util/osdep.c - qemu - Git at Google

 /*
  * QEMU low level functions
  *
  * Copyright (c) 2003 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 <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>

 /* Needed early for CONFIG_BSD etc. */
 #include "config-host.h"

 #if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
 #include <sys/mman.h>
 #endif

 #ifdef CONFIG_SOLARIS
 #include <sys/types.h>
 #include <sys/statvfs.h>
 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
    discussion about Solaris header problems */
 extern int madvise(caddr_t, size_t, int);
 #endif

 #include "qemu-common.h"
 #include "trace.h"
 #include "qemu/sockets.h"
 #include "monitor/monitor.h"

 static bool fips_enabled = false;

 static const char *qemu_version = QEMU_VERSION;

 int socket_set_cork(int fd, int v)
 {
 #if defined(SOL_TCP) && defined(TCP_CORK)
     return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
 #else
     return 0;
 #endif
 }

 int socket_set_nodelay(int fd)
 {
     int v = 1;
     return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
 }

 int qemu_madvise(void *addr, size_t len, int advice)
 {
     if (advice == QEMU_MADV_INVALID) {
         errno = EINVAL;
         return -1;
     }
 #if defined(CONFIG_MADVISE)
     return madvise(addr, len, advice);
 #elif defined(CONFIG_POSIX_MADVISE)
     return posix_madvise(addr, len, advice);
 #else
     errno = EINVAL;
     return -1;
 #endif
 }

 #ifndef _WIN32
 /*
  * Dups an fd and sets the flags
  */
 static int qemu_dup_flags(int fd, int flags)
 {
     int ret;
     int serrno;
     int dup_flags;

 #ifdef F_DUPFD_CLOEXEC
     ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
 #else
     ret = dup(fd);
     if (ret != -1) {
         qemu_set_cloexec(ret);
     }
 #endif
     if (ret == -1) {
         goto fail;
     }

     dup_flags = fcntl(ret, F_GETFL);
     if (dup_flags == -1) {
         goto fail;
     }

     if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
         errno = EINVAL;
         goto fail;
     }

     /* Set/unset flags that we can with fcntl */
     if (fcntl(ret, F_SETFL, flags) == -1) {
         goto fail;
     }

     /* Truncate the file in the cases that open() would truncate it */
     if (flags & O_TRUNC ||
             ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
         if (ftruncate(ret, 0) == -1) {
             goto fail;
         }
     }

     return ret;

 fail:
     serrno = errno;
     if (ret != -1) {
         close(ret);
     }
     errno = serrno;
     return -1;
 }

 static int qemu_parse_fdset(const char *param)
 {
     return qemu_parse_fd(param);
 }
 #endif

 /*
  * Opens a file with FD_CLOEXEC set
  */
 int qemu_open(const char *name, int flags, ...)
 {
     int ret;
     int mode = 0;

 #ifndef _WIN32
     const char *fdset_id_str;

     /* Attempt dup of fd from fd set */
     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
         int64_t fdset_id;
         int fd, dupfd;

         fdset_id = qemu_parse_fdset(fdset_id_str);
         if (fdset_id == -1) {
             errno = EINVAL;
             return -1;
         }

         fd = monitor_fdset_get_fd(fdset_id, flags);
         if (fd == -1) {
             return -1;
         }

         dupfd = qemu_dup_flags(fd, flags);
         if (dupfd == -1) {
             return -1;
         }

         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
         if (ret == -1) {
             close(dupfd);
             errno = EINVAL;
             return -1;
         }

         return dupfd;
     }
 #endif

     if (flags & O_CREAT) {
         va_list ap;

         va_start(ap, flags);
         mode = va_arg(ap, int);
         va_end(ap);
     }

 #ifdef O_CLOEXEC
     ret = open(name, flags | O_CLOEXEC, mode);
 #else
     ret = open(name, flags, mode);
     if (ret >= 0) {
         qemu_set_cloexec(ret);
     }
 #endif

