net/hub.c

   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 "monitor/monitor.h"
  17 #include "net/net.h"
  18 #include "clients.h"
  19 #include "hub.h"
  20 #include "qemu/iov.h"
  21 #include "qemu/error-report.h"
  22
  23 /*
  24  * A hub broadcasts incoming packets to all its ports except the source port.
  25  * Hubs can be used to provide independent network segments, also confusingly
  26  * named the QEMU 'vlan' feature.
  27  */
  28
  29 typedef struct NetHub NetHub;
  30
  31 typedef struct NetHubPort {
  32     NetClientState nc;
  33     QLIST_ENTRY(NetHubPort) next;
  34     NetHub *hub;
  35     int id;
  36 } NetHubPort;
  37
  38 struct NetHub {
  39     int id;
  40     QLIST_ENTRY(NetHub) next;
  41     int num_ports;
  42     QLIST_HEAD(, NetHubPort) ports;
  43 };
  44
  45 static QLIST_HEAD(, NetHub) hubs = QLIST_HEAD_INITIALIZER(&hubs);
  46
  47 static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
  48                                const uint8_t *buf, size_t len)
  49 {
  50     NetHubPort *port;
  51
  52     QLIST_FOREACH(port, &hub->ports, next) {
  53         if (port == source_port) {
  54             continue;
  55         }
  56
  57         qemu_send_packet(&port->nc, buf, len);
  58     }
  59     return len;
  60 }
  61
  62 static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
  63                                    const struct iovec *iov, int iovcnt)
  64 {
  65     NetHubPort *port;
  66     ssize_t len = iov_size(iov, iovcnt);
  67
  68     QLIST_FOREACH(port, &hub->ports, next) {
  69         if (port == source_port) {
  70             continue;
  71         }
  72
  73         qemu_sendv_packet(&port->nc, iov, iovcnt);
  74     }
  75     return len;
  76 }
  77
  78 static NetHub *net_hub_new(int id)
  79 {
  80     NetHub *hub;
  81
  82     hub = g_malloc(sizeof(*hub));
  83     hub->id = id;
  84     hub->num_ports = 0;
  85     QLIST_INIT(&hub->ports);
  86
  87     QLIST_INSERT_HEAD(&hubs, hub, next);
  88
  89     return hub;
  90 }
  91
  92 static int net_hub_port_can_receive(NetClientState *nc)
  93 {
  94     NetHubPort *port;
  95     NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
  96     NetHub *hub = src_port->hub;
  97
  98     QLIST_FOREACH(port, &hub->ports, next) {
  99         if (port == src_port) {
 100             continue;
 101         }
 102
 103         if (qemu_can_send_packet(&port->nc)) {
 104             return 1;
 105         }
 106     }
 107
 108     return 0;
 109 }
 110
 111 static ssize_t net_hub_port_receive(NetClientState *nc,
 112                                     const uint8_t *buf, size_t len)
 113 {
 114     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 115
 116     return net_hub_receive(port->hub, port, buf, len);
 117 }
 118
 119 static ssize_t net_hub_port_receive_iov(NetClientState *nc,
 120                                         const struct iovec *iov, int iovcnt)
 121 {
 122     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 123
 124     return net_hub_receive_iov(port->hub, port, iov, iovcnt);
 125 }
 126
 127 static void net_hub_port_cleanup(NetClientState *nc)
 128 {
 129     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 130
 131     QLIST_REMOVE(port, next);
 132 }
 133
 134 static NetClientInfo net_hub_port_info = {
 135     .type = NET_CLIENT_DRIVER_HUBPORT,
 136     .size = sizeof(NetHubPort),
 137     .can_receive = net_hub_port_can_receive,
 138     .receive = net_hub_port_receive,
 139     .receive_iov = net_hub_port_receive_iov,
 140     .cleanup = net_hub_port_cleanup,
 141 };
 142
 143 static NetHubPort *net_hub_port_new(NetHub *hub, const char *name)
 144 {
 145     NetClientState *nc;
 146     NetHubPort *port;
 147     int id = hub->num_ports++;
 148     char default_name[128];
 149
 150     if (!name) {
 151         snprintf(default_name, sizeof(default_name),
 152                  "hub%dport%d", hub->id, id);
 153         name = default_name;
 154     }
 155
 156     nc = qemu_new_net_client(&net_hub_port_info, NULL, "hub", name);
 157     port = DO_UPCAST(NetHubPort, nc, nc);
 158     port->id = id;
 159     port->hub = hub;
 160
 161     QLIST_INSERT_HEAD(&hub->ports, port, next);
 162
 163     return port;
 164 }
 165
 166 /**
 167  * Create a port on a given hub
 168  * @name: Net client name or NULL for default name.
 169  *
 170  * If there is no existing hub with the given id then a new hub is created.
