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wireshark/epan/tvbuff.c

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/* tvbuff.c
*
* Testy, Virtual(-izable) Buffer of guint8*'s
*
* "Testy" -- the buffer gets mad when an attempt to access data
* beyond the bounds of the buffer. An exception is thrown.
*
* "Virtual" -- the buffer can have its own data, can use a subset of
* the data of a backing tvbuff, or can be a composite of
* other tvbuffs.
*
* Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
*
* Code to convert IEEE floating point formats to native floating point
* derived from code Copyright (c) Ashok Narayanan, 2000
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "wsutil/pint.h"
#include "wsutil/sign_ext.h"
#include "wsutil/unicode-utils.h"
#include "wsutil/nstime.h"
#include "wsutil/time_util.h"
#include "wsutil/ws_mempbrk.h"
#include "tvbuff.h"
#include "tvbuff-int.h"
#include "strutil.h"
#include "to_str.h"
#include "charsets.h"
#include "proto.h" /* XXX - only used for DISSECTOR_ASSERT, probably a new header file? */
#include "exceptions.h"
/*
* Just make sure we include the prototype for strptime as well
* (needed for glibc 2.2) but make sure we do this only if not
* yet defined.
*/
#include <time.h>
/*#ifndef HAVE_STRPTIME*/
#ifndef strptime
#include "wsutil/strptime.h"
#endif
/*#endif*/
static guint64
_tvb_get_bits64(tvbuff_t *tvb, guint bit_offset, const gint total_no_of_bits);
static inline gint
_tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset);
static inline const guint8*
ensure_contiguous(tvbuff_t *tvb, const gint offset, const gint length);
static inline guint8 *
tvb_get_raw_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, const gint length);
tvbuff_t *
tvb_new(const struct tvb_ops *ops)
{
tvbuff_t *tvb;
gsize size = ops->tvb_size;
g_assert(size >= sizeof(*tvb));
tvb = (tvbuff_t *) g_slice_alloc(size);
tvb->next = NULL;
tvb->ops = ops;
tvb->initialized = FALSE;
tvb->flags = 0;
tvb->length = 0;
tvb->reported_length = 0;
tvb->real_data = NULL;
tvb->raw_offset = -1;
tvb->ds_tvb = NULL;
return tvb;
}
static void
tvb_free_internal(tvbuff_t *tvb)
{
gsize size;
DISSECTOR_ASSERT(tvb);
if (tvb->ops->tvb_free)
tvb->ops->tvb_free(tvb);
size = tvb->ops->tvb_size;
g_slice_free1(size, tvb);
}
/* XXX: just call tvb_free_chain();
* Not removed so that existing dissectors using tvb_free() need not be changed.
* I'd argue that existing calls to tvb_free() should have actually beeen
* calls to tvb_free_chain() although the calls were OK as long as no
* subsets, etc had been created on the tvb. */
void
tvb_free(tvbuff_t *tvb)
{
tvb_free_chain(tvb);
}
void
tvb_free_chain(tvbuff_t *tvb)
{
tvbuff_t *next_tvb;
DISSECTOR_ASSERT(tvb);
while (tvb) {
next_tvb = tvb->next;
tvb_free_internal(tvb);
tvb = next_tvb;
}
}
tvbuff_t *
tvb_new_chain(tvbuff_t *parent, tvbuff_t *backing)
{
tvbuff_t *tvb = tvb_new_proxy(backing);
tvb_add_to_chain(parent, tvb);
return tvb;
}
void
tvb_add_to_chain(tvbuff_t *parent, tvbuff_t *child)
{
tvbuff_t *tmp = child;
DISSECTOR_ASSERT(parent);
DISSECTOR_ASSERT(child);
while (child) {
tmp = child;
child = child->next;
tmp->next = parent->next;
parent->next = tmp;
}
}
/*
* Check whether that offset goes more than one byte past the
* end of the buffer.
*
* If not, return 0; otherwise, return exception
*/
static inline int
validate_offset(const tvbuff_t *tvb, const guint abs_offset)
{
if (G_LIKELY(abs_offset <= tvb->length))
return 0;
else if (abs_offset <= tvb->reported_length)
return BoundsError;
else if (tvb->flags & TVBUFF_FRAGMENT)
return FragmentBoundsError;
else
return ReportedBoundsError;
}
static inline int
compute_offset(const tvbuff_t *tvb, const gint offset, guint *offset_ptr)
{
if (offset >= 0) {
/* Positive offset - relative to the beginning of the packet. */
if ((guint) offset <= tvb->length) {
*offset_ptr = offset;
} else if ((guint) offset <= tvb->reported_length) {
return BoundsError;
} else if (tvb->flags & TVBUFF_FRAGMENT) {
return FragmentBoundsError;
} else {
return ReportedBoundsError;
}
}
else {
/* Negative offset - relative to the end of the packet. */
if ((guint) -offset <= tvb->length) {
*offset_ptr = tvb->length + offset;
} else if ((guint) -offset <= tvb->reported_length) {
return BoundsError;
} else if (tvb->flags & TVBUFF_FRAGMENT) {
return FragmentBoundsError;
} else {
return ReportedBoundsError;
}
}
return 0;
}
static inline int
compute_offset_and_remaining(const tvbuff_t *tvb, const gint offset, guint *offset_ptr, guint *rem_len)
{
int exception;
exception = compute_offset(tvb, offset, offset_ptr);
if (!exception)
*rem_len = tvb->length - *offset_ptr;
return exception;
}
/* Computes the absolute offset and length based on a possibly-negative offset
* and a length that is possible -1 (which means "to the end of the data").
* Returns integer indicating whether the offset is in bounds (0) or
* not (exception number). The integer ptrs are modified with the new offset and length.
* No exception is thrown.
*
* XXX - we return success (0), if the offset is positive and right
* after the end of the tvbuff (i.e., equal to the length). We do this
* so that a dissector constructing a subset tvbuff for the next protocol
* will get a zero-length tvbuff, not an exception, if there's no data
* left for the next protocol - we want the next protocol to be the one
* that gets an exception, so the error is reported as an error in that
* protocol rather than the containing protocol. */
static inline int
check_offset_length_no_exception(const tvbuff_t *tvb,
const gint offset, gint const length_val,
guint *offset_ptr, guint *length_ptr)
{
guint end_offset;
int exception;
DISSECTOR_ASSERT(offset_ptr);
DISSECTOR_ASSERT(length_ptr);
/* Compute the offset */
exception = compute_offset(tvb, offset, offset_ptr);
if (exception)
return exception;
if (length_val < -1) {
/* XXX - ReportedBoundsError? */
return BoundsError;
}
/* Compute the length */
if (length_val == -1)
*length_ptr = tvb->length - *offset_ptr;
else
*length_ptr = length_val;
/*
* Compute the offset of the first byte past the length.
*/
end_offset = *offset_ptr + *length_ptr;
/*
* Check for an overflow
*/
if (end_offset < *offset_ptr)
return BoundsError;
return validate_offset(tvb, end_offset);
}
/* Checks (+/-) offset and length and throws an exception if
* either is out of bounds. Sets integer ptrs to the new offset
* and length. */
static inline void
check_offset_length(const tvbuff_t *tvb,
const gint offset, gint const length_val,
guint *offset_ptr, guint *length_ptr)
{
int exception;
exception = check_offset_length_no_exception(tvb, offset, length_val, offset_ptr, length_ptr);
if (exception)
THROW(exception);
}
void
tvb_check_offset_length(const tvbuff_t *tvb,
const gint offset, gint const length_val,
guint *offset_ptr, guint *length_ptr)
{
check_offset_length(tvb, offset, length_val, offset_ptr, length_ptr);
}
static const unsigned char left_aligned_bitmask[] = {
0xff,
0x80,
0xc0,
0xe0,
0xf0,
0xf8,
0xfc,
0xfe
};
tvbuff_t *
tvb_new_octet_aligned(tvbuff_t *tvb, guint32 bit_offset, gint32 no_of_bits)
{
tvbuff_t *sub_tvb = NULL;
guint32 byte_offset;
gint32 datalen, i;
guint8 left, right, remaining_bits, *buf;
const guint8 *data;
DISSECTOR_ASSERT(tvb && tvb->initialized);
byte_offset = bit_offset >> 3;
left = bit_offset % 8; /* for left-shifting */
right = 8 - left; /* for right-shifting */
if (no_of_bits == -1) {
datalen = _tvb_captured_length_remaining(tvb, byte_offset);
remaining_bits = 0;
} else {
datalen = no_of_bits >> 3;
remaining_bits = no_of_bits % 8;
if (remaining_bits) {
datalen++;
}
}
/* already aligned -> shortcut */
if ((left == 0) && (remaining_bits == 0)) {
return tvb_new_subset(tvb, byte_offset, datalen, -1);
}
DISSECTOR_ASSERT(datalen>0);
/* if at least one trailing byte is available, we must use the content
* of that byte for the last shift (i.e. tvb_get_ptr() must use datalen + 1
* if non extra byte is available, the last shifted byte requires
* special treatment
*/
if (_tvb_captured_length_remaining(tvb, byte_offset) > datalen) {
data = ensure_contiguous(tvb, byte_offset, datalen + 1); /* tvb_get_ptr */
/* Do this allocation AFTER tvb_get_ptr() (which could throw an exception) */
buf = (guint8 *)g_malloc(datalen);
/* shift tvb data bit_offset bits to the left */
for (i = 0; i < datalen; i++)
buf[i] = (data[i] << left) | (data[i+1] >> right);
} else {
data = ensure_contiguous(tvb, byte_offset, datalen); /* tvb_get_ptr() */
/* Do this allocation AFTER tvb_get_ptr() (which could throw an exception) */
buf = (guint8 *)g_malloc(datalen);
/* shift tvb data bit_offset bits to the left */
for (i = 0; i < (datalen-1); i++)
buf[i] = (data[i] << left) | (data[i+1] >> right);
buf[datalen-1] = data[datalen-1] << left; /* set last octet */
}
buf[datalen-1] &= left_aligned_bitmask[remaining_bits];
sub_tvb = tvb_new_child_real_data(tvb, buf, datalen, datalen);
tvb_set_free_cb(sub_tvb, g_free);
return sub_tvb;
}
static tvbuff_t *
tvb_generic_clone_offset_len(tvbuff_t *tvb, guint offset, guint len)
{
tvbuff_t *cloned_tvb;
guint8 *data = (guint8 *) g_malloc(len);
tvb_memcpy(tvb, data, offset, len);
cloned_tvb = tvb_new_real_data(data, len, len);
tvb_set_free_cb(cloned_tvb, g_free);
return cloned_tvb;
}
tvbuff_t *
tvb_clone_offset_len(tvbuff_t *tvb, guint offset, guint len)
{
if (tvb->ops->tvb_clone) {
tvbuff_t *cloned_tvb;
cloned_tvb = tvb->ops->tvb_clone(tvb, offset, len);
if (cloned_tvb)
return cloned_tvb;
}
return tvb_generic_clone_offset_len(tvb, offset, len);
}
tvbuff_t *
tvb_clone(tvbuff_t *tvb)
{
return tvb_clone_offset_len(tvb, 0, tvb->length);
}
guint
tvb_captured_length(const tvbuff_t *tvb)
{
DISSECTOR_ASSERT(tvb && tvb->initialized);
return tvb->length;
}
/* For tvbuff internal use */
static inline gint
_tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset)
{
guint abs_offset, rem_length;
int exception;
exception = compute_offset_and_remaining(tvb, offset, &abs_offset, &rem_length);
if (exception)
return 0;
return rem_length;
}
gint
tvb_captured_length_remaining(const tvbuff_t *tvb, const gint offset)
{
guint abs_offset, rem_length;
int exception;
DISSECTOR_ASSERT(tvb && tvb->initialized);
exception = compute_offset_and_remaining(tvb, offset, &abs_offset, &rem_length);
if (exception)
return 0;
return rem_length;
}
guint
tvb_ensure_captured_length_remaining(const tvbuff_t *tvb, const gint offset)
{
guint abs_offset, rem_length;
int exception;
DISSECTOR_ASSERT(tvb && tvb->initialized);
exception = compute_offset_and_remaining(tvb, offset, &abs_offset, &rem_length);
if (exception)
THROW(exception);
if (rem_length == 0) {
/*
* This routine ensures there's at least one byte available.
