Testy, Virtual(-izable) Buffers

Classes
struct	dgt_set_t

Macros
#define	tvb_get_h_uint16   tvb_get_letohs
#define	tvb_get_h_uint32   tvb_get_letohl

Typedefs
typedef void(*	tvbuff_free_cb_t) (void *)
typedef struct dgt_set_t	dgt_set_t

Functions
WS_DLL_PUBLIC tvbuff_t *	tvb_new_octet_aligned (tvbuff_t *tvb, uint32_t bit_offset, int32_t no_of_bits)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_octet_right_aligned (tvbuff_t *tvb, uint32_t bit_offset, int32_t no_of_bits)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_chain (tvbuff_t *parent, tvbuff_t *backing)
WS_DLL_PUBLIC tvbuff_t *	tvb_clone (tvbuff_t *tvb)
WS_DLL_PUBLIC tvbuff_t *	tvb_clone_offset_len (tvbuff_t *tvb, unsigned offset, unsigned len)
WS_DLL_PUBLIC void	tvb_free (tvbuff_t *tvb)
WS_DLL_PUBLIC void	tvb_free_chain (tvbuff_t *tvb)
WS_DLL_PUBLIC void	tvb_set_free_cb (tvbuff_t *tvb, const tvbuff_free_cb_t func)
WS_DLL_PUBLIC void	tvb_set_child_real_data_tvbuff (tvbuff_t *parent, tvbuff_t *child)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_child_real_data (tvbuff_t *parent, const uint8_t *data, const unsigned length, const int reported_length)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_real_data (const uint8_t *data, const unsigned length, const int reported_length)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_subset_length_caplen (tvbuff_t *backing, const int backing_offset, const int backing_length, const int reported_length)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_subset_length (tvbuff_t *backing, const int backing_offset, const int reported_length)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_subset_remaining (tvbuff_t *backing, const int backing_offset)
WS_DLL_PUBLIC void	tvb_composite_append (tvbuff_t *tvb, tvbuff_t *member)
void	tvb_composite_prepend (tvbuff_t *tvb, tvbuff_t *member)
WS_DLL_PUBLIC tvbuff_t *	tvb_new_composite (void)
WS_DLL_PUBLIC void	tvb_composite_finalize (tvbuff_t *tvb)
WS_DLL_PUBLIC unsigned	tvb_captured_length (const tvbuff_t *tvb)
WS_DLL_PUBLIC int	tvb_captured_length_remaining (const tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC unsigned	tvb_ensure_captured_length_remaining (const tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC bool	tvb_bytes_exist (const tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC void	tvb_ensure_bytes_exist64 (const tvbuff_t *tvb, const int offset, const uint64_t length)
WS_DLL_PUBLIC void	tvb_ensure_bytes_exist (const tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC bool	tvb_offset_exists (const tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC unsigned	tvb_reported_length (const tvbuff_t *tvb)
WS_DLL_PUBLIC int	tvb_reported_length_remaining (const tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC unsigned	tvb_ensure_reported_length_remaining (const tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC void	tvb_set_reported_length (tvbuff_t *tvb, const unsigned)
WS_DLL_PUBLIC void	tvb_fix_reported_length (tvbuff_t *tvb)
WS_DLL_PUBLIC unsigned	tvb_offset_from_real_beginning (const tvbuff_t *tvb)
WS_DLL_PUBLIC int	tvb_raw_offset (tvbuff_t *tvb)
WS_DLL_PUBLIC void	tvb_set_fragment (tvbuff_t *tvb)
WS_DLL_PUBLIC struct tvbuff *	tvb_get_ds_tvb (tvbuff_t *tvb)
WS_DLL_PUBLIC uint8_t	tvb_get_uint8 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int8_t	tvb_get_int8 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint16_t	tvb_get_ntohs (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int16_t	tvb_get_ntohis (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint32_t	tvb_get_ntoh24 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int32_t	tvb_get_ntohi24 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint32_t	tvb_get_ntohl (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int32_t	tvb_get_ntohil (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_ntoh40 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_ntohi40 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_ntoh48 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_ntohi48 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_ntoh56 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_ntohi56 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_ntoh64 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_ntohi64 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC float	tvb_get_ntohieee_float (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC double	tvb_get_ntohieee_double (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint16_t	tvb_get_letohs (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int16_t	tvb_get_letohis (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint32_t	tvb_get_letoh24 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int32_t	tvb_get_letohi24 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint32_t	tvb_get_letohl (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int32_t	tvb_get_letohil (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_letoh40 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_letohi40 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_letoh48 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_letohi48 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_letoh56 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_letohi56 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint64_t	tvb_get_letoh64 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int64_t	tvb_get_letohi64 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC float	tvb_get_letohieee_float (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC double	tvb_get_letohieee_double (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC uint16_t	tvb_get_uint16 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int16_t	tvb_get_int16 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint32_t	tvb_get_uint24 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int32_t	tvb_get_int24 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint32_t	tvb_get_uint32 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int32_t	tvb_get_int32 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_uint40 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int64_t	tvb_get_int40 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_uint48 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int64_t	tvb_get_int48 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_uint56 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC int64_t	tvb_get_int56 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_uint64 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_uint64_with_length (tvbuff_t *tvb, const int offset, unsigned length, const unsigned encoding)
WS_DLL_PUBLIC int64_t	tvb_get_int64 (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC float	tvb_get_ieee_float (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC double	tvb_get_ieee_double (tvbuff_t *tvb, const int offset, const unsigned encoding)
WS_DLL_PUBLIC nstime_t *	tvb_get_string_time (tvbuff_t *tvb, const int offset, const int length, const unsigned encoding, nstime_t *ns, int *endoff)
WS_DLL_PUBLIC GByteArray *	tvb_get_string_bytes (tvbuff_t *tvb, const int offset, const int length, const unsigned encoding, GByteArray *bytes, int *endoff)
WS_DLL_PUBLIC uint32_t	tvb_get_ipv4 (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC void	tvb_get_ipv6 (tvbuff_t *tvb, const int offset, ws_in6_addr *addr)
