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qemu/util/cutils.c

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/*
* Simple C functions to supplement the C library
*
* Copyright (c) 2006 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "qemu/host-utils.h"
#include <math.h>
#include <limits.h>
#include <errno.h>
#include "qemu/sockets.h"
#include "qemu/iov.h"
#include "net/net.h"
void strpadcpy(char *buf, int buf_size, const char *str, char pad)
{
int len = qemu_strnlen(str, buf_size);
memcpy(buf, str, len);
memset(buf + len, pad, buf_size - len);
}
void pstrcpy(char *buf, int buf_size, const char *str)
{
int c;
char *q = buf;
if (buf_size <= 0)
return;
for(;;) {
c = *str++;
if (c == 0 || q >= buf + buf_size - 1)
break;
*q++ = c;
}
*q = '\0';
}
/* strcat and truncate. */
char *pstrcat(char *buf, int buf_size, const char *s)
{
int len;
len = strlen(buf);
if (len < buf_size)
pstrcpy(buf + len, buf_size - len, s);
return buf;
}
int strstart(const char *str, const char *val, const char **ptr)
{
const char *p, *q;
p = str;
q = val;
while (*q != '\0') {
if (*p != *q)
return 0;
p++;
q++;
}
if (ptr)
*ptr = p;
return 1;
}
int stristart(const char *str, const char *val, const char **ptr)
{
const char *p, *q;
p = str;
q = val;
while (*q != '\0') {
if (qemu_toupper(*p) != qemu_toupper(*q))
return 0;
p++;
q++;
}
if (ptr)
*ptr = p;
return 1;
}
/* XXX: use host strnlen if available ? */
int qemu_strnlen(const char *s, int max_len)
{
int i;
for(i = 0; i < max_len; i++) {
if (s[i] == '\0') {
break;
}
}
return i;
}
char *qemu_strsep(char **input, const char *delim)
{
char *result = *input;
if (result != NULL) {
char *p;
for (p = result; *p != '\0'; p++) {
if (strchr(delim, *p)) {
break;
}
}
if (*p == '\0') {
*input = NULL;
} else {
*p = '\0';
*input = p + 1;
}
}
return result;
}
time_t mktimegm(struct tm *tm)
{
time_t t;
int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
if (m < 3) {
m += 12;
y--;
}
t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
y / 400 - 719469);
t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
return t;
}
int qemu_fls(int i)
{
return 32 - clz32(i);
}
/*
* Make sure data goes on disk, but if possible do not bother to
* write out the inode just for timestamp updates.
*
* Unfortunately even in 2009 many operating systems do not support
* fdatasync and have to fall back to fsync.
*/
int qemu_fdatasync(int fd)
{
#ifdef CONFIG_FDATASYNC
return fdatasync(fd);
#else
return fsync(fd);
#endif
}
/*
* Searches for an area with non-zero content in a buffer
*
* Attention! The len must be a multiple of
* BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
* and addr must be a multiple of sizeof(VECTYPE) due to
* restriction of optimizations in this function.
*
* can_use_buffer_find_nonzero_offset() can be used to check
* these requirements.
*
* The return value is the offset of the non-zero area rounded
* down to a multiple of sizeof(VECTYPE) for the first
* BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
* BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
* afterwards.
*
* If the buffer is all zero the return value is equal to len.
*/
size_t buffer_find_nonzero_offset(const void *buf, size_t len)
{
const VECTYPE *p = buf;
const VECTYPE zero = (VECTYPE){0};
size_t i;
assert(can_use_buffer_find_nonzero_offset(buf, len));
if (!len) {
return 0;
}
for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
if (!ALL_EQ(p[i], zero)) {
return i * sizeof(VECTYPE);
}
}
for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
i < len / sizeof(VECTYPE);
i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
VECTYPE tmp0 = p[i + 0] | p[i + 1];
VECTYPE tmp1 = p[i + 2] | p[i + 3];
VECTYPE tmp2 = p[i + 4] | p[i + 5];
VECTYPE tmp3 = p[i + 6] | p[i + 7];
VECTYPE tmp01 = tmp0 | tmp1;
VECTYPE tmp23 = tmp2 | tmp3;
if (!ALL_EQ(tmp01 | tmp23, zero)) {
break;
}
}
return i * sizeof(VECTYPE);
}
/*
* Checks if a buffer is all zeroes
*
* Attention! The len must be a multiple of 4 * sizeof(long) due to
* restriction of optimizations in this function.
