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dfilter: Add syntax to match specific layers in the protocol stack 

Add support to display filters for matching a specific layer within a frame.
Layers are counted sequentially up the protocol stack. Each protocol
(dissector) that appears in the stack is one layer.

LINK-LAYER#1 <-> IP#1 <-> TCP#1 <-> IP#2 <-> TCP#2 <-> etc.

The syntax allows for negative indexes and ranges with the usual semantics
for slices (but note that counting starts at one):

    tcp.port#[2-4] == 1024

Matches layers 2 to 4 inclusive.

Fixes #3791.
pespin/osmux-wip
João Valverde 2022-04-09 23:03:40 +01:00 committed by A Wireshark GitLab Utility
parent c0170dad42
commit 4f3f507eee
15 changed files with 459 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
doc/wireshark-filter.adoc
View File

@ -322,6 +322,24 @@ Slices can be combined. You can concatenate them using the comma operator:
This concatenates offset 1, offsets 3-5, and offset 9 to the end of the ftp
data.
=== The layer operator
A field can be restricted to a certain layer in the protocol stack using the
layer operator (#), followed by a decimal number:
ip.addr#2 == 192.168.30.40
matches only the inner (second) layer in the packet. Layers use simple stacking
semantics and protocol layers are counted sequentially, so tcp#2 is the layer
in the stack somewhere above tcp#1.
For more complicates ranges the same syntax used with slices is valid:
tcp.port#[2-4]
means layers number 2, 3 or 4 inclusive. The hash symbol is required to
distinguish a layer range from a slice.
=== The membership operator
A field may be checked for matches against a set of values simply with the

2
docbook/release-notes.adoc
View File

@ -70,6 +70,8 @@ They previously shipped with Npcap 1.55.
** Adds new display filter functions max(), min() and abs().
** Functions can accept expressions as arguments, including other functions. Previously only protocol
fields and slices were syntactically valid function arguments.
** New syntax to match a specific layer in the protocol stack. For example ip.addr#2 == 1.1.1.1
matches only the inner layer in an IP-over-IP packet.
* text2pcap and "Import from Hex Dump":
** text2pcap supports writing the output file in all the capture file formats

