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1
/*
2
 * Virtio Network Device
3
 *
4
 * Copyright IBM, Corp. 2007
5
 *
6
 * Authors:
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 *  Anthony Liguori   <aliguori@us.ibm.com>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2.  See
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 * the COPYING file in the top-level directory.
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 *
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 */
13

    
14
#include "iov.h"
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#include "virtio.h"
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#include "net.h"
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#include "net/checksum.h"
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#include "net/tap.h"
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#include "qemu-error.h"
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#include "qemu-timer.h"
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#include "virtio-net.h"
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#include "vhost_net.h"
23

    
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#define VIRTIO_NET_VM_VERSION    11
25

    
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#define MAC_TABLE_ENTRIES    64
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#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
28

    
29
typedef struct VirtIONet
30
{
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    VirtIODevice vdev;
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    uint8_t mac[ETH_ALEN];
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    uint16_t status;
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    VirtQueue *rx_vq;
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    VirtQueue *tx_vq;
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    VirtQueue *ctrl_vq;
37
    NICState *nic;
38
    QEMUTimer *tx_timer;
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    QEMUBH *tx_bh;
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    uint32_t tx_timeout;
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    int32_t tx_burst;
42
    int tx_waiting;
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    uint32_t has_vnet_hdr;
44
    uint8_t has_ufo;
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    struct {
46
        VirtQueueElement elem;
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        ssize_t len;
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    } async_tx;
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    int mergeable_rx_bufs;
50
    uint8_t promisc;
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    uint8_t allmulti;
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    uint8_t alluni;
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    uint8_t nomulti;
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    uint8_t nouni;
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    uint8_t nobcast;
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    uint8_t vhost_started;
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    bool vm_running;
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    VMChangeStateEntry *vmstate;
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    struct {
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        int in_use;
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        int first_multi;
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        uint8_t multi_overflow;
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        uint8_t uni_overflow;
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        uint8_t *macs;
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    } mac_table;
66
    uint32_t *vlans;
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    DeviceState *qdev;
68
} VirtIONet;
69

    
70
/* TODO
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 * - we could suppress RX interrupt if we were so inclined.
72
 */
73

    
74
static VirtIONet *to_virtio_net(VirtIODevice *vdev)
75
{
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    return (VirtIONet *)vdev;
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}
78

    
79
static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
80
{
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    VirtIONet *n = to_virtio_net(vdev);
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    struct virtio_net_config netcfg;
83

    
84
    netcfg.status = n->status;
85
    memcpy(netcfg.mac, n->mac, ETH_ALEN);
86
    memcpy(config, &netcfg, sizeof(netcfg));
87
}
88

    
89
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
90
{
91
    VirtIONet *n = to_virtio_net(vdev);
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    struct virtio_net_config netcfg;
93

    
94
    memcpy(&netcfg, config, sizeof(netcfg));
95

    
96
    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
97
        memcpy(n->mac, netcfg.mac, ETH_ALEN);
98
        qemu_format_nic_info_str(&n->nic->nc, n->mac);
99
    }
100
}
101

    
102
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
103
{
104
    VirtIONet *n = to_virtio_net(vdev);
105
    if (!n->nic->nc.peer) {
106
        return;
107
    }
108
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
109
        return;
110
    }
111

    
112
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
113
        return;
114
    }
115
    if (!!n->vhost_started == ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
116
                               (n->status & VIRTIO_NET_S_LINK_UP) &&
117
                               n->vm_running)) {
118
        return;
119
    }
120
    if (!n->vhost_started) {
121
        int r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
122
        if (r < 0) {
123
            error_report("unable to start vhost net: %d: "
124
                         "falling back on userspace virtio", -r);
125
        } else {
126
            n->vhost_started = 1;
127
        }
128
    } else {
129
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
130
        n->vhost_started = 0;
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    }
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}
133

    
134
static void virtio_net_set_link_status(VLANClientState *nc)
135
{
136
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
137
    uint16_t old_status = n->status;
138

