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 (default: %u)\n",
 116                 DEFAULT_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 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         } else if (opt_userspace) {
 183                 dom.type = LTTNG_DOMAIN_UST;
 184                 if (opt_buffer_uid) {
 185                         dom.buf_type = LTTNG_BUFFER_PER_UID;
 186                 } else {
 187                         dom.buf_type = LTTNG_BUFFER_PER_PID;
 188                 }
 189         } else {
 190                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 191                 ret = CMD_ERROR;
 192                 goto error;
 193         }
 194
 195         set_default_attr(&dom);
 196
 197         if ((chan.attr.tracefile_size > 0) &&
 198                         (chan.attr.tracefile_size < chan.attr.subbuf_size)) {
 199                 ERR("Tracefile_size must be greater than or equal to subbuf_size "
 200                                 "(%" PRIu64 " < %" PRIu64 ")",
 201                                 chan.attr.tracefile_size, chan.attr.subbuf_size);
 202                 ret = CMD_ERROR;
 203                 goto error;
 204         }
 205
 206         /* Setting channel output */
 207         if (opt_output) {
 208                 if (!strncmp(output_mmap, opt_output, strlen(output_mmap))) {
 209                         chan.attr.output = LTTNG_EVENT_MMAP;
 210                 } else if (!strncmp(output_splice, opt_output, strlen(output_splice))) {
 211                         chan.attr.output = LTTNG_EVENT_SPLICE;
 212                 } else {
 213                         ERR("Unknown output type %s. Possible values are: %s, %s\n",
 214                                         opt_output, output_mmap, output_splice);
 215                         usage(stderr);
 216                         ret = CMD_ERROR;
 217                         goto error;
 218                 }
 219         }
 220
 221         handle = lttng_create_handle(session_name, &dom);
 222         if (handle == NULL) {
 223                 ret = -1;
 224                 goto error;
 225         }
 226
 227         /* Strip channel list (format: chan1,chan2,...) */
 228         channel_name = strtok(opt_channels, ",");
 229         while (channel_name != NULL) {
 230                 /* Copy channel name and normalize it */
 231                 strncpy(chan.name, channel_name, NAME_MAX);
 232                 chan.name[NAME_MAX - 1] = '\0';
 233
 234                 DBG("Enabling channel %s", channel_name);
 235
 236                 ret = lttng_enable_channel(handle, &chan);
 237                 if (ret < 0) {
 238                         switch (-ret) {
 239                         case LTTNG_ERR_KERN_CHAN_EXIST:
 240                         case LTTNG_ERR_UST_CHAN_EXIST:
 241                                 WARN("Channel %s: %s (session %s", channel_name,
 242                                                 lttng_strerror(ret), session_name);
 243                                 goto error;
 244                         default:
 245                                 ERR("Channel %s: %s (session %s)", channel_name,
 246                                                 lttng_strerror(ret), session_name);
 247                                 break;
 248                         }
 249                         warn = 1;
 250                 } else {
 251                         MSG("%s channel %s enabled for session %s",
 252                                         opt_kernel ? "Kernel" : "UST", channel_name,
 253                                         session_name);
 254                 }
 255
 256                 /* Next event */
 257                 channel_name = strtok(NULL, ",");
 258         }
 259
 260         ret = CMD_SUCCESS;
 261
 262 error:
 263         if (warn) {
 264                 ret = CMD_WARNING;
 265         }
 266
 267         lttng_destroy_handle(handle);
 268
 269         return ret;
 270 }
 271
 272 /*
 273  * Default value for channel configuration.
 274  */
 275 static void init_channel_config(void)
 276 {
 277         /*
 278          * Put -1 everywhere so we can identify those set by the command line and
 279          * those needed to be set by the default values.
 280          */
 281         memset(&chan.attr, -1, sizeof(chan.attr));
 282 }
 283
 284 /*
 285  * Add channel to trace session
 286  */
 287 int cmd_enable_channels(int argc, const char **argv)
 288 {
 289         int opt, ret = CMD_SUCCESS;
 290         static poptContext pc;
 291         char *session_name = NULL;
 292
 293         init_channel_config();
 294
 295         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 296         poptReadDefaultConfig(pc, 0);
 297
 298         while ((opt = poptGetNextOpt(pc)) != -1) {
 299                 switch (opt) {
 300                 case OPT_HELP:
 301                         usage(stdout);
 302                         goto end;
 303                 case OPT_DISCARD:
 304                         chan.attr.overwrite = 0;
 305                         DBG("Channel set to discard");
 306                         break;
 307                 case OPT_OVERWRITE:
 308                         chan.attr.overwrite = 1;
 309                         DBG("Channel set to overwrite");
 310                         break;
 311                 case OPT_SUBBUF_SIZE:
 312                         /* TODO Replace atol with strtol and check for errors */
 313                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 314                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 315                         break;
 316                 case OPT_NUM_SUBBUF:
 317                         /* TODO Replace atoi with strtol and check for errors */
 318                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 319                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 320                         break;
 321                 case OPT_SWITCH_TIMER:
 322                         /* TODO Replace atoi with strtol and check for errors */
 323                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 324                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 325                         break;
 326                 case OPT_READ_TIMER:
 327                         /* TODO Replace atoi with strtol and check for errors */
 328                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 329                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 330                         break;
 331                 case OPT_USERSPACE:
 332                         opt_userspace = 1;
 333                         break;
 334                 case OPT_TRACEFILE_SIZE:
 335                         chan.attr.tracefile_size = atoll(poptGetOptArg(pc));
 336                         DBG("Maximum tracefile size set to %" PRIu64,
 337                                         chan.attr.tracefile_size);
 338                         break;
 339                 case OPT_TRACEFILE_COUNT:
 340                         chan.attr.tracefile_count = atoll(poptGetOptArg(pc));
 341                         DBG("Maximum tracefile count set to %" PRIu64,
 342                                         chan.attr.tracefile_count);
 343                         break;
 344                 case OPT_LIST_OPTIONS:
 345                         list_cmd_options(stdout, long_options);
 346                         goto end;
 347                 default:
 348                         usage(stderr);
 349                         ret = CMD_UNDEFINED;
 350                         goto end;
 351                 }
 352         }
 353
 354         opt_channels = (char*) poptGetArg(pc);
 355         if (opt_channels == NULL) {
 356                 ERR("Missing channel name.\n");
 357                 usage(stderr);
 358                 ret = CMD_ERROR;
 359                 goto end;
 360         }
 361
 362         if (!opt_session_name) {
 363                 session_name = get_session_name();
 364                 if (session_name == NULL) {
 365                         ret = CMD_ERROR;
 366                         goto end;
 367                 }
 368         } else {
 369                 session_name = opt_session_name;
 370         }
 371
 372         ret = enable_channel(session_name);
 373
 374 end:
 375         if (!opt_session_name && session_name) {
 376                 free(session_name);
 377         }
 378         poptFreeContext(pc);
 379         return ret;
 380 }