mdoc(7) police: fixed markup and spelling.

share/man/man4/tun.4

@@ -19,27 +19,27 @@ described as the network interface analog of the
 that is,
 .Nm
 does for network interfaces what the
-.Nm pty
+.Xr pty 4
 driver does for terminals.
 .Pp
 The
 .Nm
 driver, like the
-.Nm pty
+.Xr pty 4
 driver, provides two interfaces: an interface like the usual facility
 it is simulating
 (a network interface in the case of
 .Nm ,
 or a terminal for
-.Nm pty ) ,
+.Xr pty 4 ) ,
 and a character-special device
 .Dq control
 interface.
 .Pp
 The network interfaces are named
-.Sy tun Ns Ar 0 ,
-.Sy tun Ns Ar 1 ,
-etc, one for each control device that has been opened.
+.Dq Li tun0 ,
+.Dq Li tun1 ,
+etc., one for each control device that has been opened.
 These network interfaces persist until the
 .Pa if_tun.ko
 module is unloaded (if
@@ -57,8 +57,10 @@ device is usually obtained by attempting to open
 .Pa /dev/tun0 ,
 and if that fails
 .Pa /dev/tun1
-etc, until an errno of
-.Dv EBUSY
+etc., until an
+.Va errno
+of
+.Er EBUSY
 is not received).
 .Pp
 On systems with
@@ -97,16 +99,15 @@ network interface, the packet can be read from the control device
 .Dq input
 there);
 writing a packet to the control device generates an input
-packet on the network interface, as if the
-.Pq non-existent
+packet on the network interface, as if the (non\-existent)
 hardware had just received it.
 .Pp
 The tunnel device
-.Pq Pa /dev/tun Ns Sy N
+.Pq Pa /dev/tun Ns Ar N
 is exclusive-open
 (it cannot be opened if it is already open).
 A
-.Fn read
+.Xr read 2
 call will return an error
 .Pq Er EHOSTDOWN
 if the interface is not
@@ -121,20 +122,20 @@ until one is or return
 .Er EWOULDBLOCK ,
 depending on whether non-blocking I/O has been enabled.
 If the packet is longer than is allowed for in the buffer passed to
-.Fn read ,
+.Xr read 2 ,
 the extra data will be silently dropped.
 .Pp
 If the
 .Dv TUNSLMODE
 ioctl has been set, packets read from the control device will be prepended
 with the destination address as presented to the network interface output
-routine
-.Pq Sq Li tunoutput .
+routine,
+.Fn tunoutput .
 The destination address is in
-.Sq Li struct sockaddr
+.Vt struct sockaddr
 format.
 The actual length of the prepended address is in the member
-.Sq Li sa_len .
+.Va sa_len .
 If the
 .Dv TUNSIFHEAD
 ioctl has been set, packets will be prepended with a four byte address
@@ -156,57 +157,58 @@ ioctl has been set, the address family must be prepended, otherwise the
 packet is assumed to be of type
 .Dv AF_INET .
 Each
-.Fn write
+.Xr write 2
 call supplies exactly one packet; the packet length is taken from the
 amount of data provided to
-.Fn write
-.Pq minus any supplied address family .
+.Xr write 2
+(minus any supplied address family).
 Writes will not block; if the packet cannot be accepted for a
 transient reason
-.Pq e.g., no buffer space available ,
+(e.g., no buffer space available),
 it is silently dropped; if the reason is not transient
-.Pq e.g., packet too large ,
+(e.g., packet too large),
 an error is returned.
 .Pp
 The following
 .Xr ioctl 2
 calls are supported
-.Pq defined in Aq Pa net/if_tun.h Ns :
-.Bl -tag -width TUNSIFMODE
+(defined in
+.Aq Pa net/if_tun.h ) :
+.Bl -tag -xwidth ".Dv TUNSIFMODE"
 .It Dv TUNSDEBUG
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 this sets the internal debugging variable to that value.
 What, if anything, this variable controls is not documented here; see
 the source code.
 .It Dv TUNGDEBUG
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 this stores the internal debugging variable's value into it.
 .It Dv TUNSIFINFO
 The argument should be a pointer to an
-.Va struct tuninfo
+.Vt struct tuninfo
 and allows setting the MTU, the type, and the baudrate of the tunnel
 device.
 The
-.Va struct tuninfo
+.Vt struct tuninfo
 is declared in
 .Aq Pa net/if_tun.h .
 .Pp
 The use of this ioctl is restricted to the super-user.
 .It Dv TUNGIFINFO
 The argument should be a pointer to an
-.Va struct tuninfo ,
+.Vt struct tuninfo ,
 where the current MTU, type, and baudrate will be stored.
 .It Dv TUNSIFMODE
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 its value must be either
 .Dv IFF_POINTOPOINT
 or
 .Dv IFF_BROADCAST .
 The type of the corresponding
-.Em tun Ns Sy n
+.Dq Li tun Ns Ar N
 interface is set to the supplied type.
 If the value is anything else, an
 .Er EINVAL
@@ -216,7 +218,7 @@ The interface must be down at the time; if it is up, an
 error occurs.
 .It Dv TUNSLMODE
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 a non-zero value turns off
 .Dq multi-af
 mode and turns on
@@ -227,7 +229,7 @@ the network destination address (see above).
 Will set the pid owning the tunnel device to the current process's pid.
 .It Dv TUNSIFHEAD
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 a non-zero value turns off
 .Dq link-layer
 mode, and enables
@@ -235,39 +237,39 @@ mode, and enables
 mode, where every packet is preceded with a four byte address family.
 .It Dv TUNGIFHEAD
 The argument should be a pointer to an
-.Va int ;
+.Vt int ;
 the ioctl sets the value to one if the device is in
 .Dq multi-af
 mode, and zero otherwise.
 .It Dv FIONBIO
 Turn non-blocking I/O for reads off or on, according as the argument
-.Va int Ns 's
-value is or isn't zero
-.Pq Writes are always nonblocking .
+.Vt int Ns 's
+value is or isn't zero.
+(Writes are always non-blocking.)
 .It Dv FIOASYNC
 Turn asynchronous I/O for reads
 (i.e., generation of
 .Dv SIGIO
 when data is available to be read)
 off or on, according as the argument
-.Va int Ns 's
+.Vt int Ns 's
 value is or isn't zero.
 .It Dv FIONREAD
 If any packets are queued to be read, store the size of the first one
 into the argument
-.Va int ;
+.Vt int ;
 otherwise, store zero.
 .It Dv TIOCSPGRP
 Set the process group to receive
 .Dv SIGIO
 signals, when asynchronous I/O is enabled, to the argument
-.Va int
+.Vt int
 value.
 .It Dv TIOCGPGRP
 Retrieve the process group value for
 .Dv SIGIO
 signals into the argument
-.Va int
+.Vt int
 value.
 .El
 .Pp
@@ -279,7 +281,7 @@ writes are always non-blocking.
 On the last close of the data device, by default, the interface is
 brought down
 (as if with
-.Dq ifconfig tun Ns Sy N No down ) .
+.Nm ifconfig Ar tunN Cm down ) .
 All queued packets are thrown away.
 If the interface is up when the data device is not open
 output packets are always thrown away rather than letting
@@ -294,8 +296,8 @@ them pile up.
 .Xr intro 4 ,
 .Xr pty 4 ,
 .Xr devfs 5 ,
-.Xr MAKEDEV 8 ,
-.Xr ifconfig 8
+.Xr ifconfig 8 ,
+.Xr MAKEDEV 8
 .Sh AUTHORS
 This manual page was originally obtained from
-.Bx Net .
+.Nx .