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"

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);

}