cutils.c - qemu - Git at Google

 /*
  * 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);
 }
	/*
	* 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);
	}