* There aren't any bytes available, so throw the appropriate
* exception.
*/
if (abs_offset >= tvb->reported_length) {
if (tvb->flags & TVBUFF_FRAGMENT) {
THROW(FragmentBoundsError);
} else {
THROW(ReportedBoundsError);
}
} else
THROW(BoundsError);
}
return rem_length;
}
/* Validates that 'length' bytes are available starting from
* offset (pos/neg). Does not throw an exception. */
gboolean
tvb_bytes_exist(const tvbuff_t *tvb, const gint offset, const gint length)
{
guint abs_offset, abs_length;
int exception;
DISSECTOR_ASSERT(tvb && tvb->initialized);
exception = check_offset_length_no_exception(tvb, offset, length, &abs_offset, &abs_length);
if (exception)
return FALSE;
return TRUE;
}
/* Validates that 'length' bytes are available starting from
* offset (pos/neg). Throws an exception if they aren't. */
void
tvb_ensure_bytes_exist(const tvbuff_t *tvb, const gint offset, const gint length)
{
guint real_offset, end_offset;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/*
* -1 doesn't mean "until end of buffer", as that's pointless
* for this routine. We must treat it as a Really Large Positive
* Number, so that we throw an exception; we throw
* ReportedBoundsError, as if it were past even the end of a
* reassembled packet, and past the end of even the data we
* didn't capture.
*
* We do the same with other negative lengths.
*/
if (length < 0) {
THROW(ReportedBoundsError);
}
/* XXX: Below this point could be replaced with a call to
* check_offset_length with no functional change, however this is a
* *very* hot path and check_offset_length is not well-optimized for
* this case, so we eat some code duplication for a lot of speedup. */
if (offset >= 0) {
/* Positive offset - relative to the beginning of the packet. */
if ((guint) offset <= tvb->length) {
real_offset = offset;
} else if ((guint) offset <= tvb->reported_length) {
THROW(BoundsError);
} else if (tvb->flags & TVBUFF_FRAGMENT) {
THROW(FragmentBoundsError);
} else {
THROW(ReportedBoundsError);
}
}
else {
/* Negative offset - relative to the end of the packet. */
if ((guint) -offset <= tvb->length) {
real_offset = tvb->length + offset;
} else if ((guint) -offset <= tvb->reported_length) {
THROW(BoundsError);
} else if (tvb->flags & TVBUFF_FRAGMENT) {
THROW(FragmentBoundsError);
} else {
THROW(ReportedBoundsError);
}
}
/*
* Compute the offset of the first byte past the length.
*/
end_offset = real_offset + length;
/*
* Check for an overflow
*/
if (end_offset < real_offset)
THROW(BoundsError);
if (G_LIKELY(end_offset <= tvb->length))
return;
else if (end_offset <= tvb->reported_length)
THROW(BoundsError);
else if (tvb->flags & TVBUFF_FRAGMENT)
THROW(FragmentBoundsError);
else
THROW(ReportedBoundsError);
}
gboolean
tvb_offset_exists(const tvbuff_t *tvb, const gint offset)
{
guint abs_offset;
int exception;
DISSECTOR_ASSERT(tvb && tvb->initialized);
exception = compute_offset(tvb, offset, &abs_offset);
if (exception)
return FALSE;
/* compute_offset only throws an exception on >, not >= because of the
* comment above check_offset_length_no_exception, but here we want the
* opposite behaviour so we check ourselves... */
if (abs_offset < tvb->length) {
return TRUE;
}
else {
return FALSE;
}
}
guint
tvb_reported_length(const tvbuff_t *tvb)
{
DISSECTOR_ASSERT(tvb && tvb->initialized);
return tvb->reported_length;
}
gint
tvb_reported_length_remaining(const tvbuff_t *tvb, const gint offset)
{
guint abs_offset;
int exception;
DISSECTOR_ASSERT(tvb && tvb->initialized);
exception = compute_offset(tvb, offset, &abs_offset);
if (exception)
return 0;
if (tvb->reported_length >= abs_offset)
return tvb->reported_length - abs_offset;
else
return 0;
}
/* 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 data length. */
void
tvb_set_reported_length(tvbuff_t *tvb, const guint reported_length)
{
DISSECTOR_ASSERT(tvb && tvb->initialized);
if (reported_length > tvb->reported_length)
THROW(ReportedBoundsError);
tvb->reported_length = reported_length;
if (reported_length < tvb->length)
tvb->length = reported_length;
}
guint
tvb_offset_from_real_beginning_counter(const tvbuff_t *tvb, const guint counter)
{
if (tvb->ops->tvb_offset)
return tvb->ops->tvb_offset(tvb, counter);
DISSECTOR_ASSERT_NOT_REACHED();
return 0;
}
guint
tvb_offset_from_real_beginning(const tvbuff_t *tvb)
{
return tvb_offset_from_real_beginning_counter(tvb, 0);
}
static inline const guint8*
ensure_contiguous_no_exception(tvbuff_t *tvb, const gint offset, const gint length, int *pexception)
{
guint abs_offset, abs_length;
int exception;
exception = check_offset_length_no_exception(tvb, offset, length, &abs_offset, &abs_length);
if (exception) {
if (pexception)
*pexception = exception;
return NULL;
}
/*
* We know that all the data is present in the tvbuff, so
* no exceptions should be thrown.
*/
if (tvb->real_data)
return tvb->real_data + abs_offset;
if (tvb->ops->tvb_get_ptr)
return tvb->ops->tvb_get_ptr(tvb, abs_offset, abs_length);
DISSECTOR_ASSERT_NOT_REACHED();
return NULL;
}
static inline const guint8*
ensure_contiguous(tvbuff_t *tvb, const gint offset, const gint length)
{
int exception = 0;
const guint8 *p;
p = ensure_contiguous_no_exception(tvb, offset, length, &exception);
if (p == NULL) {
DISSECTOR_ASSERT(exception > 0);
THROW(exception);
}
return p;
}
static inline const guint8*
fast_ensure_contiguous(tvbuff_t *tvb, const gint offset, const guint length)
{
guint end_offset;
guint u_offset;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/* We don't check for overflow in this fast path so we only handle simple types */
DISSECTOR_ASSERT(length <= 8);
if (offset < 0 || !tvb->real_data) {
return ensure_contiguous(tvb, offset, length);
}
u_offset = offset;
end_offset = u_offset + length;
if (end_offset <= tvb->length) {
return tvb->real_data + u_offset;
}
if (end_offset > tvb->reported_length) {
if (tvb->flags & TVBUFF_FRAGMENT) {
THROW(FragmentBoundsError);
} else {
THROW(ReportedBoundsError);
}
/* not reached */
}
THROW(BoundsError);
/* not reached */
return NULL;
}
static inline const guint8*
guint8_pbrk(const guint8* haystack, size_t haystacklen, const guint8 *needles, guchar *found_needle)
{
const guint8 *result = ws_mempbrk(haystack, haystacklen, needles);
if (result && found_needle)
*found_needle = *result;
return result;
}
/************** ACCESSORS **************/
void *
tvb_memcpy(tvbuff_t *tvb, void *target, const gint offset, size_t length)
{
guint abs_offset, abs_length;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/*
* XXX - we should eliminate the "length = -1 means 'to the end
* of the tvbuff'" convention, and use other means to achieve
* that; this would let us eliminate a bunch of checks for
* negative lengths in cases where the protocol has a 32-bit
* length field.
*
* Allowing -1 but throwing an assertion on other negative
* lengths is a bit more work with the length being a size_t;
* instead, we check for a length <= 2^31-1.
*/
DISSECTOR_ASSERT(length <= 0x7FFFFFFF);
check_offset_length(tvb, offset, (gint) length, &abs_offset, &abs_length);
if (tvb->real_data) {
return memcpy(target, tvb->real_data + abs_offset, abs_length);
}
if (tvb->ops->tvb_memcpy)
return tvb->ops->tvb_memcpy(tvb, target, abs_offset, abs_length);
/* XXX, fallback to slower method */
DISSECTOR_ASSERT_NOT_REACHED();
return NULL;
}
/*
* XXX - this doesn't treat a length of -1 as an error.
* If it did, this could replace some code that calls
* "tvb_ensure_bytes_exist()" and then allocates a buffer and copies
* data to it.
*
* "composite_get_ptr()" depends on -1 not being
* an error; does anything else depend on this routine treating -1 as
* meaning "to the end of the buffer"?
*
* If scope is NULL, memory is allocated with g_malloc() and user must
* explicitly free it with g_free().
* If scope is not NULL, memory is allocated with the corresponding pool
* lifetime.
*/
void *
tvb_memdup(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, size_t length)
{
guint abs_offset, abs_length;
void *duped;
DISSECTOR_ASSERT(tvb && tvb->initialized);
check_offset_length(tvb, offset, (gint) length, &abs_offset, &abs_length);
duped = wmem_alloc(scope, abs_length);
return tvb_memcpy(tvb, duped, abs_offset, abs_length);
}
const guint8*
tvb_get_ptr(tvbuff_t *tvb, const gint offset, const gint length)
{
return ensure_contiguous(tvb, offset, length);
}
/* ---------------- */
guint8
tvb_get_guint8(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint8));
return *ptr;
}
guint16
tvb_get_ntohs(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint16));
return pntoh16(ptr);
}
guint32
tvb_get_ntoh24(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 3);
return pntoh24(ptr);
}
guint32
tvb_get_ntohl(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint32));
return pntoh32(ptr);
}
guint64
tvb_get_ntoh40(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 5);
return pntoh40(ptr);
}
gint64
tvb_get_ntohi40(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_ntoh40(tvb, offset), 40);
return (gint64)ret;
}
guint64
tvb_get_ntoh48(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 6);
return pntoh48(ptr);
}
gint64
tvb_get_ntohi48(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_ntoh48(tvb, offset), 48);
return (gint64)ret;
}
guint64
tvb_get_ntoh56(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 7);
return pntoh56(ptr);
}
gint64
tvb_get_ntohi56(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_ntoh56(tvb, offset), 56);
return (gint64)ret;
}
guint64
tvb_get_ntoh64(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint64));
return pntoh64(ptr);
}
/*
* Stuff for IEEE float handling on platforms that don't have IEEE
* format as the native floating-point format.
