#ifndef _GLOBALS_H_ #define _GLOBALS_H_ #include "../types.h" #include "../shared/fdsignal.h" #include "../serverconfig.h" #include #include #include #include typedef struct timespec ticks; // ######### All structs/types used by the server ######## typedef struct _dnbd3_connection dnbd3_connection_t; typedef struct _dnbd3_image dnbd3_image_t; typedef struct _dnbd3_client dnbd3_client_t; // Slot is free, can be used. // Must only be set in uplink_handle_receive() or uplink_remove_client() #define ULR_FREE 0 // Slot has been filled with a request that hasn't been sent to the upstream server yet, matching request can safely rely on reuse. // Must only be set in uplink_request() #define ULR_NEW 1 // Slot is occupied, reply has not yet been received, matching request can safely rely on reuse. // Must only be set in uplink_mainloop() or uplink_request() #define ULR_PENDING 2 // Slot is being processed, do not consider for hop on. // Must only be set in uplink_handle_receive() #define ULR_PROCESSING 3 typedef struct { uint64_t handle; // Client defined handle to pass back in reply uint64_t from; // First byte offset of requested block (ie. 4096) uint64_t to; // Last byte + 1 of requested block (ie. 8192, if request len is 4096, resulting in bytes 4096-8191) dnbd3_client_t * client; // Client to send reply to int status; // status of this entry: ULR_* #ifdef _DEBUG ticks entered; // When this request entered the queue (for debugging) #endif uint8_t hopCount; // How many hops this request has already taken across proxies } dnbd3_queued_request_t; #define RTT_IDLE 0 // Not in progress #define RTT_INPROGRESS 1 // In progess, not finished #define RTT_DONTCHANGE 2 // Finished, but no better alternative found #define RTT_DOCHANGE 3 // Finished, better alternative written to .betterServer + .betterFd #define RTT_NOT_REACHABLE 4 // No uplink was reachable struct _dnbd3_connection { int fd; // socket fd to remote server int version; // remote server protocol version dnbd3_signal_t* signal; // used to wake up the process pthread_t thread; // thread holding the connection pthread_spinlock_t queueLock; // lock for synchronization on request queue etc. dnbd3_image_t *image; // image that this uplink is used for; do not call get/release for this pointer dnbd3_host_t currentServer; // Current server we're connected to pthread_spinlock_t rttLock; // When accessing rttTestResult, betterFd or betterServer int rttTestResult; // RTT_* int cacheFd; // used to write to the image, in case it is relayed. ONLY USE FROM UPLINK THREAD! int betterVersion; // protocol version of better server int betterFd; // Active connection to better server, ready to use dnbd3_host_t betterServer; // The better server uint8_t *recvBuffer; // Buffer for receiving payload uint32_t recvBufferLen; // Len of ^^ volatile bool shutdown; // signal this thread to stop, must only be set from uplink_shutdown() or cleanup in uplink_mainloop() bool replicatedLastBlock; // bool telling if the last block has been replicated yet bool cycleDetected; // connection cycle between proxies detected for current remote server int nextReplicationIndex; // Which index in the cache map we should start looking for incomplete blocks at // If BGR == BGR_HASHBLOCK, -1 means "currently no incomplete block" uint64_t replicationHandle; // Handle of pending replication request atomic_uint_fast64_t bytesReceived; // Number of bytes received by the uplink since startup. int queueLen; // length of queue int idleCount; // How many iterations of keepalive check connection was idle dnbd3_queued_request_t queue[SERVER_MAX_UPLINK_QUEUE]; }; typedef struct { char comment[COMMENT_LENGTH]; dnbd3_host_t host; unsigned int rtt[SERVER_RTT_PROBES]; unsigned int rttIndex; bool isPrivate, isClientOnly; ticks lastFail; int numFails; } dnbd3_alt_server_t; typedef struct { uint8_t host[16]; int bytes; int bitMask; int permissions; } dnbd3_access_rule_t; /** * Image struct. An image path could be something like * /mnt/images/rz/zfs/Windows7 ZfS.vmdk.r1 * and the name would then be * rz/zfs/windows7 zfs.vmdk */ struct _dnbd3_image { char *path; // absolute path of the image char *name; // public name of the image (usually relative path minus revision ID) dnbd3_connection_t *uplink; // pointer to a server connection uint8_t *cache_map; // cache map telling which parts are locally cached, NULL if complete uint64_t virtualFilesize; // virtual size of image (real size rounded up to multiple of 4k) uint64_t realFilesize; // actual file size on disk ticks atime; // last access time ticks lastWorkCheck; // last time a non-working image has been checked ticks