xref: /openbmc/qemu/io/channel-socket.c (revision 782ee711)
1 /*
2  * QEMU I/O channels sockets driver
3  *
4  * Copyright (c) 2015 Red Hat, Inc.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qapi/error.h"
22 #include "qapi/qapi-visit-sockets.h"
23 #include "qemu/module.h"
24 #include "io/channel-socket.h"
25 #include "io/channel-util.h"
26 #include "io/channel-watch.h"
27 #include "trace.h"
28 #include "qapi/clone-visitor.h"
29 #ifdef CONFIG_LINUX
30 #include <linux/errqueue.h>
31 #include <sys/socket.h>
32 
33 #if (defined(MSG_ZEROCOPY) && defined(SO_ZEROCOPY))
34 #define QEMU_MSG_ZEROCOPY
35 #endif
36 #endif
37 
38 #define SOCKET_MAX_FDS 16
39 
40 SocketAddress *
41 qio_channel_socket_get_local_address(QIOChannelSocket *ioc,
42                                      Error **errp)
43 {
44     return socket_sockaddr_to_address(&ioc->localAddr,
45                                       ioc->localAddrLen,
46                                       errp);
47 }
48 
49 SocketAddress *
50 qio_channel_socket_get_remote_address(QIOChannelSocket *ioc,
51                                       Error **errp)
52 {
53     return socket_sockaddr_to_address(&ioc->remoteAddr,
54                                       ioc->remoteAddrLen,
55                                       errp);
56 }
57 
58 QIOChannelSocket *
59 qio_channel_socket_new(void)
60 {
61     QIOChannelSocket *sioc;
62     QIOChannel *ioc;
63 
64     sioc = QIO_CHANNEL_SOCKET(object_new(TYPE_QIO_CHANNEL_SOCKET));
65     sioc->fd = -1;
66     sioc->zero_copy_queued = 0;
67     sioc->zero_copy_sent = 0;
68 
69     ioc = QIO_CHANNEL(sioc);
70     qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
71 
72 #ifdef WIN32
73     ioc->event = CreateEvent(NULL, FALSE, FALSE, NULL);
74 #endif
75 
76     trace_qio_channel_socket_new(sioc);
77 
78     return sioc;
79 }
80 
81 
82 static int
83 qio_channel_socket_set_fd(QIOChannelSocket *sioc,
84                           int fd,
85                           Error **errp)
86 {
87     if (sioc->fd != -1) {
88         error_setg(errp, "Socket is already open");
89         return -1;
90     }
91 
92     sioc->fd = fd;
93     sioc->remoteAddrLen = sizeof(sioc->remoteAddr);
94     sioc->localAddrLen = sizeof(sioc->localAddr);
95 
96 
97     if (getpeername(fd, (struct sockaddr *)&sioc->remoteAddr,
98                     &sioc->remoteAddrLen) < 0) {
99         if (errno == ENOTCONN) {
100             memset(&sioc->remoteAddr, 0, sizeof(sioc->remoteAddr));
101             sioc->remoteAddrLen = sizeof(sioc->remoteAddr);
102         } else {
103             error_setg_errno(errp, errno,
104                              "Unable to query remote socket address");
105             goto error;
106         }
107     }
108 
109     if (getsockname(fd, (struct sockaddr *)&sioc->localAddr,
110                     &sioc->localAddrLen) < 0) {
111         error_setg_errno(errp, errno,
112                          "Unable to query local socket address");
113         goto error;
114     }
115 
116 #ifndef WIN32
117     if (sioc->localAddr.ss_family == AF_UNIX) {
118         QIOChannel *ioc = QIO_CHANNEL(sioc);
119         qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS);
120     }
121 #endif /* WIN32 */
122 
123     return 0;
124 
125  error:
126     sioc->fd = -1; /* Let the caller close FD on failure */
127     return -1;
128 }
129 
130 QIOChannelSocket *
131 qio_channel_socket_new_fd(int fd,
132                           Error **errp)
133 {
134     QIOChannelSocket *ioc;
135 
136     ioc = qio_channel_socket_new();
137     if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
138         object_unref(OBJECT(ioc));
139         return NULL;
140     }
141 
142     trace_qio_channel_socket_new_fd(ioc, fd);
143 
144     return ioc;
145 }
146 
147 
148 int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
149                                     SocketAddress *addr,
150                                     Error **errp)
151 {
152     int fd;
153 
154     trace_qio_channel_socket_connect_sync(ioc, addr);
155     fd = socket_connect(addr, errp);
156     if (fd < 0) {
157         trace_qio_channel_socket_connect_fail(ioc);
158         return -1;
159     }
160 
161     trace_qio_channel_socket_connect_complete(ioc, fd);
162     if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
163         close(fd);
164         return -1;
165     }
