Commit Graph

29 Commits

Author SHA1 Message Date
João Valverde c98df5eef5 dfilter: Print syntax tree using dftest + format enhancements
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.
2022-04-05 12:04:37 +01:00
João Valverde 260942e170 dfilter: Refactor macro tree references
This replaces the current macro reference system with
a completely different implementation. Instead of a macro a reference
is a syntax element. A reference is a constant that can be filled
in the dfilter code after compilation from an existing protocol tree.
It is best understood as a field value that can be read from a fixed
tree that is not the frame being filtered. Usually this fixed tree
is the currently selected frame when the filter is applied. This
allows comparing fields in the filtered frame with fields in the
selected frame.

Because the field reference syntax uses the same sigil notation
as a macro we have to use a heuristic to distinguish them:
if the name has a dot it is a field reference, otherwise
it is a macro name.

The reference is synctatically validated at compile time.

There are two main advantages to this implementation (and a couple of
minor ones):

The protocol tree for each selected frame is only walked if we have a
display filter and if the display filter uses references. Also only the
actual reference values are copied, intead of loading the entire tree
into a hash table (in textual form even).

The other advantage is that the reference is tested like a protocol
field against all the values in the selected frame (if there is more
than one).

Currently the reference fields are not "primed" during dissection, so
the entire tree is walked to find a particular reference (this is
similar to the previous implementation).

If the display filter contains a valid reference and the reference is
not loaded at the time the filter is run the result is the same as a
non existing field for a regular READ_TREE instruction.

Fixes #17599.
2022-03-29 12:36:31 +00:00
João Valverde c5a19582e4 epan: Convert to use stdio.h from GLib
Replace:
    g_snprintf() -> snprintf()
    g_vsnprintf() -> vsnprintf()
    g_strdup_printf() -> ws_strdup_printf()
    g_strdup_vprintf() -> ws_strdup_vprintf()

This is more portable, user-friendly and faster on platforms
where GLib does not like the native I/O.

Adjust the format string to use macros from intypes.h.
2021-12-19 19:29:53 +00:00
João Valverde fbfb4959ae dfilter: Better representation for charconst 2021-11-27 18:38:22 +00:00
João Valverde 702c7f0cc8 Remove stale comment. 2021-11-24 10:45:42 +00:00
João Valverde 943c282009 dfilter: Parse character constants in lexer
Invalid character constants should be handled in the lexical scanner.

Todo: See if some code could be shared to parse double quoted strings.

It also fixes some unintuitive type coercions to string. Character
constants should be treated as characters, or maybe integers, or
maybe even throw an invalid comparison error, but coverting to a
literal string or byte array is surprising and not particularly
useful:
  '\xFF' -> "'\xFF'" (equals)
  '\xFF' -> "FF"     (contains)

Before:

    Filter: http.request.method contains "\x63"

    Constants:
    00000 PUT_FVALUE	"c" <FT_STRING> -> reg#1
    (...)

    Filter: http.request.method contains '\x63'

    Constants:
    00000 PUT_FVALUE	"63" <FT_STRING> -> reg#1
    (...)

    Filter: http.request.method == "\x63"

    Constants:
    00000 PUT_FVALUE	"c" <FT_STRING> -> reg#1
    (...)

    Filter: http.request.method == '\x63'

    Constants:
    00000 PUT_FVALUE	"'\\x63'" <FT_STRING> -> reg#1
    (...)

After:

    Filter: http.request.method contains '\x63'

    Constants:
    00000 PUT_FVALUE	"c" <FT_STRING> -> reg#1
    (...)

    Filter: http.request.method == '\x63'

    Constants:
    00000 PUT_FVALUE	"c" <FT_STRING> -> reg#1
    (...)
2021-11-24 08:40:20 +00:00
João Valverde 274531820a Move regex code to wsutil 2021-11-14 21:00:59 +00:00
João Valverde b9f2e4b7fa Make PCRE2 a required dependency 2021-11-14 21:00:59 +00:00
João Valverde ed8a02af17 dfilter: Add support for PCRE2
PCRE2 is the future of PCRE. The only advantage of GRegex is that
it comes bundled with GLib, which is not an advantage at all.
PCRE2 is widely available, the GRegex abstractions layer are not a
good fit and abstract things that don't need abstracting or that we
could handle better ourselves, there are open bugs (#12997) and
maintenance is spotty at best.

GRegex comes with many of the problems of bundled code, aggravated by
the fact that it completely falls outside of our control.
2021-11-14 21:00:59 +00:00
João Valverde 1a32a75a62 ftypes: Internal headers need to be internal
The header ftypes-int.h should not be used outside of epan/ftypes
because it is a private header.

