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         pid_t pid;
 123
 124         DEBUG_CALL("fork_exec");
 125         DEBUG_ARG("so = %lx", (long)so);
 126         DEBUG_ARG("ex = %lx", (long)ex);
 127         DEBUG_ARG("do_pty = %lx", (long)do_pty);
 128
 129         if (do_pty == 2) {
 130                 return 0;
 131         } else {
 132                 addr.sin_family = AF_INET;
 133                 addr.sin_port = 0;
 134                 addr.sin_addr.s_addr = INADDR_ANY;
 135
 136                 if ((s = qemu_socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
 137                     bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
 138                     listen(s, 1) < 0) {
 139                         lprint("Error: inet socket: %s\n", strerror(errno));
 140                         closesocket(s);
 141
 142                         return 0;
 143                 }
 144         }
 145
 146         pid = fork();
 147         switch(pid) {
 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                 setsid();
 157
 158                 /* Set the DISPLAY */
 159                 if (do_pty == 2) {
 160                         (void) close(master);
 161 #ifdef TIOCSCTTY /* XXXXX */
 162                         ioctl(s, TIOCSCTTY, (char *)NULL);
 163 #endif
 164                 } else {
 165                         getsockname(s, (struct sockaddr *)&addr, &addrlen);
 166                         close(s);
 167                         /*
 168                          * Connect to the socket
 169                          * XXX If any of these fail, we're in trouble!
 170                          */
 171                         s = qemu_socket(AF_INET, SOCK_STREAM, 0);
 172                         addr.sin_addr = loopback_addr;
 173                         do {
 174                             ret = connect(s, (struct sockaddr *)&addr, addrlen);
 175                         } while (ret < 0 && errno == EINTR);
 176                 }
 177
 178                 dup2(s, 0);
 179                 dup2(s, 1);
 180                 dup2(s, 2);
 181                 for (s = getdtablesize() - 1; s >= 3; s--)
 182                    close(s);
 183
 184                 i = 0;
 185                 bptr = qemu_strdup(ex); /* No need to free() this */
 186                 if (do_pty == 1) {
 187                         /* Setup "slirp.telnetd -x" */
 188                         argv[i++] = "slirp.telnetd";
 189                         argv[i++] = "-x";
 190                         argv[i++] = bptr;
 191                 } else
 192                    do {
 193                         /* Change the string into argv[] */
 194                         curarg = bptr;
 195                         while (*bptr != ' ' && *bptr != (char)0)
 196                            bptr++;
 197                         c = *bptr;
 198                         *bptr++ = (char)0;
 199                         argv[i++] = strdup(curarg);
 200                    } while (c);
 201
 202                 argv[i] = NULL;
 203                 execvp(argv[0], (char **)argv);
 204
 205                 /* Ooops, failed, let's tell the user why */
 206         fprintf(stderr, "Error: execvp of %s failed: %s\n",
 207                 argv[0], strerror(errno));
 208                 close(0); close(1); close(2); /* XXX */
 209                 exit(1);
 210
 211          default:
 212                 qemu_add_child_watch(pid);
 213                 if (do_pty == 2) {
 214                         close(s);
 215                         so->s = master;
 216                 } else {
 217                         /*
 218                          * XXX this could block us...
 219                          * XXX Should set a timer here, and if accept() doesn't
 220                          * return after X seconds, declare it a failure
 221                          * The only reason this will block forever is if socket()
 222                          * of connect() fail in the child process
 223                          */
 224                         do {
 225                             so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
 226                         } while (so->s < 0 && errno == EINTR);
 227                         closesocket(s);
 228                         opt = 1;
 229                         setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
 230                         opt = 1;
 231                         setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
 232                 }
 233                 fd_nonblock(so->s);
 234
 235                 /* Append the telnet options now */
 236                 if (so->so_m != NULL && do_pty == 1)  {
 237                         sbappend(so, so->so_m);
 238                         so->so_m = NULL;
 239                 }
 240
 241                 return 1;
 242         }
 243 }
 244 #endif
 245
 246 #ifndef HAVE_STRDUP
 247 char *
 248 strdup(str)
 249         const char *str;
 250 {
 251         char *bptr;
 252
 253         bptr = (char *)malloc(strlen(str)+1);
 254         strcpy(bptr, str);
 255
 256         return bptr;
 257 }
 258 #endif
 259
 260 #include "monitor.h"
 261
 262 void lprint(const char *format, ...)
