From: Christopher Davis <chrisd@mangrin.org>
Date: Thu, 1 Apr 2010 03:30:55 +0000 (-0700)
Subject: Add evutil_tv_to_msec for safe conversion of timevals to milliseconds.
X-Git-Tag: release-2.0.5-beta~57^2~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=850c3ff232659125262bb5e30bef8451fac386bf;p=libevent

Add evutil_tv_to_msec for safe conversion of timevals to milliseconds.

This is useful for backends that require their timeout values be in
milliseconds.
---

diff --git a/epoll.c b/epoll.c
index 53c1f09a..6c3cf33f 100644
--- a/epoll.c
+++ b/epoll.c
@@ -35,6 +35,7 @@
 #include <sys/queue.h>
 #include <sys/epoll.h>
 #include <signal.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -269,15 +270,16 @@ epoll_dispatch(struct event_base *base, struct timeval *tv)
 {
 	struct epollop *epollop = base->evbase;
 	struct epoll_event *events = epollop->events;
-	int i, res, timeout = -1;
-
-	if (tv != NULL)
-		timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
-
-	if (timeout > MAX_EPOLL_TIMEOUT_MSEC) {
-		/* Linux kernels can wait forever if the timeout is too big;
-		 * see comment on MAX_EPOLL_TIMEOUT_MSEC. */
-		timeout = MAX_EPOLL_TIMEOUT_MSEC;
+	int i, res;
+	long timeout = -1;
+
+	if (tv != NULL) {
+		timeout = evutil_tv_to_msec(tv);
+		if (timeout < 0 || timeout > MAX_EPOLL_TIMEOUT_MSEC) {
+			/* Linux kernels can wait forever if the timeout is
+			 * too big; see comment on MAX_EPOLL_TIMEOUT_MSEC. */
+			timeout = MAX_EPOLL_TIMEOUT_MSEC;
+		}
 	}
 
 	epoll_apply_changes(base);
diff --git a/evutil.c b/evutil.c
index 9825a878..3ca9fef9 100644
--- a/evutil.c
+++ b/evutil.c
@@ -52,6 +52,7 @@
 #include <stdlib.h>
 #endif
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #ifdef _EVENT_HAVE_ARPA_INET_H
@@ -1894,3 +1895,15 @@ evutil_sockaddr_is_loopback(const struct sockaddr *addr)
 	return 0;
 }
 
+#define MAX_SECONDS_IN_MSEC_LONG \
+	(((LONG_MAX) - 999) / 1000) 
+                            
+long
+evutil_tv_to_msec(const struct timeval *tv)
+{
+	if (tv->tv_usec > 1000000 || tv->tv_sec > MAX_SECONDS_IN_MSEC_LONG)
+		return -1;
+
+	return (tv->tv_sec * 1000) + (tv->tv_usec / 1000);
+}
+
diff --git a/poll.c b/poll.c
index 84e7944e..abbf90eb 100644
--- a/poll.c
+++ b/poll.c
@@ -35,6 +35,7 @@
 #include <sys/queue.h>
 #include <poll.h>
 #include <signal.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -117,7 +118,8 @@ poll_check_ok(struct pollop *pop)
 static int
 poll_dispatch(struct event_base *base, struct timeval *tv)
 {
-	int res, i, j, msec = -1, nfds;
+	int res, i, j, nfds;
+	long msec = -1;
 	struct pollop *pop = base->evbase;
 	struct pollfd *event_set;
 
@@ -152,8 +154,11 @@ poll_dispatch(struct event_base *base, struct timeval *tv)
 	event_set = pop->event_set;
 #endif
 
-	if (tv != NULL)
-		msec = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
+	if (tv != NULL) {
+		msec = evutil_tv_to_msec(tv);
+		if (msec < 0 || msec > INT_MAX)
+			msec = INT_MAX;
+	}
 
 	EVBASE_RELEASE_LOCK(base, th_base_lock);
 
diff --git a/util-internal.h b/util-internal.h
index f74f323c..f5fff192 100644
--- a/util-internal.h
+++ b/util-internal.h
@@ -213,6 +213,8 @@ int evutil_getaddrinfo_async(struct evdns_base *dns_base,
  * ::1). */
 int evutil_sockaddr_is_loopback(const struct sockaddr *sa);
 
+long evutil_tv_to_msec(const struct timeval *tv);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/win32select.c b/win32select.c
index 7dc68c91..a3b8dd7d 100644
--- a/win32select.c
+++ b/win32select.c
@@ -30,6 +30,7 @@
 #include <windows.h>
 #include <sys/types.h>
 #include <sys/queue.h>
+#include <limits.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -114,12 +115,6 @@ realloc_fd_sets(struct win32op *op, size_t new_size)
 	return (0);
 }
 
-static int
-timeval_to_ms(struct timeval *tv)
-{
-	return ((tv->tv_sec * 1000) + (tv->tv_usec / 1000));
-}
-
 static int
 do_fd_set(struct win32op *op, struct idx_info *ent, evutil_socket_t s, int read)
 {
@@ -303,8 +298,12 @@ win32_dispatch(struct event_base *base, struct timeval *tv)
 	    win32op->readset_out->fd_count : win32op->writeset_out->fd_count;
 
 	if (!fd_count) {
+		long msec = evutil_tv_to_msec(tv);
+		/* Sleep's DWORD argument is unsigned long */
+		if (msec < 0)
+			msec = LONG_MAX;
 		/* Windows doesn't like you to call select() with no sockets */
-		Sleep(timeval_to_ms(tv));
+		Sleep(msec);
 		evsig_process(base);
 		return (0);
 	}