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
  32 static char *opt_channels;
  33 static int opt_kernel;
  34 static char *opt_session_name;
  35 static int opt_userspace;
  36 static struct lttng_channel chan;
  37 static char *opt_output;
  38 static int opt_buffer_uid;
  39 static int opt_buffer_pid;
  40 static int opt_buffer_global;
  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         OPT_LIST_OPTIONS,
  52         OPT_TRACEFILE_SIZE,
  53         OPT_TRACEFILE_COUNT,
  54 };
  55
  56 static struct lttng_handle *handle;
  57
  58 const char *output_mmap = "mmap";
  59 const char *output_splice = "splice";
  60
  61 static struct poptOption long_options[] = {
  62         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  63         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  64         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  65         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  66         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  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         {"output",         0,   POPT_ARG_STRING, &opt_output, 0, 0, 0},
  75         {"buffers-uid",    0,   POPT_ARG_VAL, &opt_buffer_uid, 1, 0, 0},
  76         {"buffers-pid",    0,   POPT_ARG_VAL, &opt_buffer_pid, 1, 0, 0},
  77         {"buffers-global", 0,   POPT_ARG_VAL, &opt_buffer_global, 1, 0, 0},
  78         {"tracefile-size", 'C',   POPT_ARG_INT, 0, OPT_TRACEFILE_SIZE, 0, 0},
  79         {"tracefile-count", 'W',   POPT_ARG_INT, 0, OPT_TRACEFILE_COUNT, 0, 0},
  80         {0, 0, 0, 0, 0, 0, 0}
  81 };
  82
  83 /*
  84  * usage
  85  */
  86 static void usage(FILE *ofp)
  87 {
  88         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [-u|-k] [OPTIONS]\n");
  89         fprintf(ofp, "\n");
  90         fprintf(ofp, "Options:\n");
  91         fprintf(ofp, "  -h, --help               Show this help\n");
  92         fprintf(ofp, "      --list-options       Simple listing of options\n");
  93         fprintf(ofp, "  -s, --session NAME       Apply to session name\n");
  94         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
  95         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
  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: %zu, kernel default: %zu)\n",
 104                 default_get_channel_subbuf_size(),
 105                 default_get_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 (UST default: %u, kernel default: %u)\n",
 116                 DEFAULT_UST_CHANNEL_READ_TIMER, DEFAULT_KERNEL_CHANNEL_READ_TIMER);
 117         fprintf(ofp, "      --output TYPE        Channel output type (Values: %s, %s)\n",
 118                         output_mmap, output_splice);
 119         fprintf(ofp, "      --buffers-uid        Use per UID buffer (-u only)\n");
 120         fprintf(ofp, "      --buffers-pid        Use per PID buffer (-u only)\n");
 121         fprintf(ofp, "      --buffers-global     Use shared buffer for the whole system (-k only)\n");
 122         fprintf(ofp, "  -C, --tracefile-size SIZE\n");
 123         fprintf(ofp, "                           Maximum size of each tracefile within a stream (in bytes).\n");
 124         fprintf(ofp, "  -W, --tracefile-count COUNT\n");
 125         fprintf(ofp, "                           Used in conjunction with -C option, this will limit the number\n");
 126         fprintf(ofp, "                           of files created to the specified count.\n");
 127         fprintf(ofp, "\n");
 128 }
 129
 130 /*
 131  * Set default attributes depending on those already defined from the command
 132  * line.
 133  */
 134 static void set_default_attr(struct lttng_domain *dom)
 135 {
 136         struct lttng_channel_attr default_attr;
 137
 138         /* Set attributes */
 139         lttng_channel_set_default_attr(dom, &default_attr);
 140
 141         if (chan.attr.overwrite == -1) {
 142                 chan.attr.overwrite = default_attr.overwrite;
 143         }
 144         if (chan.attr.subbuf_size == -1) {
 145                 chan.attr.subbuf_size = default_attr.subbuf_size;
 146         }
 147         if (chan.attr.num_subbuf == -1) {
 148                 chan.attr.num_subbuf = default_attr.num_subbuf;
 149         }
 150         if (chan.attr.switch_timer_interval == -1) {
 151                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 152         }
 153         if (chan.attr.read_timer_interval == -1) {
 154                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 155         }
 156         if (chan.attr.output == -1) {
 157                 chan.attr.output = default_attr.output;
 158         }
 159         if (chan.attr.tracefile_count == -1) {
 160                 chan.attr.tracefile_count = default_attr.tracefile_count;
 161         }
 162         if (chan.attr.tracefile_size == -1) {
 163                 chan.attr.tracefile_size = default_attr.tracefile_size;
 164         }
 165 }
 166
 167 /*
 168  * Adding channel using the lttng API.