    
139
    if (nc->link_down)
140
        n->status &= ~VIRTIO_NET_S_LINK_UP;
141
    else
142
        n->status |= VIRTIO_NET_S_LINK_UP;
143

    
144
    if (n->status != old_status)
145
        virtio_notify_config(&n->vdev);
146

    
147
    virtio_net_set_status(&n->vdev, n->vdev.status);
148
}
149

    
150
static void virtio_net_reset(VirtIODevice *vdev)
151
{
152
    VirtIONet *n = to_virtio_net(vdev);
153

    
154
    /* Reset back to compatibility mode */
155
    n->promisc = 1;
156
    n->allmulti = 0;
157
    n->alluni = 0;
158
    n->nomulti = 0;
159
    n->nouni = 0;
160
    n->nobcast = 0;
161

    
162
    /* Flush any MAC and VLAN filter table state */
163
    n->mac_table.in_use = 0;
164
    n->mac_table.first_multi = 0;
165
    n->mac_table.multi_overflow = 0;
166
    n->mac_table.uni_overflow = 0;
167
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
168
    memset(n->vlans, 0, MAX_VLAN >> 3);
169
}
170

    
171
static int peer_has_vnet_hdr(VirtIONet *n)
172
{
173
    if (!n->nic->nc.peer)
174
        return 0;
175

    
176
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
177
        return 0;
178

    
179
    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
180

    
181
    return n->has_vnet_hdr;
182
}
183

    
184
static int peer_has_ufo(VirtIONet *n)
185
{
186
    if (!peer_has_vnet_hdr(n))
187
        return 0;
188

    
189
    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
190

    
191
    return n->has_ufo;
192
}
193

    
194
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
195
{
196
    VirtIONet *n = to_virtio_net(vdev);
197

    
198
    features |= (1 << VIRTIO_NET_F_MAC);
199

    
200
    if (peer_has_vnet_hdr(n)) {
201
        tap_using_vnet_hdr(n->nic->nc.peer, 1);
202
    } else {
203
        features &= ~(0x1 << VIRTIO_NET_F_CSUM);
204
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
205
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
206
        features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
207

    
208
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
209
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
210
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
211
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
212
    }
213

    
214
    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
215
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
216
        features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
217
    }
218

    
219
    if (!n->nic->nc.peer ||
220
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
221
        return features;
222
    }
223
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
224
        return features;
225
    }
226
    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
227
}
228

    
229
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
230
{
231
    uint32_t features = 0;
232

    
233
    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
234
     * but also these: */
235
    features |= (1 << VIRTIO_NET_F_MAC);
236
    features |= (1 << VIRTIO_NET_F_CSUM);
237
    features |= (1 << VIRTIO_NET_F_HOST_TSO4);
238
    features |= (1 << VIRTIO_NET_F_HOST_TSO6);
239
    features |= (1 << VIRTIO_NET_F_HOST_ECN);
240

    
241
    return features;
242
}
243

    
244
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
245
{
246
    VirtIONet *n = to_virtio_net(vdev);
247

    
248
    n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
249

    
250
    if (n->has_vnet_hdr) {
251
        tap_set_offload(n->nic->nc.peer,
252
                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
253
                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
254
                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
255
                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
256
                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
257
    }
258
    if (!n->nic->nc.peer ||
259
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
260
        return;
261
    }
262
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
263
        return;
264
    }
265
    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
266
}
267

    
268
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
269
                                     VirtQueueElement *elem)
270
{
271
    uint8_t on;
272

    
273
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
274
        error_report("virtio-net ctrl invalid rx mode command");
275
        exit(1);
276
    }
277

    
278
    on = ldub_p(elem->out_sg[1].iov_base);
279

    
280
    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
281
        n->promisc = on;
282
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
283
        n->allmulti = on;
284
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
285
        n->alluni = on;
286
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
287
        n->nomulti = on;
288
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
289
        n->nouni = on;
290
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
291
        n->nobcast = on;
292
    else
293
        return VIRTIO_NET_ERR;
294

