slirp/misc.c

   1 /*
   2  * Copyright (c) 1995 Danny Gasparovski.
   3  *
   4  * Please read the file COPYRIGHT for the
   5  * terms and conditions of the copyright.
   6  */
   7
   8 #include <slirp.h>
   9 #include <libslirp.h>
  10
  11 #include "monitor.h"
  12
  13 #ifdef DEBUG
  14 int slirp_debug = DBG_CALL|DBG_MISC|DBG_ERROR;
  15 #endif
  16
  17 u_int curtime, time_fasttimo, last_slowtimo;
  18
  19 /*
  20  * Get our IP address and put it in our_addr
  21  */
  22 void
  23 getouraddr(void)
  24 {
  25         char buff[256];
  26         struct hostent *he = NULL;
  27
  28         if (gethostname(buff,256) == 0)
  29             he = gethostbyname(buff);
  30         if (he)
  31             our_addr = *(struct in_addr *)he->h_addr;
  32         if (our_addr.s_addr == 0)
  33             our_addr.s_addr = loopback_addr.s_addr;
  34 }
  35
  36 struct quehead {
  37         struct quehead *qh_link;
  38         struct quehead *qh_rlink;
  39 };
  40
  41 inline void
  42 insque(void *a, void *b)
  43 {
  44         register struct quehead *element = (struct quehead *) a;
  45         register struct quehead *head = (struct quehead *) b;
  46         element->qh_link = head->qh_link;
  47         head->qh_link = (struct quehead *)element;
  48         element->qh_rlink = (struct quehead *)head;
  49         ((struct quehead *)(element->qh_link))->qh_rlink
  50         = (struct quehead *)element;
  51 }
  52
  53 inline void
  54 remque(void *a)
  55 {
  56   register struct quehead *element = (struct quehead *) a;
  57   ((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
  58   ((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
  59   element->qh_rlink = NULL;
  60 }
  61
  62 int add_exec(struct ex_list **ex_ptr, int do_pty, char *exec,
  63              struct in_addr addr, int port)
  64 {
  65         struct ex_list *tmp_ptr;
  66
  67         /* First, check if the port is "bound" */
  68         for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
  69                 if (port == tmp_ptr->ex_fport &&
  70                     addr.s_addr == tmp_ptr->ex_addr.s_addr)
  71                         return -1;
  72         }
  73
  74         tmp_ptr = *ex_ptr;
  75         *ex_ptr = (struct ex_list *)malloc(sizeof(struct ex_list));
  76         (*ex_ptr)->ex_fport = port;
  77         (*ex_ptr)->ex_addr = addr;
  78         (*ex_ptr)->ex_pty = do_pty;
  79         (*ex_ptr)->ex_exec = (do_pty == 3) ? exec : strdup(exec);
  80         (*ex_ptr)->ex_next = tmp_ptr;
  81         return 0;
  82 }
  83
  84 #ifndef HAVE_STRERROR
  85
  86 /*
  87  * For systems with no strerror
  88  */
  89
  90 extern int sys_nerr;
  91 extern char *sys_errlist[];
  92
  93 char *
  94 strerror(error)
  95         int error;
  96 {
  97         if (error < sys_nerr)
  98            return sys_errlist[error];
  99         else
 100            return "Unknown error.";
 101 }
 102
 103 #endif
 104
 105
 106 #ifdef _WIN32
 107
 108 int
 109 fork_exec(struct socket *so, const char *ex, int do_pty)
 110 {
 111     /* not implemented */
 112     return 0;
 113 }
 114
 115 #else
 116
 117 /*
 118  * XXX This is ugly
 119  * We create and bind a socket, then fork off to another
 120  * process, which connects to this socket, after which we
 121  * exec the wanted program.  If something (strange) happens,
 122  * the accept() call could block us forever.
 123  *
 124  * do_pty = 0   Fork/exec inetd style
 125  * do_pty = 1   Fork/exec using slirp.telnetd
 126  * do_ptr = 2   Fork/exec using pty
 127  */
 128 int
 129 fork_exec(struct socket *so, const char *ex, int do_pty)
 130 {
 131         int s;
 132         struct sockaddr_in addr;
 133         socklen_t addrlen = sizeof(addr);
 134         int opt;
 135         int master = -1;
 136         const char *argv[256];
 137         /* don't want to clobber the original */
 138         char *bptr;
 139         const char *curarg;
 140         int c, i, ret;
 141
 142         DEBUG_CALL("fork_exec");
 143         DEBUG_ARG("so = %lx", (long)so);
 144         DEBUG_ARG("ex = %lx", (long)ex);
 145         DEBUG_ARG("do_pty = %lx", (long)do_pty);
 146
 147         if (do_pty == 2) {
 148                 return 0;
 149         } else {
 150                 addr.sin_family = AF_INET;
 151                 addr.sin_port = 0;
 152                 addr.sin_addr.s_addr = INADDR_ANY;
 153
 154                 if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
 155                     bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
 156                     listen(s, 1) < 0) {
 157                         lprint("Error: inet socket: %s\n", strerror(errno));
 158                         closesocket(s);
 159
 160                         return 0;
 161                 }
 162         }
 163
 164         switch(fork()) {
 165          case -1:
 166                 lprint("Error: fork failed: %s\n", strerror(errno));
 167                 close(s);
 168                 if (do_pty == 2)
 169                    close(master);
 170                 return 0;
 171
 172          case 0:
 173                 /* Set the DISPLAY */
 174                 if (do_pty == 2) {
 175                         (void) close(master);
 176 #ifdef TIOCSCTTY /* XXXXX */
 177                         (void) setsid();
 178                         ioctl(s, TIOCSCTTY, (char *)NULL);
 179 #endif
 180                 } else {
 181                         getsockname(s, (struct sockaddr *)&addr, &addrlen);
 182                         close(s);
 183                         /*
 184                          * Connect to the socket
 185                          * XXX If any of these fail, we're in trouble!
