xref: /qemu/tests/vhost-user-bridge.c (revision 98206d4e6b719f650b0f2d23bcd4bab83c624341)
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 static int
105 dispatcher_remove(Dispatcher *dispr, int sock)
106 {
107     if (sock >= FD_SETSIZE) {
108         fprintf(stderr,
109                 "Error: Failed to remove event. sock %d should be less than %d\n",
110                 sock, FD_SETSIZE);
111         return -1;
112     }
113 
114     FD_CLR(sock, &dispr->fdset);
115     DPRINT("Sock %d removed from dispatcher watch.\n", sock);
116     return 0;
117 }
118 
119 /* timeout in us */
120 static int
121 dispatcher_wait(Dispatcher *dispr, uint32_t timeout)
122 {
123     struct timeval tv;
124     tv.tv_sec = timeout / 1000000;
125     tv.tv_usec = timeout % 1000000;
126 
127     fd_set fdset = dispr->fdset;
128 
129     /* wait until some of sockets become readable. */
130     int rc = select(dispr->max_sock + 1, &fdset, 0, 0, &tv);
131 
132     if (rc == -1) {
133         vubr_die("select");
134     }
135 
136     /* Timeout */
137     if (rc == 0) {
138         return 0;
139     }
140 
141     /* Now call callback for every ready socket. */
142 
143     int sock;
144     for (sock = 0; sock < dispr->max_sock + 1; sock++) {
145         /* The callback on a socket can remove other sockets from the
146          * dispatcher, thus we have to check that the socket is
147          * still not removed from dispatcher's list
148          */
149         if (FD_ISSET(sock, &fdset) && FD_ISSET(sock, &dispr->fdset)) {
150             Event *e = &dispr->events[sock];
151             e->callback(sock, e->ctx);
152         }
153     }
154 
155     return 0;
156 }
157 
158 typedef struct VubrVirtq {
159     int call_fd;
160     int kick_fd;
161     uint32_t size;
162     uint16_t last_avail_index;
163     uint16_t last_used_index;
164     struct vring_desc *desc;
165     struct vring_avail *avail;
166     struct vring_used *used;
167     uint64_t log_guest_addr;
168     int enable;
169 } VubrVirtq;
170 
171 /* Based on qemu/hw/virtio/vhost-user.c */
172 
173 #define VHOST_MEMORY_MAX_NREGIONS    8
174 #define VHOST_USER_F_PROTOCOL_FEATURES 30
175 /* v1.0 compliant. */
176 #define VIRTIO_F_VERSION_1		32
177 
178 #define VHOST_LOG_PAGE 4096
179 
180 enum VhostUserProtocolFeature {
181     VHOST_USER_PROTOCOL_F_MQ = 0,
182     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
183     VHOST_USER_PROTOCOL_F_RARP = 2,
184 
185     VHOST_USER_PROTOCOL_F_MAX
186 };
187 
188 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
189 
190 typedef enum VhostUserRequest {
191     VHOST_USER_NONE = 0,
192     VHOST_USER_GET_FEATURES = 1,
193     VHOST_USER_SET_FEATURES = 2,
194     VHOST_USER_SET_OWNER = 3,
195     VHOST_USER_RESET_OWNER = 4,
196     VHOST_USER_SET_MEM_TABLE = 5,
197     VHOST_USER_SET_LOG_BASE = 6,
198     VHOST_USER_SET_LOG_FD = 7,
199     VHOST_USER_SET_VRING_NUM = 8,
200     VHOST_USER_SET_VRING_ADDR = 9,
201     VHOST_USER_SET_VRING_BASE = 10,
202     VHOST_USER_GET_VRING_BASE = 11,
203     VHOST_USER_SET_VRING_KICK = 12,
204     VHOST_USER_SET_VRING_CALL = 13,
205     VHOST_USER_SET_VRING_ERR = 14,
206     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
207     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
208     VHOST_USER_GET_QUEUE_NUM = 17,
209     VHOST_USER_SET_VRING_ENABLE = 18,
210     VHOST_USER_SEND_RARP = 19,
211     VHOST_USER_MAX
212 } VhostUserRequest;
213 
214 typedef struct VhostUserMemoryRegion {
215     uint64_t guest_phys_addr;
216     uint64_t memory_size;
217     uint64_t userspace_addr;
218     uint64_t mmap_offset;
219 } VhostUserMemoryRegion;
220 
221 typedef struct VhostUserMemory {
222     uint32_t nregions;
223     uint32_t padding;
224     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
225 } VhostUserMemory;
226 
227 typedef struct VhostUserLog {
228     uint64_t mmap_size;
229     uint64_t mmap_offset;
230 } VhostUserLog;
231 
232 typedef struct VhostUserMsg {
233     VhostUserRequest request;
234 
235 #define VHOST_USER_VERSION_MASK     (0x3)
236 #define VHOST_USER_REPLY_MASK       (0x1<<2)
237     uint32_t flags;
238     uint32_t size; /* the following payload size */
239     union {
240 #define VHOST_USER_VRING_IDX_MASK   (0xff)
241 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
242         uint64_t u64;
243         struct vhost_vring_state state;
244         struct vhost_vring_addr addr;
245         VhostUserMemory memory;
246         VhostUserLog log;
247     } payload;
248     int fds[VHOST_MEMORY_MAX_NREGIONS];
249     int fd_num;
250 } QEMU_PACKED VhostUserMsg;
251 
252 #define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
253 
254 /* The version of the protocol we support */
255 #define VHOST_USER_VERSION    (0x1)
256 
257 #define MAX_NR_VIRTQUEUE (8)
258 
259 typedef struct VubrDevRegion {
260     /* Guest Physical address. */
261     uint64_t gpa;
262     /* Memory region size. */
263     uint64_t size;
264     /* QEMU virtual address (userspace). */
265     uint64_t qva;
266     /* Starting offset in our mmaped space. */
267     uint64_t mmap_offset;
268     /* Start address of mmaped space. */
269     uint64_t mmap_addr;
270 } VubrDevRegion;
271 
272 typedef struct VubrDev {
273     int sock;
274     Dispatcher dispatcher;
275     uint32_t nregions;
276     VubrDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
