lmtpd NUL rejection

[Lawrence Greenfield]

   From: simon.brady at otago.ac.nz
   Date: Tue, 14 Jan 2003 17:24:17 +1300 (NZDT)
[...]
   Along the way, I've discovered a related bug in lmtpd (2.1.11). If a
   misconfigured client sends a message with lines longer than 8190 chars,
   the following code in imap/lmtpengine.c (lines 672-675) will incorrectly
   report the presence of NULs:

		else if (p[0] != '\n') {
		    /* line contained a \0 not at the end */
		    r = IMAP_MESSAGE_CONTAINSNULL;
		    continue;

   (It assumes all lines end with '\n', which prot_fgets() doesn't 
   guarantee.)

   I'm not sure what the right fix is for this. It's trivial to identify the 
   long-line case, but should lmtpd return an error (and if so, what?), or 
   should it try to handle this pathological case?

SMTP only requires 1000 character line support; 8000 is pretty
generous. I would define a new error in imap_err.et
(IMAP_LINE_TOO_LONG) and return that when appropriate.

Larry