1 #ifndef lint 2 static char sccsid[] = "@(#)rsh.c 4.2 82/11/14"; 3 #endif 4 5 #include <sys/types.h> 6 #include <sys/socket.h> 7 #include <sys/ioctl.h> 8 #include <sys/file.h> 9 10 #include <netinet/in.h> 11 12 #include <stdio.h> 13 #include <errno.h> 14 #include <signal.h> 15 #include <pwd.h> 16 17 /* 18 * rsh - remote shell 19 */ 20 /* VARARGS */ 21 int error(); 22 char *index(), *rindex(), *malloc(), *getpass(), *sprintf(), *strcpy(); 23 24 struct passwd *getpwuid(); 25 26 int errno; 27 int options; 28 int rfd2; 29 int sendsig(); 30 31 main(argc, argv0) 32 int argc; 33 char **argv0; 34 { 35 int rem, pid; 36 char *host, *cp, **ap, buf[BUFSIZ], *args, **argv = argv0, *user = 0; 37 register int cc; 38 int asrsh = 0; 39 struct passwd *pwd; 40 int readfrom, ready; 41 int one = 1; 42 43 host = rindex(argv[0], '/'); 44 if (host) 45 host++; 46 else 47 host = argv[0]; 48 argv++, --argc; 49 if (!strcmp(host, "rsh")) { 50 host = *argv++, --argc; 51 asrsh = 1; 52 } 53 another: 54 if (!strcmp(*argv, "-l")) { 55 argv++, argc--; 56 if (argc > 0) 57 user = *argv++, argc--; 58 goto another; 59 } 60 if (!strcmp(*argv, "-n")) { 61 argv++, argc--; 62 (void) close(0); 63 (void) open("/dev/null", 0); 64 goto another; 65 } 66 if (!strcmp(*argv, "-d")) { 67 argv++, argc--; 68 options |= SO_DEBUG; 69 goto another; 70 } 71 if (host == 0) 72 goto usage; 73 if (argv[0] == 0) { 74 if (asrsh) 75 *argv0 = "rlogin"; 76 execv("/usr/ucb/rlogin", argv0); 77 perror("/usr/ucb/rlogin"); 78 exit(1); 79 } 80 pwd = getpwuid(getuid()); 81 if (pwd == 0) { 82 fprintf(stderr, "who are you?\n"); 83 exit(1); 84 } 85 cc = 0; 86 for (ap = argv; *ap; ap++) 87 cc += strlen(*ap) + 1; 88 cp = args = malloc(cc); 89 for (ap = argv; *ap; ap++) { 90 (void) strcpy(cp, *ap); 91 while (*cp) 92 cp++; 93 if (ap[1]) 94 *cp++ = ' '; 95 } 96 rem = rcmd(&host, IPPORT_CMDSERVER, pwd->pw_name, 97 user ? user : pwd->pw_name, args, &rfd2); 98 if (rem < 0) 99 exit(1); 100 (void) setuid(getuid()); 101 sigacts(SIG_HOLD); 102 pid = fork(); 103 if (pid < 0) { 104 perror("fork"); 105 exit(1); 106 } 107 ioctl(rfd2, FIONBIO, &one); 108 ioctl(rem, FIONBIO, &one); 109 if (pid == 0) { 110 char *bp; int rembits, wc; 111 (void) close(rfd2); 112 reread: 113 cc = read(0, buf, sizeof buf); 114 if (cc <= 0) 115 goto done; 116 bp = buf; 117 rewrite: 118 rembits = 1<<rem; 119 if (select(16, 0, &rembits, 0, 0) < 0) { 120 if (errno != EINTR) { 121 perror("select"); 122 exit(1); 123 } 124 goto rewrite; 125 } 126 if ((rembits & (1<<rem)) == 0) 127 goto rewrite; 128 wc = write(rem, bp, cc); 129 if (wc < 0) { 130 if (errno == EWOULDBLOCK) 131 goto rewrite; 132 goto done; 133 } 134 cc -= wc; bp += wc; 135 if (cc == 0) 136 goto reread; 137 goto rewrite; 138 done: 139 { int flags = 1; ioctl(rem, SIOCDONE, &flags); } 140 exit(0); 141 } 142 sigacts(sendsig); 143 readfrom = (1<<rfd2) | (1<<rem); 144 do { 145 ready = readfrom; 146 if (select(16, &ready, 0, 0, 0) < 0) { 147 if (errno != EINTR) { 148 perror("select"); 149 exit(1); 150 } 151 continue; 152 } 153 if (ready & (1<<rfd2)) { 154 errno = 0; 155 cc = read(rfd2, buf, sizeof buf); 156 if (cc <= 0) { 157 if (errno != EWOULDBLOCK) 158 readfrom &= ~(1<<rfd2); 159 } else 160 (void) write(2, buf, cc); 161 } 162 if (ready & (1<<rem)) { 163 errno = 0; 164 cc = read(rem, buf, sizeof buf); 165 if (cc <= 0) { 166 if (errno != EWOULDBLOCK) 167 readfrom &= ~(1<<rem); 168 } else 169 (void) write(1, buf, cc); 170 } 171 } while (readfrom); 172 (void) kill(pid, SIGKILL); 173 exit(0); 174 usage: 175 fprintf(stderr, 176 "usage: rsh host [ -l login ] [ -p passwd ] command\n"); 177 exit(1); 178 } 179 180 sigacts(state) 181 int (*state)(); 182 { 183 184 sigset(SIGINT, state); 185 sigset(SIGQUIT, state); 186 sigset(SIGTERM, state); 187 } 188 189 sendsig(signo) 190 int signo; 191 { 192 193 (void) write(rfd2, (char *)&signo, 1); 194 } 195