src/bin/lttng/commands/metadata.c

   1 /*
   2  * Copyright (C) 2015 - Julien Desfossez <jdesfossez@efficios.com>
   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 _LGPL_SOURCE
  19 #include <assert.h>
  20 #include <ctype.h>
  21 #include <popt.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include <common/mi-lttng.h>
  28
  29 #include "../command.h"
  30
  31 static char *opt_session_name;
  32 static char *session_name = NULL;
  33
  34 static int metadata_regenerate(int argc, const char **argv);
  35
  36 #ifdef LTTNG_EMBED_HELP
  37 static const char help_msg[] =
  38 #include <lttng-metadata.1.h>
  39 ;
  40 #endif
  41
  42 enum {
  43         OPT_HELP = 1,
  44         OPT_LIST_OPTIONS,
  45         OPT_LIST_COMMANDS,
  46 };
  47
  48 static struct mi_writer *writer;
  49
  50 static struct poptOption long_options[] = {
  51         /* { longName, shortName, argInfo, argPtr, value, descrip, argDesc, } */
  52         { "help",               'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0, },
  53         { "session",            's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  54         { "list-options",       0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, 0, 0, },
  55         { "list-commands",      0, POPT_ARG_NONE, NULL, OPT_LIST_COMMANDS},
  56         { 0, 0, 0, 0, 0, 0, 0, },
  57 };
  58
  59 static struct cmd_struct actions[] = {
  60         { "regenerate", metadata_regenerate },
  61         { NULL, NULL }  /* Array closure */
  62 };
  63
  64 /*
  65  * Count and return the number of arguments in argv.
  66  */
  67 static int count_arguments(const char **argv)
  68 {
  69         int i = 0;
  70
  71         assert(argv);
  72
  73         while (argv[i] != NULL) {
  74                 i++;
  75         }
  76
  77         return i;
  78 }
  79
  80 static int metadata_regenerate(int argc, const char **argv)
  81 {
  82         int ret;
  83
  84         if (argc > 1) {
  85                 ret = CMD_UNDEFINED;
  86                 goto end;
  87         }
  88         ret = lttng_regenerate_metadata(session_name);
  89         if (ret == 0) {
  90                 MSG("Metadata successfully regenerated for session %s", session_name);
  91         } else {
  92                 ERR("%s", lttng_strerror(ret));
  93         }
  94
  95 end:
  96         return ret;
  97 }
  98
  99 static int handle_command(const char **argv)
 100 {
 101         struct cmd_struct *cmd;
 102         int ret = CMD_SUCCESS, i = 0, argc, command_ret = CMD_SUCCESS;
 103
 104         if (argv == NULL) {
 105                 ERR("No action specified for metadata command.");
 106                 ret = CMD_ERROR;
 107                 goto end;
 108         }
 109
 110         argc = count_arguments(argv);
 111         assert(argc >= 1);
 112
 113         cmd = &actions[i];
 114         while (cmd->func != NULL) {
 115                 /* Find command */
 116                 if (strcmp(argv[0], cmd->name) == 0) {
 117                         if (lttng_opt_mi) {
 118                                 /* Action element */
 119                                 ret = mi_lttng_writer_open_element(writer,
 120                                                 mi_lttng_element_command_metadata_action);
 121                                 if (ret) {
 122                                         ret = CMD_ERROR;
 123                                         goto end;
 124                                 }
 125
 126                                 /* Name of the action */
 127                                 ret = mi_lttng_writer_write_element_string(writer,
 128                                                 config_element_name, argv[0]);
 129                                 if (ret) {
 130                                         ret = CMD_ERROR;
 131                                         goto end;
 132                                 }
 133                         }
 134                         command_ret = cmd->func(argc, argv);
 135                         if (lttng_opt_mi) {
 136                                 /* Close output and action element */
 137                                 ret = mi_lttng_writer_close_element(writer);
 138                                 if (ret) {
 139                                         ret = CMD_ERROR;
 140                                         goto end;
 141                                 }
 142                         }
 143                         goto end;
 144                 }
 145
 146                 cmd = &actions[i++];
 147         }
 148
 149         ret = CMD_UNDEFINED;
 150
 151 end:
 152         /* Overwrite ret if an error occurred in cmd->func() */
 153         ret = command_ret ? command_ret : ret;
 154         return ret;
 155 }
 156
 157 /*
 158  * Metadata command handling.
 159  */
 160 int cmd_metadata(int argc, const char **argv)
 161 {
 162         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 163         static poptContext pc;
 164
 165         if (argc < 1) {
 166                 SHOW_HELP();
 167                 ret = CMD_ERROR;
 168                 goto end;
 169         }
 170
 171         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 172         poptReadDefaultConfig(pc, 0);
 173
 174         if (lttng_opt_mi) {
 175                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 176                 if (!writer) {
 177                         ret = -LTTNG_ERR_NOMEM;
 178                         goto end;
 179                 }
 180                 /* Open command element */
 181                 ret = mi_lttng_writer_command_open(writer,
 182                                 mi_lttng_element_command_metadata);
 183                 if (ret) {
 184                         ret = CMD_ERROR;
 185                         goto end;
 186                 }
 187
 188                 /* Open output element */
 189                 ret = mi_lttng_writer_open_element(writer,
 190                                 mi_lttng_element_command_output);
 191                 if (ret) {
 192                         ret = CMD_ERROR;
 193                         goto end;
 194                 }
 195         }
 196
 197         while ((opt = poptGetNextOpt(pc)) != -1) {
 198                 switch (opt) {
 199                 case OPT_HELP:
 200                         SHOW_HELP();
 201                         goto end;
 202                 case OPT_LIST_OPTIONS:
 203                         list_cmd_options(stdout, long_options);
 204                         goto end;
 205                 case OPT_LIST_COMMANDS:
 206                         list_commands(actions, stdout);
 207                         goto end;
 208                 default:
 209                         SHOW_HELP();
 210                         ret = CMD_UNDEFINED;
 211                         goto end;
 212                 }
 213         }
 214
 215         if (!opt_session_name) {
 216                 session_name = get_session_name();
 217                 if (session_name == NULL) {
 218                         ret = CMD_ERROR;
 219                         goto end;
 220                 }
 221         } else {
 222                 session_name = opt_session_name;
 223         }
 224
 225         command_ret = handle_command(poptGetArgs(pc));
 226         if (command_ret) {
 227                 success = 0;
 228         }
 229
 230         if (lttng_opt_mi) {
 231                 /* Close output element */
 232                 ret = mi_lttng_writer_close_element(writer);
 233                 if (ret) {
 234                         ret = CMD_ERROR;
 235                         goto end;
 236                 }
 237
 238                 /* Success ? */
 239                 ret = mi_lttng_writer_write_element_bool(writer,
 240                                 mi_lttng_element_command_success, success);
 241                 if (ret) {
 242                         ret = CMD_ERROR;
 243                         goto end;
 244                 }
 245
 246                 /* Command element close */
 247                 ret = mi_lttng_writer_command_close(writer);
 248                 if (ret) {
 249                         ret = CMD_ERROR;
 250                         goto end;
 251                 }
 252         }
 253
 254 end:
 255         /* Mi clean-up */
 256         if (writer && mi_lttng_writer_destroy(writer)) {
 257                 /* Preserve original error code */
 258                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 259         }
 260
 261         if (!opt_session_name) {
 262                 free(session_name);
 263         }
 264
 265         /* Overwrite ret if an error occurred during handle_command() */
 266         ret = command_ret ? command_ret : ret;
 267
 268         poptFreeContext(pc);
 269         return ret;
 270 }