xref: /openbmc/qemu/util/qemu-sockets.c (revision 3d9569b8)
1 /*
2  *  inet and unix socket functions for qemu
3  *
4  *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; under version 2 of the License.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  * Contributions after 2012-01-13 are licensed under the terms of the
16  * GNU GPL, version 2 or (at your option) any later version.
17  */
18 #include "qemu/osdep.h"
19 
20 #ifdef CONFIG_AF_VSOCK
21 #include <linux/vm_sockets.h>
22 #endif /* CONFIG_AF_VSOCK */
23 
24 #include "qemu-common.h"
25 #include "monitor/monitor.h"
26 #include "qapi/clone-visitor.h"
27 #include "qapi/error.h"
28 #include "qapi/qapi-visit-sockets.h"
29 #include "qemu/sockets.h"
30 #include "qemu/main-loop.h"
31 #include "qapi/qobject-input-visitor.h"
32 #include "qapi/qobject-output-visitor.h"
33 #include "qemu/cutils.h"
34 
35 #ifndef AI_ADDRCONFIG
36 # define AI_ADDRCONFIG 0
37 #endif
38 
39 #ifndef AI_V4MAPPED
40 # define AI_V4MAPPED 0
41 #endif
42 
43 #ifndef AI_NUMERICSERV
44 # define AI_NUMERICSERV 0
45 #endif
46 
47 
48 static int inet_getport(struct addrinfo *e)
49 {
50     struct sockaddr_in *i4;
51     struct sockaddr_in6 *i6;
52 
53     switch (e->ai_family) {
54     case PF_INET6:
55         i6 = (void*)e->ai_addr;
56         return ntohs(i6->sin6_port);
57     case PF_INET:
58         i4 = (void*)e->ai_addr;
59         return ntohs(i4->sin_port);
60     default:
61         return 0;
62     }
63 }
64 
65 static void inet_setport(struct addrinfo *e, int port)
66 {
67     struct sockaddr_in *i4;
68     struct sockaddr_in6 *i6;
69 
70     switch (e->ai_family) {
71     case PF_INET6:
72         i6 = (void*)e->ai_addr;
73         i6->sin6_port = htons(port);
74         break;
75     case PF_INET:
76         i4 = (void*)e->ai_addr;
77         i4->sin_port = htons(port);
78         break;
79     }
80 }
81 
82 NetworkAddressFamily inet_netfamily(int family)
83 {
84     switch (family) {
85     case PF_INET6: return NETWORK_ADDRESS_FAMILY_IPV6;
86     case PF_INET:  return NETWORK_ADDRESS_FAMILY_IPV4;
87     case PF_UNIX:  return NETWORK_ADDRESS_FAMILY_UNIX;
88 #ifdef CONFIG_AF_VSOCK
89     case PF_VSOCK: return NETWORK_ADDRESS_FAMILY_VSOCK;
90 #endif /* CONFIG_AF_VSOCK */
91     }
92     return NETWORK_ADDRESS_FAMILY_UNKNOWN;
93 }
94 
95 bool fd_is_socket(int fd)
96 {
97     int optval;
98     socklen_t optlen = sizeof(optval);
99     return !qemu_getsockopt(fd, SOL_SOCKET, SO_TYPE, &optval, &optlen);
100 }
101 
102 
103 /*
104  * Matrix we're trying to apply
105  *
106  *  ipv4  ipv6   family
107  *   -     -       PF_UNSPEC
108  *   -     f       PF_INET
109  *   -     t       PF_INET6
110  *   f     -       PF_INET6
111  *   f     f       <error>
112  *   f     t       PF_INET6
113  *   t     -       PF_INET
114  *   t     f       PF_INET
115  *   t     t       PF_INET6/PF_UNSPEC
116  *
117  * NB, this matrix is only about getting the necessary results
118  * from getaddrinfo(). Some of the cases require further work
119  * after reading results from getaddrinfo in order to fully
120  * apply the logic the end user wants.
121  *
122  * In the first and last cases, we must set IPV6_V6ONLY=0
123  * when binding, to allow a single listener to potentially
124  * accept both IPv4+6 addresses.
125  */
126 int inet_ai_family_from_address(InetSocketAddress *addr,
127                                 Error **errp)
128 {
129     if (addr->has_ipv6 && addr->has_ipv4 &&
130         !addr->ipv6 && !addr->ipv4) {
131         error_setg(errp, "Cannot disable IPv4 and IPv6 at same time");
132         return PF_UNSPEC;
133     }
134     if ((addr->has_ipv6 && addr->ipv6) && (addr->has_ipv4 && addr->ipv4)) {
135         /*
136          * Some backends can only do a single listener. In that case
137          * we want empty hostname to resolve to "::" and then use the
138          * flag IPV6_V6ONLY==0 to get both protocols on 1 socket. This
139          * doesn't work for addresses other than "", so they're just
140          * inevitably broken until multiple listeners can be used,
141          * and thus we honour getaddrinfo automatic protocol detection
142          * Once all backends do multi-listener, remove the PF_INET6
143          * branch entirely.
