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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>
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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.
11
 *
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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

    
24
#define VIRTIO_NET_VM_VERSION    11
25

    
26
#define MAC_TABLE_ENTRIES    64
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#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
28

    
29
typedef struct VirtIONet
30
{
31
    VirtIODevice vdev;
32
    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;
36
    VirtQueue *ctrl_vq;
37
    NICState *nic;
38
    QEMUTimer *tx_timer;
39
    int tx_timer_active;
40
    uint32_t has_vnet_hdr;
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    uint8_t has_ufo;
42
    struct {
43
        VirtQueueElement elem;
44
        ssize_t len;
45
    } async_tx;
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    int mergeable_rx_bufs;
47
    uint8_t promisc;
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    uint8_t allmulti;
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    uint8_t alluni;
50
    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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    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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    DeviceState *qdev;
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} VirtIONet;
65

    
66
/* TODO
67
 * - we could suppress RX interrupt if we were so inclined.
68
 */
69

    
70
static VirtIONet *to_virtio_net(VirtIODevice *vdev)
71
{
72
    return (VirtIONet *)vdev;
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}
74

    
75
static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
76
{
77
    VirtIONet *n = to_virtio_net(vdev);
78
    struct virtio_net_config netcfg;
79

    
80
    netcfg.status = n->status;
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    memcpy(netcfg.mac, n->mac, ETH_ALEN);
82
    memcpy(config, &netcfg, sizeof(netcfg));
83
}
84

    
85
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
86
{
87
    VirtIONet *n = to_virtio_net(vdev);
88
    struct virtio_net_config netcfg;
89

    
90
    memcpy(&netcfg, config, sizeof(netcfg));
91

    
92
    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
93
        memcpy(n->mac, netcfg.mac, ETH_ALEN);
94
        qemu_format_nic_info_str(&n->nic->nc, n->mac);
95
    }
96
}
97

    
98
static void virtio_net_set_link_status(VLANClientState *nc)
99
{
100
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
101
    uint16_t old_status = n->status;
102

    
103
    if (nc->link_down)
104
        n->status &= ~VIRTIO_NET_S_LINK_UP;
105
    else
106
        n->status |= VIRTIO_NET_S_LINK_UP;
107

    
108
    if (n->status != old_status)
109
        virtio_notify_config(&n->vdev);
110
}
111

    
112
static void virtio_net_reset(VirtIODevice *vdev)
113
{
114
    VirtIONet *n = to_virtio_net(vdev);
115

    
116
    /* Reset back to compatibility mode */
117
    n->promisc = 1;
118
    n->allmulti = 0;
119
    n->alluni = 0;
120
    n->nomulti = 0;
121
    n->nouni = 0;
122
    n->nobcast = 0;
123
    if (n->vhost_started) {
124
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
125
        n->vhost_started = 0;
126
    }
127

    
128
    /* Flush any MAC and VLAN filter table state */
129
    n->mac_table.in_use = 0;
130
    n->mac_table.first_multi = 0;
131
    n->mac_table.multi_overflow = 0;
132
    n->mac_table.uni_overflow = 0;
133
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
134
    memset(n->vlans, 0, MAX_VLAN >> 3);
135
}
136

    
137
static int peer_has_vnet_hdr(VirtIONet *n)
138
{
139
    if (!n->nic->nc.peer)
140
        return 0;
141

    
142
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
143
        return 0;
144

    
145
    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
146

    
147
    return n->has_vnet_hdr;
148
}
149

    
150
static int peer_has_ufo(VirtIONet *n)
151
{
152
    if (!peer_has_vnet_hdr(n))
153
        return 0;
154

    
155
    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
156

    
157
    return n->has_ufo;
158
}
159

    
160
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
161
{
162
    VirtIONet *n = to_virtio_net(vdev);
163

    
164
    features |= (1 << VIRTIO_NET_F_MAC);
165

    
166
    if (peer_has_vnet_hdr(n)) {
167
        tap_using_vnet_hdr(n->nic->nc.peer, 1);
168
    } else {
169
        features &= ~(0x1 << VIRTIO_NET_F_CSUM);
170
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
171
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
172
        features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
173

