1 files changed, 164 insertions, 0 deletions
diff --git a/libbb/parse_mode.c b/libbb/parse_mode.c
new file mode 100644
index 000000000..356d95db6
--- /dev/null
+++ b/libbb/parse_mode.c
@@ -0,0 +1,164 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * parse_mode implementation for busybox
+ *
+ * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
+#include <stdlib.h>
+#include <assert.h>
+#include <sys/stat.h>
+#include "libbb.h"
+#define FILEMODEBITS    (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
+int bb_parse_mode(const char *s, mode_t *current_mode)
+{
+        static const mode_t who_mask[] = {
+                S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO, /* a */
+                S_ISUID | S_IRWXU,              /* u */
+                S_ISGID | S_IRWXG,              /* g */
+                S_IRWXO                                 /* o */
+        };
+        static const mode_t perm_mask[] = {
+                S_IRUSR | S_IRGRP | S_IROTH, /* r */
+                S_IWUSR | S_IWGRP | S_IWOTH, /* w */
+                S_IXUSR | S_IXGRP | S_IXOTH, /* x */
+                S_IXUSR | S_IXGRP | S_IXOTH, /* X -- special -- see below */
+                S_ISUID | S_ISGID,              /* s */
+                S_ISVTX                                 /* t */
+        };
+        static const char who_chars[] = "augo";
+        static const char perm_chars[] = "rwxXst";
+        const char *p;
+        mode_t wholist;
+        mode_t permlist;
+        mode_t mask;
+        mode_t new_mode;
+        char op;
+        assert(s);
+        if (((unsigned int)(*s - '0')) < 8) {
+                unsigned long tmp;
+                char *e;
+                tmp = strtol(s, &e, 8);
+                if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */
+                        return 0;
+                }
+                *current_mode = tmp;
+                return 1;
+        }
+        mask = umask(0);
+        umask(mask);
+        new_mode = *current_mode;
+        /* Note: We allow empty clauses, and hence empty modes.
+         * We treat an empty mode as no change to perms. */
+        while (*s) {    /* Process clauses. */
+                if (*s == ',') {        /* We allow empty clauses. */
+                        ++s;
+                        continue;
+                }
+                /* Get a wholist. */
+                wholist = 0;
+        WHO_LIST:
+                p = who_chars;
+                do {
+                        if (*p == *s) {
+                                wholist |= who_mask[(int)(p-who_chars)];
+                                if (!*++s) {
+                                        return 0;
+                                }
+                                goto WHO_LIST;
+                        }
+                } while (*++p);
+                do {    /* Process action list. */
+                        if ((*s != '+') && (*s != '-')) {
+                                if (*s != '=') {
+                                        return 0;
+                                }
+                                /* Since op is '=', clear all bits corresponding to the
+                                 * wholist, of all file bits if wholist is empty. */
+                                permlist = ~FILEMODEBITS;
+                                if (wholist) {
+                                        permlist = ~wholist;
+                                }
+                                new_mode &= permlist;
+                        }
+                        op = *s++;
+                        /* Check for permcopy. */
+                        p = who_chars + 1;      /* Skip 'a' entry. */
+                        do {
+                                if (*p == *s) {
+                                        int i = 0;
+                                        permlist = who_mask[(int)(p-who_chars)]
+                                                         & (S_IRWXU | S_IRWXG | S_IRWXO)
+                                                         & new_mode;
+                                        do {
+                                                if (permlist & perm_mask[i]) {
+                                                        permlist |= perm_mask[i];
+                                                }
+                                        } while (++i < 3);
+                                        ++s;
+                                        goto GOT_ACTION;
+                                }
+                        } while (*++p);
+                        /* It was not a permcopy, so get a permlist. */
+                        permlist = 0;
+                PERM_LIST:
+                        p = perm_chars;
+                        do {
+                                if (*p == *s) {
+                                        if ((*p != 'X')
+                                                || (new_mode & (S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH))
