Added support for VDE (Virtual Distributed Ethernet) network packet transport

Fixed filtering for non-pcap network packet transports (i.e. tun/tap, and vde) to properly filter the desired packets.

0readme_ethernet.txt

@@ -133,12 +133,36 @@ OSX (Snow Leopard)
     Invoke the package installer tuntap_20090913.pkg
     Click through the various prompts accepting things and eventually installing the package.
     
-    # Run simulator and:
+    # Build and Run simulator and:
        sim> attach xq tap:tap0
        sim> ! ifconfig tap0 192.168.6.1 netmask 255.255.255.0
 
-    Simulated system uses IP address 192.168.6.2 and host uses 192.167.6.1 and things work.
+    Simulated system uses IP address 192.168.6.2 and host uses 192.167.6.1 
-    As far as I can tell you must run as root for this to work.
+    and things work.
+    You must run as root for this to work.
+    
+-------------------------------------------------------------------------------
+An alternative to direct pcap and tun/tap networking on *nix environments is 
+VDE (Virtual Distributed Ethernet).
+
+Note 1: Using vde based networking is likely more flexible, but it isn't 
+        nearly as efficient.  Host OS overhead will always be higher when 
+        vde networking is used as compared to native pcap and/or tun/tap 
+        networking.
+Note 2: Root access will likely be needed to configure or start the vde 
+        environment prior to starting a simulator which may use it.
+Note 3: Simulators running using VDE networking can run without root 
+        privilege.
+
+Linux (Ubuntu 10.04):
+    apt-get install libvdeplug-dev
+    apt-get install vde2
+
+    vde_switch -s /tmp/switch1 -tap tap0 -m 666
+    ifconfig tap0 192.168.6.1 netmask 255.255.255.0 up
+    
+    # Build and Run simulator and:
+       sim> attach xq vde:/tmp/switch1  #simulator uses IP address 192.168.6.2
 
 -------------------------------------------------------------------------------
 
@@ -354,6 +378,7 @@ Dave
                                Change Log
 ===============================================================================
   
+  30-Oct-11  MP   Added support for vde (Virtual Distributed Ethernet) networking
   29-Oct-11  MP   Added support for integrated Tap networking interfaces on OSX
   17-Aug-11  RMS  Fix from Sergey Oboguev relating to XU and XQ Auto Config and 
                   vector assignments

makefile

@@ -13,6 +13,7 @@
 #
 ifeq ($(WIN32),)
   #*nix Environments (&& cygwin)
+  GCC = gcc
   ifeq (SunOS,$(shell uname))
     TEST = /bin/test
   else
@@ -62,13 +63,18 @@ ifeq ($(WIN32),)
     NETWORK_CCDEFS = -DUSE_NETWORK
     NETWORK_LDFLAGS = -lpcap
   endif
+  ifeq (vde,$(shell if $(TEST) -e /usr/include/libvdeplug.h -a \( -e /usr/lib/libvdeplug.$(LIBEXT) -o -e /usr/lib64/libvdeplug.$(LIBEXT) \); then echo vde; fi))
+    # Provide support for vde networking
+    NETWORK_CCDEFS += -DUSE_VDE_NETWORK
+    NETWORK_LDFLAGS += -lvdeplug
+  endif
   ifeq (tuntap,$(shell if $(TEST) -e /usr/include/linux/if_tun.h; then echo tuntap; fi))
     # Provide support for Tap networking on Linux
-    NETWORK_TAP_CCDEFS = -DUSE_TAP_NETWORK
+    NETWORK_CCDEFS += -DUSE_TAP_NETWORK
   endif
   ifeq (bsdtuntap,$(shell if $(TEST) -e /usr/include/net/if_tun.h -o -e /Library/Extensions/tap.kext; then echo bsdtuntap; fi))
     # Provide support for Tap networking
-    NETWORK_TAP_CCDEFS = -DUSE_TAP_NETWORK -DUSE_BSDTUNTAP
+    NETWORK_CCDEFS += -DUSE_TAP_NETWORK -DUSE_BSDTUNTAP
   endif
   ifneq (binexists,$(shell if $(TEST) -e BIN; then echo binexists; fi))
     MKDIRBIN = if $(TEST) ! -e BIN; then mkdir BIN; fi
@@ -79,6 +85,7 @@ ifeq ($(WIN32),)
   endif
 else
   #Win32 Environments (via MinGW32)
+  GCC = gcc
   GCC_Path := $(dir $(shell where gcc.exe))
   ifeq ($(NOASYNCH),)
     ifeq (pthreads,$(shell if exist ..\pthreads\Pre-built.2\include\pthread.h echo pthreads))
@@ -119,7 +126,7 @@ else
 endif
 
