1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char copyright[] = 10 "@(#) Copyright (c) 1983, 1993\n\ 11 The Regents of the University of California. All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)rexecd.c 8.1 (Berkeley) 06/04/93"; 16 #endif /* not lint */ 17 18 #include <sys/param.h> 19 #include <sys/ioctl.h> 20 #include <sys/socket.h> 21 #include <sys/time.h> 22 23 #include <netinet/in.h> 24 25 #include <errno.h> 26 #include <netdb.h> 27 #include <paths.h> 28 #include <pwd.h> 29 #include <signal.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <unistd.h> 34 35 /*VARARGS1*/ 36 int error(); 37 38 /* 39 * remote execute server: 40 * username\0 41 * password\0 42 * command\0 43 * data 44 */ 45 /*ARGSUSED*/ 46 main(argc, argv) 47 int argc; 48 char **argv; 49 { 50 struct sockaddr_in from; 51 int fromlen; 52 53 fromlen = sizeof (from); 54 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 55 (void)fprintf(stderr, 56 "rexecd: getpeername: %s\n", strerror(errno)); 57 exit(1); 58 } 59 doit(0, &from); 60 } 61 62 char username[20] = "USER="; 63 char homedir[64] = "HOME="; 64 char shell[64] = "SHELL="; 65 char path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH="; 66 char *envinit[] = 67 {homedir, shell, path, username, 0}; 68 char **environ; 69 70 struct sockaddr_in asin = { AF_INET }; 71 72 doit(f, fromp) 73 int f; 74 struct sockaddr_in *fromp; 75 { 76 char cmdbuf[NCARGS+1], *cp, *namep; 77 char user[16], pass[16]; 78 struct passwd *pwd; 79 int s; 80 u_short port; 81 int pv[2], pid, ready, readfrom, cc; 82 char buf[BUFSIZ], sig; 83 int one = 1; 84 85 (void) signal(SIGINT, SIG_DFL); 86 (void) signal(SIGQUIT, SIG_DFL); 87 (void) signal(SIGTERM, SIG_DFL); 88 #ifdef DEBUG 89 { int t = open(_PATH_TTY, 2); 90 if (t >= 0) { 91 ioctl(t, TIOCNOTTY, (char *)0); 92 (void) close(t); 93 } 94 } 95 #endif 96 dup2(f, 0); 97 dup2(f, 1); 98 dup2(f, 2); 99 (void) alarm(60); 100 port = 0; 101 for (;;) { 102 char c; 103 if (read(f, &c, 1) != 1) 104 exit(1); 105 if (c == 0) 106 break; 107 port = port * 10 + c - '0'; 108 } 109 (void) alarm(0); 110 if (port != 0) { 111 s = socket(AF_INET, SOCK_STREAM, 0); 112 if (s < 0) 113 exit(1); 114 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0) 115 exit(1); 116 (void) alarm(60); 117 fromp->sin_port = htons(port); 118 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) 119 exit(1); 120 (void) alarm(0); 121 } 122 getstr(user, sizeof(user), "username"); 123 getstr(pass, sizeof(pass), "password"); 124 getstr(cmdbuf, sizeof(cmdbuf), "command"); 125 setpwent(); 126 pwd = getpwnam(user); 127 if (pwd == NULL) { 128 error("Login incorrect.\n"); 129 exit(1); 130 } 131 endpwent(); 132 if (*pwd->pw_passwd != '\0') { 133 namep = crypt(pass, pwd->pw_passwd); 134 if (strcmp(namep, pwd->pw_passwd)) { 135 error("Password incorrect.\n"); 136 exit(1); 137 } 138 } 139 if (chdir(pwd->pw_dir) < 0) { 140 error("No remote directory.\n"); 141 exit(1); 142 } 143 (void) write(2, "\0", 1); 144 if (port) { 145 (void) pipe(pv); 146 pid = fork(); 147 if (pid == -1) { 148 error("Try again.\n"); 149 exit(1); 150 } 151 if (pid) { 152 (void) close(0); (void) close(1); (void) close(2); 153 (void) close(f); (void) close(pv[1]); 154 readfrom = (1<<s) | (1<<pv[0]); 155 ioctl(pv[1], FIONBIO, (char *)&one); 156 /* should set s nbio! */ 157 do { 158 ready = readfrom; 159 (void) select(16, (fd_set *)&ready, 160 (fd_set *)NULL, (fd_set *)NULL, 161 (struct timeval *)NULL); 162 if (ready & (1<<s)) { 163 if (read(s, &sig, 1) <= 0) 164 readfrom &= ~(1<<s); 165 else 166 killpg(pid, sig); 167 } 168 if (ready & (1<<pv[0])) { 169 cc = read(pv[0], buf, sizeof (buf)); 170 if (cc <= 0) { 171 shutdown(s, 1+1); 172 readfrom &= ~(1<<pv[0]); 173 } else 174 (void) write(s, buf, cc); 175 } 176 } while (readfrom); 177 exit(0); 178 } 179 setpgrp(0, getpid()); 180 (void) close(s); (void)close(pv[0]); 181 dup2(pv[1], 2); 182 } 183 if (*pwd->pw_shell == '\0') 184 pwd->pw_shell = _PATH_BSHELL; 185 if (f > 2) 186 (void) close(f); 187 (void) setgid((gid_t)pwd->pw_gid); 188 initgroups(pwd->pw_name, pwd->pw_gid); 189 (void) setuid((uid_t)pwd->pw_uid); 190 (void)strcat(path, _PATH_DEFPATH); 191 environ = envinit; 192 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 193 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 194 strncat(username, pwd->pw_name, sizeof(username)-6); 195 cp = strrchr(pwd->pw_shell, '/'); 196 if (cp) 197 cp++; 198 else 199 cp = pwd->pw_shell; 200 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 201 perror(pwd->pw_shell); 202 exit(1); 203 } 204 205 /*VARARGS1*/ 206 error(fmt, a1, a2, a3) 207 char *fmt; 208 int a1, a2, a3; 209 { 210 char buf[BUFSIZ]; 211 212 buf[0] = 1; 213 (void) sprintf(buf+1, fmt, a1, a2, a3); 214 (void) write(2, buf, strlen(buf)); 215 } 216 217 getstr(buf, cnt, err) 218 char *buf; 219 int cnt; 220 char *err; 221 { 222 char c; 223 224 do { 225 if (read(0, &c, 1) != 1) 226 exit(1); 227 *buf++ = c; 228 if (--cnt == 0) { 229 error("%s too long\n", err); 230 exit(1); 231 } 232 } while (c != 0); 233 } 234