#ifndef _GLOBALS_H_
#define _GLOBALS_H_
#include <dnbd3/types.h>
#include <dnbd3/shared/fdsignal.h>
#include <dnbd3/config/server.h>
#include <stdint.h>
#include <stdatomic.h>
#include <time.h>
#include <pthread.h>
#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
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_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;
/**
* 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_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;
/**
* 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;
/**
* 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_ */