vlib: don't leak node frames on refork

Free node frames in worker mains on refork. Otherwise these frames are
never returned to free pool and it causes massive memory leaks if
performed under traffic load

Type: fix
Signed-off-by: Dmitry Valter <d-valter@yandex-team.ru>
Change-Id: I15cbf024a3f4b4082445fd5e5aaa10bfcf77f363

src/plugins/vrrp/vrrp_packet.c

@@ -338,8 +338,7 @@ vrrp_adv_send (vrrp_vr_t * vr, int shutdown)
 
       if (-1 == vrrp_adv_l3_build (vr, b, dst))
 	{
-	  vlib_frame_free (vm, vlib_node_get_runtime (vm, node_index),
-			   to_frame);
+	  vlib_frame_free (vm, to_frame);
 	  vlib_buffer_free (vm, bi, n_buffers);
 	  return -1;
 	}

src/vlib/drop.c

@@ -236,7 +236,7 @@ process_drop_punt (vlib_main_t * vm,
 
       /* If there is no punt function, free the frame as well. */
       if (disposition == ERROR_DISPOSITION_PUNT && !vm->os_punt_frame)
-	vlib_frame_free (vm, node, frame);
+	vlib_frame_free (vm, frame);
     }
   else
     vm->os_punt_frame (vm, node, frame);

src/vlib/main.c

@@ -106,6 +106,7 @@ vlib_frame_alloc_to_node (vlib_main_t * vm, u32 to_node_index,
   f->vector_offset = to_node->vector_offset;
   f->aux_offset = to_node->aux_offset;
   f->flags = 0;
+  f->frame_size_index = to_node->frame_size_index;
 
   fs->n_alloc_frames += 1;
 
@@ -186,17 +187,15 @@ vlib_put_frame_to_node (vlib_main_t * vm, u32 to_node_index, vlib_frame_t * f)
 
 /* Free given frame. */
 void
-vlib_frame_free (vlib_main_t * vm, vlib_node_runtime_t * r, vlib_frame_t * f)
+vlib_frame_free (vlib_main_t *vm, vlib_frame_t *f)
 {
   vlib_node_main_t *nm = &vm->node_main;
-  vlib_node_t *node;
   vlib_frame_size_t *fs;
 
   ASSERT (vm == vlib_get_main ());
   ASSERT (f->frame_flags & VLIB_FRAME_IS_ALLOCATED);
 
-  node = vlib_get_node (vm, r->node_index);
-  fs = vec_elt_at_index (nm->frame_sizes, node->frame_size_index);
+  fs = vec_elt_at_index (nm->frame_sizes, f->frame_size_index);
 
   ASSERT (f->frame_flags & VLIB_FRAME_IS_ALLOCATED);
 
@@ -1171,7 +1170,7 @@ dispatch_pending_node (vlib_main_t * vm, uword pending_frame_index,
 	  /* The node has gained a frame, implying packets from the current frame
 	     were re-queued to this same node. we don't need the saved one
 	     anymore */
-	  vlib_frame_free (vm, n, f);
+	  vlib_frame_free (vm, f);
 	}
     }
   else
@@ -1179,7 +1178,7 @@ dispatch_pending_node (vlib_main_t * vm, uword pending_frame_index,
       if (f->frame_flags & VLIB_FRAME_FREE_AFTER_DISPATCH)
 	{
 	  ASSERT (!(n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH));
-	  vlib_frame_free (vm, n, f);
+	  vlib_frame_free (vm, f);
 	}
     }
 

src/vlib/node.c

@@ -577,7 +577,7 @@ null_node_fn (vlib_main_t * vm,
 
   vlib_node_increment_counter (vm, node->node_index, 0, n_vectors);
   vlib_buffer_free (vm, vlib_frame_vector_args (frame), n_vectors);
-  vlib_frame_free (vm, node, frame);
+  vlib_frame_free (vm, frame);
 
   return n_vectors;
 }

src/vlib/node.h

@@ -389,6 +389,9 @@ typedef struct vlib_frame_t
   /* Number of vector elements currently in frame. */
   u16 n_vectors;
 
+  /* Index of frame size corresponding to allocated node. */
+  u16 frame_size_index;
+
   /* Scalar and vector arguments to next node. */
   u8 arguments[0];
 } vlib_frame_t;

src/vlib/node_funcs.h

@@ -1256,8 +1256,7 @@ vlib_node_vectors_per_main_loop_as_integer (vlib_main_t * vm, u32 node_index)
   return v >> VLIB_LOG2_MAIN_LOOPS_PER_STATS_UPDATE;
 }
 
-void
-vlib_frame_free (vlib_main_t * vm, vlib_node_runtime_t * r, vlib_frame_t * f);
+void vlib_frame_free (vlib_main_t *vm, vlib_frame_t *f);
 
 /* Return the edge index if present, ~0 otherwise */
 uword vlib_node_get_next (vlib_main_t * vm, uword node, uword next_node);

src/vlib/threads.c

@@ -913,6 +913,17 @@ vlib_worker_thread_node_refork (void)
   vec_validate_aligned (old_counters_all_clear, j, CLIB_CACHE_LINE_BYTES);
   vm_clone->error_main.counters_last_clear = old_counters_all_clear;
 
