qemu-sockets.c

   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