nbdsrv.h

   1 #ifndef NBDSRV_H
   2 #define NBDSRV_H
   3
   4 #include "lfs.h"
   5
   6 #include <glib.h>
   7 #include <stdbool.h>
   8 #include <stdint.h>
   9
  10 #include <sys/socket.h>
  11 #include <sys/types.h>
  12 #include "nbd.h"
  13
  14 /* Structures */
  15
  16 /**
  17  * Types of virtuatlization
  18  **/
  19 typedef enum {
  20         VIRT_NONE=0,    /**< No virtualization */
  21         VIRT_IPLIT,     /**< Literal IP address as part of the filename */
  22         VIRT_IPHASH,    /**< Replacing all dots in an ip address by a / before
  23                              doing the same as in IPLIT */
  24         VIRT_CIDR,      /**< Every subnet in its own directory */
  25 } VIRT_STYLE;
  26
  27 /**
  28  * Variables associated with a server.
  29  **/
  30 typedef struct {
  31         gchar* exportname;    /**< (unprocessed) filename of the file we're exporting */
  32         uint64_t expected_size; /**< size of the exported file as it was told to
  33                                us through configuration */
  34         gchar* listenaddr;   /**< The IP address we're listening on */
  35         char* authname;      /**< filename of the authorization file */
  36         int flags;           /**< flags associated with this exported file */
  37         VIRT_STYLE virtstyle;/**< The style of virtualization, if any */
  38         uint8_t cidrlen;     /**< The length of the mask when we use
  39                                   CIDR-style virtualization */
  40         gchar* prerun;       /**< command to be ran after connecting a client,
  41                                   but before starting to serve */
  42         gchar* postrun;      /**< command that will be ran after the client
  43                                   disconnects */
  44         gchar* servename;    /**< name of the export as selected by nbd-client */
  45         int max_connections; /**< maximum number of opened connections */
  46         int numclients;      /**< number of clients connected to this export */
  47         gchar* transactionlog;/**< filename for transaction log */
  48         gchar* cowdir;       /**< directory for copy-on-write diff files. */
  49 } SERVER;
  50
  51 /**
  52   * Variables associated with a client connection
  53   */
  54 typedef struct _client {
  55         uint64_t exportsize;    /**< size of the file we're exporting */
  56         char *clientname;    /**< peer, in human-readable format */
  57         struct sockaddr_storage clientaddr; /**< peer, in binary format, network byte order */
  58         char *exportname;    /**< (processed) filename of the file we're exporting */
  59         GArray *export;    /**< array of FILE_INFO of exported files;
  60                                array size is always 1 unless we're
  61                                doing the multiple file option */
  62         pthread_rwlock_t export_lock;
  63         int net;             /**< The actual client socket */
  64         SERVER *server;      /**< The server this client is getting data from */
  65         char* difffilename;  /**< filename of the copy-on-write file, if any */
  66         int difffile;        /**< filedescriptor of copyonwrite file. @todo
  67                                shouldn't this be an array too? (cfr export) Or
  68                                make -m and -c mutually exclusive */
  69         uint32_t difffilelen;     /**< number of pages in difffile */
  70         uint32_t *difmap;            /**< see comment on the global difmap for this one */
  71         gboolean modern;     /**< client was negotiated using modern negotiation protocol */
  72         int transactionlogfd;/**< fd for transaction log */
  73         int clientfeats;     /**< Features supported by this client */
  74         pthread_mutex_t lock; /**< socket lock */
  75         void *tls_session; /**< TLS session context. Is NULL unless STARTTLS
  76                                 has been negotiated. */
  77         int (*socket_read)(struct _client*, void* buf, size_t len);
  78         int (*socket_write)(struct _client*, void* buf, size_t len);
  79         void (*socket_closed)(struct _client*);
  80 } CLIENT;
  81
  82 /**
  83  * Variables associated with an open file
  84  **/
  85 typedef struct {
  86         int fhandle;      /**< file descriptor */
  87         off_t startoff;   /**< starting offset of this file */
  88 } FILE_INFO;
  89
  90 /* Constants and macros */
  91
  92 /**
  93  * Error domain common for all NBD server errors.
  94  **/
  95 #define NBDS_ERR g_quark_from_static_string("server-error-quark")
  96
  97 /**
  98  * NBD server error codes.
