/*
* net/sched/sch_netem.c Network emulator
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Stephen Hemminger <shemminger@osdl.org>
* Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
*/
#include <linux/config.h>
#include <linux/module.h>
#include <asm/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/pkt_sched.h>
/* Network emulator
*
* This scheduler can alters spacing and order
* Similar to NISTnet and BSD Dummynet.
*/
struct netem_sched_data {
struct Qdisc *qdisc;
struct sk_buff_head delayed;
struct timer_list timer;
u32 latency;
u32 loss;
u32 limit;
u32 counter;
u32 gap;
u32 jitter;
};
/* Time stamp put into socket buffer control block */
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.
*/
#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,
};
/* 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)
{
int x;
int index;
int sigmamod, sigmadiv;
if (sigma == 0)
return mu;
index = (net_random() & (TABLESIZE-1));
sigmamod = sigma%TABLEFACTOR;
sigmadiv = sigma/TABLEFACTOR;
x = sigmamod*disttable[index];
if (x >= 0)
x += TABLEFACTOR/2;
else
x -= TABLEFACTOR/2;
x /= TABLEFACTOR;
x += sigmadiv*disttable[index];
x += mu;
return x;
}
/* Enqueue packets with underlying discipline (fifo)
* but mark them with current time first.
*/
static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
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;
pr_debug("netem_enqueue skb=%p @%lu\n", skb, jiffies);
/* Random packet drop 0 => none, ~0 => all */
if (q->loss && q->loss >= net_random()) {
sch->stats.drops++;
return 0; /* lie about loss so TCP doesn't know */
}
/* If doing simple delay then gap == 0 so all packets
* go into the delayed holding queue
* otherwise if doing out of order only "1 out of gap"
* packets will be delayed.
*/
if (q->counter < q->gap) {
int ret;
++q->counter;
ret = q->qdisc->enqueue(skb, q->qdisc);
if (ret)
sch->stats.drops++;
return ret;
}
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;
}
/* Requeue packets but don't change time stamp */
static int netem_requeue(struct sk_buff *skb, struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
int ret;
if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0)
sch->q.qlen++;
return ret;
}
static unsigned int netem_drop(struct Qdisc* sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
unsigned int len;
if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
sch->q.qlen--;
sch->stats.drops++;
}
return len;
}
/* Dequeue packet.
* Move all packets that are ready to send from the delay holding
* list to the underlying qdisc, then just call dequeue
*/
static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
psched_time_t now;
PSCHED_GET_TIME(now);
while ((skb = skb_peek(&q->delayed)) != NULL) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
long delay
= PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
pr_debug("netem_dequeue: delay queue %p@%lu %ld\n",
skb, jiffies, delay);
/* if more time remaining? */
if (delay > 0) {
mod_timer(&q->timer, jiffies + delay);
break;
}
__skb_unlink(skb, &q->delayed);
if (q->qdisc->enqueue(skb, q->qdisc))
sch->stats.drops++;
}
skb = q->qdisc->dequeue(q->qdisc);
if (skb)
sch->q.qlen--;
return skb;
}
static void netem_watchdog(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
pr_debug("netem_watchdog: fired @%lu\n", jiffies);
netif_schedule(sch->dev);
}
static void netem_reset(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
qdisc_reset(q->qdisc);
skb_queue_purge(&q->delayed);
sch->q.qlen = 0;
del_timer_sync(&q->timer);
}
static int set_fifo_limit(struct Qdisc *q, int limit)
{
struct rtattr *rta;
int ret = -ENOMEM;
rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
if (rta) {
rta->rta_type = RTM_NEWQDISC;
rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt));
((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit;
ret = q->ops->change(q, rta);
kfree(rta);
}
return ret;
}
static int netem_change(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct tc_netem_qopt *qopt = RTA_DATA(opt);
struct Qdisc *child;
int ret;
if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
return -EINVAL;
child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
if (!child)
return -EINVAL;
ret = set_fifo_limit(child, qopt->limit);
if (ret) {
qdisc_destroy(child);
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;
}
sch_tree_unlock(sch);
return 0;
}
static int netem_init(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = qdisc_priv(sch);
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);
}
static void netem_destroy(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
del_timer_sync(&q->timer);
qdisc_destroy(q->qdisc);
}
static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct netem_sched_data *q = qdisc_priv(sch);
unsigned char *b = skb->tail;
struct tc_netem_qopt qopt;
qopt.latency = q->latency;
qopt.jitter = q->jitter;
qopt.limit = q->limit;
qopt.loss = q->loss;
qopt.gap = q->gap;
RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int netem_dump_class(struct Qdisc *sch, unsigned long cl,
struct sk_buff *skb, struct tcmsg *tcm)
{
struct netem_sched_data *q = qdisc_priv(sch);
if (cl != 1) /* only one class */
return -ENOENT;
tcm->tcm_handle |= TC_H_MIN(1);
tcm->tcm_info = q->qdisc->handle;
return 0;
}
static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
struct Qdisc **old)
{
struct netem_sched_data *q = qdisc_priv(sch);
if (new == NULL)
new = &noop_qdisc;
sch_tree_lock(sch);
*old = xchg(&q->qdisc, new);
qdisc_reset(*old);
sch->q.qlen = 0;
sch_tree_unlock(sch);
return 0;
}
static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg)
{
struct netem_sched_data *q = qdisc_priv(sch);
return q->qdisc;
}
static unsigned long netem_get(struct Qdisc *sch, u32 classid)
{
return 1;
}
static void netem_put(struct Qdisc *sch, unsigned long arg)
{
}
static int netem_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
struct rtattr **tca, unsigned long *arg)
{
return -ENOSYS;
}
static int netem_delete(struct Qdisc *sch, unsigned long arg)
{
return -ENOSYS;
}
static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
if (!walker->stop) {
if (walker->count >= walker->skip)
if (walker->fn(sch, 1, walker) < 0) {
walker->stop = 1;
return;
}
walker->count++;
}
}
static struct tcf_proto **netem_find_tcf(struct Qdisc *sch, unsigned long cl)
{
return NULL;
}
static struct Qdisc_class_ops netem_class_ops = {
.graft = netem_graft,
.leaf = netem_leaf,
.get = netem_get,
.put = netem_put,
.change = netem_change_class,
.delete = netem_delete,
.walk = netem_walk,
.tcf_chain = netem_find_tcf,
.dump = netem_dump_class,
};
static struct Qdisc_ops netem_qdisc_ops = {
.id = "netem",
.cl_ops = &netem_class_ops,
.priv_size = sizeof(struct netem_sched_data),
.enqueue = netem_enqueue,
.dequeue = netem_dequeue,
.requeue = netem_requeue,
.drop = netem_drop,
.init = netem_init,
.reset = netem_reset,
.destroy = netem_destroy,
.change = netem_change,
.dump = netem_dump,
.owner = THIS_MODULE,
};
static int __init netem_module_init(void)
{
return register_qdisc(&netem_qdisc_ops);
}
static void __exit netem_module_exit(void)
{
unregister_qdisc(&netem_qdisc_ops);
}
module_init(netem_module_init)
module_exit(netem_module_exit)
MODULE_LICENSE("GPL");
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