| tap.4 (71895) | tap.4 (76175) |
|---|---|
| 1.\" $FreeBSD: head/share/man/man4/tap.4 71895 2001-02-01 16:38:02Z ru $ | 1.\" $FreeBSD: head/share/man/man4/tap.4 76175 2001-05-01 09:15:30Z schweikh $ |
| 2.\" Based on PR#2411 3.\" 4.Dd July 9, 2000 5.Os 6.Dt TAP 4 7.Sh NAME 8.Nm tap 9.Nd Ethernet tunnel software network interface 10.Sh SYNOPSIS | 2.\" Based on PR#2411 3.\" 4.Dd July 9, 2000 5.Os 6.Dt TAP 4 7.Sh NAME 8.Nm tap 9.Nd Ethernet tunnel software network interface 10.Sh SYNOPSIS |
| 11.Cd pseudo-device tap | 11.Cd device tap |
| 12.Sh DESCRIPTION 13The 14.Nm 15interface is a software loopback mechanism that can be loosely 16described as the network interface analog of the 17.Xr pty 4 , 18that is, 19.Nm --- 24 unchanged lines hidden (view full) --- 44.Xr ioctl 2 Ns s , 45such as 46.Dv SIOCSIFADDR 47and 48.Dv SIOCSIFNETMASK , 49and thus can be used with 50.Xr ifconfig 8 51like any other Ethernet interface. When the system chooses to transmit | 12.Sh DESCRIPTION 13The 14.Nm 15interface is a software loopback mechanism that can be loosely 16described as the network interface analog of the 17.Xr pty 4 , 18that is, 19.Nm --- 24 unchanged lines hidden (view full) --- 44.Xr ioctl 2 Ns s , 45such as 46.Dv SIOCSIFADDR 47and 48.Dv SIOCSIFNETMASK , 49and thus can be used with 50.Xr ifconfig 8 51like any other Ethernet interface. When the system chooses to transmit |
| 52an Ethernet frame on the network interface, the frame can be read from | 52an Ethernet frame on the network interface, the frame can be read from |
| 53the control device 54(it appears as 55.Dq input 56there); 57writing an Ethernet frame to the control device generates an input frame on 58the network interface, as if the 59.Pq non-existent 60hardware had just received it. --- 6 unchanged lines hidden (view full) --- 67A 68.Fn read 69call will return an error 70.Pq Er EHOSTDOWN 71if the interface is not 72.Dq ready . 73Once the interface is ready, 74.Fn read | 53the control device 54(it appears as 55.Dq input 56there); 57writing an Ethernet frame to the control device generates an input frame on 58the network interface, as if the 59.Pq non-existent 60hardware had just received it. --- 6 unchanged lines hidden (view full) --- 67A 68.Fn read 69call will return an error 70.Pq Er EHOSTDOWN 71if the interface is not 72.Dq ready . 73Once the interface is ready, 74.Fn read |
| 75will return an Ethernet frame if one is available; if not, it will | 75will return an Ethernet frame if one is available; if not, it will |
| 76either block until one is or return 77.Er EWOULDBLOCK , 78depending on whether non-blocking I/O has been enabled. If the frame 79is longer than is allowed for in the buffer passed to 80.Fn read , 81the extra data will be silently dropped. 82.Pp 83A --- 52 unchanged lines hidden (view full) --- 136.It Dv TIOCGPGRP 137Retrieve the process group value for 138.Dv SIGIO 139signals into the argument 140.Va int 141value. 142.It Dv SIOCGIFADDR 143Retrieve the Media Access Control | 76either block until one is or return 77.Er EWOULDBLOCK , 78depending on whether non-blocking I/O has been enabled. If the frame 79is longer than is allowed for in the buffer passed to 80.Fn read , 81the extra data will be silently dropped. 82.Pp 83A --- 52 unchanged lines hidden (view full) --- 136.It Dv TIOCGPGRP 137Retrieve the process group value for 138.Dv SIGIO 139signals into the argument 140.Va int 141value. 142.It Dv SIOCGIFADDR 143Retrieve the Media Access Control |
| 144.Pq Dv MAC | 144.Pq Dv MAC |