 #ifdef O_DIRECT
     if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
         error_report("file system may not support O_DIRECT");
         errno = EINVAL; /* in case it was clobbered */
     }
 #endif /* O_DIRECT */

     return ret;
 }

 int qemu_close(int fd)
 {
     int64_t fdset_id;

     /* Close fd that was dup'd from an fdset */
     fdset_id = monitor_fdset_dup_fd_find(fd);
     if (fdset_id != -1) {
         int ret;

         ret = close(fd);
         if (ret == 0) {
             monitor_fdset_dup_fd_remove(fd);
         }

         return ret;
     }

     return close(fd);
 }

 /*
  * A variant of write(2) which handles partial write.
  *
  * Return the number of bytes transferred.
  * Set errno if fewer than `count' bytes are written.
  *
  * This function don't work with non-blocking fd's.
  * Any of the possibilities with non-bloking fd's is bad:
  *   - return a short write (then name is wrong)
  *   - busy wait adding (errno == EAGAIN) to the loop
  */
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 {
     ssize_t ret = 0;
     ssize_t total = 0;

     while (count) {
         ret = write(fd, buf, count);
         if (ret < 0) {
             if (errno == EINTR)
                 continue;
             break;
         }

         count -= ret;
         buf += ret;
         total += ret;
     }

     return total;
 }

 /*
  * Opens a socket with FD_CLOEXEC set
  */
 int qemu_socket(int domain, int type, int protocol)
 {
     int ret;

 #ifdef SOCK_CLOEXEC
     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
     if (ret != -1 || errno != EINVAL) {
         return ret;
     }
 #endif
     ret = socket(domain, type, protocol);
     if (ret >= 0) {
         qemu_set_cloexec(ret);
     }

     return ret;
 }

 /*
  * Accept a connection and set FD_CLOEXEC
  */
 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
     int ret;

 #ifdef CONFIG_ACCEPT4
     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
     if (ret != -1 || errno != ENOSYS) {
         return ret;
     }
 #endif
     ret = accept(s, addr, addrlen);
     if (ret >= 0) {
         qemu_set_cloexec(ret);
     }

     return ret;
 }

 /*
  * A variant of send(2) which handles partial write.
  *
  * Return the number of bytes transferred, which is only
  * smaller than `count' if there is an error.
  *
  * This function won't work with non-blocking fd's.
  * Any of the possibilities with non-bloking fd's is bad:
  *   - return a short write (then name is wrong)
  *   - busy wait adding (errno == EAGAIN) to the loop
  */
 ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
 {
     ssize_t ret = 0;
     ssize_t total = 0;

     while (count) {
         ret = send(fd, buf, count, flags);
         if (ret < 0) {
             if (errno == EINTR) {
                 continue;
             }
             break;
         }

         count -= ret;
         buf += ret;
         total += ret;
     }

     return total;
 }

 /*
  * A variant of recv(2) which handles partial write.
  *
  * Return the number of bytes transferred, which is only
  * smaller than `count' if there is an error.
  *
  * This function won't work with non-blocking fd's.
  * Any of the possibilities with non-bloking fd's is bad:
  *   - return a short write (then name is wrong)
  *   - busy wait adding (errno == EAGAIN) to the loop
  */
 ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
 {
     ssize_t ret = 0;
     ssize_t total = 0;

     while (count) {
         ret = qemu_recv(fd, buf, count, flags);
         if (ret <= 0) {
             if (ret < 0 && errno == EINTR) {
                 continue;
             }
             break;
         }

         count -= ret;
         buf += ret;
         total += ret;
     }

     return total;
 }

 void qemu_set_version(const char *version)
 {
     qemu_version = version;
 }

 const char *qemu_get_version(void)
 {
     return qemu_version;
 }

 void fips_set_state(bool requested)
 {
 #ifdef __linux__
     if (requested) {
         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
         if (fds != NULL) {
             fips_enabled = (fgetc(fds) == '1');
             fclose(fds);
         }
     }
 #else
     fips_enabled = false;
 #endif /* __linux__ */

