1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /*
36 * Miscellaneous builtins.
37 */
38
39 #include <sys/types.h>
40 #include <sys/stat.h>
41 #include <sys/time.h>
42 #include <sys/resource.h>
43
44 #include <errno.h>
45 #include <poll.h>
46 #include <signal.h>
47 #include <stdint.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51
52 #include "shell.h"
53 #include "options.h"
54 #include "var.h"
55 #include "output.h"
56 #include "memalloc.h"
57 #include "error.h"
58 #include "mystring.h"
59 #include "syntax.h"
60 #include "trap.h"
61
62 #undef eflag
63
64 #define READ_BUFLEN 1024
65 struct fdctx {
66 int fd;
67 size_t off; /* offset in buf */
68 size_t buflen;
69 char *ep; /* tail pointer */
70 char buf[READ_BUFLEN];
71 };
72
73 static void fdctx_init(int, struct fdctx *);
74 static void fdctx_destroy(struct fdctx *);
75 static ssize_t fdgetc(struct fdctx *, char *);
76 int readcmd(int, char **);
77 int umaskcmd(int, char **);
78 int ulimitcmd(int, char **);
79
80 static void
fdctx_init(int fd,struct fdctx * fdc)81 fdctx_init(int fd, struct fdctx *fdc)
82 {
83 off_t cur;
84
85 /* Check if fd is seekable. */
86 cur = lseek(fd, 0, SEEK_CUR);
87 *fdc = (struct fdctx){
88 .fd = fd,
89 .buflen = (cur != -1) ? READ_BUFLEN : 1,
90 .ep = &fdc->buf[0], /* No data */
91 };
92 }
93
94 static ssize_t
fdgetc(struct fdctx * fdc,char * c)95 fdgetc(struct fdctx *fdc, char *c)
96 {
97 ssize_t nread;
98
99 if (&fdc->buf[fdc->off] == fdc->ep) {
100 nread = read(fdc->fd, fdc->buf, fdc->buflen);
101 if (nread > 0) {
102 fdc->off = 0;
103 fdc->ep = fdc->buf + nread;
104 } else
105 return (nread);
106 }
107 *c = fdc->buf[fdc->off++];
108
109 return (1);
110 }
111
112 static void
fdctx_destroy(struct fdctx * fdc)113 fdctx_destroy(struct fdctx *fdc)
114 {
115 off_t residue;
116
117 if (fdc->buflen > 1) {
118 /*
119 * Reposition the file offset. Here is the layout of buf:
120 *
121 * | off
122 * v
123 * |*****************|-------|
124 * buf ep buf+buflen
125 * |<- residue ->|
126 *
127 * off: current character
128 * ep: offset just after read(2)
129 * residue: length for reposition
130 */
131 residue = (fdc->ep - fdc->buf) - fdc->off;
132 if (residue > 0)
133 (void) lseek(fdc->fd, -residue, SEEK_CUR);
134 }
135 }
136
137 /*
138 * The read builtin. The -r option causes backslashes to be treated like
139 * ordinary characters.
140 *
141 * Note that if IFS=' :' then read x y should work so that:
142 * 'a b' x='a', y='b'
143 * ' a b ' x='a', y='b'
144 * ':b' x='', y='b'
145 * ':' x='', y=''
146 * '::' x='', y=''
147 * ': :' x='', y=''
148 * ':::' x='', y='::'
149 * ':b c:' x='', y='b c:'
150 */
151
152 int
readcmd(int argc __unused,char ** argv __unused)153 readcmd(int argc __unused, char **argv __unused)
154 {
155 char **ap;
156 int backslash;
157 char c;
158 int rflag;
159 char *prompt;
160 const char *ifs;
161 char *p;
162 int startword;
163 int status;
164 int i;
165 int is_ifs;
166 int saveall = 0;
167 ptrdiff_t lastnonifs, lastnonifsws;
168 sigset_t set, oset;
169 intmax_t number, timeout;
170 struct timespec tnow, tend, tresid;
171 struct pollfd pfd;
172 char *endptr;
173 ssize_t nread;
174 int sig;
175 struct fdctx fdctx;
176
177 rflag = 0;
178 prompt = NULL;
179 timeout = -1;
180 while ((i = nextopt("erp:t:")) != '\0') {
181 switch(i) {
182 case 'p':
183 prompt = shoptarg;
184 break;
185 case 'e':
186 break;
187 case 'r':
188 rflag = 1;
189 break;
190 case 't':
191 timeout = 0;
192 do {
193 number = strtol(shoptarg, &endptr, 0);
194 if (number < 0 || endptr == shoptarg)
195 error("timeout value");
196 switch (*endptr) {
197 case 's':
198 endptr++;
199 break;
200 case 'h':
201 number *= 60;
202 /* FALLTHROUGH */
203 case 'm':
204 number *= 60;
205 endptr++;
206 break;
207 }
208 if (*endptr != '\0' &&
209 !(*endptr >= '0' && *endptr <= '9'))
210 error("timeout unit");
211 timeout += number;
212 shoptarg = endptr;
213 } while (*shoptarg != '\0');
214 break;
215 }
216 }
217 if (prompt && isatty(0)) {
218 out2str(prompt);
219 flushall();
220 }
221 if (*(ap = argptr) == NULL)
222 error("arg count");
223 if ((ifs = bltinlookup("IFS", 1)) == NULL)
224 ifs = " \t\n";
225
226 if (timeout >= 0) {
227 /*
228 * Wait for something to become available.