    
174
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
175
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
176
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
177
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
178
    }
179

    
180
    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
181
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
182
        features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
183
    }
184

    
185
    if (!n->nic->nc.peer ||
186
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
187
        return features;
188
    }
189
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
190
        return features;
191
    }
192
    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
193
}
194

    
195
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
196
{
197
    uint32_t features = 0;
198

    
199
    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
200
     * but also these: */
201
    features |= (1 << VIRTIO_NET_F_MAC);
202
    features |= (1 << VIRTIO_NET_F_CSUM);
203
    features |= (1 << VIRTIO_NET_F_HOST_TSO4);
204
    features |= (1 << VIRTIO_NET_F_HOST_TSO6);
205
    features |= (1 << VIRTIO_NET_F_HOST_ECN);
206

    
207
    return features;
208
}
209

    
210
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
211
{
212
    VirtIONet *n = to_virtio_net(vdev);
213

    
214
    n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
215

    
216
    if (n->has_vnet_hdr) {
217
        tap_set_offload(n->nic->nc.peer,
218
                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
219
                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
220
                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
221
                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
222
                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
223
    }
224
    if (!n->nic->nc.peer ||
225
        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
226
        return;
227
    }
228
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
229
        return;
230
    }
231
    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
232
}
233

    
234
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
235
                                     VirtQueueElement *elem)
236
{
237
    uint8_t on;
238

    
239
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
240
        fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
241
        exit(1);
242
    }
243

    
244
    on = ldub_p(elem->out_sg[1].iov_base);
245

    
246
    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
247
        n->promisc = on;
248
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
249
        n->allmulti = on;
250
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
251
        n->alluni = on;
252
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
253
        n->nomulti = on;
254
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
255
        n->nouni = on;
256
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
257
        n->nobcast = on;
258
    else
259
        return VIRTIO_NET_ERR;
260

    
261
    return VIRTIO_NET_OK;
262
}
263

    
264
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
265
                                 VirtQueueElement *elem)
266
{
267
    struct virtio_net_ctrl_mac mac_data;
268

    
269
    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
270
        elem->out_sg[1].iov_len < sizeof(mac_data) ||
271
        elem->out_sg[2].iov_len < sizeof(mac_data))
272
        return VIRTIO_NET_ERR;
273

    
274
    n->mac_table.in_use = 0;
275
    n->mac_table.first_multi = 0;
276
    n->mac_table.uni_overflow = 0;
277
    n->mac_table.multi_overflow = 0;
278
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
279

    
280
    mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
281

    
282
    if (sizeof(mac_data.entries) +
283
        (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
284
        return VIRTIO_NET_ERR;
285

    
286
    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
287
        memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
288
               mac_data.entries * ETH_ALEN);
289
        n->mac_table.in_use += mac_data.entries;
290
    } else {
291
        n->mac_table.uni_overflow = 1;
292
    }
293

    
294
    n->mac_table.first_multi = n->mac_table.in_use;
295

    
296
    mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
297

    
298
    if (sizeof(mac_data.entries) +
299
        (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
300
        return VIRTIO_NET_ERR;
301

    
302
    if (mac_data.entries) {
303
        if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
304
            memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
305
                   elem->out_sg[2].iov_base + sizeof(mac_data),
306
                   mac_data.entries * ETH_ALEN);
307
            n->mac_table.in_use += mac_data.entries;
308
        } else {
309
            n->mac_table.multi_overflow = 1;
310
        }
311
    }
312

    
313
    return VIRTIO_NET_OK;
314
}
315

    
316
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
317
                                        VirtQueueElement *elem)
318
{
319
    uint16_t vid;
320

    
321
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
322
        fprintf(stderr, "virtio-net ctrl invalid vlan command\n");
323
        return VIRTIO_NET_ERR;
324
    }
325