166 
167 #ifdef QEMU_MSG_ZEROCOPY
168     int ret, v = 1;
169     ret = setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &v, sizeof(v));
170     if (ret == 0) {
171         /* Zero copy available on host */
172         qio_channel_set_feature(QIO_CHANNEL(ioc),
173                                 QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY);
174     }
175 #endif
176 
177     qio_channel_set_feature(QIO_CHANNEL(ioc),
178                             QIO_CHANNEL_FEATURE_READ_MSG_PEEK);
179 
180     return 0;
181 }
182 
183 
184 static void qio_channel_socket_connect_worker(QIOTask *task,
185                                               gpointer opaque)
186 {
187     QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
188     SocketAddress *addr = opaque;
189     Error *err = NULL;
190 
191     qio_channel_socket_connect_sync(ioc, addr, &err);
192 
193     qio_task_set_error(task, err);
194 }
195 
196 
197 void qio_channel_socket_connect_async(QIOChannelSocket *ioc,
198                                       SocketAddress *addr,
199                                       QIOTaskFunc callback,
200                                       gpointer opaque,
201                                       GDestroyNotify destroy,
202                                       GMainContext *context)
203 {
204     QIOTask *task = qio_task_new(
205         OBJECT(ioc), callback, opaque, destroy);
206     SocketAddress *addrCopy;
207 
208     addrCopy = QAPI_CLONE(SocketAddress, addr);
209 
210     /* socket_connect() does a non-blocking connect(), but it
211      * still blocks in DNS lookups, so we must use a thread */
212     trace_qio_channel_socket_connect_async(ioc, addr);
213     qio_task_run_in_thread(task,
214                            qio_channel_socket_connect_worker,
215                            addrCopy,
216                            (GDestroyNotify)qapi_free_SocketAddress,
217                            context);
218 }
219 
220 
221 int qio_channel_socket_listen_sync(QIOChannelSocket *ioc,
222                                    SocketAddress *addr,
223                                    int num,
224                                    Error **errp)
225 {
226     int fd;
227 
228     trace_qio_channel_socket_listen_sync(ioc, addr, num);
229     fd = socket_listen(addr, num, errp);
230     if (fd < 0) {
231         trace_qio_channel_socket_listen_fail(ioc);
232         return -1;
233     }
234 
235     trace_qio_channel_socket_listen_complete(ioc, fd);
236     if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
237         close(fd);
238         return -1;
239     }
240     qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_LISTEN);
241 
242     return 0;
243 }
244 
245 
246 struct QIOChannelListenWorkerData {
247     SocketAddress *addr;
248     int num; /* amount of expected connections */
249 };
250 
251 static void qio_channel_listen_worker_free(gpointer opaque)
252 {
253     struct QIOChannelListenWorkerData *data = opaque;
254 
255     qapi_free_SocketAddress(data->addr);
256     g_free(data);
257 }
258 
259 static void qio_channel_socket_listen_worker(QIOTask *task,
260                                              gpointer opaque)
261 {
262     QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
263     struct QIOChannelListenWorkerData *data = opaque;
264     Error *err = NULL;
265 
266     qio_channel_socket_listen_sync(ioc, data->addr, data->num, &err);
267 
268     qio_task_set_error(task, err);
269 }
270 
271 
272 void qio_channel_socket_listen_async(QIOChannelSocket *ioc,
273                                      SocketAddress *addr,
274                                      int num,
275                                      QIOTaskFunc callback,
276                                      gpointer opaque,
277                                      GDestroyNotify destroy,
278                                      GMainContext *context)
279 {
280     QIOTask *task = qio_task_new(
281         OBJECT(ioc), callback, opaque, destroy);
282     struct QIOChannelListenWorkerData *data;
283 
284     data = g_new0(struct QIOChannelListenWorkerData, 1);
285     data->addr = QAPI_CLONE(SocketAddress, addr);
286     data->num = num;
287 
288     /* socket_listen() blocks in DNS lookups, so we must use a thread */
289     trace_qio_channel_socket_listen_async(ioc, addr, num);
