nbd/nbd-internal.h

   1 /*
   2  * NBD Internal Declarations
   3  *
   4  * Copyright (C) 2016 Red Hat, Inc.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  */
   9
  10 #ifndef NBD_INTERNAL_H
  11 #define NBD_INTERNAL_H
  12 #include "block/nbd.h"
  13 #include "sysemu/block-backend.h"
  14 #include "io/channel-tls.h"
  15
  16 #include "qemu/coroutine.h"
  17 #include "qemu/iov.h"
  18
  19 #ifndef _WIN32
  20 #include <sys/ioctl.h>
  21 #endif
  22 #if defined(__sun__) || defined(__HAIKU__)
  23 #include <sys/ioccom.h>
  24 #endif
  25
  26 #ifdef __linux__
  27 #include <linux/fs.h>
  28 #endif
  29
  30 #include "qemu/bswap.h"
  31 #include "qemu/queue.h"
  32 #include "qemu/main-loop.h"
  33
  34 /* #define DEBUG_NBD */
  35
  36 #ifdef DEBUG_NBD
  37 #define DEBUG_NBD_PRINT 1
  38 #else
  39 #define DEBUG_NBD_PRINT 0
  40 #endif
  41
  42 #define TRACE(msg, ...) do { \
  43     if (DEBUG_NBD_PRINT) { \
  44         LOG(msg, ## __VA_ARGS__); \
  45     } \
  46 } while (0)
  47
  48 #define LOG(msg, ...) do { \
  49     fprintf(stderr, "%s:%s():L%d: " msg "\n", \
  50             __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
  51 } while (0)
  52
  53 /* This is all part of the "official" NBD API.
  54  *
  55  * The most up-to-date documentation is available at:
  56  * https://github.com/yoe/nbd/blob/master/doc/proto.md
  57  */
  58
  59 #define NBD_REQUEST_SIZE        (4 + 2 + 2 + 8 + 8 + 4)
  60 #define NBD_REPLY_SIZE          (4 + 4 + 8)
  61 #define NBD_REQUEST_MAGIC       0x25609513
  62 #define NBD_REPLY_MAGIC         0x67446698
  63 #define NBD_OPTS_MAGIC          0x49484156454F5054LL
  64 #define NBD_CLIENT_MAGIC        0x0000420281861253LL
  65 #define NBD_REP_MAGIC           0x0003e889045565a9LL
  66
  67 #define NBD_SET_SOCK            _IO(0xab, 0)
  68 #define NBD_SET_BLKSIZE         _IO(0xab, 1)
  69 #define NBD_SET_SIZE            _IO(0xab, 2)
  70 #define NBD_DO_IT               _IO(0xab, 3)
  71 #define NBD_CLEAR_SOCK          _IO(0xab, 4)
  72 #define NBD_CLEAR_QUE           _IO(0xab, 5)
  73 #define NBD_PRINT_DEBUG         _IO(0xab, 6)
  74 #define NBD_SET_SIZE_BLOCKS     _IO(0xab, 7)
  75 #define NBD_DISCONNECT          _IO(0xab, 8)
  76 #define NBD_SET_TIMEOUT         _IO(0xab, 9)
  77 #define NBD_SET_FLAGS           _IO(0xab, 10)
  78
  79 #define NBD_OPT_EXPORT_NAME     (1)
  80 #define NBD_OPT_ABORT           (2)
  81 #define NBD_OPT_LIST            (3)
  82 #define NBD_OPT_PEEK_EXPORT     (4)
  83 #define NBD_OPT_STARTTLS        (5)
  84
  85 /* NBD errors are based on errno numbers, so there is a 1:1 mapping,
  86  * but only a limited set of errno values is specified in the protocol.
  87  * Everything else is squashed to EINVAL.
  88  */
  89 #define NBD_SUCCESS    0
  90 #define NBD_EPERM      1
  91 #define NBD_EIO        5
  92 #define NBD_ENOMEM     12
  93 #define NBD_EINVAL     22
  94 #define NBD_ENOSPC     28
  95 #define NBD_ESHUTDOWN  108
  96
  97 static inline ssize_t read_sync(QIOChannel *ioc, void *buffer, size_t size)
  98 {
  99     struct iovec iov = { .iov_base = buffer, .iov_len = size };
 100     /* Sockets are kept in blocking mode in the negotiation phase.  After
 101      * that, a non-readable socket simply means that another thread stole
 102      * our request/reply.  Synchronization is done with recv_coroutine, so
 103      * that this is coroutine-safe.
 104      */
 105     return nbd_wr_syncv(ioc, &iov, 1, size, true);
 106 }
 107
 108 static inline ssize_t write_sync(QIOChannel *ioc, const void *buffer,
 109                                  size_t size)
 110 {
 111     struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size };
 112
 113     return nbd_wr_syncv(ioc, &iov, 1, size, false);
 114 }
 115
 116 struct NBDTLSHandshakeData {
 117     GMainLoop *loop;
 118     bool complete;
 119     Error *error;
 120 };
 121
 122
 123 void nbd_tls_handshake(QIOTask *task,
 124                        void *opaque);
 125
 126 #endif