xref: /openbmc/qemu/tests/vhost-user-bridge.c (revision f186d64d)
1 /*
2  * Vhost User Bridge
3  *
4  * Copyright (c) 2015 Red Hat, Inc.
5  *
6  * Authors:
7  *  Victor Kaplansky <victork@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or
10  * later.  See the COPYING file in the top-level directory.
11  */
12 
13 /*
14  * TODO:
15  *     - main should get parameters from the command line.
16  *     - implement all request handlers. Still not implemented:
17  *          vubr_get_queue_num_exec()
18  *          vubr_send_rarp_exec()
19  *     - test for broken requests and virtqueue.
20  *     - implement features defined by Virtio 1.0 spec.
21  *     - support mergeable buffers and indirect descriptors.
22  *     - implement clean shutdown.
23  *     - implement non-blocking writes to UDP backend.
24  *     - implement polling strategy.
25  *     - implement clean starting/stopping of vq processing
26  *     - implement clean starting/stopping of used and buffers
27  *       dirty page logging.
28  */
29 
30 #define _FILE_OFFSET_BITS 64
31 
32 #include "qemu/osdep.h"
33 #include <sys/socket.h>
34 #include <sys/un.h>
35 #include <sys/unistd.h>
36 #include <sys/eventfd.h>
37 #include <arpa/inet.h>
38 #include <netdb.h>
39 #include <linux/vhost.h>
40 
41 #include "qemu/atomic.h"
42 #include "standard-headers/linux/virtio_net.h"
43 #include "standard-headers/linux/virtio_ring.h"
44 
45 #define VHOST_USER_BRIDGE_DEBUG 1
46 
47 #define DPRINT(...) \
48     do { \
49         if (VHOST_USER_BRIDGE_DEBUG) { \
50             printf(__VA_ARGS__); \
51         } \
52     } while (0)
53 
54 typedef void (*CallbackFunc)(int sock, void *ctx);
55 
56 typedef struct Event {
57     void *ctx;
58     CallbackFunc callback;
59 } Event;
60 
61 typedef struct Dispatcher {
62     int max_sock;
63     fd_set fdset;
64     Event events[FD_SETSIZE];
65 } Dispatcher;
66 
67 static void
68 vubr_die(const char *s)
69 {
70     perror(s);
71     exit(1);
72 }
73 
74 static int
75 dispatcher_init(Dispatcher *dispr)
76 {
77     FD_ZERO(&dispr->fdset);
78     dispr->max_sock = -1;
79     return 0;
80 }
81 
82 static int
83 dispatcher_add(Dispatcher *dispr, int sock, void *ctx, CallbackFunc cb)
84 {
85     if (sock >= FD_SETSIZE) {
86         fprintf(stderr,
87                 "Error: Failed to add new event. sock %d should be less than %d\n",
88                 sock, FD_SETSIZE);
89         return -1;
90     }
91 
92     dispr->events[sock].ctx = ctx;
93     dispr->events[sock].callback = cb;
94 
95     FD_SET(sock, &dispr->fdset);
96     if (sock > dispr->max_sock) {
97         dispr->max_sock = sock;
98     }
99     DPRINT("Added sock %d for watching. max_sock: %d\n",
100            sock, dispr->max_sock);
101     return 0;
102 }
103 
104 /* dispatcher_remove() is not currently in use but may be useful
105  * in the future. */
106 static int
107 dispatcher_remove(Dispatcher *dispr, int sock)
108 {
109     if (sock >= FD_SETSIZE) {
110         fprintf(stderr,
111                 "Error: Failed to remove event. sock %d should be less than %d\n",
112                 sock, FD_SETSIZE);
113         return -1;
114     }
115 
116     FD_CLR(sock, &dispr->fdset);
117     DPRINT("Sock %d removed from dispatcher watch.\n", sock);
118     return 0;
119 }
120 
121 /* timeout in us */
122 static int
123 dispatcher_wait(Dispatcher *dispr, uint32_t timeout)
124 {
125     struct timeval tv;
126     tv.tv_sec = timeout / 1000000;
127     tv.tv_usec = timeout % 1000000;
128 
129     fd_set fdset = dispr->fdset;
130 
131     /* wait until some of sockets become readable. */
132     int rc = select(dispr->max_sock + 1, &fdset, 0, 0, &tv);
133 
134     if (rc == -1) {
135         vubr_die("select");
136     }
137 
138     /* Timeout */
139     if (rc == 0) {
140         return 0;
141     }
142 
143     /* Now call callback for every ready socket. */
144 
145     int sock;
146     for (sock = 0; sock < dispr->max_sock + 1; sock++) {
147         /* The callback on a socket can remove other sockets from the
148          * dispatcher, thus we have to check that the socket is
149          * still not removed from dispatcher's list
150          */
151         if (FD_ISSET(sock, &fdset) && FD_ISSET(sock, &dispr->fdset)) {
152             Event *e = &dispr->events[sock];
153             e->callback(sock, e->ctx);
154         }
155     }
156 
157     return 0;
158 }
159 
160 typedef struct VubrVirtq {
161     int call_fd;
162     int kick_fd;
163     uint32_t size;
164     uint16_t last_avail_index;
165     uint16_t last_used_index;
166     struct vring_desc *desc;
167     struct vring_avail *avail;
168     struct vring_used *used;
169     uint64_t log_guest_addr;
170     int enable;
171 } VubrVirtq;
172 
173 /* Based on qemu/hw/virtio/vhost-user.c */
174 
175 #define VHOST_MEMORY_MAX_NREGIONS    8
176 #define VHOST_USER_F_PROTOCOL_FEATURES 30
177 /* v1.0 compliant. */
178 #define VIRTIO_F_VERSION_1		32
179 
180 #define VHOST_LOG_PAGE 4096
181 
182 enum VhostUserProtocolFeature {
183     VHOST_USER_PROTOCOL_F_MQ = 0,
184     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
185     VHOST_USER_PROTOCOL_F_RARP = 2,
186 
187     VHOST_USER_PROTOCOL_F_MAX
188 };
189 
190 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
191 
192 typedef enum VhostUserRequest {
193     VHOST_USER_NONE = 0,
194     VHOST_USER_GET_FEATURES = 1,
195     VHOST_USER_SET_FEATURES = 2,
196     VHOST_USER_SET_OWNER = 3,
197     VHOST_USER_RESET_OWNER = 4,
198     VHOST_USER_SET_MEM_TABLE = 5,
199     VHOST_USER_SET_LOG_BASE = 6,
200     VHOST_USER_SET_LOG_FD = 7,
201     VHOST_USER_SET_VRING_NUM = 8,
202     VHOST_USER_SET_VRING_ADDR = 9,
