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 (at) 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 29 static 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 36 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n) 37 { 38 struct tc_red_qopt opt = {}; 39 unsigned int burst = 0; 40 unsigned int avpkt = 0; 41 double probability = 0.02; 42 unsigned int rate = 0; 43 int parm; 44 __u8 sbuf[256]; 45 __u32 max_P; 46 struct rtattr *tail; 47 48 while (argc > 0) { 49 if (strcmp(*argv, "limit") == 0) { 50 NEXT_ARG(); 51 if (get_size(&opt.limit, *argv)) { 52 fprintf(stderr, "Illegal \"limit\"\n"); 53 return -1; 54 } 55 } else if (strcmp(*argv, "min") == 0) { 56 NEXT_ARG(); 57 if (get_size(&opt.qth_min, *argv)) { 58 fprintf(stderr, "Illegal \"min\"\n"); 59 return -1; 60 } 61 } else if (strcmp(*argv, "max") == 0) { 62 NEXT_ARG(); 63 if (get_size(&opt.qth_max, *argv)) { 64 fprintf(stderr, "Illegal \"max\"\n"); 65 return -1; 66 } 67 } else if (strcmp(*argv, "burst") == 0) { 68 NEXT_ARG(); 69 if (get_unsigned(&burst, *argv, 0)) { 70 fprintf(stderr, "Illegal \"burst\"\n"); 71 return -1; 72 } 73 } else if (strcmp(*argv, "avpkt") == 0) { 74 NEXT_ARG(); 75 if (get_size(&avpkt, *argv)) { 76 fprintf(stderr, "Illegal \"avpkt\"\n"); 77 return -1; 78 } 79 } else if (strcmp(*argv, "probability") == 0) { 80 NEXT_ARG(); 81 if (sscanf(*argv, "%lg", &probability) != 1) { 82 fprintf(stderr, "Illegal \"probability\"\n"); 83 return -1; 84 } 85 } else if (strcmp(*argv, "bandwidth") == 0) { 86 NEXT_ARG(); 87 if (get_rate(&rate, *argv)) { 88 fprintf(stderr, "Illegal \"bandwidth\"\n"); 89 return -1; 90 } 91 } else if (strcmp(*argv, "ecn") == 0) { 92 opt.flags |= TC_RED_ECN; 93 } else if (strcmp(*argv, "harddrop") == 0) { 94 opt.flags |= TC_RED_HARDDROP; 95 } else if (strcmp(*argv, "adaptative") == 0) { 96 opt.flags |= TC_RED_ADAPTATIVE; 97 } else if (strcmp(*argv, "adaptive") == 0) { 98 opt.flags |= TC_RED_ADAPTATIVE; 99 } else if (strcmp(*argv, "help") == 0) { 100 explain(); 101 return -1; 102 } else { 103 fprintf(stderr, "What is \"%s\"?\n", *argv); 104 explain(); 105 return -1; 106 } 107 argc--; argv++; 108 } 109 110 if (!opt.limit || !avpkt) { 111 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n"); 112 return -1; 113 } 114 /* Compute default min/max thresholds based on 115 * Sally Floyd's recommendations: 116 * http://www.icir.org/floyd/REDparameters.txt 117 */ 118 if (!opt.qth_max) 119 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4; 120 if (!opt.qth_min) 121 opt.qth_min = opt.qth_max / 3; 122 if (!burst) 123 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt); 124 if (!rate) { 125 get_rate(&rate, "10Mbit"); 126 fprintf(stderr, "RED: set bandwidth to 10Mbit\n"); 127 } 128 if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) { 129 fprintf(stderr, "RED: failed to calculate EWMA constant.\n"); 130 return -1; 131 } 132 if (parm >= 10) 133 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst); 134 opt.Wlog = parm; 135 if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) { 136 fprintf(stderr, "RED: failed to calculate probability.\n"); 137 return -1; 138 } 139 opt.Plog = parm; 140 if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) { 141 fprintf(stderr, "RED: failed to calculate idle damping table.\n"); 142 return -1; 143 } 144 opt.Scell_log = parm; 145 146 tail = NLMSG_TAIL(n); 147 addattr_l(n, 1024, TCA_OPTIONS, NULL, 0); 148 addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt)); 149 addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256); 150 max_P = probability * pow(2, 32); 151 addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P)); 152 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; 153 return 0; 154 } 155 156 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) 157 { 158 struct rtattr *tb[TCA_RED_MAX + 1]; 159 struct tc_red_qopt *qopt; 160 __u32 max_P = 0; 161 162 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 } 201 202 static 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 } 221 222 223 struct 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