290     qio_task_run_in_thread(task,
291                            qio_channel_socket_listen_worker,
292                            data,
293                            qio_channel_listen_worker_free,
294                            context);
295 }
296 
297 
298 int qio_channel_socket_dgram_sync(QIOChannelSocket *ioc,
299                                   SocketAddress *localAddr,
300                                   SocketAddress *remoteAddr,
301                                   Error **errp)
302 {
303     int fd;
304 
305     trace_qio_channel_socket_dgram_sync(ioc, localAddr, remoteAddr);
306     fd = socket_dgram(remoteAddr, localAddr, errp);
307     if (fd < 0) {
308         trace_qio_channel_socket_dgram_fail(ioc);
309         return -1;
310     }
311 
312     trace_qio_channel_socket_dgram_complete(ioc, fd);
313     if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
314         close(fd);
315         return -1;
316     }
317 
318     return 0;
319 }
320 
321 
322 struct QIOChannelSocketDGramWorkerData {
323     SocketAddress *localAddr;
324     SocketAddress *remoteAddr;
325 };
326 
327 
328 static void qio_channel_socket_dgram_worker_free(gpointer opaque)
329 {
330     struct QIOChannelSocketDGramWorkerData *data = opaque;
331     qapi_free_SocketAddress(data->localAddr);
332     qapi_free_SocketAddress(data->remoteAddr);
333     g_free(data);
334 }
335 
336 static void qio_channel_socket_dgram_worker(QIOTask *task,
337                                             gpointer opaque)
338 {
339     QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
340     struct QIOChannelSocketDGramWorkerData *data = opaque;
341     Error *err = NULL;
342 
343     /* socket_dgram() blocks in DNS lookups, so we must use a thread */
344     qio_channel_socket_dgram_sync(ioc, data->localAddr,
345                                   data->remoteAddr, &err);
346 
347     qio_task_set_error(task, err);
348 }
349 
350 
351 void qio_channel_socket_dgram_async(QIOChannelSocket *ioc,
352                                     SocketAddress *localAddr,
353                                     SocketAddress *remoteAddr,
354                                     QIOTaskFunc callback,
355                                     gpointer opaque,
356                                     GDestroyNotify destroy,
357                                     GMainContext *context)
358 {
359     QIOTask *task = qio_task_new(
360         OBJECT(ioc), callback, opaque, destroy);
361     struct QIOChannelSocketDGramWorkerData *data = g_new0(
362         struct QIOChannelSocketDGramWorkerData, 1);
363 
364     data->localAddr = QAPI_CLONE(SocketAddress, localAddr);
365     data->remoteAddr = QAPI_CLONE(SocketAddress, remoteAddr);
366 
367     trace_qio_channel_socket_dgram_async(ioc, localAddr, remoteAddr);
368     qio_task_run_in_thread(task,
369                            qio_channel_socket_dgram_worker,
370                            data,
371                            qio_channel_socket_dgram_worker_free,
372                            context);
373 }
374 
375 
376 QIOChannelSocket *
377 qio_channel_socket_accept(QIOChannelSocket *ioc,
378                           Error **errp)
379 {
380     QIOChannelSocket *cioc;
381 
382     cioc = qio_channel_socket_new();
383     cioc->remoteAddrLen = sizeof(ioc->remoteAddr);
384     cioc->localAddrLen = sizeof(ioc->localAddr);
385 
386  retry:
387     trace_qio_channel_socket_accept(ioc);
388     cioc->fd = qemu_accept(ioc->fd, (struct sockaddr *)&cioc->remoteAddr,
389                            &cioc->remoteAddrLen);
390     if (cioc->fd < 0) {
391         if (errno == EINTR) {
392             goto retry;
393         }
394         error_setg_errno(errp, errno, "Unable to accept connection");
395         trace_qio_channel_socket_accept_fail(ioc);
396         goto error;
397     }
398 
399     if (getsockname(cioc->fd, (struct sockaddr *)&cioc->localAddr,
400                     &cioc->localAddrLen) < 0) {
401         error_setg_errno(errp, errno,
402                          "Unable to query local socket address");
403         goto error;
404     }
405 
406 #ifndef WIN32
407     if (cioc->localAddr.ss_family == AF_UNIX) {
408         QIOChannel *ioc_local = QIO_CHANNEL(cioc);
409         qio_channel_set_feature(ioc_local, QIO_CHANNEL_FEATURE_FD_PASS);
410     }
411 #endif /* WIN32 */
412 
