text: /*
   * Copyright (c) 2010, 2011, 2012, 2013, 2015, 2016, 2017 Nicira, Inc.
   *
   * 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.
   */
  
  #include <config.h>
  
  #include "dummy.h"
  
  #include <errno.h>
  #include <unistd.h>
  
  #include "dp-packet.h"
  #include "dpif-netdev.h"
  #include "flow.h"
  #include "netdev-provider.h"
  #include "netdev-vport.h"
  #include "odp-util.h"
  #include "openvswitch/dynamic-string.h"
  #include "openvswitch/list.h"
  #include "openvswitch/ofp-print.h"
  #include "openvswitch/ofpbuf.h"
  #include "openvswitch/vlog.h"
  #include "ovs-atomic.h"
  #include "packets.h"
  #include "pcap-file.h"
  #include "poll-loop.h"
  #include "openvswitch/shash.h"
  #include "sset.h"
  #include "stream.h"
  #include "unaligned.h"
  #include "timeval.h"
  #include "unixctl.h"
  #include "reconnect.h"
  
  VLOG_DEFINE_THIS_MODULE(netdev_dummy);
  
  struct reconnect;
  
  struct dummy_packet_stream {
      struct stream *stream;
      struct dp_packet rxbuf;
      struct ovs_list txq;
  };
  
  enum dummy_packet_conn_type {
      NONE,       /* No connection is configured. */
      PASSIVE,    /* Listener. */
      ACTIVE      /* Connect to listener. */
  };
  
  enum dummy_netdev_conn_state {
      CONN_STATE_CONNECTED,      /* Listener connected. */
      CONN_STATE_NOT_CONNECTED,  /* Listener not connected.  */
      CONN_STATE_UNKNOWN,        /* No relavent information.  */
  };
  
  struct dummy_packet_pconn {
      struct pstream *pstream;
      struct dummy_packet_stream **streams;
      size_t n_streams;
  };
  
  struct dummy_packet_rconn {
      struct dummy_packet_stream *rstream;
      struct reconnect *reconnect;
  };
  
  struct dummy_packet_conn {
      enum dummy_packet_conn_type type;
      union {
          struct dummy_packet_pconn pconn;
          struct dummy_packet_rconn rconn;
      } u;
  };
  
  struct pkt_list_node {
      struct dp_packet *pkt;
      struct ovs_list list_node;
  };
  
  /* Protects 'dummy_list'. */
  static struct ovs_mutex dummy_list_mutex = OVS_MUTEX_INITIALIZER;
  
  /* Contains all 'struct dummy_dev's. */
  static struct ovs_list dummy_list OVS_GUARDED_BY(dummy_list_mutex)
      = OVS_LIST_INITIALIZER(&dummy_list);
  
  struct netdev_dummy {
      struct netdev up;
  
      /* In dummy_list. */
      struct ovs_list list_node OVS_GUARDED_BY(dummy_list_mutex);
  
      /* Protects all members below. */
      struct ovs_mutex mutex OVS_ACQ_AFTER(dummy_list_mutex);
  
      struct eth_addr hwaddr OVS_GUARDED;
      int mtu OVS_GUARDED;
      struct netdev_stats stats OVS_GUARDED;
      enum netdev_flags flags OVS_GUARDED;
      int ifindex OVS_GUARDED;
      int numa_id OVS_GUARDED;
  
      struct dummy_packet_conn conn OVS_GUARDED;
  
      FILE *tx_pcap, *rxq_pcap OVS_GUARDED;
  
      struct in_addr address, netmask;
      struct in6_addr ipv6, ipv6_mask;
      struct ovs_list rxes OVS_GUARDED; /* List of child "netdev_rxq_dummy"s. */
  
      /* The following properties are for dummy-pmd and they cannot be changed
       * when a device is running, so we remember the request and update them
       * next time netdev_dummy_reconfigure() is called. */
      int requested_n_txq OVS_GUARDED;
      int requested_n_rxq OVS_GUARDED;
      int requested_numa_id OVS_GUARDED;
  };
  
  /* Max 'recv_queue_len' in struct netdev_dummy. */
  #define NETDEV_DUMMY_MAX_QUEUE 100
  
  struct netdev_rxq_dummy {
      struct netdev_rxq up;
      struct ovs_list node;       /* In netdev_dummy's "rxes" list. */
      struct ovs_list recv_queue;
      int recv_queue_len;         /* ovs_list_size(&recv_queue). */
      struct seq *seq;            /* Reports newly queued packets. */
  };
  
  static unixctl_cb_func netdev_dummy_set_admin_state;
  static int netdev_dummy_construct(struct netdev *);
  static void netdev_dummy_queue_packet(struct netdev_dummy *,
                                        struct dp_packet *, int);
  
  static void dummy_packet_stream_close(struct dummy_packet_stream *);
  
  static void pkt_list_delete(struct ovs_list *);
  
  static bool
  is_dummy_class(const struct netdev_class *class)
  {
      return class->construct == netdev_dummy_construct;
  }
  
  static struct netdev_dummy *
  netdev_dummy_cast(const struct netdev *netdev)
  {
      ovs_assert(is_dummy_class(netdev_get_class(netdev)));
      return CONTAINER_OF(netdev, struct netdev_dummy, up);
  }
  
  static struct netdev_rxq_dummy *
  netdev_rxq_dummy_cast(const struct netdev_rxq *rx)
  {
      ovs_assert(is_dummy_class(netdev_get_class(rx->netdev)));
      return CONTAINER_OF(rx, struct netdev_rxq_dummy, up);
  }
  
  static void
  dummy_packet_stream_init(struct dummy_packet_stream *s, struct stream *stream)
  {
      int rxbuf_size = stream ? 2048 : 0;
      s->stream = stream;
      dp_packet_init(&s->rxbuf, rxbuf_size);
      ovs_list_init(&s->txq);
  }
  
  static struct dummy_packet_stream *
  dummy_packet_stream_create(struct stream *stream)
  {
      struct dummy_packet_stream *s;
  
      s = xzalloc(sizeof *s);
      dummy_packet_stream_init(s, stream);
  
      return s;
  }
  
  static void
  dummy_packet_stream_wait(struct dummy_packet_stream *s)
  {
      stream_run_wait(s->stream);
      if (!ovs_list_is_empty(&s->txq)) {
          stream_send_wait(s->stream);
      }
      stream_recv_wait(s->stream);
  }
  
  static void
  dummy_packet_stream_send(struct dummy_packet_stream *s, const void *buffer, size_t size)
  {
      if (ovs_list_size(&s->txq) < NETDEV_DUMMY_MAX_QUEUE) {
          struct dp_packet *b;
          struct pkt_list_node *node;
  
          b = dp_packet_clone_data_with_headroom(buffer, size, 2);
          put_unaligned_be16(dp_packet_push_uninit(b, 2), htons(size));
  
          node = xmalloc(sizeof *node);
          node->pkt = b;
          ovs_list_push_back(&s->txq, &node->list_node);
      }
  }
  
  static int
  dummy_packet_stream_run(struct netdev_dummy *dev, struct dummy_packet_stream *s)
  {
      int error = 0;
      size_t n;
  
      stream_run(s->stream);
  
      if (!ovs_list_is_empty(&s->txq)) {
          struct pkt_list_node *txbuf_node;
          struct dp_packet *txbuf;
          int retval;
  
