/* * QEMU I/O channels files driver * * Copyright (c) 2015 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see . * */ #include "qemu/osdep.h" #include "io/channel-file.h" #include "io/channel-util.h" #include "io/channel-watch.h" #include "qapi/error.h" #include "qemu/module.h" #include "qemu/sockets.h" #include "trace.h" QIOChannelFile * qio_channel_file_new_fd(int fd) { QIOChannelFile *ioc; ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); ioc->fd = fd; if (lseek(fd, 0, SEEK_CUR) != (off_t)-1) { qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE); } trace_qio_channel_file_new_fd(ioc, fd); return ioc; } QIOChannelFile * qio_channel_file_new_path(const char *path, int flags, mode_t mode, Error **errp) { QIOChannelFile *ioc; ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); ioc->fd = qemu_open_old(path, flags, mode); if (ioc->fd < 0) { object_unref(OBJECT(ioc)); error_setg_errno(errp, errno, "Unable to open %s", path); return NULL; } if (lseek(ioc->fd, 0, SEEK_CUR) != (off_t)-1) { qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE); } trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd); return ioc; } static void qio_channel_file_init(Object *obj) { QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); ioc->fd = -1; } static void qio_channel_file_finalize(Object *obj) { QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); if (ioc->fd != -1) { qemu_close(ioc->fd); ioc->fd = -1; } } static ssize_t qio_channel_file_readv(QIOChannel *ioc, const struct iovec *iov, size_t niov, int **fds, size_t *nfds, int flags, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); ssize_t ret; retry: ret = readv(fioc->fd, iov, niov); if (ret < 0) { if (errno == EAGAIN) { return QIO_CHANNEL_ERR_BLOCK; } if (errno == EINTR) { goto retry; } error_setg_errno(errp, errno, "Unable to read from file"); return -1; } return ret; } static ssize_t qio_channel_file_writev(QIOChannel *ioc, const struct iovec *iov, size_t niov, int *fds, size_t nfds, int flags, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); ssize_t ret; retry: ret = writev(fioc->fd, iov, niov); if (ret <= 0) { if (errno == EAGAIN) { return QIO_CHANNEL_ERR_BLOCK; } if (errno == EINTR) { goto retry; } error_setg_errno(errp, errno, "Unable to write to file"); return -1; } return ret; } #ifdef CONFIG_PREADV static ssize_t qio_channel_file_preadv(QIOChannel *ioc, const struct iovec *iov, size_t niov, off_t offset, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); ssize_t ret; retry: ret = preadv(fioc->fd, iov, niov, offset); if (ret < 0) { if (errno == EAGAIN) { return QIO_CHANNEL_ERR_BLOCK; } if (errno == EINTR) { goto retry; } error_setg_errno(errp, errno, "Unable to read from file"); return -1; } return ret; } static ssize_t qio_channel_file_pwritev(QIOChannel *ioc, const struct iovec *iov, size_t niov, off_t offset, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); ssize_t ret; retry: ret = pwritev(fioc->fd, iov, niov, offset); if (ret <= 0) { if (errno == EAGAIN) { return QIO_CHANNEL_ERR_BLOCK; } if (errno == EINTR) { goto retry; } error_setg_errno(errp, errno, "Unable to write to file"); return -1; } return ret; } #endif /* CONFIG_PREADV */ static int qio_channel_file_set_blocking(QIOChannel *ioc, bool enabled, Error **errp) { #ifdef WIN32 /* not implemented */ error_setg_errno(errp, errno, "Failed to set FD nonblocking"); return -1; #else QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); if (!g_unix_set_fd_nonblocking(fioc->fd, !enabled, NULL)) { error_setg_errno(errp, errno, "Failed to set FD nonblocking"); return -1; } return 0; #endif } static off_t qio_channel_file_seek(QIOChannel *ioc, off_t offset, int whence, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); off_t ret; ret = lseek(fioc->fd, offset, whence); if (ret == (off_t)-1) { error_setg_errno(errp, errno, "Unable to seek to offset %lld whence %d in file", (long long int)offset, whence); return -1; } return ret; } static int qio_channel_file_close(QIOChannel *ioc, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); if (qemu_close(fioc->fd) < 0) { error_setg_errno(errp, errno, "Unable to close file"); return -1; } fioc->fd = -1; return 0; } static void qio_channel_file_set_aio_fd_handler(QIOChannel *ioc, AioContext *read_ctx, IOHandler *io_read, AioContext *write_ctx, IOHandler *io_write, void *opaque) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); qio_channel_util_set_aio_fd_handler(fioc->fd, read_ctx, io_read, fioc->fd, write_ctx, io_write, opaque); } static GSource *qio_channel_file_create_watch(QIOChannel *ioc, GIOCondition condition) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); return qio_channel_create_fd_watch(ioc, fioc->fd, condition); } static void qio_channel_file_class_init(ObjectClass *klass, void *class_data G_GNUC_UNUSED) { QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); ioc_klass->io_writev = qio_channel_file_writev; ioc_klass->io_readv = qio_channel_file_readv; ioc_klass->io_set_blocking = qio_channel_file_set_blocking; #ifdef CONFIG_PREADV ioc_klass->io_pwritev = qio_channel_file_pwritev; ioc_klass->io_preadv = qio_channel_file_preadv; #endif ioc_klass->io_seek = qio_channel_file_seek; ioc_klass->io_close = qio_channel_file_close; ioc_klass->io_create_watch = qio_channel_file_create_watch; ioc_klass->io_set_aio_fd_handler = qio_channel_file_set_aio_fd_handler; } static const TypeInfo qio_channel_file_info = { .parent = TYPE_QIO_CHANNEL, .name = TYPE_QIO_CHANNEL_FILE, .instance_size = sizeof(QIOChannelFile), .instance_init = qio_channel_file_init, .instance_finalize = qio_channel_file_finalize, .class_init = qio_channel_file_class_init, }; static void qio_channel_file_register_types(void) { type_register_static(&qio_channel_file_info); } type_init(qio_channel_file_register_types);