semcheck.h File Reference

#include "dfilter-int.h"

Go to the source code of this file.

Functions
bool	dfw_semcheck (dfwork_t *dfw)
	Perform semantic checking on a filter expression.
ftenum_t	check_arithmetic (dfwork_t *dfw, stnode_t *st_node, ftenum_t logical_ftype)
	Checks arithmetic operations.
ftenum_t	check_function (dfwork_t *dfw, stnode_t *st_node, ftenum_t logical_ftype)
	Checks if a function call is valid based on its parameters.
ftenum_t	check_slice (dfwork_t *dfw, stnode_t *st, ftenum_t logical_ftype)
	Checks if a slice can be resolved and returns its logical field type.
void	resolve_unparsed (dfwork_t *dfw, stnode_t *st, bool strict)
	Resolve an unparsed node in a display filter expression.
ftenum_t	get_logical_ftype (dfwork_t *dfw, stnode_t *st_node)
	Retrieves the logical field type for a given node.
bool	compatible_ftypes (ftenum_t a, ftenum_t b)
	Checks if two field types are compatible.

Detailed Description

Wireshark - Network traffic analyzer By Gerald Combs geral.nosp@m.d@wi.nosp@m.resha.nosp@m.rk.o.nosp@m.rg Copyright 2001 Gerald Combs

SPDX-License-Identifier: GPL-2.0-or-later

Function Documentation

check_arithmetic()

ftenum_t check_arithmetic	(	dfwork_t *	dfw,
		stnode_t *	st_node,
		ftenum_t	logical_ftype
	)

Checks arithmetic operations.

Parameters

dfw	Pointer to the current dissection work context.
st_node	Pointer to the syntax tree node representing the operation.
logical_ftype	The logical type of the operation.

check_function()

ftenum_t check_function	(	dfwork_t *	dfw,
		stnode_t *	st_node,
		ftenum_t	logical_ftype
	)

Checks if a function call is valid based on its parameters.

Validates that the number of arguments in a function call matches the expected range and calls the appropriate semantic check function for the function.

Parameters

dfw	The current state of the dissection work.
st_node	The syntax tree node representing the function call.
logical_ftype	The logical type of the function.

Returns

ftenum_t The result of the semantic check.

check_slice()

ftenum_t check_slice	(	dfwork_t *	dfw,
		stnode_t *	st,
		ftenum_t	logical_ftype
	)

Checks if a slice can be resolved and returns its logical field type.

This function resolves an unparsed node and determines the logical field type of the sliced entity.

Parameters

dfw	The current dissection work context.
st	The syntax tree node to check.
logical_ftype	The logical field type of the sliced entity.

Returns

ftenum_t The resolved logical field type or FT_NONE if not applicable.

compatible_ftypes()

bool compatible_ftypes	(	ftenum_t	a,
		ftenum_t	b
	)

Checks if two field types are compatible.

This function determines whether two field types can be compared or used together in a dissector filter expression.

Parameters

a	The first field type to compare.
b	The second field type to compare.

Returns

true if the field types are compatible, false otherwise.

dfw_semcheck()

bool dfw_semcheck

(

dfwork_t *

dfw

)

Perform semantic checking on a filter expression.

This function initiates the semantic checking process for a filter expression represented by the given dfwork_t structure. It checks the arithmetic and function calls within the expression to ensure they are semantically valid.

Parameters

dfw	Pointer to the dfwork_t structure containing the filter expression.

Returns

ftenum_t The result of the semantic check, indicating whether the filter is valid or not.

get_logical_ftype()

ftenum_t get_logical_ftype	(	dfwork_t *	dfw,
		stnode_t *	st_node
	)

Retrieves the logical field type for a given node.

Determines the field type based on the type of the node and its children.

Parameters

dfw	The current working context.
st_node	The node to analyze.

Returns

The logical field type.

resolve_unparsed()

void resolve_unparsed	(	dfwork_t *	dfw,
		stnode_t *	st,
		bool	strict
	)

Resolve an unparsed node in a display filter expression.

This function attempts to resolve an unparsed node by converting it into a field node if possible. If resolution fails and strict mode is enabled, it raises an error; otherwise, it mutates the node to a literal.

Parameters

dfw	The current display filter work context.
st	The node to be resolved.
strict	Whether to raise an error if resolution fails.