Merge pull request #4213 from sysown/v.2x_dns_cache_issue_4210

DNS module no longer regards the UNIX socket path as a hostname

include/MySQL_Monitor.hpp

@@ -415,7 +415,7 @@ class MySQL_Monitor {
  public:
  static std::string dns_lookup(const std::string& hostname, bool return_hostname_if_lookup_fails = true, size_t* ip_count = NULL);
  static std::string dns_lookup(const char* hostname, bool return_hostname_if_lookup_fails = true, size_t* ip_count = NULL);
- static bool dns_cache_update_socket(const std::string& hostname, int socket_fd);
+ static bool update_dns_cache_from_mysql_conn(const MYSQL* mysql);
  static void trigger_dns_cache_update();
 
 

include/ProxySQL_Cluster.hpp

@@ -95,7 +95,7 @@ class ProxySQL_Node_Address {
  uint16_t port;
  ProxySQL_Node_Address(char *h, uint16_t p) : ProxySQL_Node_Address(h, p, NULL) {
  // resolving DNS if available in Cache
- if (h) {
+ if (h && p) {
  size_t ip_count = 0;
  const std::string& ip = MySQL_Monitor::dns_lookup(h, false, &ip_count);
 

lib/MySQL_Monitor.cpp

@@ -1501,7 +1501,7 @@ bool MySQL_Monitor_State_Data::set_wait_timeout() {
 bool MySQL_Monitor_State_Data::create_new_connection() {
  mysql=mysql_init(NULL);
  assert(mysql);
- if (use_ssl) {
+ if (use_ssl && port) {
  mysql_ssl_set(mysql,
  mysql_thread___ssl_p2s_key,
  mysql_thread___ssl_p2s_cert,
@@ -1543,7 +1543,7 @@ bool MySQL_Monitor_State_Data::create_new_connection() {
 #else
  fcntl(mysql->net.fd, F_SETFL, f|O_NONBLOCK);
 #endif /* FD_CLOEXEC */
- MySQL_Monitor::dns_cache_update_socket(mysql->host, mysql->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(mysql);
  }
  return true;
 }
@@ -4527,7 +4527,9 @@ void* MySQL_Monitor::monitor_dns_cache() {
  int cols = 0;
  int affected_rows = 0;
  SQLite3_result* resultset = NULL;
- const char* query = (char*)"SELECT trim(hostname) FROM monitor_internal.mysql_servers UNION SELECT trim(hostname) FROM monitor_internal.proxysql_servers";
+ const char* query = (char*)"SELECT trim(hostname) FROM monitor_internal.mysql_servers WHERE port!=0"
+ " UNION "
+ "SELECT trim(hostname) FROM monitor_internal.proxysql_servers WHERE port!=0";
 
  t1 = monotonic_time();
 
@@ -6478,15 +6480,23 @@ std::string MySQL_Monitor::dns_lookup(const char* hostname, bool return_hostname
  return MySQL_Monitor::dns_lookup(std::string(hostname), return_hostname_if_lookup_fails, ip_count);
 }
 
-bool MySQL_Monitor::dns_cache_update_socket(const std::string& hostname, int socket_fd)
+bool MySQL_Monitor::update_dns_cache_from_mysql_conn(const MYSQL* mysql)
 {
+ assert(mysql);
+
+ // if port==0, UNIX socket is used
+ if (mysql->port == 0)
+ return false;
+
+ const std::string& hostname = mysql->host;
+
  // if IP was provided, no need to update dns cache
  if (hostname.empty() || validate_ip(hostname))
  return false;
 
  bool result = false;
 
- const std::string& ip_addr = get_connected_peer_ip_from_socket(socket_fd);
+ const std::string& ip_addr = get_connected_peer_ip_from_socket(mysql->net.fd);
 
  if (ip_addr.empty() == false) {
  result = _dns_cache_update(hostname, { ip_addr });

lib/MySQL_Session.cpp

@@ -177,7 +177,7 @@ bool Session_Regex::match(char *m) {
 KillArgs::KillArgs(char* u, char* p, char* h, unsigned int P, unsigned int _hid, unsigned long i, int kt, MySQL_Thread* _mt) :
  KillArgs(u, p, h, P, _hid, i, kt, _mt, NULL) {
  // resolving DNS if available in Cache
- if (h) {
+ if (h && P) {
  const std::string& ip = MySQL_Monitor::dns_lookup(h, false);
 
  if (ip.empty() == false) {
@@ -265,7 +265,7 @@ void * kill_query_thread(void *arg) {
  goto __exit_kill_query_thread;
  }
 
