tc: support conversions to or from 64 bit nanosecond-based time

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.

The iproute2 64 bit api uses signed values for time. Being able to
represent positive or negative time allows us to calculate +/- deltas
between, for example, the CLOCK_TAI and CLOCK_REALTIME clocks.

Time related utility functions in tc_util.c are moved to lib/utils.c.

Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David Ahern <dsahern@gmail.com>

diff --git a/include/utils.h b/include/utils.h
index 8cb4349e8a89f6f2ae3eb8818af804ef38da2c8c..eba67b6ecf44907d25a5b54db515f9305ba212aa 100644 (file)
--- a/include/utils.h
+++ b/include/utils.h
@@ -46,6 +46,11 @@ void incomplete_command(void) __attribute__((noreturn));
 #define NEXT_ARG_FWD() do { argv++; argc--; } while(0)
 #define PREV_ARG() do { argv--; argc++; } while(0)
 
+#define TIME_UNITS_PER_SEC     1000000
+#define NSEC_PER_USEC 1000
+#define NSEC_PER_MSEC 1000000
+#define NSEC_PER_SEC 1000000000LL
+
 typedef struct
 {
        __u16 flags;
@@ -310,4 +315,11 @@ size_t strlcat(char *dst, const char *src, size_t size);
 
 void drop_cap(void);
 
+int get_time(unsigned int *time, const char *str);
+int get_time64(__s64 *time, const char *str);
+void print_time(char *buf, int len, __u32 time);
+void print_time64(char *buf, int len, __s64 time);
+char *sprint_time(__u32 time, char *buf);
+char *sprint_time64(__s64 time, char *buf);
+
 #endif /* __UTILS_H__ */

diff --git a/lib/utils.c b/lib/utils.c
index 02ce67721915e14336685a5280c7133dda180773..802075fca874d6ec689c71d4d06d8b30c19667e4 100644 (file)
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -1633,3 +1633,104 @@ void drop_cap(void)
        }
 #endif
 }
+
+int get_time(unsigned int *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 *= TIME_UNITS_PER_SEC;
+               else if (strcasecmp(p, "ms") == 0 || strcasecmp(p, "msec") == 0 ||
+                        strcasecmp(p, "msecs") == 0)
+                       t *= TIME_UNITS_PER_SEC/1000;
+               else if (strcasecmp(p, "us") == 0 || strcasecmp(p, "usec") == 0 ||
+                        strcasecmp(p, "usecs") == 0)
+                       t *= TIME_UNITS_PER_SEC/1000000;
+               else
+                       return -1;
+       }
+
+       *time = t;
+       return 0;
+}
+
+
+void print_time(char *buf, int len, __u32 time)
+{
+       double tmp = time;
+
+       if (tmp >= TIME_UNITS_PER_SEC)
+               snprintf(buf, len, "%.1fs", tmp/TIME_UNITS_PER_SEC);
+       else if (tmp >= TIME_UNITS_PER_SEC/1000)
+               snprintf(buf, len, "%.1fms", tmp/(TIME_UNITS_PER_SEC/1000));
+       else
+               snprintf(buf, len, "%uus", time);
+}
+
+char *sprint_time(__u32 time, char *buf)
+{
+       print_time(buf, SPRINT_BSIZE-1, time);
+       return buf;
+}
+
+/* 64 bit times are represented internally in nanoseconds */
+int get_time64(__s64 *time, const char *str)
+{
+       double nsec;
+       char *p;
+
+       nsec = strtod(str, &p);
+       if (p == str)
+               return -1;
+
+       if (*p) {
+               if (strcasecmp(p, "s") == 0 ||
+                   strcasecmp(p, "sec") == 0 ||
+                   strcasecmp(p, "secs") == 0)
+                       nsec *= NSEC_PER_SEC;
+               else if (strcasecmp(p, "ms") == 0 ||
+                        strcasecmp(p, "msec") == 0 ||
+                        strcasecmp(p, "msecs") == 0)
+                       nsec *= NSEC_PER_MSEC;
+               else if (strcasecmp(p, "us") == 0 ||
+                        strcasecmp(p, "usec") == 0 ||
+                        strcasecmp(p, "usecs") == 0)
+                       nsec *= NSEC_PER_USEC;
+               else if (strcasecmp(p, "ns") == 0 ||
+                        strcasecmp(p, "nsec") == 0 ||
+                        strcasecmp(p, "nsecs") == 0)
+                       nsec *= 1;
+               else
+                       return -1;
+       }
+
+       *time = nsec;
+       return 0;
+}
+
+void print_time64(char *buf, int len, __s64 time)
+{
+       double nsec = time;
+
+       if (time >= NSEC_PER_SEC)
+               snprintf(buf, len, "%.3fs", nsec/NSEC_PER_SEC);
+       else if (time >= NSEC_PER_MSEC)
+               snprintf(buf, len, "%.3fms", nsec/NSEC_PER_MSEC);
+       else if (time >= NSEC_PER_USEC)
+               snprintf(buf, len, "%.3fus", nsec/NSEC_PER_USEC);
+       else
+               snprintf(buf, len, "%lldns", time);
+}
+
+char *sprint_time64(__s64 time, char *buf)
+{
+       print_time64(buf, SPRINT_BSIZE-1, time);
+       return buf;
+}

diff --git a/tc/tc_cbq.c b/tc/tc_cbq.c
index 4cd584a91a26cd99f316b5b9672bd1fad9084448..c811456b1627526939a215ca59c16b8ad0627e2f 100644 (file)
--- a/tc/tc_cbq.c
+++ b/tc/tc_cbq.c
@@ -20,6 +20,7 @@
 #include <arpa/inet.h>
 #include <string.h>
 