          ASSIGN_CONTAINER(txbuf_node, ovs_list_front(&s->txq), list_node);
          txbuf = txbuf_node->pkt;
          retval = stream_send(s->stream, dp_packet_data(txbuf), dp_packet_size(txbuf));
  
          if (retval > 0) {
              dp_packet_pull(txbuf, retval);
              if (!dp_packet_size(txbuf)) {
                  ovs_list_remove(&txbuf_node->list_node);
                  free(txbuf_node);
                  dp_packet_delete(txbuf);
              }
          } else if (retval != -EAGAIN) {
              error = -retval;
          }
      }
  
      if (!error) {
          if (dp_packet_size(&s->rxbuf) < 2) {
              n = 2 - dp_packet_size(&s->rxbuf);
          } else {
              uint16_t frame_len;
  
              frame_len = ntohs(get_unaligned_be16(dp_packet_data(&s->rxbuf)));
              if (frame_len < ETH_HEADER_LEN) {
                  error = EPROTO;
                  n = 0;
              } else {
                  n = (2 + frame_len) - dp_packet_size(&s->rxbuf);
              }
          }
      }
      if (!error) {
          int retval;
  
          dp_packet_prealloc_tailroom(&s->rxbuf, n);
          retval = stream_recv(s->stream, dp_packet_tail(&s->rxbuf), n);
  
          if (retval > 0) {
              dp_packet_set_size(&s->rxbuf, dp_packet_size(&s->rxbuf) + retval);
              if (retval == n && dp_packet_size(&s->rxbuf) > 2) {
                  dp_packet_pull(&s->rxbuf, 2);
                  netdev_dummy_queue_packet(dev,
                                            dp_packet_clone(&s->rxbuf), 0);
                  dp_packet_clear(&s->rxbuf);
              }
          } else if (retval != -EAGAIN) {
              error = (retval < 0 ? -retval
                       : dp_packet_size(&s->rxbuf) ? EPROTO
                       : EOF);
          }
      }
  
      return error;
  }
  
  static void
  dummy_packet_stream_close(struct dummy_packet_stream *s)
  {
      stream_close(s->stream);
      dp_packet_uninit(&s->rxbuf);
      pkt_list_delete(&s->txq);
  }
  
  static void
  dummy_packet_conn_init(struct dummy_packet_conn *conn)
  {
      memset(conn, 0, sizeof *conn);
      conn->type = NONE;
  }
  
  static void
  dummy_packet_conn_get_config(struct dummy_packet_conn *conn, struct smap *args)
  {
  
      switch (conn->type) {
      case PASSIVE:
          smap_add(args, "pstream", pstream_get_name(conn->u.pconn.pstream));
          break;
  
      case ACTIVE:
          smap_add(args, "stream", stream_get_name(conn->u.rconn.rstream->stream));
          break;
  
      case NONE:
      default:
          break;
      }
  }
  
  static void
  dummy_packet_conn_close(struct dummy_packet_conn *conn)
  {
      int i;
      struct dummy_packet_pconn *pconn = &conn->u.pconn;
      struct dummy_packet_rconn *rconn = &conn->u.rconn;
  
      switch (conn->type) {
      case PASSIVE:
          pstream_close(pconn->pstream);
          for (i = 0; i < pconn->n_streams; i++) {
              dummy_packet_stream_close(pconn->streams[i]);
              free(pconn->streams[i]);
          }
          free(pconn->streams);
          pconn->pstream = NULL;
          pconn->streams = NULL;
          break;
  
      case ACTIVE:
          dummy_packet_stream_close(rconn->rstream);
          free(rconn->rstream);
          rconn->rstream = NULL;
          reconnect_destroy(rconn->reconnect);
          rconn->reconnect = NULL;
          break;
  
      case NONE:
      default:
          break;
      }
  
      conn->type = NONE;
      memset(conn, 0, sizeof *conn);
  }
  
  static void
  dummy_packet_conn_set_config(struct dummy_packet_conn *conn,
                               const struct smap *args)
  {
      const char *pstream = smap_get(args, "pstream");
      const char *stream = smap_get(args, "stream");
  
      if (pstream && stream) {
           VLOG_WARN("Open failed: both %s and %s are configured",
                     pstream, stream);
           return;
      }
  
      switch (conn->type) {
      case PASSIVE:
          if (pstream &&
              !strcmp(pstream_get_name(conn->u.pconn.pstream), pstream)) {
              return;
          }
          dummy_packet_conn_close(conn);
          break;
      case ACTIVE:
          if (stream &&
              !strcmp(stream_get_name(conn->u.rconn.rstream->stream), stream)) {
              return;
          }
          dummy_packet_conn_close(conn);
          break;
      case NONE:
      default:
          break;
      }
  
      if (pstream) {
          int error;
  
          error = pstream_open(pstream, &conn->u.pconn.pstream, DSCP_DEFAULT);
          if (error) {
              VLOG_WARN("%s: open failed (%s)", pstream, ovs_strerror(error));
          } else {
              conn->type = PASSIVE;
          }
      }
  
      if (stream) {
          int error;
          struct stream *active_stream;
          struct reconnect *reconnect;
  
          reconnect = reconnect_create(time_msec());
          reconnect_set_name(reconnect, stream);
          reconnect_set_passive(reconnect, false, time_msec());
          reconnect_enable(reconnect, time_msec());
          reconnect_set_backoff(reconnect, 100, INT_MAX);
          reconnect_set_probe_interval(reconnect, 0);
          conn->u.rconn.reconnect = reconnect;
          conn->type = ACTIVE;
  
          error = stream_open(stream, &active_stream, DSCP_DEFAULT);
          conn->u.rconn.rstream = dummy_packet_stream_create(active_stream);
  
          switch (error) {
          case 0:
              reconnect_connected(reconnect, time_msec());
              break;
  
          case EAGAIN:
              reconnect_connecting(reconnect, time_msec());
              break;
  
          default:
              reconnect_connect_failed(reconnect, time_msec(), error);
              stream_close(active_stream);
              conn->u.rconn.rstream->stream = NULL;
              break;
          }
      }
  }
  
  static void
  dummy_pconn_run(struct netdev_dummy *dev)
      OVS_REQUIRES(dev->mutex)
  {
      struct stream *new_stream;
      struct dummy_packet_pconn *pconn = &dev->conn.u.pconn;
      int error;
      size_t i;
  
      error = pstream_accept(pconn->pstream, &new_stream);
      if (!error) {
          struct dummy_packet_stream *s;
  
          pconn->streams = xrealloc(pconn->streams,
                                  ((pconn->n_streams + 1)
                                   * sizeof s));
          s = xmalloc(sizeof *s);
          pconn->streams[pconn->n_streams++] = s;
          dummy_packet_stream_init(s, new_stream);
      } else if (error != EAGAIN) {
          VLOG_WARN("%s: accept failed (%s)",
                    pstream_get_name(pconn->pstream), ovs_strerror(error));
          pstream_close(pconn->pstream);
          pconn->pstream = NULL;
          dev->conn.type = NONE;
      }
  
      for (i = 0; i < pconn->n_streams; ) {
          struct dummy_packet_stream *s = pconn->streams[i];
  