int	tvb_get_ipv4_addr_with_prefix_len (tvbuff_t *tvb, int offset, ws_in4_addr *addr, uint32_t prefix_len)
int	tvb_get_ipv6_addr_with_prefix_len (tvbuff_t *tvb, int offset, ws_in6_addr *addr, uint32_t prefix_len)
WS_DLL_PUBLIC void	tvb_get_ntohguid (tvbuff_t *tvb, const int offset, e_guid_t *guid)
WS_DLL_PUBLIC void	tvb_get_letohguid (tvbuff_t *tvb, const int offset, e_guid_t *guid)
WS_DLL_PUBLIC void	tvb_get_guid (tvbuff_t *tvb, const int offset, e_guid_t *guid, const unsigned encoding)
WS_DLL_PUBLIC uint8_t *	tvb_get_bits_array (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, size_t length, size_t *data_length, const unsigned encoding)
WS_DLL_PUBLIC uint8_t	tvb_get_bits8 (tvbuff_t *tvb, unsigned bit_offset, const int no_of_bits)
WS_DLL_PUBLIC uint16_t	tvb_get_bits16 (tvbuff_t *tvb, unsigned bit_offset, const int no_of_bits, const unsigned encoding)
WS_DLL_PUBLIC uint32_t	tvb_get_bits32 (tvbuff_t *tvb, unsigned bit_offset, const int no_of_bits, const unsigned encoding)
WS_DLL_PUBLIC uint64_t	tvb_get_bits64 (tvbuff_t *tvb, unsigned bit_offset, const int no_of_bits, const unsigned encoding)
WS_DLL_PUBLIC uint32_t	tvb_get_bits (tvbuff_t *tvb, const unsigned bit_offset, const int no_of_bits, const unsigned encoding)
WS_DLL_PUBLIC void *	tvb_memcpy (tvbuff_t *tvb, void *target, const int offset, size_t length)
WS_DLL_PUBLIC void *	tvb_memdup (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, size_t length)
WS_DLL_PUBLIC const uint8_t *	tvb_get_ptr (tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC int	tvb_find_uint8 (tvbuff_t *tvb, const int offset, const int maxlength, const uint8_t needle)
WS_DLL_PUBLIC int	tvb_find_uint16 (tvbuff_t *tvb, const int offset, const int maxlength, const uint16_t needle)
WS_DLL_PUBLIC int	tvb_ws_mempbrk_pattern_uint8 (tvbuff_t *tvb, const int offset, const int maxlength, const ws_mempbrk_pattern *pattern, unsigned char *found_needle)
WS_DLL_PUBLIC unsigned	tvb_strsize (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC unsigned	tvb_unicode_strsize (tvbuff_t *tvb, const int offset)
WS_DLL_PUBLIC int	tvb_strnlen (tvbuff_t *tvb, const int offset, const unsigned maxlength)
WS_DLL_PUBLIC char *	tvb_format_text (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int size)
WS_DLL_PUBLIC char *	tvb_format_text_wsp (wmem_allocator_t *allocator, tvbuff_t *tvb, const int offset, const int size)
char *	tvb_format_stringzpad (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int size)
char *	tvb_format_stringzpad_wsp (wmem_allocator_t *allocator, tvbuff_t *tvb, const int offset, const int size)
WS_DLL_PUBLIC uint8_t *	tvb_get_string_enc (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int length, const unsigned encoding)
WS_DLL_PUBLIC char *	tvb_get_ts_23_038_7bits_string_packed (wmem_allocator_t *scope, tvbuff_t *tvb, const int bit_offset, int no_of_chars)
WS_DLL_PUBLIC char *	tvb_get_ts_23_038_7bits_string_unpacked (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, int length)
WS_DLL_PUBLIC char *	tvb_get_etsi_ts_102_221_annex_a_string (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, int length)
WS_DLL_PUBLIC char *	tvb_get_ascii_7bits_string (wmem_allocator_t *scope, tvbuff_t *tvb, const int bit_offset, int no_of_chars)
WS_DLL_PUBLIC uint8_t *	tvb_get_stringzpad (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int length, const unsigned encoding)
WS_DLL_PUBLIC uint8_t *	tvb_get_stringz_enc (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, int *lengthp, const unsigned encoding)
WS_DLL_PUBLIC const uint8_t *	tvb_get_const_stringz (tvbuff_t *tvb, const int offset, int *lengthp)
WS_DLL_PUBLIC int	tvb_get_raw_bytes_as_stringz (tvbuff_t *tvb, const int offset, const unsigned bufsize, uint8_t *buffer)
WS_DLL_PUBLIC int	tvb_get_raw_bytes_as_string (tvbuff_t *tvb, const int offset, char *buffer, size_t bufsize)
WS_DLL_PUBLIC bool	tvb_ascii_isprint (tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC bool	tvb_utf_8_isprint (tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC bool	tvb_ascii_isdigit (tvbuff_t *tvb, const int offset, const int length)
WS_DLL_PUBLIC int	tvb_find_line_end (tvbuff_t *tvb, const int offset, int len, int *next_offset, const bool desegment)
WS_DLL_PUBLIC int	tvb_find_line_end_unquoted (tvbuff_t *tvb, const int offset, int len, int *next_offset)
WS_DLL_PUBLIC int	tvb_skip_wsp (tvbuff_t *tvb, const int offset, const int maxlength)
WS_DLL_PUBLIC int	tvb_skip_wsp_return (tvbuff_t *tvb, const int offset)
int	tvb_skip_uint8 (tvbuff_t *tvb, int offset, const int maxlength, const uint8_t ch)
WS_DLL_PUBLIC int	tvb_get_token_len (tvbuff_t *tvb, const int offset, int len, int *next_offset, const bool desegment)
WS_DLL_PUBLIC int	tvb_strneql (tvbuff_t *tvb, const int offset, const char *str, const size_t size)
WS_DLL_PUBLIC int	tvb_strncaseeql (tvbuff_t *tvb, const int offset, const char *str, const size_t size)
WS_DLL_PUBLIC int	tvb_memeql (tvbuff_t *tvb, const int offset, const uint8_t *str, size_t size)
WS_DLL_PUBLIC char *	tvb_bytes_to_str_punct (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int len, const char punct)
WS_DLL_PUBLIC char *	tvb_bytes_to_str (wmem_allocator_t *allocator, tvbuff_t *tvb, const int offset, const int len)
WS_DLL_PUBLIC const char *	tvb_bcd_dig_to_str (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int len, const dgt_set_t *dgt, bool skip_first)
WS_DLL_PUBLIC const char *	tvb_bcd_dig_to_str_be (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int len, const dgt_set_t *dgt, bool skip_first)
WS_DLL_PUBLIC char *	tvb_get_bcd_string (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, int len, const dgt_set_t *dgt, bool skip_first, bool odd, bool bigendian)
WS_DLL_PUBLIC int	tvb_find_tvb (tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb, const int haystack_offset)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_zlib (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_zlib (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_brotli (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_brotli (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_snappy (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_snappy (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_lz77 (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_lz77 (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_lz77huff (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_lz77huff (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_lznt1 (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_lznt1 (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_uncompress_zstd (tvbuff_t *tvb, const int offset, int comprlen)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_zstd (tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
tvbuff_t *	base64_to_tvb (tvbuff_t *parent, const char *base64)
tvbuff_t *	base64_tvb_to_new_tvb (tvbuff_t *parent, int offset, int length)
tvbuff_t *	base64uri_tvb_to_new_tvb (tvbuff_t *parent, int offset, int length)
WS_DLL_PUBLIC wmem_strbuf_t *	tvb_get_hpack_huffman_strbuf (wmem_allocator_t *scope, tvbuff_t *tvb, const int offset, const int len)
WS_DLL_PUBLIC tvbuff_t *	tvb_child_uncompress_hpack_huff (tvbuff_t *parent, int offset, int length)
WS_DLL_PUBLIC unsigned	tvb_get_varint (tvbuff_t *tvb, unsigned offset, unsigned maxlen, uint64_t *value, const unsigned encoding)

Detailed Description

Dissector use and management

Consider a collection of tvbs as being a chain or stack of tvbs.

When dissecting a frame: The top-level dissector (packet.c) pushes the initial tvb (containing the complete frame) onto the stack (starts the chain) and then calls a sub-dissector which in turn calls the next sub-dissector and so on. Each sub-dissector may chain additional tvbs (see below) to the tvb handed to that dissector. After dissection is complete and control has returned to the top-level dissector, the chain of tvbs (stack) is free'd via a call to tvb_free_chain() (in epan_dissect_cleanup()).

A dissector:

• Can chain new tvbs (subset, real, composite) to the tvb handed to the dissector using tvb_new_subset_length_caplen(), tvb_new_subset_length(), tvb_new_subset_remaining(), tvb_new_child_real_data(), tvb_set_child_real_data_tvbuff(), tvb_composite_finalize(), and tvb_child_uncompress(). (Composite tvbs should reference only tvbs which are already part of the chain).
• Must not save for later use (e.g., when dissecting another frame) a pointer to a tvb handed to the dissector; (A higher level function may very well free the chain thus leaving a dangling pointer). This (obviously) also applies to any tvbs chained to the tvb handed to the dissector.
• Can create its own tvb chain (using tvb_new_real_data() which the dissector is free to manage as desired.

Typedef Documentation

dgt_set_t

typedef struct dgt_set_t dgt_set_t

Given a tvbuff, an offset into the tvbuff, and a length that starts at that offset (which may be -1 for "all the way to the end of the tvbuff"), fetch BCD encoded digits from a tvbuff starting from either the low or high half byte, formatting the digits according to an input digit set, if NUL a default digit set of 0-9 returning "?" for overdecadic digits will be used. A pointer to the WMEM-allocated string will be returned. Note a tvbuff content of 0xf is considered a 'filler' and will end the conversion.

tvbuff_free_cb_t

typedef void(* tvbuff_free_cb_t) (void *)

A "real" tvbuff contains a uint8_t* that points to real data. The data is allocated and contiguous.

A "subset" tvbuff has a backing tvbuff. It is a "window" through which the program sees only a portion of the backing tvbuff.

A "composite" tvbuff combines multiple tvbuffs sequentially to produce a larger byte array.

tvbuff's of any type can be used as the backing-tvbuff of a "subset" tvbuff or as a member of a "composite" tvbuff. "composite" tvbuffs can have member-tvbuffs of different types.

Once a tvbuff is create/initialized/finalized, the tvbuff is read-only. That is, it cannot point to any other data. A new tvbuff must be created if you want a tvbuff that points to other data.

tvbuff's are normally chained together to allow efficient de-allocation of tvbuff's.

Function Documentation

base64_to_tvb()

tvbuff_t * base64_to_tvb ( tvbuff_t *  parent, const char *  base64  )

extern

Return a tvb that contains the binary representation of a base64 string as a child of the indicated tvb.

Parameters

parent	The parent tvbuff.
base64	The base64 encoded string which binary representation will be returned in the child tvb.

Returns

A tvb with the binary representation of the base64 decoded string.

base64_tvb_to_new_tvb()

tvbuff_t * base64_tvb_to_new_tvb ( tvbuff_t *  parent, int  offset, int  length  )

extern

Return a tvb that contains the binary representation of a base64 encoded string in the parent tvb as a child of the indicated tvb.

Parameters

parent	The parent tvbuff.
offset	Start of the base64 string in the tvb
length	Length of the base64 string in the tvb

Returns

A tvb with the binary representation of the base64 decoded string.

tvb_ascii_isdigit()

WS_DLL_PUBLIC bool tvb_ascii_isdigit	(	tvbuff_t *	tvb,
		const int	offset,
		const int	length
	)

Iterates over the provided portion of the tvb checking that each byte is an ascii digit. Returns true if all bytes are digits, false otherwise

tvb_ascii_isprint()

WS_DLL_PUBLIC bool tvb_ascii_isprint	(	tvbuff_t *	tvb,
		const int	offset,
		const int	length
	)

Iterates over the provided portion of the tvb checking that each byte is an ascii printable character. Returns true if all bytes are printable, false otherwise

tvb_bcd_dig_to_str_be()

WS_DLL_PUBLIC const char * tvb_bcd_dig_to_str_be	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		const int	len,
		const dgt_set_t *	dgt,
		bool	skip_first
	)

