Contents of /trunk/mkinitrd-magellan/busybox/miscutils/chat.c
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Sun May 30 11:32:42 2010 UTC (14 years, 4 months ago) by niro
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Sun May 30 11:32:42 2010 UTC (14 years, 4 months ago) by niro
File MIME type: text/plain
File size: 10846 byte(s)
-updated to busybox-1.16.1 and enabled blkid/uuid support in default config
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 tarball for details. |
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 |
19 | enum { |
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 |
33 | static 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 |
42 | static 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 | |
93 | int chat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
94 | int 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 | // remove the string from abort conditions |
179 | // N.B. gotta refresh maximum length too... |
180 | #if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN |
181 | max_abort_len = 0; |
182 | #endif |
183 | for (llist_t *l = aborts; l; l = l->link) { |
184 | #if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN |
185 | size_t len = strlen(l->data); |
186 | #endif |
187 | if (!strcmp(arg, l->data)) { |
188 | llist_unlink(&aborts, l); |
189 | continue; |
190 | } |
191 | #if ENABLE_FEATURE_CHAT_VAR_ABORT_LEN |
192 | if (len > max_abort_len) |
193 | max_abort_len = len; |
194 | #endif |
195 | } |
196 | #endif |
197 | } else if (DIR_TIMEOUT == key) { |
198 | // set new timeout |
199 | // -1 means OFF |
200 | timeout = atoi(arg) * 1000; |
201 | // 0 means default |
202 | // >0 means value in msecs |
203 | if (!timeout) |
204 | timeout = DEFAULT_CHAT_TIMEOUT; |
205 | } else if (DIR_ECHO == key) { |
206 | // turn echo on/off |
207 | // N.B. echo means dumping device input/output to stderr |
208 | echo = onoff; |
209 | } else if (DIR_RECORD == key) { |
210 | // turn record on/off |
211 | // N.B. record means dumping device input to a file |
212 | // close previous record_fd |
213 | if (record_fd > 0) |
214 | close(record_fd); |
215 | // N.B. do we have to die here on open error? |
216 | record_fd = (onoff) ? xopen(arg, O_WRONLY|O_CREAT|O_TRUNC) : -1; |
217 | } else if (DIR_SAY == key) { |
218 | // just print argument verbatim |
219 | // TODO: should we use full_write() to avoid unistd/stdio conflict? |
220 | bb_error_msg("%s", arg); |
221 | } |
222 | // next, please! |
223 | argv++; |
224 | // ordinary expect-send pair! |
225 | } else { |
226 | //----------------------- |
227 | // do expect |
228 | //----------------------- |
229 | int expect_len; |
230 | size_t buf_len = 0; |
231 | size_t max_len = max_abort_len; |
232 | |
233 | struct pollfd pfd; |
234 | #if ENABLE_FEATURE_CHAT_NOFAIL |
235 | int nofail = 0; |
236 | #endif |
237 | char *expect = *argv++; |
238 | |
239 | // sanity check: shall we really expect something? |
240 | if (!expect) |
241 | goto expect_done; |
242 | |
243 | #if ENABLE_FEATURE_CHAT_NOFAIL |
244 | // if expect starts with - |
245 | if ('-' == *expect) { |
246 | // swallow - |
247 | expect++; |
248 | // and enter nofail mode |
249 | nofail++; |
250 | } |
251 | #endif |
252 | |
253 | #ifdef ___TEST___BUF___ // test behaviour with a small buffer |
254 | # undef COMMON_BUFSIZE |
255 | # define COMMON_BUFSIZE 6 |
256 | #endif |
257 | // expand escape sequences in expect |
258 | expect_len = unescape(expect, &expect_len /*dummy*/); |
259 | if (expect_len > max_len) |
260 | max_len = expect_len; |
261 | // sanity check: |
262 | // we should expect more than nothing but not more than input buffer |
263 | // TODO: later we'll get rid of fixed-size buffer |
264 | if (!expect_len) |
265 | goto expect_done; |
266 | if (max_len >= COMMON_BUFSIZE) { |
267 | exitcode = ERR_MEM; |
268 | goto expect_done; |
269 | } |
270 | |
271 | // get reply |
272 | pfd.fd = STDIN_FILENO; |
273 | pfd.events = POLLIN; |
274 | while (!exitcode |
275 | && poll(&pfd, 1, timeout) > 0 |
276 | && (pfd.revents & POLLIN) |
277 | ) { |
278 | #define buf bb_common_bufsiz1 |
279 | llist_t *l; |
280 | ssize_t delta; |
281 | |
282 | // read next char from device |
283 | if (safe_read(STDIN_FILENO, buf+buf_len, 1) > 0) { |
284 | // dump device input if RECORD fname |
285 | if (record_fd > 0) { |
286 | full_write(record_fd, buf+buf_len, 1); |
287 | } |
288 | // dump device input if ECHO ON |
