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...



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@247335 65c4cc65-6c06-0410-ace0-fbb531ad65f3
certified/1.8.6
Mark Michelson 15 years ago
parent 27a4cda821
commit 2ce7eabb24

@ -708,14 +708,14 @@ enum {
* 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 @@ char *__ast_str_helper2(struct ast_str **buf, size_t max_len,
* }
* \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 @@ AST_INLINE_API(int __attribute__((format(printf, 3, 0))) ast_str_set_va(struct a
*
* 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(char *ast_str_append_escapecommas(struct ast_str **buf, size_t ma
*/
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 @@ int __attribute__((format(printf, 3, 4))) ast_str_set(
*/
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;

@ -49,10 +49,10 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
*/
#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 @@ int __ast_str_helper(struct ast_str **buf, size_t max_len,
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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