470 lines
12 KiB
C
470 lines
12 KiB
C
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/*
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* SELinux NetLabel Support
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*
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* This file provides the necessary glue to tie NetLabel into the SELinux
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* subsystem.
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*
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* Author: Paul Moore <paul.moore@hp.com>
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*
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*/
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/*
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* (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <net/sock.h>
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#include <net/netlabel.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include "objsec.h"
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#include "security.h"
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#include "netlabel.h"
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/**
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* selinux_netlbl_sidlookup_cached - Cache a SID lookup
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* @skb: the packet
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* @secattr: the NetLabel security attributes
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* @sid: the SID
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*
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* Description:
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* Query the SELinux security server to lookup the correct SID for the given
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* security attributes. If the query is successful, cache the result to speed
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* up future lookups. Returns zero on success, negative values on failure.
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*
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*/
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static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
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struct netlbl_lsm_secattr *secattr,
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u32 *sid)
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{
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int rc;
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rc = security_netlbl_secattr_to_sid(secattr, sid);
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if (rc == 0 &&
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(secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
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(secattr->flags & NETLBL_SECATTR_CACHE))
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netlbl_cache_add(skb, secattr);
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return rc;
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}
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/**
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* selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
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* @sk: the socket
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*
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* Description:
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* Generate the NetLabel security attributes for a socket, making full use of
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* the socket's attribute cache. Returns a pointer to the security attributes
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* on success, NULL on failure.
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*
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*/
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static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
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{
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int rc;
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struct sk_security_struct *sksec = sk->sk_security;
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struct netlbl_lsm_secattr *secattr;
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if (sksec->nlbl_secattr != NULL)
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return sksec->nlbl_secattr;
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secattr = netlbl_secattr_alloc(GFP_ATOMIC);
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if (secattr == NULL)
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return NULL;
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rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
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if (rc != 0) {
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netlbl_secattr_free(secattr);
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return NULL;
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}
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sksec->nlbl_secattr = secattr;
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return secattr;
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}
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/**
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* selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
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*
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* Description:
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* Invalidate the NetLabel security attribute mapping cache.
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*
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*/
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void selinux_netlbl_cache_invalidate(void)
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{
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netlbl_cache_invalidate();
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}
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/**
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* selinux_netlbl_err - Handle a NetLabel packet error
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* @skb: the packet
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* @error: the error code
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* @gateway: true if host is acting as a gateway, false otherwise
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*
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* Description:
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* When a packet is dropped due to a call to avc_has_perm() pass the error
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* code to the NetLabel subsystem so any protocol specific processing can be
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* done. This is safe to call even if you are unsure if NetLabel labeling is
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* present on the packet, NetLabel is smart enough to only act when it should.
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*
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*/
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void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
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{
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netlbl_skbuff_err(skb, error, gateway);
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}
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/**
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* selinux_netlbl_sk_security_free - Free the NetLabel fields
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* @sssec: the sk_security_struct
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*
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* Description:
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* Free all of the memory in the NetLabel fields of a sk_security_struct.
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*
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*/
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void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec)
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{
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if (ssec->nlbl_secattr != NULL)
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netlbl_secattr_free(ssec->nlbl_secattr);
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}
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/**
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* selinux_netlbl_sk_security_reset - Reset the NetLabel fields
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* @ssec: the sk_security_struct
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* @family: the socket family
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*
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* Description:
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* Called when the NetLabel state of a sk_security_struct needs to be reset.
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* The caller is responsibile for all the NetLabel sk_security_struct locking.
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*
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*/
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void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec)
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{
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ssec->nlbl_state = NLBL_UNSET;
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}
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/**
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* selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
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* @skb: the packet
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* @family: protocol family
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* @type: NetLabel labeling protocol type
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* @sid: the SID
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*
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* Description:
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* Call the NetLabel mechanism to get the security attributes of the given
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* packet and use those attributes to determine the correct context/SID to
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* assign to the packet. Returns zero on success, negative values on failure.
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*
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*/
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int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
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u16 family,
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u32 *type,
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u32 *sid)
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{
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int rc;
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struct netlbl_lsm_secattr secattr;
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if (!netlbl_enabled()) {
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*sid = SECSID_NULL;
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return 0;
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}
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netlbl_secattr_init(&secattr);
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rc = netlbl_skbuff_getattr(skb, family, &secattr);
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if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
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rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
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else
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*sid = SECSID_NULL;
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*type = secattr.type;
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netlbl_secattr_destroy(&secattr);
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return rc;
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}
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/**
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* selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
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* @skb: the packet
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* @family: protocol family
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* @sid: the SID
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*
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* Description
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* Call the NetLabel mechanism to set the label of a packet using @sid.
