InfoMagic Source Code 1993 July

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Text File | 1991-02-28 | 19.6 KB | 567 lines

This is a distribution of both client and server telnet. These programs have been compiled on: telnet telnetd BSD 4.3 Reno X X UNICOS 5.1 X X UNICOS 6.0 X X UNICOS 6.1 X X UNICOS 7.0 X X SunOs 3.5 X X (no linemode in server) SunOs 4.1 X X (no linemode in server) DYNIX V3.0.17.9 X X (no linemode in server) Ultrix 3.1 X X (no linemode in server) Ultrix 4.0 X X (no linemode in server) In addition, previous versions have been compiled on the following machines, but were not available for testing this version. telnet telnetd SunOs 4.0.3c X X (no linemode in server) BSD 4.3 X X (no linemode in server) DYNIX V3.0.12 X X (no linemode in server) Februrary 22, 1991: Features: This version of telnet/telnetd has support for both the AUTHENTICATION and ENCRYPTION options. The AUTHENTICATION option is fairly well defined, and an option number has been assigned to it. The ENCRYPTION option is still in a state of flux; an option number has NOT been assigned to it yet. The code is provided in this release for experimental and testing purposes. The telnet "send" command can now be used to send do/dont/will/wont commands, with any telnet option name. The rules for when do/dont/will/wont are sent are still followed, so just because the user requests that one of these be sent doesn't mean that it will be sent... The telnet "getstatus" command no longer requires that option printing be enabled to see the response to the "DO STATUS" command. A -n flag has been added to telnetd to disable keepalives. A new telnet command, "auth" has been added (if AUTHENTICATE is defined). It has four sub-commands, "status", "debug", "disable", "enable" and "help". A new telnet command, "encrypt" has been added (if ENCRYPT is defined). It has many sub-commands: "enable", "type", "start", "stop", "input", "-input", "output", "-output", "status", "auto", "verbose", "debug", and "help". An "rlogin" interface has been added. If the program is named "rlogin", or the "-r" flag is given, then an rlogin type of interface will be used. ~. Terminates the session ~<susp> Suspend the session ~^] Escape to telnet command mode ~~ Pass through the ~. BUG: If you type the rlogin escape character in the middle of a line while in rlogin mode, you cannot erase it or any characters before it. Hopefully this can be fixed in a future release... General changes: A "libtelnet.a" has now been created. This libraray contains code that is common to both telnet and telnetd. This is also where library routines that are needed, but are not in the standard C library, are placed. The makefiles have been re-done. All of the site specific configuration information has now been put into a single "Config.generic" file, in the top level directory. Changing this one file will take care of all three subdirectories. Also, to add a new/local definition, a "Config.local" file may be created at the top level; if that file exists, the subdirectories will use that file instead of "Config.generic". Many 1-2 line functions in commands.c have been removed, and just inserted in-line, or replaced with a macro. Bug Fixes: The non-termio code in both telnet and telnetd was setting/clearing CTLECH in the sg_flags word. This was incorrect, and has been changed to set/clear the LCTLECH bit in the local mode word. The SRCRT #define has been removed. If IP_OPTIONS and IPPROTO_IP are defined on the system, then the source route code is automatically enabled. The NO_GETTYTAB #define has been removed; there is a compatability routine that can be built into libtelnet to achive the same results. The server, telnetd, has been switched to use getopt() for parsing the argument list. The code for getting the input/output speeds via cfgetispeed()/cfgetospeed() was still not quite right in telnet. Posix says if the ispeed is 0, then it is really equal to the ospeed. The suboption processing code in telnet now has explicit checks to make sure that we received the entire suboption (telnetd was already doing this). The telnet code for processing the terminal type could cause a core dump if an existing connection was closed, and a new connection opened without exiting telnet. Telnetd was doing a TCSADRAIN when setting the new terminal settings; This is not good, because it means that the tcsetattr() will hang waiting for output to drain, and telnetd is the only one that will drain the output... The fix is to use TCSANOW which does not wait. Telnetd was improperly setting/clearing the ISTRIP flag in the c_lflag field, it should be using the c_iflag field. When the child process of telnetd was opening the slave side of the