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 #include <src/common/sessiond-comm/sessiond-comm.h>
  31 #include <src/common/utils.h>
  32
  33 static char *opt_channels;
  34 static int opt_kernel;
  35 static char *opt_session_name;
  36 static int opt_userspace;
  37 static struct lttng_channel chan;
  38 static char *opt_output;
  39 static int opt_buffer_uid;
  40 static int opt_buffer_pid;
  41 static int opt_buffer_global;
  42
  43 enum {
  44         OPT_HELP = 1,
  45         OPT_DISCARD,
  46         OPT_OVERWRITE,
  47         OPT_SUBBUF_SIZE,
  48         OPT_NUM_SUBBUF,
  49         OPT_SWITCH_TIMER,
  50         OPT_READ_TIMER,
  51         OPT_USERSPACE,
  52         OPT_LIST_OPTIONS,
  53         OPT_TRACEFILE_SIZE,
  54         OPT_TRACEFILE_COUNT,
  55 };
  56
  57 static struct lttng_handle *handle;
  58
  59 const char *output_mmap = "mmap";
  60 const char *output_splice = "splice";
  61
  62 static struct poptOption long_options[] = {
  63         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  64         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  65         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  66         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  67         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  68         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  69         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  70         {"subbuf-size",    0,   POPT_ARG_STRING, 0, OPT_SUBBUF_SIZE, 0, 0},
  71         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  72         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  73         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  74         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  75         {"output",         0,   POPT_ARG_STRING, &opt_output, 0, 0, 0},
  76         {"buffers-uid",    0,   POPT_ARG_VAL, &opt_buffer_uid, 1, 0, 0},
  77         {"buffers-pid",    0,   POPT_ARG_VAL, &opt_buffer_pid, 1, 0, 0},
  78         {"buffers-global", 0,   POPT_ARG_VAL, &opt_buffer_global, 1, 0, 0},
  79         {"tracefile-size", 'C',   POPT_ARG_INT, 0, OPT_TRACEFILE_SIZE, 0, 0},
  80         {"tracefile-count", 'W',   POPT_ARG_INT, 0, OPT_TRACEFILE_COUNT, 0, 0},
  81         {0, 0, 0, 0, 0, 0, 0}
  82 };
  83
  84 /*
  85  * usage
  86  */
  87 static void usage(FILE *ofp)
  88 {
  89         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [-u|-k] [OPTIONS]\n");
  90         fprintf(ofp, "\n");
  91         fprintf(ofp, "Options:\n");
  92         fprintf(ofp, "  -h, --help               Show this help\n");
  93         fprintf(ofp, "      --list-options       Simple listing of options\n");
  94         fprintf(ofp, "  -s, --session NAME       Apply to session name\n");
  95         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
  96         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
  97         fprintf(ofp, "\n");
  98         fprintf(ofp, "Channel options:\n");
  99         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
 100                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
 101         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
 102                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
 103         fprintf(ofp, "      --subbuf-size SIZE   Subbuffer size in bytes {+k,+M,+G}\n");
 104         fprintf(ofp, "                               (default: %zu, kernel default: %zu)\n",
 105                 default_get_channel_subbuf_size(),
 106                 default_get_kernel_channel_subbuf_size());
 107         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 108         fprintf(ofp, "                               kernel and ust tracers\n");
 109         fprintf(ofp, "      --num-subbuf NUM     Number of subbufers\n");
 110         fprintf(ofp, "                               (default: %u)\n",
 111                 DEFAULT_CHANNEL_SUBBUF_NUM);
 112         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 113         fprintf(ofp, "                               kernel and ust tracers\n");
 114         fprintf(ofp, "      --switch-timer USEC  Switch timer interval in usec (default: %u)\n",
 115                 DEFAULT_CHANNEL_SWITCH_TIMER);
 116         fprintf(ofp, "      --read-timer USEC    Read timer interval in usec (UST default: %u, kernel default: %u)\n",
 117                 DEFAULT_UST_CHANNEL_READ_TIMER, DEFAULT_KERNEL_CHANNEL_READ_TIMER);
 118         fprintf(ofp, "      --output TYPE        Channel output type (Values: %s, %s)\n",
 119                         output_mmap, output_splice);
 120         fprintf(ofp, "      --buffers-uid        Use per UID buffer (-u only)\n");
 121         fprintf(ofp, "      --buffers-pid        Use per PID buffer (-u only)\n");
 122         fprintf(ofp, "      --buffers-global     Use shared buffer for the whole system (-k only)\n");
 123         fprintf(ofp, "  -C, --tracefile-size SIZE\n");
 124         fprintf(ofp, "                           Maximum size of each tracefile within a stream (in bytes).\n");
 125         fprintf(ofp, "  -W, --tracefile-count COUNT\n");
 126         fprintf(ofp, "                           Used in conjunction with -C option, this will limit the number\n");
 127         fprintf(ofp, "                           of files created to the specified count.\n");
 128         fprintf(ofp, "\n");
 129 }
 130
 131 /*
 132  * Set default attributes depending on those already defined from the command
 133  * line.
