3 * Testy, Virtual(-izable) Buffer of guint8*'s
5 * "Testy" -- the buffer gets mad when an attempt is made to access data
6 * beyond the bounds of the buffer. An exception is thrown.
8 * "Virtual" -- the buffer can have its own data, can use a subset of
9 * the data of a backing tvbuff, or can be a composite of
14 * Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
16 * Wireshark - Network traffic analyzer
17 * By Gerald Combs <gerald@wireshark.org>
18 * Copyright 1998 Gerald Combs
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version 2
23 * of the License, or (at your option) any later version.
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software
32 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
39 #include <epan/guid-utils.h>
40 #include <epan/wmem/wmem.h>
44 #endif /* __cplusplus */
47 * "testy, virtual(-izable) buffer". They are testy in that they get mad when
48 * an attempt is made to access data beyond the bounds of their array. In that
49 * case, they throw an exception.
51 * They are virtualizable in that new tvbuff's can be made from other tvbuffs,
52 * while only the original tvbuff may have data. That is, the new tvbuff has
57 typedef struct tvbuff tvbuff_t;
59 struct e_in6_addr; /* ipv6-utils.h */
61 /** @defgroup tvbuff Testy, Virtual(-izable) Buffers
63 * Dissector use and management
65 * Consider a collection of tvbs as being a chain or stack of tvbs.
67 * When dissecting a frame:
68 * The top-level dissector (packet.c) pushes the initial tvb (containing
69 * the complete frame) onto the stack (starts the chain) and then calls
70 * a sub-dissector which in turn calls the next sub-dissector and so on.
71 * Each sub-dissector may chain additional tvbs (see below) to the tvb
72 * handed to that dissector. After dissection is complete and control has
73 * returned to the top-level dissector, the chain of tvbs (stack) is free'd
74 * via a call to tvb_free_chain() (in epan_dissect_cleanup()).
77 * - Can chain new tvbs (subset, real, composite) to the
78 * tvb handed to the dissector using tvb_new_subset(),
79 * tvb_new_subset_length(), tvb_new_subset_remaining(),
80 * tvb_new_child_real_data(), tvb_set_child_real_data_tvbuff(),
81 * tvb_composite_finalize(), and tvb_child_uncompress(). (Composite
82 * tvbs should reference only tvbs which are already part of the chain).
83 * - Must not save for later use (e.g., when dissecting another frame) a
84 * pointer to a tvb handed to the dissector; (A higher level function
85 * may very well free the chain thus leaving a dangling pointer).
86 * This (obviously) also applies to any tvbs chained to the tvb handed
88 * - Can create its own tvb chain (using tvb_new_real_data() which the
90 * dissector is free to manage as desired.
94 /** TVBUFF_REAL_DATA contains a guint8* that points to real data.
95 * The data is allocated and contiguous.
97 * TVBUFF_SUBSET has a backing tvbuff. The TVBUFF_SUBSET is a "window"
98 * through which the program sees only a portion of the backing tvbuff.
100 * TVBUFF_COMPOSITE combines multiple tvbuffs sequentially to produce
101 * a larger byte array.
103 * tvbuff's of any type can be used as the backing-tvbuff of a
104 * TVBUFF_SUBSET or as the member of a TVBUFF_COMPOSITE.
105 * TVBUFF_COMPOSITEs can have member-tvbuffs of different types.
107 * Once a tvbuff is create/initialized/finalized, the tvbuff is read-only.
108 * That is, it cannot point to any other data. A new tvbuff must be created if
109 * you want a tvbuff that points to other data.
111 * tvbuff's are normally chained together to allow efficient de-allocation of
115 typedef void (*tvbuff_free_cb_t)(void*);
117 /** Extracts 'number of bits' starting at 'bit offset'.
118 * Returns a pointer to a newly initialized g_malloc'd REAL_DATA
119 * tvbuff with the bits octet aligned.
121 WS_DLL_PUBLIC tvbuff_t *tvb_new_octet_aligned(tvbuff_t *tvb,
122 guint32 bit_offset, gint32 no_of_bits);
124 WS_DLL_PUBLIC tvbuff_t *tvb_new_chain(tvbuff_t *parent, tvbuff_t *backing);
126 WS_DLL_PUBLIC tvbuff_t *tvb_clone(tvbuff_t *tvb);
128 WS_DLL_PUBLIC tvbuff_t *tvb_clone_offset_len(tvbuff_t *tvb, guint offset,
131 /** Free a tvbuff_t and all tvbuffs chained from it
132 * The tvbuff must be 'the 'head' (initial) tvb of a chain or
133 * must not be in a chain.
