Commit | Line | Data |
---|---|---|
cb8fa61c | 1 | /* |
e99525f9 | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
1da177e4 | 6 | #include <stdlib.h> |
e99525f9 | 7 | #include <unistd.h> |
1da177e4 | 8 | #include <errno.h> |
1d2ddcfb | 9 | #include <sched.h> |
e99525f9 JD |
10 | #include <signal.h> |
11 | #include <termios.h> | |
1da177e4 | 12 | #include <sys/ioctl.h> |
1da177e4 | 13 | #include "chan_user.h" |
37185b33 AV |
14 | #include <os.h> |
15 | #include <um_malloc.h> | |
89fe6476 JD |
16 | |
17 | void generic_close(int fd, void *unused) | |
18 | { | |
8e2d10e1 | 19 | close(fd); |
89fe6476 JD |
20 | } |
21 | ||
22 | int generic_read(int fd, char *c_out, void *unused) | |
23 | { | |
24 | int n; | |
25 | ||
8e2d10e1 JD |
26 | n = read(fd, c_out, sizeof(*c_out)); |
27 | if (n > 0) | |
28 | return n; | |
29 | else if (errno == EAGAIN) | |
89fe6476 | 30 | return 0; |
8e2d10e1 | 31 | else if (n == 0) |
89fe6476 | 32 | return -EIO; |
8e2d10e1 | 33 | return -errno; |
89fe6476 JD |
34 | } |
35 | ||
8e2d10e1 | 36 | /* XXX Trivial wrapper around write */ |
89fe6476 JD |
37 | |
38 | int generic_write(int fd, const char *buf, int n, void *unused) | |
39 | { | |
c59dbcad JD |
40 | int err; |
41 | ||
42 | err = write(fd, buf, n); | |
43 | if (err > 0) | |
44 | return err; | |
45 | else if (errno == EAGAIN) | |
46 | return 0; | |
47 | else if (err == 0) | |
48 | return -EIO; | |
49 | return -errno; | |
89fe6476 JD |
50 | } |
51 | ||
52 | int generic_window_size(int fd, void *unused, unsigned short *rows_out, | |
53 | unsigned short *cols_out) | |
54 | { | |
8e2d10e1 | 55 | struct winsize size; |
89fe6476 JD |
56 | int ret; |
57 | ||
e99525f9 | 58 | if (ioctl(fd, TIOCGWINSZ, &size) < 0) |
8e2d10e1 | 59 | return -errno; |
89fe6476 | 60 | |
8e2d10e1 | 61 | ret = ((*rows_out != size.ws_row) || (*cols_out != size.ws_col)); |
89fe6476 | 62 | |
8e2d10e1 JD |
63 | *rows_out = size.ws_row; |
64 | *cols_out = size.ws_col; | |
89fe6476 JD |
65 | |
66 | return ret; | |
67 | } | |
68 | ||
69 | void generic_free(void *data) | |
70 | { | |
71 | kfree(data); | |
72 | } | |
1da177e4 | 73 | |
55c033c1 | 74 | int generic_console_write(int fd, const char *buf, int n) |
1da177e4 | 75 | { |
ce3b642d | 76 | sigset_t old, no_sigio; |
1da177e4 LT |
77 | struct termios save, new; |
78 | int err; | |
79 | ||
e99525f9 | 80 | if (isatty(fd)) { |
ce3b642d JD |
81 | sigemptyset(&no_sigio); |
82 | sigaddset(&no_sigio, SIGIO); | |
83 | if (sigprocmask(SIG_BLOCK, &no_sigio, &old)) | |
84 | goto error; | |
85 | ||
1da177e4 LT |
86 | CATCH_EINTR(err = tcgetattr(fd, &save)); |
87 | if (err) | |
88 | goto error; | |
89 | new = save; | |
cb8fa61c JD |
90 | /* |
91 | * The terminal becomes a bit less raw, to handle \n also as | |
1da177e4 | 92 | * "Carriage Return", not only as "New Line". Otherwise, the new |
cb8fa61c JD |
93 | * line won't start at the first column. |
94 | */ | |
1da177e4 LT |
95 | new.c_oflag |= OPOST; |
96 | CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &new)); | |
97 | if (err) | |
98 | goto error; | |
99 | } | |
100 | err = generic_write(fd, buf, n, NULL); | |
cb8fa61c JD |
101 | /* |
102 | * Restore raw mode, in any case; we *must* ignore any error apart | |
103 | * EINTR, except for debug. | |
104 | */ | |
ce3b642d | 105 | if (isatty(fd)) { |
1da177e4 | 106 | CATCH_EINTR(tcsetattr(fd, TCSAFLUSH, &save)); |
ce3b642d JD |
107 | sigprocmask(SIG_SETMASK, &old, NULL); |
108 | } | |
109 | ||
e99525f9 | 110 | return err; |
1da177e4 | 111 | error: |
e99525f9 | 112 | return -errno; |
1da177e4 LT |
113 | } |
114 | ||
115 | /* | |
116 | * UML SIGWINCH handling | |
117 | * | |
42a359e3 JD |
