1 /* 2 * q_choke.c CHOKE. 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: Stephen Hemminger <shemminger (at) vyatta.com> 10 */ 11 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <unistd.h> 15 #include <syslog.h> 16 #include <fcntl.h> 17 #include <sys/socket.h> 18 #include <netinet/in.h> 19 #include <arpa/inet.h> 20 #include <string.h> 21 #include <math.h> 22 23 #include "utils.h" 24 #include "tc_util.h" 25 26 #include "tc_red.h" 27 28 static void explain(void) 29 { 30 fprintf(stderr, "Usage: ... choke limit PACKETS bandwidth KBPS [ecn]\n"); 31 fprintf(stderr, " [ min PACKETS ] [ max PACKETS ] [ burst PACKETS ]\n"); 32 } 33 34 static int choke_parse_opt(struct qdisc_util *qu, int argc, char **argv, 35 struct nlmsghdr *n) 36 { 37 struct tc_red_qopt opt; 38 unsigned burst = 0; 39 unsigned avpkt = 1000; 40 double probability = 0.02; 41 unsigned rate = 0; 42 int ecn_ok = 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_unsigned(&opt.limit, *argv, 0)) { 54 fprintf(stderr, "Illegal \"limit\"\n"); 55 return -1; 56 } 57 } else if (strcmp(*argv, "bandwidth") == 0) { 58 NEXT_ARG(); 59 if (get_rate(&rate, *argv)) { 60 fprintf(stderr, "Illegal \"bandwidth\"\n"); 61 return -1; 62 } 63 } else if (strcmp(*argv, "ecn") == 0) { 64 ecn_ok = 1; 65 } else if (strcmp(*argv, "min") == 0) { 66 NEXT_ARG(); 67 if (get_unsigned(&opt.qth_min, *argv, 0)) { 68 fprintf(stderr, "Illegal \"min\"\n"); 69 return -1; 70 } 71 } else if (strcmp(*argv, "max") == 0) { 72 NEXT_ARG(); 73 if (get_unsigned(&opt.qth_max, *argv, 0)) { 74 fprintf(stderr, "Illegal \"max\"\n"); 75 return -1; 76 } 77 } else if (strcmp(*argv, "burst") == 0) { 78 NEXT_ARG(); 79 if (get_unsigned(&burst, *argv, 0)) { 80 fprintf(stderr, "Illegal \"burst\"\n"); 81 return -1; 82 } 83 } else if (strcmp(*argv, "avpkt") == 0) { 84 NEXT_ARG(); 85 if (get_size(&avpkt, *argv)) { 86 fprintf(stderr, "Illegal \"avpkt\"\n"); 87 return -1; 88 } 89 } else if (strcmp(*argv, "probability") == 0) { 90 NEXT_ARG(); 91 if (sscanf(*argv, "%lg", &probability) != 1) { 92 fprintf(stderr, "Illegal \"probability\"\n"); 93 return -1; 94 } 95 } else if (strcmp(*argv, "help") == 0) { 96 explain(); 97 return -1; 98 } else { 99 fprintf(stderr, "What is \"%s\"?\n", *argv); 100 explain(); 101 return -1; 102 } 103 argc--; argv++; 104 } 105 106 if (!rate || !opt.limit) { 107 fprintf(stderr, "Required parameter (bandwidth, limit) is missing\n"); 108 return -1; 109 } 110 111 /* Compute default min/max thresholds based on 112 Sally Floyd's recommendations: 113 http://www.icir.org/floyd/REDparameters.txt 114 */ 115 if (!opt.qth_max) 116 opt.qth_max = opt.limit / 4; 117 if (!opt.qth_min) 118 opt.qth_min = opt.qth_max / 3; 119 if (!burst) 120 burst = (2 * opt.qth_min + opt.qth_max) / 3; 121 122 if (opt.qth_max > opt.limit) { 123 fprintf(stderr, "\"max\" is larger than \"limit\"\n"); 124 return -1; 125 } 126 127 if (opt.qth_min >= opt.qth_max) { 128 fprintf(stderr, "\"min\" is not smaller than \"max\"\n"); 129 return -1; 130 } 131 132 wlog = tc_red_eval_ewma(opt.qth_min*avpkt, burst, avpkt); 133 if (wlog < 0) { 134 fprintf(stderr, "CHOKE: failed to calculate EWMA constant.