[PATCH] audit string fields interface + consumer

Updated patch to dynamically allocate audit rule fields in kernel's internal representation. Added unlikely() calls for testing memory allocation result. Amy Griffis wrote: [Wed Jan 11 2006, 02:02:31PM EST] > Modify audit's kernel-userspace interface to allow the specification > of string fields in audit rules. > > Signed-off-by: Amy Griffis <[email protected]> Signed-off-by: Al Viro <[email protected]> (cherry picked from 5ffc4a863f92351b720fe3e9c5cd647accff9e03 commit)
yshchan · Mar 20, 2006 · 93315ed · 93315ed
1 parent af601e4
commit 93315ed
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Showing 6 changed files with 448 additions and 145 deletions.
diff --git a/include/linux/audit.h b/include/linux/audit.h
@@ -50,15 +50,18 @@
  */
 #define AUDIT_GET		1000	/* Get status */
 #define AUDIT_SET		1001	/* Set status (enable/disable/auditd) */
-#define AUDIT_LIST		1002	/* List syscall filtering rules */
-#define AUDIT_ADD		1003	/* Add syscall filtering rule */
-#define AUDIT_DEL		1004	/* Delete syscall filtering rule */
+#define AUDIT_LIST		1002	/* List syscall rules -- deprecated */
+#define AUDIT_ADD		1003	/* Add syscall rule -- deprecated */
+#define AUDIT_DEL		1004	/* Delete syscall rule -- deprecated */
 #define AUDIT_USER		1005	/* Message from userspace -- deprecated */
 #define AUDIT_LOGIN		1006	/* Define the login id and information */
 #define AUDIT_WATCH_INS		1007	/* Insert file/dir watch entry */
 #define AUDIT_WATCH_REM		1008	/* Remove file/dir watch entry */
 #define AUDIT_WATCH_LIST	1009	/* List all file/dir watches */
 #define AUDIT_SIGNAL_INFO	1010	/* Get info about sender of signal to auditd */
+#define AUDIT_ADD_RULE		1011	/* Add syscall filtering rule */
+#define AUDIT_DEL_RULE		1012	/* Delete syscall filtering rule */
+#define AUDIT_LIST_RULES	1013	/* List syscall filtering rules */
 
 #define AUDIT_FIRST_USER_MSG	1100	/* Userspace messages mostly uninteresting to kernel */
 #define AUDIT_USER_AVC		1107	/* We filter this differently */
@@ -229,6 +232,26 @@ struct audit_status {
 	__u32		backlog;	/* messages waiting in queue */
 };
 
+/* audit_rule_data supports filter rules with both integer and string
+ * fields.  It corresponds with AUDIT_ADD_RULE, AUDIT_DEL_RULE and
+ * AUDIT_LIST_RULES requests.
+ */
+struct audit_rule_data {
+	__u32		flags;	/* AUDIT_PER_{TASK,CALL}, AUDIT_PREPEND */
+	__u32		action;	/* AUDIT_NEVER, AUDIT_POSSIBLE, AUDIT_ALWAYS */
+	__u32		field_count;
+	__u32		mask[AUDIT_BITMASK_SIZE];
+	__u32		fields[AUDIT_MAX_FIELDS];
+	__u32		values[AUDIT_MAX_FIELDS];
+	__u32		fieldflags[AUDIT_MAX_FIELDS];
+	__u32		buflen;	/* total length of string fields */
+	char		buf[0];	/* string fields buffer */
+};
+
+/* audit_rule is supported to maintain backward compatibility with
+ * userspace.  It supports integer fields only and corresponds to
+ * AUDIT_ADD, AUDIT_DEL and AUDIT_LIST requests.
+ */
 struct audit_rule {		/* for AUDIT_LIST, AUDIT_ADD, and AUDIT_DEL */
 	__u32		flags;	/* AUDIT_PER_{TASK,CALL}, AUDIT_PREPEND */
 	__u32		action;	/* AUDIT_NEVER, AUDIT_POSSIBLE, AUDIT_ALWAYS */
@@ -338,7 +361,7 @@ extern void		    audit_log_d_path(struct audit_buffer *ab,
 extern int audit_filter_user(struct netlink_skb_parms *cb, int type);
 extern int audit_filter_type(int type);
 extern int  audit_receive_filter(int type, int pid, int uid, int seq,
-				 void *data, uid_t loginuid);
+				 void *data, size_t datasz, uid_t loginuid);
 #else
 #define audit_log(c,g,t,f,...) do { ; } while (0)
 #define audit_log_start(c,g,t) ({ NULL; })

diff --git a/kernel/audit.c b/kernel/audit.c
@@ -52,6 +52,7 @@
 #include <linux/audit.h>
 
 #include <net/sock.h>
+#include <net/netlink.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 
@@ -361,9 +362,12 @@ static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type)
 	switch (msg_type) {
 	case AUDIT_GET:
 	case AUDIT_LIST:
+	case AUDIT_LIST_RULES:
 	case AUDIT_SET:
 	case AUDIT_ADD:
+	case AUDIT_ADD_RULE:
 	case AUDIT_DEL:
+	case AUDIT_DEL_RULE:
 	case AUDIT_SIGNAL_INFO:
 		if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL))
 			err = -EPERM;
@@ -470,12 +474,23 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	case AUDIT_ADD:
 	case AUDIT_DEL:
-		if (nlh->nlmsg_len < sizeof(struct audit_rule))
+		if (nlmsg_len(nlh) < sizeof(struct audit_rule))
 			return -EINVAL;
 		/* fallthrough */
 	case AUDIT_LIST:
 		err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
-					   uid, seq, data, loginuid);
+					   uid, seq, data, nlmsg_len(nlh),
+					   loginuid);
+		break;
+	case AUDIT_ADD_RULE:
+	case AUDIT_DEL_RULE:
+		if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
+			return -EINVAL;
+		/* fallthrough */
+	case AUDIT_LIST_RULES:
+		err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
+					   uid, seq, data, nlmsg_len(nlh),
+					   loginuid);
 		break;
 	case AUDIT_SIGNAL_INFO:
 		sig_data.uid = audit_sig_uid;

diff --git a/kernel/audit.h b/kernel/audit.h
@@ -52,10 +52,27 @@ enum audit_state {
 };
 
 /* Rule lists */
+struct audit_field {
+	u32			type;
+	u32			val;
+	u32			op;
+};
+
+struct audit_krule {
+	int			vers_ops;
+	u32			flags;
+	u32			listnr;
+	u32			action;
+	u32			mask[AUDIT_BITMASK_SIZE];
+	u32			buflen; /* for data alloc on list rules */
+	u32			field_count;
+	struct audit_field	*fields;
+};
+
 struct audit_entry {
-	struct list_head  list;
-	struct rcu_head   rcu;
-	struct audit_rule rule;
+	struct list_head	list;
+	struct rcu_head		rcu;
+	struct audit_krule	rule;
 };