1/*	$OpenBSD: c_test.c,v 1.28 2023/06/10 07:24:21 op Exp $	*/
2
3/*
4 * test(1); version 7-like  --  author Erik Baalbergen
5 * modified by Eric Gisin to be used as built-in.
6 * modified by Arnold Robbins to add SVR3 compatibility
7 * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
8 * modified by Michael Rendell to add Korn's [[ .. ]] expressions.
9 * modified by J.T. Conklin to add POSIX compatibility.
10 */
11
12#include <sys/stat.h>
13
14#include <string.h>
15#include <unistd.h>
16
17#include "sh.h"
18#include "c_test.h"
19
20/* test(1) accepts the following grammar:
21	oexpr	::= aexpr | aexpr "-o" oexpr ;
22	aexpr	::= nexpr | nexpr "-a" aexpr ;
23	nexpr	::= primary | "!" nexpr ;
24	primary	::= unary-operator operand
25		| operand binary-operator operand
26		| operand
27		| "(" oexpr ")"
28		;
29
30	unary-operator ::= "-a"|"-r"|"-w"|"-x"|"-e"|"-f"|"-d"|"-c"|"-b"|"-p"|
31			   "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|
32			   "-L"|"-h"|"-S"|"-H";
33
34	binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
35			    "-nt"|"-ot"|"-ef"|"<"|">"
36			    ;
37	operand ::= <any thing>
38*/
39
40#define T_ERR_EXIT	2	/* POSIX says > 1 for errors */
41
42struct t_op {
43	char	op_text[4];
44	Test_op	op_num;
45};
46static const struct t_op u_ops [] = {
47	{"-a",	TO_FILAXST },
48	{"-b",	TO_FILBDEV },
49	{"-c",	TO_FILCDEV },
50	{"-d",	TO_FILID },
51	{"-e",	TO_FILEXST },
52	{"-f",	TO_FILREG },
53	{"-G",	TO_FILGID },
54	{"-g",	TO_FILSETG },
55	{"-h",	TO_FILSYM },
56	{"-H",	TO_FILCDF },
57	{"-k",	TO_FILSTCK },
58	{"-L",	TO_FILSYM },
59	{"-n",	TO_STNZE },
60	{"-O",	TO_FILUID },
61	{"-o",	TO_OPTION },
62	{"-p",	TO_FILFIFO },
63	{"-r",	TO_FILRD },
64	{"-s",	TO_FILGZ },
65	{"-S",	TO_FILSOCK },
66	{"-t",	TO_FILTT },
67	{"-u",	TO_FILSETU },
68	{"-w",	TO_FILWR },
69	{"-x",	TO_FILEX },
70	{"-z",	TO_STZER },
71	{"",	TO_NONOP }
72};
73static const struct t_op b_ops [] = {
74	{"=",	TO_STEQL },
75	{"==",	TO_STEQL },
76	{"!=",	TO_STNEQ },
77	{"<",	TO_STLT },
78	{">",	TO_STGT },
79	{"-eq",	TO_INTEQ },
80	{"-ne",	TO_INTNE },
81	{"-gt",	TO_INTGT },
82	{"-ge",	TO_INTGE },
83	{"-lt",	TO_INTLT },
84	{"-le",	TO_INTLE },
85	{"-ef",	TO_FILEQ },
86	{"-nt",	TO_FILNT },
87	{"-ot",	TO_FILOT },
88	{"",	TO_NONOP }
89};
90
91static int	test_eaccess(const char *, int);
92static int	test_oexpr(Test_env *, int);
93static int	test_aexpr(Test_env *, int);
94static int	test_nexpr(Test_env *, int);
95static int	test_primary(Test_env *, int);
96static int	ptest_isa(Test_env *, Test_meta);
97static const char *ptest_getopnd(Test_env *, Test_op, int);
98static int	ptest_eval(Test_env *, Test_op, const char *,
99		    const char *, int);
100static void	ptest_error(Test_env *, int, const char *);
101
102int
103c_test(char **wp)
104{
105	int argc;
106	int res;
107	Test_env te;
108
109	te.flags = 0;
110	te.isa = ptest_isa;
111	te.getopnd = ptest_getopnd;
112	te.eval = ptest_eval;
113	te.error = ptest_error;
114
115	for (argc = 0; wp[argc]; argc++)
116		;
117
118	if (strcmp(wp[0], "[") == 0) {
119		if (strcmp(wp[--argc], "]") != 0) {
120			bi_errorf("missing ]");
121			return T_ERR_EXIT;
122		}
123	}
124
125	te.pos.wp = wp + 1;
126	te.wp_end = wp + argc;
127
128	/*
129	 * Handle the special cases from POSIX.2, section 4.62.4.
