1 #ifndef lint 2 static char sccsid[] = "@(#)rlogin.c 4.6 82/12/05"; 3 #endif 4 5 #include <sys/types.h> 6 #include <sys/socket.h> 7 8 #include <netinet/in.h> 9 10 #include <stdio.h> 11 #include <sgtty.h> 12 #include <errno.h> 13 #include <pwd.h> 14 #include <signal.h> 15 #include <netdb.h> 16 17 /* 18 * rlogin - remote login 19 */ 20 char *index(), *rindex(), *malloc(), *getenv(); 21 struct passwd *getpwuid(); 22 char *name; 23 int rem; 24 char cmdchar = '~'; 25 int rcmdoptions = 0; 26 int eight; 27 char *speeds[] = 28 { "0", "50", "75", "110", "134", "150", "200", "300", 29 "600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" }; 30 char term[64] = "network"; 31 extern int errno; 32 int lostpeer(); 33 34 main(argc, argv) 35 int argc; 36 char **argv; 37 { 38 char *host, *cp; 39 struct sgttyb ttyb; 40 struct passwd *pwd; 41 struct servent *sp; 42 int uid; 43 44 host = rindex(argv[0], '/'); 45 if (host) 46 host++; 47 else 48 host = argv[0]; 49 argv++, --argc; 50 if (!strcmp(host, "rlogin")) 51 host = *argv++, --argc; 52 another: 53 if (!strcmp(*argv, "-d")) { 54 argv++, argc--; 55 rcmdoptions |= SO_DEBUG; 56 goto another; 57 } 58 if (!strcmp(*argv, "-l")) { 59 argv++, argc--; 60 if (argc == 0) 61 goto usage; 62 name = *argv++; argc--; 63 goto another; 64 } 65 if (!strncmp(*argv, "-e", 2)) { 66 cmdchar = argv[0][2]; 67 argv++, argc--; 68 goto another; 69 } 70 if (!strcmp(*argv, "-8")) { 71 eight = 1; 72 argv++, argc--; 73 goto another; 74 } 75 if (host == 0) 76 goto usage; 77 if (argc > 0) 78 goto usage; 79 pwd = getpwuid(getuid()); 80 if (pwd == 0) { 81 fprintf(stderr, "Who are you?\n"); 82 exit(1); 83 } 84 sp = getservbyname("login", "tcp"); 85 if (sp == 0) { 86 fprintf(stderr, "rlogin: login/tcp: unknown service\n"); 87 exit(2); 88 } 89 cp = getenv("TERM"); 90 if (cp) 91 strcpy(term, cp); 92 if (gtty(0, &ttyb)==0) { 93 strcat(term, "/"); 94 strcat(term, speeds[ttyb.sg_ospeed]); 95 } 96 signal(SIGPIPE, lostpeer); 97 rem = rcmd(&host, sp->s_port, pwd->pw_name, 98 name ? name : pwd->pw_name, term, 0); 99 if (rem < 0) 100 exit(1); 101 uid = getuid(); 102 if (setuid(uid) < 0) { 103 perror("rlogin: setuid"); 104 exit(1); 105 } 106 doit(); 107 /*NOTREACHED*/ 108 usage: 109 fprintf(stderr, 110 "usage: rlogin host [ -ex ] [ -l username ]\n"); 111 exit(1); 112 } 113 114 #define CRLF "\r\n" 115 116 int child; 117 int done(); 118 119 char tkill, terase; /* current input kill & erase */ 120 char defkill, deferase, defflags; 121 122 struct tchars deftchars; 123 struct tchars notchars = { -1, -1, CTRL(q), CTRL(s), -1, -1 }; 124 struct ltchars defltchars; 125 struct ltchars noltchars = { -1, -1, -1, -1, -1, -1 }; 126 127 doit() 128 { 129 struct sgttyb stbuf; 130 int exit(); 131 132 ioctl(0, TIOCGETP, (char *)&stbuf); 133 defkill = stbuf.sg_kill; 134 deferase = stbuf.sg_erase; 135 defflags = stbuf.sg_flags & (ECHO | CRMOD); 136 ioctl(0, TIOCGETC, (char *)&deftchars); 137 ioctl(0, TIOCGLTC, (char *)&defltchars); 138 signal(SIGINT, exit); 139 signal(SIGHUP, exit); 140 signal(SIGQUIT, exit); 141 child = fork(); 142 if (child == -1) { 143 perror("rlogin: fork"); 144 done(); 145 } 146 signal(SIGINT, SIG_IGN); 147 if (child == 0) { 148 signal(SIGPIPE, SIG_IGN); 149 reader(); 150 prf("\007Lost connection."); 151 exit(3); 152 } 153 signal(SIGCHLD, done); 154 mode(1); 155 writer(); 156 prf("Disconnected."); 157 done(); 158 } 159 160 done() 161 { 162 163 mode(0); 164 if (child > 0 && kill(child, SIGKILL) >= 0) 165 wait((int *)0); 166 exit(0); 167 } 168 169 /* 170 * writer: write to remote: 0 -> line. 171 * ~. terminate 172 * ~^Z suspend rlogin process. 