144          */
145         if (!addr->host || g_str_equal(addr->host, "")) {
146             return PF_INET6;
147         } else {
148             return PF_UNSPEC;
149         }
150     }
151     if ((addr->has_ipv6 && addr->ipv6) || (addr->has_ipv4 && !addr->ipv4)) {
152         return PF_INET6;
153     }
154     if ((addr->has_ipv4 && addr->ipv4) || (addr->has_ipv6 && !addr->ipv6)) {
155         return PF_INET;
156     }
157     return PF_UNSPEC;
158 }
159 
160 static int create_fast_reuse_socket(struct addrinfo *e)
161 {
162     int slisten = qemu_socket(e->ai_family, e->ai_socktype, e->ai_protocol);
163     if (slisten < 0) {
164         return -1;
165     }
166     socket_set_fast_reuse(slisten);
167     return slisten;
168 }
169 
170 static int try_bind(int socket, InetSocketAddress *saddr, struct addrinfo *e)
171 {
172 #ifndef IPV6_V6ONLY
173     return bind(socket, e->ai_addr, e->ai_addrlen);
174 #else
175     /*
176      * Deals with first & last cases in matrix in comment
177      * for inet_ai_family_from_address().
178      */
179     int v6only =
180         ((!saddr->has_ipv4 && !saddr->has_ipv6) ||
181          (saddr->has_ipv4 && saddr->ipv4 &&
182           saddr->has_ipv6 && saddr->ipv6)) ? 0 : 1;
183     int stat;
184 
185  rebind:
186     if (e->ai_family == PF_INET6) {
187         qemu_setsockopt(socket, IPPROTO_IPV6, IPV6_V6ONLY, &v6only,
188                         sizeof(v6only));
189     }
190 
191     stat = bind(socket, e->ai_addr, e->ai_addrlen);
192     if (!stat) {
193         return 0;
194     }
195 
196     /* If we got EADDRINUSE from an IPv6 bind & v6only is unset,
197      * it could be that the IPv4 port is already claimed, so retry
198      * with v6only set
199      */
200     if (e->ai_family == PF_INET6 && errno == EADDRINUSE && !v6only) {
201         v6only = 1;
202         goto rebind;
203     }
204     return stat;
205 #endif
206 }
207 
208 static int inet_listen_saddr(InetSocketAddress *saddr,
209                              int port_offset,
210                              Error **errp)
211 {
212     struct addrinfo ai,*res,*e;
213     char port[33];
214     char uaddr[INET6_ADDRSTRLEN+1];
215     char uport[33];
216     int rc, port_min, port_max, p;
217     int slisten = -1;
218     int saved_errno = 0;
219     bool socket_created = false;
220     Error *err = NULL;
221 
222     memset(&ai,0, sizeof(ai));
223     ai.ai_flags = AI_PASSIVE;
224     if (saddr->has_numeric && saddr->numeric) {
225         ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
226     }
227     ai.ai_family = inet_ai_family_from_address(saddr, &err);
228     ai.ai_socktype = SOCK_STREAM;
229 
230     if (err) {
231         error_propagate(errp, err);
232         return -1;
233     }
234 
235     if (saddr->host == NULL) {
236         error_setg(errp, "host not specified");
237         return -1;
238     }
239     if (saddr->port != NULL) {
240         pstrcpy(port, sizeof(port), saddr->port);
241     } else {
242         port[0] = '\0';
243     }
244 
245     /* lookup */
246     if (port_offset) {
247         unsigned long long baseport;
248         if (strlen(port) == 0) {
249             error_setg(errp, "port not specified");
250             return -1;
251         }
252         if (parse_uint_full(port, &baseport, 10) < 0) {
253             error_setg(errp, "can't convert to a number: %s", port);
254             return -1;
255         }
256         if (baseport > 65535 ||
257             baseport + port_offset > 65535) {
258             error_setg(errp, "port %s out of range", port);
259             return -1;
260         }
261         snprintf(port, sizeof(port), "%d", (int)baseport + port_offset);
262     }
263     rc = getaddrinfo(strlen(saddr->host) ? saddr->host : NULL,
264                      strlen(port) ? port : NULL, &ai, &res);
265     if (rc != 0) {
266         error_setg(errp, "address resolution failed for %s:%s: %s",
267                    saddr->host, port, gai_strerror(rc));
268         return -1;
269     }
270 
271     /* create socket + bind/listen */
272     for (e = res; e != NULL; e = e->ai_next) {
273         getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
274                         uaddr,INET6_ADDRSTRLEN,uport,32,
275                         NI_NUMERICHOST | NI_NUMERICSERV);
276 
277         port_min = inet_getport(e);
278         port_max = saddr->has_to ? saddr->to + port_offset : port_min;
279         for (p = port_min; p <= port_max; p++) {
280             inet_setport(e, p);
281 
282             slisten = create_fast_reuse_socket(e);
283             if (slisten < 0) {
284                 /* First time we expect we might fail to create the socket
285                  * eg if 'e' has AF_INET6 but ipv6 kmod is not loaded.
286                  * Later iterations should always succeed if first iteration
287                  * worked though, so treat that as fatal.
