include/asl.h

   1 /*
   2  * Copyright (c) 2004-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef __ASL_H__
  25 #define __ASL_H__
  26
  27 #include <stdint.h>
  28 #include <stdarg.h>
  29 #include <sys/cdefs.h>
  30 #include <Availability.h>
  31
  32 typedef struct __aslclient *aslclient;
  33 typedef struct __aslmsg *aslmsg;
  34 typedef struct __aslresponse *aslresponse;
  35
  36 /*! @header
  37  * These routines provide an interface to the Apple System Log facility.
  38  * The API allows client applications to create flexible, structured messages
  39  * and send them to the syslogd server.  Messages received by the server are
  40  * saved in a data store, subject to input filtering constraints.
  41  * This API also permits clients to create queries and search the message
  42  * data store for matching messages.
  43  */
  44
  45 /*
  46  * NOTE FOR HeaderDoc
  47  *
  48  * These are added to allow headerdoc2html to process
  49  * the prototypes of asl_log and asl_vlog correctly.
  50  * The "-p" option to headerdoc2html is required.
  51  */
  52 #ifndef __DARWIN_LDBL_COMPAT2
  53 /*! @parseOnly */
  54 #define __DARWIN_LDBL_COMPAT2(a)
  55 #endif
  56 #ifndef __printflike
  57 /*! @parseOnly */
  58 #define __printflike(a,b)
  59 #endif
  60
  61 /*! @defineblock Log Message Priority Levels
  62  * Log levels of the message.
  63  */
  64 #define ASL_LEVEL_EMERG   0
  65 #define ASL_LEVEL_ALERT   1
  66 #define ASL_LEVEL_CRIT    2
  67 #define ASL_LEVEL_ERR     3
  68 #define ASL_LEVEL_WARNING 4
  69 #define ASL_LEVEL_NOTICE  5
  70 #define ASL_LEVEL_INFO    6
  71 #define ASL_LEVEL_DEBUG   7
  72 /*! @/defineblock */
  73
  74 /*! @defineblock Log Message Priority Level Strings
  75  * Strings corresponding to log levels.
  76  */
  77 #define ASL_STRING_EMERG        "Emergency"
  78 #define ASL_STRING_ALERT        "Alert"
  79 #define ASL_STRING_CRIT         "Critical"
  80 #define ASL_STRING_ERR          "Error"
  81 #define ASL_STRING_WARNING  "Warning"
  82 #define ASL_STRING_NOTICE   "Notice"
  83 #define ASL_STRING_INFO         "Info"
  84 #define ASL_STRING_DEBUG        "Debug"
  85 /*! @/defineblock */
  86
  87 /*! @defineblock Attribute Matching
  88  * Attribute value comparison operations.
  89  */
  90 #define ASL_QUERY_OP_CASEFOLD      0x0010
  91 #define ASL_QUERY_OP_PREFIX                0x0020
  92 #define ASL_QUERY_OP_SUFFIX                0x0040
  93 #define ASL_QUERY_OP_SUBSTRING     0x0060
  94 #define ASL_QUERY_OP_NUMERIC       0x0080
  95 #define ASL_QUERY_OP_REGEX         0x0100
  96
  97 #define ASL_QUERY_OP_EQUAL         0x0001
  98 #define ASL_QUERY_OP_GREATER       0x0002
  99 #define ASL_QUERY_OP_GREATER_EQUAL 0x0003
 100 #define ASL_QUERY_OP_LESS          0x0004
 101 #define ASL_QUERY_OP_LESS_EQUAL    0x0005
 102 #define ASL_QUERY_OP_NOT_EQUAL     0x0006
 103 #define ASL_QUERY_OP_TRUE          0x0007
 104 /*! @/defineblock */
 105
 106 /*! @defineblock Message Attributes
 107  *
 108  * These attributes are known by ASL, and are generally
 109  * associated with all log messages.
 110  * Additional attributes may be added as desired.
