[asterisk-commits] mmichelson: trunk r247335 - in /trunk: include/asterisk/strings.h main/strings.c

SVN commits to the Asterisk project asterisk-commits at lists.digium.com
Wed Feb 17 15:22:43 CST 2010


Author: mmichelson
Date: Wed Feb 17 15:22:40 2010
New Revision: 247335

URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=247335
Log:
Fix two problems in ast_str functions found while writing a unit test.

1. The documentation for ast_str_set and ast_str_append state that
the max_len parameter may be -1 in order to limit the size of the
ast_str to its current allocated size. The problem was that the max_len
parameter in all cases was a size_t, which is unsigned. Thus a -1 was
interpreted as UINT_MAX instead of -1. Changing the max_len parameter
to be ssize_t fixed this issue.

2. Once issue 1 was fixed, there was an off-by-one error in the case
where we attempted to write a string larger than the current allotted
size to a string when -1 was passed as the max_len parameter. When trying
to write more than the allotted size, the ast_str's __AST_STR_USED was
set to 1 higher than it should have been. Thanks to Tilghman for quickly
spotting the offending line of code.

Oh, and the unit test that I referenced in the top line of this commit
will be added to reviewboard shortly. Sit tight...


Modified:
    trunk/include/asterisk/strings.h
    trunk/main/strings.c

Modified: trunk/include/asterisk/strings.h
URL: http://svnview.digium.com/svn/asterisk/trunk/include/asterisk/strings.h?view=diff&rev=247335&r1=247334&r2=247335
==============================================================================
--- trunk/include/asterisk/strings.h (original)
+++ trunk/include/asterisk/strings.h Wed Feb 17 15:22:40 2010
@@ -708,14 +708,14 @@
  *       file.
  */
 #if (defined(MALLOC_DEBUG) && !defined(STANDALONE))
-int __attribute__((format(printf, 4, 0))) __ast_debug_str_helper(struct ast_str **buf, size_t max_len,
+int __attribute__((format(printf, 4, 0))) __ast_debug_str_helper(struct ast_str **buf, ssize_t max_len,
 							   int append, const char *fmt, va_list ap, const char *file, int lineno, const char *func);
 #define __ast_str_helper(a,b,c,d,e)	__ast_debug_str_helper(a,b,c,d,e,__FILE__,__LINE__,__PRETTY_FUNCTION__)
 #else
-int __attribute__((format(printf, 4, 0))) __ast_str_helper(struct ast_str **buf, size_t max_len,
+int __attribute__((format(printf, 4, 0))) __ast_str_helper(struct ast_str **buf, ssize_t max_len,
 							   int append, const char *fmt, va_list ap);
 #endif
-char *__ast_str_helper2(struct ast_str **buf, size_t max_len,
+char *__ast_str_helper2(struct ast_str **buf, ssize_t max_len,
 	const char *src, size_t maxsrc, int append, int escapecommas);
 
 /*!
@@ -756,7 +756,7 @@
  * }
  * \endcode
  */
-AST_INLINE_API(int __attribute__((format(printf, 3, 0))) ast_str_set_va(struct ast_str **buf, size_t max_len, const char *fmt, va_list ap),
+AST_INLINE_API(int __attribute__((format(printf, 3, 0))) ast_str_set_va(struct ast_str **buf, ssize_t max_len, const char *fmt, va_list ap),
 {
 	return __ast_str_helper(buf, max_len, 0, fmt, ap);
 }
@@ -767,35 +767,35 @@
  *
  * Same as ast_str_set_va(), but append to the current content.
  */
-AST_INLINE_API(int __attribute__((format(printf, 3, 0))) ast_str_append_va(struct ast_str **buf, size_t max_len, const char *fmt, va_list ap),
+AST_INLINE_API(int __attribute__((format(printf, 3, 0))) ast_str_append_va(struct ast_str **buf, ssize_t max_len, const char *fmt, va_list ap),
 {
 	return __ast_str_helper(buf, max_len, 1, fmt, ap);
 }
 )
 