170
epan/dfilter/dfvm.c
View File

@ -24,9 +24,11 @@ dfvm_opcode_tostr(dfvm_opcode_t code)
case IF_TRUE_GOTO: return "IF_TRUE_GOTO";
case IF_FALSE_GOTO: return "IF_FALSE_GOTO";
case CHECK_EXISTS: return "CHECK_EXISTS";
case CHECK_EXISTS_R: return "CHECK_EXISTS_R";
case NOT: return "NOT";
case RETURN: return "RETURN";
case READ_TREE: return "READ_TREE";
case READ_TREE_R: return "READ_TREE_R";
case READ_REFERENCE: return "READ_REFERENCE";
case PUT_FVALUE: return "PUT_FVALUE";
case ALL_EQ: return "ALL_EQ";
@ -293,11 +295,21 @@ dfvm_dump_str(wmem_allocator_t *alloc, dfilter_t *df, gboolean print_references)
id, arg1_str);
break;
case CHECK_EXISTS_R:
wmem_strbuf_append_printf(buf, "%05d CHECK_EXISTS\t%s#[%s]\n",
id, arg1_str, arg2_str);
break;
case READ_TREE:
wmem_strbuf_append_printf(buf, "%05d READ_TREE\t\t%s -> %s\n",
id, arg1_str, arg2_str);
break;
case READ_TREE_R:
wmem_strbuf_append_printf(buf, "%05d READ_TREE\t\t%s#[%s] -> %s\n",
id, arg1_str, arg3_str, arg2_str);
break;
case READ_REFERENCE:
wmem_strbuf_append_printf(buf, "%05d READ_REFERENCE\t${%s} -> %s\n",
id, arg1_str, arg2_str);
@ -498,21 +510,98 @@ dfvm_dump(FILE *f, dfilter_t *df)
wmem_free(NULL, str);
}
static int
compare_finfo_layer(gconstpointer _a, gconstpointer _b)
{
const field_info *a = *(const field_info **)_a;
const field_info *b = *(const field_info **)_b;
return a->proto_layer_num - b->proto_layer_num;
}
static gboolean
drange_contains_layer(drange_t *dr, int num, int length)
{
drange_node *rn;
GSList *list = dr->range_list;
int lower, upper;
while (list) {
rn = list->data;
lower = rn->start_offset;
if (lower < 0) {
lower += length + 1;
}
if (rn->ending == DRANGE_NODE_END_T_LENGTH) {
upper = lower + rn->length - 1;
}
else if (rn->ending == DRANGE_NODE_END_T_OFFSET) {
upper = rn->end_offset;
}
else if (rn->ending == DRANGE_NODE_END_T_TO_THE_END) {
upper = INT_MAX;
}
if (num >= lower && num <= upper) { /* inclusive */
return TRUE;
}
list = g_slist_next(list);
}
return FALSE;
}
GSList *
filter_finfo_fvalues(GSList *fvalues, GPtrArray *finfos, drange_t *range)
{
int length; /* maximum proto layer number. The numbers are sequential. */
field_info *last_finfo, *finfo;
int cookie = -1;
gboolean cookie_matches;
int layer;
g_ptr_array_sort(finfos, compare_finfo_layer);
last_finfo = finfos->pdata[finfos->len - 1];
length = last_finfo->proto_layer_num;
for (guint i = 0; i < finfos->len; i++) {
finfo = finfos->pdata[i];
layer = finfo->proto_layer_num;
if (cookie == layer) {
if (cookie_matches) {
fvalues = g_slist_prepend(fvalues, &finfo->value);
}
}
else {
cookie = layer;
cookie_matches = drange_contains_layer(range, layer, length);
if (cookie_matches) {
fvalues = g_slist_prepend(fvalues, &finfo->value);
}
}
}
return fvalues;
}
/* Reads a field from the proto_tree and loads the fvalues into a register,
* if that field has not already been read. */
static gboolean
read_tree(dfilter_t *df, proto_tree *tree,
dfvm_value_t *arg1, dfvm_value_t *arg2)
dfvm_value_t *arg1, dfvm_value_t *arg2,
dfvm_value_t *arg3)
{
GPtrArray *finfos;
field_info *finfo;
int i, len;
GSList *fvalues = NULL;
gboolean found_something = FALSE;
drange_t *range = NULL;
header_field_info *hfinfo = arg1->value.hfinfo;
int reg = arg2->value.numeric;
if (arg3) {
range = arg3->value.drange;
}
/* Already loaded in this run of the dfilter? */
if (df->attempted_load[reg]) {
if (df->registers[reg]) {
@ -531,20 +620,22 @@ read_tree(dfilter_t *df, proto_tree *tree,
hfinfo = hfinfo->same_name_next;
continue;
}
else {
found_something = TRUE;
}
len = finfos->len;
for (i = 0; i < len; i++) {
finfo = g_ptr_array_index(finfos, i);
fvalues = g_slist_prepend(fvalues, &finfo->value);
if (range) {
fvalues = filter_finfo_fvalues(fvalues, finfos, range);
}
else {
len = finfos->len;
for (i = 0; i < len; i++) {
finfo = g_ptr_array_index(finfos, i);
fvalues = g_slist_prepend(fvalues, &finfo->value);
}
}
hfinfo = hfinfo->same_name_next;
}
if (!found_something) {
if (fvalues == NULL) {
return FALSE;
}
@ -1038,6 +1129,42 @@ stack_pop(dfilter_t *df, dfvm_value_t *arg1)
}
}
static gboolean
check_exists(proto_tree *tree, dfvm_value_t *arg1, dfvm_value_t *arg2)
{
GPtrArray *finfos;
header_field_info *hfinfo;
drange_t *range = NULL;
gboolean exists;
GSList *fvalues;
hfinfo = arg1->value.hfinfo;
if (arg2)
range = arg2->value.drange;
while (hfinfo) {
finfos = proto_get_finfo_ptr_array(tree, hfinfo->id);
if ((finfos == NULL) || (g_ptr_array_len(finfos) == 0)) {
hfinfo = hfinfo->same_name_next;
continue;
}
if (range == NULL) {
return TRUE;
}
fvalues = filter_finfo_fvalues(NULL, finfos, range);
exists = (fvalues != NULL);
g_slist_free(fvalues);
if (exists) {
return TRUE;
}
hfinfo = hfinfo->same_name_next;
}
return FALSE;
}
gboolean
dfvm_apply(dfilter_t *df, proto_tree *tree)
{
@ -1047,7 +1174,6 @@ dfvm_apply(dfilter_t *df, proto_tree *tree)
dfvm_value_t *arg1;
dfvm_value_t *arg2;
dfvm_value_t *arg3 = NULL;
header_field_info *hfinfo;
ws_assert(tree);
@ -1065,21 +1191,19 @@ dfvm_apply(dfilter_t *df, proto_tree *tree)
switch (insn->op) {
case CHECK_EXISTS:
hfinfo = arg1->value.hfinfo;
while(hfinfo) {
accum = proto_check_for_protocol_or_field(tree,
hfinfo->id);
if (accum) {
break;
}
else {
hfinfo = hfinfo->same_name_next;
}
}
accum = check_exists(tree, arg1, NULL);
break;
case CHECK_EXISTS_R:
accum = check_exists(tree, arg1, arg2);
break;
case READ_TREE:
accum = read_tree(df, tree, arg1, arg2);
accum = read_tree(df, tree, arg1, arg2, NULL);
break;
case READ_TREE_R:
accum = read_tree(df, tree, arg1, arg2, arg3);
break;
case READ_REFERENCE:

