libexec/rexecd/rexecd.c

   1 /*
   2  * Copyright (c) 1983 Regents of the University of California.
   3  * All rights reserved.  The Berkeley software License Agreement
   4  * specifies the terms and conditions for redistribution.
   5  */
   6
   7 #ifndef lint
   8 char copyright[] =
   9 "@(#) Copyright (c) 1983 Regents of the University of California.\n\
  10  All rights reserved.\n";
  11 #endif not lint
  12
  13 #ifndef lint
  14 static char sccsid[] = "@(#)rexecd.c    5.4 (Berkeley) 5/9/86";
  15 #endif not lint
  16
  17 #include <sys/ioctl.h>
  18 #include <sys/param.h>
  19 #include <sys/socket.h>
  20 #include <sys/time.h>
  21
  22 #include <netinet/in.h>
  23
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #include <pwd.h>
  27 #include <signal.h>
  28 #include <netdb.h>
  29
  30 extern  errno;
  31 struct  passwd *getpwnam();
  32 char    *crypt(), *rindex(), *strncat(), *sprintf();
  33 /*VARARGS1*/
  34 int     error();
  35
  36 /*
  37  * remote execute server:
  38  *      username\0
  39  *      password\0
  40  *      command\0
  41  *      data
  42  */
  43 /*ARGSUSED*/
  44 main(argc, argv)
  45         int argc;
  46         char **argv;
  47 {
  48         struct sockaddr_in from;
  49         int fromlen;
  50
  51         fromlen = sizeof (from);
  52         if (getpeername(0, &from, &fromlen) < 0) {
  53                 fprintf(stderr, "%s: ", argv[0]);
  54                 perror("getpeername");
  55                 exit(1);
  56         }
  57         doit(0, &from);
  58 }
  59
  60 char    username[20] = "USER=";
  61 char    homedir[64] = "HOME=";
  62 char    shell[64] = "SHELL=";
  63 char    *envinit[] =
  64             {homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
  65 char    **environ;
  66
  67 struct  sockaddr_in asin = { AF_INET };
  68
  69 doit(f, fromp)
  70         int f;
  71         struct sockaddr_in *fromp;
  72 {
  73         char cmdbuf[NCARGS+1], *cp, *namep;
  74         char user[16], pass[16];
  75         struct passwd *pwd;
  76         int s;
  77         short port;
  78         int pv[2], pid, cc;
  79         long ready, readfrom;
  80         char buf[BUFSIZ], sig;
  81         int one = 1;
  82
  83         (void) signal(SIGINT, SIG_DFL);
  84         (void) signal(SIGQUIT, SIG_DFL);
  85         (void) signal(SIGTERM, SIG_DFL);
  86 #ifdef DEBUG
  87         { int t = open("/dev/tty", 2);
  88           if (t >= 0) {
  89                 ioctl(t, TIOCNOTTY, (char *)0);
  90                 (void) close(t);
  91           }
  92         }
  93 #endif
  94         dup2(f, 0);
  95         dup2(f, 1);
  96         dup2(f, 2);
  97         (void) alarm(60);
  98         port = 0;
  99         for (;;) {
 100                 char c;
 101                 if (read(f, &c, 1) != 1)
 102                         exit(1);
 103                 if (c == 0)
 104                         break;
 105                 port = port * 10 + c - '0';
 106         }
 107         (void) alarm(0);
 108         if (port != 0) {
 109                 s = socket(AF_INET, SOCK_STREAM, 0);
 110                 if (s < 0)
 111                         exit(1);
 112                 if (bind(s, &asin, sizeof (asin)) < 0)
 113                         exit(1);
 114                 (void) alarm(60);
 115                 fromp->sin_port = htons((u_short)port);
 116                 if (connect(s, fromp, sizeof (*fromp)) < 0)
 117                         exit(1);
 118                 (void) alarm(0);
 119         }
 120         getstr(user, sizeof(user), "username");
 121         getstr(pass, sizeof(pass), "password");
 122         getstr(cmdbuf, sizeof(cmdbuf), "command");
 123         setpwent();
 124         pwd = getpwnam(user);
 125         if (pwd == NULL) {
 126                 error("Login incorrect.\n");
 127                 exit(1);
 128         }
 129         endpwent();
 130         if (*pwd->pw_passwd != '\0') {
 131                 namep = crypt(pass, pwd->pw_passwd);
