src/common/config/session-config.h

   1 /*
   2  * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #ifndef _CONFIG_H
  19 #define _CONFIG_H
  20
  21 #include <common/config/ini.h>
  22 #include <common/config/config-session-abi.h>
  23 #include <common/macros.h>
  24 #include <lttng/domain.h>
  25 #include <lttng/event.h>
  26 #include <stdint.h>
  27
  28 struct config_entry {
  29         /* section is NULL if the entry is not in a section */
  30         const char *section;
  31         const char *name;
  32         const char *value;
  33 };
  34
  35 /* Instance of a configuration writer. */
  36 struct config_writer;
  37
  38 /* Instance of a configuration document */
  39 struct config_document;
  40
  41 struct config_element;
  42
  43 /*
  44  * Return the config string representation of a kernel type.
  45  */
  46 LTTNG_HIDDEN
  47 const char *config_get_domain_str(enum lttng_domain_type domain);
  48
  49 /*
  50  * Return the config string representation of a loglevel type.
  51  */
  52 LTTNG_HIDDEN
  53 const char *config_get_loglevel_type_string(
  54                 enum lttng_loglevel_type loglevel_type);
  55
  56 /*
  57  * Return the event_type int value of lttng_event_type enumeration based on the
  58  * passed string.
  59  */
  60 LTTNG_HIDDEN
  61 int config_get_event_type(const char *event_type);
  62
  63 /*
  64  * A config_entry_handler_cb receives config_entry structures belonging to the
  65  * sections the handler has been registered to.
  66  *
  67  * The config_entry and its members are only valid for the duration of the call
  68  * and must not be freed.
  69  *
  70  * config_entry_handler_cb may return negative value to indicate an error in
  71  * the configuration file.
  72  */
  73 typedef int (*config_entry_handler_cb)(const struct config_entry *, void *);
  74
  75 /*
  76  * Read a section's entries in an INI configuration file.
  77  *
  78  * path may be NULL, in which case the following paths will be tried:
  79  *      1) $HOME/.lttng/lttng.conf
  80  *      2) /etc/lttng/lttng.conf
  81  *
  82  * handler will only be called with entries belonging to the provided section.
  83  * If section is NULL, all entries will be relayed to handler. If section is
  84  * "", only the global entries are relayed.
  85  *
  86  * Returns 0 on success. Negative values are error codes. If the return value
  87  * is positive, it represents the line number on which a parsing error occurred.
  88  */
  89 LTTNG_HIDDEN
  90 int config_get_section_entries(const char *path, const char *section,
  91                 config_entry_handler_cb handler, void *user_data);
  92
  93 /*
  94  * Parse a configuration value.
  95  *
  96  * This function expects either an unsigned integer or a boolean text option.
  97  * The following strings are recognized: true, yes, on, false, no and off.
  98  *
  99  * Returns either the value of the parsed integer, or 0/1 if a boolean text
 100  * string was recognized. Negative values indicate an error.
 101  */
 102 LTTNG_HIDDEN
 103 int config_parse_value(const char *value);
 104
 105 /*
 106  * Create an instance of a configuration writer.
 107  *
 108  * fd_output File to which the XML content must be written. The file will be
 109  * closed once the config_writer has been destroyed.
 110  *
 111  * indent If other than 0 the XML will be pretty printed
 112  * with indentation and newline.
 113  *
 114  * Returns an instance of a configuration writer on success, NULL on
 115  * error.
 116  */
 117 LTTNG_HIDDEN
 118 struct config_writer *config_writer_create(int fd_output, int indent);
 119
 120 /*
 121  * Destroy an instance of a configuration writer.
 122  *
 123  * writer An instance of a configuration writer.
 124  *
 125  * Returns zero if the XML document could be closed cleanly. Negative values
 126  * indicate an error.
 127  */
 128 LTTNG_HIDDEN
 129 int config_writer_destroy(struct config_writer *writer);
 130
 131 /*
 132  * Open an element tag.
 133  *
 134  * writer An instance of a configuration writer.
 135  *
 136  * element_name Element tag name.
