1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)miscbltin.c	8.4 (Berkeley) 5/4/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: stable/11/bin/sh/miscbltin.c 359077 2020-03-18 18:10:44Z hrs $");
40
41/*
42 * Miscellaneous builtins.
43 */
44
45#include <sys/types.h>
46#include <sys/stat.h>
47#include <sys/time.h>
48#include <sys/resource.h>
49#include <unistd.h>
50#include <errno.h>
51#include <stdint.h>
52#include <stdio.h>
53#include <stdlib.h>
54
55#include "shell.h"
56#include "options.h"
57#include "var.h"
58#include "output.h"
59#include "memalloc.h"
60#include "error.h"
61#include "mystring.h"
62#include "syntax.h"
63#include "trap.h"
64
65#undef eflag
66
67#define	READ_BUFLEN	1024
68struct fdctx {
69	int	fd;
70	size_t	off;	/* offset in buf */
71	size_t	buflen;
72	char	*ep;	/* tail pointer */
73	char	buf[READ_BUFLEN];
74};
75
76static void fdctx_init(int, struct fdctx *);
77static void fdctx_destroy(struct fdctx *);
78static ssize_t fdgetc(struct fdctx *, char *);
79int readcmd(int, char **);
80int umaskcmd(int, char **);
81int ulimitcmd(int, char **);
82
83static void
84fdctx_init(int fd, struct fdctx *fdc)
85{
86	off_t cur;
87
88	/* Check if fd is seekable. */
89	cur = lseek(fd, 0, SEEK_CUR);
90	*fdc = (struct fdctx){
91		.fd = fd,
92		.buflen = (cur != -1) ? READ_BUFLEN : 1,
93		.ep = &fdc->buf[0],	/* No data */
94	};
95}
96
97static ssize_t
98fdgetc(struct fdctx *fdc, char *c)
99{
100	ssize_t nread;
101
102	if (&fdc->buf[fdc->off] == fdc->ep) {
103		nread = read(fdc->fd, fdc->buf, fdc->buflen);
104		if (nread > 0) {
105			fdc->off = 0;
106			fdc->ep = fdc->buf + nread;
107		} else
108			return (nread);
109	}
110	*c = fdc->buf[fdc->off++];
111
112	return (1);
113}
114
115static void
116fdctx_destroy(struct fdctx *fdc)
117{
118	off_t residue;
119
120	if (fdc->buflen > 1) {
121	/*
122	 * Reposition the file offset.  Here is the layout of buf:
123	 *
124	 *     | off
125	 *     v
126	 * |*****************|-------|
127	 * buf               ep   buf+buflen
128	 *     |<- residue ->|
129	 *
130	 * off: current character
131	 * ep:  offset just after read(2)
132	 * residue: length for reposition
133	 */
134		residue = (fdc->ep - fdc->buf) - fdc->off;
135		if (residue > 0)
136			(void) lseek(fdc->fd, -residue, SEEK_CUR);
137	}
138}
139
140/*
141 * The read builtin.  The -r option causes backslashes to be treated like
142 * ordinary characters.
143 *
144 * This uses unbuffered input, which may be avoidable in some cases.
145 *
146 * Note that if IFS=' :' then read x y should work so that:
147 * 'a b'	x='a', y='b'
148 * ' a b '	x='a', y='b'
149 * ':b'		x='',  y='b'
150 * ':'		x='',  y=''
151 * '::'		x='',  y=''
152 * ': :'	x='',  y=''
153 * ':::'	x='',  y='::'
154 * ':b c:'	x='',  y='b c:'
155 */
156
157int
158readcmd(int argc __unused, char **argv __unused)
159{
160	char **ap;
161	int backslash;
162	char c;
163	int rflag;
164	char *prompt;
165	const char *ifs;
166	char *p;
167	int startword;
168	int status;
169	int i;
170	int is_ifs;
171	int saveall = 0;
172	ptrdiff_t lastnonifs, lastnonifsws;
173	struct timeval tv;
174	char *tvptr;
175	fd_set ifds;
176	ssize_t nread;
177	int sig;
178	struct fdctx fdctx;
179
180	rflag = 0;
181	prompt = NULL;
182	tv.tv_sec = -1;
183	tv.tv_usec = 0;
184	while ((i = nextopt("erp:t:")) != '\0') {
185		switch(i) {
186		case 'p':
187			prompt = shoptarg;
188			break;
189		case 'e':
190			break;
191		case 'r':
192			rflag = 1;
193			break;
194		case 't':
195			tv.tv_sec = strtol(shoptarg, &tvptr, 0);
196			if (tvptr == shoptarg)
197				error("timeout value");
198			switch(*tvptr) {
199			case 0:
200			case 's':
201				break;
202			case 'h':
203				tv.tv_sec *= 60;
204				/* FALLTHROUGH */
205			case 'm':
206				tv.tv_sec *= 60;
207				break;
208			default:
209				error("timeout unit");
210			}
211			break;
212		}
213	}
214	if (prompt && isatty(0)) {
215		out2str(prompt);
216		flushall();
217	}
218	if (*(ap = argptr) == NULL)
219		error("arg count");
220	if ((ifs = bltinlookup("IFS", 1)) == NULL)
221		ifs = " \t\n";
222
223	if (tv.tv_sec >= 0) {
224		/*
225		 * Wait for something to become available.