134 * If specified, a callback to free the tvbuff data will be invoked
135 * for each tvbuff free'd */
136 WS_DLL_PUBLIC void tvb_free(tvbuff_t *tvb);
138 /** Free the tvbuff_t and all tvbuffs chained from it.
139 * The tvbuff must be 'the 'head' (initial) tvb of a chain or
140 * must not be in a chain.
141 * If specified, a callback to free the tvbuff data will be invoked
142 * for each tvbuff free'd */
143 WS_DLL_PUBLIC void tvb_free_chain(tvbuff_t *tvb);
145 /** Set a callback function to call when a tvbuff is actually freed
146 * One argument is passed to that callback --- a void* that points
147 * to the real data. Obviously, this only applies to a
148 * TVBUFF_REAL_DATA tvbuff. */
149 WS_DLL_PUBLIC void tvb_set_free_cb(tvbuff_t *tvb, const tvbuff_free_cb_t func);
151 /** Attach a TVBUFF_REAL_DATA tvbuff to a parent tvbuff. This connection
152 * is used during a tvb_free_chain()... the "child" TVBUFF_REAL_DATA acts
153 * as if it is part of the chain-of-creation of the parent tvbuff, although it
154 * isn't. This is useful if you need to take the data from some tvbuff,
155 * run some operation on it, like decryption or decompression, and make a new
156 * tvbuff from it, yet want the new tvbuff to be part of the chain. The reality
157 * is that the new tvbuff *is* part of the "chain of creation", but in a way
158 * that these tvbuff routines are ignorant of. Use this function to make
159 * the tvbuff routines knowledgable of this fact. */
160 WS_DLL_PUBLIC void tvb_set_child_real_data_tvbuff(tvbuff_t *parent,
163 WS_DLL_PUBLIC tvbuff_t *tvb_new_child_real_data(tvbuff_t *parent,
164 const guint8 *data, const guint length, const gint reported_length);
166 /** Create a tvbuff backed by existing data. Can throw ReportedBoundsError.
167 * Normally, a callback to free the data should be registered using
168 * tvb_set_free_cb(); when this tvbuff is freed, then your callback will be
169 * called, and at that time you can free your original data. */
170 WS_DLL_PUBLIC tvbuff_t *tvb_new_real_data(const guint8 *data,
171 const guint length, const gint reported_length);
173 /** Create a tvbuff that's a subset of another tvbuff.
175 * 'backing_offset', if positive, is the offset from the beginning of
176 * the backing tvbuff at which the new tvbuff's data begins, and, if
177 * negative, is the offset from the end of the backing tvbuff at which
178 * the new tvbuff's data begins.
180 * 'backing_length' is the length of the data to include in the new
181 * tvbuff, starting with the byte at 'backing_offset"; if -1, it
182 * means "to the end of the backing tvbuff". It can be 0, although
183 * the usefulness of the buffer would be rather limited.
185 * Will throw BoundsError if 'backing_offset'/'length'
186 * is beyond the bounds of the backing tvbuff.
187 * Can throw ReportedBoundsError. */
188 WS_DLL_PUBLIC tvbuff_t *tvb_new_subset(tvbuff_t *backing,
189 const gint backing_offset, const gint backing_length,
190 const gint reported_length);
193 * Similar to tvb_new_subset() but with captured length calculated
194 * to fit within the existing captured length and the specified
195 * backing length (which is used as the reported length).
196 * Can throw ReportedBoundsError. */
197 WS_DLL_PUBLIC tvbuff_t *tvb_new_subset_length(tvbuff_t *backing,
198 const gint backing_offset, const gint backing_length);
200 /** Similar to tvb_new_subset() but with backing_length and reported_length set
201 * to -1. Can throw ReportedBoundsError. */
202 WS_DLL_PUBLIC tvbuff_t *tvb_new_subset_remaining(tvbuff_t *backing,
203 const gint backing_offset);
206 * Both tvb_composite_append and tvb_composite_prepend can throw
207 * BoundsError if member_offset/member_length goes beyond bounds of
208 * the 'member' tvbuff. */
210 /** Append to the list of tvbuffs that make up this composite tvbuff */
211 WS_DLL_PUBLIC void tvb_composite_append(tvbuff_t *tvb, tvbuff_t *member);
213 /** Prepend to the list of tvbuffs that make up this composite tvbuff */
214 extern void tvb_composite_prepend(tvbuff_t *tvb, tvbuff_t *member);
216 /** Create an empty composite tvbuff. */
217 WS_DLL_PUBLIC tvbuff_t *tvb_new_composite(void);
219 /** Mark a composite tvbuff as initialized. No further appends or prepends
220 * occur, data access can finally happen after this finalization. */
221 WS_DLL_PUBLIC void tvb_composite_finalize(tvbuff_t *tvb);
224 /* Get amount of captured data in the buffer (which is *NOT* necessarily the
225 * length of the packet). You probably want tvb_reported_length instead. */
226 WS_DLL_PUBLIC guint tvb_captured_length(const tvbuff_t *tvb);
228 /* DEPRECATED, do not use in new code, call tvb_captured_length directly! */
229 #define tvb_length tvb_captured_length
231 /** Computes bytes to end of buffer, from offset (which can be negative,
232 * to indicate bytes from end of buffer). Function returns 0 if offset is
233 * either at the end of the buffer or out of bounds. No exception is thrown.
