Contents of /tags/mkinitrd-6_1_12/busybox/loginutils/getty.c
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Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
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Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
File MIME type: text/plain
File size: 24295 byte(s)
tagged 'mkinitrd-6_1_12'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* agetty.c - another getty program for Linux. By W. Z. Venema 1989 |
3 | * Ported to Linux by Peter Orbaek <poe@daimi.aau.dk> |
4 | * This program is freely distributable. The entire man-page used to |
5 | * be here. Now read the real man-page agetty.8 instead. |
6 | * |
7 | * option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95 |
8 | * |
9 | * 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org> |
10 | * - added Native Language Support |
11 | * |
12 | * 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net> |
13 | * - enable hardware flow control before displaying /etc/issue |
14 | * |
15 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
16 | */ |
17 | |
18 | #include "libbb.h" |
19 | #include <syslog.h> |
20 | |
21 | #if ENABLE_FEATURE_UTMP |
22 | #include <utmp.h> /* updwtmp() */ |
23 | #endif |
24 | |
25 | /* |
26 | * Some heuristics to find out what environment we are in: if it is not |
27 | * System V, assume it is SunOS 4. |
28 | */ |
29 | #ifdef LOGIN_PROCESS /* defined in System V utmp.h */ |
30 | #include <sys/utsname.h> |
31 | #include <time.h> |
32 | #else /* if !sysV style, wtmp/utmp code is off */ |
33 | #undef ENABLE_FEATURE_UTMP |
34 | #undef ENABLE_FEATURE_WTMP |
35 | #define ENABLE_FEATURE_UTMP 0 |
36 | #define ENABLE_FEATURE_WTMP 0 |
37 | #endif /* LOGIN_PROCESS */ |
38 | |
39 | /* |
40 | * Things you may want to modify. |
41 | * |
42 | * You may disagree with the default line-editing etc. characters defined |
43 | * below. Note, however, that DEL cannot be used for interrupt generation |
44 | * and for line editing at the same time. |
45 | */ |
46 | |
47 | /* I doubt there are systems which still need this */ |
48 | #undef HANDLE_ALLCAPS |
49 | #undef ANCIENT_BS_KILL_CHARS |
50 | |
51 | #define _PATH_LOGIN "/bin/login" |
52 | |
53 | /* If ISSUE is not defined, getty will never display the contents of the |
54 | * /etc/issue file. You will not want to spit out large "issue" files at the |
55 | * wrong baud rate. |
56 | */ |
57 | #define ISSUE "/etc/issue" /* displayed before the login prompt */ |
58 | |
59 | /* Some shorthands for control characters. */ |
60 | #define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */ |
61 | #define CR CTL('M') /* carriage return */ |
62 | #define NL CTL('J') /* line feed */ |
63 | #define BS CTL('H') /* back space */ |
64 | #define DEL CTL('?') /* delete */ |
65 | |
66 | /* Defaults for line-editing etc. characters; you may want to change this. */ |
67 | #define DEF_ERASE DEL /* default erase character */ |
68 | #define DEF_INTR CTL('C') /* default interrupt character */ |
69 | #define DEF_QUIT CTL('\\') /* default quit char */ |
70 | #define DEF_KILL CTL('U') /* default kill char */ |
71 | #define DEF_EOF CTL('D') /* default EOF char */ |
72 | #define DEF_EOL '\n' |
73 | #define DEF_SWITCH 0 /* default switch char */ |
74 | |
75 | /* |
76 | * When multiple baud rates are specified on the command line, the first one |
77 | * we will try is the first one specified. |
78 | */ |
79 | #define MAX_SPEED 10 /* max. nr. of baud rates */ |
80 | |
81 | /* Storage for command-line options. */ |
82 | struct options { |
83 | int flags; /* toggle switches, see below */ |
