setmode.c@ 2311

Last change on this file since 2311 was 2290, checked in by bird, 16 years ago
kash: malloc/free/friends gets a psh.
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1	/* $NetBSD: setmode.c,v 1.30 2003/08/07 16:42:56 agc Exp $ */
2
3	/*
4	* Copyright (c) 1989, 1993, 1994
5	* The Regents of the University of California. All rights reserved.
6	*
7	* This code is derived from software contributed to Berkeley by
8	* Dave Borman at Cray Research, Inc.
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	#if 0
36	#if defined(LIBC_SCCS) && !defined(lint)
37	static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
38	#else
39	__RCSID("$NetBSD: setmode.c,v 1.30 2003/08/07 16:42:56 agc Exp $");
40	#endif /* LIBC_SCCS and not lint */
41	#endif
42
43	#include <sys/types.h>
44	#include <sys/stat.h>
45
46	#include <assert.h>
47	#include <ctype.h>
48	#include <errno.h>
49	#include <stdlib.h>
50	#include "shinstance.h" /* for unistd.h types/defines */
51
52	#ifdef SETMODE_DEBUG
53	#include <stdio.h>
54	#endif
55
56	#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
57	#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
58
59	typedef struct bitcmd {
60	char cmd;
61	char cmd2;
62	mode_t bits;
63	} BITCMD;
64
65	#define CMD2_CLR 0x01
66	#define CMD2_SET 0x02
67	#define CMD2_GBITS 0x04
68	#define CMD2_OBITS 0x08
69	#define CMD2_UBITS 0x10
70
71	static BITCMD addcmd(BITCMD , int, int, int, unsigned int);
72	static void compress_mode(BITCMD *);
73	#ifdef SETMODE_DEBUG
74	static void dumpmode(BITCMD *);
75	#endif
76
77	#ifndef _DIAGASSERT
78	# define _DIAGASSERT assert
79	#endif
80
81	#ifndef S_ISTXT
82	# ifdef S_ISVTX
83	# define S_ISTXT S_ISVTX
84	# else
85	# define S_ISTXT 0
86	# endif
87	#endif /* !S_ISTXT */
88
89	/*
90	* Given the old mode and an array of bitcmd structures, apply the operations
91	* described in the bitcmd structures to the old mode, and return the new mode.
92	* Note that there is no '=' command; a strict assignment is just a '-' (clear
93	* bits) followed by a '+' (set bits).
94	*/
95	mode_t
96	bsd_getmode(const void *bbox, mode_t omode)
97	{
98	const BITCMD *set;
99	mode_t clrval, newmode, value;
100
101	_DIAGASSERT(bbox != NULL);
102
103	set = (const BITCMD *)bbox;
104	newmode = omode;
105	for (value = 0;; set++)
106	switch(set->cmd) {
107	/*
108	* When copying the user, group or other bits around, we "know"
109	* where the bits are in the mode so that we can do shifts to
110	* copy them around. If we don't use shifts, it gets real
111	* grundgy with lots of single bit checks and bit sets.
112	*/
113	case 'u':
114	value = (newmode & S_IRWXU) >> 6;
115	goto common;
116
117	case 'g':
118	value = (newmode & S_IRWXG) >> 3;
119	goto common;
120
121	case 'o':
122	value = newmode & S_IRWXO;
123	common: if (set->cmd2 & CMD2_CLR) {
124	clrval =
125	(set->cmd2 & CMD2_SET) ? S_IRWXO : value;
126	if (set->cmd2 & CMD2_UBITS)
127	newmode &= ~((clrval<<6) & set->bits);
128	if (set->cmd2 & CMD2_GBITS)
129	newmode &= ~((clrval<<3) & set->bits);
130	if (set->cmd2 & CMD2_OBITS)
131	newmode &= ~(clrval & set->bits);
132	}
133	if (set->cmd2 & CMD2_SET) {
134	if (set->cmd2 & CMD2_UBITS)
135	newmode \|= (value<<6) & set->bits;
136	if (set->cmd2 & CMD2_GBITS)
137	newmode \|= (value<<3) & set->bits;
138	if (set->cmd2 & CMD2_OBITS)
139	newmode \|= value & set->bits;
140	}
141	break;
142
143	case '+':
144	newmode \|= set->bits;
145	break;
146
147	case '-':
148	newmode &= ~set->bits;
149	break;
150
151	case 'X':
152	if (omode & (S_IFDIR\|S_IXUSR\|S_IXGRP\|S_IXOTH))
153	newmode \|= set->bits;
154	break;
155
156	case '\0':
157	default:
158	#ifdef SETMODE_DEBUG
159	(void)printf("getmode:%04o -> %04o\n", omode, newmode);
160	#endif
161	return (newmode);
162	}
163	}
164
165	#define ADDCMD(a, b, c, d) do { \
166	if (set >= endset) { \
167	BITCMD *newset; \
168	setlen += SET_LEN_INCR; \
169	newset = sh_realloc(NULL, saveset, sizeof(BITCMD) * setlen); \
170	if (newset == NULL) { \
171	sh_free(NULL, saveset); \
172	return (NULL); \
173	} \
174	set = newset + (set - saveset); \
175	saveset = newset; \
176	endset = newset + (setlen - 2); \
177	} \
178	set = addcmd(set, (a), (b), (c), (d)); \
179	} while (/CONSTCOND/0)
180
181	#define STANDARD_BITS (S_ISUID\|S_ISGID\|S_IRWXU\|S_IRWXG\|S_IRWXO)
182
183	void *
184	bsd_setmode(shinstance psh, const char p)
185	{
186	int perm, who;
187	char op, *ep;
188	BITCMD set, saveset, *endset;
189	mode_t mask;
190	int equalopdone = 0; /* pacify gcc */
191	int permXbits, setlen;
192
193	if (!*p)
194	return (NULL);
195
196	/*
197	* Get a copy of the mask for the permissions that are mask relative.