          error = dummy_packet_stream_run(dev, s);
          if (error) {
              VLOG_DBG("%s: closing connection (%s)",
                       stream_get_name(s->stream),
                       ovs_retval_to_string(error));
              dummy_packet_stream_close(s);
              free(s);
              pconn->streams[i] = pconn->streams[--pconn->n_streams];
          } else {
              i++;
          }
      }
  }
  
  static void
  dummy_rconn_run(struct netdev_dummy *dev)
  OVS_REQUIRES(dev->mutex)
  {
      struct dummy_packet_rconn *rconn = &dev->conn.u.rconn;
  
      switch (reconnect_run(rconn->reconnect, time_msec())) {
      case RECONNECT_CONNECT:
          {
              int error;
  
              if (rconn->rstream->stream) {
                  error = stream_connect(rconn->rstream->stream);
              } else {
                  error = stream_open(reconnect_get_name(rconn->reconnect),
                                      &rconn->rstream->stream, DSCP_DEFAULT);
              }
  
              switch (error) {
              case 0:
                  reconnect_connected(rconn->reconnect, time_msec());
                  break;
  
              case EAGAIN:
                  reconnect_connecting(rconn->reconnect, time_msec());
                  break;
  
              default:
                  reconnect_connect_failed(rconn->reconnect, time_msec(), error);
                  stream_close(rconn->rstream->stream);
                  rconn->rstream->stream = NULL;
                  break;
              }
          }
          break;
  
      case RECONNECT_DISCONNECT:
      case RECONNECT_PROBE:
      default:
          break;
      }
  
      if (reconnect_is_connected(rconn->reconnect)) {
          int err;
  
          err = dummy_packet_stream_run(dev, rconn->rstream);
  
          if (err) {
              reconnect_disconnected(rconn->reconnect, time_msec(), err);
              stream_close(rconn->rstream->stream);
              rconn->rstream->stream = NULL;
          }
      }
  }
  
  static void
  dummy_packet_conn_run(struct netdev_dummy *dev)
      OVS_REQUIRES(dev->mutex)
  {
      switch (dev->conn.type) {
      case PASSIVE:
          dummy_pconn_run(dev);
          break;
  
      case ACTIVE:
          dummy_rconn_run(dev);
          break;
  
      case NONE:
      default:
          break;
      }
  }
  
  static void
  dummy_packet_conn_wait(struct dummy_packet_conn *conn)
  {
      int i;
      switch (conn->type) {
      case PASSIVE:
          pstream_wait(conn->u.pconn.pstream);
          for (i = 0; i < conn->u.pconn.n_streams; i++) {
              struct dummy_packet_stream *s = conn->u.pconn.streams[i];
              dummy_packet_stream_wait(s);
          }
          break;
      case ACTIVE:
          if (reconnect_is_connected(conn->u.rconn.reconnect)) {
              dummy_packet_stream_wait(conn->u.rconn.rstream);
          }
          break;
  
      case NONE:
      default:
          break;
      }
  }
  
  static void
  dummy_packet_conn_send(struct dummy_packet_conn *conn,
                         const void *buffer, size_t size)
  {
      int i;
  
      switch (conn->type) {
      case PASSIVE:
          for (i = 0; i < conn->u.pconn.n_streams; i++) {
              struct dummy_packet_stream *s = conn->u.pconn.streams[i];
  
              dummy_packet_stream_send(s, buffer, size);
              pstream_wait(conn->u.pconn.pstream);
          }
          break;
  
      case ACTIVE:
          if (reconnect_is_connected(conn->u.rconn.reconnect)) {
              dummy_packet_stream_send(conn->u.rconn.rstream, buffer, size);
              dummy_packet_stream_wait(conn->u.rconn.rstream);
          }
          break;
  
      case NONE:
      default:
          break;
      }
  }
  
  static enum dummy_netdev_conn_state
  dummy_netdev_get_conn_state(struct dummy_packet_conn *conn)
  {
      enum dummy_netdev_conn_state state;
  
      if (conn->type == ACTIVE) {
          if (reconnect_is_connected(conn->u.rconn.reconnect)) {
              state = CONN_STATE_CONNECTED;
          } else {
              state = CONN_STATE_NOT_CONNECTED;
          }
      } else {
          state = CONN_STATE_UNKNOWN;
      }
  
      return state;
  }
  
  static void
  netdev_dummy_run(const struct netdev_class *netdev_class)
  {
      struct netdev_dummy *dev;
  
      ovs_mutex_lock(&dummy_list_mutex);
      LIST_FOR_EACH (dev, list_node, &dummy_list) {
          if (netdev_get_class(&dev->up) != netdev_class) {
              continue;
          }
          ovs_mutex_lock(&dev->mutex);
          dummy_packet_conn_run(dev);
          ovs_mutex_unlock(&dev->mutex);
      }
      ovs_mutex_unlock(&dummy_list_mutex);
  }
  
  static void
  netdev_dummy_wait(const struct netdev_class *netdev_class)
  {
      struct netdev_dummy *dev;
  
      ovs_mutex_lock(&dummy_list_mutex);
      LIST_FOR_EACH (dev, list_node, &dummy_list) {
          if (netdev_get_class(&dev->up) != netdev_class) {
              continue;
          }
          ovs_mutex_lock(&dev->mutex);
          dummy_packet_conn_wait(&dev->conn);
          ovs_mutex_unlock(&dev->mutex);
      }
      ovs_mutex_unlock(&dummy_list_mutex);
  }
  
  static struct netdev *
  netdev_dummy_alloc(void)
  {
      struct netdev_dummy *netdev = xzalloc(sizeof *netdev);
      return &netdev->up;
  }
  
  static int
  netdev_dummy_construct(struct netdev *netdev_)
  {
      static atomic_count next_n = ATOMIC_COUNT_INIT(0xaa550000);
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
      unsigned int n;
  
      n = atomic_count_inc(&next_n);
  
      ovs_mutex_init(&netdev->mutex);
      ovs_mutex_lock(&netdev->mutex);
      netdev->hwaddr.ea[0] = 0xaa;
      netdev->hwaddr.ea[1] = 0x55;
      netdev->hwaddr.ea[2] = n >> 24;
      netdev->hwaddr.ea[3] = n >> 16;
      netdev->hwaddr.ea[4] = n >> 8;
      netdev->hwaddr.ea[5] = n;
      netdev->mtu = 1500;
      netdev->flags = 0;
      netdev->ifindex = -EOPNOTSUPP;
      netdev->requested_n_rxq = netdev_->n_rxq;
      netdev->requested_n_txq = netdev_->n_txq;
      netdev->numa_id = 0;
  
      dummy_packet_conn_init(&netdev->conn);
  
      ovs_list_init(&netdev->rxes);
      ovs_mutex_unlock(&netdev->mutex);
  
      ovs_mutex_lock(&dummy_list_mutex);
      ovs_list_push_back(&dummy_list, &netdev->list_node);
      ovs_mutex_unlock(&dummy_list_mutex);
  
      return 0;
  }
  
  static void
  netdev_dummy_destruct(struct netdev *netdev_)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      ovs_mutex_lock(&dummy_list_mutex);
      ovs_list_remove(&netdev->list_node);
      ovs_mutex_unlock(&dummy_list_mutex);
  
      ovs_mutex_lock(&netdev->mutex);
      dummy_packet_conn_close(&netdev->conn);
      netdev->conn.type = NONE;
  
      ovs_mutex_unlock(&netdev->mutex);
      ovs_mutex_destroy(&netdev->mutex);
  }
  
  static void
  netdev_dummy_dealloc(struct netdev *netdev_)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      free(netdev);
  }
  
  static int
  netdev_dummy_get_config(const struct netdev *dev, struct smap *args)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(dev);
  
      ovs_mutex_lock(&netdev->mutex);
  
      if (netdev->ifindex >= 0) {
          smap_add_format(args, "ifindex", "%d", netdev->ifindex);
      }
  
      dummy_packet_conn_get_config(&netdev->conn, args);
  