226		 */
227		FD_ZERO(&ifds);
228		FD_SET(0, &ifds);
229		status = select(1, &ifds, NULL, NULL, &tv);
230		/*
231		 * If there's nothing ready, return an error.
232		 */
233		if (status <= 0) {
234			sig = pendingsig;
235			return (128 + (sig != 0 ? sig : SIGALRM));
236		}
237	}
238
239	status = 0;
240	startword = 2;
241	backslash = 0;
242	STARTSTACKSTR(p);
243	lastnonifs = lastnonifsws = -1;
244	fdctx_init(STDIN_FILENO, &fdctx);
245	for (;;) {
246		nread = fdgetc(&fdctx, &c);
247		if (nread == -1) {
248			if (errno == EINTR) {
249				sig = pendingsig;
250				if (sig == 0)
251					continue;
252				status = 128 + sig;
253				break;
254			}
255			warning("read error: %s", strerror(errno));
256			status = 2;
257			break;
258		} else if (nread != 1) {
259			status = 1;
260			break;
261		}
262		if (c == '\0')
263			continue;
264		CHECKSTRSPACE(1, p);
265		if (backslash) {
266			backslash = 0;
267			if (c != '\n') {
268				startword = 0;
269				lastnonifs = lastnonifsws = p - stackblock();
270				USTPUTC(c, p);
271			}
272			continue;
273		}
274		if (!rflag && c == '\\') {
275			backslash++;
276			continue;
277		}
278		if (c == '\n')
279			break;
280		if (strchr(ifs, c))
281			is_ifs = strchr(" \t\n", c) ? 1 : 2;
282		else
283			is_ifs = 0;
284
285		if (startword != 0) {
286			if (is_ifs == 1) {
287				/* Ignore leading IFS whitespace */
288				if (saveall)
289					USTPUTC(c, p);
290				continue;
291			}
292			if (is_ifs == 2 && startword == 1) {
293				/* Only one non-whitespace IFS per word */
294				startword = 2;
295				if (saveall) {
296					lastnonifsws = p - stackblock();
297					USTPUTC(c, p);
298				}
299				continue;
300			}
301		}
302
303		if (is_ifs == 0) {
304			/* append this character to the current variable */
305			startword = 0;
306			if (saveall)
307				/* Not just a spare terminator */
308				saveall++;
309			lastnonifs = lastnonifsws = p - stackblock();
310			USTPUTC(c, p);
311			continue;
312		}
313
314		/* end of variable... */
315		startword = is_ifs;
316
317		if (ap[1] == NULL) {
318			/* Last variable needs all IFS chars */
319			saveall++;
320			if (is_ifs == 2)
321				lastnonifsws = p - stackblock();
322			USTPUTC(c, p);
323			continue;
324		}
325
326		STACKSTRNUL(p);
327		setvar(*ap, stackblock(), 0);
328		ap++;
329		STARTSTACKSTR(p);
330		lastnonifs = lastnonifsws = -1;
331	}
332	fdctx_destroy(&fdctx);
333	STACKSTRNUL(p);
334
335	/*
336	 * Remove trailing IFS chars: always remove whitespace, don't remove
337	 * non-whitespace unless it was naked
338	 */
339	if (saveall <= 1)
340		lastnonifsws = lastnonifs;
341	stackblock()[lastnonifsws + 1] = '\0';
342	setvar(*ap, stackblock(), 0);
343
344	/* Set any remaining args to "" */
345	while (*++ap != NULL)
346		setvar(*ap, "", 0);
347	return status;
348}
349
350
351
352int
353umaskcmd(int argc __unused, char **argv __unused)
354{
355	char *ap;
356	int mask;
357	int i;
358	int symbolic_mode = 0;
359
