workbench/network/stacks/AROSTCP/netlib/rcmd.c

   1 /* $Id$
   2  *
   3  *      rcmd.c - rcmd() for AmiTCP/IP and usergroup.library
   4  *
   5  *      Copyright © 1994 AmiTCP/IP Group,
   6  *                       Network Solutions Development Inc.
   7  *                       All rights reserved.
   8  */
   9
  10 /*
  11  * Copyright (c) 1983 Regents of the University of California.
  12  * All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  * 3. All advertising materials mentioning features or use of this software
  23  *    must display the following acknowledgement:
  24  *      This product includes software developed by the University of
  25  *      California, Berkeley and its contributors.
  26  * 4. Neither the name of the University nor the names of its contributors
  27  *    may be used to endorse or promote products derived from this software
  28  *    without specific prior written permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  40  * SUCH DAMAGE.
  41  */
  42
  43 #if __SASC
  44 #include <proto/dos.h>
  45 #include <proto/socket.h>
  46 #include <proto/exec.h>
  47 #elif __GNUC__
  48 #include <inline/dos.h>
  49 #include <inline/socket.h>
  50 #include <inline/exec.h>
  51 #else
  52 #include <clib/dos_protos.h>
  53 #include <clib/socket_protos.h>
  54 #include <clib/exec_protos.h>
  55 #endif
  56
  57 #include <sys/param.h>
  58 #include <sys/ioctl.h>
  59 #include <sys/socket.h>
  60 #include <sys/stat.h>
  61 #include <netinet/in.h>
  62 #include <arpa/inet.h>
  63 #if 0
  64 #include <signal.h>
  65 #endif
  66 #include <fcntl.h>
  67 #include <netdb.h>
  68 #include <pwd.h>
  69 #include <errno.h>
  70 #include <stdio.h>
  71 #include <ctype.h>
  72
  73 #include <unistd.h>
  74 #include <string.h>
  75
  76 #ifdef ioctl
  77 #undef ioctl
  78 #endif
  79 #ifdef close
  80 #undef close
  81 #endif
  82 #define ioctl IoctlSocket
  83 #define close CloseSocket
  84 #define getpid() ((pid_t)FindTask(0L))
  85
  86
  87 /****** net.lib/rcmd *********************************************************
  88
  89     NAME
  90         rcmd, rresvport - routines for returning a stream to a remote command
  91
  92     SYNOPSIS
  93         #include <clib/socket_protos.h>
  94
  95         int rcmd(char **ahost, int inport, const char *locuser,
  96                  const char *remuser, const char *cmd, int *fd2p);
  97
  98         int rresvport(int *port);
  99
 100     FUNCTION
 101         The rcmd() function is used by the super-user to execute a command on
 102         a remote machine using an authentication scheme based on reserved port
 103         numbers.  The rresvport() function returns a descriptor to a socket
 104         with an address in the privileged port space.  Both functions are
 105         present in the same file and are used by the rsh command (among
 106         others).
 107
 108         The rcmd() function looks up the host *ahost using gethostbyname(),
 109         returning -1 if the host does not exist.  Otherwise *ahost is set to
 110         the standard name of the host and a connection is established to a
 111         server residing at the well-known Internet port inport.
 112
 113         If the connection succeeds, a socket in the Internet domain of type
 114         SOCK_STREAM is returned to the caller, and given to the remote command
 115         as stdin and stdout. If fd2p is non-zero, then an auxiliary channel to
 116         a control process will be set up, and a descriptor for it will be
 117         placed in *fd2p. The control process will return diagnostic output
 118         from the command (unit 2) on this channel, and will also accept bytes
 119         on this channel as being UNIX signal numbers, to be forwarded to the
 120         process group of the command.  If fd2p is 0, then the stderr (unit 2
 121         of the remote command) will be made the same as the stdout and no
 122         provision is made for sending arbitrary signals to the remote process,
 123         although you may be able to get its attention by using out-of-band
 124         data.
 125
 126         The protocol is described in detail in netutil/rshd.
 127
 128         The rresvport() function is used to obtain a socket with a privileged
 129         address bound to it.  This socket is suitable for use by rcmd() and
 130         several other functions.  Privileged Internet ports are those in the
 131         range 0 to 1023.  Only the super-user is allowed to bind an address of
 132         this sort to a socket.
 133
 134     DIAGNOSTICS
 135         The rcmd() function returns a valid socket descriptor on success.  It
 136         returns -1 on error and prints a diagnostic message on the standard
 137         error.
 138
 139         The rresvport() function returns a valid, bound socket descriptor on
 140         success.  It returns -1 on error with the global value errno set
 141         according to the reason for failure.  The error code EAGAIN is
 142         overloaded to mean `All network ports in use.'