 186                          */
 187                         s = socket(AF_INET, SOCK_STREAM, 0);
 188                         addr.sin_addr = loopback_addr;
 189                         do {
 190                             ret = connect(s, (struct sockaddr *)&addr, addrlen);
 191                         } while (ret < 0 && errno == EINTR);
 192                 }
 193
 194                 dup2(s, 0);
 195                 dup2(s, 1);
 196                 dup2(s, 2);
 197                 for (s = getdtablesize() - 1; s >= 3; s--)
 198                    close(s);
 199
 200                 i = 0;
 201                 bptr = strdup(ex); /* No need to free() this */
 202                 if (do_pty == 1) {
 203                         /* Setup "slirp.telnetd -x" */
 204                         argv[i++] = "slirp.telnetd";
 205                         argv[i++] = "-x";
 206                         argv[i++] = bptr;
 207                 } else
 208                    do {
 209                         /* Change the string into argv[] */
 210                         curarg = bptr;
 211                         while (*bptr != ' ' && *bptr != (char)0)
 212                            bptr++;
 213                         c = *bptr;
 214                         *bptr++ = (char)0;
 215                         argv[i++] = strdup(curarg);
 216                    } while (c);
 217
 218                 argv[i] = NULL;
 219                 execvp(argv[0], (char **)argv);
 220
 221                 /* Ooops, failed, let's tell the user why */
 222                   {
 223                           char buff[256];
 224
 225                           snprintf(buff, sizeof(buff),
 226                                    "Error: execvp of %s failed: %s\n",
 227                                    argv[0], strerror(errno));
 228                           write(2, buff, strlen(buff)+1);
 229                   }
 230                 close(0); close(1); close(2); /* XXX */
 231                 exit(1);
 232
 233          default:
 234                 if (do_pty == 2) {
 235                         close(s);
 236                         so->s = master;
 237                 } else {
 238                         /*
 239                          * XXX this could block us...
 240                          * XXX Should set a timer here, and if accept() doesn't
 241                          * return after X seconds, declare it a failure
 242                          * The only reason this will block forever is if socket()
 243                          * of connect() fail in the child process
 244                          */
 245                         do {
 246                             so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
 247                         } while (so->s < 0 && errno == EINTR);
 248                         closesocket(s);
 249                         opt = 1;
 250                         setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
 251                         opt = 1;
 252                         setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
 253                 }
 254                 fd_nonblock(so->s);
 255
 256                 /* Append the telnet options now */
 257                 if (so->so_m != NULL && do_pty == 1)  {
 258                         sbappend(so, so->so_m);
 259                         so->so_m = NULL;
 260                 }
 261
 262                 return 1;
 263         }
 264 }
 265 #endif
 266
 267 #ifndef HAVE_STRDUP
 268 char *
 269 strdup(str)
 270         const char *str;
 271 {
 272         char *bptr;
 273
 274         bptr = (char *)malloc(strlen(str)+1);
 275         strcpy(bptr, str);
 276
 277         return bptr;
 278 }
 279 #endif
 280
 281 #include "monitor.h"
 282
 283 void lprint(const char *format, ...)
 284 {
 285     va_list args;
 286
 287     va_start(args, format);
 288     monitor_vprintf(cur_mon, format, args);
 289     va_end(args);
 290 }
 291
 292 #ifdef BAD_SPRINTF
 293
 294 #undef vsprintf
 295 #undef sprintf
 296
 297 /*
 298  * Some BSD-derived systems have a sprintf which returns char *
 299  */
 300
 301 int
 302 vsprintf_len(string, format, args)
 303         char *string;
 304         const char *format;
 305         va_list args;
 306 {
 307         vsprintf(string, format, args);
 308         return strlen(string);
 309 }
 310
 311 int
 312 #ifdef __STDC__
 313 sprintf_len(char *string, const char *format, ...)