360	while ((i = nextopt("S")) != '\0') {
361		symbolic_mode = 1;
362	}
363
364	INTOFF;
365	mask = umask(0);
366	umask(mask);
367	INTON;
368
369	if ((ap = *argptr) == NULL) {
370		if (symbolic_mode) {
371			char u[4], g[4], o[4];
372
373			i = 0;
374			if ((mask & S_IRUSR) == 0)
375				u[i++] = 'r';
376			if ((mask & S_IWUSR) == 0)
377				u[i++] = 'w';
378			if ((mask & S_IXUSR) == 0)
379				u[i++] = 'x';
380			u[i] = '\0';
381
382			i = 0;
383			if ((mask & S_IRGRP) == 0)
384				g[i++] = 'r';
385			if ((mask & S_IWGRP) == 0)
386				g[i++] = 'w';
387			if ((mask & S_IXGRP) == 0)
388				g[i++] = 'x';
389			g[i] = '\0';
390
391			i = 0;
392			if ((mask & S_IROTH) == 0)
393				o[i++] = 'r';
394			if ((mask & S_IWOTH) == 0)
395				o[i++] = 'w';
396			if ((mask & S_IXOTH) == 0)
397				o[i++] = 'x';
398			o[i] = '\0';
399
400			out1fmt("u=%s,g=%s,o=%s\n", u, g, o);
401		} else {
402			out1fmt("%.4o\n", mask);
403		}
404	} else {
405		if (is_digit(*ap)) {
406			mask = 0;
407			do {
408				if (*ap >= '8' || *ap < '0')
409					error("Illegal number: %s", *argptr);
410				mask = (mask << 3) + (*ap - '0');
411			} while (*++ap != '\0');
412			umask(mask);
413		} else {
414			void *set;
415			INTOFF;
416			if ((set = setmode (ap)) == NULL)
417				error("Illegal number: %s", ap);
418
419			mask = getmode (set, ~mask & 0777);
420			umask(~mask & 0777);
421			free(set);
422			INTON;
423		}
424	}
425	return 0;
426}
427
428/*
429 * ulimit builtin
430 *
431 * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
432 * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
433 * ash by J.T. Conklin.
434 *
435 * Public domain.
436 */
437
438struct limits {
439	const char *name;
440	const char *units;
441	int	cmd;
442	int	factor;	/* multiply by to get rlim_{cur,max} values */
443	char	option;
444};
445
446static const struct limits limits[] = {
447#ifdef RLIMIT_CPU
448	{ "cpu time",		"seconds",	RLIMIT_CPU,	   1, 't' },
449#endif
450#ifdef RLIMIT_FSIZE
451	{ "file size",		"512-blocks",	RLIMIT_FSIZE,	 512, 'f' },
452#endif
453#ifdef RLIMIT_DATA
454	{ "data seg size",	"kbytes",	RLIMIT_DATA,	1024, 'd' },
455#endif
456#ifdef RLIMIT_STACK
457	{ "stack size",		"kbytes",	RLIMIT_STACK,	1024, 's' },
458#endif
459#ifdef  RLIMIT_CORE
460	{ "core file size",	"512-blocks",	RLIMIT_CORE,	 512, 'c' },
461#endif
462#ifdef RLIMIT_RSS
463	{ "max memory size",	"kbytes",	RLIMIT_RSS,	1024, 'm' },
464#endif
465#ifdef RLIMIT_MEMLOCK
466	{ "locked memory",	"kbytes",	RLIMIT_MEMLOCK, 1024, 'l' },
467#endif
468#ifdef RLIMIT_NPROC
469	{ "max user processes",	(char *)0,	RLIMIT_NPROC,      1, 'u' },
470#endif
471#ifdef RLIMIT_NOFILE
472	{ "open files",		(char *)0,	RLIMIT_NOFILE,     1, 'n' },
473#endif
474#ifdef RLIMIT_VMEM
475	{ "virtual mem size",	"kbytes",	RLIMIT_VMEM,	1024, 'v' },
476#endif
477#ifdef RLIMIT_SWAP
478	{ "swap limit",		"kbytes",	RLIMIT_SWAP,	1024, 'w' },
479#endif
480#ifdef RLIMIT_SBSIZE
481	{ "socket buffer size",	"bytes",	RLIMIT_SBSIZE,	   1, 'b' },