 111  */
 112 #define ASL_KEY_TIME        "Time"          /* Timestamp.  Set automatically */
 113 #define ASL_KEY_TIME_NSEC   "TimeNanoSec"   /* Nanosecond time. */
 114 #define ASL_KEY_HOST        "Host"          /* Sender's address (set by the server). */
 115 #define ASL_KEY_SENDER      "Sender"        /* Sender's identification string.  Default is process name. */
 116 #define ASL_KEY_FACILITY    "Facility"      /* Sender's facility.  Default is "user". */
 117 #define ASL_KEY_PID         "PID"           /* Sending process ID encoded as a string.  Set automatically. */
 118 #define ASL_KEY_UID         "UID"           /* UID that sent the log message (set by the server). */
 119 #define ASL_KEY_GID         "GID"           /* GID that sent the log message (set by the server). */
 120 #define ASL_KEY_LEVEL       "Level"         /* Log level number encoded as a string.  See levels above. */
 121 #define ASL_KEY_MSG         "Message"       /* Message text. */
 122 #define ASL_KEY_READ_UID    "ReadUID"       /* User read access (-1 is any user). */
 123 #define ASL_KEY_READ_GID    "ReadGID"       /* Group read access (-1 is any group). */
 124 #define ASL_KEY_EXPIRE_TIME "ASLExpireTime" /* Expiration time for messages with long TTL. */
 125 #define ASL_KEY_MSG_ID      "ASLMessageID"  /* 64-bit message ID number (set by the server). */
 126 #define ASL_KEY_SESSION     "Session"       /* Session (set by the launchd). */
 127 #define ASL_KEY_REF_PID     "RefPID"        /* Reference PID for messages proxied by launchd */
 128 #define ASL_KEY_REF_PROC    "RefProc"       /* Reference process for messages proxied by launchd */
 129 #define ASL_KEY_AUX_TITLE   "ASLAuxTitle"   /* Auxiliary title string */
 130 #define ASL_KEY_AUX_UTI     "ASLAuxUTI"     /* Auxiliary Uniform Type ID */
 131 #define ASL_KEY_AUX_URL     "ASLAuxURL"     /* Auxiliary Uniform Resource Locator */
 132 #define ASL_KEY_AUX_DATA    "ASLAuxData"    /* Auxiliary in-line data */
 133 #define ASL_KEY_OPTION      "ASLOption"     /* Internal */
 134 #define ASL_KEY_SENDER_INSTANCE "SenderInstance"        /* Sender instance UUID. */
 135 /*! @/defineblock */
 136
 137 /*! @defineblock aslmsg Types
 138  * Message type argument passed to asl_new().
 139  */
 140 #define ASL_TYPE_MSG    0
 141 #define ASL_TYPE_QUERY  1
 142 /*! @/defineblock */
 143
 144 /*! @defineblock Filter Masks
 145  * Used in client-side filtering, which determines which
 146  * messages are sent by the client to the syslogd server.
 147  */
 148 #define ASL_FILTER_MASK_EMERG   0x01
 149 #define ASL_FILTER_MASK_ALERT   0x02
 150 #define ASL_FILTER_MASK_CRIT    0x04
 151 #define ASL_FILTER_MASK_ERR     0x08
 152 #define ASL_FILTER_MASK_WARNING 0x10
 153 #define ASL_FILTER_MASK_NOTICE  0x20
 154 #define ASL_FILTER_MASK_INFO    0x40
 155 #define ASL_FILTER_MASK_DEBUG   0x80
 156 /*! @/defineblock */
 157
 158 /*! @defineblock Filter Mask Macros
 159  * Macros to create bitmasks for filter settings - see asl_set_filter().
 160  */
 161 #define ASL_FILTER_MASK(level) (1 << (level))
 162 #define ASL_FILTER_MASK_UPTO(level) ((1 << ((level) + 1)) - 1)
 163 /*! @/defineblock */
 164
 165 /*! @defineblock Client Creation Options
 166  * Options for asl_open().
 167  */
 168 #define ASL_OPT_STDERR          0x00000001
 169 #define ASL_OPT_NO_DELAY    0x00000002
 170 #define ASL_OPT_NO_REMOTE   0x00000004
 171 /*! @/defineblock */
 172
 173 __BEGIN_DECLS
 174
 175 /*!
 176  * Initialize a connection to the ASL server.
 177  *
 178  * This call is optional in most cases.  The library will perform any
 179  * necessary initializations on the fly.  A call to asl_open() is required
 180  * if optional settings must be made before messages are sent to the server.
 181  * These include setting the client filter and managing additional output
 182  * file descriptors.  Note that the default setting of the client filter is
 183  * ASL_FILTER_MASK_UPTO(ASL_LEVEL_NOTICE), so ASL_LEVEL_DEBUG and ASL_LEVEL_INFO
 184  * messages are not sent to the server by default.
