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 /* This is all part of the "official" NBD API. 35 * 36 * The most up-to-date documentation is available at: 37 * https://github.com/yoe/nbd/blob/master/doc/proto.md 38 */ 39 40 #define NBD_REQUEST_SIZE (4 + 2 + 2 + 8 + 8 + 4) 41 #define NBD_REPLY_SIZE (4 + 4 + 8) 42 #define NBD_REQUEST_MAGIC 0x25609513 43 #define NBD_REPLY_MAGIC 0x67446698 44 #define NBD_OPTS_MAGIC 0x49484156454F5054LL 45 #define NBD_CLIENT_MAGIC 0x0000420281861253LL 46 #define NBD_REP_MAGIC 0x0003e889045565a9LL 47 48 #define NBD_SET_SOCK _IO(0xab, 0) 49 #define NBD_SET_BLKSIZE _IO(0xab, 1) 50 #define NBD_SET_SIZE _IO(0xab, 2) 51 #define NBD_DO_IT _IO(0xab, 3) 52 #define NBD_CLEAR_SOCK _IO(0xab, 4) 53 #define NBD_CLEAR_QUE _IO(0xab, 5) 54 #define NBD_PRINT_DEBUG _IO(0xab, 6) 55 #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) 56 #define NBD_DISCONNECT _IO(0xab, 8) 57 #define NBD_SET_TIMEOUT _IO(0xab, 9) 58 #define NBD_SET_FLAGS _IO(0xab, 10) 59 60 #define NBD_OPT_EXPORT_NAME (1) 61 #define NBD_OPT_ABORT (2) 62 #define NBD_OPT_LIST (3) 63 #define NBD_OPT_PEEK_EXPORT (4) 64 #define NBD_OPT_STARTTLS (5) 65 66 /* NBD errors are based on errno numbers, so there is a 1:1 mapping, 67 * but only a limited set of errno values is specified in the protocol. 68 * Everything else is squashed to EINVAL. 69 */ 70 #define NBD_SUCCESS 0 71 #define NBD_EPERM 1 72 #define NBD_EIO 5 73 #define NBD_ENOMEM 12 74 #define NBD_EINVAL 22 75 #define NBD_ENOSPC 28 76 #define NBD_ESHUTDOWN 108 77 78 /* nbd_read_eof 79 * Tries to read @size bytes from @ioc. Returns number of bytes actually read. 80 * May return a value >= 0 and < size only on EOF, i.e. when iteratively called 81 * qio_channel_readv() returns 0. So, there is no need to call nbd_read_eof 82 * iteratively. 83 */ 84 static inline ssize_t nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size, 85 Error **errp) 86 { 87 struct iovec iov = { .iov_base = buffer, .iov_len = size }; 88 /* Sockets are kept in blocking mode in the negotiation phase. After 89 * that, a non-readable socket simply means that another thread stole 90 * our request/reply. Synchronization is done with recv_coroutine, so 91 * that this is coroutine-safe. 92 */ 93 return nbd_rwv(ioc, &iov, 1, size, true, errp); 94 } 95 96 /* nbd_read 97 * Reads @size bytes from @ioc. Returns 0 on success. 98 */ 99 static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, 100 Error **errp) 101 { 102 ssize_t ret = nbd_read_eof(ioc, buffer, size, errp); 103 104 if (ret >= 0 && ret != size) { 105 ret = -EINVAL; 106 error_setg(errp, "End of file"); 107 } 108 109 return ret < 0 ? ret : 0; 110 } 111 112 /* nbd_write 113 * Writes @size bytes to @ioc. Returns 0 on success. 114 */ 115 static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size, 116 Error **errp) 117 { 118 struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size }; 119 120 ssize_t ret = nbd_rwv(ioc, &iov, 1, size, false, errp); 121 122 assert(ret < 0 || ret == size); 123 124 return ret < 0 ? ret : 0; 125 } 126 127 struct NBDTLSHandshakeData { 128 GMainLoop *loop; 129 bool complete; 130 Error *error; 131 }; 132 133 134 void nbd_tls_handshake(QIOTask *task, 135 void *opaque); 136 137 int nbd_drop(QIOChannel *ioc, size_t size, Error **errp); 138 139 #endif 140