Add argument to dfilter_compile_real() to save syntax tree text
representation.
Use it with dftest to print syntax tree.
Misc debug output format improvements.
Add support for display filter binary addition and subtraction.
The grammar is intentionally kept simple for now. The use case
is to add a constant to a protocol field, or (maybe) add two
fields in an expression.
We use signed arithmetic with unsigned numbers, checking for
overflow and casting where necessary to do the conversion.
We could legitimately opt to use traditional modular arithmetic
instead (like C) and if it turns out that that is more useful for
some reason we may want to in the future.
Fixes#15504.
This change implements a unary minus operator.
Filter: tcp.window_size_scalefactor == -tcp.dstport
Instructions:
00000 READ_TREE tcp.window_size_scalefactor -> reg#0
00001 IF_FALSE_GOTO 6
00002 READ_TREE tcp.dstport -> reg#1
00003 IF_FALSE_GOTO 6
00004 MK_MINUS -reg#1 -> reg#2
00005 ANY_EQ reg#0 == reg#2
00006 RETURN
It is supported for integer types, floats and relative time values.
The unsigned integer types are promoted to a 32 bit signed integer.
Unary plus is implemented as a no-op. The plus sign is simply ignored.
Constant arithmetic expressions are computed during compilation.
Overflow with constants is a compile time error. Overflow with
variables is a run time error and silently ignored. Only a debug
message will be printed to the console.
Related to #15504.
Add support for masking of bits. Before the bitwise operator
could only test bits, it did not support clearing bits.
This allows testing if any combination of bits are set/unset
more naturally with a single test. Previously this was only
possible by combining several bitwise predicates.
Bitwise is implemented as a test node, even though it is not.
Maybe the test node should be renamed to something else.
Fixes#17246.
To complete the set of equality operators add an "all equal"
operator that matches a frame if all fields match the condition.
The symbol chosen for "all_eq" is "===".
Use that for error messages, including any using test operators.
This allows to always use the same name as the user. It avoids
cases where the user write "a && b" and the message is "a and b"
is syntactically invalid.
It should also allow us to be more consistent with the use of
double quotes.
Wireshark defines the relation of equality A == B as
A any_eq B <=> An == Bn for at least one An, Bn.
More accurately I think this is (formally) an equivalence
relation, not true equality.
Whichever definition for "==" we choose we must keep the
definition of "!=" as !(A == B), otherwise it will
lead to logical contradictions like (A == B) AND (A != B)
being true.
Fix the '!=' relation to match the definition of equality:
A != B <=> !(A == B) <=> A all_ne B <=> An != Bn, for
every n.
This has been the recomended way to write "not equal" for a
long time in the documentation, even to the point where != was
deprecated, but it just wasn't implemented consistently in the
language, which has understandably been a persistent source
of confusion. Even a field that is normally well-behaved
with "!=" like "ip.src" or "ip.dst" will produce unexpected
results with encapsulations like IP-over-IP.
The opcode ALL_NE could have been implemented in the compiler
instead using NOT and ANY_EQ but I chose to implement it in
bytecode. It just seemed more elegant and efficient
but the difference was not very significant.
Keep around "~=" for any_ne relation, in case someone depends
on that, and because we don't have an operator for true equality:
A strict_equal B <=> A all_eq B <=> !(A any_ne B).
If there is only one value then any_ne and all_ne are the same
comparison operation.
Implementing this change did not require fixing any tests so it
is unlikely the relation "~=" (any_ne) will be very useful.
Note that the behaviour of the '<' (less than) comparison relation
is a separate, more subtle issue. In the general case the definition
of '<' that is used is only a partial order.
Use wslog to output debug information. Being able to control
it at runtime is a big advantage.
We extend the syntax tree nodes with a method to return a
canonical string representation.
Add a routine to walk the tree and return an textual representation
for debugging purposes.
Change all wireshark.org URLs to use https.
Fix some broken links while we're at it.
Change-Id: I161bf8eeca43b8027605acea666032da86f5ea1c
Reviewed-on: https://code.wireshark.org/review/34089
Reviewed-by: Guy Harris <guy@alum.mit.edu>
Added a new relational test: 'x in {a b c}'. The only LHS entity
supported at this time is a field. The generated DFVM operations are
equivalent to an OR'ed series of =='s, but with the redundant existence
tests removed.
Change-Id: Iddc89b81cf7ad6319aef1a2a94f93314cb721a8a
Reviewed-on: https://code.wireshark.org/review/10246
Reviewed-by: Hadriel Kaplan <hadrielk@yahoo.com>
Petri-Dish: Hadriel Kaplan <hadrielk@yahoo.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>
(Using sed : sed -i '/^ \* \$Id\$/,+1 d')
Fix manually some typo (in export_object_dicom.c and crc16-plain.c)
Change-Id: I4c1ae68d1c4afeace8cb195b53c715cf9e1227a8
Reviewed-on: https://code.wireshark.org/review/497
Reviewed-by: Anders Broman <a.broman58@gmail.com>
Like:
a == b == c
or
a < b <= c <= d < e
Real life example:
6660 <= tcp.port <= 6669
Just syntactic sugar, this is *NOT* optimized.
svn path=/trunk/; revision=43353
they have LF at the end of the line on UN*X and CR/LF on Windows;
hopefully this means that if a CR/LF version is checked in on Windows,
the CRs will be stripped so that they show up only when checked out on
Windows, not on UN*X.
svn path=/trunk/; revision=11400
New "matches" operater in display filter language. Uses PCRE.
If a "matches" operator is found in a dfilter
while libpcre has not been used to build the binary, then an
exception is thrown after using dfilter_fail() to set an apporporiate
error message.
svn path=/trunk/; revision=9182
into epan/ftypes.
Re-write display filter routines using Lemon parser instead of yacc.
Besides using a different tool, the new grammar is much simpler, while
the display filter engine itself is more powerful and more easily extended.
Add dftest executable, to test display filter "bytecode" generation.
Add option to "configure" to build dftest or randpkt, both of which are not
built by default.
Implement Ed Warnicke's ideas about dranges in the new display filter and
ftype code.
Remove type FT_TEXT_ONLY in favor of FT_NONE, and have protocols registered
as FT_PROTOCOL. Thus, FT_NONE is used only for simple labels in the proto tree,
while FT_PROTOCOL is used for protocols. This was necessary for being
able to make byte slices (ranges) out of protocols, like "frame[0:3]"
Win32 Makefile.nmake's will be added tonight.
svn path=/trunk/; revision=2967
João Valverde