setmode.c

最後變更在這個檔案是 3389,由 bird 提交於 5 年前
kmk: Avoid setting umask just to get it, store the current value in a global variable (g_fUMask). The umask(0777) call in cp.c raced other code (kmk_append) that created files and directories, leaving us with read-only files sometimes.
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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	/#include <sys/cdefs.h>/
36	#if defined(LIBC_SCCS) && !defined(lint)
37	#if 0
38	static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
39	#else
40	__RCSID("$NetBSD: setmode.c,v 1.30 2003/08/07 16:42:56 agc Exp $");
41	#endif
42	#endif /* LIBC_SCCS and not lint */
43
44	/#include "namespace.h"/
45	#include "config.h"
46	#include <sys/types.h>
47	#include <sys/stat.h>
48
49	#include <assert.h>
50	#include <ctype.h>
51	#include <errno.h>
52	#include <signal.h>
53	#include <stdlib.h>
54	#ifndef _MSC_VER
55	#include <unistd.h>
56	#else
57	#include "mscfakes.h"
58	#endif
59
60	#ifdef SETMODE_DEBUG
61	#include <stdio.h>
62	#endif
63
64	/*#ifdef __weak_alias
65	__weak_alias(getmode,_getmode)
66	__weak_alias(setmode,_setmode)
67	#endif*/
68
69	#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
70	#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
71
72	typedef struct bitcmd {
73	char cmd;
74	char cmd2;
75	mode_t bits;
76	} BITCMD;
77
78	#define CMD2_CLR 0x01
79	#define CMD2_SET 0x02
80	#define CMD2_GBITS 0x04
81	#define CMD2_OBITS 0x08
82	#define CMD2_UBITS 0x10
83
84	static BITCMD addcmd(BITCMD , int, int, int, u_int);
85	static void compress_mode(BITCMD *);
86	#ifdef SETMODE_DEBUG
87	static void dumpmode(BITCMD *);
88	#endif
89
90	#ifndef _DIAGASSERT
91	# define _DIAGASSERT assert
92	#endif
93
94	#ifndef S_ISTXT
95	# ifdef S_ISVTX
96	# define S_ISTXT S_ISVTX
97	# else
98	# define S_ISTXT 0
99	# endif
100	#endif /* !S_ISTXT */
101
102	extern mode_t g_fUMask; /* Initialize in main() and keep up to date. */
103
104
105	/*
106	* Given the old mode and an array of bitcmd structures, apply the operations
107	* described in the bitcmd structures to the old mode, and return the new mode.
108	* Note that there is no '=' command; a strict assignment is just a '-' (clear
109	* bits) followed by a '+' (set bits).
110	*/
111	mode_t
112	bsd_getmode(bbox, omode)
113	const void *bbox;
114	mode_t omode;
115	{
116	const BITCMD *set;
117	mode_t clrval, newmode, value;
118
119	_DIAGASSERT(bbox != NULL);
120
121	set = (const BITCMD *)bbox;
122	newmode = omode;
123	for (value = 0;; set++)
124	switch(set->cmd) {
125	/*
126	* When copying the user, group or other bits around, we "know"
127	* where the bits are in the mode so that we can do shifts to
128	* copy them around. If we don't use shifts, it gets real
129	* grundgy with lots of single bit checks and bit sets.
130	*/
131	case 'u':
132	value = (newmode & S_IRWXU) >> 6;
133	goto common;
134
135	case 'g':
136	value = (newmode & S_IRWXG) >> 3;
137	goto common;
138
139	case 'o':
140	value = newmode & S_IRWXO;
141	common: if (set->cmd2 & CMD2_CLR) {
142	clrval =
143	(set->cmd2 & CMD2_SET) ? S_IRWXO : value;
144	if (set->cmd2 & CMD2_UBITS)
145	newmode &= ~((clrval<<6) & set->bits);
146	if (set->cmd2 & CMD2_GBITS)
147	newmode &= ~((clrval<<3) & set->bits);
148	if (set->cmd2 & CMD2_OBITS)
149	newmode &= ~(clrval & set->bits);
150	}
151	if (set->cmd2 & CMD2_SET) {
152	if (set->cmd2 & CMD2_UBITS)
153	newmode \|= (value<<6) & set->bits;
154	if (set->cmd2 & CMD2_GBITS)
155	newmode \|= (value<<3) & set->bits;
156	if (set->cmd2 & CMD2_OBITS)
157	newmode \|= value & set->bits;
158	}
159	break;
160
161	case '+':
162	newmode \|= set->bits;
163	break;
164
165	case '-':
166	newmode &= ~set->bits;
167	break;
168
169	case 'X':
170	if (omode & (S_IFDIR\|S_IXUSR\|S_IXGRP\|S_IXOTH))
171	newmode \|= set->bits;
172	break;
173
174	case '\0':
175	default:
176	#ifdef SETMODE_DEBUG
177	(void)printf("getmode:%04o -> %04o\n", omode, newmode);
178	#endif
179	return (newmode);
180	}
181	}
182
183	#define ADDCMD(a, b, c, d) do { \
184	if (set >= endset) { \
185	BITCMD *newset; \
186	setlen += SET_LEN_INCR; \
187	newset = realloc(saveset, sizeof(BITCMD) * setlen); \
188	if (newset == NULL) { \
189	free(saveset); \
190	return (NULL); \
191	} \
192	set = newset + (set - saveset); \
193	saveset = newset; \
194	endset = newset + (setlen - 2); \
195	} \
196	set = addcmd(set, (a), (b), (c), (d)); \
197	} while (/CONSTCOND/0)
198
199	#define STANDARD_BITS (S_ISUID\|S_ISGID\|S_IRWXU\|S_IRWXG\|S_IRWXO)
200
201	void *
202	bsd_setmode(p)
203	const char *p;
204	{
205	int perm, who;
206	char op, *ep;
207	BITCMD set, saveset, *endset;
208	#ifndef _MSC_VER
209	sigset_t signset, sigoset;
210	#endif
211	mode_t mask;
212	int equalopdone = 0; /* pacify gcc */
213	int permXbits, setlen;
214
215	if (!*p)
216	return (NULL);
217
218	/*
219	* Get a copy of the mask for the permissions that are mask relative.