    
326
    vid = lduw_le_p(elem->out_sg[1].iov_base);
327

    
328
    if (vid >= MAX_VLAN)
329
        return VIRTIO_NET_ERR;
330

    
331
    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
332
        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
333
    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
334
        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
335
    else
336
        return VIRTIO_NET_ERR;
337

    
338
    return VIRTIO_NET_OK;
339
}
340

    
341
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
342
{
343
    VirtIONet *n = to_virtio_net(vdev);
344
    struct virtio_net_ctrl_hdr ctrl;
345
    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
346
    VirtQueueElement elem;
347

    
348
    while (virtqueue_pop(vq, &elem)) {
349
        if ((elem.in_num < 1) || (elem.out_num < 1)) {
350
            fprintf(stderr, "virtio-net ctrl missing headers\n");
351
            exit(1);
352
        }
353

    
354
        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
355
            elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
356
            fprintf(stderr, "virtio-net ctrl header not in correct element\n");
357
            exit(1);
358
        }
359

    
360
        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
361
        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
362

    
363
        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
364
            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
365
        else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
366
            status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
367
        else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
368
            status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
369

    
370
        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
371

    
372
        virtqueue_push(vq, &elem, sizeof(status));
373
        virtio_notify(vdev, vq);
374
    }
375
}
376

    
377
/* RX */
378

    
379
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
380
{
381
    VirtIONet *n = to_virtio_net(vdev);
382

    
383
    qemu_flush_queued_packets(&n->nic->nc);
384

    
385
    /* We now have RX buffers, signal to the IO thread to break out of the
386
     * select to re-poll the tap file descriptor */
387
    qemu_notify_event();
388
}
389

    
390
static int virtio_net_can_receive(VLANClientState *nc)
391
{
392
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
393

    
394
    if (!virtio_queue_ready(n->rx_vq) ||
395
        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
396
        return 0;
397

    
398
    return 1;
399
}
400

    
401
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
402
{
403
    if (virtio_queue_empty(n->rx_vq) ||
404
        (n->mergeable_rx_bufs &&
405
         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
406
        virtio_queue_set_notification(n->rx_vq, 1);
407

    
408
        /* To avoid a race condition where the guest has made some buffers
409
         * available after the above check but before notification was
410
         * enabled, check for available buffers again.
411
         */
412
        if (virtio_queue_empty(n->rx_vq) ||
413
            (n->mergeable_rx_bufs &&
414
             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
415
            return 0;
416
    }
417

    
418
    virtio_queue_set_notification(n->rx_vq, 0);
419
    return 1;
420
}
421

    
422
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
423
 * it never finds out that the packets don't have valid checksums.  This
424
 * causes dhclient to get upset.  Fedora's carried a patch for ages to
425
 * fix this with Xen but it hasn't appeared in an upstream release of
426
 * dhclient yet.
427
 *
428
 * To avoid breaking existing guests, we catch udp packets and add
429
 * checksums.  This is terrible but it's better than hacking the guest
430
 * kernels.
431
 *
432
 * N.B. if we introduce a zero-copy API, this operation is no longer free so
433
 * we should provide a mechanism to disable it to avoid polluting the host
434
 * cache.
435
 */
436
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
437
                                        const uint8_t *buf, size_t size)
438
{
439
    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
440
        (size > 27 && size < 1500) && /* normal sized MTU */
441
        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
442
        (buf[23] == 17) && /* ip.protocol == UDP */
443
        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
444
        /* FIXME this cast is evil */
445
        net_checksum_calculate((uint8_t *)buf, size);
446
        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
447
    }
448
}
449

    
450
static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
451
                          const void *buf, size_t size, size_t hdr_len)
452
{
453
    struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
454
    int offset = 0;
455

    
456
    hdr->flags = 0;
457
    hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
458

    
459
    if (n->has_vnet_hdr) {
460
        memcpy(hdr, buf, sizeof(*hdr));
461
        offset = sizeof(*hdr);
462
        work_around_broken_dhclient(hdr, buf + offset, size - offset);
463
    }
464

    
465
    /* We only ever receive a struct virtio_net_hdr from the tapfd,
466
     * but we may be passing along a larger header to the guest.
467
     */
468
    iov[0].iov_base += hdr_len;
469
    iov[0].iov_len  -= hdr_len;
470