2
epan/dfilter/dfvm.h
View File

@ -50,9 +50,11 @@ typedef enum {
IF_TRUE_GOTO,
IF_FALSE_GOTO,
CHECK_EXISTS,
CHECK_EXISTS_R,
NOT,
RETURN,
READ_TREE,
READ_TREE_R,
READ_REFERENCE,
PUT_FVALUE,
ALL_EQ,

78
epan/dfilter/gencode.c
View File

@ -73,11 +73,12 @@ dfw_append_jump(dfwork_t *dfw)
/* returns register number */
static dfvm_value_t *
dfw_append_read_tree(dfwork_t *dfw, header_field_info *hfinfo)
dfw_append_read_tree(dfwork_t *dfw, header_field_info *hfinfo,
drange_t *range)
{
dfvm_insn_t *insn;
int reg = -1;
dfvm_value_t *reg_val, *val1;
dfvm_value_t *reg_val, *val1, *val3;
gboolean added_new_hfinfo = FALSE;
void *loaded_key;
@ -89,15 +90,21 @@ dfw_append_read_tree(dfwork_t *dfw, header_field_info *hfinfo)
/* Keep track of which registers
* were used for which hfinfo's so that we
* can re-use registers. */
/* Re-use only if we are not using a range (layer filter). */
loaded_key = g_hash_table_lookup(dfw->loaded_fields, hfinfo);
if (loaded_key != NULL) {
/*
* Reg's are stored in has as reg+1, so
* that the non-existence of a hfinfo in
* the hash, or 0, can be differentiated from
* a hfinfo being loaded into register #0.
*/
reg = GPOINTER_TO_INT(loaded_key) - 1;
if (range == NULL) {
/*
* Reg's are stored in has as reg+1, so
* that the non-existence of a hfinfo in
* the hash, or 0, can be differentiated from
* a hfinfo being loaded into register #0.
*/
reg = GPOINTER_TO_INT(loaded_key) - 1;
}
else {
reg = dfw->next_register++;
}
}
else {
reg = dfw->next_register++;
@ -107,11 +114,19 @@ dfw_append_read_tree(dfwork_t *dfw, header_field_info *hfinfo)
added_new_hfinfo = TRUE;
}
insn = dfvm_insn_new(READ_TREE);
val1 = dfvm_value_new_hfinfo(hfinfo);
insn->arg1 = dfvm_value_ref(val1);
reg_val = dfvm_value_new_register(reg);
if (range) {
val3 = dfvm_value_new_drange(range);
insn = dfvm_insn_new(READ_TREE_R);
}
else {
val3 = NULL;
insn = dfvm_insn_new(READ_TREE);
}
insn->arg1 = dfvm_value_ref(val1);
insn->arg2 = dfvm_value_ref(reg_val);
insn->arg3 = dfvm_value_ref(val3);
dfw_append_insn(dfw, insn);
if (added_new_hfinfo) {
@ -189,7 +204,7 @@ dfw_append_mk_slice(dfwork_t *dfw, stnode_t *node, GSList **jumps_ptr)
insn->arg1 = dfvm_value_ref(val1);
reg_val = dfvm_value_new_register(dfw->next_register++);
insn->arg2 = dfvm_value_ref(reg_val);
val3 = dfvm_value_new_drange(sttype_range_drange(node));
val3 = dfvm_value_new_drange(sttype_range_drange_steal(node));
insn->arg3 = dfvm_value_ref(val3);
sttype_range_remove_drange(node);
dfw_append_insn(dfw, insn);
@ -439,7 +454,7 @@ gen_entity(dfwork_t *dfw, stnode_t *st_arg, GSList **jumps_ptr)
if (e_type == STTYPE_FIELD) {
hfinfo = stnode_data(st_arg);
val = dfw_append_read_tree(dfw, hfinfo);