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* Returns zero on auccess, negative values on failure.
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*
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*/
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int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
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u16 family,
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u32 sid)
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{
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int rc;
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struct netlbl_lsm_secattr secattr_storage;
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struct netlbl_lsm_secattr *secattr = NULL;
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struct sock *sk;
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/* if this is a locally generated packet check to see if it is already
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* being labeled by it's parent socket, if it is just exit */
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sk = skb->sk;
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if (sk != NULL) {
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struct sk_security_struct *sksec = sk->sk_security;
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if (sksec->nlbl_state != NLBL_REQSKB)
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return 0;
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secattr = sksec->nlbl_secattr;
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}
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if (secattr == NULL) {
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secattr = &secattr_storage;
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netlbl_secattr_init(secattr);
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rc = security_netlbl_sid_to_secattr(sid, secattr);
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if (rc != 0)
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goto skbuff_setsid_return;
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}
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rc = netlbl_skbuff_setattr(skb, family, secattr);
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skbuff_setsid_return:
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if (secattr == &secattr_storage)
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netlbl_secattr_destroy(secattr);
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return rc;
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}
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/**
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* selinux_netlbl_inet_conn_request - Label an incoming stream connection
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* @req: incoming connection request socket
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*
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* Description:
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* A new incoming connection request is represented by @req, we need to label
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* the new request_sock here and the stack will ensure the on-the-wire label
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* will get preserved when a full sock is created once the connection handshake
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* is complete. Returns zero on success, negative values on failure.
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*
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*/
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int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
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{
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int rc;
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struct netlbl_lsm_secattr secattr;
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if (family != PF_INET)
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return 0;
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netlbl_secattr_init(&secattr);
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rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
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if (rc != 0)
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goto inet_conn_request_return;
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rc = netlbl_req_setattr(req, &secattr);
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inet_conn_request_return:
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netlbl_secattr_destroy(&secattr);
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return rc;
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}
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/**
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* selinux_netlbl_inet_csk_clone - Initialize the newly created sock
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* @sk: the new sock
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*
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* Description:
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* A new connection has been established using @sk, we've already labeled the
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* socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
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* we need to set the NetLabel state here since we now have a sock structure.
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*
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*/
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void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
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{
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struct sk_security_struct *sksec = sk->sk_security;
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if (family == PF_INET)
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sksec->nlbl_state = NLBL_LABELED;
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else
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sksec->nlbl_state = NLBL_UNSET;
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}
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/**
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* selinux_netlbl_socket_post_create - Label a socket using NetLabel
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* @sock: the socket to label
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* @family: protocol family
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*
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* Description:
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* Attempt to label a socket using the NetLabel mechanism using the given
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* SID. Returns zero values on success, negative values on failure.
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*
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*/
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int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
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{
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int rc;
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struct sk_security_struct *sksec = sk->sk_security;
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struct netlbl_lsm_secattr *secattr;
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if (family != PF_INET)
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return 0;
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secattr = selinux_netlbl_sock_genattr(sk);
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if (secattr == NULL)
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return -ENOMEM;
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rc = netlbl_sock_setattr(sk, family, secattr);
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switch (rc) {
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case 0:
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sksec->nlbl_state = NLBL_LABELED;
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break;
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case -EDESTADDRREQ:
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sksec->nlbl_state = NLBL_REQSKB;
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rc = 0;
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break;
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}
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return rc;
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}
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/**
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* selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
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* @sksec: the sock's sk_security_struct
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* @skb: the packet
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* @family: protocol family
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* @ad: the audit data
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*
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* Description:
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* Fetch the NetLabel security attributes from @skb and perform an access check
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* against the receiving socket. Returns zero on success, negative values on
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* error.