203     VHOST_USER_SET_VRING_BASE = 10,
204     VHOST_USER_GET_VRING_BASE = 11,
205     VHOST_USER_SET_VRING_KICK = 12,
206     VHOST_USER_SET_VRING_CALL = 13,
207     VHOST_USER_SET_VRING_ERR = 14,
208     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
209     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
210     VHOST_USER_GET_QUEUE_NUM = 17,
211     VHOST_USER_SET_VRING_ENABLE = 18,
212     VHOST_USER_SEND_RARP = 19,
213     VHOST_USER_MAX
214 } VhostUserRequest;
215 
216 typedef struct VhostUserMemoryRegion {
217     uint64_t guest_phys_addr;
218     uint64_t memory_size;
219     uint64_t userspace_addr;
220     uint64_t mmap_offset;
221 } VhostUserMemoryRegion;
222 
223 typedef struct VhostUserMemory {
224     uint32_t nregions;
225     uint32_t padding;
226     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
227 } VhostUserMemory;
228 
229 typedef struct VhostUserLog {
230     uint64_t mmap_size;
231     uint64_t mmap_offset;
232 } VhostUserLog;
233 
234 typedef struct VhostUserMsg {
235     VhostUserRequest request;
236 
237 #define VHOST_USER_VERSION_MASK     (0x3)
238 #define VHOST_USER_REPLY_MASK       (0x1<<2)
239     uint32_t flags;
240     uint32_t size; /* the following payload size */
241     union {
242 #define VHOST_USER_VRING_IDX_MASK   (0xff)
243 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
244         uint64_t u64;
245         struct vhost_vring_state state;
246         struct vhost_vring_addr addr;
247         VhostUserMemory memory;
248         VhostUserLog log;
249     } payload;
250     int fds[VHOST_MEMORY_MAX_NREGIONS];
251     int fd_num;
252 } QEMU_PACKED VhostUserMsg;
253 
254 #define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
255 
256 /* The version of the protocol we support */
257 #define VHOST_USER_VERSION    (0x1)
258 
259 #define MAX_NR_VIRTQUEUE (8)
260 
261 typedef struct VubrDevRegion {
262     /* Guest Physical address. */
263     uint64_t gpa;
264     /* Memory region size. */
265     uint64_t size;
266     /* QEMU virtual address (userspace). */
267     uint64_t qva;
268     /* Starting offset in our mmaped space. */
269     uint64_t mmap_offset;
270     /* Start address of mmaped space. */
271     uint64_t mmap_addr;
272 } VubrDevRegion;
273 
274 typedef struct VubrDev {
275     int sock;
276     Dispatcher dispatcher;
277     uint32_t nregions;
278     VubrDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
279     VubrVirtq vq[MAX_NR_VIRTQUEUE];
280     int log_call_fd;
281     uint64_t log_size;
282     uint8_t *log_table;
283     int backend_udp_sock;
284     struct sockaddr_in backend_udp_dest;
285     int ready;
286     uint64_t features;
287     int hdrlen;
288 } VubrDev;
289 
290 static const char *vubr_request_str[] = {
291     [VHOST_USER_NONE]                   =  "VHOST_USER_NONE",
292     [VHOST_USER_GET_FEATURES]           =  "VHOST_USER_GET_FEATURES",
293     [VHOST_USER_SET_FEATURES]           =  "VHOST_USER_SET_FEATURES",
294     [VHOST_USER_SET_OWNER]              =  "VHOST_USER_SET_OWNER",
295     [VHOST_USER_RESET_OWNER]           =  "VHOST_USER_RESET_OWNER",
296     [VHOST_USER_SET_MEM_TABLE]          =  "VHOST_USER_SET_MEM_TABLE",
297     [VHOST_USER_SET_LOG_BASE]           =  "VHOST_USER_SET_LOG_BASE",
298     [VHOST_USER_SET_LOG_FD]             =  "VHOST_USER_SET_LOG_FD",
299     [VHOST_USER_SET_VRING_NUM]          =  "VHOST_USER_SET_VRING_NUM",
300     [VHOST_USER_SET_VRING_ADDR]         =  "VHOST_USER_SET_VRING_ADDR",
301     [VHOST_USER_SET_VRING_BASE]         =  "VHOST_USER_SET_VRING_BASE",
302     [VHOST_USER_GET_VRING_BASE]         =  "VHOST_USER_GET_VRING_BASE",
303     [VHOST_USER_SET_VRING_KICK]         =  "VHOST_USER_SET_VRING_KICK",
304     [VHOST_USER_SET_VRING_CALL]         =  "VHOST_USER_SET_VRING_CALL",
305     [VHOST_USER_SET_VRING_ERR]          =  "VHOST_USER_SET_VRING_ERR",
306     [VHOST_USER_GET_PROTOCOL_FEATURES]  =  "VHOST_USER_GET_PROTOCOL_FEATURES",
307     [VHOST_USER_SET_PROTOCOL_FEATURES]  =  "VHOST_USER_SET_PROTOCOL_FEATURES",
308     [VHOST_USER_GET_QUEUE_NUM]          =  "VHOST_USER_GET_QUEUE_NUM",
309     [VHOST_USER_SET_VRING_ENABLE]       =  "VHOST_USER_SET_VRING_ENABLE",
310     [VHOST_USER_SEND_RARP]              =  "VHOST_USER_SEND_RARP",
311     [VHOST_USER_MAX]                    =  "VHOST_USER_MAX",
312 };
313 
314 static void
315 print_buffer(uint8_t *buf, size_t len)
316 {
317     int i;
318     printf("Raw buffer:\n");
319     for (i = 0; i < len; i++) {
320         if (i % 16 == 0) {
321             printf("\n");
322         }
323         if (i % 4 == 0) {
324             printf("   ");
325         }
326         printf("%02x ", buf[i]);
327     }
328     printf("\n............................................................\n");
329 }
330 
331 /* Translate guest physical address to our virtual address.  */
332 static uint64_t
333 gpa_to_va(VubrDev *dev, uint64_t guest_addr)
334 {
335     int i;
336 
337     /* Find matching memory region.  */
338     for (i = 0; i < dev->nregions; i++) {
339         VubrDevRegion *r = &dev->regions[i];
340 
341         if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) {
342             return guest_addr - r->gpa + r->mmap_addr + r->mmap_offset;
343         }
344     }
345 
346     assert(!"address not found in regions");
347     return 0;
348 }
349 
350 /* Translate qemu virtual address to our virtual address.  */
351 static uint64_t
352 qva_to_va(VubrDev *dev, uint64_t qemu_addr)
353 {
354     int i;
355 
356     /* Find matching memory region.  */
357     for (i = 0; i < dev->nregions; i++) {
358         VubrDevRegion *r = &dev->regions[i];
359 
