crostini: Refactoring tests for port forwarding and extending coverage

Refactoring crostini port forwarding tests to be more readable and more
easily editable in the futre. Also adding new tests to cover interface
switching.

Tests: Running the implemented tests
Bug: 848127
Change-Id: I26fdbb65c92c2e9ea161fe20738644e12965fd5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2214804Reviewed-by: Nic Hollingum <hollingum@google.com>
Reviewed-by: Fergus Dall <sidereal@google.com>
Commit-Queue: Daniel Ng <danielng@google.com>
Cr-Commit-Position: refs/heads/master@{#772109}

chrome/browser/chromeos/crostini/crostini_port_forwarder.cc

@@ -21,11 +21,9 @@
 namespace crostini {
 
 // Currently, we are not supporting ethernet/mlan/usb port forwarding.
-const char kDefaultInterfaceToForward[] = "all";
-const char kWlanInterface[] = "wlan0";
+const char kDefaultInterfaceToForward[] = "wlan0";
 const char kPortNumberKey[] = "port_number";
 const char kPortProtocolKey[] = "protocol_type";
-const char kPortInterfaceKey[] = "input_ifname";
 const char kPortLabelKey[] = "label";
 const char kPortVmNameKey[] = "vm_name";
 const char kPortContainerNameKey[] = "container_name";
@@ -66,7 +64,7 @@ CrostiniPortForwarder* CrostiniPortForwarder::GetForProfile(Profile* profile) {
 
 CrostiniPortForwarder::CrostiniPortForwarder(Profile* profile)
     : profile_(profile) {
-  current_interface_ = kWlanInterface;
+  current_interface_ = kDefaultInterfaceToForward;
 }
 
 CrostiniPortForwarder::~CrostiniPortForwarder() = default;
@@ -81,13 +79,11 @@ bool CrostiniPortForwarder::MatchPortRuleDict(const base::Value& dict,
                                               const PortRuleKey& key) {
   base::Optional<int> port_number = dict.FindIntKey(kPortNumberKey);
   base::Optional<int> protocol_type = dict.FindIntKey(kPortProtocolKey);
-  const std::string* input_ifname = dict.FindStringKey(kPortInterfaceKey);
   const std::string* vm_name = dict.FindStringKey(kPortVmNameKey);
   const std::string* container_name = dict.FindStringKey(kPortContainerNameKey);
   return (port_number && port_number.value() == key.port_number) &&
          (protocol_type &&
           protocol_type.value() == static_cast<int>(key.protocol_type)) &&
-         (input_ifname && *input_ifname == key.input_ifname) &&
          (vm_name && *vm_name == key.container_id.vm_name) &&
          (container_name && *container_name == key.container_id.container_name);
 }
@@ -110,7 +106,6 @@ void CrostiniPortForwarder::AddNewPortPreference(const PortRuleKey& key,
   new_port_metadata.SetIntKey(kPortNumberKey, key.port_number);
   new_port_metadata.SetIntKey(kPortProtocolKey,
                               static_cast<int>(key.protocol_type));
-  new_port_metadata.SetStringKey(kPortInterfaceKey, kDefaultInterfaceToForward);
   new_port_metadata.SetStringKey(kPortLabelKey, label);
   new_port_metadata.SetStringKey(kPortVmNameKey, key.container_id.vm_name);
   new_port_metadata.SetStringKey(kPortContainerNameKey,
@@ -257,7 +252,6 @@ void CrostiniPortForwarder::AddPort(const ContainerId& container_id,
   PortRuleKey new_port_key = {
       .port_number = port_number,
       .protocol_type = protocol_type,
-      .input_ifname = kDefaultInterfaceToForward,
       .container_id = container_id,
   };
 
@@ -278,7 +272,6 @@ void CrostiniPortForwarder::ActivatePort(const ContainerId& container_id,
   PortRuleKey existing_port_key = {
       .port_number = port_number,
       .protocol_type = protocol_type,
-      .input_ifname = kDefaultInterfaceToForward,
       .container_id = container_id,
   };
 
@@ -309,7 +302,6 @@ void CrostiniPortForwarder::DeactivatePort(const ContainerId& container_id,
   PortRuleKey existing_port_key = {
       .port_number = port_number,
       .protocol_type = protocol_type,
-      .input_ifname = kDefaultInterfaceToForward,
       .container_id = container_id,
   };
 
@@ -334,7 +326,6 @@ void CrostiniPortForwarder::RemovePort(const ContainerId& container_id,
   PortRuleKey existing_port_key = {
       .port_number = port_number,
       .protocol_type = protocol_type,
-      .input_ifname = kDefaultInterfaceToForward,
       .container_id = container_id,
   };
 
@@ -399,6 +390,8 @@ base::Optional<base::Value> CrostiniPortForwarder::ReadPortPreferenceForTesting(
 
 void CrostiniPortForwarder::UpdateActivePortInterfaces() {
   for (auto& port : forwarded_ports_) {
+    // Note that this process erases the current lifeline attached to the port
+    // rule and implicitly causes the current port rule to be revoked.
     TryActivatePort(port.first, port.first.container_id, base::DoNothing());
   }
 }

chrome/browser/chromeos/crostini/crostini_port_forwarder.h

@@ -43,13 +43,11 @@ class CrostiniPortForwarder : public KeyedService {
   struct PortRuleKey {
     uint16_t port_number;
     Protocol protocol_type;
-    std::string input_ifname;
     ContainerId container_id;
 
     bool operator==(const PortRuleKey& other) const {
       return port_number == other.port_number &&
-             protocol_type == other.protocol_type &&
-             input_ifname == other.input_ifname;
+             protocol_type == other.protocol_type;
     }
   };
 
@@ -58,8 +56,7 @@ class CrostiniPortForwarder : public KeyedService {
     std::size_t operator()(const PortRuleKey& k) const {
       return ((std::hash<uint16_t>()(k.port_number) ^
                (std::hash<Protocol>()(k.protocol_type) << 1)) >>
-              1) ^
-             (std::hash<std::string>()(k.input_ifname) << 1);
+              1);
     }
   };