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         gchar* transactionlog;/**< filename for transaction log */
  47         gchar* cowdir;       /**< directory for copy-on-write diff files. */
  48 } SERVER;
  49
  50 /**
  51   * Variables associated with a client connection
  52   */
  53 typedef struct {
  54         uint64_t exportsize;    /**< size of the file we're exporting */
  55         char *clientname;    /**< peer, in human-readable format */
  56         struct sockaddr_storage clientaddr; /**< peer, in binary format, network byte order */
  57         char *exportname;    /**< (processed) filename of the file we're exporting */
  58         GArray *export;    /**< array of FILE_INFO of exported files;
  59                                array size is always 1 unless we're
  60                                doing the multiple file option */
  61         int net;             /**< The actual client socket */
  62         SERVER *server;      /**< The server this client is getting data from */
  63         char* difffilename;  /**< filename of the copy-on-write file, if any */
  64         int difffile;        /**< filedescriptor of copyonwrite file. @todo
  65                                shouldn't this be an array too? (cfr export) Or
  66                                make -m and -c mutually exclusive */
  67         uint32_t difffilelen;     /**< number of pages in difffile */
  68         uint32_t *difmap;            /**< see comment on the global difmap for this one */
  69         gboolean modern;     /**< client was negotiated using modern negotiation protocol */
  70         int transactionlogfd;/**< fd for transaction log */
  71         int clientfeats;     /**< Features supported by this client */
  72         pthread_mutex_t lock;
  73 } CLIENT;
  74
  75 /**
  76  * Variables associated with an open file
  77  **/
  78 typedef struct {
  79         int fhandle;      /**< file descriptor */
  80         off_t startoff;   /**< starting offset of this file */
  81 } FILE_INFO;
  82
  83 /* Constants and macros */
  84
  85 /**
  86  * Error domain common for all NBD server errors.
  87  **/
  88 #define NBDS_ERR g_quark_from_static_string("server-error-quark")
  89
  90 /**
  91  * NBD server error codes.
  92  **/
  93 typedef enum {
  94         NBDS_ERR_CFILE_NOTFOUND,          /**< The configuration file is not found */
  95         NBDS_ERR_CFILE_MISSING_GENERIC,   /**< The (required) group "generic" is missing */
  96         NBDS_ERR_CFILE_KEY_MISSING,       /**< A (required) key is missing */
  97         NBDS_ERR_CFILE_VALUE_INVALID,     /**< A value is syntactically invalid */
  98         NBDS_ERR_CFILE_VALUE_UNSUPPORTED, /**< A value is not supported in this build */
  99         NBDS_ERR_CFILE_NO_EXPORTS,        /**< A config file was specified that does not
 100                                                define any exports */
 101         NBDS_ERR_CFILE_INCORRECT_PORT,    /**< The reserved port was specified for an
 102                                                old-style export. */
 103         NBDS_ERR_CFILE_DIR_UNKNOWN,       /**< A directory requested does not exist*/
 104         NBDS_ERR_CFILE_READDIR_ERR,       /**< Error occurred during readdir() */
 105         NBDS_ERR_SO_LINGER,               /**< Failed to set SO_LINGER to a socket */
 106         NBDS_ERR_SO_REUSEADDR,            /**< Failed to set SO_REUSEADDR to a socket */
 107         NBDS_ERR_SO_KEEPALIVE,            /**< Failed to set SO_KEEPALIVE to a socket */
 108         NBDS_ERR_GAI,                     /**< Failed to get address info */
 109         NBDS_ERR_SOCKET,                  /**< Failed to create a socket */
 110         NBDS_ERR_BIND,                    /**< Failed to bind an address to socket */
 111         NBDS_ERR_LISTEN,                  /**< Failed to start listening on a socket */
 112         NBDS_ERR_SYS,                     /**< Underlying system call or library error */
 113 } NBDS_ERRS;
 114
 115 /**
 116   * Logging macros.
 117   *
 118   * @todo remove this. We should use g_log in all cases, and use the
 119   * logging mangler to redirect to syslog if and when necessary.
 120   */
 121 #ifdef ISSERVER
 122 #define msg(prio, ...) syslog(prio, __VA_ARGS__)
 123 #else
 124 #define msg(prio, ...) g_log(G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, __VA_ARGS__)
 125 #endif
 126 #define MY_NAME "nbd_server"
 127
 128 /** Per-export flags: */
 129 #define F_READONLY 1      /**< flag to tell us a file is readonly */
 130 #define F_MULTIFILE 2     /**< flag to tell us a file is exported using -m */
 131 #define F_COPYONWRITE 4   /**< flag to tell us a file is exported using
 132                             copyonwrite */
 133 #define F_AUTOREADONLY 8  /**< flag to tell us a file is set to autoreadonly */
 134 #define F_SPARSE 16       /**< flag to tell us copyronwrite should use a sparse file */
 135 #define F_SDP 32          /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
 136 #define F_SYNC 64         /**< Whether to fsync() after a write */
 137 #define F_FLUSH 128       /**< Whether server wants FLUSH to be sent by the client */
 138 #define F_FUA 256         /**< Whether server wants FUA to be sent by the client */
 139 #define F_ROTATIONAL 512  /**< Whether server wants the client to implement the elevator algorithm */
 140 #define F_TEMPORARY 1024  /**< Whether the backing file is temporary and should be created then unlinked */
 141 #define F_TRIM 2048       /**< Whether server wants TRIM (discard) to be sent by the client */
 142 #define F_FIXED 4096      /**< Client supports fixed new-style protocol (and can thus send us extra options */
 143 #define F_TREEFILES 8192          /**< flag to tell us a file is exported using -t */
 144
 145 /* Functions */
 146
 147 /**
 148   * Check whether a given address matches a given netmask.
 149   *
 150   * @param mask the address or netmask to check against, in ASCII representation
 151   * @param addr the address to check
 152   *
 153   * @return true if the address matches the mask, false otherwise; in case of
 154   * failure to parse netmask, returns false with err set appropriately.
 155   * @todo decide what to do with v6-mapped IPv4 addresses.
 156   */
 157 bool address_matches(const char* mask, const struct sockaddr* addr, GError** err);
 158
 159 /**
 160   * Gets a byte to allow for address masking.
 161   *
 162   * @param masklen the length of the requested mask.
 163   * @return if the length of the mask is 8 or longer, 0xFF. Otherwise, a byte
 164   * with `masklen' number of leading bits set to 1, everything else set to 0.
 165   */
 166 uint8_t getmaskbyte(int masklen) G_GNUC_PURE;
 167
 168 /**
 169  * Check whether a client is allowed to connect. Works with an authorization
 170  * file which contains one line per machine or network, with CIDR-style
 171  * netmasks.
 172  *
 173  * @param opts The client who's trying to connect.
 174  * @return 0 - authorization refused, 1 - OK
 175  **/
 176 int authorized_client(CLIENT *opts);
 177
 178 /**
 179  * duplicate server
 180  * @param s the old server we want to duplicate
 181  * @return new duplicated server
 182  **/
 183 SERVER* dup_serve(const SERVER *const s);
 184
 185 /**
 186  * Detect the size of a file.
 187  *
 188  * @param fhandle An open filedescriptor
 189  * @return the size of the file, or UINT64_MAX if detection was
 190  * impossible.
 191  **/
 192 uint64_t size_autodetect(int fhandle);
 193
 194 /**
 195  * Punch a hole in the backend file (if supported by the current system).
 196  *
 197  * @param req the request for which this is being processed
 198  * @param client the client for which we're processing this request
 199  **/
 200 int exptrim(struct nbd_request* req, CLIENT* client);
 201
 202 /**
 203  * seek to a position in a file, with error handling.
 204  * @param handle a filedescriptor
 205  * @param a position to seek to
 206  * @todo get rid of this.
 207  **/
 208 void myseek(int handle, off_t a);
 209 #endif //NBDSRV_H