parsemode: rework

- for octal input: reset mode to 0.
- take umask into account.
- make '=rwx' etc work.
- we wont support crazy but valid modes like "a+rw,g=x,o=g"
- uudecode: use parsemode, mask is 0.

Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>

chmod.c

@@ -9,8 +9,8 @@
 static void chmodr(const char *);
 
 static bool rflag = false;
-static int oper = '=';
+static char *modestr = "";
-static mode_t mode = 0;
+static mode_t mask = 0;
 
 static void
 usage(void)
@@ -45,7 +45,8 @@ main(int argc, char *argv[])
 	}
 
 done:
-	parsemode(argv[0], &mode, &oper);
+	mask = getumask();
+	modestr = argv[0];
 	argv++;
 	argc--;
 
@@ -61,22 +62,13 @@ void
 chmodr(const char *path)
 {
 	struct stat st;
+	mode_t m;
 
 	if(stat(path, &st) == -1)
 		eprintf("stat %s:", path);
 
-	switch(oper) {
+	m = parsemode(modestr, st.st_mode, mask);
-	case '+':
+	if(chmod(path, m) == -1)
-		st.st_mode |= mode;
-		break;
-	case '-':
-		st.st_mode &= ~mode;
-		break;
-	case '=':
-		st.st_mode = mode;
-		break;
-	}
-	if(chmod(path, st.st_mode) == -1)
 		weprintf("chmod %s:", path);
 	if(rflag)
 		recurse(path, chmodr);

util.h

@@ -27,4 +27,5 @@ size_t strlcat(char *, const char *, size_t);
 size_t strlcpy(char *, const char *, size_t);
 void weprintf(const char *, ...);
 
-void parsemode(const char *, mode_t *, int *);
+mode_t getumask(void);
+mode_t parsemode(const char *, mode_t, mode_t);

util/mode.c

@@ -4,74 +4,98 @@
 #include <sys/stat.h>
 #include "../util.h"
 
-void
+mode_t
-parsemode(const char *str, mode_t *mode, int *oper)
+getumask(void)
+{
+    mode_t mask = umask(0);
+    umask(mask);
+    return mask;
+}
+
+mode_t
+parsemode(const char *str, mode_t mode, mode_t mask)
 {
 	char *end;
 	const char *p;
-	int octal;
+	int octal, op = '+';
-	mode_t mask = 0;
+	mode_t gmask = 0, m = 0;
 
 	octal = strtol(str, &end, 8);
 	if(*end == '\0') {
-		if(octal < 0 || octal > 07777)
+		if(octal < 0 || octal > 07777) {
 			eprintf("%s: invalid mode\n", str);
-		if(octal & 04000) *mode |= S_ISUID;
+			return -1;
-		if(octal & 02000) *mode |= S_ISGID;
-		if(octal & 01000) *mode |= S_ISVTX;
-		if(octal & 00400) *mode |= S_IRUSR;
-		if(octal & 00200) *mode |= S_IWUSR;
-		if(octal & 00100) *mode |= S_IXUSR;
-		if(octal & 00040) *mode |= S_IRGRP;
-		if(octal & 00020) *mode |= S_IWGRP;
-		if(octal & 00010) *mode |= S_IXGRP;
-		if(octal & 00004) *mode |= S_IROTH;
-		if(octal & 00002) *mode |= S_IWOTH;
-		if(octal & 00001) *mode |= S_IXOTH;
-		return;
 		}
-	for(p = str; *p; p++)
+		mode = 0;
+		if(octal & 04000) mode |= S_ISUID;
+		if(octal & 02000) mode |= S_ISGID;
+		if(octal & 01000) mode |= S_ISVTX;
+		if(octal & 00400) mode |= S_IRUSR;
+		if(octal & 00200) mode |= S_IWUSR;
+		if(octal & 00100) mode |= S_IXUSR;
+		if(octal & 00040) mode |= S_IRGRP;
+		if(octal & 00020) mode |= S_IWGRP;
+		if(octal & 00010) mode |= S_IXGRP;
+		if(octal & 00004) mode |= S_IROTH;
+		if(octal & 00002) mode |= S_IWOTH;
+		if(octal & 00001) mode |= S_IXOTH;
+		return mode;
+	}
+	for(p = str; *p; p++) {
 		switch(*p) {
 		/* masks */
 		case 'u':
-			mask |= S_IRWXU;
+			gmask |= S_IRWXU;
 			break;
 		case 'g':
-			mask |= S_IRWXG;
+			gmask |= S_IRWXG;
 			break;
 		case 'o':
-			mask |= S_IRWXO;
+			gmask |= S_IRWXO;
 			break;
 		case 'a':
-			mask |= S_IRWXU|S_IRWXG|S_IRWXO;
+			gmask |= S_IRWXU|S_IRWXG|S_IRWXO;
 			break;
 		/* opers */
+		case '=':
 		case '+':
 		case '-':
-		case '=':
+			op = (int)*p;
-			if(oper)
-				*oper = (int)*p;
 			break;
 		/* modes */
 		case 'r':
-			*mode |= S_IRUSR|S_IRGRP|S_IROTH;
+			m |= S_IRUSR|S_IRGRP|S_IROTH;
 			break;
 		case 'w':
-			*mode |= S_IWUSR|S_IWGRP|S_IWOTH;
+			m |= S_IWUSR|S_IWGRP|S_IWOTH;
 			break;
 		case 'x':
-			*mode |= S_IXUSR|S_IXGRP|S_IXOTH;
+			m |= S_IXUSR|S_IXGRP|S_IXOTH;
 			break;
 		case 's':
-			*mode |= S_ISUID|S_ISGID;
+			m |= S_ISUID|S_ISGID;
 			break;
 		case 't':
-			*mode |= S_ISVTX;
+			m |= S_ISVTX;
 			break;
-			/* error */
 		default:
 			eprintf("%s: invalid mode\n", str);
+			return -1;
 		}
-	if(mask)
+		/* apply */
-		*mode &= mask;
+		switch(op) {
+		case '+':
+			mode |= (m & ((~mask) & 0777));
+			break;
+		case '-':
+			mode &= (~(m & ((~mask) & 0777)));
+			break;
+		case '=':
+			mode = (m & ((~mask) & 0777));
+			break;
+		}
+	}
+	if(gmask && op != '=')
+		mode &= ~gmask;
+	return mode;
 }

uudecode.c

@@ -107,7 +107,7 @@ parseheader(FILE *fp, const char *s, const char *header, mode_t *mode, char **fn
 		eprintf("malformed mode string in header\n");
 	*q++ = '\0';
 	/* now mode should be null terminated, q points to fname */
-	parsemode(p, mode, NULL);
+	*mode = parsemode(p, *mode, 0);
 	n = strlen(q);
 	while (n > 0 && (q[n - 1] == '\n' || q[n - 1] == '\r'))
 		q[--n] = '\0';