xref: /openbmc/qemu/qga/channel-posix.c (revision 3d9569b8)
1 #include "qemu/osdep.h"
2 #include <termios.h>
3 #include "qapi/error.h"
4 #include "qemu/sockets.h"
5 #include "channel.h"
6 
7 #ifdef CONFIG_SOLARIS
8 #include <stropts.h>
9 #endif
10 
11 #define GA_CHANNEL_BAUDRATE_DEFAULT B38400 /* for isa-serial channels */
12 
13 struct GAChannel {
14     GIOChannel *listen_channel;
15     GIOChannel *client_channel;
16     GAChannelMethod method;
17     GAChannelCallback event_cb;
18     gpointer user_data;
19 };
20 
21 static int ga_channel_client_add(GAChannel *c, int fd);
22 
23 static gboolean ga_channel_listen_accept(GIOChannel *channel,
24                                          GIOCondition condition, gpointer data)
25 {
26     GAChannel *c = data;
27     int ret, client_fd;
28     bool accepted = false;
29 
30     g_assert(channel != NULL);
31 
32     client_fd = qemu_accept(g_io_channel_unix_get_fd(channel), NULL, NULL);
33     if (client_fd == -1) {
34         g_warning("error converting fd to gsocket: %s", strerror(errno));
35         goto out;
36     }
37     qemu_set_nonblock(client_fd);
38     ret = ga_channel_client_add(c, client_fd);
39     if (ret) {
40         g_warning("error setting up connection");
41         close(client_fd);
42         goto out;
43     }
44     accepted = true;
45 
46 out:
47     /* only accept 1 connection at a time */
48     return !accepted;
49 }
50 
51 /* start polling for readable events on listen fd, new==true
52  * indicates we should use the existing s->listen_channel
53  */
54 static void ga_channel_listen_add(GAChannel *c, int listen_fd, bool create)
55 {
56     if (create) {
57         c->listen_channel = g_io_channel_unix_new(listen_fd);
58     }
59     g_io_add_watch(c->listen_channel, G_IO_IN, ga_channel_listen_accept, c);
60 }
61 
62 static void ga_channel_listen_close(GAChannel *c)
63 {
64     g_assert(c->listen_channel);
65     g_io_channel_shutdown(c->listen_channel, true, NULL);
66     g_io_channel_unref(c->listen_channel);
67     c->listen_channel = NULL;
68 }
69 
70 /* cleanup state for closed connection/session, start accepting new
71  * connections if we're in listening mode
72  */
73 static void ga_channel_client_close(GAChannel *c)
74 {
75     g_assert(c->client_channel);
76     g_io_channel_shutdown(c->client_channel, true, NULL);
77     g_io_channel_unref(c->client_channel);
78     c->client_channel = NULL;
79     if (c->listen_channel) {
80         ga_channel_listen_add(c, 0, false);
81     }
82 }
83 
84 static gboolean ga_channel_client_event(GIOChannel *channel,
85                                         GIOCondition condition, gpointer data)
86 {
87     GAChannel *c = data;
88     gboolean client_cont;
89 
90     g_assert(c);
91     if (c->event_cb) {
92         client_cont = c->event_cb(condition, c->user_data);
93         if (!client_cont) {
94             ga_channel_client_close(c);
95             return false;
96         }
97     }
98     return true;
99 }
100 
101 static int ga_channel_client_add(GAChannel *c, int fd)
102 {
103     GIOChannel *client_channel;
104     GError *err = NULL;
105 
106     g_assert(c && !c->client_channel);
107     client_channel = g_io_channel_unix_new(fd);
108     g_assert(client_channel);
109     g_io_channel_set_encoding(client_channel, NULL, &err);
110     if (err != NULL) {
111         g_warning("error setting channel encoding to binary");
112         g_error_free(err);
113         return -1;
114     }
115     g_io_add_watch(client_channel, G_IO_IN | G_IO_HUP,
116                    ga_channel_client_event, c);
117     c->client_channel = client_channel;
118     return 0;
119 }
120 
121 static gboolean ga_channel_open(GAChannel *c, const gchar *path,
122                                 GAChannelMethod method, int fd)
123 {
124     int ret;
125     c->method = method;
126 
127     switch (c->method) {
128     case GA_CHANNEL_VIRTIO_SERIAL: {
129         assert(fd < 0);
130         fd = qemu_open(path, O_RDWR | O_NONBLOCK
131 #ifndef CONFIG_SOLARIS
132                            | O_ASYNC
133 #endif
134                            );
135         if (fd == -1) {
136             g_critical("error opening channel: %s", strerror(errno));
137             return false;
138         }
139 #ifdef CONFIG_SOLARIS
140         ret = ioctl(fd, I_SETSIG, S_OUTPUT | S_INPUT | S_HIPRI);
141         if (ret == -1) {
142             g_critical("error setting event mask for channel: %s",
143                        strerror(errno));
144             close(fd);
145             return false;
146         }
147 #endif
148         ret = ga_channel_client_add(c, fd);
149         if (ret) {
150             g_critical("error adding channel to main loop");
151             close(fd);
