src/bin/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 modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27
  28 #include "../command.h"
  29
  30 static char *opt_channels;
  31 static int opt_kernel;
  32 static char *opt_session_name;
  33 static int opt_userspace;
  34 static struct lttng_channel chan;
  35 #if 0
  36 /* Not implemented yet */
  37 static char *opt_cmd_name;
  38 static pid_t opt_pid;
  39 #endif
  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         OPT_LIST_OPTIONS,
  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 #if 0
  61         /* Not implemented yet */
  62         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  63         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  64 #else
  65         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  66 #endif
  67         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  68         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  69         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  70         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  71         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  72         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  73         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  74         {0, 0, 0, 0, 0, 0, 0}
  75 };
  76
  77 /*
  78  * usage
  79  */
  80 static void usage(FILE *ofp)
  81 {
  82         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  83         fprintf(ofp, "\n");
  84         fprintf(ofp, "  -h, --help               Show this help\n");
  85         fprintf(ofp, "      --list-options       Simple listing of options\n");
  86         fprintf(ofp, "  -s, --session            Apply to session name\n");
  87         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
  88 #if 0
  89         fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
  90         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
  91         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
  92         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
  93 #else
  94         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
  95 #endif
  96         fprintf(ofp, "\n");
  97         fprintf(ofp, "Channel options:\n");
  98         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
  99                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
 100         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
 101                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
 102         fprintf(ofp, "      --subbuf-size SIZE   Subbuffer size in bytes\n");
 103         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
 104                 DEFAULT_CHANNEL_SUBBUF_SIZE,
 105                 DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
 106         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 107         fprintf(ofp, "                               kernel and ust tracers\n");
 108         fprintf(ofp, "      --num-subbuf NUM     Number of subbufers\n");
 109         fprintf(ofp, "                               (default: %u)\n",
 110                 DEFAULT_CHANNEL_SUBBUF_NUM);
 111         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 112         fprintf(ofp, "                               kernel and ust tracers\n");
 113         fprintf(ofp, "      --switch-timer USEC  Switch timer interval in usec (default: %u)\n",
 114                 DEFAULT_CHANNEL_SWITCH_TIMER);
 115         fprintf(ofp, "      --read-timer USEC    Read timer interval in usec (default: %u)\n",
 116                 DEFAULT_CHANNEL_READ_TIMER);
 117         fprintf(ofp, "\n");
 118 }
 119
 120 /*
 121  * Set default attributes depending on those already defined from the command
 122  * line.
 123  */
 124 static void set_default_attr(struct lttng_domain *dom)
 125 {
 126         struct lttng_channel_attr default_attr;
 127
 128         /* Set attributes */
 129         lttng_channel_set_default_attr(dom, &default_attr);
 130
 131         if (chan.attr.overwrite == -1) {
 132                 chan.attr.overwrite = default_attr.overwrite;
 133         }
 134         if (chan.attr.subbuf_size == -1) {
 135                 chan.attr.subbuf_size = default_attr.subbuf_size;
 136         }
 137         if (chan.attr.num_subbuf == -1) {
 138                 chan.attr.num_subbuf = default_attr.num_subbuf;
 139         }
 140         if (chan.attr.switch_timer_interval == -1) {
 141                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 142         }
 143         if (chan.attr.read_timer_interval == -1) {
 144                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 145         }
 146         if (chan.attr.output == -1) {
 147                 chan.attr.output = default_attr.output;
 148         }
 149 }
 150
 151 /*
 152  * Adding channel using the lttng API.
