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 #include <set-freeres.h>
  44
  45 int     rexecoptions;
  46 static char *ahostbuf;
  47
  48 int
  49 rexec_af (char **ahost, int rport, const char *name, const char *pass,
  50           const char *cmd, int *fd2p, sa_family_t af)
  51 {
  52         struct sockaddr_storage from;
  53         struct addrinfo hints, *res0;
  54         const char *orig_name = name;
  55         const char *orig_pass = pass;
  56         u_short port = 0;
  57         int s, timo = 1, s3;
  58         char c;
  59         int gai;
  60         char servbuff[NI_MAXSERV];
  61
  62         __snprintf(servbuff, sizeof(servbuff), "%d", ntohs(rport));
  63         servbuff[sizeof(servbuff) - 1] = '\0';
  64
  65         memset(&hints, '\0', sizeof(hints));
  66         hints.ai_family = af;
  67         hints.ai_socktype = SOCK_STREAM;
  68         hints.ai_flags = AI_CANONNAME;
  69         gai = getaddrinfo(*ahost, servbuff, &hints, &res0);
  70         if (gai){
  71                 /* XXX: set errno? */
  72                 return -1;
  73         }
  74
  75         if (res0->ai_canonname){
  76                 free (ahostbuf);
  77                 ahostbuf = __strdup (res0->ai_canonname);
  78                 if (ahostbuf == NULL) {
  79                         perror ("rexec: strdup");
  80                         goto bad2;
  81                 }
  82                 *ahost = ahostbuf;
  83         } else {
  84                 *ahost = NULL;
  85                 __set_errno (ENOENT);
  86                 goto bad2;
  87         }
  88         ruserpass(res0->ai_canonname, &name, &pass);
  89 retry:
  90         /* NB: No SOCK_CLOEXEC for backwards compatibility.  */
  91         s = __socket(res0->ai_family, res0->ai_socktype, 0);
  92         if (s < 0) {
  93                 perror("rexec: socket");
  94                 goto bad2;
  95         }
  96         if (__connect(s, res0->ai_addr, res0->ai_addrlen) < 0) {
  97                 if (errno == ECONNREFUSED && timo <= 16) {
  98                         (void) __close(s);
  99                         __sleep(timo);
 100                         timo *= 2;
 101                         goto retry;
 102                 }
 103                 perror(res0->ai_canonname);
 104                 goto bad;
 105         }
 106         if (fd2p == 0) {
 107                 (void) __write(s, "", 1);
 108                 port = 0;
 109         } else {
 110                 char num[32];
 111                 int s2;
 112                 union
 113                 {
 114                   struct sockaddr_storage ss;
 115                   struct sockaddr sa;
 116                 } sa2;
 117                 socklen_t sa2len;
 118
 119                 s2 = __socket(res0->ai_family, res0->ai_socktype, 0);
 120                 if (s2 < 0)
 121                         goto bad;
 122
 123                 __listen(s2, 1);
 124                 sa2len = sizeof (sa2);
 125                 if (__getsockname(s2, &sa2.sa, &sa2len) < 0) {
 126                         perror("getsockname");
 127                         (void) __close(s2);
 128                         goto bad;
 129                 } else if (sa2len != SA_LEN(&sa2.sa)) {
 130                         __set_errno(EINVAL);
 131                         (void) __close(s2);
 132                         goto bad;
 133                 }
 134                 port = 0;
 135                 if (!getnameinfo(&sa2.sa, sa2len,
 136                                  NULL, 0, servbuff, sizeof(servbuff),
 137                                  NI_NUMERICSERV))
 138                         port = strtol(servbuff, NULL, 10);
 139                 (void) sprintf(num, "%u", port);
 140                 (void) __write(s, num, strlen(num)+1);
 141                 { socklen_t len = sizeof (from);
 142                   s3 = TEMP_FAILURE_RETRY (accept(s2, (struct sockaddr *)&from,
 143                                                   &len));
 144                   __close(s2);
 145                   if (s3 < 0) {
 146                         perror("accept");
 147                         port = 0;
 148                         goto bad;
 149                   }
 150                 }
 151                 *fd2p = s3;
 152         }
 153
 154         struct iovec iov[3] =
 155           {
 156             [0] = { .iov_base = (void *) name, .iov_len = strlen (name) + 1 },
 157             /* should public key encrypt the password here */
 158             [1] = { .iov_base = (void *) pass, .iov_len = strlen (pass) + 1 },
 159             [2] = { .iov_base = (void *) cmd, .iov_len = strlen (cmd) + 1 }
 160           };
 161         (void) TEMP_FAILURE_RETRY (__writev (s, iov, 3));
 162
 163         /* We don't need the memory allocated for the name and the password
 164            in ruserpass anymore.  */
 165         if (name != orig_name)
 166           free ((char *) name);
 167         if (pass != orig_pass)
 168           free ((char *) pass);
 169
 170         if (__read(s, &c, 1) != 1) {
 171                 perror(*ahost);
 172                 goto bad;
 173         }
 174         if (c != 0) {
 175                 while (__read(s, &c, 1) == 1) {
 176                         (void) __write(2, &c, 1);
 177                         if (c == '\n')
 178                                 break;
 179                 }
 180                 goto bad;
 181         }
 182         freeaddrinfo(res0);
 183         return (s);
 184 bad:
 185         if (port)
 186                 (void) __close(*fd2p);
 187         (void) __close(s);
 188 bad2:
 189         freeaddrinfo(res0);
 190         return (-1);
 191 }
 192 libc_hidden_def (rexec_af)
 193
 194 int
 195 rexec (char **ahost, int rport, const char *name, const char *pass,
 196        const char *cmd, int *fd2p)
 197 {
 198         return rexec_af(ahost, rport, name, pass, cmd, fd2p, AF_INET);
 199 }
 200
 201 weak_alias (ahostbuf, __libc_rexec_freemem_ptr)