wireshark/dfilter-grammar.y

%{

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

#ifndef __GLIB_H__
#include <glib.h>
#endif

#include <string.h> /* during testing */

#ifndef _STDLIB_H
#include <stdlib.h>
#endif

#ifndef __PROTO_H__
#include "proto.h"
#endif

#ifndef __PACKET_H__
#include "packet.h"
#endif

#ifndef __DFILTER_H__
#include "dfilter.h"
#endif

#ifndef __RESOLV_H__
#include "resolv.h"
#endif

void dfilter_yacc_init(void);
static void dfilter_print_parse_tree(GNode *gnode);
static GNode* dfilter_mknode_join(GNode *n1, enum node_type ntype, int operand, GNode *n2);
static GNode* dfilter_mknode_unary(int operand, GNode *n2);
static GNode* dfilter_mknode_numeric_variable(gint id);
static GNode* dfilter_mknode_numeric_value(guint32 val);
static GNode* dfilter_mknode_ether_value(char *a, char *b, char *c, char *d, char *e, char *f);
static GNode* dfilter_mknode_ether_variable(gint id);
static GNode* dfilter_mknode_ipv4_value(char *host);
static GNode* dfilter_mknode_ipv4_variable(gint id);
static GNode* dfilter_mknode_existence(gint id);
static GNode* dfilter_mknode_bytes_value(GByteArray *barray);
static GNode* dfilter_mknode_bytes_variable(gint id, gint offset, gint length);
static GNode* dfilter_mknode_boolean_value(gint truth_value);
static GNode* dfilter_mknode_boolean_variable(gint id);

static guint32 string_to_value(char *s);

/* space for dfilter_nodes */
GMemChunk *gmc_dfilter_nodes = NULL;

/* this is how we pass display filter tree (dfcode) back to calling routine */
GNode *dfilter_tree = NULL;

/* list of byte arrays we allocate during parse. We can traverse this list
 * faster than the tree when we go back and free the byte arrays */
GSList *dfilter_list_byte_arrays = NULL;

%}

%union {
	gint		operand;	/* logical, relation, alternation */
	gint		variable;
	GNode*		node;
	gchar*		id;
	GByteArray*	bytes;
}

%type <node>	statement expression relation
%type <node>	numeric_value numeric_variable
%type <node>	ether_value ether_variable
%type <node>	ipv4_value ipv4_variable
%type <node>	protocol_name
%type <node>	bytes_value bytes_variable
%type <node>	boolean_value boolean_variable

%type <operand>	numeric_relation
%type <operand>	ether_relation
%type <operand>	bytes_relation
%type <operand>	boolean_relation

%type <bytes>		byte_range
%type <variable>	any_variable_type
%type <operand>		exists_operand

%token <variable>	T_FT_UINT8
%token <variable>	T_FT_UINT16
%token <variable>	T_FT_UINT32
%token <variable>	T_FT_ETHER
%token <variable>	T_FT_IPv4
%token <variable>	T_FT_NONE
%token <variable>	T_FT_BYTES
%token <variable>	T_FT_BOOLEAN
%token <variable>	T_FT_STRING

%token <id>	 	T_VAL_ID

%token <operand>	TOK_AND TOK_OR TOK_NOT TOK_XOR
%token <operand>	TOK_EQ TOK_NE TOK_GT TOK_GE TOK_LT TOK_LE
%token <operand>	TOK_EXIST TOK_EXISTS
%token <operand>	TOK_TRUE TOK_FALSE

%type <operand>		type_eq
%type <operand>		type_ne
%type <operand>		type_gt
%type <operand>		type_ge
%type <operand>		type_lt
%type <operand>		type_le

