[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, 214 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
new file mode 100644
index 00000000000..ccf237b3a12
--- /dev/null
+++ b/net/netlabel/netlabel_user.h
@@ -0,0 +1,214 @@
+/*
+ * NetLabel NETLINK Interface
+ *
+ * This file defines the NETLINK interface 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
+ *
+ */
+
+#ifndef _NETLABEL_USER_H
+#define _NETLABEL_USER_H
+
+#include <linux/skbuff.h>
+#include <linux/capability.h>
+#include <linux/genetlink.h>
+#include <net/netlabel.h>
+#include <net/genetlink.h>
+
+/* NetLabel NETLINK helper functions */
+
+/**
+ * netlbl_netlink_cap_check - Check the NETLINK msg capabilities
+ * @skb: the NETLINK buffer
+ * @req_cap: the required capability
+ *
+ * Description:
+ * Check the NETLINK buffer's capabilities against the required capabilities.
+ * Returns zero on success, negative values on failure.
+ *
+ */
+static inline int netlbl_netlink_cap_check(const struct sk_buff *skb,
+					   kernel_cap_t req_cap)
+{
+	if (cap_raised(NETLINK_CB(skb).eff_cap, req_cap))
+		return 0;
+	return -EPERM;
+}
+
+/**
+ * netlbl_getinc_u8 - Read a u8 value from a nlattr stream and move on
+ * @nla: the attribute
+ * @rem_len: remaining length
+ *
+ * Description:
+ * Return a u8 value pointed to by @nla and advance it to the next attribute.
+ *
+ */
+static inline u8 netlbl_getinc_u8(struct nlattr **nla, int *rem_len)
+{
+	u8 val = nla_get_u8(*nla);
+	*nla = nla_next(*nla, rem_len);
+	return val;
+}
+
+/**
+ * netlbl_getinc_u16 - Read a u16 value from a nlattr stream and move on
+ * @nla: the attribute
+ * @rem_len: remaining length
+ *
+ * Description:
+ * Return a u16 value pointed to by @nla and advance it to the next attribute.
+ *
+ */
+static inline u16 netlbl_getinc_u16(struct nlattr **nla, int *rem_len)
+{
+	u16 val = nla_get_u16(*nla);
+	*nla = nla_next(*nla, rem_len);
+	return val;
+}
+
+/**
+ * netlbl_getinc_u32 - Read a u32 value from a nlattr stream and move on
+ * @nla: the attribute
+ * @rem_len: remaining length
+ *
+ * Description:
+ * Return a u32 value pointed to by @nla and advance it to the next attribute.
+ *
+ */
+static inline u32 netlbl_getinc_u32(struct nlattr **nla, int *rem_len)
+{
+	u32 val = nla_get_u32(*nla);
+	*nla = nla_next(*nla, rem_len);
+	return val;
+}
+
+/**
+ * netlbl_netlink_hdr_put - Write the NETLINK buffers into a sk_buff
+ * @skb: the packet
+ * @pid: the PID of the receipient
+ * @seq: the sequence number
+ * @type: the generic NETLINK message family type
+ * @cmd: command
+ *
+ * Description:
+ * Write both a NETLINK nlmsghdr structure and a Generic NETLINK genlmsghdr
+ * struct to the packet.  Returns a pointer to the start of the payload buffer
+ * on success or NULL on failure.
+ *
+ */
+static inline void *netlbl_netlink_hdr_put(struct sk_buff *skb,
+					   u32 pid,
+					   u32 seq,
+					   int type,
+					   u8 cmd)
+{
+	return genlmsg_put(skb,
+			   pid,
+			   seq,
+			   type,
+			   0,
+			   0,
+			   cmd,
+			   NETLBL_PROTO_VERSION);
+}
+
+/**
+ * netlbl_netlink_hdr_push - Write the NETLINK buffers into a sk_buff
+ * @skb: the packet
+ * @pid: the PID of the receipient
+ * @seq: the sequence number
+ * @type: the generic NETLINK message family type
+ * @cmd: command
+ *
+ * Description:
+ * Write both a NETLINK nlmsghdr structure and a Generic NETLINK genlmsghdr
+ * struct to the packet.
+ *
+ */
+static inline void netlbl_netlink_hdr_push(struct sk_buff *skb,
+					   u32 pid,
+					   u32 seq,
+					   int type,
+					   u8 cmd)
+
+{
+	struct nlmsghdr *nlh;
+	struct genlmsghdr *hdr;
+
+	nlh = (struct nlmsghdr *)skb_push(skb, NLMSG_SPACE(GENL_HDRLEN));
+	nlh->nlmsg_type = type;
+	nlh->nlmsg_len = skb->len;
+	nlh->nlmsg_flags = 0;
+	nlh->nlmsg_pid = pid;
+	nlh->nlmsg_seq = seq;
+
+	hdr = nlmsg_data(nlh);
+	hdr->cmd = cmd;
+	hdr->version = NETLBL_PROTO_VERSION;
+	hdr->reserved = 0;
+}
+
+/**
+ * netlbl_netlink_payload_len - Return the length of the payload
+ * @skb: the NETLINK buffer
+ *
+ * Description:
+ * This function returns the length of the NetLabel payload.
+ *
+ */
+static inline u32 netlbl_netlink_payload_len(const struct sk_buff *skb)
+{
+	return nlmsg_len((struct nlmsghdr *)skb->data) - GENL_HDRLEN;
+}
+
+/**
+ * netlbl_netlink_payload_data - Returns a pointer to the start of the payload
+ * @skb: the NETLINK buffer
+ *
+ * Description:
+ * This function returns a pointer to the start of the NetLabel payload.
+ *
+ */
+static inline void *netlbl_netlink_payload_data(const struct sk_buff *skb)
+{
+  return (unsigned char *)nlmsg_data((struct nlmsghdr *)skb->data) +
+	  GENL_HDRLEN;
+}
+
+/* NetLabel common protocol functions */
+
+void netlbl_netlink_send_ack(const struct genl_info *info,
+			     u32 genl_family,
+			     u8 ack_cmd,
+			     u32 ret_code);
+
+/* NetLabel NETLINK I/O functions */
+
+int netlbl_netlink_init(void);
+int netlbl_netlink_snd(struct sk_buff *skb, u32 pid);
+int netlbl_netlink_snd_multicast(struct sk_buff *skb, u32 pid, u32 group);
+
+#endif