char-pty.c (6983B)
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 25#include "qemu/osdep.h" 26#include "qemu-common.h" 27#include "qapi/error.h" 28#include "chardev/char.h" 29#include "io/channel-file.h" 30#include "qemu/sockets.h" 31#include "qemu/error-report.h" 32#include "qemu/module.h" 33#include "qemu/qemu-print.h" 34 35#include "chardev/char-io.h" 36#include "qom/object.h" 37 38struct PtyChardev { 39 Chardev parent; 40 QIOChannel *ioc; 41 int read_bytes; 42 43 int connected; 44 GSource *timer_src; 45}; 46typedef struct PtyChardev PtyChardev; 47 48DECLARE_INSTANCE_CHECKER(PtyChardev, PTY_CHARDEV, 49 TYPE_CHARDEV_PTY) 50 51static void pty_chr_state(Chardev *chr, int connected); 52 53static void pty_chr_timer_cancel(PtyChardev *s) 54{ 55 if (s->timer_src) { 56 g_source_destroy(s->timer_src); 57 g_source_unref(s->timer_src); 58 s->timer_src = NULL; 59 } 60} 61 62static gboolean pty_chr_timer(gpointer opaque) 63{ 64 struct Chardev *chr = CHARDEV(opaque); 65 PtyChardev *s = PTY_CHARDEV(opaque); 66 67 pty_chr_timer_cancel(s); 68 if (!s->connected) { 69 /* Next poll ... */ 70 qemu_chr_be_update_read_handlers(chr, chr->gcontext); 71 } 72 return FALSE; 73} 74 75static void pty_chr_rearm_timer(Chardev *chr, int ms) 76{ 77 PtyChardev *s = PTY_CHARDEV(chr); 78 char *name; 79 80 pty_chr_timer_cancel(s); 81 name = g_strdup_printf("pty-timer-%s", chr->label); 82 s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr); 83 g_source_set_name(s->timer_src, name); 84 g_free(name); 85} 86 87static void pty_chr_update_read_handler(Chardev *chr) 88{ 89 PtyChardev *s = PTY_CHARDEV(chr); 90 GPollFD pfd; 91 int rc; 92 QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc); 93 94 pfd.fd = fioc->fd; 95 pfd.events = G_IO_OUT; 96 pfd.revents = 0; 97 do { 98 rc = g_poll(&pfd, 1, 0); 99 } while (rc == -1 && errno == EINTR); 100 assert(rc >= 0); 101 102 if (pfd.revents & G_IO_HUP) { 103 pty_chr_state(chr, 0); 104 } else { 105 pty_chr_state(chr, 1); 106 } 107} 108 109static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len) 110{ 111 PtyChardev *s = PTY_CHARDEV(chr); 112 113 if (!s->connected) { 114 return len; 115 } 116 return io_channel_send(s->ioc, buf, len); 117} 118 119static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond) 120{ 121 PtyChardev *s = PTY_CHARDEV(chr); 122 if (!s->connected) { 123 return NULL; 124 } 125 return qio_channel_create_watch(s->ioc, cond); 126} 127 128static int pty_chr_read_poll(void *opaque) 129{ 130 Chardev *chr = CHARDEV(opaque); 131 PtyChardev *s = PTY_CHARDEV(opaque); 132 133 s->read_bytes = qemu_chr_be_can_write(chr); 134 return s->read_bytes; 135} 136 137static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque) 138{ 139 Chardev *chr = CHARDEV(opaque); 140 PtyChardev *s = PTY_CHARDEV(opaque); 141 gsize len; 142 uint8_t buf[CHR_READ_BUF_LEN]; 143 ssize_t ret; 144 145 len = sizeof(buf); 146 if (len > s->read_bytes) { 147 len = s->read_bytes; 148 } 149 if (len == 0) { 150 return TRUE; 151 } 152 ret = qio_channel_read(s->ioc, (char *)buf, len, NULL); 153 if (ret <= 0) { 154 pty_chr_state(chr, 0); 155 return FALSE; 156 } else { 157 pty_chr_state(chr, 1); 158 qemu_chr_be_write(chr, buf, ret); 159 } 160 return TRUE; 161} 162 163static void pty_chr_state(Chardev *chr, int connected) 164{ 165 PtyChardev *s = PTY_CHARDEV(chr); 166 167 if (!connected) { 168 remove_fd_in_watch(chr); 169 s->connected = 0; 170 /* (re-)connect poll interval for idle guests: once per second. 171 * We check more frequently in case the guests sends data to 172 * the virtual device linked to our pty. */ 173 pty_chr_rearm_timer(chr, 1000); 174 } else { 175 pty_chr_timer_cancel(s); 176 if (!s->connected) { 177 s->connected = 1; 178 qemu_chr_be_event(chr, CHR_EVENT_OPENED); 179 } 180 if (!chr->gsource) { 181 chr->gsource = io_add_watch_poll(chr, s->ioc, 182 pty_chr_read_poll, 183 pty_chr_read, 184 chr, chr->gcontext); 185 } 186 } 187} 188 189static void char_pty_finalize(Object *obj) 190{ 191 Chardev *chr = CHARDEV(obj); 192 PtyChardev *s = PTY_CHARDEV(obj); 193 194 pty_chr_state(chr, 0); 195 object_unref(OBJECT(s->ioc)); 196 pty_chr_timer_cancel(s); 197 qemu_chr_be_event(chr, CHR_EVENT_CLOSED); 198} 199 200static void char_pty_open(Chardev *chr, 201 ChardevBackend *backend, 202 bool *be_opened, 203 Error **errp) 204{ 205 PtyChardev *s; 206 int master_fd, slave_fd; 207 char pty_name[PATH_MAX]; 208 char *name; 209 210 master_fd = qemu_openpty_raw(&slave_fd, pty_name); 211 if (master_fd < 0) { 212 error_setg_errno(errp, errno, "Failed to create PTY"); 213 return; 214 } 215 216 close(slave_fd); 217 qemu_set_nonblock(master_fd); 218 219 chr->filename = g_strdup_printf("pty:%s", pty_name); 220 qemu_printf("char device redirected to %s (label %s)\n", 221 pty_name, chr->label); 222 223 s = PTY_CHARDEV(chr); 224 s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd)); 225 name = g_strdup_printf("chardev-pty-%s", chr->label); 226 qio_channel_set_name(QIO_CHANNEL(s->ioc), name); 227 g_free(name); 228 s->timer_src = NULL; 229 *be_opened = false; 230} 231 232static void char_pty_class_init(ObjectClass *oc, void *data) 233{ 234 ChardevClass *cc = CHARDEV_CLASS(oc); 235 236 cc->open = char_pty_open; 237 cc->chr_write = char_pty_chr_write; 238 cc->chr_update_read_handler = pty_chr_update_read_handler; 239 cc->chr_add_watch = pty_chr_add_watch; 240} 241 242static const TypeInfo char_pty_type_info = { 243 .name = TYPE_CHARDEV_PTY, 244 .parent = TYPE_CHARDEV, 245 .instance_size = sizeof(PtyChardev), 246 .instance_finalize = char_pty_finalize, 247 .class_init = char_pty_class_init, 248}; 249 250static void register_types(void) 251{ 252 type_register_static(&char_pty_type_info); 253} 254 255type_init(register_types);