234 * You probably want tvb_reported_length_remaining instead. */
235 WS_DLL_PUBLIC gint tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset);
237 /* DEPRECATED, do not use in new code, call tvb_captured_length_remaining directly! */
238 #define tvb_length_remaining tvb_captured_length_remaining
240 /** Same as above, but throws an exception if the offset is out of bounds. */
241 WS_DLL_PUBLIC guint tvb_ensure_captured_length_remaining(const tvbuff_t *tvb,
244 /* DEPRECATED, do not use in new code, call tvb_ensure_captured_length_remaining directly! */
245 #define tvb_ensure_length_remaining tvb_ensure_captured_length_remaining
247 /* Checks (w/o throwing exception) that the bytes referred to by
248 * 'offset'/'length' actually exist in the buffer */
249 WS_DLL_PUBLIC gboolean tvb_bytes_exist(const tvbuff_t *tvb, const gint offset,
252 /** Checks that the bytes referred to by 'offset'/'length' actually exist
253 * in the buffer, and throws an exception if they aren't. */
254 WS_DLL_PUBLIC void tvb_ensure_bytes_exist(const tvbuff_t *tvb,
255 const gint offset, const gint length);
257 /* Checks (w/o throwing exception) that offset exists in buffer */
258 WS_DLL_PUBLIC gboolean tvb_offset_exists(const tvbuff_t *tvb,
261 /* Get reported length of buffer */
262 WS_DLL_PUBLIC guint tvb_reported_length(const tvbuff_t *tvb);
264 /** Computes bytes of reported packet data to end of buffer, from offset
265 * (which can be negative, to indicate bytes from end of buffer). Function
266 * returns 0 if offset is either at the end of the buffer or out of bounds.
267 * No exception is thrown. */
268 WS_DLL_PUBLIC gint tvb_reported_length_remaining(const tvbuff_t *tvb,
271 /** Set the reported length of a tvbuff to a given value; used for protocols
272 whose headers contain an explicit length and where the calling
273 dissector's payload may include padding as well as the packet for
276 Also adjusts the data length. */
277 WS_DLL_PUBLIC void tvb_set_reported_length(tvbuff_t *tvb, const guint);
279 WS_DLL_PUBLIC guint tvb_offset_from_real_beginning(const tvbuff_t *tvb);
281 /* Returns the offset from the first byte of real data. */
282 WS_DLL_PUBLIC gint tvb_raw_offset(tvbuff_t *tvb);
284 /** Set the "this is a fragment" flag. */
285 WS_DLL_PUBLIC void tvb_set_fragment(tvbuff_t *tvb);
287 WS_DLL_PUBLIC struct tvbuff *tvb_get_ds_tvb(tvbuff_t *tvb);
290 /************** START OF ACCESSORS ****************/
291 /* All accessors will throw an exception if appropriate */
293 WS_DLL_PUBLIC guint8 tvb_get_guint8(tvbuff_t *tvb, const gint offset);
295 WS_DLL_PUBLIC guint16 tvb_get_ntohs(tvbuff_t *tvb, const gint offset);
296 WS_DLL_PUBLIC guint32 tvb_get_ntoh24(tvbuff_t *tvb, const gint offset);
297 WS_DLL_PUBLIC guint32 tvb_get_ntohl(tvbuff_t *tvb, const gint offset);
298 WS_DLL_PUBLIC guint64 tvb_get_ntoh40(tvbuff_t *tvb, const gint offset);
299 WS_DLL_PUBLIC gint64 tvb_get_ntohi40(tvbuff_t *tvb, const gint offset);
300 WS_DLL_PUBLIC guint64 tvb_get_ntoh48(tvbuff_t *tvb, const gint offset);
301 WS_DLL_PUBLIC gint64 tvb_get_ntohi48(tvbuff_t *tvb, const gint offset);
302 WS_DLL_PUBLIC guint64 tvb_get_ntoh56(tvbuff_t *tvb, const gint offset);
303 WS_DLL_PUBLIC gint64 tvb_get_ntohi56(tvbuff_t *tvb, const gint offset);
304 WS_DLL_PUBLIC guint64 tvb_get_ntoh64(tvbuff_t *tvb, const gint offset);
305 WS_DLL_PUBLIC gfloat tvb_get_ntohieee_float(tvbuff_t *tvb, const gint offset);