%left TOK_AND
%left TOK_OR
%left TOK_XOR
%nonassoc TOK_NOT

%%

statement: expression
		{
			dfilter_tree = $1;
		}
	|	/* NULL */ { dfilter_tree = NULL; }
	;

expression:	'(' expression ')' { $$ = $2; }
	|	expression TOK_AND expression { $$ = dfilter_mknode_join($1, logical, $2, $3); }
	|	expression TOK_OR expression { $$ = dfilter_mknode_join($1, logical, $2, $3); }
	|	TOK_NOT expression { $$ = dfilter_mknode_unary(TOK_NOT, $2); }
	|	relation { $$ = $1; }
	|	protocol_name { $$ = $1; }
	;

relation:	numeric_variable numeric_relation numeric_value
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	numeric_value numeric_relation numeric_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	numeric_variable numeric_relation numeric_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}

	|	ether_variable ether_relation ether_value
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	ether_value ether_relation ether_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	ether_variable ether_relation ether_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}


	|	ipv4_variable numeric_relation ipv4_value
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	ipv4_value numeric_relation ipv4_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	ipv4_variable numeric_relation ipv4_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}

	|	bytes_variable bytes_relation bytes_value
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	bytes_value bytes_relation bytes_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	bytes_variable bytes_relation bytes_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}

	|	boolean_variable boolean_relation boolean_value
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	boolean_value boolean_relation boolean_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}
	|	boolean_variable boolean_relation boolean_variable
		{
			$$ = dfilter_mknode_join($1, relation, $2, $3);
		}

	|	exists_operand any_variable_type	{ $$ = dfilter_mknode_existence($2); }

	;


numeric_value:	T_VAL_ID		{ $$ = dfilter_mknode_numeric_value(string_to_value($1)); }
	;

ether_value:	T_VAL_ID ':' T_VAL_ID ':' T_VAL_ID ':' T_VAL_ID ':' T_VAL_ID ':' T_VAL_ID
		{
			$$ = dfilter_mknode_ether_value($1, $3, $5, $7, $9, $11);
			g_free($1);
			g_free($3);
			g_free($5);
			g_free($7);
			g_free($9);
			g_free($11);
		}
	;

ipv4_value:	T_VAL_ID		{ $$ = dfilter_mknode_ipv4_value($1); }
	;

bytes_value:	numeric_variable
	|	byte_range		{ $$ = dfilter_mknode_bytes_value($1); }
	;

byte_range:	T_VAL_ID ':' T_VAL_ID
		{
			GByteArray	*barray = g_byte_array_new();
			guint8		val;
			char		*endptr;

			dfilter_list_byte_arrays = g_slist_append(dfilter_list_byte_arrays, barray);
			val = (guint8) strtoul($1, &endptr, 16);
			g_byte_array_append(barray, &val, 1);
			val = (guint8) strtoul($3, &endptr, 16);
			$$ = g_byte_array_append(barray, &val, 1);
		}

	|	byte_range ':' T_VAL_ID
		{
			guint8		val;
			char		*endptr;

			val = (guint8) strtoul($3, &endptr, 16);
			$$ = g_byte_array_append($1, &val, 1);
		}
	;

boolean_value:	TOK_TRUE		{ $$ = dfilter_mknode_boolean_value($1); }
	|	TOK_FALSE		{ $$ = dfilter_mknode_boolean_value($1); }
	;


numeric_variable:	T_FT_UINT8	{ $$ = dfilter_mknode_numeric_variable($1); }
	|		T_FT_UINT16	{ $$ = dfilter_mknode_numeric_variable($1); }
	|		T_FT_UINT32	{ $$ = dfilter_mknode_numeric_variable($1); }
	;

ether_variable:		T_FT_ETHER	{ $$ = dfilter_mknode_ether_variable($1); }
	;

ipv4_variable:		T_FT_IPv4	{ $$ = dfilter_mknode_ipv4_variable($1); }
	;

protocol_name:		T_FT_NONE		{ $$ = dfilter_mknode_existence($1); }
	;

bytes_variable:		any_variable_type '[' T_VAL_ID ':' T_VAL_ID ']'
		{
			$$ = dfilter_mknode_bytes_variable($1, string_to_value($3), string_to_value($5));
		}
	|		any_variable_type '[' T_VAL_ID ']'
		{
			$$ = dfilter_mknode_bytes_variable($1, string_to_value($3), 0);
		}
	;