+  for (j = 0; j < vec_len (nm_clone->next_frames); j++)
+    {
+      vlib_next_frame_t *nf = &nm_clone->next_frames[j];
+      if ((nf->flags & VLIB_FRAME_IS_ALLOCATED) && nf->frame != NULL)
+	{
+	  vlib_frame_t *f = nf->frame;
+	  nf->frame = NULL;
+	  vlib_frame_free (vm_clone, f);
+	}
+    }
+
   vec_free (nm_clone->next_frames);
   nm_clone->next_frames = vec_dup_aligned (nm->next_frames,
 					   CLIB_CACHE_LINE_BYTES);

src/vnet/ipfix-export/flow_report.c

@@ -484,8 +484,7 @@ flow_report_process_send (vlib_main_t *vm, flow_report_main_t *frm,
 	vlib_put_frame_to_node (vm, next_node, nf);
       else
 	{
-	  vlib_node_runtime_t *rt = vlib_node_get_runtime (vm, next_node);
-	  vlib_frame_free (vm, rt, nf);
+	  vlib_frame_free (vm, nf);
 	}
     }
 }

src/vnet/unix/tuntap.c

@@ -912,7 +912,7 @@ tuntap_punt_frame (vlib_main_t * vm,
 		   vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   tuntap_tx (vm, node, frame);
-  vlib_frame_free (vm, node, frame);
+  vlib_frame_free (vm, frame);
 }
 
 /**
@@ -930,7 +930,7 @@ tuntap_nopunt_frame (vlib_main_t * vm,
   u32 *buffers = vlib_frame_vector_args (frame);
   uword n_packets = frame->n_vectors;
   vlib_buffer_free (vm, buffers, n_packets);
-  vlib_frame_free (vm, node, frame);
+  vlib_frame_free (vm, frame);
 }
 
 /* *INDENT-OFF* */

test/test_vlib.py

@@ -7,6 +7,9 @@ import signal
 from config import config
 from framework import VppTestCase, VppTestRunner
 from vpp_ip_route import VppIpTable, VppIpRoute, VppRoutePath
+from scapy.layers.inet import IP, ICMP
+from scapy.layers.l2 import Ether
+from scapy.packet import Raw
 
 
 @unittest.skipUnless(config.gcov, "part of code coverage tests")
@@ -220,5 +223,105 @@ class TestVlib(VppTestCase):
                     self.logger.info(cmd + " FAIL retval " + str(r.retval))
 
 
+class TestVlibFrameLeak(VppTestCase):
+    """Vlib Frame Leak Test Cases"""
+
+    vpp_worker_count = 1
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestVlibFrameLeak, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestVlibFrameLeak, cls).tearDownClass()
+
+    def setUp(self):
+        super(TestVlibFrameLeak, self).setUp()
+        # create 1 pg interface
+        self.create_pg_interfaces(range(1))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.resolve_arp()
+
+    def tearDown(self):
+        super(TestVlibFrameLeak, self).tearDown()
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.admin_down()
+
+    def test_vlib_mw_refork_frame_leak(self):
+        """Vlib worker thread refork leak test case"""
+        icmp_id = 0xB
+        icmp_seq = 5
+        icmp_load = b"\x0a" * 18
+        pkt = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg0.local_ip4)
+            / ICMP(id=icmp_id, seq=icmp_seq)
+            / Raw(load=icmp_load)
+        )
+
+        # Send a packet
+        self.pg0.add_stream(pkt)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg0.get_capture(1)
+
+        self.assertEquals(len(rx), 1)
+        rx = rx[0]
+        ether = rx[Ether]
+        ipv4 = rx[IP]
+
+        self.assertEqual(ether.src, self.pg0.local_mac)
+        self.assertEqual(ether.dst, self.pg0.remote_mac)
+
+        self.assertEqual(ipv4.src, self.pg0.local_ip4)
+        self.assertEqual(ipv4.dst, self.pg0.remote_ip4)
+
+        # Save allocated frame count
+        frame_allocated = {}
+        for fs in self.vapi.cli("show vlib frame-allocation").splitlines()[1:]:
+            spl = fs.split()
+            thread = int(spl[0])
+            size = int(spl[1])
+            alloc = int(spl[2])
+            key = (thread, size)
+            frame_allocated[key] = alloc
+
+        # cause reforks
+        _ = self.create_loopback_interfaces(1)
+
+        # send the same packet
+        self.pg0.add_stream(pkt)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg0.get_capture(1)
+
+        self.assertEquals(len(rx), 1)
+        rx = rx[0]
+        ether = rx[Ether]
+        ipv4 = rx[IP]
+
+        self.assertEqual(ether.src, self.pg0.local_mac)
+        self.assertEqual(ether.dst, self.pg0.remote_mac)
+
+        self.assertEqual(ipv4.src, self.pg0.local_ip4)
+        self.assertEqual(ipv4.dst, self.pg0.remote_ip4)
+
+        # Check that no frame were leaked during refork
+        for fs in self.vapi.cli("show vlib frame-allocation").splitlines()[1:]:
+            spl = fs.split()
+            thread = int(spl[0])
+            size = int(spl[1])
+            alloc = int(spl[2])
+            key = (thread, size)
+            self.assertEqual(frame_allocated[key], alloc)
+
+
 if __name__ == "__main__":
     unittest.main(testRunner=VppTestRunner)