277     VubrVirtq vq[MAX_NR_VIRTQUEUE];
278     int log_call_fd;
279     uint64_t log_size;
280     uint8_t *log_table;
281     int backend_udp_sock;
282     struct sockaddr_in backend_udp_dest;
283     int ready;
284     uint64_t features;
285     int hdrlen;
286 } VubrDev;
287 
288 static const char *vubr_request_str[] = {
289     [VHOST_USER_NONE]                   =  "VHOST_USER_NONE",
290     [VHOST_USER_GET_FEATURES]           =  "VHOST_USER_GET_FEATURES",
291     [VHOST_USER_SET_FEATURES]           =  "VHOST_USER_SET_FEATURES",
292     [VHOST_USER_SET_OWNER]              =  "VHOST_USER_SET_OWNER",
293     [VHOST_USER_RESET_OWNER]           =  "VHOST_USER_RESET_OWNER",
294     [VHOST_USER_SET_MEM_TABLE]          =  "VHOST_USER_SET_MEM_TABLE",
295     [VHOST_USER_SET_LOG_BASE]           =  "VHOST_USER_SET_LOG_BASE",
296     [VHOST_USER_SET_LOG_FD]             =  "VHOST_USER_SET_LOG_FD",
297     [VHOST_USER_SET_VRING_NUM]          =  "VHOST_USER_SET_VRING_NUM",
298     [VHOST_USER_SET_VRING_ADDR]         =  "VHOST_USER_SET_VRING_ADDR",
299     [VHOST_USER_SET_VRING_BASE]         =  "VHOST_USER_SET_VRING_BASE",
300     [VHOST_USER_GET_VRING_BASE]         =  "VHOST_USER_GET_VRING_BASE",
301     [VHOST_USER_SET_VRING_KICK]         =  "VHOST_USER_SET_VRING_KICK",
302     [VHOST_USER_SET_VRING_CALL]         =  "VHOST_USER_SET_VRING_CALL",
303     [VHOST_USER_SET_VRING_ERR]          =  "VHOST_USER_SET_VRING_ERR",
304     [VHOST_USER_GET_PROTOCOL_FEATURES]  =  "VHOST_USER_GET_PROTOCOL_FEATURES",
305     [VHOST_USER_SET_PROTOCOL_FEATURES]  =  "VHOST_USER_SET_PROTOCOL_FEATURES",
306     [VHOST_USER_GET_QUEUE_NUM]          =  "VHOST_USER_GET_QUEUE_NUM",
307     [VHOST_USER_SET_VRING_ENABLE]       =  "VHOST_USER_SET_VRING_ENABLE",
308     [VHOST_USER_SEND_RARP]              =  "VHOST_USER_SEND_RARP",
309     [VHOST_USER_MAX]                    =  "VHOST_USER_MAX",
310 };
311 
312 static void
313 print_buffer(uint8_t *buf, size_t len)
314 {
315     int i;
316     printf("Raw buffer:\n");
317     for (i = 0; i < len; i++) {
318         if (i % 16 == 0) {
319             printf("\n");
320         }
321         if (i % 4 == 0) {
322             printf("   ");
323         }
324         printf("%02x ", buf[i]);
325     }
326     printf("\n............................................................\n");
327 }
328 
329 /* Translate guest physical address to our virtual address.  */
330 static uint64_t
331 gpa_to_va(VubrDev *dev, uint64_t guest_addr)
332 {
333     int i;
334 
335     /* Find matching memory region.  */
336     for (i = 0; i < dev->nregions; i++) {
337         VubrDevRegion *r = &dev->regions[i];
338 
339         if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) {
340             return guest_addr - r->gpa + r->mmap_addr + r->mmap_offset;
341         }
342     }
343 
344     assert(!"address not found in regions");
345     return 0;
346 }
347 
348 /* Translate qemu virtual address to our virtual address.  */
349 static uint64_t
350 qva_to_va(VubrDev *dev, uint64_t qemu_addr)
351 {
352     int i;
353 
354     /* Find matching memory region.  */
355     for (i = 0; i < dev->nregions; i++) {
356         VubrDevRegion *r = &dev->regions[i];
357 
358         if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
359             return qemu_addr - r->qva + r->mmap_addr + r->mmap_offset;
360         }
361     }
362 
363     assert(!"address not found in regions");
364     return 0;
365 }
366 
367 static void
368 vubr_message_read(int conn_fd, VhostUserMsg *vmsg)
369 {
370     char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = { };
371     struct iovec iov = {
372         .iov_base = (char *)vmsg,
373         .iov_len = VHOST_USER_HDR_SIZE,
374     };
375     struct msghdr msg = {
376         .msg_iov = &iov,
377         .msg_iovlen = 1,
378         .msg_control = control,
379         .msg_controllen = sizeof(control),
380     };
381     size_t fd_size;
382     struct cmsghdr *cmsg;
383     int rc;
384 
385     rc = recvmsg(conn_fd, &msg, 0);
386 
387     if (rc == 0) {
388         fprintf(stderr, "Peer disconnected.\n");
389         exit(1);
390     }
391     if (rc < 0) {
392         vubr_die("recvmsg");
393     }
394 
395     vmsg->fd_num = 0;
396     for (cmsg = CMSG_FIRSTHDR(&msg);
397          cmsg != NULL;
398          cmsg = CMSG_NXTHDR(&msg, cmsg))
399     {
400         if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
401             fd_size = cmsg->cmsg_len - CMSG_LEN(0);
402             vmsg->fd_num = fd_size / sizeof(int);
403             memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
404             break;
405         }
406     }
407 
408     if (vmsg->size > sizeof(vmsg->payload)) {
409         fprintf(stderr,
410                 "Error: too big message request: %d, size: vmsg->size: %u, "
411                 "while sizeof(vmsg->payload) = %zu\n",
412                 vmsg->request, vmsg->size, sizeof(vmsg->payload));
413         exit(1);
414     }
415 
416     if (vmsg->size) {
417         rc = read(conn_fd, &vmsg->payload, vmsg->size);
418         if (rc == 0) {
419             vubr_die("recvmsg");
420             fprintf(stderr, "Peer disconnected.\n");
421             exit(1);
422         }
423         if (rc < 0) {
424             vubr_die("recvmsg");
425         }
426 
427         assert(rc == vmsg->size);
428     }
429 }
430 
431 static void
432 vubr_message_write(int conn_fd, VhostUserMsg *vmsg)
