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mdoc(7) police: tidy up the markup.

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Ruslan Ermilov 2002-01-10 13:09:00 +00:00
parent ced699e370
commit e4c7f9b607
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=89207
1 changed files with 40 additions and 22 deletions
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62
share/man/man9/pfil.9
View file

@ -40,67 +40,83 @@
.In sys/socket.h
.In net/if.h
.In net/pfil.h
.Ft struct packet_filter_hook *
.Ft "struct packet_filter_hook *"
.Fn pfil_hook_get "int flag" "struct pfil_head *ph"
.Ft int
.Fo pfil_add_hook
.Fa "int (*func)(void *, int, struct ifnet *, int, struct mbuf **)"
.Fa "int \*[lp]*func\*[rp]\*[lp]void *, int, struct ifnet *, int, struct mbuf **\*[rp]"
.Fa "int flags"
.Fa "struct pfil_head *ph"
.Fc
.Ft int
.Fo pfil_remove_hook
.Fa "int (*func)(void *, int, struct ifnet *, int, struct mbuf **)"
.Fa "int \*[lp]*func\*[rp]\*[lp]void *, int, struct ifnet *, int, struct mbuf **\*[rp]"
.Fa "int flags"
.Fa "struct pfil_head *ph"
.Fc
.\"(void *, int, struct ifnet *, int, struct mbuf **)
.Sh DESCRIPTION
The
.Nm
interface allows a function to be called on every incoming or outgoing
packets. The hooks for these are embedded in the
packets.
The hooks for these are embedded in the
.Fn ip_input
and
.Fn ip_output
routines. The
routines.
The
.Fn pfil_hook_get
function returns the first member of a particular hook, either the in or out
list. The
list.
The
.Fn pfil_add_hook
function takes a function of the form below as its first argument, and the
flags for which lists to add the function to. The possible values for these
flags are some combination of PFIL_IN and PFIL_OUT. The
flags for which lists to add the function to.
The possible values for these
flags are some combination of
.Dv PFIL_IN
and
.Dv PFIL_OUT .
The
.Fn pfil_remove_hook
removes a hook from the specified lists.
.Pp
The
.Va func
.Fa func
argument is a function with the following prototype.
.Pp
.Fn func "void *data" "int hlen" "struct ifnet *net" "int dir" "struct mbuf **m"
.Pp
The
.Va data
describes the packet. Currently, this may only be a pointer to a ip structure. The
.Va net
.Fa data
describes the packet.
Currently, this may only be a pointer to an
.Vt ip
structure.
The
.Fa net
and
.Va m
.Fa m
arguments describe the network interface and the mbuf holding data for this
packet. The
.Va dir
is the direction; 0 for incoming packets and 1 for outgoing packets. if the function
packet.
The
.Fa dir
is the direction; 0 for incoming packets and 1 for outgoing packets.
If the function
returns non-zero, this signals an error and no further processing of this packet is
performed. The function should set errno to indicate the nature of the error.
performed.
The function should set
.Va errno
to indicate the nature of the error.
It is the hook's responsibility to free the chain if the packet is being dropped.
.Pp
The
.Nm
interface is enabled in the kernel via the
.Sy PFIL_HOOKS
.Cd PFIL_HOOKS
option.
.Sh RETURN VALUES
If successful
If successful,
.Fn pfil_hook_get
returns the first member of the packet filter list,
.Fn pfil_add_hook
@ -122,7 +138,8 @@ however this was changed in
.Nx 1.4
to
.Dv TAILQ
structures. This change was to allow the input and output filters to be
structures.
This change was to allow the input and output filters to be
processed in reverse order, to allow the same path to be taken, in or out
of the kernel.
.Pp
@ -132,7 +149,8 @@ interface was changed in 1.4T to accept a 3rd parameter to both
.Fn pfil_add_hook
and
.Fn pfil_remove_hook ,
introducing the capability of per-protocol filtering. This was done
introducing the capability of per-protocol filtering.
This was done
primarily in order to support filtering of IPv6.
.Sh BUGS
The current