src/bin/lttng/commands/disable_channels.cpp

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include <popt.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/stat.h>
  14 #include <sys/types.h>
  15 #include <unistd.h>
  16
  17 #include <common/mi-lttng.hpp>
  18 #include <lttng/domain-internal.hpp>
  19
  20 #include "../command.hpp"
  21
  22 static int opt_kernel;
  23 static char *opt_session_name;
  24 static int opt_userspace;
  25
  26 #ifdef LTTNG_EMBED_HELP
  27 static const char help_msg[] =
  28 #include <lttng-disable-channel.1.h>
  29 ;
  30 #endif
  31
  32 enum {
  33         OPT_HELP = 1,
  34         OPT_USERSPACE,
  35         OPT_LIST_OPTIONS,
  36 };
  37
  38 static struct lttng_handle *handle;
  39 static struct mi_writer *writer;
  40
  41 static struct poptOption long_options[] = {
  42         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  43         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  44         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  45         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  46         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  47         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  48         {0, 0, 0, 0, 0, 0, 0}
  49 };
  50
  51 static int mi_partial_channel_print(char *channel_name, unsigned int enabled,
  52                 int success)
  53 {
  54         int ret;
  55
  56         LTTNG_ASSERT(writer);
  57         LTTNG_ASSERT(channel_name);
  58
  59         /* Open channel element */
  60         ret = mi_lttng_writer_open_element(writer, config_element_channel);
  61         if (ret) {
  62                 goto end;
  63         }
  64
  65         /* Name */
  66         ret = mi_lttng_writer_write_element_string(writer, config_element_name,
  67                         channel_name);
  68         if (ret) {
  69                 goto end;
  70         }
  71
  72         /* Enabled ? */
  73         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  74                         enabled);
  75         if (ret) {
  76                 goto end;
  77         }
  78
  79         /* Success ? */
  80         ret = mi_lttng_writer_write_element_bool(writer,
  81                         mi_lttng_element_success, success);
  82         if (ret) {
  83                 goto end;
  84         }
  85
  86         /* Closing channel element */
  87         ret = mi_lttng_writer_close_element(writer);
  88
  89 end:
  90         return ret;
  91 }
  92
  93 /*
  94  * Disabling channel using the lttng API.
  95  */
  96 static int disable_channels(char *session_name, char *channel_list)
  97 {
  98         int ret = CMD_SUCCESS, warn = 0, success;
  99
 100         /* Normal case for disable channed is enabled = 0 */
 101         unsigned int enabled = 0;
 102         char *channel_name;
 103         struct lttng_domain dom;
 104
 105         memset(&dom, 0, sizeof(dom));
 106
 107         /* Create lttng domain */
 108         if (opt_kernel) {
 109                 dom.type = LTTNG_DOMAIN_KERNEL;
 110         } else if (opt_userspace) {
 111                 dom.type = LTTNG_DOMAIN_UST;
 112         } else {
 113                 /* Checked by the caller. */
 114                 abort();
 115         }
 116
 117         handle = lttng_create_handle(session_name, &dom);
 118         if (handle == NULL) {
 119                 ret = -1;
 120                 goto error;
 121         }
 122
 123         /* Prepare MI */
 124         if (lttng_opt_mi) {
 125                 /* open a channels element */
 126                 ret = mi_lttng_writer_open_element(writer, config_element_channels);
 127                 if (ret) {
 128                         ret = CMD_ERROR;
 129                         goto error;
 130                 }
 131
 132         }
 133
 134         /* Strip channel list */
 135         channel_name = strtok(channel_list, ",");
 136         while (channel_name != NULL) {
 137                 DBG("Disabling channel %s", channel_name);
 138
 139                 ret = lttng_disable_channel(handle, channel_name);
 140                 if (ret < 0) {
 141                         ERR("Channel %s: %s (session %s)", channel_name,
 142                                         lttng_strerror(ret), session_name);
 143                         warn = 1;
 144
 145                         /*
 146                          * Mi:
 147                          * We assume that if an error occurred the channel is still active.
 148                          * This might not be the case but is a good assumption.
 149                          * The client should look at the stderr stream
 150                          * for more informations.