229 */
230 pfd.fd = STDIN_FILENO;
231 pfd.events = POLLIN;
232 status = sig = 0;
233 sigfillset(&set);
234 sigprocmask(SIG_SETMASK, &set, &oset);
235 if (pendingsig) {
236 /* caught a signal already */
237 status = -1;
238 } else if (timeout == 0) {
239 status = poll(&pfd, 1, 0);
240 } else {
241 clock_gettime(CLOCK_UPTIME, &tnow);
242 tend = tnow;
243 tend.tv_sec += timeout;
244 do {
245 timespecsub(&tend, &tnow, &tresid);
246 status = ppoll(&pfd, 1, &tresid, &oset);
247 if (status >= 0 || pendingsig != 0)
248 break;
249 clock_gettime(CLOCK_UPTIME, &tnow);
250 } while (timespeccmp(&tnow, &tend, <));
251 }
252 sigprocmask(SIG_SETMASK, &oset, NULL);
253 /*
254 * If there's nothing ready, return an error.
255 */
256 if (status <= 0) {
257 while (*ap != NULL)
258 setvar(*ap++, "", 0);
259 sig = pendingsig;
260 return (128 + (sig != 0 ? sig : SIGALRM));
261 }
262 }
263
264 status = 0;
265 startword = 2;
266 backslash = 0;
267 STARTSTACKSTR(p);
268 lastnonifs = lastnonifsws = -1;
269 fdctx_init(STDIN_FILENO, &fdctx);
270 for (;;) {
271 c = 0;
272 nread = fdgetc(&fdctx, &c);
273 if (nread == -1) {
274 if (errno == EINTR) {
275 sig = pendingsig;
276 if (sig == 0)
277 continue;
278 status = 128 + sig;
279 break;
280 }
281 warning("read error: %s", strerror(errno));
282 status = 2;
283 break;
284 } else if (nread != 1) {
285 status = 1;
286 break;
287 }
288 if (c == '\0')
289 continue;
290 CHECKSTRSPACE(1, p);
291 if (backslash) {
292 backslash = 0;
293 if (c != '\n') {
294 startword = 0;
295 lastnonifs = lastnonifsws = p - stackblock();
296 USTPUTC(c, p);
297 }
298 continue;
299 }
300 if (!rflag && c == '\\') {
301 backslash++;
302 continue;
303 }
304 if (c == '\n')
305 break;
306 if (strchr(ifs, c))
307 is_ifs = strchr(" \t\n", c) ? 1 : 2;
308 else
309 is_ifs = 0;
310
311 if (startword != 0) {
312 if (is_ifs == 1) {
313 /* Ignore leading IFS whitespace */
314 if (saveall)
315 USTPUTC(c, p);
316 continue;
317 }
318 if (is_ifs == 2 && startword == 1) {
319 /* Only one non-whitespace IFS per word */
320 startword = 2;
321 if (saveall) {
322 lastnonifsws = p - stackblock();
323 USTPUTC(c, p);
324 }
325 continue;
326 }
327 }
328
329 if (is_ifs == 0) {
330 /* append this character to the current variable */
331 startword = 0;
332 if (saveall)
333 /* Not just a spare terminator */
334 saveall++;
335 lastnonifs = lastnonifsws = p - stackblock();
336 USTPUTC(c, p);
337 continue;
338 }
339
340 /* end of variable... */
341 startword = is_ifs;
342
343 if (ap[1] == NULL) {
344 /* Last variable needs all IFS chars */
345 saveall++;
346 if (is_ifs == 2)
347 lastnonifsws = p - stackblock();
348 USTPUTC(c, p);
349 continue;
350 }
351
352 STACKSTRNUL(p);
353 setvar(*ap, stackblock(), 0);
354 ap++;
355 STARTSTACKSTR(p);
356 lastnonifs = lastnonifsws = -1;
357 }
358 fdctx_destroy(&fdctx);
359 STACKSTRNUL(p);
360
361 /*
362 * Remove trailing IFS chars: always remove whitespace, don't remove
363 * non-whitespace unless it was naked
364 */
365 if (saveall <= 1)
366 lastnonifsws = lastnonifs;
367 stackblock()[lastnonifsws + 1] = '\0';
368 setvar(*ap, stackblock(), 0);
369