val = dfw_append_read_tree(dfw, hfinfo, NULL);
*jumps_ptr = g_slist_prepend(*jumps_ptr, dfw_append_jump(dfw));
}
else if (e_type == STTYPE_REFERENCE) {
@ -447,6 +462,12 @@ gen_entity(dfwork_t *dfw, stnode_t *st_arg, GSList **jumps_ptr)
val = dfw_append_read_reference(dfw, hfinfo);
*jumps_ptr = g_slist_prepend(*jumps_ptr, dfw_append_jump(dfw));
}
else if (e_type == STTYPE_LAYER) {
stnode_t *entity = sttype_range_entity(st_arg);
drange_t *range = sttype_range_drange_steal(st_arg);
val = dfw_append_read_tree(dfw, stnode_data(entity), range);
*jumps_ptr = g_slist_prepend(*jumps_ptr, dfw_append_jump(dfw));
}
else if (e_type == STTYPE_FVALUE) {
val = dfvm_value_new_fvalue(stnode_steal_data(st_arg));
}
@ -473,16 +494,40 @@ static void
gen_exists(dfwork_t *dfw, stnode_t *st_node)
{
dfvm_insn_t *insn;
dfvm_value_t *val1, *val2 = NULL;
header_field_info *hfinfo;
stnode_t *st_arg;
drange_t *range;
hfinfo = stnode_data(st_node);
if (stnode_type_id(st_node) == STTYPE_LAYER) {
st_arg = sttype_range_entity(st_node);
range = sttype_range_drange_steal(st_node);
}
else {
st_arg = st_node;
range = NULL;
}
hfinfo = stnode_data(st_arg);
/* Rewind to find the first field of this name. */
while (hfinfo->same_name_prev_id != -1) {
hfinfo = proto_registrar_get_nth(hfinfo->same_name_prev_id);
}
insn = dfvm_insn_new(CHECK_EXISTS);
insn->arg1 = dfvm_value_new_hfinfo(hfinfo);
val1 = dfvm_value_new_hfinfo(hfinfo);
if (range) {
val2 = dfvm_value_new_drange(range);
}
if (val2) {
insn = dfvm_insn_new(CHECK_EXISTS_R);
insn->arg1 = dfvm_value_ref(val1);
insn->arg2 = dfvm_value_ref(val2);
}
else {
insn = dfvm_insn_new(CHECK_EXISTS);
insn->arg1 = dfvm_value_ref(val1);
}
dfw_append_insn(dfw, insn);
/* Record the FIELD_ID in hash of interesting fields. */
@ -621,6 +666,7 @@ gencode(dfwork_t *dfw, stnode_t *st_node)
gen_test(dfw, st_node);
break;
case STTYPE_FIELD:
case STTYPE_LAYER:
gen_exists(dfw, st_node);
break;
case STTYPE_ARITHMETIC:

19
epan/dfilter/grammar.lemon
View File

@ -121,9 +121,28 @@ atom(A) ::= LITERAL(S). { A = S; }
atom(A) ::= FIELD(F). { A = F; }
atom(A) ::= REFERENCE(F). { A = F; }
layer(R) ::= atom(F) HASH LBRACKET range_node_list(L) RBRACKET.
{
R = stnode_new(STTYPE_LAYER, NULL, NULL, NULL);
sttype_range_set(R, F, L);
g_slist_free(L);
}
layer(R) ::= atom(F) HASH INTEGER(N).
{
R = stnode_new(STTYPE_LAYER, NULL, NULL, stnode_location(F));
char *err_msg = sttype_range_set_number(R, F, stnode_token(N));
if (err_msg != NULL) {
FAIL(dfw, N, "%s", err_msg);
g_free(err_msg);
}
stnode_free(N);
}
entity(E) ::= atom(A). { E = A; }
entity(E) ::= slice(R). { E = R; }
entity(E) ::= function(F). { E = F; }
entity(E) ::= layer(L). { E = L; }
arithmetic_expr(T) ::= entity(N).
{

