#ifndef _GLOBALS_H_ #define _GLOBALS_H_ #include #include #include #include #include #include #include #include "reftypes.h" typedef struct timespec ticks; // ######### All structs/types used by the server ######## typedef struct _dnbd3_uplink dnbd3_uplink_t; typedef struct _dnbd3_image dnbd3_image_t; typedef struct _dnbd3_client dnbd3_client_t; typedef void (*uplink_callback)(void *data, uint64_t handle, uint64_t start, uint32_t length, const char *buffer); typedef struct _dnbd3_queue_client { struct _dnbd3_queue_client *next; void* data; // Passed back to callback uint64_t handle; // Passed back to callback uint64_t from, to; // Client range uplink_callback callback; // Callback function } dnbd3_queue_client_t; typedef struct _dnbd3_queue_entry { struct _dnbd3_queue_entry *next; uint64_t handle; // Our handle for this entry 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_queue_client_t *clients; #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 bool sent; // Already sent to uplink? } dnbd3_queue_entry_t; typedef struct _ns { struct _ns *next; char *name; size_t len; } dnbd3_ns_t; typedef struct { int fails; // Hard fail: Connection failed int rttIndex; uint32_t rtt[SERVER_RTT_PROBES]; bool isPrivate, isClientOnly; bool blocked; // If true count down fails until 0 to enable again ticks lastFail; // Last hard fail dnbd3_host_t host; char comment[COMMENT_LENGTH]; _Atomic(dnbd3_ns_t *) nameSpaces; // Linked list of name spaces } dnbd3_alt_server_t; typedef struct { int fails; // Soft fail: Image not found int rttIndex; uint32_t rtt[SERVER_RTT_PROBES]; bool blocked; // True if server is to be ignored and fails should be counted down bool initDone; } dnbd3_alt_local_t; typedef struct { int fd; // Socket fd for this connection int version; // Protocol version of remote server int index; // Entry in uplinks list } dnbd3_server_connection_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_uplink { ref reference; dnbd3_server_connection_t current; // Currently active connection; fd == -1 means disconnected dnbd3_server_connection_t better; // Better connection as found by altserver worker; fd == -1 means none dnbd3_signal_t* signal; // used to wake up the process pthread_t thread; // thread holding the connection pthread_mutex_t sendMutex; // For locking socket while sending pthread_mutex_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 pthread_mutex_t rttLock; // When accessing rttTestResult, betterFd or betterServer atomic_int rttTestResult; // RTT_* int cacheFd; // used to write to the image, in case it is relayed. ONLY USE FROM UPLINK THREAD! uint8_t *recvBuffer; // Buffer for receiving payload uint32_t recvBufferLen; // Len of ^^ atomic_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" atomic_uint_fast64_t bytesReceived; // Number of bytes received by the uplink since startup. atomic_uint_fast64_t bytesReceivedLastSave; // Number of bytes received when we last saved the cache map int queueLen; // length of queue int idleTime; // How many seconds the uplink was idle (apart from keep-alives) dnbd3_queue_entry_t *queue; atomic_uint_fast32_t queueId; dnbd3_alt_local_t altData[SERVER_MAX_ALTS]; }; typedef struct { uint8_t host[16]; int bytes; int bitMask; int permissions; } dnbd3_access_rule_t; typedef struct { ref reference; atomic_bool dirty; // Cache map has been modified outside uplink (only integrity checker for now) bool unchanged; // How many times in a row a reloaded cache map went unchanged _Atomic uint8_t map[]; } dnbd3_cache_map_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) weakref uplinkref; // pointer to a server connection weakref ref_cacheMap; // 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 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) atomic_int completenessEstimate; // Completeness estimate in percent atomic_int users; // clients currently using this image. XXX Lock on imageListLock when modifying and checking whether the image should be freed. Reading it elsewhere is fine without the lock. int id; // Unique ID of this image. Only unique in the context of this running instance of DNBD3-Server struct { atomic_bool read; // Error reading from file atomic_bool write; // Error writing to file atomic_bool changed; // File disappeared or changed, thorough check required if it seems to be back atomic_bool uplink; // No uplink connected atomic_bool queue; // Too many requests waiting on uplink } problem; uint16_t rid; // revision of image bool accessed; // image was accessed since .meta was written bool wantCheck; // true if the entire image should be checked as soon as the according thread is idle pthread_mutex_t lock; }; #define PIMG(x) (x)->name, (int)(x)->rid struct _dnbd3_client { #define HOSTNAMELEN (48) atomic_uint_fast64_t bytesSent; // Byte counter for this client. dnbd3_image_t * _Atomic image; // Image in use by this client, or NULL during handshake int sock; _Atomic uint8_t relayedCount; // How many requests are in-flight to the uplink server 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_mutex_t lock; pthread_t thread; }; // ####################################################### #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_uint _uplinkTimeout; /** * Read timeout when waiting for or sending data from/to client */ extern atomic_uint _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; /** * How many in-flight replication requests we should target (per uplink) */ extern atomic_int _bgrWindowSize; /** * (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; /** * If true, don't abort image replication if preallocating * the image fails, but retry with sparse file. */ extern atomic_bool _ignoreAllocErrors; /** * 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_uint _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; /** * Pretend to be a client when talking to others servers, * effectively not setting the server bit during connection * setup. Useful for local caching. */ extern atomic_bool _pretendClient; /** * Minimum uptime in seconds before proxy starts deleting old * images if running out of space. -1 disables automatic deletion. * Only relevant in proxy mode. */ extern atomic_int _autoFreeDiskSpaceDelay; /** * When handling a client request, this sets the maximum amount * of bytes we prefetch offset right at the end of the client request. * The prefetch size will be MIN( length * 3, _maxPrefetch ), if * length <= _maxPrefetch, so effectively, setting this to 0 disables * any prefetching. */ extern atomic_uint _maxPrefetch; /** * Use with care. Can severely degrade performance. * Set either 0 or very high. */ extern atomic_uint _minRequestSize; /** * 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_ */