Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 549 insertions, 0 deletions

diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
new file mode 100644
index 0000000..350794a
--- /dev/null
+++ b/security/selinux/netlabel.c
@@ -0,0 +1,549 @@
+/*
+ * SELinux NetLabel Support
+ *
+ * This file provides the necessary glue to tie NetLabel into the SELinux
+ * subsystem.
+ *
+ * Author: Paul Moore <paul.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
+ *
+ * This program is free software;  you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program;  if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/sock.h>
+#include <net/netlabel.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+#include "objsec.h"
+#include "security.h"
+#include "netlabel.h"
+
+/**
+ * selinux_netlbl_sidlookup_cached - Cache a SID lookup
+ * @skb: the packet
+ * @secattr: the NetLabel security attributes
+ * @sid: the SID
+ *
+ * Description:
+ * Query the SELinux security server to lookup the correct SID for the given
+ * security attributes.  If the query is successful, cache the result to speed
+ * up future lookups.  Returns zero on success, negative values on failure.
+ *
+ */
+static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
+					   struct netlbl_lsm_secattr *secattr,
+					   u32 *sid)
+{
+	int rc;
+
+	rc = security_netlbl_secattr_to_sid(secattr, sid);
+	if (rc == 0 &&
+	    (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
+	    (secattr->flags & NETLBL_SECATTR_CACHE))
+		netlbl_cache_add(skb, secattr);
+
+	return rc;
+}
+
+/**
+ * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
+ * @sk: the socket
+ *
+ * Description:
+ * Generate the NetLabel security attributes for a socket, making full use of
+ * the socket's attribute cache.  Returns a pointer to the security attributes
+ * on success, NULL on failure.
+ *
+ */
+static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
+{
+	int rc;
+	struct sk_security_struct *sksec = sk->sk_security;
+	struct netlbl_lsm_secattr *secattr;
+
+	if (sksec->nlbl_secattr != NULL)
+		return sksec->nlbl_secattr;
+
+	secattr = netlbl_secattr_alloc(GFP_ATOMIC);
+	if (secattr == NULL)
+		return NULL;
+	rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
+	if (rc != 0) {
+		netlbl_secattr_free(secattr);
+		return NULL;
+	}
+	sksec->nlbl_secattr = secattr;
+
+	return secattr;
+}
+
+/**
+ * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
+ * @sk: the socket to label
+ *
+ * Description:
+ * Attempt to label a socket using the NetLabel mechanism.  Returns zero values
+ * on success, negative values on failure.
+ *
+ */
+static int selinux_netlbl_sock_setsid(struct sock *sk)
+{
+	int rc;
+	struct sk_security_struct *sksec = sk->sk_security;
+	struct netlbl_lsm_secattr *secattr;
+
+	if (sksec->nlbl_state != NLBL_REQUIRE)
+		return 0;
+
+	secattr = selinux_netlbl_sock_genattr(sk);
+	if (secattr == NULL)
+		return -ENOMEM;
+	rc = netlbl_sock_setattr(sk, secattr);
+	switch (rc) {
+	case 0:
+		sksec->nlbl_state = NLBL_LABELED;
+		break;
+	case -EDESTADDRREQ:
+		sksec->nlbl_state = NLBL_REQSKB;
+		rc = 0;
+		break;
+	}
+
+	return rc;
+}
+
+/**
+ * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
+ *
+ * Description:
+ * Invalidate the NetLabel security attribute mapping cache.
+ *
+ */
+void selinux_netlbl_cache_invalidate(void)
+{
+	netlbl_cache_invalidate();
+}
+
+/**
+ * selinux_netlbl_err - Handle a NetLabel packet error
+ * @skb: the packet
+ * @error: the error code
+ * @gateway: true if host is acting as a gateway, false otherwise
+ *
+ * Description:
+ * When a packet is dropped due to a call to avc_has_perm() pass the error
+ * code to the NetLabel subsystem so any protocol specific processing can be
+ * done.  This is safe to call even if you are unsure if NetLabel labeling is
+ * present on the packet, NetLabel is smart enough to only act when it should.
+ *
+ */
+void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
+{
+	netlbl_skbuff_err(skb, error, gateway);
+}
+
+/**
+ * selinux_netlbl_sk_security_free - Free the NetLabel fields
+ * @sssec: the sk_security_struct
+ *
+ * Description:
+ * Free all of the memory in the NetLabel fields of a sk_security_struct.