152             return false;
153         }
154         break;
155     }
156     case GA_CHANNEL_ISA_SERIAL: {
157         struct termios tio;
158 
159         assert(fd < 0);
160         fd = qemu_open(path, O_RDWR | O_NOCTTY | O_NONBLOCK);
161         if (fd == -1) {
162             g_critical("error opening channel: %s", strerror(errno));
163             return false;
164         }
165         tcgetattr(fd, &tio);
166         /* set up serial port for non-canonical, dumb byte streaming */
167         tio.c_iflag &= ~(IGNBRK | BRKINT | IGNPAR | PARMRK | INPCK | ISTRIP |
168                          INLCR | IGNCR | ICRNL | IXON | IXOFF | IXANY |
169                          IMAXBEL);
170         tio.c_oflag = 0;
171         tio.c_lflag = 0;
172         tio.c_cflag |= GA_CHANNEL_BAUDRATE_DEFAULT;
173         /* 1 available byte min or reads will block (we'll set non-blocking
174          * elsewhere, else we have to deal with read()=0 instead)
175          */
176         tio.c_cc[VMIN] = 1;
177         tio.c_cc[VTIME] = 0;
178         /* flush everything waiting for read/xmit, it's garbage at this point */
179         tcflush(fd, TCIFLUSH);
180         tcsetattr(fd, TCSANOW, &tio);
181         ret = ga_channel_client_add(c, fd);
182         if (ret) {
183             g_critical("error adding channel to main loop");
184             close(fd);
185             return false;
186         }
187         break;
188     }
189     case GA_CHANNEL_UNIX_LISTEN: {
190         if (fd < 0) {
191             Error *local_err = NULL;
192 
193             fd = unix_listen(path, &local_err);
194             if (local_err != NULL) {
195                 g_critical("%s", error_get_pretty(local_err));
196                 error_free(local_err);
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             Error *local_err = NULL;
206             SocketAddress *addr;
207             char *addr_str;
208 
209             addr_str = g_strdup_printf("vsock:%s", path);
210             addr = socket_parse(addr_str, &local_err);
211             g_free(addr_str);
212             if (local_err != NULL) {
213                 g_critical("%s", error_get_pretty(local_err));
214                 error_free(local_err);
215                 return false;
216             }
217 
218             fd = socket_listen(addr, &local_err);
219             qapi_free_SocketAddress(addr);
220             if (local_err != NULL) {
221                 g_critical("%s", error_get_pretty(local_err));
222                 error_free(local_err);
223                 return false;
224             }
225         }
226         ga_channel_listen_add(c, fd, true);
227         break;
228     }
229     default:
230         g_critical("error binding/listening to specified socket");
231         return false;
232     }
233 
234     return true;
235 }
236 
237 GIOStatus ga_channel_write_all(GAChannel *c, const gchar *buf, gsize size)
238 {
239     GError *err = NULL;
240     gsize written = 0;
241     GIOStatus status = G_IO_STATUS_NORMAL;
242 
243     while (size) {
244         g_debug("sending data, count: %d", (int)size);
245         status = g_io_channel_write_chars(c->client_channel, buf, size,
246                                           &written, &err);
247         if (status == G_IO_STATUS_NORMAL) {
248             size -= written;
249             buf += written;
250         } else if (status != G_IO_STATUS_AGAIN) {
251             g_warning("error writing to channel: %s", err->message);
252             return status;
253         }
254     }
255 
256     do {
257         status = g_io_channel_flush(c->client_channel, &err);
258     } while (status == G_IO_STATUS_AGAIN);
259 
260     if (status != G_IO_STATUS_NORMAL) {
261         g_warning("error flushing channel: %s", err->message);
262     }
263 
264     return status;
265 }
266 
267 GIOStatus ga_channel_read(GAChannel *c, gchar *buf, gsize size, gsize *count)
268 {
269     return g_io_channel_read_chars(c->client_channel, buf, size, count, NULL);
270 }
271 
272 GAChannel *ga_channel_new(GAChannelMethod method, const gchar *path,
273                           int listen_fd, GAChannelCallback cb, gpointer opaque)
274 {
275     GAChannel *c = g_new0(GAChannel, 1);
276     c->event_cb = cb;
277     c->user_data = opaque;
278 
279     if (!ga_channel_open(c, path, method, listen_fd)) {
280         g_critical("error opening channel");
281         ga_channel_free(c);
282         return NULL;
283     }
284 
285     return c;
286 }
287 
288 void ga_channel_free(GAChannel *c)
289 {
290     if (c->listen_channel) {
291         ga_channel_listen_close(c);
292     }
293     if (c->client_channel) {
294         ga_channel_client_close(c);
295     }
296     g_free(c);
297 }
298