    
295
    return VIRTIO_NET_OK;
296
}
297

    
298
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
299
                                 VirtQueueElement *elem)
300
{
301
    struct virtio_net_ctrl_mac mac_data;
302

    
303
    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
304
        elem->out_sg[1].iov_len < sizeof(mac_data) ||
305
        elem->out_sg[2].iov_len < sizeof(mac_data))
306
        return VIRTIO_NET_ERR;
307

    
308
    n->mac_table.in_use = 0;
309
    n->mac_table.first_multi = 0;
310
    n->mac_table.uni_overflow = 0;
311
    n->mac_table.multi_overflow = 0;
312
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
313

    
314
    mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
315

    
316
    if (sizeof(mac_data.entries) +
317
        (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
318
        return VIRTIO_NET_ERR;
319

    
320
    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
321
        memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
322
               mac_data.entries * ETH_ALEN);
323
        n->mac_table.in_use += mac_data.entries;
324
    } else {
325
        n->mac_table.uni_overflow = 1;
326
    }
327

    
328
    n->mac_table.first_multi = n->mac_table.in_use;
329

    
330
    mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
331

    
332
    if (sizeof(mac_data.entries) +
333
        (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
334
        return VIRTIO_NET_ERR;
335

    
336
    if (mac_data.entries) {
337
        if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
338
            memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
339
                   elem->out_sg[2].iov_base + sizeof(mac_data),
340
                   mac_data.entries * ETH_ALEN);
341
            n->mac_table.in_use += mac_data.entries;
342
        } else {
343
            n->mac_table.multi_overflow = 1;
344
        }
345
    }
346

    
347
    return VIRTIO_NET_OK;
348
}
349

    
350
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
351
                                        VirtQueueElement *elem)
352
{
353
    uint16_t vid;
354

    
355
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
356
        error_report("virtio-net ctrl invalid vlan command");
357
        return VIRTIO_NET_ERR;
358
    }
359

    
360
    vid = lduw_le_p(elem->out_sg[1].iov_base);
361

    
362
    if (vid >= MAX_VLAN)
363
        return VIRTIO_NET_ERR;
364

    
365
    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
366
        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
367
    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
368
        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
369
    else
370
        return VIRTIO_NET_ERR;
371

    
372
    return VIRTIO_NET_OK;
373
}
374

    
375
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
376
{
377
    VirtIONet *n = to_virtio_net(vdev);
378
    struct virtio_net_ctrl_hdr ctrl;
379
    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
380
    VirtQueueElement elem;
381

    
382
    while (virtqueue_pop(vq, &elem)) {
383
        if ((elem.in_num < 1) || (elem.out_num < 1)) {
384
            error_report("virtio-net ctrl missing headers");
385
            exit(1);
386
        }
387

    
388
        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
389
            elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
390
            error_report("virtio-net ctrl header not in correct element");
391
            exit(1);
392
        }
393

    
394
        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
395
        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
396

    
397
        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
398
            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
399
        else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
400
            status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
401
        else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
402
            status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
403

    
404
        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
405

    
406
        virtqueue_push(vq, &elem, sizeof(status));
407
        virtio_notify(vdev, vq);
408
    }
409
}
410

    
411
/* RX */
412

    
413
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
414
{
415
    VirtIONet *n = to_virtio_net(vdev);
416

    
417
    qemu_flush_queued_packets(&n->nic->nc);
418

    
419
    /* We now have RX buffers, signal to the IO thread to break out of the
420
     * select to re-poll the tap file descriptor */
421
    qemu_notify_event();
422
}
423

    
424
static int virtio_net_can_receive(VLANClientState *nc)
425
{
426
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
427

    
428
    if (!virtio_queue_ready(n->rx_vq) ||
429
        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
430
        return 0;
431

    
432
    return 1;
433
}
434

    
435
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
436
{
437
    if (virtio_queue_empty(n->rx_vq) ||
438
        (n->mergeable_rx_bufs &&
439
         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
440
        virtio_queue_set_notification(n->rx_vq, 1);
441

