Date: Sun, 17 Mar 2019 17:13:17 +0000 From: bugzilla-noreply@freebsd.org To: ports-bugs@FreeBSD.org Subject: [Bug 236605] mail/sendmail: additional blacklisting for frequent useless connections [patch] Message-ID: <bug-236605-7788@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D236605 Bug ID: 236605 Summary: mail/sendmail: additional blacklisting for frequent useless connections [patch] Product: Ports & Packages Version: Latest Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: Individual Port(s) Assignee: dinoex@FreeBSD.org Reporter: freebsd@oldach.net Assignee: dinoex@FreeBSD.org Flags: maintainer-feedback?(dinoex@FreeBSD.org) Created attachment 202938 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D202938&action= =3Dedit patch In my maillog, I often observe hosts frequently contacting my sendmail with= out issuing any reasonable command, like this for example: Mar 17 03:02:04 nuc sm-mta[98005]: x2H21q18098005: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:02:15 nuc sm-mta[98132]: x2H2278J098132: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:02:27 nuc sm-mta[98166]: x2H22JfW098166: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:02:36 nuc sm-mta[98167]: x2H22SXD098167: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:02:44 nuc sm-mta[98168]: x2H22aUN098168: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:02:53 nuc sm-mta[98169]: x2H22if3098169: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:03:01 nuc sm-mta[98170]: x2H22rvQ098170: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:03:09 nuc sm-mta[98176]: x2H231fG098176: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:03:17 nuc sm-mta[98177]: x2H239Q3098177: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 Mar 17 03:03:26 nuc sm-mta[98211]: x2H23I3V098211: [221.227.107.69] did not issue MAIL/EXPN/VRFY/ETRN during connection to IPv4 In some cases I have observed hundreds of such connection attempts before giving up. As we have blacklisting in the port, I was thinking to use that for calming down such servers. However it appears this particular logic is not in the blacklisting patch set yet. The attached patch implements this. Admittedly it's kind of hackish as the = "did not issue" message is emitted only when sendmail's input file descriptor is already closed, so we cannot use it for hand-over to blacklist() in the same way as it's done for the other blacklist() calls. Therefore I'm dup()ing the input fd early in the command loop for use by blacklist() and close the dup= 'ed fd later. --=20 You are receiving this mail because: You are the assignee for the bug.=
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