Annotation of /tags/mkinitrd-6_1_11/busybox/miscutils/microcom.c
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Revision 928 -
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Wed Oct 28 13:31:19 2009 UTC (14 years, 7 months ago) by niro
File MIME type: text/plain
File size: 4172 byte(s)
Wed Oct 28 13:31:19 2009 UTC (14 years, 7 months ago) by niro
File MIME type: text/plain
File size: 4172 byte(s)
tagged 'mkinitrd-6_1_11'
1 | niro | 816 | /* vi: set sw=4 ts=4: */ |
2 | /* | ||
3 | * bare bones 'talk to modem' program - similar to 'cu -l $device' | ||
4 | * inspired by mgetty's microcom | ||
5 | * | ||
6 | * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com> | ||
7 | * | ||
8 | * Licensed under GPLv2, see file LICENSE in this tarball for details. | ||
9 | */ | ||
10 | #include "libbb.h" | ||
11 | |||
12 | // set raw tty mode | ||
13 | static void xget1(int fd, struct termios *t, struct termios *oldt) | ||
14 | { | ||
15 | tcgetattr(fd, oldt); | ||
16 | *t = *oldt; | ||
17 | cfmakeraw(t); | ||
18 | // t->c_lflag &= ~(ISIG|ICANON|ECHO|IEXTEN); | ||
19 | // t->c_iflag &= ~(BRKINT|IXON|ICRNL); | ||
20 | // t->c_oflag &= ~(ONLCR); | ||
21 | // t->c_cc[VMIN] = 1; | ||
22 | // t->c_cc[VTIME] = 0; | ||
23 | } | ||
24 | |||
25 | static int xset1(int fd, struct termios *tio, const char *device) | ||
26 | { | ||
27 | int ret = tcsetattr(fd, TCSAFLUSH, tio); | ||
28 | |||
29 | if (ret) { | ||
30 | bb_perror_msg("can't tcsetattr for %s", device); | ||
31 | } | ||
32 | return ret; | ||
33 | } | ||
34 | |||
35 | int microcom_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; | ||
36 | int microcom_main(int argc UNUSED_PARAM, char **argv) | ||
37 | { | ||
38 | int sfd; | ||
39 | int nfd; | ||
40 | struct pollfd pfd[2]; | ||
41 | struct termios tio0, tiosfd, tio; | ||
42 | char *device_lock_file; | ||
43 | enum { | ||
44 | OPT_X = 1 << 0, // do not respect Ctrl-X, Ctrl-@ | ||
45 | OPT_s = 1 << 1, // baudrate | ||
46 | OPT_d = 1 << 2, // wait for device response, ms | ||
47 | OPT_t = 1 << 3, // timeout, ms | ||
48 | }; | ||
49 | speed_t speed = 9600; | ||
50 | int delay = -1; | ||
51 | int timeout = -1; | ||
52 | unsigned opts; | ||
53 | |||
54 | // fetch options | ||
55 | opt_complementary = "=1:s+:d+:t+"; // exactly one arg, numeric options | ||
56 | opts = getopt32(argv, "Xs:d:t:", &speed, &delay, &timeout); | ||
57 | // argc -= optind; | ||
58 | argv += optind; | ||
59 | |||
60 | // try to create lock file in /var/lock | ||
61 | device_lock_file = (char *)bb_basename(argv[0]); | ||
62 | device_lock_file = xasprintf("/var/lock/LCK..%s", device_lock_file); | ||
63 | sfd = open(device_lock_file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644); | ||
64 | if (sfd < 0) { | ||
65 | // device already locked -> bail out | ||
66 | if (errno == EEXIST) | ||
67 | bb_perror_msg_and_die("can't create %s", device_lock_file); | ||
68 | // can't create lock -> don't care | ||
69 | if (ENABLE_FEATURE_CLEAN_UP) | ||
70 | free(device_lock_file); | ||
71 | device_lock_file = NULL; | ||
72 | } else { | ||