*
* For now, we treat only the VAX as such a platform.
*
* XXX - other non-IEEE boxes that can run UNIX include some Crays,
* and possibly other machines.
*
* It appears that the official Linux port to System/390 and
* zArchitecture uses IEEE format floating point (not a
* huge surprise).
*
* I don't know whether there are any other machines that
* could run Wireshark and that don't use IEEE format.
* As far as I know, all of the main commercial microprocessor
* families on which OSes that support Wireshark can run
* use IEEE format (x86, 68k, SPARC, MIPS, PA-RISC, Alpha,
* IA-64, and so on).
*/
#if defined(vax)
#include <math.h>
/*
* Single-precision.
*/
#define IEEE_SP_NUMBER_WIDTH 32 /* bits in number */
#define IEEE_SP_EXP_WIDTH 8 /* bits in exponent */
#define IEEE_SP_MANTISSA_WIDTH 23 /* IEEE_SP_NUMBER_WIDTH - 1 - IEEE_SP_EXP_WIDTH */
#define IEEE_SP_SIGN_MASK 0x80000000
#define IEEE_SP_EXPONENT_MASK 0x7F800000
#define IEEE_SP_MANTISSA_MASK 0x007FFFFF
#define IEEE_SP_INFINITY IEEE_SP_EXPONENT_MASK
#define IEEE_SP_IMPLIED_BIT (1 << IEEE_SP_MANTISSA_WIDTH)
#define IEEE_SP_INFINITE ((1 << IEEE_SP_EXP_WIDTH) - 1)
#define IEEE_SP_BIAS ((1 << (IEEE_SP_EXP_WIDTH - 1)) - 1)
static int
ieee_float_is_zero(const guint32 w)
{
return ((w & ~IEEE_SP_SIGN_MASK) == 0);
}
static gfloat
get_ieee_float(const guint32 w)
{
long sign;
long exponent;
long mantissa;
sign = w & IEEE_SP_SIGN_MASK;
exponent = w & IEEE_SP_EXPONENT_MASK;
mantissa = w & IEEE_SP_MANTISSA_MASK;
if (ieee_float_is_zero(w)) {
/* number is zero, unnormalized, or not-a-number */
return 0.0;
}
#if 0
/*
* XXX - how to handle this?
*/
if (IEEE_SP_INFINITY == exponent) {
/*
* number is positive or negative infinity, or a special value
*/
return (sign? MINUS_INFINITY: PLUS_INFINITY);
}
#endif
exponent = ((exponent >> IEEE_SP_MANTISSA_WIDTH) - IEEE_SP_BIAS) -
IEEE_SP_MANTISSA_WIDTH;
mantissa |= IEEE_SP_IMPLIED_BIT;
if (sign)
return -mantissa * pow(2, exponent);
else
return mantissa * pow(2, exponent);
}
/*
* Double-precision.
* We assume that if you don't have IEEE floating-point, you have a
* compiler that understands 64-bit integral quantities.
*/
#define IEEE_DP_NUMBER_WIDTH 64 /* bits in number */
#define IEEE_DP_EXP_WIDTH 11 /* bits in exponent */
#define IEEE_DP_MANTISSA_WIDTH 52 /* IEEE_DP_NUMBER_WIDTH - 1 - IEEE_DP_EXP_WIDTH */
#define IEEE_DP_SIGN_MASK G_GINT64_CONSTANT(0x8000000000000000)
#define IEEE_DP_EXPONENT_MASK G_GINT64_CONSTANT(0x7FF0000000000000)
#define IEEE_DP_MANTISSA_MASK G_GINT64_CONSTANT(0x000FFFFFFFFFFFFF)
#define IEEE_DP_INFINITY IEEE_DP_EXPONENT_MASK
#define IEEE_DP_IMPLIED_BIT (G_GINT64_CONSTANT(1) << IEEE_DP_MANTISSA_WIDTH)
#define IEEE_DP_INFINITE ((1 << IEEE_DP_EXP_WIDTH) - 1)
#define IEEE_DP_BIAS ((1 << (IEEE_DP_EXP_WIDTH - 1)) - 1)
static int
ieee_double_is_zero(const guint64 w)
{
return ((w & ~IEEE_SP_SIGN_MASK) == 0);
}
static gdouble
get_ieee_double(const guint64 w)
{
gint64 sign;
gint64 exponent;
gint64 mantissa;
sign = w & IEEE_DP_SIGN_MASK;
exponent = w & IEEE_DP_EXPONENT_MASK;
mantissa = w & IEEE_DP_MANTISSA_MASK;
if (ieee_double_is_zero(w)) {
/* number is zero, unnormalized, or not-a-number */
return 0.0;
}
#if 0
/*
* XXX - how to handle this?
*/
if (IEEE_DP_INFINITY == exponent) {
/*
* number is positive or negative infinity, or a special value
*/
return (sign? MINUS_INFINITY: PLUS_INFINITY);
}
#endif
exponent = ((exponent >> IEEE_DP_MANTISSA_WIDTH) - IEEE_DP_BIAS) -
IEEE_DP_MANTISSA_WIDTH;
mantissa |= IEEE_DP_IMPLIED_BIT;
if (sign)
return -mantissa * pow(2, exponent);
else
return mantissa * pow(2, exponent);
}
#endif
/*
* Fetches an IEEE single-precision floating-point number, in
* big-endian form, and returns a "float".
*
* XXX - should this be "double", in case there are IEEE single-
* precision numbers that won't fit in some platform's native
* "float" format?
*/
gfloat
tvb_get_ntohieee_float(tvbuff_t *tvb, const int offset)
{
#if defined(vax)
return get_ieee_float(tvb_get_ntohl(tvb, offset));
#else
union {
gfloat f;
guint32 w;
} ieee_fp_union;
ieee_fp_union.w = tvb_get_ntohl(tvb, offset);
return ieee_fp_union.f;
#endif
}
/*
* Fetches an IEEE double-precision floating-point number, in
* big-endian form, and returns a "double".
*/
gdouble
tvb_get_ntohieee_double(tvbuff_t *tvb, const int offset)
{
#if defined(vax)
union {
guint32 w[2];
guint64 dw;
} ieee_fp_union;
#else
union {
gdouble d;
guint32 w[2];
} ieee_fp_union;
#endif
#ifdef WORDS_BIGENDIAN
ieee_fp_union.w[0] = tvb_get_ntohl(tvb, offset);
ieee_fp_union.w[1] = tvb_get_ntohl(tvb, offset+4);
#else
ieee_fp_union.w[0] = tvb_get_ntohl(tvb, offset+4);
ieee_fp_union.w[1] = tvb_get_ntohl(tvb, offset);
#endif
#if defined(vax)
return get_ieee_double(ieee_fp_union.dw);
#else
return ieee_fp_union.d;
#endif
}
guint16
tvb_get_letohs(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint16));
return pletoh16(ptr);
}
guint32
tvb_get_letoh24(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 3);
return pletoh24(ptr);
}
guint32
tvb_get_letohl(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint32));
return pletoh32(ptr);
}
guint64
tvb_get_letoh40(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 5);
return pletoh40(ptr);
}
gint64
tvb_get_letohi40(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_letoh40(tvb, offset), 40);
return (gint64)ret;
}
guint64
tvb_get_letoh48(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 6);
return pletoh48(ptr);
}
gint64
tvb_get_letohi48(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_letoh48(tvb, offset), 48);
return (gint64)ret;
}
guint64
tvb_get_letoh56(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, 7);
return pletoh56(ptr);
}
gint64
tvb_get_letohi56(tvbuff_t *tvb, const gint offset)
{
guint64 ret;
ret = ws_sign_ext64(tvb_get_letoh56(tvb, offset), 56);
return (gint64)ret;
}
guint64
tvb_get_letoh64(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint64));
return pletoh64(ptr);
}
/*
* Fetches an IEEE single-precision floating-point number, in
* little-endian form, and returns a "float".
*
* XXX - should this be "double", in case there are IEEE single-
* precision numbers that won't fit in some platform's native
* "float" format?
*/
gfloat
tvb_get_letohieee_float(tvbuff_t *tvb, const int offset)
{
#if defined(vax)
return get_ieee_float(tvb_get_letohl(tvb, offset));
#else
union {
gfloat f;
guint32 w;
} ieee_fp_union;
ieee_fp_union.w = tvb_get_letohl(tvb, offset);
return ieee_fp_union.f;
#endif
}
/*
* Fetches an IEEE double-precision floating-point number, in
* little-endian form, and returns a "double".