Given a tvbuff, an offset into the tvbuff, and a length that starts at that offset (which may be -1 for "all the way to the end of the tvbuff"), fetch BCD encoded digits from a tvbuff starting from either the low or high half byte, formatting the digits according to an input digit set, if NUL a default digit set of 0-9 returning "?" for overdecadic digits will be used. A pointer to the WMEM-allocated string will be returned. Note a tvbuff content of 0xf is considered a 'filler' and will end the conversion. Function uses big endian convetion: first digit is based on high order nibble, second digit is based on low order nibble.

tvb_bytes_to_str()

WS_DLL_PUBLIC char * tvb_bytes_to_str	(	wmem_allocator_t *	allocator,
		tvbuff_t *	tvb,
		const int	offset,
		const int	len
	)

Format a bunch of data from a tvbuff as bytes, returning a pointer to the string with the formatted data.

tvb_bytes_to_str_punct()

WS_DLL_PUBLIC char * tvb_bytes_to_str_punct	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		const int	len,
		const char	punct
	)

Format a bunch of data from a tvbuff as bytes, returning a pointer to the string with the formatted data, with "punct" as a byte separator.

tvb_captured_length_remaining()

WS_DLL_PUBLIC int tvb_captured_length_remaining	(	const tvbuff_t *	tvb,
		const int	offset
	)

Computes bytes to end of buffer, from offset (which can be negative, to indicate bytes from end of buffer). Function returns 0 if offset is either at the end of the buffer or out of bounds. No exception is thrown. You probably want tvb_reported_length_remaining instead.

tvb_child_uncompress_brotli()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_brotli	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a brotli compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_lz77()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_lz77	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft Plain LZ77 compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_lz77huff()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_lz77huff	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft LZ77+Huffman compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_lznt1()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_lznt1	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft LZNT1 compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_snappy()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_snappy	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a snappy compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to tvb if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_zlib()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_zlib	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a zlib compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_child_uncompress_zstd()

WS_DLL_PUBLIC tvbuff_t * tvb_child_uncompress_zstd	(	tvbuff_t *	parent,
		tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a ZSTD compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer attached to parent if uncompression succeeded or NULL if uncompression failed.

tvb_composite_append()

WS_DLL_PUBLIC void tvb_composite_append	(	tvbuff_t *	tvb,
		tvbuff_t *	member
	)

Append to the list of tvbuffs that make up this composite tvbuff

tvb_composite_finalize()

WS_DLL_PUBLIC void tvb_composite_finalize

(

tvbuff_t *

tvb

)

Mark a composite tvbuff as initialized. No further appends or prepends occur, data access can finally happen after this finalization.

tvb_composite_prepend()

void tvb_composite_prepend ( tvbuff_t *  tvb, tvbuff_t *  member  )

extern

Prepend to the list of tvbuffs that make up this composite tvbuff

tvb_ensure_bytes_exist()

WS_DLL_PUBLIC void tvb_ensure_bytes_exist	(	const tvbuff_t *	tvb,
		const int	offset,
		const int	length
	)

Checks that the bytes referred to by 'offset'/'length' actually exist in the buffer, and throws an exception if they aren't.

tvb_ensure_bytes_exist64()

WS_DLL_PUBLIC void tvb_ensure_bytes_exist64	(	const tvbuff_t *	tvb,
		const int	offset,
		const uint64_t	length
	)

Checks that the bytes referred to by 'offset'/'length', where 'length' is a 64-bit unsigned integer, actually exist in the buffer, and throws an exception if they aren't.

tvb_ensure_captured_length_remaining()

WS_DLL_PUBLIC unsigned tvb_ensure_captured_length_remaining	(	const tvbuff_t *	tvb,
		const int	offset
	)

Same as above, but throws an exception if the offset is out of bounds.

tvb_ensure_reported_length_remaining()

WS_DLL_PUBLIC unsigned tvb_ensure_reported_length_remaining	(	const tvbuff_t *	tvb,
		const int	offset
	)

Same as above, but throws an exception if the offset is out of bounds.

tvb_find_line_end()

WS_DLL_PUBLIC int tvb_find_line_end	(	tvbuff_t *	tvb,
		const int	offset,
		int	len,
		int *	next_offset,
		const bool	desegment
	)

Given a tvbuff, an offset into the tvbuff, and a length that starts at that offset (which may be -1 for "all the way to the end of the tvbuff"), find the end of the (putative) line that starts at the specified offset in the tvbuff, going no further than the specified length.

Return the length of the line (not counting the line terminator at the end), or, if we don't find a line terminator:

if "deseg" is true, return -1;

if "deseg" is false, return the amount of data remaining in the buffer.

If "next_offset" is not NULL, set "*next_offset" to the offset of the character past the line terminator, or past the end of the buffer if we don't find a line terminator. (It's not set if we return -1.)

tvb_find_line_end_unquoted()

WS_DLL_PUBLIC int tvb_find_line_end_unquoted	(	tvbuff_t *	tvb,
		const int	offset,
		int	len,
		int *	next_offset
	)

Given a tvbuff, an offset into the tvbuff, and a length that starts at that offset (which may be -1 for "all the way to the end of the tvbuff"), find the end of the (putative) line that starts at the specified offset in the tvbuff, going no further than the specified length.

However, treat quoted strings inside the buffer specially - don't treat newlines in quoted strings as line terminators.

Return the length of the line (not counting the line terminator at the end), or the amount of data remaining in the buffer if we don't find a line terminator.

