[RFC 1/1] NetLabel: add audit support for configuration changes

[paul.moore@hp.com]

[-- Attachment #1: netlabel-audit --]
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This patch is a first attempt at adding auditing support to NetLabel, based on
a conversation with Steve Grubb on irc last Friday (9/22).  I wanted to send
this out to the audit mailing list first to get some feedback on such things
as message types and message formats.  Once I have collected your feedback I
plan on posting the next version of the patch to both the netdev and audit
mailing lists for inclusion in 2.6.19.

So please, if you have comments/concerns/etc. please share them now so this
does not get help up later - thank you.
---
 include/linux/audit.h              |    6 ++
 net/netlabel/netlabel_cipso_v4.c   |   37 +++++++++---
 net/netlabel/netlabel_domainhash.c |   36 +++++++++++-
 net/netlabel/netlabel_unlabeled.c  |   28 +++++++--
 net/netlabel/netlabel_user.c       |  110 +++++++++++++++++++++++++++++++++++++
 net/netlabel/netlabel_user.h       |    6 ++
 6 files changed, 208 insertions(+), 15 deletions(-)

Index: net-2.6/include/linux/audit.h
===================================================================
--- net-2.6.orig/include/linux/audit.h
+++ net-2.6/include/linux/audit.h
@@ -95,6 +95,12 @@
 #define AUDIT_MAC_POLICY_LOAD	1403	/* Policy file load */
 #define AUDIT_MAC_STATUS	1404	/* Changed enforcing,permissive,off */
 #define AUDIT_MAC_CONFIG_CHANGE	1405	/* Changes to booleans */
+#define AUDIT_MAC_UNLBL_ACCEPT	1406	/* NetLabel: allow unlabeled traffic */
+#define AUDIT_MAC_UNLBL_DENY	1407	/* NetLabel: deny unlabeled traffic */
+#define AUDIT_MAC_CIPSOV4_ADD	1408	/* NetLabel: add CIPSOv4 DOI entry */
+#define AUDIT_MAC_CIPSOV4_DEL	1409	/* NetLabel: del CIPSOv4 DOI entry */
+#define AUDIT_MAC_MAP_ADD	1410	/* NetLabel: add LSM domain mapping */
+#define AUDIT_MAC_MAP_DEL	1411	/* NetLabel: del LSM domain mapping */
 
 #define AUDIT_FIRST_KERN_ANOM_MSG   1700
 #define AUDIT_LAST_KERN_ANOM_MSG    1799
Index: net-2.6/net/netlabel/netlabel_cipso_v4.c
===================================================================
--- net-2.6.orig/net/netlabel/netlabel_cipso_v4.c
+++ net-2.6/net/netlabel/netlabel_cipso_v4.c
@@ -32,6 +32,7 @@
 #include <linux/socket.h>
 #include <linux/string.h>
 #include <linux/skbuff.h>
+#include <linux/audit.h>
 #include <net/sock.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
@@ -162,8 +163,7 @@ static int netlbl_cipsov4_add_std(struct
 	int nla_a_rem;
 	int nla_b_rem;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
-	    !info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
+	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
 	    !info->attrs[NLBL_CIPSOV4_A_MLSLVLLST])
 		return -EINVAL;
 
@@ -344,8 +344,7 @@ static int netlbl_cipsov4_add_pass(struc
 	int ret_val;
 	struct cipso_v4_doi *doi_def = NULL;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
-	    !info->attrs[NLBL_CIPSOV4_A_TAGLST])
+	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
 		return -EINVAL;
 
 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
@@ -381,21 +380,34 @@ static int netlbl_cipsov4_add(struct sk_
 
 {
 	int ret_val = -EINVAL;
-	u32 map_type;
+	u32 type;
+	u32 doi;
+	const char *type_str = "(unknown)";
+	struct audit_buffer *audit_buf;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_MTYPE])
+	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
+	    !info->attrs[NLBL_CIPSOV4_A_MTYPE])
 		return -EINVAL;
 
-	map_type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
-	switch (map_type) {
+	type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
+	switch (type) {
 	case CIPSO_V4_MAP_STD:
+		type_str = "std";
 		ret_val = netlbl_cipsov4_add_std(info);
 		break;
 	case CIPSO_V4_MAP_PASS:
+		type_str = "pass";
 		ret_val = netlbl_cipsov4_add_pass(info);
 		break;
 	}
 
+	if (ret_val == 0) {
+		doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD);
+		audit_log_format(audit_buf, " doi=%u type=%s", doi, type_str);
+		audit_log_end(audit_buf);
+	}
+
 	return ret_val;
 }
 
@@ -653,13 +665,20 @@ static int netlbl_cipsov4_listall(struct
 static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
 {
 	int ret_val = -EINVAL;
-	u32 doi;
+	u32 doi = 0;
+	struct audit_buffer *audit_buf;
 
 	if (info->attrs[NLBL_CIPSOV4_A_DOI]) {
 		doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
 		ret_val = cipso_v4_doi_remove(doi, netlbl_cipsov4_doi_free);
 	}
 
