signal handlers. In this case, use _exit(2) instead, following
the call to shutdown(2).
This fixes rare telnetd hangs.
PR: misc/33672
Submitted by: Umesh Krishnaswamy <umesh@juniper.net>
MFC after: 1 month
this case 16). Use dynamic FD_SETs and calculated high-water marks
throughout. There are also too many versions of telnet in the tree.
Obtained from: OpenBSD and Apple's Radar database
MFC after: 2 days
1) ANSIfy.
2) Clean up ifdefs so that
a) ones that never/always apply are appropriately either
fully removed, or just the #if junk is removed.
b) change #if defined(FOO) for appropiate values of FOO.
(currently AUTHENTICATION and ENCRYPTION)
3) WARNS=2 fixing
4) GC other unused stuff
This code can now be unifdef(1)ed to make non-crypto telnet.
This is by the kind permission of Dave Safford, formerly of TAMU who wrote the
original code. Here is an excerpt of the e-mail exchange concerning this
issue:
Dave Safford wrote:
>Nick Sayer wrote:
>> Some time ago we spoke about SRA and importing it into FreeBSD. I forgot to
>> ask if you had a prefered license boilerplate for the top of the files. It
>> has come up recently, and the SRA code in FreeBSD doesn't have one.
>I really have no preference - use whatever is most convenient in the
>FreeBSD environment.
>dave safford
This is the standard BSD license with clause 3 removed and clause 4
suitably renumbered.
MFC after: 1 day
o Because of export controls, TELNET ENCRYPT option is not supported outside
of the United States and Canada.
o Because of export controls, data encryption
is not supported outside of the United States and Canada.
src/crypto/README revision 1.5 commit log says:
> Crypto sources are no longer export controlled:
> Explain, why crypto sources are still in crypto/.
and actually telnet encryption is used outside of US and Canada now.
Pointed out by: OHSAWA Chitoshi <ohsawa@catv1.ccn-net.ne.jp>
Reviewed by: no objection on doc
to do what they are supposed to: under some circumstances output data would
be truncated, or the buffer would not actually be flushed (possibly leading
to overflows when the caller assumes the operation succeeded). Change the
semantics so that these functions ensure they complete the operation before
returning.
Comment out diagnostic code enabled by '-D reports' which causes an
infinite recursion and an eventual crash.
Patch developed with assistance from ru and assar.
o Fixed `nfrontp' calculations in output_data(). If `remaining' is
initially zero, it was possible for `nfrontp' to be decremented.
Noticed by: dillon
o Replaced leaking writenet() with output_datalen():
: * writenet
: *
: * Just a handy little function to write a bit of raw data to the net.
: * It will force a transmit of the buffer if necessary
: *
: * arguments
: * ptr - A pointer to a character string to write
: * len - How many bytes to write
: */
: void
: writenet(ptr, len)
: register unsigned char *ptr;
: register int len;
: {
: /* flush buffer if no room for new data) */
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
: if ((&netobuf[BUFSIZ] - nfrontp) < len) {
: /* if this fails, don't worry, buffer is a little big */
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
: netflush();
: }
:
: memmove(nfrontp, ptr, len);
: nfrontp += len;
:
: } /* end of writenet */
What an irony! :-)
o Optimized output_datalen() a bit.
non-crypto version)
Also update the crypto telnet's man page to reflect other options
ported from the non-crypto version.
Obtained from: Lyndon Nerenberg <lyndon@orthanc.ab.ca>
references global variables from telnetd, but is also linked into
telnet as well. I was tempted to back out the last sra.c change
as it is 100% bogus and should be taken out and shot, but for now
this bandaid should get world working again. :-(
now the default, so ignore the arguments that turn it on. Add a new -y
argument to turn off encryption in case someone wants to do that. Sync
these changes with the man page (including removing the now obsolete
statement about availability only in the US and Canada).
Sorry there were still several bugs.
-error retry at af missmatch was incomplete.
-af matching for source addr option was wrong
-socket was not freed at retry.
Approved by: jkh
-Should retry as much as possible when some of source
routing intermediate hosts' address families missmatch
happened.
(such as when a host has only A record, and another host
has each of A and AAAA record.)
-Should retry as much as possible when dest addr and
source addr(specified with -s option) address family
missmatch happend
Approved by: jkh
getnameinfo() don't return error at name resolving failure.
But it is used at doaddrlookup(-N) case in telnet, error need to be
returned to correctly initialize hostname buffer.
Discovered at checking recent KAME repository change, noticed by itojun.
SRA does a Diffie-Hellmen exchange and then DES-encrypts the
authentication data. If the authentication is successful, it also
sets up a session key for DES encryption.
SRA was originally developed at Texas A&M University.
This code is probably export restricted (despite the fact that I
originally found it at a University in Germany).
SRA is not perfect. It is vulnerable to monkey-in-the-middle attacks
and does not use tremendously large DH constants (and thus an individual
exchange probably could be factored in a few days on modern CPU
horsepower). It does not, however, require any changes in user or
administrative behavior and foils session hijacking and sniffing.
The goal of this commit is that telnet and telnetd end up in the DES
distribution and that therefore an encrypted session telnet becomes
standard issue for FreeBSD.
This change changes the default handling of linemode so that older and/or
stupider telnet clients can still get wakeup characters like <ESC> and
<CTRL>D to work correctly multiple times on the same line, as in csh
"set filec" operations. It also causes CR and LF characters to be read by
apps in certain terminal modes consistently, as opposed to returning
CR sometimes and LF sometimes, which broke existing apps. The change
was shown to fix the problem demonstrated in the FreeBSD telnet client,
along with the telnet client in Solaris, SCO, Windows '95 & NT, DEC OSF,
NCSA, and others.
A similar change was incorporated in the non-crypto version of telnetd.
This resolves bin/771 and bin/1037.
