session/fifo: make event unset atomic

Ensures that fifo cursize loads cannot be speculated to before the event
unset.

Change-Id: Ia7c20c510d58f26a8e9b82d3982c6d4143a3a4d6
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/src/vnet/session/application_interface.h b/src/vnet/session/application_interface.h
index 56d034e18ed..8323e72e768 100644
--- a/src/vnet/session/application_interface.h
+++ b/src/vnet/session/application_interface.h
@@ -475,9 +475,10 @@ app_send_dgram_raw (svm_fifo_t * f, app_session_transport_t * at,
   rv = svm_fifo_enqueue_nowait (f, sizeof (hdr), (u8 *) & hdr);
   ASSERT (rv == sizeof (hdr));
 
-  if ((rv = svm_fifo_enqueue_nowait (f, actual_write, data)) > 0)
+  rv = svm_fifo_enqueue_nowait (f, actual_write, data);
+  if (do_evt)
     {
-      if (do_evt && svm_fifo_set_event (f))
+      if (rv > 0 && svm_fifo_set_event (f))
 	app_send_io_evt_to_vpp (vpp_evt_q, f->master_session_index, evt_type,
 				noblock);
     }
@@ -499,9 +500,10 @@ app_send_stream_raw (svm_fifo_t * f, svm_msg_q_t * vpp_evt_q, u8 * data,
 {
   int rv;
 
-  if ((rv = svm_fifo_enqueue_nowait (f, len, data)) > 0)
+  rv = svm_fifo_enqueue_nowait (f, len, data);
+  if (do_evt)
     {
-      if (do_evt && svm_fifo_set_event (f))
+      if (rv > 0 && svm_fifo_set_event (f))
 	app_send_io_evt_to_vpp (vpp_evt_q, f->master_session_index, evt_type,
 				noblock);
     }

path: root/src/vnet/session

# Copyright (c) 2020 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Stream profile for T-rex traffic generator.

Stream profile:
 - Two streams sent in directions 0 --> 1 and 1 --> 0 at the same time.
 - Packet: ETH / IP /
 - Direction 0 --> 1:
   - Destination MAC address: 52:54:00:00:nf_id:01
   - Source IP address range:      10.10.10.1 - 10.10.10.254
   - Destination IP address range: 20.20.20.1
 - Direction 1 --> 0:
    - Destination MAC address: 52:54:00:00:nf_id:02
   - Source IP address range:      20.20.20.1 - 20.20.20.254
   - Destination IP address range: 10.10.10.1
"""

from trex.stl.api import *
from profile_trex_stateless_base_class import TrafficStreamsBaseClass


class TrafficStreams(TrafficStreamsBaseClass):
    """Stream profile."""

    def __init__(self):
        """Initialization and setting of streams' parameters."""

        super(TrafficStreamsBaseClass, self).__init__()

        # Service density parameters.
        self.nf_chains = 2
        self.nf_nodes = 4

        # MACs used in packet headers.
        self.p1_dst_start_mac = u"52:54:00:00:00:01"
        self.p2_dst_start_mac = u"52:54:00:00:00:02"

        # IPs used in packet headers.
        self.p1_src_start_ip = u"10.10.10.1"
        self.p1_src_end_ip = u"10.10.10.254"
        self.p1_dst_start_ip = u"20.20.20.1"

        self.p2_src_start_ip = u"20.20.20.1"
        self.p2_src_end_ip = u"20.20.20.254"
        self.p2_dst_start_ip = u"10.10.10.1"

    def define_packets(self):
        """Defines the packets to be sent from the traffic generator.

        Packet definition: | ETH | IP |

        :returns: Packets to be sent from the traffic generator.
        :rtype: tuple
        """

        # Direction 0 --> 1
        base_pkt_a = (
            Ether(
                dst=self.p1_dst_start_mac
            ) /
            IP(
                src=self.p1_src_start_ip,
                dst=self.p1_dst_start_ip,
                proto=61
            )
        )
        # Direction 1 --> 0
        base_pkt_b = (
            Ether(
                dst=self.p2_dst_start_mac
            ) /
            IP(
                src=self.p2_src_start_ip,
                dst=self.p2_dst_start_ip,
                proto=61
            )
        )

        # Direction 0 --> 1
        vm1 = STLScVmRaw(
            [
                STLVmFlowVar(
                    name=u"mac_dst",
                    min_value=1,
                    max_value=self.nf_chains*self.nf_nodes,
                    size=1,
                    step=self.nf_nodes,
                    op=u"inc"
                ),
                STLVmWrFlowVar(
                    fv_name=u"mac_dst",
                    pkt_offset=4
                ),
                STLVmFlowVar(
                    name=u"src",
                    min_value=self.p1_src_start_ip,
                    max_value=self.p1_src_end_ip,
                    size=4,
                    op=u"inc"
                ),
                STLVmWrFlowVar(
                    fv_name=u"src",
                    pkt_offset=u"IP.src"
                ),
                STLVmFixIpv4(
                    offset=u"IP"
                )
            ]
        )
        # Direction 1 --> 0
        vm2 = STLScVmRaw(
            [
                STLVmFlowVar(
                    name=u"mac_dst",
                    min_value=self.nf_nodes,
                    max_value=self.nf_chains*self.nf_nodes,
                    size=1,
                    step=self.nf_nodes,
                    op=u"inc"
                ),
                STLVmWrFlowVar(
                    fv_name=u"mac_dst",
                    pkt_offset=4
                ),
                STLVmFlowVar(
                    name=u"src",
                    min_value=self.p2_src_start_ip,
                    max_value=self.p2_src_end_ip,
                    size=4,
                    op=u"inc"
                ),
                STLVmWrFlowVar(
                    fv_name=u"src",
                    pkt_offset=u"IP.src"
                ),
                STLVmFixIpv4(
                    offset=u"IP"
                )
            ]
        )

        return base_pkt_a, base_pkt_b, vm1, vm2


def register():
    """Register this traffic profile to T-rex.

    Do not change this function.

    :return: Traffic streams.
    :rtype: Object
    """
    return TrafficStreams()