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
  13 /* Structures */
  14
  15 /**
  16  * Types of virtuatlization
  17  **/
  18 typedef enum {
  19         VIRT_NONE=0,    /**< No virtualization */
  20         VIRT_IPLIT,     /**< Literal IP address as part of the filename */
  21         VIRT_IPHASH,    /**< Replacing all dots in an ip address by a / before
  22                              doing the same as in IPLIT */
  23         VIRT_CIDR,      /**< Every subnet in its own directory */
  24 } VIRT_STYLE;
  25
  26 /**
  27  * Variables associated with a server.
  28  **/
  29 typedef struct {
  30         gchar* exportname;    /**< (unprocessed) filename of the file we're exporting */
  31         uint64_t expected_size; /**< size of the exported file as it was told to
  32                                us through configuration */
  33         gchar* listenaddr;   /**< The IP address we're listening on */
  34         unsigned int port;   /**< port we're exporting this file at */
  35         char* authname;      /**< filename of the authorization file */
  36         int flags;           /**< flags associated with this exported file */
  37         int socket;          /**< The socket of this server. */
  38         int socket_family;   /**< family of the socket */
  39         VIRT_STYLE virtstyle;/**< The style of virtualization, if any */
  40         uint8_t cidrlen;     /**< The length of the mask when we use
  41                                   CIDR-style virtualization */
  42         gchar* prerun;       /**< command to be ran after connecting a client,
  43                                   but before starting to serve */
  44         gchar* postrun;      /**< command that will be ran after the client
  45                                   disconnects */
  46         gchar* servename;    /**< name of the export as selected by nbd-client */
  47         int max_connections; /**< maximum number of opened connections */
  48         gchar* transactionlog;/**< filename for transaction log */
  49 } SERVER;
  50
  51 /**
  52   * Variables associated with a client connection
  53   */
  54 typedef struct {
  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         int net;             /**< The actual client socket */
  63         SERVER *server;      /**< The server this client is getting data from */
  64         char* difffilename;  /**< filename of the copy-on-write file, if any */
  65         int difffile;        /**< filedescriptor of copyonwrite file. @todo
  66                                shouldn't this be an array too? (cfr export) Or
  67                                make -m and -c mutually exclusive */
  68         uint32_t difffilelen;     /**< number of pages in difffile */
  69         uint32_t *difmap;            /**< see comment on the global difmap for this one */
  70         gboolean modern;     /**< client was negotiated using modern negotiation protocol */
  71         int transactionlogfd;/**< fd for transaction log */
  72         int clientfeats;     /**< Features supported by this client */
  73 } CLIENT;
  74
  75 /* Constants and macros */
  76
  77 /**
  78  * Error domain common for all NBD server errors.
  79  **/
  80 #define NBDS_ERR g_quark_from_static_string("server-error-quark")
  81
  82 /**
  83  * NBD server error codes.
  84  **/
  85 typedef enum {
  86         NBDS_ERR_CFILE_NOTFOUND,          /**< The configuration file is not found */
  87         NBDS_ERR_CFILE_MISSING_GENERIC,   /**< The (required) group "generic" is missing */
  88         NBDS_ERR_CFILE_KEY_MISSING,       /**< A (required) key is missing */
  89         NBDS_ERR_CFILE_VALUE_INVALID,     /**< A value is syntactically invalid */
  90         NBDS_ERR_CFILE_VALUE_UNSUPPORTED, /**< A value is not supported in this build */
  91         NBDS_ERR_CFILE_NO_EXPORTS,        /**< A config file was specified that does not
  92                                                define any exports */
  93         NBDS_ERR_CFILE_INCORRECT_PORT,    /**< The reserved port was specified for an
  94                                                old-style export. */
  95         NBDS_ERR_CFILE_DIR_UNKNOWN,       /**< A directory requested does not exist*/
  96         NBDS_ERR_CFILE_READDIR_ERR,       /**< Error occurred during readdir() */
  97         NBDS_ERR_SO_LINGER,               /**< Failed to set SO_LINGER to a socket */
  98         NBDS_ERR_SO_REUSEADDR,            /**< Failed to set SO_REUSEADDR to a socket */
  99         NBDS_ERR_SO_KEEPALIVE,            /**< Failed to set SO_KEEPALIVE to a socket */
 100         NBDS_ERR_GAI,                     /**< Failed to get address info */
 101         NBDS_ERR_SOCKET,                  /**< Failed to create a socket */
 102         NBDS_ERR_BIND,                    /**< Failed to bind an address to socket */
 103         NBDS_ERR_LISTEN,                  /**< Failed to start listening on a socket */
 104         NBDS_ERR_SYS,                     /**< Underlying system call or library error */
 105 } NBDS_ERRS;
 106
 107 /**
 108   * Logging macros.
 109   *
 110   * @todo remove this. We should use g_log in all cases, and use the
 111   * logging mangler to redirect to syslog if and when necessary.
 112   */
 113 #ifdef ISSERVER
 114 #define msg(prio, ...) syslog(prio, __VA_ARGS__)
 115 #else
 116 #define msg(prio, ...) g_log(G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, __VA_ARGS__)
 117 #endif
 118 #define MY_NAME "nbd_server"
 119
 120 /* Functions */
 121
 122 /**
 123   * Check whether a given address matches a given netmask.
 124   *
 125   * @param mask the address or netmask to check against, in ASCII representation
 126   * @param addr the address to check
 127   *
 128   * @return true if the address matches the mask, false otherwise; in case of
 129   * failure to parse netmask, returns false with err set appropriately.
 130   * @todo decide what to do with v6-mapped IPv4 addresses.
 131   */
 132 bool address_matches(const char* mask, const struct sockaddr* addr, GError** err);
 133
 134 /**
 135   * Gets a byte to allow for address masking.
 136   *
 137   * @param masklen the length of the requested mask.
 138   * @return if the length of the mask is 8 or longer, 0xFF. Otherwise, a byte
 139   * with `masklen' number of leading bits set to 1, everything else set to 0.
 140   */
 141 uint8_t getmaskbyte(int masklen) G_GNUC_PURE;
 142
 143 /**
 144  * Check whether a client is allowed to connect. Works with an authorization
 145  * file which contains one line per machine or network, with CIDR-style
 146  * netmasks.
 147  *
 148  * @param opts The client who's trying to connect.
 149  * @return 0 - authorization refused, 1 - OK
 150  **/
 151 int authorized_client(CLIENT *opts);
 152
 153 /**
 154  * duplicate server
 155  * @param s the old server we want to duplicate
 156  * @return new duplicated server
 157  **/
 158 SERVER* dup_serve(const SERVER *const s);
 159
 160 /**
 161  * append new server to array
 162  * @param s server
 163  * @param a server array
 164  * @return 0 success, -1 error
 165  */
 166 int append_serve(const SERVER *const s, GArray *const a);
 167
 168 /**
 169  * Detect the size of a file.
 170  *
 171  * @param fhandle An open filedescriptor
 172  * @return the size of the file, or UINT64_MAX if detection was
 173  * impossible.
 174  **/
 175 uint64_t size_autodetect(int fhandle);
 176 #endif //NBDSRV_H