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/*
* Copyright (c) 2015 FUJITSU LIMITED
* Author: Yang Hongyang <yanghy@cn.fujitsu.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "net/filter.h"
#include "net/queue.h"
#include "qapi/error.h"
#include "qemu/timer.h"
#include "qemu/iov.h"
#include "qapi/qapi-builtin-visit.h"
#include "qapi/qmp/qerror.h"
#include "qom/object.h"
#define TYPE_FILTER_BUFFER "filter-buffer"
#define FILTER_BUFFER(obj) \
OBJECT_CHECK(FilterBufferState, (obj), TYPE_FILTER_BUFFER)
typedef struct FilterBufferState {
NetFilterState parent_obj;
NetQueue *incoming_queue;
uint32_t interval;
QEMUTimer release_timer;
} FilterBufferState;
static void filter_buffer_flush(NetFilterState *nf)
{
FilterBufferState *s = FILTER_BUFFER(nf);
if (!qemu_net_queue_flush(s->incoming_queue)) {
/* Unable to empty the queue, purge remaining packets */
qemu_net_queue_purge(s->incoming_queue, nf->netdev);
}
}
static void filter_buffer_release_timer(void *opaque)
{
NetFilterState *nf = opaque;
FilterBufferState *s = FILTER_BUFFER(nf);
/*
* Note: filter_buffer_flush() drops packets that can't be sent
* TODO: We should leave them queued. But currently there's no way
* for the next filter or receiver to notify us that it can receive
* more packets.
*/
filter_buffer_flush(nf);
/* Timer rearmed to fire again in s->interval microseconds. */
timer_mod(&s->release_timer,
qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval);
}
/* filter APIs */
static ssize_t filter_buffer_receive_iov(NetFilterState *nf,
NetClientState *sender,
unsigned flags,
const struct iovec *iov,
int iovcnt,
NetPacketSent *sent_cb)
{
FilterBufferState *s = FILTER_BUFFER(nf);
/*
* We return size when buffer a packet, the sender will take it as
* a already sent packet, so sent_cb should not be called later.
*
* FIXME: Even if the guest can't receive packets for some reasons,
* the filter can still accept packets until its internal queue is full.
* For example:
* For some reason, receiver could not receive more packets
* (.can_receive() returns false). Without a filter, at most one packet
* will be queued in incoming queue and sender's poll will be disabled
* unit its sent_cb() was called. With a filter, it will keep receiving
* the packets without caring about the receiver. This is suboptimal.
* May need more thoughts (e.g keeping sent_cb).
*/
qemu_net_queue_append_iov(s->incoming_queue, sender, flags,
iov, iovcnt, NULL);
return iov_size(iov, iovcnt);
}
static void filter_buffer_cleanup(NetFilterState *nf)
{
FilterBufferState *s = FILTER_BUFFER(nf);
if (s->interval) {
timer_del(&s->release_timer);
}
/* flush packets */
if (s->incoming_queue) {
filter_buffer_flush(nf);
g_free(s->incoming_queue);
}
}
static void filter_buffer_setup_timer(NetFilterState *nf)
{
FilterBufferState *s = FILTER_BUFFER(nf);
if (s->interval) {
timer_init_us(&s->release_timer, QEMU_CLOCK_VIRTUAL,
filter_buffer_release_timer, nf);
/* Timer armed to fire in s->interval microseconds. */
timer_mod(&s->release_timer,
qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval);
}
}
static void filter_buffer_setup(NetFilterState *nf, Error **errp)
{
FilterBufferState *s = FILTER_BUFFER(nf);
/*
* We may want to accept zero interval when VM FT solutions like MC
* or COLO use this filter to release packets on demand.
*/
if (!s->interval) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "interval",
"a non-zero interval");
return;
}
s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
filter_buffer_setup_timer(nf);
}
static void filter_buffer_status_changed(NetFilterState *nf, Error **errp)
{
FilterBufferState *s = FILTER_BUFFER(nf);
if (!nf->on) {
if (s->interval) {
timer_del(&s->release_timer);
}
filter_buffer_flush(nf);
} else {
filter_buffer_setup_timer(nf);
}
}
static void filter_buffer_class_init(ObjectClass *oc, void *data)
{
NetFilterClass *nfc = NETFILTER_CLASS(oc);
nfc->setup = filter_buffer_setup;
nfc->cleanup = filter_buffer_cleanup;
nfc->receive_iov = filter_buffer_receive_iov;
nfc->status_changed = filter_buffer_status_changed;
}
static void filter_buffer_get_interval(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
FilterBufferState *s = FILTER_BUFFER(obj);
uint32_t value = s->interval;
visit_type_uint32(v, name, &value, errp);
}
static void filter_buffer_set_interval(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
FilterBufferState *s = FILTER_BUFFER(obj);
uint32_t value;
if (!visit_type_uint32(v, name, &value, errp)) {
return;
}
if (!value) {
error_setg(errp, "Property '%s.%s' requires a positive value",
object_get_typename(obj), name);
return;
}
s->interval = value;
}
static void filter_buffer_init(Object *obj)
{
object_property_add(obj, "interval", "uint32",
filter_buffer_get_interval,
filter_buffer_set_interval, NULL, NULL);
}
static const TypeInfo filter_buffer_info = {
.name = TYPE_FILTER_BUFFER,
.parent = TYPE_NETFILTER,
.class_init = filter_buffer_class_init,
.instance_init = filter_buffer_init,
.instance_size = sizeof(FilterBufferState),
};
static void register_types(void)
{
type_register_static(&filter_buffer_info);
}
type_init(register_types);
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