 132                 if (strcmp(namep, pwd->pw_passwd)) {
 133                         error("Password incorrect.\n");
 134                         exit(1);
 135                 }
 136         }
 137         if (chdir(pwd->pw_dir) < 0) {
 138                 error("No remote directory.\n");
 139                 exit(1);
 140         }
 141         (void) write(2, "\0", 1);
 142         if (port) {
 143                 (void) pipe(pv);
 144                 pid = fork();
 145                 if (pid == -1)  {
 146                         error("Try again.\n");
 147                         exit(1);
 148                 }
 149                 if (pid) {
 150                         (void) close(0); (void) close(1); (void) close(2);
 151                         (void) close(f); (void) close(pv[1]);
 152                         readfrom = (1L<<s) | (1L<<pv[0]);
 153                         ioctl(pv[1], FIONBIO, (char *)&one);
 154                         /* should set s nbio! */
 155                         do {
 156                                 ready = readfrom;
 157                                 (void) select(16, &ready, (fd_set *)0,
 158                                     (fd_set *)0, (struct timeval *)0);
 159                                 if (ready & (1L<<s)) {
 160                                         if (read(s, &sig, 1) <= 0)
 161                                                 readfrom &= ~(1L<<s);
 162                                         else
 163                                                 killpg(pid, sig);
 164                                 }
 165                                 if (ready & (1L<<pv[0])) {
 166                                         cc = read(pv[0], buf, sizeof (buf));
 167                                         if (cc <= 0) {
 168                                                 shutdown(s, 1+1);
 169                                                 readfrom &= ~(1L<<pv[0]);
 170                                         } else
 171                                                 (void) write(s, buf, cc);
 172                                 }
 173                         } while (readfrom);
 174                         exit(0);
 175                 }
 176                 setpgrp(0, getpid());
 177                 (void) close(s); (void)close(pv[0]);
 178                 dup2(pv[1], 2);
 179         }
 180         if (*pwd->pw_shell == '\0')
 181                 pwd->pw_shell = "/bin/sh";
 182         if (f > 2)
 183                 (void) close(f);
 184         (void) setgid((gid_t)pwd->pw_gid);
 185         initgroups(pwd->pw_name, pwd->pw_gid);
 186         (void) setuid((uid_t)pwd->pw_uid);
 187         environ = envinit;
 188         strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
 189         strncat(shell, pwd->pw_shell, sizeof(shell)-7);
 190         strncat(username, pwd->pw_name, sizeof(username)-6);
 191         cp = rindex(pwd->pw_shell, '/');
 192         if (cp)
 193                 cp++;
 194         else
 195                 cp = pwd->pw_shell;
 196         execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
 197         perror(pwd->pw_shell);
 198         exit(1);
 199 }
 200
 201 /*VARARGS1*/
 202 error(fmt, a1, a2, a3)
 203         char *fmt;
 204         int a1, a2, a3;
 205 {
 206         char buf[BUFSIZ];
 207
 208         buf[0] = 1;
 209         (void) sprintf(buf+1, fmt, a1, a2, a3);
 210         (void) write(2, buf, strlen(buf));
 211 }
 212
 213 getstr(buf, cnt, err)
 214         char *buf;
 215         int cnt;
 216         char *err;
 217 {
 218         char c;
 219
 220         do {
 221                 if (read(0, &c, 1) != 1)
 222                         exit(1);
 223                 *buf++ = c;
 224                 if (--cnt == 0) {
 225                         error("%s too long\n", err);
 226                         exit(1);
 227                 }
 228         } while (c != 0);
 229 }