From 3d0708ad3e20aa8dddf6894b7536be3cd59cfbca Mon Sep 17 00:00:00 2001 From: Ruben Pollan Date: Mon, 8 Sep 2014 14:22:29 -0500 Subject: Add email firewall --- pkg/linux/bitmask-root | 143 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 142 insertions(+), 1 deletion(-) (limited to 'pkg/linux') diff --git a/pkg/linux/bitmask-root b/pkg/linux/bitmask-root index fa7fc92a..ba262a2c 100755 --- a/pkg/linux/bitmask-root +++ b/pkg/linux/bitmask-root @@ -25,6 +25,8 @@ USAGE: bitmask-root firewall start [restart] GATEWAY1 GATEWAY2 ... bitmask-root openvpn stop bitmask-root openvpn start CONFIG1 CONFIG1 ... + bitmask-root fw-email stop + bitmask-root fw-email start uid All actions return exit code 0 for success, non-zero otherwise. @@ -55,6 +57,11 @@ NAMESERVER = "10.42.0.1" BITMASK_CHAIN = "bitmask" BITMASK_CHAIN_NAT_OUT = "bitmask" BITMASK_CHAIN_NAT_POST = "bitmask_postrouting" +BITMASK_CHAIN_EMAIL = "bitmask_email" +BITMASK_CHAIN_EMAIL_OUT = "bitmask_email_output" +LOCAL_INTERFACE = "lo" +IMAP_PORT = "1984" +SMTP_PORT = "2013" IP = "/bin/ip" IPTABLES = "/sbin/iptables" @@ -101,7 +108,8 @@ PARAM_FORMATS = { "^[a-zA-Z0-9_\.\@][a-zA-Z0-9_\-\.\@]*\$?$", s), # IEEE Std 1003.1-2001 "FILE": lambda s: os.path.isfile(s), "DIR": lambda s: os.path.isdir(os.path.split(s)[0]), - "UNIXSOCKET": lambda s: s == "unix" + "UNIXSOCKET": lambda s: s == "unix", + "UID": lambda s: re.match("^[a-zA-Z0-9]+$", s) } @@ -740,6 +748,119 @@ def firewall_stop(): "Please try `firewall stop` again.") +def fw_email_start(args): + """ + Bring up the email firewall. + + :param args: the user uid of the bitmask process + :type args: list + """ + # add custom chain "bitmask_email" to front of INPUT chain + if not ipv4_chain_exists(BITMASK_CHAIN_EMAIL): + ip4tables("--new-chain", BITMASK_CHAIN_EMAIL) + if not ipv6_chain_exists(BITMASK_CHAIN_EMAIL): + ip6tables("--new-chain", BITMASK_CHAIN_EMAIL) + iptables("--insert", "INPUT", "--jump", BITMASK_CHAIN_EMAIL) + + # add custom chain "bitmask_email_output" to front of OUTPUT chain + if not ipv4_chain_exists(BITMASK_CHAIN_EMAIL_OUT): + ip4tables("--new-chain", BITMASK_CHAIN_EMAIL_OUT) + if not ipv6_chain_exists(BITMASK_CHAIN_EMAIL_OUT): + ip6tables("--new-chain", BITMASK_CHAIN_EMAIL_OUT) + iptables("--insert", "OUTPUT", "--jump", BITMASK_CHAIN_EMAIL_OUT) + + # Disable the access to imap and smtp from outside + iptables("--append", BITMASK_CHAIN_EMAIL, + "--in-interface", LOCAL_INTERFACE, "--protocol", "tcp", + "--dport", IMAP_PORT, "--jump", "ACCEPT") + iptables("--append", BITMASK_CHAIN_EMAIL, + "--in-interface", LOCAL_INTERFACE, "--protocol", "tcp", + "--dport", SMTP_PORT, "--jump", "ACCEPT") + iptables("--append", BITMASK_CHAIN_EMAIL, + "--protocol", "tcp", "--dport", IMAP_PORT, "--jump", "REJECT") + iptables("--append", BITMASK_CHAIN_EMAIL, + "--protocol", "tcp", "--dport", SMTP_PORT, "--jump", "REJECT") + + if not args or not PARAM_FORMATS["UID"](args[0]): + raise Exception("No uid given") + uid = args[0] + + # Only the unix 'uid' have access to the email imap and smtp ports + iptables("--append", BITMASK_CHAIN_EMAIL_OUT, + "--out-interface", LOCAL_INTERFACE, + "--match", "owner", "--uid-owner", uid, "--protocol", "tcp", + "--dport", IMAP_PORT, "--jump", "ACCEPT") + iptables("--append", BITMASK_CHAIN_EMAIL_OUT, + "--out-interface", LOCAL_INTERFACE, + "--match", "owner", "--uid-owner", uid, "--protocol", "tcp", + "--dport", SMTP_PORT, "--jump", "ACCEPT") + iptables("--append", BITMASK_CHAIN_EMAIL_OUT, + "--out-interface", LOCAL_INTERFACE, + "--protocol", "tcp", "--dport", IMAP_PORT, "--jump", "REJECT") + iptables("--append", BITMASK_CHAIN_EMAIL_OUT, + "--out-interface", LOCAL_INTERFACE, + "--protocol", "tcp", "--dport", SMTP_PORT, "--jump", "REJECT") + + +def fw_email_stop(): + """ + Stop the email firewall. + """ + ok = True + + try: + iptables("--delete", "INPUT", "--jump", BITMASK_CHAIN_EMAIL, + throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to remove bitmask email firewall from INPUT " + "chain (maybe it is already removed?)", exc) + ok = False + + try: + iptables("--delete", "OUTPUT", "--jump", BITMASK_CHAIN_EMAIL_OUT, + throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to remove bitmask email firewall from OUTPUT " + "chain (maybe it is already removed?)", exc) + ok = False + + try: + ip4tables("--flush", BITMASK_CHAIN_EMAIL, throw=True) + ip4tables("--delete-chain", BITMASK_CHAIN_EMAIL, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to flush and delete bitmask ipv4 email firewall " + "chain (maybe it is already destroyed?)", exc) + ok = False + + try: + ip6tables("--flush", BITMASK_CHAIN_EMAIL, throw=True) + ip6tables("--delete-chain", BITMASK_CHAIN_EMAIL, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to flush and delete bitmask ipv6 email firewall " + "chain (maybe it is already destroyed?)", exc) + ok = False + + try: + ip4tables("--flush", BITMASK_CHAIN_EMAIL_OUT, throw=True) + ip4tables("--delete-chain", BITMASK_CHAIN_EMAIL_OUT, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to flush and delete bitmask ipv4 email firewall " + "chain (maybe it is already destroyed?)", exc) + ok = False + + try: + ip6tables("--flush", BITMASK_CHAIN_EMAIL_OUT, throw=True) + ip6tables("--delete-chain", BITMASK_CHAIN_EMAIL_OUT, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to flush and delete bitmask ipv6 email firewall " + "chain (maybe it is already destroyed?)", exc) + ok = False + + if not (ok or ipv4_chain_exists or ipv6_chain_exists): + raise Exception("email firewall might still be left up. " + "Please try `fw-email stop` again.") + + # # MAIN # @@ -793,6 +914,26 @@ def main(): else: bail("INFO: bitmask firewall is down") + elif command == "fw-email_start": + try: + fw_email_start(args) + except Exception as ex: + if not is_restart: + fw_email_stop() + bail("ERROR: could not start email firewall", ex) + + elif command == "fw-email_stop": + try: + fw_email_stop() + except Exception as ex: + bail("ERROR: could not stop email firewall", ex) + + elif command == "fw-email_isup": + if ipv4_chain_exists(BITMASK_CHAIN_EMAIL): + log("%s: INFO: bitmask email firewall is up" % (SCRIPT,)) + else: + bail("INFO: bitmask email firewall is down") + else: bail("ERROR: No such command") else: -- cgit v1.2.3