 169  */
 170 static int enable_channel(char *session_name)
 171 {
 172         int ret = CMD_SUCCESS, warn = 0;
 173         char *channel_name;
 174         struct lttng_domain dom;
 175
 176         memset(&dom, 0, sizeof(dom));
 177
 178         /* Create lttng domain */
 179         if (opt_kernel) {
 180                 dom.type = LTTNG_DOMAIN_KERNEL;
 181                 dom.buf_type = LTTNG_BUFFER_GLOBAL;
 182                 if (opt_buffer_uid || opt_buffer_pid) {
 183                         ERR("Buffer type not supported for domain -k");
 184                         ret = CMD_ERROR;
 185                         goto error;
 186                 }
 187         } else if (opt_userspace) {
 188                 dom.type = LTTNG_DOMAIN_UST;
 189                 if (opt_buffer_uid) {
 190                         dom.buf_type = LTTNG_BUFFER_PER_UID;
 191                 } else {
 192                         if (opt_buffer_global) {
 193                                 ERR("Buffer type not supported for domain -u");
 194                                 ret = CMD_ERROR;
 195                                 goto error;
 196                         }
 197                         dom.buf_type = LTTNG_BUFFER_PER_PID;
 198                 }
 199         } else {
 200                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 201                 ret = CMD_ERROR;
 202                 goto error;
 203         }
 204
 205         set_default_attr(&dom);
 206
 207         if ((chan.attr.tracefile_size > 0) &&
 208                         (chan.attr.tracefile_size < chan.attr.subbuf_size)) {
 209                 ERR("Tracefile_size must be greater than or equal to subbuf_size "
 210                                 "(%" PRIu64 " < %" PRIu64 ")",
 211                                 chan.attr.tracefile_size, chan.attr.subbuf_size);
 212                 ret = CMD_ERROR;
 213                 goto error;
 214         }
 215
 216         /* Setting channel output */
 217         if (opt_output) {
 218                 if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
 219                         chan.attr.output = LTTNG_EVENT_MMAP;
 220                 } else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
 221                         chan.attr.output = LTTNG_EVENT_SPLICE;
 222                 } else {
 223                         ERR("Unknown output type %s. Possible values are: %s, %s\n",
 224                                         opt_output, output_mmap, output_splice);
 225                         usage(stderr);
 226                         ret = CMD_ERROR;
 227                         goto error;
 228                 }
 229         }
 230
 231         handle = lttng_create_handle(session_name, &dom);
 232         if (handle == NULL) {
 233                 ret = -1;
 234                 goto error;
 235         }
 236
 237         /* Strip channel list (format: chan1,chan2,...) */
 238         channel_name = strtok(opt_channels, ",");
 239         while (channel_name != NULL) {
 240                 /* Copy channel name and normalize it */
 241                 strncpy(chan.name, channel_name, NAME_MAX);
 242                 chan.name[NAME_MAX - 1] = '\0';
 243
 244                 DBG("Enabling channel %s", channel_name);
 245
 246                 ret = lttng_enable_channel(handle, &chan);
 247                 if (ret < 0) {
 248                         switch (-ret) {
 249                         case LTTNG_ERR_KERN_CHAN_EXIST:
 250                         case LTTNG_ERR_UST_CHAN_EXIST:
 251                                 WARN("Channel %s: %s (session %s)", channel_name,
 252                                                 lttng_strerror(ret), session_name);
 253                                 goto error;
 254                         default:
 255                                 ERR("Channel %s: %s (session %s)", channel_name,
 256                                                 lttng_strerror(ret), session_name);
 257                                 break;
 258                         }
 259                         warn = 1;
 260                 } else {
 261                         MSG("%s channel %s enabled for session %s",
 262                                         opt_kernel ? "Kernel" : "UST", channel_name,
 263                                         session_name);
 264                 }
 265
 266                 /* Next event */
 267                 channel_name = strtok(NULL, ",");
 268         }
 269
 270         ret = CMD_SUCCESS;
 271
 272 error:
 273         if (warn) {
 274                 ret = CMD_WARNING;
 275         }
 276
 277         lttng_destroy_handle(handle);
 278
 279         return ret;
 280 }
 281
 282 /*
 283  * Default value for channel configuration.
