mirror of
https://gitlab.com/qemu-project/qemu
synced 2024-09-06 18:05:37 +00:00
![Paolo Bonzini](/assets/img/avatar_default.png)
Weak symbols were a nice idea, but they turned out not to be a good one. Toolchain support is just too sparse, in particular llvm-gcc is totally broken. This patch uses a surprisingly low-tech approach: a static library. Symbols in a static library are always overridden by symbols in an object file. Furthermore, if you place each function in a separate source file, object files for unused functions will not be taken in. This means that each function can use all the dependencies that it needs (especially QAPI stuff such as error_setg). Thus, all stubs are placed in separate object files and put together in a static library. The library then is linked to all programs. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Tested-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
403 lines
8.6 KiB
C
403 lines
8.6 KiB
C
/*
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* QEMU low level functions
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdarg.h>
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#include <stdbool.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <fcntl.h>
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/* Needed early for CONFIG_BSD etc. */
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#include "config-host.h"
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#if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
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#include <sys/mman.h>
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#endif
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#ifdef CONFIG_SOLARIS
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#include <sys/types.h>
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#include <sys/statvfs.h>
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/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
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discussion about Solaris header problems */
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extern int madvise(caddr_t, size_t, int);
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#endif
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#include "qemu-common.h"
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#include "trace.h"
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#include "qemu_socket.h"
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#include "monitor.h"
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static bool fips_enabled = false;
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static const char *qemu_version = QEMU_VERSION;
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int socket_set_cork(int fd, int v)
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{
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#if defined(SOL_TCP) && defined(TCP_CORK)
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return setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
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#else
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return 0;
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#endif
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}
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int qemu_madvise(void *addr, size_t len, int advice)
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{
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if (advice == QEMU_MADV_INVALID) {
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errno = EINVAL;
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return -1;
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}
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#if defined(CONFIG_MADVISE)
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return madvise(addr, len, advice);
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#elif defined(CONFIG_POSIX_MADVISE)
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return posix_madvise(addr, len, advice);
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#else
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errno = EINVAL;
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return -1;
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#endif
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}
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#ifndef _WIN32
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/*
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* Dups an fd and sets the flags
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*/
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static int qemu_dup_flags(int fd, int flags)
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{
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int ret;
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int serrno;
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int dup_flags;
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#ifdef F_DUPFD_CLOEXEC
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ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
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#else
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ret = dup(fd);
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if (ret != -1) {
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qemu_set_cloexec(ret);
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}
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#endif
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if (ret == -1) {
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goto fail;
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}
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dup_flags = fcntl(ret, F_GETFL);
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if (dup_flags == -1) {
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goto fail;
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}
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if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
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errno = EINVAL;
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goto fail;
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}
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/* Set/unset flags that we can with fcntl */
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if (fcntl(ret, F_SETFL, flags) == -1) {
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goto fail;
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}
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/* Truncate the file in the cases that open() would truncate it */
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if (flags & O_TRUNC ||
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((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
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if (ftruncate(ret, 0) == -1) {
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goto fail;
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}
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}
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return ret;
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fail:
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serrno = errno;
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if (ret != -1) {
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close(ret);
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}
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errno = serrno;
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return -1;
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}
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static int qemu_parse_fdset(const char *param)
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{
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return qemu_parse_fd(param);
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}
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#endif
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/*
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* Opens a file with FD_CLOEXEC set
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*/
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int qemu_open(const char *name, int flags, ...)
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{
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int ret;
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int mode = 0;
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#ifndef _WIN32
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const char *fdset_id_str;
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/* Attempt dup of fd from fd set */
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if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
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int64_t fdset_id;
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int fd, dupfd;
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fdset_id = qemu_parse_fdset(fdset_id_str);
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if (fdset_id == -1) {
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errno = EINVAL;
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return -1;
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}
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fd = monitor_fdset_get_fd(fdset_id, flags);
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if (fd == -1) {
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return -1;
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}
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dupfd = qemu_dup_flags(fd, flags);
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if (dupfd == -1) {
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return -1;
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}
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ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
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if (ret == -1) {
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close(dupfd);
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errno = EINVAL;
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return -1;
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}
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return dupfd;
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}
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#endif
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if (flags & O_CREAT) {
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va_list ap;
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va_start(ap, flags);
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mode = va_arg(ap, int);
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va_end(ap);
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}
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#ifdef O_CLOEXEC
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ret = open(name, flags | O_CLOEXEC, mode);
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#else
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ret = open(name, flags, mode);
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if (ret >= 0) {
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qemu_set_cloexec(ret);
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}
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#endif
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return ret;
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}
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int qemu_close(int fd)
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{
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int64_t fdset_id;
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/* Close fd that was dup'd from an fdset */
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fdset_id = monitor_fdset_dup_fd_find(fd);
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if (fdset_id != -1) {
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int ret;
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ret = close(fd);
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if (ret == 0) {
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monitor_fdset_dup_fd_remove(fd);
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}
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return ret;
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}
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return close(fd);
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}
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/*
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* A variant of write(2) which handles partial write.
