blob: 890e58466cc1f4ce5504e652ee60c9ee75972b68 [file] [log] [blame]
Bernhard Reutner-Fischer2c998512006-04-12 18:09:26 +00001/* vi: set sw=4 ts=4: */
Bernhard Reutner-Fischerdac7ff12006-04-12 17:55:51 +00002/*
Eric Andersen08a72202002-09-30 20:52:10 +00003 * Simple telnet server
4 * Bjorn Wesen, Axis Communications AB (bjornw@axis.com)
5 *
Rob Landley1ec5b292006-05-29 07:42:02 +00006 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
Eric Andersen08a72202002-09-30 20:52:10 +00007 *
8 * ---------------------------------------------------------------------------
9 * (C) Copyright 2000, Axis Communications AB, LUND, SWEDEN
10 ****************************************************************************
11 *
12 * The telnetd manpage says it all:
13 *
14 * Telnetd operates by allocating a pseudo-terminal device (see pty(4)) for
15 * a client, then creating a login process which has the slave side of the
16 * pseudo-terminal as stdin, stdout, and stderr. Telnetd manipulates the
17 * master side of the pseudo-terminal, implementing the telnet protocol and
18 * passing characters between the remote client and the login process.
19 *
20 * Vladimir Oleynik <dzo@simtreas.ru> 2001
21 * Set process group corrections, initial busybox port
22 */
23
24/*#define DEBUG 1 */
Mike Frysinger772a3462006-05-10 17:14:32 +000025#undef DEBUG
Eric Andersen08a72202002-09-30 20:52:10 +000026
Rob Landley099ed502006-08-28 09:41:49 +000027#include "busybox.h"
28
Eric Andersen08a72202002-09-30 20:52:10 +000029#ifdef DEBUG
30#define TELCMDS
31#define TELOPTS
32#endif
33#include <arpa/telnet.h>
Eric Andersen08a72202002-09-30 20:52:10 +000034#include <sys/syslog.h>
35
Eric Andersen08a72202002-09-30 20:52:10 +000036
37#define BUFSIZE 4000
38
Rob Landley00e76cb2005-05-10 23:53:33 +000039#ifdef CONFIG_FEATURE_IPV6
40#define SOCKET_TYPE AF_INET6
41typedef struct sockaddr_in6 sockaddr_type;
42#else
43#define SOCKET_TYPE AF_INET
44typedef struct sockaddr_in sockaddr_type;
45#endif
46
47
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +000048#ifdef CONFIG_LOGIN
Glenn L McGrathd4004ee2004-09-14 17:24:59 +000049static const char *loginpath = "/bin/login";
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +000050#else
Glenn L McGrathd4004ee2004-09-14 17:24:59 +000051static const char *loginpath;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +000052#endif
53static const char *issuefile = "/etc/issue.net";
Eric Andersen08a72202002-09-30 20:52:10 +000054
55/* shell name and arguments */
56
57static const char *argv_init[] = {NULL, NULL};
58
59/* structure that describes a session */
60
61struct tsession {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +000062#ifdef CONFIG_FEATURE_TELNETD_INETD
63 int sockfd_read, sockfd_write, ptyfd;
64#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +000065 struct tsession *next;
66 int sockfd, ptyfd;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +000067#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +000068 int shell_pid;
69 /* two circular buffers */
70 char *buf1, *buf2;
71 int rdidx1, wridx1, size1;
72 int rdidx2, wridx2, size2;
73};
74
75/*
76
77 This is how the buffers are used. The arrows indicate the movement
78 of data.
