lttng/commands/enable_channels.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; only version 2
   7  * of the License.
   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 #include <inttypes.h>
  28
  29 #include "../cmd.h"
  30 #include "../conf.h"
  31 #include "../utils.h"
  32
  33 static char *opt_channels;
  34 static char *opt_kernel;
  35 static char *opt_cmd_name;
  36 static char *opt_session_name;
  37 static int opt_pid_all;
  38 static int opt_userspace;
  39 static pid_t opt_pid;
  40 static struct lttng_channel chan;
  41
  42 enum {
  43         OPT_HELP = 1,
  44         OPT_DISCARD,
  45         OPT_OVERWRITE,
  46         OPT_SUBBUF_SIZE,
  47         OPT_NUM_SUBBUF,
  48         OPT_SWITCH_TIMER,
  49         OPT_READ_TIMER,
  50         OPT_USERSPACE,
  51 };
  52
  53 static struct poptOption long_options[] = {
  54         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  55         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  56         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  57         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  58         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
  59         {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
  60         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  61         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  62         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  63         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  64         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  65         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  66         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  67         {0, 0, 0, 0, 0, 0, 0}
  68 };
  69
  70 /*
  71  * usage
  72  */
  73 static void usage(FILE *ofp)
  74 {
  75         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  76         fprintf(ofp, "\n");
  77         fprintf(ofp, "  -h, --help               Show this help\n");
  78         fprintf(ofp, "  -s, --session            Apply on session name\n");
  79         fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
  80         fprintf(ofp, "  -u, --userspace [CMD]    Apply on the user-space tracer\n");
  81         fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
  82         fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
  83         fprintf(ofp, "\n");
  84         fprintf(ofp, "Channel options:\n");
  85         fprintf(ofp, "      --discard            Discard event when buffers are full (default)\n");
  86         fprintf(ofp, "      --overwrite          Flight recorder mode\n");
  87         fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes (default: 4096)\n");
  88         fprintf(ofp, "      --num-subbuf         Number of subbufers (default: 2)\n");
  89         fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: 0)\n");
  90         fprintf(ofp, "      --read-timer         Read timer interval in usec (default: 200)\n");
  91         fprintf(ofp, "\n");
  92 }
  93
  94 /*
  95  *  enable_channel
  96  *
  97  *  Adding channel using the lttng API.
  98  */
  99 static int enable_channel(void)
 100 {
 101         int ret = CMD_SUCCESS;
 102         char *channel_name;
 103         struct lttng_domain dom;
 104
 105         if (set_session_name(opt_session_name) < 0) {
 106                 ret = CMD_ERROR;
 107                 goto error;
 108         }
 109
 110         if (opt_kernel) {
 111                 dom.type = LTTNG_DOMAIN_KERNEL;
 112         }
 113
 114         /* Strip event list */
 115         channel_name = strtok(opt_channels, ",");
 116         while (channel_name != NULL) {
 117                 /* Kernel tracer action */
 118                 if (opt_kernel) {
 119                         DBG("Enabling kernel channel %s", channel_name);
 120
 121                         /* Copy channel name and normalize it */
 122                         strncpy(chan.name, channel_name, NAME_MAX);
 123                         chan.name[NAME_MAX - 1] = '\0';
 124
 125                         ret = lttng_enable_channel(&dom, &chan);
 126                         if (ret < 0) {
 127                                 goto error;
 128                         } else {
 129                                 MSG("Kernel channel enabled %s", channel_name);
 130                         }
 131                 } else if (opt_userspace) {             /* User-space tracer action */
 132                         /*
 133                          * TODO: Waiting on lttng UST 2.0
 134                          */
 135                         if (opt_pid_all) {
 136                         } else if (opt_pid != 0) {
 137                         }
 138                         ret = CMD_NOT_IMPLEMENTED;
 139                         goto error;
 140                 } else {
 141                         ERR("Please specify a tracer (--kernel or --userspace)");
 142                         goto error;
 143                 }
 144
 145                 /* Next event */
 146                 channel_name = strtok(NULL, ",");
 147         }
 148
 149 error:
 150         return ret;
 151 }
 152
 153 /*
 154  *  init_channel_config
 155  *
 156  *  Default value for channel configuration.
 157  */
 158 static void init_channel_config(void)
 159 {
 160         chan.attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 161         chan.attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 162         chan.attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 163         chan.attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 164         chan.attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 165         chan.attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 166 }
 167
 168 /*
 169  *  Add channel to trace session
 170  */
 171 int cmd_enable_channels(int argc, const char **argv)
 172 {
 173         int opt, ret;
 174         static poptContext pc;
 175
 176         init_channel_config();
 177
 178         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 179         poptReadDefaultConfig(pc, 0);
 180
 181         while ((opt = poptGetNextOpt(pc)) != -1) {
 182                 switch (opt) {
 183                 case OPT_HELP:
 184                         usage(stderr);
 185                         ret = CMD_SUCCESS;
 186                         goto end;
 187                 case OPT_USERSPACE:
 188                         opt_userspace = 1;
 189                         opt_cmd_name = poptGetOptArg(pc);
 190                         break;
 191                 case OPT_DISCARD:
 192                         chan.attr.overwrite = 0;
 193                         DBG("Channel set to discard");
 194                         break;
 195                 case OPT_OVERWRITE:
 196                         chan.attr.overwrite = 1;
 197                         DBG("Channel set to overwrite");
 198                         break;
 199                 case OPT_SUBBUF_SIZE:
 200                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 201                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 202                         break;
 203                 case OPT_NUM_SUBBUF:
 204                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 205                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 206                         break;
 207                 case OPT_SWITCH_TIMER:
 208                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 209                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 210                         break;
 211                 case OPT_READ_TIMER:
 212                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 213                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 214                         break;
 215                 default:
 216                         usage(stderr);
 217                         ret = CMD_UNDEFINED;
 218                         goto end;
 219                 }
 220         }
 221
 222         opt_channels = (char*) poptGetArg(pc);
 223         if (opt_channels == NULL) {
 224                 ERR("Missing channel name.\n");
 225                 usage(stderr);
 226                 ret = CMD_SUCCESS;
 227                 goto end;
 228         }
 229
 230         ret = enable_channel();
 231
 232 end:
 233         return ret;
 234 }