epan/emem.h

   1 /* emem.h
   2  * Definitions for Wireshark memory management and garbage collection
   3  * Ronnie Sahlberg 2005
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #ifndef __EMEM_H__
  27 #define __EMEM_H__
  28
  29 #include <glib.h>
  30
  31 #include "ws_symbol_export.h"
  32
  33 /**  Initialize all the memory allocation pools described below.
  34  *  This function must be called once when *shark initialize to set up the
  35  *  required structures.
  36  */
  37 WS_DLL_PUBLIC
  38 void emem_init(void);
  39
  40 /* Functions for handling memory allocation and garbage collection with
  41  * a packet lifetime scope.
  42  * These functions are used to allocate memory that will only remain persistent
  43  * until Wireshark starts dissecting the next packet in the list.
  44  * Everytime Wireshark starts decoding the next packet all memory allocated
  45  * through these functions will be released back to the free pool.
  46  *
  47  * These functions are very fast and offer automatic garbage collection:
  48  * Everytime a new packet is dissected, all memory allocations done in
  49  * the previous packet is freed.
  50  */
  51
  52 /** Allocate memory with a packet lifetime scope */
  53 WS_DLL_PUBLIC
  54 void *ep_alloc(size_t size) G_GNUC_MALLOC;
  55 #define ep_new(type) ((type*)ep_alloc(sizeof(type)))
  56
  57 /** Allocate memory with a packet lifetime scope and fill it with zeros*/
  58 WS_DLL_PUBLIC
  59 void* ep_alloc0(size_t size) G_GNUC_MALLOC;
  60 #define ep_new0(type) ((type*)ep_alloc0(sizeof(type)))
  61
  62 /** Duplicate a string with a packet lifetime scope */
  63 WS_DLL_PUBLIC
  64 gchar* ep_strdup(const gchar* src) G_GNUC_MALLOC;
  65
  66 /** Duplicate at most n characters of a string with a packet lifetime scope */
  67 WS_DLL_PUBLIC
  68 gchar* ep_strndup(const gchar* src, size_t len) G_GNUC_MALLOC;
  69
  70 /** Duplicate a buffer with a packet lifetime scope */
  71 WS_DLL_PUBLIC
  72 void* ep_memdup(const void* src, size_t len) G_GNUC_MALLOC;
  73
  74 /** Create a formatted string with a packet lifetime scope */
  75 WS_DLL_PUBLIC
  76 gchar* ep_strdup_vprintf(const gchar* fmt, va_list ap) G_GNUC_MALLOC;
  77 WS_DLL_PUBLIC
  78 gchar* ep_strdup_printf(const gchar* fmt, ...)
  79      G_GNUC_MALLOC G_GNUC_PRINTF(1, 2);
  80
  81 WS_DLL_PUBLIC
  82 gchar *ep_strconcat(const gchar *string, ...) G_GNUC_MALLOC G_GNUC_NULL_TERMINATED;
  83
  84 /** allocates with a packet lifetime scope an array of type made of num elements */
  85 #define ep_alloc_array(type,num) (type*)ep_alloc(sizeof(type)*(num))
  86
  87 /** allocates with a packet lifetime scope an array of type made of num elements,
  88  * initialised to zero.
  89  */
  90 #define ep_alloc_array0(type,num) (type*)ep_alloc0(sizeof(type)*(num))
  91
  92 /**
  93  * Splits a string into a maximum of max_tokens pieces, using the given
  94  * delimiter. If max_tokens is reached, the remainder of string is appended
  95  * to the last token. Consecutive delimiters are treated as a single delimiter.
  96  *
  97  * The vector and all the strings are allocated with packet lifetime scope
  98  */
  99 WS_DLL_PUBLIC
 100 gchar** ep_strsplit(const gchar* string, const gchar* delimiter, int max_tokens);
 101
 102 /** release all memory allocated in the previous packet dissection */
 103 void ep_free_all(void);
 104
 105
 106 /** a stack implemented using ephemeral allocators */
 107
 108 typedef struct _ep_stack_frame_t** ep_stack_t;
 109
 110 struct _ep_stack_frame_t {
 111     void* payload;
 112     struct _ep_stack_frame_t* below;
 113     struct _ep_stack_frame_t* above;
 114 };
 115
 116 /**
 117  * creates an empty stack with a packet lifetime scope
 118  */
 119 WS_DLL_PUBLIC
 120 ep_stack_t ep_stack_new(void) G_GNUC_MALLOC;
 121
 122 /**
 123  * pushes item into stack, returns item
 124  */
 125 WS_DLL_PUBLIC
 126 void* ep_stack_push(ep_stack_t stack, void* item);
 127
 128 /**
 129  * pops an item from the stack
 130  */
 131 WS_DLL_PUBLIC
 132 void* ep_stack_pop(ep_stack_t stack);
 133
 134 /**
 135  * returns the item on top of the stack without popping it
 136  */
 137 #define ep_stack_peek(stack) ((*(stack))->payload)
 138
 139
 140 /* Functions for handling memory allocation and garbage collection with
 141  * a capture lifetime scope.
