1/*
2 * q_gred.c		GRED.
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:    J Hadi Salim(hadi@nortelnetworks.com)
10 *             code ruthlessly ripped from
11 *	       Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
12 *
13 */
14
15#include <stdio.h>
16#include <stdlib.h>
17#include <unistd.h>
18#include <syslog.h>
19#include <fcntl.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <arpa/inet.h>
23#include <string.h>
24#include <math.h>
25
26#include "utils.h"
27#include "tc_util.h"
28
29#include "tc_red.h"
30
31
32#if 0
33#define DPRINTF(format,args...) fprintf(stderr,format,##args)
34#else
35#define DPRINTF(format,args...)
36#endif
37
38static void explain(void)
39{
40	fprintf(stderr, "Usage: ... gred DP drop-probability limit BYTES "
41	    "min BYTES max BYTES\n");
42	fprintf(stderr, "    avpkt BYTES burst PACKETS probability PROBABILITY "
43	    "bandwidth KBPS\n");
44	fprintf(stderr, "    [prio value]\n");
45	fprintf(stderr," OR ...\n");
46	fprintf(stderr," gred setup DPs <num of DPs> default <default DP> "
47	    "[grio]\n");
48}
49
50static int init_gred(struct qdisc_util *qu, int argc, char **argv,
51		     struct nlmsghdr *n)
52{
53
54	struct rtattr *tail;
55	struct tc_gred_sopt opt = { 0 };
56	int dps = 0;
57	int def_dp = -1;
58
59	while (argc > 0) {
60		DPRINTF(stderr,"init_gred: invoked with %s\n",*argv);
61		if (strcmp(*argv, "DPs") == 0) {
62			NEXT_ARG();
63			DPRINTF(stderr,"init_gred: next_arg with %s\n",*argv);
64			dps = strtol(*argv, (char **)NULL, 10);
65			if (dps < 0 || dps >MAX_DPs) {
66				fprintf(stderr, "DPs =%d\n", dps);
67				fprintf(stderr, "Illegal \"DPs\"\n");
68				fprintf(stderr, "GRED: only %d DPs are "
69					"currently supported\n",MAX_DPs);
70				return -1;
71			}
72		} else if (strcmp(*argv, "default") == 0) {
73			NEXT_ARG();
74			def_dp = strtol(*argv, (char **)NULL, 10);
75			if (dps == 0) {
76				fprintf(stderr, "\"default DP\" must be "
77					"defined after DPs\n");
78				return -1;
79			}
80			if (def_dp < 0 || def_dp > dps) {
81				fprintf(stderr,
82					"\"default DP\" must be less than %d\n",
83					opt.DPs);
84				return -1;
85			}
86		} else if (strcmp(*argv, "grio") == 0) {
87			opt.grio = 1;
88		} else if (strcmp(*argv, "help") == 0) {
89			explain();
90			return -1;
91		} else {
92			fprintf(stderr, "What is \"%s\"?\n", *argv);
93			explain();
94			return -1;
95		}
96		argc--; argv++;
97	}
98
99	if (!dps || def_dp == -1) {
100		fprintf(stderr, "Illegal gred setup parameters \n");
101		return -1;
102	}
103
104	opt.DPs = dps;
105	opt.def_DP = def_dp;
106
107	DPRINTF("TC_GRED: sending DPs=%d default=%d\n",opt.DPs,opt.def_DP);
108	n->nlmsg_flags|=NLM_F_CREATE;
109	tail = NLMSG_TAIL(n);
110	addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
111	addattr_l(n, 1024, TCA_GRED_DPS, &opt, sizeof(struct tc_gred_sopt));
112	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
113	return 0;
114}
115/*
116^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
117*/
118static int gred_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