288                  */
289                 if (p == port_min) {
290                     continue;
291                 } else {
292                     error_setg_errno(errp, errno,
293                                      "Failed to recreate failed listening socket");
294                     goto listen_failed;
295                 }
296             }
297             socket_created = true;
298 
299             rc = try_bind(slisten, saddr, e);
300             if (rc < 0) {
301                 if (errno != EADDRINUSE) {
302                     error_setg_errno(errp, errno, "Failed to bind socket");
303                     goto listen_failed;
304                 }
305             } else {
306                 if (!listen(slisten, 1)) {
307                     goto listen_ok;
308                 }
309                 if (errno != EADDRINUSE) {
310                     error_setg_errno(errp, errno, "Failed to listen on socket");
311                     goto listen_failed;
312                 }
313             }
314             /* Someone else managed to bind to the same port and beat us
315              * to listen on it! Socket semantics does not allow us to
316              * recover from this situation, so we need to recreate the
317              * socket to allow bind attempts for subsequent ports:
318              */
319             closesocket(slisten);
320             slisten = -1;
321         }
322     }
323     error_setg_errno(errp, errno,
324                      socket_created ?
325                      "Failed to find an available port" :
326                      "Failed to create a socket");
327 listen_failed:
328     saved_errno = errno;
329     if (slisten >= 0) {
330         closesocket(slisten);
331     }
332     freeaddrinfo(res);
333     errno = saved_errno;
334     return -1;
335 
336 listen_ok:
337     freeaddrinfo(res);
338     return slisten;
339 }
340 
341 #ifdef _WIN32
342 #define QEMU_SOCKET_RC_INPROGRESS(rc) \
343     ((rc) == -EINPROGRESS || (rc) == -EWOULDBLOCK || (rc) == -WSAEALREADY)
344 #else
345 #define QEMU_SOCKET_RC_INPROGRESS(rc) \
346     ((rc) == -EINPROGRESS)
347 #endif
348 
349 static int inet_connect_addr(struct addrinfo *addr, Error **errp);
350 
351 static int inet_connect_addr(struct addrinfo *addr, Error **errp)
352 {
353     int sock, rc;
354 
355     sock = qemu_socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
356     if (sock < 0) {
357         error_setg_errno(errp, errno, "Failed to create socket");
358         return -1;
359     }
360     socket_set_fast_reuse(sock);
361 
362     /* connect to peer */
363     do {
364         rc = 0;
365         if (connect(sock, addr->ai_addr, addr->ai_addrlen) < 0) {
366             rc = -errno;
367         }
368     } while (rc == -EINTR);
369 
370     if (rc < 0) {
371         error_setg_errno(errp, errno, "Failed to connect socket");
372         closesocket(sock);
373         return -1;
374     }
375 
376     return sock;
377 }
378 
379 static struct addrinfo *inet_parse_connect_saddr(InetSocketAddress *saddr,
380                                                  Error **errp)
381 {
382     struct addrinfo ai, *res;
383     int rc;
384     Error *err = NULL;
385     static int useV4Mapped = 1;
386 
387     memset(&ai, 0, sizeof(ai));
388 
389     ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
390     if (atomic_read(&useV4Mapped)) {
391         ai.ai_flags |= AI_V4MAPPED;
392     }
393     ai.ai_family = inet_ai_family_from_address(saddr, &err);
394     ai.ai_socktype = SOCK_STREAM;
395 
396     if (err) {
397         error_propagate(errp, err);
398         return NULL;
399     }
400 
401     if (saddr->host == NULL || saddr->port == NULL) {
402         error_setg(errp, "host and/or port not specified");
403         return NULL;
404     }
405 
406     /* lookup */
407     rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
408 
409     /* At least FreeBSD and OS-X 10.6 declare AI_V4MAPPED but
410      * then don't implement it in their getaddrinfo(). Detect
411      * this and retry without the flag since that's preferrable
412      * to a fatal error
413      */
414     if (rc == EAI_BADFLAGS &&
415         (ai.ai_flags & AI_V4MAPPED)) {
416         atomic_set(&useV4Mapped, 0);
417         ai.ai_flags &= ~AI_V4MAPPED;
418         rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
419     }
420     if (rc != 0) {
421         error_setg(errp, "address resolution failed for %s:%s: %s",
422                    saddr->host, saddr->port, gai_strerror(rc));
423         return NULL;
424     }
425     return res;
426 }
427 
428 /**
429  * Create a socket and connect it to an address.
430  *
431  * @saddr: Inet socket address specification
432  * @errp: set on error
433  *
434  * Returns: -1 on error, file descriptor on success.
