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/monitor.h"
  12 #include "qemu/error-report.h"
  13 #include "qemu/main-loop.h"
  14
  15 #ifdef DEBUG
  16 int slirp_debug = DBG_CALL|DBG_MISC|DBG_ERROR;
  17 #endif
  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 = g_new(struct ex_list, 1);
  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 : g_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         const char *argv[256];
 119         /* don't want to clobber the original */
 120         char *bptr;
 121         const char *curarg;
 122         int c, i, ret;
 123         pid_t pid;
 124
 125         DEBUG_CALL("fork_exec");
 126         DEBUG_ARG("so = %p", so);
 127         DEBUG_ARG("ex = %p", ex);
 128         DEBUG_ARG("do_pty = %x", 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 = qemu_socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
 138                     bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
 139                     listen(s, 1) < 0) {
 140                         error_report("Error: inet socket: %s", strerror(errno));
 141                         closesocket(s);
 142
 143                         return 0;
 144                 }
 145         }
 146
 147         pid = fork();
 148         switch(pid) {
 149          case -1:
 150                 error_report("Error: fork failed: %s", strerror(errno));
 151                 close(s);
 152                 return 0;
 153
 154          case 0:
 155                 setsid();
 156
 157                 /* Set the DISPLAY */
 158                 getsockname(s, (struct sockaddr *)&addr, &addrlen);
 159                 close(s);
 160                 /*
 161                  * Connect to the socket
 162                  * XXX If any of these fail, we're in trouble!
 163                  */
 164                 s = qemu_socket(AF_INET, SOCK_STREAM, 0);
 165                 addr.sin_addr = loopback_addr;
 166                 do {
 167                     ret = connect(s, (struct sockaddr *)&addr, addrlen);
 168                 } while (ret < 0 && errno == EINTR);
 169
 170                 dup2(s, 0);
 171                 dup2(s, 1);
 172                 dup2(s, 2);
 173                 for (s = getdtablesize() - 1; s >= 3; s--)
 174                    close(s);
 175
 176                 i = 0;
 177                 bptr = g_strdup(ex); /* No need to free() this */
 178                 if (do_pty == 1) {
 179                         /* Setup "slirp.telnetd -x" */
 180                         argv[i++] = "slirp.telnetd";
 181                         argv[i++] = "-x";
 182                         argv[i++] = bptr;
 183                 } else
 184                    do {
 185                         /* Change the string into argv[] */
 186                         curarg = bptr;
 187                         while (*bptr != ' ' && *bptr != (char)0)
 188                            bptr++;
 189                         c = *bptr;
 190                         *bptr++ = (char)0;
 191                         argv[i++] = g_strdup(curarg);
 192                    } while (c);
 193
 194                 argv[i] = NULL;
 195                 execvp(argv[0], (char **)argv);
 196
 197                 /* Ooops, failed, let's tell the user why */
 198         fprintf(stderr, "Error: execvp of %s failed: %s\n",
 199                 argv[0], strerror(errno));
 200                 close(0); close(1); close(2); /* XXX */
 201                 exit(1);
 202
 203          default:
 204                 qemu_add_child_watch(pid);
 205                 /*
 206                  * XXX this could block us...
