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1
/*
2
 * Virtio Network Device
3
 *
4
 * Copyright IBM, Corp. 2007
5
 *
6
 * Authors:
7
 *  Anthony Liguori   <aliguori@us.ibm.com>
8
 *
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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.
11
 *
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 */
13

    
14
#include "virtio.h"
15
#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"
22

    
23
#define VIRTIO_NET_VM_VERSION    11
24

    
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#define MAC_TABLE_ENTRIES    64
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#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
27

    
28
typedef struct VirtIONet
29
{
30
    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;
34
    VirtQueue *tx_vq;
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    VirtQueue *ctrl_vq;
36
    NICState *nic;
37
    QEMUTimer *tx_timer;
38
    int tx_timer_active;
39
    uint32_t has_vnet_hdr;
40
    uint8_t has_ufo;
41
    struct {
42
        VirtQueueElement elem;
43
        ssize_t len;
44
    } async_tx;
45
    int mergeable_rx_bufs;
46
    uint8_t promisc;
47
    uint8_t allmulti;
48
    uint8_t alluni;
49
    uint8_t nomulti;
50
    uint8_t nouni;
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    uint8_t nobcast;
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    uint8_t vhost_started;
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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;
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    uint32_t *vlans;
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} VirtIONet;
63

    
64
/* TODO
65
 * - we could suppress RX interrupt if we were so inclined.
66
 */
67

    
68
static VirtIONet *to_virtio_net(VirtIODevice *vdev)
69
{
70
    return (VirtIONet *)vdev;
71
}
72

    
73
static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
74
{
75
    VirtIONet *n = to_virtio_net(vdev);
76
    struct virtio_net_config netcfg;
77

    
78
    netcfg.status = n->status;
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    memcpy(netcfg.mac, n->mac, ETH_ALEN);
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    memcpy(config, &netcfg, sizeof(netcfg));
81
}
82

    
83
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
84
{
85
    VirtIONet *n = to_virtio_net(vdev);
86
    struct virtio_net_config netcfg;
87

    
88
    memcpy(&netcfg, config, sizeof(netcfg));
89

    
90
    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
91
        memcpy(n->mac, netcfg.mac, ETH_ALEN);
92
        qemu_format_nic_info_str(&n->nic->nc, n->mac);
93
    }
94
}
95

    
96
static void virtio_net_set_link_status(VLANClientState *nc)
97
{
98
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
99
    uint16_t old_status = n->status;
100

    
101
    if (nc->link_down)
102
        n->status &= ~VIRTIO_NET_S_LINK_UP;
103
    else
104
        n->status |= VIRTIO_NET_S_LINK_UP;
105

    
106
    if (n->status != old_status)
107
        virtio_notify_config(&n->vdev);
108
}
109

    
110
static void virtio_net_reset(VirtIODevice *vdev)
111
{
112
    VirtIONet *n = to_virtio_net(vdev);
113

    
114
    /* Reset back to compatibility mode */
115
    n->promisc = 1;
116
    n->allmulti = 0;
117
    n->alluni = 0;
118
    n->nomulti = 0;
119
    n->nouni = 0;
120
    n->nobcast = 0;
121
    if (n->vhost_started) {
122
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
123
        n->vhost_started = 0;
124
    }
125

    
126
    /* Flush any MAC and VLAN filter table state */
127
    n->mac_table.in_use = 0;
128
    n->mac_table.first_multi = 0;
129
    n->mac_table.multi_overflow = 0;
130
    n->mac_table.uni_overflow = 0;
131
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
132
    memset(n->vlans, 0, MAX_VLAN >> 3);
133
}
134

    
135
static int peer_has_vnet_hdr(VirtIONet *n)
136
{
137
    if (!n->nic->nc.peer)
138
        return 0;
139

    
140
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
141
        return 0;
142

    
143
    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
144

    
145
    return n->has_vnet_hdr;
146
}
147

    
148
static int peer_has_ufo(VirtIONet *n)
149
{
150
    if (!peer_has_vnet_hdr(n))
151
        return 0;
152

