TOMOYO: Add auditing interface.

Add /sys/kernel/security/tomoyo/audit interface. This interface generates audit
logs in the form of domain policy so that /usr/sbin/tomoyo-auditd can reuse
audit logs for appending to /sys/kernel/security/tomoyo/domain_policy
interface.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 151 insertions, 160 deletions

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 2b280350708f..6580ef35074b 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -17,9 +17,12 @@ static unsigned int tomoyo_profile_version;
 /* Profile table. Memory is allocated as needed. */
 static struct tomoyo_profile *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
 
-/* String table for functionality that takes 4 modes. */
-static const char *tomoyo_mode[4] = {
-	"disabled", "learning", "permissive", "enforcing"
+/* String table for operation mode. */
+const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE] = {
+	[TOMOYO_CONFIG_DISABLED]   = "disabled",
+	[TOMOYO_CONFIG_LEARNING]   = "learning",
+	[TOMOYO_CONFIG_PERMISSIVE] = "permissive",
+	[TOMOYO_CONFIG_ENFORCING]  = "enforcing"
 };
 
 /* String table for /sys/kernel/security/tomoyo/profile */
@@ -53,6 +56,7 @@ static const char *tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
 
 /* String table for PREFERENCE keyword. */
 static const char * const tomoyo_pref_keywords[TOMOYO_MAX_PREF] = {
+	[TOMOYO_PREF_MAX_AUDIT_LOG]      = "max_audit_log",
 	[TOMOYO_PREF_MAX_LEARNING_ENTRY] = "max_learning_entry",
 };
 
@@ -66,12 +70,10 @@ static bool tomoyo_manage_by_non_root;
  *
  * @value: Bool value.
  */
-/*
-static const char *tomoyo_yesno(const unsigned int value)
+const char *tomoyo_yesno(const unsigned int value)
 {
 	return value ? "yes" : "no";
 }
-*/
 
 /**
  * tomoyo_addprintf - strncat()-like-snprintf().
@@ -117,7 +119,7 @@ static bool tomoyo_flush(struct tomoyo_io_buffer *head)
 		head->r.w[0] = w;
 		if (*w)
 			return false;
-		/* Add '\0' for query. */
+		/* Add '\0' for audit logs and query. */
 		if (head->poll) {
 			if (!head->read_user_buf_avail ||
 			    copy_to_user(head->read_user_buf, "", 1))
@@ -300,9 +302,12 @@ static struct tomoyo_profile *tomoyo_assign_profile(const unsigned int profile)
 	ptr = tomoyo_profile_ptr[profile];
 	if (!ptr && tomoyo_memory_ok(entry)) {
 		ptr = entry;
-		ptr->default_config = TOMOYO_CONFIG_DISABLED;
+		ptr->default_config = TOMOYO_CONFIG_DISABLED |
+			TOMOYO_CONFIG_WANT_GRANT_LOG |
+			TOMOYO_CONFIG_WANT_REJECT_LOG;
 		memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT,
 		       sizeof(ptr->config));
+		ptr->pref[TOMOYO_PREF_MAX_AUDIT_LOG] = 1024;
 		ptr->pref[TOMOYO_PREF_MAX_LEARNING_ENTRY] = 2048;
 		mb(); /* Avoid out-of-order execution. */
 		tomoyo_profile_ptr[profile] = ptr;
@@ -338,7 +343,6 @@ struct tomoyo_profile *tomoyo_profile(const u8 profile)
  *
  * Returns 1 if "@find=yes" was found, 0 if "@find=no" was found, -1 otherwise.
  */
-/*
 static s8 tomoyo_find_yesno(const char *string, const char *find)
 {
 	const char *cp = strstr(string, find);
@@ -351,7 +355,6 @@ static s8 tomoyo_find_yesno(const char *string, const char *find)
 	}
 	return -1;
 }
-*/
 