If "next_offset" is not NULL, set "*next_offset" to the offset of the character past the line terminator, or past the end of the buffer if we don't find a line terminator.

tvb_find_tvb()

WS_DLL_PUBLIC int tvb_find_tvb	(	tvbuff_t *	haystack_tvb,
		tvbuff_t *	needle_tvb,
		const int	haystack_offset
	)

Locate a sub-tvbuff within another tvbuff, starting at position 'haystack_offset'. Returns the index of the beginning of 'needle' within 'haystack', or -1 if 'needle' is not found. The index is relative to the start of 'haystack', not 'haystack_offset'.

tvb_find_uint16()

WS_DLL_PUBLIC int tvb_find_uint16	(	tvbuff_t *	tvb,
		const int	offset,
		const int	maxlength,
		const uint16_t	needle
	)

Same as tvb_find_uint8() with 16bit needle.

tvb_find_uint8()

WS_DLL_PUBLIC int tvb_find_uint8	(	tvbuff_t *	tvb,
		const int	offset,
		const int	maxlength,
		const uint8_t	needle
	)

Find first occurrence of needle in tvbuff, starting at offset. Searches at most maxlength number of bytes; if maxlength is -1, searches to end of tvbuff. Returns the offset of the found needle, or -1 if not found. Will not throw an exception, even if maxlength exceeds boundary of tvbuff; in that case, -1 will be returned if the boundary is reached before finding needle.

tvb_format_stringzpad()

char * tvb_format_stringzpad ( wmem_allocator_t *  scope, tvbuff_t *  tvb, const int  offset, const int  size  )

extern

Like "tvb_format_text()", but for null-padded strings; don't show the null padding characters as "\000".

tvb_format_stringzpad_wsp()

char * tvb_format_stringzpad_wsp ( wmem_allocator_t *  allocator, tvbuff_t *  tvb, const int  offset, const int  size  )

extern

Like "tvb_format_text_wsp()", but for null-padded strings; don't show the null padding characters as "\000".

tvb_format_text()

WS_DLL_PUBLIC char * tvb_format_text	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		const int	size
	)

Format the data in the tvb from offset for size.

tvb_format_text_wsp()

WS_DLL_PUBLIC char * tvb_format_text_wsp	(	wmem_allocator_t *	allocator,
		tvbuff_t *	tvb,
		const int	offset,
		const int	size
	)

Like "tvb_format_text()", but for 'wsp'; don't show the characters as C-style escapes.

tvb_free()

WS_DLL_PUBLIC void tvb_free

(

tvbuff_t *

tvb

)

Free a tvbuff_t and all tvbuffs chained from it The tvbuff must be 'the 'head' (initial) tvb of a chain or must not be in a chain. If specified, a callback to free the tvbuff data will be invoked for each tvbuff free'd

tvb_free_chain()

WS_DLL_PUBLIC void tvb_free_chain

(

tvbuff_t *

tvb

)

Free the tvbuff_t and all tvbuffs chained from it. The tvbuff must be 'the 'head' (initial) tvb of a chain or must not be in a chain. If specified, a callback to free the tvbuff data will be invoked for each tvbuff free'd

tvb_get_ascii_7bits_string()

WS_DLL_PUBLIC char * tvb_get_ascii_7bits_string	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	bit_offset,
		int	no_of_chars
	)

Given an allocator scope, a tvbuff, an offset, and a length in 7-bit characters (not octets!), with the specified offset and length referring to a string in the ASCII 7bits encoding:

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_bcd_string()

WS_DLL_PUBLIC char * tvb_get_bcd_string	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		int	len,
		const dgt_set_t *	dgt,
		bool	skip_first,
		bool	odd,
		bool	bigendian
	)

Given a wmem scope, a tvbuff, an offset, a length, an input digit set, and a boolean indicator, fetch BCD-encoded digits from a tvbuff starting from either the low or high half byte of the first byte depending on the boolean indicator (true means "start with the high half byte, ignoring the low half byte", and false means "start with the low half byte and proceed to the high half byte), formating the digits into characters according to the input digit set, and return a pointer to a UTF-8 string, allocated using the wmem scope. A high-order nibble of 0xf is considered a 'filler' and will end the conversion. If odd is set the high order nibble in the last octet will be skipped. If bigendian is set then high order nibble is taken as first digit of a byte and low order nibble as second digit.

tvb_get_bits()

WS_DLL_PUBLIC uint32_t tvb_get_bits	(	tvbuff_t *	tvb,
		const unsigned	bit_offset,
		const int	no_of_bits,
		const unsigned	encoding
	)

This function has EXACTLY the same behavior as tvb_get_bits32()

tvb_get_const_stringz()

WS_DLL_PUBLIC const uint8_t * tvb_get_const_stringz	(	tvbuff_t *	tvb,
		const int	offset,
		int *	lengthp
	)

Given a tvbuff and an offset, with the offset assumed to refer to a null-terminated string, find the length of that string (and throw an exception if the tvbuff ends before we find the null), allocate a buffer big enough to hold the string, copy the string into it, and return a pointer to the string. Also return the length of the string (including the terminating null) through a pointer.

This returns a constant (unmodifiable) string that does not need to be freed; instead, it will automatically be freed once the next packet is dissected.

It is slightly more efficient than the other routines, but does NOT do any translation to UTF-8 - the string consists of the raw octets of the string, in whatever encoding they happen to be in, and, if the string is not valid in that encoding, with invalid octet sequences as they are in the packet.

This function is deprecated because it does no validation of the string encoding. Do not use in new code. Prefer other APIs such as: tvb_get_stringz_enc() proto_tree_add_item_ret_string_and_length() tvb_strsize() and validate the pointed to memory region manually.

tvb_get_etsi_ts_102_221_annex_a_string()

WS_DLL_PUBLIC char * tvb_get_etsi_ts_102_221_annex_a_string	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		int	length
	)

Given an allocator scope, a tvbuff, an offset, and a length in octets with the specified offset and length referring to a string in the ETSI TS 102 221 Annex A encodings; if not:

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_ipv4()

WS_DLL_PUBLIC uint32_t tvb_get_ipv4	(	tvbuff_t *	tvb,
		const int	offset
	)

Fetch an IPv4 address, in network byte order. We do not convert it to host byte order; we leave it in network byte order, as that's what its callers expect.

tvb_get_ipv4_addr_with_prefix_len()

int tvb_get_ipv4_addr_with_prefix_len ( tvbuff_t *  tvb, int  offset, ws_in4_addr *  addr, uint32_t  prefix_len  )

extern

Fetches an IPv4 address from a tvbuff and masks out bits other than those covered by a prefix length

Parameters

tvb	tvbuff to read an IPv4 address from
offset	offset in the tvbuff to read the IPv4 address from
addr	memory location where the IPv4 address read should be stored
prefix_len	the length of the prefix (in bits)

