src/bin/lttng/commands/start.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 "../command.hpp"
  10 #include "../exception.hpp"
  11 #include "../utils.hpp"
  12
  13 #include <common/exception.hpp>
  14 #include <common/mi-lttng.hpp>
  15 #include <common/sessiond-comm/sessiond-comm.hpp>
  16
  17 #include <popt.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/stat.h>
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24
  25 enum {
  26         OPT_HELP = 1,
  27         OPT_LIST_OPTIONS,
  28         OPT_ENABLE_GLOB,
  29         OPT_ALL,
  30 };
  31
  32 namespace {
  33 struct mi_writer *writer;
  34
  35 #ifdef LTTNG_EMBED_HELP
  36 const char help_msg[] =
  37 #include <lttng-start.1.h>
  38         ;
  39 #endif
  40
  41 struct poptOption long_options[] = {
  42         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  43         { "help", 'h', POPT_ARG_NONE, nullptr, OPT_HELP, nullptr, nullptr },
  44         { "list-options", 0, POPT_ARG_NONE, nullptr, OPT_LIST_OPTIONS, nullptr, nullptr },
  45         { "glob", 'g', POPT_ARG_NONE, nullptr, OPT_ENABLE_GLOB, nullptr, nullptr },
  46         { "all", 'a', POPT_ARG_NONE, nullptr, OPT_ALL, nullptr, nullptr },
  47         { nullptr, 0, 0, nullptr, 0, nullptr, nullptr }
  48 };
  49
  50 int mi_print_session(const char *session_name, int enabled)
  51 {
  52         int ret;
  53
  54         /* Open session element */
  55         ret = mi_lttng_writer_open_element(writer, config_element_session);
  56         if (ret) {
  57                 goto end;
  58         }
  59
  60         /* Print session name element */
  61         ret = mi_lttng_writer_write_element_string(writer, config_element_name, session_name);
  62         if (ret) {
  63                 goto end;
  64         }
  65
  66         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled, enabled);
  67         if (ret) {
  68                 goto end;
  69         }
  70
  71         /* Close session element */
  72         ret = mi_lttng_writer_close_element(writer);
  73
  74 end:
  75         return ret;
  76 }
  77
  78 /*
  79  *  start_tracing
  80  *
  81  *  Start tracing for all trace of the session.
  82  */
  83 cmd_error_code start_tracing(const char *session_name)
  84 {
  85         if (session_name == nullptr) {
  86                 return CMD_ERROR;
  87         }
  88
  89         DBG("Starting tracing for session `%s`", session_name);
  90
  91         const int ret = lttng_start_tracing(session_name);
  92         if (ret < 0) {
  93                 LTTNG_THROW_CTL(lttng::format("Failed to start session `{}`", session_name),
  94                                 static_cast<lttng_error_code>(-ret));
  95         }
  96
  97         MSG("Tracing started for session `%s`", session_name);
  98         if (lttng_opt_mi) {
  99                 if (mi_print_session(session_name, 1)) {
 100                         return CMD_ERROR;
 101                 }
 102         }
 103
 104         return CMD_SUCCESS;
 105 }
 106
 107 cmd_error_code start_tracing(const lttng::cli::session_spec& spec)
 108 {
 109         bool had_warning = false;
 110         bool had_error = false;
 111         bool listing_failed = false;
 112
 113         const auto sessions = [&listing_failed, &spec]() -> lttng::cli::session_list {
 114                 try {
 115                         return list_sessions(spec);
 116                 } catch (const lttng::ctl::error& ctl_exception) {
 117                         ERR_FMT("Failed to list sessions ({})",
 118                                 lttng_strerror(-ctl_exception.code()));
 119                         listing_failed = true;
 120                         return {};
 121                 } catch (const lttng::cli::no_default_session_error& cli_exception) {
 122                         /*
 123                          * The retrieval of the default session name already logs
 124                          * an error when it fails. There is no value in printing
 125                          * anything about this exception.