*/
gdouble
tvb_get_letohieee_double(tvbuff_t *tvb, const int offset)
{
#if defined(vax)
union {
guint32 w[2];
guint64 dw;
} ieee_fp_union;
#else
union {
gdouble d;
guint32 w[2];
} ieee_fp_union;
#endif
#ifdef WORDS_BIGENDIAN
ieee_fp_union.w[0] = tvb_get_letohl(tvb, offset+4);
ieee_fp_union.w[1] = tvb_get_letohl(tvb, offset);
#else
ieee_fp_union.w[0] = tvb_get_letohl(tvb, offset);
ieee_fp_union.w[1] = tvb_get_letohl(tvb, offset+4);
#endif
#if defined(vax)
return get_ieee_double(ieee_fp_union.dw);
#else
return ieee_fp_union.d;
#endif
}
static inline void
validate_single_byte_ascii_encoding(const guint encoding)
{
const guint enc = encoding & ~ENC_STR_MASK;
switch (enc) {
case ENC_UTF_16:
case ENC_UCS_2:
case ENC_UCS_4:
case ENC_3GPP_TS_23_038_7BITS:
case ENC_EBCDIC:
REPORT_DISSECTOR_BUG("Invalid string encoding type passed to tvb_get_string_XXX");
break;
default:
break;
}
/* make sure something valid was set */
if (enc == 0)
REPORT_DISSECTOR_BUG("No string encoding type passed to tvb_get_string_XXX");
}
GByteArray*
tvb_get_string_bytes(tvbuff_t *tvb, const gint offset, const gint length,
const guint encoding, GByteArray *bytes, gint *endoff)
{
const gchar *ptr = (gchar*) tvb_get_raw_string(wmem_packet_scope(), tvb, offset, length);
const gchar *begin = ptr;
const gchar *end = NULL;
GByteArray *retval = NULL;
errno = EDOM;
validate_single_byte_ascii_encoding(encoding);
if (endoff) *endoff = 0;
while (*begin == ' ') begin++;
if (*begin && bytes) {
if (hex_str_to_bytes_encoding(begin, bytes, &end, encoding, FALSE)) {
if (bytes->len > 0) {
if (endoff) *endoff = offset + (gint)(end - ptr);
errno = 0;
retval = bytes;
}
}
}
return retval;
}
/* support hex-encoded time values? */
nstime_t*
tvb_get_string_time(tvbuff_t *tvb, const gint offset, const gint length,
const guint encoding, nstime_t *ns, gint *endoff)
{
const gchar *begin = (gchar*) tvb_get_raw_string(wmem_packet_scope(), tvb, offset, length);
const gchar *ptr = begin;
const gchar *end = NULL;
struct tm tm;
nstime_t* retval = NULL;
char sign = '+';
int off_hr = 0;
int off_min = 0;
int num_chars = 0;
gboolean matched = FALSE;
errno = EDOM;
validate_single_byte_ascii_encoding(encoding);
DISSECTOR_ASSERT(ns);
memset(&tm, 0, sizeof(tm));
tm.tm_isdst = -1;
ns->secs = 0;
ns->nsecs = 0;
while (*ptr == ' ') ptr++;
if (*ptr) {
/* note: sscanf is known to be inconsistent across platforms with respect
to whether a %n is counted as a return value or not, so we have to use
'>=' a lot */
if ((encoding & ENC_ISO_8601_DATE_TIME) == ENC_ISO_8601_DATE_TIME) {
/* TODO: using sscanf this many times is probably slow; might want
to parse it by hand in the future */
/* 2014-04-07T05:41:56+00:00 */
if (sscanf(ptr, "%d-%d-%d%*c%d:%d:%d%c%d:%d%n",
&tm.tm_year,
&tm.tm_mon,
&tm.tm_mday,
&tm.tm_hour,
&tm.tm_min,
&tm.tm_sec,
&sign,
&off_hr,
&off_min,
&num_chars) >= 9)
{
matched = TRUE;
}
/* no seconds is ok */
else if (sscanf(ptr, "%d-%d-%d%*c%d:%d%c%d:%d%n",
&tm.tm_year,
&tm.tm_mon,
&tm.tm_mday,
&tm.tm_hour,
&tm.tm_min,
&sign,
&off_hr,
&off_min,
&num_chars) >= 8)
{
matched = TRUE;
}
/* 2007-04-05T14:30:56Z */
else if (sscanf(ptr, "%d-%d-%d%*c%d:%d:%dZ%n",
&tm.tm_year,
&tm.tm_mon,
&tm.tm_mday,
&tm.tm_hour,
&tm.tm_min,
&tm.tm_sec,
&num_chars) >= 6)
{
matched = TRUE;
off_hr = 0;
off_min = 0;
}
/* 2007-04-05T14:30Z no seconds is ok */
else if (sscanf(ptr, "%d-%d-%d%*c%d:%dZ%n",
&tm.tm_year,
&tm.tm_mon,
&tm.tm_mday,
&tm.tm_hour,
&tm.tm_min,
&num_chars) >= 5)
{
matched = TRUE;
off_hr = 0;
off_min = 0;
}
if (matched) {
errno = 0;
end = ptr + num_chars;
tm.tm_mon--;
if (tm.tm_year > 1900) tm.tm_year -= 1900;
if (sign == '-') off_hr = -off_hr;
}
}
else if (encoding & ENC_ISO_8601_DATE) {
/* 2014-04-07 */
if (sscanf(ptr, "%d-%d-%d%n",
&tm.tm_year,
&tm.tm_mon,
&tm.tm_mday,
&num_chars) >= 3)
{
errno = 0;
end = ptr + num_chars;
tm.tm_mon--;
if (tm.tm_year > 1900) tm.tm_year -= 1900;
}
}
else if (encoding & ENC_ISO_8601_TIME) {
/* 2014-04-07 */
if (sscanf(ptr, "%d:%d:%d%n",
&tm.tm_hour,
&tm.tm_min,
&tm.tm_sec,
&num_chars) >= 2)
{
/* what should we do about day/month/year? */
/* setting it to "now" for now */
time_t time_now = time(NULL);
struct tm *tm_now = gmtime(&time_now);
tm.tm_year = tm_now->tm_year;
tm.tm_mon = tm_now->tm_mon;
tm.tm_mday = tm_now->tm_mday;
end = ptr + num_chars;
errno = 0;
}
}
else if (encoding & ENC_RFC_822 || encoding & ENC_RFC_1123) {
if (encoding & ENC_RFC_822) {
/* this will unfortunately match ENC_RFC_1123 style
strings too, partially - probably need to do this the long way */
end = strptime(ptr, "%a, %d %b %y %H:%M:%S", &tm);
if (!end) end = strptime(ptr, "%a, %d %b %y %H:%M", &tm);
if (!end) end = strptime(ptr, "%d %b %y %H:%M:%S", &tm);
if (!end) end = strptime(ptr, "%d %b %y %H:%M", &tm);
}
else if (encoding & ENC_RFC_1123) {
end = strptime(ptr, "%a, %d %b %Y %H:%M:%S", &tm);
if (!end) end = strptime(ptr, "%a, %d %b %Y %H:%M", &tm);
if (!end) end = strptime(ptr, "%d %b %Y %H:%M:%S", &tm);
if (!end) end = strptime(ptr, "%d %b %Y %H:%M", &tm);
}
if (end) {
errno = 0;
if (*end == ' ') end++;
if (g_ascii_strncasecmp(end, "UT", 2) == 0)
{
end += 2;
}
else if (g_ascii_strncasecmp(end, "GMT", 3) == 0)
{
end += 3;
}
else if (sscanf(end, "%c%2d%2d%n",
&sign,
&off_hr,
&off_min,
&num_chars) < 3)
{
errno = ERANGE;
}
if (sign == '-') off_hr = -off_hr;
}
}
}
if (errno == 0) {
ns->secs = mktime_utc (&tm);
if (off_hr > 0)
ns->secs += (off_hr * 3600) + (off_min * 60);
else if (off_hr < 0)
ns->secs -= ((-off_hr) * 3600) + (off_min * 60);
retval = ns;
if (endoff)
*endoff = (gint)(offset + (end - begin));
}
return retval;
}
/* Fetch an IPv4 address, in network byte order.
* We do *not* convert them to host byte order; we leave them in
* network byte order. */
guint32
tvb_get_ipv4(tvbuff_t *tvb, const gint offset)
{
const guint8 *ptr;
guint32 addr;
ptr = fast_ensure_contiguous(tvb, offset, sizeof(guint32));
memcpy(&addr, ptr, sizeof addr);
return addr;
}
/* Fetch an IPv6 address. */
void
tvb_get_ipv6(tvbuff_t *tvb, const gint offset, struct e_in6_addr *addr)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, sizeof(*addr));
memcpy(addr, ptr, sizeof *addr);
}
/* Fetch a GUID. */
void
tvb_get_ntohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid)
{
const guint8 *ptr = ensure_contiguous(tvb, offset, GUID_LEN);
guid->data1 = pntoh32(ptr + 0);
guid->data2 = pntoh16(ptr + 4);
guid->data3 = pntoh16(ptr + 6);
memcpy(guid->data4, ptr + 8, sizeof guid->data4);
}
void
tvb_get_letohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid)
{
const guint8 *ptr = ensure_contiguous(tvb, offset, GUID_LEN);
guid->data1 = pletoh32(ptr + 0);
guid->data2 = pletoh16(ptr + 4);
guid->data3 = pletoh16(ptr + 6);
memcpy(guid->data4, ptr + 8, sizeof guid->data4);
}
/*
* NOTE: to support code written when proto_tree_add_item() took a
* gboolean as its last argument, with FALSE meaning "big-endian"
* and TRUE meaning "little-endian", we treat any non-zero value of
* "representation" as meaning "little-endian".
*/
void
tvb_get_guid(tvbuff_t *tvb, const gint offset, e_guid_t *guid, const guint representation)
{
if (representation) {
tvb_get_letohguid(tvb, offset, guid);
} else {
tvb_get_ntohguid(tvb, offset, guid);
}
}
static const guint8 bit_mask8[] = {
0x00,
0x01,
0x03,
0x07,
0x0f,
0x1f,
0x3f,
0x7f,
0xff
};
/* Get 1 - 8 bits */
guint8
tvb_get_bits8(tvbuff_t *tvb, guint bit_offset, const gint no_of_bits)
{
return (guint8)_tvb_get_bits64(tvb, bit_offset, no_of_bits);
}
/* Get 9 - 16 bits */
guint16
tvb_get_bits16(tvbuff_t *tvb, guint bit_offset, const gint no_of_bits,const guint encoding _U_)
{
/* note that encoding has no meaning here, as the tvb is considered to contain an octet array */
return (guint16)_tvb_get_bits64(tvb, bit_offset, no_of_bits);
}
/* Get 1 - 32 bits */
guint32
tvb_get_bits32(tvbuff_t *tvb, guint bit_offset, const gint no_of_bits, const guint encoding _U_)
{
/* note that encoding has no meaning here, as the tvb is considered to contain an octet array */
return (guint32)_tvb_get_bits64(tvb, bit_offset, no_of_bits);
}
/* Get 1 - 64 bits */
guint64
tvb_get_bits64(tvbuff_t *tvb, guint bit_offset, const gint no_of_bits, const guint encoding _U_)
{
/* note that encoding has no meaning here, as the tvb is considered to contain an octet array */
return _tvb_get_bits64(tvb, bit_offset, no_of_bits);
}
/*
* This function will dissect a sequence of bits that does not need to be byte aligned; the bits
* set will be shown in the tree as ..10 10.. and the integer value returned if return_value is set.
* Offset should be given in bits from the start of the tvb.
* The function tolerates requests for more than 64 bits, but will only return the least significant 64 bits.
