u-boot/lib/vsprintf.c
Darwin Rambo 686f60f519 lib: fix return codes when CONFIG_SYS_VSNPRINTF is enabled
When CONFIG_SYS_VSNPRINTF is enabled, it protects print operations
such as sprintf, snprintf, vsnprintf, etc., from buffer overflows.
But vsnprintf_internal includes the terminating NULL character in
the calculation of number of characters written. This affects sprintf
and snprintf return values. Fix this issue by setting pointer 'str'
back to the location of the '\0'.

Signed-off-by: Darwin Rambo <drambo@broadcom.com>
Reviewed-by: Steve Rae <srae@broadcom.com>
2014-01-24 16:59:07 -05:00

890 lines
18 KiB
C

/*
* linux/lib/vsprintf.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
/*
* Wirzenius wrote this portably, Torvalds fucked it up :-)
*
* from hush: simple_itoa() was lifted from boa-0.93.15
*/
#include <stdarg.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <errno.h>
#include <common.h>
#if !defined(CONFIG_PANIC_HANG)
#include <command.h>
#endif
#include <div64.h>
#define noinline __attribute__((noinline))
/* some reluctance to put this into a new limits.h, so it is here */
#define INT_MAX ((int)(~0U>>1))
static const char hex_asc[] = "0123456789abcdef";
#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
static inline char *pack_hex_byte(char *buf, u8 byte)
{
*buf++ = hex_asc_hi(byte);
*buf++ = hex_asc_lo(byte);
return buf;
}
unsigned long simple_strtoul(const char *cp, char **endp,
unsigned int base)
{
unsigned long result = 0;
unsigned long value;
if (*cp == '0') {
cp++;
if ((*cp == 'x') && isxdigit(cp[1])) {
base = 16;
cp++;
}
if (!base)
base = 8;
}
if (!base)
base = 10;
while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
? toupper(*cp) : *cp)-'A'+10) < base) {
result = result*base + value;
cp++;
}
if (endp)
*endp = (char *)cp;
return result;
}
int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
{
char *tail;
unsigned long val;
size_t len;
*res = 0;
len = strlen(cp);
if (len == 0)
return -EINVAL;
val = simple_strtoul(cp, &tail, base);
if (tail == cp)
return -EINVAL;
if ((*tail == '\0') ||
((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
*res = val;
return 0;
}
return -EINVAL;
}
long simple_strtol(const char *cp, char **endp, unsigned int base)
{
if (*cp == '-')
return -simple_strtoul(cp + 1, endp, base);
return simple_strtoul(cp, endp, base);
}
unsigned long ustrtoul(const char *cp, char **endp, unsigned int base)
{
unsigned long result = simple_strtoul(cp, endp, base);
switch (**endp) {
case 'G':
result *= 1024;
/* fall through */
case 'M':
result *= 1024;
/* fall through */
case 'K':
case 'k':
result *= 1024;
if ((*endp)[1] == 'i') {
if ((*endp)[2] == 'B')
(*endp) += 3;
else
(*endp) += 2;
}
}
return result;
}
unsigned long long ustrtoull(const char *cp, char **endp, unsigned int base)
{
unsigned long long result = simple_strtoull(cp, endp, base);
switch (**endp) {
case 'G':
result *= 1024;
/* fall through */
case 'M':
result *= 1024;
/* fall through */
case 'K':
case 'k':
result *= 1024;
if ((*endp)[1] == 'i') {
if ((*endp)[2] == 'B')
(*endp) += 3;
else
(*endp) += 2;
}
}
return result;
}
unsigned long long simple_strtoull(const char *cp, char **endp,
unsigned int base)
{
unsigned long long result = 0, value;
if (*cp == '0') {
cp++;
if ((*cp == 'x') && isxdigit(cp[1])) {
base = 16;
cp++;
}
if (!base)
base = 8;
}
if (!base)
base = 10;
while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp - '0'
: (islower(*cp) ? toupper(*cp) : *cp) - 'A' + 10) < base) {
result = result * base + value;
cp++;
}
if (endp)
*endp = (char *) cp;
return result;
}
/* 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;
}
/* Decimal conversion is by far the most typical, and is used
* for /proc and /sys data. This directly impacts e.g. top performance
* with many processes running. We optimize it for speed
* using code from
* http://www.cs.uiowa.edu/~jones/bcd/decimal.html
* (with permission from the author, Douglas W. Jones). */
/* Formats correctly any integer in [0,99999].
* Outputs from one to five digits depending on input.