+ *
+ */
+void selinux_netlbl_sk_security_free(struct sk_security_struct *ssec)
+{
+	if (ssec->nlbl_secattr != NULL)
+		netlbl_secattr_free(ssec->nlbl_secattr);
+}
+
+/**
+ * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
+ * @ssec: the sk_security_struct
+ * @family: the socket family
+ *
+ * Description:
+ * Called when the NetLabel state of a sk_security_struct needs to be reset.
+ * The caller is responsibile for all the NetLabel sk_security_struct locking.
+ *
+ */
+void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
+				      int family)
+{
+	if (family == PF_INET)
+		ssec->nlbl_state = NLBL_REQUIRE;
+	else
+		ssec->nlbl_state = NLBL_UNSET;
+}
+
+/**
+ * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
+ * @skb: the packet
+ * @family: protocol family
+ * @type: NetLabel labeling protocol type
+ * @sid: the SID
+ *
+ * Description:
+ * Call the NetLabel mechanism to get the security attributes of the given
+ * packet and use those attributes to determine the correct context/SID to
+ * assign to the packet.  Returns zero on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
+				 u16 family,
+				 u32 *type,
+				 u32 *sid)
+{
+	int rc;
+	struct netlbl_lsm_secattr secattr;
+
+	if (!netlbl_enabled()) {
+		*sid = SECSID_NULL;
+		return 0;
+	}
+
+	netlbl_secattr_init(&secattr);
+	rc = netlbl_skbuff_getattr(skb, family, &secattr);
+	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+		rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
+	else
+		*sid = SECSID_NULL;
+	*type = secattr.type;
+	netlbl_secattr_destroy(&secattr);
+
+	return rc;
+}
+
+/**
+ * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
+ * @skb: the packet
+ * @family: protocol family
+ * @sid: the SID
+ *
+ * Description
+ * Call the NetLabel mechanism to set the label of a packet using @sid.
+ * Returns zero on auccess, negative values on failure.
+ *
+ */
+int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
+				 u16 family,
+				 u32 sid)
+{
+	int rc;
+	struct netlbl_lsm_secattr secattr_storage;
+	struct netlbl_lsm_secattr *secattr = NULL;
+	struct sock *sk;
+
+	/* if this is a locally generated packet check to see if it is already
+	 * being labeled by it's parent socket, if it is just exit */
+	sk = skb->sk;
+	if (sk != NULL) {
+		struct sk_security_struct *sksec = sk->sk_security;
+		if (sksec->nlbl_state != NLBL_REQSKB)
+			return 0;
+		secattr = sksec->nlbl_secattr;
+	}
+	if (secattr == NULL) {
+		secattr = &secattr_storage;
+		netlbl_secattr_init(secattr);
+		rc = security_netlbl_sid_to_secattr(sid, secattr);
+		if (rc != 0)
+			goto skbuff_setsid_return;
+	}
+
+	rc = netlbl_skbuff_setattr(skb, family, secattr);
+
+skbuff_setsid_return:
+	if (secattr == &secattr_storage)
+		netlbl_secattr_destroy(secattr);
+	return rc;
+}
+
+/**
+ * selinux_netlbl_inet_conn_established - Netlabel the newly accepted connection
+ * @sk: the new connection
+ *
+ * Description:
+ * A new connection has been established on @sk so make sure it is labeled
+ * correctly with the NetLabel susbsystem.