 
-CC = gcc -std=c99 -U__STRICT_ANSI__ -g -I . $(NETWORK_CCDEFS) $(NETWORK_TAP_CCDEFS) $(OS_CCDEFS) $(ROMS_OPT)
+CC = $(GCC) -std=c99 -U__STRICT_ANSI__ -g -I . $(NETWORK_CCDEFS) $(OS_CCDEFS) $(ROMS_OPT)
 LDFLAGS = $(OS_LDFLAGS) $(NETWORK_LDFLAGS) 
 
 #

sim_ether.c

@@ -138,6 +138,15 @@
                       at open time.  This functionality is only useful/needed 
                       on *nix platforms since native sharing of Windows NIC 
                       devices works with no external magic.
+  USE_VDE_NETWORK   - Specifies that support for vde networking should be 
+                      included.  This can be leveraged, along with OS bridging
+                      capabilities to share a single LAN interface.  It also
+                      can allow a simulator to have useful networking 
+                      functionality when running without root access.  This 
+                      allows device names of the form vde:/tmp/switch to be 
+                      specified at open time.  This functionality is only 
+                      available on *nix platforms since the vde api isn't 
+                      available on Windows.
 
   NEED_PCAP_SENDPACKET
                     - Specifies that you are using an older version of libpcap
@@ -151,6 +160,11 @@
 
   Modification history:
 
+  30-Oct-11  MP   Added support for vde (Virtual Distributed Ethernet) networking
+  29-Oct-11  MP   Added support for integrated Tap networking interfaces on OSX
+  12-Aug-11  MP   Cleaned up payload length determination
+                  Fixed race condition detecting reflections when threaded 
+                  reading and writing is enabled
   18-Apr-11  MP   Fixed race condition with self loopback packets in 
                   multithreaded environments
   09-Jan-11  MP   Fixed missing crc data when USE_READER_THREAD is defined and 
@@ -793,6 +807,10 @@ void eth_show_dev (FILE* st, ETH_DEV* dev)
 #endif
 #endif /* USE_TAP_NETWORK */
 
+#ifdef USE_VDE_NETWORK
+#include <libvdeplug.h>
+#endif /* USE_VDE_NETWORK */
+
 /* Allows windows to look up user-defined adapter names */
 #if defined(_WIN32)
 #include <winreg.h>
@@ -1092,10 +1110,12 @@ static void eth_get_nic_hw_addr(ETH_DEV* dev, char *devname)
   if (!pcap_mac_if_win32(devname, (UCHAR *)&dev->host_nic_phy_hw_addr))
     dev->have_host_nic_phy_addr = 1;
 #elif !defined (__VMS)
-{
+  if (1) {
     char command[1024];
     FILE *f;
 
+    if (0 == strncmp("vde:", devname, 4))
+      return;
     memset(command, 0, sizeof(command));
     snprintf(command, sizeof(command)-1, "ifconfig %s | grep [0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F] >NIC.hwaddr", devname);
     system(command);
@@ -1148,16 +1168,24 @@ int sched_policy;
 struct sched_param sched_priority;
 #if defined (_WIN32)
 HANDLE hWait = pcap_getevent ((pcap_t*)dev->handle);
-#endif
+#else
-#if defined (MUST_DO_SELECT)
-struct timeval timeout;
 int sel_ret;
-int pcap_fd;
+int do_select = 0;
+int select_fd;
 
-if (dev->pcap_mode)
+switch (dev->eth_api) {
-  pcap_fd = pcap_get_selectable_fd((pcap_t *)dev->handle);
+  case ETH_API_PCAP:
-else
+#if defined (MUST_DO_SELECT)
-  pcap_fd = dev->fd_handle;
+    do_select = 1;
+    select_fd = pcap_get_selectable_fd((pcap_t *)dev->handle);
+#endif
+    break;
+  case ETH_API_TAP:
+  case ETH_API_VDE:
+    do_select = 1;
+    select_fd = dev->fd_handle;
+    break;
+  }
 #endif
 
 sim_debug(dev->dbit, dev->dptr, "Reader Thread Starting\n");
@@ -1169,32 +1197,35 @@ else
 ++sched_priority.sched_priority;
 pthread_setschedparam (pthread_self(), sched_policy, &sched_priority);
 