 137  *
 138  * Returns zero if the XML element could be opened.
 139  * Negative values indicate an error.
 140  */
 141 LTTNG_HIDDEN
 142 int config_writer_open_element(struct config_writer *writer,
 143                 const char *element_name);
 144
 145 /*
 146  * Write an element tag attribute.
 147  *
 148  * writer An instance of a configuration writer.
 149  *
 150  * name Attribute name.
 151  *
 152  * Returns zero if the XML element's attribute could be written.
 153  * Negative values indicate an error.
 154  */
 155 LTTNG_HIDDEN
 156 int config_writer_write_attribute(struct config_writer *writer,
 157                 const char *name, const char *value);
 158
 159 /*
 160  * Close the current element tag.
 161  *
 162  * writer An instance of a configuration writer.
 163  *
 164  * Returns zero if the XML document could be closed cleanly.
 165  * Negative values indicate an error.
 166  */
 167 LTTNG_HIDDEN
 168 int config_writer_close_element(struct config_writer *writer);
 169
 170 /*
 171  * Write an element of type unsigned int.
 172  *
 173  * writer An instance of a configuration writer.
 174  *
 175  * element_name Element name.
 176  *
 177  * value Unsigned int value of the element
 178  *
 179  * Returns zero if the element's value could be written.
 180  * Negative values indicate an error.
 181  */
 182 LTTNG_HIDDEN
 183 int config_writer_write_element_unsigned_int(struct config_writer *writer,
 184                 const char *element_name, uint64_t value);
 185
 186 /*
 187  * Write an element of type signed int.
 188  *
 189  * writer An instance of a configuration writer.
 190  *
 191  * element_name Element name.
 192  *
 193  * value Signed int value of the element
 194  *
 195  * Returns zero if the element's value could be written.
 196  * Negative values indicate an error.
 197  */LTTNG_HIDDEN
 198 int config_writer_write_element_signed_int(struct config_writer *writer,
 199                 const char *element_name, int64_t value);
 200
 201 /*
 202  * Write an element of type boolean.
 203  *
 204  * writer An instance of a configuration writer.
 205  *
 206  * element_name Element name.
 207  *
 208  * value Boolean value of the element
 209  *
 210  * Returns zero if the element's value could be written.
 211  * Negative values indicate an error.
 212  */
 213 LTTNG_HIDDEN
 214 int config_writer_write_element_bool(struct config_writer *writer,
 215                 const char *element_name, int value);
 216
 217 /*
 218  * Write an element of type string.
 219  *
 220  * writer An instance of a configuration writer.
 221  *
 222  * element_name Element name.
 223  *
 224  * value String value of the element
 225  *
 226  * Returns zero if the element's value could be written.
 227  * Negative values indicate an error.
 228  */
 229 LTTNG_HIDDEN
 230 int config_writer_write_element_string(struct config_writer *writer,
 231                 const char *element_name, const char *value);
 232
 233 /*
 234  * Write an element of type config_element.
 235  *
 236  * writer An instance of a configuration writer.
 237  *
 238  * element The config_element instance.
 239  *
 240  * Returns zero if the element could be written.
 241  * Negative values indicate an error.
 242  */
 243 LTTNG_HIDDEN
 244 int config_writer_write_config_element(struct config_writer *writer,
 245                 const struct config_element *element);
 246 /*
 247  * Load session configurations from a file.
 248  *
 249  * path Path to an LTTng session configuration file. All *.lttng files
 250  * will be loaded if path is a directory. If path is NULL, the default
 251  * paths will be searched in the following order:
 252  *      1) $HOME/.lttng/sessions
 253  *      2) /etc/lttng/sessions
 254  *
 255  * session_name Name of the session to load. Will load all
 256  * sessions from path if NULL.
 257  *
 258  * override Override current session configuration if it exists.
 259  * autoload Tell to load the auto session(s).
 260  *
 261  * Returns zero if the session could be loaded successfully. Returns
 262  * a negative LTTNG_ERR code on error.
