1/* 2 * q_red.c RED. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 */ 12 13#include <stdio.h> 14#include <stdlib.h> 15#include <unistd.h> 16#include <syslog.h> 17#include <fcntl.h> 18#include <sys/socket.h> 19#include <netinet/in.h> 20#include <arpa/inet.h> 21#include <string.h> 22#include <math.h> 23 24#include "utils.h" 25#include "tc_util.h" 26 27#include "tc_red.h" 28 29static void explain(void) 30{ 31 fprintf(stderr, "Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n"); 32 fprintf(stderr, " [adaptive] [probability PROBABILITY] bandwidth KBPS\n"); 33 fprintf(stderr, " [ecn] [harddrop]\n"); 34} 35 36static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n) 37{ 38 struct tc_red_qopt opt; 39 unsigned burst = 0; 40 unsigned avpkt = 0; 41 double probability = 0.02; 42 unsigned rate = 0; 43 int wlog; 44 __u8 sbuf[256]; 45 __u32 max_P; 46 struct rtattr *tail; 47 48 memset(&opt, 0, sizeof(opt)); 49 50 while (argc > 0) { 51 if (strcmp(*argv, "limit") == 0) { 52 NEXT_ARG(); 53 if (get_size(&opt.limit, *argv)) { 54 fprintf(stderr, "Illegal \"limit\"\n"); 55 return -1; 56 } 57 } else if (strcmp(*argv, "min") == 0) { 58 NEXT_ARG(); 59 if (get_size(&opt.qth_min, *argv)) { 60 fprintf(stderr, "Illegal \"min\"\n"); 61 return -1; 62 } 63 } else if (strcmp(*argv, "max") == 0) { 64 NEXT_ARG(); 65 if (get_size(&opt.qth_max, *argv)) { 66 fprintf(stderr, "Illegal \"max\"\n"); 67 return -1; 68 } 69 } else if (strcmp(*argv, "burst") == 0) { 70 NEXT_ARG(); 71 if (get_unsigned(&burst, *argv, 0)) { 72 fprintf(stderr, "Illegal \"burst\"\n"); 73 return -1; 74 } 75 } else if (strcmp(*argv, "avpkt") == 0) { 76 NEXT_ARG(); 77 if (get_size(&avpkt, *argv)) { 78 fprintf(stderr, "Illegal \"avpkt\"\n"); 79 return -1; 80 } 81 } else if (strcmp(*argv, "probability") == 0) { 82 NEXT_ARG(); 83 if (sscanf(*argv, "%lg", &probability) != 1) { 84 fprintf(stderr, "Illegal \"probability\"\n"); 85 return -1; 86 } 87 } else if (strcmp(*argv, "bandwidth") == 0) { 88 NEXT_ARG(); 89 if (get_rate(&rate, *argv)) { 90 fprintf(stderr, "Illegal \"bandwidth\"\n"); 91 return -1; 92 } 93 } else if (strcmp(*argv, "ecn") == 0) { 94 opt.flags |= TC_RED_ECN; 95 } else if (strcmp(*argv, "harddrop") == 0) { 96 opt.flags |= TC_RED_HARDDROP; 97 } else if (strcmp(*argv, "adaptative") == 0) { 98 opt.flags |= TC_RED_ADAPTATIVE; 99 } else if (strcmp(*argv, "adaptive") == 0) { 100 opt.flags |= TC_RED_ADAPTATIVE; 101 } else if (strcmp(*argv, "help") == 0) { 102 explain(); 103 return -1; 104 } else { 105 fprintf(stderr, "What is \"%s\"?\n", *argv); 106 explain(); 107 return -1; 108 } 109 argc--; argv++; 110 } 111 112 if (rate == 0) 113 get_rate(&rate, "10Mbit"); 114 115 if (!opt.limit || !avpkt) { 116 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n"); 117 return -1; 118 } 119 /* Compute default min/max thresholds based on 120 * Sally Floyd's recommendations: 121 * http://www.icir.org/floyd/REDparameters.txt 122 */ 123 if (!opt.qth_max) 124 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4; 125 if (!opt.qth_min) 126 opt.qth_min = opt.qth_max / 3; 127 if (!burst) 128 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt); 129 if ((wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) { 130 fprintf(stderr, "RED: failed to calculate EWMA constant.\n"); 131 return -1; 132 } 133 if (wlog >= 10) 134 fprintf(stderr, "RED: WARNING. Burst %d seems to be too large.\n", burst); 135 opt.Wlog = wlog; 136 if ((wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) { 137 fprintf(stderr, "RED: failed to calculate probability.\n"); 138 return -1; 139 } 140 opt.Plog = wlog; 141 if ((wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) { 142 fprintf(stderr, "RED: failed to calculate idle damping table.\n"); 143 return -1; 144 } 145 opt.Scell_log = wlog; 146 147 tail = NLMSG_TAIL(n); 148 addattr_l(n, 1024, TCA_OPTIONS, NULL, 0); 149 addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt)); 150 addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256); 151 max_P = probability * pow(2, 32); 152 addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P)); 153 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; 154 return 0; 155} 156 157static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) 158{ 159 struct rtattr *tb[TCA_RED_MAX + 1]; 160 struct tc_red_qopt *qopt; 161 __u32 max_P = 0; 162 SPRINT_BUF(b1); 163 SPRINT_BUF(b2); 164 SPRINT_BUF(b3); 165 166 if (opt == NULL) 167 return 0; 168 169 parse_rtattr_nested(tb, TCA_RED_MAX, opt); 170 171 if (tb[TCA_RED_PARMS] == NULL) 172 return -1; 173 qopt = RTA_DATA(tb[TCA_RED_PARMS]); 174 if (RTA_PAYLOAD(tb[TCA_RED_PARMS]) < sizeof(*qopt)) 175 return -1; 176 177 if (tb[TCA_RED_MAX_P] && 178 RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32)) 179 max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]); 180 181 fprintf(f, "limit %s min %s max %s ", 182 sprint_size(qopt->limit, b1), 183 sprint_size(qopt->qth_min, b2), 184 sprint_size(qopt->qth_max, b3)); 185 if (qopt->flags & TC_RED_ECN) 186 fprintf(f, "ecn "); 187 if (qopt->flags & TC_RED_HARDDROP) 188 fprintf(f, "harddrop "); 189 if (qopt->flags & TC_RED_ADAPTATIVE) 190 fprintf(f, "adaptive "); 191 if (show_details) { 192 fprintf(f, "ewma %u ", qopt->Wlog); 193 if (max_P) 194 fprintf(f, "probability %lg ", max_P / pow(2, 32)); 195 else 196 fprintf(f, "Plog %u ", qopt->Plog); 197 fprintf(f, "Scell_log %u", qopt->Scell_log); 198 } 199 return 0; 200} 201 202static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats) 203{ 204#ifdef TC_RED_ECN 205 struct tc_red_xstats *st; 206 207 if (xstats == NULL) 208 return 0; 209 210 if (RTA_PAYLOAD(xstats) < sizeof(*st)) 211 return -1; 212 213 st = RTA_DATA(xstats); 214 fprintf(f, " marked %u early %u pdrop %u other %u", 215 st->marked, st->early, st->pdrop, st->other); 216 return 0; 217 218#endif 219 return 0; 220} 221 222 223struct qdisc_util red_qdisc_util = { 224 .id = "red", 225 .parse_qopt = red_parse_opt, 226 .print_qopt = red_print_opt, 227 .print_xstats = red_print_xstats, 228}; 229