 #ifdef _FIPS_DEBUG
     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 	    (fips_enabled ? "enabled" : "disabled"),
 	    (requested ? "enabled" : "disabled"));
 #endif
 }

 bool fips_get_state(void)
 {
     return fips_enabled;
 }

 #ifdef _WIN32
 static void socket_cleanup(void)
 {
     WSACleanup();
 }
 #endif

 int socket_init(void)
 {
 #ifdef _WIN32
     WSADATA Data;
     int ret, err;

     ret = WSAStartup(MAKEWORD(2, 2), &Data);
     if (ret != 0) {
         err = WSAGetLastError();
         fprintf(stderr, "WSAStartup: %d\n", err);
         return -1;
     }
     atexit(socket_cleanup);
 #endif
     return 0;
 }

 #ifndef CONFIG_IOVEC
 /* helper function for iov_send_recv() */
 static ssize_t
 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
 {
     unsigned i = 0;
     ssize_t ret = 0;
     while (i < iov_cnt) {
         ssize_t r = do_write
             ? write(fd, iov[i].iov_base, iov[i].iov_len)
             : read(fd, iov[i].iov_base, iov[i].iov_len);
         if (r > 0) {
             ret += r;
         } else if (!r) {
             break;
         } else if (errno == EINTR) {
             continue;
         } else {
             /* else it is some "other" error,
              * only return if there was no data processed. */
             if (ret == 0) {
                 ret = -1;
             }
             break;
         }
         i++;
     }
     return ret;
 }

 ssize_t
 readv(int fd, const struct iovec *iov, int iov_cnt)
 {
     return readv_writev(fd, iov, iov_cnt, false);
 }

 ssize_t
 writev(int fd, const struct iovec *iov, int iov_cnt)
 {
     return readv_writev(fd, iov, iov_cnt, true);
 }
 #endif
	/*
	* QEMU low level functions
	*
	* Copyright (c) 2003 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 <stdlib.h>
	#include <stdio.h>
	#include <stdarg.h>
	#include <stdbool.h>
	#include <string.h>
	#include <errno.h>
	#include <unistd.h>
	#include <fcntl.h>

	/* Needed early for CONFIG_BSD etc. */
	#include "config-host.h"

	#if defined(CONFIG_MADVISE) \|\| defined(CONFIG_POSIX_MADVISE)
	#include <sys/mman.h>
	#endif

	#ifdef CONFIG_SOLARIS
	#include <sys/types.h>
	#include <sys/statvfs.h>
	/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
	discussion about Solaris header problems */
	extern int madvise(caddr_t, size_t, int);
	#endif

	#include "qemu-common.h"
	#include "trace.h"
	#include "qemu/sockets.h"
	#include "monitor/monitor.h"

	static bool fips_enabled = false;

	static const char *qemu_version = QEMU_VERSION;

	int socket_set_cork(int fd, int v)
	{
	#if defined(SOL_TCP) && defined(TCP_CORK)
	return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
	#else
	return 0;
	#endif
	}

	int socket_set_nodelay(int fd)
	{
	int v = 1;
	return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
	}

	int qemu_madvise(void *addr, size_t len, int advice)
	{
	if (advice == QEMU_MADV_INVALID) {
	errno = EINVAL;
	return -1;
	}
	#if defined(CONFIG_MADVISE)
	return madvise(addr, len, advice);
	#elif defined(CONFIG_POSIX_MADVISE)
	return posix_madvise(addr, len, advice);
	#else
	errno = EINVAL;
	return -1;
	#endif
	}

	#ifndef _WIN32
	/*
	* Dups an fd and sets the flags
	*/
	static int qemu_dup_flags(int fd, int flags)
	{
	int ret;
	int serrno;
	int dup_flags;

	#ifdef F_DUPFD_CLOEXEC
	ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
	#else
	ret = dup(fd);
	if (ret != -1) {
	qemu_set_cloexec(ret);
	}
	#endif
	if (ret == -1) {
	goto fail;
	}

	dup_flags = fcntl(ret, F_GETFL);
	if (dup_flags == -1) {
	goto fail;
	}

	if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
	errno = EINVAL;
	goto fail;
	}

