mdns_avahi.hpp

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#ifndef OTBR_AGENT_MDNS_AVAHI_HPP_
#define OTBR_AGENT_MDNS_AVAHI_HPP_
 
#include <memory>
#include <set>
#include <vector>
 
#include <avahi-client/client.h>
#include <avahi-client/lookup.h>
#include <avahi-client/publish.h>
#include <avahi-common/domain.h>
#include <avahi-common/watch.h>
 
#include "mdns.hpp"
#include "common/code_utils.hpp"
#include "common/mainloop.hpp"
#include "common/time.hpp"
 
namespace otbr {
 
namespace Mdns {
 
class AvahiPoller;
 
class PublisherAvahi : public Publisher
{
public:
    PublisherAvahi(StateCallback aStateCallback);
    ~PublisherAvahi(void) override;
 
    void      UnpublishService(const std::string &aName, const std::string &aType, ResultCallback &&aCallback) override;
    void      UnpublishHost(const std::string &aName, ResultCallback &&aCallback) override;
    void      SubscribeService(const std::string &aType, const std::string &aInstanceName) override;
    void      UnsubscribeService(const std::string &aType, const std::string &aInstanceName) override;
    void      SubscribeHost(const std::string &aHostName) override;
    void      UnsubscribeHost(const std::string &aHostName) override;
    otbrError Start(void) override;
    bool      IsStarted(void) const override;
    void      Stop(void) override;
 
protected:
    otbrError PublishServiceImpl(const std::string &aHostName,
                                 const std::string &aName,
                                 const std::string &aType,
                                 const SubTypeList &aSubTypeList,
                                 uint16_t           aPort,
                                 const TxtList &    aTxtList,
                                 ResultCallback &&  aCallback) override;
    otbrError PublishHostImpl(const std::string &            aName,
                              const std::vector<Ip6Address> &aAddresses,
                              ResultCallback &&              aCallback) override;
    void      OnServiceResolveFailedImpl(const std::string &aType,
                                         const std::string &aInstanceName,
                                         int32_t            aErrorCode) override;
    void      OnHostResolveFailedImpl(const std::string &aHostName, int32_t aErrorCode) override;
    otbrError DnsErrorToOtbrError(int32_t aErrorCode) override;
 
private:
    static constexpr size_t   kMaxSizeOfTxtRecord = 1024;
    static constexpr uint32_t kDefaultTtl         = 10; // In seconds.
 
    class AvahiServiceRegistration : public ServiceRegistration
    {
    public:
        AvahiServiceRegistration(const std::string &aHostName,
                                 const std::string &aName,
                                 const std::string &aType,
                                 const SubTypeList &aSubTypeList,
                                 uint16_t           aPort,
                                 const TxtList &    aTxtList,
                                 ResultCallback &&  aCallback,
                                 AvahiEntryGroup *  aEntryGroup,
                                 PublisherAvahi *   aPublisher)
            : ServiceRegistration(aHostName,
                                  aName,
                                  aType,
                                  aSubTypeList,
                                  aPort,
                                  aTxtList,
                                  std::move(aCallback),
                                  aPublisher)
            , mEntryGroup(aEntryGroup)
        {
        }
 
        ~AvahiServiceRegistration(void) override;
        const AvahiEntryGroup *GetEntryGroup(void) const { return mEntryGroup; }
 
    private:
        AvahiEntryGroup *mEntryGroup;
    };
 
    class AvahiHostRegistration : public HostRegistration
    {
    public:
        AvahiHostRegistration(const std::string &            aName,
                              const std::vector<Ip6Address> &aAddresses,
                              ResultCallback &&              aCallback,
                              AvahiEntryGroup *              aEntryGroup,
                              PublisherAvahi *               aPublisher)
            : HostRegistration(aName, aAddresses, std::move(aCallback), aPublisher)
            , mEntryGroup(aEntryGroup)
        {
        }
 
        ~AvahiHostRegistration(void) override;
        const AvahiEntryGroup *GetEntryGroup(void) const { return mEntryGroup; }
 
    private:
        AvahiEntryGroup *mEntryGroup;
    };
 
    struct Subscription : private ::NonCopyable
    {
        PublisherAvahi *mPublisherAvahi;
 
        explicit Subscription(PublisherAvahi &aPublisherAvahi)
            : mPublisherAvahi(&aPublisherAvahi)
        {
        }
    };
 
    struct ServiceSubscription : public Subscription
    {
        explicit ServiceSubscription(PublisherAvahi &aPublisherAvahi, std::string aType, std::string aInstanceName)
            : Subscription(aPublisherAvahi)
            , mType(std::move(aType))
            , mInstanceName(std::move(aInstanceName))
            , mServiceBrowser(nullptr)
        {
        }
 
