1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/* vi: set sw=4 ts=4: */
/*
* bare bones 'talk to modem' program - similar to 'cu -l $device'
* inspired by mgetty's microcom
*
* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config MICROCOM
//config: bool "microcom (5.6 kb)"
//config: default y
//config: help
//config: The poor man's minicom utility for chatting with serial port devices.
//applet:IF_MICROCOM(APPLET(microcom, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_MICROCOM) += microcom.o
//usage:#define microcom_trivial_usage
//usage: "[-d DELAY] [-t TIMEOUT] [-s SPEED] [-X] TTY"
//usage:#define microcom_full_usage "\n\n"
//usage: "Copy bytes for stdin to TTY and from TTY to stdout\n"
//usage: "\n -d Wait up to DELAY ms for TTY output before sending every"
//usage: "\n next byte to it"
//usage: "\n -t Exit if both stdin and TTY are silent for TIMEOUT ms"
//usage: "\n -s Set serial line to SPEED"
//usage: "\n -X Disable special meaning of NUL and Ctrl-X from stdin"
#include "libbb.h"
#include "common_bufsiz.h"
// set raw tty mode
static void xget1(int fd, struct termios *t, struct termios *oldt)
{
get_termios_and_make_raw(fd, t, oldt, 0
| TERMIOS_CLEAR_ISIG /* ^C is ASCII char 3, not "interrupt me!" */
| TERMIOS_RAW_INPUT /* pass all chars verbatim, no special handling or translating CR->NL */
| TERMIOS_RAW_CRNL /* dont convert NL<->CR on output too */
);
}
static int xset1(int fd, struct termios *tio, const char *device)
{
int ret = tcsetattr(fd, TCSAFLUSH, tio);
if (ret) {
bb_perror_msg("can't tcsetattr for %s", device);
}
return ret;
}
int microcom_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int microcom_main(int argc UNUSED_PARAM, char **argv)
{
int sfd;
int nfd;
struct pollfd pfd[2];
struct termios tio0, tiosfd, tio;
char *device_lock_file;
enum {
OPT_X = 1 << 0, // do not respect Ctrl-X, Ctrl-@
OPT_s = 1 << 1, // baudrate
OPT_d = 1 << 2, // wait for device response, ms
OPT_t = 1 << 3, // timeout, ms
};
speed_t speed = 9600;
int delay = -1;
int timeout = -1;
unsigned opts;
// fetch options
opts = getopt32(argv, "^" "Xs:+d:+t:+" "\0" "=1",
&speed, &delay, &timeout
);
// argc -= optind;
argv += optind;
// try to create lock file in /var/lock
device_lock_file = (char *)bb_basename(argv[0]);
device_lock_file = xasprintf("/var/lock/LCK..%s", device_lock_file);
sfd = open(device_lock_file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644);
if (sfd < 0) {
// device already locked -> bail out
if (errno == EEXIST)
bb_perror_msg_and_die("can't create '%s'", device_lock_file);
// can't create lock -> don't care
if (ENABLE_FEATURE_CLEAN_UP)
free(device_lock_file);
device_lock_file = NULL;
} else {
// %4d to make concurrent mgetty (if any) happy.
// Mgetty treats 4-bytes lock files as binary,
// not text, PID. Making 5+ char file. Brrr...
fdprintf(sfd, "%4d\n", getpid());
close(sfd);
}
// setup signals
bb_signals(0
+ (1 << SIGHUP)
+ (1 << SIGINT)
+ (1 << SIGTERM)
+ (1 << SIGPIPE)
, record_signo);
// error exit code if we fail to open the device
bb_got_signal = 1;
// open device
sfd = open_or_warn(argv[0], O_RDWR | O_NOCTTY | O_NONBLOCK);
if (sfd < 0)
goto done;
fcntl(sfd, F_SETFL, O_RDWR);
// put device to "raw mode"
xget1(sfd, &tio, &tiosfd);
// set device speed
cfsetspeed(&tio, tty_value_to_baud(speed));
if (xset1(sfd, &tio, argv[0]))
goto done;
// put stdin to "raw mode" (if stdin is a TTY),
// handle one character at a time
if (isatty(STDIN_FILENO)) {
xget1(STDIN_FILENO, &tio, &tio0);
if (xset1(STDIN_FILENO, &tio, "stdin"))
goto done;
}
// main loop: check with poll(), then read/write bytes across
pfd[0].fd = sfd;
pfd[0].events = POLLIN;
pfd[1].fd = STDIN_FILENO;
pfd[1].events = POLLIN;
bb_got_signal = 0;
nfd = 2;
// Not safe_poll: we want to exit on signal
while (!bb_got_signal && poll(pfd, nfd, timeout) > 0) {
if (nfd > 1 && pfd[1].revents) {
char c;
// read from stdin -> write to device
if (safe_read(STDIN_FILENO, &c, 1) < 1) {
// don't poll stdin anymore if we got EOF/error
nfd--;
goto skip_write;
}
// do we need special processing?
if (!(opts & OPT_X)) {
// ^@ sends Break
if (VINTR == c) {
tcsendbreak(sfd, 0);
goto skip_write;
}
// ^X exits
if (24 == c)
break;
}
write(sfd, &c, 1);
if (delay >= 0)
safe_poll(pfd, 1, delay);
skip_write: ;
}
if (pfd[0].revents) {
ssize_t len;
#define iobuf bb_common_bufsiz1
setup_common_bufsiz();
// read from device -> write to stdout
len = safe_read(sfd, iobuf, COMMON_BUFSIZE);
if (len > 0)
full_write(STDOUT_FILENO, iobuf, len);
else {
// EOF/error -> bail out
bb_got_signal = SIGHUP;
break;
}
}
}
// restore device mode
tcsetattr(sfd, TCSAFLUSH, &tiosfd);
if (isatty(STDIN_FILENO))
tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0);
done:
if (device_lock_file)
unlink(device_lock_file);
return bb_got_signal;
}
|