306 WS_DLL_PUBLIC gdouble tvb_get_ntohieee_double(tvbuff_t *tvb,
309 WS_DLL_PUBLIC guint16 tvb_get_letohs(tvbuff_t *tvb, const gint offset);
310 WS_DLL_PUBLIC guint32 tvb_get_letoh24(tvbuff_t *tvb, const gint offset);
311 WS_DLL_PUBLIC guint32 tvb_get_letohl(tvbuff_t *tvb, const gint offset);
312 WS_DLL_PUBLIC guint64 tvb_get_letoh40(tvbuff_t *tvb, const gint offset);
313 WS_DLL_PUBLIC gint64 tvb_get_letohi40(tvbuff_t *tvb, const gint offset);
314 WS_DLL_PUBLIC guint64 tvb_get_letoh48(tvbuff_t *tvb, const gint offset);
315 WS_DLL_PUBLIC gint64 tvb_get_letohi48(tvbuff_t *tvb, const gint offset);
316 WS_DLL_PUBLIC guint64 tvb_get_letoh56(tvbuff_t *tvb, const gint offset);
317 WS_DLL_PUBLIC gint64 tvb_get_letohi56(tvbuff_t *tvb, const gint offset);
318 WS_DLL_PUBLIC guint64 tvb_get_letoh64(tvbuff_t *tvb, const gint offset);
319 WS_DLL_PUBLIC gfloat tvb_get_letohieee_float(tvbuff_t *tvb, const gint offset);
320 WS_DLL_PUBLIC gdouble tvb_get_letohieee_double(tvbuff_t *tvb,
324 * Fetch an IPv4 address, in network byte order.
325 * We do *not* convert it to host byte order; we leave it in
326 * network byte order, as that's what its callers expect. */
327 WS_DLL_PUBLIC guint32 tvb_get_ipv4(tvbuff_t *tvb, const gint offset);
329 /* Fetch an IPv6 address. */
330 WS_DLL_PUBLIC void tvb_get_ipv6(tvbuff_t *tvb, const gint offset,
331 struct e_in6_addr *addr);
334 WS_DLL_PUBLIC void tvb_get_ntohguid(tvbuff_t *tvb, const gint offset,
336 WS_DLL_PUBLIC void tvb_get_letohguid(tvbuff_t *tvb, const gint offset,
338 WS_DLL_PUBLIC void tvb_get_guid(tvbuff_t *tvb, const gint offset,
339 e_guid_t *guid, const guint representation);
341 /* Fetch a specified number of bits from bit offset in a tvb. All of these
342 * functions are equivalent, except for the type of the return value. Note
343 * that the parameter encoding (where supplied) is meaningless and ignored */
345 /* get 1 - 8 bits returned in a guint8 */
346 WS_DLL_PUBLIC guint8 tvb_get_bits8(tvbuff_t *tvb, guint bit_offset,
347 const gint no_of_bits);
348 /* get 1 - 16 bits returned in a guint16 */
349 WS_DLL_PUBLIC guint16 tvb_get_bits16(tvbuff_t *tvb, guint bit_offset,
350 const gint no_of_bits, const guint encoding);
351 /* get 1 - 32 bits returned in a guint32 */
352 WS_DLL_PUBLIC guint32 tvb_get_bits32(tvbuff_t *tvb, guint bit_offset,
353 const gint no_of_bits, const guint encoding);
354 /* get 1 - 64 bits returned in a guint64 */
355 WS_DLL_PUBLIC guint64 tvb_get_bits64(tvbuff_t *tvb, guint bit_offset,
356 const gint no_of_bits, const guint encoding);
359 * This function has EXACTLY the same behavior as
362 WS_DLL_PUBLIC guint32 tvb_get_bits(tvbuff_t *tvb, const guint bit_offset,
363 const gint no_of_bits, const guint encoding);
365 /** Returns target for convenience. Does not suffer from possible
366 * expense of tvb_get_ptr(), since this routine is smart enough
367 * to copy data in chunks if the request range actually exists in
368 * different TVBUFF_REAL_DATA tvbuffs. This function assumes that the
369 * target memory is already allocated; it does not allocate or free the
371 WS_DLL_PUBLIC void *tvb_memcpy(tvbuff_t *tvb, void *target, const gint offset,
374 /** If scope is set to NULL it is the user's responsibility to wmem_free()
375 * the memory allocated by tvb_memdup(). Otherwise memory is
376 * automatically freed when the scope lifetime is reached.
