inet/rexec.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)rexec.c     8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include <sys/types.h>
  35 #include <sys/socket.h>
  36
  37 #include <netinet/in.h>
  38
  39 #include <alloca.h>
  40 #include <stdio.h>
  41 #include <netdb.h>
  42 #include <errno.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46 #include <sys/uio.h>
  47
  48 int     rexecoptions;
  49 libc_freeres_ptr (static char *ahostbuf);
  50
  51 int
  52 rexec_af (char **ahost, int rport, const char *name, const char *pass,
  53           const char *cmd, int *fd2p, sa_family_t af)
  54 {
  55         struct sockaddr_storage from;
  56         struct addrinfo hints, *res0;
  57         const char *orig_name = name;
  58         const char *orig_pass = pass;
  59         u_short port = 0;
  60         int s, timo = 1, s3;
  61         char c;
  62         int gai;
  63         char servbuff[NI_MAXSERV];
  64
  65         __snprintf(servbuff, sizeof(servbuff), "%d", ntohs(rport));
  66         servbuff[sizeof(servbuff) - 1] = '\0';
  67
  68         memset(&hints, '\0', sizeof(hints));
  69         hints.ai_family = af;
  70         hints.ai_socktype = SOCK_STREAM;
  71         hints.ai_flags = AI_CANONNAME;
  72         gai = getaddrinfo(*ahost, servbuff, &hints, &res0);
  73         if (gai){
  74                 /* XXX: set errno? */
  75                 return -1;
  76         }
  77
  78         if (res0->ai_canonname){
  79                 free (ahostbuf);
  80                 ahostbuf = strdup (res0->ai_canonname);
  81                 if (ahostbuf == NULL) {
  82                         perror ("rexec: strdup");
  83                         return (-1);
  84                 }
  85                 *ahost = ahostbuf;
  86         } else {
  87                 *ahost = NULL;
  88                 __set_errno (ENOENT);
  89                 return -1;
  90         }
  91         ruserpass(res0->ai_canonname, &name, &pass);
  92 retry:
  93         s = __socket(res0->ai_family, res0->ai_socktype, 0);
  94         if (s < 0) {
  95                 perror("rexec: socket");
  96                 return (-1);
  97         }
  98         if (__connect(s, res0->ai_addr, res0->ai_addrlen) < 0) {
  99                 if (errno == ECONNREFUSED && timo <= 16) {
 100                         (void) __close(s);
 101                         __sleep(timo);
 102                         timo *= 2;
 103                         goto retry;
 104                 }
 105                 perror(res0->ai_canonname);
 106                 return (-1);
 107         }
 108         if (fd2p == 0) {
 109                 (void) __write(s, "", 1);
 110                 port = 0;
 111         } else {
 112                 char num[32];
 113                 int s2;
 114                 union
 115                 {
 116                   struct sockaddr_storage ss;
 117                   struct sockaddr sa;
 118                 } sa2;
 119                 socklen_t sa2len;
 120
 121                 s2 = __socket(res0->ai_family, res0->ai_socktype, 0);
 122                 if (s2 < 0) {
 123                         (void) __close(s);
 124                         return (-1);
 125                 }
 126                 __listen(s2, 1);
 127                 sa2len = sizeof (sa2);
 128                 if (__getsockname(s2, &sa2.sa, &sa2len) < 0) {
 129                         perror("getsockname");
 130                         (void) __close(s2);
 131                         goto bad;
 132                 } else if (sa2len != SA_LEN(&sa2.sa)) {
 133                         __set_errno(EINVAL);
 134                         (void) __close(s2);
 135                         goto bad;
 136                 }
 137                 port = 0;
 138                 if (!getnameinfo(&sa2.sa, sa2len,
 139                                  NULL, 0, servbuff, sizeof(servbuff),
 140                                  NI_NUMERICSERV))
 141                         port = atoi(servbuff);
 142                 (void) sprintf(num, "%u", port);
 143                 (void) __write(s, num, strlen(num)+1);
 144                 { socklen_t len = sizeof (from);
 145                   s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
 146                                                   &len));
 147                   __close(s2);
 148                   if (s3 < 0) {
 149                         perror("accept");
 150                         port = 0;
 151                         goto bad;
 152                   }
 153                 }
 154                 *fd2p = s3;
 155         }
 156
 157         struct iovec iov[3] =
 158           {
 159             [0] = { .iov_base = (void *) name, .iov_len = strlen (name) + 1 },
 160             /* should public key encypt the password here */
 161             [1] = { .iov_base = (void *) pass, .iov_len = strlen (pass) + 1 },
 162             [2] = { .iov_base = (void *) cmd, .iov_len = strlen (cmd) + 1 }
 163           };
 164         (void) TEMP_FAILURE_RETRY (__writev (s, iov, 3));
 165
 166         /* We don't need the memory allocated for the name and the password
 167            in ruserpass anymore.  */
 168         if (name != orig_name)
 169           free ((char *) name);
 170         if (pass != orig_pass)
 171           free ((char *) pass);
 172
 173         if (__read(s, &c, 1) != 1) {
 174                 perror(*ahost);
 175                 goto bad;
 176         }
 177         if (c != 0) {
 178                 while (__read(s, &c, 1) == 1) {
 179                         (void) __write(2, &c, 1);
 180                         if (c == '\n')
 181                                 break;
 182                 }
 183                 goto bad;
 184         }
 185         freeaddrinfo(res0);
 186         return (s);
 187 bad:
 188         if (port)
 189                 (void) __close(*fd2p);
 190         (void) __close(s);
 191         freeaddrinfo(res0);
 192         return (-1);
 193 }
 194 libc_hidden_def (rexec_af)
 195
 196 int
 197 rexec (char **ahost, int rport, const char *name, const char *pass,
 198        const char *cmd, int *fd2p)
 199 {
 200         return rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET);
 201 }