From abf70ef494fd84de50c7523c86b512b3e8b3840f Mon Sep 17 00:00:00 2001 From: Dave Taht Date: Sun, 26 Aug 2018 19:42:28 -0700 Subject: [PATCH 1/3] 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 Signed-off-by: Dave Taht Signed-off-by: Neal Cardwell Signed-off-by: David Ahern --- include/utils.h | 12 ++++++ lib/utils.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++ tc/tc_cbq.c | 1 + tc/tc_core.c | 1 + tc/tc_core.h | 2 - tc/tc_estimator.c | 1 + tc/tc_util.c | 46 --------------------- tc/tc_util.h | 3 -- 8 files changed, 116 insertions(+), 51 deletions(-) diff --git a/include/utils.h b/include/utils.h index 8cb4349e..eba67b6e 100644 --- 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 02ce6772..802075fc 100644 --- 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 4cd584a9..c811456b 100644 --- a/tc/tc_cbq.c +++ b/tc/tc_cbq.c @@ -20,6 +20,7 @@ #include #include +#include "utils.h" #include "tc_core.h" #include "tc_cbq.h" diff --git a/tc/tc_core.c b/tc/tc_core.c index 1bde4d51..8eb11223 100644 --- a/tc/tc_core.c +++ b/tc/tc_core.c @@ -21,6 +21,7 @@ #include #include +#include "utils.h" #include "tc_core.h" #include diff --git a/tc/tc_core.h b/tc/tc_core.h index 1dfa9a4f..bd4a99f0 100644 --- a/tc/tc_core.h +++ b/tc/tc_core.h @@ -5,8 +5,6 @@ #include #include -#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 e4edfc7e..f494b7ca 100644 --- a/tc/tc_estimator.c +++ b/tc/tc_estimator.c @@ -20,6 +20,7 @@ #include #include +#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 d7578528..cafbe49f 100644 --- 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 6632c4f9..76fd986d 100644 --- 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); From b6268fbd580cb0eb0c3b78f51d36307f57fbf962 Mon Sep 17 00:00:00 2001 From: Dave Taht Date: Sun, 26 Aug 2018 19:42:29 -0700 Subject: [PATCH 2/3] q_netem: support delivering packets in delayed time slots Slotting is a crude approximation of the behaviors of shared media such as cable, wifi, and LTE, which gather up a bunch of packets within a varying delay window and deliver them, relative to that, nearly all at once. It works within the existing loss, duplication, jitter and delay parameters of netem. Some amount of inherent latency must be specified, regardless. The new "slot" parameter specifies a minimum and maximum delay between transmission attempts. The "bytes" and "packets" parameters can be used to limit the amount of information transferred per slot. Examples of use: tc qdisc add dev eth0 root netem delay 200us \ slot 800us 10ms bytes 64k packets 42 A more correct example, using stacked netem instances and a packet limit to emulate a tail drop wifi queue with slots and variable packet delivery, with a 200Mbit isochronous underlying rate, and 20ms path delay: tc qdisc add dev eth0 root handle 1: netem delay 20ms rate 200mbit \ limit 10000 tc qdisc add dev eth0 parent 1:1 handle 10:1 netem delay 200us \ slot 800us 10ms bytes 64k packets 42 limit 512 Signed-off-by: Yousuk Seung Signed-off-by: Dave Taht Signed-off-by: Neal Cardwell Signed-off-by: David Ahern --- man/man8/tc-netem.8 | 32 ++++++++++++++++++++++- tc/q_netem.c | 64 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 94 insertions(+), 2 deletions(-) diff --git a/man/man8/tc-netem.8 b/man/man8/tc-netem.8 index f2cd86b6..8d485b02 100644 --- a/man/man8/tc-netem.8 +++ b/man/man8/tc-netem.8 @@ -8,7 +8,8 @@ NetEm \- Network Emulator .I OPTIONS .IR OPTIONS " := [ " LIMIT " ] [ " DELAY " ] [ " LOSS \ -" ] [ " CORRUPT " ] [ " DUPLICATION " ] [ " REORDERING " ][ " RATE " ]" +" ] [ " CORRUPT " ] [ " DUPLICATION " ] [ " REORDERING " ] [ " RATE \ +" ] [ " SLOT " ]" .IR LIMIT " := " .B limit @@ -51,6 +52,14 @@ NetEm \- Network Emulator .B rate .IR RATE " [ " PACKETOVERHEAD " [ " CELLSIZE " [ " CELLOVERHEAD " ]]]]" +.IR SLOT " := " +.BR slot +.IR MIN_DELAY " [ " MAX_DELAY " ] [" +.BR packets +.IR PACKETS " ] [ " +.BR bytes +.IR BYTES " ]" + .SH DESCRIPTION NetEm is an enhancement of the Linux traffic control facilities @@ -162,6 +171,27 @@ granularity avoid a perfect shaping at a specific level. This will show up in an artificial packet compression (bursts). Another influence factor are network adapter buffers which can also add artificial delay. +.SS slot +defer delivering accumulated packets to within a slot, with each available slot +configured with a minimum delay to acquire, and an optional maximum delay. Slot +delays can be specified in nanoseconds, microseconds, milliseconds or seconds +(e.g. 800us). Values for the optional parameters +.I BYTES +will limit the number of bytes delivered per slot, and/or +.I PACKETS +will limit the number of packets delivered per slot. + +These slot options can provide a crude approximation of bursty MACs such as +DOCSIS, WiFi, and LTE. + +Note that slotting is limited by several factors: the kernel clock granularity, +as with a rate, and attempts to deliver many packets within a slot will be +smeared by the timer resolution, and by the underlying native bandwidth also. + +It is possible to combine slotting with a rate, in which case complex behaviors +where either the rate, or the slot limits on bytes or packets per slot, govern +the actual delivered rate. + .SH LIMITATIONS The main known limitation of Netem are related to timer granularity, since Linux is not a real-time operating system. diff --git a/tc/q_netem.c b/tc/q_netem.c index 9f9a9b3d..824018b2 100644 --- a/tc/q_netem.c +++ b/tc/q_netem.c @@ -40,7 +40,10 @@ static void explain(void) " [ loss gemodel PERCENT [R [1-H [1-K]]]\n" \ " [ ecn ]\n" \ " [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n" \ -" [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n"); +" [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n" \ +" [ slot MIN_DELAY [MAX_DELAY] [packets MAX_PACKETS]" \ +" [bytes MAX_BYTES]]\n" \ + ); } static void explain1(const char *arg) @@ -164,6 +167,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct tc_netem_gimodel gimodel; struct tc_netem_gemodel gemodel; struct tc_netem_rate rate = {}; + struct tc_netem_slot slot = {}; __s16 *dist_data = NULL; __u16 loss_type = NETEM_LOSS_UNSPEC; int present[__TCA_NETEM_MAX] = {}; @@ -412,6 +416,45 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, return -1; } } + } else if (matches(*argv, "slot") == 0) { + NEXT_ARG(); + present[TCA_NETEM_SLOT] = 1; + if (get_time64(&slot.min_delay, *argv)) { + explain1("slot min_delay"); + return -1; + } + if (NEXT_IS_NUMBER()) { + NEXT_ARG(); + if (get_time64(&slot.max_delay, *argv) || + slot.max_delay < slot.min_delay) { + explain1("slot max_delay"); + return -1; + } + } else { + slot.max_delay = slot.min_delay; + } + if (NEXT_ARG_OK() && + matches(*(argv+1), "packets") == 0) { + NEXT_ARG(); + if (!NEXT_ARG_OK() || + get_s32(&slot.max_packets, *(argv+1), 0)) { + explain1("slot packets"); + return -1; + } + NEXT_ARG(); + } + if (NEXT_ARG_OK() && + matches(*(argv+1), "bytes") == 0) { + unsigned int max_bytes; + NEXT_ARG(); + if (!NEXT_ARG_OK() || + get_size(&max_bytes, *(argv+1))) { + explain1("slot bytes"); + return -1; + } + slot.max_bytes = (int) max_bytes; + NEXT_ARG(); + } } else if (strcmp(*argv, "help") == 0) { explain(); return -1; @@ -472,6 +515,10 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0) return -1; + if (present[TCA_NETEM_SLOT] && + addattr_l(n, 1024, TCA_NETEM_SLOT, &slot, sizeof(slot)) < 0) + return -1; + if (loss_type != NETEM_LOSS_UNSPEC) { struct rtattr *start; @@ -526,6 +573,7 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) int *ecn = NULL; struct tc_netem_qopt qopt; const struct tc_netem_rate *rate = NULL; + const struct tc_netem_slot *slot = NULL; int len; __u64 rate64 = 0; @@ -586,6 +634,11 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) return -1; rate64 = rta_getattr_u64(tb[TCA_NETEM_RATE64]); } + if (tb[TCA_NETEM_SLOT]) { + if (RTA_PAYLOAD(tb[TCA_NETEM_SLOT]) < sizeof(*slot)) + return -1; + slot = RTA_DATA(tb[TCA_NETEM_SLOT]); + } } fprintf(f, "limit %d", qopt.limit); @@ -659,6 +712,15 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) fprintf(f, " celloverhead %d", rate->cell_overhead); } + if (slot) { + fprintf(f, " slot %s", sprint_time64(slot->min_delay, b1)); + fprintf(f, " %s", sprint_time64(slot->max_delay, b1)); + if (slot->max_packets) + fprintf(f, " packets %d", slot->max_packets); + if (slot->max_bytes) + fprintf(f, " bytes %d", slot->max_bytes); + } + if (ecn) fprintf(f, " ecn "); From 588dd51e2c77791c916d3785313928ad6a0fc89c Mon Sep 17 00:00:00 2001 From: Yousuk Seung Date: Sun, 26 Aug 2018 19:42:30 -0700 Subject: [PATCH 3/3] q_netem: slotting with non-uniform distribution Extend slotting with support for non-uniform distributions. This is similar to netem's non-uniform distribution delay feature. Syntax: slot distribution DISTRIBUTION DELAY JITTER [packets MAX_PACKETS] \ [bytes MAX_BYTES] The syntax and use of the distribution table is the same as in the non-uniform distribution delay feature. A file DISTRIBUTION must be present in TC_LIB_DIR (e.g. /usr/lib/tc) containing numbers scaled by NETEM_DIST_SCALE. A random value x is selected from the table and it takes DELAY + ( x * JITTER ) as delay. Correlation between values is not supported. Examples: Normal distribution delay with mean = 800us and stdev = 100us. > tc qdisc add dev eth0 root netem slot distribution normal \ 800us 100us Optionally set the max slot size in bytes and/or packets. > tc qdisc add dev eth0 root netem slot distribution normal \ 800us 100us bytes 64k packets 42 Signed-off-by: Yousuk Seung Signed-off-by: Neal Cardwell Signed-off-by: Dave Taht Signed-off-by: David Ahern --- man/man8/tc-netem.8 | 20 ++++++++---- tc/q_netem.c | 77 +++++++++++++++++++++++++++++++++++++-------- 2 files changed, 78 insertions(+), 19 deletions(-) diff --git a/man/man8/tc-netem.8 b/man/man8/tc-netem.8 index 8d485b02..111109cf 100644 --- a/man/man8/tc-netem.8 +++ b/man/man8/tc-netem.8 @@ -53,9 +53,13 @@ NetEm \- Network Emulator .IR RATE " [ " PACKETOVERHEAD " [ " CELLSIZE " [ " CELLOVERHEAD " ]]]]" .IR SLOT " := " -.BR slot -.IR MIN_DELAY " [ " MAX_DELAY " ] [" -.BR packets +.BR slot " { " +.IR MIN_DELAY " [ " MAX_DELAY " ] |" +.br +.RB " " distribution " { "uniform " | " normal " | " pareto " | " paretonormal " | " +.IR FILE " } " DELAY " " JITTER " } " +.br +.RB " [ " packets .IR PACKETS " ] [ " .BR bytes .IR BYTES " ]" @@ -172,9 +176,13 @@ an artificial packet compression (bursts). Another influence factor are network adapter buffers which can also add artificial delay. .SS slot -defer delivering accumulated packets to within a slot, with each available slot -configured with a minimum delay to acquire, and an optional maximum delay. Slot -delays can be specified in nanoseconds, microseconds, milliseconds or seconds +defer delivering accumulated packets to within a slot. Each available slot can be +configured with a minimum delay to acquire, and an optional maximum delay. +Alternatively it can be configured with the distribution similar to +.BR distribution +for +.BR delay +option. Slot delays can be specified in nanoseconds, microseconds, milliseconds