xref: /qemu/net/hub.c (revision 27a4a30e) 
1 /*
2  * Hub net client
3  *
4  * Copyright IBM, Corp. 2012
5  *
6  * Authors:
7  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
8  *  Zhi Yong Wu       <wuzhy@linux.vnet.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
11  * See the COPYING.LIB file in the top-level directory.
12  *
13  */
14 
15 #include "qemu/osdep.h"
16 #include "qapi/error.h"
17 #include "monitor/monitor.h"
18 #include "net/net.h"
19 #include "clients.h"
20 #include "hub.h"
21 #include "qemu/iov.h"
22 #include "qemu/error-report.h"
23 #include "sysemu/qtest.h"
24 
25 /*
26  * A hub broadcasts incoming packets to all its ports except the source port.
27  * Hubs can be used to provide independent emulated network segments.
28  */
29 
30 typedef struct NetHub NetHub;
31 
32 typedef struct NetHubPort {
33     NetClientState nc;
34     QLIST_ENTRY(NetHubPort) next;
35     NetHub *hub;
36     int id;
37 } NetHubPort;
38 
39 struct NetHub {
40     int id;
41     QLIST_ENTRY(NetHub) next;
42     int num_ports;
43     QLIST_HEAD(, NetHubPort) ports;
44 };
45 
46 static QLIST_HEAD(, NetHub) hubs = QLIST_HEAD_INITIALIZER(&hubs);
47 
48 static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
49                                const uint8_t *buf, size_t len)
50 {
51     NetHubPort *port;
52 
53     QLIST_FOREACH(port, &hub->ports, next) {
54         if (port == source_port) {
55             continue;
56         }
57 
58         qemu_send_packet(&port->nc, buf, len);
59     }
60     return len;
61 }
62 
63 static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
64                                    const struct iovec *iov, int iovcnt)
65 {
66     NetHubPort *port;
67     ssize_t len = iov_size(iov, iovcnt);
68 
69     QLIST_FOREACH(port, &hub->ports, next) {
70         if (port == source_port) {
71             continue;
72         }
73 
74         qemu_sendv_packet(&port->nc, iov, iovcnt);
75     }
76     return len;
77 }
78 
79 static NetHub *net_hub_new(int id)
80 {
81     NetHub *hub;
82 
83     hub = g_malloc(sizeof(*hub));
84     hub->id = id;
85     hub->num_ports = 0;
86     QLIST_INIT(&hub->ports);
87 
88     QLIST_INSERT_HEAD(&hubs, hub, next);
89 
90     return hub;
91 }
92 
93 static int net_hub_port_can_receive(NetClientState *nc)
94 {
95     NetHubPort *port;
96     NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
97     NetHub *hub = src_port->hub;
98 
99     QLIST_FOREACH(port, &hub->ports, next) {
100         if (port == src_port) {
101             continue;
102         }
103 
104         if (qemu_can_send_packet(&port->nc)) {
105             return 1;
106         }
107     }
108 
109     return 0;
110 }
111 
112 static ssize_t net_hub_port_receive(NetClientState *nc,
113                                     const uint8_t *buf, size_t len)
114 {
115     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
116 
117     return net_hub_receive(port->hub, port, buf, len);
118 }
119 
120 static ssize_t net_hub_port_receive_iov(NetClientState *nc,
121                                         const struct iovec *iov, int iovcnt)
122 {
123     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
124 
125     return net_hub_receive_iov(port->hub, port, iov, iovcnt);
126 }
127 
128 static void net_hub_port_cleanup(NetClientState *nc)
129 {
130     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
131 
132     QLIST_REMOVE(port, next);
133 }
134 
135 static NetClientInfo net_hub_port_info = {
136     .type = NET_CLIENT_DRIVER_HUBPORT,
137     .size = sizeof(NetHubPort),
138     .can_receive = net_hub_port_can_receive,
139     .receive = net_hub_port_receive,
140     .receive_iov = net_hub_port_receive_iov,
141     .cleanup = net_hub_port_cleanup,
142 };
143 
144 static NetHubPort *net_hub_port_new(NetHub *hub, const char *name,
145                                     NetClientState *hubpeer)
146 {
147     NetClientState *nc;
148     NetHubPort *port;
149     int id = hub->num_ports++;
150     char default_name[128];
151 
152     if (!name) {
153         snprintf(default_name, sizeof(default_name),
154                  "hub%dport%d", hub->id, id);
155         name = default_name;
156     }
157 
158     nc = qemu_new_net_client(&net_hub_port_info, hubpeer, "hub", name);
159     port = DO_UPCAST(NetHubPort, nc, nc);
160     port->id = id;
161     port->hub = hub;
162 
163     QLIST_INSERT_HEAD(&hub->ports, port, next);
164 
165     return port;
166 }
167 
168 /**
169  * Create a port on a given hub
170  * @hub_id: Number of the hub
171  * @name: Net client name or NULL for default name.
172  * @hubpeer: Peer to use (if "netdev=id" has been specified)
173  *
174  * If there is no existing hub with the given id then a new hub is created.
