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Commit f98a65e0 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
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[PKT_SCHED]: Update for netem scheduler. 

This is a third revision of the netem extensions which provides
	* packet duplication
	* correlated random number
	* loading distribution table

The API is backwards compatible and now uses nested elements to allow
for easier future changes.
Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83856742
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Showing with 243 additions and 592 deletions
include/linux/pkt_sched.h
View file @ f98a65e0
......@@ -402,6 +402,16 @@ enum {
#define TCA_ATM_MAX TCA_ATM_STATE
/* Network emulator */
enum
{
TCA_NETEM_UNSPEC,
TCA_NETEM_CORR,
TCA_NETEM_DELAY_DIST,
};
#define TCA_NETEM_MAX TCA_NETEM_DELAY_DIST
struct tc_netem_qopt
{
__u32 latency; /* added delay (us) */
......@@ -411,4 +421,19 @@ struct tc_netem_qopt
__u32 duplicate; /* random packet dup (0=none ~0=100%) */
__u32 jitter; /* random jitter in latency (us) */
};
struct tc_netem_corr
{
__u32 delay_corr; /* delay correlation */
__u32 loss_corr; /* packet loss correlation */
__u32 dup_corr; /* duplicate correlation */
};
struct tc_netem_dist
{
__u32 size; /* table size */
__u32 factor; /* table scaling factor */
__s16 data[0]; /* distribution table values */
};
#endif
net/sched/sch_netem.c
View file @ f98a65e0
......@@ -6,6 +6,9 @@
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Many of the algorithms and ideas for this came from
* NIST Net which is not copyrighted.
*
* Authors: Stephen Hemminger <shemminger@osdl.org>
* Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
*/
......@@ -22,11 +25,31 @@
#include <net/pkt_sched.h>
/* Network emulator
*
* This scheduler can alters spacing and order
* Similar to NISTnet and BSD Dummynet.
*/
/* Network Emulation Queuing algorithm.
====================================
Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based
Network Emulation Tool
[2] Luigi Rizzo, DummyNet for FreeBSD
----------------------------------------------------------------
This started out as a simple way to delay outgoing packets to
test TCP but has grown to include most of the functionality
of a full blown network emulator like NISTnet. It can delay
packets and add random jitter (and correlation). The random
distribution can be loaded from a table as well to provide
normal, Pareto, or experimental curves. Packet loss,
duplication, and reordering can also be emulated.
This qdisc does not do classification that can be handled in
layering other disciplines. It does not need to do bandwidth
control either since that can be handled by using token
bucket or other rate control.
The simulator is limited by the Linux timer resolution
and will create packet bursts on the HZ boundary (1ms).
*/
struct netem_sched_data {
struct Qdisc *qdisc;
......@@ -39,6 +62,18 @@ struct netem_sched_data {
u32 counter;
u32 gap;
u32 jitter;
u32 duplicate;
struct crndstate {
unsigned long last;
unsigned long rho;
} delay_cor, loss_cor, dup_cor;
struct disttable {
u32 size;
u32 factor;
s16 table[0];
} *delay_dist;
};
/* Time stamp put into socket buffer control block */
......@@ -46,576 +81,113 @@ struct netem_skb_cb {
psched_time_t time_to_send;
};
/* This is the distribution table for the normal distribution produced
* with NISTnet tools.
* The entries represent a scaled inverse of the cumulative distribution
* function.
/* init_crandom - initialize correlated random number generator
* Use entropy source for initial seed.
