text: /*
   * q_netem.c		NETEM.
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   *
   * Authors:	Stephen Hemminger <shemminger@linux-foundation.org>
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <math.h>
  #include <ctype.h>
  #include <unistd.h>
  #include <syslog.h>
  #include <fcntl.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <string.h>
  #include <errno.h>
  
  #include "utils.h"
  #include "tc_util.h"
  #include "tc_common.h"
  
  static void explain(void)
  {
  	fprintf(stderr,
  "Usage: ... netem [ limit PACKETS ] \n" \
  "                 [ delay TIME [ JITTER [CORRELATION]]]\n" \
  "                 [ distribution {uniform|normal|pareto|paretonormal} ]\n" \
  "                 [ corrupt PERCENT [CORRELATION]] \n" \
  "                 [ duplicate PERCENT [CORRELATION]]\n" \
  "                 [ loss random PERCENT [CORRELATION]]\n" \
  "                 [ loss state P13 [P31 [P32 [P23 P14]]]\n" \
  "                 [ loss gemodel PERCENT [R [1-H [1-K]]]\n" \
  "                 [ ecn ]\n" \
  "                 [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n" \
  "                 [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n");
  }
  
  static void explain1(const char *arg)
  {
  	fprintf(stderr, "Illegal \"%s\"\n", arg);
  }
  
  /* Upper bound on size of distribution
   *  really (TCA_BUF_MAX - other headers) / sizeof (__s16)
   */
  #define MAX_DIST	(16*1024)
  
  static const double max_percent_value = 0xffffffff;
  
  /* scaled value used to percent of maximum. */
  static void set_percent(__u32 *percent, double per)
  {
  	*percent = (unsigned) rint(per * max_percent_value);
  }
  
  
  /* Parse either a fraction '.3' or percent '30%
   * return: 0 = ok, -1 = error, 1 = out of range
   */
  static int parse_percent(double *val, const char *str)
  {
  	char *p;
  
  	*val = strtod(str, &p) / 100.;
  	if (*p && strcmp(p, "%") )
  		return -1;
  
  	return 0;
  }
  
  static int get_percent(__u32 *percent, const char *str)
  {
  	double per;
  
  	if (parse_percent(&per, str))
  		return -1;
  
  	set_percent(percent, per);
  	return 0;
  }
  
  static void print_percent(char *buf, int len, __u32 per)
  {
  	snprintf(buf, len, "%g%%", 100. * (double) per / max_percent_value);
  }
  
  static char * sprint_percent(__u32 per, char *buf)
  {
  	print_percent(buf, SPRINT_BSIZE-1, per);
  	return buf;
  }
  
  /*
   * Simplistic file parser for distrbution data.
   * Format is:
   *	# comment line(s)
   *	data0 data1 ...
   */
  static int get_distribution(const char *type, __s16 *data, int maxdata)
  {
  	FILE *f;
  	int n;
  	long x;
  	size_t len;
  	char *line = NULL;
  	char name[128];
  
  	snprintf(name, sizeof(name), "%s/%s.dist", get_tc_lib(), type);
  	if ((f = fopen(name, "r")) == NULL) {
  		fprintf(stderr, "No distribution data for %s (%s: %s)\n",
  			type, name, strerror(errno));
  		return -1;
  	}
  
  	n = 0;
  	while (getline(&line, &len, f) != -1) {
  		char *p, *endp;
  		if (*line == '\n' || *line == '#')
  			continue;
  
  		for (p = line; ; p = endp) {
  			x = strtol(p, &endp, 0);
  			if (endp == p)
  				break;
  
  			if (n >= maxdata) {
  				fprintf(stderr, "%s: too much data\n",
  					name);
  				n = -1;
  				goto error;
  			}
  			data[n++] = x;
  		}
  	}
   error:
  	free(line);
  	fclose(f);
  	return n;
  }
  
  #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isdigit(argv[1][0]))
  #define NEXT_IS_SIGNED_NUMBER() \
  	(NEXT_ARG_OK() && (isdigit(argv[1][0]) || argv[1][0] == '-'))
  
  /* Adjust for the fact that psched_ticks aren't always usecs
     (based on kernel PSCHED_CLOCK configuration */
  static int get_ticks(__u32 *ticks, const char *str)
  {
  	unsigned t;
  
  	if(get_time(&t, str))
  		return -1;
  
  	if (tc_core_time2big(t)) {
  		fprintf(stderr, "Illegal %u time (too large)\n", t);
  		return -1;
  	}
  
