changelog

该软件是一个有名的基于网络的入侵检测系统

	* decode.c: Rewrote the packet decode engine.  The new engine 
		    performs far fewer copies and tries to set pointers
		    to defer expensive function calls as late as possible.
		    The PrintIP and Net data structures have been eliminated
		    so that there is no global data required to perform tests
		    or log a given packet.  This will make any future multi-
		    threading efforts much easier. 

	* log.c: * Much of the logging system was rewritten to take advantage 
	           of the new detection and decoding engines.
		
		 * Made the SMB alerting a configure-time option.  If you 
		   want to use the SMB alerting feature, you need to specify
		   a "--enable-smbalerts" when you run configure.  This is a 
		   safety measure, read the INSTALL file for the reasons why!

	* snort.c: Fixed a bug in the netmask generation code that wouldn't
		   allow certain CIDR blocks to be represented.  Thanks to 
		   Nick Rogness <[e-mail]> for the heads
		   up on this one!

1999-06-21  mfr  <[e-mail]>
	
	* snort.c: * Added new command line switches: -f, -M, -r.  
		       -f: Record fragmented packets in tcpdump format
		       -M: Send alerts via WinPopup messages (requires Samba)
		       -r: Read and process files generated by tcpdump 

		   * Fixed startup dumpout code to not drop people if they just
		     want to log all packets to the system

		   * Added static netmask generation, this rids Snort of the
		     need to link to libm, which makes it more Trinux friendly.

	* rules.c: * Added new rule option types:
		      logto: log packets matching this rule to the specified
                             log file
		      minfrag: set the minimum size of fragmented packets, which
			       allows alerts to be generated for traffic coming
			       from things like nmap or fragrouter
		      tcp flags: Added the ability to include the reserved bits
			         of the tcp flags into the rules set.  These
			         flags are specified with a "1" and "2.  
			         Inclusion of these flags allows Queso 
                                 fingerprinting attempts to be detected.
		      id: The IP ID field may be specified.  This is nice for 
			  picking up handcrafted packets with recognizable ID
			  fields, like 31337 or other "elite" numbers.
		      ack: The TCP ack field.  Using this, nmap tcp "pings" may
			   be detected.
		      seq: The TCP sequence number.  This is provided for 
			   completeness (I figured since I was putting in the 
			   ack field, I may as well include the sequence as 
			   well)
		   * Rewrote the content parser.  It now accepts "\" as a 
		     literal character, so things like "\|" or "\~" will work
		     properly.

		   * fixed the parenthesis finder for the options code

		   * adjusted the acceptable character range in the rule
		     parsers

	* log.c: * fragment logging more descriptive and correct

		 * fixed IP header logging for ICMP and fragmented packets

		 * improved "bad packet" printing/logging

		 * fixed IP option output code

		 * IP packet ID field now displayed

	* decode.c: * fixed IP fragment decoders and logic streams.

		    * fragments are now fed thru the rules set (sorta)

1999-05-17  mfr  <[e-mail]>

	* snort.c: Added "-x" command line switch to explicitly activate IPX
		   packet notification so people in mixed protocol environments
                   can maintain sanity.  Also added in the new packet counter to
		   generate statistics on exit of the number/percentage of 
		   each type of packet that Snort sees.

	* decode.h: Removed the references to u_int16_t and u_int32_t and 
		    replaced them with u_short and u_long.  The u_int*_t 
		    variables caused portability headaches.  Also added in the 
		    new patch from Chris S. for the  WORDS_MUSTALIGN definition
		    for S/Linux version.

	* log.h: Fixed the LOG_AUTH/LOG_AUTHPRIV problem that Solaris users 
		 were having.

	* decode.c: Added the new packet statistics counters throughout the 
		    code.  Cleaned up the IPX code a bit.  

	* rules.c: Cleaned up the isspace(3) (et al) calls.

	* etc: Made lots of tweaks to the autoconf stuff to get the S/Linux
	       and HP-UX versions to compile cleanly out of the box.

1999-04-28  mfr  <[e-mail]>

	* rules.c: Added the code to change the order the rules are applied in.

	* snort.c: Added two new command line switches: "-o" and "-s".

	* decode.c: Added in new layer 2 decoding for SLIP and RAW packet 
	            types.

        * log.c: Added code to send alert notification to syslog.

1999-04-17  mfr  <[e-mail]>

	* rules.c: Rewrote the rules option parser.  It's now a much more
                   consistant interface for both reading rules into the program
                   and writing them as a user.  Added in new rule types to 
                   alert on TTL values, and ICMP types/codes.

	* log.c: Most of the logging code has been dramatically rewritten as 
                 well, and it now works much better. 

	* mstring.c: Added the notion of a meta character to mSplit() so that
                     it was possible to not split on every single occurence of
                     a character in a string.

	* decode.c: Smoothed out all the logging system calls to work nicely
                    with the new log code.

1999-04-08  mfr  <[e-mail]>

	* rules.c: Moved AlertPkt() and LogPkt() to log.c

	* log.c: Totally revamped the logging code to be more logical and 
                 have less duplication in the code.  There are now seperate 
                 logging functions for each of the layers of the packet.  
                 PrintIPPkt() has been totally rewritten, PrintFragHeader has
                 been eliminated, and two functions have been moved over from
                 rules.c and completely rewritten as well.

