xref: /openbmc/qemu/qga/channel-posix.c (revision d695918f)
1 #include "qemu/osdep.h"
2 #include "qemu/cutils.h"
3 #include <termios.h>
4 #include "qapi/error.h"
5 #include "qemu/sockets.h"
6 #include "channel.h"
7 #include "cutils.h"
8 
9 #ifdef CONFIG_SOLARIS
10 #include <stropts.h>
11 #endif
12 
13 #define GA_CHANNEL_BAUDRATE_DEFAULT B38400 /* for isa-serial channels */
14 
15 struct GAChannel {
16     GIOChannel *listen_channel;
17     GIOChannel *client_channel;
18     GAChannelMethod method;
19     GAChannelCallback event_cb;
20     gpointer user_data;
21 };
22 
23 static int ga_channel_client_add(GAChannel *c, int fd);
24 
25 static gboolean ga_channel_listen_accept(GIOChannel *channel,
26                                          GIOCondition condition, gpointer data)
27 {
28     GAChannel *c = data;
29     int ret, client_fd;
30     bool accepted = false;
31 
32     g_assert(channel != NULL);
33 
34     client_fd = qemu_accept(g_io_channel_unix_get_fd(channel), NULL, NULL);
35     if (client_fd == -1) {
36         g_warning("error converting fd to gsocket: %s", strerror(errno));
37         goto out;
38     }
39     qemu_socket_set_nonblock(client_fd);
40     ret = ga_channel_client_add(c, client_fd);
41     if (ret) {
42         g_warning("error setting up connection");
43         close(client_fd);
44         goto out;
45     }
46     accepted = true;
47 
48 out:
49     /* only accept 1 connection at a time */
50     return !accepted;
51 }
52 
53 /* start polling for readable events on listen fd, new==true
54  * indicates we should use the existing s->listen_channel
55  */
56 static void ga_channel_listen_add(GAChannel *c, int listen_fd, bool create)
57 {
58     if (create) {
59         c->listen_channel = g_io_channel_unix_new(listen_fd);
60     }
61     g_io_add_watch(c->listen_channel, G_IO_IN, ga_channel_listen_accept, c);
62 }
63 
64 static void ga_channel_listen_close(GAChannel *c)
65 {
66     g_assert(c->listen_channel);
67     g_io_channel_shutdown(c->listen_channel, true, NULL);
68     g_io_channel_unref(c->listen_channel);
69     c->listen_channel = NULL;
70 }
71 
72 /* cleanup state for closed connection/session, start accepting new
73  * connections if we're in listening mode
74  */
75 static void ga_channel_client_close(GAChannel *c)
76 {
77     g_assert(c->client_channel);
78     g_io_channel_shutdown(c->client_channel, true, NULL);
79     g_io_channel_unref(c->client_channel);
80     c->client_channel = NULL;
81     if (c->listen_channel) {
82         ga_channel_listen_add(c, 0, false);
83     }
84 }
85 
86 static gboolean ga_channel_client_event(GIOChannel *channel,
87                                         GIOCondition condition, gpointer data)
88 {
89     GAChannel *c = data;
90     gboolean client_cont;
91 
92     g_assert(c);
93     if (c->event_cb) {
94         client_cont = c->event_cb(condition, c->user_data);
95         if (!client_cont) {
96             ga_channel_client_close(c);
97             return false;
98         }
99     }
100     return true;
101 }
102 
103 static int ga_channel_client_add(GAChannel *c, int fd)
104 {
105     GIOChannel *client_channel;
106     GError *err = NULL;
107 
108     g_assert(c && !c->client_channel);
109     client_channel = g_io_channel_unix_new(fd);
110     g_assert(client_channel);
111     g_io_channel_set_encoding(client_channel, NULL, &err);
112     if (err != NULL) {
113         g_warning("error setting channel encoding to binary");
114         g_error_free(err);
115         return -1;
116     }
117     g_io_add_watch(client_channel, G_IO_IN | G_IO_HUP,
118                    ga_channel_client_event, c);
119     c->client_channel = client_channel;
120     return 0;
121 }
122 
123 static gboolean ga_channel_open(GAChannel *c, const gchar *path,
124                                 GAChannelMethod method, int fd, Error **errp)
125 {
126     int ret;
127     c->method = method;
128 
129     switch (c->method) {
130     case GA_CHANNEL_VIRTIO_SERIAL: {
131         assert(fd < 0);
132         fd = qga_open_cloexec(
133             path,
134 #ifndef CONFIG_SOLARIS
135             O_ASYNC |
136 #endif
137             O_RDWR | O_NONBLOCK,
138             0
139         );
140         if (fd == -1) {
141             error_setg_errno(errp, errno, "error opening channel");
142             return false;
143         }
144 #ifdef CONFIG_SOLARIS
145         ret = ioctl(fd, I_SETSIG, S_OUTPUT | S_INPUT | S_HIPRI);
146         if (ret == -1) {
147             error_setg_errno(errp, errno, "error setting event mask for channel");
148             close(fd);
149             return false;
150         }
151 #endif