*/
#define TABLESIZE 2048
#define TABLEFACTOR 8192
static const short disttable[TABLESIZE] = {
-31473, -26739, -25226, -24269,
-23560, -22993, -22518, -22109,
-21749, -21426, -21133, -20865,
-20618, -20389, -20174, -19972,
-19782, -19601, -19430, -19267,
-19112, -18962, -18819, -18681,
-18549, -18421, -18298, -18178,
-18062, -17950, -17841, -17735,
-17632, -17532, -17434, -17339,
-17245, -17155, -17066, -16979,
-16894, -16811, -16729, -16649,
-16571, -16494, -16419, -16345,
-16272, -16201, -16130, -16061,
-15993, -15926, -15861, -15796,
-15732, -15669, -15607, -15546,
-15486, -15426, -15368, -15310,
-15253, -15196, -15140, -15086,
-15031, -14977, -14925, -14872,
-14821, -14769, -14719, -14669,
-14619, -14570, -14522, -14473,
-14426, -14379, -14332, -14286,
-14241, -14196, -14150, -14106,
-14062, -14019, -13976, -13933,
-13890, -13848, -13807, -13765,
-13724, -13684, -13643, -13604,
-13564, -13525, -13486, -13447,
-13408, -13370, -13332, -13295,
-13258, -13221, -13184, -13147,
-13111, -13075, -13040, -13004,
-12969, -12934, -12899, -12865,
-12830, -12796, -12762, -12729,
-12695, -12662, -12629, -12596,
-12564, -12531, -12499, -12467,
-12435, -12404, -12372, -12341,
-12310, -12279, -12248, -12218,
-12187, -12157, -12127, -12097,
-12067, -12038, -12008, -11979,
-11950, -11921, -11892, -11863,
-11835, -11806, -11778, -11750,
-11722, -11694, -11666, -11639,
-11611, -11584, -11557, -11530,
-11503, -11476, -11450, -11423,
-11396, -11370, -11344, -11318,
-11292, -11266, -11240, -11214,
-11189, -11164, -11138, -11113,
-11088, -11063, -11038, -11013,
-10988, -10964, -10939, -10915,
-10891, -10866, -10843, -10818,
-10794, -10770, -10747, -10723,
-10700, -10676, -10652, -10630,
-10606, -10583, -10560, -10537,
-10514, -10491, -10469, -10446,
-10424, -10401, -10378, -10356,
-10334, -10312, -10290, -10267,
-10246, -10224, -10202, -10180,
-10158, -10137, -10115, -10094,
-10072, -10051, -10030, -10009,
-9988, -9967, -9945, -9925,
-9904, -9883, -9862, -9842,
-9821, -9800, -9780, -9760,
-9739, -9719, -9699, -9678,
-9658, -9638, -9618, -9599,
-9578, -9559, -9539, -9519,
-9499, -9480, -9461, -9441,
-9422, -9402, -9383, -9363,
-9344, -9325, -9306, -9287,
-9268, -9249, -9230, -9211,
-9192, -9173, -9155, -9136,
-9117, -9098, -9080, -9062,
-9043, -9025, -9006, -8988,
-8970, -8951, -8933, -8915,
-8897, -8879, -8861, -8843,
-8825, -8807, -8789, -8772,
-8754, -8736, -8718, -8701,
-8683, -8665, -8648, -8630,
-8613, -8595, -8578, -8561,
-8543, -8526, -8509, -8492,
-8475, -8458, -8441, -8423,
-8407, -8390, -8373, -8356,
-8339, -8322, -8305, -8289,
-8272, -8255, -8239, -8222,
-8206, -8189, -8172, -8156,
-8140, -8123, -8107, -8090,
-8074, -8058, -8042, -8025,
-8009, -7993, -7977, -7961,
-7945, -7929, -7913, -7897,
-7881, -7865, -7849, -7833,
-7817, -7802, -7786, -7770,
-7754, -7739, -7723, -7707,
-7692, -7676, -7661, -7645,
-7630, -7614, -7599, -7583,