360         if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
361             return qemu_addr - r->qva + r->mmap_addr + r->mmap_offset;
362         }
363     }
364 
365     assert(!"address not found in regions");
366     return 0;
367 }
368 
369 static void
370 vubr_message_read(int conn_fd, VhostUserMsg *vmsg)
371 {
372     char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = { };
373     struct iovec iov = {
374         .iov_base = (char *)vmsg,
375         .iov_len = VHOST_USER_HDR_SIZE,
376     };
377     struct msghdr msg = {
378         .msg_iov = &iov,
379         .msg_iovlen = 1,
380         .msg_control = control,
381         .msg_controllen = sizeof(control),
382     };
383     size_t fd_size;
384     struct cmsghdr *cmsg;
385     int rc;
386 
387     rc = recvmsg(conn_fd, &msg, 0);
388 
389     if (rc == 0) {
390         vubr_die("recvmsg");
391         fprintf(stderr, "Peer disconnected.\n");
392         exit(1);
393     }
394     if (rc < 0) {
395         vubr_die("recvmsg");
396     }
397 
398     vmsg->fd_num = 0;
399     for (cmsg = CMSG_FIRSTHDR(&msg);
400          cmsg != NULL;
401          cmsg = CMSG_NXTHDR(&msg, cmsg))
402     {
403         if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
404             fd_size = cmsg->cmsg_len - CMSG_LEN(0);
405             vmsg->fd_num = fd_size / sizeof(int);
406             memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
407             break;
408         }
409     }
410 
411     if (vmsg->size > sizeof(vmsg->payload)) {
412         fprintf(stderr,
413                 "Error: too big message request: %d, size: vmsg->size: %u, "
414                 "while sizeof(vmsg->payload) = %zu\n",
415                 vmsg->request, vmsg->size, sizeof(vmsg->payload));
416         exit(1);
417     }
418 
419     if (vmsg->size) {
420         rc = read(conn_fd, &vmsg->payload, vmsg->size);
421         if (rc == 0) {
422             vubr_die("recvmsg");
423             fprintf(stderr, "Peer disconnected.\n");
424             exit(1);
425         }
426         if (rc < 0) {
427             vubr_die("recvmsg");
428         }
429 
430         assert(rc == vmsg->size);
431     }
432 }
433 
434 static void
435 vubr_message_write(int conn_fd, VhostUserMsg *vmsg)
436 {
437     int rc;
438 
439     do {
440         rc = write(conn_fd, vmsg, VHOST_USER_HDR_SIZE + vmsg->size);
441     } while (rc < 0 && errno == EINTR);
442 
443     if (rc < 0) {
444         vubr_die("write");
445     }
446 }
447 
448 static void
449 vubr_backend_udp_sendbuf(VubrDev *dev, uint8_t *buf, size_t len)
450 {
451     int slen = sizeof(struct sockaddr_in);
452 
453     if (sendto(dev->backend_udp_sock, buf, len, 0,
454                (struct sockaddr *) &dev->backend_udp_dest, slen) == -1) {
455         vubr_die("sendto()");
456     }
457 }
458 
459 static int
460 vubr_backend_udp_recvbuf(VubrDev *dev, uint8_t *buf, size_t buflen)
461 {
462     int slen = sizeof(struct sockaddr_in);
463     int rc;
464 
465     rc = recvfrom(dev->backend_udp_sock, buf, buflen, 0,
466                   (struct sockaddr *) &dev->backend_udp_dest,
467                   (socklen_t *)&slen);
468     if (rc == -1) {
469         vubr_die("recvfrom()");
470     }
471 
472     return rc;
473 }
474 
475 static void
476 vubr_consume_raw_packet(VubrDev *dev, uint8_t *buf, uint32_t len)
477 {
478     int hdrlen = dev->hdrlen;
479     DPRINT("    hdrlen = %d\n", dev->hdrlen);
480 
481     if (VHOST_USER_BRIDGE_DEBUG) {
482         print_buffer(buf, len);
483     }
484     vubr_backend_udp_sendbuf(dev, buf + hdrlen, len - hdrlen);
485 }
486 
487 /* Kick the log_call_fd if required. */
488 static void
489 vubr_log_kick(VubrDev *dev)
490 {
491     if (dev->log_call_fd != -1) {
492         DPRINT("Kicking the QEMU's log...\n");
493         eventfd_write(dev->log_call_fd, 1);
494     }
495 }
496 
497 /* Kick the guest if necessary. */
498 static void
499 vubr_virtqueue_kick(VubrVirtq *vq)
500 {
501     if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
502         DPRINT("Kicking the guest...\n");
503         eventfd_write(vq->call_fd, 1);
504     }
505 }
506 
507 static void
508 vubr_log_page(uint8_t *log_table, uint64_t page)
509 {
510     DPRINT("Logged dirty guest page: %"PRId64"\n", page);
511     atomic_or(&log_table[page / 8], 1 << (page % 8));
512 }
513 
514 static void
515 vubr_log_write(VubrDev *dev, uint64_t address, uint64_t length)
516 {
517     uint64_t page;
518 
519     if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) ||
520         !dev->log_table || !length) {
521         return;
522     }
523 
524     assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8));
525 
526     page = address / VHOST_LOG_PAGE;
527     while (page * VHOST_LOG_PAGE < address + length) {
528         vubr_log_page(dev->log_table, page);
529         page += VHOST_LOG_PAGE;
530     }
531     vubr_log_kick(dev);
532 }
533 
534 static void
535 vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t *buf, int32_t len)
536 {
537     struct vring_desc *desc = vq->desc;
538     struct vring_avail *avail = vq->avail;
539     struct vring_used *used = vq->used;
540     uint64_t log_guest_addr = vq->log_guest_addr;
541     int32_t remaining_len = len;
542 
543     unsigned int size = vq->size;
544 
545     uint16_t avail_index = atomic_mb_read(&avail->idx);
546 
547     /* We check the available descriptors before posting the
548      * buffer, so here we assume that enough available
549      * descriptors. */
550     assert(vq->last_avail_index != avail_index);
551     uint16_t a_index = vq->last_avail_index % size;
552     uint16_t u_index = vq->last_used_index % size;
