xref: /qemu/util/qemu-sockets.c (revision 2af2bf6760d9b2190b5a76487577075578c475d6)
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 #include <stdio.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include <ctype.h>
19 #include <errno.h>
20 #include <unistd.h>
21 
22 #include "qemu_socket.h"
23 #include "qemu-common.h" /* for qemu_isdigit */
24 
25 #ifndef AI_ADDRCONFIG
26 # define AI_ADDRCONFIG 0
27 #endif
28 
29 static int sockets_debug = 0;
30 static const int on=1, off=0;
31 
32 /* used temporarely until all users are converted to QemuOpts */
33 QemuOptsList dummy_opts = {
34     .name = "dummy",
35     .head = TAILQ_HEAD_INITIALIZER(dummy_opts.head),
36     .desc = {
37         {
38             .name = "path",
39             .type = QEMU_OPT_STRING,
40         },
41         { /* end if list */ }
42     },
43 };
44 
45 static int inet_getport(struct addrinfo *e)
46 {
47     struct sockaddr_in *i4;
48     struct sockaddr_in6 *i6;
49 
50     switch (e->ai_family) {
51     case PF_INET6:
52         i6 = (void*)e->ai_addr;
53         return ntohs(i6->sin6_port);
54     case PF_INET:
55         i4 = (void*)e->ai_addr;
56         return ntohs(i4->sin_port);
57     default:
58         return 0;
59     }
60 }
61 
62 static void inet_setport(struct addrinfo *e, int port)
63 {
64     struct sockaddr_in *i4;
65     struct sockaddr_in6 *i6;
66 
67     switch (e->ai_family) {
68     case PF_INET6:
69         i6 = (void*)e->ai_addr;
70         i6->sin6_port = htons(port);
71         break;
72     case PF_INET:
73         i4 = (void*)e->ai_addr;
74         i4->sin_port = htons(port);
75         break;
76     }
77 }
78 
79 static const char *inet_strfamily(int family)
80 {
81     switch (family) {
82     case PF_INET6: return "ipv6";
83     case PF_INET:  return "ipv4";
84     case PF_UNIX:  return "unix";
85     }
86     return "????";
87 }
88 
89 static void inet_print_addrinfo(const char *tag, struct addrinfo *res)
90 {
91     struct addrinfo *e;
92     char uaddr[INET6_ADDRSTRLEN+1];
93     char uport[33];
94 
95     for (e = res; e != NULL; e = e->ai_next) {
96         getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
97                     uaddr,INET6_ADDRSTRLEN,uport,32,
98                     NI_NUMERICHOST | NI_NUMERICSERV);
99         fprintf(stderr,"%s: getaddrinfo: family %s, host %s, port %s\n",
100                 tag, inet_strfamily(e->ai_family), uaddr, uport);
101     }
102 }
103 
104 int inet_listen(const char *str, char *ostr, int olen,
105                 int socktype, int port_offset)
106 {
107     struct addrinfo ai,*res,*e;
108     char addr[64];
109     char port[33];
110     char uaddr[INET6_ADDRSTRLEN+1];
111     char uport[33];
112     const char *opts, *h;
113     int slisten,rc,pos,to,try_next;
114 
115     memset(&ai,0, sizeof(ai));
116     ai.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
117     ai.ai_family = PF_UNSPEC;
118     ai.ai_socktype = socktype;
119 
120     /* parse address */
121     if (str[0] == ':') {
122         /* no host given */
123         addr[0] = '\0';
124         if (1 != sscanf(str,":%32[^,]%n",port,&pos)) {
125             fprintf(stderr, "%s: portonly parse error (%s)\n",
126                     __FUNCTION__, str);
127             return -1;
128         }
129     } else if (str[0] == '[') {
130         /* IPv6 addr */
131         if (2 != sscanf(str,"[%64[^]]]:%32[^,]%n",addr,port,&pos)) {
132             fprintf(stderr, "%s: ipv6 parse error (%s)\n",
133                     __FUNCTION__, str);
134             return -1;
135         }