 185  *
 186  * Options (defined above) may be set using the opts parameter. They are:
 187  *
 188  *   ASL_OPT_STDERR    - adds stderr as an output file descriptor
 189  *
 190  *   ASL_OPT_NO_DELAY  - connects to the server immediately
 191  *
 192  *   ASL_OPT_NO_REMOTE - disables the remote-control mechanism for adjusting
 193  *                       filter levers for processes using e.g. syslog -c ...
 194  *
 195  * @param ident
 196  *    (input) Sender name
 197  * @param facility
 198  *    (input) Facility name
 199  * @param opts
 200  *    (input) Options (see asl_open Options)
 201  * @result Returns an ASL client handle
 202  */
 203 aslclient asl_open(const char *ident, const char *facility, uint32_t opts);
 204
 205 /*!
 206  * Shuts down a connection to the server.
 207  *
 208  * @param asl
 209  *    (input) An ASL client handle
 210  */
 211 void asl_close(aslclient asl);
 212
 213 /*!
 214  * Write log messages to the given file descriptor.
 215  *
 216  * Log messages will be written to this file as well as to the server.
 217  *
 218  * @param asl
 219  *    (input) An ASL client handle
 220  * @param fd
 221  *    (input) A file descriptor
 222  * @result Returns 0 on success, non-zero on failure
 223 */
 224 int asl_add_log_file(aslclient asl, int fd);
 225
 226 /*!
 227  * Stop writing log messages to the given file descriptor.
 228  * The file descripter is not closed by this routine.
 229  *
 230  * @param asl
 231  *    (input) An ASL client handle
 232  * @param fd
 233  *    (input) A file descriptor
 234  * @result Returns 0 on success, non-zero on failure
 235  */
 236 int asl_remove_log_file(aslclient asl, int fd);
 237
 238 /*!
 239  * Set a filter for messages being sent to the server.
 240  * The filter is a bitmask representing priorities.  The ASL_FILTER_MASK
 241  * macro may be used to convert a priority level into a bitmask for that
 242  * level.  The ASL_FILTER_MASK_UPTO macro creates a bitmask for all
 243  * priorities up to and including a given priority.
 244  * Messages with priority levels that do not have a corresponding bit
 245  * set in the filter are not sent to the server, although they will be
 246  * sent to any file descripters added with asl_add_log_file().
 247  * The default setting is ASL_FILTER_MASK_UPTO(ASL_LEVEL_NOTICE).
 248  * Returns the previous filter value.
 249  *
 250  * @param asl
 251  *    (input) An ASL client handle
 252  * @param f
 253  *    (input) A filter value
 254  * @result Returns the previous filter value
 255  */
 256 int asl_set_filter(aslclient asl, int f);
 257
 258 /*
 259  * Examine attribute keys.
 260  *
 261  * @param msg
 262  *    (input) An ASL message
 263  * @param n
 264  *    (input) An index value
 265  * @result Returns the key of the nth attribute in a message (beginning at zero),
 266  * or NULL if n is greater than the largest message index.
 267  */
 268 const char *asl_key(aslmsg msg, uint32_t n);
 269
 270 /*!
 271  * Create a new log message or query message.
 272  *
 273  * @param type
 274  *    (input) Message type (see aslmsg Types)
 275  * @result Returns a newly allocated asmsg of the specified type
 276  */
 277 aslmsg asl_new(uint32_t type);
 278
 279 /*!
 280  * Set or re-set a message attribute.
 281  *
 282  * @param msg
 283  *    (input) An aslmsg
 284  * @param key
 285  *    (input) Attribute key
 286  * @param value
 287  *    (input) Attribute value
 288  * @result returns 0 for success, non-zero for failure
 289  */
 290 int asl_set(aslmsg msg, const char *key, const char *value);
 291
 292 /*!
 293  * Remove a message attribute.
 294  *
 295  * @param msg
 296  *    (input) An aslmsg
 297  * @param key
 298  *    (input) Attribute key
 299  * returns 0 for success, non-zero for failure
 300  */
 301 int asl_unset(aslmsg msg, const char *key);
 302
 303 /*!
 304  * Get the value of a message attribute.