      /* 'dummy-pmd' specific config. */
      if (!netdev_is_pmd(dev)) {
          goto exit;
      }
      smap_add_format(args, "requested_rx_queues", "%d", netdev->requested_n_rxq);
      smap_add_format(args, "configured_rx_queues", "%d", dev->n_rxq);
      smap_add_format(args, "requested_tx_queues", "%d", netdev->requested_n_txq);
      smap_add_format(args, "configured_tx_queues", "%d", dev->n_txq);
  
  exit:
      ovs_mutex_unlock(&netdev->mutex);
      return 0;
  }
  
  static int
  netdev_dummy_get_addr_list(const struct netdev *netdev_, struct in6_addr **paddr,
                             struct in6_addr **pmask, int *n_addr)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
      int cnt = 0, i = 0, err = 0;
      struct in6_addr *addr, *mask;
  
      ovs_mutex_lock(&netdev->mutex);
      if (netdev->address.s_addr != INADDR_ANY) {
          cnt++;
      }
  
      if (ipv6_addr_is_set(&netdev->ipv6)) {
          cnt++;
      }
      if (!cnt) {
          err = EADDRNOTAVAIL;
          goto out;
      }
      addr = xmalloc(sizeof *addr * cnt);
      mask = xmalloc(sizeof *mask * cnt);
      if (netdev->address.s_addr != INADDR_ANY) {
          in6_addr_set_mapped_ipv4(&addr[i], netdev->address.s_addr);
          in6_addr_set_mapped_ipv4(&mask[i], netdev->netmask.s_addr);
          i++;
      }
  
      if (ipv6_addr_is_set(&netdev->ipv6)) {
          memcpy(&addr[i], &netdev->ipv6, sizeof *addr);
          memcpy(&mask[i], &netdev->ipv6_mask, sizeof *mask);
          i++;
      }
      if (paddr) {
          *paddr = addr;
          *pmask = mask;
          *n_addr = cnt;
      } else {
          free(addr);
          free(mask);
      }
  out:
      ovs_mutex_unlock(&netdev->mutex);
  
      return err;
  }
  
  static int
  netdev_dummy_set_in4(struct netdev *netdev_, struct in_addr address,
                       struct in_addr netmask)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      ovs_mutex_lock(&netdev->mutex);
      netdev->address = address;
      netdev->netmask = netmask;
      netdev_change_seq_changed(netdev_);
      ovs_mutex_unlock(&netdev->mutex);
  
      return 0;
  }
  
  static int
  netdev_dummy_set_in6(struct netdev *netdev_, struct in6_addr *in6,
                       struct in6_addr *mask)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      ovs_mutex_lock(&netdev->mutex);
      netdev->ipv6 = *in6;
      netdev->ipv6_mask = *mask;
      netdev_change_seq_changed(netdev_);
      ovs_mutex_unlock(&netdev->mutex);
  
      return 0;
  }
  
  #define DUMMY_MAX_QUEUES_PER_PORT 1024
  
  static int
  netdev_dummy_set_config(struct netdev *netdev_, const struct smap *args,
                          char **errp OVS_UNUSED)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
      const char *pcap;
      int new_n_rxq, new_n_txq, new_numa_id;
  
      ovs_mutex_lock(&netdev->mutex);
      netdev->ifindex = smap_get_int(args, "ifindex", -EOPNOTSUPP);
  
      dummy_packet_conn_set_config(&netdev->conn, args);
  
      if (netdev->rxq_pcap) {
          fclose(netdev->rxq_pcap);
      }
      if (netdev->tx_pcap && netdev->tx_pcap != netdev->rxq_pcap) {
          fclose(netdev->tx_pcap);
      }
      netdev->rxq_pcap = netdev->tx_pcap = NULL;
      pcap = smap_get(args, "pcap");
      if (pcap) {
          netdev->rxq_pcap = netdev->tx_pcap = ovs_pcap_open(pcap, "ab");
      } else {
          const char *rxq_pcap = smap_get(args, "rxq_pcap");
          const char *tx_pcap = smap_get(args, "tx_pcap");
  
          if (rxq_pcap) {
              netdev->rxq_pcap = ovs_pcap_open(rxq_pcap, "ab");
          }
          if (tx_pcap) {
              netdev->tx_pcap = ovs_pcap_open(tx_pcap, "ab");
          }
      }
  
      netdev_change_seq_changed(netdev_);
  
      /* 'dummy-pmd' specific config. */
      if (!netdev_->netdev_class->is_pmd) {
          goto exit;
      }
  
      new_n_rxq = MAX(smap_get_int(args, "n_rxq", NR_QUEUE), 1);
      new_n_txq = MAX(smap_get_int(args, "n_txq", NR_QUEUE), 1);
  
      if (new_n_rxq > DUMMY_MAX_QUEUES_PER_PORT ||
          new_n_txq > DUMMY_MAX_QUEUES_PER_PORT) {
          VLOG_WARN("The one or both of interface %s queues"
                    "(rxq: %d, txq: %d) exceed %d. Sets it %d.\n",
                    netdev_get_name(netdev_),
                    new_n_rxq,
                    new_n_txq,
                    DUMMY_MAX_QUEUES_PER_PORT,
                    DUMMY_MAX_QUEUES_PER_PORT);
  
          new_n_rxq = MIN(DUMMY_MAX_QUEUES_PER_PORT, new_n_rxq);
          new_n_txq = MIN(DUMMY_MAX_QUEUES_PER_PORT, new_n_txq);
      }
  
      new_numa_id = smap_get_int(args, "numa_id", 0);
      if (new_n_rxq != netdev->requested_n_rxq
          || new_n_txq != netdev->requested_n_txq
          || new_numa_id != netdev->requested_numa_id) {
          netdev->requested_n_rxq = new_n_rxq;
          netdev->requested_n_txq = new_n_txq;
          netdev->requested_numa_id = new_numa_id;
          netdev_request_reconfigure(netdev_);
      }
  
  exit:
      ovs_mutex_unlock(&netdev->mutex);
      return 0;
  }
  
  static int
  netdev_dummy_get_numa_id(const struct netdev *netdev_)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      ovs_mutex_lock(&netdev->mutex);
      int numa_id = netdev->numa_id;
      ovs_mutex_unlock(&netdev->mutex);
  
      return numa_id;
  }
  
  /* Sets the number of tx queues and rx queues for the dummy PMD interface. */
  static int
  netdev_dummy_reconfigure(struct netdev *netdev_)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
  
      ovs_mutex_lock(&netdev->mutex);
  