    
153
    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
154

    
155
    return n->has_ufo;
156
}
157

    
158
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
159
{
160
    VirtIONet *n = to_virtio_net(vdev);
161

    
162
    features |= (1 << VIRTIO_NET_F_MAC);
163

    
164
    if (peer_has_vnet_hdr(n)) {
165
        tap_using_vnet_hdr(n->nic->nc.peer, 1);
166
    } else {
167
        features &= ~(0x1 << VIRTIO_NET_F_CSUM);
168
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
169
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
170
        features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
171

    
172
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
173
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
174
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
175
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
176
    }
177

    
178
    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
179
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
180
        features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
181
    }
182

    
183
    if (!n->nic->nc.peer ||
184
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
185
        return features;
186
    }
187
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
188
        return features;
189
    }
190
    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
191
}
192

    
193
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
194
{
195
    uint32_t features = 0;
196

    
197
    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
198
     * but also these: */
199
    features |= (1 << VIRTIO_NET_F_MAC);
200
    features |= (1 << VIRTIO_NET_F_CSUM);
201
    features |= (1 << VIRTIO_NET_F_HOST_TSO4);
202
    features |= (1 << VIRTIO_NET_F_HOST_TSO6);
203
    features |= (1 << VIRTIO_NET_F_HOST_ECN);
204

    
205
    return features;
206
}
207

    
208
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
209
{
210
    VirtIONet *n = to_virtio_net(vdev);
211

    
212
    n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
213

    
214
    if (n->has_vnet_hdr) {
215
        tap_set_offload(n->nic->nc.peer,
216
                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
217
                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
218
                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
219
                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
220
                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
221
    }
222
    if (!n->nic->nc.peer ||
223
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
224
        return;
225
    }
226
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
227
        return;
228
    }
229
    return vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
230
}
231

    
232
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
233
                                     VirtQueueElement *elem)
234
{
235
    uint8_t on;
236

    
237
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
238
        fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
239
        exit(1);
240
    }
241

    
242
    on = ldub_p(elem->out_sg[1].iov_base);
243

    
244
    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
245
        n->promisc = on;
246
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
247
        n->allmulti = on;
248
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
249
        n->alluni = on;
250
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
251
        n->nomulti = on;
252
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
253
        n->nouni = on;
254
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
255
        n->nobcast = on;
256
    else
257
        return VIRTIO_NET_ERR;
258

    
259
    return VIRTIO_NET_OK;
260
}
261

    
262
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
263
                                 VirtQueueElement *elem)
264
{
265
    struct virtio_net_ctrl_mac mac_data;
266

    
267
    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
268
        elem->out_sg[1].iov_len < sizeof(mac_data) ||
269
        elem->out_sg[2].iov_len < sizeof(mac_data))
270
        return VIRTIO_NET_ERR;
271

    
272
    n->mac_table.in_use = 0;
273
    n->mac_table.first_multi = 0;
274
    n->mac_table.uni_overflow = 0;
275
    n->mac_table.multi_overflow = 0;
276
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
277

    
278
    mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
279

    
280
    if (sizeof(mac_data.entries) +
281
        (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
282
        return VIRTIO_NET_ERR;
283

    
284
    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
285
        memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
286
               mac_data.entries * ETH_ALEN);
287
        n->mac_table.in_use += mac_data.entries;
288
    } else {
289
        n->mac_table.uni_overflow = 1;
290
    }
291

    
292
    n->mac_table.first_multi = n->mac_table.in_use;
293

    
294
    mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
295

    
296
    if (sizeof(mac_data.entries) +
297
        (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
298
        return VIRTIO_NET_ERR;
299

    
300
    if (mac_data.entries) {
301
        if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
302
            memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
303
                   elem->out_sg[2].iov_base + sizeof(mac_data),
304
                   mac_data.entries * ETH_ALEN);
305
            n->mac_table.in_use += mac_data.entries;
306
        } else {
307
            n->mac_table.multi_overflow = 1;
308
        }
309
    }
310