 134  */
 135 static void set_default_attr(struct lttng_domain *dom)
 136 {
 137         struct lttng_channel_attr default_attr;
 138
 139         /* Set attributes */
 140         lttng_channel_set_default_attr(dom, &default_attr);
 141
 142         if (chan.attr.overwrite == -1) {
 143                 chan.attr.overwrite = default_attr.overwrite;
 144         }
 145         if (chan.attr.subbuf_size == -1) {
 146                 chan.attr.subbuf_size = default_attr.subbuf_size;
 147         }
 148         if (chan.attr.num_subbuf == -1) {
 149                 chan.attr.num_subbuf = default_attr.num_subbuf;
 150         }
 151         if (chan.attr.switch_timer_interval == -1) {
 152                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 153         }
 154         if (chan.attr.read_timer_interval == -1) {
 155                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 156         }
 157         if (chan.attr.output == -1) {
 158                 chan.attr.output = default_attr.output;
 159         }
 160         if (chan.attr.tracefile_count == -1) {
 161                 chan.attr.tracefile_count = default_attr.tracefile_count;
 162         }
 163         if (chan.attr.tracefile_size == -1) {
 164                 chan.attr.tracefile_size = default_attr.tracefile_size;
 165         }
 166 }
 167
 168 /*
 169  * Adding channel using the lttng API.
 170  */
 171 static int enable_channel(char *session_name)
 172 {
 173         int ret = CMD_SUCCESS, warn = 0;
 174         char *channel_name;
 175         struct lttng_domain dom;
 176
 177         memset(&dom, 0, sizeof(dom));
 178
 179         /* Create lttng domain */
 180         if (opt_kernel) {
 181                 dom.type = LTTNG_DOMAIN_KERNEL;
 182                 dom.buf_type = LTTNG_BUFFER_GLOBAL;
 183                 if (opt_buffer_uid || opt_buffer_pid) {
 184                         ERR("Buffer type not supported for domain -k");
 185                         ret = CMD_ERROR;
 186                         goto error;
 187                 }
 188         } else if (opt_userspace) {
 189                 dom.type = LTTNG_DOMAIN_UST;
 190                 if (opt_buffer_uid) {
 191                         dom.buf_type = LTTNG_BUFFER_PER_UID;
 192                 } else {
 193                         if (opt_buffer_global) {
 194                                 ERR("Buffer type not supported for domain -u");
 195                                 ret = CMD_ERROR;
 196                                 goto error;
 197                         }
 198                         dom.buf_type = LTTNG_BUFFER_PER_PID;
 199                 }
 200         } else {
 201                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 202                 ret = CMD_ERROR;
 203                 goto error;
 204         }
 205
 206         set_default_attr(&dom);
 207
 208         if ((chan.attr.tracefile_size > 0) &&
 209                         (chan.attr.tracefile_size < chan.attr.subbuf_size)) {
 210                 ERR("Tracefile_size must be greater than or equal to subbuf_size "
 211                                 "(%" PRIu64 " < %" PRIu64 ")",
 212                                 chan.attr.tracefile_size, chan.attr.subbuf_size);
 213                 ret = CMD_ERROR;
 214                 goto error;
 215         }
 216
 217         /* Setting channel output */
 218         if (opt_output) {
 219                 if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
 220                         chan.attr.output = LTTNG_EVENT_MMAP;
 221                 } else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
 222                         chan.attr.output = LTTNG_EVENT_SPLICE;
 223                 } else {
 224                         ERR("Unknown output type %s. Possible values are: %s, %s\n",
 225                                         opt_output, output_mmap, output_splice);
 226                         usage(stderr);
 227                         ret = CMD_ERROR;
 228                         goto error;
 229                 }
 230         }
 231
 232         handle = lttng_create_handle(session_name, &dom);
 233         if (handle == NULL) {
 234                 ret = -1;
 235                 goto error;
 236         }
 237
 238         /* Strip channel list (format: chan1,chan2,...) */
 239         channel_name = strtok(opt_channels, ",");
 240         while (channel_name != NULL) {
 241                 /* Copy channel name and normalize it */
 242                 strncpy(chan.name, channel_name, NAME_MAX);
 243                 chan.name[NAME_MAX - 1] = '\0';
 244
 245                 DBG("Enabling channel %s", channel_name);
 246
