lttng/commands/add_channel.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   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 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27
  28 #include "cmd.h"
  29 #include "config.h"
  30 #include "utils.h"
  31
  32 static char *opt_channel_name;
  33 static char *opt_kernel;
  34 static char *opt_cmd_name;
  35 static int opt_pid_all;
  36 static int opt_userspace;
  37 static pid_t opt_pid;
  38 static struct lttng_channel chan;
  39
  40 enum {
  41         OPT_HELP = 1,
  42         OPT_DISCARD,
  43         OPT_OVERWRITE,
  44         OPT_SUBBUF_SIZE,
  45         OPT_NUM_SUBBUF,
  46         OPT_SWITCH_TIMER,
  47         OPT_READ_TIMER,
  48         OPT_USERSPACE,
  49 };
  50
  51 static struct poptOption long_options[] = {
  52         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  53         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  54         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  55         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
  56         {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
  57         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  58         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  59         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  60         {"subbuf_size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  61         {"num_subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  62         {"switch_timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  63         {"read_timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  64         {0, 0, 0, 0, 0, 0, 0}
  65 };
  66
  67 /*
  68  * usage
  69  */
  70 static void usage(FILE *ofp)
  71 {
  72         fprintf(ofp, "usage: lttng add-channel NAME [options] [channel_options]\n");
  73         fprintf(ofp, "\n");
  74         fprintf(ofp, "  -h, --help               Show this help\n");
  75         fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
  76         fprintf(ofp, "  -u, --userspace [CMD]    Apply on the user-space tracer\n");
  77         fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
  78         fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
  79         fprintf(ofp, "\n");
  80         fprintf(ofp, "Channel options:\n");
  81         fprintf(ofp, "      --discard            Discard event when buffers are full (default)\n");
  82         fprintf(ofp, "      --overwrite          Flight recorder mode\n");
  83         fprintf(ofp, "      --subbuf_size        Subbuffer size in bytes (default: 4096)\n");
  84         fprintf(ofp, "      --num_subbuf         Number of subbufers (default: 2)\n");
  85         fprintf(ofp, "      --switch_timer       Switch timer interval in usec (default: 0)\n");
  86         fprintf(ofp, "      --read_timer         Read timer interval in usec (default: 200)\n");
  87         fprintf(ofp, "\n");
  88 }
  89
  90 /*
  91  *  add_channel
  92  *
  93  *  Adding channel using the lttng API.
  94  */
  95 static int add_channel(void)
  96 {
  97         int ret = CMD_SUCCESS;
  98
  99         if (set_session_name() < 0) {
 100                 ret = CMD_ERROR;
 101                 goto error;
 102         }
 103
 104         /* Copy channel name and normalize it */
 105         strncpy(chan.name, opt_channel_name, NAME_MAX);
 106         chan.name[NAME_MAX - 1] = '\0';
 107
 108         /* Kernel tracer action */
 109         if (opt_kernel) {
 110                 /* Create kernel channel */
 111                 ret = lttng_kernel_create_channel(&chan);
 112                 if (ret < 0) {
 113                         goto error;
 114                 }
 115         } else if (opt_userspace) {             /* User-space tracer action */
 116                 /*
 117                  * TODO: Waiting on lttng UST 2.0
 118                  */
 119                 if (opt_pid_all) {
 120                 } else if (opt_pid != 0) {
 121                 }
 122                 ret = CMD_NOT_IMPLEMENTED;
 123                 goto error;
 124         } else {
 125                 ERR("Please specify a tracer (kernel or user-space)");
 126                 goto error;
 127         }
 128
 129         MSG("Channel %s created", opt_channel_name);
 130
 131 error:
 132         return ret;
 133 }
 134
 135 /*
 136  *  init_channel_config
 137  *
 138  *  Default value for channel configuration.
 139  */
 140 static void init_channel_config(void)
 141 {
 142         chan.attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 143         chan.attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 144         chan.attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 145         chan.attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 146         chan.attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 147 }
 148
 149 /*
 150  *  cmd_add_channel
 151  *
 152  *  Add channel to trace session
 153  */
 154 int cmd_add_channel(int argc, const char **argv)
 155 {
 156         int opt, ret;
 157         static poptContext pc;
 158
 159         init_channel_config();
 160
 161         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 162         poptReadDefaultConfig(pc, 0);
 163
 164         while ((opt = poptGetNextOpt(pc)) != -1) {
 165                 switch (opt) {
 166                 case OPT_HELP:
 167                         usage(stderr);
 168                         ret = CMD_SUCCESS;
 169                         goto end;
 170                 case OPT_USERSPACE:
 171                         opt_userspace = 1;
 172                         opt_cmd_name = poptGetOptArg(pc);
 173                         break;
 174                 case OPT_DISCARD:
 175                         chan.attr.overwrite = 0;
 176                         DBG("Channel set to discard");
 177                         break;
 178                 case OPT_OVERWRITE:
 179                         chan.attr.overwrite = 1;
 180                         DBG("Channel set to overwrite");
 181                         break;
 182                 case OPT_SUBBUF_SIZE:
 183                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 184                         DBG("Channel subbuf size set to %lu", chan.attr.subbuf_size);
 185                         break;
 186                 case OPT_NUM_SUBBUF:
 187                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 188                         DBG("Channel subbuf num set to %lu", chan.attr.num_subbuf);
 189                         break;
 190                 case OPT_SWITCH_TIMER:
 191                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 192                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 193                         break;
 194                 case OPT_READ_TIMER:
 195                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 196                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 197                         break;
 198                 default:
 199                         usage(stderr);
 200                         ret = CMD_UNDEFINED;
 201                         goto end;
 202                 }
 203         }
 204
 205         opt_channel_name = (char*) poptGetArg(pc);
 206         if (opt_channel_name == NULL) {
 207                 ERR("Missing channel name.\n");
 208                 usage(stderr);
 209                 ret = CMD_SUCCESS;
 210                 goto end;
 211         }
 212
 213         ret = add_channel();
 214
 215 end:
 216         return ret;
 217 }