From 83bc4b162f210e4dfafca69e9b4e7735ef61405e Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Thu, 24 Jan 2019 14:05:24 +0100
Subject: [PATCH] socket_zep: fix undefined timestamp conversion behavior
---
cpu/native/socket_zep/socket_zep.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/cpu/native/socket_zep/socket_zep.c b/cpu/native/socket_zep/socket_zep.c
index c2d5da30b6..82ec572838 100644
--- a/cpu/native/socket_zep/socket_zep.c
+++ b/cpu/native/socket_zep/socket_zep.c
@@ -35,6 +35,9 @@
#include "debug.h"
#define _UNIX_NTP_ERA_OFFSET (2208988800U)
+/* can't use timex.h's US_PER_SEC as timeval's tv_usec is signed long
+ * (https://pubs.opengroup.org/onlinepubs/9699919799.2016edition/basedefs/time.h.html) */
+#define TV_USEC_PER_SEC (1000000L)
static size_t _zep_hdr_fill_v2_data(socket_zep_t *dev, zep_v2_data_hdr_t *hdr,
size_t payload_len)
@@ -49,7 +52,10 @@ static size_t _zep_hdr_fill_v2_data(socket_zep_t *dev, zep_v2_data_hdr_t *hdr,
hdr->lqi_mode = 1;
hdr->lqi_val = 0xff; /* TODO: set */
hdr->time.seconds = byteorder_htonl(tv.tv_sec + _UNIX_NTP_ERA_OFFSET);
- hdr->time.fraction = byteorder_htonl((tv.tv_usec * 1000000) / 232);
+ assert(tv.tv_usec < TV_USEC_PER_SEC);
+ hdr->time.fraction = byteorder_htonl(
+ (uint32_t)((uint64_t)tv.tv_usec * TV_USEC_PER_SEC) / 232U
+ );
hdr->seq = byteorder_htonl(dev->seq);
memset(hdr->resv, 0, sizeof(hdr->resv));
hdr->length = payload_len;
--
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