 247                 ret = lttng_enable_channel(handle, &chan);
 248                 if (ret < 0) {
 249                         switch (-ret) {
 250                         case LTTNG_ERR_KERN_CHAN_EXIST:
 251                         case LTTNG_ERR_UST_CHAN_EXIST:
 252                                 WARN("Channel %s: %s (session %s)", channel_name,
 253                                                 lttng_strerror(ret), session_name);
 254                                 goto error;
 255                         default:
 256                                 ERR("Channel %s: %s (session %s)", channel_name,
 257                                                 lttng_strerror(ret), session_name);
 258                                 break;
 259                         }
 260                         warn = 1;
 261                 } else {
 262                         MSG("%s channel %s enabled for session %s",
 263                                         opt_kernel ? "Kernel" : "UST", channel_name,
 264                                         session_name);
 265                 }
 266
 267                 /* Next event */
 268                 channel_name = strtok(NULL, ",");
 269         }
 270
 271         ret = CMD_SUCCESS;
 272
 273 error:
 274         if (warn) {
 275                 ret = CMD_WARNING;
 276         }
 277
 278         lttng_destroy_handle(handle);
 279
 280         return ret;
 281 }
 282
 283 /*
 284  * Default value for channel configuration.
 285  */
 286 static void init_channel_config(void)
 287 {
 288         /*
 289          * Put -1 everywhere so we can identify those set by the command line and
 290          * those needed to be set by the default values.
 291          */
 292         memset(&chan.attr, -1, sizeof(chan.attr));
 293 }
 294
 295 /*
 296  * Add channel to trace session
 297  */
 298 int cmd_enable_channels(int argc, const char **argv)
 299 {
 300         int opt, ret = CMD_SUCCESS;
 301         static poptContext pc;
 302         char *session_name = NULL;
 303         char *opt_arg = NULL;
 304
 305         init_channel_config();
 306
 307         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 308         poptReadDefaultConfig(pc, 0);
 309
 310         while ((opt = poptGetNextOpt(pc)) != -1) {
 311                 switch (opt) {
 312                 case OPT_HELP:
 313                         usage(stdout);
 314                         goto end;
 315                 case OPT_DISCARD:
 316                         chan.attr.overwrite = 0;
 317                         DBG("Channel set to discard");
 318                         break;
 319                 case OPT_OVERWRITE:
 320                         chan.attr.overwrite = 1;
 321                         DBG("Channel set to overwrite");
 322                         break;
 323                 case OPT_SUBBUF_SIZE:
 324                         /* Parse the size */
 325                         opt_arg = poptGetOptArg(pc);
 326                         if (utils_parse_size_suffix(opt_arg, &chan.attr.subbuf_size) < 0) {
 327                                 ERR("Wrong value the --subbuf-size parameter: %s", opt_arg);
 328                                 ret = CMD_ERROR;
 329                                 goto end;
 330                         }
 331
 332                         /* Check if power of 2 */
 333                         if ((chan.attr.subbuf_size - 1) & chan.attr.subbuf_size) {
 334                                 ERR("The subbuf size is not a power of 2: %" PRIu64 " (%s)",
 335                                                 chan.attr.subbuf_size, opt_arg);
 336                                 ret = CMD_ERROR;
 337                                 goto end;
 338                         }
 339
 340                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 341                         break;
 342                 case OPT_NUM_SUBBUF:
 343                         errno = 0;
 344                         chan.attr.num_subbuf = strtoull(poptGetOptArg(pc), NULL, 0);
 345                         if (errno != 0) {
 346                                 ERR("Wrong value the --num-subbuf parameter: %s", opt_arg);
 347                                 ret = CMD_ERROR;
 348                                 goto end;
 349                         }
 350
 351                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 352                         break;
 353                 case OPT_SWITCH_TIMER:
 354                 {
 355                         unsigned long v;
 356
 357                         errno = 0;
 358                         v = strtoul(poptGetOptArg(pc), NULL, 0);
 359                         if (errno != 0) {