118 | * The point of this is to handle SIGWINCH on consoles which have host |
119 | * ttys and relay them inside UML to whatever might be running on the | |
120 | * console and cares about the window size (since SIGWINCH notifies | |
121 | * about terminal size changes). | |
1da177e4 | 122 | * |
42a359e3 JD |
123 | * So, we have a separate thread for each host tty attached to a UML |
124 | * device (side-issue - I'm annoyed that one thread can't have | |
125 | * multiple controlling ttys for the purpose of handling SIGWINCH, but | |
126 | * I imagine there are other reasons that doesn't make any sense). | |
1da177e4 | 127 | * |
42a359e3 JD |
128 | * SIGWINCH can't be received synchronously, so you have to set up to |
129 | * receive it as a signal. That being the case, if you are going to | |
130 | * wait for it, it is convenient to sit in sigsuspend() and wait for | |
131 | * the signal to bounce you out of it (see below for how we make sure | |
132 | * to exit only on SIGWINCH). | |
1da177e4 LT |
133 | */ |
134 | ||
135 | static void winch_handler(int sig) | |
136 | { | |
137 | } | |
138 | ||
139 | struct winch_data { | |
140 | int pty_fd; | |
141 | int pipe_fd; | |
1da177e4 LT |
142 | }; |
143 | ||
144 | static int winch_thread(void *arg) | |
145 | { | |
146 | struct winch_data *data = arg; | |
147 | sigset_t sigs; | |
148 | int pty_fd, pipe_fd; | |
8ca842c4 | 149 | int count; |
1da177e4 LT |
150 | char c = 1; |
151 | ||
1da177e4 LT |
152 | pty_fd = data->pty_fd; |
153 | pipe_fd = data->pipe_fd; | |
8ca842c4 | 154 | count = write(pipe_fd, &c, sizeof(c)); |
e99525f9 JD |
155 | if (count != sizeof(c)) |
156 | printk(UM_KERN_ERR "winch_thread : failed to write " | |
157 | "synchronization byte, err = %d\n", -count); | |
1da177e4 | 158 | |
e99525f9 JD |
159 | /* |
160 | * We are not using SIG_IGN on purpose, so don't fix it as I thought to | |
ed1b58d8 | 161 | * do! If using SIG_IGN, the sigsuspend() call below would not stop on |
e99525f9 JD |
162 | * SIGWINCH. |
163 | */ | |
1da177e4 LT |
164 | |
165 | signal(SIGWINCH, winch_handler); | |
166 | sigfillset(&sigs); | |
ed1b58d8 | 167 | /* Block all signals possible. */ |
e99525f9 JD |
168 | if (sigprocmask(SIG_SETMASK, &sigs, NULL) < 0) { |
169 | printk(UM_KERN_ERR "winch_thread : sigprocmask failed, " | |
170 | "errno = %d\n", errno); | |
1da177e4 LT |
171 | exit(1); |
172 | } | |
ed1b58d8 BS |
173 | /* In sigsuspend(), block anything else than SIGWINCH. */ |
174 | sigdelset(&sigs, SIGWINCH); | |
1da177e4 | 175 | |
e99525f9 JD |
176 | if (setsid() < 0) { |
177 | printk(UM_KERN_ERR "winch_thread : setsid failed, errno = %d\n", | |
178 | errno); | |
1da177e4 LT |
179 | exit(1); |
180 | } | |
181 | ||
cb8fa61c | 182 | if (ioctl(pty_fd, TIOCSCTTY, 0) < 0) { |
8ca842c4 JD |
183 | printk(UM_KERN_ERR "winch_thread : TIOCSCTTY failed on " |
184 | "fd %d err = %d\n", pty_fd, errno); | |
185 | exit(1); | |
186 | } | |
187 | ||
cb8fa61c | 188 | if (tcsetpgrp(pty_fd, os_getpid()) < 0) { |
8ca842c4 JD |
189 | printk(UM_KERN_ERR "winch_thread : tcsetpgrp failed on " |
190 | "fd %d err = %d\n", pty_fd, errno); | |
1da177e4 LT |
191 | exit(1); |
192 | } | |
193 | ||
e99525f9 JD |
194 | /* |
195 | * These are synchronization calls between various UML threads on the | |
1da177e4 LT |
196 | * host - since they are not different kernel threads, we cannot use |
197 | * kernel semaphores. We don't use SysV semaphores because they are | |
e99525f9 JD |
198 | * persistent. |
199 | */ | |
8ca842c4 | 200 | count = read(pipe_fd, &c, sizeof(c)); |
e99525f9 JD |
201 | if (count != sizeof(c)) |
202 | printk(UM_KERN_ERR "winch_thread : failed to read " | |
8ca842c4 | 203 | "synchronization byte, err = %d\n", errno); |