119{
120	int ok=0;
121	struct tc_gred_qopt opt;
122	unsigned burst = 0;
123	unsigned avpkt = 0;
124	double probability = 0.02;
125	unsigned rate = 0;
126	int wlog;
127	__u8 sbuf[256];
128	struct rtattr *tail;
129	__u32 max_P;
130
131	memset(&opt, 0, sizeof(opt));
132
133	while (argc > 0) {
134		if (strcmp(*argv, "limit") == 0) {
135			NEXT_ARG();
136			if (get_size(&opt.limit, *argv)) {
137				fprintf(stderr, "Illegal \"limit\"\n");
138				return -1;
139			}
140			ok++;
141		} else if (strcmp(*argv, "setup") == 0) {
142			if (ok) {
143				fprintf(stderr, "Illegal \"setup\"\n");
144				return -1;
145			}
146		return init_gred(qu,argc-1, argv+1,n);
147
148		} else if (strcmp(*argv, "min") == 0) {
149			NEXT_ARG();
150			if (get_size(&opt.qth_min, *argv)) {
151				fprintf(stderr, "Illegal \"min\"\n");
152				return -1;
153			}
154			ok++;
155		} else if (strcmp(*argv, "max") == 0) {
156			NEXT_ARG();
157			if (get_size(&opt.qth_max, *argv)) {
158				fprintf(stderr, "Illegal \"max\"\n");
159				return -1;
160			}
161			ok++;
162		} else if (strcmp(*argv, "DP") == 0) {
163			NEXT_ARG();
164			opt.DP=strtol(*argv, (char **)NULL, 10);
165			DPRINTF ("\n ******* DP =%u\n",opt.DP);
166			if (opt.DP >MAX_DPs) { /* need a better error check */
167				fprintf(stderr, "DP =%u \n",opt.DP);
168				fprintf(stderr, "Illegal \"DP\"\n");
169				fprintf(stderr, "GRED: only %d DPs are currently supported\n",MAX_DPs);
170				return -1;
171			}
172			ok++;
173		} else if (strcmp(*argv, "burst") == 0) {
174			NEXT_ARG();
175                        if (get_unsigned(&burst, *argv, 0)) {
176				fprintf(stderr, "Illegal \"burst\"\n");
177				return -1;
178			}
179			ok++;
180		} else if (strcmp(*argv, "avpkt") == 0) {
181			NEXT_ARG();
182			if (get_size(&avpkt, *argv)) {
183				fprintf(stderr, "Illegal \"avpkt\"\n");
184				return -1;
185			}
186			ok++;
187		} else if (strcmp(*argv, "probability") == 0) {
188			NEXT_ARG();
189			if (sscanf(*argv, "%lg", &probability) != 1) {
190				fprintf(stderr, "Illegal \"probability\"\n");
191				return -1;
192			}
193			ok++;
194		} else if (strcmp(*argv, "prio") == 0) {
195			NEXT_ARG();
196			opt.prio=strtol(*argv, (char **)NULL, 10);
197			/* some error check here */
198			ok++;
199		} else if (strcmp(*argv, "bandwidth") == 0) {
200			NEXT_ARG();
201			if (get_rate(&rate, *argv)) {
202				fprintf(stderr, "Illegal \"bandwidth\"\n");
203				return -1;
204			}
205			ok++;
206		} else if (strcmp(*argv, "help") == 0) {
207			explain();
208			return -1;
209		} else {
210			fprintf(stderr, "What is \"%s\"?\n", *argv);
211			explain();
212			return -1;
213		}
214		argc--; argv++;
215	}
216
217	if (rate == 0)
218		get_rate(&rate, "10Mbit");
219
220	if (!opt.qth_min || !opt.qth_max || !opt.limit || !avpkt ||
221	    (opt.DP<0)) {
222		fprintf(stderr, "Required parameter (min, max, limit, "
223		    "avpkt, DP) is missing\n");
224		return -1;
225	}
226	if (!burst) {
227		burst = (2 * opt.qth_min + opt.qth_max) / (3 * avpkt);
228		fprintf(stderr, "GRED: set burst to %u\n", burst);
