From d0e66e0719ae8eb549f7cc220fdc66575d3db332 Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jonas.gorski@gmail.com>
Date: Thu, 29 Mar 2012 17:01:11 +0200
Subject: [PATCH 4/4] use monotic clock instead of time of day

The time of day might chance e.g. by daylight savings time during the
runtime, which causes timers to fire repeatedly for a long time.

Contributed by T-Labs, Deutsche Telekom Innovation Laboratories

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
---
 configure.ac    |    2 ++
 src/igmpproxy.c |   26 +++++++++++++-------------
 src/igmpproxy.h |    3 ++-
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/configure.ac b/configure.ac
index 85beb08..bd84eba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,6 +25,8 @@ AC_CHECK_MEMBERS([struct sockaddr_in.sin_len], [], [], [[
 #include <netinet/in.h>
 ]])
 
+AC_SEARCH_LIBS([clock_gettime],[rt])
+
 AC_CONFIG_FILES([
 	Makefile
 	doc/Makefile
diff --git a/src/igmpproxy.c b/src/igmpproxy.c
index 35000c7..3a9ccad 100644
--- a/src/igmpproxy.c
+++ b/src/igmpproxy.c
@@ -234,13 +234,13 @@ void igmpProxyRun() {
     int     MaxFD, Rt, secs;
     fd_set  ReadFDS;
     socklen_t dummy = 0;
-    struct  timeval  curtime, lasttime, difftime, tv; 
+    struct  timespec  curtime, lasttime, difftime, tv; 
     // The timeout is a pointer in order to set it to NULL if nessecary.
-    struct  timeval  *timeout = &tv;
+    struct  timespec  *timeout = &tv;
 
     // Initialize timer vars
-    difftime.tv_usec = 0;
-    gettimeofday(&curtime, NULL);
+    difftime.tv_nsec = 0;
+    clock_gettime(CLOCK_MONOTONIC, &curtime);
     lasttime = curtime;
 
     // First thing we send a membership query in downstream VIF's...
@@ -263,7 +263,7 @@ void igmpProxyRun() {
         if(secs == -1) {
             timeout = NULL;
         } else {
-            timeout->tv_usec = 0;
+            timeout->tv_nsec = 0;
             timeout->tv_sec = secs;
         }
 
@@ -274,7 +274,7 @@ void igmpProxyRun() {
         FD_SET( MRouterFD, &ReadFDS );
 
         // wait for input
-        Rt = select( MaxFD +1, &ReadFDS, NULL, NULL, timeout );
+        Rt = pselect( MaxFD +1, &ReadFDS, NULL, NULL, timeout, NULL );
 
         // log and ignore failures
         if( Rt < 0 ) {
@@ -307,20 +307,20 @@ void igmpProxyRun() {
              */
             if (Rt == 0) {
                 curtime.tv_sec = lasttime.tv_sec + secs;
-                curtime.tv_usec = lasttime.tv_usec;
+                curtime.tv_nsec = lasttime.tv_nsec;
                 Rt = -1; /* don't do this next time through the loop */
             } else {
-                gettimeofday(&curtime, NULL);
+                clock_gettime(CLOCK_MONOTONIC, &curtime);
             }
             difftime.tv_sec = curtime.tv_sec - lasttime.tv_sec;
-            difftime.tv_usec += curtime.tv_usec - lasttime.tv_usec;
-            while (difftime.tv_usec > 1000000) {
+            difftime.tv_nsec += curtime.tv_nsec - lasttime.tv_nsec;
+            while (difftime.tv_nsec > 1000000000) {
                 difftime.tv_sec++;
-                difftime.tv_usec -= 1000000;
+                difftime.tv_nsec -= 1000000000;
             }
-            if (difftime.tv_usec < 0) {
+            if (difftime.tv_nsec < 0) {
                 difftime.tv_sec--;
-                difftime.tv_usec += 1000000;
+                difftime.tv_nsec += 1000000000;
             }
             lasttime = curtime;
             if (secs == 0 || difftime.tv_sec > 0)
diff --git a/src/igmpproxy.h b/src/igmpproxy.h
index 4df8a79..36a4f04 100644
--- a/src/igmpproxy.h
+++ b/src/igmpproxy.h
@@ -44,12 +44,13 @@
 #include <string.h>
 #include <fcntl.h>
 #include <stdbool.h>
+#include <time.h>
 
 #include <sys/socket.h>
 #include <sys/un.h>
-#include <sys/time.h>
 #include <sys/ioctl.h>
 #include <sys/param.h>
+#include <sys/select.h>
 
 #include <net/if.h>
 #include <netinet/in.h>
-- 
1.7.2.5