1/*
2 * q_netem.c		NETEM.
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@osdl.org>
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 <errno.h>
23
24#include "utils.h"
25#include "tc_util.h"
26#include "tc_common.h"
27
28static void explain(void)
29{
30	fprintf(stderr,
31"Usage: ... netem [ limit PACKETS ] \n" \
32"                 [ delay TIME [ JITTER [CORRELATION]]]\n" \
33"                 [ distribution {uniform|normal|pareto|paretonormal} ]\n" \
34"                 [ drop PERCENT [CORRELATION]] \n" \
35"                 [ duplicate PERCENT [CORRELATION]]\n" \
36"                 [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n");
37}
38
39static void explain1(const char *arg)
40{
41	fprintf(stderr, "Illegal \"%s\"\n", arg);
42}
43
44#define usage() return(-1)
45
46/*
47 * Simplistic file parser for distrbution data.
48 * Format is:
49 *	# comment line(s)
50 *	data0 data1
51 */
52#define MAXDIST	65536
53static int get_distribution(const char *type, __s16 *data)
54{
55	FILE *f;
56	int n;
57	long x;
58	size_t len;
59	char *line = NULL;
60	char name[128];
61
62	snprintf(name, sizeof(name), "/usr/lib/tc/%s.dist", type);
63	if ((f = fopen(name, "r")) == NULL) {
64		fprintf(stderr, "No distribution data for %s (%s: %s)\n",
65			type, name, strerror(errno));
66		return -1;
67	}
68
69	n = 0;
70	while (getline(&line, &len, f) != -1) {
71		char *p, *endp;
72		if (*line == '\n' || *line == '#')
73			continue;
74
75		for (p = line; ; p = endp) {
76			x = strtol(p, &endp, 0);
77			if (endp == p)
78				break;
79
80			if (n >= MAXDIST) {
81				fprintf(stderr, "%s: too much data\n",
82					name);
83				n = -1;
84				goto error;
85			}
86			data[n++] = x;
87		}
88	}
89 error:
90	free(line);
91	fclose(f);
92	return n;
93}
94
95static int isnumber(const char *arg)
96{
97	char *p;
98	(void) strtod(arg, &p);
99	return (p != arg);
100}
101
102#define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1]))
103
104/* Adjust for the fact that psched_ticks aren't always usecs
105   (based on kernel PSCHED_CLOCK configuration */
106static int get_ticks(__u32 *ticks, const char *str)
107{
108	unsigned t;
109
110	if(get_usecs(&t, str))
111		return -1;
112
113	*ticks = tc_core_usec2tick(t);
114	return 0;
115}
116
117static char *sprint_ticks(__u32 ticks, char *buf)
118{
119	return sprint_usecs(tc_core_tick2usec(ticks), buf);
120}
121
122
123static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
124			   struct nlmsghdr *n)
125{
126	size_t dist_size = 0;
127	struct rtattr *tail;
128	struct tc_netem_qopt opt;
129	struct tc_netem_corr cor;
130	struct tc_netem_reorder reorder;
131	__s16 dist_data[MAXDIST];
132
133	memset(&opt, 0, sizeof(opt));
134	opt.limit = 1000;
135	memset(&cor, 0, sizeof(cor));
136	memset(&reorder, 0, sizeof(reorder));
137
138	while (argc > 0) {
139		if (matches(*argv, "limit") == 0) {
140			NEXT_ARG();
141			if (get_size(&opt.limit, *argv)) {
142				explain1("limit");
143				return -1;
144			}
145		} else if (matches(*argv, "latency") == 0 ||
146			   matches(*argv, "delay") == 0) {
147			NEXT_ARG();
148			if (get_ticks(&opt.latency, *argv)) {
149				explain1("latency");
150				return -1;
151			}
152
153			if (NEXT_IS_NUMBER()) {
154				NEXT_ARG();
155				if (get_ticks(&opt.jitter, *argv)) {
156					explain1("latency");
157					return -1;
158				}
159
160				if (NEXT_IS_NUMBER()) {
161					NEXT_ARG();
162					if (get_percent(&cor.delay_corr,
163							*argv)) {
164						explain1("latency");
165						return -1;
166					}
167				}
168			}
169		} else if (matches(*argv, "loss") == 0 ||
170			   matches(*argv, "drop") == 0) {
171			NEXT_ARG();
172			if (get_percent(&opt.loss, *argv)) {
173				explain1("loss");
174				return -1;
175			}
176			if (NEXT_IS_NUMBER()) {
177				NEXT_ARG();
178				if (get_percent(&cor.loss_corr, *argv)) {
179					explain1("loss");
180					return -1;
181				}
182			}
183		} else if (matches(*argv, "reorder") == 0) {
184			NEXT_ARG();
185			if (get_percent(&reorder.probability, *argv)) {
186				explain1("reorder");
187				return -1;
188			}
189			if (NEXT_IS_NUMBER()) {
190				NEXT_ARG();