+                                        ) {
+                                                permlist |= perm_mask[(int)(p-perm_chars)];
+                                        }
+                                        if (!*++s) {
+                                                break;
+                                        }
+                                        goto PERM_LIST;
+                                }
+                        } while (*++p);
+                GOT_ACTION:
+                        if (permlist) { /* The permlist was nonempty. */
+                                mode_t tmp = ~mask;
+                                if (wholist) {
+                                        tmp = wholist;
+                                }
+                                permlist &= tmp;
+                                if (op == '-') {
+                                        new_mode &= ~permlist;
+                                } else {
+                                        new_mode |= permlist;
+                                }
+                        }
+                } while (*s && (*s != ','));
+        }
+        *current_mode = new_mode;
+        return 1;
+}

diff --git a/libbb/parse_mode.c b/libbb/parse_mode.c new file mode 100644 index 000000000..356d95db6 --- /dev/null +++ b/libbb/parse_mode.c
@@ -0,0 +1,164 @@
	1	/* vi: set sw=4 ts=4: */
	2	/*
	3	* parse_mode implementation for busybox
	4	*
	5	* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
	6	*
	7	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	8	*/
	9
	10	/* http://www.opengroup.org/onlinepubs/007904975/utilities/chmod.html */
	11
	12	#include <stdlib.h>
	13	#include <assert.h>
	14	#include <sys/stat.h>
	15	#include "libbb.h"
	16
	17	#define FILEMODEBITS (S_ISUID \| S_ISGID \| S_ISVTX \| S_IRWXU \| S_IRWXG \| S_IRWXO)
	18
	19	int bb_parse_mode(const char s, mode_t current_mode)
	20	{
	21	static const mode_t who_mask[] = {
	22	S_ISUID \| S_ISGID \| S_ISVTX \| S_IRWXU \| S_IRWXG \| S_IRWXO, /* a */
	23	S_ISUID \| S_IRWXU, /* u */
	24	S_ISGID \| S_IRWXG, /* g */
	25	S_IRWXO /* o */
	26	};
	27
	28	static const mode_t perm_mask[] = {
	29	S_IRUSR \| S_IRGRP \| S_IROTH, /* r */
	30	S_IWUSR \| S_IWGRP \| S_IWOTH, /* w */
	31	S_IXUSR \| S_IXGRP \| S_IXOTH, /* x */
	32	S_IXUSR \| S_IXGRP \| S_IXOTH, /* X -- special -- see below */
	33	S_ISUID \| S_ISGID, /* s */
	34	S_ISVTX /* t */
	35	};
	36
	37	static const char who_chars[] = "augo";
	38	static const char perm_chars[] = "rwxXst";
	39
	40	const char *p;
	41
	42	mode_t wholist;
	43	mode_t permlist;
	44	mode_t mask;
	45	mode_t new_mode;
	46	char op;
	47
	48	assert(s);
	49
	50	if (((unsigned int)(*s - '0')) < 8) {
	51	unsigned long tmp;
	52	char *e;
	53
	54	tmp = strtol(s, &e, 8);
	55	if (e \|\| (tmp > 07777U)) { / Check range and trailing chars. */
	56	return 0;
	57	}
	58	*current_mode = tmp;
	59	return 1;
	60	}
	61
	62	mask = umask(0);
	63	umask(mask);
	64
	65	new_mode = *current_mode;
	66
	67	/* Note: We allow empty clauses, and hence empty modes.
	68	* We treat an empty mode as no change to perms. */
	69
	70	while (s) { / Process clauses. */
	71
	72	if (s == ',') { / We allow empty clauses. */
	73	++s;
	74	continue;
	75	}
	76
	77	/* Get a wholist. */
	78	wholist = 0;
	79
	80	WHO_LIST:
	81	p = who_chars;
	82	do {
	83	if (p == s) {
	84	wholist \|= who_mask[(int)(p-who_chars)];
	85	if (!*++s) {
	86	return 0;
	87	}
	88	goto WHO_LIST;
	89	}
	90	} while (*++p);
	91
	92	do { /* Process action list. */
	93	if ((s != '+') && (s != '-')) {
	94	if (*s != '=') {
	95	return 0;
	96	}
	97	/* Since op is '=', clear all bits corresponding to the
	98	* wholist, of all file bits if wholist is empty. */
	99	permlist = ~FILEMODEBITS;
	100	if (wholist) {
	101	permlist = ~wholist;
	102	}
	103	new_mode &= permlist;
	104	}
	105	op = *s++;
	106
	107	/* Check for permcopy. */
	108	p = who_chars + 1; /* Skip 'a' entry. */
	109	do {
	110	if (p == s) {
	111	int i = 0;
	112	permlist = who_mask[(int)(p-who_chars)]
	113	& (S_IRWXU \| S_IRWXG \| S_IRWXO)
	114	& new_mode;
	115	do {
	116	if (permlist & perm_mask[i]) {
	117	permlist \|= perm_mask[i];
	118	}
	119	} while (++i < 3);
	120	++s;
	121	goto GOT_ACTION;
	122	}
	123	} while (*++p);
	124
	125	/* It was not a permcopy, so get a permlist. */
	126	permlist = 0;
	127
	128	PERM_LIST:
	129	p = perm_chars;
	130	do {
	131	if (p == s) {
	132	if ((*p != 'X')
	133	\|\| (new_mode & (S_IFDIR \| S_IXUSR \| S_IXGRP \| S_IXOTH))
	134	) {
	135	permlist \|= perm_mask[(int)(p-perm_chars)];
	136	}
	137	if (!*++s) {
	138	break;
	139	}
	140	goto PERM_LIST;
	141	}
	142	} while (*++p);
	143
	144	GOT_ACTION:
	145	if (permlist) { /* The permlist was nonempty. */
	146	mode_t tmp = ~mask;
	147	if (wholist) {
	148	tmp = wholist;
	149	}
	150	permlist &= tmp;
	151
	152	if (op == '-') {
	153	new_mode &= ~permlist;
	154	} else {
	155	new_mode \|= permlist;
	156	}
	157	}
	158	} while (s && (s != ','));
	159	}
	160
	161	*current_mode = new_mode;
	162
	163	return 1;
	164	}