  99  **/
 100 typedef enum {
 101         NBDS_ERR_CFILE_NOTFOUND,          /**< The configuration file is not found */
 102         NBDS_ERR_CFILE_MISSING_GENERIC,   /**< The (required) group "generic" is missing */
 103         NBDS_ERR_CFILE_KEY_MISSING,       /**< A (required) key is missing */
 104         NBDS_ERR_CFILE_VALUE_INVALID,     /**< A value is syntactically invalid */
 105         NBDS_ERR_CFILE_VALUE_UNSUPPORTED, /**< A value is not supported in this build */
 106         NBDS_ERR_CFILE_NO_EXPORTS,        /**< A config file was specified that does not
 107                                                define any exports */
 108         NBDS_ERR_CFILE_INCORRECT_PORT,    /**< The reserved port was specified for an
 109                                                old-style export. */
 110         NBDS_ERR_CFILE_DIR_UNKNOWN,       /**< A directory requested does not exist*/
 111         NBDS_ERR_CFILE_READDIR_ERR,       /**< Error occurred during readdir() */
 112         NBDS_ERR_CFILE_INVALID_SPLICE,    /**< We can't use splice with the other options
 113                                                specified for the export. */
 114         NBDS_ERR_SO_LINGER,               /**< Failed to set SO_LINGER to a socket */
 115         NBDS_ERR_SO_REUSEADDR,            /**< Failed to set SO_REUSEADDR to a socket */
 116         NBDS_ERR_SO_KEEPALIVE,            /**< Failed to set SO_KEEPALIVE to a socket */
 117         NBDS_ERR_GAI,                     /**< Failed to get address info */
 118         NBDS_ERR_SOCKET,                  /**< Failed to create a socket */
 119         NBDS_ERR_BIND,                    /**< Failed to bind an address to socket */
 120         NBDS_ERR_LISTEN,                  /**< Failed to start listening on a socket */
 121         NBDS_ERR_SYS,                     /**< Underlying system call or library error */
 122         NBDS_ERR_CFILE_INVALID_WAIT,      /**< We can't use wait with the other options
 123                                                specified for the export. */
 124 } NBDS_ERRS;
 125
 126 /**
 127   * Logging macros.
 128   *
 129   * @todo remove this. We should use g_log in all cases, and use the
 130   * logging mangler to redirect to syslog if and when necessary.
 131   */
 132 #ifdef ISSERVER
 133 #define msg(prio, ...) syslog(prio, __VA_ARGS__)
 134 #else
 135 #define msg(prio, ...) g_log(G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, __VA_ARGS__)
 136 #endif
 137 #define MY_NAME "nbd_server"
 138
 139 /** Per-export flags: */
 140 #define F_READONLY 1      /**< flag to tell us a file is readonly */
 141 #define F_MULTIFILE 2     /**< flag to tell us a file is exported using -m */
 142 #define F_COPYONWRITE 4   /**< flag to tell us a file is exported using
 143                             copyonwrite */
 144 #define F_AUTOREADONLY 8  /**< flag to tell us a file is set to autoreadonly */
 145 #define F_SPARSE 16       /**< flag to tell us copyronwrite should use a sparse file */
 146 #define F_SDP 32          /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
 147 #define F_SYNC 64         /**< Whether to fsync() after a write */
 148 #define F_FLUSH 128       /**< Whether server wants FLUSH to be sent by the client */
 149 #define F_FUA 256         /**< Whether server wants FUA to be sent by the client */
 150 #define F_ROTATIONAL 512  /**< Whether server wants the client to implement the elevator algorithm */
 151 #define F_TEMPORARY 1024  /**< Whether the backing file is temporary and should be created then unlinked */
 152 #define F_TRIM 2048       /**< Whether server wants TRIM (discard) to be sent by the client */
 153 #define F_FIXED 4096      /**< Client supports fixed new-style protocol (and can thus send us extra options */
 154 #define F_TREEFILES 8192  /**< flag to tell us a file is exported using -t */
 155 #define F_FORCEDTLS 16384 /**< TLS is required, either for the server as a whole or for a given export */
 156 #define F_SPLICE 32768    /**< flag to tell us to use splice for read/write operations */
 157 #define F_WAIT 65536      /**< flag to tell us to wait for file creation */
 158
 159 /* Functions */
 160
 161 /**
 162   * Check whether a given address matches a given netmask.
 163   *
 164   * @param mask the address or netmask to check against, in ASCII representation
 165   * @param addr the address to check
 166   *
 167   * @return true if the address matches the mask, false otherwise; in case of
 168   * failure to parse netmask, returns false with err set appropriately.
 169   * @todo decide what to do with v6-mapped IPv4 addresses.
 170   */
 171 bool address_matches(const char* mask, const struct sockaddr* addr, GError** err);
 172
 173 /**
 174   * Gets a byte to allow for address masking.
 175   *
 176   * @param masklen the length of the requested mask.
 177   * @return if the length of the mask is 8 or longer, 0xFF. Otherwise, a byte
 178   * with `masklen' number of leading bits set to 1, everything else set to 0.
 179   */
 180 uint8_t getmaskbyte(int masklen) G_GNUC_PURE;
 181
 182 /**
 183  * Check whether a client is allowed to connect. Works with an authorization
 184  * file which contains one line per machine or network, with CIDR-style
 185  * netmasks.
 186  *
 187  * @param opts The client who's trying to connect.
 188  * @return 0 - authorization refused, 1 - OK
 189  **/
 190 int authorized_client(CLIENT *opts);
 191
 192 /**
 193  * duplicate server
 194  * @param s the old server we want to duplicate
 195  * @return new duplicated server
 196  **/
 197 SERVER* dup_serve(const SERVER *const s);
 198
 199 /**
 200  * Detect the size of a file.
 201  *
 202  * @param fhandle An open filedescriptor
 203  * @return the size of the file, or UINT64_MAX if detection was
 204  * impossible.
 205  **/
 206 uint64_t size_autodetect(int fhandle);
 207
 208 /**
 209  * Punch a hole in the backend file (if supported by the current system).
 210  *
 211  * @param req the request for which this is being processed
 212  * @param client the client for which we're processing this request
 213  **/
 214 int exptrim(struct nbd_request* req, CLIENT* client);
 215 #endif //NBDSRV_H