540 lines
14 KiB
C
540 lines
14 KiB
C
/*
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* QEMU I/O channels
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*
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* Copyright (c) 2015 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include "io/channel.h"
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#include "qapi/error.h"
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#include "qemu/main-loop.h"
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#include "qemu/iov.h"
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bool qio_channel_has_feature(QIOChannel *ioc,
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QIOChannelFeature feature)
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{
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return ioc->features & (1 << feature);
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}
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void qio_channel_set_feature(QIOChannel *ioc,
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QIOChannelFeature feature)
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{
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ioc->features |= (1 << feature);
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}
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void qio_channel_set_name(QIOChannel *ioc,
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const char *name)
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{
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g_free(ioc->name);
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ioc->name = g_strdup(name);
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}
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ssize_t qio_channel_readv_full(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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int **fds,
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size_t *nfds,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if ((fds || nfds) &&
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!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
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error_setg_errno(errp, EINVAL,
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"Channel does not support file descriptor passing");
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return -1;
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}
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return klass->io_readv(ioc, iov, niov, fds, nfds, errp);
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}
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ssize_t qio_channel_writev_full(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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int *fds,
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size_t nfds,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if ((fds || nfds) &&
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!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
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error_setg_errno(errp, EINVAL,
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"Channel does not support file descriptor passing");
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return -1;
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}
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return klass->io_writev(ioc, iov, niov, fds, nfds, errp);
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}
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int qio_channel_readv_all_eof(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = -1;
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struct iovec *local_iov = g_new(struct iovec, niov);
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struct iovec *local_iov_head = local_iov;
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unsigned int nlocal_iov = niov;
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bool partial = false;
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nlocal_iov = iov_copy(local_iov, nlocal_iov,
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iov, niov,
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0, iov_size(iov, niov));
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while (nlocal_iov > 0) {
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ssize_t len;
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len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
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if (len == QIO_CHANNEL_ERR_BLOCK) {
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if (qemu_in_coroutine()) {
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qio_channel_yield(ioc, G_IO_IN);
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} else {
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qio_channel_wait(ioc, G_IO_IN);
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}
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continue;
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} else if (len < 0) {
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goto cleanup;
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} else if (len == 0) {
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if (partial) {
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error_setg(errp,
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"Unexpected end-of-file before all bytes were read");
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} else {
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ret = 0;
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}
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goto cleanup;
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}
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partial = true;
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iov_discard_front(&local_iov, &nlocal_iov, len);
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}
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ret = 1;
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cleanup:
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g_free(local_iov_head);
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return ret;
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}
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int qio_channel_readv_all(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
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if (ret == 0) {
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ret = -1;
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error_setg(errp,
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"Unexpected end-of-file before all bytes were read");
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} else if (ret == 1) {
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ret = 0;
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}
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return ret;
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}
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int qio_channel_writev_all(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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int ret = -1;
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struct iovec *local_iov = g_new(struct iovec, niov);
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struct iovec *local_iov_head = local_iov;
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unsigned int nlocal_iov = niov;
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nlocal_iov = iov_copy(local_iov, nlocal_iov,
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iov, niov,
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0, iov_size(iov, niov));
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while (nlocal_iov > 0) {
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ssize_t len;
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len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
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if (len == QIO_CHANNEL_ERR_BLOCK) {
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if (qemu_in_coroutine()) {
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qio_channel_yield(ioc, G_IO_OUT);
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} else {
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qio_channel_wait(ioc, G_IO_OUT);
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}
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continue;
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}
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if (len < 0) {
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goto cleanup;
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}
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iov_discard_front(&local_iov, &nlocal_iov, len);
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}
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ret = 0;
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cleanup:
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g_free(local_iov_head);
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return ret;
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}
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ssize_t qio_channel_readv(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, errp);
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}
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ssize_t qio_channel_writev(QIOChannel *ioc,
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const struct iovec *iov,
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size_t niov,
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Error **errp)
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{
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return qio_channel_writev_full(ioc, iov, niov, NULL, 0, errp);
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}
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ssize_t qio_channel_read(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, errp);
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}
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ssize_t qio_channel_write(QIOChannel *ioc,
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const char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
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return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, errp);
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}
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int qio_channel_read_all_eof(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_all_eof(ioc, &iov, 1, errp);
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}
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int qio_channel_read_all(QIOChannel *ioc,
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char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = buflen };
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return qio_channel_readv_all(ioc, &iov, 1, errp);
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}
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int qio_channel_write_all(QIOChannel *ioc,
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const char *buf,
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size_t buflen,
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Error **errp)
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{
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struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
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return qio_channel_writev_all(ioc, &iov, 1, errp);
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}
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int qio_channel_set_blocking(QIOChannel *ioc,
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bool enabled,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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return klass->io_set_blocking(ioc, enabled, errp);
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}
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int qio_channel_close(QIOChannel *ioc,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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return klass->io_close(ioc, errp);
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}
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GSource *qio_channel_create_watch(QIOChannel *ioc,
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GIOCondition condition)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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GSource *ret = klass->io_create_watch(ioc, condition);
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if (ioc->name) {
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g_source_set_name(ret, ioc->name);
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}
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return ret;
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}
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void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
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AioContext *ctx,
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IOHandler *io_read,
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IOHandler *io_write,
