xref: /openbmc/qemu/util/qemu-sockets.c (revision a3472075147162c935d841b8f0571e5616947d6a)
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 "monitor/monitor.h"
25 #include "qapi/clone-visitor.h"
26 #include "qapi/error.h"
27 #include "qapi/qapi-visit-sockets.h"
28 #include "qemu/sockets.h"
29 #include "qemu/main-loop.h"
30 #include "qapi/qobject-input-visitor.h"
31 #include "qapi/qobject-output-visitor.h"
32 #include "qemu/cutils.h"
33 #include "trace.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 !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         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                              int num,
211                              Error **errp)
212 {
213     ERRP_GUARD();
214     struct addrinfo ai, *res, *e;
215     char port[33];
216     char uaddr[INET6_ADDRSTRLEN+1];
217     char uport[33];
218     int rc, port_min, port_max, p;
219     int slisten = -1;
220     int saved_errno = 0;
221     bool socket_created = false;
222 
223     if (saddr->keep_alive) {
224         error_setg(errp, "keep-alive option is not supported for passive "
225                    "sockets");
226         return -1;
227     }
228 
229     memset(&ai,0, sizeof(ai));
230     ai.ai_flags = AI_PASSIVE;
231     if (saddr->has_numeric && saddr->numeric) {
232         ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
233     }
234     ai.ai_socktype = SOCK_STREAM;
235     ai.ai_family = inet_ai_family_from_address(saddr, errp);
236     if (*errp) {
237         return -1;
238     }
239 
240     if (saddr->host == NULL) {
241         error_setg(errp, "host not specified");
242         return -1;
243     }
244     if (saddr->port != NULL) {
245         pstrcpy(port, sizeof(port), saddr->port);
246     } else {
247         port[0] = '\0';
248     }
249 
250     /* lookup */
251     if (port_offset) {
252         uint64_t baseport;
253         if (strlen(port) == 0) {
254             error_setg(errp, "port not specified");
255             return -1;
256         }
257         if (parse_uint_full(port, 10, &baseport) < 0) {
258             error_setg(errp, "can't convert to a number: %s", port);
259             return -1;
260         }
261         if (baseport > 65535 ||
262             baseport + port_offset > 65535) {
263             error_setg(errp, "port %s out of range", port);
264             return -1;
265         }
266         snprintf(port, sizeof(port), "%d", (int)baseport + port_offset);
267     }
268     rc = getaddrinfo(strlen(saddr->host) ? saddr->host : NULL,
269                      strlen(port) ? port : NULL, &ai, &res);
270     if (rc != 0) {
271         error_setg(errp, "address resolution failed for %s:%s: %s",
272                    saddr->host, port, gai_strerror(rc));
273         return -1;
274     }
275 
276     /* create socket + bind/listen */
277     for (e = res; e != NULL; e = e->ai_next) {
278 #ifdef HAVE_IPPROTO_MPTCP
279         if (saddr->has_mptcp && saddr->mptcp) {
280             e->ai_protocol = IPPROTO_MPTCP;
281         }
282 #endif
283         getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
284                         uaddr,INET6_ADDRSTRLEN,uport,32,
285                         NI_NUMERICHOST | NI_NUMERICSERV);
286 
287         port_min = inet_getport(e);
288         port_max = saddr->has_to ? saddr->to + port_offset : port_min;
289         for (p = port_min; p <= port_max; p++) {
290             inet_setport(e, p);
291 
292             slisten = create_fast_reuse_socket(e);
293             if (slisten < 0) {
294                 /* First time we expect we might fail to create the socket
295                  * eg if 'e' has AF_INET6 but ipv6 kmod is not loaded.
296                  * Later iterations should always succeed if first iteration
297                  * worked though, so treat that as fatal.
298                  */
299                 if (p == port_min) {
300                     continue;
301                 } else {
302                     error_setg_errno(errp, errno,
303                                      "Failed to recreate failed listening socket");
304                     goto listen_failed;
305                 }
306             }
307             socket_created = true;
308 
309             rc = try_bind(slisten, saddr, e);
310             if (rc < 0) {
311                 if (errno != EADDRINUSE) {
312                     error_setg_errno(errp, errno, "Failed to bind socket");
313                     goto listen_failed;
314                 }
315             } else {
316                 if (!listen(slisten, num)) {
317                     goto listen_ok;
318                 }
319                 if (errno != EADDRINUSE) {
320                     error_setg_errno(errp, errno, "Failed to listen on socket");
321                     goto listen_failed;
322                 }
323             }
324             /* Someone else managed to bind to the same port and beat us
325              * to listen on it! Socket semantics does not allow us to
326              * recover from this situation, so we need to recreate the
327              * socket to allow bind attempts for subsequent ports:
328              */
329             close(slisten);
330             slisten = -1;
331         }
332     }
333     error_setg_errno(errp, errno,
334                      socket_created ?