-  while ((dev->pcap_mode && dev->handle) || dev->fd_handle) {
+while (dev->handle) {
-#if defined (MUST_DO_SELECT)
-    fd_set setl;
-    FD_ZERO(&setl);
-    FD_SET(pcap_fd, &setl);
-    timeout.tv_sec = 0;
-    timeout.tv_usec = 250*1000;
-    sel_ret = select(1+pcap_fd, &setl, NULL, NULL, &timeout);
-    if (sel_ret < 0 && errno != EINTR) break;
-    if (sel_ret > 0) {
-#else /* !MUST_DO_SELECT */
 #if defined (_WIN32)
   if (WAIT_OBJECT_0 == WaitForSingleObject (hWait, 250)) {
 #else
-    if (1)  {
+  fd_set setl;
-#endif
+  struct timeval timeout;
-#endif /* MUST_DO_SELECT */
+
-      if ((dev->pcap_mode) && (!dev->handle))
+  if (do_select) {
-        break;
+    FD_ZERO(&setl);
-      if ((!dev->pcap_mode) && (!dev->fd_handle))
+    FD_SET(select_fd, &setl);
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 250*1000;
+    sel_ret = select(1+select_fd, &setl, NULL, NULL, &timeout);
+    }
+  else
+    sel_ret = 1;
+  if (sel_ret < 0 && errno != EINTR) break;
+  if (sel_ret > 0) {
+#endif /* _WIN32 */
+    if (!dev->handle)
       break;
     /* dispatch read request queue available packets */
-      if (dev->pcap_mode)
+    switch (dev->eth_api) {
+      case ETH_API_PCAP:
         status = pcap_dispatch ((pcap_t*)dev->handle, -1, &_eth_callback, (u_char*)dev);
+        break;
 #ifdef USE_TAP_NETWORK
-      else {
+      case ETH_API_TAP:
+        if (1) {
           struct pcap_pkthdr header;
           int len;
           u_char buf[ETH_MAX_JUMBO_FRAME];
@@ -1205,14 +1236,35 @@ else
             status = 1;
             header.caplen = header.len = len;
             _eth_callback((u_char *)dev, &header, buf);
-        } else {
+            }
+          else
             status = 0;
           }
-      }
+        break;
 #endif /* USE_TAP_NETWORK */
+#ifdef USE_VDE_NETWORK
+      case ETH_API_VDE:
+        if (1) {
+          struct pcap_pkthdr header;
+          int len;
+          u_char buf[ETH_MAX_JUMBO_FRAME];
 
+          memset(&header, 0, sizeof(header));
+          len = vde_recv((VDECONN *)dev->handle, buf, sizeof(buf), 0);
+          if (len > 0) {
+            status = 1;
+            header.caplen = header.len = len;
+            _eth_callback((u_char *)dev, &header, buf);
+            }
+          else
+            status = 0;
+          }
+        break;
+#endif /* USE_VDE_NETWORK */
+      }
     if ((status > 0) && (dev->asynch_io)) {
       int wakeup_needed;
+
       pthread_mutex_lock (&dev->lock);
       wakeup_needed = (dev->read_queue.count != 0);
       pthread_mutex_unlock (&dev->lock);
@@ -1246,7 +1298,7 @@ struct sched_param sched_priority;
 sim_debug(dev->dbit, dev->dptr, "Writer Thread Starting\n");
 
 pthread_mutex_lock (&dev->writer_lock);
-  while ((dev->pcap_mode && dev->handle) || dev->fd_handle) {
+while (dev->handle) {
   pthread_cond_wait (&dev->writer_cond, &dev->writer_lock);
   while (request = dev->write_requests) {
     /* Pull buffer off request list */
@@ -1330,7 +1382,8 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
   savname = eth_getname(num, temp);
   if (savname == 0) /* didn't translate */
     return SCPE_OPENERR;
-  } else {
+  }
+else {
   /* are they trying to use device description? */
   savname = eth_getname_bydesc(name, temp);
   if (savname == 0) { /* didn't translate */
@@ -1343,16 +1396,7 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
 
