diff options
| -rw-r--r-- | driver.c | 33 |
1 files changed, 32 insertions, 1 deletions
@@ -352,6 +352,17 @@ static FILE *smtp_open(struct query *ctl) batchcount = 0; } + /* + * RFC 1123 requires that the domain name in HELO address is a + * "valid principal domain name" for the client host. We + * violate this with malice aforethought in order to make the + * Received headers and logging look right. + * + * In fact this code relies on the RFC1123 requirement that the + * SMTP listener must accept messages even if verification of the + * HELO name fails (RFC1123 section 5.2.5, paragraph 2). + */ + /* if no socket to this host is already set up, try to open ESMTP */ if (lead->smtp_sockfp == (FILE *)NULL) { @@ -632,6 +643,17 @@ char *realname; /* real name of host */ * nicer). If it won't, fall back on the calling-user * ID. This won't affect replies, which use the header * From address anyway. + * + * RFC 1123 requires that the domain name part of the + * MAIL FROM address be "canonicalized", that is a + * FQDN or MX but not a CNAME. We'll assume the From + * header is already in this form here (it certainly + * is if rewrite is on). RFC 1123 is silent on whether + * a nonexistent hostname part is considered canonical. + * + * This is a potential problem if the MTAs further + * upstream didn't pass canonicalized From lines, *and* + * the local SMTP listener insists on them. */ if (!fromhdr || !(ap = nxtaddr(fromhdr))) ap = user; @@ -696,7 +718,16 @@ char *realname; /* real name of host */ } } - /* now list the recipient addressees */ + /* + * Now list the recipient addressees + * + * RFC 1123 requires that the domain name part of the + * RCPT TO address be "canonicalized", that is a FQDN + * or MX but not a CNAME. RFC1123 doesn't say whether + * the FQDN part can be null (as it frequently will be + * here), but it's hard to see how this could cause a + * problem. + */ for (idp = xmit_names; idp; idp = idp->next) if (SMTP_rcpt(sinkfp, idp->id) == SM_OK) good_addresses++; |