+	if (ret_val == 0) {
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_DEL);
+		audit_log_format(audit_buf, " doi=%u", doi);
+		audit_log_end(audit_buf);
+	}
+
 	return ret_val;
 }
 
Index: net-2.6/net/netlabel/netlabel_domainhash.c
===================================================================
--- net-2.6.orig/net/netlabel/netlabel_domainhash.c
+++ net-2.6/net/netlabel/netlabel_domainhash.c
@@ -35,12 +35,14 @@
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/audit.h>
 #include <net/netlabel.h>
 #include <net/cipso_ipv4.h>
 #include <asm/bug.h>
 
 #include "netlabel_mgmt.h"
 #include "netlabel_domainhash.h"
+#include "netlabel_user.h"
 
 struct netlbl_domhsh_tbl {
 	struct list_head *tbl;
@@ -197,6 +199,8 @@ int netlbl_domhsh_add(struct netlbl_dom_
 {
 	int ret_val;
 	u32 bkt;
+	struct audit_buffer *audit_buf;
+	char *audit_domain;
 
 	switch (entry->type) {
 	case NETLBL_NLTYPE_UNLABELED:
@@ -236,6 +240,25 @@ int netlbl_domhsh_add(struct netlbl_dom_
 		spin_unlock(&netlbl_domhsh_def_lock);
 	} else
 		ret_val = -EINVAL;
+	if (ret_val == 0) {
+		if (entry->domain != NULL)
+			audit_domain = entry->domain;
+		else
+			audit_domain = "(default)";
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD);
+		audit_log_format(audit_buf, " domain=%s", audit_domain);
+		switch (entry->type) {
+		case NETLBL_NLTYPE_UNLABELED:
+			audit_log_format(audit_buf, " protocol=unlbl");
+			break;
+		case NETLBL_NLTYPE_CIPSOV4:
+			audit_log_format(audit_buf,
+					 " protocol=cipsov4 doi=%u",
+					 entry->type_def.cipsov4->doi);
+			break;
+		}
+		audit_log_end(audit_buf);
+	}
 	rcu_read_unlock();
 
 	if (ret_val != 0) {
@@ -280,6 +303,8 @@ int netlbl_domhsh_remove(const char *dom
 {
 	int ret_val = -ENOENT;
 	struct netlbl_dom_map *entry;
+	struct audit_buffer *audit_buf;
+	char *audit_domain;
 
 	rcu_read_lock();
 	if (domain != NULL)
@@ -316,8 +341,17 @@ int netlbl_domhsh_remove(const char *dom
 			ret_val = -ENOENT;
 		spin_unlock(&netlbl_domhsh_def_lock);
 	}
-	if (ret_val == 0)
+	if (ret_val == 0) {
+		if (entry->domain != NULL)
+			audit_domain = entry->domain;
+		else
+			audit_domain = "(default)";
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL);
+		audit_log_format(audit_buf, " domain=%s", audit_domain);
+		audit_log_end(audit_buf);
+
 		call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
+	}
 
 remove_return:
 	rcu_read_unlock();
Index: net-2.6/net/netlabel/netlabel_unlabeled.c
===================================================================
--- net-2.6.orig/net/netlabel/netlabel_unlabeled.c
+++ net-2.6/net/netlabel/netlabel_unlabeled.c
@@ -64,6 +64,25 @@ static struct nla_policy netlbl_unlabel_
 };
 
 /*
+ * Helper Functions
+ */
+
+/**
+ * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
+ * @value: desired value
+ *
+ * Description:
+ * Set the value of the unlabeled accept flag to @value.
+ *
+ */
+static void netlbl_unlabel_acceptflg_set(u8 value)
+{
+	atomic_set(&netlabel_unlabel_accept_flg, value);
+	netlbl_audit_nomsg((value ?
+			    AUDIT_MAC_UNLBL_ACCEPT : AUDIT_MAC_UNLBL_DENY));
+}
+
+/*
  * NetLabel Command Handlers
  */
 
@@ -79,18 +98,17 @@ static struct nla_policy netlbl_unlabel_
  */
 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
 {
-	int ret_val = -EINVAL;
 	u8 value;
 
 	if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
 		value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
 		if (value == 1 || value == 0) {
-			atomic_set(&netlabel_unlabel_accept_flg, value);
-			ret_val = 0;
+			netlbl_unlabel_acceptflg_set(value);
+			return 0;
 		}
 	}
 
-	return ret_val;
+	return -EINVAL;
 }
 
 /**
@@ -238,7 +256,7 @@ int netlbl_unlabel_defconf(void)
 	if (ret_val != 0)
 		return ret_val;
 
