diff options
Diffstat (limited to 'src/db/upnp/Discovery.cxx')
-rw-r--r-- | src/db/upnp/Discovery.cxx | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/src/db/upnp/Discovery.cxx b/src/db/upnp/Discovery.cxx new file mode 100644 index 000000000..a94f29d8c --- /dev/null +++ b/src/db/upnp/Discovery.cxx @@ -0,0 +1,328 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#include "Discovery.hxx" +#include "Device.hxx" +#include "Domain.hxx" +#include "ContentDirectoryService.hxx" +#include "WorkQueue.hxx" +#include "upnpplib.hxx" +#include "thread/Mutex.hxx" + +#include <upnp/upnp.h> +#include <upnp/upnptools.h> + +#include <string.h> + +#include <map> + +// The service type string we are looking for. +static const char *const ContentDirectorySType = "urn:schemas-upnp-org:service:ContentDirectory:1"; + +// We don't include a version in comparisons, as we are satisfied with +// version 1 +gcc_pure +static bool +isCDService(const char *st) +{ + const size_t sz = strlen(ContentDirectorySType) - 2; + return memcmp(ContentDirectorySType, st, sz) == 0; +} + +// The type of device we're asking for in search +static const char *const MediaServerDType = "urn:schemas-upnp-org:device:MediaServer:1"; + +gcc_pure +static bool +isMSDevice(const char *st) +{ + const size_t sz = strlen(MediaServerDType) - 2; + return memcmp(MediaServerDType, st, sz) == 0; +} + +/** + * Each appropriate discovery event (executing in a libupnp thread + * context) queues the following task object for processing by the + * discovery thread. + */ +struct DiscoveredTask { + bool alive; + std::string url; + std::string deviceId; + int expires; // Seconds valid + + DiscoveredTask(bool _alive, const Upnp_Discovery *disco) + : alive(_alive), url(disco->Location), + deviceId(disco->DeviceId), + expires(disco->Expires) {} + +}; +static WorkQueue<DiscoveredTask *> discoveredQueue("DiscoveredQueue"); + +// Descriptor for one device having a Content Directory service found +// on the network. +class ContentDirectoryDescriptor { +public: + ContentDirectoryDescriptor(const std::string &url, + const std::string &description, + time_t last, int exp) + :device(url, description), last_seen(last), expires(exp+20) {} + UPnPDevice device; + time_t last_seen; + int expires; // seconds valid +}; + +// A ContentDirectoryPool holds the characteristics of the servers +// currently on the network. +// The map is referenced by deviceId (==UDN) +// The class is instanciated as a static (unenforced) singleton. +class ContentDirectoryPool { +public: + Mutex m_mutex; + std::map<std::string, ContentDirectoryDescriptor> m_directories; +}; + +static ContentDirectoryPool contentDirectories; + +// Worker routine for the discovery queue. Get messages about devices +// appearing and disappearing, and update the directory pool +// accordingly. +static void * +discoExplorer(void *) +{ + for (;;) { + DiscoveredTask *tsk = 0; + size_t qsz; + if (!discoveredQueue.take(&tsk, &qsz)) { + discoveredQueue.workerExit(); + return (void*)1; + } + + const ScopeLock protect(contentDirectories.m_mutex); + if (!tsk->alive) { + // Device signals it is going off. + auto it = contentDirectories.m_directories.find(tsk->deviceId); + if (it != contentDirectories.m_directories.end()) { + contentDirectories.m_directories.erase(it); + } + } else { + // Device signals its existence and well-being. Perform the + // UPnP "description" phase by downloading and decoding the + // description document. + char *buf; + // LINE_SIZE is defined by libupnp's upnp.h... + char contentType[LINE_SIZE]; + int code = UpnpDownloadUrlItem(tsk->url.c_str(), &buf, contentType); + if (code != UPNP_E_SUCCESS) { + continue; + } + std::string sdesc(buf); + + // Update or insert the device + ContentDirectoryDescriptor d(tsk->url, sdesc, + time(0), tsk->expires); + if (!d.device.ok) { + continue; + } + + auto e = contentDirectories.m_directories.emplace(tsk->deviceId, d); + if (!e.second) + e.first->second = d; + } + delete tsk; + } +} + +// This gets called for all libupnp asynchronous events, in a libupnp +// thread context. +// Example: ContentDirectories appearing and disappearing from the network +// We queue a task for our worker thread(s) +// It seems that this can get called by several threads. We have a +// mutex just for clarifying the message printing, the workqueue is +// mt-safe of course. +static int +cluCallBack(Upnp_EventType et, void *evp, void *) +{ + static Mutex cblock; + const ScopeLock protect(cblock); + + switch (et) { + case UPNP_DISCOVERY_SEARCH_RESULT: + case UPNP_DISCOVERY_ADVERTISEMENT_ALIVE: + { + Upnp_Discovery *disco = (Upnp_Discovery *)evp; + if (isMSDevice(disco->DeviceType) || + isCDService(disco->ServiceType)) { + DiscoveredTask *tp = new DiscoveredTask(1, disco); + if (discoveredQueue.put(tp)) + return UPNP_E_FINISH; + } + break; + } + + case UPNP_DISCOVERY_ADVERTISEMENT_BYEBYE: + { + Upnp_Discovery *disco = (Upnp_Discovery *)evp; + + if (isMSDevice(disco->DeviceType) || + isCDService(disco->ServiceType)) { + DiscoveredTask *tp = new DiscoveredTask(0, disco); + if (discoveredQueue.put(tp)) + return UPNP_E_FINISH; + } + break; + } + + default: + // Ignore other events for now + break; + } + + return UPNP_E_SUCCESS; +} + +void +UPnPDeviceDirectory::expireDevices() +{ + const ScopeLock protect(contentDirectories.m_mutex); + time_t now = time(0); + bool didsomething = false; + + for (auto it = contentDirectories.m_directories.begin(); + it != contentDirectories.m_directories.end();) { + if (now - it->second.last_seen > it->second.expires) { + it = contentDirectories.m_directories.erase(it); + didsomething = true; + } else { + it++; + } + } + + if (didsomething) + search(); +} + +UPnPDeviceDirectory::UPnPDeviceDirectory() + :m_searchTimeout(2), m_lastSearch(0) +{ + if (!discoveredQueue.start(1, discoExplorer, 0)) { + error.Set(upnp_domain, "Discover work queue start failed"); + return; + } + + LibUPnP *lib = LibUPnP::getLibUPnP(error); + if (lib == nullptr) + return; + + lib->registerHandler(UPNP_DISCOVERY_SEARCH_RESULT, cluCallBack, this); + lib->registerHandler(UPNP_DISCOVERY_ADVERTISEMENT_ALIVE, + cluCallBack, this); + lib->registerHandler(UPNP_DISCOVERY_ADVERTISEMENT_BYEBYE, + cluCallBack, this); + + search(); +} + +bool +UPnPDeviceDirectory::search() +{ + time_t now = time(0); + if (now - m_lastSearch < 10) + return true; + m_lastSearch = now; + + LibUPnP *lib = LibUPnP::getLibUPnP(error); + if (lib == nullptr) + return false; + + // We search both for device and service just in case. + int code = UpnpSearchAsync(lib->getclh(), m_searchTimeout, + ContentDirectorySType, lib); + if (code != UPNP_E_SUCCESS) { + error.Format(upnp_domain, code, + "UpnpSearchAsync() failed: %s", + UpnpGetErrorMessage(code)); + return false; + } + + code = UpnpSearchAsync(lib->getclh(), m_searchTimeout, + MediaServerDType, lib); + if (code != UPNP_E_SUCCESS) { + error.Format(upnp_domain, code, + "UpnpSearchAsync() failed: %s", + UpnpGetErrorMessage(code)); + return false; + } + + return true; +} + +UPnPDeviceDirectory *UPnPDeviceDirectory::getTheDir() +{ + // TODO: elimate static variable + static UPnPDeviceDirectory *theDevDir; + if (theDevDir == nullptr) + theDevDir = new UPnPDeviceDirectory(); + if (theDevDir && !theDevDir->ok()) + return 0; + return theDevDir; +} + +bool +UPnPDeviceDirectory::getDirServices(std::vector<ContentDirectoryService> &out) +{ + if (!ok()) + return false; + + // Has locking, do it before our own lock + expireDevices(); + + const ScopeLock protect(contentDirectories.m_mutex); + + for (auto dit = contentDirectories.m_directories.begin(); + dit != contentDirectories.m_directories.end(); dit++) { + for (const auto &service : dit->second.device.services) { + if (isCDService(service.serviceType.c_str())) { + out.emplace_back(dit->second.device, service); + } + } + } + + return true; +} + +bool +UPnPDeviceDirectory::getServer(const char *friendlyName, + ContentDirectoryService &server) +{ + std::vector<ContentDirectoryService> ds; + if (!getDirServices(ds)) { + return false; + } + + for (const auto &i : ds) { + if (strcmp(friendlyName, i.getFriendlyName()) == 0) { + server = i; + return true; + } + } + + return false; +} |