130	 * Implementation of all the rules isn't necessary since
131	 * our parser does the right thing for the omitted steps.
132	 */
133	if (argc <= 5) {
134		char **owp = wp;
135		int invert = 0;
136		Test_op	op;
137		const char *opnd1, *opnd2;
138
139		while (--argc >= 0) {
140			if ((*te.isa)(&te, TM_END))
141				return !0;
142			if (argc == 3) {
143				opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
144				if ((op = (Test_op) (*te.isa)(&te, TM_BINOP))) {
145					opnd2 = (*te.getopnd)(&te, op, 1);
146					res = (*te.eval)(&te, op, opnd1,
147					    opnd2, 1);
148					if (te.flags & TEF_ERROR)
149						return T_ERR_EXIT;
150					if (invert & 1)
151						res = !res;
152					return !res;
153				}
154				/* back up to opnd1 */
155				te.pos.wp--;
156			}
157			if (argc == 1) {
158				opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
159				res = (*te.eval)(&te, TO_STNZE, opnd1,
160				    NULL, 1);
161				if (invert & 1)
162					res = !res;
163				return !res;
164			}
165			if ((*te.isa)(&te, TM_NOT)) {
166				invert++;
167			} else
168				break;
169		}
170		te.pos.wp = owp + 1;
171	}
172
173	return test_parse(&te);
174}
175
176/*
177 * Generic test routines.
178 */
179
180Test_op
181test_isop(Test_env *te, Test_meta meta, const char *s)
182{
183	char sc1;
184	const struct t_op *otab;
185
186	otab = meta == TM_UNOP ? u_ops : b_ops;
187	if (*s) {
188		sc1 = s[1];
189		for (; otab->op_text[0]; otab++)
190			if (sc1 == otab->op_text[1] &&
191			    strcmp(s, otab->op_text) == 0)
192				return otab->op_num;
193	}
194	return TO_NONOP;
195}
196
197int
198test_eval(Test_env *te, Test_op op, const char *opnd1, const char *opnd2,
199    int do_eval)
200{
201	int res;
202	int not;
203	struct stat b1, b2;
204
205	if (!do_eval)
206		return 0;
207
208	switch ((int) op) {
209	/*
210	 * Unary Operators
211	 */
212	case TO_STNZE: /* -n */
213		return *opnd1 != '\0';
214	case TO_STZER: /* -z */
215		return *opnd1 == '\0';
216	case TO_OPTION: /* -o */
217		if ((not = *opnd1 == '!'))
218			opnd1++;
219		if ((res = option(opnd1)) < 0)
220			res = 0;
221		else {
222			res = Flag(res);
223			if (not)
224				res = !res;
225		}
226		return res;
227	case TO_FILRD: /* -r */
228		return test_eaccess(opnd1, R_OK) == 0;
229	case TO_FILWR: /* -w */
230		return test_eaccess(opnd1, W_OK) == 0;
231	case TO_FILEX: /* -x */
232		return test_eaccess(opnd1, X_OK) == 0;
233	case TO_FILAXST: /* -a */
234		return stat(opnd1, &b1) == 0;
235	case TO_FILEXST: /* -e */
236		/* at&t ksh does not appear to do the /dev/fd/ thing for
237		 * this (unless the os itself handles it)
238		 */
239		return stat(opnd1, &b1) == 0;
240	case TO_FILREG: /* -r */
241		return stat(opnd1, &b1) == 0 && S_ISREG(b1.st_mode);
242	case TO_FILID: /* -d */
243		return stat(opnd1, &b1) == 0 && S_ISDIR(b1.st_mode);
244	case TO_FILCDEV: /* -c */
245		return stat(opnd1, &b1) == 0 && S_ISCHR(b1.st_mode);
246	case TO_FILBDEV: /* -b */
247		return stat(opnd1, &b1) == 0 && S_ISBLK(b1.st_mode);
248	case TO_FILFIFO: /* -p */
249		return stat(opnd1, &b1) == 0 && S_ISFIFO(b1.st_mode);
250	case TO_FILSYM: /* -h -L */
251		return lstat(opnd1, &b1) == 0 && S_ISLNK(b1.st_mode);
252	case TO_FILSOCK: /* -S */
253		return stat(opnd1, &b1) == 0 && S_ISSOCK(b1.st_mode);
254	case TO_FILCDF:/* -H HP context dependent files (directories) */
255		return 0;
256	case TO_FILSETU: /* -u */
