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