435  */
436 int inet_connect_saddr(InetSocketAddress *saddr, Error **errp)
437 {
438     Error *local_err = NULL;
439     struct addrinfo *res, *e;
440     int sock = -1;
441 
442     res = inet_parse_connect_saddr(saddr, errp);
443     if (!res) {
444         return -1;
445     }
446 
447     for (e = res; e != NULL; e = e->ai_next) {
448         error_free(local_err);
449         local_err = NULL;
450         sock = inet_connect_addr(e, &local_err);
451         if (sock >= 0) {
452             break;
453         }
454     }
455 
456     if (sock < 0) {
457         error_propagate(errp, local_err);
458     }
459 
460     freeaddrinfo(res);
461     return sock;
462 }
463 
464 static int inet_dgram_saddr(InetSocketAddress *sraddr,
465                             InetSocketAddress *sladdr,
466                             Error **errp)
467 {
468     struct addrinfo ai, *peer = NULL, *local = NULL;
469     const char *addr;
470     const char *port;
471     int sock = -1, rc;
472     Error *err = NULL;
473 
474     /* lookup peer addr */
475     memset(&ai,0, sizeof(ai));
476     ai.ai_flags = AI_CANONNAME | AI_V4MAPPED | AI_ADDRCONFIG;
477     ai.ai_family = inet_ai_family_from_address(sraddr, &err);
478     ai.ai_socktype = SOCK_DGRAM;
479 
480     if (err) {
481         error_propagate(errp, err);
482         goto err;
483     }
484 
485     addr = sraddr->host;
486     port = sraddr->port;
487     if (addr == NULL || strlen(addr) == 0) {
488         addr = "localhost";
489     }
490     if (port == NULL || strlen(port) == 0) {
491         error_setg(errp, "remote port not specified");
492         goto err;
493     }
494 
495     if ((rc = getaddrinfo(addr, port, &ai, &peer)) != 0) {
496         error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
497                    gai_strerror(rc));
498         goto err;
499     }
500 
501     /* lookup local addr */
502     memset(&ai,0, sizeof(ai));
503     ai.ai_flags = AI_PASSIVE;
504     ai.ai_family = peer->ai_family;
505     ai.ai_socktype = SOCK_DGRAM;
506 
507     if (sladdr) {
508         addr = sladdr->host;
509         port = sladdr->port;
510         if (addr == NULL || strlen(addr) == 0) {
511             addr = NULL;
512         }
513         if (!port || strlen(port) == 0) {
514             port = "0";
515         }
516     } else {
517         addr = NULL;
518         port = "0";
519     }
520 
521     if ((rc = getaddrinfo(addr, port, &ai, &local)) != 0) {
522         error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
523                    gai_strerror(rc));
524         goto err;
525     }
526 
527     /* create socket */
528     sock = qemu_socket(peer->ai_family, peer->ai_socktype, peer->ai_protocol);
529     if (sock < 0) {
530         error_setg_errno(errp, errno, "Failed to create socket");
531         goto err;
532     }
533     socket_set_fast_reuse(sock);
534 
535     /* bind socket */
536     if (bind(sock, local->ai_addr, local->ai_addrlen) < 0) {
537         error_setg_errno(errp, errno, "Failed to bind socket");
538         goto err;
539     }
540 
541     /* connect to peer */
542     if (connect(sock,peer->ai_addr,peer->ai_addrlen) < 0) {
543         error_setg_errno(errp, errno, "Failed to connect socket");
544         goto err;
545     }
546 
547     freeaddrinfo(local);
548     freeaddrinfo(peer);
549     return sock;
550 
551 err:
552     if (sock != -1) {
553         closesocket(sock);
554     }
555     if (local) {
556         freeaddrinfo(local);
557     }
558     if (peer) {
559         freeaddrinfo(peer);
560     }
561 
562     return -1;
563 }
564 
565 /* compatibility wrapper */
566 static int inet_parse_flag(const char *flagname, const char *optstr, bool *val,
567                            Error **errp)
568 {
569     char *end;
570     size_t len;
571 
572     end = strstr(optstr, ",");
573     if (end) {
574         if (end[1] == ',') { /* Reject 'ipv6=on,,foo' */
575             error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
576             return -1;
577         }
578         len = end - optstr;
579     } else {
580         len = strlen(optstr);
581     }
582     if (len == 0 || (len == 3 && strncmp(optstr, "=on", len) == 0)) {
583         *val = true;
584     } else if (len == 4 && strncmp(optstr, "=off", len) == 0) {
585         *val = false;
586     } else {
587         error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
588         return -1;
589     }
590     return 0;
591 }
592 
593 int inet_parse(InetSocketAddress *addr, const char *str, Error **errp)
594 {
595     const char *optstr, *h;
596     char host[65];
597     char port[33];
598     int to;
599     int pos;
600     char *begin;
601 
602     memset(addr, 0, sizeof(*addr));
603 
604     /* parse address */
605     if (str[0] == ':') {
606         /* no host given */
607         host[0] = '\0';
608         if (sscanf(str, ":%32[^,]%n", port, &pos) != 1) {
609             error_setg(errp, "error parsing port in address '%s'", str);
610             return -1;
611         }
612     } else if (str[0] == '[') {
613         /* IPv6 addr */
614         if (sscanf(str, "[%64[^]]]:%32[^,]%n", host, port, &pos) != 2) {
615             error_setg(errp, "error parsing IPv6 address '%s'", str);
616             return -1;
617         }
618     } else {
619         /* hostname or IPv4 addr */
620         if (sscanf(str, "%64[^:]:%32[^,]%n", host, port, &pos) != 2) {
621             error_setg(errp, "error parsing address '%s'", str);
622             return -1;
623         }
624     }
625 
626     addr->host = g_strdup(host);
627     addr->port = g_strdup(port);
628 
629     /* parse options */
630     optstr = str + pos;
631     h = strstr(optstr, ",to=");
632     if (h) {
633         h += 4;
634         if (sscanf(h, "%d%n", &to, &pos) != 1 ||
635             (h[pos] != '\0' && h[pos] != ',')) {
636             error_setg(errp, "error parsing to= argument");
637             return -1;
638         }
639         addr->has_to = true;
640         addr->to = to;
641     }
642     begin = strstr(optstr, ",ipv4");
643     if (begin) {
644         if (inet_parse_flag("ipv4", begin + 5, &addr->ipv4, errp) < 0) {
645             return -1;
646         }
647         addr->has_ipv4 = true;
648     }
649     begin = strstr(optstr, ",ipv6");
650     if (begin) {
651         if (inet_parse_flag("ipv6", begin + 5, &addr->ipv6, errp) < 0) {
652             return -1;
653         }
654         addr->has_ipv6 = true;
655     }
656     return 0;
657 }
658 
659 
660 /**
661  * Create a blocking socket and connect it to an address.