335                      "Failed to find an available port" :
336                      "Failed to create a socket");
337 listen_failed:
338     saved_errno = errno;
339     if (slisten >= 0) {
340         close(slisten);
341     }
342     freeaddrinfo(res);
343     errno = saved_errno;
344     return -1;
345 
346 listen_ok:
347     freeaddrinfo(res);
348     return slisten;
349 }
350 
351 #ifdef _WIN32
352 #define QEMU_SOCKET_RC_INPROGRESS(rc) \
353     ((rc) == -EINPROGRESS || (rc) == -EWOULDBLOCK || (rc) == -WSAEALREADY)
354 #else
355 #define QEMU_SOCKET_RC_INPROGRESS(rc) \
356     ((rc) == -EINPROGRESS)
357 #endif
358 
359 static int inet_connect_addr(const InetSocketAddress *saddr,
360                              struct addrinfo *addr, Error **errp)
361 {
362     int sock, rc;
363 
364     sock = qemu_socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
365     if (sock < 0) {
366         error_setg_errno(errp, errno, "Failed to create socket family %d",
367                          addr->ai_family);
368         return -1;
369     }
370     socket_set_fast_reuse(sock);
371 
372     /* connect to peer */
373     do {
374         rc = 0;
375         if (connect(sock, addr->ai_addr, addr->ai_addrlen) < 0) {
376             rc = -errno;
377         }
378     } while (rc == -EINTR);
379 
380     if (rc < 0) {
381         error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
382                          saddr->host, saddr->port);
383         close(sock);
384         return -1;
385     }
386 
387     return sock;
388 }
389 
390 static struct addrinfo *inet_parse_connect_saddr(InetSocketAddress *saddr,
391                                                  Error **errp)
392 {
393     ERRP_GUARD();
394     struct addrinfo ai, *res;
395     int rc;
396     static int useV4Mapped = 1;
397 
398     memset(&ai, 0, sizeof(ai));
399 
400     ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
401     if (qatomic_read(&useV4Mapped)) {
402         ai.ai_flags |= AI_V4MAPPED;
403     }
404     ai.ai_socktype = SOCK_STREAM;
405     ai.ai_family = inet_ai_family_from_address(saddr, errp);
406     if (*errp) {
407         return NULL;
408     }
409 
410     if (saddr->host == NULL || saddr->port == NULL) {
411         error_setg(errp, "host and/or port not specified");
412         return NULL;
413     }
414 
415     /* lookup */
416     rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
417 
418     /* At least FreeBSD and OS-X 10.6 declare AI_V4MAPPED but
419      * then don't implement it in their getaddrinfo(). Detect
420      * this and retry without the flag since that's preferable
421      * to a fatal error
422      */
423     if (rc == EAI_BADFLAGS &&
424         (ai.ai_flags & AI_V4MAPPED)) {
425         qatomic_set(&useV4Mapped, 0);
426         ai.ai_flags &= ~AI_V4MAPPED;
427         rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
428     }
429     if (rc != 0) {
430         error_setg(errp, "address resolution failed for %s:%s: %s",
431                    saddr->host, saddr->port, gai_strerror(rc));
432         return NULL;
433     }
434     return res;
435 }
436 
437 /**
438  * Create a socket and connect it to an address.
439  *
440  * @saddr: Inet socket address specification
441  * @errp: set on error
442  *
443  * Returns: -1 on error, file descriptor on success.
444  */
445 int inet_connect_saddr(InetSocketAddress *saddr, Error **errp)
446 {
447     Error *local_err = NULL;
448     struct addrinfo *res, *e;
449     int sock = -1;
450 
451     res = inet_parse_connect_saddr(saddr, errp);
452     if (!res) {
453         return -1;
454     }
455 
456     for (e = res; e != NULL; e = e->ai_next) {
457         error_free(local_err);
458         local_err = NULL;
459 
460 #ifdef HAVE_IPPROTO_MPTCP
461         if (saddr->has_mptcp && saddr->mptcp) {
462             e->ai_protocol = IPPROTO_MPTCP;
463         }
464 #endif
465 
466         sock = inet_connect_addr(saddr, e, &local_err);
467         if (sock >= 0) {
468             break;
469         }
470     }
471 
472     freeaddrinfo(res);
473 
474     if (sock < 0) {
475         error_propagate(errp, local_err);
476         return sock;
477     }
478 
479     if (saddr->keep_alive) {
480         int val = 1;
481         int ret = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
482                              &val, sizeof(val));
483 
484         if (ret < 0) {
485             error_setg_errno(errp, errno, "Unable to set KEEPALIVE");
486             close(sock);
487             return -1;
488         }
489     }
490 
491     return sock;
492 }
493 
494 static int inet_dgram_saddr(InetSocketAddress *sraddr,
495                             InetSocketAddress *sladdr,
496                             Error **errp)
497 {
498     ERRP_GUARD();
499     struct addrinfo ai, *peer = NULL, *local = NULL;
