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 lttng_handle *handle;
  54
  55 static struct poptOption long_options[] = {
  56         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  57         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  58         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  59         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  60         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
  61         {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
  62         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  63         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  64         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  65         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  66         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  67         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  68         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  69         {0, 0, 0, 0, 0, 0, 0}
  70 };
  71
  72 /*
  73  * usage
  74  */
  75 static void usage(FILE *ofp)
  76 {
  77         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  78         fprintf(ofp, "\n");
  79         fprintf(ofp, "  -h, --help               Show this help\n");
  80         fprintf(ofp, "  -s, --session            Apply on session name\n");
  81         fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
  82         fprintf(ofp, "  -u, --userspace [CMD]    Apply on the user-space tracer\n");
  83         fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
  84         fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
  85         fprintf(ofp, "\n");
  86         fprintf(ofp, "Channel options:\n");
  87         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
  88                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
  89         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
  90                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
  91         fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
  92         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
  93                 DEFAULT_CHANNEL_SUBBUF_SIZE,
  94                 DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
  95         fprintf(ofp, "      --num-subbuf         Number of subbufers\n");
  96         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
  97                 DEFAULT_CHANNEL_SUBBUF_NUM,
  98                 DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
  99         fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: %u)\n",
 100                 DEFAULT_CHANNEL_SWITCH_TIMER);
 101         fprintf(ofp, "      --read-timer         Read timer interval in usec (default: %u)\n",
 102                 DEFAULT_CHANNEL_READ_TIMER);
 103         fprintf(ofp, "\n");
 104 }
 105
 106 /*
 107  * Adding channel using the lttng API.
 108  */
 109 static int enable_channel(char *session_name)
 110 {
 111         int ret = CMD_SUCCESS;
 112         char *channel_name;
 113         struct lttng_domain dom;
 114
 115         if (opt_kernel) {
 116                 dom.type = LTTNG_DOMAIN_KERNEL;
 117         } else if (opt_pid != 0) {
 118                 dom.type = LTTNG_DOMAIN_UST_PID;
 119                 dom.attr.pid = opt_pid;
 120                 DBG("PID %d set to lttng handle", opt_pid);
 121         } else {
 122                 ERR("Please specify a tracer (--kernel or --userspace)");
 123                 ret = CMD_NOT_IMPLEMENTED;
 124                 goto error;
 125         }
 126
 127         handle = lttng_create_handle(session_name, &dom);
 128         if (handle == NULL) {
 129                 ret = -1;
 130                 goto error;
 131         }
 132
 133         /* Strip channel list (format: chan1,chan2,...) */
 134         channel_name = strtok(opt_channels, ",");
 135         while (channel_name != NULL) {
 136                 /* Copy channel name and normalize it */
 137                 strncpy(chan.name, channel_name, NAME_MAX);
 138                 chan.name[NAME_MAX - 1] = '\0';
 139
 140                 DBG("Enabling channel %s", channel_name);
 141
 142                 ret = lttng_enable_channel(handle, &chan);
 143                 if (ret < 0) {
 144                         goto error;
 145                 } else {
 146                         MSG("Channel enabled %s for session %s",
 147                                         channel_name, session_name);
 148                 }
 149
 150                 /* Next event */
 151                 channel_name = strtok(NULL, ",");
 152         }
 153
 154 error:
 155         lttng_destroy_handle(handle);
 156
 157         return ret;
 158 }
 159
 160 /*
 161  * Default value for channel configuration.
 162  */
 163 static void init_channel_config(void)
 164 {
 165         if (opt_kernel) {
 166                 /* kernel default */
 167                 chan.attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 168                 chan.attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 169                 chan.attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 170
 171                 chan.attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
 172                 chan.attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
 173                 chan.attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 174         } else {
 175                 /* default behavior, used by UST. */
 176                 chan.attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 177                 chan.attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 178                 chan.attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 179
 180                 chan.attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 181                 chan.attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 182                 chan.attr.output = DEFAULT_CHANNEL_OUTPUT;
 183         }
 184 }
 185
 186 /*
 187  * Add channel to trace session
 188  */
 189 int cmd_enable_channels(int argc, const char **argv)
 190 {
 191         int opt, ret;
 192         static poptContext pc;
 193         char *session_name = NULL;
 194
 195         init_channel_config();
 196
 197         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 198         poptReadDefaultConfig(pc, 0);
 199
 200         while ((opt = poptGetNextOpt(pc)) != -1) {
 201                 switch (opt) {
 202                 case OPT_HELP:
 203                         usage(stderr);
 204                         ret = CMD_SUCCESS;
 205                         goto end;
 206                 case OPT_USERSPACE:
 207                         opt_userspace = 1;
 208                         opt_cmd_name = poptGetOptArg(pc);
 209                         break;
 210                 case OPT_DISCARD:
 211                         chan.attr.overwrite = 0;
 212                         DBG("Channel set to discard");
 213                         break;
 214                 case OPT_OVERWRITE:
 215                         chan.attr.overwrite = 1;
 216                         DBG("Channel set to overwrite");
 217                         break;
 218                 case OPT_SUBBUF_SIZE:
 219                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 220                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 221                         break;
 222                 case OPT_NUM_SUBBUF:
 223                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 224                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 225                         break;
 226                 case OPT_SWITCH_TIMER:
 227                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 228                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 229                         break;
 230                 case OPT_READ_TIMER:
 231                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 232                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 233                         break;
 234                 default:
 235                         usage(stderr);
 236                         ret = CMD_UNDEFINED;
 237                         goto end;
 238                 }
 239         }
 240
 241         opt_channels = (char*) poptGetArg(pc);
 242         if (opt_channels == NULL) {
 243                 ERR("Missing channel name.\n");
 244                 usage(stderr);
 245                 ret = CMD_SUCCESS;
 246                 goto end;
 247         }
 248
 249         if (!opt_session_name) {
 250                 session_name = get_session_name();
 251                 if (session_name == NULL) {
 252                         ret = -1;
 253                         goto end;
 254                 }
 255         } else {
 256                 session_name = opt_session_name;
 257         }
 258
 259         ret = enable_channel(session_name);
 260
 261 end:
 262         return ret;
 263 }