20
epan/dfilter/scanner.l
View File

@ -136,6 +136,7 @@ dot-bytes {hex2}(\.{hex2})+
hyphen-bytes {hex2}(-{hex2})+
%x RANGE
%x LAYER
%x DQUOTE
%x SQUOTE
%x REFERENCE
@ -194,7 +195,24 @@ hyphen-bytes {hex2}(-{hex2})+
"&" return math(TOKEN_BITWISE_AND);
"bitwise_and" return math(TOKEN_BITWISE_AND);
"[" {
"#" {
BEGIN(LAYER);
return simple(TOKEN_HASH);
}
<LAYER>[[:digit:]]+ {
BEGIN(INITIAL);
update_location(yyextra, yytext);
return set_lval_simple(yyextra, TOKEN_INTEGER, yytext, STTYPE_UNINITIALIZED);
}
<LAYER>[^[:digit:][] {
update_location(yyextra, yytext);
FAIL("Expected digit or \"[\", not \"%s\"", yytext);
return SCAN_FAILED;
}
<INITIAL,LAYER>"[" {
BEGIN(RANGE);
return simple(TOKEN_LBRACKET);
}

116
epan/dfilter/semcheck.c
View File

@ -19,6 +19,7 @@
#include "sttype-test.h"
#include "sttype-set.h"
#include "sttype-function.h"
#include "sttype-pointer.h"
#include <epan/exceptions.h>
#include <epan/packet.h>
@ -506,6 +507,7 @@ check_exists(dfwork_t *dfw, stnode_t *st_arg1)
switch (stnode_type_id(st_arg1)) {
case STTYPE_FIELD:
case STTYPE_ARITHMETIC:
case STTYPE_LAYER:
/* This is OK */
break;
case STTYPE_REFERENCE:
@ -544,6 +546,17 @@ check_exists(dfwork_t *dfw, stnode_t *st_arg1)
}
}
static void
check_exists_layer(dfwork_t *dfw, stnode_t *st_arg1)
{
stnode_t *entity;
entity = sttype_range_entity(st_arg1);
dfw_resolve_unparsed(dfw, entity);
check_exists(dfw, entity);
/* Nothing to do here? */
}
static void
check_slice_sanity(dfwork_t *dfw, stnode_t *st, ftenum_t lhs_ftype)
{
@ -581,6 +594,52 @@ check_slice_sanity(dfwork_t *dfw, stnode_t *st, ftenum_t lhs_ftype)
}
}
static ftenum_t
check_layer_sanity(dfwork_t *dfw, stnode_t *st)
{
stnode_t *entity1;
sttype_id_t e_type;
LOG_NODE(st);
entity1 = sttype_range_entity(st);
ws_assert(entity1);
dfw_resolve_unparsed(dfw, entity1);
e_type = stnode_type_id(entity1);
if (e_type == STTYPE_FIELD) {
return sttype_pointer_ftenum(entity1);
}
else if (e_type == STTYPE_REFERENCE) {
/* TODO: Implement layers with references. */
FAIL(dfw, entity1, "The # operator is not valid with a reference");
}
else {
FAIL(dfw, entity1, "%s is not a valid field value", stnode_todisplay(entity1));
}
}
#define IS_FIELD_ENTITY(ft) \
((ft) == STTYPE_FIELD || \
(ft) == STTYPE_REFERENCE || \
(ft) == STTYPE_LAYER)
static ftenum_t
field_ftenum(stnode_t *st)
{
sttype_id_t e_type;
e_type = stnode_type_id(st);
if (e_type == STTYPE_FIELD || e_type == STTYPE_REFERENCE)
return sttype_pointer_ftenum(st);
else if (e_type == STTYPE_LAYER) {
return sttype_pointer_ftenum(sttype_range_entity(st));
}
else {
ws_assert_not_reached();
}
}
static void
convert_to_bytes(stnode_t *arg)
{
@ -648,7 +707,7 @@ check_relation_LHS_FIELD(dfwork_t *dfw, test_op_t st_op,
stnode_t *st_arg1, stnode_t *st_arg2)
{
sttype_id_t type2;
header_field_info *hfinfo1, *hfinfo2;
header_field_info *hfinfo1;
ftenum_t ftype1, ftype2;
fvalue_t *fvalue;
@ -657,6 +716,8 @@ check_relation_LHS_FIELD(dfwork_t *dfw, test_op_t st_op,
again:
type2 = stnode_type_id(st_arg2);
ws_assert(stnode_type_id(st_arg1) == STTYPE_FIELD ||
stnode_type_id(st_arg1) == STTYPE_REFERENCE);
hfinfo1 = stnode_data(st_arg1);
ftype1 = hfinfo1->type;
@ -666,19 +727,18 @@ again:
stnode_todisplay(st_node));
}
if (type2 == STTYPE_FIELD || type2 == STTYPE_REFERENCE) {
hfinfo2 = stnode_data(st_arg2);
ftype2 = hfinfo2->type;
if (IS_FIELD_ENTITY(type2)) {
ftype2 = field_ftenum(st_arg2);
if (!compatible_ftypes(ftype1, ftype2)) {
FAIL(dfw, st_arg2, "%s and %s are not of compatible types.",
hfinfo1->abbrev, hfinfo2->abbrev);
hfinfo1->abbrev, stnode_todisplay(st_arg2));
}
/* Do this check even though you'd think that if
* they're compatible, then can_func() would pass. */
if (!can_func(ftype2)) {
FAIL(dfw, st_arg2, "%s (type=%s) cannot participate in specified comparison.",
hfinfo2->abbrev, ftype_pretty_name(ftype2));
stnode_todisplay(st_arg2), ftype_pretty_name(ftype2));
}