553     uint16_t d_index = avail->ring[a_index];
554 
555     int i = d_index;
556     uint32_t written_len = 0;
557 
558     do {
559         DPRINT("Post packet to guest on vq:\n");
560         DPRINT("    size             = %d\n", vq->size);
561         DPRINT("    last_avail_index = %d\n", vq->last_avail_index);
562         DPRINT("    last_used_index  = %d\n", vq->last_used_index);
563         DPRINT("    a_index = %d\n", a_index);
564         DPRINT("    u_index = %d\n", u_index);
565         DPRINT("    d_index = %d\n", d_index);
566         DPRINT("    desc[%d].addr    = 0x%016"PRIx64"\n", i, desc[i].addr);
567         DPRINT("    desc[%d].len     = %d\n", i, desc[i].len);
568         DPRINT("    desc[%d].flags   = %d\n", i, desc[i].flags);
569         DPRINT("    avail->idx = %d\n", avail_index);
570         DPRINT("    used->idx  = %d\n", used->idx);
571 
572         if (!(desc[i].flags & VRING_DESC_F_WRITE)) {
573             /* FIXME: we should find writable descriptor. */
574             fprintf(stderr, "Error: descriptor is not writable. Exiting.\n");
575             exit(1);
576         }
577 
578         void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
579         uint32_t chunk_len = desc[i].len;
580         uint32_t chunk_write_len = MIN(remaining_len, chunk_len);
581 
582         memcpy(chunk_start, buf + written_len, chunk_write_len);
583         vubr_log_write(dev, desc[i].addr, chunk_write_len);
584         remaining_len -= chunk_write_len;
585         written_len += chunk_write_len;
586 
587         if ((remaining_len == 0) || !(desc[i].flags & VRING_DESC_F_NEXT)) {
588             break;
589         }
590 
591         i = desc[i].next;
592     } while (1);
593 
594     if (remaining_len > 0) {
595             fprintf(stderr,
596                     "Too long packet for RX, remaining_len = %d, Dropping...\n",
597                     remaining_len);
598             return;
599     }
600 
601     /* Add descriptor to the used ring. */
602     used->ring[u_index].id = d_index;
603     used->ring[u_index].len = len;
604     vubr_log_write(dev,
605                    log_guest_addr + offsetof(struct vring_used, ring[u_index]),
606                    sizeof(used->ring[u_index]));
607 
608     vq->last_avail_index++;
609     vq->last_used_index++;
610 
611     atomic_mb_set(&used->idx, vq->last_used_index);
612     vubr_log_write(dev,
613                    log_guest_addr + offsetof(struct vring_used, idx),
614                    sizeof(used->idx));
615 
616     /* Kick the guest if necessary. */
617     vubr_virtqueue_kick(vq);
618 }
619 
620 static int
621 vubr_process_desc(VubrDev *dev, VubrVirtq *vq)
622 {
623     struct vring_desc *desc = vq->desc;
624     struct vring_avail *avail = vq->avail;
625     struct vring_used *used = vq->used;
626     uint64_t log_guest_addr = vq->log_guest_addr;
627 
628     unsigned int size = vq->size;
629 
630     uint16_t a_index = vq->last_avail_index % size;
631     uint16_t u_index = vq->last_used_index % size;
632     uint16_t d_index = avail->ring[a_index];
633 
634     uint32_t i, len = 0;
635     size_t buf_size = 4096;
636     uint8_t buf[4096];
637 
638     DPRINT("Chunks: ");
639     i = d_index;
640     do {
641         void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
642         uint32_t chunk_len = desc[i].len;
643 
644         assert(!(desc[i].flags & VRING_DESC_F_WRITE));
645 
646         if (len + chunk_len < buf_size) {
647             memcpy(buf + len, chunk_start, chunk_len);
648             DPRINT("%d ", chunk_len);
649         } else {
650             fprintf(stderr, "Error: too long packet. Dropping...\n");
651             break;
652         }
653 
654         len += chunk_len;
655 
656         if (!(desc[i].flags & VRING_DESC_F_NEXT)) {
657             break;
658         }
659 
660         i = desc[i].next;
661     } while (1);
662     DPRINT("\n");
663 
664     if (!len) {
665         return -1;
666     }
667 
668     /* Add descriptor to the used ring. */
669     used->ring[u_index].id = d_index;
670     used->ring[u_index].len = len;
671     vubr_log_write(dev,
672                    log_guest_addr + offsetof(struct vring_used, ring[u_index]),
673                    sizeof(used->ring[u_index]));
674 
675     vubr_consume_raw_packet(dev, buf, len);
676 
677     return 0;
678 }
679 
680 static void
681 vubr_process_avail(VubrDev *dev, VubrVirtq *vq)
682 {
683     struct vring_avail *avail = vq->avail;
684     struct vring_used *used = vq->used;
685     uint64_t log_guest_addr = vq->log_guest_addr;
686 
687     while (vq->last_avail_index != atomic_mb_read(&avail->idx)) {
688         vubr_process_desc(dev, vq);
689         vq->last_avail_index++;
690         vq->last_used_index++;
691     }
692 
693     atomic_mb_set(&used->idx, vq->last_used_index);
694     vubr_log_write(dev,
695                    log_guest_addr + offsetof(struct vring_used, idx),
696                    sizeof(used->idx));
697 }
698 
699 static void
700 vubr_backend_recv_cb(int sock, void *ctx)
701 {
702     VubrDev *dev = (VubrDev *) ctx;
703     VubrVirtq *rx_vq = &dev->vq[0];
704     uint8_t buf[4096];
705     struct virtio_net_hdr_v1 *hdr = (struct virtio_net_hdr_v1 *)buf;
706     int hdrlen = dev->hdrlen;
707     int buflen = sizeof(buf);
708     int len;
709 
710     if (!dev->ready) {
711         return;
712     }
713 
714     DPRINT("\n\n   ***   IN UDP RECEIVE CALLBACK    ***\n\n");
715     DPRINT("    hdrlen = %d\n", hdrlen);
716 
717     uint16_t avail_index = atomic_mb_read(&rx_vq->avail->idx);
718 
719     /* If there is no available descriptors, just do nothing.