 305  *
 306  * @param msg
 307  *    (input) An aslmsg
 308  * @param key
 309  *    (input) Attribute key
 310  * @result Returns the attribute value, or NULL if the message does not contain the key
 311  */
 312 const char *asl_get(aslmsg msg, const char *key);
 313
 314 /*!
 315  * Log a message with a particular log level.
 316  *
 317  * @param asl
 318  *    (input) An ASL client handle
 319  * @param msg
 320  *    (input) An aslmsg (default attributes will be supplied if msg is NULL)
 321  * @param level
 322  *    (input) Log level (ASL_LEVEL_DEBUG to ASL_LEVEL_EMERG)
 323  * @param format
 324  *    (input) A printf() - style format string followed by a list of arguments
 325  * @result Returns 0 for success, non-zero for failure
 326  */
 327 #ifdef __DARWIN_LDBL_COMPAT2
 328 int asl_log(aslclient asl, aslmsg msg, int level, const char *format, ...) __DARWIN_LDBL_COMPAT2(asl_log) __printflike(4, 5);
 329 #else
 330 int asl_log(aslclient asl, aslmsg msg, int level, const char *format, ...) __printflike(4, 5);
 331 #endif
 332
 333 /*!
 334  * Log a message with a particular log level.
 335  * Similar to asl_log, but takes a va_list argument.
 336  *
 337  * @param asl
 338  *    (input) An ASL client handle
 339  * @param msg
 340  *    (input) An aslmsg (default attributes will be supplied if msg is NULL)
 341  * @param level
 342  *    (input) Log level (ASL_LEVEL_DEBUG to ASL_LEVEL_EMERG)
 343  * @param format
 344  *    (input) A printf() - style format string followed by a list of arguments
 345  * @param ap
 346  *    (input) A va_list containing the values for the format string
 347  * @result Returns 0 for success, non-zero for failure
 348  */
 349 #ifdef __DARWIN_LDBL_COMPAT2
 350 int asl_vlog(aslclient asl, aslmsg msg, int level, const char *format, va_list ap) __DARWIN_LDBL_COMPAT2(asl_vlog) __printflike(4, 0);
 351 #else
 352 int asl_vlog(aslclient asl, aslmsg msg, int level, const char *format, va_list ap) __printflike(4, 0);
 353 #endif
 354
 355 /*!
 356  * Log a message.
 357  *
 358  * This routine may be used instead of asl_log() or asl_vlog() if asl_set()
 359  * has been used to set all of a message's attributes.
 360  *
 361  * @param asl
 362  *    (input) An ASL client handle
 363  * @param msg
 364  *    (input) An aslmsg
 365  * @result Returns 0 for success, non-zero for failure
 366  */
 367 int asl_send(aslclient asl, aslmsg msg);
 368
 369 /*!
 370  * Free a message.  Frees all the attribute keys and values.
 371  *
 372  * @param msg
 373  *    (input) An aslmsg to free
 374  */
 375 void asl_free(aslmsg msg);
 376
 377 /*!
 378  * Set arbitrary parameters of a query.
 379  * This is similar to asl_set, but allows richer query operations.
 380  * See ASL_QUERY_OP_* above.
 381  *
 382  * @param msg
 383  *    (input) An aslmsg
 384  * @param key
 385  *    (input) Attribute key
 386  * @param value
 387  *    (input) Attribute value
 388  * @param op
 389  *    (input) An operation (ASL_QUERY_OP_*)
 390  * @result Returns 0 for success, non-zero for failure
 391  */
 392 int asl_set_query(aslmsg msg, const char *key, const char *value, uint32_t op);
 393
 394 /*!
 395  * Search for messages matching the criteria described by the aslmsg.
 396  * The caller should set the attributes to match using asl_set_query() or asl_set().
 397  * The operatoin ASL_QUERY_OP_EQUAL is used for attributes set with asl_set().
 398  *
 399  * @param msg
 400  *    (input) An aslmsg to match
 401  * @result Returns a set of messages accessable using aslresponse_next(),
 402  */
 403 aslresponse asl_search(aslclient asl, aslmsg msg);
 404
 405 /*!
 406  * Iterate over responses returned from asl_search().
 407  *
 408  * @param r
 409  *    (input) An aslresponse returned by asl_search()
 410  * @result Returns the next message (an aslmsg) in the response, or NULL when there are no more messages
 411  */
 412 aslmsg aslresponse_next(aslresponse r);
 413
 414 /*!