220	* Flip the bits, we want what's not set. Since it's possible that
221	* the caller is opening files inside a signal handler, protect them
222	* as best we can.
223	*/
224	#ifndef _MSC_VER
225	sigfillset(&signset);
226	(void)sigprocmask(SIG_BLOCK, &signset, &sigoset);
227	#endif
228	mask = g_fUMask;
229	assert(mask == umask(g_fUMask));
230	mask = ~mask;
231	#ifndef _MSC_VER
232	(void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
233	#endif
234
235	setlen = SET_LEN + 2;
236
237	if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
238	return (NULL);
239	saveset = set;
240	endset = set + (setlen - 2);
241
242	/*
243	* If an absolute number, get it and return; disallow non-octal digits
244	* or illegal bits.
245	*/
246	if (isdigit((unsigned char)*p)) {
247	perm = (mode_t)strtol(p, &ep, 8);
248	if (*ep \|\| perm & ~(STANDARD_BITS\|S_ISTXT)) {
249	free(saveset);
250	return (NULL);
251	}
252	ADDCMD('=', (STANDARD_BITS\|S_ISTXT), perm, mask);
253	set->cmd = 0;
254	return (saveset);
255	}
256
257	/*
258	* Build list of structures to set/clear/copy bits as described by
259	* each clause of the symbolic mode.
260	*/
261	for (;;) {
262	/* First, find out which bits might be modified. */
263	for (who = 0;; ++p) {
264	switch (*p) {
265	case 'a':
266	who \|= STANDARD_BITS;
267	break;
268	case 'u':
269	who \|= S_ISUID\|S_IRWXU;
270	break;
271	case 'g':
272	who \|= S_ISGID\|S_IRWXG;
273	break;
274	case 'o':
275	who \|= S_IRWXO;
276	break;
277	default:
278	goto getop;
279	}
280	}
281
282	getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
283	free(saveset);
284	return (NULL);
285	}
286	if (op == '=')
287	equalopdone = 0;
288
289	who &= ~S_ISTXT;
290	for (perm = 0, permXbits = 0;; ++p) {
291	switch (*p) {
292	case 'r':
293	perm \|= S_IRUSR\|S_IRGRP\|S_IROTH;
294	break;
295	case 's':
296	/*
297	* If specific bits where requested and
298	* only "other" bits ignore set-id.
299	*/
300	if (who == 0 \|\| (who & ~S_IRWXO))
301	perm \|= S_ISUID\|S_ISGID;
302	break;
303	case 't':
304	/*
305	* If specific bits where requested and
306	* only "other" bits ignore set-id.
307	*/
308	if (who == 0 \|\| (who & ~S_IRWXO)) {
309	who \|= S_ISTXT;
310	perm \|= S_ISTXT;
311	}
312	break;
313	case 'w':
314	perm \|= S_IWUSR\|S_IWGRP\|S_IWOTH;
315	break;
316	case 'X':
317	permXbits = S_IXUSR\|S_IXGRP\|S_IXOTH;
318	break;
319	case 'x':
320	perm \|= S_IXUSR\|S_IXGRP\|S_IXOTH;
321	break;
322	case 'u':
323	case 'g':
324	case 'o':
325	/*
326	* When ever we hit 'u', 'g', or 'o', we have
327	* to flush out any partial mode that we have,
328	* and then do the copying of the mode bits.
329	*/
330	if (perm) {
331	ADDCMD(op, who, perm, mask);
332	perm = 0;
333	}
334	if (op == '=')
335	equalopdone = 1;
336	if (op == '+' && permXbits) {
337	ADDCMD('X', who, permXbits, mask);
338	permXbits = 0;
339	}
340	ADDCMD(*p, who, op, mask);
341	break;
342
343	default:
344	/*
345	* Add any permissions that we haven't already
346	* done.