720      * The buffer will be handled by next arrived UDP packet,
721      * or next kick on receive virtq. */
722     if (rx_vq->last_avail_index == avail_index) {
723         DPRINT("Got UDP packet, but no available descriptors on RX virtq.\n");
724         return;
725     }
726 
727     memset(buf, 0, hdrlen);
728     /* TODO: support mergeable buffers. */
729     if (hdrlen == 12)
730         hdr->num_buffers = 1;
731     len = vubr_backend_udp_recvbuf(dev, buf + hdrlen, buflen - hdrlen);
732 
733     vubr_post_buffer(dev, rx_vq, buf, len + hdrlen);
734 }
735 
736 static void
737 vubr_kick_cb(int sock, void *ctx)
738 {
739     VubrDev *dev = (VubrDev *) ctx;
740     eventfd_t kick_data;
741     ssize_t rc;
742 
743     rc = eventfd_read(sock, &kick_data);
744     if (rc == -1) {
745         vubr_die("eventfd_read()");
746     } else {
747         DPRINT("Got kick_data: %016"PRIx64"\n", kick_data);
748         vubr_process_avail(dev, &dev->vq[1]);
749     }
750 }
751 
752 static int
753 vubr_none_exec(VubrDev *dev, VhostUserMsg *vmsg)
754 {
755     DPRINT("Function %s() not implemented yet.\n", __func__);
756     return 0;
757 }
758 
759 static int
760 vubr_get_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
761 {
762     vmsg->payload.u64 =
763             ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
764              (1ULL << VHOST_F_LOG_ALL) |
765              (1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE) |
766              (1ULL << VHOST_USER_F_PROTOCOL_FEATURES));
767 
768     vmsg->size = sizeof(vmsg->payload.u64);
769 
770     DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
771 
772     /* Reply */
773     return 1;
774 }
775 
776 static int
777 vubr_set_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
778 {
779     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
780 
781     dev->features = vmsg->payload.u64;
782     if ((dev->features & (1ULL << VIRTIO_F_VERSION_1)) ||
783         (dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF))) {
784         dev->hdrlen = 12;
785     } else {
786         dev->hdrlen = 10;
787     }
788 
789     return 0;
790 }
791 
792 static int
793 vubr_set_owner_exec(VubrDev *dev, VhostUserMsg *vmsg)
794 {
795     return 0;
796 }
797 
798 static void
799 vubr_close_log(VubrDev *dev)
800 {
801     if (dev->log_table) {
802         if (munmap(dev->log_table, dev->log_size) != 0) {
803             vubr_die("munmap()");
804         }
805 
806         dev->log_table = 0;
807     }
808     if (dev->log_call_fd != -1) {
809         close(dev->log_call_fd);
810         dev->log_call_fd = -1;
811     }
812 }
813 
814 static int
815 vubr_reset_device_exec(VubrDev *dev, VhostUserMsg *vmsg)
816 {
817     vubr_close_log(dev);
818     dev->ready = 0;
819     dev->features = 0;
820     return 0;
821 }
822 
823 static int
824 vubr_set_mem_table_exec(VubrDev *dev, VhostUserMsg *vmsg)
825 {
826     int i;
827     VhostUserMemory *memory = &vmsg->payload.memory;
828     dev->nregions = memory->nregions;
829 
830     DPRINT("Nregions: %d\n", memory->nregions);
831     for (i = 0; i < dev->nregions; i++) {
832         void *mmap_addr;
833         VhostUserMemoryRegion *msg_region = &memory->regions[i];
834         VubrDevRegion *dev_region = &dev->regions[i];
835 
836         DPRINT("Region %d\n", i);
837         DPRINT("    guest_phys_addr: 0x%016"PRIx64"\n",
838                msg_region->guest_phys_addr);
839         DPRINT("    memory_size:     0x%016"PRIx64"\n",
840                msg_region->memory_size);
841         DPRINT("    userspace_addr   0x%016"PRIx64"\n",
842                msg_region->userspace_addr);
843         DPRINT("    mmap_offset      0x%016"PRIx64"\n",
844                msg_region->mmap_offset);
845 
846         dev_region->gpa = msg_region->guest_phys_addr;
847         dev_region->size = msg_region->memory_size;
848         dev_region->qva = msg_region->userspace_addr;
849         dev_region->mmap_offset = msg_region->mmap_offset;
850 
851         /* We don't use offset argument of mmap() since the
852          * mapped address has to be page aligned, and we use huge
853          * pages.  */
854         mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
855                          PROT_READ | PROT_WRITE, MAP_SHARED,
856                          vmsg->fds[i], 0);
857 
858         if (mmap_addr == MAP_FAILED) {
859             vubr_die("mmap");
860         }
861         dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
862         DPRINT("    mmap_addr:       0x%016"PRIx64"\n", dev_region->mmap_addr);
863 
864         close(vmsg->fds[i]);
865     }
866 
867     return 0;
868 }
869 
870 static int
871 vubr_set_log_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
872 {
873     int fd;
874     uint64_t log_mmap_size, log_mmap_offset;
875     void *rc;
876 
877     assert(vmsg->fd_num == 1);
878     fd = vmsg->fds[0];
879 
880     assert(vmsg->size == sizeof(vmsg->payload.log));
881     log_mmap_offset = vmsg->payload.log.mmap_offset;
882     log_mmap_size = vmsg->payload.log.mmap_size;
883     DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset);
884     DPRINT("Log mmap_size:   %"PRId64"\n", log_mmap_size);
885 
886     rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
887               log_mmap_offset);
888     if (rc == MAP_FAILED) {
889         vubr_die("mmap");
890     }
891     dev->log_table = rc;
892     dev->log_size = log_mmap_size;
893 
894     vmsg->size = sizeof(vmsg->payload.u64);
895     /* Reply */
896     return 1;
897 }
898 
899 static int
900 vubr_set_log_fd_exec(VubrDev *dev, VhostUserMsg *vmsg)
901 {
902     assert(vmsg->fd_num == 1);
903     dev->log_call_fd = vmsg->fds[0];
904     DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]);
905     return 0;
906 }
907 
908 static int
909 vubr_set_vring_num_exec(VubrDev *dev, VhostUserMsg *vmsg)