pty, it was re-setting the EXTPROC bit too early, and some of the other initialization code was wiping it out. This would cause telnetd to go out of linemode and into single character mode. One instance of leaving linemode in telnetd forgot to send a WILL ECHO to the client, the net result would be that the user would see double character echo. If the MODE was being changed several times very quickly, telnetd could get out of sync with the state changes and the returning acks; and wind up being left in the wrong state. September 14, 1990: Switch the client to use getopt() for parsing the argument list. The 4.3Reno getopt.c is included for systems that don't have getopt(). Use the posix _POSIX_VDISABLE value for what value to use when disabling special characters. If this is undefined, it defaults to 0x3ff. For non-termio systems, TIOCSETP was being used to change the state of the terminal. This causes the input queue to be flushed, which we don't want. This is now changed to TIOCSETN. Take out the "#ifdef notdef" around the code in the server that generates a "sync" when the pty oputput is flushed. The potential problem is that some older telnet clients may go into an infinate loop when they receive a "sync", if so, the server can be compiled with "NO_URGENT" defined. Fix the client where it was setting/clearing the OPOST bit in the c_lflag field, not the c_oflag field. Fix the client where it was setting/clearing the ISTRIP bit in the c_lflag field, not the c_iflag field. (On 4.3Reno, this is the ECHOPRT bit in the c_lflag field.) The client also had its interpretation of WILL BINARY and DO BINARY reversed. Fix a bug in client that would cause a core dump when attempting to remove the last environment variable. In the client, there were a few places were switch() was being passed a character, and if it was a negative value, it could get sign extended, and not match the 8 bit case statements. The fix is to and the switch value with 0xff. Add a couple more printoption() calls in the client, I don't think there are any more places were a telnet command can be received and not printed out when "options" is on. A new flag has been added to the client, "-a". Currently, this just causes the USER name to be sent across, in the future this may be used to signify that automatic authentication is requested. The USER variable is now only sent by the client if the "-a" or "-l user" options are explicity used, or if the user explicitly asks for the "USER" environment variable to be exported. In the server, if it receives the "USER" environment variable, it won't print out the banner message, so that only "Password:" will be printed. This makes the symantics more like rlogin, and should be more familiar to the user. (People are not used to getting a banner message, and then getting just a "Password:" prompt.) Re-vamp the code for starting up the child login process. The code was getting ugly, and it was hard to tell what was really going on. What we do now is after the fork(), in the child: 1) make sure we have no controlling tty 2) open and initialize the tty 3) do a setsid()/setpgrp() 4) makes the tty our controlling tty. On some systems, #2 makes the tty our controlling tty, and #4 is a no-op. The parent process does a gets rid of any controlling tty after the child is fork()ed. Use the strdup() library routine in telnet, instead of the local savestr() routine. If you don't have strdup(), you need to define NO_STRDUP. Add support for ^T (SIGINFO/VSTATUS), found in the 4.3Reno distribution. This maps to the AYT character. You need a 4-line bugfix in the kernel to get this to work properly: > *** tty_pty.c.ORG Tue Sep 11 09:41:53 1990 > --- tty_pty.c Tue Sep 11 17:48:03 1990 > *************** > *** 609,613 **** > if ((tp->t_lflag&NOFLSH) == 0) > ttyflush(tp, FREAD|FWRITE); > ! pgsignal(tp->t_pgrp, *(unsigned int *)data); > return(0); > } > --- 609,616 ---- > if ((tp->t_lflag&NOFLSH) == 0) > ttyflush(tp, FREAD|FWRITE); > ! pgsignal(tp->t_pgrp, *(unsigned int *)data, 1); > ! if ((*(unsigned int *)data == SIGINFO) && > ! ((tp->t_lflag&NOKERNINFO) == 0)) > ! ttyinfo(tp); > return(0); > } The client is now smarter when setting the telnet escape character; it only sets it to one of VEOL and VEOL2 if one of them is undefined, and the other one is not already defined to the telnet escape character. Handle TERMIOS systems that have seperate input and output line speed settings imbedded in the flags. Many other minor bug fixes. June 20, 1990: Re-organize makefiles and source tree. The telnet/Source directory is now gone, and all the source that was in telnet/Source is now just in the telnet directory. Seperate makefile for each system are now gone. There are two