      netdev_->n_txq = netdev->requested_n_txq;
      netdev_->n_rxq = netdev->requested_n_rxq;
      netdev->numa_id = netdev->requested_numa_id;
  
      ovs_mutex_unlock(&netdev->mutex);
      return 0;
  }
  
  static struct netdev_rxq *
  netdev_dummy_rxq_alloc(void)
  {
      struct netdev_rxq_dummy *rx = xzalloc(sizeof *rx);
      return &rx->up;
  }
  
  static int
  netdev_dummy_rxq_construct(struct netdev_rxq *rxq_)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
      struct netdev_dummy *netdev = netdev_dummy_cast(rx->up.netdev);
  
      ovs_mutex_lock(&netdev->mutex);
      ovs_list_push_back(&netdev->rxes, &rx->node);
      ovs_list_init(&rx->recv_queue);
      rx->recv_queue_len = 0;
      rx->seq = seq_create();
      ovs_mutex_unlock(&netdev->mutex);
  
      return 0;
  }
  
  static void
  netdev_dummy_rxq_destruct(struct netdev_rxq *rxq_)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
      struct netdev_dummy *netdev = netdev_dummy_cast(rx->up.netdev);
  
      ovs_mutex_lock(&netdev->mutex);
      ovs_list_remove(&rx->node);
      pkt_list_delete(&rx->recv_queue);
      ovs_mutex_unlock(&netdev->mutex);
      seq_destroy(rx->seq);
  }
  
  static void
  netdev_dummy_rxq_dealloc(struct netdev_rxq *rxq_)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
  
      free(rx);
  }
  
  static int
  netdev_dummy_rxq_recv(struct netdev_rxq *rxq_, struct dp_packet_batch *batch)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
      struct netdev_dummy *netdev = netdev_dummy_cast(rx->up.netdev);
      struct dp_packet *packet;
  
      ovs_mutex_lock(&netdev->mutex);
      if (!ovs_list_is_empty(&rx->recv_queue)) {
          struct pkt_list_node *pkt_node;
  
          ASSIGN_CONTAINER(pkt_node, ovs_list_pop_front(&rx->recv_queue), list_node);
          packet = pkt_node->pkt;
          free(pkt_node);
          rx->recv_queue_len--;
      } else {
          packet = NULL;
      }
      ovs_mutex_unlock(&netdev->mutex);
  
      if (!packet) {
          if (netdev_is_pmd(&netdev->up)) {
              /* If 'netdev' is a PMD device, this is called as part of the PMD
               * thread busy loop.  We yield here (without quiescing) for two
               * reasons:
               *
               * - To reduce the CPU utilization during the testsuite
               * - To give valgrind a chance to switch thread. According
               *   to the valgrind documentation, there's a big lock that
               *   prevents multiple thread from being executed at the same
               *   time.  On my system, without this sleep, the pmd threads
               *   testcases fail under valgrind, because ovs-vswitchd becomes
               *   unresponsive. */
              sched_yield();
          }
          return EAGAIN;
      }
      ovs_mutex_lock(&netdev->mutex);
      netdev->stats.rx_packets++;
      netdev->stats.rx_bytes += dp_packet_size(packet);
      ovs_mutex_unlock(&netdev->mutex);
  
      batch->packets[0] = packet;
      batch->count = 1;
      return 0;
  }
  
  static void
  netdev_dummy_rxq_wait(struct netdev_rxq *rxq_)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
      struct netdev_dummy *netdev = netdev_dummy_cast(rx->up.netdev);
      uint64_t seq = seq_read(rx->seq);
  
      ovs_mutex_lock(&netdev->mutex);
      if (!ovs_list_is_empty(&rx->recv_queue)) {
          poll_immediate_wake();
      } else {
          seq_wait(rx->seq, seq);
      }
      ovs_mutex_unlock(&netdev->mutex);
  }
  
  static int
  netdev_dummy_rxq_drain(struct netdev_rxq *rxq_)
  {
      struct netdev_rxq_dummy *rx = netdev_rxq_dummy_cast(rxq_);
      struct netdev_dummy *netdev = netdev_dummy_cast(rx->up.netdev);
  
      ovs_mutex_lock(&netdev->mutex);
      pkt_list_delete(&rx->recv_queue);
      rx->recv_queue_len = 0;
      ovs_mutex_unlock(&netdev->mutex);
  
      seq_change(rx->seq);
  
      return 0;
  }
  
  static int
  netdev_dummy_send(struct netdev *netdev, int qid OVS_UNUSED,
                    struct dp_packet_batch *batch, bool may_steal,
                    bool concurrent_txq OVS_UNUSED)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
      int error = 0;
  
      struct dp_packet *packet;
      DP_PACKET_BATCH_FOR_EACH(packet, batch) {
          const void *buffer = dp_packet_data(packet);
          size_t size = dp_packet_size(packet);
  
          if (batch->packets[i]->packet_type != htonl(PT_ETH)) {
              error = EPFNOSUPPORT;
              break;
          }
  
          size -= dp_packet_get_cutlen(packet);
  
          if (size < ETH_HEADER_LEN) {
              error = EMSGSIZE;
              break;
          } else {
              const struct eth_header *eth = buffer;
              int max_size;
  
              ovs_mutex_lock(&dev->mutex);
              max_size = dev->mtu + ETH_HEADER_LEN;
              ovs_mutex_unlock(&dev->mutex);
  
              if (eth->eth_type == htons(ETH_TYPE_VLAN)) {
                  max_size += VLAN_HEADER_LEN;
              }
              if (size > max_size) {
                  error = EMSGSIZE;
                  break;
              }
          }
  
          ovs_mutex_lock(&dev->mutex);
          dev->stats.tx_packets++;
          dev->stats.tx_bytes += size;
  
          dummy_packet_conn_send(&dev->conn, buffer, size);
  
          /* Reply to ARP requests for 'dev''s assigned IP address. */
          if (dev->address.s_addr) {
              struct dp_packet packet;
              struct flow flow;
  
              dp_packet_use_const(&packet, buffer, size);
              flow_extract(&packet, &flow);
              if (flow.dl_type == htons(ETH_TYPE_ARP)
                  && flow.nw_proto == ARP_OP_REQUEST
                  && flow.nw_dst == dev->address.s_addr) {
                  struct dp_packet *reply = dp_packet_new(0);
                  compose_arp(reply, ARP_OP_REPLY, dev->hwaddr, flow.dl_src,
                              false, flow.nw_dst, flow.nw_src);
                  netdev_dummy_queue_packet(dev, reply, 0);
              }
          }
  
          if (dev->tx_pcap) {
              struct dp_packet packet;
  
              dp_packet_use_const(&packet, buffer, size);
              ovs_pcap_write(dev->tx_pcap, &packet);
              fflush(dev->tx_pcap);
          }
  
          ovs_mutex_unlock(&dev->mutex);
      }
  
      dp_packet_delete_batch(batch, may_steal);
  
      return error;
  }
  
  static int
  netdev_dummy_set_etheraddr(struct netdev *netdev, const struct eth_addr mac)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dev->mutex);
      if (!eth_addr_equals(dev->hwaddr, mac)) {
          dev->hwaddr = mac;
          netdev_change_seq_changed(netdev);
      }
      ovs_mutex_unlock(&dev->mutex);
  
      return 0;
  }
  
  static int
  netdev_dummy_get_etheraddr(const struct netdev *netdev, struct eth_addr *mac)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dev->mutex);
      *mac = dev->hwaddr;
      ovs_mutex_unlock(&dev->mutex);
  
      return 0;
  }
  
  static int
  netdev_dummy_get_mtu(const struct netdev *netdev, int *mtup)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dev->mutex);
      *mtup = dev->mtu;
      ovs_mutex_unlock(&dev->mutex);
  
      return 0;
  }
  
  #define DUMMY_MIN_MTU 68
  #define DUMMY_MAX_MTU 65535
  
  static int
  netdev_dummy_set_mtu(struct netdev *netdev, int mtu)
  {
      if (mtu < DUMMY_MIN_MTU || mtu > DUMMY_MAX_MTU) {
          return EINVAL;
      }
  