662  *
663  * @str: address string
664  * @errp: set in case of an error
665  *
666  * Returns -1 in case of error, file descriptor on success
667  **/
668 int inet_connect(const char *str, Error **errp)
669 {
670     int sock = -1;
671     InetSocketAddress *addr = g_new(InetSocketAddress, 1);
672 
673     if (!inet_parse(addr, str, errp)) {
674         sock = inet_connect_saddr(addr, errp);
675     }
676     qapi_free_InetSocketAddress(addr);
677     return sock;
678 }
679 
680 #ifdef CONFIG_AF_VSOCK
681 static bool vsock_parse_vaddr_to_sockaddr(const VsockSocketAddress *vaddr,
682                                           struct sockaddr_vm *svm,
683                                           Error **errp)
684 {
685     unsigned long long val;
686 
687     memset(svm, 0, sizeof(*svm));
688     svm->svm_family = AF_VSOCK;
689 
690     if (parse_uint_full(vaddr->cid, &val, 10) < 0 ||
691         val > UINT32_MAX) {
692         error_setg(errp, "Failed to parse cid '%s'", vaddr->cid);
693         return false;
694     }
695     svm->svm_cid = val;
696 
697     if (parse_uint_full(vaddr->port, &val, 10) < 0 ||
698         val > UINT32_MAX) {
699         error_setg(errp, "Failed to parse port '%s'", vaddr->port);
700         return false;
701     }
702     svm->svm_port = val;
703 
704     return true;
705 }
706 
707 static int vsock_connect_addr(const struct sockaddr_vm *svm, Error **errp)
708 {
709     int sock, rc;
710 
711     sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
712     if (sock < 0) {
713         error_setg_errno(errp, errno, "Failed to create socket");
714         return -1;
715     }
716 
717     /* connect to peer */
718     do {
719         rc = 0;
720         if (connect(sock, (const struct sockaddr *)svm, sizeof(*svm)) < 0) {
721             rc = -errno;
722         }
723     } while (rc == -EINTR);
724 
725     if (rc < 0) {
726         error_setg_errno(errp, errno, "Failed to connect socket");
727         closesocket(sock);
728         return -1;
729     }
730 
731     return sock;
732 }
733 
734 static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
735 {
736     struct sockaddr_vm svm;
737     int sock = -1;
738 
739     if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
740         return -1;
741     }
742 
743     sock = vsock_connect_addr(&svm, errp);
744 
745     return sock;
746 }
747 
748 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
749                               Error **errp)
750 {
751     struct sockaddr_vm svm;
752     int slisten;
753 
754     if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
755         return -1;
756     }
757 
758     slisten = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
759     if (slisten < 0) {
760         error_setg_errno(errp, errno, "Failed to create socket");
761         return -1;
762     }
763 
764     if (bind(slisten, (const struct sockaddr *)&svm, sizeof(svm)) != 0) {
765         error_setg_errno(errp, errno, "Failed to bind socket");
766         closesocket(slisten);
767         return -1;
768     }
769 
770     if (listen(slisten, 1) != 0) {
771         error_setg_errno(errp, errno, "Failed to listen on socket");
772         closesocket(slisten);
773         return -1;
774     }
775     return slisten;
776 }
777 
778 static int vsock_parse(VsockSocketAddress *addr, const char *str,
779                        Error **errp)
780 {
781     char cid[33];
782     char port[33];
783     int n;
784 
785     if (sscanf(str, "%32[^:]:%32[^,]%n", cid, port, &n) != 2) {
786         error_setg(errp, "error parsing address '%s'", str);
787         return -1;
788     }
789     if (str[n] != '\0') {
790         error_setg(errp, "trailing characters in address '%s'", str);
791         return -1;
792     }
793 
794     addr->cid = g_strdup(cid);
795     addr->port = g_strdup(port);
796     return 0;
797 }
798 #else
799 static void vsock_unsupported(Error **errp)
800 {
801     error_setg(errp, "socket family AF_VSOCK unsupported");
802 }
803 
804 static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
805 {
806     vsock_unsupported(errp);
807     return -1;
808 }
809 
810 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
811                               Error **errp)
812 {
813     vsock_unsupported(errp);
814     return -1;
815 }
816 
817 static int vsock_parse(VsockSocketAddress *addr, const char *str,
818                         Error **errp)
819 {
820     vsock_unsupported(errp);
821     return -1;
822 }
823 #endif /* CONFIG_AF_VSOCK */
824 
825 #ifndef _WIN32
826 
827 static int unix_listen_saddr(UnixSocketAddress *saddr,
828                              Error **errp)
829 {
830     struct sockaddr_un un;
831     int sock, fd;
832     char *pathbuf = NULL;
833     const char *path;
834     size_t pathlen;
835 
836     sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
837     if (sock < 0) {
838         error_setg_errno(errp, errno, "Failed to create Unix socket");
839         return -1;
840     }
841 
842     if (saddr->path && saddr->path[0]) {
843         path = saddr->path;
844     } else {
845         const char *tmpdir = getenv("TMPDIR");
846         tmpdir = tmpdir ? tmpdir : "/tmp";
847         path = pathbuf = g_strdup_printf("%s/qemu-socket-XXXXXX", tmpdir);
848     }
849 
850     pathlen = strlen(path);
851     if (pathlen > sizeof(un.sun_path)) {
852         error_setg(errp, "UNIX socket path '%s' is too long", path);
853         error_append_hint(errp, "Path must be less than %zu bytes\n",
854                           sizeof(un.sun_path));
855         goto err;
856     }
857 
858     if (pathbuf != NULL) {
859         /*
860          * This dummy fd usage silences the mktemp() unsecure warning.
