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 burst = 0;
40 unsigned avpkt = 0;
41 double probability = 0.02;
42 unsigned rate = 0;
43 int parm;
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 (!opt.limit || !avpkt) {
113 fprintf(stderr, "RED: Required parameter (limit, avpkt) is missing\n");
114 return -1;
115 }
116 /* Compute default min/max thresholds based on
117 * Sally Floyd's recommendations:
118 * http://www.icir.org/floyd/REDparameters.txt
119 */
120 if (!opt.qth_max)
121 opt.qth_max = opt.qth_min ? opt.qth_min * 3 : opt.limit / 4;
122 if (!opt.qth_min)
123 opt.qth_min = opt.qth_max / 3;
124 if (!burst)
125 burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
126 if (!rate) {
127 get_rate(&rate, "10Mbit");
128 fprintf(stderr, "RED: set bandwidth to 10Mbit\n");
129 }
130 if ((parm = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
131 fprintf(stderr, "RED: failed to calculate EWMA constant.\n");
132 return -1;
133 }
134 if (parm >= 10)
135 fprintf(stderr, "RED: WARNING. Burst %u seems to be too large.\n", burst);
136 opt.Wlog = parm;
137 if ((parm = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
138 fprintf(stderr, "RED: failed to calculate probability.\n");
139 return -1;
140 }
141 opt.Plog = parm;
142 if ((parm = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0) {
143 fprintf(stderr, "RED: failed to calculate idle damping table.\n");
144 return -1;
145 }
146 opt.Scell_log = parm;
147
148 tail = NLMSG_TAIL(n);
149 addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
150 addattr_l(n, 1024, TCA_RED_PARMS, &opt, sizeof(opt));
151 addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
152 max_P = probability * pow(2, 32);
153 addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
154 tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
155 return 0;
156 }
157
red_print_opt(struct qdisc_util * qu,FILE * f,struct rtattr * opt)158 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
159 {
160 struct rtattr *tb[TCA_RED_MAX + 1];
161 struct tc_red_qopt *qopt;
162 __u32 max_P = 0;
163 SPRINT_BUF(b1);
164 SPRINT_BUF(b2);
165 SPRINT_BUF(b3);
166
167 if (opt == NULL)
168 return 0;
169
170 parse_rtattr_nested(tb, TCA_RED_MAX, opt);
171
172 if (tb[TCA_RED_PARMS] == NULL)
173 return -1;
174 qopt = RTA_DATA(tb[TCA_RED_PARMS]);
175 if (RTA_PAYLOAD(tb[TCA_RED_PARMS]) < sizeof(*qopt))
176 return -1;
177
178 if (tb[TCA_RED_MAX_P] &&
179 RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
180 max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
181
182 fprintf(f, "limit %s min %s max %s ",
183 sprint_size(qopt->limit, b1),
184 sprint_size(qopt->qth_min, b2),
185 sprint_size(qopt->qth_max, b3));
186 if (qopt->flags & TC_RED_ECN)
187 fprintf(f, "ecn ");
188 if (qopt->flags & TC_RED_HARDDROP)
189 fprintf(f, "harddrop ");
190 if (qopt->flags & TC_RED_ADAPTATIVE)
191 fprintf(f, "adaptive ");
192 if (show_details) {
193 fprintf(f, "ewma %u ", qopt->Wlog);
194 if (max_P)
195 fprintf(f, "probability %lg ", max_P / pow(2, 32));
196 else
197 fprintf(f, "Plog %u ", qopt->Plog);
198 fprintf(f, "Scell_log %u", qopt->Scell_log);
199 }
200 return 0;
201 }
202
red_print_xstats(struct qdisc_util * qu,FILE * f,struct rtattr * xstats)203 static int red_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
204 {
205 #ifdef TC_RED_ECN
206 struct tc_red_xstats *st;
207
208 if (xstats == NULL)
209 return 0;
210
211 if (RTA_PAYLOAD(xstats) < sizeof(*st))
212 return -1;
213
214 st = RTA_DATA(xstats);
215 fprintf(f, " marked %u early %u pdrop %u other %u",
216 st->marked, st->early, st->pdrop, st->other);
217 return 0;
218
219 #endif
220 return 0;
221 }
222
223
224 struct qdisc_util red_qdisc_util = {
225 .id = "red",
226 .parse_qopt = red_parse_opt,
227 .print_qopt = red_print_opt,
228 .print_xstats = red_print_xstats,
229 };
230