 151                          */
 152                         enabled = 1;
 153                         success = 0;
 154
 155                 } else {
 156                         MSG("%s channel %s disabled for session %s",
 157                                         lttng_domain_type_str(dom.type),
 158                                         channel_name, session_name);
 159                         enabled = 0;
 160                         success = 1;
 161                 }
 162
 163                 /* Print the channel */
 164                 if (lttng_opt_mi) {
 165                         ret = mi_partial_channel_print(channel_name, enabled, success);
 166                         if (ret) {
 167                                 ret = CMD_ERROR;
 168                                 goto error;
 169                         }
 170                 }
 171
 172                 /* Next channel */
 173                 channel_name = strtok(NULL, ",");
 174         }
 175
 176         ret = CMD_SUCCESS;
 177
 178         /* Close Mi */
 179         if (lttng_opt_mi) {
 180                 /* Close channels element */
 181                 ret = mi_lttng_writer_close_element(writer);
 182                 if (ret) {
 183                         ret = CMD_ERROR;
 184                         goto error;
 185                 }
 186         }
 187
 188 error:
 189         /* Bypass the warning if a more important error happened */
 190         if (!ret && warn) {
 191                 ret = CMD_WARNING;
 192         }
 193
 194         lttng_destroy_handle(handle);
 195
 196         return ret;
 197 }
 198
 199 /*
 200  *  cmd_disable_channels
 201  *
 202  *  Disable channel to trace session
 203  */
 204 int cmd_disable_channels(int argc, const char **argv)
 205 {
 206         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 207         static poptContext pc;
 208         char *session_name = NULL;
 209         char *channel_list = NULL;
 210         const char *arg_channel_list = NULL;
 211         const char *leftover = NULL;
 212
 213         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 214         poptReadDefaultConfig(pc, 0);
 215
 216         while ((opt = poptGetNextOpt(pc)) != -1) {
 217                 switch (opt) {
 218                 case OPT_HELP:
 219                         SHOW_HELP();
 220                         goto end;
 221                 case OPT_USERSPACE:
 222                         opt_userspace = 1;
 223                         break;
 224                 case OPT_LIST_OPTIONS:
 225                         list_cmd_options(stdout, long_options);
 226                         goto end;
 227                 default:
 228                         ret = CMD_UNDEFINED;
 229                         goto end;
 230                 }
 231         }
 232
 233         ret = print_missing_or_multiple_domains(
 234                         opt_kernel + opt_userspace, false);
 235         if (ret) {
 236                 ret = CMD_ERROR;
 237                 goto end;
 238         }
 239
 240         arg_channel_list = poptGetArg(pc);
 241         if (arg_channel_list == NULL) {
 242                 ERR("Missing channel name(s).");
 243                 ret = CMD_ERROR;
 244                 goto end;
 245         }
 246
 247         channel_list = strdup(arg_channel_list);
 248         if (channel_list == NULL) {
 249                 PERROR("Failed to copy channel name");
 250                 ret = CMD_ERROR;
 251                 goto end;
 252         }
 253
 254         leftover = poptGetArg(pc);
 255         if (leftover) {
 256                 ERR("Unknown argument: %s", leftover);
 257                 ret = CMD_ERROR;
 258                 goto end;
 259         }
 260
 261         if (!opt_session_name) {
 262                 session_name = get_session_name();
 263                 if (session_name == NULL) {
 264                         ret = CMD_ERROR;
 265                         goto end;
 266                 }
 267         } else {
 268                 session_name = opt_session_name;
 269         }
 270
 271         /* Mi check */
 272         if (lttng_opt_mi) {
 273                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 274                 if (!writer) {
 275                         ret = -LTTNG_ERR_NOMEM;
 276                         goto end;
 277                 }
 278
 279                 /* Open command element */
 280                 ret = mi_lttng_writer_command_open(writer,
 281                                 mi_lttng_element_command_disable_channel);
 282                 if (ret) {
 283                         ret = CMD_ERROR;
 284                         goto end;
 285                 }
 286
 287                 /* Open output element */
 288                 ret = mi_lttng_writer_open_element(writer,
 289                                 mi_lttng_element_command_output);
 290                 if (ret) {
 291                         ret = CMD_ERROR;
 292                         goto end;
 293                 }
 294         }
 295
 296         command_ret = disable_channels(session_name, channel_list);
 297         if (command_ret) {
 298                 success = 0;
 299         }
 300
 301         /* Mi closing */
 302         if (lttng_opt_mi) {
 303                 /* Close  output element */
 304                 ret = mi_lttng_writer_close_element(writer);
 305                 if (ret) {
 306                         ret = CMD_ERROR;
 307                         goto end;
 308                 }
 309
 310                 /* Success ? */
 311                 ret = mi_lttng_writer_write_element_bool(writer,
 312                                 mi_lttng_element_success, success);
 313                 if (ret) {
 314                         ret = CMD_ERROR;
 315                         goto end;
 316                 }
 317
 318                 /* Command element close */
 319                 ret = mi_lttng_writer_command_close(writer);
 320                 if (ret) {
 321                         ret = CMD_ERROR;
 322                         goto end;
 323                 }
 324         }
 325
 326 end:
 327         /* Mi clean-up */
 328         if (writer && mi_lttng_writer_destroy(writer)) {
 329                 /* Preserve original error code */
 330                 ret = ret ? ret : LTTNG_ERR_MI_IO_FAIL;
 331         }
 332
 333         if (!opt_session_name && session_name) {
 334                 free(session_name);
 335         }
 336
 337         free(channel_list);
 338
 339         /* Overwrite ret if an error occurred in disable_channels */
 340         ret = command_ret ? command_ret : ret;
 341
 342         poptFreeContext(pc);
 343         return ret;
 344 }