84 | unsigned timeout; /* time-out period */ |
85 | const char *login; /* login program */ |
86 | const char *tty; /* name of tty */ |
87 | const char *initstring; /* modem init string */ |
88 | const char *issue; /* alternative issue file */ |
89 | int numspeed; /* number of baud rates to try */ |
90 | int speeds[MAX_SPEED]; /* baud rates to be tried */ |
91 | }; |
92 | |
93 | /* Storage for things detected while the login name was read. */ |
94 | struct chardata { |
95 | unsigned char erase; /* erase character */ |
96 | unsigned char kill; /* kill character */ |
97 | unsigned char eol; /* end-of-line character */ |
98 | unsigned char parity; /* what parity did we see */ |
99 | /* (parity & 1): saw odd parity char with 7th bit set */ |
100 | /* (parity & 2): saw even parity char with 7th bit set */ |
101 | /* parity == 0: probably 7-bit, space parity? */ |
102 | /* parity == 1: probably 7-bit, odd parity? */ |
103 | /* parity == 2: probably 7-bit, even parity? */ |
104 | /* parity == 3: definitely 8 bit, no parity! */ |
105 | /* Hmm... with any value of "parity" 8 bit, no parity is possible */ |
106 | #ifdef HANDLE_ALLCAPS |
107 | unsigned char capslock; /* upper case without lower case */ |
108 | #endif |
109 | }; |
110 | |
111 | |
112 | /* Initial values for the above. */ |
113 | static const struct chardata init_chardata = { |
114 | DEF_ERASE, /* default erase character */ |
115 | DEF_KILL, /* default kill character */ |
116 | 13, /* default eol char */ |
117 | 0, /* space parity */ |
118 | #ifdef HANDLE_ALLCAPS |
119 | 0, /* no capslock */ |
120 | #endif |
121 | }; |
122 | |
123 | static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn"; |
124 | #define F_INITSTRING (1 << 0) /* -I initstring is set */ |
125 | #define F_LOCAL (1 << 1) /* -L force local */ |
126 | #define F_FAKEHOST (1 << 2) /* -H fake hostname */ |
127 | #define F_CUSTISSUE (1 << 3) /* -f give alternative issue file */ |
128 | #define F_RTSCTS (1 << 4) /* -h enable RTS/CTS flow control */ |
129 | #define F_ISSUE (1 << 5) /* -i display /etc/issue */ |
130 | #define F_LOGIN (1 << 6) /* -l non-default login program */ |
131 | #define F_PARSE (1 << 7) /* -m process modem status messages */ |
132 | #define F_TIMEOUT (1 << 8) /* -t time out */ |
133 | #define F_WAITCRLF (1 << 9) /* -w wait for CR or LF */ |
134 | #define F_NOPROMPT (1 << 10) /* -n don't ask for login name */ |
135 | |
136 | |
137 | #define line_buf bb_common_bufsiz1 |
138 | |
139 | /* The following is used for understandable diagnostics. */ |
140 | #ifdef DEBUGGING |
141 | static FILE *dbf; |
142 | #define DEBUGTERM "/dev/ttyp0" |
143 | #define debug(...) do { fprintf(dbf, __VA_ARGS__); fflush(dbf); } while (0) |
144 | #else |
145 | #define debug(...) ((void)0) |
146 | #endif |
147 | |
148 | |
149 | /* bcode - convert speed string to speed code; return <= 0 on failure */ |
150 | static int bcode(const char *s) |
151 | { |
152 | int value = bb_strtou(s, NULL, 10); /* yes, int is intended! */ |
153 | if (value < 0) /* bad terminating char, overflow, etc */ |
154 | return value; |
155 | return tty_value_to_baud(value); |
156 | } |
157 | |
158 | /* parse_speeds - parse alternate baud rates */ |
159 | static void parse_speeds(struct options *op, char *arg) |
160 | { |
161 | char *cp; |
162 | |
163 | /* NB: at least one iteration is always done */ |
164 | debug("entered parse_speeds\n"); |
165 | while ((cp = strsep(&arg, ",")) != NULL) { |
166 | op->speeds[op->numspeed] = bcode(cp); |
167 | if (op->speeds[op->numspeed] <= 0) |
168 | bb_error_msg_and_die("bad speed: %s", cp); |