910 {
911     unsigned int index = vmsg->payload.state.index;
912     unsigned int num = vmsg->payload.state.num;
913 
914     DPRINT("State.index: %d\n", index);
915     DPRINT("State.num:   %d\n", num);
916     dev->vq[index].size = num;
917     return 0;
918 }
919 
920 static int
921 vubr_set_vring_addr_exec(VubrDev *dev, VhostUserMsg *vmsg)
922 {
923     struct vhost_vring_addr *vra = &vmsg->payload.addr;
924     unsigned int index = vra->index;
925     VubrVirtq *vq = &dev->vq[index];
926 
927     DPRINT("vhost_vring_addr:\n");
928     DPRINT("    index:  %d\n", vra->index);
929     DPRINT("    flags:  %d\n", vra->flags);
930     DPRINT("    desc_user_addr:   0x%016llx\n", vra->desc_user_addr);
931     DPRINT("    used_user_addr:   0x%016llx\n", vra->used_user_addr);
932     DPRINT("    avail_user_addr:  0x%016llx\n", vra->avail_user_addr);
933     DPRINT("    log_guest_addr:   0x%016llx\n", vra->log_guest_addr);
934 
935     vq->desc = (struct vring_desc *)(uintptr_t)qva_to_va(dev, vra->desc_user_addr);
936     vq->used = (struct vring_used *)(uintptr_t)qva_to_va(dev, vra->used_user_addr);
937     vq->avail = (struct vring_avail *)(uintptr_t)qva_to_va(dev, vra->avail_user_addr);
938     vq->log_guest_addr = vra->log_guest_addr;
939 
940     DPRINT("Setting virtq addresses:\n");
941     DPRINT("    vring_desc  at %p\n", vq->desc);
942     DPRINT("    vring_used  at %p\n", vq->used);
943     DPRINT("    vring_avail at %p\n", vq->avail);
944 
945     vq->last_used_index = vq->used->idx;
946 
947     if (vq->last_avail_index != vq->used->idx) {
948         DPRINT("Last avail index != used index: %d != %d, resuming",
949                vq->last_avail_index, vq->used->idx);
950         vq->last_avail_index = vq->used->idx;
951     }
952 
953     return 0;
954 }
955 
956 static int
957 vubr_set_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
958 {
959     unsigned int index = vmsg->payload.state.index;
960     unsigned int num = vmsg->payload.state.num;
961 
962     DPRINT("State.index: %d\n", index);
963     DPRINT("State.num:   %d\n", num);
964     dev->vq[index].last_avail_index = num;
965 
966     return 0;
967 }
968 
969 static int
970 vubr_get_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
971 {
972     unsigned int index = vmsg->payload.state.index;
973 
974     DPRINT("State.index: %d\n", index);
975     vmsg->payload.state.num = dev->vq[index].last_avail_index;
976     vmsg->size = sizeof(vmsg->payload.state);
977     /* FIXME: this is a work-around for a bug in QEMU enabling
978      * too early vrings. When protocol features are enabled,
979      * we have to respect * VHOST_USER_SET_VRING_ENABLE request. */
980     dev->ready = 0;
981 
982     if (dev->vq[index].call_fd != -1) {
983         close(dev->vq[index].call_fd);
984         dispatcher_remove(&dev->dispatcher, dev->vq[index].call_fd);
985         dev->vq[index].call_fd = -1;
986     }
987     if (dev->vq[index].kick_fd != -1) {
988         close(dev->vq[index].kick_fd);
989         dispatcher_remove(&dev->dispatcher, dev->vq[index].kick_fd);
990         dev->vq[index].kick_fd = -1;
991     }
992 
993     /* Reply */
994     return 1;
995 }
996 
997 static int
998 vubr_set_vring_kick_exec(VubrDev *dev, VhostUserMsg *vmsg)
999 {
1000     uint64_t u64_arg = vmsg->payload.u64;
1001     int index = u64_arg & VHOST_USER_VRING_IDX_MASK;
1002 
1003     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1004 
1005     assert((u64_arg & VHOST_USER_VRING_NOFD_MASK) == 0);
1006     assert(vmsg->fd_num == 1);
1007 
1008     if (dev->vq[index].kick_fd != -1) {
1009         close(dev->vq[index].kick_fd);
1010         dispatcher_remove(&dev->dispatcher, dev->vq[index].kick_fd);
1011     }
1012     dev->vq[index].kick_fd = vmsg->fds[0];
1013     DPRINT("Got kick_fd: %d for vq: %d\n", vmsg->fds[0], index);
1014 
1015     if (index % 2 == 1) {
1016         /* TX queue. */
1017         dispatcher_add(&dev->dispatcher, dev->vq[index].kick_fd,
1018                        dev, vubr_kick_cb);
1019 
1020         DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
1021                dev->vq[index].kick_fd, index);
1022     }
1023     /* We temporarily use this hack to determine that both TX and RX
1024      * queues are set up and ready for processing.
1025      * FIXME: we need to rely in VHOST_USER_SET_VRING_ENABLE and
1026      * actual kicks. */
1027     if (dev->vq[0].kick_fd != -1 &&
1028         dev->vq[1].kick_fd != -1) {
1029         dev->ready = 1;
1030         DPRINT("vhost-user-bridge is ready for processing queues.\n");
1031     }
1032     return 0;
1033 
1034 }
1035 
1036 static int
1037 vubr_set_vring_call_exec(VubrDev *dev, VhostUserMsg *vmsg)
1038 {
1039     uint64_t u64_arg = vmsg->payload.u64;
1040     int index = u64_arg & VHOST_USER_VRING_IDX_MASK;
1041 
1042     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1043     assert((u64_arg & VHOST_USER_VRING_NOFD_MASK) == 0);
1044     assert(vmsg->fd_num == 1);
1045 
1046     if (dev->vq[index].call_fd != -1) {
1047         close(dev->vq[index].call_fd);
1048         dispatcher_remove(&dev->dispatcher, dev->vq[index].call_fd);
1049     }
1050     dev->vq[index].call_fd = vmsg->fds[0];
1051     DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
1052 
1053     return 0;
1054 }
1055 
1056 static int
1057 vubr_set_vring_err_exec(VubrDev *dev, VhostUserMsg *vmsg)
1058 {
1059     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1060     return 0;
1061 }
1062 
1063 static int
1064 vubr_get_protocol_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
1065 {
1066     vmsg->payload.u64 = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD;
1067     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1068     vmsg->size = sizeof(vmsg->payload.u64);
1069 
1070     /* Reply */
1071     return 1;
1072 }
1073 