377 * Calls tvb_memcpy() */
378 WS_DLL_PUBLIC void *tvb_memdup(wmem_allocator_t *scope, tvbuff_t *tvb,
379 const gint offset, size_t length);
381 /** WARNING! This function is possibly expensive, temporarily allocating
382 * another copy of the packet data. Furthermore, it's dangerous because once
383 * this pointer is given to the user, there's no guarantee that the user will
384 * honor the 'length' and not overstep the boundaries of the buffer.
386 * If you're thinking of using tvb_get_ptr, STOP WHAT YOU ARE DOING
387 * IMMEDIATELY. Go take a break. Consider that tvb_get_ptr hands you
388 * a raw, unprotected pointer that you can easily use to create a
389 * security vulnerability or otherwise crash Wireshark. Then consider
390 * that you can probably find a function elsewhere in this file that
391 * does exactly what you want in a much more safe and robust manner.
393 * The returned pointer is data that is internal to the tvbuff, so do not
394 * attempt to free it. Don't modify the data, either, because another tvbuff
395 * that might be using this tvbuff may have already copied that portion of
396 * the data (sometimes tvbuff's need to make copies of data, but that's the
397 * internal implementation that you need not worry about). Assume that the
398 * guint8* points to read-only data that the tvbuff manages.
400 * Return a pointer into our buffer if the data asked for via 'offset'/'length'
401 * is contiguous (which might not be the case for TVBUFF_COMPOSITE). If the
402 * data is not contiguous, a tvb_memdup() is called for the entire buffer
403 * and the pointer to the newly-contiguous data is returned. This dynamically-
404 * allocated memory will be freed when the tvbuff is freed, after the
405 * tvbuff_free_cb_t() is called, if any. */
406 WS_DLL_PUBLIC const guint8 *tvb_get_ptr(tvbuff_t *tvb, const gint offset,
409 /** Find first occurrence of needle in tvbuff, starting at offset. Searches
410 * at most maxlength number of bytes; if maxlength is -1, searches to
412 * Returns the offset of the found needle, or -1 if not found.
413 * Will not throw an exception, even if maxlength exceeds boundary of tvbuff;
414 * in that case, -1 will be returned if the boundary is reached before
416 WS_DLL_PUBLIC gint tvb_find_guint8(tvbuff_t *tvb, const gint offset,
417 const gint maxlength, const guint8 needle);
419 /** Find first occurrence of any of the needles in tvbuff, starting at offset.
420 * Searches at most maxlength number of bytes. Returns the offset of the
421 * found needle, or -1 if not found and the found needle.
422 * Will not throw an exception, even if
423 * maxlength exceeds boundary of tvbuff; in that case, -1 will be returned if
424 * the boundary is reached before finding needle. */
425 WS_DLL_PUBLIC gint tvb_pbrk_guint8(tvbuff_t *tvb, const gint offset,
426 const gint maxlength, const guint8 *needles, guchar *found_needle);
428 /** Find size of stringz (NUL-terminated string) by looking for terminating
429 * NUL. The size of the string includes the terminating NUL.
431 * If the NUL isn't found, it throws the appropriate exception.
433 WS_DLL_PUBLIC guint tvb_strsize(tvbuff_t *tvb, const gint offset);
435 /** Find size of UCS-2 or UTF-16 stringz (NUL-terminated string) by
436 * looking for terminating 16-bit NUL. The size of the string includes
437 * the terminating NUL.
439 * If the NUL isn't found, it throws the appropriate exception.