 284  */
 285 static void init_channel_config(void)
 286 {
 287         /*
 288          * Put -1 everywhere so we can identify those set by the command line and
 289          * those needed to be set by the default values.
 290          */
 291         memset(&chan.attr, -1, sizeof(chan.attr));
 292 }
 293
 294 /*
 295  * Add channel to trace session
 296  */
 297 int cmd_enable_channels(int argc, const char **argv)
 298 {
 299         int opt, ret = CMD_SUCCESS;
 300         static poptContext pc;
 301         char *session_name = NULL;
 302
 303         init_channel_config();
 304
 305         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 306         poptReadDefaultConfig(pc, 0);
 307
 308         while ((opt = poptGetNextOpt(pc)) != -1) {
 309                 switch (opt) {
 310                 case OPT_HELP:
 311                         usage(stdout);
 312                         goto end;
 313                 case OPT_DISCARD:
 314                         chan.attr.overwrite = 0;
 315                         DBG("Channel set to discard");
 316                         break;
 317                 case OPT_OVERWRITE:
 318                         chan.attr.overwrite = 1;
 319                         DBG("Channel set to overwrite");
 320                         break;
 321                 case OPT_SUBBUF_SIZE:
 322                         /* TODO Replace atol with strtol and check for errors */
 323                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 324                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 325                         break;
 326                 case OPT_NUM_SUBBUF:
 327                         /* TODO Replace atoi with strtol and check for errors */
 328                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 329                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 330                         break;
 331                 case OPT_SWITCH_TIMER:
 332                         /* TODO Replace atoi with strtol and check for errors */
 333                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 334                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 335                         break;
 336                 case OPT_READ_TIMER:
 337                         /* TODO Replace atoi with strtol and check for errors */
 338                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 339                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 340                         break;
 341                 case OPT_USERSPACE:
 342                         opt_userspace = 1;
 343                         break;
 344                 case OPT_TRACEFILE_SIZE:
 345                         chan.attr.tracefile_size = atoll(poptGetOptArg(pc));
 346                         DBG("Maximum tracefile size set to %" PRIu64,
 347                                         chan.attr.tracefile_size);
 348                         break;
 349                 case OPT_TRACEFILE_COUNT:
 350                         chan.attr.tracefile_count = atoll(poptGetOptArg(pc));
 351                         DBG("Maximum tracefile count set to %" PRIu64,
 352                                         chan.attr.tracefile_count);
 353                         break;
 354                 case OPT_LIST_OPTIONS:
 355                         list_cmd_options(stdout, long_options);
 356                         goto end;
 357                 default:
 358                         usage(stderr);
 359                         ret = CMD_UNDEFINED;
 360                         goto end;
 361                 }
 362         }
 363
 364         opt_channels = (char*) poptGetArg(pc);
 365         if (opt_channels == NULL) {
 366                 ERR("Missing channel name.\n");
 367                 usage(stderr);
 368                 ret = CMD_ERROR;
 369                 goto end;
 370         }
 371
 372         if (!opt_session_name) {
 373                 session_name = get_session_name();
 374                 if (session_name == NULL) {
 375                         ret = CMD_ERROR;
 376                         goto end;
 377                 }
 378         } else {
 379                 session_name = opt_session_name;
 380         }
 381
 382         ret = enable_channel(session_name);
 383
 384 end:
 385         if (!opt_session_name && session_name) {
 386                 free(session_name);
 387         }
 388         poptFreeContext(pc);
 389         return ret;
 390 }