blob: 98d862744432d25be36bceeac57e3de12a612a5f
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Adapted from ash applet code |
4 | * |
5 | * This code is derived from software contributed to Berkeley by |
6 | * Kenneth Almquist. |
7 | * |
8 | * Copyright (c) 1989, 1991, 1993, 1994 |
9 | * The Regents of the University of California. All rights reserved. |
10 | * |
11 | * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au> |
12 | * was re-ported from NetBSD and debianized. |
13 | * |
14 | * Copyright (c) 2010 Denys Vlasenko |
15 | * Split from ash.c |
16 | * |
17 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
18 | */ |
19 | #include "libbb.h" |
20 | #include "shell_common.h" |
21 | #include <sys/resource.h> /* getrlimit */ |
22 | |
23 | const char defifsvar[] ALIGN1 = "IFS= \t\n"; |
24 | const char defoptindvar[] ALIGN1 = "OPTIND=1"; |
25 | |
26 | |
27 | int FAST_FUNC is_well_formed_var_name(const char *s, char terminator) |
28 | { |
29 | if (!s || !(isalpha(*s) || *s == '_')) |
30 | return 0; |
31 | |
32 | do |
33 | s++; |
34 | while (isalnum(*s) || *s == '_'); |
35 | |
36 | return *s == terminator; |
37 | } |
38 | |
39 | /* read builtin */ |
40 | |
41 | /* Needs to be interruptible: shell must handle traps and shell-special signals |
42 | * while inside read. To implement this, be sure to not loop on EINTR |
43 | * and return errno == EINTR reliably. |
44 | */ |
45 | //TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL" |
46 | //string. hush naturally has it, and ash has setvareq(). |
47 | //Here we can simply store "VAR=" at buffer start and store read data directly |
48 | //after "=", then pass buffer to setvar() to consume. |
49 | const char* FAST_FUNC |
50 | shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val), |
51 | char **argv, |
52 | const char *ifs, |
53 | int read_flags, |
54 | const char *opt_n, |
55 | const char *opt_p, |
56 | const char *opt_t, |
57 | const char *opt_u |
58 | ) |
59 | { |
60 | unsigned err; |
61 | unsigned end_ms; /* -t TIMEOUT */ |
62 | int fd; /* -u FD */ |
63 | int nchars; /* -n NUM */ |
64 | char **pp; |
65 | char *buffer; |
66 | struct termios tty, old_tty; |
67 | const char *retval; |
68 | int bufpos; /* need to be able to hold -1 */ |
69 | int startword; |
70 | smallint backslash; |
71 | |
72 | errno = err = 0; |
73 | |
74 | pp = argv; |
75 | while (*pp) { |
76 | if (!is_well_formed_var_name(*pp, '\0')) { |
77 | /* Mimic bash message */ |
78 | bb_error_msg("read: '%s': not a valid identifier", *pp); |
79 | return (const char *)(uintptr_t)1; |
80 | } |
81 | pp++; |
82 | } |
83 | |
84 | nchars = 0; /* if != 0, -n is in effect */ |
85 | if (opt_n) { |
86 | nchars = bb_strtou(opt_n, NULL, 10); |
87 | if (nchars < 0 || errno) |
88 | return "invalid count"; |
89 | /* note: "-n 0": off (bash 3.2 does this too) */ |
90 | } |
91 | end_ms = 0; |
92 | if (opt_t) { |
93 | end_ms = bb_strtou(opt_t, NULL, 10); |
94 | if (errno || end_ms > UINT_MAX / 2048) |
95 | return "invalid timeout"; |
96 | end_ms *= 1000; |
97 | #if 0 /* even bash has no -t N.NNN support */ |
98 | ts.tv_sec = bb_strtou(opt_t, &p, 10); |
99 | ts.tv_usec = 0; |
100 | /* EINVAL means number is ok, but not terminated by NUL */ |
101 | if (*p == '.' && errno == EINVAL) { |
102 | char *p2; |
103 | if (*++p) { |
104 | int scale; |
105 | ts.tv_usec = bb_strtou(p, &p2, 10); |
106 | if (errno) |
107 | return "invalid timeout"; |
108 | scale = p2 - p; |
109 | /* normalize to usec */ |
110 | if (scale > 6) |
111 | return "invalid timeout"; |
112 | while (scale++ < 6) |
113 | ts.tv_usec *= 10; |
114 | } |