169 | op->numspeed++; |
170 | if (op->numspeed > MAX_SPEED) |
171 | bb_error_msg_and_die("too many alternate speeds"); |
172 | } |
173 | debug("exiting parse_speeds\n"); |
174 | } |
175 | |
176 | /* parse_args - parse command-line arguments */ |
177 | static void parse_args(char **argv, struct options *op, char **fakehost_p) |
178 | { |
179 | char *ts; |
180 | |
181 | opt_complementary = "-2:t+"; /* at least 2 args; -t N */ |
182 | op->flags = getopt32(argv, opt_string, |
183 | &(op->initstring), fakehost_p, &(op->issue), |
184 | &(op->login), &op->timeout); |
185 | argv += optind; |
186 | if (op->flags & F_INITSTRING) { |
187 | const char *p = op->initstring; |
188 | char *q; |
189 | |
190 | op->initstring = q = xstrdup(p); |
191 | /* copy optarg into op->initstring decoding \ddd |
192 | octal codes into chars */ |
193 | while (*p) { |
194 | if (*p == '\\') { |
195 | p++; |
196 | *q++ = bb_process_escape_sequence(&p); |
197 | } else { |
198 | *q++ = *p++; |
199 | } |
200 | } |
201 | *q = '\0'; |
202 | } |
203 | op->flags ^= F_ISSUE; /* invert flag "show /etc/issue" */ |
204 | debug("after getopt\n"); |
205 | |
206 | /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */ |
207 | op->tty = argv[0]; /* tty name */ |
208 | ts = argv[1]; /* baud rate(s) */ |
209 | if (isdigit(argv[0][0])) { |
210 | /* a number first, assume it's a speed (BSD style) */ |
211 | op->tty = ts; /* tty name is in argv[1] */ |
212 | ts = argv[0]; /* baud rate(s) */ |
213 | } |
214 | parse_speeds(op, ts); |
215 | |
216 | // TODO: if applet_name is set to "getty: TTY", bb_error_msg's get simpler! |
217 | // grep for "%s:" |
218 | |
219 | if (argv[2]) |
220 | xsetenv("TERM", argv[2]); |
221 | |
222 | debug("exiting parse_args\n"); |
223 | } |
224 | |
225 | /* open_tty - set up tty as standard { input, output, error } */ |
226 | static void open_tty(const char *tty) |
227 | { |
228 | /* Set up new standard input, unless we are given an already opened port. */ |
229 | if (NOT_LONE_DASH(tty)) { |
230 | // struct stat st; |
231 | // int cur_dir_fd; |
232 | // int fd; |
233 | |
234 | /* Sanity checks... */ |
235 | // cur_dir_fd = xopen(".", O_DIRECTORY | O_NONBLOCK); |
236 | // xchdir("/dev"); |
237 | // xstat(tty, &st); |
238 | // if ((st.st_mode & S_IFMT) != S_IFCHR) |
239 | // bb_error_msg_and_die("%s: not a character device", tty); |
240 | |
241 | if (tty[0] != '/') |
242 | tty = xasprintf("/dev/%s", tty); /* will leak it */ |
243 | |
244 | /* Open the tty as standard input. */ |
245 | debug("open(2)\n"); |
246 | close(0); |
247 | /*fd =*/ xopen(tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */ |
248 | |
249 | // /* Restore current directory */ |
250 | // fchdir(cur_dir_fd); |
251 | |
252 | /* Open the tty as standard input, continued */ |
253 | // xmove_fd(fd, 0); |
254 | // /* fd is >= cur_dir_fd, and cur_dir_fd gets closed too here: */ |
255 | // while (fd > 2) |
256 | // close(fd--); |
257 | |
258 | /* Set proper protections and ownership. */ |
259 | fchown(0, 0, 0); /* 0:0 */ |
260 | fchmod(0, 0620); /* crw--w---- */ |
261 | } else { |
262 | /* |
263 | * Standard input should already be connected to an open port. Make |
264 | * sure it is open for read/write. |
265 | */ |
266 | if ((fcntl(0, F_GETFL) & O_RDWR) != O_RDWR) |
267 | bb_error_msg_and_die("stdin is not open for read/write"); |
268 | } |
269 | } |
270 | |
271 | /* termios_init - initialize termios settings */ |
272 | static void termios_init(struct termios *tp, int speed, struct options *op) |
273 | { |
274 | /* |