191				if (get_percent(&reorder.correlation, *argv)) {
192					explain1("reorder");
193					return -1;
194				}
195			}
196		} else if (matches(*argv, "gap") == 0) {
197			NEXT_ARG();
198			if (get_u32(&opt.gap, *argv, 0)) {
199				explain1("gap");
200				return -1;
201			}
202		} else if (matches(*argv, "duplicate") == 0) {
203			NEXT_ARG();
204			if (get_percent(&opt.duplicate, *argv)) {
205				explain1("duplicate");
206				return -1;
207			}
208			if (NEXT_IS_NUMBER()) {
209				NEXT_ARG();
210				if (get_percent(&cor.dup_corr, *argv)) {
211					explain1("duplicate");
212					return -1;
213				}
214			}
215		} else if (matches(*argv, "distribution") == 0) {
216			NEXT_ARG();
217			dist_size = get_distribution(*argv, dist_data);
218			if (dist_size < 0)
219				return -1;
220		} else if (strcmp(*argv, "help") == 0) {
221			explain();
222			return -1;
223		} else {
224			fprintf(stderr, "What is \"%s\"?\n", *argv);
225			explain();
226			return -1;
227		}
228		argc--; argv++;
229	}
230
231	tail = NLMSG_TAIL(n);
232
233	if (reorder.probability) {
234		if (opt.latency == 0) {
235			fprintf(stderr, "reordering not possible without specifying some delay\n");
236		}
237		if (opt.gap == 0)
238			opt.gap = 1;
239	} else if (opt.gap > 0) {
240		fprintf(stderr, "gap specified without reorder probability\n");
241		explain();
242		return -1;
243	}
244
245	if (dist_size > 0 && (opt.latency == 0 || opt.jitter == 0)) {
246		fprintf(stderr, "distribution specified but no latency and jitter values\n");
247		explain();
248		return -1;
249	}
250
251	addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt));
252	addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor));
253	addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder));
254
255	if (dist_size > 0) {
256		addattr_l(n, 32768, TCA_NETEM_DELAY_DIST,
257			  dist_data, dist_size*sizeof(dist_data[0]));
258	}
259	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
260	return 0;
261}
262
263static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
264{
265	const struct tc_netem_corr *cor = NULL;
266	const struct tc_netem_reorder *reorder = NULL;
267	struct tc_netem_qopt qopt;
268	int len = RTA_PAYLOAD(opt) - sizeof(qopt);
269	SPRINT_BUF(b1);
270
271	if (opt == NULL)
272		return 0;
273
274	if (len < 0) {
275		fprintf(stderr, "options size error\n");
276		return -1;
277	}
278	memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
279
280	if (len > 0) {
281		struct rtattr *tb[TCA_NETEM_MAX+1];
282		parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
283			     len);
284
285		if (tb[TCA_NETEM_CORR]) {
286			if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
287				return -1;
288			cor = RTA_DATA(tb[TCA_NETEM_CORR]);
289		}
290		if (tb[TCA_NETEM_REORDER]) {
291			if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
292				return -1;
293			reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
294		}
295	}
296
297	fprintf(f, "limit %d", qopt.limit);
298
299	if (qopt.latency) {
300		fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
301
302		if (qopt.jitter) {
303			fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
304			if (cor && cor->delay_corr)
305				fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
306		}
307	}
308
309	if (qopt.loss) {
310		fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
311		if (cor && cor->loss_corr)
312			fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
313	}
314
315	if (qopt.duplicate) {
316		fprintf(f, " duplicate %s",
317			sprint_percent(qopt.duplicate, b1));
318		if (cor && cor->dup_corr)
319			fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
320	}
321
322	if (reorder && reorder->probability) {
323		fprintf(f, " reorder %s",
324			sprint_percent(reorder->probability, b1));
325		if (reorder->correlation)
326			fprintf(f, " %s",
327				sprint_percent(reorder->correlation, b1));
328	}
329
330	if (qopt.gap)
331		fprintf(f, " gap %lu", (unsigned long)qopt.gap);
332
333	return 0;
334}
335
336struct qdisc_util netem_qdisc_util = {
337	.id	   	= "netem",
338	.parse_qopt	= netem_parse_opt,
339	.print_qopt	= netem_print_opt,
340};
341
342