433 {
434     int rc;
435 
436     do {
437         rc = write(conn_fd, vmsg, VHOST_USER_HDR_SIZE + vmsg->size);
438     } while (rc < 0 && errno == EINTR);
439 
440     if (rc < 0) {
441         vubr_die("write");
442     }
443 }
444 
445 static void
446 vubr_backend_udp_sendbuf(VubrDev *dev, uint8_t *buf, size_t len)
447 {
448     int slen = sizeof(struct sockaddr_in);
449 
450     if (sendto(dev->backend_udp_sock, buf, len, 0,
451                (struct sockaddr *) &dev->backend_udp_dest, slen) == -1) {
452         vubr_die("sendto()");
453     }
454 }
455 
456 static int
457 vubr_backend_udp_recvbuf(VubrDev *dev, uint8_t *buf, size_t buflen)
458 {
459     int slen = sizeof(struct sockaddr_in);
460     int rc;
461 
462     rc = recvfrom(dev->backend_udp_sock, buf, buflen, 0,
463                   (struct sockaddr *) &dev->backend_udp_dest,
464                   (socklen_t *)&slen);
465     if (rc == -1) {
466         vubr_die("recvfrom()");
467     }
468 
469     return rc;
470 }
471 
472 static void
473 vubr_consume_raw_packet(VubrDev *dev, uint8_t *buf, uint32_t len)
474 {
475     int hdrlen = dev->hdrlen;
476     DPRINT("    hdrlen = %d\n", dev->hdrlen);
477 
478     if (VHOST_USER_BRIDGE_DEBUG) {
479         print_buffer(buf, len);
480     }
481     vubr_backend_udp_sendbuf(dev, buf + hdrlen, len - hdrlen);
482 }
483 
484 /* Kick the log_call_fd if required. */
485 static void
486 vubr_log_kick(VubrDev *dev)
487 {
488     if (dev->log_call_fd != -1) {
489         DPRINT("Kicking the QEMU's log...\n");
490         eventfd_write(dev->log_call_fd, 1);
491     }
492 }
493 
494 /* Kick the guest if necessary. */
495 static void
496 vubr_virtqueue_kick(VubrVirtq *vq)
497 {
498     if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
499         DPRINT("Kicking the guest...\n");
500         eventfd_write(vq->call_fd, 1);
501     }
502 }
503 
504 static void
505 vubr_log_page(uint8_t *log_table, uint64_t page)
506 {
507     DPRINT("Logged dirty guest page: %"PRId64"\n", page);
508     atomic_or(&log_table[page / 8], 1 << (page % 8));
509 }
510 
511 static void
512 vubr_log_write(VubrDev *dev, uint64_t address, uint64_t length)
513 {
514     uint64_t page;
515 
516     if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) ||
517         !dev->log_table || !length) {
518         return;
519     }
520 
521     assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8));
522 
523     page = address / VHOST_LOG_PAGE;
524     while (page * VHOST_LOG_PAGE < address + length) {
525         vubr_log_page(dev->log_table, page);
526         page += VHOST_LOG_PAGE;
527     }
528     vubr_log_kick(dev);
529 }
530 
531 static void
532 vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t *buf, int32_t len)
533 {
534     struct vring_desc *desc = vq->desc;
535     struct vring_avail *avail = vq->avail;
536     struct vring_used *used = vq->used;
537     uint64_t log_guest_addr = vq->log_guest_addr;
538     int32_t remaining_len = len;
539 
540     unsigned int size = vq->size;
541 
542     uint16_t avail_index = atomic_mb_read(&avail->idx);
543 
544     /* We check the available descriptors before posting the
545      * buffer, so here we assume that enough available
546      * descriptors. */
547     assert(vq->last_avail_index != avail_index);
548     uint16_t a_index = vq->last_avail_index % size;
549     uint16_t u_index = vq->last_used_index % size;
550     uint16_t d_index = avail->ring[a_index];
551 
552     int i = d_index;
553     uint32_t written_len = 0;
554 
555     do {
556         DPRINT("Post packet to guest on vq:\n");
557         DPRINT("    size             = %d\n", vq->size);
558         DPRINT("    last_avail_index = %d\n", vq->last_avail_index);
559         DPRINT("    last_used_index  = %d\n", vq->last_used_index);
560         DPRINT("    a_index = %d\n", a_index);
561         DPRINT("    u_index = %d\n", u_index);
562         DPRINT("    d_index = %d\n", d_index);
563         DPRINT("    desc[%d].addr    = 0x%016"PRIx64"\n", i, desc[i].addr);
564         DPRINT("    desc[%d].len     = %d\n", i, desc[i].len);
565         DPRINT("    desc[%d].flags   = %d\n", i, desc[i].flags);
566         DPRINT("    avail->idx = %d\n", avail_index);
567         DPRINT("    used->idx  = %d\n", used->idx);
568 
569         if (!(desc[i].flags & VRING_DESC_F_WRITE)) {
570             /* FIXME: we should find writable descriptor. */
571             fprintf(stderr, "Error: descriptor is not writable. Exiting.\n");
572             exit(1);
573         }
574 
575         void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
576         uint32_t chunk_len = desc[i].len;
577         uint32_t chunk_write_len = MIN(remaining_len, chunk_len);
578 
579         memcpy(chunk_start, buf + written_len, chunk_write_len);
580         vubr_log_write(dev, desc[i].addr, chunk_write_len);
581         remaining_len -= chunk_write_len;
582         written_len += chunk_write_len;
583 
584         if ((remaining_len == 0) || !(desc[i].flags & VRING_DESC_F_NEXT)) {
585             break;
586         }
587 
588         i = desc[i].next;
589     } while (1);
590 
591     if (remaining_len > 0) {
592             fprintf(stderr,
593                     "Too long packet for RX, remaining_len = %d, Dropping...\n",
594                     remaining_len);
595             return;
596     }
597 
598     /* Add descriptor to the used ring. */