73 | // %4d to make concurrent mgetty (if any) happy. | ||
74 | // Mgetty treats 4-bytes lock files as binary, | ||
75 | // not text, PID. Making 5+ char file. Brrr... | ||
76 | fdprintf(sfd, "%4d\n", getpid()); | ||
77 | close(sfd); | ||
78 | } | ||
79 | |||
80 | // setup signals | ||
81 | bb_signals(0 | ||
82 | + (1 << SIGHUP) | ||
83 | + (1 << SIGINT) | ||
84 | + (1 << SIGTERM) | ||
85 | + (1 << SIGPIPE) | ||
86 | , record_signo); | ||
87 | |||
88 | // error exit code if we fail to open the device | ||
89 | bb_got_signal = 1; | ||
90 | |||
91 | // open device | ||
92 | sfd = open_or_warn(argv[0], O_RDWR | O_NOCTTY | O_NONBLOCK); | ||
93 | if (sfd < 0) | ||
94 | goto done; | ||
95 | fcntl(sfd, F_SETFL, 0); | ||
96 | |||
97 | // put device to "raw mode" | ||
98 | xget1(sfd, &tio, &tiosfd); | ||
99 | // set device speed | ||
100 | cfsetspeed(&tio, tty_value_to_baud(speed)); | ||
101 | if (xset1(sfd, &tio, argv[0])) | ||
102 | goto done; | ||
103 | |||
104 | // put stdin to "raw mode" (if stdin is a TTY), | ||
105 | // handle one character at a time | ||
106 | if (isatty(STDIN_FILENO)) { | ||
107 | xget1(STDIN_FILENO, &tio, &tio0); | ||
108 | if (xset1(STDIN_FILENO, &tio, "stdin")) | ||
109 | goto done; | ||
110 | } | ||
111 | |||
112 | // main loop: check with poll(), then read/write bytes across | ||
113 | pfd[0].fd = sfd; | ||
114 | pfd[0].events = POLLIN; | ||
115 | pfd[1].fd = STDIN_FILENO; | ||
116 | pfd[1].events = POLLIN; | ||
117 | |||
118 | bb_got_signal = 0; | ||
119 | nfd = 2; | ||
120 | while (!bb_got_signal && safe_poll(pfd, nfd, timeout) > 0) { | ||
121 | if (nfd > 1 && pfd[1].revents) { | ||
122 | char c; | ||
123 | // read from stdin -> write to device | ||
124 | if (safe_read(STDIN_FILENO, &c, 1) < 1) { | ||
125 | // don't poll stdin anymore if we got EOF/error | ||
126 | nfd--; | ||
127 | goto skip_write; | ||
128 | } | ||
129 | // do we need special processing? | ||
130 | if (!(opts & OPT_X)) { | ||
131 | // ^@ sends Break | ||
132 | if (VINTR == c) { | ||
133 | tcsendbreak(sfd, 0); | ||
134 | goto skip_write; | ||
135 | } | ||
136 | // ^X exits | ||
137 | if (24 == c) | ||
138 | break; | ||
139 | } | ||
140 | write(sfd, &c, 1); | ||
141 | if (delay >= 0) | ||
142 | safe_poll(pfd, 1, delay); | ||
143 | skip_write: ; | ||
144 | } | ||
145 | if (pfd[0].revents) { | ||
146 | #define iobuf bb_common_bufsiz1 | ||
147 | ssize_t len; | ||
148 | // read from device -> write to stdout | ||
149 | len = safe_read(sfd, iobuf, sizeof(iobuf)); | ||
150 | if (len > 0) | ||
151 | full_write(STDOUT_FILENO, iobuf, len); | ||
152 | else { | ||
153 | // EOF/error -> bail out | ||
154 | bb_got_signal = SIGHUP; | ||
155 | break; | ||
156 | } | ||
157 | } | ||
158 | } | ||
159 | |||
160 | // restore device mode | ||
161 | tcsetattr(sfd, TCSAFLUSH, &tiosfd); | ||
162 | |||
163 | if (isatty(STDIN_FILENO)) | ||
164 | tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0); | ||
165 | |||
166 | done: | ||
167 | if (device_lock_file) | ||
168 | unlink(device_lock_file); | ||
169 | |||
170 | return bb_got_signal; | ||
171 | } |