79
80 +-------+ wridx1++ +------+ rdidx1++ +----------+
81 | | <-------------- | buf1 | <-------------- | |
82 | | size1-- +------+ size1++ | |
Mike Frysingerd2c8fd62006-05-10 17:17:09 +000083 | pty | | socket |
Eric Andersen08a72202002-09-30 20:52:10 +000084 | | rdidx2++ +------+ wridx2++ | |
85 | | --------------> | buf2 | --------------> | |
86 +-------+ size2++ +------+ size2-- +----------+
87
88 Each session has got two buffers.
89
90*/
91
92static int maxfd;
93
94static struct tsession *sessions;
95
96
97/*
98
Bernhard Reutner-Fischere0387a62006-06-07 13:31:59 +000099 Remove all IAC's from the buffer pointed to by bf (received IACs are ignored
Eric Andersen08a72202002-09-30 20:52:10 +0000100 and must be removed so as to not be interpreted by the terminal). Make an
101 uninterrupted string of characters fit for the terminal. Do this by packing
102 all characters meant for the terminal sequentially towards the end of bf.
103
104 Return a pointer to the beginning of the characters meant for the terminal.
105 and make *num_totty the number of characters that should be sent to
106 the terminal.
107
108 Note - If an IAC (3 byte quantity) starts before (bf + len) but extends
109 past (bf + len) then that IAC will be left unprocessed and *processed will be
110 less than len.
111
112 FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
113 what is the escape character? We aren't handling that situation here.
114
Eric Andersen3752d332003-12-19 11:30:13 +0000115 CR-LF ->'s CR mapping is also done here, for convenience
116
Eric Andersen08a72202002-09-30 20:52:10 +0000117 */
118static char *
119remove_iacs(struct tsession *ts, int *pnum_totty) {
Eric Andersen0cb6f352006-01-30 22:30:41 +0000120 unsigned char *ptr0 = (unsigned char *)ts->buf1 + ts->wridx1;
Eric Andersen08a72202002-09-30 20:52:10 +0000121 unsigned char *ptr = ptr0;
122 unsigned char *totty = ptr;
123 unsigned char *end = ptr + MIN(BUFSIZE - ts->wridx1, ts->size1);
124 int processed;
125 int num_totty;
126
127 while (ptr < end) {
128 if (*ptr != IAC) {
Eric Andersen3752d332003-12-19 11:30:13 +0000129 int c = *ptr;
Eric Andersen08a72202002-09-30 20:52:10 +0000130 *totty++ = *ptr++;
Eric Andersen3752d332003-12-19 11:30:13 +0000131 /* We now map \r\n ==> \r for pragmatic reasons.
132 * Many client implementations send \r\n when
133 * the user hits the CarriageReturn key.
134 */
135 if (c == '\r' && (*ptr == '\n' || *ptr == 0) && ptr < end)
136 ptr++;
Eric Andersen08a72202002-09-30 20:52:10 +0000137 }
138 else {
Glenn L McGrath90ed9a02004-02-22 09:45:57 +0000139 /*
140 * TELOPT_NAWS support!
141 */
142 if ((ptr+2) >= end) {
Eric Andersen08a72202002-09-30 20:52:10 +0000143 /* only the beginning of the IAC is in the
144 buffer we were asked to process, we can't
145 process this char. */
146 break;
147 }
Glenn L McGrath90ed9a02004-02-22 09:45:57 +0000148
149 /*
150 * IAC -> SB -> TELOPT_NAWS -> 4-byte -> IAC -> SE
151 */
152 else if (ptr[1] == SB && ptr[2] == TELOPT_NAWS) {
153 struct winsize ws;
154 if ((ptr+8) >= end)
Tim Rikerc1ef7bd2006-01-25 00:08:53 +0000155 break; /* incomplete, can't process */
Glenn L McGrath90ed9a02004-02-22 09:45:57 +0000156 ws.ws_col = (ptr[3] << 8) | ptr[4];
157 ws.ws_row = (ptr[5] << 8) | ptr[6];
158 (void) ioctl(ts->ptyfd, TIOCSWINSZ, (char *)&ws);
159 ptr += 9;
160 }
161 else {
162 /* skip 3-byte IAC non-SB cmd */
163#ifdef DEBUG
164 fprintf(stderr, "Ignoring IAC %s,%s\n",
165 TELCMD(*(ptr+1)), TELOPT(*(ptr+2)));
166#endif
167 ptr += 3;
168 }
Eric Andersen08a72202002-09-30 20:52:10 +0000169 }
170 }
171
172 processed = ptr - ptr0;
173 num_totty = totty - ptr0;
174 /* the difference between processed and num_to tty
175 is all the iacs we removed from the stream.