115 | } else if (ts.tv_sec < 0 || errno) { |
116 | return "invalid timeout"; |
117 | } |
118 | if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */ |
119 | return "invalid timeout"; |
120 | } |
121 | #endif /* if 0 */ |
122 | } |
123 | fd = STDIN_FILENO; |
124 | if (opt_u) { |
125 | fd = bb_strtou(opt_u, NULL, 10); |
126 | if (fd < 0 || errno) |
127 | return "invalid file descriptor"; |
128 | } |
129 | |
130 | if (opt_p && isatty(fd)) { |
131 | fputs(opt_p, stderr); |
132 | fflush_all(); |
133 | } |
134 | |
135 | if (ifs == NULL) |
136 | ifs = defifs; |
137 | |
138 | if (nchars || (read_flags & BUILTIN_READ_SILENT)) { |
139 | tcgetattr(fd, &tty); |
140 | old_tty = tty; |
141 | if (nchars) { |
142 | tty.c_lflag &= ~ICANON; |
143 | // Setting it to more than 1 breaks poll(): |
144 | // it blocks even if there's data. !?? |
145 | //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; |
146 | /* reads would block only if < 1 char is available */ |
147 | tty.c_cc[VMIN] = 1; |
148 | /* no timeout (reads block forever) */ |
149 | tty.c_cc[VTIME] = 0; |
150 | } |
151 | if (read_flags & BUILTIN_READ_SILENT) { |
152 | tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); |
153 | } |
154 | /* This forces execution of "restoring" tcgetattr later */ |
155 | read_flags |= BUILTIN_READ_SILENT; |
156 | /* if tcgetattr failed, tcsetattr will fail too. |
157 | * Ignoring, it's harmless. */ |
158 | tcsetattr(fd, TCSANOW, &tty); |
159 | } |
160 | |
161 | retval = (const char *)(uintptr_t)0; |
162 | startword = 1; |
163 | backslash = 0; |
164 | if (end_ms) /* NB: end_ms stays nonzero: */ |
165 | end_ms = ((unsigned)monotonic_ms() + end_ms) | 1; |
166 | buffer = NULL; |
167 | bufpos = 0; |
168 | do { |
169 | char c; |
170 | struct pollfd pfd[1]; |
171 | int timeout; |
172 | |
173 | if ((bufpos & 0xff) == 0) |
174 | buffer = xrealloc(buffer, bufpos + 0x101); |
175 | |
176 | timeout = -1; |
177 | if (end_ms) { |
178 | timeout = end_ms - (unsigned)monotonic_ms(); |
179 | if (timeout <= 0) { /* already late? */ |
180 | retval = (const char *)(uintptr_t)1; |
181 | goto ret; |
182 | } |
183 | } |
184 | |
185 | /* We must poll even if timeout is -1: |
186 | * we want to be interrupted if signal arrives, |
187 | * regardless of SA_RESTART-ness of that signal! |
188 | */ |
189 | errno = 0; |
190 | pfd[0].fd = fd; |
191 | pfd[0].events = POLLIN; |
192 | if (poll(pfd, 1, timeout) != 1) { |
193 | /* timed out, or EINTR */ |
194 | err = errno; |
195 | retval = (const char *)(uintptr_t)1; |
196 | goto ret; |
197 | } |
198 | if (read(fd, &buffer[bufpos], 1) != 1) { |
199 | err = errno; |
200 | retval = (const char *)(uintptr_t)1; |
201 | break; |
202 | } |
203 | |
204 | c = buffer[bufpos]; |
205 | if (c == '\0') |
206 | continue; |
207 | if (backslash) { |
208 | backslash = 0; |
209 | if (c != '\n') |
210 | goto put; |
211 | continue; |
212 | } |
213 | if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') { |
214 | backslash = 1; |
215 | continue; |
216 | } |
217 | if (c == '\n') |
218 | break; |
219 | |
220 | /* $IFS splitting. NOT done if we run "read" |
221 | * without variable names (bash compat). |
222 | * Thus, "read" and "read REPLY" are not the same. |
223 | */ |
224 | if (argv[0]) { |
225 | /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */ |
226 | const char *is_ifs = strchr(ifs, c); |
227 | if (startword && is_ifs) { |
228 | if (isspace(c)) |
229 | continue; |
230 | /* it is a non-space ifs char */ |
231 | startword--; |
232 | if (startword == 1) /* first one? */ |
233 | continue; /* yes, it is not next word yet */ |
234 | } |
235 | startword = 0; |
