Eduardo Habkost | bee223b | 2014-10-01 17:34:36 -0300 | [diff] [blame] | 1 | /* |
| 2 | * QEMU System Emulator |
| 3 | * |
| 4 | * Copyright (c) 2003-2008 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | #include "qemu-common.h" |
| 25 | #include "qemu/iov.h" |
| 26 | #include "qemu/sockets.h" |
| 27 | #include "block/coroutine.h" |
| 28 | #include "migration/qemu-file.h" |
| 29 | |
| 30 | typedef struct QEMUFileSocket { |
| 31 | int fd; |
| 32 | QEMUFile *file; |
| 33 | } QEMUFileSocket; |
| 34 | |
| 35 | static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, |
| 36 | int64_t pos) |
| 37 | { |
| 38 | QEMUFileSocket *s = opaque; |
| 39 | ssize_t len; |
| 40 | ssize_t size = iov_size(iov, iovcnt); |
| 41 | |
| 42 | len = iov_send(s->fd, iov, iovcnt, 0, size); |
| 43 | if (len < size) { |
| 44 | len = -socket_error(); |
| 45 | } |
| 46 | return len; |
| 47 | } |
| 48 | |
| 49 | static int socket_get_fd(void *opaque) |
| 50 | { |
| 51 | QEMUFileSocket *s = opaque; |
| 52 | |
| 53 | return s->fd; |
| 54 | } |
| 55 | |
| 56 | static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) |
| 57 | { |
| 58 | QEMUFileSocket *s = opaque; |
| 59 | ssize_t len; |
| 60 | |
| 61 | for (;;) { |
| 62 | len = qemu_recv(s->fd, buf, size, 0); |
| 63 | if (len != -1) { |
| 64 | break; |
| 65 | } |
| 66 | if (socket_error() == EAGAIN) { |
| 67 | yield_until_fd_readable(s->fd); |
| 68 | } else if (socket_error() != EINTR) { |
| 69 | break; |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | if (len == -1) { |
| 74 | len = -socket_error(); |
| 75 | } |
| 76 | return len; |
| 77 | } |
| 78 | |
| 79 | static int socket_close(void *opaque) |
| 80 | { |
| 81 | QEMUFileSocket *s = opaque; |
| 82 | closesocket(s->fd); |
| 83 | g_free(s); |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, |
| 88 | int64_t pos) |
| 89 | { |
| 90 | QEMUFileSocket *s = opaque; |
| 91 | ssize_t len, offset; |
| 92 | ssize_t size = iov_size(iov, iovcnt); |
| 93 | ssize_t total = 0; |
| 94 | |
| 95 | assert(iovcnt > 0); |
| 96 | offset = 0; |
| 97 | while (size > 0) { |
| 98 | /* Find the next start position; skip all full-sized vector elements */ |
| 99 | while (offset >= iov[0].iov_len) { |
| 100 | offset -= iov[0].iov_len; |
| 101 | iov++, iovcnt--; |
| 102 | } |
| 103 | |
| 104 | /* skip `offset' bytes from the (now) first element, undo it on exit */ |
| 105 | assert(iovcnt > 0); |
| 106 | iov[0].iov_base += offset; |
| 107 | iov[0].iov_len -= offset; |
| 108 | |
| 109 | do { |
| 110 | len = writev(s->fd, iov, iovcnt); |
| 111 | } while (len == -1 && errno == EINTR); |
| 112 | if (len == -1) { |
| 113 | return -errno; |
| 114 | } |
| 115 | |
| 116 | /* Undo the changes above */ |
| 117 | iov[0].iov_base -= offset; |
| 118 | iov[0].iov_len += offset; |
| 119 | |
| 120 | /* Prepare for the next iteration */ |
| 121 | offset += len; |
| 122 | total += len; |
| 123 | size -= len; |
| 124 | } |
| 125 | |
| 126 | return total; |
| 127 | } |
| 128 | |
| 129 | static int unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) |
| 130 | { |
| 131 | QEMUFileSocket *s = opaque; |
| 132 | ssize_t len; |
| 133 | |
| 134 | for (;;) { |
| 135 | len = read(s->fd, buf, size); |
| 136 | if (len != -1) { |
| 137 | break; |
| 138 | } |
| 139 | if (errno == EAGAIN) { |
| 140 | yield_until_fd_readable(s->fd); |
| 141 | } else if (errno != EINTR) { |
| 142 | break; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (len == -1) { |
| 147 | len = -errno; |
| 148 | } |
| 149 | return len; |
| 150 | } |
| 151 | |
| 152 | static int unix_close(void *opaque) |
| 153 | { |
| 154 | QEMUFileSocket *s = opaque; |
| 155 | close(s->fd); |
| 156 | g_free(s); |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static const QEMUFileOps unix_read_ops = { |
| 161 | .get_fd = socket_get_fd, |
| 162 | .get_buffer = unix_get_buffer, |
| 163 | .close = unix_close |
| 164 | }; |
| 165 | |
| 166 | static const QEMUFileOps unix_write_ops = { |
| 167 | .get_fd = socket_get_fd, |
| 168 | .writev_buffer = unix_writev_buffer, |
| 169 | .close = unix_close |
| 170 | }; |
| 171 | |
| 172 | QEMUFile *qemu_fdopen(int fd, const char *mode) |
| 173 | { |
| 174 | QEMUFileSocket *s; |
| 175 | |
| 176 | if (mode == NULL || |
| 177 | (mode[0] != 'r' && mode[0] != 'w') || |
| 178 | mode[1] != 'b' || mode[2] != 0) { |
| 179 | fprintf(stderr, "qemu_fdopen: Argument validity check failed\n"); |
| 180 | return NULL; |
| 181 | } |
| 182 | |
| 183 | s = g_malloc0(sizeof(QEMUFileSocket)); |
| 184 | s->fd = fd; |
| 185 | |
| 186 | if (mode[0] == 'r') { |
| 187 | s->file = qemu_fopen_ops(s, &unix_read_ops); |
| 188 | } else { |
| 189 | s->file = qemu_fopen_ops(s, &unix_write_ops); |
| 190 | } |
| 191 | return s->file; |
| 192 | } |
| 193 | |
| 194 | static const QEMUFileOps socket_read_ops = { |
| 195 | .get_fd = socket_get_fd, |
| 196 | .get_buffer = socket_get_buffer, |
| 197 | .close = socket_close |
| 198 | }; |
| 199 | |
| 200 | static const QEMUFileOps socket_write_ops = { |
| 201 | .get_fd = socket_get_fd, |
| 202 | .writev_buffer = socket_writev_buffer, |
| 203 | .close = socket_close |
| 204 | }; |
| 205 | |
| 206 | QEMUFile *qemu_fopen_socket(int fd, const char *mode) |
| 207 | { |
| 208 | QEMUFileSocket *s; |
| 209 | |
| 210 | if (qemu_file_mode_is_not_valid(mode)) { |
| 211 | return NULL; |
| 212 | } |
| 213 | |
| 214 | s = g_malloc0(sizeof(QEMUFileSocket)); |
| 215 | s->fd = fd; |
| 216 | if (mode[0] == 'w') { |
| 217 | qemu_set_block(s->fd); |
| 218 | s->file = qemu_fopen_ops(s, &socket_write_ops); |
| 219 | } else { |
| 220 | s->file = qemu_fopen_ops(s, &socket_read_ops); |
| 221 | } |
| 222 | return s->file; |
| 223 | } |