176 Adjust buf1 accordingly. */
177 ts->wridx1 += processed - num_totty;
178 ts->size1 -= processed - num_totty;
179 *pnum_totty = num_totty;
180 /* move the chars meant for the terminal towards the end of the
181 buffer. */
182 return memmove(ptr - num_totty, ptr0, num_totty);
183}
184
185
186static int
187getpty(char *line)
188{
189 int p;
Glenn L McGrathf234e7c2002-11-10 22:26:19 +0000190#ifdef CONFIG_FEATURE_DEVPTS
Eric Andersen08a72202002-09-30 20:52:10 +0000191 p = open("/dev/ptmx", 2);
192 if (p > 0) {
193 grantpt(p);
194 unlockpt(p);
195 strcpy(line, ptsname(p));
196 return(p);
197 }
198#else
199 struct stat stb;
200 int i;
201 int j;
202
203 strcpy(line, "/dev/ptyXX");
204
205 for (i = 0; i < 16; i++) {
206 line[8] = "pqrstuvwxyzabcde"[i];
207 line[9] = '0';
208 if (stat(line, &stb) < 0) {
209 continue;
210 }
211 for (j = 0; j < 16; j++) {
212 line[9] = j < 10 ? j + '0' : j - 10 + 'a';
Mike Frysinger772a3462006-05-10 17:14:32 +0000213#ifdef DEBUG
214 fprintf(stderr, "Trying to open device: %s\n", line);
215#endif
Eric Andersen08a72202002-09-30 20:52:10 +0000216 if ((p = open(line, O_RDWR | O_NOCTTY)) >= 0) {
217 line[5] = 't';
218 return p;
219 }
220 }
221 }
Glenn L McGrathf234e7c2002-11-10 22:26:19 +0000222#endif /* CONFIG_FEATURE_DEVPTS */
Eric Andersen08a72202002-09-30 20:52:10 +0000223 return -1;
224}
225
226
227static void
228send_iac(struct tsession *ts, unsigned char command, int option)
229{
230 /* We rely on that there is space in the buffer for now. */
231 char *b = ts->buf2 + ts->rdidx2;
232 *b++ = IAC;
233 *b++ = command;
234 *b++ = option;
235 ts->rdidx2 += 3;
236 ts->size2 += 3;
237}
238
239
240static struct tsession *
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000241#ifdef CONFIG_FEATURE_TELNETD_INETD
242make_new_session(void)
243#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000244make_new_session(int sockfd)
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000245#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000246{
247 struct termios termbuf;
248 int pty, pid;
249 char tty_name[32];
Rob Landley1ec5b292006-05-29 07:42:02 +0000250 struct tsession *ts = xzalloc(sizeof(struct tsession) + BUFSIZE * 2);
Eric Andersen08a72202002-09-30 20:52:10 +0000251
252 ts->buf1 = (char *)(&ts[1]);
253 ts->buf2 = ts->buf1 + BUFSIZE;
254
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000255#ifdef CONFIG_FEATURE_TELNETD_INETD
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000256 ts->sockfd_write = 1;
257#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000258 ts->sockfd = sockfd;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000259#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000260
Eric Andersen08a72202002-09-30 20:52:10 +0000261 /* Got a new connection, set up a tty and spawn a shell. */
262
263 pty = getpty(tty_name);
264
265 if (pty < 0) {
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000266 bb_error_msg("all terminals in use");
Eric Andersen08a72202002-09-30 20:52:10 +0000267 return 0;
268 }
269
270 if (pty > maxfd)
271 maxfd = pty;
272
273 ts->ptyfd = pty;
274
275 /* Make the telnet client understand we will echo characters so it
276 * should not do it locally. We don't tell the client to run linemode,
277 * because we want to handle line editing and tab completion and other
278 * stuff that requires char-by-char support.