makefiles, Makefile and Makefile.generic. The "Makefile" has the definitions for the various system, and "Makefile.generic" does all the work. There is a variable called "WHAT" that is used to specify what to make. For example, in the telnet directory, you might say: make 4.4bsd WHAT=clean to clean out the directory. Add support for the ENVIRON and XDISPLOC options. In order for the server to work, login has to have the "-p" option to preserve environment variables. Add the SOFT_TAB and LIT_ECHO modes in the LINEMODE support. Add the "-l user" option to command line and open command (This is passed through the ENVIRON option). Add the "-e" command line option, for setting the escape character. Add the "-D", diagnostic, option to the server. This allows the server to print out debug information, which is very useful when trying to debug a telnet that doesn't have any debugging ability. Turn off the literal next character when not in LINEMODE. Don't recognize ^Y locally, just pass it through. Make minor modifications for Sun4.0 and Sun4.1 Add support for both FORW1 and FORW2 characters. The telnet escpape character is set to whichever of the two is not being used. If both are in use, the escape character is not set, so when in linemode the user will have to follow the escape character with a <CR> or <EOF) to get it passed through. Commands can now be put in single and double quotes, and a backslash is now an escape character. This is needed for allowing arbitrary strings to be assigned to environment variables. Switch telnetd to use macros like telnet for keeping track of the state of all the options. Fix telnetd's processing of options so that we always do the right processing of the LINEMODE option, regardless of who initiates the request to turn it on. Also, make sure that if the other side went "WILL ECHO" in response to our "DO ECHO", that we send a "DONT ECHO" to get the option turned back off! Fix the TERMIOS setting of the terminal speed to handle both BSD's seperate fields, and the SYSV method of CBAUD bits. Change how we deal with the other side refusing to enable an option. The sequence used to be: send DO option; receive WONT option; send DONT option. Now, the sequence is: send DO option; receive WONT option. Both should be valid according to the spec, but there has been at least one client implementation of telnet identified that can get really confused by this. (The exact sequence, from a trace on the server side, is (numbers are number of responses that we expect to get after that line...): send WILL ECHO 1 (initial request) send WONT ECHO 2 (server is changing state) recv DO ECHO 1 (first reply, ok. expect DONT ECHO next) send WILL ECHO 2 (server changes state again) recv DONT ECHO 1 (second reply, ok. expect DO ECHO next) recv DONT ECHO 0 (third reply, wrong answer. got DONT!!!) *** send WONT ECHO (send WONT to acknowledge the DONT) send WILL ECHO 1 (ask again to enable option) recv DO ECHO 0 recv DONT ECHO 0 send WONT ECHO 1 recv DONT ECHO 0 recv DO ECHO 1 send WILL ECHO 0 (and the last 5 lines loop forever) The line with the "***" is last of the WILL/DONT/WONT sequence. The change to the server to not generate that makes this same example become: send will ECHO 1 send wont ECHO 2 recv do ECHO 1 send will ECHO 2 recv dont ECHO 1 recv dont ECHO 0 recv do ECHO 1 send will ECHO 0 There is other option negotiation going on, and not sending the third part changes some of the timings, but this specific example no longer gets stuck in a loop. The "telnet.state" file has been modified to reflect this change to the algorithm. A bunch of miscellaneous bug fixes and changes to make lint happier. This version of telnet also has some KERBEROS stuff in it. This has not been tested, it uses an un-authorized telnet option number, and uses an out-of-date version of the (still being defined) AUTHENTICATION option. There is no support for this code, do not enable it. March 1, 1990: CHANGES/BUGFIXES SINCE LAST RELEASE: Some support for IP TOS has been added. Requires that the kernel support the IP_TOS socket option (currently this is only in UNICOS 6.0). Both telnet and telnetd now use the cc_t typedef. typedefs are included for systems that don't have it (in termios.h). SLC_SUSP was not supported properly before. It is now. IAC EOF was not translated properly in telnetd for SYSV_TERMIO when not in linemode. It now saves a copy of the VEOF character, so that when ICANON is turned off and we can't trust it anymore (because it is now the VMIN character) we use the saved value. There were two missing "break" commands in the linemode processing code in telnetd. Telnetd wasn't setting the kernel window size information properly. It was using the rows for