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dev->mutex);
      if (dev->mtu != mtu) {
          dev->mtu = mtu;
          netdev_change_seq_changed(netdev);
      }
      ovs_mutex_unlock(&dev->mutex);
  
      return 0;
  }
  
  static int
  netdev_dummy_get_stats(const struct netdev *netdev, struct netdev_stats *stats)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dev->mutex);
      /* Passing only collected counters */
      stats->tx_packets = dev->stats.tx_packets;
      stats->tx_bytes = dev->stats.tx_bytes;
      stats->rx_packets = dev->stats.rx_packets;
      stats->rx_bytes = dev->stats.rx_bytes;
      ovs_mutex_unlock(&dev->mutex);
  
      return 0;
  }
  
  static int
  netdev_dummy_get_queue(const struct netdev *netdev OVS_UNUSED,
                         unsigned int queue_id, struct smap *details OVS_UNUSED)
  {
      if (queue_id == 0) {
          return 0;
      } else {
          return EINVAL;
      }
  }
  
  static void
  netdev_dummy_init_queue_stats(struct netdev_queue_stats *stats)
  {
      *stats = (struct netdev_queue_stats) {
          .tx_bytes = UINT64_MAX,
          .tx_packets = UINT64_MAX,
          .tx_errors = UINT64_MAX,
          .created = LLONG_MIN,
      };
  }
  
  static int
  netdev_dummy_get_queue_stats(const struct netdev *netdev OVS_UNUSED,
                               unsigned int queue_id,
                               struct netdev_queue_stats *stats)
  {
      if (queue_id == 0) {
          netdev_dummy_init_queue_stats(stats);
          return 0;
      } else {
          return EINVAL;
      }
  }
  
  struct netdev_dummy_queue_state {
      unsigned int next_queue;
  };
  
  static int
  netdev_dummy_queue_dump_start(const struct netdev *netdev OVS_UNUSED,
                                void **statep)
  {
      struct netdev_dummy_queue_state *state = xmalloc(sizeof *state);
      state->next_queue = 0;
      *statep = state;
      return 0;
  }
  
  static int
  netdev_dummy_queue_dump_next(const struct netdev *netdev OVS_UNUSED,
                               void *state_,
                               unsigned int *queue_id,
                               struct smap *details OVS_UNUSED)
  {
      struct netdev_dummy_queue_state *state = state_;
      if (state->next_queue == 0) {
          *queue_id = 0;
          state->next_queue++;
          return 0;
      } else {
          return EOF;
      }
  }
  
  static int
  netdev_dummy_queue_dump_done(const struct netdev *netdev OVS_UNUSED,
                               void *state)
  {
      free(state);
      return 0;
  }
  
  static int
  netdev_dummy_dump_queue_stats(const struct netdev *netdev OVS_UNUSED,
                                void (*cb)(unsigned int queue_id,
                                           struct netdev_queue_stats *,
                                           void *aux),
                                void *aux)
  {
      struct netdev_queue_stats stats;
      netdev_dummy_init_queue_stats(&stats);
      cb(0, &stats, aux);
      return 0;
  }
  
  static int
  netdev_dummy_get_ifindex(const struct netdev *netdev)
  {
      struct netdev_dummy *dev = netdev_dummy_cast(netdev);
      int ifindex;
  
      ovs_mutex_lock(&dev->mutex);
      ifindex = dev->ifindex;
      ovs_mutex_unlock(&dev->mutex);
  
      return ifindex;
  }
  
  static int
  netdev_dummy_update_flags__(struct netdev_dummy *netdev,
                              enum netdev_flags off, enum netdev_flags on,
                              enum netdev_flags *old_flagsp)
      OVS_REQUIRES(netdev->mutex)
  {
      if ((off | on) & ~(NETDEV_UP | NETDEV_PROMISC)) {
          return EINVAL;
      }
  
      *old_flagsp = netdev->flags;
      netdev->flags |= on;
      netdev->flags &= ~off;
      if (*old_flagsp != netdev->flags) {
          netdev_change_seq_changed(&netdev->up);
      }
  
      return 0;
  }
  
  static int
  netdev_dummy_update_flags(struct netdev *netdev_,
                            enum netdev_flags off, enum netdev_flags on,
                            enum netdev_flags *old_flagsp)
  {
      struct netdev_dummy *netdev = netdev_dummy_cast(netdev_);
      int error;
  
      ovs_mutex_lock(&netdev->mutex);
      error = netdev_dummy_update_flags__(netdev, off, on, old_flagsp);
      ovs_mutex_unlock(&netdev->mutex);
  
      return error;
  }
  
  /* Helper functions. */
  
  #define NETDEV_DUMMY_CLASS(NAME, PMD, RECOFIGURE)               \
  {                                                               \
      NAME,                                                       \
      PMD,                        /* is_pmd */                    \
      NULL,                       /* init */                      \
      netdev_dummy_run,                                           \
      netdev_dummy_wait,                                          \
                                                                  \
      netdev_dummy_alloc,                                         \
      netdev_dummy_construct,                                     \
      netdev_dummy_destruct,                                      \
      netdev_dummy_dealloc,                                       \
      netdev_dummy_get_config,                                    \
      netdev_dummy_set_config,                                    \
      NULL,                       /* get_tunnel_config */         \
      NULL,                       /* build header */              \
      NULL,                       /* push header */               \
      NULL,                       /* pop header */                \
      netdev_dummy_get_numa_id,                                   \
      NULL,                       /* set_tx_multiq */             \
                                                                  \
      netdev_dummy_send,          /* send */                      \
      NULL,                       /* send_wait */                 \
                                                                  \
      netdev_dummy_set_etheraddr,                                 \
      netdev_dummy_get_etheraddr,                                 \
      netdev_dummy_get_mtu,                                       \
      netdev_dummy_set_mtu,                                       \
      netdev_dummy_get_ifindex,                                   \
      NULL,                       /* get_carrier */               \
      NULL,                       /* get_carrier_resets */        \
      NULL,                       /* get_miimon */                \
      netdev_dummy_get_stats,                                     \
                                                                  \
      NULL,                       /* get_features */              \
      NULL,                       /* set_advertisements */        \
                                                                  \
      NULL,                       /* set_policing */              \
      NULL,                       /* get_qos_types */             \
      NULL,                       /* get_qos_capabilities */      \
      NULL,                       /* get_qos */                   \
      NULL,                       /* set_qos */                   \
      netdev_dummy_get_queue,                                     \
      NULL,                       /* set_queue */                 \
      NULL,                       /* delete_queue */              \
      netdev_dummy_get_queue_stats,                               \
      netdev_dummy_queue_dump_start,                              \
      netdev_dummy_queue_dump_next,                               \
      netdev_dummy_queue_dump_done,                               \
      netdev_dummy_dump_queue_stats,                              \
                                                                  \
      NULL,                       /* set_in4 */                   \
      netdev_dummy_get_addr_list,                                 \
      NULL,                       /* add_router */                \
      NULL,                       /* get_next_hop */              \
      NULL,                       /* get_status */                \
      NULL,                       /* arp_lookup */                \
                                                                  \
      netdev_dummy_update_flags,                                  \
      RECOFIGURE,                                                 \
                                                                  \
      netdev_dummy_rxq_alloc,                                     \
      netdev_dummy_rxq_construct,                                 \
      netdev_dummy_rxq_destruct,                                  \
      netdev_dummy_rxq_dealloc,                                   \
      netdev_dummy_rxq_recv,                                      \
      netdev_dummy_rxq_wait,                                      \
      netdev_dummy_rxq_drain,                                     \
                                                                  \
      NO_OFFLOAD_API                                              \
  }
  
