netfilter/ipvs/ip_vs_nfct.c
@@ -93,6 +93,10 @@ ip_vs_update_conntrack(struct sk_buff *skb, struct ip_vs_conn *cp, int outin)
 	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
 		return;
 
+	/* Never alter conntrack for OPS conns (no reply is expected) */
+	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
+		return;
+
 	/* Alter reply only in original direction */
 	if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 		return;
diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
index 0a6eb5c0d9e9..d07ef9e31c12 100644
--- a/net/netfilter/ipvs/ip_vs_pe_sip.c
+++ b/net/netfilter/ipvs/ip_vs_pe_sip.c
@@ -143,6 +143,20 @@ static int ip_vs_sip_show_pe_data(const struct ip_vs_conn *cp, char *buf)
 	return cp->pe_data_len;
 }
 
+static struct ip_vs_conn *
+ip_vs_sip_conn_out(struct ip_vs_service *svc,
+		   struct ip_vs_dest *dest,
+		   struct sk_buff *skb,
+		   const struct ip_vs_iphdr *iph,
+		   __be16 dport,
+		   __be16 cport)
+{
+	if (likely(iph->protocol == IPPROTO_UDP))
+		return ip_vs_new_conn_out(svc, dest, skb, iph, dport, cport);
+	/* currently no need to handle other than UDP */
+	return NULL;
+}
+
 static struct ip_vs_pe ip_vs_sip_pe =
 {
 	.name =			"sip",
@@ -153,6 +167,7 @@ static struct ip_vs_pe ip_vs_sip_pe =
 	.ct_match =		ip_vs_sip_ct_match,
 	.hashkey_raw =		ip_vs_sip_hashkey_raw,
 	.show_pe_data =		ip_vs_sip_show_pe_data,
+	.conn_out =		ip_vs_sip_conn_out,
 };
 
 static int __init ip_vs_sip_init(void)