482#endif
483#ifdef RLIMIT_NPTS
484	{ "pseudo-terminals",	(char *)0,	RLIMIT_NPTS,	   1, 'p' },
485#endif
486#ifdef RLIMIT_KQUEUES
487	{ "kqueues",		(char *)0,	RLIMIT_KQUEUES,	   1, 'k' },
488#endif
489#ifdef RLIMIT_UMTXP
490	{ "umtx shared locks",	(char *)0,	RLIMIT_UMTXP,	   1, 'o' },
491#endif
492	{ (char *) 0,		(char *)0,	0,		   0, '\0' }
493};
494
495enum limithow { SOFT = 0x1, HARD = 0x2 };
496
497static void
498printlimit(enum limithow how, const struct rlimit *limit,
499    const struct limits *l)
500{
501	rlim_t val = 0;
502
503	if (how & SOFT)
504		val = limit->rlim_cur;
505	else if (how & HARD)
506		val = limit->rlim_max;
507	if (val == RLIM_INFINITY)
508		out1str("unlimited\n");
509	else
510	{
511		val /= l->factor;
512		out1fmt("%jd\n", (intmax_t)val);
513	}
514}
515
516int
517ulimitcmd(int argc __unused, char **argv __unused)
518{
519	rlim_t val = 0;
520	enum limithow how = SOFT | HARD;
521	const struct limits	*l;
522	int		set, all = 0;
523	int		optc, what;
524	struct rlimit	limit;
525
526	what = 'f';
527	while ((optc = nextopt("HSatfdsmcnuvlbpwko")) != '\0')
528		switch (optc) {
529		case 'H':
530			how = HARD;
531			break;
532		case 'S':
533			how = SOFT;
534			break;
535		case 'a':
536			all = 1;
537			break;
538		default:
539			what = optc;
540		}
541
542	for (l = limits; l->name && l->option != what; l++)
543		;
544	if (!l->name)
545		error("internal error (%c)", what);
546
547	set = *argptr ? 1 : 0;
548	if (set) {
549		char *p = *argptr;
550
551		if (all || argptr[1])
552			error("too many arguments");
553		if (strcmp(p, "unlimited") == 0)
554			val = RLIM_INFINITY;
555		else {
556			char *end;
557			uintmax_t uval;
558
559			if (*p < '0' || *p > '9')
560				error("bad number");
561			errno = 0;
562			uval = strtoumax(p, &end, 10);
563			if (errno != 0 || *end != '\0')
564				error("bad number");
565			if (uval > UINTMAX_MAX / l->factor)
566				error("bad number");
567			uval *= l->factor;
568			val = (rlim_t)uval;
569			if (val < 0 || (uintmax_t)val != uval ||
570			    val == RLIM_INFINITY)
571				error("bad number");
572		}
573	}
574	if (all) {
575		for (l = limits; l->name; l++) {
576			char optbuf[40];
577			if (getrlimit(l->cmd, &limit) < 0)
578				error("can't get limit: %s", strerror(errno));
579
580			if (l->units)
581				snprintf(optbuf, sizeof(optbuf),
582					"(%s, -%c) ", l->units, l->option);
583			else
584				snprintf(optbuf, sizeof(optbuf),
585					"(-%c) ", l->option);
586			out1fmt("%-18s %18s ", l->name, optbuf);
587			printlimit(how, &limit, l);
588		}
589		return 0;
590	}
591
592	if (getrlimit(l->cmd, &limit) < 0)
593		error("can't get limit: %s", strerror(errno));
594	if (set) {
595		if (how & SOFT)
596			limit.rlim_cur = val;
597		if (how & HARD)
598			limit.rlim_max = val;
599		if (setrlimit(l->cmd, &limit) < 0)
600			error("bad limit: %s", strerror(errno));
601	} else
602		printlimit(how, &limit, l);
603	return 0;
604}
605