*/
static guint64
_tvb_get_bits64(tvbuff_t *tvb, guint bit_offset, const gint total_no_of_bits)
{
guint64 value;
guint octet_offset = bit_offset >> 3;
guint8 required_bits_in_first_octet = 8 - (bit_offset % 8);
if(required_bits_in_first_octet > total_no_of_bits)
{
/* the required bits don't extend to the end of the first octet */
guint8 right_shift = required_bits_in_first_octet - total_no_of_bits;
value = (tvb_get_guint8(tvb, octet_offset) >> right_shift) & bit_mask8[total_no_of_bits % 8];
}
else
{
guint8 remaining_bit_length = total_no_of_bits;
/* get the bits up to the first octet boundary */
value = 0;
required_bits_in_first_octet %= 8;
if(required_bits_in_first_octet != 0)
{
value = tvb_get_guint8(tvb, octet_offset) & bit_mask8[required_bits_in_first_octet];
remaining_bit_length -= required_bits_in_first_octet;
octet_offset ++;
}
/* take the biggest words, shorts or octets that we can */
while (remaining_bit_length > 7)
{
switch (remaining_bit_length >> 4)
{
case 0:
/* 8 - 15 bits. (note that 0 - 7 would have dropped out of the while() loop) */
value <<= 8;
value += tvb_get_guint8(tvb, octet_offset);
remaining_bit_length -= 8;
octet_offset ++;
break;
case 1:
/* 16 - 31 bits */
value <<= 16;
value += tvb_get_ntohs(tvb, octet_offset);
remaining_bit_length -= 16;
octet_offset += 2;
break;
case 2:
case 3:
/* 32 - 63 bits */
value <<= 32;
value += tvb_get_ntohl(tvb, octet_offset);
remaining_bit_length -= 32;
octet_offset += 4;
break;
default:
/* 64 bits (or more???) */
value = tvb_get_ntoh64(tvb, octet_offset);
remaining_bit_length -= 64;
octet_offset += 8;
break;
}
}
/* get bits from any partial octet at the tail */
if(remaining_bit_length)
{
value <<= remaining_bit_length;
value += (tvb_get_guint8(tvb, octet_offset) >> (8 - remaining_bit_length));
}
}
return value;
}
/* Get 1 - 32 bits (should be deprecated as same as tvb_get_bits32??) */
guint32
tvb_get_bits(tvbuff_t *tvb, const guint bit_offset, const gint no_of_bits, const guint encoding _U_)
{
/* note that encoding has no meaning here, as the tvb is considered to contain an octet array */
return (guint32)_tvb_get_bits64(tvb, bit_offset, no_of_bits);
}
static gint
tvb_find_guint8_generic(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
{
const guint8 *ptr;
const guint8 *result;
ptr = ensure_contiguous(tvb, abs_offset, limit); /* tvb_get_ptr() */
result = (const guint8 *) memchr(ptr, needle, limit);
if (!result)
return -1;
return (gint) ((result - ptr) + abs_offset);
}
/* 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. */
gint
tvb_find_guint8(tvbuff_t *tvb, const gint offset, const gint maxlength, const guint8 needle)
{
const guint8 *result;
guint abs_offset;
guint tvbufflen;
guint limit;
DISSECTOR_ASSERT(tvb && tvb->initialized);
check_offset_length(tvb, offset, -1, &abs_offset, &tvbufflen);
/* Only search to end of tvbuff, w/o throwing exception. */
if (maxlength == -1) {
/* No maximum length specified; search to end of tvbuff. */
limit = tvbufflen;
}
else if (tvbufflen < (guint) maxlength) {
/* Maximum length goes past end of tvbuff; search to end
of tvbuff. */
limit = tvbufflen;
}
else {
/* Maximum length doesn't go past end of tvbuff; search
to that value. */
limit = maxlength;
}
/* If we have real data, perform our search now. */
if (tvb->real_data) {
result = (const guint8 *)memchr(tvb->real_data + abs_offset, needle, limit);
if (result == NULL) {
return -1;
}
else {
return (gint) (result - tvb->real_data);
}
}
if (tvb->ops->tvb_find_guint8)
return tvb->ops->tvb_find_guint8(tvb, abs_offset, limit, needle);
return tvb_find_guint8_generic(tvb, offset, limit, needle);
}
static inline gint
tvb_pbrk_guint8_generic(tvbuff_t *tvb, guint abs_offset, guint limit, const guint8 *needles, guchar *found_needle)
{
const guint8 *ptr;
const guint8 *result;
ptr = ensure_contiguous(tvb, abs_offset, limit); /* tvb_get_ptr */
result = guint8_pbrk(ptr, limit, needles, found_needle);
if (!result)
return -1;
return (gint) ((result - ptr) + abs_offset);
}
/* Find first occurrence of any of the needles 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. */
gint
tvb_pbrk_guint8(tvbuff_t *tvb, const gint offset, const gint maxlength, const guint8 *needles, guchar *found_needle)
{
const guint8 *result;
guint abs_offset;
guint tvbufflen;
guint limit;
DISSECTOR_ASSERT(tvb && tvb->initialized);
check_offset_length(tvb, offset, -1, &abs_offset, &tvbufflen);
/* Only search to end of tvbuff, w/o throwing exception. */
if (maxlength == -1) {
/* No maximum length specified; search to end of tvbuff. */
limit = tvbufflen;
}
else if (tvbufflen < (guint) maxlength) {
/* Maximum length goes past end of tvbuff; search to end
of tvbuff. */
limit = tvbufflen;
}
else {
/* Maximum length doesn't go past end of tvbuff; search
to that value. */
limit = maxlength;
}
/* If we have real data, perform our search now. */
if (tvb->real_data) {
result = guint8_pbrk(tvb->real_data + abs_offset, limit, needles, found_needle);
if (result == NULL) {
return -1;
}
else {
return (gint) (result - tvb->real_data);
}
}
if (tvb->ops->tvb_pbrk_guint8)
return tvb->ops->tvb_pbrk_guint8(tvb, abs_offset, limit, needles, found_needle);
return tvb_pbrk_guint8_generic(tvb, abs_offset, limit, needles, found_needle);
}
/* 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.
*/
guint
tvb_strsize(tvbuff_t *tvb, const gint offset)
{
guint abs_offset, junk_length;
gint nul_offset;
DISSECTOR_ASSERT(tvb && tvb->initialized);
check_offset_length(tvb, offset, 0, &abs_offset, &junk_length);
nul_offset = tvb_find_guint8(tvb, abs_offset, -1, 0);
if (nul_offset == -1) {
/*
* OK, we hit the end of the tvbuff, so we should throw
* an exception.
*
* Did we hit the end of the captured data, or the end
* of the actual data? If there's less captured data
* than actual data, we presumably hit the end of the
* captured data, otherwise we hit the end of the actual
* data.
*/
if (tvb->length < tvb->reported_length) {
THROW(BoundsError);
} else {
if (tvb->flags & TVBUFF_FRAGMENT) {
THROW(FragmentBoundsError);
} else {
THROW(ReportedBoundsError);
}
}
}
return (nul_offset - abs_offset) + 1;
}
/* UTF-16/UCS-2 version of tvb_strsize */
/* Returns number of bytes including the (two-bytes) null terminator */
guint
tvb_unicode_strsize(tvbuff_t *tvb, const gint offset)
{
guint i = 0;
gunichar2 uchar;
DISSECTOR_ASSERT(tvb && tvb->initialized);
do {
/* Endianness doesn't matter when looking for null */
uchar = tvb_get_ntohs(tvb, offset + i);
i += 2;
} while(uchar != 0);
return i;
}
/* Find length of string by looking for end of string ('\0'), up to
* 'maxlength' characters'; if 'maxlength' is -1, searches to end
* of tvbuff.
* Returns -1 if 'maxlength' reached before finding EOS. */
gint
tvb_strnlen(tvbuff_t *tvb, const gint offset, const guint maxlength)
{
gint result_offset;
guint abs_offset, junk_length;
DISSECTOR_ASSERT(tvb && tvb->initialized);
check_offset_length(tvb, offset, 0, &abs_offset, &junk_length);
result_offset = tvb_find_guint8(tvb, abs_offset, maxlength, 0);
if (result_offset == -1) {
return -1;
}
else {
return result_offset - abs_offset;
}
}
/*
* Implement strneql etc
*/
/*
* Call strncmp after checking if enough chars left, returning 0 if
* it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
*/
gint
tvb_strneql(tvbuff_t *tvb, const gint offset, const gchar *str, const size_t size)
{
const guint8 *ptr;
ptr = ensure_contiguous_no_exception(tvb, offset, (gint)size, NULL);
if (ptr) {
int cmp = strncmp((const char *)ptr, str, size);
/*
* Return 0 if equal, -1 otherwise.
*/
return (cmp == 0 ? 0 : -1);
} else {
/*
* Not enough characters in the tvbuff to match the
* string.
*/
return -1;
}
}
/*
* Call g_ascii_strncasecmp after checking if enough chars left, returning
* 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
*/
gint
tvb_strncaseeql(tvbuff_t *tvb, const gint offset, const gchar *str, const size_t size)
{
const guint8 *ptr;
ptr = ensure_contiguous_no_exception(tvb, offset, (gint)size, NULL);
if (ptr) {
int cmp = g_ascii_strncasecmp((const char *)ptr, str, size);
/*
* Return 0 if equal, -1 otherwise.
*/
return (cmp == 0 ? 0 : -1);
} else {
/*
* Not enough characters in the tvbuff to match the
* string.
*/
return -1;
}
}
/*
* Call memcmp after checking if enough chars left, returning 0 if
* it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
*/
gint
tvb_memeql(tvbuff_t *tvb, const gint offset, const guint8 *str, size_t size)
{
const guint8 *ptr;
ptr = ensure_contiguous_no_exception(tvb, offset, (gint) size, NULL);
if (ptr) {
int cmp = memcmp(ptr, str, size);
/*
* Return 0 if equal, -1 otherwise.
*/
return (cmp == 0 ? 0 : -1);
} else {
/*
* Not enough characters in the tvbuff to match the
* string.
*/
return -1;
}
}
/*
* Format the data in the tvb from offset for length ...
*/
gchar *
tvb_format_text(tvbuff_t *tvb, const gint offset, const gint size)
{
const guint8 *ptr;
gint len;
len = (size > 0) ? size : 0;
ptr = ensure_contiguous(tvb, offset, size);
return format_text(ptr, len);
}
/*
* Format the data in the tvb from offset for length ...
*/
gchar *
tvb_format_text_wsp(tvbuff_t *tvb, const gint offset, const gint size)
{
const guint8 *ptr;
gint len;
len = (size > 0) ? size : 0;
ptr = ensure_contiguous(tvb, offset, size);
return format_text_wsp(ptr, len);
}
/*
* Like "tvb_format_text()", but for null-padded strings; don't show
* the null padding characters as "\000".
*/
gchar *
tvb_format_stringzpad(tvbuff_t *tvb, const gint offset, const gint size)
{
const guint8 *ptr, *p;
gint len;
gint stringlen;
len = (size > 0) ? size : 0;
ptr = ensure_contiguous(tvb, offset, size);
for (p = ptr, stringlen = 0; stringlen < len && *p != '\0'; p++, stringlen++)
;
return format_text(ptr, stringlen);
}
/*
* Like "tvb_format_text_wsp()", but for null-padded strings; don't show
* the null padding characters as "\000".