Returns

the length (in bytes) of the address on success, or -1 on failure

tvb_get_ipv6_addr_with_prefix_len()

int tvb_get_ipv6_addr_with_prefix_len ( tvbuff_t *  tvb, int  offset, ws_in6_addr *  addr, uint32_t  prefix_len  )

extern

Fetches an IPv6 address from a tvbuff and masks out bits other than those covered by a prefix length

Parameters

tvb	tvbuff to read an IPv6 address from
offset	offset in the tvbuff to read the IPv6 address from
addr	memory location where the IPv6 address read should be stored
prefix_len	the length of the prefix (in bits)

Returns

the length (in bytes) of the address on success, or -1 on failure

tvb_get_ptr()

WS_DLL_PUBLIC const uint8_t * tvb_get_ptr	(	tvbuff_t *	tvb,
		const int	offset,
		const int	length
	)

WARNING! This function is possibly expensive, temporarily allocating another copy of the packet data. Furthermore, it's dangerous because once this pointer is given to the user, there's no guarantee that the user will honor the 'length' and not overstep the boundaries of the buffer.

If you're thinking of using tvb_get_ptr, STOP WHAT YOU ARE DOING IMMEDIATELY. Go take a break. Consider that tvb_get_ptr hands you a raw, unprotected pointer that you can easily use to create a security vulnerability or otherwise crash Wireshark. Then consider that you can probably find a function elsewhere in this file that does exactly what you want in a much more safe and robust manner.

The returned pointer is data that is internal to the tvbuff, so do not attempt to free it. Don't modify the data, either, because another tvbuff that might be using this tvbuff may have already copied that portion of the data (sometimes tvbuff's need to make copies of data, but that's the internal implementation that you need not worry about). Assume that the uint8_t* points to read-only data that the tvbuff manages.

Return a pointer into our buffer if the data asked for via 'offset'/'length' is contiguous (which might not be the case for a "composite" tvbuff). If the data is not contiguous, a tvb_memdup() is called for the entire buffer and the pointer to the newly-contiguous data is returned. This dynamically- allocated memory will be freed when the tvbuff is freed, after the tvbuff_free_cb_t() is called, if any.

tvb_get_raw_bytes_as_stringz()

WS_DLL_PUBLIC int tvb_get_raw_bytes_as_stringz	(	tvbuff_t *	tvb,
		const int	offset,
		const unsigned	bufsize,
		uint8_t *	buffer
	)

Looks for a NUL byte in tvbuff and copies no more than bufsize number of bytes, including terminating NUL, to buffer. Returns number of bytes copied (not including terminating NUL).

When processing a packet where the remaining number of bytes is less than bufsize, an exception is not thrown if the end of the packet is reached before the NUL is found. The byte buffer is guaranteed to have a terminating NUL.

tvb_get_string_enc()

WS_DLL_PUBLIC uint8_t * tvb_get_string_enc	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		const int	length,
		const unsigned	encoding
	)

Given an allocator scope, a tvbuff, a byte offset, a byte length, and a string encoding, with the specified offset and length referring to a string in the specified encoding:

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_stringz_enc()

WS_DLL_PUBLIC uint8_t * tvb_get_stringz_enc	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		int *	lengthp,
		const unsigned	encoding
	)

Given an allocator scope, a tvbuff, a byte offset, a pointer to a int, and a string encoding, with the specified offset referring to a null-terminated string in the specified encoding:

find the length of that string (and throw an exception if the tvbuff ends before we find the null);

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

if the pointer to the int is non-null, set the int to which it points to the length of the string;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_stringzpad()

WS_DLL_PUBLIC uint8_t * tvb_get_stringzpad	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		const int	length,
		const unsigned	encoding
	)

Given an allocator scope, a tvbuff, a byte offset, a byte length, and a string encoding, with the specified offset and length referring to a null-padded string in the specified encoding:

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_token_len()

WS_DLL_PUBLIC int tvb_get_token_len	(	tvbuff_t *	tvb,
		const int	offset,
		int	len,
		int *	next_offset,
		const bool	desegment
	)

Given a tvbuff, an offset into the tvbuff, and a length that starts at that offset (which may be -1 for "all the way to the end of the tvbuff"), find the end of the token that starts at the specified offset in the tvbuff, going no further than the specified length.

Return the length of the token, or, if we don't find a terminator:

if "deseg" is true, return -1;

if "deseg" is false, return the amount of data remaining in the buffer.

Set "*next_offset" to the offset of the character past the terminator, or past the end of the buffer if we don't find a line terminator. (It's not set if we return -1.)

tvb_get_ts_23_038_7bits_string_packed()

WS_DLL_PUBLIC char * tvb_get_ts_23_038_7bits_string_packed	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	bit_offset,
		int	no_of_chars
	)

Given an allocator scope, a tvbuff, a bit offset, and a length in 7-bit characters (not octets!), with the specified offset and length referring to a string in the 3GPP TS 23.038 7bits encoding, with code points packed into 7 bits:

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_ts_23_038_7bits_string_unpacked()

WS_DLL_PUBLIC char * tvb_get_ts_23_038_7bits_string_unpacked	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		int	length
	)

Given an allocator scope, a tvbuff, an offset, and a length in octets with the specified offset and length referring to a string in the 3GPP TS 23.038 7bits encoding, with one octet per code poiint (the 8th bit of each octet should be 0; if not, the octet is invalid):

allocate a buffer using the specified scope;

convert the string from the specified encoding to UTF-8, possibly mapping some characters or invalid octet sequences to the Unicode REPLACEMENT CHARACTER, and put the resulting UTF-8 string, plus a trailing '\0', into that buffer;

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the string does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_get_varint()

WS_DLL_PUBLIC unsigned tvb_get_varint	(	tvbuff_t *	tvb,
		unsigned	offset,
		unsigned	maxlen,
		uint64_t *	value,
		const unsigned	encoding
	)

Extract a variable length integer from a tvbuff. Each byte in a varint, except the last byte, has the most significant bit (msb) set – this indicates that there are further bytes to come. For example, 1010 1100 0000 0010 is 300

