path: root/lib/libautofs/libautofs.3

.\" Copyright (c) 2004 Alfred Perlstein <alfred@FreeBSD.org>
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.\" $Id: libautofs.3,v 1.4 2004/09/08 08:12:21 bright Exp $
.\" $FreeBSD$
.Dd August 30, 2004
.Dt LIBAUTOFS 3
.Os
.Sh NAME
.Nm libautofs
.Nd "procedural interface to managing an autofs filesystem"
.Sh SYNOPSIS
.In libautofs.h
.Ft int
.Fn autoh_get "const char *path" "autoh_t *hndlp"
.Ft void
.Fn autoh_free "autoh_t hndl"
.Ft int
.Fn autoh_getall "autoh_t **hndlpp" "int *cnt"
.Ft void
.Fn autoh_freeall "autoh_t *hndlep"
.Ft int
.Fn autoh_fd "autoh_t hndl"
.Ft const char *
.Fn autoh_mp "autoh_t hndl"
.Ft int
.Fn autoreq_get "autoh_t hndl" "autoreq_t **reqpp" "int *cntp"
.Ft void
.Fn autoreq_free "autoh_t hndl" "autoreq_t *reqp"
.Ft int
.Fn autoreq_serv "autoh_t hndl" "autoreq_t req"
.Ft enum autoreq_op
.Fn autoreq_getop "autoreq_t req"
.Ft const char *
.Fn autoreq_getpath "autoreq_t req"
.Ft autoino_t
.Fn autoreq_getino "autoreq_t req"
.Ft autoino_t
.Fn autoreq_getdirino "autoreq_t req"
.Ft void
.Fn autoreq_getaux "autoreq_t req" "void **auxdatap" "size_t *auxsizep"
.Ft void
.Fn autoreq_getoffset "autoreq_t req" "off_t *offp"
.Ft void
.Fn autoreq_setino "autoreq_t req" "autoino_t ino"
.Ft void
.Fn autoreq_seterrno "autoreq_t req" "int errno"
.Ft void
.Fn autoreq_setaux "autoreq_t req" "void *auxdata" "size_t auxsize"
.Ft void
.Fn autoreq_seteof "autoreq_t req" "int eof"
.Ft int
.Fn autoh_togglepath "autoh_t hndl" "int toggle" "pid_t pid" "const char *path"
.Ft int
.Fn autoh_togglefd "autoh_t hndl" "int toggle" "pid_t pid" "int fd"
.Sh DESCRIPTION
The
.Nm libautofs
libarary provides a "mostly" stable interface to the
.Xr autofs 9
filesystem.
.Pp
The inteface to
.Xr autofs 9
is managed via handles of type
.Fa autoh_t
and
.Fa autoreq_t
which refer to handles to
.Xr autofs 9
mount points and requests respectively.
.Pp
The
.Fn autoh_get
function returns a handle to an
.Xr autofs 9
filesystem based on the
.Fn path
parameter.
The handle returned should be freed via the
.Fn autoh_free
function.
.Pp
The
.Fn autoh_getall
function returns an array of handles to all mounted
.Xr autofs 9
filesystems, each of which should be released via the
.Fn autoh_free
function or released en-mass via the
.Fn autoh_freeall
function.
.Pp
The
.Fn autoh_fd
function returns a file descriptor that can selected or polled on
for "excecption" data to detect an
.Xr autofs 9
event.
.Pp
The
.Fn autoh_mp
function returns the path to the autofs filesystem that the
.Fa hndl
is derived from.
.Pp
The
.Fn autoreq_get
function returns an array of autofs requests in
.Fa reqpp ,
the number of requests is stored into
.Fa cntp .
Each request should be released using the
.Fn autoreq_free
function.
.Pp
Requests that are retrieved via the
.Fn autoreq_get
are served via the "autoreq_" functions.
.Pp
The following functions returns information about the request.
.Bl -tag -width indent
.It Fn autoreq_getop
return the operation type of the request, that would be one of
AUTOREQ_OP_UNKNOWN, AUTOREQ_OP_LOOKUP, AUTOREQ_OP_STAT, AUTOREQ_OP_READDIR
depending on the type of request that
.Xr autofs 9
requires service from.
.It Fn autoreq_getpath
return the path of the mountpoint associated with the request
.Fa req .
.It Fn autoreq_getino
return the inode associated with the request
.Fa req .
.It Fn autoreq_getdirno
return the directory inode associated with the request
.Fa req .
.It Fn autoreq_getaux
return the auxilliray data associated with the request
.Fa req .
.It Fn autoreq_getoffset
return the offset request associated with the request
.Fa req .
(used for readdir request)
.El
.Pp
The following functions allow one to set the response sent to
.Xr autofs 9
to the requesting userland application.
.Bl -tag -width indent
.It Fn autoreq_setino
Set the request
.Fa req
inode to
.Fa ino ,
this is typically unused.
.It Fn autoreq_seterrno
set the error returned to the application sending the request, typically
this is left alone, or set to ENOENT if the request is for a non-existant
name.  The default error is no error.  Meaning the application will see
a successful return.
.It Fn autoreq_setaux
used to set the auxilliray data for a request, currently used to set
the dirent structures for serving a readdir request.  Default is no
auxilliary data.
.It Fn autoreq_seteof
used to set the eof flag for readdir requests (default is not eof.)
.El
.Pp
The functions
.Fn autoh_togglepath
and
.Fn autoh_togglefd
are used to set options on an
.Xr autofs 9
directory via
.Fa path
and
.Fa fd
respectively.  The
.Fa pid
argument should be set to the pid of the process serving
.Xr autofs 9
requests, or -1 to disable the option.  The options are
.Bl -tag -width AUTO_INDIRECT
.It Fa AUTO_MOUNTER
set this process as the one responsible for the
.Xr autofs 9
node, if this process exits, then requests into the autofs will begin to fail.
.It Fa AUTO_BROWSE
dispatch directory read requests for this node to the process identified by
.Fa pid .
Specifically, calls to
.Xr getdirentries 2
and
.Xr getdents 2
will be routed to userland after the current actual directory contents
are read into userland.
.It Fa AUTO_DIRECT
Set the directory as a mount trigger.  Any request to enter the directory
will trigger a callback into the process
.Fa pid .
.It Fa AUTO_INDIRECT
Set the directory as an indirect trigger.  Any request for an entry inside
the directory will be routed to the process identified by
.Fa pid .
.El
.Sh EXAMPLES
See /usr/share/examples/autofs/driver/
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 6.0 .
.Sh AUTHORS
This manual page and the autofs filesystem suite were written by
.An Alfred Perlstein .