 142  * These functions are used to allocate memory that will only remain persistent
 143  * until Wireshark opens a new capture or capture file.
 144  * Everytime Wireshark starts a new capture or opens a new capture file
 145  * all the data allocated through these functions will be released back
 146  * to the free pool.
 147  *
 148  * These functions are very fast and offer automatic garbage collection.
 149  */
 150
 151 /** Allocate memory with a capture lifetime scope */
 152 WS_DLL_PUBLIC
 153 void *se_alloc(size_t size) G_GNUC_MALLOC;
 154 #define se_new(type) ((type*)se_alloc(sizeof(type)))
 155
 156 /** Allocate memory with a capture lifetime scope and fill it with zeros*/
 157 WS_DLL_PUBLIC
 158 void* se_alloc0(size_t size) G_GNUC_MALLOC;
 159 #define se_new0(type) ((type*)se_alloc0(sizeof(type)))
 160
 161 /** Duplicate a string with a capture lifetime scope */
 162 WS_DLL_PUBLIC
 163 gchar* se_strdup(const gchar* src) G_GNUC_MALLOC;
 164
 165 /** Duplicate at most n characters of a string with a capture lifetime scope */
 166 WS_DLL_PUBLIC
 167 gchar* se_strndup(const gchar* src, size_t len) G_GNUC_MALLOC;
 168
 169 /** Duplicate a buffer with a capture lifetime scope */
 170 WS_DLL_PUBLIC
 171 void* se_memdup(const void* src, size_t len) G_GNUC_MALLOC;
 172
 173 /* Create a formatted string with a capture lifetime scope */
 174 WS_DLL_PUBLIC
 175 gchar* se_strdup_vprintf(const gchar* fmt, va_list ap) G_GNUC_MALLOC;
 176 WS_DLL_PUBLIC
 177 gchar* se_strdup_printf(const gchar* fmt, ...)
 178      G_GNUC_MALLOC G_GNUC_PRINTF(1, 2);
 179
 180 /** allocates with a capture lifetime scope an array of type made of num elements */
 181 #define se_alloc_array(type,num) (type*)se_alloc(sizeof(type)*(num))
 182
 183 /** release all memory allocated */
 184 void se_free_all(void);
 185
 186 /**************************************************************
 187  * slab allocator
 188  **************************************************************/
 189 struct _emem_chunk_t;
 190
 191 /* G_MEM_ALIGN is not always enough: http://mail.gnome.org/archives/gtk-devel-list/2004-December/msg00091.html
 192  * So, we check (in configure) if we need 8-byte alignment.  (Windows
 193  * shouldn't need such a check until someone trys running it 32-bit on a CPU
 194  * with more stringent alignment requirements than i386.)
 195  *
 196  * Yes, this ignores the possibility of needing 16-byte alignment for long doubles.
 197  */
 198 #if defined(NEED_8_BYTE_ALIGNMENT) && (G_MEM_ALIGN < 8)
 199 #define WS_MEM_ALIGN 8
 200 #else
 201 #define WS_MEM_ALIGN G_MEM_ALIGN
 202 #endif
 203
 204 /**************************************************************
 205  * binary trees
 206  **************************************************************/
 207 typedef struct _emem_tree_node_t {
 208         struct _emem_tree_node_t *parent;
 209         struct _emem_tree_node_t *left;
 210         struct _emem_tree_node_t *right;
 211         struct {
 212 #define EMEM_TREE_RB_COLOR_RED          0
 213 #define EMEM_TREE_RB_COLOR_BLACK        1
 214                 guint32 rb_color:1;
 215 #define EMEM_TREE_NODE_IS_DATA          0
 216 #define EMEM_TREE_NODE_IS_SUBTREE       1
 217                 guint32 is_subtree:1;
 218         } u;
 219         guint32 key32;
 220         void *data;
 221 } emem_tree_node_t;
 222
 223 /** Right now we only do basic red/black trees   but in the future we might want
 224  * to try something different, such as a tree where each node keeps track
 225  * of how many times it has been looked up, and letting often looked up
 226  * nodes bubble upwards in the tree using rotate_right/left.