both rows and columns... Questions/comments go to David Borman Cray Research, Inc. 655F Lone Oak Drive Eagan, MN 55123 dab@cray.com. README: You are reading it. Config.generic: This file contains all the OS specific definitions. It has pre-definitions for many common system types, and is in standard makefile fromat. See the comments at the top of the file for more information. Config.local: This is not part of the distribution, but if this file exists, it is used instead of "Config.generic". This allows site specific configuration without having to modify the distributed "Config.generic" file. kern.diff: This file contains the diffs for the changes needed for the kernel to support LINEMODE is the server. These changes are for a 4.3BSD system. You may need to make some changes for your particular system. There is a new bit in the terminal state word, TS_EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn of these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl()s: TIOCEXT Turn on/off the TS_EXTPROC bit TIOCGSTATE Get t_state of tty to look at TS_EXTPROC bit TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the TS_EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set, and the data will contain the following: struct xx { struct sgttyb a; struct tchars b; struct ltchars c; int t_state; int t_flags; } This allows the process on the server side of the pty to know when the state of the terminal has changed, and what the new state is. However, if you define USE_TERMIO or SYSV_TERMIO, the code will expect that the structure returned in the TIOCPKT_IOCTL is the termio/termios structure. stty.diff: This file contains the changes needed for the stty(1) program to report on the current status of the TS_EXTPROC bit. It also allows the user to turn on/off the TS_EXTPROC bit. This is useful because it allows the user to say "stty -extproc", and the LINEMODE option will be automatically disabled, and saying "stty extproc" will re-enable the LINEMODE option. telnet.state: Both the client and server have code in them to deal with option negotiation loops. The algorithm that is used is described in this file. tmac.doc: Macros for use in formatting the man pages on non-4.3Reno systems. telnet: This directory contains the client code. No kernel changes are needed to use this code. telnetd: This directory contains the server code. If LINEMODE or KLUDGELINEMODE are defined, then the kernel modifications listed above are needed. libtelnet: This directory contains code that is common to both the client and the server. arpa: This directory has a new <arpa/telnet.h> The following TELNET options are supported: LINEMODE: The LINEMODE option is supported as per RFC1116. The FORWARDMASK option is not currently supported. BINARY: The client has the ability to turn on/off the BINARY option in each direction. Turning on BINARY from server to client causes the LITOUT bit to get set in the terminal driver on both ends, turning on BINARY from the client to the server causes the PASS8 bit to get set in the terminal driver on both ends. TERMINAL-TYPE: This is supported as per RFC1091. On the server side, when a terminal type is received, termcap/terminfo is consulted to determine if it is a known terminal type. It keeps requesting terminal types until it gets one that it recongnizes, or hits the end of the list. The server side looks up the entry in the termcap/terminfo data base, and generates a list of names which it then passes one at a time to each request for a terminal type, duplicating the last entry in the list before cycling back to the beginning. NAWS: The Negotiate about Window Size, as per RFC 1073. TERMINAL-SPEED: Implemented as per RFC 1079 TOGGLE-FLOW-CONTROL: Implemented as per RFC 1080 TIMING-MARK: As per RFC 860 SGA: As per RFC 858 ECHO: As per RFC 857 STATUS: The server will send its current status upon request. It does not ask for the clients status. The client will request the servers current status from the "send getstatus" command. ENVIRON: This option is currently being defined by the IETF Telnet Working Group, and an RFC has not yet been issued, but should be in the near future... X-DISPLAY-LOCATION: This functionality can be done through the ENVIRON option, it is added here for completeness. AUTHENTICATION: This option is currently being defined by the IETF Telnet Working Group, and an RFC has not yet been issued. The basic framework is pretty much decided, but the definitions for the specific authentication schemes is still in a state of flux. ENCRYPT: This option is currently being defined by the IETF Telnet Working Group, and an RFC has not yet been issued. The draft RFC is still in a state of flux, so this code may change in the future.