Adopt network to running instance

src/core/sm/networkmanager/itf/firewall.hpp

@@ -53,6 +53,14 @@
     StaticArray<OutputAccessConfig, cMaxNumFirewallRules> mOutput;
 };
 
+/**
+ * Masquerade rule identity.
+ */
+struct MasqueradeParams {
+    StaticString<cSubnetLen>    mSubnet;
+    StaticString<cInterfaceLen> mOutIfName;
+};
+
 /**
  * Firewall interface.
  *
@@ -69,7 +77,8 @@
 
     /**
      * Starts the firewall: creates the `inet aos` table, base chains and
-     * netfilter hooks (forward filter, postrouting nat).
+     * netfilter hooks (forward filter, postrouting nat) when they are absent.
+     * Rules that are already there are left alone.
      *
      * @return Error.
      */
@@ -82,6 +91,21 @@
      */
     virtual Error Stop() = 0;
 
+    /**
+     * Removes the instance chains and masquerade rules that no longer belong
+     * to anything known, keeping the rest in place.
+     *
+     * Called on start so that artifacts left by a crashed SM are reaped
+     * without touching the rules of the instances that kept running.
+     *
+     * @param knownInstanceIDs instance ids whose chains must be kept.
+     * @param knownMasquerades masquerade rules that must be kept.
+     * @return Error.
+     */
+    virtual Error RemoveOrphans(
+        const Array<StaticString<cIDLen>>& knownInstanceIDs, const Array<MasqueradeParams>& knownMasquerades)
+        = 0;
+
     /**
      * Adds a per-instance chain with the given input/output access rules.
      *

src/core/sm/networkmanager/itf/interfacemanager.hpp

@@ -7,14 +7,45 @@
 #ifndef AOS_CORE_SM_NETWORKMANAGER_ITF_INTERFACEMANAGER_HPP_
 #define AOS_CORE_SM_NETWORKMANAGER_ITF_INTERFACEMANAGER_HPP_
 
+#include <core/common/tools/enum.hpp>
 #include <core/common/types/common.hpp>
+#include <core/common/types/network.hpp>
 
 namespace aos::sm::networkmanager {
 
 /** @addtogroup sm Service Manager
  *  @{
  */
 
+/**
+ * Link kind type.
+ */
+class LinkKindType {
+public:
+    enum class Enum { eUnknown, eBridge, eVlan, eVeth };
+
+    static const Array<const char* const> GetStrings()
+    {
+        static const char* const sLinkKindStrings[] = {"unknown", "bridge", "vlan", "veth"};
+
+        return Array<const char* const>(sLinkKindStrings, ArraySize(sLinkKindStrings));
+    };
+};
+
+using LinkKindEnum = LinkKindType::Enum;
+using LinkKind     = EnumStringer<LinkKindType>;
+
+/**
+ * Network link attributes as seen on the system.
+ */
+struct LinkInfo {
+    StaticString<cInterfaceLen> mName;
+    LinkKind                    mKind;
+    StaticString<cInterfaceLen> mMaster;
+    uint64_t                    mVlanID {};
+    bool                        mUp {};
+};
+
 /**
  * Network interface manager interface.
  */
@@ -25,6 +56,15 @@
      */
     virtual ~InterfaceManagerItf() = default;
 
+    /**
+     * Returns link attributes as they are on the system.
+     *
+     * @param ifname interface name.
+     * @param[out] info link attributes.
+     * @return Error, eNotFound if the link doesn't exist.
+     */
+    virtual Error GetLink(const String& ifname, LinkInfo& info) const = 0;
+
     /**
      * Removes interface.
      *

src/core/sm/networkmanager/itf/namespacemanager.hpp

@@ -33,6 +33,14 @@ class NamespaceManagerItf {
      */
     virtual Error CreateNetworkNamespace(const String& ns) = 0;
 
+    /**
+     * Checks whether network namespace exists on the system.
+     *
+     * @param ns network namespace name.
+     * @return RetWithError<bool>.
+     */
+    virtual RetWithError<bool> IsNetworkNamespaceExist(const String& ns) const = 0;
+
     /**
      * Returns network namespace path.
      *