*/
bool buffer_is_zero(const void *buf, size_t len)
{
/*
* Use long as the biggest available internal data type that fits into the
* CPU register and unroll the loop to smooth out the effect of memory
* latency.
*/
size_t i;
long d0, d1, d2, d3;
const long * const data = buf;
/* use vector optimized zero check if possible */
if (can_use_buffer_find_nonzero_offset(buf, len)) {
return buffer_find_nonzero_offset(buf, len) == len;
}
assert(len % (4 * sizeof(long)) == 0);
len /= sizeof(long);
for (i = 0; i < len; i += 4) {
d0 = data[i + 0];
d1 = data[i + 1];
d2 = data[i + 2];
d3 = data[i + 3];
if (d0 || d1 || d2 || d3) {
return false;
}
}
return true;
}
#ifndef _WIN32
/* Sets a specific flag */
int fcntl_setfl(int fd, int flag)
{
int flags;
flags = fcntl(fd, F_GETFL);
if (flags == -1)
return -errno;
if (fcntl(fd, F_SETFL, flags | flag) == -1)
return -errno;
return 0;
}
#endif
static int64_t suffix_mul(char suffix, int64_t unit)
{
switch (qemu_toupper(suffix)) {
case STRTOSZ_DEFSUFFIX_B:
return 1;
case STRTOSZ_DEFSUFFIX_KB:
return unit;
case STRTOSZ_DEFSUFFIX_MB:
return unit * unit;
case STRTOSZ_DEFSUFFIX_GB:
return unit * unit * unit;
case STRTOSZ_DEFSUFFIX_TB:
return unit * unit * unit * unit;
case STRTOSZ_DEFSUFFIX_PB:
return unit * unit * unit * unit * unit;
case STRTOSZ_DEFSUFFIX_EB:
return unit * unit * unit * unit * unit * unit;
}
return -1;
}
/*
* Convert string to bytes, allowing either B/b for bytes, K/k for KB,
* M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
* in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
* other error.
*/
int64_t strtosz_suffix_unit(const char *nptr, char **end,
const char default_suffix, int64_t unit)
{
int64_t retval = -EINVAL;
char *endptr;
unsigned char c;
int mul_required = 0;
double val, mul, integral, fraction;
errno = 0;
val = strtod(nptr, &endptr);
if (isnan(val) || endptr == nptr || errno != 0) {
goto fail;
}
fraction = modf(val, &integral);
if (fraction != 0) {
mul_required = 1;
}
c = *endptr;
mul = suffix_mul(c, unit);
if (mul >= 0) {
endptr++;
} else {
mul = suffix_mul(default_suffix, unit);
assert(mul >= 0);
}
if (mul == 1 && mul_required) {
goto fail;
}
if ((val * mul >= INT64_MAX) || val < 0) {
retval = -ERANGE;
goto fail;
}
retval = val * mul;
fail:
if (end) {
*end = endptr;
}
return retval;
}
int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
{
return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
}
int64_t strtosz(const char *nptr, char **end)
{
return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
}
/**
* parse_uint:
*
* @s: String to parse
* @value: Destination for parsed integer value
* @endptr: Destination for pointer to first character not consumed
* @base: integer base, between 2 and 36 inclusive, or 0
*
* Parse unsigned integer
*
* Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
* '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
*
* If @s is null, or @base is invalid, or @s doesn't start with an
* integer in the syntax above, set *@value to 0, *@endptr to @s, and
* return -EINVAL.