 /* attempt to connect device */
 memset(errbuf, 0, sizeof(errbuf));
-  if (strncmp("tap:", savname, 4)) {
+if (0 == strncmp("tap:", savname, 4)) {
-    dev->handle = (void*) pcap_open_live(savname, bufsz, ETH_PROMISC, PCAP_READ_TIMEOUT, errbuf);
-    if (!dev->handle) { /* can't open device */
-      msg = "Eth: pcap_open_live error - %s\r\n";
-      printf (msg, errbuf);
-      if (sim_log) fprintf (sim_log, msg, errbuf);
-      return SCPE_OPENERR;
-    }
-    dev->pcap_mode = 1;
-  } else {
   int  tun = -1;    /* TUN/TAP Socket */
   int  on = 1;
   char dev_name[64] = "";
@@ -1374,18 +1418,21 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
     strcpy(ifr.ifr_name, savname+4);
     ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
 
-      // Send interface requests to TUN/TAP driver.
+    /* Send interface requests to TUN/TAP driver. */
     if (ioctl(tun, TUNSETIFF, &ifr) >= 0) {
       if (ioctl(tun, FIONBIO, &on)) {
         strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
         close(tun);
-        } else {
+        }
+      else {
         dev->fd_handle = tun;
         strcpy(savname, ifr.ifr_name);
         }
-      } else
+      }
+    else
       strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
-    } else
+    }
+  else
     strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
 #elif defined(USE_BSDTUNTAP) && defined(USE_TAP_NETWORK)
   snprintf(dev_name, sizeof(dev_name)-1, "/dev/%s", savname+4);
@@ -1395,7 +1442,8 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
     if (ioctl(tun, FIONBIO, &on)) {
       strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
       close(tun);
-      } else {
+      }
+    else {
       dev->fd_handle = tun;
       strcpy(savname, savname+4);
       }
@@ -1416,12 +1464,48 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
         }
       }
 #endif
-    } else {
-      strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
     }
+  else
+    strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
 #else
   strncpy(errbuf, "No support for tap: devices", sizeof(errbuf)-1);
 #endif /* !defined(__linux) && !defined(USE_BSDTUNTAP) */
+  if (0 == errbuf[0]) {
+    dev->eth_api = ETH_API_TAP;
+    dev->handle = (void *)1;  /* Flag used to indicated open */
+    }
+  }
+else
+  if (0 == strncmp("vde:", savname, 4)) {
+#if defined(USE_VDE_NETWORK)
+    struct vde_open_args voa;
+
+    memset(&voa, 0, sizeof(voa));
+    if (!strcmp(savname, "vde:vdedevice")) {
+      msg = "Eth: Must specify actual vde device name (i.e. vde:/tmp/switch)\r\n";
+      printf (msg, errbuf);
+      if (sim_log) fprintf (sim_log, msg, errbuf);
+      return SCPE_OPENERR;
+      }
+    if (!(dev->handle = (void*) vde_open(savname+4, "simh", &voa)))
+      strncpy(errbuf, strerror(errno), sizeof(errbuf)-1);
+    else {
+      dev->eth_api = ETH_API_VDE;
+      dev->fd_handle = vde_datafd((VDECONN*)dev->handle);
+      }
+#else
+    strncpy(errbuf, "No support for vde: network devices", sizeof(errbuf)-1);
+#endif /* !defined(__linux) && !defined(USE_BSDTUNTAP) */
+    }
+  else {
+    dev->handle = (void*) pcap_open_live(savname, bufsz, ETH_PROMISC, PCAP_READ_TIMEOUT, errbuf);
+    if (!dev->handle) { /* can't open device */
+      msg = "Eth: pcap_open_live error - %s\r\n";
+      printf (msg, errbuf);
+      if (sim_log) fprintf (sim_log, msg, errbuf);
+      return SCPE_OPENERR;
+      }
+    dev->eth_api = ETH_API_PCAP;
     }
 if (errbuf[0]) {
   msg = "Eth: open error - %s\r\n";
@@ -1447,14 +1531,14 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
 #if !defined(HAS_PCAP_SENDPACKET) && defined (xBSD) && !defined (__APPLE__)
 /* Tell the kernel that the header is fully-formed when it gets it.
    This is required in order to fake the src address. */
-  if (dev->pcap_mode) {
+if (dev->eth_api == ETH_API_PCAP) {
   int one = 1;
   ioctl(pcap_fileno(dev->handle), BIOCSHDRCMPLT, &one);
   }
 #endif /* xBSD */
 
 #if defined (USE_READER_THREAD)
-  {
+if (1) {
   pthread_attr_t attr;
 