599     used->ring[u_index].id = d_index;
600     used->ring[u_index].len = len;
601     vubr_log_write(dev,
602                    log_guest_addr + offsetof(struct vring_used, ring[u_index]),
603                    sizeof(used->ring[u_index]));
604 
605     vq->last_avail_index++;
606     vq->last_used_index++;
607 
608     atomic_mb_set(&used->idx, vq->last_used_index);
609     vubr_log_write(dev,
610                    log_guest_addr + offsetof(struct vring_used, idx),
611                    sizeof(used->idx));
612 
613     /* Kick the guest if necessary. */
614     vubr_virtqueue_kick(vq);
615 }
616 
617 static int
618 vubr_process_desc(VubrDev *dev, VubrVirtq *vq)
619 {
620     struct vring_desc *desc = vq->desc;
621     struct vring_avail *avail = vq->avail;
622     struct vring_used *used = vq->used;
623     uint64_t log_guest_addr = vq->log_guest_addr;
624 
625     unsigned int size = vq->size;
626 
627     uint16_t a_index = vq->last_avail_index % size;
628     uint16_t u_index = vq->last_used_index % size;
629     uint16_t d_index = avail->ring[a_index];
630 
631     uint32_t i, len = 0;
632     size_t buf_size = 4096;
633     uint8_t buf[4096];
634 
635     DPRINT("Chunks: ");
636     i = d_index;
637     do {
638         void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
639         uint32_t chunk_len = desc[i].len;
640 
641         assert(!(desc[i].flags & VRING_DESC_F_WRITE));
642 
643         if (len + chunk_len < buf_size) {
644             memcpy(buf + len, chunk_start, chunk_len);
645             DPRINT("%d ", chunk_len);
646         } else {
647             fprintf(stderr, "Error: too long packet. Dropping...\n");
648             break;
649         }
650 
651         len += chunk_len;
652 
653         if (!(desc[i].flags & VRING_DESC_F_NEXT)) {
654             break;
655         }
656 
657         i = desc[i].next;
658     } while (1);
659     DPRINT("\n");
660 
661     if (!len) {
662         return -1;
663     }
664 
665     /* Add descriptor to the used ring. */
666     used->ring[u_index].id = d_index;
667     used->ring[u_index].len = len;
668     vubr_log_write(dev,
669                    log_guest_addr + offsetof(struct vring_used, ring[u_index]),
670                    sizeof(used->ring[u_index]));
671 
672     vubr_consume_raw_packet(dev, buf, len);
673 
674     return 0;
675 }
676 
677 static void
678 vubr_process_avail(VubrDev *dev, VubrVirtq *vq)
679 {
680     struct vring_avail *avail = vq->avail;
681     struct vring_used *used = vq->used;
682     uint64_t log_guest_addr = vq->log_guest_addr;
683 
684     while (vq->last_avail_index != atomic_mb_read(&avail->idx)) {
685         vubr_process_desc(dev, vq);
686         vq->last_avail_index++;
687         vq->last_used_index++;
688     }
689 
690     atomic_mb_set(&used->idx, vq->last_used_index);
691     vubr_log_write(dev,
692                    log_guest_addr + offsetof(struct vring_used, idx),
693                    sizeof(used->idx));
694 }
695 
696 static void
697 vubr_backend_recv_cb(int sock, void *ctx)
698 {
699     VubrDev *dev = (VubrDev *) ctx;
700     VubrVirtq *rx_vq = &dev->vq[0];
701     uint8_t buf[4096];
702     struct virtio_net_hdr_v1 *hdr = (struct virtio_net_hdr_v1 *)buf;
703     int hdrlen = dev->hdrlen;
704     int buflen = sizeof(buf);
705     int len;
706 
707     if (!dev->ready) {
708         return;
709     }
710 
711     DPRINT("\n\n   ***   IN UDP RECEIVE CALLBACK    ***\n\n");
712     DPRINT("    hdrlen = %d\n", hdrlen);
713 
714     uint16_t avail_index = atomic_mb_read(&rx_vq->avail->idx);
715 
716     /* If there is no available descriptors, just do nothing.
717      * The buffer will be handled by next arrived UDP packet,
718      * or next kick on receive virtq. */
719     if (rx_vq->last_avail_index == avail_index) {
720         DPRINT("Got UDP packet, but no available descriptors on RX virtq.\n");
721         return;
722     }
723 
724     memset(buf, 0, hdrlen);
725     /* TODO: support mergeable buffers. */
726     if (hdrlen == 12)
727         hdr->num_buffers = 1;
728     len = vubr_backend_udp_recvbuf(dev, buf + hdrlen, buflen - hdrlen);
729 
730     vubr_post_buffer(dev, rx_vq, buf, len + hdrlen);
731 }
732 
733 static void
734 vubr_kick_cb(int sock, void *ctx)
735 {
736     VubrDev *dev = (VubrDev *) ctx;
737     eventfd_t kick_data;
738     ssize_t rc;
739 
740     rc = eventfd_read(sock, &kick_data);
741     if (rc == -1) {
742         vubr_die("eventfd_read()");
743     } else {
744         DPRINT("Got kick_data: %016"PRIx64"\n", kick_data);
745         vubr_process_avail(dev, &dev->vq[1]);
746     }
747 }
748 
749 static int
750 vubr_none_exec(VubrDev *dev, VhostUserMsg *vmsg)
751 {
752     DPRINT("Function %s() not implemented yet.\n", __func__);
753     return 0;
754 }
755 
756 static int
757 vubr_get_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
758 {
759     vmsg->payload.u64 =
760             ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
761              (1ULL << VHOST_F_LOG_ALL) |
762              (1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE) |
763              (1ULL << VHOST_USER_F_PROTOCOL_FEATURES));
764 
765     vmsg->size = sizeof(vmsg->payload.u64);
766 
767     DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
768 
769     /* Reply */
770     return 1;
771 }
772 
773 static int
774 vubr_set_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