279 */
280
281 send_iac(ts, DO, TELOPT_ECHO);
Glenn L McGrath90ed9a02004-02-22 09:45:57 +0000282 send_iac(ts, DO, TELOPT_NAWS);
Eric Andersen08a72202002-09-30 20:52:10 +0000283 send_iac(ts, DO, TELOPT_LFLOW);
284 send_iac(ts, WILL, TELOPT_ECHO);
285 send_iac(ts, WILL, TELOPT_SGA);
286
Eric Andersen08a72202002-09-30 20:52:10 +0000287 if ((pid = fork()) < 0) {
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000288 bb_perror_msg("fork");
Eric Andersen08a72202002-09-30 20:52:10 +0000289 }
290 if (pid == 0) {
291 /* In child, open the child's side of the tty. */
292 int i;
293
294 for(i = 0; i <= maxfd; i++)
295 close(i);
296 /* make new process group */
297 setsid();
298
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000299 xopen(tty_name, O_RDWR /*| O_NOCTTY*/);
Eric Andersen08a72202002-09-30 20:52:10 +0000300 dup(0);
301 dup(0);
302
303 tcsetpgrp(0, getpid());
304
305 /* The pseudo-terminal allocated to the client is configured to operate in
306 * cooked mode, and with XTABS CRMOD enabled (see tty(4)).
307 */
308
309 tcgetattr(0, &termbuf);
310 termbuf.c_lflag |= ECHO; /* if we use readline we dont want this */
311 termbuf.c_oflag |= ONLCR|XTABS;
312 termbuf.c_iflag |= ICRNL;
313 termbuf.c_iflag &= ~IXOFF;
314 /*termbuf.c_lflag &= ~ICANON;*/
315 tcsetattr(0, TCSANOW, &termbuf);
316
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000317 print_login_issue(issuefile, NULL);
318
Eric Andersen08a72202002-09-30 20:52:10 +0000319 /* exec shell, with correct argv and env */
320 execv(loginpath, (char *const *)argv_init);
321
322 /* NOT REACHED */
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000323 bb_perror_msg_and_die("execv");
Eric Andersen08a72202002-09-30 20:52:10 +0000324 }
325
326 ts->shell_pid = pid;
327
328 return ts;
329}
330
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000331#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000332static void
333free_session(struct tsession *ts)
334{
335 struct tsession *t = sessions;
336
337 /* Unlink this telnet session from the session list. */
Mike Frysinger731f81c2006-05-10 15:23:12 +0000338 if (t == ts)
Eric Andersen08a72202002-09-30 20:52:10 +0000339 sessions = ts->next;
340 else {
341 while(t->next != ts)
342 t = t->next;
343 t->next = ts->next;
344 }
345
346 kill(ts->shell_pid, SIGKILL);
347
348 wait4(ts->shell_pid, NULL, 0, NULL);
349
350 close(ts->ptyfd);
351 close(ts->sockfd);
352
Mike Frysinger731f81c2006-05-10 15:23:12 +0000353 if (ts->ptyfd == maxfd || ts->sockfd == maxfd)
Eric Andersen08a72202002-09-30 20:52:10 +0000354 maxfd--;
Mike Frysinger731f81c2006-05-10 15:23:12 +0000355 if (ts->ptyfd == maxfd || ts->sockfd == maxfd)
Eric Andersen08a72202002-09-30 20:52:10 +0000356 maxfd--;
357
358 free(ts);
359}
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000360#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000361
362int
363telnetd_main(int argc, char **argv)
364{
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000365#ifndef CONFIG_FEATURE_TELNETD_INETD
Tim Rikerc1ef7bd2006-01-25 00:08:53 +0000366 sockaddr_type sa;
Eric Andersen08a72202002-09-30 20:52:10 +0000367 int master_fd;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000368#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000369 fd_set rdfdset, wrfdset;
370 int selret;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000371#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000372 int on = 1;
373 int portnbr = 23;
Rob Landley64a5f962005-11-10 22:37:40 +0000374 struct in_addr bind_addr = { .s_addr = 0x0 };
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000375#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000376 int c;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000377 static const char options[] =
378#ifdef CONFIG_FEATURE_TELNETD_INETD
379 "f:l:";
380#else /* CONFIG_EATURE_TELNETD_INETD */
Rob Landley64a5f962005-11-10 22:37:40 +0000381 "f:l:p:b:";
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000382#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen86f2cce2003-04-25 12:32:37 +0000383 int maxlen, w, r;
Eric Andersen08a72202002-09-30 20:52:10 +0000384
Glenn L McGrathc2b91862003-09-12 11:27:15 +0000385#ifndef CONFIG_LOGIN
386 loginpath = DEFAULT_SHELL;
387#endif
388
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000389 /* We use inetd-style operation unconditionally
390 * (no --foreground option), user most likely will
391 * look into syslog for all errors, even early ones.