 207                  * XXX Should set a timer here, and if accept() doesn't
 208                  * return after X seconds, declare it a failure
 209                  * The only reason this will block forever is if socket()
 210                  * of connect() fail in the child process
 211                  */
 212                 do {
 213                     so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
 214                 } while (so->s < 0 && errno == EINTR);
 215                 closesocket(s);
 216                 socket_set_fast_reuse(so->s);
 217                 opt = 1;
 218                 qemu_setsockopt(so->s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
 219                 qemu_set_nonblock(so->s);
 220
 221                 /* Append the telnet options now */
 222                 if (so->so_m != NULL && do_pty == 1)  {
 223                         sbappend(so, so->so_m);
 224                         so->so_m = NULL;
 225                 }
 226
 227                 return 1;
 228         }
 229 }
 230 #endif
 231
 232 void slirp_connection_info(Slirp *slirp, Monitor *mon)
 233 {
 234     const char * const tcpstates[] = {
 235         [TCPS_CLOSED]       = "CLOSED",
 236         [TCPS_LISTEN]       = "LISTEN",
 237         [TCPS_SYN_SENT]     = "SYN_SENT",
 238         [TCPS_SYN_RECEIVED] = "SYN_RCVD",
 239         [TCPS_ESTABLISHED]  = "ESTABLISHED",
 240         [TCPS_CLOSE_WAIT]   = "CLOSE_WAIT",
 241         [TCPS_FIN_WAIT_1]   = "FIN_WAIT_1",
 242         [TCPS_CLOSING]      = "CLOSING",
 243         [TCPS_LAST_ACK]     = "LAST_ACK",
 244         [TCPS_FIN_WAIT_2]   = "FIN_WAIT_2",
 245         [TCPS_TIME_WAIT]    = "TIME_WAIT",
 246     };
 247     struct in_addr dst_addr;
 248     struct sockaddr_in src;
 249     socklen_t src_len;
 250     uint16_t dst_port;
 251     struct socket *so;
 252     const char *state;
 253     char buf[20];
 254
 255     monitor_printf(mon, "  Protocol[State]    FD  Source Address  Port   "
 256                         "Dest. Address  Port RecvQ SendQ\n");
 257
 258     for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
 259         if (so->so_state & SS_HOSTFWD) {
 260             state = "HOST_FORWARD";
 261         } else if (so->so_tcpcb) {
 262             state = tcpstates[so->so_tcpcb->t_state];
 263         } else {
 264             state = "NONE";
 265         }
 266         if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
 267             src_len = sizeof(src);
 268             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 269             dst_addr = so->so_laddr;
 270             dst_port = so->so_lport;
 271         } else {
 272             src.sin_addr = so->so_laddr;
 273             src.sin_port = so->so_lport;
 274             dst_addr = so->so_faddr;
 275             dst_port = so->so_fport;
 276         }
 277         snprintf(buf, sizeof(buf), "  TCP[%s]", state);
 278         monitor_printf(mon, "%-19s %3d %15s %5d ", buf, so->s,
 279                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 280                        ntohs(src.sin_port));
 281         monitor_printf(mon, "%15s %5d %5d %5d\n",
 282                        inet_ntoa(dst_addr), ntohs(dst_port),
 283                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 284     }
 285
 286     for (so = slirp->udb.so_next; so != &slirp->udb; so = so->so_next) {
 287         if (so->so_state & SS_HOSTFWD) {
 288             snprintf(buf, sizeof(buf), "  UDP[HOST_FORWARD]");
 289             src_len = sizeof(src);
 290             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 291             dst_addr = so->so_laddr;
 292             dst_port = so->so_lport;
 293         } else {
 294             snprintf(buf, sizeof(buf), "  UDP[%d sec]",
 295                          (so->so_expire - curtime) / 1000);
 296             src.sin_addr = so->so_laddr;
 297             src.sin_port = so->so_lport;
 298             dst_addr = so->so_faddr;
 299             dst_port = so->so_fport;
 300         }
 301         monitor_printf(mon, "%-19s %3d %15s %5d ", buf, so->s,
 302                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 303                        ntohs(src.sin_port));
 304         monitor_printf(mon, "%15s %5d %5d %5d\n",
 305                        inet_ntoa(dst_addr), ntohs(dst_port),
 306                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 307     }
 308
 309     for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so->so_next) {
 310         snprintf(buf, sizeof(buf), "  ICMP[%d sec]",
 311                      (so->so_expire - curtime) / 1000);
 312         src.sin_addr = so->so_laddr;
 313         dst_addr = so->so_faddr;
 314         monitor_printf(mon, "%-19s %3d %15s  -    ", buf, so->s,
 315                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*");
 316         monitor_printf(mon, "%15s  -    %5d %5d\n", inet_ntoa(dst_addr),
 317                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 318     }
 319 }