347	*/
348	if (perm \|\| (op == '=' && !equalopdone)) {
349	if (op == '=')
350	equalopdone = 1;
351	ADDCMD(op, who, perm, mask);
352	perm = 0;
353	}
354	if (permXbits) {
355	ADDCMD('X', who, permXbits, mask);
356	permXbits = 0;
357	}
358	goto apply;
359	}
360	}
361
362	apply: if (!*p)
363	break;
364	if (*p != ',')
365	goto getop;
366	++p;
367	}
368	set->cmd = 0;
369	#ifdef SETMODE_DEBUG
370	(void)printf("Before compress_mode()\n");
371	dumpmode(saveset);
372	#endif
373	compress_mode(saveset);
374	#ifdef SETMODE_DEBUG
375	(void)printf("After compress_mode()\n");
376	dumpmode(saveset);
377	#endif
378	return (saveset);
379	}
380
381	static BITCMD *
382	addcmd(set, op, who, oparg, mask)
383	BITCMD *set;
384	int oparg, who;
385	int op;
386	u_int mask;
387	{
388
389	_DIAGASSERT(set != NULL);
390
391	switch (op) {
392	case '=':
393	set->cmd = '-';
394	set->bits = who ? who : STANDARD_BITS;
395	set++;
396
397	op = '+';
398	/* FALLTHROUGH */
399	case '+':
400	case '-':
401	case 'X':
402	set->cmd = op;
403	set->bits = (who ? (mode_t)who : mask) & oparg;
404	break;
405
406	case 'u':
407	case 'g':
408	case 'o':
409	set->cmd = op;
410	if (who) {
411	set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) \|
412	((who & S_IRGRP) ? CMD2_GBITS : 0) \|
413	((who & S_IROTH) ? CMD2_OBITS : 0);
414	set->bits = (mode_t)~0;
415	} else {
416	set->cmd2 = CMD2_UBITS \| CMD2_GBITS \| CMD2_OBITS;
417	set->bits = mask;
418	}
419
420	if (oparg == '+')
421	set->cmd2 \|= CMD2_SET;
422	else if (oparg == '-')
423	set->cmd2 \|= CMD2_CLR;
424	else if (oparg == '=')
425	set->cmd2 \|= CMD2_SET\|CMD2_CLR;
426	break;
427	}
428	return (set + 1);
429	}
430
431	#ifdef SETMODE_DEBUG
432	static void
433	dumpmode(set)
434	BITCMD *set;
435	{
436
437	_DIAGASSERT(set != NULL);
438
439	for (; set->cmd; ++set)
440	(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
441	set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
442	set->cmd2 & CMD2_CLR ? " CLR" : "",
443	set->cmd2 & CMD2_SET ? " SET" : "",
444	set->cmd2 & CMD2_UBITS ? " UBITS" : "",
445	set->cmd2 & CMD2_GBITS ? " GBITS" : "",
446	set->cmd2 & CMD2_OBITS ? " OBITS" : "");
447	}
448	#endif
449
450	/*
451	* Given an array of bitcmd structures, compress by compacting consecutive
452	* '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
453	* 'g' and 'o' commands continue to be separate. They could probably be
454	* compacted, but it's not worth the effort.
455	*/
456	static void
457	compress_mode(set)
458	BITCMD *set;
459	{
460	BITCMD *nset;
461	int setbits, clrbits, Xbits, op;
462
463	_DIAGASSERT(set != NULL);
464
465	for (nset = set;;) {
466	/* Copy over any 'u', 'g' and 'o' commands. */
467	while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
468	set++ = nset++;
469	if (!op)
470	return;
471	}
472
473	for (setbits = clrbits = Xbits = 0;; nset++) {
474	if ((op = nset->cmd) == '-') {
475	clrbits \|= nset->bits;
476	setbits &= ~nset->bits;
477	Xbits &= ~nset->bits;
478	} else if (op == '+') {
479	setbits \|= nset->bits;
480	clrbits &= ~nset->bits;
481	Xbits &= ~nset->bits;
482	} else if (op == 'X')
483	Xbits \|= nset->bits & ~setbits;
484	else
485	break;
486	}
487	if (clrbits) {
488	set->cmd = '-';
489	set->cmd2 = 0;
490	set->bits = clrbits;
491	set++;
492	}
493	if (setbits) {
494	set->cmd = '+';
495	set->cmd2 = 0;
496	set->bits = setbits;
497	set++;
498	}
499	if (Xbits) {
500	set->cmd = 'X';
501	set->cmd2 = 0;
502	set->bits = Xbits;
503	set++;
504	}
505	}
506	}

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source: kBuild/trunk/src/kmk/kmkbuiltin/setmode.c

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