\n"); 135 return -1; 136 } 137 if (wlog >= 10) 138 fprintf(stderr, "CHOKE: WARNING. Burst %d seems to be too large.\n", burst); 139 opt.Wlog = wlog; 140 141 wlog = tc_red_eval_P(opt.qth_min*avpkt, opt.qth_max*avpkt, probability); 142 if (wlog < 0) { 143 fprintf(stderr, "CHOKE: failed to calculate probability.\n"); 144 return -1; 145 } 146 opt.Plog = wlog; 147 148 wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf); 149 if (wlog < 0) { 150 fprintf(stderr, "CHOKE: failed to calculate idle damping table.\n"); 151 return -1; 152 } 153 opt.Scell_log = wlog; 154 if (ecn_ok) 155 opt.flags |= TC_RED_ECN; 156 157 tail = NLMSG_TAIL(n); 158 addattr_l(n, 1024, TCA_OPTIONS, NULL, 0); 159 addattr_l(n, 1024, TCA_CHOKE_PARMS, &opt, sizeof(opt)); 160 addattr_l(n, 1024, TCA_CHOKE_STAB, sbuf, 256); 161 max_P = probability * pow(2, 32); 162 addattr_l(n, 1024, TCA_CHOKE_MAX_P, &max_P, sizeof(max_P)); 163 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; 164 return 0; 165 } 166 167 static int choke_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) 168 { 169 struct rtattr *tb[TCA_CHOKE_MAX+1]; 170 const struct tc_red_qopt *qopt; 171 __u32 max_P = 0; 172 173 if (opt == NULL) 174 return 0; 175 176 parse_rtattr_nested(tb, TCA_CHOKE_MAX, opt); 177 178 if (tb[TCA_CHOKE_PARMS] == NULL) 179 return -1; 180 qopt = RTA_DATA(tb[TCA_CHOKE_PARMS]); 181 if (RTA_PAYLOAD(tb[TCA_CHOKE_PARMS]) < sizeof(*qopt)) 182 return -1; 183 if (tb[TCA_CHOKE_MAX_P] && 184 RTA_PAYLOAD(tb[TCA_CHOKE_MAX_P]) >= sizeof(__u32)) 185 max_P = rta_getattr_u32(tb[TCA_CHOKE_MAX_P]); 186 187 fprintf(f, "limit %up min %up max %up ", 188 qopt->limit, qopt->qth_min, qopt->qth_max); 189 190 if (qopt->flags & TC_RED_ECN) 191 fprintf(f, "ecn "); 192 193 if (show_details) { 194 fprintf(f, "ewma %u ", qopt->Wlog); 195 if (max_P) 196 fprintf(f, "probability %g ", max_P / pow(2, 32)); 197 else 198 fprintf(f, "Plog %u ", qopt->Plog); 199 fprintf(f, "Scell_log %u", qopt->Scell_log); 200 } 201 return 0; 202 } 203 204 static int choke_print_xstats(struct qdisc_util *qu, FILE *f, 205 struct rtattr *xstats) 206 { 207 struct tc_choke_xstats *st; 208 209 if (xstats == NULL) 210 return 0; 211 212 if (RTA_PAYLOAD(xstats) < sizeof(*st)) 213 return -1; 214 215 st = RTA_DATA(xstats); 216 fprintf(f, " marked %u early %u pdrop %u other %u matched %u", 217 st->marked, st->early, st->pdrop, st->other, st->matched); 218 return 0; 219 220 } 221 222 struct qdisc_util choke_qdisc_util = { 223 .id = "choke", 224 .parse_qopt = choke_parse_opt, 225 .print_qopt = choke_print_opt, 226 .print_xstats = choke_print_xstats, 227 }; 228
