source: MondoRescue/branches/3.2/mindi-busybox/miscutils/chat.c@ 3186

Last change on this file since 3186 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
  • Property svn:eol-style set to native
File size: 10.6 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * bare bones chat utility
4 * inspired by ppp's chat
5 *
6 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
7 *
8 * Licensed under GPLv2, see file LICENSE in this source tree.
9 */
10#include "libbb.h"
11
12// default timeout: 45 sec
13#define DEFAULT_CHAT_TIMEOUT 45*1000
14// max length of "abort string",
15// i.e. device reply which causes termination
16#define MAX_ABORT_LEN 50
17
18// possible exit codes
19enum {
20 ERR_OK = 0, // all's well
21 ERR_MEM, // read too much while expecting
22 ERR_IO, // signalled or I/O error
23 ERR_TIMEOUT, // timed out while expecting
24 ERR_ABORT, // first abort condition was met
25// ERR_ABORT2, // second abort condition was met
26// ...
27};
28
29// exit code
30#define exitcode bb_got_signal
31
32// trap for critical signals
33static void signal_handler(UNUSED_PARAM int signo)
34{
35 // report I/O error condition
36 exitcode = ERR_IO;
37}
38
39#if !ENABLE_FEATURE_CHAT_IMPLICIT_CR
40#define unescape(s, nocr) unescape(s)
41#endif
42static size_t unescape(char *s, int *nocr)
43{
44 char *start = s;
45 char *p = s;
46
47 while (*s) {
48 char c = *s;
49 // do we need special processing?
50 // standard escapes + \s for space and \N for \0
51 // \c inhibits terminating \r for commands and is noop for expects
52 if ('\\' == c) {
53 c = *++s;
54 if (c) {
55#if ENABLE_FEATURE_CHAT_IMPLICIT_CR
56 if ('c' == c) {
57 *nocr = 1;
58 goto next;
59 }
60#endif
61 if ('N' == c) {
62 c = '\0';
63 } else if ('s' == c) {
64 c = ' ';
65#if ENABLE_FEATURE_CHAT_NOFAIL
66 // unescape leading dash only
67 // TODO: and only for expect, not command string
68 } else if ('-' == c && (start + 1 == s)) {
69 //c = '-';
70#endif
71 } else {
72 c = bb_process_escape_sequence((const char **)&s);
73 s--;
74 }
75 }
76 // ^A becomes \001, ^B -- \002 and so on...
77 } else if ('^' == c) {
78 c = *++s-'@';
79 }
80 // put unescaped char
81 *p++ = c;
82#if ENABLE_FEATURE_CHAT_IMPLICIT_CR
83 next:
84#endif
85 // next char
86 s++;
87 }
88 *p = '\0';
89
90 return p - start;
91}
92
93int chat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
94int chat_main(int argc UNUSED_PARAM, char **argv)
95{
96 int record_fd = -1;
97 bool echo = 0;
98 // collection of device replies which cause unconditional termination
99 llist_t *aborts = NULL;
100 // inactivity period
101 int timeout = DEFAULT_CHAT_TIMEOUT;
102 // maximum length of abort string
103#if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN
104 size_t max_abort_len = 0;
105#else
106#define max_abort_len MAX_ABORT_LEN
107#endif
108#if ENABLE_FEATURE_CHAT_TTY_HIFI
109 struct termios tio0, tio;
110#endif
111 // directive names
112 enum {
113 DIR_HANGUP = 0,
114 DIR_ABORT,
115#if ENABLE_FEATURE_CHAT_CLR_ABORT
116 DIR_CLR_ABORT,
117#endif
118 DIR_TIMEOUT,
119 DIR_ECHO,
120 DIR_SAY,
121 DIR_RECORD,
122 };
123
124 // make x* functions fail with correct exitcode
125 xfunc_error_retval = ERR_IO;
126
127 // trap vanilla signals to prevent process from being killed suddenly
128 bb_signals(0
129 + (1 << SIGHUP)
130 + (1 << SIGINT)
131 + (1 << SIGTERM)
132 + (1 << SIGPIPE)
133 , signal_handler);
134
135#if ENABLE_FEATURE_CHAT_TTY_HIFI
136 tcgetattr(STDIN_FILENO, &tio);
137 tio0 = tio;
138 cfmakeraw(&tio);
139 tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio);
140#endif
141
142#if ENABLE_FEATURE_CHAT_SWALLOW_OPTS
143 getopt32(argv, "vVsSE");
144 argv += optind;
145#else
146 argv++; // goto first arg
147#endif
148 // handle chat expect-send pairs
149 while (*argv) {
150 // directive given? process it
151 int key = index_in_strings(
152 "HANGUP\0" "ABORT\0"
153#if ENABLE_FEATURE_CHAT_CLR_ABORT
154 "CLR_ABORT\0"
155#endif
156 "TIMEOUT\0" "ECHO\0" "SAY\0" "RECORD\0"
157 , *argv
158 );
159 if (key >= 0) {
160 // cache directive value
161 char *arg = *++argv;
162 // OFF -> 0, anything else -> 1
163 bool onoff = (0 != strcmp("OFF", arg));
164 // process directive
165 if (DIR_HANGUP == key) {
166 // turn SIGHUP on/off
167 signal(SIGHUP, onoff ? signal_handler : SIG_IGN);
168 } else if (DIR_ABORT == key) {
169 // append the string to abort conditions
170#if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN
171 size_t len = strlen(arg);
172 if (len > max_abort_len)
173 max_abort_len = len;
174#endif
175 llist_add_to_end(&aborts, arg);
176#if ENABLE_FEATURE_CHAT_CLR_ABORT
177 } else if (DIR_CLR_ABORT == key) {
178 llist_t *l;
179 // remove the string from abort conditions
180 // N.B. gotta refresh maximum length too...