236 | if (argv[1] != NULL && is_ifs) { |
237 | buffer[bufpos] = '\0'; |
238 | bufpos = 0; |
239 | setvar(*argv, buffer); |
240 | argv++; |
241 | /* can we skip one non-space ifs char? (2: yes) */ |
242 | startword = isspace(c) ? 2 : 1; |
243 | continue; |
244 | } |
245 | } |
246 | put: |
247 | bufpos++; |
248 | } while (--nchars); |
249 | |
250 | if (argv[0]) { |
251 | /* Remove trailing space $IFS chars */ |
252 | while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL) |
253 | continue; |
254 | buffer[bufpos + 1] = '\0'; |
255 | /* Use the remainder as a value for the next variable */ |
256 | setvar(*argv, buffer); |
257 | /* Set the rest to "" */ |
258 | while (*++argv) |
259 | setvar(*argv, ""); |
260 | } else { |
261 | /* Note: no $IFS removal */ |
262 | buffer[bufpos] = '\0'; |
263 | setvar("REPLY", buffer); |
264 | } |
265 | |
266 | ret: |
267 | free(buffer); |
268 | if (read_flags & BUILTIN_READ_SILENT) |
269 | tcsetattr(fd, TCSANOW, &old_tty); |
270 | |
271 | errno = err; |
272 | return retval; |
273 | } |
274 | |
275 | /* ulimit builtin */ |
276 | |
277 | struct limits { |
278 | uint8_t cmd; /* RLIMIT_xxx fit into it */ |
279 | uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */ |
280 | char option; |
281 | const char *name; |
282 | }; |
283 | |
284 | static const struct limits limits_tbl[] = { |
285 | #ifdef RLIMIT_FSIZE |
286 | { RLIMIT_FSIZE, 9, 'f', "file size (blocks)" }, |
287 | #endif |
288 | #ifdef RLIMIT_CPU |
289 | { RLIMIT_CPU, 0, 't', "cpu time (seconds)" }, |
290 | #endif |
291 | #ifdef RLIMIT_DATA |
292 | { RLIMIT_DATA, 10, 'd', "data seg size (kb)" }, |
293 | #endif |
294 | #ifdef RLIMIT_STACK |
295 | { RLIMIT_STACK, 10, 's', "stack size (kb)" }, |
296 | #endif |
297 | #ifdef RLIMIT_CORE |
298 | { RLIMIT_CORE, 9, 'c', "core file size (blocks)" }, |
299 | #endif |
300 | #ifdef RLIMIT_RSS |
301 | { RLIMIT_RSS, 10, 'm', "resident set size (kb)" }, |
302 | #endif |
303 | #ifdef RLIMIT_MEMLOCK |
304 | { RLIMIT_MEMLOCK, 10, 'l', "locked memory (kb)" }, |
305 | #endif |
306 | #ifdef RLIMIT_NPROC |
307 | { RLIMIT_NPROC, 0, 'p', "processes" }, |
308 | #endif |
309 | #ifdef RLIMIT_NOFILE |
310 | { RLIMIT_NOFILE, 0, 'n', "file descriptors" }, |
311 | #endif |
312 | #ifdef RLIMIT_AS |
313 | { RLIMIT_AS, 10, 'v', "address space (kb)" }, |
314 | #endif |
315 | #ifdef RLIMIT_LOCKS |
316 | { RLIMIT_LOCKS, 0, 'w', "locks" }, |
317 | #endif |
318 | #ifdef RLIMIT_NICE |
319 | { RLIMIT_NICE, 0, 'e', "scheduling priority" }, |
320 | #endif |
321 | #ifdef RLIMIT_RTPRIO |
322 | { RLIMIT_RTPRIO, 0, 'r', "real-time priority" }, |
323 | #endif |
324 | }; |
325 | |
326 | enum { |
327 | OPT_hard = (1 << 0), |
328 | OPT_soft = (1 << 1), |
329 | }; |
330 | |
331 | /* "-": treat args as parameters of option with ASCII code 1 */ |
332 | static const char ulimit_opt_string[] ALIGN1 = "-HSa" |
333 | #ifdef RLIMIT_FSIZE |
334 | "f::" |
335 | #endif |
336 | #ifdef RLIMIT_CPU |
337 | "t::" |
338 | #endif |
339 | #ifdef RLIMIT_DATA |
340 | "d::" |
341 | #endif |
342 | #ifdef RLIMIT_STACK |
343 | "s::" |
344 | #endif |
345 | #ifdef RLIMIT_CORE |
346 | "c::" |
347 | #endif |
348 | #ifdef RLIMIT_RSS |
349 | "m::" |
350 | #endif |
351 | #ifdef RLIMIT_MEMLOCK |
352 | "l::" |
353 | #endif |
354 | #ifdef RLIMIT_NPROC |
355 | "p::" |
356 | #endif |
357 | #ifdef RLIMIT_NOFILE |
358 | "n::" |
359 | #endif |
360 | #ifdef RLIMIT_AS |
361 | "v::" |
362 | #endif |
363 | #ifdef RLIMIT_LOCKS |
364 | "w::" |
365 | #endif |
366 | #ifdef RLIMIT_NICE |
367 | "e::" |
368 | #endif |
369 | #ifdef RLIMIT_RTPRIO |
370 | "r::" |
371 | #endif |
372 | ; |