775 {
776     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
777 
778     dev->features = vmsg->payload.u64;
779     if ((dev->features & (1ULL << VIRTIO_F_VERSION_1)) ||
780         (dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF))) {
781         dev->hdrlen = 12;
782     } else {
783         dev->hdrlen = 10;
784     }
785 
786     return 0;
787 }
788 
789 static int
790 vubr_set_owner_exec(VubrDev *dev, VhostUserMsg *vmsg)
791 {
792     return 0;
793 }
794 
795 static void
796 vubr_close_log(VubrDev *dev)
797 {
798     if (dev->log_table) {
799         if (munmap(dev->log_table, dev->log_size) != 0) {
800             vubr_die("munmap()");
801         }
802 
803         dev->log_table = 0;
804     }
805     if (dev->log_call_fd != -1) {
806         close(dev->log_call_fd);
807         dev->log_call_fd = -1;
808     }
809 }
810 
811 static int
812 vubr_reset_device_exec(VubrDev *dev, VhostUserMsg *vmsg)
813 {
814     vubr_close_log(dev);
815     dev->ready = 0;
816     dev->features = 0;
817     return 0;
818 }
819 
820 static int
821 vubr_set_mem_table_exec(VubrDev *dev, VhostUserMsg *vmsg)
822 {
823     int i;
824     VhostUserMemory *memory = &vmsg->payload.memory;
825     dev->nregions = memory->nregions;
826 
827     DPRINT("Nregions: %d\n", memory->nregions);
828     for (i = 0; i < dev->nregions; i++) {
829         void *mmap_addr;
830         VhostUserMemoryRegion *msg_region = &memory->regions[i];
831         VubrDevRegion *dev_region = &dev->regions[i];
832 
833         DPRINT("Region %d\n", i);
834         DPRINT("    guest_phys_addr: 0x%016"PRIx64"\n",
835                msg_region->guest_phys_addr);
836         DPRINT("    memory_size:     0x%016"PRIx64"\n",
837                msg_region->memory_size);
838         DPRINT("    userspace_addr   0x%016"PRIx64"\n",
839                msg_region->userspace_addr);
840         DPRINT("    mmap_offset      0x%016"PRIx64"\n",
841                msg_region->mmap_offset);
842 
843         dev_region->gpa = msg_region->guest_phys_addr;
844         dev_region->size = msg_region->memory_size;
845         dev_region->qva = msg_region->userspace_addr;
846         dev_region->mmap_offset = msg_region->mmap_offset;
847 
848         /* We don't use offset argument of mmap() since the
849          * mapped address has to be page aligned, and we use huge
850          * pages.  */
851         mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
852                          PROT_READ | PROT_WRITE, MAP_SHARED,
853                          vmsg->fds[i], 0);
854 
855         if (mmap_addr == MAP_FAILED) {
856             vubr_die("mmap");
857         }
858         dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
859         DPRINT("    mmap_addr:       0x%016"PRIx64"\n", dev_region->mmap_addr);
860 
861         close(vmsg->fds[i]);
862     }
863 
864     return 0;
865 }
866 
867 static int
868 vubr_set_log_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
869 {
870     int fd;
871     uint64_t log_mmap_size, log_mmap_offset;
872     void *rc;
873 
874     assert(vmsg->fd_num == 1);
875     fd = vmsg->fds[0];
876 
877     assert(vmsg->size == sizeof(vmsg->payload.log));
878     log_mmap_offset = vmsg->payload.log.mmap_offset;
879     log_mmap_size = vmsg->payload.log.mmap_size;
880     DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset);
881     DPRINT("Log mmap_size:   %"PRId64"\n", log_mmap_size);
882 
883     rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
884               log_mmap_offset);
885     if (rc == MAP_FAILED) {
886         vubr_die("mmap");
887     }
888     dev->log_table = rc;
889     dev->log_size = log_mmap_size;
890 
891     vmsg->size = sizeof(vmsg->payload.u64);
892     /* Reply */
893     return 1;
894 }
895 
896 static int
897 vubr_set_log_fd_exec(VubrDev *dev, VhostUserMsg *vmsg)
898 {
899     assert(vmsg->fd_num == 1);
900     dev->log_call_fd = vmsg->fds[0];
901     DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]);
902     return 0;
903 }
904 
905 static int
906 vubr_set_vring_num_exec(VubrDev *dev, VhostUserMsg *vmsg)
907 {
908     unsigned int index = vmsg->payload.state.index;
909     unsigned int num = vmsg->payload.state.num;
910 
911     DPRINT("State.index: %d\n", index);
912     DPRINT("State.num:   %d\n", num);
913     dev->vq[index].size = num;
914     return 0;
915 }
916 
917 static int
918 vubr_set_vring_addr_exec(VubrDev *dev, VhostUserMsg *vmsg)
919 {
920     struct vhost_vring_addr *vra = &vmsg->payload.addr;
921     unsigned int index = vra->index;
922     VubrVirtq *vq = &dev->vq[index];
923 
924     DPRINT("vhost_vring_addr:\n");
925     DPRINT("    index:  %d\n", vra->index);
926     DPRINT("    flags:  %d\n", vra->flags);
927     DPRINT("    desc_user_addr:   0x%016llx\n", vra->desc_user_addr);
928     DPRINT("    used_user_addr:   0x%016llx\n", vra->used_user_addr);
929     DPRINT("    avail_user_addr:  0x%016llx\n", vra->avail_user_addr);
930     DPRINT("    log_guest_addr:   0x%016llx\n", vra->log_guest_addr);
931 
932     vq->desc = (struct vring_desc *)(uintptr_t)qva_to_va(dev, vra->desc_user_addr);
933     vq->used = (struct vring_used *)(uintptr_t)qva_to_va(dev, vra->used_user_addr);
934     vq->avail = (struct vring_avail *)(uintptr_t)qva_to_va(dev, vra->avail_user_addr);
935     vq->log_guest_addr = vra->log_guest_addr;
936 