    
311
    return VIRTIO_NET_OK;
312
}
313

    
314
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
315
                                        VirtQueueElement *elem)
316
{
317
    uint16_t vid;
318

    
319
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
320
        fprintf(stderr, "virtio-net ctrl invalid vlan command\n");
321
        return VIRTIO_NET_ERR;
322
    }
323

    
324
    vid = lduw_le_p(elem->out_sg[1].iov_base);
325

    
326
    if (vid >= MAX_VLAN)
327
        return VIRTIO_NET_ERR;
328

    
329
    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
330
        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
331
    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
332
        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
333
    else
334
        return VIRTIO_NET_ERR;
335

    
336
    return VIRTIO_NET_OK;
337
}
338

    
339
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
340
{
341
    VirtIONet *n = to_virtio_net(vdev);
342
    struct virtio_net_ctrl_hdr ctrl;
343
    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
344
    VirtQueueElement elem;
345

    
346
    while (virtqueue_pop(vq, &elem)) {
347
        if ((elem.in_num < 1) || (elem.out_num < 1)) {
348
            fprintf(stderr, "virtio-net ctrl missing headers\n");
349
            exit(1);
350
        }
351

    
352
        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
353
            elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
354
            fprintf(stderr, "virtio-net ctrl header not in correct element\n");
355
            exit(1);
356
        }
357

    
358
        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
359
        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
360

    
361
        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
362
            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
363
        else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
364
            status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
365
        else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
366
            status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
367

    
368
        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
369

    
370
        virtqueue_push(vq, &elem, sizeof(status));
371
        virtio_notify(vdev, vq);
372
    }
373
}
374

    
375
/* RX */
376

    
377
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
378
{
379
    VirtIONet *n = to_virtio_net(vdev);
380

    
381
    qemu_flush_queued_packets(&n->nic->nc);
382

    
383
    /* We now have RX buffers, signal to the IO thread to break out of the
384
     * select to re-poll the tap file descriptor */
385
    qemu_notify_event();
386
}
387

    
388
static int virtio_net_can_receive(VLANClientState *nc)
389
{
390
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
391

    
392
    if (!virtio_queue_ready(n->rx_vq) ||
393
        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
394
        return 0;
395

    
396
    return 1;
397
}
398

    
399
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
400
{
401
    if (virtio_queue_empty(n->rx_vq) ||
402
        (n->mergeable_rx_bufs &&
403
         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
404
        virtio_queue_set_notification(n->rx_vq, 1);
405

    
406
        /* To avoid a race condition where the guest has made some buffers
407
         * available after the above check but before notification was
408
         * enabled, check for available buffers again.
409
         */
410
        if (virtio_queue_empty(n->rx_vq) ||
411
            (n->mergeable_rx_bufs &&
412
             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
413
            return 0;
414
    }
415

    
416
    virtio_queue_set_notification(n->rx_vq, 0);
417
    return 1;
418
}
419

    
420
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
421
 * it never finds out that the packets don't have valid checksums.  This
422
 * causes dhclient to get upset.  Fedora's carried a patch for ages to
423
 * fix this with Xen but it hasn't appeared in an upstream release of
424
 * dhclient yet.
425
 *
426
 * To avoid breaking existing guests, we catch udp packets and add
427
 * checksums.  This is terrible but it's better than hacking the guest
428
 * kernels.
429
 *
430
 * N.B. if we introduce a zero-copy API, this operation is no longer free so
431
 * we should provide a mechanism to disable it to avoid polluting the host
432
 * cache.
433
 */
434
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
435
                                        const uint8_t *buf, size_t size)
436
{
437
    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
438
        (size > 27 && size < 1500) && /* normal sized MTU */
439
        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
440
        (buf[23] == 17) && /* ip.protocol == UDP */
441
        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
442
        /* FIXME this cast is evil */
443
        net_checksum_calculate((uint8_t *)buf, size);
444
        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
445
    }
446
}
447

    
448
static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)
449
{
450
    int offset, i;
451

