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