	* decode.c: Reworked the routines which called the logging functions.

1999-04-06  mfr  <[e-mail]>

	* decode.c: added code to display/log the Fragment ID field of the IP
                    header.  Got a nice patch from Sebastian to add in TOS 
                    decoding as well.  Added ethernet header logging and 
                    display code.

	* mstring.c: fixed the match() routine.  It had a tendency to miss some
                     things some of the time.  (oops!)  Content based matching
                     should work all the time now.

	* log.c: added code to display some of the new stuff that's decoded.

	* snort.c: add a new command line switch: "-e".  This will display the 
                   ethernet header data in both the log files and on the screen.

1999-03-24  mfr  <[e-mail]>
        
        * decode.c: fixed the damned TCP and IP options decoders.  These things
                    were a friggin pain in the ass to program up properly.
                    Recoding them stopped the huge loop that they had a bad
                    tendancy to get stuck in, thereby making the rest of the 
                    program nigh infinitely more useful for just about any
                    friggin problem under the friggin sun.  Frig it.

	* log.c: Stopped the insanity of unnessary carriage returns in the log
                 files and on screen printouts.  Another PITA.

        * rules.c: Fixed output formatting yet again.


1999-03-21  mfr  <[e-mail]>

	* snort.c: fixed a bug in the timestamp code so the month prints out
                   right

	* decode.c: added code to detect and decode IP and TCP Options.  Also
                 added code to print packet fragments with truncated headers
                 into a PACKET_FRAG file which gets dumped in the default log
                 directory.

	* log.c: added code and data structures to print out IP and TCP Options
                 plus I fixed the f'd up fragment print out logic.  Changed
                 OpenLogFile() to include a mode argument for packet fragment
                 print out.

	* rules.c: rewired the entire rules test routine and added some long
                   needed goto's into the program.  I feel manly now.  Also
                   added a new rule field: TCP flags.  This allows us to 
                   alert/log/pass on tcp flags.  Also added in port range 
                   functionality, you can now specify a range of ports, or 
                   greater than/less than a specified port.
 

1999-03-08  mfr  <[e-mail]>

	* snort.c: Ripped off the timestamp printout routines from tcpdump
		   and stuffed them into snort.c, yum yum.  This gives us
		   millisecond timestamping on the packets for those of you
		   interested in such things.


1999-03-06  mfr  <[e-mail]>

	* mstring.c: mContainsSubstring has been replaced.  mContainsSubstring 
		     is a brute force pattern matcher, and is therefore very
		     slow and not too efficient.  The new routine, match(), 
		     implements a Boyer-Moore string search algorithm and is 
		     much faster in the general case and much more tolerent of
		     "poor" pattern selection.

	* log.c: PrintNetData has been completely rewritten.  It should now be
                 much faster and only needs to generate the print out buffer
                 once per packet.  This routine was a major source of slow 
                 down/dropped packets before.  You still shouldn't use verbose 
                 mode with the "-d" command line switch if you're using Snort 
                 as an IDS, because it's still slow enough to drop some large
                 packets.  Packet print out has changed as well, with the 
                 different packet layers seperated by onto their own lines
                 (well, mostly).  Fragmented packets are now recorded in a 
                 "FRAG" file.

	* decode.c: Snort now detects fragmented packets, plus the DF and MF 
                    bits, and decodes the fragment offset.  
     
	* snort.c: Now displays packet collected/dropped statistics when 
                   shutting down.


1999-02-18  mfr  <[e-mail]>

	* snort.c: Code cleanup and some error checking was added.  The system
		   now accepts the interface name you give it at the command
		   line.  Fixed a problem with underallocating the interface
		   name buffer for names specified on the command line.  
		   Suprisingly, this only came to light when tested on the 
  		   Sparc architecture.

	* log.c: ICMP logging now includes the ICMP code description in the 
		 filename.  This makes it easier to see what you're interested
		 in without having to go digging into the log files.

	* decode.c: Made the ICMP types and codes a little more compatible with
		    being used as a filename.


1999-01-28  mfr  <[e-mail]>

        * rules.c: Rules sorting is now implemented.  There are actually three
                   seperate lists (Pass, Log, Alert) now, with the rules being
                   placed on to the lists in the order they're read from the 
                   rules file.  The rule execution order was changed, now
                   Alert rules are applied first, then Pass Rules, the Log 
                   rules.  Content based rules are available now, the actual
                   application layer data can be searched, both binary and 
                   text, for a specific pattern to activate a rule on.

        * decode.c: Minor changes to reflect the new rules structure.


1999-01-19  mfr  <[e-mail]>

        * snort.c: Modularized the code, big time!  New source modules are log,
                   rules, decode, and mstring.  Dumped SetFlow() for now.

        * rules.c: Rules based packet logging now enabled!

        * log.c: Now keeps track of TCP/UDP conversations better!

        * decode.c: Enhanced decoding of packets, including ICMP ECHO seq and
                    id!
 

1999-01-08  mfr  <[e-mail]>

        * snort.c: Made a fix to SetFlow() so that it wouldn't dump the
                   program if it got traffic from 0.0.0.0 or 255.255.255.255.

        * snort.h: Removed the "#define VERSION" since it's handled in config.h.

        * README: Proper README file included with this distro


1998-12-21  mfr  <[e-mail]>
	* snort.c: Made this file, figured out autoconf