 /*!\brief Set a dynamic string to a non-NULL terminated substring. */
-AST_INLINE_API(char *ast_str_set_substr(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc),
+AST_INLINE_API(char *ast_str_set_substr(struct ast_str **buf, ssize_t maxlen, const char *src, size_t maxsrc),
 {
 	return __ast_str_helper2(buf, maxlen, src, maxsrc, 0, 0);
 }
 )
 
 /*!\brief Append a non-NULL terminated substring to the end of a dynamic string. */
-AST_INLINE_API(char *ast_str_append_substr(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc),
+AST_INLINE_API(char *ast_str_append_substr(struct ast_str **buf, ssize_t maxlen, const char *src, size_t maxsrc),
 {
 	return __ast_str_helper2(buf, maxlen, src, maxsrc, 1, 0);
 }
 )
 
 /*!\brief Set a dynamic string to a non-NULL terminated substring, with escaping of commas. */
-AST_INLINE_API(char *ast_str_set_escapecommas(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc),
+AST_INLINE_API(char *ast_str_set_escapecommas(struct ast_str **buf, ssize_t maxlen, const char *src, size_t maxsrc),
 {
 	return __ast_str_helper2(buf, maxlen, src, maxsrc, 0, 1);
 }
 )
 
 /*!\brief Append a non-NULL terminated substring to the end of a dynamic string, with escaping of commas. */
-AST_INLINE_API(char *ast_str_append_escapecommas(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc),
+AST_INLINE_API(char *ast_str_append_escapecommas(struct ast_str **buf, ssize_t maxlen, const char *src, size_t maxsrc),
 {
 	return __ast_str_helper2(buf, maxlen, src, maxsrc, 1, 1);
 }
@@ -820,7 +820,7 @@
  */
 AST_INLINE_API(
 int __attribute__((format(printf, 3, 4))) ast_str_set(
-	struct ast_str **buf, size_t max_len, const char *fmt, ...),
+	struct ast_str **buf, ssize_t max_len, const char *fmt, ...),
 {
 	int res;
 	va_list ap;
@@ -841,7 +841,7 @@
  */
 AST_INLINE_API(
 int __attribute__((format(printf, 3, 4))) ast_str_append(
-	struct ast_str **buf, size_t max_len, const char *fmt, ...),
+	struct ast_str **buf, ssize_t max_len, const char *fmt, ...),
 {
 	int res;
 	va_list ap;

Modified: trunk/main/strings.c
URL: http://svnview.digium.com/svn/asterisk/trunk/main/strings.c?view=diff&rev=247335&r1=247334&r2=247335
==============================================================================
--- trunk/main/strings.c (original)
+++ trunk/main/strings.c Wed Feb 17 15:22:40 2010
@@ -49,10 +49,10 @@
  */
 
 #if (defined(MALLOC_DEBUG) && !defined(STANDALONE))
-int __ast_debug_str_helper(struct ast_str **buf, size_t max_len,
+int __ast_debug_str_helper(struct ast_str **buf, ssize_t max_len,
 	int append, const char *fmt, va_list ap, const char *file, int lineno, const char *function)
 #else
-int __ast_str_helper(struct ast_str **buf, size_t max_len,
+int __ast_str_helper(struct ast_str **buf, ssize_t max_len,
 	int append, const char *fmt, va_list ap)
 #endif
 {
@@ -106,12 +106,12 @@
 		break;
 	} while (1);
 	/* update space used, keep in mind the truncation */
-	(*buf)->__AST_STR_USED = (res + offset > (*buf)->__AST_STR_LEN) ? (*buf)->__AST_STR_LEN : res + offset;
+	(*buf)->__AST_STR_USED = (res + offset > (*buf)->__AST_STR_LEN) ? (*buf)->__AST_STR_LEN - 1: res + offset;
 
 	return res;
 }
 
-char *__ast_str_helper2(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc, int append, int escapecommas)
+char *__ast_str_helper2(struct ast_str **buf, ssize_t maxlen, const char *src, size_t maxsrc, int append, int escapecommas)
 {
 	int dynamic = 0;
 	char *ptr = append ? &((*buf)->__AST_STR_STR[(*buf)->__AST_STR_USED]) : (*buf)->__AST_STR_STR;




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