 #if defined(_WIN32)
@@ -1474,7 +1558,7 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
 #else /* !defined (USE_READER_THREAD */
 #ifdef USE_SETNONBLOCK
 /* set ethernet device non-blocking so pcap_dispatch() doesn't hang */
-  if (dev->pcap_mode && (pcap_setnonblock (dev->handle, 1, errbuf) == -1)) {
+if ((dev->eth_api == ETH_API_PCAP) && (pcap_setnonblock (dev->handle, 1, errbuf) == -1)) {
   msg = "Eth: Failed to set non-blocking: %s\r\n";
   printf (msg, errbuf);
   if (sim_log) fprintf (sim_log, msg, errbuf);
@@ -1482,7 +1566,7 @@ t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit)
 #endif
 #endif /* !defined (USE_READER_THREAD */
 #if defined (__APPLE__)
-  if (dev->pcap_mode) {
+if (dev->eth_api == ETH_API_PCAP) {
   /* Deliver packets immediately, needed for OS X 10.6.2 and later
    * (Snow-Leopard).
    * See this thread on libpcap and Mac Os X 10.6 Snow Leopard on
@@ -1520,7 +1604,6 @@ t_stat eth_close(ETH_DEV* dev)
 pthread_cond_destroy (&dev->writer_cond);
 if (1) {
   struct write_request *buffer;
-
    while (buffer = dev->write_buffers) {
     dev->write_buffers = buffer->next;
     free(buffer);
@@ -1533,12 +1616,21 @@ t_stat eth_close(ETH_DEV* dev)
 ethq_destroy (&dev->read_queue);         /* release FIFO queue */
 #endif
 
-  if (dev->pcap_mode)
+switch (dev->eth_api) {
+  case ETH_API_PCAP:
     pcap_close(pcap);
+    break;
 #ifdef USE_TAP_NETWORK
-  else
+  case ETH_API_TAP:
     close(pcap_fd);
+    break;
 #endif
+#ifdef USE_VDE_NETWORK
+  case ETH_API_VDE:
+    vde_close((VDECONN*)pcap);
+    break;
+#endif
+  }
 printf (msg, dev->name);
 if (sim_log) fprintf (sim_log, msg, dev->name);
 
@@ -1645,13 +1737,28 @@ t_stat _eth_write(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine)
     }
 
     /* dispatch write request (synchronous; no need to save write info to dev) */
-    if (dev->pcap_mode)
+  switch (dev->eth_api) {
+    case ETH_API_PCAP:
       status = pcap_sendpacket((pcap_t*)dev->handle, (u_char*)packet->msg, packet->len);
+      break;
 #ifdef USE_TAP_NETWORK
-    else
+    case ETH_API_TAP:
       status = ((packet->len == write(dev->fd_handle, (void *)packet->msg, packet->len)) ? 0 : -1);
+      break;
 #endif
-
+#ifdef USE_VDE_NETWORK
+    case ETH_API_VDE:
+      status = vde_send((VDECONN*)dev->handle, (void *)packet->msg, packet->len, 0);
+      if ((status == packet->len) || (status == 0))
+        status = 0;
+      else
+        if ((status == -1) && ((errno == EAGAIN) || (errno == EWOULDBLOCK)))
+          status = 0;
+        else
+          status = 1;
+      break;
+#endif
+    }
   /* On error, correct loopback bookkeeping */
   if ((status != 0) && loopback_self_frame) {
 #ifdef USE_READER_THREAD
@@ -1710,7 +1817,8 @@ t_stat eth_write(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine)
     ++write_queue_size;
     }
   last_request->next = request;
-  } else
+  }
+else
     dev->write_requests = request;
 if (write_queue_size > dev->write_queue_peak)
   dev->write_queue_peak = write_queue_size;
@@ -1762,12 +1870,14 @@ _eth_hash_validate(ETH_MAC *MultiCastList, int count, ETH_MULTIHASH hash)
          lhash[0], lhash[1], lhash[2], lhash[3], 
          lhash[4], lhash[5], lhash[6], lhash[7]);
   }
+else {
   printf("Should be: %02X %02X %02X %02X %02X %02X %02X %02X\n", 
          hash[0], hash[1], hash[2], hash[3], 
          hash[4], hash[5], hash[6], hash[7]);
   printf("Was:       %02X %02X %02X %02X %02X %02X %02X %02X\n", 
          lhash[0], lhash[1], lhash[2], lhash[3], 
          lhash[4], lhash[5], lhash[6], lhash[7]);
+  }
 return 0;
 }
 
