1 #ifndef lint 2 static char sccsid[] = "@(#)rsh.c 4.1 82/04/02"; 3 #endif 4 5 #include <stdio.h> 6 #include <sys/types.h> 7 #include <sys/socket.h> 8 #include <net/in.h> 9 #include <sys/file.h> 10 #include <errno.h> 11 #include <signal.h> 12 #include <sys/ioctl.h> 13 #include <pwd.h> 14 15 /* 16 * rsh - remote shell 17 */ 18 /* VARARGS */ 19 int error(); 20 char *index(), *rindex(), *malloc(), *getpass(), *sprintf(), *strcpy(); 21 22 struct passwd *getpwuid(); 23 24 int errno; 25 int options; 26 int rfd2; 27 int sendsig(); 28 29 main(argc, argv0) 30 int argc; 31 char **argv0; 32 { 33 int rem, pid; 34 char *host, *cp, **ap, buf[BUFSIZ], *args, **argv = argv0, *user = 0; 35 register int cc; 36 int asrsh = 0; 37 struct passwd *pwd; 38 int readfrom, ready; 39 int one = 1; 40 41 host = rindex(argv[0], '/'); 42 if (host) 43 host++; 44 else 45 host = argv[0]; 46 argv++, --argc; 47 if (!strcmp(host, "rsh")) { 48 host = *argv++, --argc; 49 asrsh = 1; 50 } 51 another: 52 if (!strcmp(*argv, "-l")) { 53 argv++, argc--; 54 if (argc > 0) 55 user = *argv++, argc--; 56 goto another; 57 } 58 if (!strcmp(*argv, "-n")) { 59 argv++, argc--; 60 (void) close(0); 61 (void) open("/dev/null", 0); 62 goto another; 63 } 64 if (!strcmp(*argv, "-d")) { 65 argv++, argc--; 66 options |= SO_DEBUG; 67 goto another; 68 } 69 if (host == 0) 70 goto usage; 71 if (argv[0] == 0) { 72 if (asrsh) 73 *argv0 = "rlogin"; 74 execv("/usr/ucb/rlogin", argv0); 75 perror("/usr/ucb/rlogin"); 76 exit(1); 77 } 78 pwd = getpwuid(getuid()); 79 if (pwd == 0) { 80 fprintf(stderr, "who are you?\n"); 81 exit(1); 82 } 83 cc = 0; 84 for (ap = argv; *ap; ap++) 85 cc += strlen(*ap) + 1; 86 cp = args = malloc(cc); 87 for (ap = argv; *ap; ap++) { 88 (void) strcpy(cp, *ap); 89 while (*cp) 90 cp++; 91 if (ap[1]) 92 *cp++ = ' '; 93 } 94 rem = rcmd(&host, IPPORT_CMDSERVER, pwd->pw_name, 95 user ? user : pwd->pw_name, args, &rfd2); 96 if (rem < 0) 97 exit(1); 98 (void) setuid(getuid()); 99 sigacts(SIG_HOLD); 100 pid = fork(); 101 if (pid < 0) { 102 perror("fork"); 103 exit(1); 104 } 105 ioctl(rfd2, FIONBIO, &one); 106 ioctl(rem, FIONBIO, &one); 107 if (pid == 0) { 108 char *bp; int rembits, wc; 109 (void) close(rfd2); 110 reread: 111 cc = read(0, buf, sizeof buf); 112 if (cc <= 0) 113 goto done; 114 bp = buf; 115 rewrite: 116 rembits = 1<<rem; 117 (void) select(20, 0, &rembits, 100000); 118 if ((rembits & (1<<rem)) == 0) 119 goto rewrite; 120 wc = write(rem, bp, cc); 121 if (wc < 0) { 122 if (errno == EWOULDBLOCK) 123 goto rewrite; 124 goto done; 125 } 126 cc -= wc; bp += wc; 127 if (cc == 0) 128 goto reread; 129 goto rewrite; 130 done: 131 { int flags = 1; ioctl(rem, SIOCDONE, &flags); } 132 exit(0); 133 } 134 sigacts(sendsig); 135 readfrom = (1<<rfd2) | (1<<rem); 136 do { 137 ready = readfrom; 138 (void) select(32, &ready, 0, 10000000); 139 if (ready & (1<<rfd2)) { 140 errno = 0; 141 cc = read(rfd2, buf, sizeof buf); 142 if (cc <= 0) { 143 if (errno != EWOULDBLOCK) 144 readfrom &= ~(1<<rfd2); 145 } else 146 (void) write(2, buf, cc); 147 } 148 if (ready & (1<<rem)) { 149 errno = 0; 150 cc = read(rem, buf, sizeof buf); 151 if (cc <= 0) { 152 if (errno != EWOULDBLOCK) 153 readfrom &= ~(1<<rem); 154 } else 155 (void) write(1, buf, cc); 156 } 157 } while (readfrom); 158 (void) kill(pid, SIGKILL); 159 exit(0); 160 usage: 161 fprintf(stderr, 162 "usage: rsh host [ -l login ] [ -p passwd ] command\n"); 163 exit(1); 164 } 165 166 sigacts(state) 167 int (*state)(); 168 { 169 170 sigset(SIGINT, state); 171 sigset(SIGQUIT, state); 172 sigset(SIGTERM, state); 173 } 174 175 sendsig(signo) 176 int signo; 177 { 178 179 (void) write(rfd2, (char *)&signo, 1); 180 } 181