-7568, -7553, -7537, -7522,
-7507, -7492, -7476, -7461,
-7446, -7431, -7416, -7401,
-7385, -7370, -7356, -7340,
-7325, -7311, -7296, -7281,
-7266, -7251, -7236, -7221,
-7207, -7192, -7177, -7162,
-7148, -7133, -7118, -7104,
-7089, -7075, -7060, -7046,
-7031, -7016, -7002, -6988,
-6973, -6959, -6944, -6930,
-6916, -6901, -6887, -6873,
-6859, -6844, -6830, -6816,
-6802, -6788, -6774, -6760,
-6746, -6731, -6717, -6704,
-6690, -6675, -6661, -6647,
-6633, -6620, -6606, -6592,
-6578, -6564, -6550, -6537,
-6523, -6509, -6495, -6482,
-6468, -6454, -6441, -6427,
-6413, -6400, -6386, -6373,
-6359, -6346, -6332, -6318,
-6305, -6291, -6278, -6264,
-6251, -6238, -6224, -6211,
-6198, -6184, -6171, -6158,
-6144, -6131, -6118, -6105,
-6091, -6078, -6065, -6052,
-6039, -6025, -6012, -5999,
-5986, -5973, -5960, -5947,
-5934, -5921, -5908, -5895,
-5882, -5869, -5856, -5843,
-5830, -5817, -5804, -5791,
-5779, -5766, -5753, -5740,
-5727, -5714, -5702, -5689,
-5676, -5663, -5650, -5638,
-5625, -5612, -5600, -5587,
-5575, -5562, -5549, -5537,
-5524, -5512, -5499, -5486,
-5474, -5461, -5449, -5436,
-5424, -5411, -5399, -5386,
-5374, -5362, -5349, -5337,
-5324, -5312, -5299, -5287,
-5275, -5263, -5250, -5238,
-5226, -5213, -5201, -5189,
-5177, -5164, -5152, -5140,
-5128, -5115, -5103, -5091,
-5079, -5067, -5055, -5043,
-5030, -5018, -5006, -4994,
-4982, -4970, -4958, -4946,
-4934, -4922, -4910, -4898,
-4886, -4874, -4862, -4850,
-4838, -4826, -4814, -4803,
-4791, -4778, -4767, -4755,
-4743, -4731, -4719, -4708,
-4696, -4684, -4672, -4660,
-4649, -4637, -4625, -4613,
-4601, -4590, -4578, -4566,
-4554, -4543, -4531, -4520,
-4508, -4496, -4484, -4473,
-4461, -4449, -4438, -4427,
-4415, -4403, -4392, -4380,
-4368, -4357, -4345, -4334,
-4322, -4311, -4299, -4288,
-4276, -4265, -4253, -4242,
-4230, -4219, -4207, -4196,
-4184, -4173, -4162, -4150,
-4139, -4128, -4116, -4105,
-4094, -4082, -4071, -4060,
-4048, -4037, -4026, -4014,
-4003, -3992, -3980, -3969,
-3958, -3946, -3935, -3924,
-3913, -3901, -3890, -3879,
-3868, -3857, -3845, -3834,
-3823, -3812, -3801, -3790,
-3779, -3767, -3756, -3745,
-3734, -3723, -3712, -3700,
-3689, -3678, -3667, -3656,
-3645, -3634, -3623, -3612,
-3601, -3590, -3579, -3568,
-3557, -3545, -3535, -3524,
-3513, -3502, -3491, -3480,
-3469, -3458, -3447, -3436,
-3425, -3414, -3403, -3392,
-3381, -3370, -3360, -3348,
-3337, -3327, -3316, -3305,
-3294, -3283, -3272, -3262,
-3251, -3240, -3229, -3218,
-3207, -3197, -3185, -3175,
-3164, -3153, -3142, -3132,
-3121, -3110, -3099, -3088,
-3078, -3067, -3056, -3045,
-3035, -3024, -3013, -3003,
-2992, -2981, -2970, -2960,
-2949, -2938, -2928, -2917,
-2906, -2895, -2885, -2874,
-2864, -2853, -2842, -2832,
-2821, -2810, -2800, -2789,
-2778, -2768, -2757, -2747,
-2736, -2725, -2715, -2704,
-2694, -2683, -2673, -2662,
-2651, -2641, -2630, -2620,
-2609, -2599, -2588, -2578,
-2567, -2556, -2546, -2535,