* On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
static char *put_dec_trunc(char *buf, unsigned q)
{
unsigned d3, d2, d1, d0;
d1 = (q>>4) & 0xf;
d2 = (q>>8) & 0xf;
d3 = (q>>12);
d0 = 6*(d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10*q;
*buf++ = d0 + '0'; /* least significant digit */
d1 = q + 9*d3 + 5*d2 + d1;
if (d1 != 0) {
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10*q;
*buf++ = d1 + '0'; /* next digit */
d2 = q + 2*d2;
if ((d2 != 0) || (d3 != 0)) {
q = (d2 * 0xd) >> 7;
d2 = d2 - 10*q;
*buf++ = d2 + '0'; /* next digit */
d3 = q + 4*d3;
if (d3 != 0) {
q = (d3 * 0xcd) >> 11;
d3 = d3 - 10*q;
*buf++ = d3 + '0'; /* next digit */
if (q != 0)
*buf++ = q + '0'; /* most sign. digit */
}
}
}
return buf;
}
/* Same with if's removed. Always emits five digits */
static char *put_dec_full(char *buf, unsigned q)
{
/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
/* but anyway, gcc produces better code with full-sized ints */
unsigned d3, d2, d1, d0;
d1 = (q>>4) & 0xf;
d2 = (q>>8) & 0xf;
d3 = (q>>12);
/*
* Possible ways to approx. divide by 10
* gcc -O2 replaces multiply with shifts and adds
* (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
* (x * 0x67) >> 10: 1100111
* (x * 0x34) >> 9: 110100 - same
* (x * 0x1a) >> 8: 11010 - same
* (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
*/
d0 = 6*(d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10*q;
*buf++ = d0 + '0';
d1 = q + 9*d3 + 5*d2 + d1;
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10*q;
*buf++ = d1 + '0';
d2 = q + 2*d2;
q = (d2 * 0xd) >> 7;
d2 = d2 - 10*q;
*buf++ = d2 + '0';
d3 = q + 4*d3;
q = (d3 * 0xcd) >> 11; /* - shorter code */
/* q = (d3 * 0x67) >> 10; - would also work */
d3 = d3 - 10*q;
*buf++ = d3 + '0';
*buf++ = q + '0';
return buf;
}
/* No inlining helps gcc to use registers better */
static noinline char *put_dec(char *buf, u64 num)
{
while (1) {
unsigned rem;
if (num < 100000)
return put_dec_trunc(buf, num);
rem = do_div(num, 100000);
buf = put_dec_full(buf, rem);
}
}
#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 SMALL 32 /* Must be 32 == 0x20 */
#define SPECIAL 64 /* 0x */
#ifdef CONFIG_SYS_VSNPRINTF
/*
* Macro to add a new character to our output string, but only if it will
* fit. The macro moves to the next character position in the output string.
*/
#define ADDCH(str, ch) do { \
if ((str) < end) \
*(str) = (ch); \
++str; \
} while (0)
#else
#define ADDCH(str, ch) (*(str)++ = (ch))
#endif
static char *number(char *buf, char *end, u64 num,
int base, int size, int precision, int type)
{
/* we are called with base 8, 10 or 16, only, thus don't need "G..." */
static const char digits[16] = "0123456789ABCDEF";
char tmp[66];
char sign;
char locase;
int need_pfx = ((type & SPECIAL) && base != 10);
int i;
/* locase = 0 or 0x20. ORing digits or letters with 'locase'
* produces same digits or (maybe lowercased) letters */
locase = (type & SMALL);
if (type & LEFT)
type &= ~ZEROPAD;
sign = 0;
if (type & SIGN) {
if ((s64) num < 0) {
sign = '-';
num = -(s64) num;
size--;
} else if (type & PLUS) {
sign = '+';
size--;
} else if (type & SPACE) {
sign = ' ';
size--;
}
}
if (need_pfx) {
size--;
if (base == 16)
size--;
}
/* generate full string in tmp[], in reverse order */
i = 0;
if (num == 0)
tmp[i++] = '0';
/* Generic code, for any base:
else do {
tmp[i++] = (digits[do_div(num,base)] | locase);
} while (num != 0);
*/
else if (base != 10) { /* 8 or 16 */
int mask = base - 1;
int shift = 3;
if (base == 16)
shift = 4;
do {
tmp[i++] = (digits[((unsigned char)num) & mask]
| locase);
num >>= shift;
} while (num);
} else { /* base 10 */
i = put_dec(tmp, num) - tmp;
}
/* printing 100 using %2d gives "100", not "00" */
if (i > precision)
precision = i;
/* leading space padding */
size -= precision;
if (!(type & (ZEROPAD + LEFT))) {
while (--size >= 0)
ADDCH(buf, ' ');
}
/* sign */
if (sign)
ADDCH(buf, sign);
/* "0x" / "0" prefix */
if (need_pfx) {
ADDCH(buf, '0');
if (base == 16)
ADDCH(buf, 'X' | locase);
}
/* zero or space padding */
if (!(type & LEFT)) {
char c = (type & ZEROPAD) ? '0' : ' ';
while (--size >= 0)
ADDCH(buf, c);
