[NetLabel]: core NetLabel subsystem

Add a new kernel subsystem, NetLabel, to provide explicit packet
labeling services (CIPSO, RIPSO, etc.) to LSM developers.  NetLabel is
designed to work in conjunction with a LSM to intercept and decode
security labels on incoming network packets as well as ensure that
outgoing network packets are labeled according to the security
mechanism employed by the LSM.  The NetLabel subsystem is configured
through a Generic NETLINK interface described in the header files
included in this patch.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 231 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
new file mode 100644
index 0000000..0fd8aaa
--- /dev/null
+++ b/net/netlabel/netlabel_kapi.c
@@ -0,0 +1,231 @@
+/*
+ * NetLabel Kernel API
+ *
+ * This file defines the kernel API for the NetLabel system.  The NetLabel
+ * system manages static and dynamic label mappings for network protocols such
+ * as CIPSO and RIPSO.
+ *
+ * Author: Paul Moore <paul.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ *
+ * 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/init.h>
+#include <linux/types.h>
+#include <net/ip.h>
+#include <net/netlabel.h>
+#include <net/cipso_ipv4.h>
+#include <asm/bug.h>
+
+#include "netlabel_domainhash.h"
+#include "netlabel_unlabeled.h"
+#include "netlabel_user.h"
+
+/*
+ * LSM Functions
+ */
+
+/**
+ * netlbl_socket_setattr - Label a socket using the correct protocol
+ * @sock: the socket to label
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Attach the correct label to the given socket using the security attributes
+ * specified in @secattr.  This function requires exclusive access to
+ * @sock->sk, which means it either needs to be in the process of being
+ * created or locked via lock_sock(sock->sk).  Returns zero on success,
+ * negative values on failure.
+ *
+ */
+int netlbl_socket_setattr(const struct socket *sock,
+			  const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val = -ENOENT;
+	struct netlbl_dom_map *dom_entry;
+
+	rcu_read_lock();
+	dom_entry = netlbl_domhsh_getentry(secattr->domain);
+	if (dom_entry == NULL)
+		goto socket_setattr_return;
+	switch (dom_entry->type) {
+	case NETLBL_NLTYPE_CIPSOV4:
+		ret_val = cipso_v4_socket_setattr(sock,
+						  dom_entry->type_def.cipsov4,
+						  secattr);
+		break;
+	case NETLBL_NLTYPE_UNLABELED:
+		ret_val = 0;
+		break;
+	default:
+		ret_val = -ENOENT;
+	}
+
+socket_setattr_return:
+	rcu_read_unlock();
+	return ret_val;
+}
+
+/**
+ * netlbl_socket_getattr - Determine the security attributes of a socket
+ * @sock: the socket
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Examines the given socket to see any NetLabel style labeling has been
+ * applied to the socket, if so it parses the socket label and returns the
+ * security attributes in @secattr.  Returns zero on success, negative values
+ * on failure.
+ *
+ */
+int netlbl_socket_getattr(const struct socket *sock,
+			  struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+
+	ret_val = cipso_v4_socket_getattr(sock, secattr);
+	if (ret_val == 0)
+		return 0;
+
+	return netlbl_unlabel_getattr(secattr);
+}
+
+/**
+ * netlbl_skbuff_getattr - Determine the security attributes of a packet
+ * @skb: the packet
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Examines the given packet to see if a recognized form of packet labeling
+ * is present, if so it parses the packet label and returns the security
+ * attributes in @secattr.  Returns zero on success, negative values on
+ * failure.
+ *
+ */
+int netlbl_skbuff_getattr(const struct sk_buff *skb,
+			  struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+
+	ret_val = cipso_v4_skbuff_getattr(skb, secattr);
+	if (ret_val == 0)
+		return 0;
+
+	return netlbl_unlabel_getattr(secattr);
+}
+
+/**
+ * netlbl_skbuff_err - Handle a LSM error on a sk_buff
+ * @skb: the packet
+ * @error: the error code
+ *
+ * Description:
+ * Deal with a LSM problem when handling the packet in @skb, typically this is
+ * a permission denied problem (-EACCES).  The correct action is determined
+ * according to the packet's labeling protocol.
+ *
+ */
+void netlbl_skbuff_err(struct sk_buff *skb, int error)
+{
+	if (CIPSO_V4_OPTEXIST(skb))
+		cipso_v4_error(skb, error, 0);
+}
+
+/**
+ * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
+ *
+ * Description:
+ * For all of the NetLabel protocols that support some form of label mapping
+ * cache, invalidate the cache.  Returns zero on success, negative values on
+ * error.
+ *
+ */
+void netlbl_cache_invalidate(void)
+{
+	cipso_v4_cache_invalidate();
+}
+
+/**
+ * netlbl_cache_add - Add an entry to a NetLabel protocol cache
+ * @skb: the packet
+ * @secattr: the packet's security attributes
+ *
+ * Description:
+ * Add the LSM security attributes for the given packet to the underlying
+ * NetLabel protocol's label mapping cache.  Returns zero on success, negative
+ * values on error.
+ *
+ */
+int netlbl_cache_add(const struct sk_buff *skb,
+		     const struct netlbl_lsm_secattr *secattr)
+{
+	if (secattr->cache.data == NULL)
+		return -ENOMSG;
+
+	if (CIPSO_V4_OPTEXIST(skb))
+		return cipso_v4_cache_add(skb, secattr);
+
+	return -ENOMSG;
+}
+
+/*
+ * Setup Functions
+ */
+
+/**
+ * netlbl_init - Initialize NetLabel
+ *
+ * Description:
+ * Perform the required NetLabel initialization before first use.
+ *
+ */
+static int __init netlbl_init(void)
+{
+	int ret_val;
+
+	printk(KERN_INFO "NetLabel: Initializing\n");
+	printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
+	       (1 << NETLBL_DOMHSH_BITSIZE));
+	printk(KERN_INFO "NetLabel:  protocols ="
+	       " UNLABELED"
+	       " CIPSOv4"
+	       "\n");
+
+	ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
+	if (ret_val != 0)
+		goto init_failure;
+
+	ret_val = netlbl_netlink_init();
+	if (ret_val != 0)
+		goto init_failure;
+
+	ret_val = netlbl_unlabel_defconf();
+	if (ret_val != 0)
+		goto init_failure;
+	printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
+
+	return 0;
+
+init_failure:
+	panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
+}
+
+subsys_initcall(netlbl_init);