[git commit] udhcp: make arpping code resistant to time jumps
Denys Vlasenko
vda.linux at googlemail.com
Tue Apr 17 15:10:31 UTC 2012
commit: http://git.busybox.net/busybox/commit/?id=6500d123d01af895d2b8eae1a36e553a1f75e211
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
networking/udhcp/arpping.c | 9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c
index ff63478..b43e52e 100644
--- a/networking/udhcp/arpping.c
+++ b/networking/udhcp/arpping.c
@@ -118,8 +118,13 @@ int FAST_FUNC arpping(uint32_t test_nip,
break;
}
}
- timeout_ms -= (unsigned)monotonic_ms() - prevTime;
- } while (timeout_ms > 0);
+ timeout_ms -= (unsigned)monotonic_ms() - prevTime + 1;
+
+ /* We used to check "timeout_ms > 0", but
+ * this is more under/overflow-resistant
+ * (people did see overflows here when system time jumps):
+ */
+ } while ((unsigned)timeout_ms <= 2000);
ret:
close(s);
More information about the busybox-cvs
mailing list