 /**
  * tomoyo_set_uint - Set value for specified preference.
@@ -412,6 +415,24 @@ static int tomoyo_set_mode(char *name, const char *value,
 				 * 'config' from 'TOMOYO_CONFIG_USE_DEAFULT'.
 				 */
 				config = (config & ~7) | mode;
+		if (config != TOMOYO_CONFIG_USE_DEFAULT) {
+			switch (tomoyo_find_yesno(value, "grant_log")) {
+			case 1:
+				config |= TOMOYO_CONFIG_WANT_GRANT_LOG;
+				break;
+			case 0:
+				config &= ~TOMOYO_CONFIG_WANT_GRANT_LOG;
+				break;
+			}
+			switch (tomoyo_find_yesno(value, "reject_log")) {
+			case 1:
+				config |= TOMOYO_CONFIG_WANT_REJECT_LOG;
+				break;
+			case 0:
+				config &= ~TOMOYO_CONFIG_WANT_REJECT_LOG;
+				break;
+			}
+		}
 	}
 	if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
 		profile->config[i] = config;
@@ -469,15 +490,30 @@ static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 	return tomoyo_set_mode(data, cp, profile);
 }
 
+/**
+ * tomoyo_print_config - Print mode for specified functionality.
+ *
+ * @head:   Pointer to "struct tomoyo_io_buffer".
+ * @config: Mode for that functionality.
+ *
+ * Returns nothing.
+ *
+ * Caller prints functionality's name.
+ */
 static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config)
 {
-	tomoyo_io_printf(head, "={ mode=%s }\n", tomoyo_mode[config & 3]);
+	tomoyo_io_printf(head, "={ mode=%s grant_log=%s reject_log=%s }\n",
+			 tomoyo_mode[config & 3],
+			 tomoyo_yesno(config & TOMOYO_CONFIG_WANT_GRANT_LOG),
+			 tomoyo_yesno(config & TOMOYO_CONFIG_WANT_REJECT_LOG));
 }
 
 /**
  * tomoyo_read_profile - Read profile table.
  *
  * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns nothing.
  */
 static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
 {
@@ -488,7 +524,7 @@ static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
 	profile = tomoyo_profile_ptr[index];
 	switch (head->r.step) {
 	case 0:
-		tomoyo_io_printf(head, "PROFILE_VERSION=%s\n", "20090903");
+		tomoyo_io_printf(head, "PROFILE_VERSION=%u\n", 20090903);
 		head->r.step++;
 		break;
 	case 1:
@@ -1359,92 +1395,28 @@ static void tomoyo_read_exception(struct tomoyo_io_buffer *head)
 	head->r.eof = true;
 }
 
-/**
- * tomoyo_print_header - Get header line of audit log.
- *
- * @r: Pointer to "struct tomoyo_request_info".
- *
- * Returns string representation.
- *
- * This function uses kmalloc(), so caller must kfree() if this function
- * didn't return NULL.
- */
-static char *tomoyo_print_header(struct tomoyo_request_info *r)
-{
-	struct timeval tv;
-	const pid_t gpid = task_pid_nr(current);
-	static const int tomoyo_buffer_len = 4096;
-	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
-	pid_t ppid;
-	if (!buffer)
-		return NULL;
-	do_gettimeofday(&tv);
-	rcu_read_lock();
-	ppid = task_tgid_vnr(current->real_parent);
-	rcu_read_unlock();
-	snprintf(buffer, tomoyo_buffer_len - 1,
-		 "#timestamp=%lu profile=%u mode=%s (global-pid=%u)"
-		 " task={ pid=%u ppid=%u uid=%u gid=%u euid=%u"
-		 " egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }",
-		 tv.tv_sec, r->profile, tomoyo_mode[r->mode], gpid,
-		 task_tgid_vnr(current), ppid,
-		 current_uid(), current_gid(), current_euid(),
-		 current_egid(), current_suid(), current_sgid(),
-		 current_fsuid(), current_fsgid());
-	return buffer;
-}
-
-/**
- * tomoyo_init_audit_log - Allocate buffer for audit logs.
- *
- * @len: Required size.
- * @r:   Pointer to "struct tomoyo_request_info".
- *
- * Returns pointer to allocated memory.
- *
- * The @len is updated to add the header lines' size on success.
- *
- * This function uses kzalloc(), so caller must kfree() if this function
- * didn't return NULL.
- */
-static char *tomoyo_init_audit_log(int *len, struct tomoyo_request_info *r)
-{
-	char *buf = NULL;
-	const char *header;
-	const char *domainname;
-	if (!r->domain)
-		r->domain = tomoyo_domain();
-	domainname = r->domain->domainname->name;
-	header = tomoyo_print_header(r);
-	if (!header)
-		return NULL;
-	*len += strlen(domainname) + strlen(header) + 10;
-	buf = kzalloc(*len, GFP_NOFS);
-	if (buf)
-		snprintf(buf, (*len) - 1, "%s\n%s\n", header, domainname);
-	kfree(header);
-	return buf;
-}
-
-/* Wait queue for tomoyo_query_list. */
+/* Wait queue for kernel -> userspace notification. */
 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait);
-
-/* Lock for manipulating tomoyo_query_list. */
-static DEFINE_SPINLOCK(tomoyo_query_list_lock);
+/* Wait queue for userspace -> kernel notification. */
+static DECLARE_WAIT_QUEUE_HEAD(tomoyo_answer_wait);
 
