Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) | |
3 | * Licensed under the GPL | |
4 | */ | |
5 | ||
6 | #include <unistd.h> | |
7 | #include <stdlib.h> | |
8 | #include <errno.h> | |
9 | #include <termios.h> | |
10 | #include <string.h> | |
11 | #include <signal.h> | |
1d2ddcfb | 12 | #include <sched.h> |
1da177e4 LT |
13 | #include <sys/stat.h> |
14 | #include <sys/ioctl.h> | |
15 | #include <sys/socket.h> | |
16 | #include "kern_util.h" | |
1da177e4 LT |
17 | #include "chan_user.h" |
18 | #include "user.h" | |
1da177e4 LT |
19 | #include "os.h" |
20 | #include "choose-mode.h" | |
21 | #include "mode.h" | |
89fe6476 JD |
22 | #include "um_malloc.h" |
23 | ||
24 | void generic_close(int fd, void *unused) | |
25 | { | |
8e2d10e1 | 26 | close(fd); |
89fe6476 JD |
27 | } |
28 | ||
29 | int generic_read(int fd, char *c_out, void *unused) | |
30 | { | |
31 | int n; | |
32 | ||
8e2d10e1 JD |
33 | n = read(fd, c_out, sizeof(*c_out)); |
34 | if (n > 0) | |
35 | return n; | |
36 | else if (errno == EAGAIN) | |
89fe6476 | 37 | return 0; |
8e2d10e1 | 38 | else if (n == 0) |
89fe6476 | 39 | return -EIO; |
8e2d10e1 | 40 | return -errno; |
89fe6476 JD |
41 | } |
42 | ||
8e2d10e1 | 43 | /* XXX Trivial wrapper around write */ |
89fe6476 JD |
44 | |
45 | int generic_write(int fd, const char *buf, int n, void *unused) | |
46 | { | |
8e2d10e1 | 47 | return write(fd, buf, n); |
89fe6476 JD |
48 | } |
49 | ||
50 | int generic_window_size(int fd, void *unused, unsigned short *rows_out, | |
51 | unsigned short *cols_out) | |
52 | { | |
8e2d10e1 | 53 | struct winsize size; |
89fe6476 JD |
54 | int ret; |
55 | ||
8e2d10e1 JD |
56 | if(ioctl(fd, TIOCGWINSZ, &size) < 0) |
57 | return -errno; | |
89fe6476 | 58 | |
8e2d10e1 | 59 | ret = ((*rows_out != size.ws_row) || (*cols_out != size.ws_col)); |
89fe6476 | 60 | |
8e2d10e1 JD |
61 | *rows_out = size.ws_row; |
62 | *cols_out = size.ws_col; | |
89fe6476 JD |
63 | |
64 | return ret; | |
65 | } | |
66 | ||
67 | void generic_free(void *data) | |
68 | { | |
69 | kfree(data); | |
70 | } | |
1da177e4 | 71 | |
55c033c1 | 72 | int generic_console_write(int fd, const char *buf, int n) |
1da177e4 LT |
73 | { |
74 | struct termios save, new; | |
75 | int err; | |
76 | ||
77 | if(isatty(fd)){ | |
78 | CATCH_EINTR(err = tcgetattr(fd, &save)); | |
79 | if (err) | |
80 | goto error; | |
81 | new = save; | |
82 | /* The terminal becomes a bit less raw, to handle \n also as | |
83 | * "Carriage Return", not only as "New Line". Otherwise, the new | |
84 | * line won't start at the first column.*/ | |
85 | new.c_oflag |= OPOST; | |
86 | CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &new)); | |
87 | if (err) | |
88 | goto error; | |
89 | } | |
90 | err = generic_write(fd, buf, n, NULL); | |
91 | /* Restore raw mode, in any case; we *must* ignore any error apart | |
92 | * EINTR, except for debug.*/ | |
93 | if(isatty(fd)) | |
94 | CATCH_EINTR(tcsetattr(fd, TCSAFLUSH, &save)); | |
95 | return(err); | |
96 | error: | |
97 | return(-errno); | |
98 | } | |
99 | ||
100 | /* | |
101 | * UML SIGWINCH handling | |
102 | * | |
42a359e3 JD |
103 | * The point of this is to handle SIGWINCH on consoles which have host |
