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"                 [ corrupt PERCENT [CORRELATION]] \n" \
36"                 [ duplicate PERCENT [CORRELATION]]\n" \
37"                 [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n");
38}
39
40static void explain1(const char *arg)
41{
42	fprintf(stderr, "Illegal \"%s\"\n", arg);
43}
44
45/* Upper bound on size of distribution
46 *  really (TCA_BUF_MAX - other headers) / sizeof (__s16)
47 */
48#define MAX_DIST	(16*1024)
49
50/*
51 * Simplistic file parser for distrbution data.
52 * Format is:
53 *	# comment line(s)
54 *	data0 data1 ...
55 */
56static int get_distribution(const char *type, __s16 *data, int maxdata)
57{
58	FILE *f;
59	int n;
60	long x;
61	size_t len;
62	char *line = NULL;
63	char name[128];
64
65	snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
66	if ((f = fopen(name, "r")) == NULL) {
67		fprintf(stderr, "No distribution data for %s (%s: %s)\n",
68			type, name, strerror(errno));
69		return -1;
70	}
71
72	n = 0;
73	while (getline(&line, &len, f) != -1) {
74		char *p, *endp;
75		if (*line == '\n' || *line == '#')
76			continue;
77
78		for (p = line; ; p = endp) {
79			x = strtol(p, &endp, 0);
80			if (endp == p)
81				break;
82
83			if (n >= maxdata) {
84				fprintf(stderr, "%s: too much data\n",
85					name);
86				n = -1;
87				goto error;
88			}
89			data[n++] = x;
90		}
91	}
92 error:
93	free(line);
94	fclose(f);
95	return n;
96}
97
98static int isnumber(const char *arg)
99{
100	char *p;
101
102	return strtod(arg, &p) != 0 || p != arg;
103}
104
105#define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1]))
106
107/* Adjust for the fact that psched_ticks aren't always usecs
108   (based on kernel PSCHED_CLOCK configuration */
109static int get_ticks(__u32 *ticks, const char *str)
110{
111	unsigned t;
112
113	if(get_time(&t, str))
114		return -1;
115
116	if (tc_core_time2big(t)) {
117		fprintf(stderr, "Illegal %u time (too large)\n", t);
118		return -1;
119	}
120
121	*ticks = tc_core_time2tick(t);
122	return 0;
123}
124
125static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
126			   struct nlmsghdr *n)
127{
128	size_t dist_size = 0;
129	struct rtattr *tail;
130	struct tc_netem_qopt opt;
131	struct tc_netem_corr cor;
132	struct tc_netem_reorder reorder;
133	struct tc_netem_corrupt corrupt;
134	__s16 *dist_data = NULL;
135	int present[__TCA_NETEM_MAX];
136
137	memset(&opt, 0, sizeof(opt));
138	opt.limit = 1000;
139	memset(&cor, 0, sizeof(cor));
140	memset(&reorder, 0, sizeof(reorder));
141	memset(&corrupt, 0, sizeof(corrupt));
142	memset(present, 0, sizeof(present));
143
144	while (argc > 0) {
145		if (matches(*argv, "limit") == 0) {
146			NEXT_ARG();
147			if (get_size(&opt.limit, *argv)) {
148				explain1("limit");
149				return -1;
150			}
151		} else if (matches(*argv, "latency") == 0 ||
152			   matches(*argv, "delay") == 0) {
153			NEXT_ARG();
154			if (get_ticks(&opt.latency, *argv)) {
155				explain1("latency");
156				return -1;
157			}
158
159			if (NEXT_IS_NUMBER()) {
160				NEXT_ARG();
161				if (get_ticks(&opt.jitter, *argv)) {
162					explain1("latency");
163					return -1;
164				}
165
166				if (NEXT_IS_NUMBER()) {
167					NEXT_ARG();
168					++present[TCA_NETEM_CORR];
169					if (get_percent(&cor.delay_corr,							*argv)) {
170						explain1("latency");
171						return -1;
172					}
173				}
174			}
175		} else if (matches(*argv, "loss") == 0 ||
176			   matches(*argv, "drop") == 0) {
177			NEXT_ARG();
178			if (get_percent(&opt.loss, *argv)) {
179				explain1("loss");
180				return -1;
181			}
182			if (NEXT_IS_NUMBER()) {
183				NEXT_ARG();
184				++present[TCA_NETEM_CORR];
185				if (get_percent(&cor.loss_corr, *argv)) {
186					explain1("loss");
187					return -1;
188				}
189			}
190		} else if (matches(*argv, "reorder") == 0) {
191			NEXT_ARG();
192			present[TCA_NETEM_REORDER] = 1;
193			if (get_percent(&reorder.probability, *argv)) {
194				explain1("reorder");
195				return -1;
196			}
197			if (NEXT_IS_NUMBER()) {
198				NEXT_ARG();
199				++present[TCA_NETEM_CORR];
200				if (get_percent(&reorder.correlation, *argv)) {
201					explain1("reorder");
202					return -1;
203				}
204			}
205		} else if (matches(*argv, "corrupt") == 0) {
206			NEXT_ARG();
207			present[TCA_NETEM_CORRUPT] = 1;
208			if (get_percent(&corrupt.probability, *argv)) {
209				explain1("corrupt");
210				return -1;
211			}
212			if (NEXT_IS_NUMBER()) {
213				NEXT_ARG();
214				++present[TCA_NETEM_CORR];
215				if (get_percent(&corrupt.correlation, *argv)) {
216					explain1("corrupt");
217					return -1;
218				}
219			}
220		} else if (matches(*argv, "gap") == 0) {
221			NEXT_ARG();
222			if (get_u32(&opt.gap, *argv, 0)) {
223				explain1("gap");
224				return -1;
225			}
