diff options
Diffstat (limited to 'lib/printf.c')
| -rw-r--r-- | lib/printf.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/lib/printf.c b/lib/printf.c index 21453ddc..8e6ec76e 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; } |