-2525, -2515, -2504, -2493,
-2483, -2472, -2462, -2451,
-2441, -2431, -2420, -2410,
-2399, -2389, -2378, -2367,
-2357, -2347, -2336, -2326,
-2315, -2305, -2295, -2284,
-2274, -2263, -2253, -2243,
-2232, -2222, -2211, -2201,
-2191, -2180, -2170, -2159,
-2149, -2139, -2128, -2118,
-2107, -2097, -2087, -2076,
-2066, -2056, -2046, -2035,
-2025, -2014, -2004, -1994,
-1983, -1973, -1963, -1953,
-1942, -1932, -1921, -1911,
-1901, -1891, -1880, -1870,
-1860, -1849, -1839, -1829,
-1819, -1808, -1798, -1788,
-1778, -1767, -1757, -1747,
-1736, -1726, -1716, -1706,
-1695, -1685, -1675, -1665,
-1654, -1644, -1634, -1624,
-1613, -1603, -1593, -1583,
-1573, -1563, -1552, -1542,
-1532, -1522, -1511, -1501,
-1491, -1481, -1471, -1461,
-1450, -1440, -1430, -1420,
-1409, -1400, -1389, -1379,
-1369, -1359, -1348, -1339,
-1328, -1318, -1308, -1298,
-1288, -1278, -1267, -1257,
-1247, -1237, -1227, -1217,
-1207, -1196, -1186, -1176,
-1166, -1156, -1146, -1135,
-1126, -1115, -1105, -1095,
-1085, -1075, -1065, -1055,
-1044, -1034, -1024, -1014,
-1004, -994, -984, -974,
-964, -954, -944, -933,
-923, -913, -903, -893,
-883, -873, -863, -853,
-843, -833, -822, -812,
-802, -792, -782, -772,
-762, -752, -742, -732,
-722, -712, -702, -691,
-682, -671, -662, -651,
-641, -631, -621, -611,
-601, -591, -581, -571,
-561, -551, -541, -531,
-521, -511, -501, -491,
-480, -471, -460, -451,
-440, -430, -420, -410,
-400, -390, -380, -370,
-360, -350, -340, -330,
-320, -310, -300, -290,
-280, -270, -260, -250,
-240, -230, -220, -210,
-199, -190, -179, -170,
-159, -150, -139, -129,
-119, -109, -99, -89,
-79, -69, -59, -49,
-39, -29, -19, -9,
1, 11, 21, 31,
41, 51, 61, 71,
81, 91, 101, 111,
121, 131, 141, 152,
161, 172, 181, 192,
202, 212, 222, 232,
242, 252, 262, 272,
282, 292, 302, 312,
322, 332, 342, 352,
362, 372, 382, 392,
402, 412, 422, 433,
442, 453, 462, 473,
483, 493, 503, 513,
523, 533, 543, 553,
563, 573, 583, 593,
603, 613, 623, 633,
643, 653, 664, 673,
684, 694, 704, 714,
724, 734, 744, 754,
764, 774, 784, 794,
804, 815, 825, 835,
845, 855, 865, 875,
885, 895, 905, 915,
925, 936, 946, 956,
966, 976, 986, 996,
1006, 1016, 1026, 1037,
1047, 1057, 1067, 1077,
1087, 1097, 1107, 1117,
1128, 1138, 1148, 1158,
1168, 1178, 1188, 1198,
1209, 1219, 1229, 1239,
1249, 1259, 1269, 1280,
1290, 1300, 1310, 1320,
1330, 1341, 1351, 1361,
1371, 1381, 1391, 1402,
1412, 1422, 1432, 1442,
1452, 1463, 1473, 1483,
1493, 1503, 1513, 1524,
1534, 1544, 1554, 1565,
1575, 1585, 1595, 1606,
1616, 1626, 1636, 1647,
1656, 1667, 1677, 1687,
1697, 1708, 1718, 1729,
1739, 1749, 1759, 1769,
1780, 1790, 1800, 1810,
1821, 1831, 1841, 1851,
1862, 1872, 1883, 1893,
1903, 1913, 1923, 1934,
1944, 1955, 1965, 1975,
1985, 1996, 2006, 2016,
2027, 2037, 2048, 2058,
2068, 2079, 2089, 2099,
2110, 2120, 2130, 2141,
2151, 2161, 2172, 2182,
2193, 2203, 2213, 2224,
2234, 2245, 2255, 2265,
2276, 2286, 2297, 2307,
