🚀 go-pugleaf

In article <3153@hermes.ai.mit.edu> wisner@zug.AI.MIT.EDU (Bill Wisner) writes:
>When sending mail to a host that isn't currently reachable, I should
>be seeing error messages like
>  Deferred: Connection timed out during user open with basel.ai.mit.edu
>Instead, I get this:
>  Deferred: Not a typewriter
>I think that somewhere between the time the connection actually times
>out and the time the error message is generated, something happens to
>change errno to ENOTTY. But what? Anyone know how to fix this?

i believe the problem you are seeing is that errno gets clobbered
during a fprintf() call in usersmtp.c.  look in smtpinit() for the
fprintf() call where one of the arguments is errstring(errno) and add
two assignments to save & restore errno before calling fprintf, ala

				r = errno;
  				fprintf(CurEnv->e_xfp,
  					"421 %s.%s... Deferred: %s\n",
  					pvp[1], m->m_name, errstring(errno));
				errno = r;

of course, why errno is getting set to ENOTTY or some other value by
fprintf is in itself an interesting question ...

dsc

-In article <3153@hermes.ai.mit.edu> wisner@zug.AI.MIT.EDU (Bill Wisner) writes:
->... I should be seeing error messages like
->  Deferred: Connection timed out during user open with basel.ai.mit.edu
->Instead, I get this:
->  Deferred: Not a typewriter

In article <30999@uunet.UU.NET> dsc@izimbra.CSS.GOV
(card carrying aclu member) writes:
-i believe the problem you are seeing is that errno gets clobbered
-during a fprintf() call in usersmtp.c.  look in smtpinit() for the
-fprintf() call where one of the arguments is errstring(errno) and add
-two assignments to save & restore errno before calling fprintf, ala
-
-				r = errno;
-  				fprintf(CurEnv->e_xfp,
-  					"421 %s.%s... Deferred: %s\n",
-  					pvp[1], m->m_name, errstring(errno));
-				errno = r;

This will work, but there are other fixes.

-of course, why errno is getting set to ENOTTY or some other value by
-fprintf is in itself an interesting question ...

fprintf calls isatty when printing the first character to a FILE.
isatty calls ioctl(fd, TIOCGETP) and checks for errors.  TIOCGETP
succeeds only on terminals.  The error, of course, is ENOTTY.

I fixed(?) this by changing the C library routine isatty() to itself
save and restore errno; but a proper program should never check errno
except immediately after a failing system call.  A better fix to
sendmail itself (with or without the change in the C library) is to
have it retain the error number (or string) in the envelope structure.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris