nbdsrv.h

   1 #ifndef NBDSRV_H
   2 #define NBDSRV_H
   3
   4 #include <glib.h>
   5 #include <stdbool.h>
   6 #include <stdint.h>
   7
   8 #include <sys/socket.h>
   9 #include <sys/types.h>
  10
  11 /* Structures */
  12
  13 /**
  14  * Types of virtuatlization
  15  **/
  16 typedef enum {
  17         VIRT_NONE=0,    /**< No virtualization */
  18         VIRT_IPLIT,     /**< Literal IP address as part of the filename */
  19         VIRT_IPHASH,    /**< Replacing all dots in an ip address by a / before
  20                              doing the same as in IPLIT */
  21         VIRT_CIDR,      /**< Every subnet in its own directory */
  22 } VIRT_STYLE;
  23
  24 /**
  25  * Variables associated with a server.
  26  **/
  27 typedef struct {
  28         gchar* exportname;    /**< (unprocessed) filename of the file we're exporting */
  29         off_t expected_size; /**< size of the exported file as it was told to
  30                                us through configuration */
  31         gchar* listenaddr;   /**< The IP address we're listening on */
  32         unsigned int port;   /**< port we're exporting this file at */
  33         char* authname;      /**< filename of the authorization file */
  34         int flags;           /**< flags associated with this exported file */
  35         int socket;          /**< The socket of this server. */
  36         int socket_family;   /**< family of the socket */
  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 } SERVER;
  48
  49 /**
  50   * Variables associated with a client connection
  51   */
  52 typedef struct {
  53         off_t exportsize;    /**< size of the file we're exporting */
  54         char *clientname;    /**< peer, in human-readable format */
  55         struct sockaddr_storage clientaddr; /**< peer, in binary format, network byte order */
  56         char *exportname;    /**< (processed) filename of the file we're exporting */
  57         GArray *export;    /**< array of FILE_INFO of exported files;
  58                                array size is always 1 unless we're
  59                                doing the multiple file option */
  60         int net;             /**< The actual client socket */
  61         SERVER *server;      /**< The server this client is getting data from */
  62         char* difffilename;  /**< filename of the copy-on-write file, if any */
  63         int difffile;        /**< filedescriptor of copyonwrite file. @todo
  64                                shouldn't this be an array too? (cfr export) Or
  65                                make -m and -c mutually exclusive */
  66         uint32_t difffilelen;     /**< number of pages in difffile */
  67         uint32_t *difmap;            /**< see comment on the global difmap for this one */
  68         gboolean modern;     /**< client was negotiated using modern negotiation protocol */
  69         int transactionlogfd;/**< fd for transaction log */
  70         int clientfeats;     /**< Features supported by this client */
  71 } CLIENT;
  72
  73 /* Constants and macros */
  74
  75 /**
  76  * Error domain common for all NBD server errors.
  77  **/
  78 #define NBDS_ERR g_quark_from_static_string("server-error-quark")
  79
  80 /**
  81  * NBD server error codes.
  82  **/
  83 typedef enum {
  84         NBDS_ERR_CFILE_NOTFOUND,          /**< The configuration file is not found */
  85         NBDS_ERR_CFILE_MISSING_GENERIC,   /**< The (required) group "generic" is missing */
  86         NBDS_ERR_CFILE_KEY_MISSING,       /**< A (required) key is missing */
  87         NBDS_ERR_CFILE_VALUE_INVALID,     /**< A value is syntactically invalid */
  88         NBDS_ERR_CFILE_VALUE_UNSUPPORTED, /**< A value is not supported in this build */
  89         NBDS_ERR_CFILE_NO_EXPORTS,        /**< A config file was specified that does not
  90                                                define any exports */
  91         NBDS_ERR_CFILE_INCORRECT_PORT,    /**< The reserved port was specified for an
  92                                                old-style export. */
  93         NBDS_ERR_CFILE_DIR_UNKNOWN,       /**< A directory requested does not exist*/
  94         NBDS_ERR_CFILE_READDIR_ERR,       /**< Error occurred during readdir() */
  95         NBDS_ERR_SO_LINGER,               /**< Failed to set SO_LINGER to a socket */
  96         NBDS_ERR_SO_REUSEADDR,            /**< Failed to set SO_REUSEADDR to a socket */
  97         NBDS_ERR_SO_KEEPALIVE,            /**< Failed to set SO_KEEPALIVE to a socket */
  98         NBDS_ERR_GAI,                     /**< Failed to get address info */
  99         NBDS_ERR_SOCKET,                  /**< Failed to create a socket */
 100         NBDS_ERR_BIND,                    /**< Failed to bind an address to socket */
 101         NBDS_ERR_LISTEN,                  /**< Failed to start listening on a socket */
 102         NBDS_ERR_SYS,                     /**< Underlying system call or library error */
 103 } NBDS_ERRS;
 104
 105 /**
 106   * Logging macros.
 107   *
 108   * @todo remove this. We should use g_log in all cases, and use the
 109   * logging mangler to redirect to syslog if and when necessary.
 110   */
 111 #ifdef ISSERVER
 112 #define msg(prio, ...) syslog(prio, __VA_ARGS__)
 113 #else
 114 #define msg(prio, ...) g_log(G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, __VA_ARGS__)
 115 #endif
 116 #define MY_NAME "nbd_server"
 117
 118 /* Functions */
 119
 120 /**
 121   * Check whether a given address matches a given netmask.
 122   *
 123   * @param mask the address or netmask to check against, in ASCII representation
 124   * @param addr the address to check, in network byte order
 125   * @param af the address family of the passed address (AF_INET or AF_INET6)
 126   *
 127   * @return true if the address matches the mask, false otherwise; in case of
 128   * failure to parse netmask, returns false with err set appropriately.
 129   * @todo decide what to do with v6-mapped IPv4 addresses.
 130   */
 131 bool address_matches(const char* mask, const void* addr, int af, GError** err);
 132
 133 /**
 134   * Gets a byte to allow for address masking.
 135   *
 136   * @param masklen the length of the requested mask.
 137   * @return if the length of the mask is 8 or longer, 0xFF. Otherwise, a byte
 138   * with `masklen' number of leading bits set to 1, everything else set to 0.
 139   */
 140 uint8_t getmaskbyte(int masklen) G_GNUC_PURE;
 141
 142 /**
 143  * Check whether a client is allowed to connect. Works with an authorization
 144  * file which contains one line per machine or network, with CIDR-style
 145  * netmasks.
 146  *
 147  * @param opts The client who's trying to connect.
 148  * @return 0 - authorization refused, 1 - OK
 149  **/
 150 int authorized_client(CLIENT *opts);
 151
 152 /**
 153  * duplicate server
 154  * @param s the old server we want to duplicate
 155  * @return new duplicated server
 156  **/
 157 SERVER* dup_serve(const SERVER *const s);
 158
 159 /**
 160  * append new server to array
 161  * @param s server
 162  * @param a server array
 163  * @return 0 success, -1 error
 164  */
 165 int append_serve(const SERVER *const s, GArray *const a);
 166
 167 /**
 168  * Detect the size of a file.
 169  *
 170  * @param fhandle An open filedescriptor
 171  * @return the size of the file, or OFFT_MAX if detection was
 172  * impossible.
 173  **/
 174 off_t size_autodetect(int fhandle);
 175 #endif //NBDSRV_H