[NetLabel]: core network changes

Changes to the core network stack to support the NetLabel subsystem.  This
includes changes to the IPv4 option handling to support CIPSO labels.

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

1 files changed, 291 insertions, 0 deletions

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
new file mode 100644
index 00000000000..7cae730832c
--- /dev/null
+++ b/include/net/netlabel.h
@@ -0,0 +1,291 @@
+/*
+ * 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
+ *
+ */
+
+#ifndef _NETLABEL_H
+#define _NETLABEL_H
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+
+/*
+ * NetLabel - A management interface for maintaining network packet label
+ *            mapping tables for explicit packet labling protocols.
+ *
+ * Network protocols such as CIPSO and RIPSO require a label translation layer
+ * to convert the label on the packet into something meaningful on the host
+ * machine.  In the current Linux implementation these mapping tables live
+ * inside the kernel; NetLabel provides a mechanism for user space applications
+ * to manage these mapping tables.
+ *
+ * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
+ * send messages between kernel and user space.  The general format of a
+ * NetLabel message is shown below:
+ *
+ *  +-----------------+-------------------+--------- --- -- -
+ *  | struct nlmsghdr | struct genlmsghdr | payload
+ *  +-----------------+-------------------+--------- --- -- -
+ *
+ * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
+ * The payload is dependent on the subsystem specified in the
+ * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
+ * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
+ * file.  All of the fields in the NetLabel payload are NETLINK attributes, the
+ * length of each field is the length of the NETLINK attribute payload, see
+ * include/net/netlink.h for more information on NETLINK attributes.
+ *
+ */
+
+/*
+ * NetLabel NETLINK protocol
+ */
+
+#define NETLBL_PROTO_VERSION            1
+
+/* NetLabel NETLINK types/families */
+#define NETLBL_NLTYPE_NONE              0
+#define NETLBL_NLTYPE_MGMT              1
+#define NETLBL_NLTYPE_MGMT_NAME         "NLBL_MGMT"
+#define NETLBL_NLTYPE_RIPSO             2
+#define NETLBL_NLTYPE_RIPSO_NAME        "NLBL_RIPSO"
+#define NETLBL_NLTYPE_CIPSOV4           3
+#define NETLBL_NLTYPE_CIPSOV4_NAME      "NLBL_CIPSOv4"
+#define NETLBL_NLTYPE_CIPSOV6           4
+#define NETLBL_NLTYPE_CIPSOV6_NAME      "NLBL_CIPSOv6"
+#define NETLBL_NLTYPE_UNLABELED         5
+#define NETLBL_NLTYPE_UNLABELED_NAME    "NLBL_UNLBL"
+
+/* NetLabel return codes */
+#define NETLBL_E_OK                     0
+
+/*
+ * Helper functions
+ */
+
+#define NETLBL_LEN_U8                   nla_total_size(sizeof(u8))
+#define NETLBL_LEN_U16                  nla_total_size(sizeof(u16))
+#define NETLBL_LEN_U32                  nla_total_size(sizeof(u32))
+
+/**
+ * netlbl_netlink_alloc_skb - Allocate a NETLINK message buffer
+ * @head: the amount of headroom in bytes
+ * @body: the desired size (minus headroom) in bytes
+ * @gfp_flags: the alloc flags to pass to alloc_skb()
+ *
+ * Description:
+ * Allocate a NETLINK message buffer based on the sizes given in @head and
+ * @body.  If @head is greater than zero skb_reserve() is called to reserve
+ * @head bytes at the start of the buffer.  Returns a valid sk_buff pointer on
+ * success, NULL on failure.
+ *
+ */
+static inline struct sk_buff *netlbl_netlink_alloc_skb(size_t head,
+						       size_t body,
+						       int gfp_flags)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(NLMSG_ALIGN(head + body), gfp_flags);
+	if (skb == NULL)
+		return NULL;
+	if (head > 0) {
+		skb_reserve(skb, head);
+		if (skb_tailroom(skb) < body) {
+			kfree_skb(skb);
+			return NULL;
+		}
+	}
+
+	return skb;
+}
+
+/*
+ * NetLabel - Kernel API for accessing the network packet label mappings.
+ *
+ * The following functions are provided for use by other kernel modules,
+ * specifically kernel LSM modules, to provide a consistent, transparent API