}
else if (type2 == STTYPE_STRING || type2 == STTYPE_LITERAL || type2 == STTYPE_UNPARSED) {
@ -757,6 +817,21 @@ again:
}
}
static void
check_relation_LHS_LAYER(dfwork_t *dfw, test_op_t st_op,
FtypeCanFunc can_func,
gboolean allow_partial_value,
stnode_t *st_node,
stnode_t *st_arg1, stnode_t *st_arg2)
{
stnode_t *entity;
check_layer_sanity(dfw, st_arg1);
entity = sttype_range_entity(st_arg1);
ws_assert(stnode_type_id(entity) == STTYPE_FIELD);
check_relation_LHS_FIELD(dfw, st_op, can_func, allow_partial_value, st_node, entity, st_arg2);
}
static void
check_relation_LHS_SLICE(dfwork_t *dfw, test_op_t st_op,
FtypeCanFunc can_func _U_,
@ -765,7 +840,6 @@ check_relation_LHS_SLICE(dfwork_t *dfw, test_op_t st_op,
stnode_t *st_arg1, stnode_t *st_arg2)
{
sttype_id_t type2;
header_field_info *hfinfo2;
ftenum_t ftype2;
fvalue_t *fvalue;
@ -776,14 +850,13 @@ check_relation_LHS_SLICE(dfwork_t *dfw, test_op_t st_op,
again:
type2 = stnode_type_id(st_arg2);
if (type2 == STTYPE_FIELD || type2 == STTYPE_REFERENCE) {
hfinfo2 = stnode_data(st_arg2);
ftype2 = hfinfo2->type;
if (IS_FIELD_ENTITY(type2)) {
ftype2 = field_ftenum(st_arg2);
if (!is_bytes_type(ftype2)) {
if (!ftype_can_slice(ftype2)) {
FAIL(dfw, st_arg2, "\"%s\" is a %s and cannot be converted into a sequence of bytes.",
hfinfo2->abbrev,
stnode_todisplay(st_arg2),
ftype_pretty_name(ftype2));
}
@ -858,7 +931,6 @@ check_relation_LHS_FUNCTION(dfwork_t *dfw, test_op_t st_op,
stnode_t *st_arg1, stnode_t *st_arg2)
{
sttype_id_t type2;
header_field_info *hfinfo2;
ftenum_t ftype1, ftype2;
fvalue_t *fvalue;
@ -875,19 +947,18 @@ check_relation_LHS_FUNCTION(dfwork_t *dfw, test_op_t st_op,
again:
type2 = stnode_type_id(st_arg2);
if (type2 == STTYPE_FIELD || type2 == STTYPE_REFERENCE) {
hfinfo2 = stnode_data(st_arg2);
ftype2 = hfinfo2->type;
if (IS_FIELD_ENTITY(type2)) {
ftype2 = field_ftenum(st_arg2);
if (!compatible_ftypes(ftype1, ftype2)) {
FAIL(dfw, st_arg2, "Function %s and %s are not of compatible types.",
sttype_function_name(st_arg2), hfinfo2->abbrev);
sttype_function_name(st_arg2), stnode_todisplay(st_arg2));
}
/* Do this check even though you'd think that if
* they're compatible, then can_func() would pass. */
if (!can_func(ftype2)) {
FAIL(dfw, st_arg2, "%s (type=%s) cannot participate in specified comparison.",
hfinfo2->abbrev, ftype_pretty_name(ftype2));
stnode_todisplay(st_arg2), ftype_pretty_name(ftype2));
}
}
else if (type2 == STTYPE_STRING) {
@ -974,7 +1045,7 @@ check_relation_LHS_ARITHMETIC(dfwork_t *dfw, test_op_t st_op _U_,
sttype_test_get(st_arg1, NULL, &entity, NULL);
entity_type = stnode_type_id(entity);
if (entity_type == STTYPE_FIELD || entity_type == STTYPE_REFERENCE) {
if (IS_FIELD_ENTITY(entity_type)) {
check_relation_LHS_FIELD(dfw, st_op, can_func, allow_partial_value, st_node, entity, st_arg2);
}
else if (entity_type == STTYPE_FUNCTION) {
@ -1007,6 +1078,10 @@ check_relation(dfwork_t *dfw, test_op_t st_op,
check_relation_LHS_FIELD(dfw, st_op, can_func,
allow_partial_value, st_node, st_arg1, st_arg2);
break;
case STTYPE_LAYER:
check_relation_LHS_LAYER(dfw, st_op, can_func,
allow_partial_value, st_node, st_arg1, st_arg2);
break;
case STTYPE_SLICE:
check_relation_LHS_SLICE(dfw, st_op, can_func,
allow_partial_value, st_node, st_arg1, st_arg2);
@ -1020,7 +1095,7 @@ check_relation(dfwork_t *dfw, test_op_t st_op,
allow_partial_value, st_node, st_arg1, st_arg2);
break;
default:
FAIL(dfw, st_arg1, "Left side of %s expression must be a field or function, not %s.",
FAIL(dfw, st_arg1, "Left side of \"%s\" expression must be a field or function, not %s.",
stnode_todisplay(st_node), stnode_todisplay(st_arg1));
}
}
@ -1344,6 +1419,9 @@ semcheck(dfwork_t *dfw, stnode_t *st_node)
case STTYPE_ARITHMETIC:
check_arithmetic_expr(dfw, st_node, FT_NONE);
break;
case STTYPE_LAYER:
check_exists_layer(dfw, st_node);
break;
default:
check_exists(dfw, st_node);
}

