blob: 944cf1bd62aab4456fda9a97014d8394bb1548f6 [file] [log] [blame]
Eric Andersen28c70b32000-06-14 20:42:57 +00001/* vi: set sw=4 ts=4: */
Erik Andersenf7c49ef2000-02-22 17:17:45 +00002/*
Eric Andersen28c70b32000-06-14 20:42:57 +00003 * telnet implementation for busybox
Erik Andersenf7c49ef2000-02-22 17:17:45 +00004 *
Eric Andersen28c70b32000-06-14 20:42:57 +00005 * Author: Tomi Ollila <too@iki.fi>
6 * Copyright (C) 1994-2000 by Tomi Ollila
7 *
8 * Created: Thu Apr 7 13:29:41 1994 too
9 * Last modified: Fri Jun 9 14:34:24 2000 too
Erik Andersenf7c49ef2000-02-22 17:17:45 +000010 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +020011 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
Erik Andersenf7c49ef2000-02-22 17:17:45 +000012 *
Eric Andersen28c70b32000-06-14 20:42:57 +000013 * HISTORY
14 * Revision 3.1 1994/04/17 11:31:54 too
15 * initial revision
Eric Andersencb81e642003-07-14 21:21:08 +000016 * Modified 2000/06/13 for inclusion into BusyBox by Erik Andersen <andersen@codepoet.org>
Eric Andersen7e1273e2001-05-07 17:57:45 +000017 * Modified 2001/05/07 to add ability to pass TTYPE to remote host by Jim McQuillan
18 * <jam@ltsp.org>
Eric Andersen539ffc92004-02-22 12:25:47 +000019 * Modified 2004/02/11 to add ability to pass the USER variable to remote host
20 * by Fernando Silveira <swrh@gmx.net>
Erik Andersenf7c49ef2000-02-22 17:17:45 +000021 *
Erik Andersenf7c49ef2000-02-22 17:17:45 +000022 */
23
Pere Orga5bc8c002011-04-11 03:29:49 +020024//usage:#if ENABLE_FEATURE_TELNET_AUTOLOGIN
25//usage:#define telnet_trivial_usage
26//usage: "[-a] [-l USER] HOST [PORT]"
27//usage:#define telnet_full_usage "\n\n"
28//usage: "Connect to telnet server\n"
Pere Orga5bc8c002011-04-11 03:29:49 +020029//usage: "\n -a Automatic login with $USER variable"
30//usage: "\n -l USER Automatic login as USER"
31//usage:
32//usage:#else
33//usage:#define telnet_trivial_usage
34//usage: "HOST [PORT]"
35//usage:#define telnet_full_usage "\n\n"
36//usage: "Connect to telnet server"
37//usage:#endif
38
Eric Andersen28c70b32000-06-14 20:42:57 +000039#include <arpa/telnet.h>
Eric Andersen28c70b32000-06-14 20:42:57 +000040#include <netinet/in.h>
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000041#include "libbb.h"
Erik Andersenf7c49ef2000-02-22 17:17:45 +000042
Denys Vlasenko14bd16a2011-07-08 08:49:40 +020043#ifdef __BIONIC__
44/* should be in arpa/telnet.h */
45# define IAC 255 /* interpret as command: */
46# define DONT 254 /* you are not to use option */
47# define DO 253 /* please, you use option */
48# define WONT 252 /* I won't use option */
49# define WILL 251 /* I will use option */
50# define SB 250 /* interpret as subnegotiation */
51# define SE 240 /* end sub negotiation */
52# define TELOPT_ECHO 1 /* echo */
53# define TELOPT_SGA 3 /* suppress go ahead */
54# define TELOPT_TTYPE 24 /* terminal type */
55# define TELOPT_NAWS 31 /* window size */
56#endif
57
Pavel Roskin616d13b2000-07-28 19:38:27 +000058#ifdef DOTRACE
Denys Vlasenko14bd16a2011-07-08 08:49:40 +020059# define TRACE(x, y) do { if (x) printf y; } while (0)
Eric Andersen28c70b32000-06-14 20:42:57 +000060#else
Denys Vlasenko14bd16a2011-07-08 08:49:40 +020061# define TRACE(x, y)
Eric Andersen28c70b32000-06-14 20:42:57 +000062#endif
63
Mark Whitley59ab0252001-01-23 22:30:04 +000064enum {
Denis Vlasenkof24cdf12007-03-19 14:47:09 +000065 DATABUFSIZE = 128,
66 IACBUFSIZE = 128,
67
Rob Landleybc68cd12006-03-10 19:22:06 +000068 CHM_TRY = 0,
69 CHM_ON = 1,
70 CHM_OFF = 2,
71
72 UF_ECHO = 0x01,
73 UF_SGA = 0x02,
74
Denys Vlasenko036dbb92010-10-29 02:12:22 +020075 TS_NORMAL = 0,
76 TS_COPY = 1,
Mark Whitley59ab0252001-01-23 22:30:04 +000077 TS_IAC = 2,
78 TS_OPT = 3,
79 TS_SUB1 = 4,
80 TS_SUB2 = 5,
Denys Vlasenko036dbb92010-10-29 02:12:22 +020081 TS_CR = 6,
Mark Whitley59ab0252001-01-23 22:30:04 +000082};
Eric Andersen28c70b32000-06-14 20:42:57 +000083
Eric Andersen28c70b32000-06-14 20:42:57 +000084typedef unsigned char byte;
85
Denis Vlasenko1101d1c2008-07-21 09:22:28 +000086enum { netfd = 3 };
87
Denis Vlasenkof24cdf12007-03-19 14:47:09 +000088struct globals {
Denis Vlasenko1101d1c2008-07-21 09:22:28 +000089 int iaclen; /* could even use byte, but it's a loss on x86 */
Eric Andersen28c70b32000-06-14 20:42:57 +000090 byte telstate; /* telnet negotiation state from network input */
91 byte telwish; /* DO, DONT, WILL, WONT */
92 byte charmode;
93 byte telflags;
Paul Foxf2ddc052005-07-20 19:55:19 +000094 byte do_termios;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +000095#if ENABLE_FEATURE_TELNET_TTYPE
96 char *ttype;
97#endif
98#if ENABLE_FEATURE_TELNET_AUTOLOGIN
99 const char *autologin;
100#endif
101#if ENABLE_FEATURE_AUTOWIDTH
Denis Vlasenko55995022008-05-18 22:28:26 +0000102 unsigned win_width, win_height;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000103#endif
104 /* same buffer used both for network and console read/write */
