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 /* Size of all NBD_OPT_*, without payload */ 41 #define NBD_REQUEST_SIZE (4 + 2 + 2 + 8 + 8 + 4) 42 /* Size of all NBD_REP_* sent in answer to most NBD_OPT_*, without payload */ 43 #define NBD_REPLY_SIZE (4 + 4 + 8) 44 /* Size of reply to NBD_OPT_EXPORT_NAME */ 45 #define NBD_REPLY_EXPORT_NAME_SIZE (8 + 2 + 124) 46 /* Size of oldstyle negotiation */ 47 #define NBD_OLDSTYLE_NEGOTIATE_SIZE (8 + 8 + 8 + 4 + 124) 48 49 #define NBD_REQUEST_MAGIC 0x25609513 50 #define NBD_REPLY_MAGIC 0x67446698 51 #define NBD_OPTS_MAGIC 0x49484156454F5054LL 52 #define NBD_CLIENT_MAGIC 0x0000420281861253LL 53 #define NBD_REP_MAGIC 0x0003e889045565a9LL 54 55 #define NBD_SET_SOCK _IO(0xab, 0) 56 #define NBD_SET_BLKSIZE _IO(0xab, 1) 57 #define NBD_SET_SIZE _IO(0xab, 2) 58 #define NBD_DO_IT _IO(0xab, 3) 59 #define NBD_CLEAR_SOCK _IO(0xab, 4) 60 #define NBD_CLEAR_QUE _IO(0xab, 5) 61 #define NBD_PRINT_DEBUG _IO(0xab, 6) 62 #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) 63 #define NBD_DISCONNECT _IO(0xab, 8) 64 #define NBD_SET_TIMEOUT _IO(0xab, 9) 65 #define NBD_SET_FLAGS _IO(0xab, 10) 66 67 /* NBD errors are based on errno numbers, so there is a 1:1 mapping, 68 * but only a limited set of errno values is specified in the protocol. 69 * Everything else is squashed to EINVAL. 70 */ 71 #define NBD_SUCCESS 0 72 #define NBD_EPERM 1 73 #define NBD_EIO 5 74 #define NBD_ENOMEM 12 75 #define NBD_EINVAL 22 76 #define NBD_ENOSPC 28 77 #define NBD_ESHUTDOWN 108 78 79 /* nbd_read_eof 80 * Tries to read @size bytes from @ioc. Returns number of bytes actually read. 81 * May return a value >= 0 and < size only on EOF, i.e. when iteratively called 82 * qio_channel_readv() returns 0. So, there is no need to call nbd_read_eof 83 * iteratively. 84 */ 85 static inline ssize_t nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size, 86 Error **errp) 87 { 88 struct iovec iov = { .iov_base = buffer, .iov_len = size }; 89 /* Sockets are kept in blocking mode in the negotiation phase. After 90 * that, a non-readable socket simply means that another thread stole 91 * our request/reply. Synchronization is done with recv_coroutine, so 92 * that this is coroutine-safe. 93 */ 94 return nbd_rwv(ioc, &iov, 1, size, true, errp); 95 } 96 97 /* nbd_read 98 * Reads @size bytes from @ioc. Returns 0 on success. 99 */ 100 static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, 101 Error **errp) 102 { 103 ssize_t ret = nbd_read_eof(ioc, buffer, size, errp); 104 105 if (ret >= 0 && ret != size) { 106 ret = -EINVAL; 107 error_setg(errp, "End of file"); 108 } 109 110 return ret < 0 ? ret : 0; 111 } 112 113 /* nbd_write 114 * Writes @size bytes to @ioc. Returns 0 on success. 115 */ 116 static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size, 117 Error **errp) 118 { 119 struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size }; 120 121 ssize_t ret = nbd_rwv(ioc, &iov, 1, size, false, errp); 122 123 assert(ret < 0 || ret == size); 124 125 return ret < 0 ? ret : 0; 126 } 127 128 struct NBDTLSHandshakeData { 129 GMainLoop *loop; 130 bool complete; 131 Error *error; 132 }; 133 134 135 void nbd_tls_handshake(QIOTask *task, 136 void *opaque); 137 const char *nbd_opt_lookup(uint32_t opt); 138 const char *nbd_rep_lookup(uint32_t rep); 139 const char *nbd_info_lookup(uint16_t info); 140 const char *nbd_cmd_lookup(uint16_t info); 141 142 int nbd_drop(QIOChannel *ioc, size_t size, Error **errp); 143 144 #endif 145