257		return stat(opnd1, &b1) == 0 &&
258		    (b1.st_mode & S_ISUID) == S_ISUID;
259	case TO_FILSETG: /* -g */
260		return stat(opnd1, &b1) == 0 &&
261		    (b1.st_mode & S_ISGID) == S_ISGID;
262	case TO_FILSTCK: /* -k */
263		return stat(opnd1, &b1) == 0 &&
264		    (b1.st_mode & S_ISVTX) == S_ISVTX;
265	case TO_FILGZ: /* -s */
266		return stat(opnd1, &b1) == 0 && b1.st_size > 0L;
267	case TO_FILTT: /* -t */
268		if (!bi_getn(opnd1, &res)) {
269			te->flags |= TEF_ERROR;
270			return 0;
271		}
272		return isatty(res);
273	case TO_FILUID: /* -O */
274		return stat(opnd1, &b1) == 0 && b1.st_uid == ksheuid;
275	case TO_FILGID: /* -G */
276		return stat(opnd1, &b1) == 0 && b1.st_gid == getegid();
277	/*
278	 * Binary Operators
279	 */
280	case TO_STEQL: /* = */
281		if (te->flags & TEF_DBRACKET)
282			return gmatch(opnd1, opnd2, false);
283		return strcmp(opnd1, opnd2) == 0;
284	case TO_STNEQ: /* != */
285		if (te->flags & TEF_DBRACKET)
286			return !gmatch(opnd1, opnd2, false);
287		return strcmp(opnd1, opnd2) != 0;
288	case TO_STLT: /* < */
289		return strcmp(opnd1, opnd2) < 0;
290	case TO_STGT: /* > */
291		return strcmp(opnd1, opnd2) > 0;
292	case TO_INTEQ: /* -eq */
293	case TO_INTNE: /* -ne */
294	case TO_INTGE: /* -ge */
295	case TO_INTGT: /* -gt */
296	case TO_INTLE: /* -le */
297	case TO_INTLT: /* -lt */
298		{
299			int64_t v1, v2;
300
301			if (!evaluate(opnd1, &v1, KSH_RETURN_ERROR, false) ||
302			    !evaluate(opnd2, &v2, KSH_RETURN_ERROR, false)) {
303				/* error already printed.. */
304				te->flags |= TEF_ERROR;
305				return 1;
306			}
307			switch ((int) op) {
308			case TO_INTEQ:
309				return v1 == v2;
310			case TO_INTNE:
311				return v1 != v2;
312			case TO_INTGE:
313				return v1 >= v2;
314			case TO_INTGT:
315				return v1 > v2;
316			case TO_INTLE:
317				return v1 <= v2;
318			case TO_INTLT:
319				return v1 < v2;
320			}
321		}
322	case TO_FILNT: /* -nt */
323		{
324			int s2;
325			/* ksh88/ksh93 succeed if file2 can't be stated
326			 * (subtly different from `does not exist').
327			 */
328			return stat(opnd1, &b1) == 0 &&
329			    (((s2 = stat(opnd2, &b2)) == 0 &&
330			    b1.st_mtime > b2.st_mtime) || s2 < 0);
331		}
332	case TO_FILOT: /* -ot */
333		{
334			int s1;
335			/* ksh88/ksh93 succeed if file1 can't be stated
336			 * (subtly different from `does not exist').
337			 */
338			return stat(opnd2, &b2) == 0 &&
339			    (((s1 = stat(opnd1, &b1)) == 0 &&
340			    b1.st_mtime < b2.st_mtime) || s1 < 0);
341		}
342	case TO_FILEQ: /* -ef */
343		return stat (opnd1, &b1) == 0 && stat (opnd2, &b2) == 0 &&
344		    b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino;
345	}
346	(*te->error)(te, 0, "internal error: unknown op");
347	return 1;
348}
349
350/* Routine to deal with X_OK on non-directories when running as root.
351 */
352static int
353test_eaccess(const char *path, int amode)
354{
355	int res;
356
357	res = access(path, amode);
358	/*
359	 * On most (all?) unixes, access() says everything is executable for
360	 * root - avoid this on files by using stat().
361	 */
362	if (res == 0 && ksheuid == 0 && (amode & X_OK)) {
363		struct stat statb;
364
365		if (stat(path, &statb) == -1)
366			res = -1;
367		else if (S_ISDIR(statb.st_mode))
368			res = 0;
369		else
370			res = (statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) ?