 171  */
 172 NetClientState *net_hub_add_port(int hub_id, const char *name)
 173 {
 174     NetHub *hub;
 175     NetHubPort *port;
 176
 177     QLIST_FOREACH(hub, &hubs, next) {
 178         if (hub->id == hub_id) {
 179             break;
 180         }
 181     }
 182
 183     if (!hub) {
 184         hub = net_hub_new(hub_id);
 185     }
 186
 187     port = net_hub_port_new(hub, name);
 188     return &port->nc;
 189 }
 190
 191 /**
 192  * Find a specific client on a hub
 193  */
 194 NetClientState *net_hub_find_client_by_name(int hub_id, const char *name)
 195 {
 196     NetHub *hub;
 197     NetHubPort *port;
 198     NetClientState *peer;
 199
 200     QLIST_FOREACH(hub, &hubs, next) {
 201         if (hub->id == hub_id) {
 202             QLIST_FOREACH(port, &hub->ports, next) {
 203                 peer = port->nc.peer;
 204
 205                 if (peer && strcmp(peer->name, name) == 0) {
 206                     return peer;
 207                 }
 208             }
 209         }
 210     }
 211     return NULL;
 212 }
 213
 214 /**
 215  * Find a available port on a hub; otherwise create one new port
 216  */
 217 NetClientState *net_hub_port_find(int hub_id)
 218 {
 219     NetHub *hub;
 220     NetHubPort *port;
 221     NetClientState *nc;
 222
 223     QLIST_FOREACH(hub, &hubs, next) {
 224         if (hub->id == hub_id) {
 225             QLIST_FOREACH(port, &hub->ports, next) {
 226                 nc = port->nc.peer;
 227                 if (!nc) {
 228                     return &(port->nc);
 229                 }
 230             }
 231             break;
 232         }
 233     }
 234
 235     nc = net_hub_add_port(hub_id, NULL);
 236     return nc;
 237 }
 238
 239 /**
 240  * Print hub configuration
 241  */
 242 void net_hub_info(Monitor *mon)
 243 {
 244     NetHub *hub;
 245     NetHubPort *port;
 246
 247     QLIST_FOREACH(hub, &hubs, next) {
 248         monitor_printf(mon, "hub %d\n", hub->id);
 249         QLIST_FOREACH(port, &hub->ports, next) {
 250             monitor_printf(mon, " \\ %s", port->nc.name);
 251             if (port->nc.peer) {
 252                 monitor_printf(mon, ": ");
 253                 print_net_client(mon, port->nc.peer);
 254             } else {
 255                 monitor_printf(mon, "\n");
 256             }
 257         }
 258     }
 259 }
 260
 261 /**
 262  * Get the hub id that a client is connected to
 263  *
 264  * @id: Pointer for hub id output, may be NULL
 265  */
 266 int net_hub_id_for_client(NetClientState *nc, int *id)
 267 {
 268     NetHubPort *port;
 269
 270     if (nc->info->type == NET_CLIENT_DRIVER_HUBPORT) {
 271         port = DO_UPCAST(NetHubPort, nc, nc);
 272     } else if (nc->peer != NULL && nc->peer->info->type ==
 273             NET_CLIENT_DRIVER_HUBPORT) {
 274         port = DO_UPCAST(NetHubPort, nc, nc->peer);
 275     } else {
 276         return -ENOENT;
 277     }
 278
 279     if (id) {
 280         *id = port->hub->id;
 281     }
 282     return 0;
 283 }
 284
 285 int net_init_hubport(const Netdev *netdev, const char *name,
 286                      NetClientState *peer, Error **errp)
 287 {
 288     const NetdevHubPortOptions *hubport;
 289
 290     assert(netdev->type == NET_CLIENT_DRIVER_HUBPORT);
 291     assert(!peer);
 292     hubport = &netdev->u.hubport;
 293
 294     net_hub_add_port(hubport->hubid, name);
 295     return 0;
 296 }
 297
 298 /**
 299  * Warn if hub configurations are likely wrong
 300  */
 301 void net_hub_check_clients(void)
 302 {
 303     NetHub *hub;
 304     NetHubPort *port;
 305     NetClientState *peer;
 306
 307     QLIST_FOREACH(hub, &hubs, next) {
 308         int has_nic = 0, has_host_dev = 0;
 309
 310         QLIST_FOREACH(port, &hub->ports, next) {
 311             peer = port->nc.peer;
 312             if (!peer) {
 313                 warn_report("hub port %s has no peer", port->nc.name);
 314                 continue;
 315             }
 316
 317             switch (peer->info->type) {
 318             case NET_CLIENT_DRIVER_NIC:
 319                 has_nic = 1;
 320                 break;
 321             case NET_CLIENT_DRIVER_USER:
 322             case NET_CLIENT_DRIVER_TAP:
 323             case NET_CLIENT_DRIVER_SOCKET:
 324             case NET_CLIENT_DRIVER_VDE:
 325             case NET_CLIENT_DRIVER_VHOST_USER:
 326                 has_host_dev = 1;
 327                 break;
 328             default:
 329                 break;
 330             }
 331         }
 332         if (has_host_dev && !has_nic) {
 333             warn_report("vlan %d with no nics", hub->id);
 334         }
 335         if (has_nic && !has_host_dev) {
 336             warn_report("vlan %d is not connected to host network", hub->id);
 337         }
 338     }
 339 }
 340
 341 bool net_hub_flush(NetClientState *nc)
 342 {
 343     NetHubPort *port;
 344     NetHubPort *source_port = DO_UPCAST(NetHubPort, nc, nc);
 345     int ret = 0;
 346
 347     QLIST_FOREACH(port, &source_port->hub->ports, next) {
 348         if (port != source_port) {
 349             ret += qemu_net_queue_flush(port->nc.incoming_queue);
 350         }
 351     }
 352     return ret ? true : false;
 353 }