nextCompletenessEstimate; // next time the completeness estimate should be updated uint32_t *crc32; // list of crc32 checksums for each 16MiB block in image uint32_t masterCrc32; // CRC-32 of the crc-32 list int readFd; // used to read the image. Used from multiple threads, so use atomic operations (pread et al) int completenessEstimate; // Completeness estimate in percent int users; // clients currently using this image int id; // Unique ID of this image. Only unique in the context of this running instance of DNBD3-Server bool working; // true if image exists and completeness is == 100% or a working upstream proxy is connected uint16_t rid; // revision of image pthread_spinlock_t lock; }; struct _dnbd3_client { #define HOSTNAMELEN (48) atomic_uint_fast64_t bytesSent; // Byte counter for this client. dnbd3_image_t *image; // Image in use by this client, or NULL during handshake int sock; bool isServer; // true if a server in proxy mode, false if real client dnbd3_host_t host; char hostName[HOSTNAMELEN]; // inet_ntop version of host pthread_mutex_t sendMutex; // Held while writing to sock if image is incomplete (since uplink uses socket too) pthread_spinlock_t lock; }; // ####################################################### #define CONFIG_FILENAME "server.conf" /** * Base directory where the configuration files reside. Will never have a trailing slash. */ extern char *_configDir; /** * Base directory where all images are stored in. Will never have a trailing slash. */ extern char *_basePath; /** * Whether or not simple *.vmdk files should be treated as revision 1 */ extern atomic_bool _vmdkLegacyMode; /** * How much artificial delay should we add when a server connects to us? */ extern atomic_int _serverPenalty; /** * How much artificial delay should we add when a client connects to us? */ extern atomic_int _clientPenalty; /** * Is server shutting down? */ extern atomic_bool _shutdown; /** * Is server allowed to provide images in proxy mode? */ extern atomic_bool _isProxy; /** * Only use servers as upstream proxy which are private? */ extern atomic_bool _proxyPrivateOnly; /** * Whether to remove missing images from image list on SIGHUP */ extern atomic_bool _removeMissingImages; /** * Read timeout when waiting for or sending data on an uplink */ extern atomic_int _uplinkTimeout; /** * Read timeout when waiting for or sending data from/to client */ extern atomic_int _clientTimeout; /** * If true, images with no active client will have their fd closed after some * idle time. */ extern atomic_bool _closeUnusedFd; /** * Should we replicate incomplete images in the background? * Otherwise, only blocks that were explicitly requested will be cached. */ extern atomic_int _backgroundReplication; #define BGR_DISABLED (0) #define BGR_FULL (1) #define BGR_HASHBLOCK (2) /** * Minimum connected clients for background replication to kick in */ extern atomic_int _bgrMinClients; /** * (In proxy mode): If connecting client is a proxy, and the requested image * is not known locally, should we ask our known alt servers for it? * Otherwise the request is rejected. */ extern atomic_bool _lookupMissingForProxy; /** * Should we preallocate proxied images right at the start to make * sure we can cache it entirely, or rather create sparse files * with holes in them? With sparse files, we just keep writing * cached blocks to disk until it is full, and only then will we * start to delete old images. This might be a bit flaky so use * only in space restricted environments. Also make sure your * file system actually supports sparse files / files with holes * in them, or you might get really shitty performance. * This setting will have no effect if background replication is * turned on. */ extern atomic_bool _sparseFiles; /** * Port to listen on (default: #define PORT (5003)) */ extern atomic_int _listenPort; /** * Max number of DNBD3 clients we accept */ extern atomic_int _maxClients; /** * Max number of Images we support (in baseDir) */ extern atomic_int _maxImages; /** * Maximum payload length we accept on uplinks and thus indirectly * from clients in case the requested range is not cached locally. * Usually this isn't even a megabyte for "real" clients (blockdev * or fuse). */ extern atomic_int _maxPayload; /** * If in proxy mode, don't replicate images that are * larger than this according to the uplink server. */ extern atomic_uint_fast64_t _maxReplicationSize; /** * Load the server configuration. */ void globals_loadConfig(); /** * Dump the effective configuration in use to given buffer. */ size_t globals_dumpConfig(char *buffer, size_t size); #endif /* GLOBALS_H_ */