    
442
        /* To avoid a race condition where the guest has made some buffers
443
         * available after the above check but before notification was
444
         * enabled, check for available buffers again.
445
         */
446
        if (virtio_queue_empty(n->rx_vq) ||
447
            (n->mergeable_rx_bufs &&
448
             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
449
            return 0;
450
    }
451

    
452
    virtio_queue_set_notification(n->rx_vq, 0);
453
    return 1;
454
}
455

    
456
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
457
 * it never finds out that the packets don't have valid checksums.  This
458
 * causes dhclient to get upset.  Fedora's carried a patch for ages to
459
 * fix this with Xen but it hasn't appeared in an upstream release of
460
 * dhclient yet.
461
 *
462
 * To avoid breaking existing guests, we catch udp packets and add
463
 * checksums.  This is terrible but it's better than hacking the guest
464
 * kernels.
465
 *
466
 * N.B. if we introduce a zero-copy API, this operation is no longer free so
467
 * we should provide a mechanism to disable it to avoid polluting the host
468
 * cache.
469
 */
470
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
471
                                        const uint8_t *buf, size_t size)
472
{
473
    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
474
        (size > 27 && size < 1500) && /* normal sized MTU */
475
        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
476
        (buf[23] == 17) && /* ip.protocol == UDP */
477
        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
478
        /* FIXME this cast is evil */
479
        net_checksum_calculate((uint8_t *)buf, size);
480
        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
481
    }
482
}
483

    
484
static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
485
                          const void *buf, size_t size, size_t hdr_len)
486
{
487
    struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
488
    int offset = 0;
489

    
490
    hdr->flags = 0;
491
    hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
492

    
493
    if (n->has_vnet_hdr) {
494
        memcpy(hdr, buf, sizeof(*hdr));
495
        offset = sizeof(*hdr);
496
        work_around_broken_dhclient(hdr, buf + offset, size - offset);
497
    }
498

    
499
    /* We only ever receive a struct virtio_net_hdr from the tapfd,
500
     * but we may be passing along a larger header to the guest.
501
     */
502
    iov[0].iov_base += hdr_len;
503
    iov[0].iov_len  -= hdr_len;
504

    
505
    return offset;
506
}
507

    
508
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
509
{
510
    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
511
    static const uint8_t vlan[] = {0x81, 0x00};
512
    uint8_t *ptr = (uint8_t *)buf;
513
    int i;
514

    
515
    if (n->promisc)
516
        return 1;
517

    
518
    if (n->has_vnet_hdr) {
519
        ptr += sizeof(struct virtio_net_hdr);
520
    }
521

    
522
    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
523
        int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
524
        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
525
            return 0;
526
    }
527

    
528
    if (ptr[0] & 1) { // multicast
529
        if (!memcmp(ptr, bcast, sizeof(bcast))) {
530
            return !n->nobcast;
531
        } else if (n->nomulti) {
532
            return 0;
533
        } else if (n->allmulti || n->mac_table.multi_overflow) {
534
            return 1;
535
        }
536

    
537
        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
538
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
539
                return 1;
540
            }
541
        }
542
    } else { // unicast
543
        if (n->nouni) {
544
            return 0;
545
        } else if (n->alluni || n->mac_table.uni_overflow) {
546
            return 1;
547
        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
548
            return 1;
549
        }
550

    
551
        for (i = 0; i < n->mac_table.first_multi; i++) {
552
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
553
                return 1;
554
            }
555
        }
556
    }
557

    
558
    return 0;
559
}
560

    
561
static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
562
{
563
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
564
    struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
565
    size_t guest_hdr_len, offset, i, host_hdr_len;
566

    
567
    if (!virtio_net_can_receive(&n->nic->nc))
568
        return -1;
569

    
570
    /* hdr_len refers to the header we supply to the guest */
571
    guest_hdr_len = n->mergeable_rx_bufs ?
572
        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
573

    
574

    
575
    host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
576
    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
577
        return 0;
578