275 | * Initial termios settings: 8-bit characters, raw-mode, blocking i/o. |
276 | * Special characters are set after we have read the login name; all |
277 | * reads will be done in raw mode anyway. Errors will be dealt with |
278 | * later on. |
279 | */ |
280 | #ifdef __linux__ |
281 | /* flush input and output queues, important for modems! */ |
282 | ioctl(0, TCFLSH, TCIOFLUSH); /* tcflush(0, TCIOFLUSH)? - same */ |
283 | #endif |
284 | |
285 | tp->c_cflag = CS8 | HUPCL | CREAD | speed; |
286 | if (op->flags & F_LOCAL) |
287 | tp->c_cflag |= CLOCAL; |
288 | |
289 | tp->c_iflag = tp->c_lflag = tp->c_line = 0; |
290 | tp->c_oflag = OPOST | ONLCR; |
291 | tp->c_cc[VMIN] = 1; |
292 | tp->c_cc[VTIME] = 0; |
293 | |
294 | /* Optionally enable hardware flow control */ |
295 | #ifdef CRTSCTS |
296 | if (op->flags & F_RTSCTS) |
297 | tp->c_cflag |= CRTSCTS; |
298 | #endif |
299 | |
300 | tcsetattr_stdin_TCSANOW(tp); |
301 | |
302 | debug("term_io 2\n"); |
303 | } |
304 | |
305 | /* auto_baud - extract baud rate from modem status message */ |
306 | static void auto_baud(char *buf, unsigned size_buf, struct termios *tp) |
307 | { |
308 | int speed; |
309 | int vmin; |
310 | unsigned iflag; |
311 | char *bp; |
312 | int nread; |
313 | |
314 | /* |
315 | * This works only if the modem produces its status code AFTER raising |
316 | * the DCD line, and if the computer is fast enough to set the proper |
317 | * baud rate before the message has gone by. We expect a message of the |
318 | * following format: |
319 | * |
320 | * <junk><number><junk> |
321 | * |
322 | * The number is interpreted as the baud rate of the incoming call. If the |
323 | * modem does not tell us the baud rate within one second, we will keep |
324 | * using the current baud rate. It is advisable to enable BREAK |
325 | * processing (comma-separated list of baud rates) if the processing of |
326 | * modem status messages is enabled. |
327 | */ |
328 | |
329 | /* |
330 | * Use 7-bit characters, don't block if input queue is empty. Errors will |
331 | * be dealt with later on. |
332 | */ |
333 | iflag = tp->c_iflag; |
334 | tp->c_iflag |= ISTRIP; /* enable 8th-bit stripping */ |
335 | vmin = tp->c_cc[VMIN]; |
336 | tp->c_cc[VMIN] = 0; /* don't block if queue empty */ |
337 | tcsetattr_stdin_TCSANOW(tp); |
338 | |
339 | /* |
340 | * Wait for a while, then read everything the modem has said so far and |
341 | * try to extract the speed of the dial-in call. |
342 | */ |
343 | sleep(1); |
344 | nread = safe_read(STDIN_FILENO, buf, size_buf - 1); |
345 | if (nread > 0) { |
346 | buf[nread] = '\0'; |
347 | for (bp = buf; bp < buf + nread; bp++) { |
348 | if (isdigit(*bp)) { |
349 | speed = bcode(bp); |
350 | if (speed > 0) { |
351 | tp->c_cflag &= ~CBAUD; |
352 | tp->c_cflag |= speed; |
353 | } |
354 | break; |
355 | } |
356 | } |
357 | } |
358 | |
359 | /* Restore terminal settings. Errors will be dealt with later on. */ |
360 | tp->c_iflag = iflag; |
361 | tp->c_cc[VMIN] = vmin; |
362 | tcsetattr_stdin_TCSANOW(tp); |
363 | } |
364 | |
365 | /* do_prompt - show login prompt, optionally preceded by /etc/issue contents */ |
366 | static void do_prompt(struct options *op) |
367 | { |
368 | #ifdef ISSUE |
369 | print_login_issue(op->issue, op->tty); |
370 | #endif |
371 | print_login_prompt(); |
372 | } |
373 | |
374 | #ifdef HANDLE_ALLCAPS |
375 | /* all_is_upcase - string contains upper case without lower case */ |
376 | /* returns 1 if true, 0 if false */ |
377 | static int all_is_upcase(const char *s) |
378 | { |
379 | while (*s) |
380 | if (islower(*s++)) |
381 | return 0; |