 143
 144     SEE ALSO
 145         netutil/rlogin,  netutil/rsh,  rexec(),  netutil/rexecd,
 146         netutil/rlogind, netutil/rshd
 147
 148 ******************************************************************************
 149 */
 150
 151 #include <clib/netlib_protos.h>
 152
 153 int
 154 rcmd(char **ahost,
 155      int rport,
 156      const char *locuser,
 157      const char *remuser,
 158      const char *cmd,
 159      int *fd2p)                 /* Socket for stderr  */
 160 {
 161   int s, timo = 1;
 162   pid_t pid;
 163   struct sockaddr_in sin, from;
 164   char c;
 165   int lport = IPPORT_RESERVED - 1;
 166   struct hostent *hp;
 167   fd_set reads;
 168
 169   pid = getpid();
 170   hp = gethostbyname(*ahost);
 171   if (hp == 0) {
 172     herror(*ahost);
 173     errno = EADDRNOTAVAIL;
 174     return (-1);
 175   }
 176   *ahost = hp->h_name;
 177
 178   for (;;) {
 179     s = rresvport(&lport);
 180     if (s < 0) {
 181       errno == EAGAIN ?
 182         fprintf(stderr, "socket: All ports in use\n")
 183           : perror("rcmd: socket");
 184       return (-1);
 185     }
 186     ioctl(s, FIOSETOWN, (caddr_t)&pid);
 187     sin.sin_len = sizeof(sin);
 188     sin.sin_family = hp->h_addrtype;
 189     bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
 190     sin.sin_port = rport;
 191     if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
 192       break;
 193     (void) close(s);
 194     if (errno == EADDRINUSE) {
 195       lport--;
 196       continue;
 197     }
 198     if (errno == ECONNREFUSED && timo <= 16) {
 199       sleep(timo);
 200       timo *= 2;
 201       continue;
 202     }
 203     if (hp->h_addr_list[1] != NULL) {
 204       int oerrno = errno;
 205
 206       fprintf(stderr, "connect to address %s: ", inet_ntoa(sin.sin_addr));
 207       errno = oerrno;
 208       perror("");
 209       hp->h_addr_list++;
 210       bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
 211       fprintf(stderr, "Trying %s...\n", inet_ntoa(sin.sin_addr));
 212       continue;
 213     }
 214     perror(hp->h_name);
 215     return (-1);
 216   }
 217
 218   lport--;
 219   if (fd2p == 0) {
 220     send(s, "", 1, 0);
 221     lport = 0;
 222   } else {
 223     char num[8];
 224     long s2 = rresvport(&lport), s3;
 225     long len = sizeof (from);
 226
 227     if (s2 < 0)
 228       goto bad;
 229     listen(s2, 1);
 230     (void) sprintf(num, "%ld", lport);
 231     if (send(s, num, strlen(num)+1, 0) != strlen(num)+1) {
 232       perror("send: setting up stderr");
 233       (void) close(s2);
 234       goto bad;
 235     }
 236     FD_ZERO(&reads);
 237     FD_SET(s, &reads);
 238     FD_SET(s2, &reads);
 239     errno = 0;
 240     if (select(((s > s2) ? s : s2) + 1,
 241                &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)) {
 242       errno != 0 ?
 243           perror("select: setting up stderr")
 244           :
 245           fprintf(stderr, "select: protocol failure in circuit setup.\n");
 246       (void) close(s2);
 247       goto bad;
 248     }
 249     s3 = accept(s2, (struct sockaddr *)&from, &len);
 250     (void) close(s2);
 251     if (s3 < 0) {
 252       perror("accept");
 253       lport = 0;
 254       goto bad;
 255     }
 256     *fd2p = s3;
 257     from.sin_port = ntohs((u_short)from.sin_port);
 258     if (from.sin_family != AF_INET ||
 259         from.sin_port >= IPPORT_RESERVED ||
 260         from.sin_port < IPPORT_RESERVED / 2) {
 261       fprintf(stderr, "socket: protocol failure in circuit setup.\n");
 262       goto bad2;
 263     }
 264   }
 265   (void) send(s, locuser, strlen(locuser) + 1, 0);
 266   (void) send(s, remuser, strlen(remuser) + 1, 0);
 267   (void) send(s, cmd, strlen(cmd) + 1, 0);
 268   if (recv(s, &c, 1, 0) != 1) {
 269     perror(*ahost);
 270     goto bad2;
 271   }
 272   if (c != 0) {
 273     while (recv(s, &c, 1, 0) == 1) {
 274       (void) fputc(c, stderr);
 275       if (c == '\n')
 276         break;
 277     }
 278     goto bad2;
 279   }
 280
 281   return (s);
 282  bad2:
 283   if (lport)
 284     (void) close(*fd2p);
 285  bad:
 286   (void) close(s);
 287   return (-1);
 288 }
 289
 290 int rresvport(int *alport)
 291 {
 292   struct sockaddr_in sin;
 293   int s;
 294
 295   sin.sin_len = sizeof(sin);
 296   sin.sin_family = AF_INET;
 297   sin.sin_addr.s_addr = INADDR_ANY;
 298   s = socket(AF_INET, SOCK_STREAM, 0);
 299   if (s < 0)
 300     return (-1);
 301   for (;;) {
 302     sin.sin_port = htons((u_short)*alport);
 303     if (bind(s, (struct sockaddr *)&sin, sizeof (sin)) >= 0)
 304       return (s);
 305     if (errno != EADDRINUSE) {
 306       (void) close(s);
 307       return (-1);
 308     }
 309     (*alport)--;
 310     if (*alport == IPPORT_RESERVED/2) {
 311       (void) close(s);
 312       errno = EAGAIN;           /* close */
 313       return (-1);
 314     }
 315   }
 316 }