	/* Set/unset flags that we can with fcntl */
	if (fcntl(ret, F_SETFL, flags) == -1) {
	goto fail;
	}

	/* Truncate the file in the cases that open() would truncate it */
	if (flags & O_TRUNC \|\|
	((flags & (O_CREAT \| O_EXCL)) == (O_CREAT \| O_EXCL))) {
	if (ftruncate(ret, 0) == -1) {
	goto fail;
	}
	}

	return ret;

	fail:
	serrno = errno;
	if (ret != -1) {
	close(ret);
	}
	errno = serrno;
	return -1;
	}

	static int qemu_parse_fdset(const char *param)
	{
	return qemu_parse_fd(param);
	}
	#endif

	/*
	* Opens a file with FD_CLOEXEC set
	*/
	int qemu_open(const char *name, int flags, ...)
	{
	int ret;
	int mode = 0;

	#ifndef _WIN32
	const char *fdset_id_str;

	/* Attempt dup of fd from fd set */
	if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
	int64_t fdset_id;
	int fd, dupfd;

	fdset_id = qemu_parse_fdset(fdset_id_str);
	if (fdset_id == -1) {
	errno = EINVAL;
	return -1;
	}

	fd = monitor_fdset_get_fd(fdset_id, flags);
	if (fd == -1) {
	return -1;
	}

	dupfd = qemu_dup_flags(fd, flags);
	if (dupfd == -1) {
	return -1;
	}

	ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
	if (ret == -1) {
	close(dupfd);
	errno = EINVAL;
	return -1;
	}

	return dupfd;
	}
	#endif

	if (flags & O_CREAT) {
	va_list ap;

	va_start(ap, flags);
	mode = va_arg(ap, int);
	va_end(ap);
	}

	#ifdef O_CLOEXEC
	ret = open(name, flags \| O_CLOEXEC, mode);
	#else
	ret = open(name, flags, mode);
	if (ret >= 0) {
	qemu_set_cloexec(ret);
	}
	#endif

	#ifdef O_DIRECT
	if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
	error_report("file system may not support O_DIRECT");
	errno = EINVAL; /* in case it was clobbered */
	}
	#endif /* O_DIRECT */

	return ret;
	}

	int qemu_close(int fd)
	{
	int64_t fdset_id;

	/* Close fd that was dup'd from an fdset */
	fdset_id = monitor_fdset_dup_fd_find(fd);
	if (fdset_id != -1) {
	int ret;

	ret = close(fd);
	if (ret == 0) {
	monitor_fdset_dup_fd_remove(fd);
	}

	return ret;
	}

	return close(fd);
	}

	/*
	* A variant of write(2) which handles partial write.
	*
	* Return the number of bytes transferred.
	* Set errno if fewer than `count' bytes are written.
	*
	* This function don't work with non-blocking fd's.
	* Any of the possibilities with non-bloking fd's is bad:
	* - return a short write (then name is wrong)
	* - busy wait adding (errno == EAGAIN) to the loop
	*/
	ssize_t qemu_write_full(int fd, const void *buf, size_t count)
	{
	ssize_t ret = 0;
	ssize_t total = 0;

	while (count) {
	ret = write(fd, buf, count);
	if (ret < 0) {
	if (errno == EINTR)
	continue;
	break;
	}

	count -= ret;
	buf += ret;
	total += ret;
	}

	return total;
	}

	/*
	* Opens a socket with FD_CLOEXEC set
	*/
	int qemu_socket(int domain, int type, int protocol)
	{
	int ret;

	#ifdef SOCK_CLOEXEC
	ret = socket(domain, type \| SOCK_CLOEXEC, protocol);
	if (ret != -1 \|\| errno != EINVAL) {
	return ret;
	}
	#endif
	ret = socket(domain, type, protocol);
	if (ret >= 0) {
	qemu_set_cloexec(ret);
	}

	return ret;
	}

	/*
	* Accept a connection and set FD_CLOEXEC
	*/
	int qemu_accept(int s, struct sockaddr addr, socklen_t addrlen)
	{
	int ret;