226		} else if (matches(*argv, "duplicate") == 0) {
227			NEXT_ARG();
228			if (get_percent(&opt.duplicate, *argv)) {
229				explain1("duplicate");
230				return -1;
231			}
232			if (NEXT_IS_NUMBER()) {
233				NEXT_ARG();
234				if (get_percent(&cor.dup_corr, *argv)) {
235					explain1("duplicate");
236					return -1;
237				}
238			}
239		} else if (matches(*argv, "distribution") == 0) {
240			NEXT_ARG();
241			dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
242			dist_size = get_distribution(*argv, dist_data, MAX_DIST);
243			if (dist_size <= 0) {
244				free(dist_data);
245				return -1;
246			}
247		} else if (strcmp(*argv, "help") == 0) {
248			explain();
249			return -1;
250		} else {
251			fprintf(stderr, "What is \"%s\"?\n", *argv);
252			explain();
253			return -1;
254		}
255		argc--; argv++;
256	}
257
258	tail = NLMSG_TAIL(n);
259
260	if (reorder.probability) {
261		if (opt.latency == 0) {
262			fprintf(stderr, "reordering not possible without specifying some delay\n");
263		}
264		if (opt.gap == 0)
265			opt.gap = 1;
266	} else if (opt.gap > 0) {
267		fprintf(stderr, "gap specified without reorder probability\n");
268		explain();
269		return -1;
270	}
271
272	if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
273		fprintf(stderr, "distribution specified but no latency and jitter values\n");
274		explain();
275		return -1;
276	}
277
278	if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
279		return -1;
280
281	if (present[TCA_NETEM_CORR] &&
282	    addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
283			return -1;
284
285	if (present[TCA_NETEM_REORDER] &&
286	    addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
287		return -1;
288
289	if (present[TCA_NETEM_CORRUPT] &&
290	    addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
291		return -1;
292
293	if (dist_data) {
294		if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
295			      TCA_NETEM_DELAY_DIST,
296			      dist_data, dist_size * sizeof(dist_data[0])) < 0)
297			return -1;
298		free(dist_data);
299	}
300	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
301	return 0;
302}
303
304static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
305{
306	const struct tc_netem_corr *cor = NULL;
307	const struct tc_netem_reorder *reorder = NULL;
308	const struct tc_netem_corrupt *corrupt = NULL;
309	struct tc_netem_qopt qopt;
310	int len = RTA_PAYLOAD(opt) - sizeof(qopt);
311	SPRINT_BUF(b1);
312
313	if (opt == NULL)
314		return 0;
315
316	if (len < 0) {
317		fprintf(stderr, "options size error\n");
318		return -1;
319	}
320	memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
321
322	if (len > 0) {
323		struct rtattr *tb[TCA_NETEM_MAX+1];
324		parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
325			     len);
326
327		if (tb[TCA_NETEM_CORR]) {
328			if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
329				return -1;
330			cor = RTA_DATA(tb[TCA_NETEM_CORR]);
331		}
332		if (tb[TCA_NETEM_REORDER]) {
333			if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
334				return -1;
335			reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
336		}
337		if (tb[TCA_NETEM_CORRUPT]) {
338			if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
339				return -1;
340			corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
341		}
342	}
343
344	fprintf(f, "limit %d", qopt.limit);
345
346	if (qopt.latency) {
347		fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
348
349		if (qopt.jitter) {
350			fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
351			if (cor && cor->delay_corr)
352				fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
353		}
354	}
355
356	if (qopt.loss) {
357		fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
358		if (cor && cor->loss_corr)
359			fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
360	}
361
362	if (qopt.duplicate) {
363		fprintf(f, " duplicate %s",
364			sprint_percent(qopt.duplicate, b1));
365		if (cor && cor->dup_corr)
366			fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
367	}
368
369	if (reorder && reorder->probability) {
370		fprintf(f, " reorder %s",
371			sprint_percent(reorder->probability, b1));
372		if (reorder->correlation)
373			fprintf(f, " %s",
374				sprint_percent(reorder->correlation, b1));
375	}
376
377	if (corrupt && corrupt->probability) {
378		fprintf(f, " corrupt %s",
379			sprint_percent(corrupt->probability, b1));
380		if (corrupt->correlation)
381			fprintf(f, " %s",
382				sprint_percent(corrupt->correlation, b1));
383	}
384
385	if (qopt.gap)
386		fprintf(f, " gap %lu", (unsigned long)qopt.gap);
387
388	return 0;
389}
390
391struct qdisc_util netem_qdisc_util = {
392	.id	   	= "netem",
393	.parse_qopt	= netem_parse_opt,
394	.print_qopt	= netem_print_opt,
395};
396
397