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 #include <sys/types.h>
  31 #include <sys/socket.h>
  32
  33 #include <netinet/in.h>
  34
  35 #include <alloca.h>
  36 #include <stdio.h>
  37 #include <netdb.h>
  38 #include <errno.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42 #include <sys/uio.h>
  43
  44 int     rexecoptions;
  45 libc_freeres_ptr (static char *ahostbuf);
  46
  47 int
  48 rexec_af (char **ahost, int rport, const char *name, const char *pass,
  49           const char *cmd, int *fd2p, sa_family_t af)
  50 {
  51         struct sockaddr_storage from;
  52         struct addrinfo hints, *res0;
  53         const char *orig_name = name;
  54         const char *orig_pass = pass;
  55         u_short port = 0;
  56         int s, timo = 1, s3;
  57         char c;
  58         int gai;
  59         char servbuff[NI_MAXSERV];
  60
  61         __snprintf(servbuff, sizeof(servbuff), "%d", ntohs(rport));
  62         servbuff[sizeof(servbuff) - 1] = '\0';
  63
  64         memset(&hints, '\0', sizeof(hints));
  65         hints.ai_family = af;
  66         hints.ai_socktype = SOCK_STREAM;
  67         hints.ai_flags = AI_CANONNAME;
  68         gai = getaddrinfo(*ahost, servbuff, &hints, &res0);
  69         if (gai){
  70                 /* XXX: set errno? */
  71                 return -1;
  72         }
  73
  74         if (res0->ai_canonname){
  75                 free (ahostbuf);
  76                 ahostbuf = __strdup (res0->ai_canonname);
  77                 if (ahostbuf == NULL) {
  78                         perror ("rexec: strdup");
  79                         goto bad2;
  80                 }
  81                 *ahost = ahostbuf;
  82         } else {
  83                 *ahost = NULL;
  84                 __set_errno (ENOENT);
  85                 goto bad2;
  86         }
  87         ruserpass(res0->ai_canonname, &name, &pass);
  88 retry:
  89         /* NB: No SOCK_CLOEXEC for backwards compatibility.  */
  90         s = __socket(res0->ai_family, res0->ai_socktype, 0);
  91         if (s < 0) {
  92                 perror("rexec: socket");
  93                 goto bad2;
  94         }
  95         if (__connect(s, res0->ai_addr, res0->ai_addrlen) < 0) {
  96                 if (errno == ECONNREFUSED && timo <= 16) {
  97                         (void) __close(s);
  98                         __sleep(timo);
  99                         timo *= 2;
 100                         goto retry;
 101                 }
 102                 perror(res0->ai_canonname);
 103                 goto bad;
 104         }
 105         if (fd2p == 0) {
 106                 (void) __write(s, "", 1);
 107                 port = 0;
 108         } else {
 109                 char num[32];
 110                 int s2;
 111                 union
 112                 {
 113                   struct sockaddr_storage ss;
 114                   struct sockaddr sa;
 115                 } sa2;
 116                 socklen_t sa2len;
 117
 118                 s2 = __socket(res0->ai_family, res0->ai_socktype, 0);
 119                 if (s2 < 0)
 120                         goto bad;
 121
 122                 __listen(s2, 1);
 123                 sa2len = sizeof (sa2);
 124                 if (__getsockname(s2, &sa2.sa, &sa2len) < 0) {
 125                         perror("getsockname");
 126                         (void) __close(s2);
 127                         goto bad;
 128                 } else if (sa2len != SA_LEN(&sa2.sa)) {
 129                         __set_errno(EINVAL);
 130                         (void) __close(s2);
 131                         goto bad;
 132                 }
 133                 port = 0;
 134                 if (!getnameinfo(&sa2.sa, sa2len,
 135                                  NULL, 0, servbuff, sizeof(servbuff),
 136                                  NI_NUMERICSERV))
 137                         port = strtol(servbuff, NULL, 10);
 138                 (void) sprintf(num, "%u", port);
 139                 (void) __write(s, num, strlen(num)+1);
 140                 { socklen_t len = sizeof (from);
 141                   s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
 142                                                   &len));
 143                   __close(s2);
 144                   if (s3 < 0) {
 145                         perror("accept");
 146                         port = 0;
 147                         goto bad;
 148                   }
 149                 }
 150                 *fd2p = s3;
 151         }
 152
 153         struct iovec iov[3] =
 154           {
 155             [0] = { .iov_base = (void *) name, .iov_len = strlen (name) + 1 },
 156             /* should public key encypt the password here */
 157             [1] = { .iov_base = (void *) pass, .iov_len = strlen (pass) + 1 },
 158             [2] = { .iov_base = (void *) cmd, .iov_len = strlen (cmd) + 1 }
 159           };
 160         (void) TEMP_FAILURE_RETRY (__writev (s, iov, 3));
 161
 162         /* We don't need the memory allocated for the name and the password
 163            in ruserpass anymore.  */
 164         if (name != orig_name)
 165           free ((char *) name);
 166         if (pass != orig_pass)
 167           free ((char *) pass);
 168
 169         if (__read(s, &c, 1) != 1) {
 170                 perror(*ahost);
 171                 goto bad;
 172         }
 173         if (c != 0) {
 174                 while (__read(s, &c, 1) == 1) {
 175                         (void) __write(2, &c, 1);
 176                         if (c == '\n')
 177                                 break;
 178                 }
 179                 goto bad;
 180         }
 181         freeaddrinfo(res0);
 182         return (s);
 183 bad:
 184         if (port)
 185                 (void) __close(*fd2p);
 186         (void) __close(s);
 187 bad2:
 188         freeaddrinfo(res0);
 189         return (-1);
 190 }
 191 libc_hidden_def (rexec_af)
 192
 193 int
 194 rexec (char **ahost, int rport, const char *name, const char *pass,
 195        const char *cmd, int *fd2p)
 196 {
 197         return rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET);
 198 }