diff options
Diffstat (limited to 'pkg/linux')
| -rwxr-xr-x | pkg/linux/bitmask-root | 74 |
1 files changed, 64 insertions, 10 deletions
diff --git a/pkg/linux/bitmask-root b/pkg/linux/bitmask-root index 6fbafff9..58f9a103 100755 --- a/pkg/linux/bitmask-root +++ b/pkg/linux/bitmask-root @@ -55,6 +55,8 @@ VERSION = "1" SCRIPT = "bitmask-root" NAMESERVER = "10.42.0.1" BITMASK_CHAIN = "bitmask" +BITMASK_CHAIN_NAT_OUT = "bitmask" +BITMASK_CHAIN_NAT_POST = "bitmask_postrouting" IP = "/bin/ip" IPTABLES = "/sbin/iptables" @@ -565,11 +567,16 @@ def firewall_start(args): # the 'filter' and the 'nat' tables. if not ipv4_chain_exists(BITMASK_CHAIN): ip4tables("--new-chain", BITMASK_CHAIN) - if not ipv4_chain_exists(BITMASK_CHAIN, 'nat'): - ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN) + if not ipv4_chain_exists(BITMASK_CHAIN_NAT_OUT, 'nat'): + ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN_NAT_OUT) + if not ipv4_chain_exists(BITMASK_CHAIN_NAT_POST, 'nat'): + ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN_NAT_POST) if not ipv6_chain_exists(BITMASK_CHAIN): ip6tables("--new-chain", BITMASK_CHAIN) - ip4tables("--table", "nat", "--insert", "OUTPUT", "--jump", BITMASK_CHAIN) + ip4tables("--table", "nat", "--insert", "OUTPUT", + "--jump", BITMASK_CHAIN_NAT_OUT) + ip4tables("--table", "nat", "--insert", "POSTROUTING", + "--jump", BITMASK_CHAIN_NAT_POST) iptables("--insert", "OUTPUT", "--jump", BITMASK_CHAIN) # route all ipv4 DNS over VPN @@ -581,16 +588,32 @@ def firewall_start(args): "--jump", "ACCEPT") # rewrite all outgoing packets to use VPN DNS server # (DNS does sometimes use TCP!) - ip4tables("-t", "nat", "--append", BITMASK_CHAIN, "--protocol", "udp", + ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_OUT, "-p", "udp", "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53") - ip4tables("-t", "nat", "--append", BITMASK_CHAIN, "--protocol", "tcp", + ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_OUT, "-p", "tcp", "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53") - - # allow traffic to IPs on local network + # enable masquerading, so that DNS packets rewritten by DNAT will + # have the correct source IPs + ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_POST, + "--protocol", "udp", "--dport", "53", "--jump", "MASQUERADE") + ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_POST, + "--protocol", "tcp", "--dport", "53", "--jump", "MASQUERADE") + + # allow local network traffic if local_network_ipv4: + # allow local network destinations ip4tables("--append", BITMASK_CHAIN, "--destination", local_network_ipv4, "-o", default_device, "--jump", "ACCEPT") + # allow local network sources for DNS + # (required to allow local network DNS that gets rewritten by NAT + # to get passed through so that MASQUERADE can set correct source IP) + ip4tables("--append", BITMASK_CHAIN, + "--source", local_network_ipv4, "-o", default_device, + "-p", "udp", "--dport", "53", "--jump", "ACCEPT") + ip4tables("--append", BITMASK_CHAIN, + "--source", local_network_ipv4, "-o", default_device, + "-p", "tcp", "--dport", "53", "--jump", "ACCEPT") # allow multicast Simple Service Discovery Protocol ip4tables("--append", BITMASK_CHAIN, "--protocol", "udp", @@ -649,19 +672,34 @@ def firewall_stop(): command can be run at a time). """ ok = True + + # -t filter -D OUTPUT -j bitmask try: iptables("--delete", "OUTPUT", "--jump", BITMASK_CHAIN, throw=True) except subprocess.CalledProcessError as exc: debug("INFO: not able to remove bitmask firewall from OUTPUT chain " "(maybe it is already removed?)", exc) ok = False + + # -t nat -D OUTPUT -j bitmask try: ip4tables("-t", "nat", "--delete", "OUTPUT", - "--jump", BITMASK_CHAIN, throw=True) + "--jump", BITMASK_CHAIN_NAT_OUT, throw=True) except subprocess.CalledProcessError as exc: debug("INFO: not able to remove bitmask firewall from OUTPUT chain " "in 'nat' table (maybe it is already removed?)", exc) ok = False + + # -t nat -D POSTROUTING -j bitmask_postrouting + try: + ip4tables("-t", "nat", "--delete", "POSTROUTING", + "--jump", BITMASK_CHAIN_NAT_POST, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to remove bitmask firewall from POSTROUTING " + "chain in 'nat' table (maybe it is already removed?)", exc) + ok = False + + # -t filter --delete-chain bitmask try: ip4tables("--flush", BITMASK_CHAIN, throw=True) ip4tables("--delete-chain", BITMASK_CHAIN, throw=True) @@ -669,13 +707,28 @@ def firewall_stop(): debug("INFO: not able to flush and delete bitmask ipv4 firewall " "chain (maybe it is already destroyed?)", exc) ok = False + + # -t nat --delete-chain bitmask + try: + ip4tables("-t", "nat", "--flush", BITMASK_CHAIN_NAT_OUT, throw=True) + ip4tables("-t", "nat", "--delete-chain", + BITMASK_CHAIN_NAT_OUT, throw=True) + except subprocess.CalledProcessError as exc: + debug("INFO: not able to flush and delete bitmask ipv4 firewall " + "chain in 'nat' table (maybe it is already destroyed?)", exc) + ok = False + + # -t nat --delete-chain bitmask_postrouting try: - ip4tables("-t", "nat", "--flush", BITMASK_CHAIN, throw=True) - ip4tables("-t", "nat", "--delete-chain", BITMASK_CHAIN, throw=True) + ip4tables("-t", "nat", "--flush", BITMASK_CHAIN_NAT_POST, throw=True) + ip4tables("-t", "nat", "--delete-chain", + BITMASK_CHAIN_NAT_POST, throw=True) except subprocess.CalledProcessError as exc: debug("INFO: not able to flush and delete bitmask ipv4 firewall " "chain in 'nat' table (maybe it is already destroyed?)", exc) ok = False + + # -t filter --delete-chain bitmask (ipv6) try: ip6tables("--flush", BITMASK_CHAIN, throw=True) ip6tables("--delete-chain", BITMASK_CHAIN, throw=True) @@ -683,6 +736,7 @@ def firewall_stop(): debug("INFO: not able to flush and delete bitmask ipv6 firewall " "chain (maybe it is already destroyed?)", exc) ok = False + if not (ok or ipv4_chain_exists or ipv6_chain_exists): raise Exception("firewall might still be left up. " "Please try `firewall stop` again.") |