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-rw-r--r--lib/printf.c63
-rw-r--r--lib/string.h2
2 files changed, 52 insertions, 13 deletions
diff --git a/lib/printf.c b/lib/printf.c
index 21453dd..8e6ec76 100644
--- a/lib/printf.c
+++ b/lib/printf.c
@@ -4,6 +4,7 @@
* (c) 1991, 1992 Lars Wirzenius & Linus Torvalds
*
* Hacked up for BIRD by Martin Mares <mj@ucw.cz>
+ * Buffer size limitation implemented by Martin Mares.
*/
#include "nest/bird.h"
@@ -38,13 +39,15 @@ __res = ((unsigned long) n) % (unsigned) base; \
n = ((unsigned long) n) / (unsigned) base; \
__res; })
-static char * number(char * str, long num, int base, int size, int precision
- ,int type)
+static char * number(char * str, long num, int base, int size, int precision,
+ int type, int remains)
{
char c,sign,tmp[66];
const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
int i;
+ if (size >= 0 && (remains -= size) < 0)
+ return NULL;
if (type & LARGE)
digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
if (type & LEFT)
@@ -80,6 +83,8 @@ static char * number(char * str, long num, int base, int size, int precision
if (i > precision)
precision = i;
size -= precision;
+ if (size < 0 && -size > remains)
+ return NULL;
if (!(type&(ZEROPAD+LEFT)))
while(size-->0)
*str++ = ' ';
@@ -105,12 +110,12 @@ static char * number(char * str, long num, int base, int size, int precision
return str;
}
-int bvsprintf(char *buf, const char *fmt, va_list args)
+int bvsnprintf(char *buf, int size, const char *fmt, va_list args)
{
int len;
unsigned long num;
int i, base;
- char * str;
+ char *str, *start;
const char *s;
int flags; /* flags to number() */
@@ -120,8 +125,10 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
number of chars for from string */
int qualifier; /* 'h', 'l', or 'L' for integer fields */
- for (str=buf ; *fmt ; ++fmt) {
+ for (start=str=buf ; *fmt ; ++fmt, size-=(str-start), start=str) {
if (*fmt != '%') {
+ if (!size)
+ return -1;
*str++ = *fmt;
continue;
}
@@ -177,6 +184,8 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
/* default base */
base = 10;
+ if (field_width > size)
+ return -1;
switch (*fmt) {
case 'c':
if (!(flags & LEFT))
@@ -199,6 +208,8 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
len = strlen(s);
if (precision >= 0 && len > precision)
len = precision;
+ if (len > size)
+ return -1;
if (!(flags & LEFT))
while (len < field_width--)
@@ -216,7 +227,9 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
}
str = number(str,
(unsigned long) va_arg(args, void *), 16,
- field_width, precision, flags);
+ field_width, precision, flags, size);
+ if (!str)
+ return -1;
continue;
@@ -232,6 +245,8 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
/* IP address */
case 'I':
+ if (size < STD_ADDRESS_P_LENGTH)
+ return -1;
if (flags & SPECIAL)
str = ip_ntox(va_arg(args, ip_addr), str);
else {
@@ -261,6 +276,8 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
break;
default:
+ if (size < 2)
+ return -1;
if (*fmt != '%')
*str++ = '%';
if (*fmt)
@@ -280,19 +297,39 @@ int bvsprintf(char *buf, const char *fmt, va_list args)
num = va_arg(args, int);
else
num = va_arg(args, unsigned int);
- str = number(str, num, base, field_width, precision, flags);
+ str = number(str, num, base, field_width, precision, flags, size);
+ if (!str)
+ return -1;
}
+ if (!size)
+ return -1;
*str = '\0';
return str-buf;
}
+int bvsprintf(char *buf, const char *fmt, va_list args)
+{
+ return bvsnprintf(buf, 1000000000, fmt, args);
+}
+
int bsprintf(char * buf, const char *fmt, ...)
{
- va_list args;
- int i;
+ va_list args;
+ int i;
- va_start(args, fmt);
- i=bvsprintf(buf,fmt,args);
- va_end(args);
- return i;
+ va_start(args, fmt);
+ i=bvsnprintf(buf, 1000000000, fmt, args);
+ va_end(args);
+ return i;
+}
+
+int bsnprintf(char * buf, int size, const char *fmt, ...)
+{
+ va_list args;
+ int i;
+
+ va_start(args, fmt);
+ i=bvsnprintf(buf, size, fmt, args);
+ va_end(args);
+ return i;
}
diff --git a/lib/string.h b/lib/string.h
index 9f72cb7..202db0a 100644
--- a/lib/string.h
+++ b/lib/string.h
@@ -13,5 +13,7 @@
int bsprintf(char *str, const char *fmt, ...);
int bvsprintf(char *str, const char *fmt, va_list args);
+int bsnprintf(char *str, int size, const char *fmt, ...);
+int bvsnprintf(char *str, int size, const char *fmt, va_list args);
#endif