qemu/net/vde.c
Eric Blake 32bafa8fdd qapi: Don't special-case simple union wrappers
Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type().  But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:

| struct q_obj_ImageInfoSpecificQCow2_wrapper {
|     ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
|     ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
|     ImageInfoSpecificKind type;
|     union { /* union tag is @type */
|         void *data;
|-        ImageInfoSpecificQCow2 *qcow2;
|-        ImageInfoSpecificVmdk *vmdk;
|+        q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+        q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
|     } u;
| };

Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation).  Using the implicit type
also lets us get rid of the simple_union_type() hack.

Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access.  The generated
qapi-visit.c code is also affected by the layout change:

|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
|     }
|     switch (obj->type) {
|     case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|-        visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+        visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
|         break;
|     case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|-        visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+        visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
|         break;
|     default:
|         abort();

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:26 +01:00

129 lines
3.6 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 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"
#include <libvdeplug.h>
#include "net/net.h"
#include "clients.h"
#include "qemu-common.h"
#include "qemu/option.h"
#include "qemu/main-loop.h"
typedef struct VDEState {
NetClientState nc;
VDECONN *vde;
} VDEState;
static void vde_to_qemu(void *opaque)
{
VDEState *s = opaque;
uint8_t buf[NET_BUFSIZE];
int size;
size = vde_recv(s->vde, (char *)buf, sizeof(buf), 0);
if (size > 0) {
qemu_send_packet(&s->nc, buf, size);
}
}
static ssize_t vde_receive(NetClientState *nc, const uint8_t *buf, size_t size)
{
VDEState *s = DO_UPCAST(VDEState, nc, nc);
ssize_t ret;
do {
ret = vde_send(s->vde, (const char *)buf, size, 0);
} while (ret < 0 && errno == EINTR);
return ret;
}
static void vde_cleanup(NetClientState *nc)
{
VDEState *s = DO_UPCAST(VDEState, nc, nc);
qemu_set_fd_handler(vde_datafd(s->vde), NULL, NULL, NULL);
vde_close(s->vde);
}
static NetClientInfo net_vde_info = {
.type = NET_CLIENT_OPTIONS_KIND_VDE,
.size = sizeof(VDEState),
.receive = vde_receive,
.cleanup = vde_cleanup,
};
static int net_vde_init(NetClientState *peer, const char *model,
const char *name, const char *sock,
int port, const char *group, int mode)
{
NetClientState *nc;
VDEState *s;
VDECONN *vde;
char *init_group = (char *)group;
char *init_sock = (char *)sock;
struct vde_open_args args = {
.port = port,
.group = init_group,
.mode = mode,
};
vde = vde_open(init_sock, (char *)"QEMU", &args);
if (!vde){
return -1;
}
nc = qemu_new_net_client(&net_vde_info, peer, model, name);
snprintf(nc->info_str, sizeof(nc->info_str), "sock=%s,fd=%d",
sock, vde_datafd(vde));
s = DO_UPCAST(VDEState, nc, nc);
s->vde = vde;
qemu_set_fd_handler(vde_datafd(s->vde), vde_to_qemu, NULL, s);
return 0;
}
int net_init_vde(const NetClientOptions *opts, const char *name,
NetClientState *peer, Error **errp)
{
/* FIXME error_setg(errp, ...) on failure */
const NetdevVdeOptions *vde;
assert(opts->type == NET_CLIENT_OPTIONS_KIND_VDE);
vde = opts->u.vde.data;
/* missing optional values have been initialized to "all bits zero" */
if (net_vde_init(peer, "vde", name, vde->sock, vde->port, vde->group,
vde->has_mode ? vde->mode : 0700) == -1) {
return -1;
}
return 0;
}