  	*ticks = tc_core_time2tick(t);
  	return 0;
  }
  
  static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
  			   struct nlmsghdr *n)
  {
  	int dist_size = 0;
  	struct rtattr *tail;
  	struct tc_netem_qopt opt = { .limit = 1000 };
  	struct tc_netem_corr cor;
  	struct tc_netem_reorder reorder;
  	struct tc_netem_corrupt corrupt;
  	struct tc_netem_gimodel gimodel;
  	struct tc_netem_gemodel gemodel;
  	struct tc_netem_rate rate;
  	__s16 *dist_data = NULL;
  	__u16 loss_type = NETEM_LOSS_UNSPEC;
  	int present[__TCA_NETEM_MAX];
  	__u64 rate64 = 0;
  
  	memset(&cor, 0, sizeof(cor));
  	memset(&reorder, 0, sizeof(reorder));
  	memset(&corrupt, 0, sizeof(corrupt));
  	memset(&rate, 0, sizeof(rate));
  	memset(present, 0, sizeof(present));
  
  	for( ; argc > 0; --argc, ++argv) {
  		if (matches(*argv, "limit") == 0) {
  			NEXT_ARG();
  			if (get_size(&opt.limit, *argv)) {
  				explain1("limit");
  				return -1;
  			}
  		} else if (matches(*argv, "latency") == 0 ||
  			   matches(*argv, "delay") == 0) {
  			NEXT_ARG();
  			if (get_ticks(&opt.latency, *argv)) {
  				explain1("latency");
  				return -1;
  			}
  
  			if (NEXT_IS_NUMBER()) {
  				NEXT_ARG();
  				if (get_ticks(&opt.jitter, *argv)) {
  					explain1("latency");
  					return -1;
  				}
  
  				if (NEXT_IS_NUMBER()) {
  					NEXT_ARG();
  					++present[TCA_NETEM_CORR];
  					if (get_percent(&cor.delay_corr, *argv)) {
  						explain1("latency");
  						return -1;
  					}
  				}
  			}
  		} else if (matches(*argv, "loss") == 0 ||
  			   matches(*argv, "drop") == 0) {
  			if (opt.loss > 0 || loss_type != NETEM_LOSS_UNSPEC) {
  				explain1("duplicate loss argument\n");
  				return -1;
  			}
  
  			NEXT_ARG();
  			/* Old (deprecated) random loss model syntax */
  			if (isdigit(argv[0][0]))
  				goto random_loss_model;
  
  			if (!strcmp(*argv, "random")) {
  				NEXT_ARG();
  	random_loss_model:
  				if (get_percent(&opt.loss, *argv)) {
  					explain1("loss percent");
  					return -1;
  				}
  				if (NEXT_IS_NUMBER()) {
  					NEXT_ARG();
  					++present[TCA_NETEM_CORR];
  					if (get_percent(&cor.loss_corr, *argv)) {
  						explain1("loss correllation");
  						return -1;
  					}
  				}
  			} else if (!strcmp(*argv, "state")) {
  				double p13;
  
  				NEXT_ARG();
  				if (parse_percent(&p13, *argv)) {
  					explain1("loss p13");
  					return -1;
  				}
  
  				/* set defaults */
  				set_percent(&gimodel.p13, p13);
  				set_percent(&gimodel.p31, 1. - p13);
  				set_percent(&gimodel.p32, 0);
  				set_percent(&gimodel.p23, 1.);
  				set_percent(&gimodel.p14, 0);
  				loss_type = NETEM_LOSS_GI;
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gimodel.p31, *argv)) {
  					explain1("loss p31");
  					return -1;
  				}
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gimodel.p32, *argv)) {
  					explain1("loss p32");
  					return -1;
  				}
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gimodel.p23, *argv)) {
  					explain1("loss p23");
  					return -1;
  				}
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gimodel.p14, *argv)) {
  					explain1("loss p14");
  					return -1;
  				}
  
  			} else if (!strcmp(*argv, "gemodel")) {
  				NEXT_ARG();
  				if (get_percent(&gemodel.p, *argv)) {
  					explain1("loss gemodel p");
  					return -1;
  				}
  
