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-rw-r--r--lib/libc/gen/setmode.c458
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diff --git a/lib/libc/gen/setmode.c b/lib/libc/gen/setmode.c
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+/* $NetBSD: setmode.c,v 1.12 1995/03/23 19:51:13 jtc Exp $ */
+
+/*
+ * Copyright (c) 1989, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Dave Borman at Cray Research, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)setmode.c 8.2 (Berkeley) 3/25/94";
+#else
+static char rcsid[] = "$NetBSD: setmode.c,v 1.12 1995/03/23 19:51:13 jtc Exp $";
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+
+#ifdef SETMODE_DEBUG
+#include <stdio.h>
+#endif
+
+#define SET_LEN 6 /* initial # of bitcmd struct to malloc */
+#define SET_LEN_INCR 4 /* # of bitcmd structs to add as needed */
+
+typedef struct bitcmd {
+ char cmd;
+ char cmd2;
+ mode_t bits;
+} BITCMD;
+
+#define CMD2_CLR 0x01
+#define CMD2_SET 0x02
+#define CMD2_GBITS 0x04
+#define CMD2_OBITS 0x08
+#define CMD2_UBITS 0x10
+
+static BITCMD *addcmd __P((BITCMD *, int, int, int, u_int));
+static int compress_mode __P((BITCMD *));
+#ifdef SETMODE_DEBUG
+static void dumpmode __P((BITCMD *));
+#endif
+
+/*
+ * Given the old mode and an array of bitcmd structures, apply the operations
+ * described in the bitcmd structures to the old mode, and return the new mode.
+ * Note that there is no '=' command; a strict assignment is just a '-' (clear
+ * bits) followed by a '+' (set bits).
+ */
+mode_t
+getmode(bbox, omode)
+ void *bbox;
+ mode_t omode;
+{
+ register BITCMD *set;
+ register mode_t clrval, newmode, value;
+
+ set = (BITCMD *)bbox;
+ newmode = omode;
+ for (value = 0;; set++)
+ switch(set->cmd) {
+ /*
+ * When copying the user, group or other bits around, we "know"
+ * where the bits are in the mode so that we can do shifts to
+ * copy them around. If we don't use shifts, it gets real
+ * grundgy with lots of single bit checks and bit sets.
+ */
+ case 'u':
+ value = (newmode & S_IRWXU) >> 6;
+ goto common;
+
+ case 'g':
+ value = (newmode & S_IRWXG) >> 3;
+ goto common;
+
+ case 'o':
+ value = newmode & S_IRWXO;
+common: if (set->cmd2 & CMD2_CLR) {
+ clrval =
+ (set->cmd2 & CMD2_SET) ? S_IRWXO : value;
+ if (set->cmd2 & CMD2_UBITS)
+ newmode &= ~((clrval<<6) & set->bits);
+ if (set->cmd2 & CMD2_GBITS)
+ newmode &= ~((clrval<<3) & set->bits);
+ if (set->cmd2 & CMD2_OBITS)
+ newmode &= ~(clrval & set->bits);
+ }
+ if (set->cmd2 & CMD2_SET) {
+ if (set->cmd2 & CMD2_UBITS)
+ newmode |= (value<<6) & set->bits;
+ if (set->cmd2 & CMD2_GBITS)
+ newmode |= (value<<3) & set->bits;
+ if (set->cmd2 & CMD2_OBITS)
+ newmode |= value & set->bits;
+ }
+ break;
+
+ case '+':
+ newmode |= set->bits;
+ break;
+
+ case '-':
+ newmode &= ~set->bits;
+ break;
+
+ case 'X':
+ if (omode & (S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH))
+ newmode |= set->bits;
+ break;
+
+ case '\0':
+ default:
+#ifdef SETMODE_DEBUG
+ (void)printf("getmode:%04o -> %04o\n", omode, newmode);
+#endif
+ return (newmode);
+ }
+}
+
+#define ADDCMD(a, b, c, d) \
+ if (set >= endset) { \
+ register BITCMD *newset; \
+ setlen += SET_LEN_INCR; \
+ newset = realloc(saveset, sizeof(BITCMD) * setlen); \
+ if (!saveset) \
+ return (NULL); \
+ set = newset + (set - saveset); \
+ saveset = newset; \
+ endset = newset + (setlen - 2); \
+ } \
+ set = addcmd(set, (a), (b), (c), (d))
+
+#define STANDARD_BITS (S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO)
+
+void *
+setmode(p)
+ register char *p;
+{
+ register int perm, who;
+ register char op;
+ BITCMD *set, *saveset, *endset;
+ sigset_t sigset, sigoset;
+ mode_t mask;
+ int equalopdone, permXbits, setlen;
+
+ if (!*p)
+ return (NULL);
+
+ /*
+ * Get a copy of the mask for the permissions that are mask relative.
