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qemu/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 "host-utils.h"
#include <math.h>
#include "qemu_socket.h"
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;
}
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 = 86400 * (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
}
/* io vectors */
void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
{
qiov->iov = g_malloc(alloc_hint * sizeof(struct iovec));
qiov->niov = 0;
qiov->nalloc = alloc_hint;
qiov->size = 0;
}
void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
{
int i;
qiov->iov = iov;
qiov->niov = niov;
qiov->nalloc = -1;
qiov->size = 0;
for (i = 0; i < niov; i++)
qiov->size += iov[i].iov_len;
}
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
{
assert(qiov->nalloc != -1);
if (qiov->niov == qiov->nalloc) {
qiov->nalloc = 2 * qiov->nalloc + 1;
qiov->iov = g_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
}
qiov->iov[qiov->niov].iov_base = base;
qiov->iov[qiov->niov].iov_len = len;
qiov->size += len;
++qiov->niov;
}
/*
* Copies iovecs from src to the end of dst. It starts copying after skipping
* the given number of bytes in src and copies until src is completely copied
* or the total size of the copied iovec reaches size.The size of the last
* copied iovec is changed in order to fit the specified total size if it isn't
* a perfect fit already.
*/
void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
size_t size)
{
int i;
size_t done;
void *iov_base;
uint64_t iov_len;
assert(dst->nalloc != -1);
done = 0;
for (i = 0; (i < src->niov) && (done != size); i++) {
if (skip >= src->iov[i].iov_len) {
/* Skip the whole iov */
skip -= src->iov[i].iov_len;
continue;
} else {
/* Skip only part (or nothing) of the iov */
iov_base = (uint8_t*) src->iov[i].iov_base + skip;
iov_len = src->iov[i].iov_len - skip;
skip = 0;
}
if (done + iov_len > size) {
qemu_iovec_add(dst, iov_base, size - done);
break;
} else {
qemu_iovec_add(dst, iov_base, iov_len);
}
done += iov_len;
}
}
void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
{
qemu_iovec_copy(dst, src, 0, size);
}
void qemu_iovec_destroy(QEMUIOVector *qiov)
{
assert(qiov->nalloc != -1);
qemu_iovec_reset(qiov);
g_free(qiov->iov);
qiov->nalloc = 0;
qiov->iov = NULL;
}
void qemu_iovec_reset(QEMUIOVector *qiov)
{
assert(qiov->nalloc != -1);
qiov->niov = 0;
qiov->size = 0;
}
void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
{
uint8_t *p = (uint8_t *)buf;
int i;
for (i = 0; i < qiov->niov; ++i) {
memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
p += qiov->iov[i].iov_len;
}
}
void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count)
{
const uint8_t *p = (const uint8_t *)buf;
size_t copy;
int i;
for (i = 0; i < qiov->niov && count; ++i) {
copy = count;
if (copy > qiov->iov[i].iov_len)
copy = qiov->iov[i].iov_len;
memcpy(qiov->iov[i].iov_base, p, copy);
p += copy;
count -= copy;
}
}
void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
{
size_t n;
int i;
for (i = 0; i < qiov->niov && count; ++i) {
n = MIN(count, qiov->iov[i].iov_len);
memset(qiov->iov[i].iov_base, c, n);
count -= n;
}
}
void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
size_t skip)
{
int i;
size_t done;
void *iov_base;
uint64_t iov_len;
done = 0;
for (i = 0; (i < qiov->niov) && (done != count); i++) {
if (skip >= qiov->iov[i].iov_len) {
/* Skip the whole iov */
skip -= qiov->iov[i].iov_len;
continue;
} else {
/* Skip only part (or nothing) of the iov */
iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
iov_len = qiov->iov[i].iov_len - skip;
skip = 0;
}
if (done + iov_len > count) {
memset(iov_base, c, count - done);
break;
} else {
memset(iov_base, c, iov_len);
}
done += iov_len;
}
}
/*
* 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;
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;
}
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 -1 on error.
*/
int64_t strtosz_suffix_unit(const char *nptr, char **end,
const char default_suffix, int64_t unit)
{
int64_t retval = -1;
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) {
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);
}
int qemu_parse_fd(const char *param)
{
int fd;
char *endptr = NULL;
fd = strtol(param, &endptr, 10);
if (*endptr || (fd == 0 && param == endptr)) {
return -1;
}
return fd;
}
/*
* Send/recv data with iovec buffers
*
* This function send/recv data from/to the iovec buffer directly.
* The first `offset' bytes in the iovec buffer are skipped and next
* `len' bytes are used.
*
* For example,
*
* do_sendv_recvv(sockfd, iov, len, offset, 1);
*
* is equal to
*
* char *buf = malloc(size);
* iov_to_buf(iov, iovcnt, buf, offset, size);
* send(sockfd, buf, size, 0);
* free(buf);
*/
static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
int do_sendv)
{
int ret, diff, iovlen;
struct iovec *last_iov;
/* last_iov is inclusive, so count from one. */
iovlen = 1;
last_iov = iov;
len += offset;
while (last_iov->iov_len < len) {
len -= last_iov->iov_len;
last_iov++;
iovlen++;
}
diff = last_iov->iov_len - len;
last_iov->iov_len -= diff;
while (iov->iov_len <= offset) {
offset -= iov->iov_len;
iov++;
iovlen--;
}
iov->iov_base = (char *) iov->iov_base + offset;
iov->iov_len -= offset;
{
#if defined CONFIG_IOVEC && defined CONFIG_POSIX
struct msghdr msg;
memset(&msg, 0, sizeof(msg));
msg.msg_iov = iov;
msg.msg_iovlen = iovlen;
do {
if (do_sendv) {
ret = sendmsg(sockfd, &msg, 0);
} else {
ret = recvmsg(sockfd, &msg, 0);
}
} while (ret == -1 && errno == EINTR);
#else
struct iovec *p = iov;
ret = 0;
while (iovlen > 0) {
int rc;
if (do_sendv) {
rc = send(sockfd, p->iov_base, p->iov_len, 0);
} else {
rc = qemu_recv(sockfd, p->iov_base, p->iov_len, 0);
}
if (rc == -1) {
if (errno == EINTR) {
continue;
}
if (ret == 0) {
ret = -1;
}
break;
}
if (rc == 0) {
break;
}
ret += rc;
iovlen--, p++;
}
#endif
}
/* Undo the changes above */
iov->iov_base = (char *) iov->iov_base - offset;
iov->iov_len += offset;
last_iov->iov_len += diff;
return ret;
}
int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset)
{
return do_sendv_recvv(sockfd, iov, len, iov_offset, 0);
}
int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
{
return do_sendv_recvv(sockfd, iov, len, iov_offset, 1);
}
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