173 */ 174 writer() 175 { 176 char b[600], c; 177 register char *p; 178 179 top: 180 p = b; 181 while (read(0, &c, 1) > 0) { 182 int local; 183 184 if (eight == 0) 185 c &= 0177; 186 /* 187 * If we're at the beginning of the line 188 * and recognize a command character, then 189 * we echo locally. Otherwise, characters 190 * are echo'd remotely. If the command 191 * character is doubled, this acts as a 192 * force and local echo is suppressed. 193 */ 194 if (p == b) 195 local = (c == cmdchar); 196 if (p == b + 1 && *b == cmdchar) 197 local = (c != cmdchar); 198 if (!local) { 199 if (write(rem, &c, 1) == 0) { 200 prf("line gone"); 201 return; 202 } 203 if (eight == 0) 204 c &= 0177; 205 } else { 206 if (c == 0177) 207 c = tkill; 208 if (c == '\r' || c == '\n') { 209 switch (b[1]) { 210 211 case '.': 212 case CTRL(d): 213 write(0, CRLF, sizeof(CRLF)); 214 return; 215 216 case CTRL(z): 217 write(0, CRLF, sizeof(CRLF)); 218 mode(0); 219 signal(SIGCHLD, SIG_IGN); 220 kill(0, SIGTSTP); 221 signal(SIGCHLD, done); 222 mode(1); 223 goto top; 224 } 225 *p++ = c; 226 write(rem, b, p - b); 227 goto top; 228 } 229 write(1, &c, 1); 230 } 231 *p++ = c; 232 if (c == terase) { 233 p -= 2; 234 if (p < b) 235 goto top; 236 } 237 if (c == tkill || c == 0177 || c == CTRL(d) || 238 c == '\r' || c == '\n') 239 goto top; 240 } 241 } 242 243 oob() 244 { 245 int out = 1+1; 246 char waste[BUFSIZ], mark; 247 248 signal(SIGURG, oob); 249 ioctl(1, TIOCFLUSH, (char *)&out); 250 for (;;) { 251 if (ioctl(rem, SIOCATMARK, &mark) < 0) { 252 perror("ioctl"); 253 break; 254 } 255 if (mark) 256 break; 257 (void) read(rem, waste, sizeof (waste)); 258 } 259 recv(rem, &mark, 1, SOF_OOB); 260 if (mark & TIOCPKT_NOSTOP) { 261 notchars.t_stopc = -1; 262 notchars.t_startc = -1; 263 ioctl(0, TIOCSETC, (char *)¬chars); 264 } 265 if (mark & TIOCPKT_DOSTOP) { 266 notchars.t_stopc = CTRL(s); 267 notchars.t_startc = CTRL(q); 268 ioctl(0, TIOCSETC, (char *)¬chars); 269 } 270 } 271 272 /* 273 * reader: read from remote: line -> 1 274 */ 275 reader() 276 { 277 char rb[BUFSIZ]; 278 register int cnt; 279 280 signal(SIGURG, oob); 281 { int pid = -getpid(); 282 ioctl(rem, SIOCSPGRP, (char *)&pid); } 283 for (;;) { 284 cnt = read(rem, rb, sizeof (rb)); 285 if (cnt <= 0) { 286 if (errno == EINTR) 287 continue; 288 break; 289 } 290 write(1, rb, cnt); 291 } 292 } 293 294 mode(f) 295 { 296 struct sgttyb stbuf; 297 298 ioctl(0, TIOCGETP, (char *)&stbuf); 299 if (f == 0) { 300 stbuf.sg_flags &= ~CBREAK; 301 stbuf.sg_flags |= defflags; 302 ioctl(0, TIOCSETC, (char *)&deftchars); 303 ioctl(0, TIOCSLTC, (char *)&defltchars); 304 stbuf.sg_kill = defkill; 305 stbuf.sg_erase = deferase; 306 } 307 if (f == 1) { 308 stbuf.sg_flags |= CBREAK; 309 stbuf.sg_flags &= ~(ECHO|CRMOD); 310 ioctl(0, TIOCSETC, (char *)¬chars); 311 ioctl(0, TIOCSLTC, (char *)&noltchars); 312 stbuf.sg_kill = -1; 313 stbuf.sg_erase = -1; 314 } 315 if (f == 2) { 316 stbuf.sg_flags &= ~CBREAK; 317 stbuf.sg_flags &= ~(ECHO|CRMOD); 318 ioctl(0, TIOCSETC, (char *)&deftchars); 319 ioctl(0, TIOCSLTC, (char *)&defltchars); 320 stbuf.sg_kill = -1; 321 stbuf.sg_erase = -1; 322 } 323 ioctl(0, TIOCSETN, (char *)&stbuf); 324 } 325 326 /*VARARGS*/ 327 prf(f, a1, a2, a3) 328 char *f; 329 { 330 fprintf(stderr, f, a1, a2, a3); 331 fprintf(stderr, CRLF); 332 } 333 334 lostpeer() 335 { 336 signal(SIGPIPE, SIG_IGN); 337 prf("\007Lost connection"); 338 done(); 339 } 340