861          * Using mkstemp() doesn't make things more secure here
862          * though.  bind() complains about existing files, so we have
863          * to unlink first and thus re-open the race window.  The
864          * worst case possible is bind() failing, i.e. a DoS attack.
865          */
866         fd = mkstemp(pathbuf);
867         if (fd < 0) {
868             error_setg_errno(errp, errno,
869                              "Failed to make a temporary socket %s", pathbuf);
870             goto err;
871         }
872         close(fd);
873     }
874 
875     if (unlink(path) < 0 && errno != ENOENT) {
876         error_setg_errno(errp, errno,
877                          "Failed to unlink socket %s", path);
878         goto err;
879     }
880 
881     memset(&un, 0, sizeof(un));
882     un.sun_family = AF_UNIX;
883     memcpy(un.sun_path, path, pathlen);
884 
885     if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
886         error_setg_errno(errp, errno, "Failed to bind socket to %s", path);
887         goto err;
888     }
889     if (listen(sock, 1) < 0) {
890         error_setg_errno(errp, errno, "Failed to listen on socket");
891         goto err;
892     }
893 
894     g_free(pathbuf);
895     return sock;
896 
897 err:
898     g_free(pathbuf);
899     closesocket(sock);
900     return -1;
901 }
902 
903 static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
904 {
905     struct sockaddr_un un;
906     int sock, rc;
907     size_t pathlen;
908 
909     if (saddr->path == NULL) {
910         error_setg(errp, "unix connect: no path specified");
911         return -1;
912     }
913 
914     sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
915     if (sock < 0) {
916         error_setg_errno(errp, errno, "Failed to create socket");
917         return -1;
918     }
919 
920     pathlen = strlen(saddr->path);
921     if (pathlen > sizeof(un.sun_path)) {
922         error_setg(errp, "UNIX socket path '%s' is too long", saddr->path);
923         error_append_hint(errp, "Path must be less than %zu bytes\n",
924                           sizeof(un.sun_path));
925         goto err;
926     }
927 
928     memset(&un, 0, sizeof(un));
929     un.sun_family = AF_UNIX;
930     memcpy(un.sun_path, saddr->path, pathlen);
931 
932     /* connect to peer */
933     do {
934         rc = 0;
935         if (connect(sock, (struct sockaddr *) &un, sizeof(un)) < 0) {
936             rc = -errno;
937         }
938     } while (rc == -EINTR);
939 
940     if (rc < 0) {
941         error_setg_errno(errp, -rc, "Failed to connect socket %s",
942                          saddr->path);
943         goto err;
944     }
945 
946     return sock;
947 
948  err:
949     close(sock);
950     return -1;
951 }
952 
953 #else
954 
955 static int unix_listen_saddr(UnixSocketAddress *saddr,
956                              Error **errp)
957 {
958     error_setg(errp, "unix sockets are not available on windows");
959     errno = ENOTSUP;
960     return -1;
961 }
962 
963 static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
964 {
965     error_setg(errp, "unix sockets are not available on windows");
966     errno = ENOTSUP;
967     return -1;
968 }
969 #endif
970 
971 /* compatibility wrapper */
972 int unix_listen(const char *str, Error **errp)
973 {
974     UnixSocketAddress *saddr;
975     int sock;
976 
977     saddr = g_new0(UnixSocketAddress, 1);
978     saddr->path = g_strdup(str);
979     sock = unix_listen_saddr(saddr, errp);
980     qapi_free_UnixSocketAddress(saddr);
981     return sock;
982 }
983 
984 int unix_connect(const char *path, Error **errp)
985 {
986     UnixSocketAddress *saddr;
987     int sock;
988 
989     saddr = g_new0(UnixSocketAddress, 1);
990     saddr->path = g_strdup(path);
991     sock = unix_connect_saddr(saddr, errp);
992     qapi_free_UnixSocketAddress(saddr);
993     return sock;
994 }
995 
996 
997 SocketAddress *socket_parse(const char *str, Error **errp)
998 {
999     SocketAddress *addr;
1000 
1001     addr = g_new0(SocketAddress, 1);
1002     if (strstart(str, "unix:", NULL)) {
1003         if (str[5] == '\0') {
1004             error_setg(errp, "invalid Unix socket address");
1005             goto fail;
1006         } else {
1007             addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1008             addr->u.q_unix.path = g_strdup(str + 5);
1009         }
1010     } else if (strstart(str, "fd:", NULL)) {
1011         if (str[3] == '\0') {
1012             error_setg(errp, "invalid file descriptor address");
1013             goto fail;
1014         } else {
1015             addr->type = SOCKET_ADDRESS_TYPE_FD;
1016             addr->u.fd.str = g_strdup(str + 3);
1017         }
