setmode.c@ 285

Last change on this file since 285 was 227, checked in by bird, 20 years ago
builtin stuff.
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1	/*
2	* Copyright (c) 1989, 1993, 1994
3	* The Regents of the University of California. All rights reserved.
4	*
5	* This code is derived from software contributed to Berkeley by
6	* Dave Borman at Cray Research, Inc.
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	* 3. All advertising materials mentioning features or use of this software
17	* must display the following acknowledgement:
18	* This product includes software developed by the University of
19	* California, Berkeley and its contributors.
20	* 4. Neither the name of the University nor the names of its contributors
21	* may be used to endorse or promote products derived from this software
22	* without specific prior written permission.
23	*
24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34	* SUCH DAMAGE.
35	*/
36
37	#if defined(LIBC_SCCS) && !defined(lint)
38	static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
39	#endif /* LIBC_SCCS and not lint */
40	#include <sys/cdefs.h>
41	//__FBSDID("$FreeBSD: src/lib/libc/gen/setmode.c,v 1.9 2003/02/23 00:24:03 mikeh Exp $");
42
43	//#include "namespace.h"
44	#include <sys/types.h>
45	#include <sys/stat.h>
46
47	#include <ctype.h>
48	#include <signal.h>
49	#include <stddef.h>
50	#include <stdlib.h>
51	#include <unistd.h>
52
53	#ifdef SETMODE_DEBUG
54	#include <stdio.h>
55	#endif
56	//#include "un-namespace.h"
57
58	#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
59	#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
60
61	typedef struct bitcmd {
62	char cmd;
63	char cmd2;
64	mode_t bits;
65	} BITCMD;
66
67	#define CMD2_CLR 0x01
68	#define CMD2_SET 0x02
69	#define CMD2_GBITS 0x04
70	#define CMD2_OBITS 0x08
71	#define CMD2_UBITS 0x10
72
73	static BITCMD addcmd(BITCMD , int, int, int, u_int);
74	static void compress_mode(BITCMD *);
75	#ifdef SETMODE_DEBUG
76	static void dumpmode(BITCMD *);
77	#endif
78
79	#ifndef S_ISTXT
80	#ifdef S_ISVTX
81	#define S_ISTXT S_ISVTX
82	#else
83	#define S_ISTXT 0
84	#endif
85	#endif /* !S_ISTXT */
86
87	/*
88	* Given the old mode and an array of bitcmd structures, apply the operations
89	* described in the bitcmd structures to the old mode, and return the new mode.
90	* Note that there is no '=' command; a strict assignment is just a '-' (clear
91	* bits) followed by a '+' (set bits).
92	*/
93	mode_t
94	getmode(bbox, omode)
95	const void *bbox;
96	mode_t omode;
97	{
98	const BITCMD *set;
99	mode_t clrval, newmode, value;
100
101	set = (const BITCMD *)bbox;
102	newmode = omode;
103	for (value = 0;; set++)
104	switch(set->cmd) {
105	/*
106	* When copying the user, group or other bits around, we "know"
107	* where the bits are in the mode so that we can do shifts to
108	* copy them around. If we don't use shifts, it gets real
109	* grundgy with lots of single bit checks and bit sets.
110	*/
111	case 'u':
112	value = (newmode & S_IRWXU) >> 6;
113	goto common;
114
115	case 'g':
116	value = (newmode & S_IRWXG) >> 3;
117	goto common;
118
119	case 'o':
120	value = newmode & S_IRWXO;
121	common: if (set->cmd2 & CMD2_CLR) {
122	clrval =
123	(set->cmd2 & CMD2_SET) ? S_IRWXO : value;
124	if (set->cmd2 & CMD2_UBITS)
125	newmode &= ~((clrval<<6) & set->bits);
126	if (set->cmd2 & CMD2_GBITS)
127	newmode &= ~((clrval<<3) & set->bits);
128	if (set->cmd2 & CMD2_OBITS)
129	newmode &= ~(clrval & set->bits);
130	}
131	if (set->cmd2 & CMD2_SET) {
132	if (set->cmd2 & CMD2_UBITS)
133	newmode \|= (value<<6) & set->bits;
134	if (set->cmd2 & CMD2_GBITS)
135	newmode \|= (value<<3) & set->bits;
136	if (set->cmd2 & CMD2_OBITS)
137	newmode \|= value & set->bits;
138	}
139	break;
140
141	case '+':
142	newmode \|= set->bits;
143	break;
144
145	case '-':
146	newmode &= ~set->bits;
147	break;
148
149	case 'X':
150	if (omode & (S_IFDIR\|S_IXUSR\|S_IXGRP\|S_IXOTH))
151	newmode \|= set->bits;
152	break;
153
154	case '\0':
155	default:
156	#ifdef SETMODE_DEBUG
157	(void)printf("getmode:%04o -> %04o\n", omode, newmode);
158	#endif
159	return (newmode);
160	}
161	}
162
163	#define ADDCMD(a, b, c, d) \
164	if (set >= endset) { \
165	BITCMD *newset; \
166	setlen += SET_LEN_INCR; \
167	newset = realloc(saveset, sizeof(BITCMD) * setlen); \
168	if (!newset) { \
169	if (saveset) \
170	free(saveset); \
171	saveset = NULL; \
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
180	#define STANDARD_BITS (S_ISUID\|S_ISGID\|S_IRWXU\|S_IRWXG\|S_IRWXO)
181
182	void *
183	setmode(p)
184	const char *p;
185	{
186	int perm, who;
187	char op, *ep;
188	BITCMD set, saveset, *endset;
189	sigset_t sigset, sigoset;
190	mode_t mask;
191	int equalopdone=0, permXbits, setlen;
192	long perml;
193
194	if (!*p)
195	return (NULL);
196
197	/*
198	* Get a copy of the mask for the permissions that are mask relative.