2318, 2328, 2338, 2349,
2359, 2370, 2380, 2391,
2401, 2412, 2422, 2433,
2443, 2454, 2464, 2475,
2485, 2496, 2506, 2517,
2527, 2537, 2548, 2559,
2569, 2580, 2590, 2601,
2612, 2622, 2632, 2643,
2654, 2664, 2675, 2685,
2696, 2707, 2717, 2728,
2738, 2749, 2759, 2770,
2781, 2791, 2802, 2813,
2823, 2834, 2845, 2855,
2866, 2877, 2887, 2898,
2909, 2919, 2930, 2941,
2951, 2962, 2973, 2984,
2994, 3005, 3015, 3027,
3037, 3048, 3058, 3069,
3080, 3091, 3101, 3113,
3123, 3134, 3145, 3156,
3166, 3177, 3188, 3199,
3210, 3220, 3231, 3242,
3253, 3264, 3275, 3285,
3296, 3307, 3318, 3329,
3340, 3351, 3362, 3373,
3384, 3394, 3405, 3416,
3427, 3438, 3449, 3460,
3471, 3482, 3493, 3504,
3515, 3526, 3537, 3548,
3559, 3570, 3581, 3592,
3603, 3614, 3625, 3636,
3647, 3659, 3670, 3681,
3692, 3703, 3714, 3725,
3736, 3747, 3758, 3770,
3781, 3792, 3803, 3814,
3825, 3837, 3848, 3859,
3870, 3881, 3893, 3904,
3915, 3926, 3937, 3949,
3960, 3971, 3983, 3994,
4005, 4017, 4028, 4039,
4051, 4062, 4073, 4085,
4096, 4107, 4119, 4130,
4141, 4153, 4164, 4175,
4187, 4198, 4210, 4221,
4233, 4244, 4256, 4267,
4279, 4290, 4302, 4313,
4325, 4336, 4348, 4359,
4371, 4382, 4394, 4406,
4417, 4429, 4440, 4452,
4464, 4475, 4487, 4499,
4510, 4522, 4533, 4545,
4557, 4569, 4581, 4592,
4604, 4616, 4627, 4639,
4651, 4663, 4674, 4686,
4698, 4710, 4722, 4734,
4746, 4758, 4769, 4781,
4793, 4805, 4817, 4829,
4841, 4853, 4865, 4877,
4889, 4900, 4913, 4925,
4936, 4949, 4961, 4973,
4985, 4997, 5009, 5021,
5033, 5045, 5057, 5070,
5081, 5094, 5106, 5118,
5130, 5143, 5155, 5167,
5179, 5191, 5204, 5216,
5228, 5240, 5253, 5265,
5278, 5290, 5302, 5315,
5327, 5340, 5352, 5364,
5377, 5389, 5401, 5414,
5426, 5439, 5451, 5464,
5476, 5489, 5502, 5514,
5527, 5539, 5552, 5564,
5577, 5590, 5603, 5615,
5628, 5641, 5653, 5666,
5679, 5691, 5704, 5717,
5730, 5743, 5756, 5768,
5781, 5794, 5807, 5820,
5833, 5846, 5859, 5872,
5885, 5897, 5911, 5924,
5937, 5950, 5963, 5976,
5989, 6002, 6015, 6028,
6042, 6055, 6068, 6081,
6094, 6108, 6121, 6134,
6147, 6160, 6174, 6187,
6201, 6214, 6227, 6241,
6254, 6267, 6281, 6294,
6308, 6321, 6335, 6348,
6362, 6375, 6389, 6403,
6416, 6430, 6443, 6457,
6471, 6485, 6498, 6512,
6526, 6540, 6554, 6567,
6581, 6595, 6609, 6623,
6637, 6651, 6665, 6679,
6692, 6706, 6721, 6735,
6749, 6763, 6777, 6791,
6805, 6819, 6833, 6848,
6862, 6876, 6890, 6905,
6919, 6933, 6948, 6962,
6976, 6991, 7005, 7020,
7034, 7049, 7064, 7078,
7093, 7107, 7122, 7136,
7151, 7166, 7180, 7195,
7210, 7225, 7240, 7254,
7269, 7284, 7299, 7314,
7329, 7344, 7359, 7374,
7389, 7404, 7419, 7434,
7449, 7465, 7480, 7495,
7510, 7526, 7541, 7556,
7571, 7587, 7602, 7618,
7633, 7648, 7664, 7680,
7695, 7711, 7726, 7742,
7758, 7773, 7789, 7805,
7821, 7836, 7852, 7868,
7884, 7900, 7916, 7932,
7948, 7964, 7981, 7997,
8013, 8029, 8045, 8061,
8078, 8094, 8110, 8127,
8143, 8160, 8176, 8193,
8209, 8226, 8242, 8259,
8276, 8292, 8309, 8326,
8343, 8360, 8377, 8394,