 153  */
 154 static int enable_channel(char *session_name)
 155 {
 156         int ret = CMD_SUCCESS, warn = 0;
 157         char *channel_name;
 158         struct lttng_domain dom;
 159
 160         memset(&dom, 0, sizeof(dom));
 161
 162         /* Create lttng domain */
 163         if (opt_kernel) {
 164                 dom.type = LTTNG_DOMAIN_KERNEL;
 165         } else if (opt_userspace) {
 166                 dom.type = LTTNG_DOMAIN_UST;
 167         } else {
 168                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 169                 ret = CMD_ERROR;
 170                 goto error;
 171         }
 172
 173         set_default_attr(&dom);
 174
 175         handle = lttng_create_handle(session_name, &dom);
 176         if (handle == NULL) {
 177                 ret = -1;
 178                 goto error;
 179         }
 180
 181         /* Strip channel list (format: chan1,chan2,...) */
 182         channel_name = strtok(opt_channels, ",");
 183         while (channel_name != NULL) {
 184                 /* Copy channel name and normalize it */
 185                 strncpy(chan.name, channel_name, NAME_MAX);
 186                 chan.name[NAME_MAX - 1] = '\0';
 187
 188                 DBG("Enabling channel %s", channel_name);
 189
 190                 ret = lttng_enable_channel(handle, &chan);
 191                 if (ret < 0) {
 192                         ERR("Channel %s: %s (session %s)", channel_name,
 193                                         lttng_strerror(ret), session_name);
 194                         warn = 1;
 195                 } else {
 196                         MSG("%s channel %s enabled for session %s",
 197                                         opt_kernel ? "Kernel" : "UST", channel_name,
 198                                         session_name);
 199                 }
 200
 201                 /* Next event */
 202                 channel_name = strtok(NULL, ",");
 203         }
 204
 205         ret = CMD_SUCCESS;
 206
 207 error:
 208         if (warn) {
 209                 ret = CMD_WARNING;
 210         }
 211
 212         lttng_destroy_handle(handle);
 213
 214         return ret;
 215 }
 216
 217 /*
 218  * Default value for channel configuration.
 219  */
 220 static void init_channel_config(void)
 221 {
 222         /*
 223          * Put -1 everywhere so we can identify those set by the command line and
 224          * those needed to be set by the default values.
 225          */
 226         memset(&chan.attr, -1, sizeof(chan.attr));
 227 }
 228
 229 /*
 230  * Add channel to trace session
 231  */
 232 int cmd_enable_channels(int argc, const char **argv)
 233 {
 234         int opt, ret = CMD_SUCCESS;
 235         static poptContext pc;
 236         char *session_name = NULL;
 237
 238         init_channel_config();
 239
 240         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 241         poptReadDefaultConfig(pc, 0);
 242
 243         while ((opt = poptGetNextOpt(pc)) != -1) {
 244                 switch (opt) {
 245                 case OPT_HELP:
 246                         usage(stdout);
 247                         goto end;
 248                 case OPT_DISCARD:
 249                         chan.attr.overwrite = 0;
 250                         DBG("Channel set to discard");
 251                         break;
 252                 case OPT_OVERWRITE:
 253                         chan.attr.overwrite = 1;
 254                         DBG("Channel set to overwrite");
 255                         break;
 256                 case OPT_SUBBUF_SIZE:
 257                         /* TODO Replace atol with strtol and check for errors */
 258                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 259                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 260                         break;
 261                 case OPT_NUM_SUBBUF:
 262                         /* TODO Replace atoi with strtol and check for errors */
 263                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 264                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 265                         break;
 266                 case OPT_SWITCH_TIMER:
 267                         /* TODO Replace atoi with strtol and check for errors */
 268                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 269                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 270                         break;
 271                 case OPT_READ_TIMER:
 272                         /* TODO Replace atoi with strtol and check for errors */
 273                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 274                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 275                         break;
 276                 case OPT_USERSPACE:
 277                         opt_userspace = 1;
 278                         break;
 279                 case OPT_LIST_OPTIONS:
 280                         list_cmd_options(stdout, long_options);
 281                         goto end;
 282                 default:
 283                         usage(stderr);
 284                         ret = CMD_UNDEFINED;
 285                         goto end;
 286                 }
 287         }
 288
 289         opt_channels = (char*) poptGetArg(pc);
 290         if (opt_channels == NULL) {
 291                 ERR("Missing channel name.\n");
 292                 usage(stderr);
 293                 ret = CMD_ERROR;
 294                 goto end;
 295         }
 296
 297         if (!opt_session_name) {
 298                 session_name = get_session_name();
 299                 if (session_name == NULL) {
 300                         ret = CMD_ERROR;
 301                         goto end;
 302                 }
 303         } else {
 304                 session_name = opt_session_name;
 305         }
 306
 307         ret = enable_channel(session_name);
 308
 309 end:
 310         if (!opt_session_name && session_name) {
 311                 free(session_name);
 312         }
 313         poptFreeContext(pc);
 314         return ret;
 315 }