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*
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* Return the number of bytes transferred.
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* Set errno if fewer than `count' bytes are written.
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*
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* This function don't work with non-blocking fd's.
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* Any of the possibilities with non-bloking fd's is bad:
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* - return a short write (then name is wrong)
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* - busy wait adding (errno == EAGAIN) to the loop
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*/
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ssize_t qemu_write_full(int fd, const void *buf, size_t count)
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{
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ssize_t ret = 0;
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ssize_t total = 0;
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while (count) {
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ret = write(fd, buf, count);
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if (ret < 0) {
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if (errno == EINTR)
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continue;
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break;
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}
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count -= ret;
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buf += ret;
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total += ret;
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}
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return total;
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}
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/*
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* Opens a socket with FD_CLOEXEC set
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*/
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int qemu_socket(int domain, int type, int protocol)
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{
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int ret;
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#ifdef SOCK_CLOEXEC
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ret = socket(domain, type | SOCK_CLOEXEC, protocol);
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if (ret != -1 || errno != EINVAL) {
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return ret;
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}
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#endif
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ret = socket(domain, type, protocol);
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if (ret >= 0) {
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qemu_set_cloexec(ret);
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}
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return ret;
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}
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/*
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* Accept a connection and set FD_CLOEXEC
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*/
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int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
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{
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int ret;
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#ifdef CONFIG_ACCEPT4
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ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
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if (ret != -1 || errno != ENOSYS) {
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return ret;
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}
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#endif
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ret = accept(s, addr, addrlen);
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if (ret >= 0) {
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qemu_set_cloexec(ret);
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}
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return ret;
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}
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/*
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* A variant of send(2) which handles partial write.
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*
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* Return the number of bytes transferred, which is only
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* smaller than `count' if there is an error.
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*
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* This function won't work with non-blocking fd's.
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* Any of the possibilities with non-bloking fd's is bad:
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* - return a short write (then name is wrong)
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* - busy wait adding (errno == EAGAIN) to the loop
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*/
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ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
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{
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ssize_t ret = 0;
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ssize_t total = 0;
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while (count) {
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ret = send(fd, buf, count, flags);
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if (ret < 0) {
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if (errno == EINTR) {
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continue;
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}
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break;
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}
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count -= ret;
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buf += ret;
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total += ret;
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}
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return total;
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}
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/*
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* A variant of recv(2) which handles partial write.
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*
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* Return the number of bytes transferred, which is only
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* smaller than `count' if there is an error.
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*
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* This function won't work with non-blocking fd's.
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* Any of the possibilities with non-bloking fd's is bad:
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* - return a short write (then name is wrong)
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* - busy wait adding (errno == EAGAIN) to the loop
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*/
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ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
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{
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ssize_t ret = 0;
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ssize_t total = 0;
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while (count) {
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ret = qemu_recv(fd, buf, count, flags);
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if (ret <= 0) {
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if (ret < 0 && errno == EINTR) {
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continue;
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}
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break;
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}
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count -= ret;
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buf += ret;
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total += ret;
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}
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return total;
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}
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void qemu_set_version(const char *version)
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{
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qemu_version = version;
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}
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const char *qemu_get_version(void)
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{
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return qemu_version;
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}
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void fips_set_state(bool requested)
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{
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#ifdef __linux__
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if (requested) {
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FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
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if (fds != NULL) {
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fips_enabled = (fgetc(fds) == '1');
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fclose(fds);
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}
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}
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#else
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fips_enabled = false;
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#endif /* __linux__ */
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#ifdef _FIPS_DEBUG
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fprintf(stderr, "FIPS mode %s (requested %s)\n",
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(fips_enabled ? "enabled" : "disabled"),
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(requested ? "enabled" : "disabled"));
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#endif
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}
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bool fips_get_state(void)
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{
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return fips_enabled;
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}
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