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