changed ping_recv_unix to use clock_gettime() instead of gettimeofday()

4 files changed, 127 insertions, 14 deletions

diff --git a/config.h.in b/config.h.in
index c15430b..d78f33f 100644
--- a/config.h.in
+++ b/config.h.in
@@ -21,6 +21,9 @@
 /* Define to 1 if you have the `pcap' library (-lpcap). */
 #undef HAVE_LIBPCAP
 
+/* Define to 1 if you have the `rt' library (-lrt). */
+#undef HAVE_LIBRT
+
 /* Define to 1 if you have the `socket' library (-lsocket). */
 #undef HAVE_LIBSOCKET
 
diff --git a/configure b/configure
index b9bdb6e..2dd4cbf 100755
--- a/configure
+++ b/configure
@@ -3727,6 +3727,77 @@ _ACEOF
 
 fi
 
+
+{ echo "$as_me:$LINENO: checking for clock_gettime in -lrt" >&5
+echo $ECHO_N "checking for clock_gettime in -lrt... $ECHO_C" >&6; }
+if test "${ac_cv_lib_rt_clock_gettime+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lrt  $LIBS"
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char clock_gettime ();
+int
+main ()
+{
+return clock_gettime ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext &&
+       $as_test_x conftest$ac_exeext; then
+  ac_cv_lib_rt_clock_gettime=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_cv_lib_rt_clock_gettime=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_lib_rt_clock_gettime" >&5
+echo "${ECHO_T}$ac_cv_lib_rt_clock_gettime" >&6; }
+if test $ac_cv_lib_rt_clock_gettime = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBRT 1
+_ACEOF
+
+  LIBS="-lrt $LIBS"
+
+fi
+
 { echo "$as_me:$LINENO: checking for libnet_name_resolve in -lnet" >&5
 echo $ECHO_N "checking for libnet_name_resolve in -lnet... $ECHO_C" >&6; }
 if test "${ac_cv_lib_net_libnet_name_resolve+set}" = set; then
diff --git a/configure.ac b/configure.ac
index 2b42253..0f43c28 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,6 +18,7 @@ AC_PROG_MAKE_SET
 # Checks for libraries.
 AC_CHECK_LIB([socket], [socket])
 AC_CHECK_LIB([nsl], [gethostbyname])
+AC_CHECK_LIB([rt], [clock_gettime])
 AC_CHECK_LIB([net], [libnet_name_resolve],
       [AC_MSG_ERROR([libnet 1.0.x found. Arping 2.x requires libnet 1.1.x])])
 AC_CHECK_LIB([net], [libnet_init], ,[AC_MSG_ERROR([libnet 1.1.x not found])])
diff --git a/src/arping.c b/src/arping.c
index 7b5e43e..593ff93 100644
--- a/src/arping.c
+++ b/src/arping.c
@@ -38,6 +38,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <poll.h>
+#include <time.h>
 
 #if HAVE_UNISTD_H
 #include <unistd.h>
@@ -830,6 +831,19 @@ fixup_timeval(struct timeval *tv)
 }
 
 /**
+ * while negative microseconds, take from whole seconds.
+ * help function for measuring deltas.
+ */
+static void
+fixup_timespec(struct timespec *tv)
+{
+	while (tv->tv_nsec < 0) {
+		tv->tv_sec--;
+		tv->tv_nsec += 1000000000;
+	}
+}
+
+/**
  * idiot-proof gettimeofday() wrapper
  */
 static void
@@ -843,36 +857,52 @@ gettv(struct timeval *tv)
 	}
 }
 
+/**
+ * idiot-proof clock_gettime() wrapper
+ */
+static void
+getclock(struct timespec *tv)
+{
+	if (-1 == clock_gettime(CLOCK_MONOTONIC, tv)) {
+		fprintf(stderr, "arping: "
+			"clock_gettime(): %s\n",
+			strerror(errno));
+		sigint(0);
+	}
+}
+
 
 /**
- * 
+ * try to receive a packet for 'packetwait' microseconds
  */
 static void
-ping_recv_unix(pcap_t *pcap,uint32_t packetwait, pcap_handler func)
+ping_recv_unix(pcap_t *pcap, uint32_t packetwait, pcap_handler func)
 {
-       struct timeval tv;
-       struct timeval endtime;
+       struct timespec tv;
+       struct timespec endtime;
        char done = 0;
+       int fd;
 
-       gettv(&tv);
+       getclock(&tv);
        endtime.tv_sec = tv.tv_sec + (packetwait / 1000000);
-       endtime.tv_usec = tv.tv_usec + (packetwait % 1000000);
-       fixup_timeval(&endtime);
-
-       int fd;
+       endtime.tv_nsec = tv.tv_nsec + 1000 * (packetwait % 1000000);
+       fixup_timespec(&endtime);
 
        fd = pcap_get_selectable_fd(pcap);
 
        for (;!done;) {
 	       int trydispatch = 0;
 
-	       gettv(&tv);
+	       getclock(&tv);
 	       tv.tv_sec = endtime.tv_sec - tv.tv_sec;
-	       tv.tv_usec = endtime.tv_usec - tv.tv_usec;
-	       fixup_timeval(&tv);
+	       tv.tv_nsec = endtime.tv_nsec - tv.tv_nsec;
+	       fixup_timespec(&tv);
+               if (verbose) {
+                       printf("waid for %d.%09d sec\n", tv.tv_sec, tv.tv_nsec);
+               }
 	       if (tv.tv_sec < 0) {
 		       tv.tv_sec = 0;
-		       tv.tv_usec = 1;
+		       tv.tv_nsec = 1;
 		       done = 1;
 	       }
 	       if (time_to_die) {
@@ -886,7 +916,9 @@ ping_recv_unix(pcap_t *pcap,uint32_t packetwait, pcap_handler func)
 		       p.fd = fd;
 		       p.events = POLLIN | POLLPRI;
 
-		       r = poll(&p, 1, tv.tv_sec * 1000 + tv.tv_usec / 1000);
+                       /* poll has ms resolution, but has less false
+                          positives than select() */
+		       r = poll(&p, 1,tv.tv_sec * 1000 + tv.tv_nsec / 1000000);
 		       switch (r) {
 		       case 0: /* timeout */
 			       done = 1;
@@ -1120,6 +1152,12 @@ int main(int argc, char **argv)
 		}
 	}
 
+        if (verbose) {
+                struct timespec ts;
+                clock_getres(CLOCK_MONOTONIC, &ts);
+                printf("clock_getres() = %d %d\n", ts.tv_sec, ts.tv_nsec);
+        }
+
         if (display == DOT) {
                 setvbuf(stdout, NULL, _IONBF, 0);
         }