1
epan/dfilter/sttype-pointer.c
View File

@ -115,6 +115,7 @@ sttype_pointer_ftenum(stnode_t *node)
{
switch (node->type->id) {
case STTYPE_FIELD:
case STTYPE_REFERENCE:
return ((header_field_info *)node->data)->type;
case STTYPE_FVALUE:
return fvalue_type_ftenum(node->data);

53
epan/dfilter/sttype-range.c
View File

@ -73,7 +73,7 @@ range_free(gpointer value)
}
static char *
range_tostr(const void *data, gboolean pretty)
slice_tostr(const void *data, gboolean pretty)
{
const range_t *range = data;
ws_assert_magic(range, RANGE_MAGIC);
@ -89,6 +89,23 @@ range_tostr(const void *data, gboolean pretty)
return repr;
}
static char *
layer_tostr(const void *data, gboolean pretty)
{
const range_t *range = data;
ws_assert_magic(range, RANGE_MAGIC);
char *repr, *drange_str;
drange_str = drange_tostr(range->drange);
repr = ws_strdup_printf("%s#[%s]",
stnode_tostr(range->entity, pretty),
drange_str);
g_free(drange_str);
return repr;
}
void
sttype_range_remove_drange(stnode_t *node)
{
@ -100,6 +117,18 @@ sttype_range_remove_drange(stnode_t *node)
range->drange = NULL;
}
drange_t *
sttype_range_drange_steal(stnode_t *node)
{
range_t *range;
drange_t *dr;
range = stnode_data(node);
ws_assert_magic(range, RANGE_MAGIC);
dr = range->drange;
range->drange = NULL;
return dr;
}
/* Set a range */
void
@ -121,6 +150,17 @@ sttype_range_set1(stnode_t *node, stnode_t *entity, drange_node *rn)
sttype_range_set(node, entity, g_slist_append(NULL, rn));
}
char *
sttype_range_set_number(stnode_t *node, stnode_t *entity, const char *number_str)
{
char *err_msg = NULL;
drange_node *rn = drange_node_from_str(number_str, &err_msg);
if (err_msg != NULL)
return err_msg;
sttype_range_set1(node, entity, rn);
return NULL;
}
stnode_t *
sttype_range_entity(stnode_t *node)
{
@ -146,10 +186,19 @@ sttype_register_range(void)
range_new,
range_free,
range_dup,
range_tostr
slice_tostr
};
static sttype_t layer_type = {
STTYPE_LAYER,
"LAYER",
range_new,
range_free,
range_dup,
layer_tostr
};
sttype_register(&slice_type);
sttype_register(&layer_type);
}
/*