289 | if (echo > 0) { |
290 | // if (buf[buf_len] < ' ') { |
291 | // full_write(STDERR_FILENO, "^", 1); |
292 | // buf[buf_len] += '@'; |
293 | // } |
294 | full_write(STDERR_FILENO, buf+buf_len, 1); |
295 | } |
296 | buf_len++; |
297 | // move input frame if we've reached higher bound |
298 | if (buf_len > COMMON_BUFSIZE) { |
299 | memmove(buf, buf+buf_len-max_len, max_len); |
300 | buf_len = max_len; |
301 | } |
302 | } |
303 | // N.B. rule of thumb: values being looked for can |
304 | // be found only at the end of input buffer |
305 | // this allows to get rid of strstr() and memmem() |
306 | |
307 | // TODO: make expect and abort strings processed uniformly |
308 | // abort condition is met? -> bail out |
309 | for (l = aborts, exitcode = ERR_ABORT; l; l = l->link, ++exitcode) { |
310 | size_t len = strlen(l->data); |
311 | delta = buf_len-len; |
312 | if (delta >= 0 && !memcmp(buf+delta, l->data, len)) |
313 | goto expect_done; |
314 | } |
315 | exitcode = ERR_OK; |
316 | |
317 | // expected reply received? -> goto next command |
318 | delta = buf_len - expect_len; |
319 | if (delta >= 0 && !memcmp(buf+delta, expect, expect_len)) |
320 | goto expect_done; |
321 | #undef buf |
322 | } /* while (have data) */ |
323 | |
324 | // device timed out or unexpected reply received |
325 | exitcode = ERR_TIMEOUT; |
326 | expect_done: |
327 | #if ENABLE_FEATURE_CHAT_NOFAIL |
328 | // on success and when in nofail mode |
329 | // we should skip following subsend-subexpect pairs |
330 | if (nofail) { |
331 | if (!exitcode) { |
332 | // find last send before non-dashed expect |
333 | while (*argv && argv[1] && '-' == argv[1][0]) |
334 | argv += 2; |
335 | // skip the pair |
336 | // N.B. do we really need this?! |
337 | if (!*argv++ || !*argv++) |
338 | break; |
339 | } |
340 | // nofail mode also clears all but IO errors (or signals) |
341 | if (ERR_IO != exitcode) |
342 | exitcode = ERR_OK; |
343 | } |
344 | #endif |
345 | // bail out unless we expected successfully |
346 | if (exitcode) |
347 | break; |
348 | |
349 | //----------------------- |
350 | // do send |
351 | //----------------------- |
352 | if (*argv) { |
353 | #if ENABLE_FEATURE_CHAT_IMPLICIT_CR |
354 | int nocr = 0; // inhibit terminating command with \r |
355 | #endif |
356 | char *loaded = NULL; // loaded command |
357 | size_t len; |
358 | char *buf = *argv++; |
359 | |
360 | // if command starts with @ |
361 | // load "real" command from file named after @ |
362 | if ('@' == *buf) { |
363 | // skip the @ and any following white-space |
364 | trim(++buf); |
365 | buf = loaded = xmalloc_xopen_read_close(buf, NULL); |
366 | } |
367 | // expand escape sequences in command |
368 | len = unescape(buf, &nocr); |
369 | |
370 | // send command |
371 | alarm(timeout); |
372 | pfd.fd = STDOUT_FILENO; |
373 | pfd.events = POLLOUT; |
374 | while (len && !exitcode |
375 | && poll(&pfd, 1, -1) > 0 |
376 | && (pfd.revents & POLLOUT) |
377 | ) { |
378 | #if ENABLE_FEATURE_CHAT_SEND_ESCAPES |
379 | // "\\d" means 1 sec delay, "\\p" means 0.01 sec delay |
380 | // "\\K" means send BREAK |
381 | char c = *buf; |
382 | if ('\\' == c) { |
383 | c = *++buf; |
384 | if ('d' == c) { |
385 | sleep(1); |
386 | len--; |
387 | continue; |
388 | } |
389 | if ('p' == c) { |
390 | usleep(10000); |
391 | len--; |
392 | continue; |
393 | } |
394 | if ('K' == c) { |
395 | tcsendbreak(STDOUT_FILENO, 0); |
396 | len--; |
397 | continue; |
398 | } |
399 | buf--; |
400 | } |
401 | if (safe_write(STDOUT_FILENO, buf, 1) != 1) |
402 | break; |
403 | len--; |
404 | buf++; |
405 | #else |
406 | len -= full_write(STDOUT_FILENO, buf, len); |
407 | #endif |
408 | } /* while (can write) */ |
409 | alarm(0); |
410 | |
411 | // report I/O error if there still exists at least one non-sent char |
412 | if (len) |
413 | exitcode = ERR_IO; |
414 | |
415 | // free loaded command (if any) |
416 | if (loaded) |
417 | free(loaded); |
418 | #if ENABLE_FEATURE_CHAT_IMPLICIT_CR |
419 | // or terminate command with \r (if not inhibited) |
420 | else if (!nocr) |
421 | xwrite(STDOUT_FILENO, "\r", 1); |
422 | #endif |
423 | // bail out unless we sent command successfully |
424 | if (exitcode) |
425 | break; |
426 | } /* if (*argv) */ |
427 | } |
428 | } /* while (*argv) */ |
429 | |
430 | #if ENABLE_FEATURE_CHAT_TTY_HIFI |
431 | tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio0); |
432 | #endif |
433 | |
434 | return exitcode; |
435 | } |