 227  * That would probably be good for things like nfs filehandles
 228  */
 229 #define EMEM_TREE_TYPE_RED_BLACK        1
 230 typedef struct _emem_tree_t {
 231         struct _emem_tree_t *next;
 232         int type;
 233         const char *name;    /**< just a string to make debugging easier */
 234         emem_tree_node_t *tree;
 235         void *(*malloc)(size_t);
 236 } emem_tree_t;
 237
 238 /* *******************************************************************
 239  * Tree functions for SE memory allocation scope
 240  * ******************************************************************* */
 241 /** This function is used to create a se based tree with monitoring.
 242  * When the SE heap is released back to the system the pointer to the
 243  * tree is automatically reset to NULL.
 244  *
 245  * type is : EMEM_TREE_TYPE_RED_BLACK for a standard red/black tree.
 246  */
 247 WS_DLL_PUBLIC
 248 emem_tree_t *se_tree_create(int type, const char *name) G_GNUC_MALLOC;
 249
 250 /** se_tree_insert32
 251  * Insert data into the tree and key it by a 32bit integer value
 252  */
 253 #define se_tree_insert32 emem_tree_insert32
 254
 255 /** se_tree_lookup32
 256  * Retrieve the data at the search key. The search key is a 32bit integer value
 257  */
 258 #define se_tree_lookup32 emem_tree_lookup32
 259
 260 /** se_tree_lookup32_le
 261  * Retrieve the data for the largest key that is less than or equal
 262  * to the search key.
 263  */
 264 #define se_tree_lookup32_le emem_tree_lookup32_le
 265
 266 /** se_tree_insert32_array
 267  * Insert data into the tree and key it by a 32bit integer value
 268  */
 269 #define se_tree_insert32_array emem_tree_insert32_array
 270
 271 /** se_tree_lookup32_array
 272  * Lookup data from the tree that is index by an array
 273  */
 274 #define se_tree_lookup32_array emem_tree_lookup32_array
 275
 276 /** se_tree_lookup32_array_le
 277  * Retrieve the data for the largest key that is less than or equal
 278  * to the search key.
 279  */
 280 #define se_tree_lookup32_array_le emem_tree_lookup32_array_le
 281
 282 /* ******************************************************************
 283  * Real tree functions
 284  * ****************************************************************** */
 285
 286 /** This function is used to insert a node indexed by a guint32 key value.
 287  * The data pointer should be allocated by the appropriate storage scope
 288  * so that it will be released at the same time as the tree itself is
 289  * destroyed.
 290  */
 291 WS_DLL_PUBLIC
 292 void emem_tree_insert32(emem_tree_t *se_tree, guint32 key, void *data);
 293
 294 /** This function will look up a node in the tree indexed by a guint32 integer
 295  * value.
 296  */
 297 WS_DLL_PUBLIC
 298 void *emem_tree_lookup32(emem_tree_t *se_tree, guint32 key);
 299
 300 /** This function will look up a node in the tree indexed by a guint32 integer
 301  * value.
 302  * The function will return the node that has the largest key that is
 303  * equal to or smaller than the search key, or NULL if no such key was
 304  * found.
 305  */
 306 WS_DLL_PUBLIC
 307 void *emem_tree_lookup32_le(emem_tree_t *se_tree, guint32 key);
 308
 309 typedef struct _emem_tree_key_t {
 310         guint32 length;                 /**< length in guint32 words */
 311         guint32 *key;
 312 } emem_tree_key_t;
 313
 314 /** This function is used to insert a node indexed by a sequence of guint32
 315  * key values.
 316  * The data pointer should be allocated by SE allocators so that the
 317  * data will be released at the same time as the tree itself is destroyed.
 318  *
 319  * Note: all the "key" members of the "key" argument MUST be aligned on
 320  * 32-bit boundaries; otherwise, this code will crash on platforms such
 321  * as SPARC that require aligned pointers.
 322  *
 323  * If you use ...32_array() calls you MUST make sure that every single node
 324  * you add to a specific tree always has a key of exactly the same number of
 325  * keylen words or things will most likely crash. Or at least that every single
 326  * item that sits behind the same top level node always have exactly the same
 327  * number of words.
 328  *
 329  * One way to guarantee this is the way that NFS does this for the
 330  * nfs_name_snoop_known tree which holds filehandles for both v2 and v3.
 331  * v2 filehandles are always 32 bytes (8 words) while v3 filehandles can have
 332  * any length (though 32 bytes are most common).