198	* Flip the bits, we want what's not set.
199	*/
200	mask = shfile_get_umask(&psh->fdtab);
201
202	setlen = SET_LEN + 2;
203
204	if ((set = sh_malloc(NULL, sizeof(BITCMD) * setlen)) == NULL)
205	return (NULL);
206	saveset = set;
207	endset = set + (setlen - 2);
208
209	/*
210	* If an absolute number, get it and return; disallow non-octal digits
211	* or illegal bits.
212	*/
213	if (isdigit((unsigned char)*p)) {
214	perm = (mode_t)strtol(p, &ep, 8);
215	if (*ep \|\| perm & ~(STANDARD_BITS\|S_ISTXT)) {
216	sh_free(NULL, saveset);
217	return (NULL);
218	}
219	ADDCMD('=', (STANDARD_BITS\|S_ISTXT), perm, mask);
220	set->cmd = 0;
221	return (saveset);
222	}
223
224	/*
225	* Build list of structures to set/clear/copy bits as described by
226	* each clause of the symbolic mode.
227	*/
228	for (;;) {
229	/* First, find out which bits might be modified. */
230	for (who = 0;; ++p) {
231	switch (*p) {
232	case 'a':
233	who \|= STANDARD_BITS;
234	break;
235	case 'u':
236	who \|= S_ISUID\|S_IRWXU;
237	break;
238	case 'g':
239	who \|= S_ISGID\|S_IRWXG;
240	break;
241	case 'o':
242	who \|= S_IRWXO;
243	break;
244	default:
245	goto getop;
246	}
247	}
248
249	getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
250	sh_free(NULL, saveset);
251	return (NULL);
252	}
253	if (op == '=')
254	equalopdone = 0;
255
256	who &= ~S_ISTXT;
257	for (perm = 0, permXbits = 0;; ++p) {
258	switch (*p) {
259	case 'r':
260	perm \|= S_IRUSR\|S_IRGRP\|S_IROTH;
261	break;
262	case 's':
263	/*
264	* If specific bits where requested and
265	* only "other" bits ignore set-id.
266	*/
267	if (who == 0 \|\| (who & ~S_IRWXO))
268	perm \|= S_ISUID\|S_ISGID;
269	break;
270	case 't':
271	/*
272	* If specific bits where requested and
273	* only "other" bits ignore set-id.
274	*/
275	if (who == 0 \|\| (who & ~S_IRWXO)) {
276	who \|= S_ISTXT;
277	perm \|= S_ISTXT;
278	}
279	break;
280	case 'w':
281	perm \|= S_IWUSR\|S_IWGRP\|S_IWOTH;
282	break;
283	case 'X':
284	permXbits = S_IXUSR\|S_IXGRP\|S_IXOTH;
285	break;
286	case 'x':
287	perm \|= S_IXUSR\|S_IXGRP\|S_IXOTH;
288	break;
289	case 'u':
290	case 'g':
291	case 'o':
292	/*
293	* When ever we hit 'u', 'g', or 'o', we have
294	* to flush out any partial mode that we have,
295	* and then do the copying of the mode bits.
296	*/
297	if (perm) {
298	ADDCMD(op, who, perm, mask);
299	perm = 0;
300	}
301	if (op == '=')
302	equalopdone = 1;
303	if (op == '+' && permXbits) {
304	ADDCMD('X', who, permXbits, mask);
305	permXbits = 0;
306	}
307	ADDCMD(*p, who, op, mask);
308	break;
309
310	default:
311	/*
312	* Add any permissions that we haven't already
313	* done.