The functions fvalue_free() and fvalue_cleanup() need not and should
not be macros either.
2021-11-11 03:15:31 +00:00
João Valverde db04d188e1 Remove some unnecessary casts.
Casts are best avoided unless they are truly required. Fix some
constness mismatches this revealed.
2021-10-27 10:24:20 +01:00
João Valverde e8800ff3c4 dfilter: Add a thin encapsulation layer for REs 2021-10-18 12:09:36 +00:00
João Valverde 07371d4557 dfilter: Split tostr() into debug and pretty print 2021-10-11 21:55:45 +00:00
João Valverde 3ea2a61f2a dfilter: Display syntax tree for debugging
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.
2021-09-30 16:29:11 +01:00
Guy Harris b61fd6d76a dfilter, ftypes: get rid of FT_PCRE.
It's not a valid field type, it's only a hack to support regular
expression matching in packet-matching expressions.

Instead, in the packet-matching code, have a separate syntax tree type
for Perl-compatible regular expressions, and a separate instruction to
load one into a register, and have the "matching" operator for field
types take a GRegex * as the second argument.
2021-03-21 03:27:44 -07:00
Guy Harris 20800366dd HTTPS (almost) everywhere.
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>
2019-07-26 18:44:40 +00:00
Peter Wu e8e60df4ce dfilter: fix memory leaks if a dfilter fails to compile
A display filter can contain values such as strings, numbers, etc. These
are internally stored in a fvalue_t structure. While compiling a display
filter, it will store a fvalue_t in a node of type STTYPE_FVALUE.

These nodes are created while parsing the dfilter in dfilter_compile().
If the semantic check and conversion (dfw_semcheck()) succeeds, it will
transfer the values of the parsed tree to dfw_gencode(). After that,
dfwork_free will dispose the tree while a compiled dfilter code remains.
When the dfilter code is destroyed, it will free the values too.

However, when dfw_semcheck() fails (for example, due to an illegal
filter such as "len(badname)==1"), it will skip "dfw_gencode()" and
consequently the fvalue data is not transferred nor freed. Fix this by
always freeing the data (unless the data was stolen by dfw_gencode()).

Fixes a memory leak reported for case_dfunction_string::test_fail_2
which was detected by ASAN.

Bug: 15442
Change-Id: I9b1cb613659890c8ddcfa57f11f9d3f61a51a3f9
Reviewed-on: https://code.wireshark.org/review/31757
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
2019-01-28 11:09:17 +00:00
Dario Lombardo 55c68ee69c epan: use SPDX indentifiers.
Skipping dissectors dir for now.

Change-Id: I717b66bfbc7cc81b83f8c2cbc011fcad643796aa
Reviewed-on: https://code.wireshark.org/review/25694
Petri-Dish: Dario Lombardo <lomato@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
2018-02-08 19:29:45 +00:00
Bill Meier 3e3fc9fc5e epan/dfilter/*.c: As needed: Add editor modelines & Fix indentation
Change-Id: I410839329a98bd806c60961dfb9693d5eeeeb702
Reviewed-on: https://code.wireshark.org/review/7104
Reviewed-by: Bill Meier <wmeier@newsguy.com>
2015-02-13 19:04:44 +00:00
Alexis La Goutte 296591399f Remove all $Id$ from top of file
(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>
2014-03-04 14:27:33 +00:00
Jeff Morriss 3729335973 We always HAVE_CONFIG_H so don't bother checking whether we have it or not.
svn path=/trunk/; revision=45016
2012-09-20 01:48:30 +00:00
Jakub Zawadzki bf81b42e1e Update Free Software Foundation address.
(COPYING will be updated in next commit)

svn path=/trunk/; revision=43536
2012-06-28 22:56:06 +00:00
Jakub Zawadzki addf9236dc Support multiple relation test without logic and (python-like)
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
2012-06-19 12:12:41 +00:00
Stig Bjørlykke 6d4a2e7ebf Changed email address for Gerald from zing.org to wireshark.org
in a lot of files, which I suppose is correct.

svn path=/trunk/; revision=24034
2008-01-08 22:54:51 +00:00
Ronnie Sahlberg 89f022b12b name change
svn path=/trunk/; revision=18197
2006-05-21 05:12:17 +00:00
Guy Harris 8a8b883450 Set the svn:eol-style property on all text files to "native", so that
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
2004-07-18 00:24:25 +00:00
Jörg Mayer 48be4e530d Removed trailing whitespaces from .h and .c files using the
winapi_cleanup tool written by Patrik Stridvall for the wine
project.

svn path=/trunk/; revision=6116
2002-08-28 20:41:00 +00:00
Gilbert Ramirez 96e0398fc6 Grumble, grumble. I forgot to add the license comment at the top
of these files.

svn path=/trunk/; revision=2968
2001-02-01 20:31:21 +00:00
Gilbert Ramirez 8f1fff2e6a Create a more modular type system for the FT_* types. Put them
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
2001-02-01 20:21:25 +00:00