8410, 8428, 8444, 8462,
8479, 8496, 8513, 8530,
8548, 8565, 8582, 8600,
8617, 8634, 8652, 8670,
8687, 8704, 8722, 8740,
8758, 8775, 8793, 8811,
8829, 8847, 8865, 8883,
8901, 8919, 8937, 8955,
8974, 8992, 9010, 9029,
9047, 9066, 9084, 9103,
9121, 9140, 9159, 9177,
9196, 9215, 9234, 9253,
9272, 9291, 9310, 9329,
9349, 9368, 9387, 9406,
9426, 9445, 9465, 9484,
9504, 9524, 9544, 9563,
9583, 9603, 9623, 9643,
9663, 9683, 9703, 9723,
9744, 9764, 9785, 9805,
9826, 9846, 9867, 9888,
9909, 9930, 9950, 9971,
9993, 10013, 10035, 10056,
10077, 10099, 10120, 10142,
10163, 10185, 10207, 10229,
10251, 10273, 10294, 10317,
10339, 10361, 10384, 10406,
10428, 10451, 10474, 10496,
10519, 10542, 10565, 10588,
10612, 10635, 10658, 10682,
10705, 10729, 10752, 10776,
10800, 10824, 10848, 10872,
10896, 10921, 10945, 10969,
10994, 11019, 11044, 11069,
11094, 11119, 11144, 11169,
11195, 11221, 11246, 11272,
11298, 11324, 11350, 11376,
11402, 11429, 11456, 11482,
11509, 11536, 11563, 11590,
11618, 11645, 11673, 11701,
11728, 11756, 11785, 11813,
11842, 11870, 11899, 11928,
11957, 11986, 12015, 12045,
12074, 12104, 12134, 12164,
12194, 12225, 12255, 12286,
12317, 12348, 12380, 12411,
12443, 12475, 12507, 12539,
12571, 12604, 12637, 12670,
12703, 12737, 12771, 12804,
12839, 12873, 12907, 12942,
12977, 13013, 13048, 13084,
13120, 13156, 13192, 13229,
13267, 13304, 13341, 13379,
13418, 13456, 13495, 13534,
13573, 13613, 13653, 13693,
13734, 13775, 13817, 13858,
13901, 13943, 13986, 14029,
14073, 14117, 14162, 14206,
14252, 14297, 14343, 14390,
14437, 14485, 14533, 14582,
14631, 14680, 14731, 14782,
14833, 14885, 14937, 14991,
15044, 15099, 15154, 15210,
15266, 15324, 15382, 15441,
15500, 15561, 15622, 15684,
15747, 15811, 15877, 15943,
16010, 16078, 16148, 16218,
16290, 16363, 16437, 16513,
16590, 16669, 16749, 16831,
16915, 17000, 17088, 17177,
17268, 17362, 17458, 17556,
17657, 17761, 17868, 17977,
18090, 18207, 18328, 18452,
18581, 18715, 18854, 18998,
19149, 19307, 19472, 19645,
19828, 20021, 20226, 20444,
20678, 20930, 21204, 21503,
21835, 22206, 22630, 23124,
23721, 24478, 25529, 27316,
};
static void init_crandom(struct crndstate *state, unsigned long rho)
{
state->rho = rho;
state->last = net_random();
}
/* get_crandom - correlated random number generator
* Next number depends on last value.
* rho is scaled to avoid floating point.
*/
static unsigned long get_crandom(struct crndstate *state)
{
u64 value, rho;
unsigned long answer;
if (state->rho == 0) /* no correllation */
return net_random();
value = net_random();
rho = (u64)state->rho + 1;
answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32;
state->last = answer;
return answer;
}
/* tabledist - return a pseudo-randomly distributed value with mean mu and
* std deviation sigma. Uses table lookup to approximate the desired
* distribution, and a uniformly-distributed pseudo-random source.