    
452
    offset = i = 0;
453
    while (offset < count && i < iovcnt) {
454
        int len = MIN(iov[i].iov_len, count - offset);
455
        memcpy(iov[i].iov_base, buf + offset, len);
456
        offset += len;
457
        i++;
458
    }
459

    
460
    return offset;
461
}
462

    
463
static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
464
                          const void *buf, size_t size, size_t hdr_len)
465
{
466
    struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
467
    int offset = 0;
468

    
469
    hdr->flags = 0;
470
    hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
471

    
472
    if (n->has_vnet_hdr) {
473
        memcpy(hdr, buf, sizeof(*hdr));
474
        offset = sizeof(*hdr);
475
        work_around_broken_dhclient(hdr, buf + offset, size - offset);
476
    }
477

    
478
    /* We only ever receive a struct virtio_net_hdr from the tapfd,
479
     * but we may be passing along a larger header to the guest.
480
     */
481
    iov[0].iov_base += hdr_len;
482
    iov[0].iov_len  -= hdr_len;
483

    
484
    return offset;
485
}
486

    
487
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
488
{
489
    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
490
    static const uint8_t vlan[] = {0x81, 0x00};
491
    uint8_t *ptr = (uint8_t *)buf;
492
    int i;
493

    
494
    if (n->promisc)
495
        return 1;
496

    
497
    if (n->has_vnet_hdr) {
498
        ptr += sizeof(struct virtio_net_hdr);
499
    }
500

    
501
    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
502
        int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
503
        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
504
            return 0;
505
    }
506

    
507
    if (ptr[0] & 1) { // multicast
508
        if (!memcmp(ptr, bcast, sizeof(bcast))) {
509
            return !n->nobcast;
510
        } else if (n->nomulti) {
511
            return 0;
512
        } else if (n->allmulti || n->mac_table.multi_overflow) {
513
            return 1;
514
        }
515

    
516
        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
517
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
518
                return 1;
519
            }
520
        }
521
    } else { // unicast
522
        if (n->nouni) {
523
            return 0;
524
        } else if (n->alluni || n->mac_table.uni_overflow) {
525
            return 1;
526
        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
527
            return 1;
528
        }
529

    
530
        for (i = 0; i < n->mac_table.first_multi; i++) {
531
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
532
                return 1;
533
            }
534
        }
535
    }
536

    
537
    return 0;
538
}
539

    
540
static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
541
{
542
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
543
    struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
544
    size_t hdr_len, offset, i;
545

    
546
    if (!virtio_net_can_receive(&n->nic->nc))
547
        return -1;
548

    
549
    if (!virtio_net_has_buffers(n, size))
550
        return 0;
551

    
552
    if (!receive_filter(n, buf, size))
553
        return size;
554

    
555
    /* hdr_len refers to the header we supply to the guest */
556
    hdr_len = n->mergeable_rx_bufs ?
557
        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
558

    
559
    offset = i = 0;
560

    
561
    while (offset < size) {
562
        VirtQueueElement elem;
563
        int len, total;
564
        struct iovec sg[VIRTQUEUE_MAX_SIZE];
565

    
566
        total = 0;
567

    
568
        if ((i != 0 && !n->mergeable_rx_bufs) ||
569
            virtqueue_pop(n->rx_vq, &elem) == 0) {
570
            if (i == 0)
571
                return -1;
572
            fprintf(stderr, "virtio-net truncating packet\n");
573
            exit(1);
574
        }
575

    
576
        if (elem.in_num < 1) {
577
            fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
578
            exit(1);
579
        }
580

    
581
        if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
582
            fprintf(stderr, "virtio-net header not in first element\n");
583
            exit(1);
584
        }
585

    
586
        memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
587

    
588
        if (i == 0) {
589
            if (n->mergeable_rx_bufs)
590
                mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
591

    
592
            offset += receive_header(n, sg, elem.in_num,
593
                                     buf + offset, size - offset, hdr_len);
594
            total += hdr_len;
595
        }
596

