xref: /openbmc/linux/arch/um/drivers/xterm.c (revision c21b37f6)
1 /*
2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5 
6 #include <stdlib.h>
7 #include <stdio.h>
8 #include <unistd.h>
9 #include <string.h>
10 #include <errno.h>
11 #include <termios.h>
12 #include "chan_user.h"
13 #include "os.h"
14 #include "init.h"
15 #include "user.h"
16 #include "xterm.h"
17 #include "kern_constants.h"
18 
19 struct xterm_chan {
20 	int pid;
21 	int helper_pid;
22 	char *title;
23 	int device;
24 	int raw;
25 	struct termios tt;
26 };
27 
28 static void *xterm_init(char *str, int device, const struct chan_opts *opts)
29 {
30 	struct xterm_chan *data;
31 
32 	data = malloc(sizeof(*data));
33 	if (data == NULL)
34 		return NULL;
35 	*data = ((struct xterm_chan) { .pid 		= -1,
36 				       .helper_pid 	= -1,
37 				       .device 		= device,
38 				       .title 		= opts->xterm_title,
39 				       .raw  		= opts->raw } );
40 	return data;
41 }
42 
43 /* Only changed by xterm_setup, which is a setup */
44 static char *terminal_emulator = "xterm";
45 static char *title_switch = "-T";
46 static char *exec_switch = "-e";
47 
48 static int __init xterm_setup(char *line, int *add)
49 {
50 	*add = 0;
51 	terminal_emulator = line;
52 
53 	line = strchr(line, ',');
54 	if (line == NULL)
55 		return 0;
56 
57 	*line++ = '\0';
58 	if (*line)
59 		title_switch = line;
60 
61 	line = strchr(line, ',');
62 	if (line == NULL)
63 		return 0;
64 
65 	*line++ = '\0';
66 	if (*line)
67 		exec_switch = line;
68 
69 	return 0;
70 }
71 
72 __uml_setup("xterm=", xterm_setup,
73 "xterm=<terminal emulator>,<title switch>,<exec switch>\n"
74 "    Specifies an alternate terminal emulator to use for the debugger,\n"
75 "    consoles, and serial lines when they are attached to the xterm channel.\n"
76 "    The values are the terminal emulator binary, the switch it uses to set\n"
77 "    its title, and the switch it uses to execute a subprocess,\n"
78 "    respectively.  The title switch must have the form '<switch> title',\n"
79 "    not '<switch>=title'.  Similarly, the exec switch must have the form\n"
80 "    '<switch> command arg1 arg2 ...'.\n"
81 "    The default values are 'xterm=xterm,-T,-e'.  Values for gnome-terminal\n"
82 "    are 'xterm=gnome-terminal,-t,-x'.\n\n"
83 );
84 
85 static int xterm_open(int input, int output, int primary, void *d,
86 		      char **dev_out)
87 {
88 	struct xterm_chan *data = d;
89 	int pid, fd, new, err;
90 	char title[256], file[] = "/tmp/xterm-pipeXXXXXX";
91 	char *argv[] = { terminal_emulator, title_switch, title, exec_switch,
92 			 "/usr/lib/uml/port-helper", "-uml-socket",
93 			 file, NULL };
94 
95 	if (access(argv[4], X_OK) < 0)
96 		argv[4] = "port-helper";
97 
98 	/* Check that DISPLAY is set, this doesn't guarantee the xterm
99 	 * will work but w/o it we can be pretty sure it won't. */
100 	if (getenv("DISPLAY") == NULL) {
101 		printk(UM_KERN_ERR "xterm_open: $DISPLAY not set.\n");
102 		return -ENODEV;
103 	}
104 
105 	/*
106 	 * This business of getting a descriptor to a temp file,
107 	 * deleting the file and closing the descriptor is just to get
108 	 * a known-unused name for the Unix socket that we really
109 	 * want.
110 	 */
111 	fd = mkstemp(file);
112 	if (fd < 0) {
113 		err = -errno;
114 		printk(UM_KERN_ERR "xterm_open : mkstemp failed, errno = %d\n",
115 		       errno);
116 		return err;
117 	}
118 
119 	if (unlink(file)) {
120 		err = -errno;
121 		printk(UM_KERN_ERR "xterm_open : unlink failed, errno = %d\n",
122 		       errno);
123 		return err;
124 	}
125 	close(fd);
126 
127 	fd = os_create_unix_socket(file, sizeof(file), 1);
128 	if (fd < 0) {
129 		printk(UM_KERN_ERR "xterm_open : create_unix_socket failed, "
130 		       "errno = %d\n", -fd);
131 		return fd;
132 	}
133 
134 	sprintf(title, data->title, data->device);
135 	pid = run_helper(NULL, NULL, argv);
136 	if (pid < 0) {
137 		err = pid;
138 		printk(UM_KERN_ERR "xterm_open : run_helper failed, "
139 		       "errno = %d\n", -err);
140 		goto out_close1;
141 	}
142 
143 	err = os_set_fd_block(fd, 0);
144 	if (err < 0) {
145 		printk(UM_KERN_ERR "xterm_open : failed to set descriptor "
146 		       "non-blocking, err = %d\n", -err);
147 		goto out_kill;
148 	}
149 
150 	new = xterm_fd(fd, &data->helper_pid);
151 	if (new < 0) {
152 		err = new;
153 		printk(UM_KERN_ERR "xterm_open : os_rcv_fd failed, err = %d\n",
154 		       -err);
155 		goto out_kill;
156 	}
157 
158 	err = os_set_fd_block(new, 0);
159 	if (err) {
160 		printk(UM_KERN_ERR "xterm_open : failed to set xterm "
161 		       "descriptor non-blocking, err = %d\n", -err);
162 		goto out_close2;
163 	}
164 
165 	CATCH_EINTR(err = tcgetattr(new, &data->tt));
166 	if (err) {
167 		new = err;
168 		goto out_close2;
169 	}
170 
171 	if (data->raw) {
172 		err = raw(new);
173 		if (err) {
174 			new = err;
175 			goto out_close2;
176 		}
177 	}
178 
179 	unlink(file);
180 	data->pid = pid;
181 	*dev_out = NULL;
182 
183 	return new;
184 
185  out_close2:
186 	close(new);
187  out_kill:
188 	os_kill_process(pid, 1);
189  out_close1:
190 	close(fd);
191 
192 	return err;
193 }
194 
195 static void xterm_close(int fd, void *d)
196 {
197 	struct xterm_chan *data = d;
198 
199 	if (data->pid != -1)
200 		os_kill_process(data->pid, 1);
201 	data->pid = -1;
202 
203 	if (data->helper_pid != -1)
204 		os_kill_process(data->helper_pid, 0);
205 	data->helper_pid = -1;
206 
207 	os_close_file(fd);
208 }
209 
210 static void xterm_free(void *d)
211 {
212 	free(d);
213 }
214 
215 const struct chan_ops xterm_ops = {
216 	.type		= "xterm",
217 	.init		= xterm_init,
218 	.open		= xterm_open,
219 	.close		= xterm_close,
220 	.read		= generic_read,
221 	.write		= generic_write,
222 	.console_write	= generic_console_write,
223 	.window_size	= generic_window_size,
224 	.free		= xterm_free,
225 	.winch		= 1,
226 };
227