qemu/net/hub.c

341 lines
7.8 KiB
C

/*
* Hub net client
*
* Copyright IBM, Corp. 2012
*
* Authors:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
* Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "monitor/monitor.h"
#include "net/net.h"
#include "clients.h"
#include "hub.h"
#include "qemu/iov.h"
/*
* A hub broadcasts incoming packets to all its ports except the source port.
* Hubs can be used to provide independent network segments, also confusingly
* named the QEMU 'vlan' feature.
*/
typedef struct NetHub NetHub;
typedef struct NetHubPort {
NetClientState nc;
QLIST_ENTRY(NetHubPort) next;
NetHub *hub;
int id;
} NetHubPort;
struct NetHub {
int id;
QLIST_ENTRY(NetHub) next;
int num_ports;
QLIST_HEAD(, NetHubPort) ports;
};
static QLIST_HEAD(, NetHub) hubs = QLIST_HEAD_INITIALIZER(&hubs);
static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
const uint8_t *buf, size_t len)
{
NetHubPort *port;
QLIST_FOREACH(port, &hub->ports, next) {
if (port == source_port) {
continue;
}
qemu_send_packet(&port->nc, buf, len);
}
return len;
}
static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
const struct iovec *iov, int iovcnt)
{
NetHubPort *port;
ssize_t len = iov_size(iov, iovcnt);
QLIST_FOREACH(port, &hub->ports, next) {
if (port == source_port) {
continue;
}
qemu_sendv_packet(&port->nc, iov, iovcnt);
}
return len;
}
static NetHub *net_hub_new(int id)
{
NetHub *hub;
hub = g_malloc(sizeof(*hub));
hub->id = id;
hub->num_ports = 0;
QLIST_INIT(&hub->ports);
QLIST_INSERT_HEAD(&hubs, hub, next);
return hub;
}
static int net_hub_port_can_receive(NetClientState *nc)
{
NetHubPort *port;
NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
NetHub *hub = src_port->hub;
QLIST_FOREACH(port, &hub->ports, next) {
if (port == src_port) {
continue;
}
if (qemu_can_send_packet(&port->nc)) {
return 1;
}
}
return 0;
}
static ssize_t net_hub_port_receive(NetClientState *nc,
const uint8_t *buf, size_t len)
{
NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
return net_hub_receive(port->hub, port, buf, len);
}
static ssize_t net_hub_port_receive_iov(NetClientState *nc,
const struct iovec *iov, int iovcnt)
{
NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
return net_hub_receive_iov(port->hub, port, iov, iovcnt);
}
static void net_hub_port_cleanup(NetClientState *nc)
{
NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
QLIST_REMOVE(port, next);
}
static NetClientInfo net_hub_port_info = {
.type = NET_CLIENT_OPTIONS_KIND_HUBPORT,
.size = sizeof(NetHubPort),
.can_receive = net_hub_port_can_receive,
.receive = net_hub_port_receive,
.receive_iov = net_hub_port_receive_iov,
.cleanup = net_hub_port_cleanup,
};
static NetHubPort *net_hub_port_new(NetHub *hub, const char *name)
{
NetClientState *nc;
NetHubPort *port;
int id = hub->num_ports++;
char default_name[128];
if (!name) {
snprintf(default_name, sizeof(default_name),
"hub%dport%d", hub->id, id);
name = default_name;
}
nc = qemu_new_net_client(&net_hub_port_info, NULL, "hub", name);
port = DO_UPCAST(NetHubPort, nc, nc);
port->id = id;
port->hub = hub;
QLIST_INSERT_HEAD(&hub->ports, port, next);
return port;
}
/**
* Create a port on a given hub
* @name: Net client name or NULL for default name.
*
* If there is no existing hub with the given id then a new hub is created.