    
579
    if (!receive_filter(n, buf, size))
580
        return size;
581

    
582
    offset = i = 0;
583

    
584
    while (offset < size) {
585
        VirtQueueElement elem;
586
        int len, total;
587
        struct iovec sg[VIRTQUEUE_MAX_SIZE];
588

    
589
        total = 0;
590

    
591
        if (virtqueue_pop(n->rx_vq, &elem) == 0) {
592
            if (i == 0)
593
                return -1;
594
            error_report("virtio-net unexpected empty queue: "
595
                    "i %zd mergeable %d offset %zd, size %zd, "
596
                    "guest hdr len %zd, host hdr len %zd guest features 0x%x",
597
                    i, n->mergeable_rx_bufs, offset, size,
598
                    guest_hdr_len, host_hdr_len, n->vdev.guest_features);
599
            exit(1);
600
        }
601

    
602
        if (elem.in_num < 1) {
603
            error_report("virtio-net receive queue contains no in buffers");
604
            exit(1);
605
        }
606

    
607
        if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != guest_hdr_len) {
608
            error_report("virtio-net header not in first element");
609
            exit(1);
610
        }
611

    
612
        memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
613

    
614
        if (i == 0) {
615
            if (n->mergeable_rx_bufs)
616
                mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
617

    
618
            offset += receive_header(n, sg, elem.in_num,
619
                                     buf + offset, size - offset, guest_hdr_len);
620
            total += guest_hdr_len;
621
        }
622

    
623
        /* copy in packet.  ugh */
624
        len = iov_from_buf(sg, elem.in_num,
625
                           buf + offset, size - offset);
626
        total += len;
627
        offset += len;
628
        /* If buffers can't be merged, at this point we
629
         * must have consumed the complete packet.
630
         * Otherwise, drop it. */
631
        if (!n->mergeable_rx_bufs && offset < size) {
632
#if 0
633
            error_report("virtio-net truncated non-mergeable packet: "
634
                         "i %zd mergeable %d offset %zd, size %zd, "
635
                         "guest hdr len %zd, host hdr len %zd",
636
                         i, n->mergeable_rx_bufs,
637
                         offset, size, guest_hdr_len, host_hdr_len);
638
#endif
639
            return size;
640
        }
641

    
642
        /* signal other side */
643
        virtqueue_fill(n->rx_vq, &elem, total, i++);
644
    }
645

    
646
    if (mhdr)
647
        mhdr->num_buffers = i;
648

    
649
    virtqueue_flush(n->rx_vq, i);
650
    virtio_notify(&n->vdev, n->rx_vq);
651

    
652
    return size;
653
}
654

    
655
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
656

    
657
static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
658
{
659
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
660

    
661
    virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
662
    virtio_notify(&n->vdev, n->tx_vq);
663

    
664
    n->async_tx.elem.out_num = n->async_tx.len = 0;
665

    
666
    virtio_queue_set_notification(n->tx_vq, 1);
667
    virtio_net_flush_tx(n, n->tx_vq);
668
}
669

    
670
/* TX */
671
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
672
{
673
    VirtQueueElement elem;
674
    int32_t num_packets = 0;
675

    
676
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
677
        return num_packets;
678
    }
679

    
680
    if (n->async_tx.elem.out_num) {
681
        virtio_queue_set_notification(n->tx_vq, 0);
682
        return num_packets;
683
    }
684

    
685
    while (virtqueue_pop(vq, &elem)) {
686
        ssize_t ret, len = 0;
687
        unsigned int out_num = elem.out_num;
688
        struct iovec *out_sg = &elem.out_sg[0];
689
        unsigned hdr_len;
690

    
691
        /* hdr_len refers to the header received from the guest */
692
        hdr_len = n->mergeable_rx_bufs ?
693
            sizeof(struct virtio_net_hdr_mrg_rxbuf) :
694
            sizeof(struct virtio_net_hdr);
695

    
696
        if (out_num < 1 || out_sg->iov_len != hdr_len) {
697
            error_report("virtio-net header not in first element");
698
            exit(1);
699
        }
700