1018     } else if (strstart(str, "vsock:", NULL)) {
1019         addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1020         if (vsock_parse(&addr->u.vsock, str + strlen("vsock:"), errp)) {
1021             goto fail;
1022         }
1023     } else {
1024         addr->type = SOCKET_ADDRESS_TYPE_INET;
1025         if (inet_parse(&addr->u.inet, str, errp)) {
1026             goto fail;
1027         }
1028     }
1029     return addr;
1030 
1031 fail:
1032     qapi_free_SocketAddress(addr);
1033     return NULL;
1034 }
1035 
1036 static int socket_get_fd(const char *fdstr, Error **errp)
1037 {
1038     int fd;
1039     if (cur_mon) {
1040         fd = monitor_get_fd(cur_mon, fdstr, errp);
1041         if (fd < 0) {
1042             return -1;
1043         }
1044     } else {
1045         if (qemu_strtoi(fdstr, NULL, 10, &fd) < 0) {
1046             error_setg_errno(errp, errno,
1047                              "Unable to parse FD number %s",
1048                              fdstr);
1049             return -1;
1050         }
1051     }
1052     if (!fd_is_socket(fd)) {
1053         error_setg(errp, "File descriptor '%s' is not a socket", fdstr);
1054         close(fd);
1055         return -1;
1056     }
1057     return fd;
1058 }
1059 
1060 int socket_connect(SocketAddress *addr, Error **errp)
1061 {
1062     int fd;
1063 
1064     switch (addr->type) {
1065     case SOCKET_ADDRESS_TYPE_INET:
1066         fd = inet_connect_saddr(&addr->u.inet, errp);
1067         break;
1068 
1069     case SOCKET_ADDRESS_TYPE_UNIX:
1070         fd = unix_connect_saddr(&addr->u.q_unix, errp);
1071         break;
1072 
1073     case SOCKET_ADDRESS_TYPE_FD:
1074         fd = socket_get_fd(addr->u.fd.str, errp);
1075         break;
1076 
1077     case SOCKET_ADDRESS_TYPE_VSOCK:
1078         fd = vsock_connect_saddr(&addr->u.vsock, errp);
1079         break;
1080 
1081     default:
1082         abort();
1083     }
1084     return fd;
1085 }
1086 
1087 int socket_listen(SocketAddress *addr, Error **errp)
1088 {
1089     int fd;
1090 
1091     switch (addr->type) {
1092     case SOCKET_ADDRESS_TYPE_INET:
1093         fd = inet_listen_saddr(&addr->u.inet, 0, errp);
1094         break;
1095 
1096     case SOCKET_ADDRESS_TYPE_UNIX:
1097         fd = unix_listen_saddr(&addr->u.q_unix, errp);
1098         break;
1099 
1100     case SOCKET_ADDRESS_TYPE_FD:
1101         fd = socket_get_fd(addr->u.fd.str, errp);
1102         break;
1103 
1104     case SOCKET_ADDRESS_TYPE_VSOCK:
1105         fd = vsock_listen_saddr(&addr->u.vsock, errp);
1106         break;
1107 
1108     default:
1109         abort();
1110     }
1111     return fd;
1112 }
1113 
1114 void socket_listen_cleanup(int fd, Error **errp)
1115 {
1116     SocketAddress *addr;
1117 
1118     addr = socket_local_address(fd, errp);
1119     if (!addr) {
1120         return;
1121     }
1122 
1123     if (addr->type == SOCKET_ADDRESS_TYPE_UNIX
1124         && addr->u.q_unix.path) {
1125         if (unlink(addr->u.q_unix.path) < 0 && errno != ENOENT) {
1126             error_setg_errno(errp, errno,
1127                              "Failed to unlink socket %s",
1128                              addr->u.q_unix.path);
1129         }
1130     }
1131 
1132     qapi_free_SocketAddress(addr);
1133 }
1134 
1135 int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp)
1136 {
1137     int fd;
1138 
1139     /*
1140      * TODO SOCKET_ADDRESS_TYPE_FD when fd is AF_INET or AF_INET6
1141      * (although other address families can do SOCK_DGRAM, too)
1142      */
1143     switch (remote->type) {
1144     case SOCKET_ADDRESS_TYPE_INET:
1145         fd = inet_dgram_saddr(&remote->u.inet,
1146                               local ? &local->u.inet : NULL, errp);
1147         break;
1148 
1149     default:
1150         error_setg(errp, "socket type unsupported for datagram");
1151         fd = -1;
1152     }
1153     return fd;
1154 }
1155 
1156 
1157 static SocketAddress *
1158 socket_sockaddr_to_address_inet(struct sockaddr_storage *sa,
1159                                 socklen_t salen,
1160                                 Error **errp)
1161 {
1162     char host[NI_MAXHOST];
1163     char serv[NI_MAXSERV];
1164     SocketAddress *addr;
1165     InetSocketAddress *inet;
1166     int ret;
1167 
1168     ret = getnameinfo((struct sockaddr *)sa, salen,
1169                       host, sizeof(host),
1170                       serv, sizeof(serv),
1171                       NI_NUMERICHOST | NI_NUMERICSERV);
1172     if (ret != 0) {
1173         error_setg(errp, "Cannot format numeric socket address: %s",
1174                    gai_strerror(ret));
1175         return NULL;
1176     }
1177 
1178     addr = g_new0(SocketAddress, 1);
1179     addr->type = SOCKET_ADDRESS_TYPE_INET;