136         ai.ai_family = PF_INET6;
137     } else if (qemu_isdigit(str[0])) {
138         /* IPv4 addr */
139         if (2 != sscanf(str,"%64[0-9.]:%32[^,]%n",addr,port,&pos)) {
140             fprintf(stderr, "%s: ipv4 parse error (%s)\n",
141                     __FUNCTION__, str);
142             return -1;
143         }
144         ai.ai_family = PF_INET;
145     } else {
146         /* hostname */
147         if (2 != sscanf(str,"%64[^:]:%32[^,]%n",addr,port,&pos)) {
148             fprintf(stderr, "%s: hostname parse error (%s)\n",
149                     __FUNCTION__, str);
150             return -1;
151         }
152     }
153 
154     /* parse options */
155     opts = str + pos;
156     h = strstr(opts, ",to=");
157     to = h ? atoi(h+4) : 0;
158     if (strstr(opts, ",ipv4"))
159         ai.ai_family = PF_INET;
160     if (strstr(opts, ",ipv6"))
161         ai.ai_family = PF_INET6;
162 
163     /* lookup */
164     if (port_offset)
165         snprintf(port, sizeof(port), "%d", atoi(port) + port_offset);
166     rc = getaddrinfo(strlen(addr) ? addr : NULL, port, &ai, &res);
167     if (rc != 0) {
168         fprintf(stderr,"%s: getaddrinfo(%s,%s): %s\n", __FUNCTION__,
169                 addr, port, gai_strerror(rc));
170         return -1;
171     }
172     if (sockets_debug)
173         inet_print_addrinfo(__FUNCTION__, res);
174 
175     /* create socket + bind */
176     for (e = res; e != NULL; e = e->ai_next) {
177         getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
178 		        uaddr,INET6_ADDRSTRLEN,uport,32,
179 		        NI_NUMERICHOST | NI_NUMERICSERV);
180         slisten = socket(e->ai_family, e->ai_socktype, e->ai_protocol);
181         if (slisten < 0) {
182             fprintf(stderr,"%s: socket(%s): %s\n", __FUNCTION__,
183                     inet_strfamily(e->ai_family), strerror(errno));
184             continue;
185         }
186 
187         setsockopt(slisten,SOL_SOCKET,SO_REUSEADDR,(void*)&on,sizeof(on));
188 #ifdef IPV6_V6ONLY
189         if (e->ai_family == PF_INET6) {
190             /* listen on both ipv4 and ipv6 */
191             setsockopt(slisten,IPPROTO_IPV6,IPV6_V6ONLY,(void*)&off,
192                 sizeof(off));
193         }
194 #endif
195 
196         for (;;) {
197             if (bind(slisten, e->ai_addr, e->ai_addrlen) == 0) {
198                 if (sockets_debug)
199                     fprintf(stderr,"%s: bind(%s,%s,%d): OK\n", __FUNCTION__,
200                         inet_strfamily(e->ai_family), uaddr, inet_getport(e));
201                 goto listen;
202             }
203             try_next = to && (inet_getport(e) <= to + port_offset);
204             if (!try_next || sockets_debug)
205                 fprintf(stderr,"%s: bind(%s,%s,%d): %s\n", __FUNCTION__,
206                         inet_strfamily(e->ai_family), uaddr, inet_getport(e),
207                         strerror(errno));
208             if (try_next) {
209                 inet_setport(e, inet_getport(e) + 1);
210                 continue;
211             }
212             break;
213         }
214         closesocket(slisten);
215     }
216     fprintf(stderr, "%s: FAILED\n", __FUNCTION__);
217     freeaddrinfo(res);
218     return -1;
219 
220 listen:
221     if (listen(slisten,1) != 0) {
222         perror("listen");
223         closesocket(slisten);
224         freeaddrinfo(res);
225         return -1;
226     }
227     if (ostr) {
228         if (e->ai_family == PF_INET6) {
229             snprintf(ostr, olen, "[%s]:%d%s", uaddr,
230                      inet_getport(e) - port_offset, opts);
