Hi, "- there are already rules for avahi (bonjour) to make discovery work, but connections to the discovered services would need rules allowing the connection"
Then connection to port 8612 should work, but it doesn't. PC talks to 8612 of the printer, and then the printer replies from 8612. And this reply gets blocked. It does not matter whether ufw gets stateful for sane or not. ufw may get this wrong, because the communication starts out as a multicast, thus the recipient address is different than the address that answers. But: It gets even blocked, when a new rule is introduced to allow ALL inbound traffic to 8612, so this rule just simply doesn't work. Adding nf_conntrack_sane DOES NOT fix the problem... I have added nf_conntrack_sane. And yes, I have restarted ufw... This printer/scanner, btw, is not an Epson, but a Canon MX 925. And yes, I have added the BJNP protocol to Sane. But it's not only Sane that does not discover the scanner, also Vuescan does not discover it, and Vuetracks author Ed Hamrick advises me to sniff the packets... Syslog excerpt of an attempted network discovery: .31 is the PC, .251 is the printer, .254 would be the router to the internet (not used here, of course). Dec 17 16:56:09 FSC-neu kernel: [255876.935983] [UFW ALLOW] IN= OUT=eth0 SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12815 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 PC multicast to (all) printers port 8612, ALLOWed Dec 17 16:56:09 FSC-neu kernel: [255876.936015] [UFW ALLOW] IN=eth0 OUT= MAC= SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12815 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 Another multicast... Dec 17 16:56:09 FSC-neu kernel: [255876.937195] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=26547 PROTO=UDP SPT=8612 DPT=59438 LEN=40 Printers reply from 8612 gets BLOCKed Dec 17 16:56:10 FSC-neu kernel: [255877.438000] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=146 TOS=0x00 PREC=0x00 TTL=64 ID=51278 PROTO=UDP SPT=5353 DPT=59438 LEN=126 Dec 17 16:56:10 FSC-neu kernel: [255877.487316] [UFW ALLOW] IN= OUT=eth0 SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12879 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 Dec 17 16:56:10 FSC-neu kernel: [255877.487333] [UFW ALLOW] IN=eth0 OUT= MAC= SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12879 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 PC repeating the mulicast to the printer Dec 17 16:56:10 FSC-neu kernel: [255877.488620] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=59770 PROTO=UDP SPT=8612 DPT=59438 LEN=40 Printers responsed BLOCKed again... Dec 17 16:56:10 FSC-neu kernel: [255877.986032] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=146 TOS=0x00 PREC=0x00 TTL=64 ID=53766 PROTO=UDP SPT=5353 DPT=59438 LEN=126 Communication from the AVAHI port gets BLOCKed also, despite the rule that should allow that Dec 17 16:56:10 FSC-neu kernel: [255878.035296] [UFW ALLOW] IN= OUT=eth0 SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12957 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 Dec 17 16:56:10 FSC-neu kernel: [255878.035318] [UFW ALLOW] IN=eth0 OUT= MAC= SRC=192.168.1.31 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=12957 DF PROTO=UDP SPT=59438 DPT=8612 LEN=24 Dec 17 16:56:10 FSC-neu kernel: [255878.036566] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=11059 PROTO=UDP SPT=8612 DPT=59438 LEN=40 And the printer gets BLOCKed one more time. So the questions remaining are: a) ufw seems unaware of a protocol that starts multicast, and gets unicast replies. b) ufw ignores rules that completely open up an incoming port Yours Oliver ** This bug is no longer a duplicate of bug 1595046 UFW and saned... not working togheter... -- You received this bug notification because you are a member of Gufw Developers, which is subscribed to Gufw. https://bugs.launchpad.net/bugs/1650489 Title: ufw broken on Linux Mint 17.3 Status in Gufw: New Status in Linux Mint: New Status in ufw: New Bug description: Hi, on my Linux Mint 17.3 x64 Cinnamon, ufw appears to be broken (0.34~rc- 0ubuntu2). Networking seemed to work alright, surfing was no problem, also FTP and SSH worked. But not Bonjour, which I need to use the scanner that is inside my Canon MX925. So I used gufw (14.04.2-0ubuntu1.2) to add rules that allow packets sent to ports 8610 and 8612, and packets coming from 5353 (Bonjour). But still, some of these packets get blocked, according to syslog. Looking deeper inside the matter, I realised that the default inbound policy is deny. So surfing should not be possible, but it works alright. sudo ufw status verbose Status: Aktiv Protokollierung: on (medium) Voreinstellung: reject (eingehend), allow (abgehend), disabled (gesendet) Neue Profile: skip Zu Aktion Von -- ------ --- 8612 ALLOW IN Anywhere (log) 5353 ALLOW IN Anywhere (log) 8612 (v6) ALLOW IN Anywhere (v6) (log) 5353 (v6) ALLOW IN Anywhere (v6) (log) 8610 ALLOW OUT Anywhere (log) 8612 ALLOW OUT Anywhere (log) 8610 (v6) ALLOW OUT Anywhere (v6) (log) 8612 (v6) ALLOW OUT Anywhere (v6) (log) Bonjour should be the only thing working, but in fact, it's the only thing NOT working. So I looked at those predefined sets of rules that ufw should come with, according to http://www.larrytalkstech.com/ufw-the-linux-uncomplicated-firewall/ but most of the ones mentioned there are missing. sudo ufw app list Verfügbare Anwendungen: CUPS Samba Only CUPS and Samba are known? Not even DNS or tcp/80 ? Since surfing works alright, my guess is that ufw does not really work together with iptables, which to my understanding is the "real firewall" that (g)ufw is only a frontend for. So ufw does not show all rules that are in force, and ufw does not correctly apply new rules at the correct position in the chain, so they get defeated by the existing rules, thus Bonjour gets broken. Dec 15 14:00:30 FSC-neu kernel: [72537.358551] [UFW BLOCK] IN=eth0 OUT= MAC=90:1b:0e:18:56:e3:60:12:8b:46:ce:55:08:00 SRC=192.168.1.251 DST=192.168.1.31 LEN=146 TOS=0x00 PREC=0x00 TTL=64 ID=63636 PROTO=UDP SPT=5353 DPT=36762 LEN=126 Thanks Oliver To manage notifications about this bug go to: https://bugs.launchpad.net/gui-ufw/+bug/1650489/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~gufw-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~gufw-developers More help : https://help.launchpad.net/ListHelp