 126                          */
 127                         listing_failed = true;
 128                         return {};
 129                 }
 130         }();
 131
 132         if (!listing_failed && sessions.size() == 0 &&
 133             spec.type_ == lttng::cli::session_spec::type::NAME) {
 134                 ERR_FMT("Session `{}` not found", spec.value);
 135                 return CMD_ERROR;
 136         }
 137
 138         if (listing_failed) {
 139                 return CMD_FATAL;
 140         }
 141
 142         for (const auto& session : sessions) {
 143                 cmd_error_code sub_ret;
 144
 145                 try {
 146                         sub_ret = start_tracing(session.name);
 147                 } catch (const lttng::ctl::error& ctl_exception) {
 148                         switch (ctl_exception.code()) {
 149                         case LTTNG_ERR_TRACE_ALREADY_STARTED:
 150                                 WARN_FMT("Tracing already started for session `{}`", session.name);
 151                                 sub_ret = CMD_SUCCESS;
 152                                 break;
 153                         case LTTNG_ERR_NO_SESSION:
 154                                 if (spec.type_ != lttng::cli::session_spec::type::NAME) {
 155                                         /* Session destroyed during command, ignore and carry-on. */
 156                                         sub_ret = CMD_SUCCESS;
 157                                         break;
 158                                 } else {
 159                                         sub_ret = CMD_ERROR;
 160                                         break;
 161                                 }
 162                         case LTTNG_ERR_NO_SESSIOND:
 163                                 /* Don't keep going on a fatal error. */
 164                                 return CMD_FATAL;
 165                         default:
 166                                 /* Generic error. */
 167                                 sub_ret = CMD_ERROR;
 168                                 ERR_FMT("Failed to start session `{}` ({})",
 169                                         session.name,
 170                                         lttng_strerror(-ctl_exception.code()));
 171                                 break;
 172                         }
 173                 }
 174
 175                 /* Keep going, but report the most serious state. */
 176                 had_warning |= sub_ret == CMD_WARNING;
 177                 had_error |= sub_ret == CMD_ERROR;
 178         }
 179
 180         if (had_error) {
 181                 return CMD_ERROR;
 182         } else if (had_warning) {
 183                 return CMD_WARNING;
 184         } else {
 185                 return CMD_SUCCESS;
 186         }
 187 }
 188 } /* namespace */
 189
 190 /*
 191  *  cmd_start
 192  *
 193  *  The 'start <options>' first level command
 194  */
 195 int cmd_start(int argc, const char **argv)
 196 {
 197         int opt;
 198         cmd_error_code command_ret = CMD_SUCCESS;
 199         bool success = true;
 200         static poptContext pc;
 201         const char *leftover = nullptr;
 202         lttng::cli::session_spec session_spec(lttng::cli::session_spec::type::NAME);
 203
 204         pc = poptGetContext(nullptr, argc, argv, long_options, 0);
 205         poptReadDefaultConfig(pc, 0);
 206
 207         while ((opt = poptGetNextOpt(pc)) != -1) {
 208                 switch (opt) {
 209                 case OPT_HELP:
 210                 {
 211                         int ret;
 212
 213                         SHOW_HELP();
 214                         command_ret = static_cast<cmd_error_code>(ret);
 215                         goto end;
 216                 }
 217                 case OPT_LIST_OPTIONS:
 218                         list_cmd_options(stdout, long_options);
 219                         goto end;
 220                 case OPT_ENABLE_GLOB:
 221                         session_spec.type_ = lttng::cli::session_spec::type::GLOB_PATTERN;
 222                         break;
 223                 case OPT_ALL:
 224                         session_spec.type_ = lttng::cli::session_spec::type::ALL;
 225                         break;
 226                 default:
 227                         command_ret = CMD_UNDEFINED;
 228                         goto end;
 229                 }
 230         }
 231
 232         session_spec.value = poptGetArg(pc);
 233
 234         leftover = poptGetArg(pc);
 235         if (leftover) {
 236                 ERR("Unknown argument: %s", leftover);
 237                 command_ret = CMD_ERROR;
 238                 goto end;
 239         }
 240
 241         /* Mi check */
 242         if (lttng_opt_mi) {
 243                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 244                 if (!writer) {
 245                         command_ret = CMD_ERROR;
 246                         goto end;
 247                 }
 248
 249                 /* Open command element */
 250                 if (mi_lttng_writer_command_open(writer, mi_lttng_element_command_start)) {
 251                         command_ret = CMD_ERROR;
 252                         goto end;
 253                 }
 254
 255                 /* Open output element */
 256                 if (mi_lttng_writer_open_element(writer, mi_lttng_element_command_output)) {
 257                         command_ret = CMD_ERROR;
 258                         goto end;
 259                 }
 260
 261                 /*
 262                  * Open sessions element
 263                  * For validation purpose
 264                  */
 265                 if (mi_lttng_writer_open_element(writer, config_element_sessions)) {
 266                         command_ret = CMD_ERROR;
 267                         goto end;
 268                 }
 269         }
 270
 271         command_ret = start_tracing(session_spec);
 272         if (command_ret != CMD_SUCCESS) {
 273                 success = false;
 274         }
 275
 276         /* Mi closing */
 277         if (lttng_opt_mi) {
 278                 /* Close  sessions and output element */
 279                 if (mi_lttng_close_multi_element(writer, 2)) {
 280                         command_ret = CMD_ERROR;
 281                         goto end;
 282                 }
 283
 284                 /* Success ? */
 285                 if (mi_lttng_writer_write_element_bool(
 286                             writer, mi_lttng_element_command_success, success)) {
 287                         command_ret = CMD_ERROR;
 288                         goto end;
 289                 }
 290
 291                 /* Command element close */
 292                 if (mi_lttng_writer_command_close(writer)) {
 293                         command_ret = CMD_ERROR;
 294                         goto end;
 295                 }
 296         }
 297
 298 end:
 299         /* Mi clean-up */
 300         if (writer && mi_lttng_writer_destroy(writer)) {
 301                 command_ret = CMD_ERROR;
 302         }
 303
 304         poptFreeContext(pc);
 305         return command_ret;
 306 }