    
471
    return offset;
472
}
473

    
474
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
475
{
476
    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
477
    static const uint8_t vlan[] = {0x81, 0x00};
478
    uint8_t *ptr = (uint8_t *)buf;
479
    int i;
480

    
481
    if (n->promisc)
482
        return 1;
483

    
484
    if (n->has_vnet_hdr) {
485
        ptr += sizeof(struct virtio_net_hdr);
486
    }
487

    
488
    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
489
        int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
490
        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
491
            return 0;
492
    }
493

    
494
    if (ptr[0] & 1) { // multicast
495
        if (!memcmp(ptr, bcast, sizeof(bcast))) {
496
            return !n->nobcast;
497
        } else if (n->nomulti) {
498
            return 0;
499
        } else if (n->allmulti || n->mac_table.multi_overflow) {
500
            return 1;
501
        }
502

    
503
        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
504
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
505
                return 1;
506
            }
507
        }
508
    } else { // unicast
509
        if (n->nouni) {
510
            return 0;
511
        } else if (n->alluni || n->mac_table.uni_overflow) {
512
            return 1;
513
        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
514
            return 1;
515
        }
516

    
517
        for (i = 0; i < n->mac_table.first_multi; i++) {
518
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
519
                return 1;
520
            }
521
        }
522
    }
523

    
524
    return 0;
525
}
526

    
527
static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
528
{
529
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
530
    struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
531
    size_t guest_hdr_len, offset, i, host_hdr_len;
532

    
533
    if (!virtio_net_can_receive(&n->nic->nc))
534
        return -1;
535

    
536
    /* hdr_len refers to the header we supply to the guest */
537
    guest_hdr_len = n->mergeable_rx_bufs ?
538
        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
539

    
540

    
541
    host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
542
    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
543
        return 0;
544

    
545
    if (!receive_filter(n, buf, size))
546
        return size;
547

    
548
    offset = i = 0;
549

    
550
    while (offset < size) {
551
        VirtQueueElement elem;
552
        int len, total;
553
        struct iovec sg[VIRTQUEUE_MAX_SIZE];
554

    
555
        total = 0;
556

    
557
        if (virtqueue_pop(n->rx_vq, &elem) == 0) {
558
            if (i == 0)
559
                return -1;
560
            fprintf(stderr, "virtio-net unexpected empty queue: "
561
                    "i %zd mergeable %d offset %zd, size %zd, "
562
                    "guest hdr len %zd, host hdr len %zd guest features 0x%x\n",
563
                    i, n->mergeable_rx_bufs, offset, size,
564
                    guest_hdr_len, host_hdr_len, n->vdev.guest_features);
565
            exit(1);
566
        }
567

    
568
        if (elem.in_num < 1) {
569
            fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
570
            exit(1);
571
        }
572

    
573
        if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != guest_hdr_len) {
574
            fprintf(stderr, "virtio-net header not in first element\n");
575
            exit(1);
576
        }
577

    
578
        memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
579

    
580
        if (i == 0) {
581
            if (n->mergeable_rx_bufs)
582
                mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
583

    
584
            offset += receive_header(n, sg, elem.in_num,
585
                                     buf + offset, size - offset, guest_hdr_len);
586
            total += guest_hdr_len;
587
        }
588

    
589
        /* copy in packet.  ugh */
590
        len = iov_from_buf(sg, elem.in_num,
591
                           buf + offset, size - offset);
592
        total += len;
593
        offset += len;
594
        /* If buffers can't be merged, at this point we
595
         * must have consumed the complete packet.
596
         * Otherwise, drop it. */
597
        if (!n->mergeable_rx_bufs && offset < size) {
598
#if 0
599
            fprintf(stderr, "virtio-net truncated non-mergeable packet: "
600

601
                    "i %zd mergeable %d offset %zd, size %zd, "
602
                    "guest hdr len %zd, host hdr len %zd\n",
603
                    i, n->mergeable_rx_bufs,
604
                    offset, size, guest_hdr_len, host_hdr_len);
605
#endif
606
            return size;
607
        }
608