413     qio_channel_set_feature(QIO_CHANNEL(cioc),
414                             QIO_CHANNEL_FEATURE_READ_MSG_PEEK);
415 
416     trace_qio_channel_socket_accept_complete(ioc, cioc, cioc->fd);
417     return cioc;
418 
419  error:
420     object_unref(OBJECT(cioc));
421     return NULL;
422 }
423 
424 static void qio_channel_socket_init(Object *obj)
425 {
426     QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
427     ioc->fd = -1;
428 }
429 
430 static void qio_channel_socket_finalize(Object *obj)
431 {
432     QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
433 
434     if (ioc->fd != -1) {
435         QIOChannel *ioc_local = QIO_CHANNEL(ioc);
436         if (qio_channel_has_feature(ioc_local, QIO_CHANNEL_FEATURE_LISTEN)) {
437             Error *err = NULL;
438 
439             socket_listen_cleanup(ioc->fd, &err);
440             if (err) {
441                 error_report_err(err);
442                 err = NULL;
443             }
444         }
445 #ifdef WIN32
446         qemu_socket_unselect(ioc->fd, NULL);
447 #endif
448         close(ioc->fd);
449         ioc->fd = -1;
450     }
451 }
452 
453 
454 #ifndef WIN32
455 static void qio_channel_socket_copy_fds(struct msghdr *msg,
456                                         int **fds, size_t *nfds)
457 {
458     struct cmsghdr *cmsg;
459 
460     *nfds = 0;
461     *fds = NULL;
462 
463     for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
464         int fd_size, i;
465         int gotfds;
466 
467         if (cmsg->cmsg_len < CMSG_LEN(sizeof(int)) ||
468             cmsg->cmsg_level != SOL_SOCKET ||
469             cmsg->cmsg_type != SCM_RIGHTS) {
470             continue;
471         }
472 
473         fd_size = cmsg->cmsg_len - CMSG_LEN(0);
474 
475         if (!fd_size) {
476             continue;
477         }
478 
479         gotfds = fd_size / sizeof(int);
480         *fds = g_renew(int, *fds, *nfds + gotfds);
481         memcpy(*fds + *nfds, CMSG_DATA(cmsg), fd_size);
482 
483         for (i = 0; i < gotfds; i++) {
484             int fd = (*fds)[*nfds + i];
485             if (fd < 0) {
486                 continue;
487             }
488 
489             /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */
490             qemu_socket_set_block(fd);
491 
492 #ifndef MSG_CMSG_CLOEXEC
493             qemu_set_cloexec(fd);
494 #endif
495         }
496         *nfds += gotfds;
497     }
498 }
499 
500 
501 static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
502                                         const struct iovec *iov,
503                                         size_t niov,
504                                         int **fds,
505                                         size_t *nfds,
506                                         int flags,
507                                         Error **errp)
508 {
509     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
510     ssize_t ret;
511     struct msghdr msg = { NULL, };
512     char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
513     int sflags = 0;
514 
515     memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS));
516 
517     msg.msg_iov = (struct iovec *)iov;
518     msg.msg_iovlen = niov;
519     if (fds && nfds) {
520         msg.msg_control = control;
521         msg.msg_controllen = sizeof(control);
522 #ifdef MSG_CMSG_CLOEXEC
523         sflags |= MSG_CMSG_CLOEXEC;
524 #endif
525 
526     }
527 
528     if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) {
529         sflags |= MSG_PEEK;
530     }
531 
532  retry:
533     ret = recvmsg(sioc->fd, &msg, sflags);
534     if (ret < 0) {
535         if (errno == EAGAIN) {
536             return QIO_CHANNEL_ERR_BLOCK;
537         }
538         if (errno == EINTR) {
539             goto retry;
540         }
541 
542         error_setg_errno(errp, errno,
543                          "Unable to read from socket");
544         return -1;
545     }
546 
547     if (fds && nfds) {
548         qio_channel_socket_copy_fds(&msg, fds, nfds);
549     }
550 
551     return ret;
552 }
553 
554 static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
555                                          const struct iovec *iov,
556                                          size_t niov,
557                                          int *fds,
558                                          size_t nfds,
