Added acknowledged field to lastseen DB

This field can be used to acknowledge an update to an incoming or
outgoing host entry in the lastseen DB. The field is set to `false` when
a key-value pair is updated. `cf-hub` may at any time acknowledge that
the update has been observed by setting the field to `true`.

Ticket: ENT-11838
Changelog: Title
Signed-off-by: Lars Erik Wik <[email protected]>

cf-check/db_structs.h

@@ -17,6 +17,7 @@
 // Struct used for quality entries in /var/cfengine/state/cf_lastseen.lmdb:
 typedef struct
 {
+    bool acknowledged;
     time_t lastseen;
     QPoint Q;
 } KeyHostSeen; // Keep in sync with lastseen.h

cf-check/dump.c

@@ -107,6 +107,7 @@ static void print_struct_lastseen_quality(
         memcpy(&quality, value.mv_data, sizeof(quality));
         const time_t lastseen = quality.lastseen;
         const QPoint Q = quality.Q;
+        bool acknowledged = quality.acknowledged;
 
         JsonElement *q_json = JsonObjectCreate(4);
         JsonObjectAppendReal(q_json, "q", Q.q);
@@ -115,6 +116,7 @@ static void print_struct_lastseen_quality(
         JsonObjectAppendReal(q_json, "dq", Q.dq);
 
         JsonElement *top_json = JsonObjectCreate(2);
+        JsonObjectAppendBool(top_json, "acknowledged", acknowledged);
         JsonObjectAppendInteger(top_json, "lastseen", lastseen);
         JsonObjectAppendObject(top_json, "Q", q_json);
 

libpromises/dbm_migration_lastseen.c

@@ -34,6 +34,12 @@ typedef struct
     double var;
 } QPoint0;
 
+typedef struct
+{
+    time_t lastseen;
+    QPoint Q; // Average time between connections (rolling weighted average)
+} KeyHostSeen1;
+
 #define QPOINT0_OFFSET 128
 
 /*
@@ -182,8 +188,96 @@ static bool LastseenMigrationVersion0(DBHandle *db)
     return !errors;
 }
 
+static bool LastseenMigrationVersion1(DBHandle *db)
+{
+    DBCursor *cursor;
+    if (!NewDBCursor(db, &cursor))
+    {
+        Log(LOG_LEVEL_ERR,
+            "Unable to create database cursor during lastseen migration");
+        return false;
+    }
+
+    char *key;
+    void *value;
+    int key_size, value_size;
+
+    // Iterate through all key-value pairs
+    while (NextDB(cursor, &key, &key_size, &value, &value_size))
+    {
+        if (key_size == 0)
+        {
+            Log(LOG_LEVEL_WARNING,
+                "Found zero-length key during lastseen migration");
+            continue;
+        }
+
+        // Only look for old KeyHostSeen entries
+        if (key[0] != 'q')
+        {
+            // Warn about completely unexpected keys
+            if ((key[0] != 'k') && (key[0] != 'a'))
+            {
+                Log(LOG_LEVEL_WARNING,
+                    "Found unexpected key '%s' during lastseen migration",
+                    key);
+            }
+            continue;
+        }
+
+        KeyHostSeen1 *old_value = value;
+        KeyHostSeen new_value = {
+            .acknowledged = true, // We don't know, assume yes
+            .lastseen = old_value->lastseen,
+            .Q = old_value->Q,
+        };
+
+        if (!DBCursorDeleteEntry(cursor))
+        {
+            Log(LOG_LEVEL_ERR,
+                "Unable to delete version 1 of entry for key '%s' during lastseen migration",
+                key);
+            if (DeleteDBCursor(cursor) == false)
+            {
+                Log(LOG_LEVEL_ERR,
+                    "Unable to close cursor during lastseen migration");
+            }
+            return false;
+        }
+
+        if (!DBCursorWriteEntry(db, &new_value, sizeof(new_value)))
+        {
+            Log(LOG_LEVEL_INFO,
+                "Unable to write version 2 of entry for key '%s' during lastseen migration",
+                key);
+            if (DeleteDBCursor(cursor) == false)
+            {
+                Log(LOG_LEVEL_ERR,
+                    "Unable to close cursor during lastseen migration");
+            }
+            return false;
+        }
+    }
+
+    if (!DeleteDBCursor(cursor))
+    {
+        Log(LOG_LEVEL_ERR, "Unable to close cursor during lastseen migration");
+        return false;
+    }
+
+    if (!WriteDB(db, "version", "2", sizeof("2")))
+    {
+        Log(LOG_LEVEL_ERR, "Failed to update version number durling lastseen migration");
+        return false;
+    }
+
+    Log(LOG_LEVEL_INFO, "Migrated lastseen database from version 1 to 2");
+    return true;
+}
+
 const DBMigrationFunction dbm_migration_plan_lastseen[] =
 {
     LastseenMigrationVersion0,
+    LastseenMigrationVersion1,
     NULL
 };

libpromises/lastseen.c

@@ -121,7 +121,10 @@ void UpdateLastSawHost(const char *hostkey, const char *address,
     char quality_key[CF_BUFSIZE];
     snprintf(quality_key, CF_BUFSIZE, "q%c%s", incoming ? 'i' : 'o', hostkey);
 
-    KeyHostSeen newq = { .lastseen = timestamp };
+    KeyHostSeen newq = {
+        .acknowledged = false,
+        .lastseen = timestamp,
+    };
 
     KeyHostSeen q;
     if (ReadDB(db, quality_key, &q, sizeof(q)))

libpromises/lastseen.h

@@ -29,6 +29,7 @@
 
 typedef struct
 {
+    bool acknowledged; // True when acknowledged by cf-hub, false when updated
     time_t lastseen;
     QPoint Q; // Average time between connections (rolling weighted average)
 } KeyHostSeen;

tests/unit/lastseen_test.c

@@ -70,6 +70,7 @@ static void test_newentry(void)
     KeyHostSeen q;
     assert_int_equal(ReadDB(db, "qiSHA-12345", &q, sizeof(q)), true);
 
+    assert_false(q.acknowledged);
     assert_int_equal(q.lastseen, 666);
     assert_double_close(q.Q.q, 0.0);
     assert_double_close(q.Q.dq, 0.0);
@@ -102,6 +103,7 @@ static void test_update(void)
     KeyHostSeen q;
     assert_int_equal(ReadDB(db, "qiSHA-12345", &q, sizeof(q)), true);
 
+    assert_false(q.acknowledged);
     assert_int_equal(q.lastseen, 1110);
     assert_double_close(q.Q.q, 555.0);
     assert_double_close(q.Q.dq, 555.0);