@@ -2000,7 +2110,8 @@ _eth_fix_ip_jumbo_offload(ETH_DEV* dev, const u_char* msg, int len)
       if (payload_len > mtu_payload) {
         ip_flags |= IP_MF_FLAG;
         IP->total_len = htons(((mtu_payload>>3)<<3) + IP_HLEN(IP));
-        } else {
+        }
+      else {
         IP->total_len = htons(payload_len + IP_HLEN(IP));
         }
       IP->flags = htons(ip_flags);
@@ -2009,7 +2120,8 @@ _eth_fix_ip_jumbo_offload(ETH_DEV* dev, const u_char* msg, int len)
       header.caplen = header.len = 14 + ntohs(IP->total_len);
       eth_packet_trace (dev, ((u_char *)IP)-14, header.len, "reading Datagram fragment");
 #if ETH_MIN_JUMBO_FRAME < ETH_MAX_PACKET
-          { /* Debugging is easier if we read packets directly with pcap
+      if (1) {
+        /* Debugging is easier if we read packets directly with pcap
            (i.e. we can use Wireshark to verify packet contents)
            we don't want to do this all the time for 2 reasons:
              1) sending through pcap involves kernel transitions and
@@ -2050,7 +2162,8 @@ _eth_fix_ip_jumbo_offload(ETH_DEV* dev, const u_char* msg, int len)
       if (payload_len > mtu_payload) {
         TCP->data_offset_and_flags = htons(orig_tcp_flags&~(TCP_PSH_FLAG|TCP_FIN_FLAG|TCP_RST_FLAG));
         IP->total_len = htons(mtu_payload + IP_HLEN(IP) + TCP_DATA_OFFSET(TCP));
-        } else {
+        }
+      else {
         TCP->data_offset_and_flags = htons(orig_tcp_flags);
         IP->total_len = htons(payload_len + IP_HLEN(IP) + TCP_DATA_OFFSET(TCP));
         }
@@ -2061,7 +2174,8 @@ _eth_fix_ip_jumbo_offload(ETH_DEV* dev, const u_char* msg, int len)
       header.caplen = header.len = 14 + ntohs(IP->total_len);
       eth_packet_trace_ex (dev, ((u_char *)IP)-14, header.len, "reading TCP segment", 1, dev->dbit);
 #if ETH_MIN_JUMBO_FRAME < ETH_MAX_PACKET
-          { /* Debugging is easier if we read packets directly with pcap
+      if (1) {
+        /* Debugging is easier if we read packets directly with pcap
            (i.e. we can use Wireshark to verify packet contents)
            we don't want to do this all the time for 2 reasons:
              1) sending through pcap involves kernel transitions and
@@ -2155,19 +2269,27 @@ static void
 _eth_callback(u_char* info, const struct pcap_pkthdr* header, const u_char* data)
 {
 ETH_DEV*  dev = (ETH_DEV*) info;
-#ifdef USE_BPF
+int to_me;
-  int to_me = 1;
+int from_me = 0;
+int i;
+int bpf_used;
 
+switch (dev->eth_api) {
+  case ETH_API_PCAP:
+#ifdef USE_BPF
+    bpf_used = 1;
+    to_me = 1;
     /* AUTODIN II hash mode? */
     if ((dev->hash_filter) && (data[0] & 0x01) && (!dev->promiscuous) && (!dev->all_multicast))
       to_me = _eth_hash_lookup(dev->hash, data);
-#else /* !USE_BPF */
+    break;
-  int to_me = 0;
+#endif /* USE_BPF */
-  int from_me = 0;
+  case ETH_API_TAP:
-  int i;
+  case ETH_API_VDE:
-
+    bpf_used = 0;
+    to_me = 0;
     eth_packet_trace (dev, data, header->len, "received");
-f
+
     for (i = 0; i < dev->addr_count; i++) {
       if (memcmp(data, dev->filter_address[i], 6) == 0) to_me = 1;
       if (memcmp(&data[6], dev->filter_address[i], 6) == 0) from_me = 1;
@@ -2182,7 +2304,8 @@ f
     /* AUTODIN II hash mode? */
     if ((dev->hash_filter) && (!to_me) && (data[0] & 0x01))
       to_me = _eth_hash_lookup(dev->hash, data);
-#endif /* USE_BPF */
+    break;
+  }
 