| 145address of the 146.Dq remote 147side. This command is used by the VMware port and expected to be executed on 148descriptor, associated with control device 149(usually | 145address of the 146.Dq remote 147side. This command is used by the VMware port and expected to be executed on 148descriptor, associated with control device 149(usually |
| 150.Pa /dev/vmnet Ns Sy N | 150.Pa /dev/vmnet Ns Sy N |
| 151or 152.Pa /dev/tap Ns Sy N ) . 153The 154.Va buffer , 155which is passed as the argument, is expected to have enough space to store 156the 157.Dv MAC 158address. At the open time both --- 17 unchanged lines hidden (view full) --- 176.Pp 177The control device also supports 178.Xr select 2 179for read; selecting for write is pointless, and always succeeds, since 180writes are always non-blocking. 181.Pp 182On the last close of the data device, the interface is 183brought down | 151or 152.Pa /dev/tap Ns Sy N ) . 153The 154.Va buffer , 155which is passed as the argument, is expected to have enough space to store 156the 157.Dv MAC 158address. At the open time both --- 17 unchanged lines hidden (view full) --- 176.Pp 177The control device also supports 178.Xr select 2 179for read; selecting for write is pointless, and always succeeds, since 180writes are always non-blocking. 181.Pp 182On the last close of the data device, the interface is 183brought down |
| 184(as if with | 184(as if with |
| 185.Dq ifconfig tap Ns Sy N No down ) 186unless the devices is a VMnet device. | 185.Dq ifconfig tap Ns Sy N No down ) 186unless the devices is a VMnet device. |
| 187All queued frames are thrown away. If the interface is up when the data 188device is not open, output frames are thrown away rather than | 187All queued frames are thrown away. If the interface is up when the data 188device is not open, output frames are thrown away rather than |
| 189letting them pile up. 190.Pp | 189letting them pile up. 190.Pp |
| 191The | 191The |
| 192.Nm 193device is also can be used with the VMware port as a replacement 194for the old VMnet device driver. The driver uses the minor number 195to select between 196.Nm 197and 198.Nm vmnet 199devices. VMnet minor numbers begin at | 192.Nm 193device is also can be used with the VMware port as a replacement 194for the old VMnet device driver. The driver uses the minor number 195to select between 196.Nm 197and 198.Nm vmnet 199devices. VMnet minor numbers begin at |
| 200.Va 0x10000 | 200.Va 0x10000 |
| 201+ | 201+ |
| 202.Va N . | 202.Va N . |
| 203Where | 203Where |
| 204.Va N 205is a VMnet unit number. In this case control device is expected to be | 204.Va N 205is a VMnet unit number. In this case control device is expected to be |
| 206.Pa /dev/vmnet Ns Sy N , 207and network interface will be 208.Sy vmnet Ns Ar N . 209Additionally, VMnet devices do not ifconfig themselves down when the | 206.Pa /dev/vmnet Ns Sy N , 207and network interface will be 208.Sy vmnet Ns Ar N . 209Additionally, VMnet devices do not ifconfig themselves down when the |
| 210control device is closed. Everything else is the same. | 210control device is closed. Everything else is the same. |
| 211.Pp 212In addition to mentioned above 213.Xr ioctl 2 214there is one additional one for the VMware port. 215.Bl -tag -width VMIO_SIOCSETMACADDR 216.It Dv VMIO_SIOCSIFFLAGS | 211.Pp 212In addition to mentioned above 213.Xr ioctl 2 214there is one additional one for the VMware port. 215.Bl -tag -width VMIO_SIOCSETMACADDR 216.It Dv VMIO_SIOCSIFFLAGS |
| 217VMware | 217VMware |
| 218.Dv SIOCSIFFLAGS . 219.El 220.Sh SEE ALSO 221.Xr inet 4 , 222.Xr intro 4 223.\" .Sh BUGS 224.Sh AUTHORS 225This man page has been obtained from 226.Fx . | 218.Dv SIOCSIFFLAGS . 219.El 220.Sh SEE ALSO 221.Xr inet 4 , 222.Xr intro 4 223.\" .Sh BUGS 224.Sh AUTHORS 225This man page has been obtained from 226.Fx . |