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6#include <stdlib.h>
7#include <unistd.h>
8#include <errno.h>
9#include <sched.h>
10#include <signal.h>
11#include <termios.h>
12#include <sys/ioctl.h>
13#include "chan_user.h"
14#include "kern_constants.h"
15#include "os.h"
16#include "um_malloc.h"
17#include "user.h"
18
19void generic_close(int fd, void *unused)
20{
21 close(fd);
22}
23
24int generic_read(int fd, char *c_out, void *unused)
25{
26 int n;
27
28 n = read(fd, c_out, sizeof(*c_out));
29 if (n > 0)
30 return n;
31 else if (errno == EAGAIN)
32 return 0;
33 else if (n == 0)
34 return -EIO;
35 return -errno;
36}
37
38
39
40int generic_write(int fd, const char *buf, int n, void *unused)
41{
42 int err;
43
44 err = write(fd, buf, n);
45 if (err > 0)
46 return err;
47 else if (errno == EAGAIN)
48 return 0;
49 else if (err == 0)
50 return -EIO;
51 return -errno;
52}
53
54int generic_window_size(int fd, void *unused, unsigned short *rows_out,
55 unsigned short *cols_out)
56{
57 struct winsize size;
58 int ret;
59
60 if (ioctl(fd, TIOCGWINSZ, &size) < 0)
61 return -errno;
62
63 ret = ((*rows_out != size.ws_row) || (*cols_out != size.ws_col));
64
65 *rows_out = size.ws_row;
66 *cols_out = size.ws_col;
67
68 return ret;
69}
70
71void generic_free(void *data)
72{
73 kfree(data);
74}
75
76int generic_console_write(int fd, const char *buf, int n)
77{
78 sigset_t old, no_sigio;
79 struct termios save, new;
80 int err;
81
82 if (isatty(fd)) {
83 sigemptyset(&no_sigio);
84 sigaddset(&no_sigio, SIGIO);
85 if (sigprocmask(SIG_BLOCK, &no_sigio, &old))
86 goto error;
87
88 CATCH_EINTR(err = tcgetattr(fd, &save));
89 if (err)
90 goto error;
91 new = save;
92
93
94
95
96
97 new.c_oflag |= OPOST;
98 CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &new));
99 if (err)
100 goto error;
101 }
102 err = generic_write(fd, buf, n, NULL);
103
104
105
106
107 if (isatty(fd)) {
108 CATCH_EINTR(tcsetattr(fd, TCSAFLUSH, &save));
109 sigprocmask(SIG_SETMASK, &old, NULL);
110 }
111
112 return err;
113error:
114 return -errno;
115}
116
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118
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122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137static void winch_handler(int sig)
138{
139}
140
141struct winch_data {
142 int pty_fd;
143 int pipe_fd;
144};
145
146static int winch_thread(void *arg)
147{
148 struct winch_data *data = arg;
149 sigset_t sigs;
150 int pty_fd, pipe_fd;
151 int count;
152 char c = 1;
153
154 pty_fd = data->pty_fd;
155 pipe_fd = data->pipe_fd;
156 count = write(pipe_fd, &c, sizeof(c));
157 if (count != sizeof(c))
158 printk(UM_KERN_ERR "winch_thread : failed to write "
159 "synchronization byte, err = %d\n", -count);
160
161
162
163
164
165
166
167 signal(SIGWINCH, winch_handler);
168 sigfillset(&sigs);
169
170 if (sigprocmask(SIG_SETMASK, &sigs, NULL) < 0) {
171 printk(UM_KERN_ERR "winch_thread : sigprocmask failed, "
172 "errno = %d\n", errno);
173 exit(1);
174 }
175
176 sigdelset(&sigs, SIGWINCH);
177
178 if (setsid() < 0) {
179 printk(UM_KERN_ERR "winch_thread : setsid failed, errno = %d\n",
180 errno);
181 exit(1);
182 }
183
184 if (ioctl(pty_fd, TIOCSCTTY, 0) < 0) {
185 printk(UM_KERN_ERR "winch_thread : TIOCSCTTY failed on "
186 "fd %d err = %d\n", pty_fd, errno);
187 exit(1);
188 }
189
190 if (tcsetpgrp(pty_fd, os_getpid()) < 0) {
191 printk(UM_KERN_ERR "winch_thread : tcsetpgrp failed on "
192 "fd %d err = %d\n", pty_fd, errno);
193 exit(1);
194 }
195
196
197
198
199
200
201
202 count = read(pipe_fd, &c, sizeof(c));
203 if (count != sizeof(c))
204 printk(UM_KERN_ERR "winch_thread : failed to read "
205 "synchronization byte, err = %d\n", errno);
206
207 while(1) {
208
209
210
211
212 sigsuspend(&sigs);
213
214 count = write(pipe_fd, &c, sizeof(c));
215 if (count != sizeof(c))
216 printk(UM_KERN_ERR "winch_thread : write failed, "
217 "err = %d\n", errno);
218 }
219}
220
221static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out,
222 unsigned long *stack_out)
223{
224 struct winch_data data;
225 int fds[2], n, err;
226 char c;
227
228 err = os_pipe(fds, 1, 1);
229 if (err < 0) {
230 printk(UM_KERN_ERR "winch_tramp : os_pipe failed, err = %d\n",
231 -err);
232 goto out;
233 }
234
235 data = ((struct winch_data) { .pty_fd = fd,
236 .pipe_fd = fds[1] } );
237
238
239
240
241
242
243 err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out);
244 if (err < 0) {
245 printk(UM_KERN_ERR "fork of winch_thread failed - errno = %d\n",
246 -err);
247 goto out_close;
248 }
249
250 *fd_out = fds[0];
251 n = read(fds[0], &c, sizeof(c));
252 if (n != sizeof(c)) {
253 printk(UM_KERN_ERR "winch_tramp : failed to read "
254 "synchronization byte\n");
255 printk(UM_KERN_ERR "read failed, err = %d\n", errno);
256 printk(UM_KERN_ERR "fd %d will not support SIGWINCH\n", fd);
257 err = -EINVAL;
258 goto out_close;
259 }
260
261 if (os_set_fd_block(*fd_out, 0)) {
262 printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
263 "non-blocking.\n");
264 goto out_close;
265 }
266
267 return err;
268
269 out_close:
270 close(fds[1]);
271 close(fds[0]);
272 out:
273 return err;
274}
275
276void register_winch(int fd, struct tty_struct *tty)
277{
278 unsigned long stack;
279 int pid, thread, count, thread_fd = -1;
280 char c = 1;
281
282 if (!isatty(fd))
283 return;
284
285 pid = tcgetpgrp(fd);
286 if (!is_skas_winch(pid, fd, tty) && (pid == -1)) {
287 thread = winch_tramp(fd, tty, &thread_fd, &stack);
288 if (thread < 0)
289 return;
290
291 register_winch_irq(thread_fd, fd, thread, tty, stack);
292
293 count = write(thread_fd, &c, sizeof(c));
294 if (count != sizeof(c))
295 printk(UM_KERN_ERR "register_winch : failed to write "
296 "synchronization byte, err = %d\n", errno);
297 }
298}
299