Bug 171719 – net-firewall/firehol - "group with dst" creates backwards rules

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Marshal Newrock 2007-03-21 20:11:56 UTC]

With "group with dst" in the config file, it generates rules such as:
-A in_public -d $ip -j in_group1
-A out_public -s $ip -j out_group2

This makes it check only the source IP for outgoing and the destination for
incoming, but using the IP of the requested destination. The result is
that no packets may go through for this case.


Reproducible: Always

Steps to Reproduce:




Upstream bug submitted at http://sourceforge.net/tracker/index.php?func=detail&aid=1685505&group_id=58425&atid=487692

[Comment 1 Marshal Newrock 2007-03-21 20:12:39 UTC]

Created attachment 114011 [details, diff]
check "group with" direction to create correct firewall rules

[Comment 2 Dominik Stadler (RETIRED) 2007-04-26 21:16:04 UTC]

This is fixed in 1.250-r1 which will be available on the mirrors soon.

[Comment 3 Mike Nerone 2007-05-01 01:08:12 UTC]

Please note at upstream bug submission URL in comment #1 that the author does not believe this to be a bug.

[Comment 4 Mike Nerone 2007-05-02 23:35:25 UTC]

This patch broke "group with". Example (output captured from "firehol debug", with IPs changed to protect the innocent, or even me):

firehol-1.250, CORRECT:

# === CONFIGURATION STATEMENT =================================================
# CONF:INIT>>>  group with dst 1.2.3.4


# INFO>>> Starting new group No 1, under 'main'

# INFO>>> Creating chain 'in_group1' under 'in_main' in table 'filter'
/sbin/iptables -t filter -N in_group1
/sbin/iptables -t filter -A in_main -d 1.2.3.4 -j in_group1

# INFO>>> Creating chain 'out_group1' under 'out_main' in table 'filter'
/sbin/iptables -t filter -N out_group1
/sbin/iptables -t filter -A out_main -s 1.2.3.4 -j out_group1


firehol-1.250-r1, BROKEN:

# === CONFIGURATION STATEMENT =================================================
# CONF:INIT>>>  group with dst 1.2.3.4


# INFO>>> Starting new group No 1, under 'main'

# INFO>>> Creating chain 'in_group1' under 'in_main' in table 'filter'
/sbin/iptables -t filter -N in_group1
/sbin/iptables -t filter -A in_main -s 1.2.3.4 -j in_group1

# INFO>>> Creating chain 'out_group1' under 'out_main' in table 'filter'
/sbin/iptables -t filter -N out_group1
/sbin/iptables -t filter -A out_main -d 1.2.3.4 -j out_group1

Consider the input side for the moment: as you can see, when clearly using "group with" to to apply only to a *destination* of 1.2.3.4 (this box has multiple IPs and this group is for services I want only accessible on 1.2.3.4), firehol-1.250-r1 generates an input rule with "-s 1.2.3.4", checking only the source address. The mirror mistake is made on the output side. firehol-1.250 did it correctly.

This mistake ended up cutting off all access to my server.

[Comment 5 Mike Nerone 2007-05-03 00:02:18 UTC]

BTW, at the upstream bug report (http://sourceforge.net/tracker/index.php?func=detail&aid=1685505&group_id=58425&atid=487692), the author clearly explains why this "bug" is a result of a fundamental misunderstanding by the user, and is not a bug at all.

[Comment 6 Dominik Stadler (RETIRED) 2007-05-05 12:02:29 UTC]

FYI, see Bug 176862 for the issue with this patch.