 360                                 ERR("Wrong value the --switch-timer parameter: %s", opt_arg);
 361                                 ret = CMD_ERROR;
 362                                 goto end;
 363                         }
 364                         if (v != (uint32_t) v) {
 365                                 ERR("32-bit overflow in --switch-timer parameter: %s", opt_arg);
 366                                 ret = CMD_ERROR;
 367                                 goto end;
 368                         }
 369                         chan.attr.switch_timer_interval = (uint32_t) v;
 370                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 371                         break;
 372                 }
 373                 case OPT_READ_TIMER:
 374                 {
 375                         unsigned long v;
 376
 377                         errno = 0;
 378                         v = strtoul(poptGetOptArg(pc), NULL, 0);
 379                         if (errno != 0) {
 380                                 ERR("Wrong value the --read-timer parameter: %s", opt_arg);
 381                                 ret = CMD_ERROR;
 382                                 goto end;
 383                         }
 384                         if (v != (uint32_t) v) {
 385                                 ERR("32-bit overflow in --read-timer parameter: %s", opt_arg);
 386                                 ret = CMD_ERROR;
 387                                 goto end;
 388                         }
 389                         chan.attr.read_timer_interval = (uint32_t) v;
 390                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 391                         break;
 392                 }
 393                 case OPT_USERSPACE:
 394                         opt_userspace = 1;
 395                         break;
 396                 case OPT_TRACEFILE_SIZE:
 397                         if (utils_parse_size_suffix(opt_arg, &chan.attr.tracefile_size) < 0) {
 398                                 ERR("Wrong value the --tracefile-size parameter: %s", opt_arg);
 399                                 ret = CMD_ERROR;
 400                                 goto end;
 401                         }
 402                         DBG("Maximum tracefile size set to %" PRIu64,
 403                                         chan.attr.tracefile_size);
 404                         break;
 405                 case OPT_TRACEFILE_COUNT:
 406                 {
 407                         unsigned long v;
 408
 409                         errno = 0;
 410                         v = strtoul(poptGetOptArg(pc), NULL, 0);
 411                         if (errno != 0) {
 412                                 ERR("Wrong value the --tracefile-count parameter: %s", opt_arg);
 413                                 ret = CMD_ERROR;
 414                                 goto end;
 415                         }
 416                         if (v != (uint32_t) v) {
 417                                 ERR("32-bit overflow in --tracefile-count parameter: %s", opt_arg);
 418                                 ret = CMD_ERROR;
 419                                 goto end;
 420                         }
 421                         chan.attr.tracefile_count = (uint32_t) v;
 422                         DBG("Maximum tracefile count set to %" PRIu64,
 423                                         chan.attr.tracefile_count);
 424                         break;
 425                 }
 426                 case OPT_LIST_OPTIONS:
 427                         list_cmd_options(stdout, long_options);
 428                         goto end;
 429                 default:
 430                         usage(stderr);
 431                         ret = CMD_UNDEFINED;
 432                         goto end;
 433                 }
 434         }
 435
 436         opt_channels = (char*) poptGetArg(pc);
 437         if (opt_channels == NULL) {
 438                 ERR("Missing channel name.\n");
 439                 usage(stderr);
 440                 ret = CMD_ERROR;
 441                 goto end;
 442         }
 443
 444         if (!opt_session_name) {
 445                 session_name = get_session_name();
 446                 if (session_name == NULL) {
 447                         ret = CMD_ERROR;
 448                         goto end;
 449                 }
 450         } else {
 451                 session_name = opt_session_name;
 452         }
 453
 454         ret = enable_channel(session_name);
 455
 456 end:
 457         if (!opt_session_name && session_name) {
 458                 free(session_name);
 459         }
 460         poptFreeContext(pc);
 461         return ret;
 462 }