104 | * ttys and relay them inside UML to whatever might be running on the | |
105 | * console and cares about the window size (since SIGWINCH notifies | |
106 | * about terminal size changes). | |
1da177e4 | 107 | * |
42a359e3 JD |
108 | * So, we have a separate thread for each host tty attached to a UML |
109 | * device (side-issue - I'm annoyed that one thread can't have | |
110 | * multiple controlling ttys for the purpose of handling SIGWINCH, but | |
111 | * I imagine there are other reasons that doesn't make any sense). | |
1da177e4 | 112 | * |
42a359e3 JD |
113 | * SIGWINCH can't be received synchronously, so you have to set up to |
114 | * receive it as a signal. That being the case, if you are going to | |
115 | * wait for it, it is convenient to sit in sigsuspend() and wait for | |
116 | * the signal to bounce you out of it (see below for how we make sure | |
117 | * to exit only on SIGWINCH). | |
1da177e4 LT |
118 | */ |
119 | ||
120 | static void winch_handler(int sig) | |
121 | { | |
122 | } | |
123 | ||
124 | struct winch_data { | |
125 | int pty_fd; | |
126 | int pipe_fd; | |
1da177e4 LT |
127 | }; |
128 | ||
129 | static int winch_thread(void *arg) | |
130 | { | |
131 | struct winch_data *data = arg; | |
132 | sigset_t sigs; | |
133 | int pty_fd, pipe_fd; | |
134 | int count, err; | |
135 | char c = 1; | |
136 | ||
1da177e4 LT |
137 | pty_fd = data->pty_fd; |
138 | pipe_fd = data->pipe_fd; | |
a6ea4cce | 139 | count = os_write_file(pipe_fd, &c, sizeof(c)); |
1da177e4 LT |
140 | if(count != sizeof(c)) |
141 | printk("winch_thread : failed to write synchronization " | |
142 | "byte, err = %d\n", -count); | |
143 | ||
144 | /* We are not using SIG_IGN on purpose, so don't fix it as I thought to | |
ed1b58d8 | 145 | * do! If using SIG_IGN, the sigsuspend() call below would not stop on |
1da177e4 LT |
146 | * SIGWINCH. */ |
147 | ||
148 | signal(SIGWINCH, winch_handler); | |
149 | sigfillset(&sigs); | |
ed1b58d8 | 150 | /* Block all signals possible. */ |
1da177e4 LT |
151 | if(sigprocmask(SIG_SETMASK, &sigs, NULL) < 0){ |
152 | printk("winch_thread : sigprocmask failed, errno = %d\n", | |
153 | errno); | |
154 | exit(1); | |
155 | } | |
ed1b58d8 BS |
156 | /* In sigsuspend(), block anything else than SIGWINCH. */ |
157 | sigdelset(&sigs, SIGWINCH); | |
1da177e4 LT |
158 | |
159 | if(setsid() < 0){ | |
160 | printk("winch_thread : setsid failed, errno = %d\n", errno); | |
161 | exit(1); | |
162 | } | |
163 | ||
164 | err = os_new_tty_pgrp(pty_fd, os_getpid()); | |
165 | if(err < 0){ | |
42a359e3 JD |
166 | printk("winch_thread : new_tty_pgrp failed on fd %d, " |
167 | "err = %d\n", pty_fd, -err); | |
1da177e4 LT |
168 | exit(1); |
169 | } | |
170 | ||
171 | /* These are synchronization calls between various UML threads on the | |
172 | * host - since they are not different kernel threads, we cannot use | |
173 | * kernel semaphores. We don't use SysV semaphores because they are | |
03a67a46 | 174 | * persistent. */ |
a6ea4cce | 175 | count = os_read_file(pipe_fd, &c, sizeof(c)); |
1da177e4 LT |
176 | if(count != sizeof(c)) |
177 | printk("winch_thread : failed to read synchronization byte, " | |
178 | "err = %d\n", -count); | |