559                                          int flags,
560                                          Error **errp)
561 {
562     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
563     ssize_t ret;
564     struct msghdr msg = { NULL, };
565     char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
566     size_t fdsize = sizeof(int) * nfds;
567     struct cmsghdr *cmsg;
568     int sflags = 0;
569 
570     memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS));
571 
572     msg.msg_iov = (struct iovec *)iov;
573     msg.msg_iovlen = niov;
574 
575     if (nfds) {
576         if (nfds > SOCKET_MAX_FDS) {
577             error_setg_errno(errp, EINVAL,
578                              "Only %d FDs can be sent, got %zu",
579                              SOCKET_MAX_FDS, nfds);
580             return -1;
581         }
582 
583         msg.msg_control = control;
584         msg.msg_controllen = CMSG_SPACE(sizeof(int) * nfds);
585 
586         cmsg = CMSG_FIRSTHDR(&msg);
587         cmsg->cmsg_len = CMSG_LEN(fdsize);
588         cmsg->cmsg_level = SOL_SOCKET;
589         cmsg->cmsg_type = SCM_RIGHTS;
590         memcpy(CMSG_DATA(cmsg), fds, fdsize);
591     }
592 
593     if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) {
594 #ifdef QEMU_MSG_ZEROCOPY
595         sflags = MSG_ZEROCOPY;
596 #else
597         /*
598          * We expect QIOChannel class entry point to have
599          * blocked this code path already
600          */
601         g_assert_not_reached();
602 #endif
603     }
604 
605  retry:
606     ret = sendmsg(sioc->fd, &msg, sflags);
607     if (ret <= 0) {
608         switch (errno) {
609         case EAGAIN:
610             return QIO_CHANNEL_ERR_BLOCK;
611         case EINTR:
612             goto retry;
613         case ENOBUFS:
614             if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) {
615                 error_setg_errno(errp, errno,
616                                  "Process can't lock enough memory for using MSG_ZEROCOPY");
617                 return -1;
618             }
619             break;
620         }
621 
622         error_setg_errno(errp, errno,
623                          "Unable to write to socket");
624         return -1;
625     }
626 
627     if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) {
628         sioc->zero_copy_queued++;
629     }
630 
631     return ret;
632 }
633 #else /* WIN32 */
634 static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
635                                         const struct iovec *iov,
636                                         size_t niov,
637                                         int **fds,
638                                         size_t *nfds,
639                                         int flags,
640                                         Error **errp)
641 {
642     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
643     ssize_t done = 0;
644     ssize_t i;
645     int sflags = 0;
646 
647     if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) {
648         sflags |= MSG_PEEK;
649     }
650 
651     for (i = 0; i < niov; i++) {
652         ssize_t ret;
653     retry:
654         ret = recv(sioc->fd,
655                    iov[i].iov_base,
656                    iov[i].iov_len,
657                    sflags);
658         if (ret < 0) {
659             if (errno == EAGAIN) {
660                 if (done) {
661                     return done;
662                 } else {
663                     return QIO_CHANNEL_ERR_BLOCK;
664                 }
665             } else if (errno == EINTR) {
666                 goto retry;
667             } else {
668                 error_setg_errno(errp, errno,
669                                  "Unable to read from socket");
670                 return -1;
671             }
672         }
673         done += ret;
674         if (ret < iov[i].iov_len) {
675             return done;
676         }
677     }
678 
679     return done;
680 }
681 
682 static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
683                                          const struct iovec *iov,
684                                          size_t niov,
685                                          int *fds,
686                                          size_t nfds,
687                                          int flags,
688                                          Error **errp)
689 {