 415  * Free a response returned from asl_search().
 416  * @param r
 417  *    (input) An aslresponse returned by asl_search()
 418  */
 419 void aslresponse_free(aslresponse r);
 420
 421 /*!
 422  * Creates an auxiliary file that may be used to save arbitrary data.  The ASL message msg
 423  * will be saved at the time that the auxiliary file is closed with asl_close_auxiliary_file().
 424  * The log entry will include any keys and values found in msg, and it will include the title
 425  * and Uniform Type Identifier specified.  If NULL is supplied as a value for the uti parameter,
 426  * the type "public.data" is used.  Console.app will display a hyperlink to the file.
 427  * Output parameter out_fd will contain a readable and writable file descriptor for the new
 428  * auxiliary file.
 429  *
 430  * By default, the file will be world-readable.  If the message contains a ReadUID and/or a
 431  * ReadGID key, then the values for those keys will determine read access to the file.
 432  *
 433  * The file will be deleted at the same time that the message expires from the ASL data store.
 434  * The aslmanager utility manages message expiry.  If msg contains a value for ASLExpireTime,
 435  * then the message and the file will not be deleted before that time.  The value may be in
 436  * seconds after the Epoch, or it may be ctime() format, e.g "Thu Jun 24 18:22:48 2010".
 437  *
 438  * @param msg
 439  *    (input) An aslmsg
 440  * @param tite
 441  *    (input) A title string for the file
 442  * @param uti
 443  *    (input) Uniform Type Identifier for the file
 444  * @param out_fd
 445  *    (output) A writable file descriptor
 446  * @result Returns 0 for success, non-zero for failure
 447  */
 448 int asl_create_auxiliary_file(aslmsg msg, const char *title, const char *uti, int *out_fd)
 449 __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_5_0);
 450
 451 /*!
 452  * Close an auxiliary file opened by asl_create_auxiliary_file() when writing is complete.
 453  * syslogd will log the message provided to asl_create_auxiliary_file() when this routine
 454  * is called.
 455  *
 456  * @param fd
 457  *    (input) The file descriptor
 458  * @result Returns 0 for success, non-zero for failure
 459  */
 460 int asl_close_auxiliary_file(int fd)
 461 __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_5_0);
 462
 463 /*!
 464  * Sends an ASL message to syslogd along with a title string, Uniform Resource Locator,
 465  * and Uniform Type Identifier specified.  Console.app will hyperlink the title string to
 466  * the specified URL.  If NULL is supplied as a value for the uti parameter, the default
 467  * type "public.data" is used.
 468  *
 469  * @param msg
 470  *    (input) An aslmsg
 471  * @param title
 472  *    (input) A title string for the file
 473  * @param uti
 474  *    (input) Uniform Type Identifier for the file
 475  * @param url
 476  *    (input) Uniform Type Locator
 477  * @result Returns 0 for success, non-zero for failure
 478  */
 479 int asl_log_auxiliary_location(aslmsg msg, const char *title, const char *uti, const char *url)
 480 __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_5_0);
 481
 482 /*!
 483  * Creates an aslclient for logging to a file descriptor.  The file must be opened for read and
 484  * write access.  This routine may be used in conjunction with asl_create_auxiliary_file() to
 485  * save ASL format log messages to an auxiliary file.
 486  *
 487  * The file will be truncated if it is not empty.  When logging to the auxiliary file is complete,
 488  * aslclient should be closed using asl_close().  The file should be closed using
 489  * asl_close_auxiliary_file() if it was returned by asl_create_auxiliary_file(), or close()
 490  * otherwise.
 491  *
 492  * The returned aslclient is thread-safe.
 493  *
 494  * Note that per-message read access controls (ReadUID and ReadGID) and message expire
 495  * times (ASLExpireTime) keys have no effect for messages written to this file.
 496  *
 497  * @param fd
 498  *    (input) A file descriptor
 499  * @param ident
 500  *    (input) Sender name
 501  * @param facility
 502  *    (input) Facility name
 503  * @result An aslclient
 504  */
 505 aslclient asl_open_from_file(int fd, const char *ident, const char *facility)
 506 __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_5_0);
 507
 508 __END_DECLS
 509
 510 #endif /* __ASL_H__ */