382 | return 1; |
383 | } |
384 | #endif |
385 | |
386 | /* get_logname - get user name, establish parity, speed, erase, kill, eol; |
387 | * return NULL on BREAK, logname on success */ |
388 | static char *get_logname(char *logname, unsigned size_logname, |
389 | struct options *op, struct chardata *cp) |
390 | { |
391 | char *bp; |
392 | char c; /* input character, full eight bits */ |
393 | char ascval; /* low 7 bits of input character */ |
394 | int bits; /* # of "1" bits per character */ |
395 | int mask; /* mask with 1 bit up */ |
396 | static const char erase[][3] = {/* backspace-space-backspace */ |
397 | "\010\040\010", /* space parity */ |
398 | "\010\040\010", /* odd parity */ |
399 | "\210\240\210", /* even parity */ |
400 | "\010\040\010", /* 8 bit no parity */ |
401 | }; |
402 | |
403 | /* NB: *cp is pre-initialized with init_chardata */ |
404 | |
405 | /* Flush pending input (esp. after parsing or switching the baud rate). */ |
406 | sleep(1); |
407 | ioctl(0, TCFLSH, TCIFLUSH); /* tcflush(0, TCIOFLUSH)? - same */ |
408 | |
409 | /* Prompt for and read a login name. */ |
410 | logname[0] = '\0'; |
411 | while (!logname[0]) { |
412 | /* Write issue file and prompt, with "parity" bit == 0. */ |
413 | do_prompt(op); |
414 | |
415 | /* Read name, watch for break, parity, erase, kill, end-of-line. */ |
416 | bp = logname; |
417 | cp->eol = '\0'; |
418 | while (cp->eol == '\0') { |
419 | |
420 | /* Do not report trivial EINTR/EIO errors. */ |
421 | if (read(STDIN_FILENO, &c, 1) < 1) { |
422 | if (errno == EINTR || errno == EIO) |
423 | exit(EXIT_SUCCESS); |
424 | bb_perror_msg_and_die("%s: read", op->tty); |
425 | } |
426 | |
427 | /* BREAK. If we have speeds to try, |
428 | * return NULL (will switch speeds and return here) */ |
429 | if (c == '\0' && op->numspeed > 1) |
430 | return NULL; |
431 | |
432 | /* Do parity bit handling. */ |
433 | if (!(op->flags & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */ |
434 | bits = 1; |
435 | mask = 1; |
436 | while (mask & 0x7f) { |
437 | if (mask & c) |
438 | bits++; /* count "1" bits */ |
439 | mask <<= 1; |
440 | } |
441 | /* ... |= 2 - even, 1 - odd */ |
442 | cp->parity |= 2 - (bits & 1); |
443 | } |
444 | |
445 | /* Do erase, kill and end-of-line processing. */ |
446 | ascval = c & 0x7f; |
447 | switch (ascval) { |
448 | case CR: |
449 | case NL: |
450 | *bp = '\0'; /* terminate logname */ |
451 | cp->eol = ascval; /* set end-of-line char */ |
452 | break; |
453 | case BS: |
454 | case DEL: |
455 | #ifdef ANCIENT_BS_KILL_CHARS |
456 | case '#': |
457 | #endif |
458 | cp->erase = ascval; /* set erase character */ |
459 | if (bp > logname) { |
460 | full_write(STDOUT_FILENO, erase[cp->parity], 3); |
461 | bp--; |
462 | } |
463 | break; |
464 | case CTL('U'): |
465 | #ifdef ANCIENT_BS_KILL_CHARS |
466 | case '@': |
467 | #endif |
468 | cp->kill = ascval; /* set kill character */ |
469 | while (bp > logname) { |
470 | full_write(STDOUT_FILENO, erase[cp->parity], 3); |
471 | bp--; |
472 | } |
473 | break; |
474 | case CTL('D'): |
475 | exit(EXIT_SUCCESS); |
476 | default: |
477 | if (!isascii(ascval) || !isprint(ascval)) { |
478 | /* ignore garbage characters */ |
479 | } else if ((int)(bp - logname) >= size_logname - 1) { |
480 | bb_error_msg_and_die("%s: input overrun", op->tty); |
481 | } else { |
482 | full_write(STDOUT_FILENO, &c, 1); /* echo the character */ |
483 | *bp++ = ascval; /* and store it */ |
484 | } |
485 | break; |
486 | } |
487 | } |
488 | } |
489 | /* Handle names with upper case and no lower case. */ |
490 | |
491 | #ifdef HANDLE_ALLCAPS |
