#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
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_ */
