/* * 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 * Catalin(ux aka Dino) BOIE */ #include #include #include #include #include #include #include #include #include #include /* 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 = (struct netem_sched_data *)sch->data; 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 */ __skb_queue_tail(&q->delayed, skb); sch->q.qlen++; sch->stats.bytes += skb->len; sch->stats.packets++; return 0; } /* Requeue packets but don't change time stamp */ static int netem_requeue(struct sk_buff *skb, struct Qdisc *sch) { struct netem_sched_data *q = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; 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 = (struct netem_sched_data *)sch->data; del_timer_sync(&q->timer); } static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) { struct netem_sched_data *q = (struct netem_sched_data *)sch->data; unsigned char *b = skb->tail; struct tc_netem_qopt qopt; qopt.latency = q->latency; qopt.jitter = q->jitter; qopt.limit = sch->dev->tx_queue_len; 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 struct Qdisc_ops netem_qdisc_ops = { .id = "netem", .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");