937     DPRINT("Setting virtq addresses:\n");
938     DPRINT("    vring_desc  at %p\n", vq->desc);
939     DPRINT("    vring_used  at %p\n", vq->used);
940     DPRINT("    vring_avail at %p\n", vq->avail);
941 
942     vq->last_used_index = vq->used->idx;
943 
944     if (vq->last_avail_index != vq->used->idx) {
945         DPRINT("Last avail index != used index: %d != %d, resuming",
946                vq->last_avail_index, vq->used->idx);
947         vq->last_avail_index = vq->used->idx;
948     }
949 
950     return 0;
951 }
952 
953 static int
954 vubr_set_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
955 {
956     unsigned int index = vmsg->payload.state.index;
957     unsigned int num = vmsg->payload.state.num;
958 
959     DPRINT("State.index: %d\n", index);
960     DPRINT("State.num:   %d\n", num);
961     dev->vq[index].last_avail_index = num;
962 
963     return 0;
964 }
965 
966 static int
967 vubr_get_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
968 {
969     unsigned int index = vmsg->payload.state.index;
970 
971     DPRINT("State.index: %d\n", index);
972     vmsg->payload.state.num = dev->vq[index].last_avail_index;
973     vmsg->size = sizeof(vmsg->payload.state);
974     /* FIXME: this is a work-around for a bug in QEMU enabling
975      * too early vrings. When protocol features are enabled,
976      * we have to respect * VHOST_USER_SET_VRING_ENABLE request. */
977     dev->ready = 0;
978 
979     if (dev->vq[index].call_fd != -1) {
980         close(dev->vq[index].call_fd);
981         dev->vq[index].call_fd = -1;
982     }
983     if (dev->vq[index].kick_fd != -1) {
984         close(dev->vq[index].kick_fd);
985         dispatcher_remove(&dev->dispatcher, dev->vq[index].kick_fd);
986         dev->vq[index].kick_fd = -1;
987     }
988 
989     /* Reply */
990     return 1;
991 }
992 
993 static int
994 vubr_set_vring_kick_exec(VubrDev *dev, VhostUserMsg *vmsg)
995 {
996     uint64_t u64_arg = vmsg->payload.u64;
997     int index = u64_arg & VHOST_USER_VRING_IDX_MASK;
998 
999     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1000 
1001     assert((u64_arg & VHOST_USER_VRING_NOFD_MASK) == 0);
1002     assert(vmsg->fd_num == 1);
1003 
1004     if (dev->vq[index].kick_fd != -1) {
1005         close(dev->vq[index].kick_fd);
1006         dispatcher_remove(&dev->dispatcher, dev->vq[index].kick_fd);
1007     }
1008     dev->vq[index].kick_fd = vmsg->fds[0];
1009     DPRINT("Got kick_fd: %d for vq: %d\n", vmsg->fds[0], index);
1010 
1011     if (index % 2 == 1) {
1012         /* TX queue. */
1013         dispatcher_add(&dev->dispatcher, dev->vq[index].kick_fd,
1014                        dev, vubr_kick_cb);
1015 
1016         DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
1017                dev->vq[index].kick_fd, index);
1018     }
1019     /* We temporarily use this hack to determine that both TX and RX
1020      * queues are set up and ready for processing.
1021      * FIXME: we need to rely in VHOST_USER_SET_VRING_ENABLE and
1022      * actual kicks. */
1023     if (dev->vq[0].kick_fd != -1 &&
1024         dev->vq[1].kick_fd != -1) {
1025         dev->ready = 1;
1026         DPRINT("vhost-user-bridge is ready for processing queues.\n");
1027     }
1028     return 0;
1029 
1030 }
1031 
1032 static int
1033 vubr_set_vring_call_exec(VubrDev *dev, VhostUserMsg *vmsg)
1034 {
1035     uint64_t u64_arg = vmsg->payload.u64;
1036     int index = u64_arg & VHOST_USER_VRING_IDX_MASK;
1037 
1038     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1039     assert((u64_arg & VHOST_USER_VRING_NOFD_MASK) == 0);
1040     assert(vmsg->fd_num == 1);
1041 
1042     if (dev->vq[index].call_fd != -1) {
1043         close(dev->vq[index].call_fd);
1044     }
1045     dev->vq[index].call_fd = vmsg->fds[0];
1046     DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
1047 
1048     return 0;
1049 }
1050 
1051 static int
1052 vubr_set_vring_err_exec(VubrDev *dev, VhostUserMsg *vmsg)
1053 {
1054     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1055     return 0;
1056 }
1057 
1058 static int
1059 vubr_get_protocol_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
1060 {
1061     vmsg->payload.u64 = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD;
1062     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1063     vmsg->size = sizeof(vmsg->payload.u64);
1064 
1065     /* Reply */
1066     return 1;
1067 }
1068 
1069 static int
1070 vubr_set_protocol_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
1071 {
1072     /* FIXME: unimplented */
1073     DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
1074     return 0;
1075 }
1076 
1077 static int
1078 vubr_get_queue_num_exec(VubrDev *dev, VhostUserMsg *vmsg)
1079 {
1080     DPRINT("Function %s() not implemented yet.\n", __func__);
1081     return 0;
1082 }
1083 
1084 static int
1085 vubr_set_vring_enable_exec(VubrDev *dev, VhostUserMsg *vmsg)
1086 {
1087     unsigned int index = vmsg->payload.state.index;
1088     unsigned int enable = vmsg->payload.state.num;
1089 
1090     DPRINT("State.index: %d\n", index);
1091     DPRINT("State.enable:   %d\n", enable);
1092     dev->vq[index].enable = enable;
1093     return 0;
1094 }
1095 
1096 static int
1097 vubr_send_rarp_exec(VubrDev *dev, VhostUserMsg *vmsg)
1098 {
1099     DPRINT("Function %s() not implemented yet.\n", __func__);
1100     return 0;
1101 }
1102 
1103 static int
