multi: timeout handles even without connection

When there is a "change" in a multi handle and pending handles are moved
back to the main list to be retested if they can proceed further (for
example a previous transfer completed or a connection has a confirmed
multiplexed state), the timeout check in multi_runsingle() would not
trigger because it required an established connection.

This could make a pending tranfer go back to pending state even though
it had been "in progress" for a longer time than permitted. By removing
the requirement for an associated connection, the timeout check will be
done proper even for transfers that has not yet been assigned one.

Ref #13227
Reported-by: Rahul Krishna M
Closes #13276

lib/multi.c

@@ -1744,47 +1744,48 @@ static bool multi_handle_timeout(struct Curl_easy *data,
  CURLcode *result,
  bool connect_timeout)
 {
- timediff_t timeout_ms;
- timeout_ms = Curl_timeleft(data, now, connect_timeout);
+ timediff_t timeout_ms = Curl_timeleft(data, now, connect_timeout);
 
  if(timeout_ms < 0) {
  /* Handle timed out */
+ struct curltime since;
+ if(connect_timeout)
+ since = data->progress.t_startsingle;
+ else
+ since = data->progress.t_startop;
  if(data->mstate == MSTATE_RESOLVING)
  failf(data, "Resolving timed out after %" CURL_FORMAT_TIMEDIFF_T
- " milliseconds",
- Curl_timediff(*now, data->progress.t_startsingle));
+ " milliseconds", Curl_timediff(*now, since));
  else if(data->mstate == MSTATE_CONNECTING)
  failf(data, "Connection timed out after %" CURL_FORMAT_TIMEDIFF_T
- " milliseconds",
- Curl_timediff(*now, data->progress.t_startsingle));
+ " milliseconds", Curl_timediff(*now, since));
  else {
  struct SingleRequest *k = &data->req;
  if(k->size != -1) {
  failf(data, "Operation timed out after %" CURL_FORMAT_TIMEDIFF_T
  " milliseconds with %" CURL_FORMAT_CURL_OFF_T " out of %"
  CURL_FORMAT_CURL_OFF_T " bytes received",
- Curl_timediff(*now, data->progress.t_startsingle),
- k->bytecount, k->size);
+ Curl_timediff(*now, since), k->bytecount, k->size);
  }
  else {
  failf(data, "Operation timed out after %" CURL_FORMAT_TIMEDIFF_T
  " milliseconds with %" CURL_FORMAT_CURL_OFF_T
- " bytes received",
- Curl_timediff(*now, data->progress.t_startsingle),
- k->bytecount);
+ " bytes received", Curl_timediff(*now, since), k->bytecount);
  }
  }
-
- /* Force connection closed if the connection has indeed been used */
- if(data->mstate > MSTATE_DO) {
- streamclose(data->conn, "Disconnected with pending data");
- *stream_error = TRUE;
- }
  *result = CURLE_OPERATION_TIMEDOUT;
- (void)multi_done(data, *result, TRUE);
+ if(data->conn) {
+ /* Force connection closed if the connection has indeed been used */
+ if(data->mstate > MSTATE_DO) {
+ streamclose(data->conn, "Disconnect due to timeout");
+ *stream_error = TRUE;
+ }
+ (void)multi_done(data, *result, TRUE);
+ }
+ return TRUE;
  }
 
- return (timeout_ms < 0);
+ return FALSE;
 }
 
 /*
@@ -1942,23 +1943,12 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
  return CURLM_INTERNAL_ERROR;
  }
 
- if(data->conn &&
- (data->mstate >= MSTATE_CONNECT) &&
- (data->mstate < MSTATE_COMPLETED)) {
- /* Check for overall operation timeout here but defer handling the
- * connection timeout to later, to allow for a connection to be set up
- * in the window since we last checked timeout. This prevents us
- * tearing down a completed connection in the case where we were slow
- * to check the timeout (e.g. process descheduled during this loop).
- * We set connect_timeout=FALSE to do this. */
-
- /* we need to wait for the connect state as only then is the start time
- stored, but we must not check already completed handles */
- if(multi_handle_timeout(data, nowp, &stream_error, &result, FALSE)) {
- /* Skip the statemachine and go directly to error handling section. */
- goto statemachine_end;
- }
- }
+ /* Wait for the connect state as only then is the start time stored, but
+ we must not check already completed handles */
+ if((data->mstate >= MSTATE_CONNECT) && (data->mstate < MSTATE_COMPLETED) &&
+ multi_handle_timeout(data, nowp, &stream_error, &result, FALSE))
+ /* Skip the statemachine and go directly to error handling section. */
+ goto statemachine_end;
 
  switch(data->mstate) {
  case MSTATE_INIT:
@@ -2629,8 +2619,7 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
  return CURLM_INTERNAL_ERROR;
  }
 
- if(data->conn &&
- data->mstate >= MSTATE_CONNECT &&
+ if(data->mstate >= MSTATE_CONNECT &&
  data->mstate < MSTATE_DO &&
  rc != CURLM_CALL_MULTI_PERFORM &&
  !multi_ischanged(multi, false)) {