FreeBSD/Linux Kernel Cross Reference
sys/security/mac_seeotheruids/mac_seeotheruids.c

     /*-
      * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
      * Copyright (c) 2001, 2002 Networks Associates Technology, Inc.
      * All rights reserved.
      *
      * This software was developed by Robert Watson for the TrustedBSD Project.
      *
      * This software was developed for the FreeBSD Project in part by Network
      * Associates Laboratories, the Security Research Division of Network
     * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
     * as part of the DARPA CHATS research program.
     *
     * 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.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
     *
     * $FreeBSD: releng/5.1/sys/security/mac_seeotheruids/mac_seeotheruids.c 112717 2003-03-27 19:26:39Z rwatson $
     */
    
    /*
     * Developed by the TrustedBSD Project.
     * Prevent processes owned by a particular uid from seeing various transient
     * kernel objects associated with other uids.
     */
    
    #include <sys/types.h>
    #include <sys/param.h>
    #include <sys/conf.h>
    #include <sys/kernel.h>
    #include <sys/mac.h>
    #include <sys/mount.h>
    #include <sys/proc.h>
    #include <sys/systm.h>
    #include <sys/sysproto.h>
    #include <sys/sysent.h>
    #include <sys/vnode.h>
    #include <sys/file.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/sysctl.h>
    
    #include <net/bpfdesc.h>
    #include <net/if.h>
    #include <net/if_types.h>
    #include <net/if_var.h>
    
    #include <vm/vm.h>
    
    #include <sys/mac_policy.h>
    
    SYSCTL_DECL(_security_mac);
    
    SYSCTL_NODE(_security_mac, OID_AUTO, seeotheruids, CTLFLAG_RW, 0,
        "TrustedBSD mac_seeotheruids policy controls");
    
    static int      mac_seeotheruids_enabled = 1;
    SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, enabled, CTLFLAG_RW,
        &mac_seeotheruids_enabled, 0, "Enforce seeotheruids policy");
    
    /*
     * Exception: allow credentials to be aware of other credentials with the
     * same primary gid.
     */
    static int      primarygroup_enabled = 0;
    SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, primarygroup_enabled,
        CTLFLAG_RW, &primarygroup_enabled, 0, "Make an exception for credentials "
        "with the same real primary group id");
    
    /*
     * Exception: allow processes with a specific gid to be exempt from the
     * policy.  One sysctl enables this functionality; the other sets the
     * exempt gid.
     */
    static int      specificgid_enabled = 0;
    SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid_enabled,
        CTLFLAG_RW, &specificgid_enabled, 0, "Make an exception for credentials "
        "with a specific gid as their real primary group id or group set");
    
    static gid_t    specificgid = 0;
    SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid, CTLFLAG_RW,
        &specificgid, 0, "Specific gid to be exempt from seeotheruids policy");
    
   static int
   mac_seeotheruids_check(struct ucred *u1, struct ucred *u2)
   {
   
           if (!mac_seeotheruids_enabled)
                   return (0);
   
           if (primarygroup_enabled) {
                   if (u1->cr_rgid == u2->cr_rgid)
                           return (0);
           }
   
           if (specificgid_enabled) {
                   if (u1->cr_rgid == specificgid || groupmember(specificgid, u1))
                           return (0);
           }
   
           if (u1->cr_ruid == u2->cr_ruid)
                   return (0);
   
           return (ESRCH);
   }
   
   static int
   mac_seeotheruids_check_cred_visible(struct ucred *u1, struct ucred *u2)
   {
   
           return (mac_seeotheruids_check(u1, u2));
   }
   
   static int
   mac_seeotheruids_check_proc_signal(struct ucred *cred, struct proc *proc,
       int signum)
   {
   
           return (mac_seeotheruids_check(cred, proc->p_ucred));
   }
   
   static int
   mac_seeotheruids_check_proc_sched(struct ucred *cred, struct proc *proc)
   {
   
           return (mac_seeotheruids_check(cred, proc->p_ucred));
   }
   
   static int
   mac_seeotheruids_check_proc_debug(struct ucred *cred, struct proc *proc)
   {
   
           return (mac_seeotheruids_check(cred, proc->p_ucred));
   }
   
   static int
   mac_seeotheruids_check_socket_visible(struct ucred *cred, struct socket *socket,
       struct label *socketlabel)
   {
   
           return (mac_seeotheruids_check(cred, socket->so_cred));
   }
   
   static struct mac_policy_ops mac_seeotheruids_ops =
   {
           .mpo_check_cred_visible = mac_seeotheruids_check_cred_visible,
           .mpo_check_proc_debug = mac_seeotheruids_check_proc_debug,
           .mpo_check_proc_sched = mac_seeotheruids_check_proc_sched,
           .mpo_check_proc_signal = mac_seeotheruids_check_proc_signal,
           .mpo_check_socket_visible = mac_seeotheruids_check_socket_visible,
   };
   
   MAC_POLICY_SET(&mac_seeotheruids_ops, mac_seeotheruids,
       "TrustedBSD MAC/seeotheruids", MPC_LOADTIME_FLAG_UNLOADOK, NULL);

Cache object: 921c80afaa5f47e01f3eaf7edb22dd9b