1180     inet = &addr->u.inet;
1181     inet->host = g_strdup(host);
1182     inet->port = g_strdup(serv);
1183     if (sa->ss_family == AF_INET) {
1184         inet->has_ipv4 = inet->ipv4 = true;
1185     } else {
1186         inet->has_ipv6 = inet->ipv6 = true;
1187     }
1188 
1189     return addr;
1190 }
1191 
1192 
1193 #ifndef WIN32
1194 static SocketAddress *
1195 socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
1196                                 socklen_t salen,
1197                                 Error **errp)
1198 {
1199     SocketAddress *addr;
1200     struct sockaddr_un *su = (struct sockaddr_un *)sa;
1201 
1202     addr = g_new0(SocketAddress, 1);
1203     addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1204     if (su->sun_path[0]) {
1205         addr->u.q_unix.path = g_strndup(su->sun_path, sizeof(su->sun_path));
1206     }
1207 
1208     return addr;
1209 }
1210 #endif /* WIN32 */
1211 
1212 #ifdef CONFIG_AF_VSOCK
1213 static SocketAddress *
1214 socket_sockaddr_to_address_vsock(struct sockaddr_storage *sa,
1215                                  socklen_t salen,
1216                                  Error **errp)
1217 {
1218     SocketAddress *addr;
1219     VsockSocketAddress *vaddr;
1220     struct sockaddr_vm *svm = (struct sockaddr_vm *)sa;
1221 
1222     addr = g_new0(SocketAddress, 1);
1223     addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1224     vaddr = &addr->u.vsock;
1225     vaddr->cid = g_strdup_printf("%u", svm->svm_cid);
1226     vaddr->port = g_strdup_printf("%u", svm->svm_port);
1227 
1228     return addr;
1229 }
1230 #endif /* CONFIG_AF_VSOCK */
1231 
1232 SocketAddress *
1233 socket_sockaddr_to_address(struct sockaddr_storage *sa,
1234                            socklen_t salen,
1235                            Error **errp)
1236 {
1237     switch (sa->ss_family) {
1238     case AF_INET:
1239     case AF_INET6:
1240         return socket_sockaddr_to_address_inet(sa, salen, errp);
1241 
1242 #ifndef WIN32
1243     case AF_UNIX:
1244         return socket_sockaddr_to_address_unix(sa, salen, errp);
1245 #endif /* WIN32 */
1246 
1247 #ifdef CONFIG_AF_VSOCK
1248     case AF_VSOCK:
1249         return socket_sockaddr_to_address_vsock(sa, salen, errp);
1250 #endif
1251 
1252     default:
1253         error_setg(errp, "socket family %d unsupported",
1254                    sa->ss_family);
1255         return NULL;
1256     }
1257     return 0;
1258 }
1259 
1260 
1261 SocketAddress *socket_local_address(int fd, Error **errp)
1262 {
1263     struct sockaddr_storage ss;
1264     socklen_t sslen = sizeof(ss);
1265 
1266     if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0) {
1267         error_setg_errno(errp, errno, "%s",
1268                          "Unable to query local socket address");
1269         return NULL;
1270     }
1271 
1272     return socket_sockaddr_to_address(&ss, sslen, errp);
1273 }
1274 
1275 
1276 SocketAddress *socket_remote_address(int fd, Error **errp)
1277 {
1278     struct sockaddr_storage ss;
1279     socklen_t sslen = sizeof(ss);
1280 
1281     if (getpeername(fd, (struct sockaddr *)&ss, &sslen) < 0) {
1282         error_setg_errno(errp, errno, "%s",
1283                          "Unable to query remote socket address");
1284         return NULL;
1285     }
1286 
1287     return socket_sockaddr_to_address(&ss, sslen, errp);
1288 }
1289 
1290 
1291 SocketAddress *socket_address_flatten(SocketAddressLegacy *addr_legacy)
1292 {
1293     SocketAddress *addr;
1294 
1295     if (!addr_legacy) {
1296         return NULL;
1297     }
1298 
1299     addr = g_new(SocketAddress, 1);
1300 
1301     switch (addr_legacy->type) {
1302     case SOCKET_ADDRESS_LEGACY_KIND_INET:
1303         addr->type = SOCKET_ADDRESS_TYPE_INET;
1304         QAPI_CLONE_MEMBERS(InetSocketAddress, &addr->u.inet,
1305                            addr_legacy->u.inet.data);
1306         break;
1307     case SOCKET_ADDRESS_LEGACY_KIND_UNIX:
1308         addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1309         QAPI_CLONE_MEMBERS(UnixSocketAddress, &addr->u.q_unix,
1310                            addr_legacy->u.q_unix.data);
1311         break;
1312     case SOCKET_ADDRESS_LEGACY_KIND_VSOCK:
1313         addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1314         QAPI_CLONE_MEMBERS(VsockSocketAddress, &addr->u.vsock,
1315                            addr_legacy->u.vsock.data);
1316         break;
1317     case SOCKET_ADDRESS_LEGACY_KIND_FD:
1318         addr->type = SOCKET_ADDRESS_TYPE_FD;
1319         QAPI_CLONE_MEMBERS(String, &addr->u.fd, addr_legacy->u.fd.data);
1320         break;
1321     default:
1322         abort();
1323     }
1324 
1325     return addr;
1326 }
1327