179 | ||
180 | while(1){ | |
42a359e3 JD |
181 | /* This will be interrupted by SIGWINCH only, since |
182 | * other signals are blocked. | |
183 | */ | |
ed1b58d8 | 184 | sigsuspend(&sigs); |
1da177e4 | 185 | |
a6ea4cce | 186 | count = os_write_file(pipe_fd, &c, sizeof(c)); |
1da177e4 LT |
187 | if(count != sizeof(c)) |
188 | printk("winch_thread : write failed, err = %d\n", | |
189 | -count); | |
190 | } | |
191 | } | |
192 | ||
42a359e3 JD |
193 | static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out, |
194 | unsigned long *stack_out) | |
1da177e4 LT |
195 | { |
196 | struct winch_data data; | |
1f96ddb4 | 197 | int fds[2], n, err; |
1da177e4 LT |
198 | char c; |
199 | ||
200 | err = os_pipe(fds, 1, 1); | |
201 | if(err < 0){ | |
202 | printk("winch_tramp : os_pipe failed, err = %d\n", -err); | |
1f96ddb4 | 203 | goto out; |
1da177e4 LT |
204 | } |
205 | ||
206 | data = ((struct winch_data) { .pty_fd = fd, | |
1d2ddcfb JD |
207 | .pipe_fd = fds[1] } ); |
208 | /* CLONE_FILES so this thread doesn't hold open files which are open | |
42a359e3 JD |
209 | * now, but later closed in a different thread. This is a |
210 | * problem with /dev/net/tun, which if held open by this | |
211 | * thread, prevents the TUN/TAP device from being reused. | |
1d2ddcfb | 212 | */ |
c4399016 | 213 | err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out); |
1f96ddb4 | 214 | if(err < 0){ |
b16895b6 | 215 | printk("fork of winch_thread failed - errno = %d\n", -err); |
1f96ddb4 | 216 | goto out_close; |
1da177e4 LT |
217 | } |
218 | ||
1da177e4 | 219 | *fd_out = fds[0]; |
a6ea4cce | 220 | n = os_read_file(fds[0], &c, sizeof(c)); |
1da177e4 LT |
221 | if(n != sizeof(c)){ |
222 | printk("winch_tramp : failed to read synchronization byte\n"); | |
223 | printk("read failed, err = %d\n", -n); | |
224 | printk("fd %d will not support SIGWINCH\n", fd); | |
1f96ddb4 | 225 | err = -EINVAL; |
1d2ddcfb | 226 | goto out_close; |
1da177e4 | 227 | } |
89df6bfc EGM |
228 | |
229 | if (os_set_fd_block(*fd_out, 0)) { | |
230 | printk("winch_tramp: failed to set thread_fd non-blocking.\n"); | |
231 | goto out_close; | |
232 | } | |
233 | ||
234 | return err; | |
1f96ddb4 JD |
235 | |
236 | out_close: | |
237 | os_close_file(fds[1]); | |
1f96ddb4 JD |
238 | os_close_file(fds[0]); |
239 | out: | |
240 | return err; | |
1da177e4 LT |
241 | } |
242 | ||
243 | void register_winch(int fd, struct tty_struct *tty) | |
244 | { | |
42a359e3 JD |
245 | unsigned long stack; |
246 | int pid, thread, count, thread_fd = -1; | |
1da177e4 LT |
247 | char c = 1; |
248 | ||
249 | if(!isatty(fd)) | |
250 | return; | |
251 | ||
252 | pid = tcgetpgrp(fd); | |
42a359e3 JD |
253 | if (!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd, tty) && |
254 | (pid == -1)) { | |
255 | thread = winch_tramp(fd, tty, &thread_fd, &stack); | |
256 | if (thread < 0) | |
257 | return; | |
258 | ||
259 | register_winch_irq(thread_fd, fd, thread, tty, stack); | |
260 | ||
261 | count = os_write_file(thread_fd, &c, sizeof(c)); | |
262 | if(count != sizeof(c)) | |
263 | printk("register_winch : failed to write " | |
264 | "synchronization byte, err = %d\n", -count); | |
1da177e4 LT |
265 | } |
266 | } |