Thanks,
I thought this might be the case. Is there any solution to enforce this
on the proxy? If not, will a feature request be considered anytime soon?
I see the proxies as the first line of defense against IMAP "abuse" and
I think it's consistent having the same configurable option available on
both backends and the proxies.
---
Adi Pircalabu
On 14-03-2017 20:17, Sami Ketola wrote:
Hi,
mail_max_userip_connections is only enforced at the backend level. The
setting has no effect on proxy. If you want to force the limit then
you can only do it in the backend.
Sami
On 9 Mar 2017, at 12.05, Adi Pircalabu <a...@ddns.com.au> wrote:
Quick follow-up: updated the proxies to 2.2.28, but I still couldn't
find a way to limit the inbound IMAP connections per IP & username. I
know "mail_max_userip_connections" limit works for the mail stores,
but it doesn't seem to have any effect on the proxies. I'm using a mix
of Dovecot & Courier-IMAP servers as backends.
Basically I need to find a way to enforce the maximum limit for the
username<>remoteip so that, if I have:
ESTCONNS=`doveadm -f flow proxy list | grep
"username=us...@domain.com.proto=imap" | wc -l`
$ESTCONNS is lower or equal than the configured limit.
The proxies are configured as per
https://wiki2.dovecot.org/PasswordDatabase/ExtraFields/Proxy to
forward the password to the remote server using MySQL. In
dovecot-sql.conf.ext I have:
password_query = SELECT NULL AS password, 'Y' as nopassword, host,
email as email, 'any-cert' as 'starttls', 'Y' AS proxy FROM mailbox
WHERE email = '%u' AND disabled_smtpauth=0
At the moment the only way I can limit the number of established
connections per source IP address on the Dovecot proxies is using
iptables, which isn't what I want.
Where else can I look?
Adi Pircalabu, System Administrator
DDNS, a Total Internet Company
159 Barkly Avenue, Burnley, Vic 3121, T +61 3 9815 6868
On 08/03/17 12:32, Adi Pircalabu wrote:
Hi,
Trying to keep abusive/buggy IMAP clients at bay on a number of
Dovecot proxy servers, I've reconfigured them to use
"mail_max_userip_connections = 50" in the "protocol imap" section,
followed by restarting Dovecot. Yet, I'm still seeing 160+
established connections from a single IP address for the same email
account. Am I missing anything?
# 2.2.27 (c0f36b0): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.16 (fed8554)
# OS: Linux 2.6.32-642.4.2.el6.x86_64 x86_64 CentOS release 6.8
(Final)
auth_cache_negative_ttl = 5 mins
auth_cache_size = 16 M
auth_cache_ttl = 18 hours
default_client_limit = 6120
default_process_limit = 500
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope
encoded-character vacation subaddress comparator-i;ascii-numeric
relational regex imap4flags copy include variables body enotify
environment mailbox date index ihave duplicate mime foreverypart
extracttext imapflags notify
mbox_write_locks = fcntl
namespace inbox {
inbox = yes
location =
mailbox Drafts {
special_use = \Drafts
}
mailbox Junk {
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
special_use = \Trash
}
prefix =
}
passdb {
args = /etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
plugin {
sieve = file:~/sieve;active=~/.dovecot.sieve
sieve_extensions = +notify +imapflags
}
protocols = imap pop3 lmtp sieve
service auth {
client_limit = 6120
}
service imap-login {
process_limit = 2048
process_min_avail = 20
service_count = 0
vsz_limit = 256 M
}
service imap {
process_limit = 2048
}
service managesieve-login {
inet_listener sieve {
port = 4190
}
service_count = 0
vsz_limit = 128 M
}
service managesieve {
process_limit = 1024
}
service pop3 {
process_limit = 1024
}
[...]
protocol imap {
imap_capability = IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE
mail_max_userip_connections = 50
}