 /* Structure for query. */
 struct tomoyo_query {
 	struct list_head list;
 	char *query;
-	int query_len;
+	size_t query_len;
 	unsigned int serial;
-	int timer;
-	int answer;
+	u8 timer;
+	u8 answer;
+	u8 retry;
 };
 
 /* The list for "struct tomoyo_query". */
 static LIST_HEAD(tomoyo_query_list);
 
+/* Lock for manipulating tomoyo_query_list. */
+static DEFINE_SPINLOCK(tomoyo_query_list_lock);
+
 /*
  * Number of "struct file" referring /sys/kernel/security/tomoyo/query
  * interface.
@@ -1452,10 +1424,39 @@ static LIST_HEAD(tomoyo_query_list);
 static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
 
 /**
+ * tomoyo_add_entry - Add an ACL to current thread's domain. Used by learning mode.
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @header: Lines containing ACL.
+ *
+ * Returns nothing.
+ */
+static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
+{
+	char *buffer;
+	char *cp = strchr(header, '\n');
+	int len;
+	if (!cp)
+		return;
+	cp = strchr(cp + 1, '\n');
+	if (!cp)
+		return;
+	*cp++ = '\0';
+	len = strlen(cp) + 1;
+	buffer = kmalloc(len, GFP_NOFS);
+	if (!buffer)
+		return;
+	snprintf(buffer, len - 1, "%s", cp);
+	tomoyo_normalize_line(buffer);
+	tomoyo_write_domain2(&domain->acl_info_list, buffer, false);
+	kfree(buffer);
+}
+
+/**
  * tomoyo_supervisor - Ask for the supervisor's decision.
  *
- * @r:       Pointer to "struct tomoyo_request_info".
- * @fmt:     The printf()'s format string, followed by parameters.
+ * @r:   Pointer to "struct tomoyo_request_info".
+ * @fmt: The printf()'s format string, followed by parameters.
  *
  * Returns 0 if the supervisor decided to permit the access request which
  * violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the
@@ -1465,88 +1466,77 @@ static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
 int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
 {
 	va_list args;
-	int error = -EPERM;
-	int pos;
+	int error;
 	int len;
 	static unsigned int tomoyo_serial;
-	struct tomoyo_query *entry = NULL;
+	struct tomoyo_query entry = { };
 	bool quota_exceeded = false;
-	char *header;
+	va_start(args, fmt);
+	len = vsnprintf((char *) &len, 1, fmt, args) + 1;
+	va_end(args);
+	/* Write /sys/kernel/security/tomoyo/audit. */
+	va_start(args, fmt);
+	tomoyo_write_log2(r, len, fmt, args);
+	va_end(args);
+	/* Nothing more to do if granted. */
+	if (r->granted)
+		return 0;
 	switch (r->mode) {
-		char *buffer;
+	case TOMOYO_CONFIG_ENFORCING:
+		error = -EPERM;
+		if (atomic_read(&tomoyo_query_observers))
+			break;
+		goto out;
 	case TOMOYO_CONFIG_LEARNING:
-		if (!tomoyo_domain_quota_is_ok(r))
-			return 0;
-		va_start(args, fmt);
-		len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 4;
-		va_end(args);
-		buffer = kmalloc(len, GFP_NOFS);
-		if (!buffer)
-			return 0;
-		va_start(args, fmt);
-		vsnprintf(buffer, len - 1, fmt, args);
-		va_end(args);
-		tomoyo_normalize_line(buffer);
-		tomoyo_write_domain2(&r->domain->acl_info_list, buffer, false);
-		kfree(buffer);
+		error = 0;
+		/* Check max_learning_entry parameter. */
+		if (tomoyo_domain_quota_is_ok(r))
+			break;
 		/* fall through */
-	case TOMOYO_CONFIG_PERMISSIVE:
