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1999-10-12Re-implemented fix to keep display filter from reading data from outsideGilbert Ramirez1-1/+20
the packet boundary. Now the field boundary is honored. The frame boundary is ignored, but of course we put proper field lengths in the proto_tree, right? :) Implemented negative offsets in byte-strings: frame[-4:4] will read the last 4 bytes of a frame. Implemented "offset-only" byte-string comparisons, since the dfilter compiler knows the length of the byte-string you supplied. These are now legal: frame[-4] == 0.0.0.1 tr.dst[0] == 00:06:29 Implemented the use of integers if you're comparing one byte. These are legal: llc[0] == 0xaa llc[0:1] == 0xaa All these forms check against the length of the field, so these will be reported as bad to the user: eth.src[5] == 00:06:29 (goes beyond field boundary) eth.dst == 1.2.3.4.5.6.7 (too long, goes beyond field boundary) Thes is also reported as bad: eth.dst[0:3] == 1.2 (incorrect number of bytes specified) eth.dst[0:1] == eth.src[0:2] (disparate lengths) I had to add a new function, proto_registrar_get_length() in proto.c, which reports the length of a field as can be determined at registration time. There are some shift/reduce errors in the grammar that I need to get rid of. svn path=/trunk/; revision=811
1999-10-11- add handling of FT_IPv6 variablesLaurent Deniel1-4/+2
there is still some work to do in resolv.c (get_host_ipaddr6) - add display filters of this kind in packet-ipv6.c just for testing (display filtering is incomplete) svn path=/trunk/; revision=808
1999-10-11Have "get_host_ipaddr()" return a Boolean indicating whether itGuy Harris1-6/+11
succeeded or failed, and, if it succeeded, have it fill in the IP address if found through a pointer passed as the second argument. Have it first try interpreting its first argument as a dotted-quad IP address, with "inet_aton()", and, if that fails, have it try to interpret it as a host name with "gethostbyname()"; don't bother with "gethostbyaddr()", as we should be allowed to filter on IP addresses even if there's no host name associated with them (there's no guarantee that "gethostbyaddr()" will succeed if handed an IP address with no corresponding name - and it looks as if FreeBSD 3.2, at least, may not succeed in that case). Add a "dfilter_fail()" routine that takes "printf()"-like arguments and uses them to set an error message for the parse; doing so means that even if the filter expression is syntactically valid, we treat it as being invalid. (Is there a better way to force a parse to fail from arbitrary places in routines called by the parser?) Use that routine in the lexical analyzer. If that error message was set, use it as is as the failure message, rather than adding "Unable to parse filter string XXX" to it. Have the code to handle IP addresses and host names in display filters check whether "get_host_ipaddr()" succeeded or failed and, if it failed, arrange that the parse fail with an error message indicating the source of the problem. svn path=/trunk/; revision=802
1999-10-09Fix a typo in error message.Laurent Deniel1-2/+2
svn path=/trunk/; revision=796
1999-10-07Make "dfilter_error()" available to the lexical analyzer.Guy Harris1-9/+29
Get rid of the declaration of the non-existent "dfilter_yyerror()", and put in some #defines to work around the fact that the #defines to replace "yy" with "dfilter_" in the names of Flex-generated and Yacc-generated routines aren't put into a header file, they're put into ".c" files. Have it remember the error message it was handed (unless it's Yacc's boring "parse error" message). When generating the message to be shown to the user on a parse error, make it be the "Unable to parse filter string" message, and, if a non-boring error message was supplied to "dfilter_error()", take that error message onto the end. Don't panic if a field type we don't yet support in the parser is seen; generate an error, telling the user we don't support filter on that type yet. Don't assume that "global_df" has been set if we see an empty statement (if the first token was the end-marker, because, say, the first token the lexical analyzer found was a field of a type not yet supported in filter expressions, "global_df" won't have been set). svn path=/trunk/; revision=783
1999-10-06Fix dfilter scanner to accept hyphenated hostnames for IPv4 addresses.Gilbert Ramirez1-2/+2
svn path=/trunk/; revision=776
1999-10-04Removed dummy protocol and removed bug which prevented the firstGilbert Ramirez1-2/+2
registered protocol's name from being used in a display filter. svn path=/trunk/; revision=766
1999-09-15Changed (again) the way that the FT_BOOLEAN field type works internally.Gilbert Ramirez1-4/+5