*/
gchar *
tvb_format_stringzpad_wsp(tvbuff_t *tvb, const gint offset, const gint size)
{
const guint8 *ptr, *p;
gint len;
gint stringlen;
len = (size > 0) ? size : 0;
ptr = ensure_contiguous(tvb, offset, size);
for (p = ptr, stringlen = 0; stringlen < len && *p != '\0'; p++, stringlen++)
;
return format_text_wsp(ptr, stringlen);
}
/* Unicode REPLACEMENT CHARACTER */
#define UNREPL 0x00FFFD
/*
* All string functions below take a scope as an argument.
*
*
* If scope is NULL, memory is allocated with g_malloc() and user must
* explicitly free it with g_free().
* If scope is not NULL, memory is allocated with the corresponding pool
* lifetime.
*
* All functions throw an exception if the tvbuff ends before the string
* does.
*/
/*
* Given a wmem scope, tvbuff, an offset, and a length, treat the string
* of bytes referred to by the tvbuff, offset, and length as an ASCII string,
* with all bytes with the high-order bit set being invalid, and return a
* pointer to a UTF-8 string, allocated using the wmem scope.
*
* Octets with the highest bit set will be converted to the Unicode
* REPLACEMENT CHARACTER.
*/
static guint8 *
tvb_get_ascii_string(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint length)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_ascii_string(scope, ptr, length);
}
/*
* Given a wmem scope, a tvbuff, an offset, and a length, treat the string
* of bytes referred to by the tvbuff, the offset. and the length as a UTF-8
* string, and return a pointer to that string, allocated using the wmem scope.
*
* XXX - should map invalid UTF-8 sequences to UNREPL.
*/
static guint8 *
tvb_get_utf_8_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, const gint length)
{
guint8 *strbuf;
tvb_ensure_bytes_exist(tvb, offset, length); /* make sure length = -1 fails */
strbuf = (guint8 *)wmem_alloc(scope, length + 1);
tvb_memcpy(tvb, strbuf, offset, length);
strbuf[length] = '\0';
return strbuf;
}
/*
* Given a wmem scope, tvbuff, an offset, and a length, treat the string
* of bytes referred to by the tvbuff, the offset, and the length as a
* raw string, and return a pointer to that string, allocated using the
* wmem scope. This means a null is appended at the end, but no replacement
* checking is done otherwise. Currently tvb_get_utf_8_string() does not
* replace either, but it might in the future.
*
* Also, this one allows a length of -1 to mean get all, but does not
* allow a negative offset.
*/
static inline guint8 *
tvb_get_raw_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, const gint length)
{
guint8 *strbuf;
gint abs_length = length;
DISSECTOR_ASSERT(offset >= 0);
DISSECTOR_ASSERT(abs_length >= -1);
if (abs_length < 0)
abs_length = tvb->length - offset;
tvb_ensure_bytes_exist(tvb, offset, abs_length);
strbuf = (guint8 *)wmem_alloc(scope, abs_length + 1);
tvb_memcpy(tvb, strbuf, offset, abs_length);
strbuf[abs_length] = '\0';
return strbuf;
}
/*
* Given a wmem scope, a tvbuff, an offset, and a length, treat the string
* of bytes referred to by the tvbuff, the offset, and the length as an
* ISO 8859/1 string, and return a pointer to a UTF-8 string, allocated
* using the wmem scope.
*/
static guint8 *
tvb_get_string_8859_1(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint length)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_8859_1_string(scope, ptr, length);
}
/*
* Given a wmem scope, a tvbuff, an offset, and a length, and a translation
* table, treat the string of bytes referred to by the tvbuff, the offset,
* and the length as a string encoded using one octet per character, with
* octets with the high-order bit clear being ASCII and octets with the
* high-order bit set being mapped by the translation table to 2-byte
* Unicode Basic Multilingual Plane characters (including REPLACEMENT
* CHARACTER), and return a pointer to a UTF-8 string, allocated with the
* wmem scope.
*/
static guint8 *
tvb_get_string_unichar2(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint length, const gunichar2 table[0x80])
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_unichar2_string(scope, ptr, length, table);
}
/*
* Given a wmem scope, a tvbuff, an offset, a length, and an encoding
* giving the byte order, treat the string of bytes referred to by the
* tvbuff, the offset, and the length as a UCS-2 encoded string in
* the byte order in question, containing characters from the Basic
* Multilingual Plane (plane 0) of Unicode, and return a pointer to a
* UTF-8 string, allocated with the wmem scope.
*
* Encoding parameter should be ENC_BIG_ENDIAN or ENC_LITTLE_ENDIAN.
*
* Specify length in bytes.
*
* XXX - should map lead and trail surrogate values to REPLACEMENT
* CHARACTERs (0xFFFD)?
* XXX - if there are an odd number of bytes, should put a
* REPLACEMENT CHARACTER at the end.
*/
static guint8 *
tvb_get_ucs_2_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint length, const guint encoding)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_ucs_2_string(scope, ptr, length, encoding);
}
/*
* Given a wmem scope, a tvbuff, an offset, a length, and an encoding
* giving the byte order, treat the string of bytes referred to by the
* tvbuff, the offset, and the length as a UTF-16 encoded string in
* the byte order in question, and return a pointer to a UTF-8 string,
* allocated with the wmem scope.
*
* Encoding parameter should be ENC_BIG_ENDIAN or ENC_LITTLE_ENDIAN.
*
* Specify length in bytes.
*
* XXX - should map surrogate errors to REPLACEMENT CHARACTERs (0xFFFD).
* XXX - should map code points > 10FFFF to REPLACEMENT CHARACTERs.
* XXX - if there are an odd number of bytes, should put a
* REPLACEMENT CHARACTER at the end.
*/
static guint8 *
tvb_get_utf_16_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint length, const guint encoding)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_utf_16_string(scope, ptr, length, encoding);
}
/*
* Given a wmem scope, a tvbuff, an offset, a length, and an encoding
* giving the byte order, treat the string of bytes referred to by the
* tvbuff, the offset, and the length as a UCS-4 encoded string in
* the byte order in question, and return a pointer to a UTF-8 string,
* allocated with the wmem scope.
*
* Encoding parameter should be ENC_BIG_ENDIAN or ENC_LITTLE_ENDIAN
*
* Specify length in bytes
*
* XXX - should map lead and trail surrogate values to a "substitute"
* UTF-8 character?
* XXX - should map code points > 10FFFF to REPLACEMENT CHARACTERs.
* XXX - if the number of bytes isn't a multiple of 4, should put a
* REPLACEMENT CHARACTER at the end.
*/
static gchar *
tvb_get_ucs_4_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint length, const guint encoding)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_ucs_4_string(scope, ptr, length, encoding);
}
gchar *
tvb_get_ts_23_038_7bits_string(wmem_allocator_t *scope, tvbuff_t *tvb,
const gint bit_offset, gint no_of_chars)
{
gint in_offset = bit_offset >> 3; /* Current pointer to the input buffer */
gint length = ((no_of_chars + 1) * 7 + (bit_offset & 0x07)) >> 3;
const guint8 *ptr;
DISSECTOR_ASSERT(tvb && tvb->initialized);
ptr = ensure_contiguous(tvb, in_offset, length);
return get_ts_23_038_7bits_string(scope, ptr, bit_offset, no_of_chars);
}
gchar *
tvb_get_ascii_7bits_string(wmem_allocator_t *scope, tvbuff_t *tvb,
const gint bit_offset, gint no_of_chars)
{
gint in_offset = bit_offset >> 3; /* Current pointer to the input buffer */
gint length = ((no_of_chars + 1) * 7 + (bit_offset & 0x07)) >> 3;
const guint8 *ptr;
DISSECTOR_ASSERT(tvb && tvb->initialized);
ptr = ensure_contiguous(tvb, in_offset, length);
return get_ascii_7bits_string(scope, ptr, bit_offset, no_of_chars);
}
/*
* Given a wmem scope, a tvbuff, an offset, and a length, treat the string
* of bytes referred to by the tvbuff, offset, and length as a string encoded
* in EBCDIC using one octet per character, and return a pointer to a
* UTF-8 string, allocated using the wmem scope.
*/
static guint8 *
tvb_get_ebcdic_string(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint length)
{
const guint8 *ptr;
ptr = ensure_contiguous(tvb, offset, length);
return get_ebcdic_string(scope, ptr, length);
}
/*
* Given a tvbuff, an offset, a length, and an encoding, allocate a
* buffer big enough to hold a non-null-terminated string of that length
* at that offset, plus a trailing '\0', copy into the buffer the
* string as converted from the appropriate encoding to UTF-8, and
* return a pointer to the string.
*/
guint8 *
tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
const gint length, const guint encoding)
{
guint8 *strptr;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/* make sure length = -1 fails */
if (length < 0) {
THROW(ReportedBoundsError);
}
switch (encoding & ENC_CHARENCODING_MASK) {
case ENC_ASCII:
default:
/*
* For now, we treat bogus values as meaning
* "ASCII" rather than reporting an error,
* for the benefit of old dissectors written
* when the last argument to proto_tree_add_item()
* was a gboolean for the byte order, not an
* encoding value, and passed non-zero values
* other than TRUE to mean "little-endian".
*/
strptr = tvb_get_ascii_string(scope, tvb, offset, length);
break;
case ENC_UTF_8:
/*
* XXX - should map lead and trail surrogate value code
* points to a "substitute" UTF-8 character?
* XXX - should map code points > 10FFFF to REPLACEMENT
* CHARACTERs.
*/
strptr = tvb_get_utf_8_string(scope, tvb, offset, length);
break;
case ENC_UTF_16:
strptr = tvb_get_utf_16_string(scope, tvb, offset, length,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_UCS_2:
strptr = tvb_get_ucs_2_string(scope, tvb, offset, length,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_UCS_4:
strptr = tvb_get_ucs_4_string(scope, tvb, offset, length,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_ISO_8859_1:
/*
* ISO 8859-1 printable code point values are equal
* to the equivalent Unicode code point value, so
* no translation table is needed.
*/
strptr = tvb_get_string_8859_1(scope, tvb, offset, length);
break;
case ENC_ISO_8859_2:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_2);
break;
case ENC_ISO_8859_3:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_3);
break;
case ENC_ISO_8859_4:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_4);
break;
case ENC_ISO_8859_5:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_5);
break;
case ENC_ISO_8859_6:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_6);
break;
case ENC_ISO_8859_7:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_7);
break;
case ENC_ISO_8859_8:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_8);
break;
case ENC_ISO_8859_9:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_9);
break;
case ENC_ISO_8859_10:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_10);
break;
case ENC_ISO_8859_11:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_11);
break;
case ENC_ISO_8859_13:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_13);
break;
case ENC_ISO_8859_14:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_14);
break;
case ENC_ISO_8859_15:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_15);
break;
case ENC_ISO_8859_16:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_iso_8859_16);
break;
case ENC_WINDOWS_1250:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_cp1250);
break;
case ENC_MAC_ROMAN:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_mac_roman);
break;
case ENC_CP437:
strptr = tvb_get_string_unichar2(scope, tvb, offset, length, charset_table_cp437);
break;
case ENC_3GPP_TS_23_038_7BITS:
{
gint bit_offset = offset << 3;
gint no_of_chars = (length << 3) / 7;
strptr = tvb_get_ts_23_038_7bits_string(scope, tvb, bit_offset, no_of_chars);
}
break;
case ENC_ASCII_7BITS:
{
gint bit_offset = offset << 3;
gint no_of_chars = (length << 3) / 7;
strptr = tvb_get_ascii_7bits_string(scope, tvb, bit_offset, no_of_chars);
}
break;
case ENC_EBCDIC:
/*
* XXX - multiple "dialects" of EBCDIC?
