freebsd/lib/libprocstat/libprocstat.3

.\" Copyright (c) 2011 Sergey Kandaurov <pluknet@FreeBSD.org>
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.Dd July 12, 2011
.Dt LIBPROCSTAT 3
.Os
.Sh NAME
.Nm procstat_open_kvm ,
.Nm procstat_open_sysctl ,
.Nm procstat_close ,
.Nm procstat_getfiles ,
.Nm procstat_getprocs ,
.Nm procstat_freefiles ,
.Nm procstat_freeprocs ,
.Nm procstat_get_pipe_info ,
.Nm procstat_get_pts_info ,
.Nm procstat_get_socket_info ,
.Nm procstat_get_vnode_info
.Nd library interface for file and process information retrieval
.Sh LIBRARY
.Lb libprocstat
.Sh SYNOPSIS
.In sys/param.h
.In sys/queue.h
.In libprocstat.h
.Ft void
.Fn procstat_close "struct procstat *procstat"
.Ft void
.Fo procstat_freefiles
.Fa "struct procstat *procstat"
.Fa "struct filestat_list *head"
.Fc
.Ft void
.Fn procstat_freeprocs "struct procstat *procstat" "struct kinfo_proc *p"
.Ft int
.Fo procstat_get_pipe_info
.Fa "struct procstat *procstat"
.Fa "struct filestat *fst"
.Fa "struct pipestat *pipe"
.Fa "char *errbuf"
.Fc
.Ft int
.Fo procstat_get_pts_info
.Fa "struct procstat *procstat"
.Fa "struct filestat *fst"
.Fa "struct ptsstat *pts"
.Fa "char *errbuf"
.Fc
.Ft int
.Fo procstat_get_socket_info
.Fa "struct procstat *procstat"
.Fa "struct filestat *fst"
.Fa "struct sockstat *sock"
.Fa "char *errbuf"
.Fc
.Ft int
.Fo procstat_get_vnode_info
.Fa "struct procstat *procstat"
.Fa "struct filestat *fst"
.Fa "struct vnstat *vn"
.Fa "char *errbuf"
.Fc
.Ft "struct filestat_list *"
.Fo procstat_getfiles
.Fa "struct procstat *procstat"
.Fa "struct kinfo_proc *kp"
.Fa "int mmapped"
.Fc
.Ft "struct kinfo_proc *"
.Fo procstat_getprocs
.Fa "struct procstat *procstat"
.Fa "int what"
.Fa "int arg"
.Fa "unsigned int *count"
.Fc
.Ft "struct procstat *"
.Fn procstat_open_kvm "const char *nlistf" "const char *memf"
.Ft "struct procstat *"
.Fn procstat_open_sysctl void
.Sh DESCRIPTION
The
.Nm libprocstat
library contains the API for runtime file and process information
retrieval from the running kernel via the
.Xr sysctl 3
library backend, and for post-mortem analysis via the
.Xr kvm 3
library backend.
.Pp
The
.Fn procstat_open_kvm
and
.Fn procstat_open_sysctl
functions use the
.Xr kvm 3
or
.Xr sysctl 3
library routines, respectively, to access kernel state information
used to retrieve processes and files states.
The
.Fa nlistf
argument is the executable image of the kernel being examined.
If this argument is
.Dv NULL ,
the currently running kernel is assumed.
The
.Fa memf
argument is the kernel memory device file.
If this argument is
.Dv NULL ,
then
.Pa /dev/mem
is assumed.
See
.Xr kvm_open 3
for more details.
Both functions dynamically allocate and return a
.Vt procstat
structure pointer used in the rest of the
.Nm libprocstat
library routines until the corresponding
.Fn procstat_close
call that cleans up the resources allocated by the
.Fn procstat_open_*
functions.
.Pp
The
.Fn procstat_getprocs
function gets a pointer to the
.Vt procstat
structure from one of the
.Fn procstat_open_*
functions and returns a dynamically allocated (sub-)set of active processes
in the kernel filled in to array of
.Vt kinfo_proc
structures.
The
.Fa what
and
.Fa arg
arguments constitute a filtering predicate as described in the
.Xr kvm_getprocs 3
function.
The number of processes found is returned in the reference parameter
.Fa cnt .
The caller is responsible to free the allocated memory with a subsequent
.Fn procstat_freeprocs
function call.
.Pp
The
.Fn procstat_getfiles
function gets a pointer to the
.Vt procstat
structure initialized with one of the
.Fn procstat_open_*
functions, a pointer to
.Vt kinfo_proc
structure from the array obtained from the
.Fn kvm_getprocs
function, and returns a dynamically allocated linked list of filled in
.Vt filestat_list
structures using the STAILQ macros defined in
.Xr queue 3 .
The caller is responsible to free the allocated memory with a subsequent
.Fn procstat_freefiles
function call.
.Pp
The
.Fn procstat_get_pipe_info ,
.Fn procstat_get_pts_info ,
.Fn procstat_get_socket_info
and
.Fn procstat_get_vnode_info
functions are used to retrive information about pipes, pseudo-terminals,
sockets, and vnodes, respectively.
Each of them have a similar interface API.
The
.Fa procstat
argument is a pointer obtained from one of
.Fn procstat_open_*
functions.
The
.Ft filestat Fa fst
argument is an element of STAILQ linked list as obtained from the
.Fn procstat_getfiles
function.
The
.Ft filestat
structure contains a
.Fa fs_type
field that specifies a file type and a corresponding function to be
called among the
.Nm procstat_get_*_info
function family.
The actual object is returned in the 3rd reference parameter.
The
.Fa errbuf
argument indicates an actual error message in case of failure.
.Pp
.Bl -tag -width 20n -compact -offset indent
.It Li PS_FST_TYPE_FIFO
.Nm procstat_get_vnode_info
.It Li PS_FST_TYPE_VNODE
.Nm procstat_get_vnode_info
.It Li PS_FST_TYPE_SOCKET
.Nm procstat_get_socket_info
.It Li PS_FST_TYPE_PIPE
.Nm procstat_get_pipe_info
.It Li PS_FST_TYPE_PTS
.Nm procstat_get_pts_info
.El
.Sh SEE ALSO
.Xr fstat 1 ,
.Xr fuser 1 ,
.Xr pipe 2 ,
.Xr socket 2 ,
.Xr kvm 3 ,
.Xr queue 3 ,
.Xr sysctl 3 ,
.Xr pts 4 ,
.Xr vnode 9
.Sh HISTORY
The
.Nm libprocstat
library appeared in
.Fx 9.0 .
.Sh AUTHORS
.An Stanislav Sedov Aq stas@FreeBSD.org