392 * Direct all output to syslog at once.
393 */
394 openlog(bb_applet_name, 0, LOG_USER);
395 logmode = LOGMODE_SYSLOG;
396
Eric Andersen08a72202002-09-30 20:52:10 +0000397 for (;;) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000398 c = getopt( argc, argv, options);
Eric Andersen08a72202002-09-30 20:52:10 +0000399 if (c == EOF) break;
400 switch (c) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000401 case 'f':
Glenn L McGrathd4004ee2004-09-14 17:24:59 +0000402 issuefile = optarg;
Eric Andersen08a72202002-09-30 20:52:10 +0000403 break;
404 case 'l':
Glenn L McGrathd4004ee2004-09-14 17:24:59 +0000405 loginpath = optarg;
Eric Andersen08a72202002-09-30 20:52:10 +0000406 break;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000407#ifndef CONFIG_FEATURE_TELNETD_INETD
408 case 'p':
409 portnbr = atoi(optarg);
410 break;
Rob Landley64a5f962005-11-10 22:37:40 +0000411 case 'b':
412 if (inet_aton(optarg, &bind_addr) == 0)
413 bb_show_usage();
414 break;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000415#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000416 default:
Manuel Novoa III cad53642003-03-19 09:13:01 +0000417 bb_show_usage();
Eric Andersen08a72202002-09-30 20:52:10 +0000418 }
419 }
420
421 if (access(loginpath, X_OK) < 0) {
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000422 bb_error_msg_and_die("'%s' unavailable", loginpath);
Eric Andersen08a72202002-09-30 20:52:10 +0000423 }
424
425 argv_init[0] = loginpath;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000426
427#ifdef CONFIG_FEATURE_TELNETD_INETD
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000428 maxfd = 1;
Glenn L McGrath8eb214e2003-01-22 21:09:48 +0000429 sessions = make_new_session();
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000430#else /* CONFIG_EATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000431 sessions = 0;
432
433 /* Grab a TCP socket. */
434
Rob Landley099ed502006-08-28 09:41:49 +0000435 master_fd = xsocket(SOCKET_TYPE, SOCK_STREAM, 0);
Eric Andersen08a72202002-09-30 20:52:10 +0000436 (void)setsockopt(master_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
437
438 /* Set it to listen to specified port. */
439
440 memset((void *)&sa, 0, sizeof(sa));
Rob Landley00e76cb2005-05-10 23:53:33 +0000441#ifdef CONFIG_FEATURE_IPV6
442 sa.sin6_family = AF_INET6;
443 sa.sin6_port = htons(portnbr);
Rob Landley64a5f962005-11-10 22:37:40 +0000444 /* sa.sin6_addr = bind_addr6; */
Rob Landley00e76cb2005-05-10 23:53:33 +0000445#else
Eric Andersen08a72202002-09-30 20:52:10 +0000446 sa.sin_family = AF_INET;
447 sa.sin_port = htons(portnbr);
Rob Landley64a5f962005-11-10 22:37:40 +0000448 sa.sin_addr = bind_addr;
Rob Landley00e76cb2005-05-10 23:53:33 +0000449#endif
Eric Andersen08a72202002-09-30 20:52:10 +0000450
Rob Landley099ed502006-08-28 09:41:49 +0000451 xbind(master_fd, (struct sockaddr *) &sa, sizeof(sa));
452 xlisten(master_fd, 1);
453 xdaemon(0, 0);
Eric Andersen08a72202002-09-30 20:52:10 +0000454
455 maxfd = master_fd;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000456#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000457
458 do {
459 struct tsession *ts;
460
461 FD_ZERO(&rdfdset);
462 FD_ZERO(&wrfdset);
463
464 /* select on the master socket, all telnet sockets and their
465 * ptys if there is room in their respective session buffers.