        ~ServiceSubscription() { Release(); }
 
        void Release(void);
        void Browse(void);
        void Resolve(uint32_t           aInterfaceIndex,
                     AvahiProtocol      aProtocol,
                     const std::string &aInstanceName,
                     const std::string &aType);
        void AddServiceResolver(AvahiServiceResolver *aServiceResolver);
        void RemoveServiceResolver(AvahiServiceResolver *aServiceResolver);
 
        static void HandleBrowseResult(AvahiServiceBrowser *  aServiceBrowser,
                                       AvahiIfIndex           aInterfaceIndex,
                                       AvahiProtocol          aProtocol,
                                       AvahiBrowserEvent      aEvent,
                                       const char *           aName,
                                       const char *           aType,
                                       const char *           aDomain,
                                       AvahiLookupResultFlags aFlags,
                                       void *                 aContext);
 
        void HandleBrowseResult(AvahiServiceBrowser *  aServiceBrowser,
                                AvahiIfIndex           aInterfaceIndex,
                                AvahiProtocol          aProtocol,
                                AvahiBrowserEvent      aEvent,
                                const char *           aName,
                                const char *           aType,
                                const char *           aDomain,
                                AvahiLookupResultFlags aFlags);
 
        static void HandleResolveResult(AvahiServiceResolver * aServiceResolver,
                                        AvahiIfIndex           aInterfaceIndex,
                                        AvahiProtocol          Protocol,
                                        AvahiResolverEvent     aEvent,
                                        const char *           aName,
                                        const char *           aType,
                                        const char *           aDomain,
                                        const char *           aHostName,
                                        const AvahiAddress *   aAddress,
                                        uint16_t               aPort,
                                        AvahiStringList *      aTxt,
                                        AvahiLookupResultFlags aFlags,
                                        void *                 aContext);
 
        void HandleResolveResult(AvahiServiceResolver * aServiceResolver,
                                 AvahiIfIndex           aInterfaceIndex,
                                 AvahiProtocol          Protocol,
                                 AvahiResolverEvent     aEvent,
                                 const char *           aName,
                                 const char *           aType,
                                 const char *           aDomain,
                                 const char *           aHostName,
                                 const AvahiAddress *   aAddress,
                                 uint16_t               aPort,
                                 AvahiStringList *      aTxt,
                                 AvahiLookupResultFlags aFlags);
 
        std::string                      mType;
        std::string                      mInstanceName;
        AvahiServiceBrowser *            mServiceBrowser;
        std::set<AvahiServiceResolver *> mServiceResolvers;
    };
 
    struct HostSubscription : public Subscription
    {
        explicit HostSubscription(PublisherAvahi &aAvahiPublisher, std::string aHostName)
            : Subscription(aAvahiPublisher)
            , mHostName(std::move(aHostName))
            , mRecordBrowser(nullptr)
        {
        }
 
        ~HostSubscription() { Release(); }
 
        void        Release(void);
        void        Resolve(void);
        static void HandleResolveResult(AvahiRecordBrowser *   aRecordBrowser,
                                        AvahiIfIndex           aInterfaceIndex,
                                        AvahiProtocol          aProtocol,
                                        AvahiBrowserEvent      aEvent,
                                        const char *           aName,
                                        uint16_t               aClazz,
                                        uint16_t               aType,
                                        const void *           aRdata,
                                        size_t                 aSize,
                                        AvahiLookupResultFlags aFlags,
                                        void *                 aContext);
 
        void HandleResolveResult(AvahiRecordBrowser *   aRecordBrowser,
                                 AvahiIfIndex           aInterfaceIndex,
                                 AvahiProtocol          aProtocol,
                                 AvahiBrowserEvent      aEvent,
                                 const char *           aName,
                                 uint16_t               aClazz,
                                 uint16_t               aType,
                                 const void *           aRdata,
                                 size_t                 aSize,
                                 AvahiLookupResultFlags aFlags);
 
        std::string         mHostName;
        DiscoveredHostInfo  mHostInfo;
        AvahiRecordBrowser *mRecordBrowser;
    };
 
    typedef std::vector<std::unique_ptr<ServiceSubscription>> ServiceSubscriptionList;
    typedef std::vector<std::unique_ptr<HostSubscription>>    HostSubscriptionList;
 
    static void HandleClientState(AvahiClient *aClient, AvahiClientState aState, void *aContext);
    void        HandleClientState(AvahiClient *aClient, AvahiClientState aState);
 
    AvahiEntryGroup *CreateGroup(AvahiClient *aClient);
    static void      ReleaseGroup(AvahiEntryGroup *aGroup);
 
    static void HandleGroupState(AvahiEntryGroup *aGroup, AvahiEntryGroupState aState, void *aContext);
    void        HandleGroupState(AvahiEntryGroup *aGroup, AvahiEntryGroupState aState);
    void        CallHostOrServiceCallback(AvahiEntryGroup *aGroup, otbrError aError);
 
    static otbrError TxtListToAvahiStringList(const TxtList &   aTxtList,
                                              AvahiStringList * aBuffer,
                                              size_t            aBufferSize,
                                              AvahiStringList *&aHead);
 
    ServiceRegistration *FindServiceRegistration(const AvahiEntryGroup *aEntryGroup);
    HostRegistration *   FindHostRegistration(const AvahiEntryGroup *aEntryGroup);
 
    AvahiClient *                mClient;
    std::unique_ptr<AvahiPoller> mPoller;
    State                        mState;
    StateCallback                mStateCallback;
 
    ServiceSubscriptionList mSubscribedServices;
    HostSubscriptionList    mSubscribedHosts;
};
 
} // namespace Mdns
 
} // namespace otbr
 
#endif // OTBR_AGENT_MDNS_AVAHI_HPP_