441 WS_DLL_PUBLIC guint tvb_unicode_strsize(tvbuff_t *tvb, const gint offset);
443 /** Find length of string by looking for end of zero terminated string, up to
444 * 'maxlength' characters'; if 'maxlength' is -1, searches to end
446 * Returns -1 if 'maxlength' reached before finding EOS. */
447 WS_DLL_PUBLIC gint tvb_strnlen(tvbuff_t *tvb, const gint offset,
448 const guint maxlength);
451 * Format the data in the tvb from offset for size ...
453 WS_DLL_PUBLIC gchar *tvb_format_text(tvbuff_t *tvb, const gint offset,
457 * Like "tvb_format_text()", but for 'wsp'; don't show
458 * the characters as C-style escapes.
460 WS_DLL_PUBLIC gchar *tvb_format_text_wsp(tvbuff_t *tvb, const gint offset,
464 * Like "tvb_format_text()", but for null-padded strings; don't show
465 * the null padding characters as "\000".
467 extern gchar *tvb_format_stringzpad(tvbuff_t *tvb, const gint offset,
471 * Like "tvb_format_text_wsp()", but for null-padded strings; don't show
472 * the null padding characters as "\000".
474 extern gchar *tvb_format_stringzpad_wsp(tvbuff_t *tvb, const gint offset,
478 * Given an allocator scope, a tvbuff, a byte offset, a byte length, and
479 * a string encoding, with the specified offset and length referring to
480 * a string in the specified encoding:
482 * allocate a buffer using the specified scope;
484 * convert the string from the specified encoding to UTF-8, possibly
485 * mapping some characters or invalid octet sequences to the Unicode
486 * REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a
487 * trailing '\0', into that buffer;
489 * and return a pointer to the buffer.
491 * Throws an exception if the tvbuff ends before the string does.
493 * If scope is set to NULL it is the user's responsibility to wmem_free()
494 * the memory allocated. Otherwise memory is automatically freed when the scope
495 * lifetime is reached.
497 WS_DLL_PUBLIC guint8 *tvb_get_string_enc(wmem_allocator_t *scope,
498 tvbuff_t *tvb, const gint offset, const gint length, const guint encoding);
501 * DEPRECATED, do not use in new code, call tvb_get_string_enc directly with
502 * the appropriate extension! Do not assume that ENC_ASCII will work
503 * with arbitrary string encodings; it will map all bytes with the 8th
504 * bit set to the Unicode REPLACEMENT CHARACTER, so it won't show non-ASCII
505 * characters as anything other than an ugly blob.
507 #define tvb_get_string(SCOPE, TVB, OFFSET, LENGTH) \
508 tvb_get_string_enc(SCOPE, TVB, OFFSET, LENGTH, ENC_ASCII)
511 * Given an allocator scope, a tvbuff, a bit offset, and a length in
512 * 7-bit characters (not octets!), with the specified offset and
513 * length referring to a string in the 3GPP TS 23.038 7bits encoding:
515 * allocate a buffer using the specified scope;
517 * convert the string from the specified encoding to UTF-8, possibly
518 * mapping some characters or invalid octet sequences to the Unicode
519 * REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a
520 * trailing '\0', into that buffer;
522 * and return a pointer to the buffer.
524 * Throws an exception if the tvbuff ends before the string does.
526 * If scope is set to NULL it is the user's responsibility to wmem_free()
527 * the memory allocated. Otherwise memory is automatically freed when the
528 * scope lifetime is reached.
530 WS_DLL_PUBLIC gchar *tvb_get_ts_23_038_7bits_string(wmem_allocator_t *scope,
531 tvbuff_t *tvb, const gint bit_offset, gint no_of_chars);
534 * Given an allocator scope, a tvbuff, a byte offset, a pointer to a
535 * gint, and a string encoding, with the specified offset referring to
536 * a null-terminated string in the specified encoding:
538 * find the length of that string (and throw an exception if the tvbuff
539 * ends before we find the null);
541 * allocate a buffer using the specified scope;
543 * convert the string from the specified encoding to UTF-8, possibly
544 * mapping some characters or invalid octet sequences to the Unicode
545 * REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a
546 * trailing '\0', into that buffer;
548 * if the pointer to the gint is non-null, set the gint to which it
549 * points to the length of the string;
551 * and return a pointer to the buffer.
553 * Throws an exception if the tvbuff ends before the string does.
555 * If scope is set to NULL it is the user's responsibility to wmem_free()
556 * the memory allocated. Otherwise memory is automatically freed when the scope
557 * lifetime is reached.