466 */
467
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000468#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000469 FD_SET(master_fd, &rdfdset);
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000470#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000471
472 ts = sessions;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000473#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000474 while (ts) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000475#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000476 /* buf1 is used from socket to pty
477 * buf2 is used from pty to socket
478 */
479 if (ts->size1 > 0) {
480 FD_SET(ts->ptyfd, &wrfdset); /* can write to pty */
481 }
482 if (ts->size1 < BUFSIZE) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000483#ifdef CONFIG_FEATURE_TELNETD_INETD
484 FD_SET(ts->sockfd_read, &rdfdset); /* can read from socket */
485#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000486 FD_SET(ts->sockfd, &rdfdset); /* can read from socket */
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000487#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000488 }
489 if (ts->size2 > 0) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000490#ifdef CONFIG_FEATURE_TELNETD_INETD
491 FD_SET(ts->sockfd_write, &wrfdset); /* can write to socket */
492#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000493 FD_SET(ts->sockfd, &wrfdset); /* can write to socket */
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000494#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000495 }
496 if (ts->size2 < BUFSIZE) {
497 FD_SET(ts->ptyfd, &rdfdset); /* can read from pty */
498 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000499#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000500 ts = ts->next;
501 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000502#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000503
504 selret = select(maxfd + 1, &rdfdset, &wrfdset, 0, 0);
505
506 if (!selret)
507 break;
508
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000509#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000510 /* First check for and accept new sessions. */
511 if (FD_ISSET(master_fd, &rdfdset)) {
Mike Frysinger06b00e82006-05-10 17:18:11 +0000512 int fd;
513 socklen_t salen;
Eric Andersen08a72202002-09-30 20:52:10 +0000514
515 salen = sizeof(sa);
516 if ((fd = accept(master_fd, (struct sockaddr *)&sa,
517 &salen)) < 0) {
518 continue;
519 } else {
520 /* Create a new session and link it into
521 our active list. */
522 struct tsession *new_ts = make_new_session(fd);
523 if (new_ts) {
524 new_ts->next = sessions;
525 sessions = new_ts;
526 if (fd > maxfd)
527 maxfd = fd;
528 } else {
529 close(fd);
530 }
531 }
532 }
533
534 /* Then check for data tunneling. */
535
536 ts = sessions;
537 while (ts) { /* For all sessions... */
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000538#endif /* CONFIG_FEATURE_TELNETD_INETD */
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000539#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000540 struct tsession *next = ts->next; /* in case we free ts. */
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000541#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000542
Eric Andersen08a72202002-09-30 20:52:10 +0000543 if (ts->size1 && FD_ISSET(ts->ptyfd, &wrfdset)) {
544 int num_totty;
545 char *ptr;
546 /* Write to pty from buffer 1. */
547
548 ptr = remove_iacs(ts, &num_totty);
549
550 w = write(ts->ptyfd, ptr, num_totty);
551 if (w < 0) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000552#ifdef CONFIG_FEATURE_TELNETD_INETD
553 exit(0);
554#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000555 free_session(ts);
556 ts = next;
557 continue;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000558#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000559 }
