sim: Add a netdev backed by VPNKit

arch/sim/Kconfig

@@ -117,15 +117,35 @@ config SIM_NETDEV
 	select ARCH_HAVE_NETDEV_STATISTICS
 	select SCHED_LPWORK
 	select SIM_WALLTIME
+	---help---
+		Build in support for a simulated network device.
+
+if SIM_NETDEV
+
+choice
+	prompt "Simulated Network Device Type"
+	default SIM_NETDEV_TAP
+
+config SIM_NETDEV_TAP
+	bool "Simulated Network Device with TAP/WPCAP"
 	---help---
 		Build in support for a simulated network device using a TAP device on Linux or
 		WPCAP on Windows.
 
+config SIM_NETDEV_VPNKIT
+	bool "Simulated Network Device with VPNKit"
+	---help---
+		Build in support for a simulated network device using VPNKit.
+
+endchoice
+
+endif
+
 if HOST_LINUX
 choice
 	prompt "Simulation Network Type"
 	default SIM_NET_HOST_ROUTE
-	depends on SIM_NETDEV
+	depends on SIM_NETDEV_TAP
 
 config SIM_NET_HOST_ROUTE
 	bool "Use local host route"

arch/sim/src/Makefile

@@ -157,7 +157,7 @@ ifeq ($(CONFIG_ARCH_ROMGETC),y)
   CSRCS += up_romgetc.c
 endif
 
-ifeq ($(CONFIG_SIM_NETDEV),y)
+ifeq ($(CONFIG_SIM_NETDEV_TAP),y)
   CSRCS += up_netdriver.c
   HOSTCFLAGS += -DNETDEV_BUFSIZE=$(CONFIG_NET_ETH_PKTSIZE)
 ifneq ($(HOSTOS),Cygwin)
@@ -173,7 +173,12 @@ else # HOSTOS != Cygwin
   HOSTSRCS += up_wpcap.c
   DRVLIB = /lib/w32api/libws2_32.a /lib/w32api/libiphlpapi.a
 endif # HOSTOS != Cygwin
-endif # CONFIG_SIM_NETDEV
+else ifeq ($(CONFIG_SIM_NETDEV_VPNKIT),y)
+  CSRCS += up_netdriver.c
+  HOSTSRCS += up_vpnkit.c
+  VPATH += :sim/vpnkit
+  HOSTSRCS += protocol.c negotiate.c
+endif
 
 ifeq ($(CONFIG_RPTUN),y)
   CSRCS += up_rptun.c

arch/sim/src/sim/up_internal.h

@@ -314,7 +314,7 @@ FAR struct ioexpander_dev_s *sim_ioexpander_initialize(void);
 
 /* up_tapdev.c **************************************************************/
 
-#if defined(CONFIG_SIM_NETDEV) && !defined(__CYGWIN__)
+#if defined(CONFIG_SIM_NETDEV_TAP) && !defined(__CYGWIN__)
 void tapdev_init(void);
 int tapdev_avail(void);
 unsigned int tapdev_read(unsigned char *buf, unsigned int buflen);
@@ -332,7 +332,7 @@ void tapdev_ifdown(void);
 
 /* up_wpcap.c ***************************************************************/
 
-#if defined(CONFIG_SIM_NETDEV) && defined(__CYGWIN__)
+#if defined(CONFIG_SIM_NETDEV_TAP) && defined(__CYGWIN__)
 void wpcap_init(void);
 unsigned int wpcap_read(unsigned char *buf, unsigned int buflen);
 void wpcap_send(unsigned char *buf, unsigned int buflen);
@@ -345,6 +345,24 @@ void wpcap_send(unsigned char *buf, unsigned int buflen);
 #  define netdev_ifdown()         {}
 #endif
 
+/* up_vpnkit.c **************************************************************/
+
+#if defined(CONFIG_SIM_NETDEV_VPNKIT)
+void vpnkit_init(void);
+int vpnkit_avail(void);
+unsigned int vpnkit_read(unsigned char *buf, unsigned int buflen);
+void vpnkit_send(unsigned char *buf, unsigned int buflen);
+void vpnkit_ifup(in_addr_t ifaddr);
+void vpnkit_ifdown(void);
+
+#  define netdev_init()           vpnkit_init()
+#  define netdev_avail()          vpnkit_avail()
+#  define netdev_read(buf,buflen) vpnkit_read(buf,buflen)
+#  define netdev_send(buf,buflen) vpnkit_send(buf,buflen)
+#  define netdev_ifup(ifaddr)     vpnkit_ifup(ifaddr)
+#  define netdev_ifdown()         vpnkit_ifdown()
+#endif
+
 /* up_netdriver.c ***********************************************************/
 