+	default:
 		return 0;
 	}
-	if (!r->domain)
-		r->domain = tomoyo_domain();
-	if (!atomic_read(&tomoyo_query_observers))
-		return -EPERM;
+	/* Get message. */
 	va_start(args, fmt);
-	len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 32;
+	entry.query = tomoyo_init_log(r, len, fmt, args);
 	va_end(args);
-	header = tomoyo_init_audit_log(&len, r);
-	if (!header)
+	if (!entry.query)
 		goto out;
-	entry = kzalloc(sizeof(*entry), GFP_NOFS);
-	if (!entry)
-		goto out;
-	entry->query = kzalloc(len, GFP_NOFS);
-	if (!entry->query)
+	entry.query_len = strlen(entry.query) + 1;
+	if (!error) {
+		tomoyo_add_entry(r->domain, entry.query);
 		goto out;
-	len = ksize(entry->query);
+	}
+	len = tomoyo_round2(entry.query_len);
 	spin_lock(&tomoyo_query_list_lock);
-	if (tomoyo_quota_for_query && tomoyo_query_memory_size + len +
-	    sizeof(*entry) >= tomoyo_quota_for_query) {
+	if (tomoyo_memory_quota[TOMOYO_MEMORY_QUERY] &&
+	    tomoyo_memory_used[TOMOYO_MEMORY_QUERY] + len
+	    >= tomoyo_memory_quota[TOMOYO_MEMORY_QUERY]) {
 		quota_exceeded = true;
 	} else {
-		tomoyo_query_memory_size += len + sizeof(*entry);
-		entry->serial = tomoyo_serial++;
+		entry.serial = tomoyo_serial++;
+		entry.retry = r->retry;
+		tomoyo_memory_used[TOMOYO_MEMORY_QUERY] += len;
+		list_add_tail(&entry.list, &tomoyo_query_list);
 	}
 	spin_unlock(&tomoyo_query_list_lock);
 	if (quota_exceeded)
 		goto out;
-	pos = snprintf(entry->query, len - 1, "Q%u-%hu\n%s",
-		       entry->serial, r->retry, header);
-	kfree(header);
-	header = NULL;
-	va_start(args, fmt);
-	vsnprintf(entry->query + pos, len - 1 - pos, fmt, args);
-	entry->query_len = strlen(entry->query) + 1;
-	va_end(args);
-	spin_lock(&tomoyo_query_list_lock);
-	list_add_tail(&entry->list, &tomoyo_query_list);
-	spin_unlock(&tomoyo_query_list_lock);
 	/* Give 10 seconds for supervisor's opinion. */
-	for (entry->timer = 0;
-	     atomic_read(&tomoyo_query_observers) && entry->timer < 100;
-	     entry->timer++) {
-		wake_up(&tomoyo_query_wait);
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(HZ / 10);
-		if (entry->answer)
+	while (entry.timer < 10) {
+		wake_up_all(&tomoyo_query_wait);
+		if (wait_event_interruptible_timeout
+		    (tomoyo_answer_wait, entry.answer ||
+		     !atomic_read(&tomoyo_query_observers), HZ))
 			break;
+		else
+			entry.timer++;
 	}
 	spin_lock(&tomoyo_query_list_lock);
-	list_del(&entry->list);
-	tomoyo_query_memory_size -= len + sizeof(*entry);
+	list_del(&entry.list);
+	tomoyo_memory_used[TOMOYO_MEMORY_QUERY] -= len;
 	spin_unlock(&tomoyo_query_list_lock);
-	switch (entry->answer) {
+	switch (entry.answer) {
 	case 3: /* Asked to retry by administrator. */
 		error = TOMOYO_RETRY_REQUEST;
 		r->retry++;
@@ -1555,18 +1545,12 @@ int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
 		/* Granted by administrator. */
 		error = 0;
 		break;
-	case 0:
-		/* Timed out. */
-		break;
 	default:
-		/* Rejected by administrator. */
+		/* Timed out or rejected by administrator. */
 		break;
 	}
- out:
-	if (entry)
-		kfree(entry->query);
-	kfree(entry);
-	kfree(header);
+out:
+	kfree(entry.query);
 	return error;
 }
 