1074 static int
1075 vubr_set_protocol_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
1076 {
1077     /* FIXME: unimplented */
1078     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1079     return 0;
1080 }
1081 
1082 static int
1083 vubr_get_queue_num_exec(VubrDev *dev, VhostUserMsg *vmsg)
1084 {
1085     DPRINT("Function %s() not implemented yet.\n", __func__);
1086     return 0;
1087 }
1088 
1089 static int
1090 vubr_set_vring_enable_exec(VubrDev *dev, VhostUserMsg *vmsg)
1091 {
1092     unsigned int index = vmsg->payload.state.index;
1093     unsigned int enable = vmsg->payload.state.num;
1094 
1095     DPRINT("State.index: %d\n", index);
1096     DPRINT("State.enable:   %d\n", enable);
1097     dev->vq[index].enable = enable;
1098     return 0;
1099 }
1100 
1101 static int
1102 vubr_send_rarp_exec(VubrDev *dev, VhostUserMsg *vmsg)
1103 {
1104     DPRINT("Function %s() not implemented yet.\n", __func__);
1105     return 0;
1106 }
1107 
1108 static int
1109 vubr_execute_request(VubrDev *dev, VhostUserMsg *vmsg)
1110 {
1111     /* Print out generic part of the request. */
1112     DPRINT(
1113            "==================   Vhost user message from QEMU   ==================\n");
1114     DPRINT("Request: %s (%d)\n", vubr_request_str[vmsg->request],
1115            vmsg->request);
1116     DPRINT("Flags:   0x%x\n", vmsg->flags);
1117     DPRINT("Size:    %d\n", vmsg->size);
1118 
1119     if (vmsg->fd_num) {
1120         int i;
1121         DPRINT("Fds:");
1122         for (i = 0; i < vmsg->fd_num; i++) {
1123             DPRINT(" %d", vmsg->fds[i]);
1124         }
1125         DPRINT("\n");
1126     }
1127 
1128     switch (vmsg->request) {
1129     case VHOST_USER_NONE:
1130         return vubr_none_exec(dev, vmsg);
1131     case VHOST_USER_GET_FEATURES:
1132         return vubr_get_features_exec(dev, vmsg);
1133     case VHOST_USER_SET_FEATURES:
1134         return vubr_set_features_exec(dev, vmsg);
1135     case VHOST_USER_SET_OWNER:
1136         return vubr_set_owner_exec(dev, vmsg);
1137     case VHOST_USER_RESET_OWNER:
1138         return vubr_reset_device_exec(dev, vmsg);
1139     case VHOST_USER_SET_MEM_TABLE:
1140         return vubr_set_mem_table_exec(dev, vmsg);
1141     case VHOST_USER_SET_LOG_BASE:
1142         return vubr_set_log_base_exec(dev, vmsg);
1143     case VHOST_USER_SET_LOG_FD:
1144         return vubr_set_log_fd_exec(dev, vmsg);
1145     case VHOST_USER_SET_VRING_NUM:
1146         return vubr_set_vring_num_exec(dev, vmsg);
1147     case VHOST_USER_SET_VRING_ADDR:
1148         return vubr_set_vring_addr_exec(dev, vmsg);
1149     case VHOST_USER_SET_VRING_BASE:
1150         return vubr_set_vring_base_exec(dev, vmsg);
1151     case VHOST_USER_GET_VRING_BASE:
1152         return vubr_get_vring_base_exec(dev, vmsg);
1153     case VHOST_USER_SET_VRING_KICK:
1154         return vubr_set_vring_kick_exec(dev, vmsg);
1155     case VHOST_USER_SET_VRING_CALL:
1156         return vubr_set_vring_call_exec(dev, vmsg);
1157     case VHOST_USER_SET_VRING_ERR:
1158         return vubr_set_vring_err_exec(dev, vmsg);
1159     case VHOST_USER_GET_PROTOCOL_FEATURES:
1160         return vubr_get_protocol_features_exec(dev, vmsg);
1161     case VHOST_USER_SET_PROTOCOL_FEATURES:
1162         return vubr_set_protocol_features_exec(dev, vmsg);
1163     case VHOST_USER_GET_QUEUE_NUM:
1164         return vubr_get_queue_num_exec(dev, vmsg);
1165     case VHOST_USER_SET_VRING_ENABLE:
1166         return vubr_set_vring_enable_exec(dev, vmsg);
1167     case VHOST_USER_SEND_RARP:
1168         return vubr_send_rarp_exec(dev, vmsg);
1169 
1170     case VHOST_USER_MAX:
1171         assert(vmsg->request != VHOST_USER_MAX);
1172     }
1173     return 0;
1174 }
1175 
1176 static void
1177 vubr_receive_cb(int sock, void *ctx)
1178 {
1179     VubrDev *dev = (VubrDev *) ctx;
1180     VhostUserMsg vmsg;
1181     int reply_requested;
1182 
1183     vubr_message_read(sock, &vmsg);
1184     reply_requested = vubr_execute_request(dev, &vmsg);
1185     if (reply_requested) {
1186         /* Set the version in the flags when sending the reply */
1187         vmsg.flags &= ~VHOST_USER_VERSION_MASK;
1188         vmsg.flags |= VHOST_USER_VERSION;
1189         vmsg.flags |= VHOST_USER_REPLY_MASK;
1190         vubr_message_write(sock, &vmsg);
1191     }
1192 }
1193 
1194 static void
1195 vubr_accept_cb(int sock, void *ctx)
1196 {
1197     VubrDev *dev = (VubrDev *)ctx;
1198     int conn_fd;
1199     struct sockaddr_un un;
1200     socklen_t len = sizeof(un);
1201 
1202     conn_fd = accept(sock, (struct sockaddr *) &un, &len);
1203     if (conn_fd == -1) {
1204         vubr_die("accept()");
1205     }
1206     DPRINT("Got connection from remote peer on sock %d\n", conn_fd);
1207     dispatcher_add(&dev->dispatcher, conn_fd, ctx, vubr_receive_cb);
1208 }
1209 
1210 static VubrDev *
1211 vubr_new(const char *path, bool client)
1212 {
1213     VubrDev *dev = (VubrDev *) calloc(1, sizeof(VubrDev));
1214     dev->nregions = 0;
1215     int i;
1216     struct sockaddr_un un;
1217     CallbackFunc cb;
1218     size_t len;
1219 
1220     for (i = 0; i < MAX_NR_VIRTQUEUE; i++) {
1221         dev->vq[i] = (VubrVirtq) {
1222             .call_fd = -1, .kick_fd = -1,
1223             .size = 0,
1224             .last_avail_index = 0, .last_used_index = 0,
1225             .desc = 0, .avail = 0, .used = 0,
1226             .enable = 0,
1227         };
1228     }
1229 
1230     /* Init log */
1231     dev->log_call_fd = -1;
1232     dev->log_size = 0;
1233     dev->log_table = 0;
1234     dev->ready = 0;
1235     dev->features = 0;
1236 
1237     /* Get a UNIX socket. */
1238     dev->sock = socket(AF_UNIX, SOCK_STREAM, 0);
1239     if (dev->sock == -1) {
1240         vubr_die("socket");
1241     }
1242 
1243     un.sun_family = AF_UNIX;
1244     strcpy(un.sun_path, path);
1245     len = sizeof(un.sun_family) + strlen(path);
1246 
1247     if (!client) {
1248         unlink(path);
1249 
1250         if (bind(dev->sock, (struct sockaddr *) &un, len) == -1) {
1251             vubr_die("bind");
1252         }
1253 
1254         if (listen(dev->sock, 1) == -1) {
1255             vubr_die("listen");
1256         }
1257         cb = vubr_accept_cb;
1258 
1259         DPRINT("Waiting for connections on UNIX socket %s ...\n", path);
1260     } else {
1261         if (connect(dev->sock, (struct sockaddr *)&un, len) == -1) {
1262             vubr_die("connect");
1263         }
1264         cb = vubr_receive_cb;
1265     }
1266 
1267     dispatcher_init(&dev->dispatcher);
1268     dispatcher_add(&dev->dispatcher, dev->sock, (void *)dev, cb);
1269 
1270     return dev;
1271 }
1272 
1273 static void
1274 vubr_set_host(struct sockaddr_in *saddr, const char *host)
1275 {
1276     if (isdigit(host[0])) {
1277         if (!inet_aton(host, &saddr->sin_addr)) {
1278             fprintf(stderr, "inet_aton() failed.\n");
1279             exit(1);
1280         }
1281     } else {
1282         struct hostent *he = gethostbyname(host);
1283 
1284         if (!he) {
1285             fprintf(stderr, "gethostbyname() failed.\n");
1286             exit(1);
1287         }
1288         saddr->sin_addr = *(struct in_addr *)he->h_addr;
1289     }
1290 }
1291 
1292 static void
1293 vubr_backend_udp_setup(VubrDev *dev,
1294                        const char *local_host,
1295                        const char *local_port,
1296                        const char *remote_host,
1297                        const char *remote_port)
1298 {
1299     int sock;
1300     const char *r;
1301 
1302     int lport, rport;
1303 
1304     lport = strtol(local_port, (char **)&r, 0);
1305     if (r == local_port) {
1306         fprintf(stderr, "lport parsing failed.\n");
1307         exit(1);
1308     }
1309 
1310     rport = strtol(remote_port, (char **)&r, 0);
1311     if (r == remote_port) {
1312         fprintf(stderr, "rport parsing failed.\n");
1313         exit(1);
1314     }
1315 
1316     struct sockaddr_in si_local = {
1317         .sin_family = AF_INET,
1318         .sin_port = htons(lport),
1319     };
1320 
1321     vubr_set_host(&si_local, local_host);
1322 
1323     /* setup destination for sends */
1324     dev->backend_udp_dest = (struct sockaddr_in) {
1325         .sin_family = AF_INET,
1326         .sin_port = htons(rport),
1327     };
1328     vubr_set_host(&dev->backend_udp_dest, remote_host);
1329 
1330     sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1331     if (sock == -1) {
1332         vubr_die("socket");
1333     }
1334 
1335     if (bind(sock, (struct sockaddr *)&si_local, sizeof(si_local)) == -1) {
1336         vubr_die("bind");
1337     }
1338 
1339     dev->backend_udp_sock = sock;
1340     dispatcher_add(&dev->dispatcher, sock, dev, vubr_backend_recv_cb);
1341     DPRINT("Waiting for data from udp backend on %s:%d...\n",
1342            local_host, lport);
1343 }
1344 
1345 static void
1346 vubr_run(VubrDev *dev)
1347 {
1348     while (1) {
1349         /* timeout 200ms */
1350         dispatcher_wait(&dev->dispatcher, 200000);
1351         /* Here one can try polling strategy. */
1352     }
1353 }
1354 
1355 static int
1356 vubr_parse_host_port(const char **host, const char **port, const char *buf)
1357 {
1358     char *p = strchr(buf, ':');
1359 
1360     if (!p) {
1361         return -1;
1362     }
1363     *p = '\0';
1364     *host = strdup(buf);
1365     *port = strdup(p + 1);
1366     return 0;
1367 }
1368 
1369 #define DEFAULT_UD_SOCKET "/tmp/vubr.sock"
1370 #define DEFAULT_LHOST "127.0.0.1"
1371 #define DEFAULT_LPORT "4444"
1372 #define DEFAULT_RHOST "127.0.0.1"
1373 #define DEFAULT_RPORT "5555"
1374 
1375 static const char *ud_socket_path = DEFAULT_UD_SOCKET;
1376 static const char *lhost = DEFAULT_LHOST;
1377 static const char *lport = DEFAULT_LPORT;
1378 static const char *rhost = DEFAULT_RHOST;
1379 static const char *rport = DEFAULT_RPORT;
1380 
1381 int
1382 main(int argc, char *argv[])
1383 {
1384     VubrDev *dev;
1385     int opt;
1386     bool client = false;
1387 
1388     while ((opt = getopt(argc, argv, "l:r:u:c")) != -1) {
1389 
1390         switch (opt) {
1391         case 'l':
1392             if (vubr_parse_host_port(&lhost, &lport, optarg) < 0) {
1393                 goto out;
1394             }
1395             break;
1396         case 'r':
1397             if (vubr_parse_host_port(&rhost, &rport, optarg) < 0) {
1398                 goto out;
1399             }
1400             break;
1401         case 'u':
1402             ud_socket_path = strdup(optarg);
1403             break;
1404         case 'c':
1405             client = true;
1406             break;
1407         default:
1408             goto out;
1409         }
1410     }
1411 
1412     DPRINT("ud socket: %s (%s)\n", ud_socket_path,
1413            client ? "client" : "server");
1414     DPRINT("local:     %s:%s\n", lhost, lport);
1415     DPRINT("remote:    %s:%s\n", rhost, rport);
1416 
1417     dev = vubr_new(ud_socket_path, client);
1418     if (!dev) {
1419         return 1;
1420     }
1421 
1422     vubr_backend_udp_setup(dev, lhost, lport, rhost, rport);
1423     vubr_run(dev);
1424     return 0;
1425 
1426 out:
1427     fprintf(stderr, "Usage: %s ", argv[0]);
1428     fprintf(stderr, "[-c] [-u ud_socket_path] [-l lhost:lport] [-r rhost:rport]\n");
1429     fprintf(stderr, "\t-u path to unix doman socket. default: %s\n",
1430             DEFAULT_UD_SOCKET);
1431     fprintf(stderr, "\t-l local host and port. default: %s:%s\n",
1432             DEFAULT_LHOST, DEFAULT_LPORT);
1433     fprintf(stderr, "\t-r remote host and port. default: %s:%s\n",
1434             DEFAULT_RHOST, DEFAULT_RPORT);
1435     fprintf(stderr, "\t-c client mode\n");
1436 
1437     return 1;
1438 }
1439