175  */
176 NetClientState *net_hub_add_port(int hub_id, const char *name,
177                                  NetClientState *hubpeer)
178 {
179     NetHub *hub;
180     NetHubPort *port;
181 
182     QLIST_FOREACH(hub, &hubs, next) {
183         if (hub->id == hub_id) {
184             break;
185         }
186     }
187 
188     if (!hub) {
189         hub = net_hub_new(hub_id);
190     }
191 
192     port = net_hub_port_new(hub, name, hubpeer);
193     return &port->nc;
194 }
195 
196 /**
197  * Find a available port on a hub; otherwise create one new port
198  */
199 NetClientState *net_hub_port_find(int hub_id)
200 {
201     NetHub *hub;
202     NetHubPort *port;
203     NetClientState *nc;
204 
205     QLIST_FOREACH(hub, &hubs, next) {
206         if (hub->id == hub_id) {
207             QLIST_FOREACH(port, &hub->ports, next) {
208                 nc = port->nc.peer;
209                 if (!nc) {
210                     return &(port->nc);
211                 }
212             }
213             break;
214         }
215     }
216 
217     nc = net_hub_add_port(hub_id, NULL, NULL);
218     return nc;
219 }
220 
221 /**
222  * Print hub configuration
223  */
224 void net_hub_info(Monitor *mon)
225 {
226     NetHub *hub;
227     NetHubPort *port;
228 
229     QLIST_FOREACH(hub, &hubs, next) {
230         monitor_printf(mon, "hub %d\n", hub->id);
231         QLIST_FOREACH(port, &hub->ports, next) {
232             monitor_printf(mon, " \\ %s", port->nc.name);
233             if (port->nc.peer) {
234                 monitor_printf(mon, ": ");
235                 print_net_client(mon, port->nc.peer);
236             } else {
237                 monitor_printf(mon, "\n");
238             }
239         }
240     }
241 }
242 
243 /**
244  * Get the hub id that a client is connected to
245  *
246  * @id: Pointer for hub id output, may be NULL
247  */
248 int net_hub_id_for_client(NetClientState *nc, int *id)
249 {
250     NetHubPort *port;
251 
252     if (nc->info->type == NET_CLIENT_DRIVER_HUBPORT) {
253         port = DO_UPCAST(NetHubPort, nc, nc);
254     } else if (nc->peer != NULL && nc->peer->info->type ==
255             NET_CLIENT_DRIVER_HUBPORT) {
256         port = DO_UPCAST(NetHubPort, nc, nc->peer);
257     } else {
258         return -ENOENT;
259     }
260 
261     if (id) {
262         *id = port->hub->id;
263     }
264     return 0;
265 }
266 
267 int net_init_hubport(const Netdev *netdev, const char *name,
268                      NetClientState *peer, Error **errp)
269 {
270     const NetdevHubPortOptions *hubport;
271     NetClientState *hubpeer = NULL;
272 
273     assert(netdev->type == NET_CLIENT_DRIVER_HUBPORT);
274     assert(!peer);
275     hubport = &netdev->u.hubport;
276 
277     if (hubport->has_netdev) {
278         hubpeer = qemu_find_netdev(hubport->netdev);
279         if (!hubpeer) {
280             error_setg(errp, "netdev '%s' not found", hubport->netdev);
281             return -1;
282         }
283     }
284 
285     net_hub_add_port(hubport->hubid, name, hubpeer);
286 
287     return 0;
288 }
289 
290 /**
291  * Warn if hub configurations are likely wrong
292  */
293 void net_hub_check_clients(void)
294 {
295     NetHub *hub;
296     NetHubPort *port;
297     NetClientState *peer;
298 
299     QLIST_FOREACH(hub, &hubs, next) {
300         int has_nic = 0, has_host_dev = 0;
301 
302         QLIST_FOREACH(port, &hub->ports, next) {
303             peer = port->nc.peer;
304             if (!peer) {
305                 warn_report("hub port %s has no peer", port->nc.name);
306                 continue;
307             }
308 
309             switch (peer->info->type) {
310             case NET_CLIENT_DRIVER_NIC:
311                 has_nic = 1;
312                 break;
313             case NET_CLIENT_DRIVER_USER:
314             case NET_CLIENT_DRIVER_TAP:
315             case NET_CLIENT_DRIVER_SOCKET:
316             case NET_CLIENT_DRIVER_VDE:
317             case NET_CLIENT_DRIVER_VHOST_USER:
318                 has_host_dev = 1;
319                 break;
320             default:
321                 break;
322             }
323         }
324         if (has_host_dev && !has_nic) {
325             warn_report("hub %d with no nics", hub->id);
326         }
327         if (has_nic && !has_host_dev && !qtest_enabled()) {
328             warn_report("hub %d is not connected to host network", hub->id);
329         }
330     }
331 }
332 
333 bool net_hub_flush(NetClientState *nc)
334 {
335     NetHubPort *port;
336     NetHubPort *source_port = DO_UPCAST(NetHubPort, nc, nc);
337     int ret = 0;
338 
339     QLIST_FOREACH(port, &source_port->hub->ports, next) {
340         if (port != source_port) {
341             ret += qemu_net_queue_flush(port->nc.incoming_queue);
342         }
343     }
344     return ret ? true : false;
345 }
346