@@ -1637,7 +1621,7 @@ static void tomoyo_read_query(struct tomoyo_io_buffer *head)
 		head->r.query_index = 0;
 		return;
 	}
-	buf = kzalloc(len, GFP_NOFS);
+	buf = kzalloc(len + 32, GFP_NOFS);
 	if (!buf)
 		return;
 	pos = 0;
@@ -1653,7 +1637,8 @@ static void tomoyo_read_query(struct tomoyo_io_buffer *head)
 		 * can change, but I don't care.
 		 */
 		if (len == ptr->query_len)
-			memmove(buf, ptr->query, len);
+			snprintf(buf, len + 31, "Q%u-%hu\n%s", ptr->serial,
+				 ptr->retry, ptr->query);
 		break;
 	}
 	spin_unlock(&tomoyo_query_list_lock);
@@ -1764,6 +1749,11 @@ int tomoyo_open_control(const u8 type, struct file *file)
 		head->write = tomoyo_write_exception;
 		head->read = tomoyo_read_exception;
 		break;
+	case TOMOYO_AUDIT:
+		/* /sys/kernel/security/tomoyo/audit */
+		head->poll = tomoyo_poll_log;
+		head->read = tomoyo_read_log;
+		break;
 	case TOMOYO_SELFDOMAIN:
 		/* /sys/kernel/security/tomoyo/self_domain */
 		head->read = tomoyo_read_self_domain;
@@ -1837,7 +1827,7 @@ int tomoyo_open_control(const u8 type, struct file *file)
 			return -ENOMEM;
 		}
 	}
-	if (type != TOMOYO_QUERY)
+	if (type != TOMOYO_QUERY && type != TOMOYO_AUDIT)
 		head->reader_idx = tomoyo_read_lock();
 	file->private_data = head;
 	/*
@@ -1858,7 +1848,8 @@ int tomoyo_open_control(const u8 type, struct file *file)
  * @wait: Pointer to "poll_table".
  *
  * Waits for read readiness.
- * /sys/kernel/security/tomoyo/query is handled by /usr/sbin/tomoyo-queryd .
+ * /sys/kernel/security/tomoyo/query is handled by /usr/sbin/tomoyo-queryd and
+ * /sys/kernel/security/tomoyo/audit is handled by /usr/sbin/tomoyo-auditd.
  */
 int tomoyo_poll_control(struct file *file, poll_table *wait)
 {
@@ -1970,7 +1961,7 @@ int tomoyo_close_control(struct tomoyo_io_buffer *head)
 	 */
 	if (head->type == TOMOYO_QUERY)
 		atomic_dec(&tomoyo_query_observers);
-	else
+	else if (head->type != TOMOYO_AUDIT)
 		tomoyo_read_unlock(head->reader_idx);
 	/* Release memory used for policy I/O. */
 	kfree(head->read_buf);