    
597
        /* copy in packet.  ugh */
598
        len = iov_fill(sg, elem.in_num,
599
                       buf + offset, size - offset);
600
        total += len;
601

    
602
        /* signal other side */
603
        virtqueue_fill(n->rx_vq, &elem, total, i++);
604

    
605
        offset += len;
606
    }
607

    
608
    if (mhdr)
609
        mhdr->num_buffers = i;
610

    
611
    virtqueue_flush(n->rx_vq, i);
612
    virtio_notify(&n->vdev, n->rx_vq);
613

    
614
    return size;
615
}
616

    
617
static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
618

    
619
static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
620
{
621
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
622

    
623
    virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
624
    virtio_notify(&n->vdev, n->tx_vq);
625

    
626
    n->async_tx.elem.out_num = n->async_tx.len = 0;
627

    
628
    virtio_queue_set_notification(n->tx_vq, 1);
629
    virtio_net_flush_tx(n, n->tx_vq);
630
}
631

    
632
/* TX */
633
static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
634
{
635
    VirtQueueElement elem;
636

    
637
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
638
        return;
639

    
640
    if (n->async_tx.elem.out_num) {
641
        virtio_queue_set_notification(n->tx_vq, 0);
642
        return;
643
    }
644

    
645
    while (virtqueue_pop(vq, &elem)) {
646
        ssize_t ret, len = 0;
647
        unsigned int out_num = elem.out_num;
648
        struct iovec *out_sg = &elem.out_sg[0];
649
        unsigned hdr_len;
650

    
651
        /* hdr_len refers to the header received from the guest */
652
        hdr_len = n->mergeable_rx_bufs ?
653
            sizeof(struct virtio_net_hdr_mrg_rxbuf) :
654
            sizeof(struct virtio_net_hdr);
655

    
656
        if (out_num < 1 || out_sg->iov_len != hdr_len) {
657
            fprintf(stderr, "virtio-net header not in first element\n");
658
            exit(1);
659
        }
660

    
661
        /* ignore the header if GSO is not supported */
662
        if (!n->has_vnet_hdr) {
663
            out_num--;
664
            out_sg++;
665
            len += hdr_len;
666
        } else if (n->mergeable_rx_bufs) {
667
            /* tapfd expects a struct virtio_net_hdr */
668
            hdr_len -= sizeof(struct virtio_net_hdr);
669
            out_sg->iov_len -= hdr_len;
670
            len += hdr_len;
671
        }
672

    
673
        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
674
                                      virtio_net_tx_complete);
675
        if (ret == 0) {
676
            virtio_queue_set_notification(n->tx_vq, 0);
677
            n->async_tx.elem = elem;
678
            n->async_tx.len  = len;
679
            return;
680
        }
681

    
682
        len += ret;
683

    
684
        virtqueue_push(vq, &elem, len);
685
        virtio_notify(&n->vdev, vq);
686
    }
687
}
688

    
689
static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
690
{
691
    VirtIONet *n = to_virtio_net(vdev);
692

    
693
    if (n->tx_timer_active) {
694
        virtio_queue_set_notification(vq, 1);
695
        qemu_del_timer(n->tx_timer);
696
        n->tx_timer_active = 0;
697
        virtio_net_flush_tx(n, vq);
698
    } else {
699
        qemu_mod_timer(n->tx_timer,
700
                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
701
        n->tx_timer_active = 1;
702
        virtio_queue_set_notification(vq, 0);
703
    }
704
}
705

    
706
static void virtio_net_tx_timer(void *opaque)
707
{
708
    VirtIONet *n = opaque;
709

    
710
    n->tx_timer_active = 0;
711

    
712
    /* Just in case the driver is not ready on more */
713
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
714
        return;
715

    
716
    virtio_queue_set_notification(n->tx_vq, 1);
717
    virtio_net_flush_tx(n, n->tx_vq);
718
}
719

    
720
static void virtio_net_save(QEMUFile *f, void *opaque)
721
{
722
    VirtIONet *n = opaque;
723