 /* detect reception of loopback packet to our physical address */
 if (LOOPBACK_SELF_FRAME(dev->physical_addr, data)) {
@@ -2196,20 +2319,15 @@ f
     dev->loopback_self_sent--;
     to_me = 0;
     }
-#ifndef USE_BPF
   else
+    if (!bpf_used)
       from_me = 0;
-#endif
 #ifdef USE_READER_THREAD
   pthread_mutex_unlock (&dev->self_lock);
 #endif
   }
 
-#ifdef USE_BPF
+if (bpf_used ? to_me : (to_me && !from_me)) {
-  if (to_me) {
-#else /* !USE_BPF */
-  if (to_me && !from_me) {
-#endif
   if (header->len > ETH_MIN_JUMBO_FRAME) {
     if (header->len <= header->caplen) /* Whole Frame captured? */
       _eth_fix_ip_jumbo_offload(dev, data, header->len);
@@ -2247,7 +2365,7 @@ f
     pthread_mutex_unlock (&dev->lock);
     free(moved_data);
     }
-#else
+#else /* !USE_READER_THREAD */
   /* set data in passed read packet */
   dev->read_packet->len = header->len;
   memcpy(dev->read_packet->msg, data, header->len);
@@ -2298,10 +2416,13 @@ int eth_read(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine)
 
 /* dispatch read request to either receive a filtered packet or timeout */
 do {
-    if (dev->pcap_mode)
+  switch (dev->eth_api) {
+    case ETH_API_PCAP:
       status = pcap_dispatch((pcap_t*)dev->handle, 1, &_eth_callback, (u_char*)dev);
+      break;
 #ifdef USE_TAP_NETWORK
-    else {
+    case ETH_API_TAP:
+      if (1) {
         struct pcap_pkthdr header;
         int len;
         u_char buf[ETH_MAX_JUMBO_FRAME];
@@ -2312,11 +2433,32 @@ int eth_read(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine)
           status = 1;
           header.caplen = header.len = len;
           _eth_callback((u_char *)dev, &header, buf);
-      } else {
+          }
+        else
           status = 0;
         }
-    }
+      break;
 #endif /* USE_TAP_NETWORK */
+#ifdef USE_VDE_NETWORK
+    case ETH_API_VDE:
+      if (1) {
+        struct pcap_pkthdr header;
+        int len;
+        u_char buf[ETH_MAX_JUMBO_FRAME];
+
+        memset(&header, 0, sizeof(header));
+        len = vde_recv((VDECONN*)dev->handle, buf, sizeof(buf), 0);
+        if (len > 0) {
+          status = 1;
+          header.caplen = header.len = len;
+          _eth_callback((u_char *)dev, &header, buf);
+          }
+        else
+          status = 0;
+        }
+      break;
+#endif /* USE_VDE_NETWORK */
+    }
   } while ((status) && (0 == packet->len));
 
 #else /* USE_READER_THREAD */
@@ -2484,12 +2626,11 @@ t_stat eth_filter_hash(ETH_DEV* dev, int addr_count, ETH_MAC* const addresses,
 sim_debug(dev->dbit, dev->dptr, "BPF string is: |%s|\n", buf);
 
 /* get netmask, which is required for compiling */
-  if (dev->pcap_mode && (pcap_lookupnet(dev->handle, &bpf_subnet, &bpf_netmask, errbuf)<0)) {
+if ((dev->eth_api == ETH_API_PCAP) && (pcap_lookupnet(dev->handle, &bpf_subnet, &bpf_netmask, errbuf)<0))
   bpf_netmask = 0;
-  }
 
