Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Highlights:

   1) Steady transitioning of the BPF instructure to a generic spot so
      all kernel subsystems can make use of it, from Alexei Starovoitov.

   2) SFC driver supports busy polling, from Alexandre Rames.

   3) Take advantage of hash table in UDP multicast delivery, from David
      Held.

   4) Lighten locking, in particular by getting rid of the LRU lists, in
      inet frag handling.  From Florian Westphal.

   5) Add support for various RFC6458 control messages in SCTP, from
      Geir Ola Vaagland.

   6) Allow to filter bridge forwarding database dumps by device, from
      Jamal Hadi Salim.

   7) virtio-net also now supports busy polling, from Jason Wang.

   8) Some low level optimization tweaks in pktgen from Jesper Dangaard
      Brouer.

   9) Add support for ipv6 address generation modes, so that userland
      can have some input into the process.  From Jiri Pirko.

  10) Consolidate common TCP connection request code in ipv4 and ipv6,
      from Octavian Purdila.

  11) New ARP packet logger in netfilter, from Pablo Neira Ayuso.

  12) Generic resizable RCU hash table, with intial users in netlink and
      nftables.  From Thomas Graf.

  13) Maintain a name assignment type so that userspace can see where a
      network device name came from (enumerated by kernel, assigned
      explicitly by userspace, etc.) From Tom Gundersen.

  14) Automatic flow label generation on transmit in ipv6, from Tom
      Herbert.

  15) New packet timestamping facilities from Willem de Bruijn, meant to
      assist in measuring latencies going into/out-of the packet
      scheduler, latency from TCP data transmission to ACK, etc"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1536 commits)
  cxgb4 : Disable recursive mailbox commands when enabling vi
  net: reduce USB network driver config options.
  tg3: Modify tg3_tso_bug() to handle multiple TX rings
  amd-xgbe: Perform phy connect/disconnect at dev open/stop
  amd-xgbe: Use dma_set_mask_and_coherent to set DMA mask
  net: sun4i-emac: fix memory leak on bad packet
  sctp: fix possible seqlock seadlock in sctp_packet_transmit()
  Revert "net: phy: Set the driver when registering an MDIO bus device"
  cxgb4vf: Turn off SGE RX/TX Callback Timers and interrupts in PCI shutdown routine
  team: Simplify return path of team_newlink
  bridge: Update outdated comment on promiscuous mode
  net-timestamp: ACK timestamp for bytestreams
  net-timestamp: TCP timestamping
  net-timestamp: SCHED timestamp on entering packet scheduler
  net-timestamp: add key to disambiguate concurrent datagrams
  net-timestamp: move timestamp flags out of sk_flags
  net-timestamp: extend SCM_TIMESTAMPING ancillary data struct
  cxgb4i : Move stray CPL definitions to cxgb4 driver
  tcp: reduce spurious retransmits due to transient SACK reneging
  qlcnic: Initialize dcbnl_ops before register_netdev
  ...

1 files changed, 39 insertions, 11 deletions

diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index e70d8b18e962..fe5cda0deb39 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -38,7 +38,7 @@
 #include "vport.h"
 
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
-			const struct nlattr *attr, int len, bool keep_skb);
+			      const struct nlattr *attr, int len);
 
 static int make_writable(struct sk_buff *skb, int write_len)
 {
@@ -434,11 +434,17 @@ static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 	return ovs_dp_upcall(dp, skb, &upcall);
 }
 
+static bool last_action(const struct nlattr *a, int rem)
+{
+	return a->nla_len == rem;
+}
+
 static int sample(struct datapath *dp, struct sk_buff *skb,
 		  const struct nlattr *attr)
 {
 	const struct nlattr *acts_list = NULL;
 	const struct nlattr *a;
+	struct sk_buff *sample_skb;
 	int rem;
 
 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
@@ -455,8 +461,34 @@ static int sample(struct datapath *dp, struct sk_buff *skb,
 		}
 	}
 
-	return do_execute_actions(dp, skb, nla_data(acts_list),
-						 nla_len(acts_list), true);
+	rem = nla_len(acts_list);
+	a = nla_data(acts_list);
+
+	/* Actions list is either empty or only contains a single user-space
+	 * action, the latter being a special case as it is the only known
+	 * usage of the sample action.
+	 * In these special cases don't clone the skb as there are no
+	 * side-effects in the nested actions.
+	 * Otherwise, clone in case the nested actions have side effects.
+	 */
+	if (likely(rem == 0 || (nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
+				last_action(a, rem)))) {
+		sample_skb = skb;
+		skb_get(skb);
+	} else {
+		sample_skb = skb_clone(skb, GFP_ATOMIC);
+		if (!sample_skb) /* Skip sample action when out of memory. */
+			return 0;
+	}
+
+	/* Note that do_execute_actions() never consumes skb.
+	 * In the case where skb has been cloned above it is the clone that
+	 * is consumed.  Otherwise the skb_get(skb) call prevents
+	 * consumption by do_execute_actions(). Thus, it is safe to simply
+	 * return the error code and let the caller (also
+	 * do_execute_actions()) free skb on error.
+	 */
+	return do_execute_actions(dp, sample_skb, a, rem);
 }
 
 static int execute_set_action(struct sk_buff *skb,
@@ -507,7 +539,7 @@ static int execute_set_action(struct sk_buff *skb,
 
 /* Execute a list of actions against 'skb'. */
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
-			const struct nlattr *attr, int len, bool keep_skb)
+			      const struct nlattr *attr, int len)
 {
 	/* Every output action needs a separate clone of 'skb', but the common
 	 * case is just a single output action, so that doing a clone and
@@ -562,12 +594,9 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 		}
 	}
 
-	if (prev_port != -1) {
-		if (keep_skb)
-			skb = skb_clone(skb, GFP_ATOMIC);
-
+	if (prev_port != -1)
 		do_output(dp, skb, prev_port);
-	} else if (!keep_skb)
+	else
 		consume_skb(skb);
 
 	return 0;
@@ -579,6 +608,5 @@ int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
 	struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
 
 	OVS_CB(skb)->tun_key = NULL;
-	return do_execute_actions(dp, skb, acts->actions,
-					 acts->actions_len, false);
+	return do_execute_actions(dp, skb, acts->actions, acts->actions_len);
 }