559 WS_DLL_PUBLIC guint8 *tvb_get_stringz_enc(wmem_allocator_t *scope,
560 tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding);
563 * DEPRECATED, do not use in new code, call tvb_get_string_enc directly with
564 * the appropriate extension! Do not assume that ENC_ASCII will work
565 * with arbitrary string encodings; it will map all bytes with the 8th
566 * bit set to the Unicode REPLACEMENT CHARACTER, so it won't show non-ASCII
567 * characters as anything other than an ugly blob.
569 #define tvb_get_stringz(SCOPE, TVB, OFFSET, LENGTHP) \
570 tvb_get_stringz_enc(SCOPE, TVB, OFFSET, LENGTHP, ENC_ASCII)
573 * Given a tvbuff and an offset, with the offset assumed to refer to
574 * a null-terminated string, find the length of that string (and throw
575 * an exception if the tvbuff ends before we find the null), allocate
576 * a buffer big enough to hold the string, copy the string into it,
577 * and return a pointer to the string. Also return the length of the
578 * string (including the terminating null) through a pointer.
580 * This returns a constant (unmodifiable) string that does not need
581 * to be freed; instead, it will automatically be freed once the next
582 * packet is dissected.
584 * It is slightly more efficient than the other routines, but does *NOT*
585 * do any translation to UTF-8 - the string consists of the raw octets
586 * of the string, in whatever encoding they happen to be in, and, if
587 * the string is not valid in that encoding, with invalid octet sequences
588 * as they are in the packet.
590 WS_DLL_PUBLIC const guint8 *tvb_get_const_stringz(tvbuff_t *tvb,
591 const gint offset, gint *lengthp);
593 /** Looks for a stringz (NUL-terminated string) in tvbuff and copies
594 * no more than bufsize number of bytes, including terminating NUL, to buffer.
595 * Returns length of string (not including terminating NUL), or -1 if the
596 * string was truncated in the buffer due to not having reached the terminating
597 * NUL. In this way, it acts like g_snprintf().
599 * When processing a packet where the remaining number of bytes is less
600 * than bufsize, an exception is not thrown if the end of the packet
601 * is reached before the NUL is found. If no NUL is found before reaching
602 * the end of the short packet, -1 is still returned, and the string
603 * is truncated with a NUL, albeit not at buffer[bufsize - 1], but
604 * at the correct spot, terminating the string.
606 WS_DLL_PUBLIC gint tvb_get_nstringz(tvbuff_t *tvb, const gint offset,
607 const guint bufsize, guint8 *buffer);
609 /** Like tvb_get_nstringz(), but never returns -1. The string is guaranteed to
610 * have a terminating NUL. If the string was truncated when copied into buffer,
611 * a NUL is placed at the end of buffer to terminate it.
613 * bufsize MUST be greater than 0.
615 WS_DLL_PUBLIC gint tvb_get_nstringz0(tvbuff_t *tvb, const gint offset,
616 const guint bufsize, guint8 *buffer);
619 * Given a tvbuff, an offset into the tvbuff, and a length that starts
620 * at that offset (which may be -1 for "all the way to the end of the
621 * tvbuff"), find the end of the (putative) line that starts at the
622 * specified offset in the tvbuff, going no further than the specified
625 * Return the length of the line (not counting the line terminator at
626 * the end), or, if we don't find a line terminator:
628 * if "deseg" is true, return -1;
630 * if "deseg" is false, return the amount of data remaining in
633 * Set "*next_offset" to the offset of the character past the line
634 * terminator, or past the end of the buffer if we don't find a line
635 * terminator. (It's not set if we return -1.)
637 WS_DLL_PUBLIC gint tvb_find_line_end(tvbuff_t *tvb, const gint offset, int len,
638 gint *next_offset, const gboolean desegment);
641 * Given a tvbuff, an offset into the tvbuff, and a length that starts
642 * at that offset (which may be -1 for "all the way to the end of the
643 * tvbuff"), find the end of the (putative) line that starts at the
644 * specified offset in the tvbuff, going no further than the specified
647 * However, treat quoted strings inside the buffer specially - don't
648 * treat newlines in quoted strings as line terminators.
650 * Return the length of the line (not counting the line terminator at
651 * the end), or the amount of data remaining in the buffer if we don't
652 * find a line terminator.
654 * Set "*next_offset" to the offset of the character past the line
655 * terminator, or past the end of the buffer if we don't find a line
658 WS_DLL_PUBLIC gint tvb_find_line_end_unquoted(tvbuff_t *tvb, const gint offset,
659 int len, gint *next_offset);
662 * Copied from the mgcp dissector. (This function should be moved to /epan )
663 * tvb_skip_wsp - Returns the position in tvb of the first non-whitespace
664 * character following offset or offset + maxlength -1 whichever
668 * tvb - The tvbuff in which we are skipping whitespace.