  				/* set defaults */
  				set_percent(&gemodel.r, 1.);
  				set_percent(&gemodel.h, 0);
  				set_percent(&gemodel.k1, 0);
  				loss_type = NETEM_LOSS_GE;
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gemodel.r, *argv)) {
  					explain1("loss gemodel r");
  					return -1;
  				}
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gemodel.h, *argv)) {
  					explain1("loss gemodel h");
  					return -1;
  				}
  				/* netem option is "1-h" but kernel
  				 * expects "h".
  				 */
  				gemodel.h = max_percent_value - gemodel.h;
  
  				if (!NEXT_IS_NUMBER())
  					continue;
  				NEXT_ARG();
  				if (get_percent(&gemodel.k1, *argv)) {
  					explain1("loss gemodel k");
  					return -1;
  				}
  			} else {
  				fprintf(stderr, "Unknown loss parameter: %s\n",
  					*argv);
  				return -1;
  			}
  		} else if (matches(*argv, "ecn") == 0) {
  				present[TCA_NETEM_ECN] = 1;
  		} else if (matches(*argv, "reorder") == 0) {
  			NEXT_ARG();
  			present[TCA_NETEM_REORDER] = 1;
  			if (get_percent(&reorder.probability, *argv)) {
  				explain1("reorder");
  				return -1;
  			}
  			if (NEXT_IS_NUMBER()) {
  				NEXT_ARG();
  				++present[TCA_NETEM_CORR];
  				if (get_percent(&reorder.correlation, *argv)) {
  					explain1("reorder");
  					return -1;
  				}
  			}
  		} else if (matches(*argv, "corrupt") == 0) {
  			NEXT_ARG();
  			present[TCA_NETEM_CORRUPT] = 1;
  			if (get_percent(&corrupt.probability, *argv)) {
  				explain1("corrupt");
  				return -1;
  			}
  			if (NEXT_IS_NUMBER()) {
  				NEXT_ARG();
  				++present[TCA_NETEM_CORR];
  				if (get_percent(&corrupt.correlation, *argv)) {
  					explain1("corrupt");
  					return -1;
  				}
  			}
  		} else if (matches(*argv, "gap") == 0) {
  			NEXT_ARG();
  			if (get_u32(&opt.gap, *argv, 0)) {
  				explain1("gap");
  				return -1;
  			}
  		} else if (matches(*argv, "duplicate") == 0) {
  			NEXT_ARG();
  			if (get_percent(&opt.duplicate, *argv)) {
  				explain1("duplicate");
  				return -1;
  			}
  			if (NEXT_IS_NUMBER()) {
  				NEXT_ARG();
  				if (get_percent(&cor.dup_corr, *argv)) {
  					explain1("duplicate");
  					return -1;
  				}
  			}
  		} else if (matches(*argv, "distribution") == 0) {
  			NEXT_ARG();
  			dist_data = calloc(sizeof(dist_data[0]), MAX_DIST);
  			dist_size = get_distribution(*argv, dist_data, MAX_DIST);
  			if (dist_size <= 0) {
  				free(dist_data);
  				return -1;
  			}
  		} else if (matches(*argv, "rate") == 0) {
  			++present[TCA_NETEM_RATE];
  			NEXT_ARG();
  			if (get_rate64(&rate64, *argv)) {
  				explain1("rate");
  				return -1;
  			}
  			if (NEXT_IS_SIGNED_NUMBER()) {
  				NEXT_ARG();
  				if (get_s32(&rate.packet_overhead, *argv, 0)) {
  					explain1("rate");
  					return -1;
  				}
  			}
  			if (NEXT_IS_NUMBER()) {
  				NEXT_ARG();
  				if (get_u32(&rate.cell_size, *argv, 0)) {
  					explain1("rate");
  					return -1;
  				}
  			}
  			if (NEXT_IS_SIGNED_NUMBER()) {
  				NEXT_ARG();
  				if (get_s32(&rate.cell_overhead, *argv, 0)) {
  					explain1("rate");
  					return -1;
  				}
  			}
  		} else if (strcmp(*argv, "help") == 0) {
  			explain();
  			return -1;
  		} else {
  			fprintf(stderr, "What is \"%s\"?\n", *argv);
  			explain();
  			return -1;
  		}
  	}
  
  	tail = NLMSG_TAIL(n);
  
  	if (reorder.probability) {
  		if (opt.latency == 0) {
  			fprintf(stderr, "reordering not possible without specifying some delay\n");
  			explain();
  			return -1;
  		}
  		if (opt.gap == 0)
  			opt.gap = 1;
  	} else if (opt.gap > 0) {
  		fprintf(stderr, "gap specified without reorder probability\n");
  		explain();
  		return -1;
  	}
  
  	if (present[TCA_NETEM_ECN]) {
  		if (opt.loss <= 0 && loss_type == NETEM_LOSS_UNSPEC) {
  			fprintf(stderr, "ecn requested without loss model\n");
  			explain();
  			return -1;
  		}
  	}
  