  static const struct netdev_class dummy_class =
      NETDEV_DUMMY_CLASS("dummy", false, NULL);
  
  static const struct netdev_class dummy_internal_class =
      NETDEV_DUMMY_CLASS("dummy-internal", false, NULL);
  
  static const struct netdev_class dummy_pmd_class =
      NETDEV_DUMMY_CLASS("dummy-pmd", true,
                         netdev_dummy_reconfigure);
  
  static void
  pkt_list_delete(struct ovs_list *l)
  {
      struct pkt_list_node *pkt;
  
      LIST_FOR_EACH_POP(pkt, list_node, l) {
          dp_packet_delete(pkt->pkt);
          free(pkt);
      }
  }
  
  static struct dp_packet *
  eth_from_packet(const char *s)
  {
      struct dp_packet *packet;
      eth_from_hex(s, &packet);
      return packet;
  }
  
  static struct dp_packet *
  eth_from_flow(const char *s)
  {
      enum odp_key_fitness fitness;
      struct dp_packet *packet;
      struct ofpbuf odp_key;
      struct flow flow;
      int error;
  
      /* Convert string to datapath key.
       *
       * It would actually be nicer to parse an OpenFlow-like flow key here, but
       * the code for that currently calls exit() on parse error.  We have to
       * settle for parsing a datapath key for now.
       */
      ofpbuf_init(&odp_key, 0);
      error = odp_flow_from_string(s, NULL, &odp_key, NULL);
      if (error) {
          ofpbuf_uninit(&odp_key);
          return NULL;
      }
  
      /* Convert odp_key to flow. */
      fitness = odp_flow_key_to_flow(odp_key.data, odp_key.size, &flow);
      if (fitness == ODP_FIT_ERROR) {
          ofpbuf_uninit(&odp_key);
          return NULL;
      }
  
      packet = dp_packet_new(0);
      flow_compose(packet, &flow);
  
      ofpbuf_uninit(&odp_key);
      return packet;
  }
  
  static void
  netdev_dummy_queue_packet__(struct netdev_rxq_dummy *rx, struct dp_packet *packet)
  {
      struct pkt_list_node *pkt_node = xmalloc(sizeof *pkt_node);
  
      pkt_node->pkt = packet;
      ovs_list_push_back(&rx->recv_queue, &pkt_node->list_node);
      rx->recv_queue_len++;
      seq_change(rx->seq);
  }
  
  static void
  netdev_dummy_queue_packet(struct netdev_dummy *dummy, struct dp_packet *packet,
                            int queue_id)
      OVS_REQUIRES(dummy->mutex)
  {
      struct netdev_rxq_dummy *rx, *prev;
  
      if (dummy->rxq_pcap) {
          ovs_pcap_write(dummy->rxq_pcap, packet);
          fflush(dummy->rxq_pcap);
      }
      prev = NULL;
      LIST_FOR_EACH (rx, node, &dummy->rxes) {
          if (rx->up.queue_id == queue_id &&
              rx->recv_queue_len < NETDEV_DUMMY_MAX_QUEUE) {
              if (prev) {
                  netdev_dummy_queue_packet__(prev, dp_packet_clone(packet));
              }
              prev = rx;
          }
      }
      if (prev) {
          netdev_dummy_queue_packet__(prev, packet);
      } else {
          dp_packet_delete(packet);
      }
  }
  
  static void
  netdev_dummy_receive(struct unixctl_conn *conn,
                       int argc, const char *argv[], void *aux OVS_UNUSED)
  {
      struct netdev_dummy *dummy_dev;
      struct netdev *netdev;
      int i, k = 1, rx_qid = 0;
  
      netdev = netdev_from_name(argv[k++]);
      if (!netdev || !is_dummy_class(netdev->netdev_class)) {
          unixctl_command_reply_error(conn, "no such dummy netdev");
          goto exit_netdev;
      }
      dummy_dev = netdev_dummy_cast(netdev);
  
      ovs_mutex_lock(&dummy_dev->mutex);
  
      if (argc > k + 1 && !strcmp(argv[k], "--qid")) {
          rx_qid = strtol(argv[k + 1], NULL, 10);
          if (rx_qid < 0 || rx_qid >= netdev->n_rxq) {
              unixctl_command_reply_error(conn, "bad rx queue id.");
              goto exit;
          }
          k += 2;
      }
  
      for (i = k; i < argc; i++) {
          struct dp_packet *packet;
  
          /* Try to parse 'argv[i]' as packet in hex. */
          packet = eth_from_packet(argv[i]);
  
          if (!packet) {
              /* Try parse 'argv[i]' as odp flow. */
              packet = eth_from_flow(argv[i]);
  
              if (!packet) {
                  unixctl_command_reply_error(conn, "bad packet or flow syntax");
                  goto exit;
              }
  
              /* Parse optional --len argument immediately follows a 'flow'.  */
              if (argc >= i + 2 && !strcmp(argv[i + 1], "--len")) {
                  int packet_size = strtol(argv[i + 2], NULL, 10);
                  dp_packet_set_size(packet, packet_size);
                  i+=2;
              }
          }
  
          netdev_dummy_queue_packet(dummy_dev, packet, rx_qid);
      }
  
      unixctl_command_reply(conn, NULL);
  
  exit:
      ovs_mutex_unlock(&dummy_dev->mutex);
  exit_netdev:
      netdev_close(netdev);
  }
  
  static void
  netdev_dummy_set_admin_state__(struct netdev_dummy *dev, bool admin_state)
      OVS_REQUIRES(dev->mutex)
  {
      enum netdev_flags old_flags;
  
      if (admin_state) {
          netdev_dummy_update_flags__(dev, 0, NETDEV_UP, &old_flags);
      } else {
          netdev_dummy_update_flags__(dev, NETDEV_UP, 0, &old_flags);
      }
  }
  
  static void
  netdev_dummy_set_admin_state(struct unixctl_conn *conn, int argc,
                               const char *argv[], void *aux OVS_UNUSED)
  {
      bool up;
  