500     const char *addr;
501     const char *port;
502     int sock = -1, rc;
503 
504     /* lookup peer addr */
505     memset(&ai,0, sizeof(ai));
506     ai.ai_flags = AI_CANONNAME | AI_V4MAPPED | AI_ADDRCONFIG;
507     ai.ai_socktype = SOCK_DGRAM;
508     ai.ai_family = inet_ai_family_from_address(sraddr, errp);
509     if (*errp) {
510         goto err;
511     }
512 
513     addr = sraddr->host;
514     port = sraddr->port;
515     if (addr == NULL || strlen(addr) == 0) {
516         addr = "localhost";
517     }
518     if (port == NULL || strlen(port) == 0) {
519         error_setg(errp, "remote port not specified");
520         goto err;
521     }
522 
523     if ((rc = getaddrinfo(addr, port, &ai, &peer)) != 0) {
524         error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
525                    gai_strerror(rc));
526         goto err;
527     }
528 
529     /* lookup local addr */
530     memset(&ai,0, sizeof(ai));
531     ai.ai_flags = AI_PASSIVE;
532     ai.ai_family = peer->ai_family;
533     ai.ai_socktype = SOCK_DGRAM;
534 
535     if (sladdr) {
536         addr = sladdr->host;
537         port = sladdr->port;
538         if (addr == NULL || strlen(addr) == 0) {
539             addr = NULL;
540         }
541         if (!port || strlen(port) == 0) {
542             port = "0";
543         }
544     } else {
545         addr = NULL;
546         port = "0";
547     }
548 
549     if ((rc = getaddrinfo(addr, port, &ai, &local)) != 0) {
550         error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
551                    gai_strerror(rc));
552         goto err;
553     }
554 
555     /* create socket */
556     sock = qemu_socket(peer->ai_family, peer->ai_socktype, peer->ai_protocol);
557     if (sock < 0) {
558         error_setg_errno(errp, errno, "Failed to create socket family %d",
559                          peer->ai_family);
560         goto err;
561     }
562     socket_set_fast_reuse(sock);
563 
564     /* bind socket */
565     if (bind(sock, local->ai_addr, local->ai_addrlen) < 0) {
566         error_setg_errno(errp, errno, "Failed to bind socket");
567         goto err;
568     }
569 
570     /* connect to peer */
571     if (connect(sock,peer->ai_addr,peer->ai_addrlen) < 0) {
572         error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
573                          addr, port);
574         goto err;
575     }
576 
577     freeaddrinfo(local);
578     freeaddrinfo(peer);
579     return sock;
580 
581 err:
582     if (sock != -1) {
583         close(sock);
584     }
585     if (local) {
586         freeaddrinfo(local);
587     }
588     if (peer) {
589         freeaddrinfo(peer);
590     }
591 
592     return -1;
593 }
594 
595 /* compatibility wrapper */
596 static int inet_parse_flag(const char *flagname, const char *optstr, bool *val,
597                            Error **errp)
598 {
599     char *end;
600     size_t len;
601 
602     end = strstr(optstr, ",");
603     if (end) {
604         if (end[1] == ',') { /* Reject 'ipv6=on,,foo' */
605             error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
606             return -1;
607         }
608         len = end - optstr;
609     } else {
610         len = strlen(optstr);
611     }
612     if (len == 0 || (len == 3 && strncmp(optstr, "=on", len) == 0)) {
613         *val = true;
614     } else if (len == 4 && strncmp(optstr, "=off", len) == 0) {
615         *val = false;
616     } else {
617         error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
618         return -1;
619     }
620     return 0;
621 }
622 
623 int inet_parse(InetSocketAddress *addr, const char *str, Error **errp)
624 {
625     const char *optstr, *h;
626     char host[65];
627     char port[33];
628     int to;
629     int pos;
630     char *begin;
631 
632     memset(addr, 0, sizeof(*addr));
633 
634     /* parse address */
635     if (str[0] == ':') {
636         /* no host given */
637         host[0] = '\0';
638         if (sscanf(str, ":%32[^,]%n", port, &pos) != 1) {
639             error_setg(errp, "error parsing port in address '%s'", str);
640             return -1;
641         }
642     } else if (str[0] == '[') {
643         /* IPv6 addr */
644         if (sscanf(str, "[%64[^]]]:%32[^,]%n", host, port, &pos) != 2) {
645             error_setg(errp, "error parsing IPv6 address '%s'", str);
646             return -1;
647         }
648     } else {
649         /* hostname or IPv4 addr */
650         if (sscanf(str, "%64[^:]:%32[^,]%n", host, port, &pos) != 2) {
651             error_setg(errp, "error parsing address '%s'", str);
652             return -1;
653         }
654     }
655 
656     addr->host = g_strdup(host);
657     addr->port = g_strdup(port);
658 
659     /* parse options */
660     optstr = str + pos;
661     h = strstr(optstr, ",to=");