    
724
    if (n->vhost_started) {
725
        /* TODO: should we really stop the backend?
726
         * If we don't, it might keep writing to memory. */
727
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
728
        n->vhost_started = 0;
729
    }
730
    virtio_save(&n->vdev, f);
731

    
732
    qemu_put_buffer(f, n->mac, ETH_ALEN);
733
    qemu_put_be32(f, n->tx_timer_active);
734
    qemu_put_be32(f, n->mergeable_rx_bufs);
735
    qemu_put_be16(f, n->status);
736
    qemu_put_byte(f, n->promisc);
737
    qemu_put_byte(f, n->allmulti);
738
    qemu_put_be32(f, n->mac_table.in_use);
739
    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
740
    qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
741
    qemu_put_be32(f, n->has_vnet_hdr);
742
    qemu_put_byte(f, n->mac_table.multi_overflow);
743
    qemu_put_byte(f, n->mac_table.uni_overflow);
744
    qemu_put_byte(f, n->alluni);
745
    qemu_put_byte(f, n->nomulti);
746
    qemu_put_byte(f, n->nouni);
747
    qemu_put_byte(f, n->nobcast);
748
    qemu_put_byte(f, n->has_ufo);
749
}
750

    
751
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
752
{
753
    VirtIONet *n = opaque;
754
    int i;
755

    
756
    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
757
        return -EINVAL;
758

    
759
    virtio_load(&n->vdev, f);
760

    
761
    qemu_get_buffer(f, n->mac, ETH_ALEN);
762
    n->tx_timer_active = qemu_get_be32(f);
763
    n->mergeable_rx_bufs = qemu_get_be32(f);
764

    
765
    if (version_id >= 3)
766
        n->status = qemu_get_be16(f);
767

    
768
    if (version_id >= 4) {
769
        if (version_id < 8) {
770
            n->promisc = qemu_get_be32(f);
771
            n->allmulti = qemu_get_be32(f);
772
        } else {
773
            n->promisc = qemu_get_byte(f);
774
            n->allmulti = qemu_get_byte(f);
775
        }
776
    }
777

    
778
    if (version_id >= 5) {
779
        n->mac_table.in_use = qemu_get_be32(f);
780
        /* MAC_TABLE_ENTRIES may be different from the saved image */
781
        if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
782
            qemu_get_buffer(f, n->mac_table.macs,
783
                            n->mac_table.in_use * ETH_ALEN);
784
        } else if (n->mac_table.in_use) {
785
            qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
786
            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
787
            n->mac_table.in_use = 0;
788
        }
789
    }
790
 
791
    if (version_id >= 6)
792
        qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
793

    
794
    if (version_id >= 7) {
795
        if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
796
            error_report("virtio-net: saved image requires vnet_hdr=on");
797
            return -1;
798
        }
799

    
800
        if (n->has_vnet_hdr) {
801
            tap_using_vnet_hdr(n->nic->nc.peer, 1);
802
            tap_set_offload(n->nic->nc.peer,
803
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
804
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
805
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
806
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
807
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
808
        }
809
    }
810

    
811
    if (version_id >= 9) {
812
        n->mac_table.multi_overflow = qemu_get_byte(f);
813
        n->mac_table.uni_overflow = qemu_get_byte(f);
814
    }
815

    
816
    if (version_id >= 10) {
817
        n->alluni = qemu_get_byte(f);
818
        n->nomulti = qemu_get_byte(f);
819
        n->nouni = qemu_get_byte(f);
820
        n->nobcast = qemu_get_byte(f);
821
    }
822

    
823
    if (version_id >= 11) {
824
        if (qemu_get_byte(f) && !peer_has_ufo(n)) {
825
            error_report("virtio-net: saved image requires TUN_F_UFO support");
826
            return -1;
827
        }
828
    }
829

    
830
    /* Find the first multicast entry in the saved MAC filter */
831
    for (i = 0; i < n->mac_table.in_use; i++) {
832
        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
833
            break;
834
        }
835
    }
836
    n->mac_table.first_multi = i;
837