+ * Flip the bits, we want what's not set. Since it's possible that
+ * the caller is opening files inside a signal handler, protect them
+ * as best we can.
+ */
+ sigfillset(&sigset);
+ (void)sigprocmask(SIG_BLOCK, &sigset, &sigoset);
+ (void)umask(mask = umask(0));
+ mask = ~mask;
+ (void)sigprocmask(SIG_SETMASK, &sigoset, NULL);
+
+ setlen = SET_LEN + 2;
+
+ if ((set = malloc((u_int)(sizeof(BITCMD) * setlen))) == NULL)
+ return (NULL);
+ saveset = set;
+ endset = set + (setlen - 2);
+
+ /*
+ * If an absolute number, get it and return; disallow non-octal digits
+ * or illegal bits.
+ */
+ if (isdigit(*p)) {
+ perm = (mode_t)strtol(p, NULL, 8);
+ if (perm & ~(STANDARD_BITS|S_ISTXT)) {
+ free(saveset);
+ return (NULL);
+ }
+ while (*++p)
+ if (*p < '0' || *p > '7') {
+ free(saveset);
+ return (NULL);
+ }
+ ADDCMD('=', (STANDARD_BITS|S_ISTXT), perm, mask);
+ return (saveset);
+ }
+
+ /*
+ * Build list of structures to set/clear/copy bits as described by
+ * each clause of the symbolic mode.
+ */
+ for (;;) {
+ /* First, find out which bits might be modified. */
+ for (who = 0;; ++p) {
+ switch (*p) {
+ case 'a':
+ who |= STANDARD_BITS;
+ break;
+ case 'u':
+ who |= S_ISUID|S_IRWXU;
+ break;
+ case 'g':
+ who |= S_ISGID|S_IRWXG;
+ break;
+ case 'o':
+ who |= S_IRWXO;
+ break;
+ default:
+ goto getop;
+ }
+ }
+
+getop: if ((op = *p++) != '+' && op != '-' && op != '=') {
+ free(saveset);
+ return (NULL);
+ }
+ if (op == '=')
+ equalopdone = 0;
+
+ who &= ~S_ISTXT;
+ for (perm = 0, permXbits = 0;; ++p) {
+ switch (*p) {
+ case 'r':
+ perm |= S_IRUSR|S_IRGRP|S_IROTH;
+ break;
+ case 's':
+ /* If only "other" bits ignore set-id. */
+ if (who & ~S_IRWXO)
+ perm |= S_ISUID|S_ISGID;
+ break;
+ case 't':
+ /* If only "other" bits ignore sticky. */
+ if (who & ~S_IRWXO) {
+ who |= S_ISTXT;
+ perm |= S_ISTXT;
+ }
+ break;
+ case 'w':
+ perm |= S_IWUSR|S_IWGRP|S_IWOTH;
+ break;
+ case 'X':
+ permXbits = S_IXUSR|S_IXGRP|S_IXOTH;
+ break;
+ case 'x':
+ perm |= S_IXUSR|S_IXGRP|S_IXOTH;
+ break;
+ case 'u':
+ case 'g':
+ case 'o':
+ /*
+ * When ever we hit 'u', 'g', or 'o', we have
+ * to flush out any partial mode that we have,
+ * and then do the copying of the mode bits.
+ */
+ if (perm) {
+ ADDCMD(op, who, perm, mask);
+ perm = 0;
+ }
+ if (op == '=')
+ equalopdone = 1;
+ if (op == '+' && permXbits) {
+ ADDCMD('X', who, permXbits, mask);
+ permXbits = 0;
+ }
+ ADDCMD(*p, who, op, mask);
+ break;
+
+ default:
+ /*
+ * Add any permissions that we haven't already
+ * done.