*/
static inline int tabledist(int mu, int sigma)
static unsigned long tabledist(int mu, int sigma,
struct crndstate *state,
const struct disttable *dist)
{
int x;
int index;
int sigmamod, sigmadiv;
int t, x, factor;
unsigned long rnd;
if (sigma == 0)
return mu;
index = (net_random() & (TABLESIZE-1));
sigmamod = sigma%TABLEFACTOR;
sigmadiv = sigma/TABLEFACTOR;
x = sigmamod*disttable[index];
rnd = get_crandom(state);
/* default uniform distribution */
if (dist == NULL)
return (rnd % (2*sigma)) - sigma + mu;
factor = dist->factor;
t = dist->table[rnd % dist->size];
x = (sigma % factor) * t;
if (x >= 0)
x += TABLEFACTOR/2;
x += factor/2;
else
x -= TABLEFACTOR/2;
x -= factor/2;
x /= TABLEFACTOR;
x += sigmadiv*disttable[index];
x += mu;
return x;
return (x + (sigma / factor) * t) / factor + mu;
}
/* Enqueue packets with underlying discipline (fifo)
* but mark them with current time first.
*/
static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
/* Put skb in the private delayed queue. */
static int delay_skb(struct Qdisc *sch, struct sk_buff *skb)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
psched_time_t now;
long delay;
PSCHED_GET_TIME(now);
PSCHED_TADD2(now, tabledist(q->latency, q->jitter,
&q->delay_cor, q->delay_dist),
cb->time_to_send);
/* Always queue at tail to keep packets in order */
if (likely(q->delayed.qlen < q->limit)) {
__skb_queue_tail(&q->delayed, skb);
sch->q.qlen++;
sch->stats.bytes += skb->len;
sch->stats.packets++;
return NET_XMIT_SUCCESS;
}
sch->stats.drops++;
kfree_skb(skb);
return NET_XMIT_DROP;
}
static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
pr_debug("netem_enqueue skb=%p @%lu\n", skb, jiffies);
/* Random packet drop 0 => none, ~0 => all */
if (q->loss && q->loss >= net_random()) {
if (q->loss && q->loss >= get_crandom(&q->loss_cor)) {
pr_debug("netem_enqueue: random loss\n");
sch->stats.drops++;
return 0; /* lie about loss so TCP doesn't know */
}
/* Random duplication */
if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
pr_debug("netem_enqueue: dup %p\n", skb2);
if (skb2)
delay_skb(sch, skb2);
}
/* If doing simple delay then gap == 0 so all packets
* go into the delayed holding queue
......@@ -634,26 +206,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
q->counter = 0;
PSCHED_GET_TIME(now);
if (q->jitter)
delay = tabledist(q->latency, q->jitter);
else
delay = q->latency;
PSCHED_TADD2(now, delay, cb->time_to_send);
/* Always queue at tail to keep packets in order */
if (likely(q->delayed.qlen < q->limit)) {
__skb_queue_tail(&q->delayed, skb);
sch->q.qlen++;
sch->stats.bytes += skb->len;
sch->stats.packets++;
return 0;
}
sch->stats.drops++;
kfree_skb(skb);
return NET_XMIT_DROP;
return delay_skb(sch, skb);
}
/* Requeue packets but don't change time stamp */
......@@ -752,39 +305,94 @@ static int set_fifo_limit(struct Qdisc *q, int limit)
return ret;
}
static int netem_change(struct Qdisc *sch, struct rtattr *opt)
static int get_dist_table(struct Qdisc *sch, const struct rtattr *attr)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct tc_netem_qopt *qopt = RTA_DATA(opt);
struct Qdisc *child;
int ret;
const struct tc_netem_dist *dist = RTA_DATA(attr);
struct disttable *d;
int i;
if (RTA_PAYLOAD(attr) < sizeof(*dist) ||
dist->factor < 2 || dist->factor > 1<<16 || dist->size > 65536)
return -EINVAL;
d = kmalloc(sizeof(*d) + dist->size*sizeof(d->table[0]), GFP_KERNEL);
if (!d)
return -ENOMEM;
d->size = dist->size;