662     if (h) {
663         h += 4;
664         if (sscanf(h, "%d%n", &to, &pos) != 1 ||
665             (h[pos] != '\0' && h[pos] != ',')) {
666             error_setg(errp, "error parsing to= argument");
667             return -1;
668         }
669         addr->has_to = true;
670         addr->to = to;
671     }
672     begin = strstr(optstr, ",ipv4");
673     if (begin) {
674         if (inet_parse_flag("ipv4", begin + 5, &addr->ipv4, errp) < 0) {
675             return -1;
676         }
677         addr->has_ipv4 = true;
678     }
679     begin = strstr(optstr, ",ipv6");
680     if (begin) {
681         if (inet_parse_flag("ipv6", begin + 5, &addr->ipv6, errp) < 0) {
682             return -1;
683         }
684         addr->has_ipv6 = true;
685     }
686     begin = strstr(optstr, ",keep-alive");
687     if (begin) {
688         if (inet_parse_flag("keep-alive", begin + strlen(",keep-alive"),
689                             &addr->keep_alive, errp) < 0)
690         {
691             return -1;
692         }
693         addr->has_keep_alive = true;
694     }
695 #ifdef HAVE_IPPROTO_MPTCP
696     begin = strstr(optstr, ",mptcp");
697     if (begin) {
698         if (inet_parse_flag("mptcp", begin + strlen(",mptcp"),
699                             &addr->mptcp, errp) < 0)
700         {
701             return -1;
702         }
703         addr->has_mptcp = true;
704     }
705 #endif
706     return 0;
707 }
708 
709 
710 #ifdef CONFIG_AF_VSOCK
711 static bool vsock_parse_vaddr_to_sockaddr(const VsockSocketAddress *vaddr,
712                                           struct sockaddr_vm *svm,
713                                           Error **errp)
714 {
715     uint64_t val;
716 
717     memset(svm, 0, sizeof(*svm));
718     svm->svm_family = AF_VSOCK;
719 
720     if (parse_uint_full(vaddr->cid, 10, &val) < 0 ||
721         val > UINT32_MAX) {
722         error_setg(errp, "Failed to parse cid '%s'", vaddr->cid);
723         return false;
724     }
725     svm->svm_cid = val;
726 
727     if (parse_uint_full(vaddr->port, 10, &val) < 0 ||
728         val > UINT32_MAX) {
729         error_setg(errp, "Failed to parse port '%s'", vaddr->port);
730         return false;
731     }
732     svm->svm_port = val;
733 
734     return true;
735 }
736 
737 static int vsock_connect_addr(const VsockSocketAddress *vaddr,
738                               const struct sockaddr_vm *svm, Error **errp)
739 {
740     int sock, rc;
741 
742     sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
743     if (sock < 0) {
744         error_setg_errno(errp, errno, "Failed to create socket family %d",
745                          AF_VSOCK);
746         return -1;
747     }
748 
749     /* connect to peer */
750     do {
751         rc = 0;
752         if (connect(sock, (const struct sockaddr *)svm, sizeof(*svm)) < 0) {
753             rc = -errno;
754         }
755     } while (rc == -EINTR);
756 
757     if (rc < 0) {
758         error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
759                          vaddr->cid, vaddr->port);
760         close(sock);
761         return -1;
762     }
763 
764     return sock;
765 }
766 
767 static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
768 {
769     struct sockaddr_vm svm;
770 
771     if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
772         return -1;
773     }
774 
775     return vsock_connect_addr(vaddr, &svm, errp);
776 }
777 
778 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
779                               int num,
780                               Error **errp)
781 {
782     struct sockaddr_vm svm;
783     int slisten;
784 
785     if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
786         return -1;
787     }
788 
789     slisten = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
790     if (slisten < 0) {
791         error_setg_errno(errp, errno, "Failed to create socket");
792         return -1;
793     }
794 
795     if (bind(slisten, (const struct sockaddr *)&svm, sizeof(svm)) != 0) {
796         error_setg_errno(errp, errno, "Failed to bind socket");
797         close(slisten);
798         return -1;
799     }
800 
801     if (listen(slisten, num) != 0) {
802         error_setg_errno(errp, errno, "Failed to listen on socket");
803         close(slisten);
804         return -1;
805     }
806     return slisten;
807 }
808 
809 static int vsock_parse(VsockSocketAddress *addr, const char *str,
810                        Error **errp)
811 {
812     char cid[33];
813     char port[33];
814     int n;
815 
816     if (sscanf(str, "%32[^:]:%32[^,]%n", cid, port, &n) != 2) {
817         error_setg(errp, "error parsing address '%s'", str);
818         return -1;
819     }
820     if (str[n] != '\0') {
821         error_setg(errp, "trailing characters in address '%s'", str);