181# if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN
182 max_abort_len = 0;
183# endif
184 for (l = aborts; l; l = l->link) {
185# if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN
186 size_t len = strlen(l->data);
187# endif
188 if (strcmp(arg, l->data) == 0) {
189 llist_unlink(&aborts, l);
190 continue;
191 }
192# if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN
193 if (len > max_abort_len)
194 max_abort_len = len;
195# endif
196 }
197#endif
198 } else if (DIR_TIMEOUT == key) {
199 // set new timeout
200 // -1 means OFF
201 timeout = atoi(arg) * 1000;
202 // 0 means default
203 // >0 means value in msecs
204 if (!timeout)
205 timeout = DEFAULT_CHAT_TIMEOUT;
206 } else if (DIR_ECHO == key) {
207 // turn echo on/off
208 // N.B. echo means dumping device input/output to stderr
209 echo = onoff;
210 } else if (DIR_RECORD == key) {
211 // turn record on/off
212 // N.B. record means dumping device input to a file
213 // close previous record_fd
214 if (record_fd > 0)
215 close(record_fd);
216 // N.B. do we have to die here on open error?
217 record_fd = (onoff) ? xopen(arg, O_WRONLY|O_CREAT|O_TRUNC) : -1;
218 } else if (DIR_SAY == key) {
219 // just print argument verbatim
220 // TODO: should we use full_write() to avoid unistd/stdio conflict?
221 bb_error_msg("%s", arg);
222 }
223 // next, please!
224 argv++;
225 // ordinary expect-send pair!
226 } else {
227 //-----------------------
228 // do expect
229 //-----------------------
230 int expect_len;
231 size_t buf_len = 0;
232 size_t max_len = max_abort_len;
233
234 struct pollfd pfd;
235#if ENABLE_FEATURE_CHAT_NOFAIL
236 int nofail = 0;
237#endif
238 char *expect = *argv++;
239
240 // sanity check: shall we really expect something?
241 if (!expect)
242 goto expect_done;
243
244#if ENABLE_FEATURE_CHAT_NOFAIL
245 // if expect starts with -
246 if ('-' == *expect) {
247 // swallow -
248 expect++;
249 // and enter nofail mode
250 nofail++;
251 }
252#endif
253
254#ifdef ___TEST___BUF___ // test behaviour with a small buffer
255# undef COMMON_BUFSIZE
256# define COMMON_BUFSIZE 6
257#endif
258 // expand escape sequences in expect
259 expect_len = unescape(expect, &expect_len /*dummy*/);
260 if (expect_len > max_len)
261 max_len = expect_len;
262 // sanity check:
263 // we should expect more than nothing but not more than input buffer
264 // TODO: later we'll get rid of fixed-size buffer
265 if (!expect_len)
266 goto expect_done;
267 if (max_len >= COMMON_BUFSIZE) {
268 exitcode = ERR_MEM;
269 goto expect_done;
270 }
271
272 // get reply
273 pfd.fd = STDIN_FILENO;
274 pfd.events = POLLIN;
275 while (!exitcode
276 && poll(&pfd, 1, timeout) > 0
277 && (pfd.revents & POLLIN)
278 ) {
279#define buf bb_common_bufsiz1
280 llist_t *l;
281 ssize_t delta;
282
283 // read next char from device
284 if (safe_read(STDIN_FILENO, buf+buf_len, 1) > 0) {
285 // dump device input if RECORD fname
286 if (record_fd > 0) {
287 full_write(record_fd, buf+buf_len, 1);
288 }
289 // dump device input if ECHO ON
290 if (echo > 0) {
291// if (buf[buf_len] < ' ') {
292// full_write(STDERR_FILENO, "^", 1);
293// buf[buf_len] += '@';
294// }
295 full_write(STDERR_FILENO, buf+buf_len, 1);
296 }
297 buf_len++;
298 // move input frame if we've reached higher bound
299 if (buf_len > COMMON_BUFSIZE) {
300 memmove(buf, buf+buf_len-max_len, max_len);
301 buf_len = max_len;
302 }
303 }
304 // N.B. rule of thumb: values being looked for can
