netlabel: Add network address selectors to the NetLabel/LSM domain mapping

This patch extends the NetLabel traffic labeling capabilities to individual
packets based not only on the LSM domain but the by the destination address
as well.  The changes here only affect the core NetLabel infrastructre,
changes to the NetLabel KAPI and individial protocol engines are also
required but are split out into a different patch to ease review.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>

1 files changed, 130 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_addrlist.c b/net/netlabel/netlabel_addrlist.c
index dd928aa..b0925a3 100644
--- a/net/netlabel/netlabel_addrlist.c
+++ b/net/netlabel/netlabel_addrlist.c
@@ -39,6 +39,7 @@
 #include <linux/ipv6.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
+#include <linux/audit.h>
 
 #include "netlabel_addrlist.h"
 
@@ -69,6 +70,32 @@ struct netlbl_af4list *netlbl_af4list_search(__be32 addr,
 	return NULL;
 }
 
+/**
+ * netlbl_af4list_search_exact - Search for an exact IPv4 address entry
+ * @addr: IPv4 address
+ * @mask: IPv4 address mask
+ * @head: the list head
+ *
+ * Description:
+ * Searches the IPv4 address list given by @head.  If an exact match if found
+ * it is returned, otherwise NULL is returned.  The caller is responsible for
+ * calling the rcu_read_[un]lock() functions.
+ *
+ */
+struct netlbl_af4list *netlbl_af4list_search_exact(__be32 addr,
+						   __be32 mask,
+						   struct list_head *head)
+{
+	struct netlbl_af4list *iter;
+
+	list_for_each_entry_rcu(iter, head, list)
+		if (iter->valid && iter->addr == addr && iter->mask == mask)
+			return iter;
+
+	return NULL;
+}
+
+
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 /**
  * netlbl_af6list_search - Search for a matching IPv6 address entry
@@ -93,6 +120,33 @@ struct netlbl_af6list *netlbl_af6list_search(const struct in6_addr *addr,
 
 	return NULL;
 }
+
+/**
+ * netlbl_af6list_search_exact - Search for an exact IPv6 address entry
+ * @addr: IPv6 address
+ * @mask: IPv6 address mask
+ * @head: the list head
+ *
+ * Description:
+ * Searches the IPv6 address list given by @head.  If an exact match if found
+ * it is returned, otherwise NULL is returned.  The caller is responsible for
+ * calling the rcu_read_[un]lock() functions.
+ *
+ */
+struct netlbl_af6list *netlbl_af6list_search_exact(const struct in6_addr *addr,
+						   const struct in6_addr *mask,
+						   struct list_head *head)
+{
+	struct netlbl_af6list *iter;
+
+	list_for_each_entry_rcu(iter, head, list)
+		if (iter->valid &&
+		    ipv6_addr_equal(&iter->addr, addr) &&
+		    ipv6_addr_equal(&iter->mask, mask))
+			return iter;
+
+	return NULL;
+}
 #endif /* IPv6 */
 
 /**
@@ -256,3 +310,79 @@ struct netlbl_af6list *netlbl_af6list_remove(const struct in6_addr *addr,
 	return NULL;
 }
 #endif /* IPv6 */
+
+/*
+ * Audit Helper Functions
+ */
+
+/**
+ * netlbl_af4list_audit_addr - Audit an IPv4 address
+ * @audit_buf: audit buffer
+ * @src: true if source address, false if destination
+ * @dev: network interface
+ * @addr: IP address
+ * @mask: IP address mask
+ *
+ * Description:
+ * Write the IPv4 address and address mask, if necessary, to @audit_buf.
+ *
+ */
+void netlbl_af4list_audit_addr(struct audit_buffer *audit_buf,
+					int src, const char *dev,
+					__be32 addr, __be32 mask)
+{
+	u32 mask_val = ntohl(mask);
+	char *dir = (src ? "src" : "dst");
+
+	if (dev != NULL)
+		audit_log_format(audit_buf, " netif=%s", dev);
+	audit_log_format(audit_buf, " %s=" NIPQUAD_FMT, dir, NIPQUAD(addr));
+	if (mask_val != 0xffffffff) {
+		u32 mask_len = 0;
+		while (mask_val > 0) {
+			mask_val <<= 1;
+			mask_len++;
+		}
+		audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
+	}
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+/**
+ * netlbl_af6list_audit_addr - Audit an IPv6 address
+ * @audit_buf: audit buffer
+ * @src: true if source address, false if destination
+ * @dev: network interface
+ * @addr: IP address
+ * @mask: IP address mask
+ *
+ * Description:
+ * Write the IPv6 address and address mask, if necessary, to @audit_buf.
+ *
+ */
+void netlbl_af6list_audit_addr(struct audit_buffer *audit_buf,
+				 int src,
+				 const char *dev,
+				 const struct in6_addr *addr,
+				 const struct in6_addr *mask)
+{
+	char *dir = (src ? "src" : "dst");
+
+	if (dev != NULL)
+		audit_log_format(audit_buf, " netif=%s", dev);
+	audit_log_format(audit_buf, " %s=" NIP6_FMT, dir, NIP6(*addr));
+	if (ntohl(mask->s6_addr32[3]) != 0xffffffff) {
+		u32 mask_len = 0;
+		u32 mask_val;
+		int iter = -1;
+		while (ntohl(mask->s6_addr32[++iter]) == 0xffffffff)
+			mask_len += 32;
+		mask_val = ntohl(mask->s6_addr32[iter]);
+		while (mask_val > 0) {
+			mask_val <<= 1;
+			mask_len++;
+		}
+		audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
+	}
+}
+#endif /* IPv6 */