152         ret = ga_channel_client_add(c, fd);
153         if (ret) {
154             error_setg(errp, "error adding channel to main loop");
155             close(fd);
156             return false;
157         }
158         break;
159     }
160     case GA_CHANNEL_ISA_SERIAL: {
161         struct termios tio;
162 
163         assert(fd < 0);
164         fd = qga_open_cloexec(path, O_RDWR | O_NOCTTY | O_NONBLOCK, 0);
165         if (fd == -1) {
166             error_setg_errno(errp, errno, "error opening channel");
167             return false;
168         }
169         tcgetattr(fd, &tio);
170         /* set up serial port for non-canonical, dumb byte streaming */
171         tio.c_iflag &= ~(IGNBRK | BRKINT | IGNPAR | PARMRK | INPCK | ISTRIP |
172                          INLCR | IGNCR | ICRNL | IXON | IXOFF | IXANY |
173                          IMAXBEL);
174         tio.c_oflag = 0;
175         tio.c_lflag = 0;
176         tio.c_cflag |= GA_CHANNEL_BAUDRATE_DEFAULT;
177         /* 1 available byte min or reads will block (we'll set non-blocking
178          * elsewhere, else we have to deal with read()=0 instead)
179          */
180         tio.c_cc[VMIN] = 1;
181         tio.c_cc[VTIME] = 0;
182         /* flush everything waiting for read/xmit, it's garbage at this point */
183         tcflush(fd, TCIFLUSH);
184         tcsetattr(fd, TCSANOW, &tio);
185         ret = ga_channel_client_add(c, fd);
186         if (ret) {
187             error_setg(errp, "error adding channel to main loop");
188             close(fd);
189             return false;
190         }
191         break;
192     }
193     case GA_CHANNEL_UNIX_LISTEN: {
194         if (fd < 0) {
195             fd = unix_listen(path, errp);
196             if (fd < 0) {
197                 return false;
198             }
199         }
200         ga_channel_listen_add(c, fd, true);
201         break;
202     }
203     case GA_CHANNEL_VSOCK_LISTEN: {
204         if (fd < 0) {
205             SocketAddress *addr;
206             char *addr_str;
207 
208             addr_str = g_strdup_printf("vsock:%s", path);
209             addr = socket_parse(addr_str, errp);
210             g_free(addr_str);
211             if (!addr) {
212                 return false;
213             }
214 
215             fd = socket_listen(addr, 1, errp);
216             qapi_free_SocketAddress(addr);
217             if (fd < 0) {
218                 return false;
219             }
220         }
221         ga_channel_listen_add(c, fd, true);
222         break;
223     }
224     default:
225         error_setg(errp, "error binding/listening to specified socket");
226         return false;
227     }
228 
229     return true;
230 }
231 
232 GIOStatus ga_channel_write_all(GAChannel *c, const gchar *buf, gsize size)
233 {
234     GError *err = NULL;
235     gsize written = 0;
236     GIOStatus status = G_IO_STATUS_NORMAL;
237 
238     while (size) {
239         g_debug("sending data, count: %d", (int)size);
240         status = g_io_channel_write_chars(c->client_channel, buf, size,
241                                           &written, &err);
242         if (status == G_IO_STATUS_NORMAL) {
243             size -= written;
244             buf += written;
245         } else if (status != G_IO_STATUS_AGAIN) {
246             g_warning("error writing to channel: %s", err->message);
247             return status;
248         }
249     }
250 
251     do {
252         status = g_io_channel_flush(c->client_channel, &err);
253     } while (status == G_IO_STATUS_AGAIN);
254 
255     if (status != G_IO_STATUS_NORMAL) {
256         g_warning("error flushing channel: %s", err->message);
257     }
258 
259     return status;
260 }
261 
262 GIOStatus ga_channel_read(GAChannel *c, gchar *buf, gsize size, gsize *count)
263 {
264     return g_io_channel_read_chars(c->client_channel, buf, size, count, NULL);
265 }
266 
267 GAChannel *ga_channel_new(GAChannelMethod method, const gchar *path,
268                           int listen_fd, GAChannelCallback cb, gpointer opaque)
269 {
270     Error *err = NULL;
271     GAChannel *c = g_new0(GAChannel, 1);
272     c->event_cb = cb;
273     c->user_data = opaque;
274 
275     if (!ga_channel_open(c, path, method, listen_fd, &err)) {
276         g_critical("%s", error_get_pretty(err));
277         error_free(err);
278         ga_channel_free(c);
279         return NULL;
280     }
281 
282     return c;
283 }
284 
285 void ga_channel_free(GAChannel *c)
286 {
287     if (c->listen_channel) {
288         ga_channel_listen_close(c);
289     }
290     if (c->client_channel) {
291         ga_channel_client_close(c);
292     }
293     g_free(c);
294 }
295