    
838
    if (n->tx_timer_active) {
839
        qemu_mod_timer(n->tx_timer,
840
                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
841
    }
842
    return 0;
843
}
844

    
845
static void virtio_net_cleanup(VLANClientState *nc)
846
{
847
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
848

    
849
    n->nic = NULL;
850
}
851

    
852
static NetClientInfo net_virtio_info = {
853
    .type = NET_CLIENT_TYPE_NIC,
854
    .size = sizeof(NICState),
855
    .can_receive = virtio_net_can_receive,
856
    .receive = virtio_net_receive,
857
        .cleanup = virtio_net_cleanup,
858
    .link_status_changed = virtio_net_set_link_status,
859
};
860

    
861
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
862
{
863
    VirtIONet *n = to_virtio_net(vdev);
864
    if (!n->nic->nc.peer) {
865
        return;
866
    }
867
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
868
        return;
869
    }
870

    
871
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
872
        return;
873
    }
874
    if (!!n->vhost_started == !!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
875
        return;
876
    }
877
    if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
878
        int r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), vdev);
879
        if (r < 0) {
880
            fprintf(stderr, "unable to start vhost net: %d: "
881
                    "falling back on userspace virtio\n", -r);
882
        } else {
883
            n->vhost_started = 1;
884
        }
885
    } else {
886
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
887
        n->vhost_started = 0;
888
    }
889
}
890

    
891
static void virtio_net_vmstate_change(void *opaque, int running, int reason)
892
{
893
    VirtIONet *n = opaque;
894
    if (!running) {
895
        return;
896
    }
897
    /* This is called when vm is started, it will start vhost backend if
898
     * appropriate e.g. after migration. */
899
    virtio_net_set_status(&n->vdev, n->vdev.status);
900
}
901

    
902
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
903
{
904
    VirtIONet *n;
905
    static int virtio_net_id;
906

    
907
    n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
908
                                        sizeof(struct virtio_net_config),
909
                                        sizeof(VirtIONet));
910

    
911
    n->vdev.get_config = virtio_net_get_config;
912
    n->vdev.set_config = virtio_net_set_config;
913
    n->vdev.get_features = virtio_net_get_features;
914
    n->vdev.set_features = virtio_net_set_features;
915
    n->vdev.bad_features = virtio_net_bad_features;
916
    n->vdev.reset = virtio_net_reset;
917
    n->vdev.set_status = virtio_net_set_status;
918
    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
919
    n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
920
    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
921
    qemu_macaddr_default_if_unset(&conf->macaddr);
922
    memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
923
    n->status = VIRTIO_NET_S_LINK_UP;
924

    
925
    n->nic = qemu_new_nic(&net_virtio_info, conf, dev->info->name, dev->id, n);
926

    
927
    qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
928

    
929
    n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
930
    n->tx_timer_active = 0;
931
    n->mergeable_rx_bufs = 0;
932
    n->promisc = 1; /* for compatibility */
933

    
934
    n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
935

    
936
    n->vlans = qemu_mallocz(MAX_VLAN >> 3);
937

    
938
    register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
939
                    virtio_net_save, virtio_net_load, n);
940
    n->vmstate = qemu_add_vm_change_state_handler(virtio_net_vmstate_change, n);
941

    
942
    return &n->vdev;
943
}
944

    
945
void virtio_net_exit(VirtIODevice *vdev)
946
{
947
    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
948
    qemu_del_vm_change_state_handler(n->vmstate);
949

    
950
    if (n->vhost_started) {
951
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
952
    }
953

    
954
    qemu_purge_queued_packets(&n->nic->nc);
955

    
956
    unregister_savevm("virtio-net", n);
957

    
958
    qemu_free(n->mac_table.macs);
959
    qemu_free(n->vlans);
960

    
961
    qemu_del_timer(n->tx_timer);
962
    qemu_free_timer(n->tx_timer);
963

    
964
    virtio_cleanup(&n->vdev);
965
    qemu_del_vlan_client(&n->nic->nc);
966
}