371			    0 : -1;
372	}
373
374	return res;
375}
376
377int
378test_parse(Test_env *te)
379{
380	int res;
381
382	res = test_oexpr(te, 1);
383
384	if (!(te->flags & TEF_ERROR) && !(*te->isa)(te, TM_END))
385		(*te->error)(te, 0, "unexpected operator/operand");
386
387	return (te->flags & TEF_ERROR) ? T_ERR_EXIT : !res;
388}
389
390static int
391test_oexpr(Test_env *te, int do_eval)
392{
393	int res;
394
395	res = test_aexpr(te, do_eval);
396	if (res)
397		do_eval = 0;
398	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_OR))
399		return test_oexpr(te, do_eval) || res;
400	return res;
401}
402
403static int
404test_aexpr(Test_env *te, int do_eval)
405{
406	int res;
407
408	res = test_nexpr(te, do_eval);
409	if (!res)
410		do_eval = 0;
411	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_AND))
412		return test_aexpr(te, do_eval) && res;
413	return res;
414}
415
416static int
417test_nexpr(Test_env *te, int do_eval)
418{
419	if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_NOT))
420		return !test_nexpr(te, do_eval);
421	return test_primary(te, do_eval);
422}
423
424static int
425test_primary(Test_env *te, int do_eval)
426{
427	const char *opnd1, *opnd2;
428	int res;
429	Test_op op;
430
431	if (te->flags & TEF_ERROR)
432		return 0;
433	if ((*te->isa)(te, TM_OPAREN)) {
434		res = test_oexpr(te, do_eval);
435		if (te->flags & TEF_ERROR)
436			return 0;
437		if (!(*te->isa)(te, TM_CPAREN)) {
438			(*te->error)(te, 0, "missing closing paren");
439			return 0;
440		}
441		return res;
442	}
443	/*
444	 * Binary should have precedence over unary in this case
445	 * so that something like test \( -f = -f \) is accepted
446	 */
447	if ((te->flags & TEF_DBRACKET) || (&te->pos.wp[1] < te->wp_end &&
448	    !test_isop(te, TM_BINOP, te->pos.wp[1]))) {
449		if ((op = (Test_op) (*te->isa)(te, TM_UNOP))) {
450			/* unary expression */
451			opnd1 = (*te->getopnd)(te, op, do_eval);
452			if (!opnd1) {
453				(*te->error)(te, -1, "missing argument");
454				return 0;
455			}
456
457			return (*te->eval)(te, op, opnd1, NULL,
458			    do_eval);
459		}
460	}
461	opnd1 = (*te->getopnd)(te, TO_NONOP, do_eval);
462	if (!opnd1) {
463		(*te->error)(te, 0, "expression expected");
464		return 0;
465	}
466	if ((op = (Test_op) (*te->isa)(te, TM_BINOP))) {
467		/* binary expression */
468		opnd2 = (*te->getopnd)(te, op, do_eval);
469		if (!opnd2) {
470			(*te->error)(te, -1, "missing second argument");
471			return 0;
472		}
473
474		return (*te->eval)(te, op, opnd1, opnd2, do_eval);
475	}
476	if (te->flags & TEF_DBRACKET) {
477		(*te->error)(te, -1, "missing expression operator");
478		return 0;
479	}
480	return (*te->eval)(te, TO_STNZE, opnd1, NULL, do_eval);
481}
482
483/*
484 * Plain test (test and [ .. ]) specific routines.
485 */
486
487/* Test if the current token is a whatever.  Accepts the current token if
488 * it is.  Returns 0 if it is not, non-zero if it is (in the case of
489 * TM_UNOP and TM_BINOP, the returned value is a Test_op).
490 */
491static int
492ptest_isa(Test_env *te, Test_meta meta)
493{
494	/* Order important - indexed by Test_meta values */
495	static const char *const tokens[] = {
496		"-o", "-a", "!", "(", ")"
497	};
498	int ret;
499
500	if (te->pos.wp >= te->wp_end)
501		return meta == TM_END;
502
503	if (meta == TM_UNOP || meta == TM_BINOP)
504		ret = (int) test_isop(te, meta, *te->pos.wp);
505	else if (meta == TM_END)
506		ret = 0;
507	else
508		ret = strcmp(*te->pos.wp, tokens[(int) meta]) == 0;
509
510	/* Accept the token? */
511	if (ret)
512		te->pos.wp++;
513
514	return ret;
515}
516
517static const char *
518ptest_getopnd(Test_env *te, Test_op op, int do_eval)
519{
520	if (te->pos.wp >= te->wp_end)
521		return NULL;
522	return *te->pos.wp++;
523}
524
525static int
526ptest_eval(Test_env *te, Test_op op, const char *opnd1, const char *opnd2,
527    int do_eval)
528{
529	return test_eval(te, op, opnd1, opnd2, do_eval);
530}
531
532static void
533ptest_error(Test_env *te, int offset, const char *msg)
534{
535	const char *op = te->pos.wp + offset >= te->wp_end ?
536	    NULL : te->pos.wp[offset];
537
538	te->flags |= TEF_ERROR;
539	if (op)
540		bi_errorf("%s: %s", op, msg);
541	else
542		bi_errorf("%s", msg);
543}
544