qemu-e2k/net/filter-buffer.c

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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"
2016-03-14 09:01:28 +01:00
#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"
OBJECT_DECLARE_SIMPLE_TYPE(FilterBufferState, FILTER_BUFFER)
struct FilterBufferState {
NetFilterState parent_obj;
NetQueue *incoming_queue;
uint32_t interval;
QEMUTimer release_timer;
};
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;
qapi: Swap visit_* arguments for consistent 'name' placement JSON uses "name":value, but many of our visitor interfaces were called with visit_type_FOO(v, &value, name, errp). This can be a bit confusing to have to mentally swap the parameter order to match JSON order. It's particularly bad for visit_start_struct(), where the 'name' parameter is smack in the middle of the otherwise-related group of 'obj, kind, size' parameters! It's time to do a global swap of the parameter ordering, so that the 'name' parameter is always immediately after the Visitor argument. Additional reason in favor of the swap: the existing include/qjson.h prefers listing 'name' first in json_prop_*(), and I have plans to unify that file with the qapi visitors; listing 'name' first in qapi will minimize churn to the (admittedly few) qjson.h clients. Later patches will then fix docs, object.h, visitor-impl.h, and those clients to match. Done by first patching scripts/qapi*.py by hand to make generated files do what I want, then by running the following Coccinelle script to affect the rest of the code base: $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'` I then had to apply some touchups (Coccinelle insisted on TAB indentation in visitor.h, and botched the signature of visit_type_enum() by rewriting 'const char *const strings[]' to the syntactically invalid 'const char*const[] strings'). The movement of parameters is sufficient to provoke compiler errors if any callers were missed. // Part 1: Swap declaration order @@ type TV, TErr, TObj, T1, T2; identifier OBJ, ARG1, ARG2; @@ void visit_start_struct -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp) { ... } @@ type bool, TV, T1; identifier ARG1; @@ bool visit_optional -(TV v, T1 ARG1, const char *name) +(TV v, const char *name, T1 ARG1) { ... } @@ type TV, TErr, TObj, T1; identifier OBJ, ARG1; @@ void visit_get_next_type -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp) { ... } @@ type TV, TErr, TObj, T1, T2; identifier OBJ, ARG1, ARG2; @@ void visit_type_enum -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp) { ... } @@ type TV, TErr, TObj; identifier OBJ; identifier VISIT_TYPE =~ "^visit_type_"; @@ void VISIT_TYPE -(TV v, TObj OBJ, const char *name, TErr errp) +(TV v, const char *name, TObj OBJ, TErr errp) { ... } // Part 2: swap caller order @@ expression V, NAME, OBJ, ARG1, ARG2, ERR; identifier VISIT_TYPE =~ "^visit_type_"; @@ ( -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR) +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR) | -visit_optional(V, ARG1, NAME) +visit_optional(V, NAME, ARG1) | -visit_get_next_type(V, OBJ, ARG1, NAME, ERR) +visit_get_next_type(V, NAME, OBJ, ARG1, ERR) | -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR) +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR) | -VISIT_TYPE(V, OBJ, NAME, ERR) +VISIT_TYPE(V, NAME, OBJ, ERR) ) Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-01-29 14:48:54 +01:00
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;
error: Eliminate error_propagate() with Coccinelle, part 1 When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-07 18:06:02 +02:00
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,
qom: Drop parameter @errp of object_property_add() & friends The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-05 17:29:22 +02:00
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);