373 | |
374 | static void printlim(unsigned opts, const struct rlimit *limit, |
375 | const struct limits *l) |
376 | { |
377 | rlim_t val; |
378 | |
379 | val = limit->rlim_max; |
380 | if (!(opts & OPT_hard)) |
381 | val = limit->rlim_cur; |
382 | |
383 | if (val == RLIM_INFINITY) |
384 | puts("unlimited"); |
385 | else { |
386 | val >>= l->factor_shift; |
387 | printf("%llu\n", (long long) val); |
388 | } |
389 | } |
390 | |
391 | int FAST_FUNC |
392 | shell_builtin_ulimit(char **argv) |
393 | { |
394 | unsigned opts; |
395 | unsigned argc; |
396 | |
397 | /* We can't use getopt32: need to handle commands like |
398 | * ulimit 123 -c2 -l 456 |
399 | */ |
400 | |
401 | /* In case getopt was already called: |
402 | * reset the libc getopt() function, which keeps internal state. |
403 | */ |
404 | #ifdef __GLIBC__ |
405 | optind = 0; |
406 | #else /* BSD style */ |
407 | optind = 1; |
408 | /* optreset = 1; */ |
409 | #endif |
410 | /* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */ |
411 | |
412 | argc = 1; |
413 | while (argv[argc]) |
414 | argc++; |
415 | |
416 | opts = 0; |
417 | while (1) { |
418 | struct rlimit limit; |
419 | const struct limits *l; |
420 | int opt_char = getopt(argc, argv, ulimit_opt_string); |
421 | |
422 | if (opt_char == -1) |
423 | break; |
424 | if (opt_char == 'H') { |
425 | opts |= OPT_hard; |
426 | continue; |
427 | } |
428 | if (opt_char == 'S') { |
429 | opts |= OPT_soft; |
430 | continue; |
431 | } |
432 | |
433 | if (opt_char == 'a') { |
434 | for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) { |
435 | getrlimit(l->cmd, &limit); |
436 | printf("-%c: %-30s ", l->option, l->name); |
437 | printlim(opts, &limit, l); |
438 | } |
439 | continue; |
440 | } |
441 | |
442 | if (opt_char == 1) |
443 | opt_char = 'f'; |
444 | for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) { |
445 | if (opt_char == l->option) { |
446 | char *val_str; |
447 | |
448 | getrlimit(l->cmd, &limit); |
449 | |
450 | val_str = optarg; |
451 | if (!val_str && argv[optind] && argv[optind][0] != '-') |
452 | val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */ |
453 | if (val_str) { |
454 | rlim_t val; |
455 | |
456 | if (strcmp(val_str, "unlimited") == 0) |
457 | val = RLIM_INFINITY; |
458 | else { |
459 | if (sizeof(val) == sizeof(int)) |
460 | val = bb_strtou(val_str, NULL, 10); |
461 | else if (sizeof(val) == sizeof(long)) |
462 | val = bb_strtoul(val_str, NULL, 10); |
463 | else |
464 | val = bb_strtoull(val_str, NULL, 10); |
465 | if (errno) { |
466 | bb_error_msg("invalid number '%s'", val_str); |
467 | return EXIT_FAILURE; |
468 | } |
469 | val <<= l->factor_shift; |
470 | } |
471 | //bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val); |
472 | /* from man bash: "If neither -H nor -S |
473 | * is specified, both the soft and hard |
474 | * limits are set. */ |
475 | if (!opts) |
476 | opts = OPT_hard + OPT_soft; |
477 | if (opts & OPT_hard) |
478 | limit.rlim_max = val; |
479 | if (opts & OPT_soft) |
480 | limit.rlim_cur = val; |
481 | //bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max); |
482 | if (setrlimit(l->cmd, &limit) < 0) { |
483 | bb_perror_msg("error setting limit"); |
484 | return EXIT_FAILURE; |
485 | } |
486 | } else { |
487 | printlim(opts, &limit, l); |
488 | } |
489 | break; |
490 | } |
491 | } /* for (every possible opt) */ |
492 | |
493 | if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) { |
494 | /* bad option. getopt already complained. */ |
495 | break; |
496 | } |
497 | } /* while (there are options) */ |
498 | |
499 | return 0; |
500 | } |
501 |