    
701
        /* ignore the header if GSO is not supported */
702
        if (!n->has_vnet_hdr) {
703
            out_num--;
704
            out_sg++;
705
            len += hdr_len;
706
        } else if (n->mergeable_rx_bufs) {
707
            /* tapfd expects a struct virtio_net_hdr */
708
            hdr_len -= sizeof(struct virtio_net_hdr);
709
            out_sg->iov_len -= hdr_len;
710
            len += hdr_len;
711
        }
712

    
713
        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
714
                                      virtio_net_tx_complete);
715
        if (ret == 0) {
716
            virtio_queue_set_notification(n->tx_vq, 0);
717
            n->async_tx.elem = elem;
718
            n->async_tx.len  = len;
719
            return -EBUSY;
720
        }
721

    
722
        len += ret;
723

    
724
        virtqueue_push(vq, &elem, len);
725
        virtio_notify(&n->vdev, vq);
726

    
727
        if (++num_packets >= n->tx_burst) {
728
            break;
729
        }
730
    }
731
    return num_packets;
732
}
733

    
734
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
735
{
736
    VirtIONet *n = to_virtio_net(vdev);
737

    
738
    if (n->tx_waiting) {
739
        virtio_queue_set_notification(vq, 1);
740
        qemu_del_timer(n->tx_timer);
741
        n->tx_waiting = 0;
742
        virtio_net_flush_tx(n, vq);
743
    } else {
744
        qemu_mod_timer(n->tx_timer,
745
                       qemu_get_clock(vm_clock) + n->tx_timeout);
746
        n->tx_waiting = 1;
747
        virtio_queue_set_notification(vq, 0);
748
    }
749
}
750

    
751
static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
752
{
753
    VirtIONet *n = to_virtio_net(vdev);
754

    
755
    if (unlikely(n->tx_waiting)) {
756
        return;
757
    }
758
    virtio_queue_set_notification(vq, 0);
759
    qemu_bh_schedule(n->tx_bh);
760
    n->tx_waiting = 1;
761
}
762

    
763
static void virtio_net_tx_timer(void *opaque)
764
{
765
    VirtIONet *n = opaque;
766

    
767
    n->tx_waiting = 0;
768

    
769
    /* Just in case the driver is not ready on more */
770
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
771
        return;
772

    
773
    virtio_queue_set_notification(n->tx_vq, 1);
774
    virtio_net_flush_tx(n, n->tx_vq);
775
}
776

    
777
static void virtio_net_tx_bh(void *opaque)
778
{
779
    VirtIONet *n = opaque;
780
    int32_t ret;
781

    
782
    n->tx_waiting = 0;
783

    
784
    /* Just in case the driver is not ready on more */
785
    if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
786
        return;
787

    
788
    ret = virtio_net_flush_tx(n, n->tx_vq);
789
    if (ret == -EBUSY) {
790
        return; /* Notification re-enable handled by tx_complete */
791
    }
792

    
793
    /* If we flush a full burst of packets, assume there are
794
     * more coming and immediately reschedule */
795
    if (ret >= n->tx_burst) {
796
        qemu_bh_schedule(n->tx_bh);
797
        n->tx_waiting = 1;
798
        return;
799
    }
800

    
801
    /* If less than a full burst, re-enable notification and flush
802
     * anything that may have come in while we weren't looking.  If
803
     * we find something, assume the guest is still active and reschedule */
804
    virtio_queue_set_notification(n->tx_vq, 1);
805
    if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
806
        virtio_queue_set_notification(n->tx_vq, 0);
807
        qemu_bh_schedule(n->tx_bh);
808
        n->tx_waiting = 1;
809
    }
810
}
811

    
812
static void virtio_net_save(QEMUFile *f, void *opaque)
813
{
814
    VirtIONet *n = opaque;
815

    
816
    /* At this point, backend must be stopped, otherwise
817
     * it might keep writing to memory. */
818
    assert(!n->vhost_started);
819
    virtio_save(&n->vdev, f);
820

