From: Christos Zoulas <christos@zoulas.com>
Date: Wed, 12 May 2004 14:53:01 +0000 (+0000)
Subject: Add a check_format function to make sure that printf formats in magic
X-Git-Tag: FILE5_05~866
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=11c4b2263b75f96c2c35fc87104c3de03a7302c1;p=file

Add a check_format function to make sure that printf formats in magic
files make sense.
---

diff --git a/src/apprentice.c b/src/apprentice.c
index f8f4bd9b..5bcbf5cf 100644
--- a/src/apprentice.c
+++ b/src/apprentice.c
@@ -50,7 +50,7 @@
 #endif
 
 #ifndef	lint
-FILE_RCSID("@(#)$Id: apprentice.c,v 1.75 2004/03/22 18:48:56 christos Exp $")
+FILE_RCSID("@(#)$Id: apprentice.c,v 1.76 2004/05/12 14:53:01 christos Exp $")
 #endif	/* lint */
 
 #define	EATAB {while (isascii((unsigned char) *l) && \
@@ -96,6 +96,7 @@ private int apprentice_map(struct magic_set *, struct magic **, uint32_t *,
     const char *);
 private int apprentice_compile(struct magic_set *, struct magic **, uint32_t *,
     const char *);
+private int check_format(struct magic *);
 
 private size_t maxmagic = 0;
 private size_t magicsize = sizeof(struct magic);
@@ -704,6 +705,10 @@ GetDesc:
 	while ((m->desc[i++] = *l++) != '\0' && i < MAXDESC)
 		/* NULLBODY */;
 
+	if (ms->flags & MAGIC_CHECK) {
+		if (!check_format(m))
+			return -1;
+	}
 #ifndef COMPILE_ONLY
 	if (action == FILE_CHECK) {
 		file_mdump(m);
@@ -713,6 +718,57 @@ GetDesc:
 	return 0;
 }
 
+/*
+ * Check that the optional printf format in description matches
+ * the type of the magic.
+ */
+private int
+check_format(struct magic *m)
+{
+	static const char *formats[] = { FILE_FORMAT_STRING };
+	static const char *names[] = { FILE_FORMAT_NAME };
+	char *ptr;
+
+	for (ptr = m->desc; *ptr; ptr++)
+		if (*ptr == '%')
+			break;
+	if (*ptr == '\0') {
+		/* No format string; ok */
+		return 1;
+	}
+	if (m->type >= sizeof(formats)/sizeof(formats[0])) {
+		file_magwarn("Internal error inconsistency between m->type"
+		    " and format strings");
+		return 0;
+	}
+	if (formats[m->type] == NULL) {
+		file_magwarn("No format string for `%s' with description `%s'",
+		    m->desc, names[m->type]);
+		return 0;
+	}
+	for (; *ptr; ptr++) {
+		if (*ptr == 'l' || *ptr == 'h') {
+			/* XXX: we should really fix this one day */
+			continue;
+		}
+		if (islower((unsigned char)*ptr) || *ptr == 'X')
+			break;
+	}
+	if (*ptr == '\0') {
+		/* Missing format string; bad */
+		file_magwarn("Invalid format `%s' for type `%s'",
+			m->desc, names[m->type]);
+		return 0;
+	}
+	if (strchr(formats[m->type], *ptr) == NULL) {
+		file_magwarn("Printf format `%c' is not valid for type `%s'"
+		    " in description `%s'",
+			*ptr, names[m->type], m->desc);
+		return 0;
+	}
+	return 1;
+}
+
 /* 
  * Read a numeric value from a pointer, into the value union of a magic 
  * pointer, according to the magic type.  Update the string pointer to point 
diff --git a/src/file.h b/src/file.h
index abdbdd9f..d5fe2cc9 100644
--- a/src/file.h
+++ b/src/file.h
@@ -32,7 +32,7 @@
  */
 /*
  * file.h - definitions for file(1) program
- * @(#)$Id: file.h,v 1.60 2004/03/22 19:12:15 christos Exp $
+ * @(#)$Id: file.h,v 1.61 2004/05/12 14:53:01 christos Exp $
  */
 
 #ifndef __file_h__
@@ -113,6 +113,50 @@ struct magic {
 #define				FILE_BELDATE	15
 #define				FILE_LELDATE	16
 #define				FILE_REGEX	17
+
+#define				FILE_FORMAT_NAME	\
+/* 0 */ 			"invalid 0",		\
+/* 1 */				"byte",			\
+/* 2 */ 			"short",		\
+/* 3 */ 			"invalid 3",		\
+/* 4 */ 			"long",			\
+/* 5 */ 			"string",		\
+/* 6 */ 			"date",			\
+/* 7 */ 			"beshort",		\
+/* 8 */ 			"belong",		\
+/* 9 */ 			"bedate"		\
+/* 10 */ 			"leshort",		\
+/* 11 */ 			"lelong",		\
+/* 12 */ 			"ledate",		\
+/* 13 */ 			"pstring",		\
+/* 14 */ 			"ldate",		\
+/* 15 */ 			"beldate",		\
+/* 16 */ 			"leldate",		\
+/* 17 */ 			"regex",
+
+#define	FILE_FMT_NUM	"cduxXi"
+#define FILE_FMT_STR	"s"	
+
+#define				FILE_FORMAT_STRING	\
+/* 0 */ 			NULL,			\
+/* 1 */				FILE_FMT_NUM,		\
+/* 2 */ 			FILE_FMT_NUM,		\
+/* 3 */ 			NULL,			\
+/* 4 */ 			FILE_FMT_NUM,		\
+/* 5 */ 			FILE_FMT_STR,		\
+/* 6 */ 			FILE_FMT_STR,		\
+/* 7 */ 			FILE_FMT_NUM,		\
+/* 8 */ 			FILE_FMT_NUM,		\
+/* 9 */ 			FILE_FMT_STR,		\
+/* 10 */ 			FILE_FMT_NUM,		\
+/* 11 */ 			FILE_FMT_NUM,		\
+/* 12 */ 			FILE_FMT_STR,		\
+/* 13 */ 			FILE_FMT_STR,		\
+/* 14 */ 			FILE_FMT_STR,		\
+/* 15 */ 			FILE_FMT_STR,		\
+/* 16 */ 			FILE_FMT_STR,		\
+/* 17 */ 			FILE_FMT_STR,
+
 	/* Word 3 */
 	uint8_t in_op;		/* operator for indirection */
 	uint8_t mask_op;	/* operator for mask */