690     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
691     ssize_t done = 0;
692     ssize_t i;
693 
694     for (i = 0; i < niov; i++) {
695         ssize_t ret;
696     retry:
697         ret = send(sioc->fd,
698                    iov[i].iov_base,
699                    iov[i].iov_len,
700                    0);
701         if (ret < 0) {
702             if (errno == EAGAIN) {
703                 if (done) {
704                     return done;
705                 } else {
706                     return QIO_CHANNEL_ERR_BLOCK;
707                 }
708             } else if (errno == EINTR) {
709                 goto retry;
710             } else {
711                 error_setg_errno(errp, errno,
712                                  "Unable to write to socket");
713                 return -1;
714             }
715         }
716         done += ret;
717         if (ret < iov[i].iov_len) {
718             return done;
719         }
720     }
721 
722     return done;
723 }
724 #endif /* WIN32 */
725 
726 
727 #ifdef QEMU_MSG_ZEROCOPY
728 static int qio_channel_socket_flush(QIOChannel *ioc,
729                                     Error **errp)
730 {
731     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
732     struct msghdr msg = {};
733     struct sock_extended_err *serr;
734     struct cmsghdr *cm;
735     char control[CMSG_SPACE(sizeof(*serr))];
736     int received;
737     int ret;
738 
739     if (sioc->zero_copy_queued == sioc->zero_copy_sent) {
740         return 0;
741     }
742 
743     msg.msg_control = control;
744     msg.msg_controllen = sizeof(control);
745     memset(control, 0, sizeof(control));
746 
747     ret = 1;
748 
749     while (sioc->zero_copy_sent < sioc->zero_copy_queued) {
750         received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE);
751         if (received < 0) {
752             switch (errno) {
753             case EAGAIN:
754                 /* Nothing on errqueue, wait until something is available */
755                 qio_channel_wait(ioc, G_IO_ERR);
756                 continue;
757             case EINTR:
758                 continue;
759             default:
760                 error_setg_errno(errp, errno,
761                                  "Unable to read errqueue");
762                 return -1;
763             }
764         }
765 
766         cm = CMSG_FIRSTHDR(&msg);
767         if (cm->cmsg_level != SOL_IP   && cm->cmsg_type != IP_RECVERR &&
768             cm->cmsg_level != SOL_IPV6 && cm->cmsg_type != IPV6_RECVERR) {
769             error_setg_errno(errp, EPROTOTYPE,
770                              "Wrong cmsg in errqueue");
771             return -1;
772         }
773 
774         serr = (void *) CMSG_DATA(cm);
775         if (serr->ee_errno != SO_EE_ORIGIN_NONE) {
776             error_setg_errno(errp, serr->ee_errno,
777                              "Error on socket");
778             return -1;
779         }
780         if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
781             error_setg_errno(errp, serr->ee_origin,
782                              "Error not from zero copy");
783             return -1;
784         }
785 
786         /* No errors, count successfully finished sendmsg()*/
787         sioc->zero_copy_sent += serr->ee_data - serr->ee_info + 1;
788 
789         /* If any sendmsg() succeeded using zero copy, return 0 at the end */
790         if (serr->ee_code != SO_EE_CODE_ZEROCOPY_COPIED) {
791             ret = 0;
792         }
793     }
794 
795     return ret;
796 }
797 
798 #endif /* QEMU_MSG_ZEROCOPY */
799 
800 static int
801 qio_channel_socket_set_blocking(QIOChannel *ioc,
802                                 bool enabled,
803                                 Error **errp)
804 {
805     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
806 
807     if (enabled) {
808         qemu_socket_set_block(sioc->fd);
809     } else {
810         qemu_socket_set_nonblock(sioc->fd);
811     }
812     return 0;
813 }
814 
815 
816 static void
817 qio_channel_socket_set_delay(QIOChannel *ioc,
818                              bool enabled)
819 {
820     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
821     int v = enabled ? 0 : 1;
822 
823     setsockopt(sioc->fd,
824                IPPROTO_TCP, TCP_NODELAY,
825                &v, sizeof(v));
826 }
827 
828 
829 static void