Dissector code can add FT_BOOLEAN fields to the proto_tree and pass TRUE or FALSE values (non-zero and zero values). The display filter language, however, treats the checking for the existence of a FT_BOOLEAN field as the checking for its truth. Before this change, packet-tr.c was the only dissector using FT_BOOLEAN fields, and it only added the field to the proto_tree if the TRUE; the dissector was determining the difference between the check for existence and the check for truth. I made this change because packet-ppp.c added some FT_BOOLEAN fields and added them to the tree regardless of truth value, It's more natural just to do it this way and let the display filter code worry about whether to check for existence or truth. So that's how it works now. svn path=/trunk/; revision=679
1999-08-27Changed packet-tr.c to insert tr.sr, a FT_BOOLEAN field, only if tr.srGilbert Ramirez1-4/+1
is true. The test for truth now becomes a test for existence. The dfilter grammar no longer recognizes 'true' and 'false', since you can now check a boolean field via: tr.sr or by its negation: !tr.sr svn path=/trunk/; revision=591
1999-08-20Changed some symbols inside parser, fixed default error message inGilbert Ramirez1-3/+3
dfilter_compile, and removed debug printf that I left in match_selected. svn path=/trunk/; revision=532
1999-08-20Made handling of byte strings in scanner and parser much simpler,Gilbert Ramirez1-72/+9
improving size of grammar and creating the possibility of dfilter_compile reporting errors back to user. In this case, if an ETHER variable is compared against a byte string that is not 6 bytes, an error condition is flagged appropriately. I have not put in the code to conver that error flag to a message to the user, but that's what I'm working on next. Also, fixed sample debug session in README to show correct gdb prompt. svn path=/trunk/; revision=522
1999-08-14Modified YACC grammar to use non-yy symbols, to avoid conflicts withGilbert Ramirez1-28/+28
libpcap's that were compiled with symbols beginning with 'yy'. svn path=/trunk/; revision=487
1999-08-13Moved global memory alloction used in display filters (which was storedGilbert Ramirez1-2/+3
in dfilter-grammar.y) to a new struct dfilter. Display filters now have their own struct, rather than simply being GNode's. This allows multiple display filters to exist at once, aiding John McDermott in his work on colorization. svn path=/trunk/; revision=480
1999-08-12Create a "dfilter-int.h" file, containing stuff used internally to theGuy Harris1-4/+3
display filter code but not outside it (and not static to one of the modules in the display filter code), with most of that stuff moved there from "dfilter.h". Add a declaration of "byte_str_to_guint8_array()" to "dfilter-int.h". svn path=/trunk/; revision=479
1999-08-12One small regex change, just to be safe.Gilbert Ramirez1-2/+2
svn path=/trunk/; revision=478
1999-08-12Fixed two bugs in display filter parsing.Gilbert Ramirez1-5/+17
1. Some IP addresses (like 0.0.0.0) would be interpreted as byte ranges. 2. Parens were being ignored. Thanks to Guy for pointing these out to me. svn path=/trunk/; revision=477
1999-08-05Logical operands needed to set the yylval as well as return theGilbert Ramirez1-11/+11
token to the yacc parser. svn path=/trunk/; revision=446
1999-08-03Removed the "exists" keyword from the grammar. The name of a protocol or aGilbert Ramirez1-36/+16
field by itself assumes you are checking for the existence of that protocol or field. Changed the format of the list of filterable fields in the man page. Developers: run "./configure" so that your configure script will re-create dfilter2pod from the new dfilter2pod.in svn path=/trunk/; revision=426
1999-08-01Changed the display filter scanner from GLIB's GScanner to lex. The codeGilbert Ramirez1-0/+353
as it standed depends on your lex being flex, but that only matters if you're a developer. The distribution will include the dfilter-scanner.c file, so that if the user doesn't modify dfilter-scanner.l, he won't need flex to re-create the *.c file. The new lex scanner gives me better syntax checking for ether addresses. I thought I could get by using GScanner, but it simply wasn't powerful enough. All operands have English-like abbreviations and C-like syntax: and, && ; or, || ; eq, == ; ne, != ; , etc. I removed the ETHER_VENDOR type in favor of letting the user use the [x:y] notation: ether.src[0:3] == 0:6:29 instead of ether.srcvendor == 00:06:29 I implemented the IPXNET field type; it had been there before, but was not implemented. I chose to make it use integer values rather than byte ranges, since an IPX Network is 4 bytes. So a display filter looks like this: ipx.srcnet == 0xc0a82c00 rather than this: ipx.srcnet == c0:a8:2c:00 I can supposrt the byte-range type IPXNET in the future, very trivially. I still have more work to do on the parser though. It needs to check ranges when extracting byte ranges ([x:y]) from packets. And I need to get rid of those reduce/reduce errors from yacc! svn path=/trunk/; revision=414