boolean_variable:	T_FT_BOOLEAN	{ $$ = dfilter_mknode_boolean_variable($1); }
	;

any_variable_type:	T_FT_UINT8 { $$ = $1; }
	|		T_FT_UINT16 { $$ = $1; }
	|		T_FT_UINT32 { $$ = $1; }
	|		T_FT_ETHER { $$ = $1; }
	|		T_FT_IPv4 { $$ = $1; }
	|		T_FT_NONE { $$ = $1; }
	|		T_FT_BYTES { $$ = $1; }
	|		T_FT_BOOLEAN { $$ = $1; }
	|		T_FT_STRING { $$ = $1; }
	;

numeric_relation:	type_eq { $$ = $1; }
	|		type_ne { $$ = $1; }
	|		type_gt { $$ = $1; }
	|		type_ge { $$ = $1; }
	|		type_lt { $$ = $1; }
	|		type_le { $$ = $1; }
	;

ether_relation:		type_eq { $$ = $1; }
	|		type_ne { $$ = $1; }
	;

bytes_relation:		type_eq { $$ = $1; }
	|		type_ne { $$ = $1; }
	|		type_gt { $$ = $1; }
	|		type_lt { $$ = $1; }
	;

boolean_relation:	type_eq { $$ = $1; }
	|		type_ne { $$ = $1; }
	;

exists_operand:		TOK_EXIST	{ $$ = $1; }
	|		TOK_EXISTS	{ $$ = $1; }
	|		'?'		{ $$ = TOK_EXIST; }
	;

type_eq:		TOK_EQ	{ $$ = $1; }
	|		'=' '='	{ $$ = TOK_EQ; }
	;

type_ne:		TOK_NE	{ $$ = $1; }
	|		'!' '='	{ $$ = TOK_NE; }
	;

type_gt:		TOK_GT	{ $$ = $1; }
	|		'>'	{ $$ = TOK_GT; }
	;

type_ge:		TOK_GE	{ $$ = $1; }
	|		'>' '='	{ $$ = TOK_GE; }
	;

type_lt:		TOK_LT	{ $$ = $1; }
	|		'<'	{ $$ = TOK_LT; }
	;

type_le:		TOK_LE	{ $$ = $1; }
	|		'<' '='	{ $$ = TOK_LE; }
	;


%%

void
dfilter_yacc_init(void)
{
	if (gmc_dfilter_nodes)
		g_mem_chunk_destroy(gmc_dfilter_nodes);

	gmc_dfilter_nodes = g_mem_chunk_new("gmc_dfilter_nodes",
		sizeof(dfilter_node), 50 * sizeof(dfilter_node),
		G_ALLOC_ONLY);

	if (dfilter_list_byte_arrays) {
		/* clear the byte arrays */
		g_slist_free(dfilter_list_byte_arrays);
	}
		
}

void
dfilter_yacc_cleanup(void)
{
	if (gmc_dfilter_nodes)
		g_mem_chunk_destroy(gmc_dfilter_nodes);
}


static GNode*
dfilter_mknode_join(GNode *n1, enum node_type ntype, int operand, GNode *n2)
{
	dfilter_node	*node_root;
	GNode		*gnode_root;

	node_root = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node_root->ntype = ntype;
	node_root->elem_size = 0;
	node_root->fill_array_func = NULL;
	node_root->check_relation_func = NULL;
	if (ntype == relation) {
		node_root->value.relation = operand;
	}
	else if (ntype == logical) {
		node_root->value.logical = operand;
	}
	else {
		g_assert_not_reached();
	}

	gnode_root = g_node_new(node_root);
	g_node_append(gnode_root, n1);
	g_node_append(gnode_root, n2);

	return gnode_root;
}

static GNode*
dfilter_mknode_unary(int operand, GNode *n2)
{
	dfilter_node	*node_root;
	GNode		*gnode_root;