d->factor = dist->factor;
for (i = 0; i < dist->size; i++)
d->table[i] = dist->data[i];
spin_lock_bh(&sch->dev->queue_lock);
d = xchg(&q->delay_dist, d);
spin_unlock_bh(&sch->dev->queue_lock);
kfree(d);
return 0;
}
if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
static int get_correlation(struct Qdisc *sch, const struct rtattr *attr)
{
struct netem_sched_data *q = qdisc_priv(sch);
const struct tc_netem_corr *c = RTA_DATA(attr);
if (RTA_PAYLOAD(attr) != sizeof(*c))
return -EINVAL;
child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
if (!child)
init_crandom(&q->delay_cor, c->delay_corr);
init_crandom(&q->loss_cor, c->loss_corr);
init_crandom(&q->dup_cor, c->dup_corr);
return 0;
}
static int netem_change(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct tc_netem_qopt *qopt;
int ret;
if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
return -EINVAL;
ret = set_fifo_limit(child, qopt->limit);
qopt = RTA_DATA(opt);
ret = set_fifo_limit(q->qdisc, qopt->limit);
if (ret) {
qdisc_destroy(child);
pr_debug("netem: can't set fifo limit\n");
return ret;
}
sch_tree_lock(sch);
if (child) {
child = xchg(&q->qdisc, child);
if (child != &noop_qdisc)
qdisc_destroy(child);
q->latency = qopt->latency;
q->jitter = qopt->jitter;
q->limit = qopt->limit;
q->gap = qopt->gap;
q->loss = qopt->loss;
q->duplicate = qopt->duplicate;
/* Handle nested options after initial queue options.
* Should have put all options in nested format but too late now.
*/
if (RTA_PAYLOAD(opt) > sizeof(*qopt)) {
struct rtattr *tb[TCA_NETEM_MAX];
if (rtattr_parse(tb, TCA_NETEM_MAX,
RTA_DATA(opt) + sizeof(*qopt),
RTA_PAYLOAD(opt) - sizeof(*qopt)))
return -EINVAL;
if (tb[TCA_NETEM_CORR-1]) {
ret = get_correlation(sch, tb[TCA_NETEM_CORR-1]);
if (ret)
return ret;
}
sch_tree_unlock(sch);
if (tb[TCA_NETEM_DELAY_DIST-1]) {
ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST-1]);
if (ret)
return ret;
}
}
return 0;
}
......@@ -792,19 +400,29 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt)
static int netem_init(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
int ret;
if (!opt)
return -EINVAL;
skb_queue_head_init(&q->delayed);
q->qdisc = &noop_qdisc;
init_timer(&q->timer);
q->timer.function = netem_watchdog;
q->timer.data = (unsigned long) sch;
q->counter = 0;
return netem_change(sch, opt);
q->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
if (!q->qdisc) {
pr_debug("netem: qdisc create failed\n");
return -ENOMEM;
}
ret = netem_change(sch, opt);
if (ret) {
pr_debug("netem: change failed\n");
qdisc_destroy(q->qdisc);
}
return ret;
}
static void netem_destroy(struct Qdisc *sch)
......@@ -817,18 +435,26 @@ static void netem_destroy(struct Qdisc *sch)
static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct netem_sched_data *q = qdisc_priv(sch);
const struct netem_sched_data *q = qdisc_priv(sch);
unsigned char *b = skb->tail;
struct rtattr *rta = (struct rtattr *) b;
struct tc_netem_qopt qopt;
struct tc_netem_corr cor;
qopt.latency = q->latency;
qopt.jitter = q->jitter;
qopt.limit = q->limit;
qopt.loss = q->loss;
qopt.gap = q->gap;
qopt.duplicate = q->duplicate;
RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);
cor.delay_corr = q->delay_cor.rho;
cor.loss_corr = q->loss_cor.rho;
cor.dup_corr = q->dup_cor.rho;
RTA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor);
rta->rta_len = skb->tail - b;
return skb->len;
rtattr_failure:
......
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