    
609
        /* signal other side */
610
        virtqueue_fill(n->rx_vq, &elem, total, i++);
611
    }
612

    
613
    if (mhdr)
614
        mhdr->num_buffers = i;
615

    
616
    virtqueue_flush(n->rx_vq, i);
617
    virtio_notify(&n->vdev, n->rx_vq);
618

    
619
    return size;
620
}
621

    
622
static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
623

    
624
static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
625
{
626
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
627

    
628
    virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
629
    virtio_notify(&n->vdev, n->tx_vq);
630

    
631
    n->async_tx.elem.out_num = n->async_tx.len = 0;
632

    
633
    virtio_queue_set_notification(n->tx_vq, 1);
634
    virtio_net_flush_tx(n, n->tx_vq);
635
}
636

    
637
/* TX */
638
static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
639
{
640
    VirtQueueElement elem;
641

    
642
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
643
        return;
644

    
645
    if (n->async_tx.elem.out_num) {
646
        virtio_queue_set_notification(n->tx_vq, 0);
647
        return;
648
    }
649

    
650
    while (virtqueue_pop(vq, &elem)) {
651
        ssize_t ret, len = 0;
652
        unsigned int out_num = elem.out_num;
653
        struct iovec *out_sg = &elem.out_sg[0];
654
        unsigned hdr_len;
655

    
656
        /* hdr_len refers to the header received from the guest */
657
        hdr_len = n->mergeable_rx_bufs ?
658
            sizeof(struct virtio_net_hdr_mrg_rxbuf) :
659
            sizeof(struct virtio_net_hdr);
660

    
661
        if (out_num < 1 || out_sg->iov_len != hdr_len) {
662
            fprintf(stderr, "virtio-net header not in first element\n");
663
            exit(1);
664
        }
665

    
666
        /* ignore the header if GSO is not supported */
667
        if (!n->has_vnet_hdr) {
668
            out_num--;
669
            out_sg++;
670
            len += hdr_len;
671
        } else if (n->mergeable_rx_bufs) {
672
            /* tapfd expects a struct virtio_net_hdr */
673
            hdr_len -= sizeof(struct virtio_net_hdr);
674
            out_sg->iov_len -= hdr_len;
675
            len += hdr_len;
676
        }
677

    
678
        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
679
                                      virtio_net_tx_complete);
680
        if (ret == 0) {
681
            virtio_queue_set_notification(n->tx_vq, 0);
682
            n->async_tx.elem = elem;
683
            n->async_tx.len  = len;
684
            return;
685
        }
686

    
687
        len += ret;
688

    
689
        virtqueue_push(vq, &elem, len);
690
        virtio_notify(&n->vdev, vq);
691
    }
692
}
693

    
694
static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
695
{
696
    VirtIONet *n = to_virtio_net(vdev);
697

    
698
    if (n->tx_timer_active) {
699
        virtio_queue_set_notification(vq, 1);
700
        qemu_del_timer(n->tx_timer);
701
        n->tx_timer_active = 0;
702
        virtio_net_flush_tx(n, vq);
703
    } else {
704
        qemu_mod_timer(n->tx_timer,
705
                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
706
        n->tx_timer_active = 1;
707
        virtio_queue_set_notification(vq, 0);
708
    }
709
}
710

    
711
static void virtio_net_tx_timer(void *opaque)
712
{
713
    VirtIONet *n = opaque;
714

    
715
    n->tx_timer_active = 0;
716

    
717
    /* Just in case the driver is not ready on more */
718
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
719
        return;
720

    
721
    virtio_queue_set_notification(n->tx_vq, 1);
722
    virtio_net_flush_tx(n, n->tx_vq);
723
}
724

    
725
static void virtio_net_save(QEMUFile *f, void *opaque)
726
{
727
    VirtIONet *n = opaque;
728

