bird/lib/printf.c

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/*
* BIRD Library -- Formatted Output
*
* (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"
#include "string.h"
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#include <errno.h>
/* we use this so that we can do without the ctype library */
#define is_digit(c) ((c) >= '0' && (c) <= '9')
static int skip_atoi(const char **s)
{
int i=0;
while (is_digit(**s))
i = i*10 + *((*s)++) - '0';
return i;
}
#define ZEROPAD 1 /* pad with zero */
#define SIGN 2 /* unsigned/signed long */
#define PLUS 4 /* show plus */
#define SPACE 8 /* space if plus */
#define LEFT 16 /* left justified */
#define SPECIAL 32 /* 0x */
#define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
#define do_div(n,base) ({ \
int __res; \
__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, 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)
type &= ~ZEROPAD;
if (base < 2 || base > 36)
return 0;
c = (type & ZEROPAD) ? '0' : ' ';
sign = 0;
if (type & SIGN) {
if (num < 0) {
sign = '-';
num = -num;
size--;
} else if (type & PLUS) {
sign = '+';
size--;
} else if (type & SPACE) {
sign = ' ';
size--;
}
}
if (type & SPECIAL) {
if (base == 16)
size -= 2;
else if (base == 8)
size--;
}
i = 0;
if (num == 0)
tmp[i++]='0';
else while (num != 0)
tmp[i++] = digits[do_div(num,base)];
if (i > precision)
precision = i;
size -= precision;
if (size < 0 && -size > remains)
return NULL;
if (!(type&(ZEROPAD+LEFT)))
while(size-->0)
*str++ = ' ';
if (sign)
*str++ = sign;
if (type & SPECIAL) {
if (base==8)
*str++ = '0';
else if (base==16) {
*str++ = '0';
*str++ = digits[33];
}
}
if (!(type & LEFT))
while (size-- > 0)
*str++ = c;
while (i < precision--)
*str++ = '0';
while (i-- > 0)
*str++ = tmp[i];
while (size-- > 0)
*str++ = ' ';
return str;
}
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/**
* bvsnprintf - BIRD's vsnprintf()
* @buf: destination buffer
* @size: size of the buffer
* @fmt: format string
* @args: a list of arguments to be formatted
*
* This functions acts like ordinary sprintf() except that it checks
* available space to avoid buffer overflows and it allows some more
* format specifiers: |%I| for formatting of IP addresses and |%M| for
* error messages (uses strerror() to translate @errno code to
* message text). On the other hand, it doesn't support floating
* point numbers.
*
* Result: number of characters of the output string or -1 if
* the buffer space was insufficient.
*/
int bvsnprintf(char *buf, int size, const char *fmt, va_list args)
{
int len;
unsigned long num;
int i, base;
char *str, *start;
const char *s;
int flags; /* flags to number() */
int field_width; /* width of output field */
int precision; /* min. # of digits for integers; max
number of chars for from string */
int qualifier; /* 'h', 'l', or 'L' for integer fields */
for (start=str=buf ; *fmt ; ++fmt, size-=(str-start), start=str) {
if (*fmt != '%') {
if (!size)
return -1;
*str++ = *fmt;
continue;
}
/* process flags */
flags = 0;
repeat:
++fmt; /* this also skips first '%' */
switch (*fmt) {
case '-': flags |= LEFT; goto repeat;
case '+': flags |= PLUS; goto repeat;
case ' ': flags |= SPACE; goto repeat;
case '#': flags |= SPECIAL; goto repeat;
case '0': flags |= ZEROPAD; goto repeat;
}
/* get field width */
field_width = -1;
if (is_digit(*fmt))
field_width = skip_atoi(&fmt);
else if (*fmt == '*') {
++fmt;
/* it's the next argument */
field_width = va_arg(args, int);
if (field_width < 0) {
field_width = -field_width;
flags |= LEFT;
}
}
/* get the precision */
precision = -1;
if (*fmt == '.') {
++fmt;