}
/* hmm even more zero padding? */
while (i <= --precision)
ADDCH(buf, '0');
/* actual digits of result */
while (--i >= 0)
ADDCH(buf, tmp[i]);
/* trailing space padding */
while (--size >= 0)
ADDCH(buf, ' ');
return buf;
}
static char *string(char *buf, char *end, char *s, int field_width,
int precision, int flags)
{
int len, i;
if (s == NULL)
s = "<NULL>";
len = strnlen(s, precision);
if (!(flags & LEFT))
while (len < field_width--)
ADDCH(buf, ' ');
for (i = 0; i < len; ++i)
ADDCH(buf, *s++);
while (len < field_width--)
ADDCH(buf, ' ');
return buf;
}
#ifdef CONFIG_CMD_NET
static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
int precision, int flags)
{
/* (6 * 2 hex digits), 5 colons and trailing zero */
char mac_addr[6 * 3];
char *p = mac_addr;
int i;
for (i = 0; i < 6; i++) {
p = pack_hex_byte(p, addr[i]);
if (!(flags & SPECIAL) && i != 5)
*p++ = ':';
}
*p = '\0';
return string(buf, end, mac_addr, field_width, precision,
flags & ~SPECIAL);
}
static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width,
int precision, int flags)
{
/* (8 * 4 hex digits), 7 colons and trailing zero */
char ip6_addr[8 * 5];
char *p = ip6_addr;
int i;
for (i = 0; i < 8; i++) {
p = pack_hex_byte(p, addr[2 * i]);
p = pack_hex_byte(p, addr[2 * i + 1]);
if (!(flags & SPECIAL) && i != 7)
*p++ = ':';
}
*p = '\0';
return string(buf, end, ip6_addr, field_width, precision,
flags & ~SPECIAL);
}
static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
int precision, int flags)
{
/* (4 * 3 decimal digits), 3 dots and trailing zero */
char ip4_addr[4 * 4];
char temp[3]; /* hold each IP quad in reverse order */
char *p = ip4_addr;
int i, digits;
for (i = 0; i < 4; i++) {
digits = put_dec_trunc(temp, addr[i]) - temp;
/* reverse the digits in the quad */
while (digits--)
*p++ = temp[digits];
if (i != 3)
*p++ = '.';
}
*p = '\0';
return string(buf, end, ip4_addr, field_width, precision,
flags & ~SPECIAL);
}
#endif
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed
* by an extra set of alphanumeric characters that are extended format
* specifiers.
*
* Right now we handle:
*
* - 'M' For a 6-byte MAC address, it prints the address in the
* usual colon-separated hex notation
* - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
* decimal for v4 and colon separated network-order 16 bit hex for v6)
* - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
* currently the same
*
* Note: The difference between 'S' and 'F' is that on ia64 and ppc64
* function pointers are really function descriptors, which contain a
* pointer to the real address.
*/
static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
int field_width, int precision, int flags)
{
/*
* Being a boot loader, we explicitly allow pointers to
* (physical) address null.
*/
#if 0
if (!ptr)
return string(buf, end, "(null)", field_width, precision,
flags);
#endif
#ifdef CONFIG_CMD_NET
switch (*fmt) {
case 'm':
flags |= SPECIAL;
/* Fallthrough */
case 'M':
return mac_address_string(buf, end, ptr, field_width,
precision, flags);
case 'i':
flags |= SPECIAL;
/* Fallthrough */
case 'I':
if (fmt[1] == '6')
return ip6_addr_string(buf, end, ptr, field_width,
precision, flags);
if (fmt[1] == '4')
return ip4_addr_string(buf, end, ptr, field_width,
precision, flags);
flags &= ~SPECIAL;
break;
}
#endif
flags |= SMALL;
if (field_width == -1) {
field_width = 2*sizeof(void *);
flags |= ZEROPAD;
}
return number(buf, end, (unsigned long)ptr, 16, field_width,
precision, flags);
}
static int vsnprintf_internal(char *buf, size_t size, const char *fmt,
va_list args)
{
u64 num;
int base;
char *str;
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 */
/* 'z' support added 23/7/1999 S.H. */
/* 'z' changed to 'Z' --davidm 1/25/99 */
/* 't' added for ptrdiff_t */
char *end = buf + size;
#ifdef CONFIG_SYS_VSNPRINTF
/* Make sure end is always >= buf - do we want this in U-Boot? */
if (end < buf) {
end = ((void *)-1);
size = end - buf;
}
#endif
str = buf;
for (; *fmt ; ++fmt) {
if (*fmt != '%') {
ADDCH(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' ||
*fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