305 // be found only at the end of input buffer
306 // this allows to get rid of strstr() and memmem()
307
308 // TODO: make expect and abort strings processed uniformly
309 // abort condition is met? -> bail out
310 for (l = aborts, exitcode = ERR_ABORT; l; l = l->link, ++exitcode) {
311 size_t len = strlen(l->data);
312 delta = buf_len-len;
313 if (delta >= 0 && !memcmp(buf+delta, l->data, len))
314 goto expect_done;
315 }
316 exitcode = ERR_OK;
317
318 // expected reply received? -> goto next command
319 delta = buf_len - expect_len;
320 if (delta >= 0 && !memcmp(buf+delta, expect, expect_len))
321 goto expect_done;
322#undef buf
323 } /* while (have data) */
324
325 // device timed out or unexpected reply received
326 exitcode = ERR_TIMEOUT;
327 expect_done:
328#if ENABLE_FEATURE_CHAT_NOFAIL
329 // on success and when in nofail mode
330 // we should skip following subsend-subexpect pairs
331 if (nofail) {
332 if (!exitcode) {
333 // find last send before non-dashed expect
334 while (*argv && argv[1] && '-' == argv[1][0])
335 argv += 2;
336 // skip the pair
337 // N.B. do we really need this?!
338 if (!*argv++ || !*argv++)
339 break;
340 }
341 // nofail mode also clears all but IO errors (or signals)
342 if (ERR_IO != exitcode)
343 exitcode = ERR_OK;
344 }
345#endif
346 // bail out unless we expected successfully
347 if (exitcode)
348 break;
349
350 //-----------------------
351 // do send
352 //-----------------------
353 if (*argv) {
354#if ENABLE_FEATURE_CHAT_IMPLICIT_CR
355 int nocr = 0; // inhibit terminating command with \r
356#endif
357 char *loaded = NULL; // loaded command
358 size_t len;
359 char *buf = *argv++;
360
361 // if command starts with @
362 // load "real" command from file named after @
363 if ('@' == *buf) {
364 // skip the @ and any following white-space
365 trim(++buf);
366 buf = loaded = xmalloc_xopen_read_close(buf, NULL);
367 }
368 // expand escape sequences in command
369 len = unescape(buf, &nocr);
370
371 // send command
372 alarm(timeout);
373 pfd.fd = STDOUT_FILENO;
374 pfd.events = POLLOUT;
375 while (len && !exitcode
376 && poll(&pfd, 1, -1) > 0
377 && (pfd.revents & POLLOUT)
378 ) {
379#if ENABLE_FEATURE_CHAT_SEND_ESCAPES
380 // "\\d" means 1 sec delay, "\\p" means 0.01 sec delay
381 // "\\K" means send BREAK
382 char c = *buf;
383 if ('\\' == c) {
384 c = *++buf;
385 if ('d' == c) {
386 sleep(1);
387 len--;
388 continue;
389 }
390 if ('p' == c) {
391 usleep(10000);
392 len--;
393 continue;
394 }
395 if ('K' == c) {
396 tcsendbreak(STDOUT_FILENO, 0);
397 len--;
398 continue;
399 }
400 buf--;
401 }
402 if (safe_write(STDOUT_FILENO, buf, 1) != 1)
403 break;
404 len--;
405 buf++;
406#else
407 len -= full_write(STDOUT_FILENO, buf, len);
408#endif
409 } /* while (can write) */
410 alarm(0);
411
412 // report I/O error if there still exists at least one non-sent char
413 if (len)
414 exitcode = ERR_IO;
415
416 // free loaded command (if any)
417 if (loaded)
418 free(loaded);
419#if ENABLE_FEATURE_CHAT_IMPLICIT_CR
420 // or terminate command with \r (if not inhibited)
421 else if (!nocr)
422 xwrite(STDOUT_FILENO, "\r", 1);
423#endif
424 // bail out unless we sent command successfully
425 if (exitcode)
426 break;
427 } /* if (*argv) */
428 }
429 } /* while (*argv) */
430
431#if ENABLE_FEATURE_CHAT_TTY_HIFI
432 tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0);
433#endif
434
435 return exitcode;
436}
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