      if (!strcasecmp(argv[argc - 1], "up")) {
          up = true;
      } else if ( !strcasecmp(argv[argc - 1], "down")) {
          up = false;
      } else {
          unixctl_command_reply_error(conn, "Invalid Admin State");
          return;
      }
  
      if (argc > 2) {
          struct netdev *netdev = netdev_from_name(argv[1]);
          if (netdev && is_dummy_class(netdev->netdev_class)) {
              struct netdev_dummy *dummy_dev = netdev_dummy_cast(netdev);
  
              ovs_mutex_lock(&dummy_dev->mutex);
              netdev_dummy_set_admin_state__(dummy_dev, up);
              ovs_mutex_unlock(&dummy_dev->mutex);
  
              netdev_close(netdev);
          } else {
              unixctl_command_reply_error(conn, "Unknown Dummy Interface");
              netdev_close(netdev);
              return;
          }
      } else {
          struct netdev_dummy *netdev;
  
          ovs_mutex_lock(&dummy_list_mutex);
          LIST_FOR_EACH (netdev, list_node, &dummy_list) {
              ovs_mutex_lock(&netdev->mutex);
              netdev_dummy_set_admin_state__(netdev, up);
              ovs_mutex_unlock(&netdev->mutex);
          }
          ovs_mutex_unlock(&dummy_list_mutex);
      }
      unixctl_command_reply(conn, "OK");
  }
  
  static void
  display_conn_state__(struct ds *s, const char *name,
                       enum dummy_netdev_conn_state state)
  {
      ds_put_format(s, "%s: ", name);
  
      switch (state) {
      case CONN_STATE_CONNECTED:
          ds_put_cstr(s, "connected\n");
          break;
  
      case CONN_STATE_NOT_CONNECTED:
          ds_put_cstr(s, "disconnected\n");
          break;
  
      case CONN_STATE_UNKNOWN:
      default:
          ds_put_cstr(s, "unknown\n");
          break;
      };
  }
  
  static void
  netdev_dummy_conn_state(struct unixctl_conn *conn, int argc,
                          const char *argv[], void *aux OVS_UNUSED)
  {
      enum dummy_netdev_conn_state state = CONN_STATE_UNKNOWN;
      struct ds s;
  
      ds_init(&s);
  
      if (argc > 1) {
          const char *dev_name = argv[1];
          struct netdev *netdev = netdev_from_name(dev_name);
  
          if (netdev && is_dummy_class(netdev->netdev_class)) {
              struct netdev_dummy *dummy_dev = netdev_dummy_cast(netdev);
  
              ovs_mutex_lock(&dummy_dev->mutex);
              state = dummy_netdev_get_conn_state(&dummy_dev->conn);
              ovs_mutex_unlock(&dummy_dev->mutex);
  
              netdev_close(netdev);
          }
          display_conn_state__(&s, dev_name, state);
      } else {
          struct netdev_dummy *netdev;
  
          ovs_mutex_lock(&dummy_list_mutex);
          LIST_FOR_EACH (netdev, list_node, &dummy_list) {
              ovs_mutex_lock(&netdev->mutex);
              state = dummy_netdev_get_conn_state(&netdev->conn);
              ovs_mutex_unlock(&netdev->mutex);
              if (state != CONN_STATE_UNKNOWN) {
                  display_conn_state__(&s, netdev->up.name, state);
              }
          }
          ovs_mutex_unlock(&dummy_list_mutex);
      }
  
      unixctl_command_reply(conn, ds_cstr(&s));
      ds_destroy(&s);
  }
  
  static void
  netdev_dummy_ip4addr(struct unixctl_conn *conn, int argc OVS_UNUSED,
                       const char *argv[], void *aux OVS_UNUSED)
  {
      struct netdev *netdev = netdev_from_name(argv[1]);
  
      if (netdev && is_dummy_class(netdev->netdev_class)) {
          struct in_addr ip, mask;
          char *error;
  
          error = ip_parse_masked(argv[2], &ip.s_addr, &mask.s_addr);
          if (!error) {
              netdev_dummy_set_in4(netdev, ip, mask);
              unixctl_command_reply(conn, "OK");
          } else {
              unixctl_command_reply_error(conn, error);
              free(error);
          }
      } else {
          unixctl_command_reply_error(conn, "Unknown Dummy Interface");
      }
  
      netdev_close(netdev);
  }
  
  static void
  netdev_dummy_ip6addr(struct unixctl_conn *conn, int argc OVS_UNUSED,
                       const char *argv[], void *aux OVS_UNUSED)
  {
      struct netdev *netdev = netdev_from_name(argv[1]);
  
      if (netdev && is_dummy_class(netdev->netdev_class)) {
          struct in6_addr ip6;
          char *error;
          uint32_t plen;
  
          error = ipv6_parse_cidr(argv[2], &ip6, &plen);
          if (!error) {
              struct in6_addr mask;
  
              mask = ipv6_create_mask(plen);
              netdev_dummy_set_in6(netdev, &ip6, &mask);
              unixctl_command_reply(conn, "OK");
          } else {
              unixctl_command_reply_error(conn, error);
              free(error);
          }
          netdev_close(netdev);
      } else {
          unixctl_command_reply_error(conn, "Unknown Dummy Interface");
      }
  
      netdev_close(netdev);
  }
  
  
  static void
  netdev_dummy_override(const char *type)
  {
      if (!netdev_unregister_provider(type)) {
          struct netdev_class *class;
          int error;
  
          class = xmemdup(&dummy_class, sizeof dummy_class);
          class->type = xstrdup(type);
          error = netdev_register_provider(class);
          if (error) {
              VLOG_ERR("%s: failed to register netdev provider (%s)",
                       type, ovs_strerror(error));
              free(CONST_CAST(char *, class->type));
              free(class);
          }
      }
  }
  
  void
  netdev_dummy_register(enum dummy_level level)
  {
      unixctl_command_register("netdev-dummy/receive",
                               "name [--qid queue_id] packet|flow [--len packet_len]",
                               2, INT_MAX, netdev_dummy_receive, NULL);
      unixctl_command_register("netdev-dummy/set-admin-state",
                               "[netdev] up|down", 1, 2,
                               netdev_dummy_set_admin_state, NULL);
      unixctl_command_register("netdev-dummy/conn-state",
                               "[netdev]", 0, 1,
                               netdev_dummy_conn_state, NULL);
      unixctl_command_register("netdev-dummy/ip4addr",
                               "[netdev] ipaddr/mask-prefix-len", 2, 2,
                               netdev_dummy_ip4addr, NULL);
      unixctl_command_register("netdev-dummy/ip6addr",
                               "[netdev] ip6addr", 2, 2,
                               netdev_dummy_ip6addr, NULL);
  
      if (level == DUMMY_OVERRIDE_ALL) {
          struct sset types;
          const char *type;
  
          sset_init(&types);
          netdev_enumerate_types(&types);
          SSET_FOR_EACH (type, &types) {
              if (strcmp(type, "patch")) {
                  netdev_dummy_override(type);
              }
          }
          sset_destroy(&types);
      } else if (level == DUMMY_OVERRIDE_SYSTEM) {
          netdev_dummy_override("system");
      }
      netdev_register_provider(&dummy_class);
      netdev_register_provider(&dummy_internal_class);
      netdev_register_provider(&dummy_pmd_class);
  
      netdev_vport_tunnel_register();
  }
  