231         } else {
232             snprintf(ostr, olen, "%s:%d%s", uaddr,
233                      inet_getport(e) - port_offset, opts);
234         }
235     }
236     freeaddrinfo(res);
237     return slisten;
238 }
239 
240 int inet_connect(const char *str, int socktype)
241 {
242     struct addrinfo ai,*res,*e;
243     char addr[64];
244     char port[33];
245     char uaddr[INET6_ADDRSTRLEN+1];
246     char uport[33];
247     int sock,rc;
248 
249     memset(&ai,0, sizeof(ai));
250     ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
251     ai.ai_family = PF_UNSPEC;
252     ai.ai_socktype = socktype;
253 
254     /* parse address */
255     if (str[0] == '[') {
256         /* IPv6 addr */
257         if (2 != sscanf(str,"[%64[^]]]:%32[^,]",addr,port)) {
258             fprintf(stderr, "%s: ipv6 parse error (%s)\n",
259                     __FUNCTION__, str);
260             return -1;
261         }
262         ai.ai_family = PF_INET6;
263     } else if (qemu_isdigit(str[0])) {
264         /* IPv4 addr */
265         if (2 != sscanf(str,"%64[0-9.]:%32[^,]",addr,port)) {
266             fprintf(stderr, "%s: ipv4 parse error (%s)\n",
267                     __FUNCTION__, str);
268             return -1;
269         }
270         ai.ai_family = PF_INET;
271     } else {
272         /* hostname */
273         if (2 != sscanf(str,"%64[^:]:%32[^,]",addr,port)) {
274             fprintf(stderr, "%s: hostname parse error (%s)\n",
275                     __FUNCTION__, str);
276             return -1;
277         }
278     }
279 
280     /* parse options */
281     if (strstr(str, ",ipv4"))
282         ai.ai_family = PF_INET;
283     if (strstr(str, ",ipv6"))
284         ai.ai_family = PF_INET6;
285 
286     /* lookup */
287     if (0 != (rc = getaddrinfo(addr, port, &ai, &res))) {
288         fprintf(stderr,"getaddrinfo(%s,%s): %s\n", gai_strerror(rc),
289                 addr, port);
290 	return -1;
291     }
292     if (sockets_debug)
293         inet_print_addrinfo(__FUNCTION__, res);
294 
295     for (e = res; e != NULL; e = e->ai_next) {
296         if (getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
297                             uaddr,INET6_ADDRSTRLEN,uport,32,
298                             NI_NUMERICHOST | NI_NUMERICSERV) != 0) {
299             fprintf(stderr,"%s: getnameinfo: oops\n", __FUNCTION__);
300             continue;
301         }
302         sock = socket(e->ai_family, e->ai_socktype, e->ai_protocol);
303         if (sock < 0) {
304             fprintf(stderr,"%s: socket(%s): %s\n", __FUNCTION__,
305             inet_strfamily(e->ai_family), strerror(errno));
306             continue;
307         }
308         setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(void*)&on,sizeof(on));
309 
310         /* connect to peer */
311         if (connect(sock,e->ai_addr,e->ai_addrlen) < 0) {
312             if (sockets_debug || NULL == e->ai_next)
313                 fprintf(stderr, "%s: connect(%s,%s,%s,%s): %s\n", __FUNCTION__,
314                         inet_strfamily(e->ai_family),
315                         e->ai_canonname, uaddr, uport, strerror(errno));
316             closesocket(sock);
317             continue;
318         }
319         if (sockets_debug)
320             fprintf(stderr, "%s: connect(%s,%s,%s,%s): OK\n", __FUNCTION__,
321                     inet_strfamily(e->ai_family),
322                     e->ai_canonname, uaddr, uport);
323         freeaddrinfo(res);
324         return sock;
325     }
326     freeaddrinfo(res);