or seconds (e.g. 800us). Values for the optional parameters .I BYTES will limit the number of bytes delivered per slot, and/or diff --git a/tc/q_netem.c b/tc/q_netem.c index 824018b2..6e0e8a8c 100644 --- a/tc/q_netem.c +++ b/tc/q_netem.c @@ -43,7 +43,9 @@ static void explain(void) " [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n" \ " [ slot MIN_DELAY [MAX_DELAY] [packets MAX_PACKETS]" \ " [bytes MAX_BYTES]]\n" \ - ); +" [ slot distribution" \ +" {uniform|normal|pareto|paretonormal|custom} DELAY JITTER" \ +" [packets MAX_PACKETS] [bytes MAX_BYTES]]\n"); } static void explain1(const char *arg) @@ -159,6 +161,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n, const char *dev) { int dist_size = 0; + int slot_dist_size = 0; struct rtattr *tail; struct tc_netem_qopt opt = { .limit = 1000 }; struct tc_netem_corr cor = {}; @@ -169,6 +172,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct tc_netem_rate rate = {}; struct tc_netem_slot slot = {}; __s16 *dist_data = NULL; + __s16 *slot_dist_data = NULL; __u16 loss_type = NETEM_LOSS_UNSPEC; int present[__TCA_NETEM_MAX] = {}; __u64 rate64 = 0; @@ -417,21 +421,55 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, } } } else if (matches(*argv, "slot") == 0) { - NEXT_ARG(); - present[TCA_NETEM_SLOT] = 1; - if (get_time64(&slot.min_delay, *argv)) { - explain1("slot min_delay"); - return -1; - } if (NEXT_IS_NUMBER()) { NEXT_ARG(); - if (get_time64(&slot.max_delay, *argv) || - slot.max_delay < slot.min_delay) { - explain1("slot max_delay"); + present[TCA_NETEM_SLOT] = 1; + if (get_time64(&slot.min_delay, *argv)) { + explain1("slot min_delay"); return -1; } + if (NEXT_IS_NUMBER()) { + NEXT_ARG(); + if (get_time64(&slot.max_delay, *argv) || + slot.max_delay < slot.min_delay) { + explain1("slot max_delay"); + return -1; + } + } else { + slot.max_delay = slot.min_delay; + } } else { - slot.max_delay = slot.min_delay; + NEXT_ARG(); + if (strcmp(*argv, "distribution") == 0) { + present[TCA_NETEM_SLOT] = 1; + NEXT_ARG(); + slot_dist_data = calloc(sizeof(slot_dist_data[0]), MAX_DIST); + if (!slot_dist_data) + return -1; + slot_dist_size = get_distribution(*argv, slot_dist_data, MAX_DIST); + if (slot_dist_size <= 0) { + free(slot_dist_data); + return -1; + } + NEXT_ARG(); + if (get_time64(&slot.dist_delay, *argv)) { + explain1("slot delay"); + return -1; + } + NEXT_ARG(); + if (get_time64(&slot.dist_jitter, *argv)) { + explain1("slot jitter"); + return -1; + } + if (slot.dist_jitter <= 0) { + fprintf(stderr, "Non-positive jitter\n"); + return -1; + } + } else { + fprintf(stderr, "Unknown slot parameter: %s\n", + *argv); + return -1; + } } if (NEXT_ARG_OK() && matches(*(argv+1), "packets") == 0) { @@ -559,6 +597,14 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, return -1; free(dist_data); } + + if (slot_dist_data) { + if (addattr_l(n, MAX_DIST * sizeof(slot_dist_data[0]), + TCA_NETEM_SLOT_DIST, + slot_dist_data, slot_dist_size * sizeof(slot_dist_data[0])) < 0) + return -1; + free(slot_dist_data); + } tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; return 0; } @@ -713,8 +759,13 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) } if (slot) { - fprintf(f, " slot %s", sprint_time64(slot->min_delay, b1)); - fprintf(f, " %s", sprint_time64(slot->max_delay, b1)); + if (slot->dist_jitter > 0) { + fprintf(f, " slot distribution %s", sprint_time64(slot->dist_delay, b1)); + fprintf(f, " %s", sprint_time64(slot->dist_jitter, b1)); + } else { + fprintf(f, " slot %s", sprint_time64(slot->min_delay, b1)); + fprintf(f, " %s", sprint_time64(slot->max_delay, b1)); + } if (slot->max_packets) fprintf(f, " packets %d", slot->max_packets); if (slot->max_bytes)