if (is_digit(*fmt))
precision = skip_atoi(&fmt);
else if (*fmt == '*') {
++fmt;
/* it's the next argument */
precision = va_arg(args, int);
}
if (precision < 0)
precision = 0;
}
/* get the conversion qualifier */
qualifier = -1;
if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
qualifier = *fmt;
++fmt;
}
/* default base */
base = 10;
if (field_width > size)
return -1;
switch (*fmt) {
case 'c':
if (!(flags & LEFT))
while (--field_width > 0)
*str++ = ' ';
*str++ = (unsigned char) va_arg(args, int);
while (--field_width > 0)
*str++ = ' ';
continue;
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case 'm':
s = strerror(errno);
goto str;
case 'M':
s = strerror(va_arg(args, int));
goto str;
case 's':
s = va_arg(args, char *);
if (!s)
s = "<NULL>";
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str:
len = strlen(s);
if (precision >= 0 && len > precision)
len = precision;
if (len > size)
return -1;
if (!(flags & LEFT))
while (len < field_width--)
*str++ = ' ';
for (i = 0; i < len; ++i)
*str++ = *s++;
while (len < field_width--)
*str++ = ' ';
continue;
case 'p':
if (field_width == -1) {
field_width = 2*sizeof(void *);
flags |= ZEROPAD;
}
str = number(str,
(unsigned long) va_arg(args, void *), 16,
field_width, precision, flags, size);
if (!str)
return -1;
continue;
case 'n':
if (qualifier == 'l') {
long * ip = va_arg(args, long *);
*ip = (str - buf);
} else {
int * ip = va_arg(args, int *);
*ip = (str - buf);
}
continue;
/* 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 {
len = ip_ntop(va_arg(args, ip_addr), str) - str;
str += len;
if (field_width >= 0)
while (len++ < STD_ADDRESS_P_LENGTH)
*str++ = ' ';
}
continue;
/* integer number formats - set up the flags and "break" */
case 'o':
base = 8;
break;
case 'X':
flags |= LARGE;
case 'x':
base = 16;
break;
case 'd':
case 'i':
flags |= SIGN;
case 'u':
break;
default:
if (size < 2)
return -1;
if (*fmt != '%')
*str++ = '%';
if (*fmt)
*str++ = *fmt;
else
--fmt;
continue;
}
if (qualifier == 'l')
num = va_arg(args, unsigned long);
else if (qualifier == 'h') {
num = (unsigned short) va_arg(args, int);
if (flags & SIGN)
num = (short) num;
} else if (flags & SIGN)
num = va_arg(args, int);
else
num = va_arg(args, unsigned int);
str = number(str, num, base, field_width, precision, flags, size);
if (!str)
return -1;
}
if (!size)
return -1;
*str = '\0';
return str-buf;
}
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/**
* bvsprintf - BIRD's vsprintf()
* @buf: buffer
* @fmt: format string
* @args: a list of arguments to be formatted
*
* This function is equivalent to bvsnprintf() with an infinite
* buffer size. Please use carefully only when you are absolutely
* sure the buffer won't overflow.
*/
int bvsprintf(char *buf, const char *fmt, va_list args)
{
return bvsnprintf(buf, 1000000000, fmt, args);
}
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/**
* bsprintf - BIRD's sprintf()
* @buf: buffer
* @fmt: format string
*
* This function is equivalent to bvsnprintf() with an infinite
* buffer size and variable arguments instead of a &va_list.
* Please use carefully only when you are absolutely
* sure the buffer won't overflow.
*/
int bsprintf(char * buf, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i=bvsnprintf(buf, 1000000000, fmt, args);
va_end(args);
return i;
}
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/**
* bsnprintf - BIRD's snprintf()
* @buf: buffer
* @size: buffer size
* @fmt: format string
*
* This function is equivalent to bsnprintf() with variable arguments instead of a &va_list.
*/
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;
}