 333  * The NFS dissector handles this by providing a guint32 containing the length
 334  * as the very first item in this vector :
 335  *
 336  *                      emem_tree_key_t fhkey[3];
 337  *
 338  *                      fhlen=nns->fh_length;
 339  *                      fhkey[0].length=1;
 340  *                      fhkey[0].key=&fhlen;
 341  *                      fhkey[1].length=fhlen/4;
 342  *                      fhkey[1].key=nns->fh;
 343  *                      fhkey[2].length=0;
 344  */
 345 WS_DLL_PUBLIC
 346 void emem_tree_insert32_array(emem_tree_t *se_tree, emem_tree_key_t *key, void *data);
 347
 348 /** This function will look up a node in the tree indexed by a sequence of
 349  * guint32 integer values.
 350  */
 351 WS_DLL_PUBLIC
 352 void *emem_tree_lookup32_array(emem_tree_t *se_tree, emem_tree_key_t *key);
 353
 354 /** This function will look up a node in the tree indexed by a
 355  * multi-part tree value.
 356  * The function will return the node that has the largest key that is
 357  * equal to or smaller than the search key, or NULL if no such key was
 358  * found.
 359  * Note:  The key returned will be "less" in key order.  The usefullness
 360  * of the returned node must be verified prior to use.
 361  */
 362 WS_DLL_PUBLIC
 363 void *emem_tree_lookup32_array_le(emem_tree_t *se_tree, emem_tree_key_t *key);
 364
 365 /** case insensitive strings as keys */
 366 #define EMEM_TREE_STRING_NOCASE                 0x00000001
 367 /** Insert a new value under a string key */
 368 WS_DLL_PUBLIC
 369 void emem_tree_insert_string(emem_tree_t* h, const gchar* k, void* v, guint32 flags);
 370
 371 /** Lookup the value under a string key */
 372 WS_DLL_PUBLIC
 373 void* emem_tree_lookup_string(emem_tree_t* h, const gchar* k, guint32 flags);
 374
 375
 376 /** traverse a tree. if the callback returns TRUE the traversal will end */
 377 typedef gboolean (*tree_foreach_func)(void *value, void *userdata);
 378
 379 WS_DLL_PUBLIC
 380 gboolean emem_tree_foreach(emem_tree_t* emem_tree, tree_foreach_func callback, void *user_data);
 381
 382
 383 /* ******************************************************************
 384  * String buffers - Growable strings similar to GStrings
 385  * ****************************************************************** */
 386
 387 typedef struct _emem_strbuf_t {
 388     gchar *str;             /**< Points to the character data. It may move as text is       */
 389                             /*  added. The str field is null-terminated and so can        */
 390                             /*  be used as an ordinary C string.                          */
 391     gsize len;              /**< strlen: ie: length of str not including trailing '\0'      */
 392     gsize alloc_len;        /**< num bytes curently allocated for str: 1 .. MAX_STRBUF_LEN  */
 393     gsize max_alloc_len;    /**< max num bytes to allocate for str: 1 .. MAX_STRBUF_LEN     */
 394 } emem_strbuf_t;
 395
 396 /*
 397  * The maximum length is limited to 64K. If you need something bigger, you
 398  * should probably use an actual GString or GByteArray.
 399  */
 400
 401 /**
 402  * Allocate an ephemeral string buffer with "unlimited" size.
 403  *
 404  * @param init The initial string for the buffer, or NULL to allocate an initial zero-length string.
 405  *
 406  * @return A newly-allocated string buffer.
 407  */
 408 WS_DLL_PUBLIC
 409 emem_strbuf_t *ep_strbuf_new(const gchar *init) G_GNUC_MALLOC;
 410
 411 /**
 412  * Allocate an ephemeral string buffer suitable for the protocol tree.
 413  * The string will never grow beyond the maximum tree item length.
 414  *
 415  * @param init The initial string for the buffer, or NULL to allocate an initial zero-length string.
 416  *
 417  * @return A newly-allocated string buffer.
 418  */
 419 WS_DLL_PUBLIC
 420 emem_strbuf_t *ep_strbuf_new_label(const gchar *init) G_GNUC_MALLOC;
 421
 422 /**
 423  * Allocate an ephemeral string buffer with enough initial space for alloc_len bytes
 424  * and a maximum of max_alloc_len bytes.
 425  *
 426  * @param alloc_len The initial size of the buffer. This value can be 0, but a nonzero
 427  * value is recommended.
 428  * @param max_alloc_len The maximum size of the buffer. 0 means "unlimited" (within
 429  * reason).
 430  *
 431  * @return A newly-allocated string buffer. str will be empty.