  	if (dist_data && (opt.latency == 0 || opt.jitter == 0)) {
  		fprintf(stderr, "distribution specified but no latency and jitter values\n");
  		explain();
  		return -1;
  	}
  
  	if (addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)) < 0)
  		return -1;
  
  	if (present[TCA_NETEM_CORR] &&
  	    addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)) < 0)
  			return -1;
  
  	if (present[TCA_NETEM_REORDER] &&
  	    addattr_l(n, 1024, TCA_NETEM_REORDER, &reorder, sizeof(reorder)) < 0)
  		return -1;
  
  	if (present[TCA_NETEM_ECN] &&
  	    addattr_l(n, 1024, TCA_NETEM_ECN, &present[TCA_NETEM_ECN],
  		      sizeof(present[TCA_NETEM_ECN])) < 0)
  			return -1;
  
  	if (present[TCA_NETEM_CORRUPT] &&
  	    addattr_l(n, 1024, TCA_NETEM_CORRUPT, &corrupt, sizeof(corrupt)) < 0)
  		return -1;
  
  	if (loss_type != NETEM_LOSS_UNSPEC) {
  		struct rtattr *start;
  
  		start = addattr_nest(n, 1024, TCA_NETEM_LOSS | NLA_F_NESTED);
  		if (loss_type == NETEM_LOSS_GI) {
  			if (addattr_l(n, 1024, NETEM_LOSS_GI,
  				      &gimodel, sizeof(gimodel)) < 0)
  			    return -1;
  		} else if (loss_type == NETEM_LOSS_GE) {
  			if (addattr_l(n, 1024, NETEM_LOSS_GE,
  				      &gemodel, sizeof(gemodel)) < 0)
  			    return -1;
  		} else {
  			fprintf(stderr, "loss in the weeds!\n");
  			return -1;
  		}
  
  		addattr_nest_end(n, start);
  	}
  
  	if (present[TCA_NETEM_RATE]) {
  		if (rate64 >= (1ULL << 32)) {
  			if (addattr_l(n, 1024,
  				      TCA_NETEM_RATE64, &rate64, sizeof(rate64)) < 0)
  				return -1;
  			rate.rate = ~0U;
  		} else {
  			rate.rate = rate64;
  		}
  		if (addattr_l(n, 1024, TCA_NETEM_RATE, &rate, sizeof(rate)) < 0)
  			return -1;
  	}
  
  	if (dist_data) {
  		if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
  			      TCA_NETEM_DELAY_DIST,
  			      dist_data, dist_size * sizeof(dist_data[0])) < 0)
  			return -1;
  		free(dist_data);
  	}
  	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
  	return 0;
  }
  
  static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
  {
  	const struct tc_netem_corr *cor = NULL;
  	const struct tc_netem_reorder *reorder = NULL;
  	const struct tc_netem_corrupt *corrupt = NULL;
  	const struct tc_netem_gimodel *gimodel = NULL;
  	const struct tc_netem_gemodel *gemodel = NULL;
  	int *ecn = NULL;
  	struct tc_netem_qopt qopt;
  	const struct tc_netem_rate *rate = NULL;
  	int len = RTA_PAYLOAD(opt) - sizeof(qopt);
  	__u64 rate64 = 0;
  	SPRINT_BUF(b1);
  
  	if (opt == NULL)
  		return 0;
  
  	if (len < 0) {
  		fprintf(stderr, "options size error\n");
  		return -1;
  	}
  	memcpy(&qopt, RTA_DATA(opt), sizeof(qopt));
  
  	if (len > 0) {
  		struct rtattr *tb[TCA_NETEM_MAX+1];
  		parse_rtattr(tb, TCA_NETEM_MAX, RTA_DATA(opt) + sizeof(qopt),
  			     len);
  
  		if (tb[TCA_NETEM_CORR]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_CORR]) < sizeof(*cor))
  				return -1;
  			cor = RTA_DATA(tb[TCA_NETEM_CORR]);
  		}
  		if (tb[TCA_NETEM_REORDER]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_REORDER]) < sizeof(*reorder))
  				return -1;
  			reorder = RTA_DATA(tb[TCA_NETEM_REORDER]);
  		}
  		if (tb[TCA_NETEM_CORRUPT]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_CORRUPT]) < sizeof(*corrupt))
  				return -1;
  			corrupt = RTA_DATA(tb[TCA_NETEM_CORRUPT]);
  		}
  		if (tb[TCA_NETEM_LOSS]) {
  			struct rtattr *lb[NETEM_LOSS_MAX + 1];
  