+ * for dealing with explicit packet labeling protocols such as CIPSO and
+ * RIPSO.  The functions defined here are implemented in the
+ * net/netlabel/netlabel_kapi.c file.
+ *
+ */
+
+/* Domain mapping definition struct */
+struct netlbl_dom_map;
+
+/* Domain mapping operations */
+int netlbl_domhsh_remove(const char *domain);
+
+/* LSM security attributes */
+struct netlbl_lsm_cache {
+	void (*free) (const void *data);
+	void *data;
+};
+struct netlbl_lsm_secattr {
+	char *domain;
+
+	u32 mls_lvl;
+	u32 mls_lvl_vld;
+	unsigned char *mls_cat;
+	size_t mls_cat_len;
+
+	struct netlbl_lsm_cache cache;
+};
+
+/*
+ * LSM security attribute operations
+ */
+
+
+/**
+ * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
+ * @secattr: the struct to initialize
+ *
+ * Description:
+ * Initialize an already allocated netlbl_lsm_secattr struct.  Returns zero on
+ * success, negative values on error.
+ *
+ */
+static inline int netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
+{
+	memset(secattr, 0, sizeof(*secattr));
+	return 0;
+}
+
+/**
+ * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
+ * @secattr: the struct to clear
+ * @clear_cache: cache clear flag
+ *
+ * Description:
+ * Destroys the @secattr struct, including freeing all of the internal buffers.
+ * If @clear_cache is true then free the cache fields, otherwise leave them
+ * intact.  The struct must be reset with a call to netlbl_secattr_init()
+ * before reuse.
+ *
+ */
+static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr,
+					  u32 clear_cache)
+{
+	if (clear_cache && secattr->cache.data != NULL && secattr->cache.free)
+		secattr->cache.free(secattr->cache.data);
+	kfree(secattr->domain);
+	kfree(secattr->mls_cat);
+}
+
+/**
+ * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
+ * @flags: the memory allocation flags
+ *
+ * Description:
+ * Allocate and initialize a netlbl_lsm_secattr struct.  Returns a valid
+ * pointer on success, or NULL on failure.
+ *
+ */
+static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(int flags)
+{
+	return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
+}
+
+/**
+ * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
+ * @secattr: the struct to free
+ * @clear_cache: cache clear flag
+ *
+ * Description:
+ * Frees @secattr including all of the internal buffers.  If @clear_cache is
+ * true then free the cache fields, otherwise leave them intact.
+ *
+ */
+static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr,
+				       u32 clear_cache)
+{
+	netlbl_secattr_destroy(secattr, clear_cache);
+	kfree(secattr);
+}
+
+/*
+ * LSM protocol operations
+ */
+
+#ifdef CONFIG_NETLABEL
+int netlbl_socket_setattr(const struct socket *sock,
+			  const struct netlbl_lsm_secattr *secattr);
+int netlbl_socket_getattr(const struct socket *sock,
+			  struct netlbl_lsm_secattr *secattr);
+int netlbl_skbuff_getattr(const struct sk_buff *skb,
+			  struct netlbl_lsm_secattr *secattr);
+void netlbl_skbuff_err(struct sk_buff *skb, int error);
+#else
+static inline int netlbl_socket_setattr(const struct socket *sock,
+				     const struct netlbl_lsm_secattr *secattr)
+{
+	return -ENOSYS;
+}
+
+static inline int netlbl_socket_getattr(const struct socket *sock,
+					struct netlbl_lsm_secattr *secattr)
+{
+	return -ENOSYS;
+}
+
+static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
+					struct netlbl_lsm_secattr *secattr)
+{
+	return -ENOSYS;
+}
+
+static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
+{
+	return;
+}
+#endif /* CONFIG_NETLABEL */
+
+/*
+ * LSM label mapping cache operations
+ */
+
+#ifdef CONFIG_NETLABEL
+void netlbl_cache_invalidate(void);
+int netlbl_cache_add(const struct sk_buff *skb,
+		     const struct netlbl_lsm_secattr *secattr);
+#else
+static inline void netlbl_cache_invalidate(void)
+{
+	return;
+}
+
+static inline int netlbl_cache_add(const struct sk_buff *skb,
+				   const struct netlbl_lsm_secattr *secattr)
+{
+	return 0;
+}
+#endif /* CONFIG_NETLABEL */
+
+#endif /* _NETLABEL_H */