199	* Flip the bits, we want what's not set. Since it's possible that
200	* the caller is opening files inside a signal handler, protect them
201	* as best we can.
202	*/
203	sigfillset(&sigset);
204	(void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
205	(void)umask(mask = umask(0));
206	mask = ~mask;
207	(void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
208
209	setlen = SET_LEN + 2;
210
211	if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
212	return (NULL);
213	saveset = set;
214	endset = set + (setlen - 2);
215
216	/*
217	* If an absolute number, get it and return; disallow non-octal digits
218	* or illegal bits.
219	*/
220	if (isdigit((unsigned char)*p)) {
221	perml = strtol(p, &ep, 8);
222	if (*ep \|\| perml < 0 \|\| perml & ~(STANDARD_BITS\|S_ISTXT)) {
223	free(saveset);
224	return (NULL);
225	}
226	perm = (mode_t)perml;
227	ADDCMD('=', (STANDARD_BITS\|S_ISTXT), perm, mask);
228	set->cmd = 0;
229	return (saveset);
230	}
231
232	/*
233	* Build list of structures to set/clear/copy bits as described by
234	* each clause of the symbolic mode.
235	*/
236	for (;;) {
237	/* First, find out which bits might be modified. */
238	for (who = 0;; ++p) {
239	switch (*p) {
240	case 'a':
241	who \|= STANDARD_BITS;
242	break;
243	case 'u':
244	who \|= S_ISUID\|S_IRWXU;
245	break;
246	case 'g':
247	who \|= S_ISGID\|S_IRWXG;
248	break;
249	case 'o':
250	who \|= S_IRWXO;
251	break;
252	default:
253	goto getop;
254	}
255	}
256
257	getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
258	free(saveset);
259	return (NULL);
260	}
261	if (op == '=')
262	equalopdone = 0;
263
264	who &= ~S_ISTXT;
265	for (perm = 0, permXbits = 0;; ++p) {
266	switch (*p) {
267	case 'r':
268	perm \|= S_IRUSR\|S_IRGRP\|S_IROTH;
269	break;
270	case 's':
271	/* If only "other" bits ignore set-id. */
272	if (!who \|\| who & ~S_IRWXO)
273	perm \|= S_ISUID\|S_ISGID;
274	break;
275	case 't':
276	/* If only "other" bits ignore sticky. */
277	if (!who \|\| who & ~S_IRWXO) {
278	who \|= S_ISTXT;
279	perm \|= S_ISTXT;
280	}
281	break;
282	case 'w':
283	perm \|= S_IWUSR\|S_IWGRP\|S_IWOTH;
284	break;
285	case 'X':
286	permXbits = S_IXUSR\|S_IXGRP\|S_IXOTH;
287	break;
288	case 'x':
289	perm \|= S_IXUSR\|S_IXGRP\|S_IXOTH;
290	break;
291	case 'u':
292	case 'g':
293	case 'o':
294	/*
295	* When ever we hit 'u', 'g', or 'o', we have
296	* to flush out any partial mode that we have,
297	* and then do the copying of the mode bits.
298	*/
299	if (perm) {
300	ADDCMD(op, who, perm, mask);
301	perm = 0;
302	}
303	if (op == '=')
304	equalopdone = 1;
305	if (op == '+' && permXbits) {
306	ADDCMD('X', who, permXbits, mask);
307	permXbits = 0;
308	}
309	ADDCMD(*p, who, op, mask);
310	break;
311
312	default:
313	/*
314	* Add any permissions that we haven't already
315	* done.