*/
strptr = tvb_get_ebcdic_string(scope, tvb, offset, length);
break;
}
return strptr;
}
/*
* This is like tvb_get_string_enc(), except that it handles null-padded
* strings.
*
* Currently, string values are stored as UTF-8 null-terminated strings,
* so nothing needs to be done differently for null-padded strings; we
* could save a little memory by not storing the null padding.
*
* If we ever store string values differently, in a fashion that doesn't
* involve null termination, that might change.
*/
guint8 *
tvb_get_stringzpad(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
const gint length, const guint encoding)
{
return tvb_get_string_enc(scope, tvb, offset, length, encoding);
}
/*
* These routines are like the above routines, except that they handle
* null-terminated strings. They find the length of that string (and
* throw an exception if the tvbuff ends before we find the null), and
* also return through a pointer the length of the string, in bytes,
* including the terminating null (the terminating null being 2 bytes
* for UCS-2 and UTF-16, 4 bytes for UCS-4, and 1 byte for other
* encodings).
*/
static guint8 *
tvb_get_ascii_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint *lengthp)
{
guint size;
const guint8 *ptr;
size = tvb_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_ascii_string(scope, ptr, size);
}
static guint8 *
tvb_get_utf_8_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp)
{
guint size;
guint8 *strptr;
size = tvb_strsize(tvb, offset);
strptr = (guint8 *)wmem_alloc(scope, size);
tvb_memcpy(tvb, strptr, offset, size);
if (lengthp)
*lengthp = size;
return strptr;
}
static guint8 *
tvb_get_stringz_8859_1(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint *lengthp)
{
guint size;
const guint8 *ptr;
size = tvb_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_8859_1_string(scope, ptr, size);
}
static guint8 *
tvb_get_stringz_unichar2(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint *lengthp, const gunichar2 table[0x80])
{
guint size;
const guint8 *ptr;
size = tvb_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_unichar2_string(scope, ptr, size, table);
}
/*
* 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), ensure that
* the TVB is flat, and return a pointer to the string (in the TVB).
* Also return the length of the string (including the terminating null)
* through a pointer.
*
* As long as we aren't using composite TVBs, this saves the cycles used
* (often unnecessariliy) in allocating a buffer and copying the string into
* it. (If we do start using composite TVBs, we may want to replace this
* function with the _ephemeral version.)
*/
const guint8 *
tvb_get_const_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp)
{
guint size;
const guint8 *strptr;
size = tvb_strsize(tvb, offset);
strptr = ensure_contiguous(tvb, offset, size);
if (lengthp)
*lengthp = size;
return strptr;
}
static gchar *
tvb_get_ucs_2_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding)
{
gint size; /* Number of bytes in string */
const guint8 *ptr;
size = tvb_unicode_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_ucs_2_string(scope, ptr, size, encoding);
}
static gchar *
tvb_get_utf_16_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding)
{
gint size;
const guint8 *ptr;
size = tvb_unicode_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_utf_16_string(scope, ptr, size, encoding);
}
static gchar *
tvb_get_ucs_4_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding)
{
gint size;
gunichar uchar;
const guint8 *ptr;
size = 0;
do {
/* Endianness doesn't matter when looking for null */
uchar = tvb_get_ntohl(tvb, offset + size);
size += 4;
} while(uchar != 0);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_ucs_4_string(scope, ptr, size, encoding);
}
static guint8 *
tvb_get_ebcdic_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint *lengthp)
{
guint size;
const guint8 *ptr;
size = tvb_strsize(tvb, offset);
ptr = ensure_contiguous(tvb, offset, size);
/* XXX, conversion between signed/unsigned integer */
if (lengthp)
*lengthp = size;
return get_ebcdic_string(scope, ptr, size);
}
guint8 *
tvb_get_stringz_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding)
{
guint8 *strptr;
DISSECTOR_ASSERT(tvb && tvb->initialized);
switch (encoding & ENC_CHARENCODING_MASK) {
case ENC_ASCII:
default:
/*
* For now, we treat bogus values as meaning
* "ASCII" rather than reporting an error,
* for the benefit of old dissectors written
* when the last argument to proto_tree_add_item()
* was a gboolean for the byte order, not an
* encoding value, and passed non-zero values
* other than TRUE to mean "little-endian".
*/
strptr = tvb_get_ascii_stringz(scope, tvb, offset, lengthp);
break;
case ENC_UTF_8:
/*
* XXX - should map all invalid UTF-8 sequences
* to a "substitute" UTF-8 character.
* XXX - should map code points > 10FFFF to REPLACEMENT
* CHARACTERs.
*/
strptr = tvb_get_utf_8_stringz(scope, tvb, offset, lengthp);
break;
case ENC_UTF_16:
strptr = tvb_get_utf_16_stringz(scope, tvb, offset, lengthp,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_UCS_2:
strptr = tvb_get_ucs_2_stringz(scope, tvb, offset, lengthp,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_UCS_4:
strptr = tvb_get_ucs_4_stringz(scope, tvb, offset, lengthp,
encoding & ENC_LITTLE_ENDIAN);
break;
case ENC_ISO_8859_1:
/*
* ISO 8859-1 printable code point values are equal
* to the equivalent Unicode code point value, so
* no translation table is needed.
*/
strptr = tvb_get_stringz_8859_1(scope, tvb, offset, lengthp);
break;
case ENC_ISO_8859_2:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_2);
break;
case ENC_ISO_8859_3:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_3);
break;
case ENC_ISO_8859_4:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_4);
break;
case ENC_ISO_8859_5:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_5);
break;
case ENC_ISO_8859_6:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_6);
break;
case ENC_ISO_8859_7:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_7);
break;
case ENC_ISO_8859_8:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_8);
break;
case ENC_ISO_8859_9:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_9);
break;
case ENC_ISO_8859_10:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_10);
break;
case ENC_ISO_8859_11:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_11);
break;
case ENC_ISO_8859_13:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_13);
break;
case ENC_ISO_8859_14:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_14);
break;
case ENC_ISO_8859_15:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_15);
break;
case ENC_ISO_8859_16:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_iso_8859_16);
break;
case ENC_WINDOWS_1250:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_cp1250);
break;
case ENC_MAC_ROMAN:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_mac_roman);
break;
case ENC_CP437:
strptr = tvb_get_stringz_unichar2(scope, tvb, offset, lengthp, charset_table_cp437);
break;
case ENC_3GPP_TS_23_038_7BITS:
REPORT_DISSECTOR_BUG("TS 23.038 7bits has no null character and doesn't support null-terminated strings");
break;
case ENC_ASCII_7BITS:
REPORT_DISSECTOR_BUG("tvb_get_stringz_enc function with ENC_ASCII_7BITS not implemented yet");
break;
case ENC_EBCDIC:
/*
* XXX - multiple "dialects" of EBCDIC?
*/
strptr = tvb_get_ebcdic_stringz(scope, tvb, offset, lengthp);
break;
}
return strptr;
}
/* Looks for a stringz (NUL-terminated string) in tvbuff and copies
* no more than bufsize number of bytes, including terminating NUL, to buffer.
* Returns length of string (not including terminating NUL), or -1 if the string was
* truncated in the buffer due to not having reached the terminating NUL.
* In this way, it acts like g_snprintf().
*
* bufsize MUST be greater than 0.
*
* 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. If no NUL is found before reaching
* the end of the short packet, -1 is still returned, and the string
* is truncated with a NUL, albeit not at buffer[bufsize - 1], but
* at the correct spot, terminating the string.
*
* *bytes_copied will contain the number of bytes actually copied,
* including the terminating-NUL.
*/
static gint
_tvb_get_nstringz(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8* buffer, gint *bytes_copied)
{
gint stringlen;
guint abs_offset;
gint limit, len;
gboolean decreased_max = FALSE;
/* Only read to end of tvbuff, w/o throwing exception. */
check_offset_length(tvb, offset, -1, &abs_offset, &len);
/* There must at least be room for the terminating NUL. */
DISSECTOR_ASSERT(bufsize != 0);
/* If there's no room for anything else, just return the NUL. */
if (bufsize == 1) {
buffer[0] = 0;
*bytes_copied = 1;
return 0;
}
/* check_offset_length() won't throw an exception if we're
* looking at the byte immediately after the end of the tvbuff. */
if (len == 0) {
THROW(ReportedBoundsError);
}
/* This should not happen because check_offset_length() would
* have already thrown an exception if 'offset' were out-of-bounds.
*/
DISSECTOR_ASSERT(len != -1);
/*
* If we've been passed a negative number, bufsize will
* be huge.
*/
DISSECTOR_ASSERT(bufsize <= G_MAXINT);
if ((guint)len < bufsize) {
limit = len;
decreased_max = TRUE;
}
else {
limit = bufsize;
}
stringlen = tvb_strnlen(tvb, abs_offset, limit - 1);
/* If NUL wasn't found, copy the data and return -1 */
if (stringlen == -1) {
tvb_memcpy(tvb, buffer, abs_offset, limit);
if (decreased_max) {
buffer[limit] = 0;
/* Add 1 for the extra NUL that we set at buffer[limit],
* pretending that it was copied as part of the string. */
*bytes_copied = limit + 1;
}
else {
*bytes_copied = limit;
}
return -1;
}
/* Copy the string to buffer */
tvb_memcpy(tvb, buffer, abs_offset, stringlen + 1);
*bytes_copied = stringlen + 1;
return stringlen;
}
/* Looks for a stringz (NUL-terminated string) in tvbuff and copies
* no more than bufsize number of bytes, including terminating NUL, to buffer.
* Returns length of string (not including terminating NUL), or -1 if the string was
* truncated in the buffer due to not having reached the terminating NUL.
* In this way, it acts like g_snprintf().
*
* 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. If no NUL is found before reaching
* the end of the short packet, -1 is still returned, and the string
* is truncated with a NUL, albeit not at buffer[bufsize - 1], but
* at the correct spot, terminating the string.
*/
gint
tvb_get_nstringz(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8 *buffer)
{
gint bytes_copied;
DISSECTOR_ASSERT(tvb && tvb->initialized);
return _tvb_get_nstringz(tvb, offset, bufsize, buffer, &bytes_copied);
}
/* Like tvb_get_nstringz(), but never returns -1. The string is guaranteed to
* have a terminating NUL. If the string was truncated when copied into buffer,
* a NUL is placed at the end of buffer to terminate it.
