Fix problems in watchdog processing json data.

Comment on the patch from the author:

In the watchdog source code (src/watchdog/wd_json_data.c), there are some instances of bad handling of values read from json data.
For example:
1) The boolean pool configuration settings "load_balance_mode" and "master_slave_mode" are read using json_get_int_value_for_key(), resulting in 4-bytes being written into their location within the POOL_CONFIG, yet (being bool) they are only 1-byte long. This corrupts the values of the structure members following them.
2) Similarly, when parsing node function json data, "Flags" is read using json_get_int_value_for_key(), resulting in 4-bytes being written into an "unsigned char flags" variable on the stack, overwriting 3-bytes of stack memory following it. On a big-endian system (e.g. Solaris-sparc or Linux for IBM Z), this causes regression test "013.watchdog_failover_require_consensus" to fail, since 0 is written into Flags, rather than the intended value which is in the least significant byte of the int value written.

Bug reported in:
https://www.pgpool.net/mantisbt/view.php?id=596

Patch author:
Greg Nancarrow (Fujitsu Australia)

diff --git a/src/watchdog/wd_json_data.c b/src/watchdog/wd_json_data.c
index d0abc2c69ae0873a960d0e58720d470d6a3f5746..6d043f051b7419263d2f52e57cc41f8aa1821395 100644 (file)
--- a/src/watchdog/wd_json_data.c
+++ b/src/watchdog/wd_json_data.c
@@ -66,7 +66,7 @@ get_pool_config_from_json(char *json_data, int data_len)
                goto ERROR_EXIT;
        if (json_get_bool_value_for_key(root, "enable_pool_hba", &config->enable_pool_hba))
                goto ERROR_EXIT;
-       if (json_get_int_value_for_key(root, "load_balance_mode", (int *) &config->load_balance_mode))
+       if (json_get_bool_value_for_key(root, "load_balance_mode", &config->load_balance_mode))
                goto ERROR_EXIT;
        if (json_get_bool_value_for_key(root, "replication_stop_on_mismatch", &config->replication_stop_on_mismatch))
                goto ERROR_EXIT;
@@ -76,7 +76,7 @@ get_pool_config_from_json(char *json_data, int data_len)
                goto ERROR_EXIT;
        if (json_get_bool_value_for_key(root, "replicate_select", &config->replicate_select))
                goto ERROR_EXIT;
-       if (json_get_int_value_for_key(root, "master_slave_mode", (int *) &config->master_slave_mode))
+       if (json_get_bool_value_for_key(root, "master_slave_mode", &config->master_slave_mode))
                goto ERROR_EXIT;
        if (json_get_bool_value_for_key(root, "connection_cache", &config->connection_cache))
                goto ERROR_EXIT;
@@ -187,12 +187,12 @@ get_pool_config_json(void)
        jw_put_int(jNode, "max_pool", pool_config->max_pool);
        jw_put_bool(jNode, "replication_mode", pool_config->replication_mode);
        jw_put_bool(jNode, "enable_pool_hba", pool_config->enable_pool_hba);
-       jw_put_int(jNode, "load_balance_mode", pool_config->load_balance_mode);
+       jw_put_bool(jNode, "load_balance_mode", pool_config->load_balance_mode);
        jw_put_bool(jNode, "allow_clear_text_frontend_auth", pool_config->allow_clear_text_frontend_auth);
        jw_put_bool(jNode, "replication_stop_on_mismatch", pool_config->replication_stop_on_mismatch);
        jw_put_bool(jNode, "failover_if_affected_tuples_mismatch", pool_config->failover_if_affected_tuples_mismatch);
        jw_put_bool(jNode, "replicate_select", pool_config->replicate_select);
-       jw_put_int(jNode, "master_slave_mode", pool_config->master_slave_mode);
+       jw_put_bool(jNode, "master_slave_mode", pool_config->master_slave_mode);
        jw_put_bool(jNode, "connection_cache", pool_config->connection_cache);
        jw_put_int(jNode, "health_check_timeout", pool_config->health_check_timeout);
        jw_put_int(jNode, "health_check_period", pool_config->health_check_period);
@@ -792,6 +792,7 @@ parse_wd_node_function_json(char *json_data, int data_len, char **func_name, int
        char       *ptr;
        int                     node_count = 0;
        int                     i;
+       int                     tmpflags = 0;
 
        *node_id_set = NULL;
        *func_name = NULL;
@@ -819,12 +820,17 @@ parse_wd_node_function_json(char *json_data, int data_len, char **func_name, int
        }
        *func_name = pstrdup(ptr);
        /* If it is a node function ? */
-       if (json_get_int_value_for_key(root, "Flags", (int *)flags))
+       if (json_get_int_value_for_key(root, "Flags", &tmpflags))
        {
                /* node count not found, But we don't care much about this */
                *flags = 0;
                /* it may be from the old version */
        }
+       else
+       {
+               *flags = (unsigned char)tmpflags;
+       }
+
        if (json_get_int_value_for_key(root, "NodeCount", &node_count))
        {
                /* node count not found, But we don't care much about this */