316	*/
317	if (perm \|\| (op == '=' && !equalopdone)) {
318	if (op == '=')
319	equalopdone = 1;
320	ADDCMD(op, who, perm, mask);
321	perm = 0;
322	}
323	if (permXbits) {
324	ADDCMD('X', who, permXbits, mask);
325	permXbits = 0;
326	}
327	goto apply;
328	}
329	}
330
331	apply: if (!*p)
332	break;
333	if (*p != ',')
334	goto getop;
335	++p;
336	}
337	set->cmd = 0;
338	#ifdef SETMODE_DEBUG
339	(void)printf("Before compress_mode()\n");
340	dumpmode(saveset);
341	#endif
342	compress_mode(saveset);
343	#ifdef SETMODE_DEBUG
344	(void)printf("After compress_mode()\n");
345	dumpmode(saveset);
346	#endif
347	return (saveset);
348	}
349
350	static BITCMD *
351	addcmd(set, op, who, oparg, mask)
352	BITCMD *set;
353	int oparg, who;
354	int op;
355	u_int mask;
356	{
357	switch (op) {
358	case '=':
359	set->cmd = '-';
360	set->bits = who ? who : STANDARD_BITS;
361	set++;
362
363	op = '+';
364	/* FALLTHROUGH */
365	case '+':
366	case '-':
367	case 'X':
368	set->cmd = op;
369	set->bits = (who ? who : mask) & oparg;
370	break;
371
372	case 'u':
373	case 'g':
374	case 'o':
375	set->cmd = op;
376	if (who) {
377	set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) \|
378	((who & S_IRGRP) ? CMD2_GBITS : 0) \|
379	((who & S_IROTH) ? CMD2_OBITS : 0);
380	set->bits = (mode_t)~0;
381	} else {
382	set->cmd2 = CMD2_UBITS \| CMD2_GBITS \| CMD2_OBITS;
383	set->bits = mask;
384	}
385
386	if (oparg == '+')
387	set->cmd2 \|= CMD2_SET;
388	else if (oparg == '-')
389	set->cmd2 \|= CMD2_CLR;
390	else if (oparg == '=')
391	set->cmd2 \|= CMD2_SET\|CMD2_CLR;
392	break;
393	}
394	return (set + 1);
395	}
396
397	#ifdef SETMODE_DEBUG
398	static void
399	dumpmode(set)
400	BITCMD *set;
401	{
402	for (; set->cmd; ++set)
403	(void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
404	set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
405	set->cmd2 & CMD2_CLR ? " CLR" : "",
406	set->cmd2 & CMD2_SET ? " SET" : "",
407	set->cmd2 & CMD2_UBITS ? " UBITS" : "",
408	set->cmd2 & CMD2_GBITS ? " GBITS" : "",
409	set->cmd2 & CMD2_OBITS ? " OBITS" : "");
410	}
411	#endif
412
413	/*
414	* Given an array of bitcmd structures, compress by compacting consecutive
415	* '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
416	* 'g' and 'o' commands continue to be separate. They could probably be
417	* compacted, but it's not worth the effort.
418	*/
419	static void
420	compress_mode(set)
421	BITCMD *set;
422	{
423	BITCMD *nset;
424	int setbits, clrbits, Xbits, op;
425
426	for (nset = set;;) {
427	/* Copy over any 'u', 'g' and 'o' commands. */
428	while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
429	set++ = nset++;
430	if (!op)
431	return;
432	}
433
434	for (setbits = clrbits = Xbits = 0;; nset++) {
435	if ((op = nset->cmd) == '-') {
436	clrbits \|= nset->bits;
437	setbits &= ~nset->bits;
438	Xbits &= ~nset->bits;
439	} else if (op == '+') {
440	setbits \|= nset->bits;
441	clrbits &= ~nset->bits;
442	Xbits &= ~nset->bits;
443	} else if (op == 'X')
444	Xbits \|= nset->bits & ~setbits;
445	else
446	break;
447	}
448	if (clrbits) {
449	set->cmd = '-';
450	set->cmd2 = 0;
451	set->bits = clrbits;
452	set++;
453	}
454	if (setbits) {
455	set->cmd = '+';
456	set->cmd2 = 0;
457	set->bits = setbits;
458	set++;
459	}
460	if (Xbits) {
461	set->cmd = 'X';
462	set->cmd2 = 0;
463	set->bits = Xbits;
464	set++;
465	}
466	}
467	}

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source: kBuild/trunk/src/gmake/kmkbuiltin/setmode.c@ 285

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