.\" .\" Copyright (c) 1996,1997 Berkeley Software Design, Inc. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by Berkeley Software Design, .\" Inc. .\" 4. The name of Berkeley Software Design, Inc. may not be used to endorse .\" or promote products derived from this software without specific prior .\" written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $OpenBSD: login_cap.3,v 1.8 2002/02/23 00:39:06 millert Exp $ .\" BSDI $From: login_cap.3,v 1.4 1997/11/07 16:22:27 jch Exp $ .\" .Dd July 16, 1996 .Dt LOGIN_CAP 3 .Os .Sh NAME .Nm login_getclass , .Nm login_getstyle , .Nm login_getcapbool , .Nm login_getcapnum , .Nm login_getcapsize , .Nm login_getcapstr , .Nm login_getcaptime , .Nm login_close , .Nm secure_path , .Nm setclasscontext , .Nm setusercontext .Nd query login.conf database about a user class .Sh SYNOPSIS .Fd #include .Ft login_cap_t * .Fn login_getclass "char *class" .Ft char * .Fn login_getstyle "login_cap_t *lc" "char *style" "char *type" .Ft int .Fn login_getcapbool "login_cap_t *lc" "char *cap" "u_int def" .Ft quad_t .Fn login_getcapnum "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err" .Ft quad_t .Fn login_getcapsize "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err" .Ft char * .Fn login_getcapstr "login_cap_t *lc" "char *cap" "char *def" "char *err" .Ft quad_t .Fn login_getcaptime "login_cap_t *lc" "char *cap" "quad_t def" "quad_t err" .Ft void .Fn login_close "login_cap_t *lc" .Ft int .Fn secure_path "char *path" .Ft int .Fn setclasscontext "char *class" "u_int flags" .Ft int .Fn setusercontext "login_cap_t *lc" "struct passwd *pwd" "uid_t uid" "u_int flags" .Sh DESCRIPTION The .Fn login_getclass function extracts the entry specified by .Ar class (or .Li default if .Ar class is .Dv NULL or the empty string) from .Pa /etc/login.conf (see .Xr login.conf 5 ) . If the entry is found, a .Li login_cap_t pointer is returned. .Dv NULL is returned if the user class is not found. When the .Li login_cap_t structure is no longer needed, it should be freed by the .Fn login_close function. .Pp Once .Ar lc has been returned by .Fn login_getclass , any of the other .Fn login_* functions may be called. The .Fn login_getstyle function is used to obtain the style of authentication that should be used for this user class. The .Ar style argument may either be .Dv NULL or the desired style of authentication. If .Dv NULL , the first available authentication style will be used. The .Ar type argument refers to the type of authentication being performed. This is used to override the standard .Li auth entry in the database. By convention this should be of the form "auth-type". Future releases may remove the requirement for the "auth-" prefix and add it if it is missing. If .Ar type is .Dv NULL then only "auth" will be looked at. (See .Xr login.conf 5 ) . The .Fn login_getstyle function will return .Dv NULL if the desired style of authentication is not available, or if no style is available. .Pp The .Fn login_getcapnum , .Fn login_getcapsize , .Fn login_getcapstr , and .Fn login_getcaptime functions all query the database entry for a field named .Ar cap . If the field is found, its value is returned. If the field is not found, the value specified by .Ar def is returned. If an error is encountered while trying to find the field, .Ar err is returned. See .Xr login.conf 5 for a discussion of the various textual forms the value may take. The .Fn login_getcapbool function is slightly different. It returns .Ar def if no capabilities were found for this class (typically meaning that the default class was used and the .Li /etc/login.conf file is missing). It returns a non-zero value if .Ar cap , with no value, was found, zero otherwise. .Pp The .Fn secure_path function takes a path name and returns 0 if the path name is secure, \-1 if not. To be secure a path must exist, be a regular file (and not a directory), owned by root, and only writable by the owner (root). .Pp The .Fn setclasscontext function takes .Ar class , the name of a user class, and sets the resources defined by that class according to .Ar flags. Only the .Dv LOGIN_SETPATH , .Dv LOGIN_SETPRIORITY , .Dv LOGIN_SETRESOURCES , and .Dv LOGIN_SETUMASK bits are used. (See .Fn setusercontext below). It returns 0 on success and \-1 on failure. .Pp The .Fn setusercontext function sets the resources according to .Ar flags . The .Ar lc argument, if not .Dv NULL , contains the class information that should be used. The .Ar pwd argument, if not .Dv NULL , provides information about the user. Both .Ar lc and .Ar pwd cannot be .Dv NULL . The .Ar uid argument is used in place of the user ID contained in the .Ar pwd structure when calling .Xr setuid 2 . The .Fn setusercontext function returns 0 on success and -1 on failure. The various bits available to be or-ed together to make up .Ar flags are: .Bl -tag -width LOGIN_SETRESOURCESXX .It Dv LOGIN_SETGROUP Set the group id and call .Xr initgroups 3 . Requires the .Xr pwd field be specified. .It Dv LOGIN_SETLOGIN Sets the login name by .Xr setlogin 2 . Requires the .Ar pwd field be specified. .It Dv LOGIN_SETPATH Sets the .Ev PATH environment variable. .It Dv LOGIN_SETPRIORITY Sets the priority by .Xr setpriority 2 . .It Dv LOGIN_SETRESOURCES Sets the various system resources by .Xr setrlimit 2 . .It Dv LOGIN_SETUMASK Sets the umask by .Xr umask 2 . .It Dv LOGIN_SETUSER Sets the user ID to .Ar uid by .Xr setuid 2 . .It Dv LOGIN_SETALL Sets all of the above. .El .Sh SEE ALSO .Xr setlogin 2 , .Xr setpriority 2 , .Xr setrlimit 2 , .Xr setuid 2 , .Xr umask 2 , .Xr initgroups 3 , .Xr login.conf 5 .Sh HISTORY The .Nm function first appeared in .Ox 2.8 . .Sh CAVEATS The string returned by .Fn login_getcapstr is allocated via .Xr malloc 3 when the specified capability is present and thus it is the responsibility of the caller to .Fn free this space. However, if the capability was not found or an error occurred and .Fa def or .Fa err (whichever is relevant) are non-NULL the returned value is simply what was passed in to .Fn login_getcapstr . Therefore it is not possible to blindly .Fn free the return value without first checking it against .Fa def and .Fa err . .Pp The same warnings set forth in .Xr setlogin 2 apply to .Fn setusercontext when the .Dv LOGIN_SETLOGIN flag is used. Specifically, changing the login name affects all processes in the current session, not just the current process. See .Xr setlogin 2 for more information.