-	atomic_set(&netlabel_unlabel_accept_flg, 1);
+	netlbl_unlabel_acceptflg_set(1);
 
 	return 0;
 }
Index: net-2.6/net/netlabel/netlabel_user.c
===================================================================
--- net-2.6.orig/net/netlabel/netlabel_user.c
+++ net-2.6/net/netlabel/netlabel_user.c
@@ -32,6 +32,8 @@
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/socket.h>
+#include <linux/audit.h>
+#include <linux/tty.h>
 #include <net/sock.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
@@ -74,3 +76,111 @@ int netlbl_netlink_init(void)
 
 	return 0;
 }
+
+/*
+ * NetLabel Audit Functions
+ */
+
+/**
+ * netlbl_audit_start_common - Start an audit message
+ * @type: audit message type
+ *
+ * Description:
+ * Start an audit message using the type specified in @type and fill the audit
+ * message with some fields common to all NetLabel audit messages.  Returns
+ * a pointer to the audit buffer on success, NULL on failure.
+ *
+ */
+struct audit_buffer *netlbl_audit_start_common(int type)
+{
+	struct audit_context *audit_ctx = current->audit_context;
+	struct audit_buffer *audit_buf;
+	uid_t audit_loginuid;
+	const char *audit_tty;
+	char audit_comm[sizeof(current->comm)];
+	struct vm_area_struct *vma;
+
+	audit_buf = audit_log_start(audit_ctx, GFP_ATOMIC, type);
+	if (audit_buf == NULL)
+		return NULL;
+
+	switch (type) {
+	case AUDIT_MAC_UNLBL_ACCEPT:
+		audit_log_format(audit_buf,
+				 "netlabel: module=unlbl action=accept");
+		break;
+	case AUDIT_MAC_UNLBL_DENY:
+		audit_log_format(audit_buf,
+				 "netlabel: module=unlbl action=deny");
+		break;
+	case AUDIT_MAC_CIPSOV4_ADD:
+		audit_log_format(audit_buf,
+				 "netlabel: module=cipsov4 action=add");
+		break;
+	case AUDIT_MAC_CIPSOV4_DEL:
+		audit_log_format(audit_buf,
+				 "netlabel: module=cipsov4 action=del");
+		break;
+	case AUDIT_MAC_MAP_ADD:
+		audit_log_format(audit_buf,
+				 "netlabel: module=map action=add");
+		break;
+	case AUDIT_MAC_MAP_DEL:
+		audit_log_format(audit_buf,
+				 "netlabel: module=map action=del");
+		break;
+	}
+
+	audit_loginuid = audit_get_loginuid(audit_ctx);
+	if (current->signal &&
+	    current->signal->tty &&
+	    current->signal->tty->name)
+		audit_tty = current->signal->tty->name;
+	else
+		audit_tty = "(none)";
+	get_task_comm(audit_comm, current);
+
+	audit_log_format(audit_buf,
+			 " auid=%u uid=%u euid=%u tty=%s pid=%d",
+			 audit_loginuid,
+			 current->uid,
+			 current->euid,
+			 audit_tty,
+			 current->pid);
+	audit_log_format(audit_buf, " comm=");
+	audit_log_untrustedstring(audit_buf, audit_comm);
+	if (current->mm) {
+		down_read(&current->mm->mmap_sem);
+		vma = current->mm->mmap;
+		while (vma) {
+			if ((vma->vm_flags & VM_EXECUTABLE) &&
+			    vma->vm_file) {
+				audit_log_d_path(audit_buf,
+						 " exe=",
+						 vma->vm_file->f_dentry,
+						 vma->vm_file->f_vfsmnt);
+				break;
+			}
+			vma = vma->vm_next;
+		}
+		up_read(&current->mm->mmap_sem);
+	}
+
+	return audit_buf;
+}
+
+/**
+ * netlbl_audit_nomsg - Send an audit message without additional text
+ * @type: audit message type
+ *
+ * Description:
+ * Send an audit message with only the common NetLabel audit fields.
+ *
+ */
+void netlbl_audit_nomsg(int type)
+{
+	struct audit_buffer *audit_buf;
+
+	audit_buf = netlbl_audit_start_common(type);
+	audit_log_end(audit_buf);
+}
Index: net-2.6/net/netlabel/netlabel_user.h
===================================================================
--- net-2.6.orig/net/netlabel/netlabel_user.h
+++ net-2.6/net/netlabel/netlabel_user.h
@@ -34,6 +34,7 @@
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/capability.h>
+#include <linux/audit.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
 #include <net/netlabel.h>
@@ -75,4 +76,9 @@ static inline void *netlbl_netlink_hdr_p
 
 int netlbl_netlink_init(void);
 
+/* NetLabel Audit Functions */
+
+struct audit_buffer *netlbl_audit_start_common(int type);
+void netlbl_audit_nomsg(int type);
+
 #endif

--
paul moore
linux security @ hp