timediff: return timediff_t from the time diff functions

... to cater for systems with unsigned time_t variables.

- Renamed the functions to curlx_timediff and Curl_timediff_us.

- Added overflow protection for both of them in either direction for
  both 32 bit and 64 bit time_ts

- Reprefixed the curlx_time functions to use Curl_*

Reported-by: Peter Piekarski
Fixes #2004
Closes #2005

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/connect.c b/lib/connect.c
index b7d10af55..7bf82d14a 100755
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -225,10 +225,10 @@ time_t Curl_timeleft(struct Curl_easy *data,
   /* subtract elapsed time */
   if(duringconnect)
     /* since this most recent connect started */
-    timeout_ms -= Curl_tvdiff(*nowp, data->progress.t_startsingle);
+    timeout_ms -= Curl_timediff(*nowp, data->progress.t_startsingle);
   else
     /* since the entire operation started */
-    timeout_ms -= Curl_tvdiff(*nowp, data->progress.t_startop);
+    timeout_ms -= Curl_timediff(*nowp, data->progress.t_startop);
   if(!timeout_ms)
     /* avoid returning 0 as that means no timeout! */
     return -1;
@@ -765,7 +765,7 @@ CURLcode Curl_is_connected(struct connectdata *conn,
 
     if(rc == 0) { /* no connection yet */
       error = 0;
-      if(curlx_tvdiff(now, conn->connecttime) >= conn->timeoutms_per_addr) {
+      if(Curl_timediff(now, conn->connecttime) >= conn->timeoutms_per_addr) {
         infof(data, "After %ldms connect time, move on!\n",
               conn->timeoutms_per_addr);
         error = ETIMEDOUT;
@@ -773,7 +773,7 @@ CURLcode Curl_is_connected(struct connectdata *conn,
 
       /* should we try another protocol family? */
       if(i == 0 && conn->tempaddr[1] == NULL &&
-         curlx_tvdiff(now, conn->connecttime) >= HAPPY_EYEBALLS_TIMEOUT) {
+         Curl_timediff(now, conn->connecttime) >= HAPPY_EYEBALLS_TIMEOUT) {
         trynextip(conn, sockindex, 1);
       }
     }