/* * 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 * */ #include #include #include #include #include #include #include #include #include #include #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" \ " [ drop PERCENT [CORRELATION]] \n" \ " [ duplicate PERCENT [CORRELATION]]\n" \ " [ distribution {uniform|normal|pareto|paretonormal} ]\n" \ " [ gap PACKETS ]\n"); } static void explain1(const char *arg) { fprintf(stderr, "Illegal \"%s\"\n", arg); } #define usage() return(-1) /* * Simplistic file parser for distrbution data. * Format is: * # comment line(s) * data0 data1 */ #define MAXDIST 65536 static int get_distribution(const char *type, __s16 *data) { FILE *f; int n; long x; size_t len; char *line = NULL; char name[128]; snprintf(name, sizeof(name), "/usr/lib/tc/%s.dist", 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 >= MAXDIST) { fprintf(stderr, "%s: too much data\n", name); n = -1; goto error; } data[n++] = x; } } error: free(line); fclose(f); return n; } static int isnumber(const char *arg) { char *p; (void) strtod(arg, &p); return (p != arg); } #define NEXT_IS_NUMBER() (NEXT_ARG_OK() && isnumber(argv[1])) /* 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_usecs(&t, str)) return -1; *ticks = tc_core_usec2tick(t); return 0; } static char *sprint_ticks(__u32 ticks, char *buf) { return sprint_usecs(tc_core_tick2usec(ticks), buf); } static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n) { size_t dist_size = 0; struct rtattr *tail; struct tc_netem_qopt opt; struct tc_netem_corr cor; __s16 dist_data[MAXDIST]; memset(&opt, 0, sizeof(opt)); opt.limit = 1000; memset(&cor, 0, sizeof(cor)); while (argc > 0) { 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(); if (get_percent(&cor.delay_corr, *argv)) { explain1("latency"); return -1; } } } } else if (matches(*argv, "loss") == 0 || matches(*argv, "drop") == 0) { NEXT_ARG(); if (get_percent(&opt.loss, *argv)) { explain1("loss"); return -1; } if (NEXT_IS_NUMBER()) { NEXT_ARG(); if (get_percent(&cor.loss_corr, *argv)) { explain1("loss"); 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_size = get_distribution(*argv, dist_data); if (dist_size < 0) return -1; } else if (strcmp(*argv, "help") == 0) { explain(); return -1; } else { fprintf(stderr, "What is \"%s\"?\n", *argv); explain(); return -1; } argc--; argv++; } tail = NLMSG_TAIL(n); addattr_l(n, 1024, TCA_OPTIONS, &opt, sizeof(opt)); addattr_l(n, 1024, TCA_NETEM_CORR, &cor, sizeof(cor)); if (dist_size > 0) { addattr_l(n, 32768, TCA_NETEM_DELAY_DIST, dist_data, dist_size*sizeof(dist_data[0])); } 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; struct tc_netem_qopt qopt; int len = RTA_PAYLOAD(opt) - sizeof(qopt); 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]); } } 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 (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 (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, };