 263 {
 264     va_list args;
 265
 266     va_start(args, format);
 267     monitor_vprintf(default_mon, format, args);
 268     va_end(args);
 269 }
 270
 271 void
 272 u_sleep(int usec)
 273 {
 274         struct timeval t;
 275         fd_set fdset;
 276
 277         FD_ZERO(&fdset);
 278
 279         t.tv_sec = 0;
 280         t.tv_usec = usec * 1000;
 281
 282         select(0, &fdset, &fdset, &fdset, &t);
 283 }
 284
 285 /*
 286  * Set fd blocking and non-blocking
 287  */
 288
 289 void
 290 fd_nonblock(int fd)
 291 {
 292 #ifdef FIONBIO
 293 #ifdef _WIN32
 294         unsigned long opt = 1;
 295 #else
 296         int opt = 1;
 297 #endif
 298
 299         ioctlsocket(fd, FIONBIO, &opt);
 300 #else
 301         int opt;
 302
 303         opt = fcntl(fd, F_GETFL, 0);
 304         opt |= O_NONBLOCK;
 305         fcntl(fd, F_SETFL, opt);
 306 #endif
 307 }
 308
 309 void
 310 fd_block(int fd)
 311 {
 312 #ifdef FIONBIO
 313 #ifdef _WIN32
 314         unsigned long opt = 0;
 315 #else
 316         int opt = 0;
 317 #endif
 318
 319         ioctlsocket(fd, FIONBIO, &opt);
 320 #else
 321         int opt;
 322
 323         opt = fcntl(fd, F_GETFL, 0);
 324         opt &= ~O_NONBLOCK;
 325         fcntl(fd, F_SETFL, opt);
 326 #endif
 327 }
 328
 329 void slirp_connection_info(Slirp *slirp, Monitor *mon)
 330 {
 331     const char * const tcpstates[] = {
 332         [TCPS_CLOSED]       = "CLOSED",
 333         [TCPS_LISTEN]       = "LISTEN",
 334         [TCPS_SYN_SENT]     = "SYN_SENT",
 335         [TCPS_SYN_RECEIVED] = "SYN_RCVD",
 336         [TCPS_ESTABLISHED]  = "ESTABLISHED",
 337         [TCPS_CLOSE_WAIT]   = "CLOSE_WAIT",
 338         [TCPS_FIN_WAIT_1]   = "FIN_WAIT_1",
 339         [TCPS_CLOSING]      = "CLOSING",
 340         [TCPS_LAST_ACK]     = "LAST_ACK",
 341         [TCPS_FIN_WAIT_2]   = "FIN_WAIT_2",
 342         [TCPS_TIME_WAIT]    = "TIME_WAIT",
 343     };
 344     struct in_addr dst_addr;
 345     struct sockaddr_in src;
 346     socklen_t src_len;
 347     uint16_t dst_port;
 348     struct socket *so;
 349     const char *state;
 350     char buf[20];
 351     int n;
 352
 353     monitor_printf(mon, "  Protocol[State]    FD  Source Address  Port   "
 354                         "Dest. Address  Port RecvQ SendQ\n");
 355
 356     for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
 357         if (so->so_state & SS_HOSTFWD) {
 358             state = "HOST_FORWARD";
 359         } else if (so->so_tcpcb) {
 360             state = tcpstates[so->so_tcpcb->t_state];
 361         } else {
 362             state = "NONE";
 363         }
 364         if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
 365             src_len = sizeof(src);
 366             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 367             dst_addr = so->so_laddr;
 368             dst_port = so->so_lport;
 369         } else {
 370             src.sin_addr = so->so_laddr;
 371             src.sin_port = so->so_lport;
 372             dst_addr = so->so_faddr;
 373             dst_port = so->so_fport;
 374         }
 375         n = snprintf(buf, sizeof(buf), "  TCP[%s]", state);
 376         memset(&buf[n], ' ', 19 - n);
 377         buf[19] = 0;
 378         monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
 379                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 380                        ntohs(src.sin_port));
 381         monitor_printf(mon, "%15s %5d %5d %5d\n",
 382                        inet_ntoa(dst_addr), ntohs(dst_port),
 383                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 384     }
 385
 386     for (so = slirp->udb.so_next; so != &slirp->udb; so = so->so_next) {
 387         if (so->so_state & SS_HOSTFWD) {
 388             n = snprintf(buf, sizeof(buf), "  UDP[HOST_FORWARD]");
 389             src_len = sizeof(src);
 390             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 391             dst_addr = so->so_laddr;
 392             dst_port = so->so_lport;
 393         } else {
 394             n = snprintf(buf, sizeof(buf), "  UDP[%d sec]",
 395                          (so->so_expire - curtime) / 1000);
 396             src.sin_addr = so->so_laddr;
 397             src.sin_port = so->so_lport;
 398             dst_addr = so->so_faddr;
 399             dst_port = so->so_fport;
 400         }
 401         memset(&buf[n], ' ', 19 - n);
 402         buf[19] = 0;
 403         monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
 404                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 405                        ntohs(src.sin_port));
 406         monitor_printf(mon, "%15s %5d %5d %5d\n",
 407                        inet_ntoa(dst_addr), ntohs(dst_port),
 408                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 409     }
 410
 411     for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so->so_next) {
 412         n = snprintf(buf, sizeof(buf), "  ICMP[%d sec]",
 413                      (so->so_expire - curtime) / 1000);
 414         src.sin_addr = so->so_laddr;
 415         dst_addr = so->so_faddr;
 416         memset(&buf[n], ' ', 19 - n);
 417         buf[19] = 0;
 418         monitor_printf(mon, "%s %3d %15s  -    ", buf, so->s,
 419                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*");
 420         monitor_printf(mon, "%15s  -    %5d %5d\n", inet_ntoa(dst_addr),
 421                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 422     }
 423 }