 263  */
 264 LTTNG_HIDDEN
 265 int config_load_session(const char *path, const char *session_name,
 266                 int override, unsigned int autoload);
 267
 268 /*
 269  * Load session configuration from a document
 270  *
 271  * document The document to be loaded as a configuration
 272  * session_name Name of the session to load. Will load all sessions from the
 273  * passed document if NULL
 274  *
 275  * override Override current session configuration if it exists.
 276  *
 277  * Returns zero if the session could be loaded successfully. Returns
 278  * a negative LTTNG_ERR code on error.
 279  */
 280 LTTNG_HIDDEN
 281 int config_load_configuration_sessions(struct config_document *document,
 282                 const char *session_name, int override);
 283
 284 /*
 285  * Get the document corresponding to the path.
 286  *
 287  * path Path to a configuration file.
 288  * xsd_validation Whether or not to do a xsd validation
 289  *
 290  * Returns an new allocated config_document when successful.
 291  * Returns NULL on error;
 292  *
 293  * The caller is responsible of freeing the document via config_document_free.
 294  */
 295 LTTNG_HIDDEN
 296 struct config_document *config_document_get(const char *path);
 297
 298 /*
 299  * Free an allocated document.
 300  *
 301  * document The document to free.
 302  */
 303 LTTNG_HIDDEN
 304 void config_document_free(struct config_document *document);
 305
 306 /*
 307  * Replace the value of a document element
 308  *
 309  * document The document containing the element to be modified.
 310  * xpath The xpath string to the element.
 311  * value The value to be placed inside the element.
 312  *
 313  * Returns zero if the session could be loaded successfully. Returns
 314  * a negative LTTNG_ERR code on error.
 315  * */
 316 LTTNG_HIDDEN
 317 int config_document_replace_element_value(struct config_document *document, const char *xpath, const char *value);
 318
 319 /*
 320  * Swap a document node by the passed element.
 321  *
 322  * document The document containing the element to be modified.
 323  * xpath The xpath string to the element.
 324  * element The replacement element.
 325  *
 326  * Returns zero if the session could be loaded successfully. Returns
 327  * a negative LTTNG_ERR code on error.
 328  */
 329 LTTNG_HIDDEN
 330 int config_document_replace_element(struct config_document *document, const char *xpath, const struct config_element *element);
 331
 332 /*
 333  * Get the value of a document element.
 334  *
 335  * document The document to be searched.
 336  * xpath The xpath string to the element.
 337  *
 338  * Return null if multiple values exists or there is no
 339  * value for the passed path.
 340  */
 341 LTTNG_HIDDEN
 342 char *config_document_get_element_value(struct config_document *document, const char *xpath);
 343
 344 /*
 345  * Check if an element exists inside a document.
 346  *
 347  * document The document to be searched.
 348  * xpath The xpath string to the element.
 349  *
 350  * Returns 1 on success and 0 on failure.
 351  */
 352 LTTNG_HIDDEN
 353 int config_document_element_exist(struct config_document *document, const char *xpath);
 354
 355 /*
 356  *
 357  */
 358 LTTNG_HIDDEN
 359 void config_element_free(struct config_element *element);
 360
 361 LTTNG_HIDDEN
 362 struct config_element *config_element_create(const char *name, const char *value);
 363
 364 /*
 365  * Add a child element to an element.
 366  *
 367  * parent The parent element.
 368  * child The element to add as a child.
 369  *
 370  * Returns zero if the session could be loaded successfully. Returns
 371  * a negative LTTNG_ERR code on error.
 372  */
 373 LTTNG_HIDDEN
 374 int config_element_add_child(struct config_element *parent, const struct config_element *child);
 375
 376 /*
 377  * Insert element to an existing document.
 378  *
 379  * document The document to be modified.
 380  * xpath The xpath string to the insertion path.
 381  * element The element to be inserted.
 382  *
 383  * Returns zero if the session could be loaded successfully. Returns
 384  * a negative LTTNG_ERR code on error.
 385  */
 386 LTTNG_HIDDEN
 387 int config_document_insert_element(struct config_document *document, const char *xpath, const struct config_element *element);
 388
 389
 390 #endif /* _CONFIG_H */