    
821
    qemu_put_buffer(f, n->mac, ETH_ALEN);
822
    qemu_put_be32(f, n->tx_waiting);
823
    qemu_put_be32(f, n->mergeable_rx_bufs);
824
    qemu_put_be16(f, n->status);
825
    qemu_put_byte(f, n->promisc);
826
    qemu_put_byte(f, n->allmulti);
827
    qemu_put_be32(f, n->mac_table.in_use);
828
    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
829
    qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
830
    qemu_put_be32(f, n->has_vnet_hdr);
831
    qemu_put_byte(f, n->mac_table.multi_overflow);
832
    qemu_put_byte(f, n->mac_table.uni_overflow);
833
    qemu_put_byte(f, n->alluni);
834
    qemu_put_byte(f, n->nomulti);
835
    qemu_put_byte(f, n->nouni);
836
    qemu_put_byte(f, n->nobcast);
837
    qemu_put_byte(f, n->has_ufo);
838
}
839

    
840
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
841
{
842
    VirtIONet *n = opaque;
843
    int i;
844

    
845
    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
846
        return -EINVAL;
847

    
848
    virtio_load(&n->vdev, f);
849

    
850
    qemu_get_buffer(f, n->mac, ETH_ALEN);
851
    n->tx_waiting = qemu_get_be32(f);
852
    n->mergeable_rx_bufs = qemu_get_be32(f);
853

    
854
    if (version_id >= 3)
855
        n->status = qemu_get_be16(f);
856

    
857
    if (version_id >= 4) {
858
        if (version_id < 8) {
859
            n->promisc = qemu_get_be32(f);
860
            n->allmulti = qemu_get_be32(f);
861
        } else {
862
            n->promisc = qemu_get_byte(f);
863
            n->allmulti = qemu_get_byte(f);
864
        }
865
    }
866

    
867
    if (version_id >= 5) {
868
        n->mac_table.in_use = qemu_get_be32(f);
869
        /* MAC_TABLE_ENTRIES may be different from the saved image */
870
        if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
871
            qemu_get_buffer(f, n->mac_table.macs,
872
                            n->mac_table.in_use * ETH_ALEN);
873
        } else if (n->mac_table.in_use) {
874
            qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
875
            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
876
            n->mac_table.in_use = 0;
877
        }
878
    }
879
 
880
    if (version_id >= 6)
881
        qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
882

    
883
    if (version_id >= 7) {
884
        if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
885
            error_report("virtio-net: saved image requires vnet_hdr=on");
886
            return -1;
887
        }
888

    
889
        if (n->has_vnet_hdr) {
890
            tap_using_vnet_hdr(n->nic->nc.peer, 1);
891
            tap_set_offload(n->nic->nc.peer,
892
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
893
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
894
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
895
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
896
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
897
        }
898
    }
899

    
900
    if (version_id >= 9) {
901
        n->mac_table.multi_overflow = qemu_get_byte(f);
902
        n->mac_table.uni_overflow = qemu_get_byte(f);
903
    }
904

    
905
    if (version_id >= 10) {
906
        n->alluni = qemu_get_byte(f);
907
        n->nomulti = qemu_get_byte(f);
908
        n->nouni = qemu_get_byte(f);
909
        n->nobcast = qemu_get_byte(f);
910
    }
911

    
912
    if (version_id >= 11) {
913
        if (qemu_get_byte(f) && !peer_has_ufo(n)) {
914
            error_report("virtio-net: saved image requires TUN_F_UFO support");
915
            return -1;
916
        }
917
    }
918

    
919
    /* Find the first multicast entry in the saved MAC filter */
920
    for (i = 0; i < n->mac_table.in_use; i++) {
921
        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
922
            break;
923
        }
924
    }
925
    n->mac_table.first_multi = i;
926

    
927
    if (n->tx_waiting) {
928
        if (n->tx_timer) {
929
            qemu_mod_timer(n->tx_timer,
930
                           qemu_get_clock(vm_clock) + n->tx_timeout);
931
        } else {
932
            qemu_bh_schedule(n->tx_bh);
933
        }
934
    }
935
    return 0;
936
}
937

