tc/m_sample.c

   1 /*
   2  * m_sample.c           ingress/egress packet sampling module
   3  *
   4  *              This program is free software; you can distribute 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:     Yotam Gigi <yotamg@mellanox.com>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include "utils.h"
  15 #include "tc_util.h"
  16 #include "tc_common.h"
  17 #include <linux/tc_act/tc_sample.h>
  18
  19 static void explain(void)
  20 {
  21         fprintf(stderr, "Usage: sample SAMPLE_CONF\n");
  22         fprintf(stderr, "where:\n");
  23         fprintf(stderr, "\tSAMPLE_CONF := SAMPLE_PARAMS | SAMPLE_INDEX\n");
  24         fprintf(stderr, "\tSAMPLE_PARAMS := rate RATE group GROUP [trunc SIZE] [SAMPLE_INDEX]\n");
  25         fprintf(stderr, "\tSAMPLE_INDEX := index INDEX\n");
  26         fprintf(stderr, "\tRATE := The ratio of packets observed at the data source to the samples generated.\n");
  27         fprintf(stderr, "\tGROUP := the psample sampling group\n");
  28         fprintf(stderr, "\tSIZE := the truncation size\n");
  29         fprintf(stderr, "\tINDEX := integer index of the sample action\n");
  30 }
  31
  32 static void usage(void)
  33 {
  34         explain();
  35         exit(-1);
  36 }
  37
  38 static int parse_sample(struct action_util *a, int *argc_p, char ***argv_p,
  39                         int tca_id, struct nlmsghdr *n)
  40 {
  41         struct tc_sample p = { 0 };
  42         bool trunc_set = false;
  43         bool group_set = false;
  44         bool rate_set = false;
  45         char **argv = *argv_p;
  46         struct rtattr *tail;
  47         int argc = *argc_p;
  48         __u32 trunc;
  49         __u32 group;
  50         __u32 rate;
  51
  52         if (argc <= 1) {
  53                 fprintf(stderr, "sample bad argument count %d\n", argc);
  54                 usage();
  55                 return -1;
  56         }
  57
  58         if (matches(*argv, "sample") == 0) {
  59                 NEXT_ARG();
  60         } else {
  61                 fprintf(stderr, "sample bad argument %s\n", *argv);
  62                 return -1;
  63         }
  64
  65         while (argc > 0) {
  66                 if (matches(*argv, "rate") == 0) {
  67                         NEXT_ARG();
  68                         if (get_unsigned(&rate, *argv, 10) != 0) {
  69                                 fprintf(stderr, "Illegal rate %s\n", *argv);
  70                                 usage();
  71                                 return -1;
  72                         }
  73                         rate_set = true;
  74                 } else if (matches(*argv, "group") == 0) {
  75                         NEXT_ARG();
  76                         if (get_unsigned(&group, *argv, 10) != 0) {
  77                                 fprintf(stderr, "Illegal group num %s\n",
  78                                         *argv);
  79                                 usage();
  80                                 return -1;
  81                         }
  82                         group_set = true;
  83                 } else if (matches(*argv, "trunc") == 0) {
  84                         NEXT_ARG();
  85                         if (get_unsigned(&trunc, *argv, 10) != 0) {
  86                                 fprintf(stderr, "Illegal truncation size %s\n",
  87                                         *argv);
  88                                 usage();
  89                                 return -1;
  90                         }
  91                         trunc_set = true;
  92                 } else if (matches(*argv, "help") == 0) {
  93                         usage();
  94                 } else {
  95                         break;
  96                 }
  97
  98                 NEXT_ARG_FWD();
  99         }
 100
 101         parse_action_control_dflt(&argc, &argv, &p.action, false, TC_ACT_PIPE);
 102
 103         if (argc) {
 104                 if (matches(*argv, "index") == 0) {
 105                         NEXT_ARG();
 106                         if (get_u32(&p.index, *argv, 10)) {
 107                                 fprintf(stderr, "sample: Illegal \"index\"\n");
 108                                 return -1;
 109                         }
 110                         NEXT_ARG_FWD();
 111                 }
 112         }
 113
 114         if (!p.index && !group_set) {
 115                 fprintf(stderr, "param \"group\" not set\n");
 116                 usage();
 117         }
 118
 119         if (!p.index && !rate_set) {
 120                 fprintf(stderr, "param \"rate\" not set\n");
 121                 usage();
 122         }
 123
 124         tail = NLMSG_TAIL(n);
 125         addattr_l(n, MAX_MSG, tca_id, NULL, 0);
 126         addattr_l(n, MAX_MSG, TCA_SAMPLE_PARMS, &p, sizeof(p));
 127         if (rate_set)
 128                 addattr32(n, MAX_MSG, TCA_SAMPLE_RATE, rate);
 129         if (group_set)
 130                 addattr32(n, MAX_MSG, TCA_SAMPLE_PSAMPLE_GROUP, group);
 131         if (trunc_set)
 132                 addattr32(n, MAX_MSG, TCA_SAMPLE_TRUNC_SIZE, trunc);
 133
 134         tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
 135
 136         *argc_p = argc;
 137         *argv_p = argv;
 138         return 0;
 139 }
 140
 141 static int print_sample(struct action_util *au, FILE *f, struct rtattr *arg)
 142 {
 143         struct rtattr *tb[TCA_SAMPLE_MAX + 1];
 144         struct tc_sample *p;
 145
 146         if (arg == NULL)
 147                 return -1;
 148
 149         parse_rtattr_nested(tb, TCA_SAMPLE_MAX, arg);
 150
 151         if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] ||
 152             !tb[TCA_SAMPLE_PSAMPLE_GROUP]) {
 153                 fprintf(f, "[NULL sample parameters]");
 154                 return -1;
 155         }
 156         p = RTA_DATA(tb[TCA_SAMPLE_PARMS]);
 157
 158         fprintf(f, "sample rate 1/%d group %d",
 159                 rta_getattr_u32(tb[TCA_SAMPLE_RATE]),
 160                 rta_getattr_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]));
 161
 162         if (tb[TCA_SAMPLE_TRUNC_SIZE])
 163                 fprintf(f, " trunc_size %d",
 164                         rta_getattr_u32(tb[TCA_SAMPLE_TRUNC_SIZE]));
 165
 166         fprintf(f, "\n\tindex %d ref %d bind %d", p->index, p->refcnt,
 167                 p->bindcnt);
 168
 169         if (show_stats) {
 170                 if (tb[TCA_SAMPLE_TM]) {
 171                         struct tcf_t *tm = RTA_DATA(tb[TCA_SAMPLE_TM]);
 172
 173                         print_tm(f, tm);
 174                 }
 175         }
 176         fprintf(f, "\n");
 177         return 0;
 178 }
 179
 180 struct action_util sample_action_util = {
 181         .id = "sample",
 182         .parse_aopt = parse_sample,
 183         .print_aopt = print_sample,
 184 };