qualifier = *fmt;
++fmt;
if (qualifier == 'l' && *fmt == 'l') {
qualifier = 'L';
++fmt;
}
}
/* default base */
base = 10;
switch (*fmt) {
case 'c':
if (!(flags & LEFT)) {
while (--field_width > 0)
ADDCH(str, ' ');
}
ADDCH(str, (unsigned char) va_arg(args, int));
while (--field_width > 0)
ADDCH(str, ' ');
continue;
case 's':
str = string(str, end, va_arg(args, char *),
field_width, precision, flags);
continue;
case 'p':
str = pointer(fmt + 1, str, end,
va_arg(args, void *),
field_width, precision, flags);
/* Skip all alphanumeric pointer suffixes */
while (isalnum(fmt[1]))
fmt++;
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;
case '%':
ADDCH(str, '%');
continue;
/* integer number formats - set up the flags and "break" */
case 'o':
base = 8;
break;
case 'x':
flags |= SMALL;
case 'X':
base = 16;
break;
case 'd':
case 'i':
flags |= SIGN;
case 'u':
break;
default:
ADDCH(str, '%');
if (*fmt)
ADDCH(str, *fmt);
else
--fmt;
continue;
}
if (qualifier == 'L') /* "quad" for 64 bit variables */
num = va_arg(args, unsigned long long);
else if (qualifier == 'l') {
num = va_arg(args, unsigned long);
if (flags & SIGN)
num = (signed long) num;
} else if (qualifier == 'Z' || qualifier == 'z') {
num = va_arg(args, size_t);
} else if (qualifier == 't') {
num = va_arg(args, ptrdiff_t);
} else if (qualifier == 'h') {
num = (unsigned short) va_arg(args, int);
if (flags & SIGN)
num = (signed short) num;
} else {
num = va_arg(args, unsigned int);
if (flags & SIGN)
num = (signed int) num;
}
str = number(str, end, num, base, field_width, precision,
flags);
}
#ifdef CONFIG_SYS_VSNPRINTF
if (size > 0) {
ADDCH(str, '\0');
if (str > end)
end[-1] = '\0';
--str;
}
#else
*str = '\0';
#endif
/* the trailing null byte doesn't count towards the total */
return str - buf;
}
#ifdef CONFIG_SYS_VSNPRINTF
int vsnprintf(char *buf, size_t size, const char *fmt,
va_list args)
{
return vsnprintf_internal(buf, size, fmt, args);
}
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
int i;
i = vsnprintf(buf, size, fmt, args);
if (likely(i < size))
return i;
if (size != 0)
return size - 1;
return 0;
}
int snprintf(char *buf, size_t size, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = vsnprintf(buf, size, fmt, args);
va_end(args);
return i;
}
int scnprintf(char *buf, size_t size, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = vscnprintf(buf, size, fmt, args);
va_end(args);
return i;
}
#endif /* CONFIG_SYS_VSNPRINT */
/**
* Format a string and place it in a buffer (va_list version)
*
* @param buf The buffer to place the result into
* @param fmt The format string to use
* @param args Arguments for the format string
*
* The function returns the number of characters written
* into @buf. Use vsnprintf() or vscnprintf() in order to avoid
* buffer overflows.
*
* If you're not already dealing with a va_list consider using sprintf().
*/
int vsprintf(char *buf, const char *fmt, va_list args)
{
return vsnprintf_internal(buf, INT_MAX, fmt, args);
}
int sprintf(char *buf, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = vsprintf(buf, fmt, args);
va_end(args);
return i;
}
void panic(const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vprintf(fmt, args);
putc('\n');
va_end(args);
#if defined(CONFIG_PANIC_HANG)
hang();
#else
udelay(100000); /* allow messages to go out */
do_reset(NULL, 0, 0, NULL);
#endif
while (1)
;
}
void __assert_fail(const char *assertion, const char *file, unsigned line,
const char *function)
{
/* This will not return */
panic("%s:%u: %s: Assertion `%s' failed.", file, line, function,
assertion);
}
char *simple_itoa(ulong i)
{
/* 21 digits plus null terminator, good for 64-bit or smaller ints */
static char local[22];
char *p = &local[21];
*p-- = '\0';
do {
*p-- = '0' + i % 10;
i /= 10;
} while (i > 0);
return p + 1;
}
/* We don't seem to have %'d in U-Boot */
void print_grouped_ull(unsigned long long int_val, int digits)
{
char str[21], *s;
int grab = 3;
digits = (digits + 2) / 3;
sprintf(str, "%*llu", digits * 3, int_val);
for (s = str; *s; s += grab) {
if (s != str)
putc(s[-1] != ' ' ? ',' : ' ');
printf("%.*s", grab, s);
grab = 3;
}
}