314	*/
315	if (perm \|\| (op == '=' && !equalopdone)) {
316	if (op == '=')
317	equalopdone = 1;
318	ADDCMD(op, who, perm, mask);
319	perm = 0;
320	}
321	if (permXbits) {
322	ADDCMD('X', who, permXbits, mask);
323	permXbits = 0;
324	}
325	goto apply;
326	}
327	}
328
329	apply: if (!*p)
330	break;
331	if (*p != ',')
332	goto getop;
333	++p;
334	}
335	set->cmd = 0;
336	#ifdef SETMODE_DEBUG
337	(void)printf("Before compress_mode()\n");
338	dumpmode(saveset);
339	#endif
340	compress_mode(saveset);
341	#ifdef SETMODE_DEBUG
342	(void)printf("After compress_mode()\n");
343	dumpmode(saveset);
344	#endif
345	return (saveset);
346	}
347
348	static BITCMD *
349	addcmd(set, op, who, oparg, mask)
350	BITCMD *set;
351	int oparg, who;
352	int op;
353	unsigned int mask;
354	{
355
356	_DIAGASSERT(set != NULL);
357
358	switch (op) {
359	case '=':
360	set->cmd = '-';
361	set->bits = who ? who : STANDARD_BITS;
362	set++;
363
364	op = '+';
365	/* FALLTHROUGH */
366	case '+':
367	case '-':
368	case 'X':
369	set->cmd = op;
370	set->bits = (who ? who : mask) & oparg;
371	break;
372
373	case 'u':
374	case 'g':
375	case 'o':
376	set->cmd = op;
377	if (who) {
378	set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) \|
379	((who & S_IRGRP) ? CMD2_GBITS : 0) \|
380	((who & S_IROTH) ? CMD2_OBITS : 0);
381	set->bits = (mode_t)~0;
382	} else {
383	set->cmd2 = CMD2_UBITS \| CMD2_GBITS \| CMD2_OBITS;
384	set->bits = mask;
385	}
386
387	if (oparg == '+')
388	set->cmd2 \|= CMD2_SET;
389	else if (oparg == '-')
390	set->cmd2 \|= CMD2_CLR;
391	else if (oparg == '=')
392	set->cmd2 \|= CMD2_SET\|CMD2_CLR;
393	break;
394	}
395	return (set + 1);
396	}
397
398	#ifdef SETMODE_DEBUG
399	static void
400	dumpmode(set)
401	BITCMD *set;
402	{
403
404	_DIAGASSERT(set != NULL);
405
406	for (; set->cmd; ++set)
407	(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
408	set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
409	set->cmd2 & CMD2_CLR ? " CLR" : "",
410	set->cmd2 & CMD2_SET ? " SET" : "",
411	set->cmd2 & CMD2_UBITS ? " UBITS" : "",
412	set->cmd2 & CMD2_GBITS ? " GBITS" : "",
413	set->cmd2 & CMD2_OBITS ? " OBITS" : "");
414	}
415	#endif
416
417	/*
418	* Given an array of bitcmd structures, compress by compacting consecutive
419	* '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
420	* 'g' and 'o' commands continue to be separate. They could probably be
421	* compacted, but it's not worth the effort.
422	*/
423	static void
424	compress_mode(set)
425	BITCMD *set;
426	{
427	BITCMD *nset;
428	int setbits, clrbits, Xbits, op;
429
430	_DIAGASSERT(set != NULL);
431
432	for (nset = set;;) {
433	/* Copy over any 'u', 'g' and 'o' commands. */
434	while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
435	set++ = nset++;
436	if (!op)
437	return;
438	}
439
440	for (setbits = clrbits = Xbits = 0;; nset++) {
441	if ((op = nset->cmd) == '-') {
442	clrbits \|= nset->bits;
443	setbits &= ~nset->bits;
444	Xbits &= ~nset->bits;
445	} else if (op == '+') {
446	setbits \|= nset->bits;
447	clrbits &= ~nset->bits;
448	Xbits &= ~nset->bits;
449	} else if (op == 'X')
450	Xbits \|= nset->bits & ~setbits;
451	else
452	break;
453	}
454	if (clrbits) {
455	set->cmd = '-';
456	set->cmd2 = 0;
457	set->bits = clrbits;
458	set++;
459	}
460	if (setbits) {
461	set->cmd = '+';
462	set->cmd2 = 0;
463	set->bits = setbits;
464	set++;
465	}
466	if (Xbits) {
467	set->cmd = 'X';
468	set->cmd2 = 0;
469	set->bits = Xbits;
470	set++;
471	}
472	}
473	}

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source: kBuild/trunk/src/kash/setmode.c@ 2311

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