370 /* Set any remaining args to "" */
371 while (*++ap != NULL)
372 setvar(*ap, "", 0);
373 return status;
374 }
375
376
377
378 int
umaskcmd(int argc __unused,char ** argv __unused)379 umaskcmd(int argc __unused, char **argv __unused)
380 {
381 char *ap;
382 int mask;
383 int i;
384 int symbolic_mode = 0;
385
386 while ((i = nextopt("S")) != '\0') {
387 symbolic_mode = 1;
388 }
389
390 INTOFF;
391 mask = umask(0);
392 umask(mask);
393 INTON;
394
395 if ((ap = *argptr) == NULL) {
396 if (symbolic_mode) {
397 char u[4], g[4], o[4];
398
399 i = 0;
400 if ((mask & S_IRUSR) == 0)
401 u[i++] = 'r';
402 if ((mask & S_IWUSR) == 0)
403 u[i++] = 'w';
404 if ((mask & S_IXUSR) == 0)
405 u[i++] = 'x';
406 u[i] = '\0';
407
408 i = 0;
409 if ((mask & S_IRGRP) == 0)
410 g[i++] = 'r';
411 if ((mask & S_IWGRP) == 0)
412 g[i++] = 'w';
413 if ((mask & S_IXGRP) == 0)
414 g[i++] = 'x';
415 g[i] = '\0';
416
417 i = 0;
418 if ((mask & S_IROTH) == 0)
419 o[i++] = 'r';
420 if ((mask & S_IWOTH) == 0)
421 o[i++] = 'w';
422 if ((mask & S_IXOTH) == 0)
423 o[i++] = 'x';
424 o[i] = '\0';
425
426 out1fmt("u=%s,g=%s,o=%s\n", u, g, o);
427 } else {
428 out1fmt("%.4o\n", mask);
429 }
430 } else {
431 if (is_digit(*ap)) {
432 mask = 0;
433 do {
434 if (*ap >= '8' || *ap < '0')
435 error("Illegal number: %s", *argptr);
436 mask = (mask << 3) + (*ap - '0');
437 } while (*++ap != '\0');
438 umask(mask);
439 } else {
440 void *set;
441 INTOFF;
442 if ((set = setmode (ap)) == NULL)
443 error("Illegal number: %s", ap);
444
445 mask = getmode (set, ~mask & 0777);
446 umask(~mask & 0777);
447 free(set);
448 INTON;
449 }
450 }
451 return 0;
452 }
453
454 /*
455 * ulimit builtin
456 *
457 * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
458 * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
459 * ash by J.T. Conklin.
460 *
461 * Public domain.
462 */
463
464 struct limits {
465 const char *name;
466 const char *units;
467 int cmd;
468 short factor; /* multiply by to get rlim_{cur,max} values */
469 char option;
470 };
471
472 static const struct limits limits[] = {
473 #ifdef RLIMIT_CPU
474 { "cpu time", "seconds", RLIMIT_CPU, 1, 't' },
475 #endif
476 #ifdef RLIMIT_FSIZE
477 { "file size", "512-blocks", RLIMIT_FSIZE, 512, 'f' },
478 #endif
479 #ifdef RLIMIT_DATA
480 { "data seg size", "kbytes", RLIMIT_DATA, 1024, 'd' },
481 #endif
482 #ifdef RLIMIT_STACK
483 { "stack size", "kbytes", RLIMIT_STACK, 1024, 's' },
484 #endif
485 #ifdef RLIMIT_CORE
486 { "core file size", "512-blocks", RLIMIT_CORE, 512, 'c' },
487 #endif
488 #ifdef RLIMIT_RSS
489 { "max memory size", "kbytes", RLIMIT_RSS, 1024, 'm' },
490 #endif
491 #ifdef RLIMIT_MEMLOCK
492 { "locked memory", "kbytes", RLIMIT_MEMLOCK, 1024, 'l' },
493 #endif
494 #ifdef RLIMIT_NPROC
495 { "max user processes", (char *)0, RLIMIT_NPROC, 1, 'u' },
496 #endif
497 #ifdef RLIMIT_NOFILE
498 { "open files", (char *)0, RLIMIT_NOFILE, 1, 'n' },
499 #endif
500 #ifdef RLIMIT_VMEM
501 { "virtual mem size", "kbytes", RLIMIT_VMEM, 1024, 'v' },
502 #endif
503 #ifdef RLIMIT_SWAP
504 { "swap limit", "kbytes", RLIMIT_SWAP, 1024, 'w' },
505 #endif