822         return -1;
823     }
824 
825     addr->cid = g_strdup(cid);
826     addr->port = g_strdup(port);
827     return 0;
828 }
829 #else
830 static void vsock_unsupported(Error **errp)
831 {
832     error_setg(errp, "socket family AF_VSOCK unsupported");
833 }
834 
835 static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
836 {
837     vsock_unsupported(errp);
838     return -1;
839 }
840 
841 static int vsock_listen_saddr(VsockSocketAddress *vaddr,
842                               int num,
843                               Error **errp)
844 {
845     vsock_unsupported(errp);
846     return -1;
847 }
848 
849 static int vsock_parse(VsockSocketAddress *addr, const char *str,
850                         Error **errp)
851 {
852     vsock_unsupported(errp);
853     return -1;
854 }
855 #endif /* CONFIG_AF_VSOCK */
856 
857 static bool saddr_is_abstract(UnixSocketAddress *saddr)
858 {
859 #ifdef CONFIG_LINUX
860     return saddr->abstract;
861 #else
862     return false;
863 #endif
864 }
865 
866 static bool saddr_is_tight(UnixSocketAddress *saddr)
867 {
868 #ifdef CONFIG_LINUX
869     return !saddr->has_tight || saddr->tight;
870 #else
871     return false;
872 #endif
873 }
874 
875 static int unix_listen_saddr(UnixSocketAddress *saddr,
876                              int num,
877                              Error **errp)
878 {
879     bool abstract = saddr_is_abstract(saddr);
880     struct sockaddr_un un;
881     int sock, fd;
882     char *pathbuf = NULL;
883     const char *path;
884     size_t pathlen;
885     size_t addrlen;
886 
887     sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
888     if (sock < 0) {
889         error_setg_errno(errp, errno, "Failed to create Unix socket");
890         return -1;
891     }
892 
893     if (saddr->path[0] || abstract) {
894         path = saddr->path;
895     } else {
896         path = pathbuf = g_strdup_printf("%s/qemu-socket-XXXXXX",
897                                          g_get_tmp_dir());
898     }
899 
900     pathlen = strlen(path);
901     if (pathlen > sizeof(un.sun_path) ||
902         (abstract && pathlen > (sizeof(un.sun_path) - 1))) {
903         error_setg(errp, "UNIX socket path '%s' is too long", path);
904         error_append_hint(errp, "Path must be less than %zu bytes\n",
905                           abstract ? sizeof(un.sun_path) - 1 :
906                           sizeof(un.sun_path));
907         goto err;
908     }
909 
910     if (pathbuf != NULL) {
911         /*
912          * This dummy fd usage silences the mktemp() insecure warning.
913          * Using mkstemp() doesn't make things more secure here
914          * though.  bind() complains about existing files, so we have
915          * to unlink first and thus re-open the race window.  The
916          * worst case possible is bind() failing, i.e. a DoS attack.
917          */
918         fd = mkstemp(pathbuf);
919         if (fd < 0) {
920             error_setg_errno(errp, errno,
921                              "Failed to make a temporary socket %s", pathbuf);
922             goto err;
923         }
924         close(fd);
925     }
926 
927     if (!abstract && unlink(path) < 0 && errno != ENOENT) {
928         error_setg_errno(errp, errno,
929                          "Failed to unlink socket %s", path);
930         goto err;
931     }
932 
933     memset(&un, 0, sizeof(un));
934     un.sun_family = AF_UNIX;
935     addrlen = sizeof(un);
936 
937     if (abstract) {
938         un.sun_path[0] = '\0';
939         memcpy(&un.sun_path[1], path, pathlen);
940         if (saddr_is_tight(saddr)) {
941             addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen;
942         }
943     } else {
944         memcpy(un.sun_path, path, pathlen);
945     }
946 
947     if (bind(sock, (struct sockaddr *) &un, addrlen) < 0) {
948         error_setg_errno(errp, errno, "Failed to bind socket to %s", path);
949         goto err;
950     }
951     if (listen(sock, num) < 0) {
952         error_setg_errno(errp, errno, "Failed to listen on socket");
953         goto err;
954     }
955 
956     g_free(pathbuf);
957     return sock;
958 
959 err:
960     g_free(pathbuf);
961     close(sock);
962     return -1;
963 }
964 
965 static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
966 {
967     bool abstract = saddr_is_abstract(saddr);
968     struct sockaddr_un un;
969     int sock, rc;
970     size_t pathlen;
971     size_t addrlen;
972 
973     if (saddr->path == NULL) {
974         error_setg(errp, "unix connect: no path specified");
975         return -1;
976     }
977 
978     sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
979     if (sock < 0) {
980         error_setg_errno(errp, errno, "Failed to create socket");
981         return -1;
982     }
983 
984     pathlen = strlen(saddr->path);