	#ifdef CONFIG_ACCEPT4
	ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
	if (ret != -1 \|\| errno != ENOSYS) {
	return ret;
	}
	#endif
	ret = accept(s, addr, addrlen);
	if (ret >= 0) {
	qemu_set_cloexec(ret);
	}

	return ret;
	}

	/*
	* A variant of send(2) which handles partial write.
	*
	* Return the number of bytes transferred, which is only
	* smaller than `count' if there is an error.
	*
	* This function won't work with non-blocking fd's.
	* Any of the possibilities with non-bloking fd's is bad:
	* - return a short write (then name is wrong)
	* - busy wait adding (errno == EAGAIN) to the loop
	*/
	ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
	{
	ssize_t ret = 0;
	ssize_t total = 0;

	while (count) {
	ret = send(fd, buf, count, flags);
	if (ret < 0) {
	if (errno == EINTR) {
	continue;
	}
	break;
	}

	count -= ret;
	buf += ret;
	total += ret;
	}

	return total;
	}

	/*
	* A variant of recv(2) which handles partial write.
	*
	* Return the number of bytes transferred, which is only
	* smaller than `count' if there is an error.
	*
	* This function won't work with non-blocking fd's.
	* Any of the possibilities with non-bloking fd's is bad:
	* - return a short write (then name is wrong)
	* - busy wait adding (errno == EAGAIN) to the loop
	*/
	ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
	{
	ssize_t ret = 0;
	ssize_t total = 0;

	while (count) {
	ret = qemu_recv(fd, buf, count, flags);
	if (ret <= 0) {
	if (ret < 0 && errno == EINTR) {
	continue;
	}
	break;
	}

	count -= ret;
	buf += ret;
	total += ret;
	}

	return total;
	}

	void qemu_set_version(const char *version)
	{
	qemu_version = version;
	}

	const char *qemu_get_version(void)
	{
	return qemu_version;
	}

	void fips_set_state(bool requested)
	{
	#ifdef __linux__
	if (requested) {
	FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
	if (fds != NULL) {
	fips_enabled = (fgetc(fds) == '1');
	fclose(fds);
	}
	}
	#else
	fips_enabled = false;
	#endif /* __linux__ */

	#ifdef _FIPS_DEBUG
	fprintf(stderr, "FIPS mode %s (requested %s)\n",
	(fips_enabled ? "enabled" : "disabled"),
	(requested ? "enabled" : "disabled"));
	#endif
	}

	bool fips_get_state(void)
	{
	return fips_enabled;
	}

	#ifdef _WIN32
	static void socket_cleanup(void)
	{
	WSACleanup();
	}
	#endif

	int socket_init(void)
	{
	#ifdef _WIN32
	WSADATA Data;
	int ret, err;

	ret = WSAStartup(MAKEWORD(2, 2), &Data);
	if (ret != 0) {
	err = WSAGetLastError();
	fprintf(stderr, "WSAStartup: %d\n", err);
	return -1;
	}
	atexit(socket_cleanup);
	#endif
	return 0;
	}

	#ifndef CONFIG_IOVEC
	/* helper function for iov_send_recv() */
	static ssize_t
	readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
	{
	unsigned i = 0;
	ssize_t ret = 0;
	while (i < iov_cnt) {
	ssize_t r = do_write
	? write(fd, iov[i].iov_base, iov[i].iov_len)
	: read(fd, iov[i].iov_base, iov[i].iov_len);
	if (r > 0) {
	ret += r;
	} else if (!r) {
	break;
	} else if (errno == EINTR) {
	continue;
	} else {
	/* else it is some "other" error,
	* only return if there was no data processed. */
	if (ret == 0) {
	ret = -1;
	}
	break;
	}
	i++;
	}
	return ret;
	}

	ssize_t
	readv(int fd, const struct iovec *iov, int iov_cnt)
	{
	return readv_writev(fd, iov, iov_cnt, false);
	}

	ssize_t
	writev(int fd, const struct iovec *iov, int iov_cnt)
	{
	return readv_writev(fd, iov, iov_cnt, true);
	}
	#endif