    
729
    if (n->vhost_started) {
730
        /* TODO: should we really stop the backend?
731
         * If we don't, it might keep writing to memory. */
732
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
733
        n->vhost_started = 0;
734
    }
735
    virtio_save(&n->vdev, f);
736

    
737
    qemu_put_buffer(f, n->mac, ETH_ALEN);
738
    qemu_put_be32(f, n->tx_timer_active);
739
    qemu_put_be32(f, n->mergeable_rx_bufs);
740
    qemu_put_be16(f, n->status);
741
    qemu_put_byte(f, n->promisc);
742
    qemu_put_byte(f, n->allmulti);
743
    qemu_put_be32(f, n->mac_table.in_use);
744
    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
745
    qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
746
    qemu_put_be32(f, n->has_vnet_hdr);
747
    qemu_put_byte(f, n->mac_table.multi_overflow);
748
    qemu_put_byte(f, n->mac_table.uni_overflow);
749
    qemu_put_byte(f, n->alluni);
750
    qemu_put_byte(f, n->nomulti);
751
    qemu_put_byte(f, n->nouni);
752
    qemu_put_byte(f, n->nobcast);
753
    qemu_put_byte(f, n->has_ufo);
754
}
755

    
756
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
757
{
758
    VirtIONet *n = opaque;
759
    int i;
760

    
761
    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
762
        return -EINVAL;
763

    
764
    virtio_load(&n->vdev, f);
765

    
766
    qemu_get_buffer(f, n->mac, ETH_ALEN);
767
    n->tx_timer_active = qemu_get_be32(f);
768
    n->mergeable_rx_bufs = qemu_get_be32(f);
769

    
770
    if (version_id >= 3)
771
        n->status = qemu_get_be16(f);
772

    
773
    if (version_id >= 4) {
774
        if (version_id < 8) {
775
            n->promisc = qemu_get_be32(f);
776
            n->allmulti = qemu_get_be32(f);
777
        } else {
778
            n->promisc = qemu_get_byte(f);
779
            n->allmulti = qemu_get_byte(f);
780
        }
781
    }
782

    
783
    if (version_id >= 5) {
784
        n->mac_table.in_use = qemu_get_be32(f);
785
        /* MAC_TABLE_ENTRIES may be different from the saved image */
786
        if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
787
            qemu_get_buffer(f, n->mac_table.macs,
788
                            n->mac_table.in_use * ETH_ALEN);
789
        } else if (n->mac_table.in_use) {
790
            qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
791
            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
792
            n->mac_table.in_use = 0;
793
        }
794
    }
795
 
796
    if (version_id >= 6)
797
        qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
798

    
799
    if (version_id >= 7) {
800
        if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
801
            error_report("virtio-net: saved image requires vnet_hdr=on");
802
            return -1;
803
        }
804

    
805
        if (n->has_vnet_hdr) {
806
            tap_using_vnet_hdr(n->nic->nc.peer, 1);
807
            tap_set_offload(n->nic->nc.peer,
808
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
809
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
810
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
811
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
812
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
813
        }
814
    }
815

    
816
    if (version_id >= 9) {
817
        n->mac_table.multi_overflow = qemu_get_byte(f);
818
        n->mac_table.uni_overflow = qemu_get_byte(f);
819
    }
820

    
821
    if (version_id >= 10) {
822
        n->alluni = qemu_get_byte(f);
823
        n->nomulti = qemu_get_byte(f);
824
        n->nouni = qemu_get_byte(f);
825
        n->nobcast = qemu_get_byte(f);
826
    }
827

    
828
    if (version_id >= 11) {
829
        if (qemu_get_byte(f) && !peer_has_ufo(n)) {
830
            error_report("virtio-net: saved image requires TUN_F_UFO support");
831
            return -1;
832
        }
833
    }
834

    
835
    /* Find the first multicast entry in the saved MAC filter */
836
    for (i = 0; i < n->mac_table.in_use; i++) {
837
        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
838
            break;
839
        }
840
    }
841
    n->mac_table.first_multi = i;
842

    
843
    if (n->tx_timer_active) {
844
        qemu_mod_timer(n->tx_timer,
845
                       qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
846
    }
847
    return 0;
848
}
849