1da177e4 | 204 | |
e99525f9 JD |
205 | while(1) { |
206 | /* | |
207 | * This will be interrupted by SIGWINCH only, since | |
42a359e3 JD |
208 | * other signals are blocked. |
209 | */ | |
ed1b58d8 | 210 | sigsuspend(&sigs); |
1da177e4 | 211 | |
8ca842c4 | 212 | count = write(pipe_fd, &c, sizeof(c)); |
e99525f9 JD |
213 | if (count != sizeof(c)) |
214 | printk(UM_KERN_ERR "winch_thread : write failed, " | |
8ca842c4 | 215 | "err = %d\n", errno); |
1da177e4 LT |
216 | } |
217 | } | |
218 | ||
2116bda6 | 219 | static int winch_tramp(int fd, struct tty_port *port, int *fd_out, |
42a359e3 | 220 | unsigned long *stack_out) |
1da177e4 LT |
221 | { |
222 | struct winch_data data; | |
1f96ddb4 | 223 | int fds[2], n, err; |
1da177e4 LT |
224 | char c; |
225 | ||
226 | err = os_pipe(fds, 1, 1); | |
e99525f9 JD |
227 | if (err < 0) { |
228 | printk(UM_KERN_ERR "winch_tramp : os_pipe failed, err = %d\n", | |
229 | -err); | |
1f96ddb4 | 230 | goto out; |
1da177e4 LT |
231 | } |
232 | ||
233 | data = ((struct winch_data) { .pty_fd = fd, | |
1d2ddcfb | 234 | .pipe_fd = fds[1] } ); |
e99525f9 JD |
235 | /* |
236 | * CLONE_FILES so this thread doesn't hold open files which are open | |
42a359e3 JD |
237 | * now, but later closed in a different thread. This is a |
238 | * problem with /dev/net/tun, which if held open by this | |
239 | * thread, prevents the TUN/TAP device from being reused. | |
1d2ddcfb | 240 | */ |
c4399016 | 241 | err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out); |
e99525f9 JD |
242 | if (err < 0) { |
243 | printk(UM_KERN_ERR "fork of winch_thread failed - errno = %d\n", | |
244 | -err); | |
1f96ddb4 | 245 | goto out_close; |
1da177e4 LT |
246 | } |
247 | ||
1da177e4 | 248 | *fd_out = fds[0]; |
8ca842c4 | 249 | n = read(fds[0], &c, sizeof(c)); |
e99525f9 JD |
250 | if (n != sizeof(c)) { |
251 | printk(UM_KERN_ERR "winch_tramp : failed to read " | |
252 | "synchronization byte\n"); | |
8ca842c4 | 253 | printk(UM_KERN_ERR "read failed, err = %d\n", errno); |
e99525f9 JD |
254 | printk(UM_KERN_ERR "fd %d will not support SIGWINCH\n", fd); |
255 | err = -EINVAL; | |
1d2ddcfb | 256 | goto out_close; |
1da177e4 | 257 | } |
89df6bfc EGM |
258 | |
259 | if (os_set_fd_block(*fd_out, 0)) { | |
e99525f9 JD |
260 | printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd " |
261 | "non-blocking.\n"); | |
89df6bfc EGM |
262 | goto out_close; |
263 | } | |
264 | ||
265 | return err; | |
1f96ddb4 JD |
266 | |
267 | out_close: | |
8ca842c4 JD |
268 | close(fds[1]); |
269 | close(fds[0]); | |
1f96ddb4 JD |
270 | out: |
271 | return err; | |
1da177e4 LT |
272 | } |
273 | ||
2116bda6 | 274 | void register_winch(int fd, struct tty_port *port) |
1da177e4 | 275 | { |
42a359e3 JD |
276 | unsigned long stack; |
277 | int pid, thread, count, thread_fd = -1; | |
1da177e4 LT |
278 | char c = 1; |
279 | ||
e99525f9 | 280 | if (!isatty(fd)) |
1da177e4 LT |
281 | return; |
282 | ||
283 | pid = tcgetpgrp(fd); | |
2116bda6 RW |
284 | if (is_skas_winch(pid, fd, port)) { |
285 | register_winch_irq(-1, fd, -1, port, 0); | |
17e05209 AV |
286 | return; |
287 | } | |
288 | ||
289 | if (pid == -1) { | |
2116bda6 | 290 | thread = winch_tramp(fd, port, &thread_fd, &stack); |
42a359e3 JD |
291 | if (thread < 0) |
292 | return; | |
293 | ||
2116bda6 | 294 | register_winch_irq(thread_fd, fd, thread, port, stack); |
42a359e3 | 295 | |
8ca842c4 | 296 | count = write(thread_fd, &c, sizeof(c)); |
e99525f9 JD |
297 | if (count != sizeof(c)) |
298 | printk(UM_KERN_ERR "register_winch : failed to write " | |
8ca842c4 | 299 | "synchronization byte, err = %d\n", errno); |
1da177e4 LT |
300 | } |
301 | } |