    
938
static void virtio_net_cleanup(VLANClientState *nc)
939
{
940
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
941

    
942
    n->nic = NULL;
943
}
944

    
945
static NetClientInfo net_virtio_info = {
946
    .type = NET_CLIENT_TYPE_NIC,
947
    .size = sizeof(NICState),
948
    .can_receive = virtio_net_can_receive,
949
    .receive = virtio_net_receive,
950
        .cleanup = virtio_net_cleanup,
951
    .link_status_changed = virtio_net_set_link_status,
952
};
953

    
954
static void virtio_net_vmstate_change(void *opaque, int running, int reason)
955
{
956
    VirtIONet *n = opaque;
957
    n->vm_running = running;
958
    /* This is called when vm is started/stopped,
959
     * it will start/stop vhost backend if appropriate
960
     * e.g. after migration. */
961
    virtio_net_set_status(&n->vdev, n->vdev.status);
962
}
963

    
964
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
965
                              virtio_net_conf *net)
966
{
967
    VirtIONet *n;
968

    
969
    n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
970
                                        sizeof(struct virtio_net_config),
971
                                        sizeof(VirtIONet));
972

    
973
    n->vdev.get_config = virtio_net_get_config;
974
    n->vdev.set_config = virtio_net_set_config;
975
    n->vdev.get_features = virtio_net_get_features;
976
    n->vdev.set_features = virtio_net_set_features;
977
    n->vdev.bad_features = virtio_net_bad_features;
978
    n->vdev.reset = virtio_net_reset;
979
    n->vdev.set_status = virtio_net_set_status;
980
    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
981

    
982
    if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
983
        error_report("virtio-net: "
984
                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
985
                     net->tx);
986
        error_report("Defaulting to \"bh\"");
987
    }
988

    
989
    if (net->tx && !strcmp(net->tx, "timer")) {
990
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
991
        n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
992
        n->tx_timeout = net->txtimer;
993
    } else {
994
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
995
        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
996
    }
997
    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
998
    qemu_macaddr_default_if_unset(&conf->macaddr);
999
    memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
1000
    n->status = VIRTIO_NET_S_LINK_UP;
1001

    
1002
    n->nic = qemu_new_nic(&net_virtio_info, conf, dev->info->name, dev->id, n);
1003

    
1004
    qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
1005

    
1006
    n->tx_waiting = 0;
1007
    n->tx_burst = net->txburst;
1008
    n->mergeable_rx_bufs = 0;
1009
    n->promisc = 1; /* for compatibility */
1010

    
1011
    n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
1012

    
1013
    n->vlans = qemu_mallocz(MAX_VLAN >> 3);
1014

    
1015
    n->qdev = dev;
1016
    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
1017
                    virtio_net_save, virtio_net_load, n);
1018
    n->vmstate = qemu_add_vm_change_state_handler(virtio_net_vmstate_change, n);
1019

    
1020
    return &n->vdev;
1021
}
1022

    
1023
void virtio_net_exit(VirtIODevice *vdev)
1024
{
1025
    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
1026
    qemu_del_vm_change_state_handler(n->vmstate);
1027

    
1028
    /* This will stop vhost backend if appropriate. */
1029
    virtio_net_set_status(vdev, 0);
1030

    
1031
    qemu_purge_queued_packets(&n->nic->nc);
1032

    
1033
    unregister_savevm(n->qdev, "virtio-net", n);
1034

    
1035
    qemu_free(n->mac_table.macs);
1036
    qemu_free(n->vlans);
1037

    
1038
    if (n->tx_timer) {
1039
        qemu_del_timer(n->tx_timer);
1040
        qemu_free_timer(n->tx_timer);
1041
    } else {
1042
        qemu_bh_delete(n->tx_bh);
1043
    }
1044

    
1045
    virtio_cleanup(&n->vdev);
1046
    qemu_del_vlan_client(&n->nic->nc);
1047
}