Connect to Postgres remotely, open port 5432 for Postgres in iptables

Question

I am trying to connect to Postgres remotely but I need to open port 5432 in iptables. My current iptables configuration is as follows:

*filter


#  Allows all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT


#  Accepts all established inbound connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT


#  Allows all outbound traffic
#  You can modify this to only allow certain traffic
-A OUTPUT -j ACCEPT


# Allows HTTP and HTTPS connections from anywhere (the normal ports for websites)
-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT


#  Allows SSH connections
#
# THE -dport NUMBER IS THE SAME ONE YOU SET UP IN THE SSHD_CONFIG FILE
#
-A INPUT -p tcp -m state --state NEW --dport 30000 -j ACCEPT


# Allow ping
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT


# log iptables denied calls
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7


# Reject all other inbound - default deny unless explicitly allowed policy
-A INPUT -j REJECT
-A FORWARD -j REJECT

COMMIT

What would I have to add in iptables to open the port? I'm trying to install phppgadmin on a different server to access the postgres database.

Thank you.

Answer 1

Before the "log iptables denied" and "reject all other inbound" commands you'd add

-A INPUT -p tcp --dport 5432 -s xxx.xxx.xxx.xxx -j ACCEPT

Where xxx.xxx.xxx.xxx is the IP of the server you're connecting from so you're not opening postgres up to the world.

Answer 2

At any point in the config, so long as it is before the log and default rejection, add the line:

-A INPUT -s $SOURCE -p tcp --dport 5432 -j ACCEPT

This permits connections on the INPUT chain from IP address or network block, in CIDR notation, limited to TCP connections on the given port.

Setting a properly restricted source is very important since you should not allow database connections globally.