+ *
+ */
+void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family)
+{
+	int rc;
+	struct sk_security_struct *sksec = sk->sk_security;
+	struct netlbl_lsm_secattr *secattr;
+	struct inet_sock *sk_inet = inet_sk(sk);
+	struct sockaddr_in addr;
+
+	if (sksec->nlbl_state != NLBL_REQUIRE)
+		return;
+
+	secattr = selinux_netlbl_sock_genattr(sk);
+	if (secattr == NULL)
+		return;
+
+	rc = netlbl_sock_setattr(sk, secattr);
+	switch (rc) {
+	case 0:
+		sksec->nlbl_state = NLBL_LABELED;
+		break;
+	case -EDESTADDRREQ:
+		/* no PF_INET6 support yet because we don't support any IPv6
+		 * labeling protocols */
+		if (family != PF_INET) {
+			sksec->nlbl_state = NLBL_UNSET;
+			return;
+		}
+
+		addr.sin_family = family;
+		addr.sin_addr.s_addr = sk_inet->daddr;
+		if (netlbl_conn_setattr(sk, (struct sockaddr *)&addr,
+					secattr) != 0) {
+			/* we failed to label the connected socket (could be
+			 * for a variety of reasons, the actual "why" isn't
+			 * important here) so we have to go to our backup plan,
+			 * labeling the packets individually in the netfilter
+			 * local output hook.  this is okay but we need to
+			 * adjust the MSS of the connection to take into
+			 * account any labeling overhead, since we don't know
+			 * the exact overhead at this point we'll use the worst
+			 * case value which is 40 bytes for IPv4 */
+			struct inet_connection_sock *sk_conn = inet_csk(sk);
+			sk_conn->icsk_ext_hdr_len += 40 -
+				      (sk_inet->opt ? sk_inet->opt->optlen : 0);
+			sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
+
+			sksec->nlbl_state = NLBL_REQSKB;
+		} else
+			sksec->nlbl_state = NLBL_CONNLABELED;
+		break;
+	default:
+		/* note that we are failing to label the socket which could be
+		 * a bad thing since it means traffic could leave the system
+		 * without the desired labeling, however, all is not lost as
+		 * we have a check in selinux_netlbl_inode_permission() to
+		 * pick up the pieces that we might drop here because we can't
+		 * return an error code */
+		break;
+	}
+}
+
+/**
+ * selinux_netlbl_socket_post_create - Label a socket using NetLabel
+ * @sock: the socket to label
+ *
+ * Description:
+ * Attempt to label a socket using the NetLabel mechanism using the given
+ * SID.  Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_post_create(struct socket *sock)
+{
+	return selinux_netlbl_sock_setsid(sock->sk);
+}
+
+/**
+ * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
+ * @inode: the file descriptor's inode
+ * @mask: the permission mask
+ *
+ * Description:
+ * Looks at a file's inode and if it is marked as a socket protected by
+ * NetLabel then verify that the socket has been labeled, if not try to label
+ * the socket now with the inode's SID.  Returns zero on success, negative
+ * values on failure.
+ *
+ */
+int selinux_netlbl_inode_permission(struct inode *inode, int mask)
+{
+	int rc;
+	struct sock *sk;
+	struct socket *sock;
+	struct sk_security_struct *sksec;
+
+	if (!S_ISSOCK(inode->i_mode) ||
+	    ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
+		return 0;
+	sock = SOCKET_I(inode);
+	sk = sock->sk;
+	if (sk == NULL)
+		return 0;
+	sksec = sk->sk_security;
+	if (sksec == NULL || sksec->nlbl_state != NLBL_REQUIRE)
+		return 0;
+
+	local_bh_disable();
+	bh_lock_sock_nested(sk);
+	if (likely(sksec->nlbl_state == NLBL_REQUIRE))
+		rc = selinux_netlbl_sock_setsid(sk);
+	else
+		rc = 0;
+	bh_unlock_sock(sk);
+	local_bh_enable();
+
+	return rc;
+}
+
+/**
+ * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
+ * @sksec: the sock's sk_security_struct
+ * @skb: the packet
+ * @family: protocol family
+ * @ad: the audit data
+ *
+ * Description:
+ * Fetch the NetLabel security attributes from @skb and perform an access check
+ * against the receiving socket.  Returns zero on success, negative values on
+ * error.
+ *
+ */
+int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+				struct sk_buff *skb,
+				u16 family,
+				struct avc_audit_data *ad)
+{
+	int rc;
+	u32 nlbl_sid;
+	u32 perm;
+	struct netlbl_lsm_secattr secattr;
+
+	if (!netlbl_enabled())
+		return 0;
+
+	netlbl_secattr_init(&secattr);
+	rc = netlbl_skbuff_getattr(skb, family, &secattr);
+	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+		rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
+	else
+		nlbl_sid = SECINITSID_UNLABELED;
+	netlbl_secattr_destroy(&secattr);
+	if (rc != 0)
+		return rc;
+
+	switch (sksec->sclass) {
+	case SECCLASS_UDP_SOCKET:
+		perm = UDP_SOCKET__RECVFROM;
+		break;
+	case SECCLASS_TCP_SOCKET:
+		perm = TCP_SOCKET__RECVFROM;
+		break;
+	default:
+		perm = RAWIP_SOCKET__RECVFROM;
+	}
+
+	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
+	if (rc == 0)
+		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;
+}