+#include "utils.h"
 #include "tc_core.h"
 #include "tc_cbq.h"
 

diff --git a/tc/tc_core.c b/tc/tc_core.c
index 1bde4d51e5dc956f486c389ede1ddc122fd283f7..8eb11223eb9d9c7fe0adabd76eb994d25b0508c3 100644 (file)
--- a/tc/tc_core.c
+++ b/tc/tc_core.c
@@ -21,6 +21,7 @@
 #include <arpa/inet.h>
 #include <string.h>
 
+#include "utils.h"
 #include "tc_core.h"
 #include <linux/atm.h>
 

diff --git a/tc/tc_core.h b/tc/tc_core.h
index 1dfa9a4f773bd5b4039e35fb4b15e8fd1e964ab3..bd4a99f0d8dd2862b2294869b09c0d6b731536e6 100644 (file)
--- a/tc/tc_core.h
+++ b/tc/tc_core.h
@@ -5,8 +5,6 @@
 #include <asm/types.h>
 #include <linux/pkt_sched.h>
 
-#define TIME_UNITS_PER_SEC     1000000
-
 enum link_layer {
        LINKLAYER_UNSPEC,
        LINKLAYER_ETHERNET,

diff --git a/tc/tc_estimator.c b/tc/tc_estimator.c
index e4edfc7e98d9c002e2d78c0f6db973575d94ec82..f494b7caa44ea10732b475c7ed774a2c4ef59c30 100644 (file)
--- a/tc/tc_estimator.c
+++ b/tc/tc_estimator.c
@@ -20,6 +20,7 @@
 #include <arpa/inet.h>
 #include <string.h>
 
+#include "utils.h"
 #include "tc_core.h"
 
 int tc_setup_estimator(unsigned int A, unsigned int time_const, struct tc_estimator *est)

diff --git a/tc/tc_util.c b/tc/tc_util.c
index d7578528a31b1932bab12d793ac1798fef4ac13f..cafbe49f3ec87aad1cd2d40762e2adde5425954a 100644 (file)
--- a/tc/tc_util.c
+++ b/tc/tc_util.c
@@ -334,52 +334,6 @@ char *sprint_rate(__u64 rate, char *buf)
        return buf;
 }
 
-int get_time(unsigned int *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 *= TIME_UNITS_PER_SEC;
-               else if (strcasecmp(p, "ms") == 0 || strcasecmp(p, "msec") == 0 ||
-                        strcasecmp(p, "msecs") == 0)
-                       t *= TIME_UNITS_PER_SEC/1000;
-               else if (strcasecmp(p, "us") == 0 || strcasecmp(p, "usec") == 0 ||
-                        strcasecmp(p, "usecs") == 0)
-                       t *= TIME_UNITS_PER_SEC/1000000;
-               else
-                       return -1;
-       }
-
-       *time = t;
-       return 0;
-}
-
-
-void print_time(char *buf, int len, __u32 time)
-{
-       double tmp = time;
-
-       if (tmp >= TIME_UNITS_PER_SEC)
-               snprintf(buf, len, "%.1fs", tmp/TIME_UNITS_PER_SEC);
-       else if (tmp >= TIME_UNITS_PER_SEC/1000)
-               snprintf(buf, len, "%.1fms", tmp/(TIME_UNITS_PER_SEC/1000));
-       else
-               snprintf(buf, len, "%uus", time);
-}
-
-char *sprint_time(__u32 time, char *buf)
-{
-       print_time(buf, SPRINT_BSIZE-1, time);
-       return buf;
-}
-
 char *sprint_ticks(__u32 ticks, char *buf)
 {
        return sprint_time(tc_core_tick2time(ticks), buf);

diff --git a/tc/tc_util.h b/tc/tc_util.h
index 6632c4f9c528265a2568f94f5e17249c3f94551e..76fd986d6e4cba69450fd1238d66db1b8d7b9320 100644 (file)
--- a/tc/tc_util.h
+++ b/tc/tc_util.h
@@ -81,13 +81,11 @@ int get_rate64(__u64 *rate, const char *str);
 int get_percent_rate64(__u64 *rate, const char *str, const char *dev);
 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_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_linklayer(char *buf, int len, unsigned int linklayer);
 void print_devname(enum output_type type, int ifindex);
 
@@ -95,7 +93,6 @@ char *sprint_rate(__u64 rate, char *buf);
 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_ticks(__u32 ticks, char *buf);
 char *sprint_linklayer(unsigned int linklayer, char *buf);