 432  */
 433 WS_DLL_PUBLIC
 434 emem_strbuf_t *ep_strbuf_sized_new(gsize alloc_len, gsize max_alloc_len) G_GNUC_MALLOC;
 435
 436 /**
 437  * Append vprintf-style formatted text to a string buffer.
 438  *
 439  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 440  * @param format A printf-style string format.
 441  * @param ap The list of arguments to append.
 442  */
 443 WS_DLL_PUBLIC
 444 void ep_strbuf_append_vprintf(emem_strbuf_t *strbuf, const gchar *format, va_list ap);
 445
 446 /**
 447  * Apply printf-style formatted text to a string buffer.
 448  *
 449  * @param strbuf The ep_strbuf-allocated string buffer to set to.
 450  * @param format A printf-style string format.
 451  */
 452 WS_DLL_PUBLIC
 453 void ep_strbuf_printf(emem_strbuf_t *strbuf, const gchar *format, ...)
 454      G_GNUC_PRINTF(2, 3);
 455
 456 /**
 457  * Append printf-style formatted text to a string buffer.
 458  *
 459  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 460  * @param format A printf-style string format.
 461  */
 462 WS_DLL_PUBLIC
 463 void ep_strbuf_append_printf(emem_strbuf_t *strbuf, const gchar *format, ...)
 464     G_GNUC_PRINTF(2, 3);
 465
 466 /**
 467  * Append a string to a string buffer.
 468  *
 469  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 470  * @param str A null-terminated string.
 471  *
 472  * @return strbuf
 473  */
 474 WS_DLL_PUBLIC
 475 emem_strbuf_t *ep_strbuf_append(emem_strbuf_t *strbuf, const gchar *str);
 476
 477 /**
 478  * Append a character to a string buffer.
 479  *
 480  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 481  * @param c The character to append.
 482  *
 483  * @return strbuf
 484  */
 485 WS_DLL_PUBLIC
 486 emem_strbuf_t *ep_strbuf_append_c(emem_strbuf_t *strbuf, const gchar c);
 487
 488 /**
 489  * Append a Unicode characeter converted to UTF-8 to a string buffer.
 490  *
 491  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 492  * @param c The Unicode character to append.
 493  *
 494  * @return strbuf
 495  */
 496 WS_DLL_PUBLIC
 497 emem_strbuf_t *ep_strbuf_append_unichar(emem_strbuf_t *strbuf, const gunichar c);
 498
 499 /**
 500  * Chop off the end of a string buffer.
 501  *
 502  * @param strbuf The ep_strbuf-allocated string buffer to append to.
 503  * @param len The new string length.
 504  *
 505  * @return strbuf
 506  */
 507 WS_DLL_PUBLIC
 508 emem_strbuf_t *ep_strbuf_truncate(emem_strbuf_t *strbuf, gsize len);
 509
 510 /**
 511  * Dump the whole tree (of trees) to stdout.
 512  *
 513  * @param emem_tree The tree to dump to standard output.
 514  *
 515  *
 516  */
 517 void emem_print_tree(emem_tree_t* emem_tree);
 518
 519 /* #define DEBUG_INTENSE_CANARY_CHECKS */
 520
 521 /** Helper to troubleshoot ep memory corruption.
 522  * If compiled and the environment variable WIRESHARK_DEBUG_EP_INTENSE_CANARY exists
 523  * it will check the canaries and when found corrupt stop there in the hope
 524  * the corruptor is still there in the stack.
 525  * Some checkpoints are already set in packet.c in strategic points
 526  * before and after dissection of a frame or a dissector call.
 527  */
 528
 529 #ifdef DEBUG_INTENSE_CANARY_CHECKS
 530 void ep_check_canary_integrity(const char* fmt, ...)
 531     G_GNUC_PRINTF(1, 2);
 532 #define EP_CHECK_CANARY(args) ep_check_canary_integrity args
 533 #else
 534 #define EP_CHECK_CANARY(args)
 535 #endif
 536
 537 /**
 538  * Verify that the given pointer is of ephemeral type.
 539  *
 540  * @param ptr The pointer to verify
 541  *
 542  * @return TRUE if the pointer belongs to the ephemeral pool.
 543  */
 544 gboolean ep_verify_pointer(const void *ptr);
 545 /**
 546  * Verify that the given pointer is of seasonal type.
 547  *
 548  * @param ptr The pointer to verify
 549  *
 550  * @return TRUE if the pointer belongs to the seasonal pool.
 551  */
 552 gboolean se_verify_pointer(const void *ptr);
 553
 554 #endif /* emem.h */