brianhansonxyz/vpnhotspotmod
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Handle VPNs without addDnsServer calls

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Test case: HTTP Injector
This commit is contained in:
Mygod
2019-03-18 21:43:45 +08:00
parent 48024d2dfd
commit d641af5d40
1 changed files with 19 additions and 10 deletions
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29
mobile/src/main/java/be/mygod/vpnhotspot/net/Routing.kt
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@@ -31,6 +31,7 @@ class Routing(private val caller: Any, private val downstream: String) : IpNeigh
*
* Source: https://android.googlesource.com/platform/system/netd/+/b9baf26/server/RouteController.cpp#65
*/
private const val RULE_PRIORITY_DNS = 17700
private const val RULE_PRIORITY_UPSTREAM = 17800
private const val RULE_PRIORITY_UPSTREAM_FALLBACK = 17900
@@ -52,11 +53,17 @@ class Routing(private val caller: Any, private val downstream: String) : IpNeigh
it.execQuiet("while $IPTABLES -t nat -D POSTROUTING -j vpnhotspot_masquerade; do done")
it.execQuiet("$IPTABLES -t nat -F vpnhotspot_masquerade")
it.execQuiet("$IPTABLES -t nat -X vpnhotspot_masquerade")
it.execQuiet("while ip rule del priority $RULE_PRIORITY_DNS; do done")
it.execQuiet("while ip rule del priority $RULE_PRIORITY_UPSTREAM; do done")
it.execQuiet("while ip rule del priority $RULE_PRIORITY_UPSTREAM_FALLBACK; do done")
}
}
private fun RootSession.Transaction.ipRule(rule: String, downstream: String, upstream: String, priority: Int) =
exec("ip rule add $rule iif $downstream lookup $upstream priority $priority",
// by the time stopScript is called, table entry for upstream may already get removed
"ip rule del $rule iif $downstream priority $priority")
private fun RootSession.Transaction.iptables(command: String, revert: String) {
val result = execQuiet(command, revert)
val message = RootSession.checkOutput(command, result, err = false)
@@ -100,11 +107,7 @@ class Routing(private val caller: Any, private val downstream: String) : IpNeigh
*/
inner class Subrouting(priority: Int, val upstream: String? = null) {
val transaction = RootSession.beginTransaction().safeguard {
if (upstream != null) {
exec("ip rule add from all iif $downstream lookup $upstream priority $priority",
// by the time stopScript is called, table entry for upstream may already get removed
"ip rule del from all iif $downstream priority $priority")
}
if (upstream != null) ipRule("from all", downstream, upstream, priority)
fun simpleMasquerade() {
// note: specifying -i wouldn't work for POSTROUTING
iptablesAdd(if (upstream == null) "vpnhotspot_masquerade -s $hostSubnet -j MASQUERADE" else
@@ -259,21 +262,27 @@ class Routing(private val caller: Any, private val downstream: String) : IpNeigh
}
}
private inner class DnsRoute(val dns: String) {
private inner class DnsRoute(val upstream: String, val dns: String) {
val transaction = RootSession.beginTransaction().safeguard {
val hostAddress = hostAddress.address.hostAddress
ipRule("from $hostSubnet to $dns", downstream, upstream, RULE_PRIORITY_DNS)
iptablesAdd("PREROUTING -i $downstream -p tcp -d $hostAddress --dport 53 -j DNAT --to-destination $dns", "nat")
iptablesAdd("PREROUTING -i $downstream -p udp -d $hostAddress --dport 53 -j DNAT --to-destination $dns", "nat")
}
}
private var currentDns: DnsRoute? = null
private fun updateDnsRoute() {
var dns = (upstream.dns + fallbackUpstream.dns).firstOrNull { it is Inet4Address }?.hostAddress
val selected = sequenceOf(upstream, fallbackUpstream).flatMap { upstream ->
val ifname = upstream.subrouting?.upstream
if (ifname == null) emptySequence() else upstream.dns.asSequence().map { ifname to it }
}.firstOrNull { it.second is Inet4Address }
val upstream = selected?.first
var dns = selected?.second?.hostAddress
if (dns.isNullOrBlank()) dns = null
if (dns != currentDns?.dns) {
if (upstream != currentDns?.upstream || dns != currentDns?.dns) {
currentDns?.transaction?.revert()
currentDns = if (dns == null) null else try {
DnsRoute(dns)
currentDns = if (upstream == null || dns == null) null else try {
DnsRoute(upstream, dns)
} catch (e: RuntimeException) {
Timber.w(e)
SmartSnackbar.make(e).show()