492 | cp->capslock = all_is_upcase(logname); |
493 | if (cp->capslock) { |
494 | for (bp = logname; *bp; bp++) |
495 | if (isupper(*bp)) |
496 | *bp = tolower(*bp); /* map name to lower case */ |
497 | } |
498 | #endif |
499 | return logname; |
500 | } |
501 | |
502 | /* termios_final - set the final tty mode bits */ |
503 | static void termios_final(struct options *op, struct termios *tp, struct chardata *cp) |
504 | { |
505 | /* General terminal-independent stuff. */ |
506 | tp->c_iflag |= IXON | IXOFF; /* 2-way flow control */ |
507 | tp->c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE; |
508 | /* no longer| ECHOCTL | ECHOPRT */ |
509 | tp->c_oflag |= OPOST; |
510 | /* tp->c_cflag = 0; */ |
511 | tp->c_cc[VINTR] = DEF_INTR; /* default interrupt */ |
512 | tp->c_cc[VQUIT] = DEF_QUIT; /* default quit */ |
513 | tp->c_cc[VEOF] = DEF_EOF; /* default EOF character */ |
514 | tp->c_cc[VEOL] = DEF_EOL; |
515 | tp->c_cc[VSWTC] = DEF_SWITCH; /* default switch character */ |
516 | |
517 | /* Account for special characters seen in input. */ |
518 | if (cp->eol == CR) { |
519 | tp->c_iflag |= ICRNL; /* map CR in input to NL */ |
520 | tp->c_oflag |= ONLCR; /* map NL in output to CR-NL */ |
521 | } |
522 | tp->c_cc[VERASE] = cp->erase; /* set erase character */ |
523 | tp->c_cc[VKILL] = cp->kill; /* set kill character */ |
524 | |
525 | /* Account for the presence or absence of parity bits in input. */ |
526 | switch (cp->parity) { |
527 | case 0: /* space (always 0) parity */ |
528 | // I bet most people go here - they use only 7-bit chars in usernames.... |
529 | break; |
530 | case 1: /* odd parity */ |
531 | tp->c_cflag |= PARODD; |
532 | /* FALLTHROUGH */ |
533 | case 2: /* even parity */ |
534 | tp->c_cflag |= PARENB; |
535 | tp->c_iflag |= INPCK | ISTRIP; |
536 | /* FALLTHROUGH */ |
537 | case (1 | 2): /* no parity bit */ |
538 | tp->c_cflag &= ~CSIZE; |
539 | tp->c_cflag |= CS7; |
540 | // FIXME: wtf? case 3: we saw both even and odd 8-bit bytes - |
541 | // it's probably some umlauts etc, but definitely NOT 7-bit!!! |
542 | // Entire parity detection madness here just begs for deletion... |
543 | break; |
544 | } |
545 | |
546 | /* Account for upper case without lower case. */ |
547 | #ifdef HANDLE_ALLCAPS |
548 | if (cp->capslock) { |
549 | tp->c_iflag |= IUCLC; |
550 | tp->c_lflag |= XCASE; |
551 | tp->c_oflag |= OLCUC; |
552 | } |
553 | #endif |
554 | /* Optionally enable hardware flow control */ |
555 | #ifdef CRTSCTS |
556 | if (op->flags & F_RTSCTS) |
557 | tp->c_cflag |= CRTSCTS; |
558 | #endif |
559 | |
560 | /* Finally, make the new settings effective */ |
561 | /* It's tcsetattr_stdin_TCSANOW() + error check */ |
562 | ioctl_or_perror_and_die(0, TCSETS, tp, "%s: TCSETS", op->tty); |
563 | } |
564 | |
565 | #if ENABLE_FEATURE_UTMP |
566 | static void touch(const char *filename) |
567 | { |
568 | if (access(filename, R_OK | W_OK) == -1) |
569 | close(open(filename, O_WRONLY | O_CREAT, 0664)); |
570 | } |
571 | |
572 | /* update_utmp - update our utmp entry */ |
573 | static void update_utmp(const char *line, char *fakehost) |
574 | { |
575 | struct utmp ut; |
576 | struct utmp *utp; |
577 | int mypid = getpid(); |
578 | |
579 | /* In case we won't find an entry below... */ |
580 | memset(&ut, 0, sizeof(ut)); |
581 | safe_strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id)); |
582 | |
583 | /* |
584 | * The utmp file holds miscellaneous information about things started by |
585 | * /sbin/init and other system-related events. Our purpose is to update |