*/
gint
tvb_get_nstringz0(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8* buffer)
{
gint len, bytes_copied;
DISSECTOR_ASSERT(tvb && tvb->initialized);
len = _tvb_get_nstringz(tvb, offset, bufsize, buffer, &bytes_copied);
if (len == -1) {
buffer[bufsize - 1] = 0;
return bytes_copied - 1;
}
else {
return len;
}
}
/*
* 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.
*
* 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.)
*/
gint
tvb_find_line_end(tvbuff_t *tvb, const gint offset, int len, gint *next_offset, const gboolean desegment)
{
#ifdef WIN32
static const char __declspec(align(16)) crlf[] = "\r\n" ;
#else
static const char crlf[] __attribute__((aligned(16))) = "\r\n" ;
#endif
gint eob_offset;
gint eol_offset;
int linelen;
guchar found_needle = 0;
DISSECTOR_ASSERT(tvb && tvb->initialized);
if (len == -1)
len = _tvb_captured_length_remaining(tvb, offset);
/*
* XXX - what if "len" is still -1, meaning "offset is past the
* end of the tvbuff"?
*/
eob_offset = offset + len;
/*
* Look either for a CR or an LF.
*/
eol_offset = tvb_pbrk_guint8(tvb, offset, len, crlf, &found_needle);
if (eol_offset == -1) {
/*
* No CR or LF - line is presumably continued in next packet.
*/
if (desegment) {
/*
* Tell our caller we saw no EOL, so they can
* try to desegment and get the entire line
* into one tvbuff.
*/
return -1;
} else {
/*
* Pretend the line runs to the end of the tvbuff.
*/
linelen = eob_offset - offset;
if (next_offset)
*next_offset = eob_offset;
}
} else {
/*
* Find the number of bytes between the starting offset
* and the CR or LF.
*/
linelen = eol_offset - offset;
/*
* Is it a CR?
*/
if (found_needle == '\r') {
/*
* Yes - is it followed by an LF?
*/
if (eol_offset + 1 >= eob_offset) {
/*
* Dunno - the next byte isn't in this
* tvbuff.
*/
if (desegment) {
/*
* We'll return -1, although that
* runs the risk that if the line
* really *is* terminated with a CR,
* we won't properly dissect this
* tvbuff.
*
* It's probably more likely that
* the line ends with CR-LF than
* that it ends with CR by itself.
*/
return -1;
}
} else {
/*
* Well, we can at least look at the next
* byte.
*/
if (tvb_get_guint8(tvb, eol_offset + 1) == '\n') {
/*
* It's an LF; skip over the CR.
*/
eol_offset++;
}
}
}
/*
* Return the offset of the character after the last
* character in the line, skipping over the last character
* in the line terminator.
*/
if (next_offset)
*next_offset = eol_offset + 1;
}
return linelen;
}
/*
* 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.
*
* 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.
*/
gint
tvb_find_line_end_unquoted(tvbuff_t *tvb, const gint offset, int len, gint *next_offset)
{
gint cur_offset, char_offset;
gboolean is_quoted;
guchar c = 0;
gint eob_offset;
int linelen;
DISSECTOR_ASSERT(tvb && tvb->initialized);
if (len == -1)
len = _tvb_captured_length_remaining(tvb, offset);
/*
* XXX - what if "len" is still -1, meaning "offset is past the
* end of the tvbuff"?
*/
eob_offset = offset + len;
cur_offset = offset;
is_quoted = FALSE;
for (;;) {
/*
* Is this part of the string quoted?
*/
if (is_quoted) {
/*
* Yes - look only for the terminating quote.
*/
char_offset = tvb_find_guint8(tvb, cur_offset, len,
'"');
} else {
/*
* Look either for a CR, an LF, or a '"'.
*/
char_offset = tvb_pbrk_guint8(tvb, cur_offset, len, "\r\n\"", &c);
}
if (char_offset == -1) {
/*
* Not found - line is presumably continued in
* next packet.
* We pretend the line runs to the end of the tvbuff.
*/
linelen = eob_offset - offset;
if (next_offset)
*next_offset = eob_offset;
break;
}
if (is_quoted) {
/*
* We're processing a quoted string.
* We only looked for ", so we know it's a ";
* as we're processing a quoted string, it's a
* closing quote.
*/
is_quoted = FALSE;
} else {
/*
* OK, what is it?
*/
if (c == '"') {
/*
* Un-quoted "; it begins a quoted
* string.
*/
is_quoted = TRUE;
} else {
/*
* It's a CR or LF; we've found a line
* terminator.
*
* Find the number of bytes between the
* starting offset and the CR or LF.
*/
linelen = char_offset - offset;
/*
* Is it a CR?
*/
if (c == '\r') {
/*
* Yes; is it followed by an LF?
*/
if (char_offset + 1 < eob_offset &&
tvb_get_guint8(tvb, char_offset + 1)
== '\n') {
/*
* Yes; skip over the CR.
*/
char_offset++;
}
}
/*
* Return the offset of the character after
* the last character in the line, skipping
* over the last character in the line
* terminator, and quit.
*/
if (next_offset)
*next_offset = char_offset + 1;
break;
}
}
/*
* Step past the character we found.
*/
cur_offset = char_offset + 1;
if (cur_offset >= eob_offset) {
/*
* The character we found was the last character
* in the tvbuff - line is presumably continued in
* next packet.
* We pretend the line runs to the end of the tvbuff.
*/
linelen = eob_offset - offset;
if (next_offset)
*next_offset = eob_offset;
break;
}
}
return linelen;
}
/*
* 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.
*/
gint
tvb_skip_wsp(tvbuff_t *tvb, const gint offset, const gint maxlength)
{
gint counter = offset;
gint end, tvb_len;
guint8 tempchar;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/* Get the length remaining */
/*tvb_len = tvb_captured_length(tvb);*/
tvb_len = tvb->length;
end = offset + maxlength;
if (end >= tvb_len)
{
end = tvb_len;
}
/* Skip past spaces, tabs, CRs and LFs until run out or meet something else */
for (counter = offset;
counter < end &&
((tempchar = tvb_get_guint8(tvb,counter)) == ' ' ||
tempchar == '\t' || tempchar == '\r' || tempchar == '\n');
counter++);
return (counter);
}
gint
tvb_skip_wsp_return(tvbuff_t *tvb, const gint offset) {
gint counter = offset;
guint8 tempchar;
for(counter = offset; counter > 0 &&
((tempchar = tvb_get_guint8(tvb,counter)) == ' ' ||
tempchar == '\t' || tempchar == '\n' || tempchar == '\r'); counter--);
counter++;
return (counter);
}
int
tvb_skip_guint8(tvbuff_t *tvb, int offset, const int maxlength, const guint8 ch)
{
int end, tvb_len;
DISSECTOR_ASSERT(tvb && tvb->initialized);
/* Get the length remaining */
/*tvb_len = tvb_captured_length(tvb);*/
tvb_len = tvb->length;
end = offset + maxlength;
if (end >= tvb_len)
end = tvb_len;
while (offset < end) {
guint8 tempch = tvb_get_guint8(tvb, offset);
if (tempch != ch)
break;
offset++;
}
return offset;
}
/*
* 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.
*/
gchar *
tvb_bytes_to_ep_str_punct(tvbuff_t *tvb, const gint offset, const gint len, const gchar punct)
{
return bytes_to_ep_str_punct(ensure_contiguous(tvb, offset, len), len, punct);
}
/*
* 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, formating the digits according to an input digit set,
* if NUll a default digit set of 0-9 returning "?" for overdecadic digits will be used.
* A pointer to the packet scope allocated string will be returned.
* Note a tvbuff content of 0xf is considered a 'filler' and will end the conversion.
*/
static dgt_set_t Dgt1_9_bcd = {
{
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f*/
'0','1','2','3','4','5','6','7','8','9','?','?','?','?','?','?'
}
};
const gchar *
tvb_bcd_dig_to_wmem_packet_str(tvbuff_t *tvb, const gint offset, const gint len, dgt_set_t *dgt, gboolean skip_first)
{
int length;
guint8 octet;
int i = 0;
char *digit_str;
gint t_offset = offset;
DISSECTOR_ASSERT(tvb && tvb->initialized);
if (!dgt)
dgt = &Dgt1_9_bcd;
if (len == -1) {
/*length = tvb_captured_length(tvb);*/
length = tvb->length;
if (length < offset) {
return "";
}
} else {
length = offset + len;
}
digit_str = (char *)wmem_alloc(wmem_packet_scope(), (length - offset)*2+1);
while (t_offset < length) {
octet = tvb_get_guint8(tvb,t_offset);
if (!skip_first) {
digit_str[i] = dgt->out[octet & 0x0f];
i++;
}
skip_first = FALSE;
/*
* unpack second value in byte
*/
octet = octet >> 4;
if (octet == 0x0f) /* odd number bytes - hit filler */
break;
digit_str[i] = dgt->out[octet & 0x0f];
i++;
t_offset++;
}
digit_str[i]= '\0';
return digit_str;
}
/*
* Format a bunch of data from a tvbuff as bytes, returning a pointer
* to the string with the formatted data.
*/
gchar *
tvb_bytes_to_ep_str(tvbuff_t *tvb, const gint offset, const gint len)
{
return bytes_to_ep_str(ensure_contiguous(tvb, offset, len), len);
}
/* Find a needle tvbuff within a haystack tvbuff. */
gint
tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb, const gint haystack_offset)
{
guint haystack_abs_offset, haystack_abs_length;
const guint8 *haystack_data;
const guint8 *needle_data;
const guint needle_len = needle_tvb->length;
const guint8 *location;
DISSECTOR_ASSERT(haystack_tvb && haystack_tvb->initialized);
if (haystack_tvb->length < 1 || needle_tvb->length < 1) {
return -1;
}
/* Get pointers to the tvbuffs' data. */
haystack_data = ensure_contiguous(haystack_tvb, 0, -1);
needle_data = ensure_contiguous(needle_tvb, 0, -1);
check_offset_length(haystack_tvb, haystack_offset, -1,
&haystack_abs_offset, &haystack_abs_length);
location = epan_memmem(haystack_data + haystack_abs_offset, haystack_abs_length,
needle_data, needle_len);
if (location) {
return (gint) (location - haystack_data);
}
return -1;
}
gint
tvb_raw_offset(tvbuff_t *tvb)
{
return ((tvb->raw_offset==-1) ? (tvb->raw_offset = tvb_offset_from_real_beginning(tvb)) : tvb->raw_offset);
}
void
tvb_set_fragment(tvbuff_t *tvb)
{
tvb->flags |= TVBUFF_FRAGMENT;
}
struct tvbuff *
tvb_get_ds_tvb(tvbuff_t *tvb)
{
return(tvb->ds_tvb);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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