+ */
+ if (perm || (op == '=' && !equalopdone)) {
+ if (op == '=')
+ equalopdone = 1;
+ ADDCMD(op, who, perm, mask);
+ perm = 0;
+ }
+ if (permXbits) {
+ ADDCMD('X', who, permXbits, mask);
+ permXbits = 0;
+ }
+ goto apply;
+ }
+ }
+
+apply: if (!*p)
+ break;
+ if (*p != ',')
+ goto getop;
+ ++p;
+ }
+ set->cmd = 0;
+#ifdef SETMODE_DEBUG
+ (void)printf("Before compress_mode()\n");
+ dumpmode(saveset);
+#endif
+ compress_mode(saveset);
+#ifdef SETMODE_DEBUG
+ (void)printf("After compress_mode()\n");
+ dumpmode(saveset);
+#endif
+ return (saveset);
+}
+
+static BITCMD *
+addcmd(set, op, who, oparg, mask)
+ BITCMD *set;
+ register int oparg, who;
+ register int op;
+ u_int mask;
+{
+ switch (op) {
+ case '=':
+ set->cmd = '-';
+ set->bits = who ? who : STANDARD_BITS;
+ set++;
+
+ op = '+';
+ /* FALLTHROUGH */
+ case '+':
+ case '-':
+ case 'X':
+ set->cmd = op;
+ set->bits = (who ? who : mask) & oparg;
+ break;
+
+ case 'u':
+ case 'g':
+ case 'o':
+ set->cmd = op;
+ if (who) {
+ set->cmd2 = ((who & S_IRUSR) ? CMD2_UBITS : 0) |
+ ((who & S_IRGRP) ? CMD2_GBITS : 0) |
+ ((who & S_IROTH) ? CMD2_OBITS : 0);
+ set->bits = ~0;
+ } else {
+ set->cmd2 = CMD2_UBITS | CMD2_GBITS | CMD2_OBITS;
+ set->bits = mask;
+ }
+
+ if (oparg == '+')
+ set->cmd2 |= CMD2_SET;
+ else if (oparg == '-')
+ set->cmd2 |= CMD2_CLR;
+ else if (oparg == '=')
+ set->cmd2 |= CMD2_SET|CMD2_CLR;
+ break;
+ }
+ return (set + 1);
+}
+
+#ifdef SETMODE_DEBUG
+static void
+dumpmode(set)
+ register BITCMD *set;
+{
+ for (; set->cmd; ++set)
+ (void)printf("cmd: '%c' bits %04o%s%s%s%s%s%s\n",
+ set->cmd, set->bits, set->cmd2 ? " cmd2:" : "",
+ set->cmd2 & CMD2_CLR ? " CLR" : "",
+ set->cmd2 & CMD2_SET ? " SET" : "",
+ set->cmd2 & CMD2_UBITS ? " UBITS" : "",
+ set->cmd2 & CMD2_GBITS ? " GBITS" : "",
+ set->cmd2 & CMD2_OBITS ? " OBITS" : "");
+}
+#endif
+
+/*
+ * Given an array of bitcmd structures, compress by compacting consecutive
+ * '+', '-' and 'X' commands into at most 3 commands, one of each. The 'u',
+ * 'g' and 'o' commands continue to be separate. They could probably be
+ * compacted, but it's not worth the effort.
+ */
+static int
+compress_mode(set)
+ register BITCMD *set;
+{
+ register BITCMD *nset;
+ register int setbits, clrbits, Xbits, op;
+
+ for (nset = set;;) {
+ /* Copy over any 'u', 'g' and 'o' commands. */
+ while ((op = nset->cmd) != '+' && op != '-' && op != 'X') {
+ *set++ = *nset++;
+ if (!op)
+ return;
+ }
+
+ for (setbits = clrbits = Xbits = 0;; nset++) {
+ if ((op = nset->cmd) == '-') {
+ clrbits |= nset->bits;
+ setbits &= ~nset->bits;
+ Xbits &= ~nset->bits;
+ } else if (op == '+') {
+ setbits |= nset->bits;
+ clrbits &= ~nset->bits;
+ Xbits &= ~nset->bits;
+ } else if (op == 'X')
+ Xbits |= nset->bits & ~setbits;
+ else
+ break;
+ }
+ if (clrbits) {
+ set->cmd = '-';
+ set->cmd2 = 0;
+ set->bits = clrbits;
+ set++;
+ }
+ if (setbits) {
+ set->cmd = '+';
+ set->cmd2 = 0;
+ set->bits = setbits;
+ set++;
+ }
+ if (Xbits) {
+ set->cmd = 'X';
+ set->cmd2 = 0;
+ set->bits = Xbits;
+ set++;
+ }
+ }
+}
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