Archipelago » qemu

/*

 * 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"

#include "iov.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;

}

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;

}

/*

 * Concatenates (partial) iovecs from src to the end of dst.

 * It starts copying after skipping `soffset' bytes at the

 * beginning of src and adds individual vectors from src to

 * dst copies up to `sbytes' bytes total, or up to the end

 * of src if it comes first.  This way, it is okay to specify

 * very large value for `sbytes' to indicate "up to the end

 * of src".

 * Only vector pointers are processed, not the actual data buffers.

 */

void qemu_iovec_concat(QEMUIOVector *dst,

                       QEMUIOVector *src, size_t soffset, size_t sbytes)

{

    int i;

    size_t done;

    struct iovec *siov = src->iov;

    assert(dst->nalloc != -1);

    assert(src->size >= soffset);

    for (i = 0, done = 0; done < sbytes && i < src->niov; i++) {

        if (soffset < siov[i].iov_len) {

            size_t len = MIN(siov[i].iov_len - soffset, sbytes - done);

            qemu_iovec_add(dst, siov[i].iov_base + soffset, len);

            done += len;

            soffset = 0;

        } else {

            soffset -= siov[i].iov_len;

        }

    }

    /* return done; */

}

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;

}

size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,

                         void *buf, size_t bytes)

{

    return iov_to_buf(qiov->iov, qiov->niov, offset, buf, bytes);

}

size_t qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,

                           const void *buf, size_t bytes)

{

    return iov_from_buf(qiov->iov, qiov->niov, offset, buf, bytes);

}

size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,

                         int fillc, size_t bytes)

{

    return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes);

}

/*

 * 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;

}

int qemu_parse_fdset(const char *param)

{

    return qemu_parse_fd(param);

}

/* 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;

}

/*

 * 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;

    }

}