88 lines
3.1 KiB
Markdown
88 lines
3.1 KiB
Markdown
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QMdnsEngine provides an implementation of multicast DNS as per RFC 6762.
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Some of QMdnsEngine's features include:
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- Supports Windows, macOS, Linux, and most other platforms supported by Qt
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- Requires only QtCore and QtNetwork - no other dependencies
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- Includes an exhaustive set of unit tests
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## Build Requirements
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QMdnsEngine requires the following in order to build the library:
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- CMake 3.2+
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- Qt 5.4+
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- C++ compiler with C++11 support
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## Build Instructions
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QMdnsEngine uses CMake for building the library. The options shown below allow the build to be customized:
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- Installation:
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- `BIN_INSTALL_DIR` - binary installation directory relative to the install prefix
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- `LIB_INSTALL_DIR` - library installation directory relative to the install prefix
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- `INCLUDE_INSTALL_DIR` - header installation directory relative to the install prefix
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- Customization:
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- `BUILD_DOC` - build the documentation for the library with Doxygen
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- `BUILD_EXAMPLES` - build example applications that use the library
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- `BUILD_TESTS` - build the test suite
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## Basic Provider Usage
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To provide a service on the local network, begin by creating a [Server](@ref QMdnsEngine::Server), a [Hostname](@ref QMdnsEngine::Hostname), and a [Provider](@ref QMdnsEngine::Provider):
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@code
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QMdnsEngine::Server server;
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QMdnsEngine::Hostname hostname(&server);
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QMdnsEngine::Provider provider(&server, &hostname);
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@endcode
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The server sends and receives raw DNS packets. The hostname finds a unique hostname that is not in use to identify the device. Lastly, the provider manages the records for a service.
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The next step is to create the service and update the provider:
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@code
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QMdnsEngine::Service service;
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service.setType("_http._tcp.local.");
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service.setName("My Service");
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service.setPort(1234);
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provider.update(service);
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@endcode
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That's it! As long as the provider remains in scope, the service will be available on the local network and other devices will be able to find it.
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## Basic Browser Usage
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To find services on the local network, begin by creating a [Server](@ref QMdnsEngine::Server) and a [Browser](@ref QMdnsEngine::Browser):
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@code
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QMdnsEngine::Server server;
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QMdnsEngine::Cache cache;
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QMdnsEngine::Browser browser(&server, "_http._tcp.local.", &cache);
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@endcode
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The cache is optional but helps save time later when resolving services. The browser is provided with a service type which is used to filter services.
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To receive a notification when services are added, connect to the [Browser::serviceAdded()](@ref QMdnsEngine::Browser::serviceAdded) signal:
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@code
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QObject::connect(&browser, &QMdnsEngine::Browser::serviceAdded,
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[](const QMdnsEngine::Service &service) {
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qDebug() << service.name() << "discovered!";
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}
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);
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@endcode
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To resolve the service, use a [Resolver](@ref QMdnsEngine::Resolver):
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@code
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QMdnsEngine::Resolver resolver(&server, service.hostname(), &cache);
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QObject::connect(&resolver, &QMdnsEngine::Resolver::resolved,
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[](const QHostAddress &address) {
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qDebug() << "resolved to" << address;
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}
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);
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@endcode
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Note that [Resolver::resolved()](@ref QMdnsEngine::Resolver::resolved) may be emitted once for each address provided by the service.
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