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
explain(void)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
red_parse_opt(struct qdisc_util * qu,int argc,char ** argv,struct nlmsghdr * n)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
red_print_opt(struct qdisc_util * qu,FILE * f,struct rtattr * opt)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
red_print_xstats(struct qdisc_util * qu,FILE * f,struct rtattr * xstats)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