*/
NetClientState *net_hub_add_port(int hub_id, const char *name)
{
NetHub *hub;
NetHubPort *port;
QLIST_FOREACH(hub, &hubs, next) {
if (hub->id == hub_id) {
break;
}
}
if (!hub) {
hub = net_hub_new(hub_id);
}
port = net_hub_port_new(hub, name);
return &port->nc;
}
/**
* Find a specific client on a hub
*/
NetClientState *net_hub_find_client_by_name(int hub_id, const char *name)
{
NetHub *hub;
NetHubPort *port;
NetClientState *peer;
QLIST_FOREACH(hub, &hubs, next) {
if (hub->id == hub_id) {
QLIST_FOREACH(port, &hub->ports, next) {
peer = port->nc.peer;
if (peer && strcmp(peer->name, name) == 0) {
return peer;
}
}
}
}
return NULL;
}
/**
* Find a available port on a hub; otherwise create one new port
*/
NetClientState *net_hub_port_find(int hub_id)
{
NetHub *hub;
NetHubPort *port;
NetClientState *nc;
QLIST_FOREACH(hub, &hubs, next) {
if (hub->id == hub_id) {
QLIST_FOREACH(port, &hub->ports, next) {
nc = port->nc.peer;
if (!nc) {
return &(port->nc);
}
}
break;
}
}
nc = net_hub_add_port(hub_id, NULL);
return nc;
}
/**
* Print hub configuration
*/
void net_hub_info(Monitor *mon)
{
NetHub *hub;
NetHubPort *port;
QLIST_FOREACH(hub, &hubs, next) {
monitor_printf(mon, "hub %d\n", hub->id);
QLIST_FOREACH(port, &hub->ports, next) {
if (port->nc.peer) {
monitor_printf(mon, " \\ ");
print_net_client(mon, port->nc.peer);
}
}
}
}
/**
* Get the hub id that a client is connected to
*
* @id: Pointer for hub id output, may be NULL
*/
int net_hub_id_for_client(NetClientState *nc, int *id)
{
NetHubPort *port;
if (nc->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
port = DO_UPCAST(NetHubPort, nc, nc);
} else if (nc->peer != NULL && nc->peer->info->type ==
NET_CLIENT_OPTIONS_KIND_HUBPORT) {
port = DO_UPCAST(NetHubPort, nc, nc->peer);
} else {
return -ENOENT;
}
if (id) {
*id = port->hub->id;
}
return 0;
}
int net_init_hubport(const NetClientOptions *opts, const char *name,
NetClientState *peer)
{
const NetdevHubPortOptions *hubport;
assert(opts->kind == NET_CLIENT_OPTIONS_KIND_HUBPORT);
hubport = opts->hubport;
/* Treat hub port like a backend, NIC must be the one to peer */
if (peer) {
return -EINVAL;
}
net_hub_add_port(hubport->hubid, name);
return 0;
}
/**
* Warn if hub configurations are likely wrong
*/
void net_hub_check_clients(void)
{
NetHub *hub;
NetHubPort *port;
NetClientState *peer;
QLIST_FOREACH(hub, &hubs, next) {
int has_nic = 0, has_host_dev = 0;
QLIST_FOREACH(port, &hub->ports, next) {
peer = port->nc.peer;
if (!peer) {
fprintf(stderr, "Warning: hub port %s has no peer\n",
port->nc.name);
continue;
}
switch (peer->info->type) {
case NET_CLIENT_OPTIONS_KIND_NIC:
has_nic = 1;
break;
case NET_CLIENT_OPTIONS_KIND_USER:
case NET_CLIENT_OPTIONS_KIND_TAP:
case NET_CLIENT_OPTIONS_KIND_SOCKET:
case NET_CLIENT_OPTIONS_KIND_VDE:
has_host_dev = 1;
break;
default:
break;
}
}
if (has_host_dev && !has_nic) {
fprintf(stderr, "Warning: vlan %d with no nics\n", hub->id);
}
if (has_nic && !has_host_dev) {
fprintf(stderr,
"Warning: vlan %d is not connected to host network\n",
hub->id);
}
}
}