669 * offset - The offset in tvb from which we begin trying to skip whitespace.
670 * maxlength - The maximum distance from offset that we may try to skip
673 * Returns: The position in tvb of the first non-whitespace
674 * character following offset or offset + maxlength -1 whichever
678 WS_DLL_PUBLIC gint tvb_skip_wsp(tvbuff_t *tvb, const gint offset,
679 const gint maxlength);
681 WS_DLL_PUBLIC gint tvb_skip_wsp_return(tvbuff_t *tvb, const gint offset);
683 int tvb_skip_guint8(tvbuff_t *tvb, int offset, const int maxlength, const guint8 ch);
686 * Call strncmp after checking if enough chars left, returning 0 if
687 * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
689 WS_DLL_PUBLIC gint tvb_strneql(tvbuff_t *tvb, const gint offset,
690 const gchar *str, const size_t size);
693 * Call g_ascii_strncasecmp after checking if enough chars left, returning
694 * 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
696 WS_DLL_PUBLIC gint tvb_strncaseeql(tvbuff_t *tvb, const gint offset,
697 const gchar *str, const size_t size);
700 * Call memcmp after checking if enough chars left, returning 0 if
701 * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
703 WS_DLL_PUBLIC gint tvb_memeql(tvbuff_t *tvb, const gint offset,
704 const guint8 *str, size_t size);
707 * Format a bunch of data from a tvbuff as bytes, returning a pointer
708 * to the string with the formatted data, with "punct" as a byte
711 WS_DLL_PUBLIC gchar *tvb_bytes_to_ep_str_punct(tvbuff_t *tvb, const gint offset,
712 const gint len, const gchar punct);
715 * Format a bunch of data from a tvbuff as bytes, returning a pointer
716 * to the string with the formatted data.
718 WS_DLL_PUBLIC gchar *tvb_bytes_to_ep_str(tvbuff_t *tvb, const gint offset,
722 * Given a tvbuff, an offset into the tvbuff, and a length that starts
723 * at that offset (which may be -1 for "all the way to the end of the
724 * tvbuff"), fetch BCD encoded digits from a tvbuff starting from either
725 * the low or high half byte, formatting the digits according to an input digit
726 * set, if NUL a default digit set of 0-9 returning "?" for overdecadic digits
727 * will be used. A pointer to the EP allocated string will be returned.
728 * Note a tvbuff content of 0xf is considered a 'filler' and will end the
731 typedef struct dgt_set_t
733 const unsigned char out[16];
737 WS_DLL_PUBLIC const gchar *tvb_bcd_dig_to_wmem_packet_str(tvbuff_t *tvb,
738 const gint offset, const gint len, dgt_set_t *dgt, gboolean skip_first);
740 /** Locate a sub-tvbuff within another tvbuff, starting at position
741 * 'haystack_offset'. Returns the index of the beginning of 'needle' within
742 * 'haystack', or -1 if 'needle' is not found. The index is relative
743 * to the start of 'haystack', not 'haystack_offset'. */
744 WS_DLL_PUBLIC gint tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb,
745 const gint haystack_offset);
747 /* From tvbuff_zlib.c */
750 * Uncompresses a zlib compressed packet inside a tvbuff at offset with
751 * length comprlen. Returns an uncompressed tvbuffer if uncompression
752 * succeeded or NULL if uncompression failed.
754 WS_DLL_PUBLIC tvbuff_t *tvb_uncompress(tvbuff_t *tvb, const int offset,
758 * Uncompresses a zlib compressed packet inside a tvbuff at offset with
759 * length comprlen. Returns an uncompressed tvbuffer attached to tvb if
760 * uncompression succeeded or NULL if uncompression failed.
762 extern tvbuff_t *tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb,
763 const int offset, int comprlen);
765 /* From tvbuff_base64.c */
767 /** Return a tvb that contains the binary representation of a base64
770 extern tvbuff_t* base64_to_tvb(tvbuff_t *parent, const char *base64);
772 /************** END OF ACCESSORS ****************/
778 #endif /* __cplusplus */
780 #endif /* __TVBUFF_H__ */
783 * Editor modelines - http://www.wireshark.org/tools/modelines.html
788 * indent-tabs-mode: nil
791 * vi: set shiftwidth=4 tabstop=4 expandtab:
792 * :indentSize=4:tabSize=4:noTabs=true: