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 15 #include "qemu/coroutine.h" 16 17 #include <errno.h> 18 #include <string.h> 19 #ifndef _WIN32 20 #include <sys/ioctl.h> 21 #endif 22 #if defined(__sun__) || defined(__HAIKU__) 23 #include <sys/ioccom.h> 24 #endif 25 #include <ctype.h> 26 #include <inttypes.h> 27 28 #ifdef __linux__ 29 #include <linux/fs.h> 30 #endif 31 32 #include "qemu/sockets.h" 33 #include "qemu/queue.h" 34 #include "qemu/main-loop.h" 35 36 /* #define DEBUG_NBD */ 37 38 #ifdef DEBUG_NBD 39 #define TRACE(msg, ...) do { \ 40 LOG(msg, ## __VA_ARGS__); \ 41 } while(0) 42 #else 43 #define TRACE(msg, ...) \ 44 do { } while (0) 45 #endif 46 47 #define LOG(msg, ...) do { \ 48 fprintf(stderr, "%s:%s():L%d: " msg "\n", \ 49 __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ 50 } while(0) 51 52 /* This is all part of the "official" NBD API. 53 * 54 * The most up-to-date documentation is available at: 55 * https://github.com/yoe/nbd/blob/master/doc/proto.txt 56 */ 57 58 #define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4) 59 #define NBD_REPLY_SIZE (4 + 4 + 8) 60 #define NBD_REQUEST_MAGIC 0x25609513 61 #define NBD_REPLY_MAGIC 0x67446698 62 #define NBD_OPTS_MAGIC 0x49484156454F5054LL 63 #define NBD_CLIENT_MAGIC 0x0000420281861253LL 64 #define NBD_REP_MAGIC 0x3e889045565a9LL 65 66 #define NBD_SET_SOCK _IO(0xab, 0) 67 #define NBD_SET_BLKSIZE _IO(0xab, 1) 68 #define NBD_SET_SIZE _IO(0xab, 2) 69 #define NBD_DO_IT _IO(0xab, 3) 70 #define NBD_CLEAR_SOCK _IO(0xab, 4) 71 #define NBD_CLEAR_QUE _IO(0xab, 5) 72 #define NBD_PRINT_DEBUG _IO(0xab, 6) 73 #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) 74 #define NBD_DISCONNECT _IO(0xab, 8) 75 #define NBD_SET_TIMEOUT _IO(0xab, 9) 76 #define NBD_SET_FLAGS _IO(0xab, 10) 77 78 #define NBD_OPT_EXPORT_NAME (1) 79 #define NBD_OPT_ABORT (2) 80 #define NBD_OPT_LIST (3) 81 82 /* NBD errors are based on errno numbers, so there is a 1:1 mapping, 83 * but only a limited set of errno values is specified in the protocol. 84 * Everything else is squashed to EINVAL. 85 */ 86 #define NBD_SUCCESS 0 87 #define NBD_EPERM 1 88 #define NBD_EIO 5 89 #define NBD_ENOMEM 12 90 #define NBD_EINVAL 22 91 #define NBD_ENOSPC 28 92 93 static inline ssize_t read_sync(int fd, void *buffer, size_t size) 94 { 95 /* Sockets are kept in blocking mode in the negotiation phase. After 96 * that, a non-readable socket simply means that another thread stole 97 * our request/reply. Synchronization is done with recv_coroutine, so 98 * that this is coroutine-safe. 99 */ 100 return nbd_wr_sync(fd, buffer, size, true); 101 } 102 103 static inline ssize_t write_sync(int fd, void *buffer, size_t size) 104 { 105 int ret; 106 do { 107 /* For writes, we do expect the socket to be writable. */ 108 ret = nbd_wr_sync(fd, buffer, size, false); 109 } while (ret == -EAGAIN); 110 return ret; 111 } 112 113 #endif 114