*
* Set *@endptr to point right beyond the parsed integer (even if the integer
* overflows or is negative, all digits will be parsed and *@endptr will
* point right beyond them).
*
* If the integer is negative, set *@value to 0, and return -ERANGE.
*
* If the integer overflows unsigned long long, set *@value to
* ULLONG_MAX, and return -ERANGE.
*
* Else, set *@value to the parsed integer, and return 0.
*/
int parse_uint(const char *s, unsigned long long *value, char **endptr,
int base)
{
int r = 0;
char *endp = (char *)s;
unsigned long long val = 0;
if (!s) {
r = -EINVAL;
goto out;
}
errno = 0;
val = strtoull(s, &endp, base);
if (errno) {
r = -errno;
goto out;
}
if (endp == s) {
r = -EINVAL;
goto out;
}
/* make sure we reject negative numbers: */
while (isspace((unsigned char)*s)) {
s++;
}
if (*s == '-') {
val = 0;
r = -ERANGE;
goto out;
}
out:
*value = val;
*endptr = endp;
return r;
}
/**
* parse_uint_full:
*
* @s: String to parse
* @value: Destination for parsed integer value
* @base: integer base, between 2 and 36 inclusive, or 0
*
* Parse unsigned integer from entire string
*
* Have the same behavior of parse_uint(), but with an additional check
* for additional data after the parsed number. If extra characters are present
* after the parsed number, the function will return -EINVAL, and *@v will
* be set to 0.
*/
int parse_uint_full(const char *s, unsigned long long *value, int base)
{
char *endp;
int r;
r = parse_uint(s, value, &endp, base);
if (r < 0) {
return r;
}
if (*endp) {
*value = 0;
return -EINVAL;
}
return 0;
}
int qemu_parse_fd(const char *param)
{
long fd;
char *endptr;
errno = 0;
fd = strtol(param, &endptr, 10);
if (param == endptr /* no conversion performed */ ||
errno != 0 /* not representable as long; possibly others */ ||
*endptr != '\0' /* final string not empty */ ||
fd < 0 /* invalid as file descriptor */ ||
fd > INT_MAX /* not representable as int */) {
return -1;
}
return fd;
}
/* round down to the nearest power of 2*/
int64_t pow2floor(int64_t value)
{
if (!is_power_of_2(value)) {
value = 0x8000000000000000ULL >> clz64(value);
}
return value;
}
/* round up to the nearest power of 2 (0 if overflow) */
uint64_t pow2ceil(uint64_t value)
{
uint8_t nlz = clz64(value);
if (is_power_of_2(value)) {
return value;
}
if (!nlz) {
return 0;
}
return 1ULL << (64 - nlz);
}
/*
* Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128)
* Input is limited to 14-bit numbers
*/
int uleb128_encode_small(uint8_t *out, uint32_t n)
{
g_assert(n <= 0x3fff);
if (n < 0x80) {
*out++ = n;
return 1;
} else {
*out++ = (n & 0x7f) | 0x80;
*out++ = n >> 7;
return 2;
}
}
int uleb128_decode_small(const uint8_t *in, uint32_t *n)
{
if (!(*in & 0x80)) {
*n = *in++;
return 1;
} else {
*n = *in++ & 0x7f;
/* we exceed 14 bit number */
if (*in & 0x80) {
return -1;
}
*n |= *in++ << 7;
return 2;
}
}
/*
* helper to parse debug environment variables
*/
int parse_debug_env(const char *name, int max, int initial)
{
char *debug_env = getenv(name);
char *inv = NULL;
long debug;
if (!debug_env) {
return initial;
}
errno = 0;
debug = strtol(debug_env, &inv, 10);
if (inv == debug_env) {
return initial;
}
if (debug < 0 || debug > max || errno != 0) {
fprintf(stderr, "warning: %s not in [0, %d]", name, max);
return initial;
}
return debug;
}
/*
* Helper to print ethernet mac address
*/
const char *qemu_ether_ntoa(const MACAddr *mac)
{
static char ret[18];
snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
return ret;
}
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