560 ts->wridx1 += w;
561 ts->size1 -= w;
562 if (ts->wridx1 == BUFSIZE)
563 ts->wridx1 = 0;
564 }
565
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000566#ifdef CONFIG_FEATURE_TELNETD_INETD
567 if (ts->size2 && FD_ISSET(ts->sockfd_write, &wrfdset)) {
568#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000569 if (ts->size2 && FD_ISSET(ts->sockfd, &wrfdset)) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000570#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000571 /* Write to socket from buffer 2. */
572 maxlen = MIN(BUFSIZE - ts->wridx2, ts->size2);
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000573#ifdef CONFIG_FEATURE_TELNETD_INETD
574 w = write(ts->sockfd_write, ts->buf2 + ts->wridx2, maxlen);
575 if (w < 0)
576 exit(0);
577#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000578 w = write(ts->sockfd, ts->buf2 + ts->wridx2, maxlen);
579 if (w < 0) {
580 free_session(ts);
581 ts = next;
582 continue;
583 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000584#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000585 ts->wridx2 += w;
586 ts->size2 -= w;
587 if (ts->wridx2 == BUFSIZE)
588 ts->wridx2 = 0;
589 }
590
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000591#ifdef CONFIG_FEATURE_TELNETD_INETD
592 if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd_read, &rdfdset)) {
593#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000594 if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd, &rdfdset)) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000595#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000596 /* Read from socket to buffer 1. */
597 maxlen = MIN(BUFSIZE - ts->rdidx1,
598 BUFSIZE - ts->size1);
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000599#ifdef CONFIG_FEATURE_TELNETD_INETD
600 r = read(ts->sockfd_read, ts->buf1 + ts->rdidx1, maxlen);
601 if (!r || (r < 0 && errno != EINTR))
602 exit(0);
603#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000604 r = read(ts->sockfd, ts->buf1 + ts->rdidx1, maxlen);
605 if (!r || (r < 0 && errno != EINTR)) {
606 free_session(ts);
607 ts = next;
608 continue;
609 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000610#endif /* CONFIG_FEATURE_TELNETD_INETD */
Mike Frysinger731f81c2006-05-10 15:23:12 +0000611 if (!*(ts->buf1 + ts->rdidx1 + r - 1)) {
Eric Andersen08a72202002-09-30 20:52:10 +0000612 r--;
Mike Frysinger731f81c2006-05-10 15:23:12 +0000613 if (!r)
Eric Andersen08a72202002-09-30 20:52:10 +0000614 continue;
615 }
616 ts->rdidx1 += r;
617 ts->size1 += r;
618 if (ts->rdidx1 == BUFSIZE)
619 ts->rdidx1 = 0;
620 }
621
622 if (ts->size2 < BUFSIZE && FD_ISSET(ts->ptyfd, &rdfdset)) {
623 /* Read from pty to buffer 2. */
624 maxlen = MIN(BUFSIZE - ts->rdidx2,
625 BUFSIZE - ts->size2);
626 r = read(ts->ptyfd, ts->buf2 + ts->rdidx2, maxlen);
627 if (!r || (r < 0 && errno != EINTR)) {
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000628#ifdef CONFIG_FEATURE_TELNETD_INETD
629 exit(0);
630#else /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000631 free_session(ts);
632 ts = next;
633 continue;
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000634#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000635 }
636 ts->rdidx2 += r;
637 ts->size2 += r;
638 if (ts->rdidx2 == BUFSIZE)
639 ts->rdidx2 = 0;
640 }
641
642 if (ts->size1 == 0) {
643 ts->rdidx1 = 0;
644 ts->wridx1 = 0;
645 }
646 if (ts->size2 == 0) {
647 ts->rdidx2 = 0;
648 ts->wridx2 = 0;
649 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000650#ifndef CONFIG_FEATURE_TELNETD_INETD
Eric Andersen08a72202002-09-30 20:52:10 +0000651 ts = next;
652 }
Glenn L McGrath9e5d6c02003-01-21 20:55:56 +0000653#endif /* CONFIG_FEATURE_TELNETD_INETD */
Eric Andersen08a72202002-09-30 20:52:10 +0000654
655 } while (1);
656
657 return 0;
658}