/* * 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 "qemu/osdep.h" /* Needed early for CONFIG_BSD etc. */ #ifdef CONFIG_SOLARIS #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 "qemu/cutils.h" #include "qemu/sockets.h" #include "qemu/error-report.h" #include "monitor/monitor.h" static bool fips_enabled = false; static const char *hw_version = QEMU_HW_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 } static int qemu_mprotect__osdep(void *addr, size_t size, int prot) { g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask)); g_assert(!(size & ~qemu_real_host_page_mask)); #ifdef _WIN32 DWORD old_protect; if (!VirtualProtect(addr, size, prot, &old_protect)) { error_report("%s: VirtualProtect failed with error code %ld", __func__, GetLastError()); return -1; } return 0; #else if (mprotect(addr, size, prot)) { error_report("%s: mprotect failed: %s", __func__, strerror(errno)); return -1; } return 0; #endif } int qemu_mprotect_rwx(void *addr, size_t size) { #ifdef _WIN32 return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE); #else return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); #endif } int qemu_mprotect_none(void *addr, size_t size) { #ifdef _WIN32 return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS); #else return qemu_mprotect__osdep(addr, size, PROT_NONE); #endif } #ifndef _WIN32 static int fcntl_op_setlk = -1; static int fcntl_op_getlk = -1; /* * Dups an fd and sets the flags */ static int qemu_dup_flags(int fd, int flags) { int ret; int serrno; int dup_flags; ret = qemu_dup(fd); 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; } int qemu_dup(int fd) { int ret; #ifdef F_DUPFD_CLOEXEC ret = fcntl(fd, F_DUPFD_CLOEXEC, 0); #else ret = dup(fd); if (ret != -1) { qemu_set_cloexec(ret); } #endif return ret; } static int qemu_parse_fdset(const char *param) { return qemu_parse_fd(param); } static void qemu_probe_lock_ops(void) { if (fcntl_op_setlk == -1) { #ifdef F_OFD_SETLK int fd; int ret; struct flock fl = { .l_whence = SEEK_SET, .l_start = 0, .l_len = 0, .l_type = F_WRLCK, }; fd = open("/dev/null", O_RDWR); if (fd < 0) { fprintf(stderr, "Failed to open /dev/null for OFD lock probing: %s\n", strerror(errno)); fcntl_op_setlk = F_SETLK; fcntl_op_getlk = F_GETLK; return; } ret = fcntl(fd, F_OFD_GETLK, &fl); close(fd); if (!ret) { fcntl_op_setlk = F_OFD_SETLK; fcntl_op_getlk = F_OFD_GETLK; } else { fcntl_op_setlk = F_SETLK; fcntl_op_getlk = F_GETLK; } #else fcntl_op_setlk = F_SETLK; fcntl_op_getlk = F_GETLK; #endif } } bool qemu_has_ofd_lock(void) { qemu_probe_lock_ops(); #ifdef F_OFD_SETLK return fcntl_op_setlk == F_OFD_SETLK; #else return false; #endif } static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type) { int ret; struct flock fl = { .l_whence = SEEK_SET, .l_start = start, .l_len = len, .l_type = fl_type, }; qemu_probe_lock_ops(); do { ret = fcntl(fd, fcntl_op_setlk, &fl); } while (ret == -1 && errno == EINTR); return ret == -1 ? -errno : 0; } int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive) { return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK); } int qemu_unlock_fd(int fd, int64_t start, int64_t len) { return qemu_lock_fcntl(fd, start, len, F_UNLCK); } int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive) { int ret; struct flock fl = { .l_whence = SEEK_SET, .l_start = start, .l_len = len, .l_type = exclusive ? F_WRLCK : F_RDLCK, }; qemu_probe_lock_ops(); ret = fcntl(fd, fcntl_op_getlk, &fl); if (ret == -1) { return -errno; } else { return fl.l_type == F_UNLCK ? 0 : -EAGAIN; } } #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; } void qemu_set_hw_version(const char *version) { hw_version = version; } const char *qemu_hw_version(void) { return hw_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; } #if !GLIB_CHECK_VERSION(2, 31, 0) /* Ensure that glib is running in multi-threaded mode * Old versions of glib require explicit initialization. Failure to do * this results in the single-threaded code paths being taken inside * glib. For example, the g_slice allocator will not be thread-safe * and cause crashes. */ static void __attribute__((constructor)) thread_init(void) { if (!g_thread_supported()) { g_thread_init(NULL); } } #endif #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