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void *opaque)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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klass->io_set_aio_fd_handler(ioc, ctx, io_read, io_write, opaque);
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}
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guint qio_channel_add_watch_full(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify,
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GMainContext *context)
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{
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GSource *source;
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guint id;
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source = qio_channel_create_watch(ioc, condition);
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g_source_set_callback(source, (GSourceFunc)func, user_data, notify);
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id = g_source_attach(source, context);
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g_source_unref(source);
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return id;
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}
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guint qio_channel_add_watch(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify)
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{
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return qio_channel_add_watch_full(ioc, condition, func,
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user_data, notify, NULL);
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}
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GSource *qio_channel_add_watch_source(QIOChannel *ioc,
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GIOCondition condition,
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QIOChannelFunc func,
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gpointer user_data,
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GDestroyNotify notify,
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GMainContext *context)
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{
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GSource *source;
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guint id;
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id = qio_channel_add_watch_full(ioc, condition, func,
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user_data, notify, context);
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source = g_main_context_find_source_by_id(context, id);
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g_source_ref(source);
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return source;
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}
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int qio_channel_shutdown(QIOChannel *ioc,
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QIOChannelShutdown how,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (!klass->io_shutdown) {
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error_setg(errp, "Data path shutdown not supported");
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return -1;
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}
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return klass->io_shutdown(ioc, how, errp);
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}
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void qio_channel_set_delay(QIOChannel *ioc,
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bool enabled)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (klass->io_set_delay) {
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klass->io_set_delay(ioc, enabled);
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}
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}
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void qio_channel_set_cork(QIOChannel *ioc,
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bool enabled)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (klass->io_set_cork) {
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klass->io_set_cork(ioc, enabled);
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}
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}
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off_t qio_channel_io_seek(QIOChannel *ioc,
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off_t offset,
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int whence,
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Error **errp)
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{
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QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
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if (!klass->io_seek) {
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error_setg(errp, "Channel does not support random access");
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return -1;
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}
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return klass->io_seek(ioc, offset, whence, errp);
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}
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static void qio_channel_set_aio_fd_handlers(QIOChannel *ioc);
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static void qio_channel_restart_read(void *opaque)
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{
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QIOChannel *ioc = opaque;
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Coroutine *co = ioc->read_coroutine;
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ioc->read_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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aio_co_wake(co);
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}
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static void qio_channel_restart_write(void *opaque)
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{
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QIOChannel *ioc = opaque;
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Coroutine *co = ioc->write_coroutine;
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ioc->write_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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aio_co_wake(co);
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}
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static void qio_channel_set_aio_fd_handlers(QIOChannel *ioc)
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{
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IOHandler *rd_handler = NULL, *wr_handler = NULL;
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AioContext *ctx;
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if (ioc->read_coroutine) {
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rd_handler = qio_channel_restart_read;
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}
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if (ioc->write_coroutine) {
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wr_handler = qio_channel_restart_write;
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}
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ctx = ioc->ctx ? ioc->ctx : iohandler_get_aio_context();
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qio_channel_set_aio_fd_handler(ioc, ctx, rd_handler, wr_handler, ioc);
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}
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void qio_channel_attach_aio_context(QIOChannel *ioc,
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AioContext *ctx)
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{
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assert(!ioc->read_coroutine);
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assert(!ioc->write_coroutine);
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ioc->ctx = ctx;
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}
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void qio_channel_detach_aio_context(QIOChannel *ioc)
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{
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ioc->read_coroutine = NULL;
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ioc->write_coroutine = NULL;
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qio_channel_set_aio_fd_handlers(ioc);
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ioc->ctx = NULL;
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}
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void coroutine_fn qio_channel_yield(QIOChannel *ioc,
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GIOCondition condition)
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{
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assert(qemu_in_coroutine());
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if (condition == G_IO_IN) {
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assert(!ioc->read_coroutine);
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ioc->read_coroutine = qemu_coroutine_self();
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} else if (condition == G_IO_OUT) {
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assert(!ioc->write_coroutine);
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ioc->write_coroutine = qemu_coroutine_self();
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} else {
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abort();
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}
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qio_channel_set_aio_fd_handlers(ioc);
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qemu_coroutine_yield();
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}
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static gboolean qio_channel_wait_complete(QIOChannel *ioc,
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GIOCondition condition,
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gpointer opaque)
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{
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GMainLoop *loop = opaque;
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g_main_loop_quit(loop);
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return FALSE;
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}
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void qio_channel_wait(QIOChannel *ioc,
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GIOCondition condition)
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{
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GMainContext *ctxt = g_main_context_new();
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GMainLoop *loop = g_main_loop_new(ctxt, TRUE);
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GSource *source;
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source = qio_channel_create_watch(ioc, condition);
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g_source_set_callback(source,
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(GSourceFunc)qio_channel_wait_complete,
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loop,
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NULL);
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g_source_attach(source, ctxt);
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g_main_loop_run(loop);
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g_source_unref(source);
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g_main_loop_unref(loop);
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g_main_context_unref(ctxt);
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}
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static void qio_channel_finalize(Object *obj)
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{
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QIOChannel *ioc = QIO_CHANNEL(obj);
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g_free(ioc->name);
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#ifdef _WIN32
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if (ioc->event) {
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CloseHandle(ioc->event);
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}
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#endif
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}
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static const TypeInfo qio_channel_info = {
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.parent = TYPE_OBJECT,
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.name = TYPE_QIO_CHANNEL,
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.instance_size = sizeof(QIOChannel),
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.instance_finalize = qio_channel_finalize,
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.abstract = true,
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.class_size = sizeof(QIOChannelClass),
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};
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static void qio_channel_register_types(void)
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{
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type_register_static(&qio_channel_info);
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}
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type_init(qio_channel_register_types);
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