985     if (pathlen > sizeof(un.sun_path) ||
986         (abstract && pathlen > (sizeof(un.sun_path) - 1))) {
987         error_setg(errp, "UNIX socket path '%s' is too long", saddr->path);
988         error_append_hint(errp, "Path must be less than %zu bytes\n",
989                           abstract ? sizeof(un.sun_path) - 1 :
990                           sizeof(un.sun_path));
991         goto err;
992     }
993 
994     memset(&un, 0, sizeof(un));
995     un.sun_family = AF_UNIX;
996     addrlen = sizeof(un);
997 
998     if (abstract) {
999         un.sun_path[0] = '\0';
1000         memcpy(&un.sun_path[1], saddr->path, pathlen);
1001         if (saddr_is_tight(saddr)) {
1002             addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen;
1003         }
1004     } else {
1005         memcpy(un.sun_path, saddr->path, pathlen);
1006     }
1007     /* connect to peer */
1008     do {
1009         rc = 0;
1010         if (connect(sock, (struct sockaddr *) &un, addrlen) < 0) {
1011             rc = -errno;
1012         }
1013     } while (rc == -EINTR);
1014 
1015     if (rc < 0) {
1016         error_setg_errno(errp, -rc, "Failed to connect to '%s'",
1017                          saddr->path);
1018         goto err;
1019     }
1020 
1021     return sock;
1022 
1023  err:
1024     close(sock);
1025     return -1;
1026 }
1027 
1028 /* compatibility wrapper */
1029 int unix_listen(const char *str, Error **errp)
1030 {
1031     UnixSocketAddress *saddr;
1032     int sock;
1033 
1034     saddr = g_new0(UnixSocketAddress, 1);
1035     saddr->path = g_strdup(str);
1036     sock = unix_listen_saddr(saddr, 1, errp);
1037     qapi_free_UnixSocketAddress(saddr);
1038     return sock;
1039 }
1040 
1041 int unix_connect(const char *path, Error **errp)
1042 {
1043     UnixSocketAddress *saddr;
1044     int sock;
1045 
1046     saddr = g_new0(UnixSocketAddress, 1);
1047     saddr->path = g_strdup(path);
1048     sock = unix_connect_saddr(saddr, errp);
1049     qapi_free_UnixSocketAddress(saddr);
1050     return sock;
1051 }
1052 
1053 char *socket_uri(SocketAddress *addr)
1054 {
1055     switch (addr->type) {
1056     case SOCKET_ADDRESS_TYPE_INET:
1057         return g_strdup_printf("tcp:%s:%s",
1058                                addr->u.inet.host,
1059                                addr->u.inet.port);
1060     case SOCKET_ADDRESS_TYPE_UNIX:
1061         return g_strdup_printf("unix:%s",
1062                                addr->u.q_unix.path);
1063     case SOCKET_ADDRESS_TYPE_FD:
1064         return g_strdup_printf("fd:%s", addr->u.fd.str);
1065     case SOCKET_ADDRESS_TYPE_VSOCK:
1066         return g_strdup_printf("vsock:%s:%s",
1067                                addr->u.vsock.cid,
1068                                addr->u.vsock.port);
1069     default:
1070         return g_strdup("unknown address type");
1071     }
1072 }
1073 
1074 SocketAddress *socket_parse(const char *str, Error **errp)
1075 {
1076     SocketAddress *addr;
1077 
1078     addr = g_new0(SocketAddress, 1);
1079     if (strstart(str, "unix:", NULL)) {
1080         if (str[5] == '\0') {
1081             error_setg(errp, "invalid Unix socket address");
1082             goto fail;
1083         } else {
1084             addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1085             addr->u.q_unix.path = g_strdup(str + 5);
1086         }
1087     } else if (strstart(str, "fd:", NULL)) {
1088         if (str[3] == '\0') {
1089             error_setg(errp, "invalid file descriptor address");
1090             goto fail;
1091         } else {
1092             addr->type = SOCKET_ADDRESS_TYPE_FD;
1093             addr->u.fd.str = g_strdup(str + 3);
1094         }
1095     } else if (strstart(str, "vsock:", NULL)) {
1096         addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1097         if (vsock_parse(&addr->u.vsock, str + strlen("vsock:"), errp)) {
1098             goto fail;
1099         }
1100     } else if (strstart(str, "tcp:", NULL)) {
1101         addr->type = SOCKET_ADDRESS_TYPE_INET;
1102         if (inet_parse(&addr->u.inet, str + strlen("tcp:"), errp)) {
1103             goto fail;
1104         }
1105     } else {
1106         addr->type = SOCKET_ADDRESS_TYPE_INET;
1107         if (inet_parse(&addr->u.inet, str, errp)) {
1108             goto fail;
1109         }
1110     }
1111     return addr;
1112 
1113 fail:
1114     qapi_free_SocketAddress(addr);
1115     return NULL;
1116 }
1117 
1118 static int socket_get_fd(const char *fdstr, Error **errp)
1119 {
1120     Monitor *cur_mon = monitor_cur();
1121     int fd;
1122     if (cur_mon) {
1123         fd = monitor_get_fd(cur_mon, fdstr, errp);
1124         if (fd < 0) {
1125             return -1;
1126         }
1127     } else {
1128         if (qemu_strtoi(fdstr, NULL, 10, &fd) < 0) {
1129             error_setg_errno(errp, errno,
