Using a 32 bit field to represent time in nanoseconds results in a
maximum value of about 4.3 seconds, which is well below many observed
delays in WiFi and LTE, and barely in the ballpark for a trip past the
Earth's moon, Luna.
Using 64 bit time fields in nanoseconds allows us to simulate
network diameters of several hundred light-years. However, only
conversions to and from ns, us, ms, and seconds are provided.
Signed-off-by: Dave Taht <dave.t...@gmail.com>
---
tc/tc_core.h | 3 +++
tc/tc_util.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
tc/tc_util.h | 3 +++
3 files changed, 62 insertions(+)
diff --git a/tc/tc_core.h b/tc/tc_core.h
index 8a63b79..e8bda8b 100644
--- a/tc/tc_core.h
+++ b/tc/tc_core.h
@@ -5,6 +5,9 @@
#include <linux/pkt_sched.h>
#define TIME_UNITS_PER_SEC 1000000
+#define USEC_PER_SEC 1000
+#define MSEC_PER_SEC (1000 * 1000)
+#define NSEC_PER_SEC (1000 * 1000 * 1000)
enum link_layer {
LINKLAYER_UNSPEC,
diff --git a/tc/tc_util.c b/tc/tc_util.c
index b39e550..dafbbc3 100644
--- a/tc/tc_util.c
+++ b/tc/tc_util.c
@@ -323,6 +323,62 @@ char *sprint_ticks(__u32 ticks, char *buf)
return sprint_time(tc_core_tick2time(ticks), buf);
}
+/* 64 bit times are represented internally in nanoseconds */
+
+int get_time64(__s64 *time, const char *str)
+{
+ double t;
+ char *p;
+
+ t = strtod(str, &p);
+ if (p == str)
+ return -1;
+
+ if (*p) {
+ if (strcasecmp(p, "s") == 0 ||
+ strcasecmp(p, "sec") == 0 ||
+ strcasecmp(p, "secs") == 0)
+ t *= NSEC_PER_SEC;
+ else if (strcasecmp(p, "ms") == 0 ||
+ strcasecmp(p, "msec") == 0 ||
+ strcasecmp(p, "msecs") == 0)
+ t *= MSEC_PER_SEC;
+ else if (strcasecmp(p, "us") == 0 ||
+ strcasecmp(p, "usec") == 0 ||
+ strcasecmp(p, "usecs") == 0)
+ t *= USEC_PER_SEC;
+ else if (strcasecmp(p, "ns") == 0 ||
+ strcasecmp(p, "nsec") == 0 ||
+ strcasecmp(p, "nsecs") == 0)
+ t *= 1;
+ else
+ return -1;
+ }
+
+ *time = t;
+ return 0;
+}
+
+void print_time64(char *buf, int len, __s64 time)
+{
+ double tmp = time;
+
+ if (time >= NSEC_PER_SEC)
+ snprintf(buf, len, "%.3fs", tmp/NSEC_PER_SEC);
+ else if (time >= MSEC_PER_SEC)
+ snprintf(buf, len, "%.3fms", tmp/MSEC_PER_SEC);
+ else if (time >= USEC_PER_SEC)
+ snprintf(buf, len, "%.3fus", tmp/USEC_PER_SEC);
+ else
+ snprintf(buf, len, "%lldns", time);
+}
+
+char *sprint_time64(__s64 time, char *buf)
+{
+ print_time64(buf, SPRINT_BSIZE-1, time);
+ return buf;
+}
+
int get_size(unsigned int *size, const char *str)
{
double sz;
diff --git a/tc/tc_util.h b/tc/tc_util.h
index 583a21a..7a8559b 100644
--- a/tc/tc_util.h
+++ b/tc/tc_util.h
@@ -72,12 +72,14 @@ int get_rate64(__u64 *rate, const char *str);
int get_size(unsigned int *size, const char *str);
int get_size_and_cell(unsigned int *size, int *cell_log, char *str);
int get_time(unsigned int *time, const char *str);
+int get_time64(__s64 *time, const char *str);
int get_linklayer(unsigned int *val, const char *arg);
void print_rate(char *buf, int len, __u64 rate);
void print_size(char *buf, int len, __u32 size);
void print_qdisc_handle(char *buf, int len, __u32 h);
void print_time(char *buf, int len, __u32 time);
+void print_time64(char *buf, int len, __s64 time);
void print_linklayer(char *buf, int len, unsigned int linklayer);
char *sprint_rate(__u64 rate, char *buf);
@@ -85,6 +87,7 @@ char *sprint_size(__u32 size, char *buf);
char *sprint_qdisc_handle(__u32 h, char *buf);
char *sprint_tc_classid(__u32 h, char *buf);
char *sprint_time(__u32 time, char *buf);
+char *sprint_time64(__s64 time, char *buf);
char *sprint_ticks(__u32 ticks, char *buf);
char *sprint_linklayer(unsigned int linklayer, char *buf);
--
2.7.4