  			parse_rtattr_nested(lb, NETEM_LOSS_MAX, tb[TCA_NETEM_LOSS]);
  			if (lb[NETEM_LOSS_GI])
  				gimodel = RTA_DATA(lb[NETEM_LOSS_GI]);
  			if (lb[NETEM_LOSS_GE])
  				gemodel = RTA_DATA(lb[NETEM_LOSS_GE]);
  		}
  		if (tb[TCA_NETEM_RATE]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_RATE]) < sizeof(*rate))
  				return -1;
  			rate = RTA_DATA(tb[TCA_NETEM_RATE]);
  		}
  		if (tb[TCA_NETEM_ECN]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_ECN]) < sizeof(*ecn))
  				return -1;
  			ecn = RTA_DATA(tb[TCA_NETEM_ECN]);
  		}
  		if (tb[TCA_NETEM_RATE64]) {
  			if (RTA_PAYLOAD(tb[TCA_NETEM_RATE64]) < sizeof(rate64))
  				return -1;
  			rate64 = rta_getattr_u64(tb[TCA_NETEM_RATE64]);
  		}
  	}
  
  	fprintf(f, "limit %d", qopt.limit);
  
  	if (qopt.latency) {
  		fprintf(f, " delay %s", sprint_ticks(qopt.latency, b1));
  
  		if (qopt.jitter) {
  			fprintf(f, "  %s", sprint_ticks(qopt.jitter, b1));
  			if (cor && cor->delay_corr)
  				fprintf(f, " %s", sprint_percent(cor->delay_corr, b1));
  		}
  	}
  
  	if (qopt.loss) {
  		fprintf(f, " loss %s", sprint_percent(qopt.loss, b1));
  		if (cor && cor->loss_corr)
  			fprintf(f, " %s", sprint_percent(cor->loss_corr, b1));
  	}
  
  	if (gimodel) {
  		fprintf(f, " loss state p13 %s", sprint_percent(gimodel->p13, b1));
  		fprintf(f, " p31 %s", sprint_percent(gimodel->p31, b1));
  		fprintf(f, " p32 %s", sprint_percent(gimodel->p32, b1));
  		fprintf(f, " p23 %s", sprint_percent(gimodel->p23, b1));
  		fprintf(f, " p14 %s", sprint_percent(gimodel->p14, b1));
  	}
  
  	if (gemodel) {
  		fprintf(f, " loss gemodel p %s",
  			sprint_percent(gemodel->p, b1));
  		fprintf(f, " r %s", sprint_percent(gemodel->r, b1));
  		fprintf(f, " 1-h %s", sprint_percent(max_percent_value -
  						     gemodel->h, b1));
  		fprintf(f, " 1-k %s", sprint_percent(gemodel->k1, b1));
  	}
  
  	if (qopt.duplicate) {
  		fprintf(f, " duplicate %s",
  			sprint_percent(qopt.duplicate, b1));
  		if (cor && cor->dup_corr)
  			fprintf(f, " %s", sprint_percent(cor->dup_corr, b1));
  	}
  
  	if (reorder && reorder->probability) {
  		fprintf(f, " reorder %s",
  			sprint_percent(reorder->probability, b1));
  		if (reorder->correlation)
  			fprintf(f, " %s",
  				sprint_percent(reorder->correlation, b1));
  	}
  
  	if (corrupt && corrupt->probability) {
  		fprintf(f, " corrupt %s",
  			sprint_percent(corrupt->probability, b1));
  		if (corrupt->correlation)
  			fprintf(f, " %s",
  				sprint_percent(corrupt->correlation, b1));
  	}
  
  	if (rate && rate->rate) {
  		if (rate64)
  			fprintf(f, " rate %s", sprint_rate(rate64, b1));
  		else
  			fprintf(f, " rate %s", sprint_rate(rate->rate, b1));
  		if (rate->packet_overhead)
  			fprintf(f, " packetoverhead %d", rate->packet_overhead);
  		if (rate->cell_size)
  			fprintf(f, " cellsize %u", rate->cell_size);
  		if (rate->cell_overhead)
  			fprintf(f, " celloverhead %d", rate->cell_overhead);
  	}
  
  	if (ecn)
  		fprintf(f, " ecn ");
  
  	if (qopt.gap)
  		fprintf(f, " gap %lu", (unsigned long)qopt.gap);
  
  
  	return 0;
  }
  
  struct qdisc_util netem_qdisc_util = {
  	.id	   	= "netem",
  	.parse_qopt	= netem_parse_opt,
  	.print_qopt	= netem_print_opt,
  };
  
  