1104 vubr_execute_request(VubrDev *dev, VhostUserMsg *vmsg)
1105 {
1106     /* Print out generic part of the request. */
1107     DPRINT(
1108            "==================   Vhost user message from QEMU   ==================\n");
1109     DPRINT("Request: %s (%d)\n", vubr_request_str[vmsg->request],
1110            vmsg->request);
1111     DPRINT("Flags:   0x%x\n", vmsg->flags);
1112     DPRINT("Size:    %d\n", vmsg->size);
1113 
1114     if (vmsg->fd_num) {
1115         int i;
1116         DPRINT("Fds:");
1117         for (i = 0; i < vmsg->fd_num; i++) {
1118             DPRINT(" %d", vmsg->fds[i]);
1119         }
1120         DPRINT("\n");
1121     }
1122 
1123     switch (vmsg->request) {
1124     case VHOST_USER_NONE:
1125         return vubr_none_exec(dev, vmsg);
1126     case VHOST_USER_GET_FEATURES:
1127         return vubr_get_features_exec(dev, vmsg);
1128     case VHOST_USER_SET_FEATURES:
1129         return vubr_set_features_exec(dev, vmsg);
1130     case VHOST_USER_SET_OWNER:
1131         return vubr_set_owner_exec(dev, vmsg);
1132     case VHOST_USER_RESET_OWNER:
1133         return vubr_reset_device_exec(dev, vmsg);
1134     case VHOST_USER_SET_MEM_TABLE:
1135         return vubr_set_mem_table_exec(dev, vmsg);
1136     case VHOST_USER_SET_LOG_BASE:
1137         return vubr_set_log_base_exec(dev, vmsg);
1138     case VHOST_USER_SET_LOG_FD:
1139         return vubr_set_log_fd_exec(dev, vmsg);
1140     case VHOST_USER_SET_VRING_NUM:
1141         return vubr_set_vring_num_exec(dev, vmsg);
1142     case VHOST_USER_SET_VRING_ADDR:
1143         return vubr_set_vring_addr_exec(dev, vmsg);
1144     case VHOST_USER_SET_VRING_BASE:
1145         return vubr_set_vring_base_exec(dev, vmsg);
1146     case VHOST_USER_GET_VRING_BASE:
1147         return vubr_get_vring_base_exec(dev, vmsg);
1148     case VHOST_USER_SET_VRING_KICK:
1149         return vubr_set_vring_kick_exec(dev, vmsg);
1150     case VHOST_USER_SET_VRING_CALL:
1151         return vubr_set_vring_call_exec(dev, vmsg);
1152     case VHOST_USER_SET_VRING_ERR:
1153         return vubr_set_vring_err_exec(dev, vmsg);
1154     case VHOST_USER_GET_PROTOCOL_FEATURES:
1155         return vubr_get_protocol_features_exec(dev, vmsg);
1156     case VHOST_USER_SET_PROTOCOL_FEATURES:
1157         return vubr_set_protocol_features_exec(dev, vmsg);
1158     case VHOST_USER_GET_QUEUE_NUM:
1159         return vubr_get_queue_num_exec(dev, vmsg);
1160     case VHOST_USER_SET_VRING_ENABLE:
1161         return vubr_set_vring_enable_exec(dev, vmsg);
1162     case VHOST_USER_SEND_RARP:
1163         return vubr_send_rarp_exec(dev, vmsg);
1164 
1165     case VHOST_USER_MAX:
1166         assert(vmsg->request != VHOST_USER_MAX);
1167     }
1168     return 0;
1169 }
1170 
1171 static void
1172 vubr_receive_cb(int sock, void *ctx)
1173 {
1174     VubrDev *dev = (VubrDev *) ctx;
1175     VhostUserMsg vmsg;
1176     int reply_requested;
1177 
1178     vubr_message_read(sock, &vmsg);
1179     reply_requested = vubr_execute_request(dev, &vmsg);
1180     if (reply_requested) {
1181         /* Set the version in the flags when sending the reply */
1182         vmsg.flags &= ~VHOST_USER_VERSION_MASK;
1183         vmsg.flags |= VHOST_USER_VERSION;
1184         vmsg.flags |= VHOST_USER_REPLY_MASK;
1185         vubr_message_write(sock, &vmsg);
1186     }
1187 }
1188 
1189 static void
1190 vubr_accept_cb(int sock, void *ctx)
1191 {
1192     VubrDev *dev = (VubrDev *)ctx;
1193     int conn_fd;
1194     struct sockaddr_un un;
1195     socklen_t len = sizeof(un);
1196 
1197     conn_fd = accept(sock, (struct sockaddr *) &un, &len);
1198     if (conn_fd == -1) {
1199         vubr_die("accept()");
1200     }
1201     DPRINT("Got connection from remote peer on sock %d\n", conn_fd);
1202     dispatcher_add(&dev->dispatcher, conn_fd, ctx, vubr_receive_cb);
1203     dispatcher_remove(&dev->dispatcher, sock);
1204 }
1205 
1206 static VubrDev *
1207 vubr_new(const char *path, bool client)
1208 {
1209     VubrDev *dev = (VubrDev *) calloc(1, sizeof(VubrDev));
1210     dev->nregions = 0;
1211     int i;
1212     struct sockaddr_un un;
1213     CallbackFunc cb;
1214     size_t len;
1215 
1216     for (i = 0; i < MAX_NR_VIRTQUEUE; i++) {
1217         dev->vq[i] = (VubrVirtq) {
1218             .call_fd = -1, .kick_fd = -1,
1219             .size = 0,
1220             .last_avail_index = 0, .last_used_index = 0,
1221             .desc = 0, .avail = 0, .used = 0,
1222             .enable = 0,
1223         };
1224     }
1225 
1226     /* Init log */
1227     dev->log_call_fd = -1;
1228     dev->log_size = 0;
1229     dev->log_table = 0;
1230     dev->ready = 0;
1231     dev->features = 0;
1232 
1233     /* Get a UNIX socket. */
1234     dev->sock = socket(AF_UNIX, SOCK_STREAM, 0);
1235     if (dev->sock == -1) {
1236         vubr_die("socket");
1237     }
1238 
1239     un.sun_family = AF_UNIX;
1240     strcpy(un.sun_path, path);
1241     len = sizeof(un.sun_family) + strlen(path);
1242 
1243     if (!client) {
1244         unlink(path);
1245 
1246         if (bind(dev->sock, (struct sockaddr *) &un, len) == -1) {
1247             vubr_die("bind");
1248         }
1249 
1250         if (listen(dev->sock, 1) == -1) {
1251             vubr_die("listen");
1252         }
1253         cb = vubr_accept_cb;
1254 
1255         DPRINT("Waiting for connections on UNIX socket %s ...\n", path);
1256     } else {
