.\"	$KAME: ipsec_strerror.3,v 1.9 2001/08/17 07:21:36 itojun Exp $
.\"
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.\" $FreeBSD: head/lib/libipsec/ipsec_strerror.3 226436 2011-10-16 14:30:28Z eadler $
.\"
.Dd February 14, 2006
.Dt IPSEC_STRERROR 3
.Os
.\"
.Sh NAME
.Nm ipsec_strerror
.Nd error messages for the IPsec policy manipulation library
.\"
.Sh SYNOPSIS
.In netipsec/ipsec.h
.Ft "const char *"
.Fn ipsec_strerror
.\"
.Sh DESCRIPTION
.In netipsec/ipsec.h
declares
.Pp
.Dl extern int ipsec_errcode;
.Pp
which is used to pass an error code from IPsec policy manipulation library
to a user program.
The
.Fn ipsec_strerror
function can be used to obtain the error message string for the error code.
.Pp
The array pointed to is not to be modified by the program.
Since
.Fn ipsec_strerror
uses
.Xr strerror 3
as an underlying function, calling
.Xr strerror 3
after
.Fn ipsec_strerror
would overwrite the return value from
.Fn ipsec_strerror
and make it invalid.
.\"
.Sh RETURN VALUES
The
.Fn ipsec_strerror
function always returns a pointer to C string.
The C string must not be overwritten by the caller.
.\"
.Sh SEE ALSO
.Xr ipsec_set_policy 3
.\"
.Sh HISTORY
The
.Fn ipsec_strerror
function first appeared in WIDE/KAME IPv6 protocol stack kit.
.\"
.Sh BUGS
The
.Fn ipsec_strerror
function will return its result which may be overwritten by subsequent calls.
.Pp
.Va ipsec_errcode
is not thread safe.