 314 #else
 315 sprintf_len(va_alist) va_dcl
 316 #endif
 317 {
 318         va_list args;
 319 #ifdef __STDC__
 320         va_start(args, format);
 321 #else
 322         char *string;
 323         char *format;
 324         va_start(args);
 325         string = va_arg(args, char *);
 326         format = va_arg(args, char *);
 327 #endif
 328         vsprintf(string, format, args);
 329         return strlen(string);
 330 }
 331
 332 #endif
 333
 334 void
 335 u_sleep(int usec)
 336 {
 337         struct timeval t;
 338         fd_set fdset;
 339
 340         FD_ZERO(&fdset);
 341
 342         t.tv_sec = 0;
 343         t.tv_usec = usec * 1000;
 344
 345         select(0, &fdset, &fdset, &fdset, &t);
 346 }
 347
 348 /*
 349  * Set fd blocking and non-blocking
 350  */
 351
 352 void
 353 fd_nonblock(int fd)
 354 {
 355 #ifdef FIONBIO
 356 #ifdef _WIN32
 357         unsigned long opt = 1;
 358 #else
 359         int opt = 1;
 360 #endif
 361
 362         ioctlsocket(fd, FIONBIO, &opt);
 363 #else
 364         int opt;
 365
 366         opt = fcntl(fd, F_GETFL, 0);
 367         opt |= O_NONBLOCK;
 368         fcntl(fd, F_SETFL, opt);
 369 #endif
 370 }
 371
 372 void
 373 fd_block(int fd)
 374 {
 375 #ifdef FIONBIO
 376 #ifdef _WIN32
 377         unsigned long opt = 0;
 378 #else
 379         int opt = 0;
 380 #endif
 381
 382         ioctlsocket(fd, FIONBIO, &opt);
 383 #else
 384         int opt;
 385
 386         opt = fcntl(fd, F_GETFL, 0);
 387         opt &= ~O_NONBLOCK;
 388         fcntl(fd, F_SETFL, opt);
 389 #endif
 390 }
 391
 392 void slirp_connection_info(Monitor *mon)
 393 {
 394     const char * const tcpstates[] = {
 395         [TCPS_CLOSED]       = "CLOSED",
 396         [TCPS_LISTEN]       = "LISTEN",
 397         [TCPS_SYN_SENT]     = "SYN_SENT",
 398         [TCPS_SYN_RECEIVED] = "SYN_RCVD",
 399         [TCPS_ESTABLISHED]  = "ESTABLISHED",
 400         [TCPS_CLOSE_WAIT]   = "CLOSE_WAIT",
 401         [TCPS_FIN_WAIT_1]   = "FIN_WAIT_1",
 402         [TCPS_CLOSING]      = "CLOSING",
 403         [TCPS_LAST_ACK]     = "LAST_ACK",
 404         [TCPS_FIN_WAIT_2]   = "FIN_WAIT_2",
 405         [TCPS_TIME_WAIT]    = "TIME_WAIT",
 406     };
 407     struct in_addr dst_addr;
 408     struct sockaddr_in src;
 409     socklen_t src_len;
 410     uint16_t dst_port;
 411     struct socket *so;
 412     const char *state;
 413     char buf[20];
 414     int n;
 415
 416     monitor_printf(mon, "  Protocol[State]    FD  Source Address  Port   "
 417                         "Dest. Address  Port RecvQ SendQ\n");
 418
 419     for (so = tcb.so_next; so != &tcb; so = so->so_next) {
 420         if (so->so_state & SS_HOSTFWD) {
 421             state = "HOST_FORWARD";
 422         } else if (so->so_tcpcb) {
 423             state = tcpstates[so->so_tcpcb->t_state];
 424         } else {
 425             state = "NONE";
 426         }
 427         if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
 428             src_len = sizeof(src);
 429             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 430             dst_addr = so->so_laddr;
 431             dst_port = so->so_lport;
 432         } else {
 433             src.sin_addr = so->so_laddr;
 434             src.sin_port = so->so_lport;
 435             dst_addr = so->so_faddr;
 436             dst_port = so->so_fport;
 437         }
 438         n = snprintf(buf, sizeof(buf), "  TCP[%s]", state);
 439         memset(&buf[n], ' ', 19 - n);
 440         buf[19] = 0;
 441         monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
 442                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 443                        ntohs(src.sin_port));
 444         monitor_printf(mon, "%15s %5d %5d %5d\n",
 445                        inet_ntoa(dst_addr), ntohs(dst_port),
 446                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 447     }
 448
 449     for (so = udb.so_next; so != &udb; so = so->so_next) {
 450         if (so->so_state & SS_HOSTFWD) {
 451             n = snprintf(buf, sizeof(buf), "  UDP[HOST_FORWARD]");
 452             src_len = sizeof(src);
 453             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 454             dst_addr = so->so_laddr;
 455             dst_port = so->so_lport;
 456         } else {
 457             n = snprintf(buf, sizeof(buf), "  UDP[%d sec]",
 458                          (so->so_expire - curtime) / 1000);
 459             src.sin_addr = so->so_laddr;
 460             src.sin_port = so->so_lport;
 461             dst_addr = so->so_faddr;
 462             dst_port = so->so_fport;
 463         }
 464         memset(&buf[n], ' ', 19 - n);
 465         buf[19] = 0;
 466         monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
 467                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 468                        ntohs(src.sin_port));
 469         monitor_printf(mon, "%15s %5d %5d %5d\n",
 470                        inet_ntoa(dst_addr), ntohs(dst_port),
 471                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 472     }
 473 }