327     return -1;
328 }
329 
330 #ifndef _WIN32
331 
332 int unix_listen(const char *str, char *ostr, int olen)
333 {
334     struct sockaddr_un un;
335     char *path, *opts;
336     int sock, fd, len;
337 
338     sock = socket(PF_UNIX, SOCK_STREAM, 0);
339     if (sock < 0) {
340         perror("socket(unix)");
341         return -1;
342     }
343 
344     opts = strchr(str, ',');
345     if (opts) {
346         len = opts - str;
347         path = qemu_malloc(len+1);
348         snprintf(path, len+1, "%.*s", len, str);
349     } else
350         path = qemu_strdup(str);
351 
352     memset(&un, 0, sizeof(un));
353     un.sun_family = AF_UNIX;
354     if (path && strlen(path)) {
355         snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
356     } else {
357         char *tmpdir = getenv("TMPDIR");
358         snprintf(un.sun_path, sizeof(un.sun_path), "%s/qemu-socket-XXXXXX",
359                  tmpdir ? tmpdir : "/tmp");
360         /*
361          * This dummy fd usage silences the mktemp() unsecure warning.
362          * Using mkstemp() doesn't make things more secure here
363          * though.  bind() complains about existing files, so we have
364          * to unlink first and thus re-open the race window.  The
365          * worst case possible is bind() failing, i.e. a DoS attack.
366          */
367         fd = mkstemp(un.sun_path); close(fd);
368     }
369     snprintf(ostr, olen, "%s%s", un.sun_path, opts ? opts : "");
370 
371     unlink(un.sun_path);
372     if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
373         fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
374         goto err;
375     }
376     if (listen(sock, 1) < 0) {
377         fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
378         goto err;
379     }
380 
381     if (sockets_debug)
382         fprintf(stderr, "bind(unix:%s): OK\n", un.sun_path);
383     qemu_free(path);
384     return sock;
385 
386 err:
387     qemu_free(path);
388     closesocket(sock);
389     return -1;
390 }
391 
392 int unix_connect_opts(QemuOpts *opts)
393 {
394     struct sockaddr_un un;
395     const char *path = qemu_opt_get(opts, "path");
396     int sock;
397 
398     if (NULL == path) {
399         fprintf(stderr, "unix connect: no path specified\n");
400         return -1;
401     }
402 
403     sock = socket(PF_UNIX, SOCK_STREAM, 0);
404     if (sock < 0) {
405         perror("socket(unix)");
406         return -1;
407     }
408 
409     memset(&un, 0, sizeof(un));
410     un.sun_family = AF_UNIX;
411     snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
412     if (connect(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
413         fprintf(stderr, "connect(unix:%s): %s\n", path, strerror(errno));
414 	return -1;
415     }
416 
417     if (sockets_debug)
418         fprintf(stderr, "connect(unix:%s): OK\n", path);
419     return sock;
420 }
421 
422 /* compatibility wrapper */
423 int unix_connect(const char *path)
424 {
425     QemuOpts *opts;
426     int sock;
427 
428     opts = qemu_opts_create(&dummy_opts, NULL, 0);
429     qemu_opt_set(opts, "path", path);
430     sock = unix_connect_opts(opts);
431     qemu_opts_del(opts);
432     return sock;
433 }
434 
435 #else
436 
437 int unix_listen(const char *path, char *ostr, int olen)
438 {
439     fprintf(stderr, "unix sockets are not available on windows\n");
440     return -1;
441 }
442 
443 int unix_connect(const char *path)
444 {
445     fprintf(stderr, "unix sockets are not available on windows\n");
446     return -1;
447 }
448 
449 #endif
450