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