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Diffstat (limited to 'src/server/globals.h')
| -rw-r--r-- | src/server/globals.h | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/src/server/globals.h b/src/server/globals.h new file mode 100644 index 0000000..2b30bc2 --- /dev/null +++ b/src/server/globals.h @@ -0,0 +1,277 @@ +#ifndef _GLOBALS_H_ +#define _GLOBALS_H_ + +#include "../types.h" +#include "../shared/fdsignal.h" +#include "../serverconfig.h" +#include <stdint.h> +#include <stdatomic.h> +#include <time.h> +#include <pthread.h> + +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 + uint32_t idleTime; // How many seconds the uplink was idle (apart from keep-alives) + 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_ */ |