- MySQL_Monitor::dns_cache_update_socket(mysql->host, mysql->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(mysql);
 
  char buf[100];
  switch (ka->kill_type) {

lib/ProxySQL_Cluster.cpp

@@ -100,7 +100,7 @@ void * ProxySQL_Cluster_Monitor_thread(void *args) {
 // }
  //char *query = query1;
  if (rc_conn) {
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  rc_query = mysql_query(conn,(char *)"SELECT @@version");
  if (rc_query == 0) {
@@ -308,7 +308,7 @@ void ProxySQL_Node_Metrics::reset() {
 ProxySQL_Node_Entry::ProxySQL_Node_Entry(char *_hostname, uint16_t _port, uint64_t _weight, char * _comment) : 
  ProxySQL_Node_Entry(_hostname, _port, _weight, _comment, NULL) {
  // resolving DNS if available in Cache
- if (_hostname) {
+ if (_hostname && _port) {
  size_t ip_count = 0;
  const std::string& ip = MySQL_Monitor::dns_lookup(_hostname, false, &ip_count);
 
@@ -1041,7 +1041,7 @@ void ProxySQL_Cluster::pull_mysql_query_rules_from_peer(const string& expected_c
  proxy_info("Cluster: Fetching MySQL Query Rules from peer %s:%d started. Expected checksum: %s\n", hostname, port, expected_checksum.c_str());
  rc_conn = mysql_real_connect(conn, ip_address ? ip_address : hostname, username, password, NULL, port, NULL, 0);
  if (rc_conn) {
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  MYSQL_RES *result1 = NULL;
  MYSQL_RES *result2 = NULL;
@@ -1323,8 +1323,8 @@ void ProxySQL_Cluster::pull_mysql_users_from_peer(const string& expected_checksu
 
  goto __exit_pull_mysql_users_from_peer;
  }
- 
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  rc_query = mysql_query(conn, CLUSTER_QUERY_MYSQL_USERS);
  if (rc_query == 0) {
@@ -1635,7 +1635,7 @@ void ProxySQL_Cluster::pull_mysql_servers_from_peer(const std::string& checksum,
  proxy_info("Cluster: Fetching MySQL Servers from peer %s:%d started. Expected checksum %s\n", hostname, port, peer_checksum);
  rc_conn = mysql_real_connect(conn, ip_address ? ip_address : hostname, username, password, NULL, port, NULL, 0);
  if (rc_conn) {
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  std::vector<MYSQL_RES*> results {};
 
@@ -2054,7 +2054,7 @@ void ProxySQL_Cluster::pull_global_variables_from_peer(const string& var_type, c
  rc_conn = mysql_real_connect(conn, ip_address ? ip_address : hostname, username, password, NULL, port, NULL, 0);
 
  if (rc_conn) {
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  std::string s_query = "";
  string_format("SELECT * FROM runtime_global_variables WHERE variable_name LIKE '%s-%%'", s_query, var_type.c_str());
@@ -2208,7 +2208,7 @@ void ProxySQL_Cluster::pull_proxysql_servers_from_peer(const std::string& expect
  );
  rc_conn = mysql_real_connect(conn, ip_address ? ip_address : hostname, username, password, NULL, port, NULL, 0);
  if (rc_conn) {
- MySQL_Monitor::dns_cache_update_socket(conn->host, conn->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(conn);
 
  rc_query = mysql_query(conn,"SELECT hostname, port, weight, comment FROM runtime_proxysql_servers ORDER BY hostname, port");
  if ( rc_query == 0 ) {

lib/mysql_connection.cpp

@@ -710,7 +710,7 @@ void MySQL_Connection::connect_start() {
  }
  mysql_options4(mysql, MYSQL_OPT_CONNECT_ATTR_ADD, "mysql_bug_102266", "Avoid MySQL bug https://bugs.mysql.com/bug.php?id=102266 , https://github.com/sysown/proxysql/issues/3276");
  }
- if (parent->use_ssl) {
+ if (parent->use_ssl && parent->port) {
  mysql_ssl_set(mysql,
  mysql_thread___ssl_p2s_key,
  mysql_thread___ssl_p2s_cert,
@@ -857,6 +857,7 @@ void MySQL_Connection::connect_start() {
 
  async_exit_status=mysql_real_connect_start(&ret_mysql, mysql, host_ip, userinfo->username, auth_password, userinfo->schemaname, parent->port, NULL, client_flags);
  } else {
+ client_flags &= ~(CLIENT_COMPRESS); // disabling compression for connections made via Unix socket
  async_exit_status=mysql_real_connect_start(&ret_mysql, mysql, "localhost", userinfo->username, auth_password, userinfo->schemaname, parent->port, parent->address, client_flags);
  }
  fd=mysql_get_socket(mysql);
@@ -1166,7 +1167,7 @@ MDB_ASYNC_ST MySQL_Connection::handler(short event) {
  //vio_blocking(mysql->net.vio, FALSE, 0);
  //fcntl(mysql->net.vio->sd, F_SETFL, O_RDWR|O_NONBLOCK);
  //}
- MySQL_Monitor::dns_cache_update_socket(mysql->host, mysql->net.fd);
+ MySQL_Monitor::update_dns_cache_from_mysql_conn(mysql);
  break;
  case ASYNC_CONNECT_FAILED:
  MyHGM->p_update_mysql_error_counter(p_mysql_error_type::mysql, parent->myhgc->hid, parent->address, parent->port, mysql_errno(mysql));