1130                              "Unable to parse FD number %s",
1131                              fdstr);
1132             return -1;
1133         }
1134     }
1135     if (!fd_is_socket(fd)) {
1136         error_setg(errp, "File descriptor '%s' is not a socket", fdstr);
1137         close(fd);
1138         return -1;
1139     }
1140     return fd;
1141 }
1142 
1143 int socket_address_parse_named_fd(SocketAddress *addr, Error **errp)
1144 {
1145     int fd;
1146 
1147     if (addr->type != SOCKET_ADDRESS_TYPE_FD) {
1148         return 0;
1149     }
1150 
1151     fd = socket_get_fd(addr->u.fd.str, errp);
1152     if (fd < 0) {
1153         return fd;
1154     }
1155 
1156     g_free(addr->u.fd.str);
1157     addr->u.fd.str = g_strdup_printf("%d", fd);
1158 
1159     return 0;
1160 }
1161 
1162 int socket_connect(SocketAddress *addr, Error **errp)
1163 {
1164     int fd;
1165 
1166     switch (addr->type) {
1167     case SOCKET_ADDRESS_TYPE_INET:
1168         fd = inet_connect_saddr(&addr->u.inet, errp);
1169         break;
1170 
1171     case SOCKET_ADDRESS_TYPE_UNIX:
1172         fd = unix_connect_saddr(&addr->u.q_unix, errp);
1173         break;
1174 
1175     case SOCKET_ADDRESS_TYPE_FD:
1176         fd = socket_get_fd(addr->u.fd.str, errp);
1177         break;
1178 
1179     case SOCKET_ADDRESS_TYPE_VSOCK:
1180         fd = vsock_connect_saddr(&addr->u.vsock, errp);
1181         break;
1182 
1183     default:
1184         abort();
1185     }
1186     return fd;
1187 }
1188 
1189 int socket_listen(SocketAddress *addr, int num, Error **errp)
1190 {
1191     int fd;
1192 
1193     trace_socket_listen(num);
1194     switch (addr->type) {
1195     case SOCKET_ADDRESS_TYPE_INET:
1196         fd = inet_listen_saddr(&addr->u.inet, 0, num, errp);
1197         break;
1198 
1199     case SOCKET_ADDRESS_TYPE_UNIX:
1200         fd = unix_listen_saddr(&addr->u.q_unix, num, errp);
1201         break;
1202 
1203     case SOCKET_ADDRESS_TYPE_FD:
1204         fd = socket_get_fd(addr->u.fd.str, errp);
1205         if (fd < 0) {
1206             return -1;
1207         }
1208 
1209         /*
1210          * If the socket is not yet in the listen state, then transition it to
1211          * the listen state now.
1212          *
1213          * If it's already listening then this updates the backlog value as
1214          * requested.
1215          *
1216          * If this socket cannot listen because it's already in another state
1217          * (e.g. unbound or connected) then we'll catch the error here.
1218          */
1219         if (listen(fd, num) != 0) {
1220             error_setg_errno(errp, errno, "Failed to listen on fd socket");
1221             close(fd);
1222             return -1;
1223         }
1224         break;
1225 
1226     case SOCKET_ADDRESS_TYPE_VSOCK:
1227         fd = vsock_listen_saddr(&addr->u.vsock, num, errp);
1228         break;
1229 
1230     default:
1231         abort();
1232     }
1233     return fd;
1234 }
1235 
1236 void socket_listen_cleanup(int fd, Error **errp)
1237 {
1238     SocketAddress *addr;
1239 
1240     addr = socket_local_address(fd, errp);
1241     if (!addr) {
1242         return;
1243     }
1244 
1245     if (addr->type == SOCKET_ADDRESS_TYPE_UNIX
1246         && addr->u.q_unix.path) {
1247         if (unlink(addr->u.q_unix.path) < 0 && errno != ENOENT) {
1248             error_setg_errno(errp, errno,
1249                              "Failed to unlink socket %s",
1250                              addr->u.q_unix.path);
1251         }
1252     }
1253 
1254     qapi_free_SocketAddress(addr);
1255 }
1256 
1257 int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp)
1258 {
1259     int fd;
1260 
1261     /*
1262      * TODO SOCKET_ADDRESS_TYPE_FD when fd is AF_INET or AF_INET6
1263      * (although other address families can do SOCK_DGRAM, too)
1264      */
1265     switch (remote->type) {
1266     case SOCKET_ADDRESS_TYPE_INET:
1267         fd = inet_dgram_saddr(&remote->u.inet,
1268                               local ? &local->u.inet : NULL, errp);
1269         break;
1270 
1271     default:
1272         error_setg(errp, "socket type unsupported for datagram");
1273         fd = -1;
1274     }
1275     return fd;
1276 }
1277 
1278 
1279 static SocketAddress *
1280 socket_sockaddr_to_address_inet(struct sockaddr_storage *sa,
1281                                 socklen_t salen,
1282                                 Error **errp)
1283 {
1284     char host[NI_MAXHOST];
1285     char serv[NI_MAXSERV];
1286     SocketAddress *addr;
1287     InetSocketAddress *inet;
1288     int ret;
1289 
1290     ret = getnameinfo((struct sockaddr *)sa, salen,
1291                       host, sizeof(host),
1292                       serv, sizeof(serv),
1293                       NI_NUMERICHOST | NI_NUMERICSERV);
1294     if (ret != 0) {