586 | * the utmp entry for the current process, in particular the process type |
587 | * and the tty line we are listening to. Return successfully only if the |
588 | * utmp file can be opened for update, and if we are able to find our |
589 | * entry in the utmp file. |
590 | */ |
591 | touch(_PATH_UTMP); |
592 | |
593 | utmpname(_PATH_UTMP); |
594 | setutent(); |
595 | while ((utp = getutent()) != NULL) { |
596 | if (utp->ut_type == INIT_PROCESS && utp->ut_pid == mypid) { |
597 | memcpy(&ut, utp, sizeof(ut)); |
598 | break; |
599 | } |
600 | } |
601 | |
602 | strcpy(ut.ut_user, "LOGIN"); |
603 | safe_strncpy(ut.ut_line, line, sizeof(ut.ut_line)); |
604 | if (fakehost) |
605 | safe_strncpy(ut.ut_host, fakehost, sizeof(ut.ut_host)); |
606 | ut.ut_tv.tv_sec = time(NULL); |
607 | ut.ut_type = LOGIN_PROCESS; |
608 | ut.ut_pid = mypid; |
609 | |
610 | pututline(&ut); |
611 | endutent(); |
612 | |
613 | #if ENABLE_FEATURE_WTMP |
614 | touch(bb_path_wtmp_file); |
615 | updwtmp(bb_path_wtmp_file, &ut); |
616 | #endif |
617 | } |
618 | #endif /* CONFIG_FEATURE_UTMP */ |
619 | |
620 | int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
621 | int getty_main(int argc UNUSED_PARAM, char **argv) |
622 | { |
623 | int n; |
624 | char *fakehost = NULL; /* Fake hostname for ut_host */ |
625 | char *logname; /* login name, given to /bin/login */ |
626 | /* Merging these into "struct local" may _seem_ to reduce |
627 | * parameter passing, but today's gcc will inline |
628 | * statics which are called once anyway, so don't do that */ |
629 | struct chardata chardata; /* set by get_logname() */ |
630 | struct termios termios; /* terminal mode bits */ |
631 | struct options options; |
632 | |
633 | chardata = init_chardata; |
634 | |
635 | memset(&options, 0, sizeof(options)); |
636 | options.login = _PATH_LOGIN; /* default login program */ |
637 | options.tty = "tty1"; /* default tty line */ |
638 | options.initstring = ""; /* modem init string */ |
639 | #ifdef ISSUE |
640 | options.issue = ISSUE; /* default issue file */ |
641 | #endif |
642 | |
643 | /* Parse command-line arguments. */ |
644 | parse_args(argv, &options, &fakehost); |
645 | |
646 | logmode = LOGMODE_NONE; |
647 | |
648 | /* Create new session, lose controlling tty, if any */ |
649 | /* docs/ctty.htm says: |
650 | * "This is allowed only when the current process |
651 | * is not a process group leader" - is this a problem? */ |
652 | setsid(); |
653 | /* close stdio, and stray descriptors, just in case */ |
654 | n = xopen(bb_dev_null, O_RDWR); |
655 | /* dup2(n, 0); - no, we need to handle "getty - 9600" too */ |
656 | xdup2(n, 1); |
657 | xdup2(n, 2); |
658 | while (n > 2) |
659 | close(n--); |
660 | |
661 | /* Logging. We want special flavor of error_msg_and_die */ |
662 | die_sleep = 10; |
663 | msg_eol = "\r\n"; |
664 | /* most likely will internally use fd #3 in CLOEXEC mode: */ |
665 | openlog(applet_name, LOG_PID, LOG_AUTH); |
666 | logmode = LOGMODE_BOTH; |
667 | |
668 | #ifdef DEBUGGING |
669 | dbf = xfopen_for_write(DEBUGTERM); |
670 | for (n = 1; argv[n]; n++) { |
671 | debug(argv[n]); |
672 | debug("\n"); |
673 | } |
674 | #endif |
675 | |
676 | /* Open the tty as standard input, if it is not "-" */ |
677 | /* If it's not "-" and not taken yet, it will become our ctty */ |
678 | debug("calling open_tty\n"); |
679 | open_tty(options.tty); |
680 | ndelay_off(0); |
681 | debug("duping\n"); |
682 | xdup2(0, 1); |
683 | xdup2(0, 2); |
684 | |
685 | /* |
686 | * The following ioctl will fail if stdin is not a tty, but also when |
687 | * there is noise on the modem control lines. In the latter case, the |