6
epan/dfilter/sttype-range.h
View File

@ -21,6 +21,9 @@ sttype_range_entity(stnode_t *node);
drange_t *
sttype_range_drange(stnode_t *node);
drange_t *
sttype_range_drange_steal(stnode_t *node);
/* Set a range */
void
sttype_range_set(stnode_t *node, stnode_t *field, GSList* drange_list);
@ -28,6 +31,9 @@ sttype_range_set(stnode_t *node, stnode_t *field, GSList* drange_list);
void
sttype_range_set1(stnode_t *node, stnode_t *field, drange_node *rn);
char *
sttype_range_set_number(stnode_t *node, stnode_t *entity, const char *number_str);
/* Clear the 'drange' variable to remove responsibility for
* freeing it. */
void

7
epan/dfilter/syntax-tree.c
View File

@ -273,12 +273,7 @@ stnode_tostr(stnode_t *node, gboolean pretty)
if (pretty && node->repr_token != NULL) {
g_free(node->repr_display);
if (stnode_type_id(node) == STTYPE_CHARCONST) {
node->repr_display = g_strdup(node->repr_token);
}
else {
node->repr_display = ws_strdup_printf("\"%s\"", node->repr_token);
}
node->repr_display = g_strdup(node->repr_token);
return node->repr_display;
}

1
epan/dfilter/syntax-tree.h
View File

@ -31,6 +31,7 @@ typedef enum {
STTYPE_FIELD,
STTYPE_FVALUE,
STTYPE_SLICE,
STTYPE_LAYER,
STTYPE_RANGE_NODE,
STTYPE_FUNCTION,
STTYPE_SET,

BIN
test/captures/ipoipoip.pcap Normal file
View File

Binary file not shown.

33
test/suite_dfilter/group_syntax.py
View File

@ -279,3 +279,36 @@ class case_field_reference(unittest.TestCase):
dfilter = 'frame.number < ${frame.number}'
# select frame 3, expect 2 frames out of 4.
checkDFilterCountWithSelectedFrame(dfilter, 2, 3)
@fixtures.uses_fixtures
class case_field_reference(unittest.TestCase):
trace_file = "ipoipoip.pcap"
def test_layer_1(self, checkDFilterCount):
dfilter = 'ip.addr#2 == 4.4.4.4'
checkDFilterCount(dfilter, 1)
def test_layer_2(self, checkDFilterCount):
dfilter = 'ip.addr#5'
checkDFilterCount(dfilter, 1)
def test_layer_3(self, checkDFilterCount):
dfilter = 'ip.addr#6'
checkDFilterCount(dfilter, 0)
def test_layer_4(self, checkDFilterCount):
dfilter = 'ip.dst#[2-4] == 8.8.8.8'
checkDFilterCount(dfilter, 1)
def test_layer_5(self, checkDFilterCount):
dfilter = 'ip.dst#[-1] == 8.8.8.8'
checkDFilterCount(dfilter, 0)
def test_layer_6(self, checkDFilterCount):
dfilter = 'ip.dst#[-1] == 9.9.9.9'
checkDFilterCount(dfilter, 1)
def test_layer_7(self, checkDFilterCount):
dfilter = 'ip.dst#[-5] == 2.2.2.2'
checkDFilterCount(dfilter, 1)