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