229	}
230
231	if ((wlog = tc_red_eval_ewma(opt.qth_min, burst, avpkt)) < 0) {
232		fprintf(stderr, "GRED: failed to calculate EWMA constant.\n");
233		return -1;
234	}
235	if (wlog >= 10)
236		fprintf(stderr, "GRED: WARNING. Burst %d seems to be too "
237		    "large.\n", burst);
238	opt.Wlog = wlog;
239	if ((wlog = tc_red_eval_P(opt.qth_min, opt.qth_max, probability)) < 0) {
240		fprintf(stderr, "GRED: failed to calculate probability.\n");
241		return -1;
242	}
243	opt.Plog = wlog;
244	if ((wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf)) < 0)
245	    {
246		fprintf(stderr, "GRED: failed to calculate idle damping "
247		    "table.\n");
248		return -1;
249	}
250	opt.Scell_log = wlog;
251
252	tail = NLMSG_TAIL(n);
253	addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
254	addattr_l(n, 1024, TCA_GRED_PARMS, &opt, sizeof(opt));
255	addattr_l(n, 1024, TCA_GRED_STAB, sbuf, 256);
256	max_P = probability * pow(2, 32);
257	addattr32(n, 1024, TCA_GRED_MAX_P, max_P);
258	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
259	return 0;
260}
261
262static int gred_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
263{
264	struct rtattr *tb[TCA_GRED_MAX + 1];
265	struct tc_gred_qopt *qopt;
266	__u32 *max_p = NULL;
267	int i;
268	SPRINT_BUF(b1);
269	SPRINT_BUF(b2);
270	SPRINT_BUF(b3);
271	SPRINT_BUF(b4);
272	SPRINT_BUF(b5);
273
274	if (opt == NULL)
275		return 0;
276
277	parse_rtattr_nested(tb, TCA_GRED_MAX, opt);
278
279	if (tb[TCA_GRED_PARMS] == NULL)
280		return -1;
281
282	if (tb[TCA_GRED_MAX_P] &&
283	    RTA_PAYLOAD(tb[TCA_GRED_MAX_P]) >= sizeof(__u32) * MAX_DPs)
284		max_p = RTA_DATA(tb[TCA_GRED_MAX_P]);
285
286	qopt = RTA_DATA(tb[TCA_GRED_PARMS]);
287	if (RTA_PAYLOAD(tb[TCA_GRED_PARMS])  < sizeof(*qopt)*MAX_DPs) {
288		fprintf(f,"\n GRED received message smaller than expected\n");
289		return -1;
290		}
291
292/* Bad hack! should really return a proper message as shown above*/
293
294	for (i=0;i<MAX_DPs;i++, qopt++) {
295		if (qopt->DP >= MAX_DPs) continue;
296		fprintf(f, "\n DP:%d (prio %d) Average Queue %s Measured "
297		    "Queue %s  ",
298			qopt->DP,
299			qopt->prio,
300			sprint_size(qopt->qave, b4),
301			sprint_size(qopt->backlog, b5));
302		fprintf(f, "\n\t Packet drops: %d (forced %d early %d)  ",
303			qopt->forced+qopt->early,
304			qopt->forced,
305			qopt->early);
306		fprintf(f, "\n\t Packet totals: %u (bytes %u)  ",
307			qopt->packets,
308			qopt->bytesin);
309		if (show_details)
310			fprintf(f, "\n limit %s min %s max %s ",
311				sprint_size(qopt->limit, b1),
312				sprint_size(qopt->qth_min, b2),
313				sprint_size(qopt->qth_max, b3));
314		fprintf(f, "ewma %u ", qopt->Wlog);
315		if (max_p)
316			fprintf(f, "probability %lg ", max_p[i] / pow(2, 32));
317		else
318			fprintf(f, "Plog %u ", qopt->Plog);
319		fprintf(f, "Scell_log %u", qopt->Scell_log);
320	}
321	return 0;
322}
323
324struct qdisc_util gred_qdisc_util = {
325	.id		= "gred",
326	.parse_qopt	= gred_parse_opt,
327	.print_qopt	= gred_print_opt,
328};
329