    
850
static void virtio_net_cleanup(VLANClientState *nc)
851
{
852
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
853

    
854
    n->nic = NULL;
855
}
856

    
857
static NetClientInfo net_virtio_info = {
858
    .type = NET_CLIENT_TYPE_NIC,
859
    .size = sizeof(NICState),
860
    .can_receive = virtio_net_can_receive,
861
    .receive = virtio_net_receive,
862
        .cleanup = virtio_net_cleanup,
863
    .link_status_changed = virtio_net_set_link_status,
864
};
865

    
866
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
867
{
868
    VirtIONet *n = to_virtio_net(vdev);
869
    if (!n->nic->nc.peer) {
870
        return;
871
    }
872
    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
873
        return;
874
    }
875

    
876
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
877
        return;
878
    }
879
    if (!!n->vhost_started == !!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
880
        return;
881
    }
882
    if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
883
        int r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), vdev);
884
        if (r < 0) {
885
            fprintf(stderr, "unable to start vhost net: %d: "
886
                    "falling back on userspace virtio\n", -r);
887
        } else {
888
            n->vhost_started = 1;
889
        }
890
    } else {
891
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
892
        n->vhost_started = 0;
893
    }
894
}
895

    
896
static void virtio_net_vmstate_change(void *opaque, int running, int reason)
897
{
898
    VirtIONet *n = opaque;
899
    uint8_t status = running ? VIRTIO_CONFIG_S_DRIVER_OK : 0;
900
    /* This is called when vm is started/stopped,
901
     * it will start/stop vhost backend if * appropriate
902
     * e.g. after migration. */
903
    virtio_net_set_status(&n->vdev, n->vdev.status & status);
904
}
905

    
906
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)
907
{
908
    VirtIONet *n;
909

    
910
    n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
911
                                        sizeof(struct virtio_net_config),
912
                                        sizeof(VirtIONet));
913

    
914
    n->vdev.get_config = virtio_net_get_config;
915
    n->vdev.set_config = virtio_net_set_config;
916
    n->vdev.get_features = virtio_net_get_features;
917
    n->vdev.set_features = virtio_net_set_features;
918
    n->vdev.bad_features = virtio_net_bad_features;
919
    n->vdev.reset = virtio_net_reset;
920
    n->vdev.set_status = virtio_net_set_status;
921
    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
922
    n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
923
    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
924
    qemu_macaddr_default_if_unset(&conf->macaddr);
925
    memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
926
    n->status = VIRTIO_NET_S_LINK_UP;
927

    
928
    n->nic = qemu_new_nic(&net_virtio_info, conf, dev->info->name, dev->id, n);
929

    
930
    qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
931

    
932
    n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
933
    n->tx_timer_active = 0;
934
    n->mergeable_rx_bufs = 0;
935
    n->promisc = 1; /* for compatibility */
936

    
937
    n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
938

    
939
    n->vlans = qemu_mallocz(MAX_VLAN >> 3);
940

    
941
    n->qdev = dev;
942
    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
943
                    virtio_net_save, virtio_net_load, n);
944
    n->vmstate = qemu_add_vm_change_state_handler(virtio_net_vmstate_change, n);
945

    
946
    return &n->vdev;
947
}
948

    
949
void virtio_net_exit(VirtIODevice *vdev)
950
{
951
    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
952
    qemu_del_vm_change_state_handler(n->vmstate);
953

    
954
    if (n->vhost_started) {
955
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), vdev);
956
    }
957

    
958
    qemu_purge_queued_packets(&n->nic->nc);
959

    
960
    unregister_savevm(n->qdev, "virtio-net", n);
961

    
962
    qemu_free(n->mac_table.macs);
963
    qemu_free(n->vlans);
964

    
965
    qemu_del_timer(n->tx_timer);
966
    qemu_free_timer(n->tx_timer);
967

    
968
    virtio_cleanup(&n->vdev);
969
    qemu_del_vlan_client(&n->nic->nc);
970
}