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*
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*/
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int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
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struct sk_buff *skb,
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u16 family,
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struct common_audit_data *ad)
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{
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int rc;
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u32 nlbl_sid;
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u32 perm;
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struct netlbl_lsm_secattr secattr;
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if (!netlbl_enabled())
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return 0;
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netlbl_secattr_init(&secattr);
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rc = netlbl_skbuff_getattr(skb, family, &secattr);
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if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
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rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
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else
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nlbl_sid = SECINITSID_UNLABELED;
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netlbl_secattr_destroy(&secattr);
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if (rc != 0)
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return rc;
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switch (sksec->sclass) {
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case SECCLASS_UDP_SOCKET:
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perm = UDP_SOCKET__RECVFROM;
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break;
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case SECCLASS_TCP_SOCKET:
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perm = TCP_SOCKET__RECVFROM;
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break;
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default:
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perm = RAWIP_SOCKET__RECVFROM;
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}
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rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
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if (rc == 0)
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|
return 0;
|
||
|
|
|
||
|
|
if (nlbl_sid != SECINITSID_UNLABELED)
|
||
|
|
netlbl_skbuff_err(skb, rc, 0);
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
|
||
|
|
* @sock: the socket
|
||
|
|
* @level: the socket level or protocol
|
||
|
|
* @optname: the socket option name
|
||
|
|
*
|
||
|
|
* Description:
|
||
|
|
* Check the setsockopt() call and if the user is trying to replace the IP
|
||
|
|
* options on a socket and a NetLabel is in place for the socket deny the
|
||
|
|
* access; otherwise allow the access. Returns zero when the access is
|
||
|
|
* allowed, -EACCES when denied, and other negative values on error.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
int selinux_netlbl_socket_setsockopt(struct socket *sock,
|
||
|
|
int level,
|
||
|
|
int optname)
|
||
|
|
{
|
||
|
|
int rc = 0;
|
||
|
|
struct sock *sk = sock->sk;
|
||
|
|
struct sk_security_struct *sksec = sk->sk_security;
|
||
|
|
struct netlbl_lsm_secattr secattr;
|
||
|
|
|
||
|
|
if (level == IPPROTO_IP && optname == IP_OPTIONS &&
|
||
|
|
(sksec->nlbl_state == NLBL_LABELED ||
|
||
|
|
sksec->nlbl_state == NLBL_CONNLABELED)) {
|
||
|
|
netlbl_secattr_init(&secattr);
|
||
|
|
lock_sock(sk);
|
||
|
|
rc = netlbl_sock_getattr(sk, &secattr);
|
||
|
|
release_sock(sk);
|
||
|
|
if (rc == 0)
|
||
|
|
rc = -EACCES;
|
||
|
|
else if (rc == -ENOMSG)
|
||
|
|
rc = 0;
|
||
|
|
netlbl_secattr_destroy(&secattr);
|
||
|
|
}
|
||
|
|
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* selinux_netlbl_socket_connect - Label a client-side socket on connect
|
||
|
|
* @sk: the socket to label
|
||
|
|
* @addr: the destination address
|
||
|
|
*
|
||
|
|
* Description:
|
||
|
|
* Attempt to label a connected socket with NetLabel using the given address.
|
||
|
|
* Returns zero values on success, negative values on failure.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
|
||
|
|
{
|
||
|
|
int rc;
|
||
|
|
struct sk_security_struct *sksec = sk->sk_security;
|
||
|
|
struct netlbl_lsm_secattr *secattr;
|
||
|
|
|
||
|
|
if (sksec->nlbl_state != NLBL_REQSKB &&
|
||
|
|
sksec->nlbl_state != NLBL_CONNLABELED)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
local_bh_disable();
|
||
|
|
bh_lock_sock_nested(sk);
|
||
|
|
|
||
|
|
/* connected sockets are allowed to disconnect when the address family
|
||
|
|
* is set to AF_UNSPEC, if that is what is happening we want to reset
|
||
|
|
* the socket */
|
||
|
|
if (addr->sa_family == AF_UNSPEC) {
|
||
|
|
netlbl_sock_delattr(sk);
|
||
|
|
sksec->nlbl_state = NLBL_REQSKB;
|
||
|
|
rc = 0;
|
||
|
|
goto socket_connect_return;
|
||
|
|
}
|
||
|
|
secattr = selinux_netlbl_sock_genattr(sk);
|
||
|
|
if (secattr == NULL) {
|
||
|
|
rc = -ENOMEM;
|
||
|
|
goto socket_connect_return;
|
||
|
|
}
|
||
|
|
rc = netlbl_conn_setattr(sk, addr, secattr);
|
||
|
|
if (rc == 0)
|
||
|
|
sksec->nlbl_state = NLBL_CONNLABELED;
|
||
|
|
|
||
|
|
socket_connect_return:
|
||
|
|
bh_unlock_sock(sk);
|
||
|
|
local_bh_enable();
|
||
|
|
return rc;
|
||
|
|
}
|