[PATCH v2 01/15] net: Add a hub net client

zwu.kernel
2012-05-23T15:13:51Z

From: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

The vlan feature can be implemented in terms of hubs. By introducing a
hub net client it becomes possible to remove the special case vlan code
from net.c and push the vlan feature out of generic networking code.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
Makefile.objs | 2 +-
net.h | 1 +
net/hub.c | 200 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
net/hub.h | 23 +++++++
4 files changed, 225 insertions(+), 1 deletions(-)
create mode 100644 net/hub.c
create mode 100644 net/hub.h

diff --git a/Makefile.objs b/Makefile.objs
index 70c5c79..a3a3a8a 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -63,7 +63,7 @@ block-nested-$(CONFIG_RBD) += rbd.o
block-obj-y += $(addprefix block/, $(block-nested-y))

net-obj-y = net.o
-net-nested-y = queue.o checksum.o util.o
+net-nested-y = queue.o checksum.o util.o hub.o
net-nested-y += socket.o
net-nested-y += dump.o
net-nested-$(CONFIG_POSIX) += tap.o
diff --git a/net.h b/net.h
index 64993b4..50c55ad 100644
--- a/net.h
+++ b/net.h
@@ -38,6 +38,7 @@ typedef enum {
NET_CLIENT_TYPE_VDE,
NET_CLIENT_TYPE_DUMP,
NET_CLIENT_TYPE_BRIDGE,
+ NET_CLIENT_TYPE_HUB,

NET_CLIENT_TYPE_MAX
} net_client_type;
diff --git a/net/hub.c b/net/hub.c
new file mode 100644
index 0000000..0d3df7f
--- /dev/null
+++ b/net/hub.c
@@ -0,0 +1,200 @@
+/*
+ * Hub net client
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * Stefan Hajnoczi <stefanha@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.h"
+#include "net.h"
+#include "hub.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 {
+ VLANClientState nc;
+ QLIST_ENTRY(NetHubPort) next;
+ NetHub *hub;
+ unsigned int id;
+} NetHubPort;
+
+struct NetHub {
+ unsigned int id;
+ QLIST_ENTRY(NetHub) next;
+ unsigned 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 ret = 0;
+
+ QLIST_FOREACH(port, &hub->ports, next) {
+ if (port == source_port) {
+ continue;
+ }
+
+ ret = qemu_sendv_packet(&port->nc, iov, iovcnt);
+ }
+ return ret;
+}
+
+static NetHub *net_hub_new(unsigned 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 ssize_t net_hub_port_receive(VLANClientState *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(VLANClientState *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(VLANClientState *nc)
+{
+ NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
+
+ QLIST_REMOVE(port, next);
+}
+
+static NetClientInfo net_hub_port_info = {
+ .type = NET_CLIENT_TYPE_HUB,
+ .size = sizeof(NetHubPort),
+ .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)
+{
+ VLANClientState *nc;
+ NetHubPort *port;
+ unsigned int id = hub->num_ports++;
+ char name[128];
+
+ snprintf(name, sizeof name, "hub%uport%u", hub->id, id);
+
+ nc = qemu_new_net_client(&net_hub_port_info, NULL, 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
+ *
+ * If there is no existing hub with the given id then a new hub is created.
+ */
+VLANClientState *net_hub_add_port(unsigned int hub_id)
+{
+ 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);
+ return &port->nc;
+}
+
+/**
+ * Print hub configuration
+ */
+void net_hub_info(Monitor *mon)
+{
+ NetHub *hub;
+ NetHubPort *port;
+
+ QLIST_FOREACH(hub, &hubs, next) {
+ monitor_printf(mon, "hub %u\n", hub->id);
+ QLIST_FOREACH(port, &hub->ports, next) {
+ monitor_printf(mon, " port %u peer %s\n", port->id,
+ port->nc.peer ? port->nc.peer->name : "<none>");
+ }
+ }
+}
+
+/**
+ * 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(VLANClientState *nc, unsigned int *id)
+{
+ NetHub *hub;
+ NetHubPort *port;
+
+ QLIST_FOREACH(hub, &hubs, next) {
+ QLIST_FOREACH(port, &hub->ports, next) {
+ if (&port->nc == nc ||
+ (port->nc.peer && port->nc.peer == nc)) {
+ if (id) {
+ *id = hub->id;
+ }
+ return 0;
+ }
+ }
+ }
+ return -ENOENT;
+}
diff --git a/net/hub.h b/net/hub.h
new file mode 100644
index 0000000..3ca05dc
--- /dev/null
+++ b/net/hub.h
@@ -0,0 +1,23 @@
+/*
+ * Hub net client
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ * Stefan Hajnoczi <stefanha@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.
+ *
+ */
+
+#ifndef NET_HUB_H
+#define NET_HUB_H
+
+#include "qemu-common.h"
+
+VLANClientState *net_hub_add_port(unsigned int hub_id);
+void net_hub_info(Monitor *mon);
+int net_hub_id_for_client(VLANClientState *nc, unsigned int *id);
+
+#endif /* NET_HUB_H */
--
1.7.6