1295         error_setg(errp, "Cannot format numeric socket address: %s",
1296                    gai_strerror(ret));
1297         return NULL;
1298     }
1299 
1300     addr = g_new0(SocketAddress, 1);
1301     addr->type = SOCKET_ADDRESS_TYPE_INET;
1302     inet = &addr->u.inet;
1303     inet->host = g_strdup(host);
1304     inet->port = g_strdup(serv);
1305     if (sa->ss_family == AF_INET) {
1306         inet->has_ipv4 = inet->ipv4 = true;
1307     } else {
1308         inet->has_ipv6 = inet->ipv6 = true;
1309     }
1310 
1311     return addr;
1312 }
1313 
1314 
1315 static SocketAddress *
1316 socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
1317                                 socklen_t salen,
1318                                 Error **errp)
1319 {
1320     SocketAddress *addr;
1321     struct sockaddr_un *su = (struct sockaddr_un *)sa;
1322 
1323     addr = g_new0(SocketAddress, 1);
1324     addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1325     salen -= offsetof(struct sockaddr_un, sun_path);
1326 #ifdef CONFIG_LINUX
1327     if (salen > 0 && !su->sun_path[0]) {
1328         /* Linux abstract socket */
1329         addr->u.q_unix.path = g_strndup(su->sun_path + 1, salen - 1);
1330         addr->u.q_unix.has_abstract = true;
1331         addr->u.q_unix.abstract = true;
1332         addr->u.q_unix.has_tight = true;
1333         addr->u.q_unix.tight = salen < sizeof(su->sun_path);
1334         return addr;
1335     }
1336 #endif
1337 
1338     addr->u.q_unix.path = g_strndup(su->sun_path, salen);
1339     return addr;
1340 }
1341 
1342 #ifdef CONFIG_AF_VSOCK
1343 static SocketAddress *
1344 socket_sockaddr_to_address_vsock(struct sockaddr_storage *sa,
1345                                  socklen_t salen,
1346                                  Error **errp)
1347 {
1348     SocketAddress *addr;
1349     VsockSocketAddress *vaddr;
1350     struct sockaddr_vm *svm = (struct sockaddr_vm *)sa;
1351 
1352     addr = g_new0(SocketAddress, 1);
1353     addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1354     vaddr = &addr->u.vsock;
1355     vaddr->cid = g_strdup_printf("%u", svm->svm_cid);
1356     vaddr->port = g_strdup_printf("%u", svm->svm_port);
1357 
1358     return addr;
1359 }
1360 #endif /* CONFIG_AF_VSOCK */
1361 
1362 SocketAddress *
1363 socket_sockaddr_to_address(struct sockaddr_storage *sa,
1364                            socklen_t salen,
1365                            Error **errp)
1366 {
1367     switch (sa->ss_family) {
1368     case AF_INET:
1369     case AF_INET6:
1370         return socket_sockaddr_to_address_inet(sa, salen, errp);
1371 
1372     case AF_UNIX:
1373         return socket_sockaddr_to_address_unix(sa, salen, errp);
1374 
1375 #ifdef CONFIG_AF_VSOCK
1376     case AF_VSOCK:
1377         return socket_sockaddr_to_address_vsock(sa, salen, errp);
1378 #endif
1379 
1380     default:
1381         error_setg(errp, "socket family %d unsupported",
1382                    sa->ss_family);
1383         return NULL;
1384     }
1385     return 0;
1386 }
1387 
1388 
1389 SocketAddress *socket_local_address(int fd, Error **errp)
1390 {
1391     struct sockaddr_storage ss;
1392     socklen_t sslen = sizeof(ss);
1393 
1394     if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0) {
1395         error_setg_errno(errp, errno, "%s",
1396                          "Unable to query local socket address");
1397         return NULL;
1398     }
1399 
1400     return socket_sockaddr_to_address(&ss, sslen, errp);
1401 }
1402 
1403 
1404 SocketAddress *socket_address_flatten(SocketAddressLegacy *addr_legacy)
1405 {
1406     SocketAddress *addr;
1407 
1408     if (!addr_legacy) {
1409         return NULL;
1410     }
1411 
1412     addr = g_new(SocketAddress, 1);
1413 
1414     switch (addr_legacy->type) {
1415     case SOCKET_ADDRESS_TYPE_INET:
1416         addr->type = SOCKET_ADDRESS_TYPE_INET;
1417         QAPI_CLONE_MEMBERS(InetSocketAddress, &addr->u.inet,
1418                            addr_legacy->u.inet.data);
1419         break;
1420     case SOCKET_ADDRESS_TYPE_UNIX:
1421         addr->type = SOCKET_ADDRESS_TYPE_UNIX;
1422         QAPI_CLONE_MEMBERS(UnixSocketAddress, &addr->u.q_unix,
1423                            addr_legacy->u.q_unix.data);
1424         break;
1425     case SOCKET_ADDRESS_TYPE_VSOCK:
1426         addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
1427         QAPI_CLONE_MEMBERS(VsockSocketAddress, &addr->u.vsock,
1428                            addr_legacy->u.vsock.data);
1429         break;
1430     case SOCKET_ADDRESS_TYPE_FD:
1431         addr->type = SOCKET_ADDRESS_TYPE_FD;
1432         QAPI_CLONE_MEMBERS(FdSocketAddress, &addr->u.fd,
1433                            addr_legacy->u.fd.data);
1434         break;
1435     default:
1436         abort();
1437     }
1438 
1439     return addr;
1440 }
1441