688 | * common course of action is (1) fix your cables (2) give the modem more |
689 | * time to properly reset after hanging up. SunOS users can achieve (2) |
690 | * by patching the SunOS kernel variable "zsadtrlow" to a larger value; |
691 | * 5 seconds seems to be a good value. |
692 | */ |
693 | /* tcgetattr() + error check */ |
694 | ioctl_or_perror_and_die(0, TCGETS, &termios, "%s: TCGETS", options.tty); |
695 | |
696 | #ifdef __linux__ |
697 | // FIXME: do we need this? Otherwise "-" case seems to be broken... |
698 | // /* Forcibly make fd 0 our controlling tty, even if another session |
699 | // * has it as a ctty. (Another session loses ctty). */ |
700 | // ioctl(0, TIOCSCTTY, (void*)1); |
701 | /* Make ourself a foreground process group within our session */ |
702 | tcsetpgrp(0, getpid()); |
703 | #endif |
704 | |
705 | #if ENABLE_FEATURE_UTMP |
706 | /* Update the utmp file. This tty is ours now! */ |
707 | update_utmp(options.tty, fakehost); |
708 | #endif |
709 | |
710 | /* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */ |
711 | debug("calling termios_init\n"); |
712 | termios_init(&termios, options.speeds[0], &options); |
713 | |
714 | /* Write the modem init string and DON'T flush the buffers */ |
715 | if (options.flags & F_INITSTRING) { |
716 | debug("writing init string\n"); |
717 | full_write(STDOUT_FILENO, options.initstring, strlen(options.initstring)); |
718 | } |
719 | |
720 | /* Optionally detect the baud rate from the modem status message */ |
721 | debug("before autobaud\n"); |
722 | if (options.flags & F_PARSE) |
723 | auto_baud(line_buf, sizeof(line_buf), &termios); |
724 | |
725 | /* Set the optional timer */ |
726 | alarm(options.timeout); /* if 0, alarm is not set */ |
727 | |
728 | /* Optionally wait for CR or LF before writing /etc/issue */ |
729 | if (options.flags & F_WAITCRLF) { |
730 | char ch; |
731 | |
732 | debug("waiting for cr-lf\n"); |
733 | while (safe_read(STDIN_FILENO, &ch, 1) == 1) { |
734 | debug("read %x\n", (unsigned char)ch); |
735 | ch &= 0x7f; /* strip "parity bit" */ |
736 | if (ch == '\n' || ch == '\r') |
737 | break; |
738 | } |
739 | } |
740 | |
741 | logname = NULL; |
742 | if (!(options.flags & F_NOPROMPT)) { |
743 | /* NB:termios_init already set line speed |
744 | * to options.speeds[0] */ |
745 | int baud_index = 0; |
746 | |
747 | while (1) { |
748 | /* Read the login name. */ |
749 | debug("reading login name\n"); |
750 | logname = get_logname(line_buf, sizeof(line_buf), |
751 | &options, &chardata); |
752 | if (logname) |
753 | break; |
754 | /* we are here only if options.numspeed > 1 */ |
755 | baud_index = (baud_index + 1) % options.numspeed; |
756 | termios.c_cflag &= ~CBAUD; |
757 | termios.c_cflag |= options.speeds[baud_index]; |
758 | tcsetattr_stdin_TCSANOW(&termios); |
759 | } |
760 | } |
761 | |
762 | /* Disable timer. */ |
763 | alarm(0); |
764 | |
765 | /* Finalize the termios settings. */ |
766 | termios_final(&options, &termios, &chardata); |
767 | |
768 | /* Now the newline character should be properly written. */ |
769 | full_write(STDOUT_FILENO, "\n", 1); |
770 | |
771 | /* Let the login program take care of password validation. */ |
772 | /* We use PATH because we trust that root doesn't set "bad" PATH, |
773 | * and getty is not suid-root applet. */ |
774 | /* With -n, logname == NULL, and login will ask for username instead */ |
775 | BB_EXECLP(options.login, options.login, "--", logname, NULL); |
776 | bb_error_msg_and_die("%s: can't exec %s", options.tty, options.login); |
777 | } |