	node_root = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node_root->ntype = logical;
	node_root->value.logical = operand;
	node_root->elem_size = 0;
	node_root->fill_array_func = NULL;
	node_root->check_relation_func = NULL;

	gnode_root = g_node_new(node_root);
	g_node_append(gnode_root, n2);

	return gnode_root;
}


static GNode*
dfilter_mknode_numeric_variable(gint id)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = variable;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_numeric_variable;
	node->check_relation_func = check_relation_numeric;
	node->value.variable = id;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_ether_variable(gint id)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = variable;
	node->elem_size = sizeof(guint8) * 6;
	node->fill_array_func = fill_array_ether_variable;
	node->check_relation_func = check_relation_ether;
	node->value.variable = id;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_ipv4_variable(gint id)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = variable;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_numeric_variable; /* cheating ! */
	node->check_relation_func = check_relation_numeric; /* cheating ! */
	node->value.variable = id;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_bytes_variable(gint id, gint offset, gint length)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = variable;
	/*node->elem_size = length * sizeof(guint8);*/
	node->elem_size = sizeof(GByteArray*);
	node->fill_array_func = fill_array_bytes_variable;
	node->check_relation_func = check_relation_bytes;
	node->value.variable = id;
	node->offset = offset;
	node->length = length;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_boolean_variable(gint id)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = variable;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_boolean_variable; /* cheating ! */
	node->check_relation_func = check_relation_boolean; /* cheating ! */
	node->value.variable = id;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_numeric_value(guint32 val)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = numeric;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_numeric_value;
	node->check_relation_func = check_relation_numeric;
	node->value.numeric = val;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_ether_value(char *a, char *b, char *c, char *d, char *e, char *f)
{
	dfilter_node	*node;
	GNode		*gnode;
	char		*endptr;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = ether;
	node->elem_size = sizeof(guint8) * 6;
	node->fill_array_func = fill_array_ether_value;
	node->check_relation_func = check_relation_ether;

	node->value.ether[0] = (guint8) strtoul(a, &endptr, 16);
	node->value.ether[1] = (guint8) strtoul(b, &endptr, 16);
	node->value.ether[2] = (guint8) strtoul(c, &endptr, 16);
	node->value.ether[3] = (guint8) strtoul(d, &endptr, 16);
	node->value.ether[4] = (guint8) strtoul(e, &endptr, 16);
	node->value.ether[5] = (guint8) strtoul(f, &endptr, 16);

	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_ipv4_value(char *host)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = numeric;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_numeric_value; /* cheating ! */
	node->check_relation_func = check_relation_numeric; /* cheating ! */
	node->value.numeric = get_host_ipaddr(host);
	node->value.numeric = htonl(node->value.numeric);
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_bytes_value(GByteArray *barray)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = bytes;
	/*node->elem_size = barray->len * sizeof(guint8);*/
	node->elem_size = sizeof(GByteArray*);
	node->fill_array_func = fill_array_bytes_value;
	node->check_relation_func = check_relation_bytes;
	node->value.bytes = barray;
	node->offset = G_MAXINT;
	node->length = barray->len;
	gnode = g_node_new(node);

	return gnode;
}

static GNode*
dfilter_mknode_boolean_value(gint truth_value)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = numeric;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = fill_array_boolean_value;
	node->check_relation_func = check_relation_boolean;
	node->value.boolean = truth_value == TOK_TRUE ? TRUE : FALSE;
	gnode = g_node_new(node);

	return gnode;
}

static guint32
string_to_value(char *s)
{
	char	*endptr;
	guint32	val;

	val = strtoul(s, &endptr, 0);
	/* I should probably check errno here */

	return (guint32)val;
}
	
static GNode*
dfilter_mknode_existence(gint id)
{
	dfilter_node	*node;
	GNode		*gnode;

	node = g_mem_chunk_alloc(gmc_dfilter_nodes);
	node->ntype = existence;
	node->elem_size = sizeof(guint32);
	node->fill_array_func = NULL;
	node->check_relation_func = NULL;
	node->value.variable = id;
	gnode = g_node_new(node);

	return gnode;
}