TOMOYO: Rename meminfo to stat and show more statistics.

Show statistics such as last policy update time and last policy violation time
in addition to memory usage.

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

6 files changed, 206 insertions, 143 deletions

diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index 45e0a9f3c384..f2c869767d79 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -10,47 +10,6 @@
 #include <linux/slab.h>
 
 /**
- * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
- *
- * @time:  Seconds since 1970/01/01 00:00:00.
- * @stamp: Pointer to "struct tomoyo_time".
- *
- * Returns nothing.
- *
- * This function does not handle Y2038 problem.
- */
-static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
-{
-        static const u16 tomoyo_eom[2][12] = {
-                { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
-                { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
-        };
-        u16 y;
-        u8 m;
-        bool r;
-        stamp->sec = time % 60;
-        time /= 60;
-        stamp->min = time % 60;
-        time /= 60;
-        stamp->hour = time % 24;
-        time /= 24;
-        for (y = 1970; ; y++) {
-                const unsigned short days = (y & 3) ? 365 : 366;
-                if (time < days)
-                        break;
-                time -= days;
-        }
-        r = (y & 3) == 0;
-        for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
-                ;
-        if (m)
-                time -= tomoyo_eom[r][m - 1];
-        stamp->year = y;
-        stamp->month = ++m;
-        stamp->day = ++time;
-}
-
-/**
  * tomoyo_print_header - Get header line of audit log.
  *
  * @r: Pointer to "struct tomoyo_request_info".
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 6402183e2a6b..7bc0d1d95867 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -1584,8 +1584,9 @@ static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
                 return;
         snprintf(buffer, len - 1, "%s", cp);
         tomoyo_normalize_line(buffer);
-        tomoyo_write_domain2(domain->ns, &domain->acl_info_list, buffer,
-                             false);
+        if (!tomoyo_write_domain2(domain->ns, &domain->acl_info_list, buffer,
+                                  false))
+                tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
         kfree(buffer);
 }
 
@@ -1618,6 +1619,8 @@ int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
         /* Nothing more to do if granted. */
         if (r->granted)
                 return 0;
+        if (r->mode)
+                tomoyo_update_stat(r->mode);
         switch (r->mode) {
         case TOMOYO_CONFIG_ENFORCING:
                 error = -EPERM;
@@ -1857,6 +1860,104 @@ static void tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
         }
 }
 
+/* String table for /sys/kernel/security/tomoyo/stat interface. */
+static const char * const tomoyo_policy_headers[TOMOYO_MAX_POLICY_STAT] = {
+        [TOMOYO_STAT_POLICY_UPDATES]    = "update:",
+        [TOMOYO_STAT_POLICY_LEARNING]   = "violation in learning mode:",
+        [TOMOYO_STAT_POLICY_PERMISSIVE] = "violation in permissive mode:",
+        [TOMOYO_STAT_POLICY_ENFORCING]  = "violation in enforcing mode:",
+};
+
+/* String table for /sys/kernel/security/tomoyo/stat interface. */
+static const char * const tomoyo_memory_headers[TOMOYO_MAX_MEMORY_STAT] = {
+        [TOMOYO_MEMORY_POLICY] = "policy:",
+        [TOMOYO_MEMORY_AUDIT]  = "audit log:",
+        [TOMOYO_MEMORY_QUERY]  = "query message:",
+};
+
+/* Timestamp counter for last updated. */
+static unsigned int tomoyo_stat_updated[TOMOYO_MAX_POLICY_STAT];
+/* Counter for number of updates. */
+static unsigned int tomoyo_stat_modified[TOMOYO_MAX_POLICY_STAT];
+
+/**
+ * tomoyo_update_stat - Update statistic counters.
+ *
+ * @index: Index for policy type.
+ *
+ * Returns nothing.
+ */
+void tomoyo_update_stat(const u8 index)
+{
+        struct timeval tv;
+        do_gettimeofday(&tv);
+        /*
+         * I don't use atomic operations because race condition is not fatal.
+         */
+        tomoyo_stat_updated[index]++;
+        tomoyo_stat_modified[index] = tv.tv_sec;
+}
+
+/**
+ * tomoyo_read_stat - Read statistic data.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns nothing.
+ */
+static void tomoyo_read_stat(struct tomoyo_io_buffer *head)
+{
+        u8 i;
+        unsigned int total = 0;
+        if (head->r.eof)
+                return;
+        for (i = 0; i < TOMOYO_MAX_POLICY_STAT; i++) {
+                tomoyo_io_printf(head, "Policy %-30s %10u",
+                                 tomoyo_policy_headers[i],
+                                 tomoyo_stat_updated[i]);
+                if (tomoyo_stat_modified[i]) {
+                        struct tomoyo_time stamp;
+                        tomoyo_convert_time(tomoyo_stat_modified[i], &stamp);
+                        tomoyo_io_printf(head, " (Last: %04u/%02u/%02u "
+                                         "%02u:%02u:%02u)",
+                                         stamp.year, stamp.month, stamp.day,
+                                         stamp.hour, stamp.min, stamp.sec);
+                }
+                tomoyo_set_lf(head);
+        }
+        for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++) {
+                unsigned int used = tomoyo_memory_used[i];
+                total += used;
+                tomoyo_io_printf(head, "Memory used by %-22s %10u",
+                                 tomoyo_memory_headers[i], used);
+                used = tomoyo_memory_quota[i];
+                if (used)
+                        tomoyo_io_printf(head, " (Quota: %10u)", used);
+                tomoyo_set_lf(head);
+        }
+        tomoyo_io_printf(head, "Total memory used:                    %10u\n",
+                         total);
+        head->r.eof = true;
+}
+
+/**
+ * tomoyo_write_stat - Set memory quota.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns 0.
+ */
+static int tomoyo_write_stat(struct tomoyo_io_buffer *head)
+{
+        char *data = head->write_buf;
+        u8 i;
+        if (tomoyo_str_starts(&data, "Memory used by "))
+                for (i = 0; i < TOMOYO_MAX_MEMORY_STAT; i++)
+                        if (tomoyo_str_starts(&data, tomoyo_memory_headers[i]))
+                                sscanf(data, "%u", &tomoyo_memory_quota[i]);
+        return 0;
+}
+
 /**
  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
  *
@@ -1908,11 +2009,11 @@ int tomoyo_open_control(const u8 type, struct file *file)
                 head->read = tomoyo_read_version;
                 head->readbuf_size = 128;