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PyOS_vsnprintf(char *str, size_t size, const char *format, va_list va) | PyOS_vsnprintf(char *str, size_t size, const char *format, va_list va) |
{ | { |
int len; /* # bytes written, excluding \0 */ | int len; /* # bytes written, excluding \0 */ |
#ifndef HAVE_SNPRINTF |
#ifdef HAVE_SNPRINTF |
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#define _PyOS_vsnprintf_EXTRA_SPACE 1 |
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#else |
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#define _PyOS_vsnprintf_EXTRA_SPACE 512 |
char *buffer; | char *buffer; |
#endif | #endif |
assert(str != NULL); | assert(str != NULL); |
assert(size > 0); | assert(size > 0); |
assert(format != NULL); | assert(format != NULL); |
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/* We take a size_t as input but return an int. Sanity check |
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* our input so that it won't cause an overflow in the |
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* vsnprintf return value or the buffer malloc size. */ |
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if (size > INT_MAX - _PyOS_vsnprintf_EXTRA_SPACE) { |
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len = -666; |
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goto Done; |
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} |
| |
#ifdef HAVE_SNPRINTF | #ifdef HAVE_SNPRINTF |
len = vsnprintf(str, size, format, va); | len = vsnprintf(str, size, format, va); |
#else | #else |
/* Emulate it. */ | /* Emulate it. */ |
buffer = PyMem_MALLOC(size + 512); |
buffer = PyMem_MALLOC(size + _PyOS_vsnprintf_EXTRA_SPACE); |
if (buffer == NULL) { | if (buffer == NULL) { |
len = -666; | len = -666; |
goto Done; | goto Done; |
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Lines 75-81
PyOS_vsnprintf(char *str, size_t size, c
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Link Here
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if (len < 0) | if (len < 0) |
/* ignore the error */; | /* ignore the error */; |
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else if ((size_t)len >= size + 512) |
else if ((size_t)len >= size + _PyOS_vsnprintf_EXTRA_SPACE) |
Py_FatalError("Buffer overflow in PyOS_snprintf/PyOS_vsnprintf"); | Py_FatalError("Buffer overflow in PyOS_snprintf/PyOS_vsnprintf"); |
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else { | else { |
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Lines 86-93
PyOS_vsnprintf(char *str, size_t size, c
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Link Here
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str[to_copy] = '\0'; | str[to_copy] = '\0'; |
} | } |
PyMem_FREE(buffer); | PyMem_FREE(buffer); |
Done: |
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#endif | #endif |
str[size-1] = '\0'; |
Done: |
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if (size > 0) |
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str[size-1] = '\0'; |
return len; | return len; |
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#undef _PyOS_vsnprintf_EXTRA_SPACE |
} | } |