 #ifdef CONFIG_SIM_NETDEV

arch/sim/src/sim/up_vpnkit.c

@@ -0,0 +1,259 @@
+/****************************************************************************
+ * arch/sim/src/sim/up_vpnkit.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <sys/types.h>
+#include <sys/un.h>
+
+/* XXX broken api: mixing nuttx and host in_addr_t */
+
+#include <netinet/in.h>
+
+#include <poll.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "vpnkit/protocol.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define ERROR(fmt, ...) \
+        fprintf(stderr, "up_vpnkit: " fmt "\r\n", ##__VA_ARGS__)
+#define INFO(fmt, ...) \
+        fprintf(stderr, "up_vpnkit: " fmt "\r\n", ##__VA_ARGS__)
+#define DEBUG(fmt, ...)
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const char *g_vpnkit_socket_path = "/tmp/vpnkit-nuttx"; /* XXX config */
+static struct vif_info g_vifinfo;
+static int g_vpnkit_fd = -1;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+int negotiate(int fd, struct vif_info *vif);
+void netdriver_setmacaddr(unsigned char *macaddr);
+
+static void vpnkit_connect()
+{
+  struct sockaddr_un sun;
+  int fd;
+
+  if (g_vpnkit_fd != -1)
+    {
+      return;
+    }
+
+  fd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (fd == -1)
+    {
+      ERROR("failed to create a socket");
+      return;
+    }
+
+  memset(&sun, 0, sizeof(sun));
+  sun.sun_family = AF_UNIX;
+  strncpy(sun.sun_path, g_vpnkit_socket_path, sizeof(sun.sun_path) - 1);
+
+  if (connect(fd, (const struct sockaddr *)&sun, sizeof(sun)) == -1)
+    {
+      ERROR("failed to connect to the vpnkit socket %s",
+            g_vpnkit_socket_path);
+      close(fd);
+      return;
+    }
+
+  if (negotiate(fd, &g_vifinfo))
+    {
+      ERROR("failed to negotiate with vpnkit");
+      close(fd);
+      return;
+    }
+
+  INFO("Successfully negotiated with vpnkit");
+  g_vpnkit_fd = fd;
+}
+
+static void vpnkit_disconnect()
+{
+  if (g_vpnkit_fd == -1)
+    {
+      return;
+    }
+
+  INFO("disconnecting from vpnkit");
+  close(g_vpnkit_fd);
+  g_vpnkit_fd = -1;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: vpnkit_init
+ *
+ ****************************************************************************/
+
+void vpnkit_init(void)
+{
+  vpnkit_connect();
+  netdriver_setmacaddr(g_vifinfo.mac);
+}
+
+/****************************************************************************
+ * Name: vpnkit_avail
+ *
+ ****************************************************************************/
+
+int vpnkit_avail(void)
+{
+  struct pollfd pfd;
+  int ret;
+
+  vpnkit_connect();
+  memset(&pfd, 0, sizeof(pfd));
+  pfd.fd = g_vpnkit_fd;
+  pfd.events = POLLIN;
+  ret = poll(&pfd, 1, 0);
+  if (ret == -1)
+    {
+      ERROR("poll failed on vpnkit socket");
+      vpnkit_disconnect();
+      return 0;
+    }
+  else if (ret != 0)
+    {
+      DEBUG("vpnkit_avail is returning 1");
+    }
+
+  return ret != 0;
+}
+
+/****************************************************************************
+ * Name: vpnkit_read
+ *
+ ****************************************************************************/
+
+unsigned int vpnkit_read(unsigned char *buf, unsigned int buflen)
+{
+  uint8_t header[2]; /* 16-bit payload length in little endian */
+  size_t packet_len;
+  ssize_t ret;
+  DEBUG("vpnkit_read called");
+
+  vpnkit_connect();
+  ret = really_read(g_vpnkit_fd, header, sizeof(header));
+  if (ret == -1)
+    {
+      ERROR("failed to read packet header");
+      vpnkit_disconnect();
+      return 0;
+    }
+
+  packet_len = (header[1] << 8) | header[0];
+  if (packet_len > buflen)
+    {
+      INFO("packet larger (%zu) than buffer size (%u)", packet_len, buflen);
+
+      /* XXX it's better to drop this particular packet it. */
+
+      vpnkit_disconnect();
+      return 0;
+    }
+
+  ret = really_read(g_vpnkit_fd, buf, packet_len);
+  if (ret == -1)
+    {
+      ERROR("failed to read packet");
+      vpnkit_disconnect();
+      return 0;
+    }
+
+  DEBUG("a packet received (size %zu)", packet_len);
+  return packet_len;
+}
+
+/****************************************************************************
+ * Name: vpnkit_send
+ *
+ ****************************************************************************/
+
+void vpnkit_send(unsigned char *buf, unsigned int buflen)
+{
+  uint8_t header[2]; /* 16-bit payload length in little endian */
+  ssize_t ret;
+
+  DEBUG("vpnkit_send called");
+  vpnkit_connect();
+  header[0] = buflen & 0xff;
+  header[1] = (buflen >> 8) & 0xff;
+  ret = really_write(g_vpnkit_fd, header, sizeof(header));
+  if (ret == -1)
+    {
+      ERROR("failed to write packet header");
+      vpnkit_disconnect();
+      return;
+    }
+
+  ret = really_write(g_vpnkit_fd, buf, buflen);
+  if (ret == -1)
+    {
+      ERROR("failed to write packet payload");
+      vpnkit_disconnect();
+      return;
+    }
+
+  DEBUG("a packet sent (size %u)", buflen);
+}
+
+/****************************************************************************
+ * Name: vpnkit_ifup
+ *
+ ****************************************************************************/
+
+void vpnkit_ifup(in_addr_t ifaddr)
+{
+  DEBUG("vpnkit_ifup called");
+}
+
+/****************************************************************************
+ * Name: vpnkit_ifdown
+ *
+ ****************************************************************************/
+
+void vpnkit_ifdown(void)
+{
+  DEBUG("vpnkit_ifdown called");
+}