830 qio_channel_socket_set_cork(QIOChannel *ioc,
831                             bool enabled)
832 {
833     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
834     int v = enabled ? 1 : 0;
835 
836     socket_set_cork(sioc->fd, v);
837 }
838 
839 
840 static int
841 qio_channel_socket_close(QIOChannel *ioc,
842                          Error **errp)
843 {
844     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
845     int rc = 0;
846     Error *err = NULL;
847 
848     if (sioc->fd != -1) {
849 #ifdef WIN32
850         qemu_socket_unselect(sioc->fd, NULL);
851 #endif
852         if (qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_LISTEN)) {
853             socket_listen_cleanup(sioc->fd, errp);
854         }
855 
856         if (close(sioc->fd) < 0) {
857             sioc->fd = -1;
858             error_setg_errno(&err, errno, "Unable to close socket");
859             error_propagate(errp, err);
860             return -1;
861         }
862         sioc->fd = -1;
863     }
864     return rc;
865 }
866 
867 static int
868 qio_channel_socket_shutdown(QIOChannel *ioc,
869                             QIOChannelShutdown how,
870                             Error **errp)
871 {
872     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
873     int sockhow;
874 
875     switch (how) {
876     case QIO_CHANNEL_SHUTDOWN_READ:
877         sockhow = SHUT_RD;
878         break;
879     case QIO_CHANNEL_SHUTDOWN_WRITE:
880         sockhow = SHUT_WR;
881         break;
882     case QIO_CHANNEL_SHUTDOWN_BOTH:
883     default:
884         sockhow = SHUT_RDWR;
885         break;
886     }
887 
888     if (shutdown(sioc->fd, sockhow) < 0) {
889         error_setg_errno(errp, errno,
890                          "Unable to shutdown socket");
891         return -1;
892     }
893     return 0;
894 }
895 
896 static void qio_channel_socket_set_aio_fd_handler(QIOChannel *ioc,
897                                                   AioContext *read_ctx,
898                                                   IOHandler *io_read,
899                                                   AioContext *write_ctx,
900                                                   IOHandler *io_write,
901                                                   void *opaque)
902 {
903     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
904 
905     qio_channel_util_set_aio_fd_handler(sioc->fd, read_ctx, io_read,
906                                         sioc->fd, write_ctx, io_write,
907                                         opaque);
908 }
909 
910 static GSource *qio_channel_socket_create_watch(QIOChannel *ioc,
911                                                 GIOCondition condition)
912 {
913     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
914     return qio_channel_create_socket_watch(ioc,
915                                            sioc->fd,
916                                            condition);
917 }
918 
919 static void qio_channel_socket_class_init(ObjectClass *klass,
920                                           void *class_data G_GNUC_UNUSED)
921 {
922     QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
923 
924     ioc_klass->io_writev = qio_channel_socket_writev;
925     ioc_klass->io_readv = qio_channel_socket_readv;
926     ioc_klass->io_set_blocking = qio_channel_socket_set_blocking;
927     ioc_klass->io_close = qio_channel_socket_close;
928     ioc_klass->io_shutdown = qio_channel_socket_shutdown;
929     ioc_klass->io_set_cork = qio_channel_socket_set_cork;
930     ioc_klass->io_set_delay = qio_channel_socket_set_delay;
931     ioc_klass->io_create_watch = qio_channel_socket_create_watch;
932     ioc_klass->io_set_aio_fd_handler = qio_channel_socket_set_aio_fd_handler;
933 #ifdef QEMU_MSG_ZEROCOPY
934     ioc_klass->io_flush = qio_channel_socket_flush;
935 #endif
936 }
937 
938 static const TypeInfo qio_channel_socket_info = {
939     .parent = TYPE_QIO_CHANNEL,
940     .name = TYPE_QIO_CHANNEL_SOCKET,
941     .instance_size = sizeof(QIOChannelSocket),
942     .instance_init = qio_channel_socket_init,
943     .instance_finalize = qio_channel_socket_finalize,
944     .class_init = qio_channel_socket_class_init,
945 };
946 
947 static void qio_channel_socket_register_types(void)
948 {
949     type_register_static(&qio_channel_socket_info);
950 }
951 
952 type_init(qio_channel_socket_register_types);
953