Parameters

tvb	The tvbuff in which we are extracting integer.
offset	The offset in tvb from which we begin trying to extract integer.
maxlen	The maximum distance from offset that we may try to extract integer
value	if parsing succeeds, parsed varint will store here.
encoding	The ENC_* that defines the format (e.g., ENC_VARINT_PROTOBUF, ENC_VARINT_QUIC, ENC_VARINT_ZIGZAG, ENC_VARINT_SDNV)

Returns

the length of this varint in tvb. 0 means parsing failed.

tvb_memcpy()

WS_DLL_PUBLIC void * tvb_memcpy	(	tvbuff_t *	tvb,
		void *	target,
		const int	offset,
		size_t	length
	)

Returns target for convenience. Does not suffer from possible expense of tvb_get_ptr(), since this routine is smart enough to copy data in chunks if the request range actually exists in different "real" tvbuffs. This function assumes that the target memory is already allocated; it does not allocate or free the target memory.

tvb_memdup()

WS_DLL_PUBLIC void * tvb_memdup	(	wmem_allocator_t *	scope,
		tvbuff_t *	tvb,
		const int	offset,
		size_t	length
	)

Given an allocator scope, a tvbuff, a byte offset, a byte length:

allocate a buffer using the specified scope;

copy the data from the tvbuff specified by the offset and length into that buffer, using tvb_memcpy();

and return a pointer to the buffer.

Throws an exception if the tvbuff ends before the data being copied does.

If scope is set to NULL it is the user's responsibility to wmem_free() the memory allocated. Otherwise memory is automatically freed when the scope lifetime is reached.

tvb_memeql()

WS_DLL_PUBLIC int tvb_memeql	(	tvbuff_t *	tvb,
		const int	offset,
		const uint8_t *	str,
		size_t	size
	)

Call memcmp after checking if enough chars left, returning 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.

tvb_new_composite()

WS_DLL_PUBLIC tvbuff_t * tvb_new_composite

(

void

)

Create an empty composite tvbuff.

tvb_new_octet_aligned()

WS_DLL_PUBLIC tvbuff_t * tvb_new_octet_aligned	(	tvbuff_t *	tvb,
		uint32_t	bit_offset,
		int32_t	no_of_bits
	)

Extracts 'number of bits' starting at 'bit offset'. Returns a pointer to a newly initialized g_malloc'd REAL_DATA tvbuff with the bits octet aligned. Bits are counted from MSB (0) to LSB (7) within octets.

tvb_new_octet_right_aligned()

WS_DLL_PUBLIC tvbuff_t * tvb_new_octet_right_aligned	(	tvbuff_t *	tvb,
		uint32_t	bit_offset,
		int32_t	no_of_bits
	)

Extracts 'number of bits' starting at 'bit offset'. Bits are counted from LSB (0) to MSB (7) within octets.

tvb_new_real_data()

WS_DLL_PUBLIC tvbuff_t * tvb_new_real_data	(	const uint8_t *	data,
		const unsigned	length,
		const int	reported_length
	)

Create a tvbuff backed by existing data. Can throw ReportedBoundsError. Normally, a callback to free the data should be registered using tvb_set_free_cb(); when this tvbuff is freed, then your callback will be called, and at that time you can free your original data.

tvb_new_subset_length()

WS_DLL_PUBLIC tvbuff_t * tvb_new_subset_length	(	tvbuff_t *	backing,
		const int	backing_offset,
		const int	reported_length
	)

Similar to tvb_new_subset_length_caplen() but with captured length calculated to fit within the existing captured length and the specified reported length. Can throw ReportedBoundsError.

tvb_new_subset_length_caplen()

WS_DLL_PUBLIC tvbuff_t * tvb_new_subset_length_caplen	(	tvbuff_t *	backing,
		const int	backing_offset,
		const int	backing_length,
		const int	reported_length
	)

Create a tvbuff that's a subset of another tvbuff, with the captured length explicitly given. You probably want tvb_new_subset_length() or tvb_new_subset_remaining() instead.

Parameters

backing	The backing tvbuff onto which the new tvbuff is a view
backing_offset	If positive, is the offset from the beginning of the backing tvbuff at which the new tvbuff's data begins, and, if negative, is the offset from the end of the backing tvbuff at which the new tvbuff's data begins.
backing_length	The length of the data to include in the new tvbuff, starting with the byte at 'backing_offset'; if -1, it means "to the end of the backing tvbuff". It can be 0, although the usefulness of the buffer would be rather limited. The length actually included will be no more than the reported length.
reported_length	The reported length of the new tvbuff; if -1, it means "the reported length to the end of the backing tvbuff". It can be 0, although the usefulness of the buffer would be rather limited.

Returns

A tvbuff that is a subset of the backing tvbuff beginning at backing_offset (which is offset 0 in the subset) and with the given reported_length, with captured length no more than backing_length.

Note

In most cases use tvb_new_subset_length() (or equivalently, pass -1 as 'backing_length') or tvb_new_subset_remaining() instead. Use this when the backing tvbuff includes bytes at the end that must not be included in the subset regardless of the reported length, such as an FCS or padding. In such cases it may still be simpler to call tvb_new_subset_length() twice, once to remove the trailing bytes and once to select the chosen payload bytes.

Warning

Will throw BoundsError if 'backing_offset'/'length' is beyond the bounds of the backing tvbuff. Can throw ReportedBoundsError.

tvb_new_subset_remaining()

WS_DLL_PUBLIC tvbuff_t * tvb_new_subset_remaining	(	tvbuff_t *	backing,
		const int	backing_offset
	)

Similar to tvb_new_subset_length_caplen() but with backing_length and reported_length set to -1. Can throw ReportedBoundsError.

tvb_reported_length_remaining()

WS_DLL_PUBLIC int tvb_reported_length_remaining	(	const tvbuff_t *	tvb,
		const int	offset
	)

Computes bytes of reported packet data to end of buffer, from offset (which can be negative, to indicate bytes from end of buffer). Function returns 0 if offset is either at the end of the buffer or out of bounds. No exception is thrown.

tvb_set_child_real_data_tvbuff()

WS_DLL_PUBLIC void tvb_set_child_real_data_tvbuff	(	tvbuff_t *	parent,
		tvbuff_t *	child
	)