506 #ifdef RLIMIT_SBSIZE
507 { "socket buffer size", "bytes", RLIMIT_SBSIZE, 1, 'b' },
508 #endif
509 #ifdef RLIMIT_NPTS
510 { "pseudo-terminals", (char *)0, RLIMIT_NPTS, 1, 'p' },
511 #endif
512 #ifdef RLIMIT_KQUEUES
513 { "kqueues", (char *)0, RLIMIT_KQUEUES, 1, 'k' },
514 #endif
515 #ifdef RLIMIT_UMTXP
516 { "umtx shared locks", (char *)0, RLIMIT_UMTXP, 1, 'o' },
517 #endif
518 #ifdef RLIMIT_PIPEBUF
519 { "pipebuf", (char *)0, RLIMIT_PIPEBUF, 1024, 'y' },
520 #endif
521 { (char *) 0, (char *)0, 0, 0, '\0' }
522 };
523
524 enum limithow { SOFT = 0x1, HARD = 0x2 };
525
526 static void
printlimit(enum limithow how,const struct rlimit * limit,const struct limits * l)527 printlimit(enum limithow how, const struct rlimit *limit,
528 const struct limits *l)
529 {
530 rlim_t val = 0;
531
532 if (how & SOFT)
533 val = limit->rlim_cur;
534 else if (how & HARD)
535 val = limit->rlim_max;
536 if (val == RLIM_INFINITY)
537 out1str("unlimited\n");
538 else
539 {
540 val /= l->factor;
541 out1fmt("%jd\n", (intmax_t)val);
542 }
543 }
544
545 int
ulimitcmd(int argc __unused,char ** argv __unused)546 ulimitcmd(int argc __unused, char **argv __unused)
547 {
548 rlim_t val = 0;
549 enum limithow how = SOFT | HARD;
550 const struct limits *l;
551 int set, all = 0;
552 int optc, what;
553 struct rlimit limit;
554
555 what = 'f';
556 while ((optc = nextopt("HSatfdsmcnuvlbpwkoy")) != '\0')
557 switch (optc) {
558 case 'H':
559 how = HARD;
560 break;
561 case 'S':
562 how = SOFT;
563 break;
564 case 'a':
565 all = 1;
566 break;
567 default:
568 what = optc;
569 }
570
571 for (l = limits; l->name && l->option != what; l++)
572 ;
573 if (!l->name)
574 error("internal error (%c)", what);
575
576 set = *argptr ? 1 : 0;
577 if (set) {
578 char *p = *argptr;
579
580 if (all || argptr[1])
581 error("too many arguments");
582 if (strcmp(p, "unlimited") == 0)
583 val = RLIM_INFINITY;
584 else {
585 char *end;
586 uintmax_t uval;
587
588 if (*p < '0' || *p > '9')
589 error("bad number");
590 errno = 0;
591 uval = strtoumax(p, &end, 10);
592 if (errno != 0 || *end != '\0')
593 error("bad number");
594 if (uval > UINTMAX_MAX / l->factor)
595 error("bad number");
596 uval *= l->factor;
597 val = (rlim_t)uval;
598 if (val < 0 || (uintmax_t)val != uval ||
599 val == RLIM_INFINITY)
600 error("bad number");
601 }
602 }
603 if (all) {
604 for (l = limits; l->name; l++) {
605 char optbuf[40];
606 if (getrlimit(l->cmd, &limit) < 0)
607 error("can't get limit: %s", strerror(errno));
608
609 if (l->units)
610 snprintf(optbuf, sizeof(optbuf),
611 "(%s, -%c) ", l->units, l->option);
612 else
613 snprintf(optbuf, sizeof(optbuf),
614 "(-%c) ", l->option);
615 out1fmt("%-18s %18s ", l->name, optbuf);
616 printlimit(how, &limit, l);
617 }
618 return 0;
619 }
620
621 if (getrlimit(l->cmd, &limit) < 0)
622 error("can't get limit: %s", strerror(errno));
623 if (set) {
624 if (how & SOFT)
625 limit.rlim_cur = val;
626 if (how & HARD)
627 limit.rlim_max = val;
628 if (setrlimit(l->cmd, &limit) < 0)
629 error("bad limit: %s", strerror(errno));
630 } else
631 printlimit(how, &limit, l);
632 return 0;
633 }
634