 #ifdef USE_BPF
-  if (dev->pcap_mode) {
+if (dev->eth_api == ETH_API_PCAP) {
   /* compile filter string */
   if ((status = pcap_compile(dev->handle, &bpf, buf, 1, bpf_netmask)) < 0) {
     sprintf(errbuf, "%s", pcap_geterr(dev->handle));
@@ -2501,7 +2642,8 @@ t_stat eth_filter_hash(ETH_DEV* dev, int addr_count, ETH_MAC* const addresses,
     msg = "Eth: BPF string is: |%s|\r\n";
     printf (msg, buf);
     if (sim_log) fprintf (sim_log, msg, buf);
-    } else {
+    }
+  else {
     /* apply compiled filter string */
     if ((status = pcap_setfilter(dev->handle, &bpf)) < 0) {
       sprintf(errbuf, "%s", pcap_geterr(dev->handle));
@@ -2509,7 +2651,8 @@ t_stat eth_filter_hash(ETH_DEV* dev, int addr_count, ETH_MAC* const addresses,
       printf(msg, errbuf);
       if (sim_log) fprintf (sim_log, msg, errbuf);
       sim_debug(dev->dbit, dev->dptr, "Eth: pcap_setfilter error: %s\n", errbuf);
-      } else {
+      }
+    else {
 #ifdef USE_SETNONBLOCK
       /* set file non-blocking */
       status = pcap_setnonblock (dev->handle, 1, errbuf);
@@ -2584,9 +2727,8 @@ int eth_host_devices(int used, int max, ETH_LIST* list)
     sprintf( regkey, "SYSTEM\\CurrentControlSet\\Control\\Network\\"
              "{4D36E972-E325-11CE-BFC1-08002BE10318}\\%hs\\Connection", list[i].name+
              strlen( "\\Device\\NPF_" ) );
-      if((status = RegOpenKeyExA (HKEY_LOCAL_MACHINE, regkey, 0, KEY_QUERY_VALUE, &reghnd)) != ERROR_SUCCESS) {
+    if ((status = RegOpenKeyExA (HKEY_LOCAL_MACHINE, regkey, 0, KEY_QUERY_VALUE, &reghnd)) != ERROR_SUCCESS)
       continue;
-      }
     reglen = sizeof(regval);
 
     /* look for user-defined adapter name, bail if not found */  
@@ -2619,6 +2761,14 @@ int eth_host_devices(int used, int max, ETH_LIST* list)
   ++used;
   }
 #endif
+#ifdef USE_VDE_NETWORK
+if (used < max) {
+  list[used].num = used;
+  sprintf(list[used].name, "%s", "vde:device");
+  sprintf(list[used].desc, "%s", "Integrated VDE support");
+  ++used;
+  }
+#endif
 
 return used;
 }
@@ -2636,7 +2786,8 @@ int eth_devices(int max, ETH_LIST* list)
   char* msg = "Eth: error in pcap_findalldevs: %s\r\n";
   printf (msg, errbuf);
   if (sim_log) fprintf (sim_log, msg, errbuf);
-  } else {
+  }
+else {
   /* copy device list into the passed structure */
   for (i=0, dev=alldevs; dev; dev=dev->next) {
     if ((dev->flags & PCAP_IF_LOOPBACK) || (!strcmp("any", dev->name))) continue;

sim_ether.h

@@ -28,6 +28,7 @@
 
   Modification history:
 
+  30-Oct-11  MP   Added support for vde (Virtual Distributed Ethernet) networking
   18-Apr-11  MP   Fixed race condition with self loopback packets in 
                   multithreaded environments
   09-Dec-10  MP   Added support to determine if network address conflicts exist
@@ -89,13 +90,13 @@
 #if defined (USE_READER_THREAD)
 #if defined (USE_SETNONBLOCK)
 #undef USE_SETNONBLOCK
-#endif
+#endif /* USE_SETNONBLOCK */
 #undef PCAP_READ_TIMEOUT
 #define PCAP_READ_TIMEOUT 15
-#if !defined (xBSD) && !defined(_WIN32) && !defined(VMS)
+#if (!defined (xBSD) && !defined(_WIN32) && !defined(VMS)) || defined (USE_TAP_NETWORK) || defined (USE_VDE_NETWORK)
-#define MUST_DO_SELECT
+#define MUST_DO_SELECT 1
-#endif
 #endif
+#endif /* USE_READER_THREAD */
 
 /*
   USE_BPF is defined to let this code leverage the libpcap/OS kernel provided 
@@ -175,7 +176,10 @@ struct eth_device {
   char*         name;                                   /* name of ethernet device */
   void*         handle;                                 /* handle of implementation-specific device */
   int           fd_handle;                              /* fd to kernel device (where needed) */
-  int           pcap_mode;                              /* Flag indicating if pcap API are being used to move packets */
+  int           eth_api;                                /* Designator for which API is being used to move packets */
+#define ETH_API_PCAP 0                                  /* Pcap API in use */
+#define ETH_API_TAP  1                                  /* tun/tap API in use */
+#define ETH_API_VDE  2                                  /* VDE API in use */
   ETH_PCALLBACK read_callback;                          /* read callback function */
   ETH_PCALLBACK write_callback;                         /* write callback function */
   ETH_PACK*     read_packet;                            /* read packet */