Attach a "real" tvbuff to a parent tvbuff. This connection is used during a tvb_free_chain()... the "child" "real" tvbuff acts as if it is part of the chain-of-creation of the parent tvbuff, although it isn't. This is useful if you need to take the data from some tvbuff, run some operation on it, like decryption or decompression, and make a new tvbuff from it, yet want the new tvbuff to be part of the chain. The reality is that the new tvbuff is part of the "chain of creation", but in a way that these tvbuff routines are ignorant of. Use this function to make the tvbuff routines knowledgable of this fact.

tvb_set_fragment()

WS_DLL_PUBLIC void tvb_set_fragment

(

tvbuff_t *

tvb

)

Set the "this is a fragment" flag. This affects whether FragmentBoundsError is thrown instead of ContainedBoundsError or ReportedBoundsError.

tvb_set_free_cb()

WS_DLL_PUBLIC void tvb_set_free_cb	(	tvbuff_t *	tvb,
		const tvbuff_free_cb_t	func
	)

Set a callback function to call when a tvbuff is actually freed One argument is passed to that callback — a void* that points to the real data. Obviously, this only applies to a "real" tvbuff.

tvb_set_reported_length()

WS_DLL_PUBLIC void tvb_set_reported_length	(	tvbuff_t *	tvb,
		const unsigned	reported_length
	)

Set the reported length of a tvbuff to a given value; used for protocols whose headers contain an explicit length and where the calling dissector's payload may include padding as well as the packet for this protocol.

Also adjusts the available and contained length.

tvb_skip_wsp()

WS_DLL_PUBLIC int tvb_skip_wsp	(	tvbuff_t *	tvb,
		const int	offset,
		const int	maxlength
	)

Copied from the mgcp dissector. (This function should be moved to /epan ) tvb_skip_wsp - Returns the position in tvb of the first non-whitespace character following offset or offset + maxlength -1 whichever is smaller.

Parameters: tvb - The tvbuff in which we are skipping whitespace. offset - The offset in tvb from which we begin trying to skip whitespace. maxlength - The maximum distance from offset that we may try to skip whitespace.

Returns: The position in tvb of the first non-whitespace character following offset or offset + maxlength -1 whichever is smaller.

tvb_strncaseeql()

WS_DLL_PUBLIC int tvb_strncaseeql	(	tvbuff_t *	tvb,
		const int	offset,
		const char *	str,
		const size_t	size
	)

Call g_ascii_strncasecmp after checking if enough chars left, returning 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.

tvb_strneql()

WS_DLL_PUBLIC int tvb_strneql	(	tvbuff_t *	tvb,
		const int	offset,
		const char *	str,
		const size_t	size
	)

Call strncmp after checking if enough chars left, returning 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.

tvb_strnlen()

WS_DLL_PUBLIC int tvb_strnlen	(	tvbuff_t *	tvb,
		const int	offset,
		const unsigned	maxlength
	)

Find length of string by looking for end of zero terminated string, up to 'maxlength' characters'; if 'maxlength' is -1, searches to end of tvbuff. Returns -1 if 'maxlength' reached before finding EOS.

tvb_strsize()

WS_DLL_PUBLIC unsigned tvb_strsize	(	tvbuff_t *	tvb,
		const int	offset
	)

Find size of stringz (NUL-terminated string) by looking for terminating NUL. The size of the string includes the terminating NUL.

If the NUL isn't found, it throws the appropriate exception.

tvb_uncompress_brotli()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_brotli	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a brotli compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress_brotli to simplify memory management.

tvb_uncompress_lz77()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_lz77	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft Plain LZ77 compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress_lz77 to simplify memory management.

tvb_uncompress_lz77huff()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_lz77huff	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft LZ77+Huffman compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress_lz77huff to simplify memory management.

tvb_uncompress_lznt1()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_lznt1	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a Microsoft LZNT1 compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress_lznt1 to simplify memory management.

tvb_uncompress_snappy()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_snappy	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a snappy compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

tvb_uncompress_zlib()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_zlib	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a zlib compressed packet inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress to simplify memory management.

tvb_uncompress_zstd()

WS_DLL_PUBLIC tvbuff_t * tvb_uncompress_zstd	(	tvbuff_t *	tvb,
		const int	offset,
		int	comprlen
	)

Uncompresses a ZSTD compressed payload inside a tvbuff at offset with length comprlen. Returns an uncompressed tvbuffer if uncompression succeeded or NULL if uncompression failed.

The returned tvbuffer must be freed with tvb_free or added to the chain of another tvbuffer to avoid a memory leak. Consider using tvb_child_uncompress_zstd to simplify memory management.

tvb_unicode_strsize()

WS_DLL_PUBLIC unsigned tvb_unicode_strsize	(	tvbuff_t *	tvb,
		const int	offset
	)

Find size of UCS-2 or UTF-16 stringz (NUL-terminated string) by looking for terminating 16-bit NUL. The size of the string includes the terminating NUL.

If the NUL isn't found, it throws the appropriate exception.

tvb_utf_8_isprint()

WS_DLL_PUBLIC bool tvb_utf_8_isprint	(	tvbuff_t *	tvb,
		const int	offset,
		const int	length
	)

Iterates over the provided portion of the tvb checking that it is valid UTF-8 consisting entirely of printable characters. (The characters must be complete; if the portion ends in a partial sequence that could begin a valid character, this returns false.) The length may be -1 for "all the way to the end of the tvbuff". Returns true if printable, false otherwise

See also

isprint_utf8_string()

tvb_ws_mempbrk_pattern_uint8()

WS_DLL_PUBLIC int tvb_ws_mempbrk_pattern_uint8	(	tvbuff_t *	tvb,
		const int	offset,
		const int	maxlength,
		const ws_mempbrk_pattern *	pattern,
		unsigned char *	found_needle
	)

Find first occurrence of any of the needles of the pre-compiled pattern in tvbuff, starting at offset. The passed in pattern must have been "compiled" before-hand, using ws_mempbrk_compile(). Searches at most maxlength number of bytes. Returns the offset of the found needle, or -1 if not found and the found needle. Will not throw an exception, even if maxlength exceeds boundary of tvbuff; in that case, -1 will be returned if the boundary is reached before finding needle.