1257         if (connect(dev->sock, (struct sockaddr *)&un, len) == -1) {
1258             vubr_die("connect");
1259         }
1260         cb = vubr_receive_cb;
1261     }
1262 
1263     dispatcher_init(&dev->dispatcher);
1264     dispatcher_add(&dev->dispatcher, dev->sock, (void *)dev, cb);
1265 
1266     return dev;
1267 }
1268 
1269 static void
1270 vubr_set_host(struct sockaddr_in *saddr, const char *host)
1271 {
1272     if (isdigit(host[0])) {
1273         if (!inet_aton(host, &saddr->sin_addr)) {
1274             fprintf(stderr, "inet_aton() failed.\n");
1275             exit(1);
1276         }
1277     } else {
1278         struct hostent *he = gethostbyname(host);
1279 
1280         if (!he) {
1281             fprintf(stderr, "gethostbyname() failed.\n");
1282             exit(1);
1283         }
1284         saddr->sin_addr = *(struct in_addr *)he->h_addr;
1285     }
1286 }
1287 
1288 static void
1289 vubr_backend_udp_setup(VubrDev *dev,
1290                        const char *local_host,
1291                        const char *local_port,
1292                        const char *remote_host,
1293                        const char *remote_port)
1294 {
1295     int sock;
1296     const char *r;
1297 
1298     int lport, rport;
1299 
1300     lport = strtol(local_port, (char **)&r, 0);
1301     if (r == local_port) {
1302         fprintf(stderr, "lport parsing failed.\n");
1303         exit(1);
1304     }
1305 
1306     rport = strtol(remote_port, (char **)&r, 0);
1307     if (r == remote_port) {
1308         fprintf(stderr, "rport parsing failed.\n");
1309         exit(1);
1310     }
1311 
1312     struct sockaddr_in si_local = {
1313         .sin_family = AF_INET,
1314         .sin_port = htons(lport),
1315     };
1316 
1317     vubr_set_host(&si_local, local_host);
1318 
1319     /* setup destination for sends */
1320     dev->backend_udp_dest = (struct sockaddr_in) {
1321         .sin_family = AF_INET,
1322         .sin_port = htons(rport),
1323     };
1324     vubr_set_host(&dev->backend_udp_dest, remote_host);
1325 
1326     sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1327     if (sock == -1) {
1328         vubr_die("socket");
1329     }
1330 
1331     if (bind(sock, (struct sockaddr *)&si_local, sizeof(si_local)) == -1) {
1332         vubr_die("bind");
1333     }
1334 
1335     dev->backend_udp_sock = sock;
1336     dispatcher_add(&dev->dispatcher, sock, dev, vubr_backend_recv_cb);
1337     DPRINT("Waiting for data from udp backend on %s:%d...\n",
1338            local_host, lport);
1339 }
1340 
1341 static void
1342 vubr_run(VubrDev *dev)
1343 {
1344     while (1) {
1345         /* timeout 200ms */
1346         dispatcher_wait(&dev->dispatcher, 200000);
1347         /* Here one can try polling strategy. */
1348     }
1349 }
1350 
1351 static int
1352 vubr_parse_host_port(const char **host, const char **port, const char *buf)
1353 {
1354     char *p = strchr(buf, ':');
1355 
1356     if (!p) {
1357         return -1;
1358     }
1359     *p = '\0';
1360     *host = strdup(buf);
1361     *port = strdup(p + 1);
1362     return 0;
1363 }
1364 
1365 #define DEFAULT_UD_SOCKET "/tmp/vubr.sock"
1366 #define DEFAULT_LHOST "127.0.0.1"
1367 #define DEFAULT_LPORT "4444"
1368 #define DEFAULT_RHOST "127.0.0.1"
1369 #define DEFAULT_RPORT "5555"
1370 
1371 static const char *ud_socket_path = DEFAULT_UD_SOCKET;
1372 static const char *lhost = DEFAULT_LHOST;
1373 static const char *lport = DEFAULT_LPORT;
1374 static const char *rhost = DEFAULT_RHOST;
1375 static const char *rport = DEFAULT_RPORT;
1376 
1377 int
1378 main(int argc, char *argv[])
1379 {
1380     VubrDev *dev;
1381     int opt;
1382     bool client = false;
1383 
1384     while ((opt = getopt(argc, argv, "l:r:u:c")) != -1) {
1385 
1386         switch (opt) {
1387         case 'l':
1388             if (vubr_parse_host_port(&lhost, &lport, optarg) < 0) {
1389                 goto out;
1390             }
1391             break;
1392         case 'r':
1393             if (vubr_parse_host_port(&rhost, &rport, optarg) < 0) {
1394                 goto out;
1395             }
1396             break;
1397         case 'u':
1398             ud_socket_path = strdup(optarg);
1399             break;
1400         case 'c':
1401             client = true;
1402             break;
1403         default:
1404             goto out;
1405         }
1406     }
1407 
1408     DPRINT("ud socket: %s (%s)\n", ud_socket_path,
1409            client ? "client" : "server");
1410     DPRINT("local:     %s:%s\n", lhost, lport);
1411     DPRINT("remote:    %s:%s\n", rhost, rport);
1412 
1413     dev = vubr_new(ud_socket_path, client);
1414     if (!dev) {
1415         return 1;
1416     }
1417 
1418     vubr_backend_udp_setup(dev, lhost, lport, rhost, rport);
1419     vubr_run(dev);
1420     return 0;
1421 
1422 out:
1423     fprintf(stderr, "Usage: %s ", argv[0]);
1424     fprintf(stderr, "[-c] [-u ud_socket_path] [-l lhost:lport] [-r rhost:rport]\n");
1425     fprintf(stderr, "\t-u path to unix doman socket. default: %s\n",
1426             DEFAULT_UD_SOCKET);
1427     fprintf(stderr, "\t-l local host and port. default: %s:%s\n",
1428             DEFAULT_LHOST, DEFAULT_LPORT);
1429     fprintf(stderr, "\t-r remote host and port. default: %s:%s\n",
1430             DEFAULT_RHOST, DEFAULT_RPORT);
1431     fprintf(stderr, "\t-c client mode\n");
1432 
1433     return 1;
1434 }
1435