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000105 char buf[DATABUFSIZE];
106 /* buffer to handle telnet negotiations */
Glenn L McGrath78b0e372001-06-26 02:06:08 +0000107 char iacbuf[IACBUFSIZE];
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000108 struct termios termios_def;
109 struct termios termios_raw;
Denys Vlasenko98a4c7c2010-02-04 15:00:15 +0100110} FIX_ALIASING;
Denis Vlasenko4e5f82c2007-06-03 22:30:22 +0000111#define G (*(struct globals*)&bb_common_bufsiz1)
Denis Vlasenko74324c82007-06-04 10:16:52 +0000112#define INIT_G() do { \
Denys Vlasenko7b85ec32015-10-13 17:17:34 +0200113 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
Denis Vlasenko74324c82007-06-04 10:16:52 +0000114} while (0)
Eric Andersen28c70b32000-06-14 20:42:57 +0000115
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200116
Eric Andersencd8c4362001-11-10 11:22:46 +0000117static void rawmode(void);
118static void cookmode(void);
119static void do_linemode(void);
120static void will_charmode(void);
Eric Andersen28c70b32000-06-14 20:42:57 +0000121static void telopt(byte c);
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200122static void subneg(byte c);
Eric Andersen28c70b32000-06-14 20:42:57 +0000123
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000124static void iac_flush(void)
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000125{
Denys Vlasenkof76fd172013-05-12 02:13:24 +0200126 full_write(netfd, G.iacbuf, G.iaclen);
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000127 G.iaclen = 0;
128}
Eric Andersen7e1273e2001-05-07 17:57:45 +0000129
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000130static void doexit(int ev) NORETURN;
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000131static void doexit(int ev)
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000132{
Eric Andersen28c70b32000-06-14 20:42:57 +0000133 cookmode();
134 exit(ev);
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000135}
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000136
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000137static void con_escape(void)
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000138{
Eric Andersen28c70b32000-06-14 20:42:57 +0000139 char b;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000140
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000141 if (bb_got_signal) /* came from line mode... go raw */
Eric Andersen28c70b32000-06-14 20:42:57 +0000142 rawmode();
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000143
Denys Vlasenkof76fd172013-05-12 02:13:24 +0200144 full_write1_str("\r\nConsole escape. Commands are:\r\n\n"
Eric Andersen28c70b32000-06-14 20:42:57 +0000145 " l go to line mode\r\n"
146 " c go to character mode\r\n"
147 " z suspend telnet\r\n"
148 " e exit telnet\r\n");
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000149
Bernhard Reutner-Fischer5e25ddb2008-05-19 09:48:17 +0000150 if (read(STDIN_FILENO, &b, 1) <= 0)
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000151 doexit(EXIT_FAILURE);
Eric Andersen28c70b32000-06-14 20:42:57 +0000152
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000153 switch (b) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000154 case 'l':
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000155 if (!bb_got_signal) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000156 do_linemode();
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000157 goto ret;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000158 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000159 break;
160 case 'c':
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000161 if (bb_got_signal) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000162 will_charmode();
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000163 goto ret;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000164 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000165 break;
166 case 'z':
167 cookmode();
168 kill(0, SIGTSTP);
169 rawmode();
170 break;
171 case 'e':
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000172 doexit(EXIT_SUCCESS);
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000173 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000174
Denys Vlasenkof76fd172013-05-12 02:13:24 +0200175 full_write1_str("continuing...\r\n");
Eric Andersen28c70b32000-06-14 20:42:57 +0000176
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000177 if (bb_got_signal)
Eric Andersen28c70b32000-06-14 20:42:57 +0000178 cookmode();
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000179 ret:
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000180 bb_got_signal = 0;
Eric Andersen28c70b32000-06-14 20:42:57 +0000181}
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000182
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000183static void handle_net_output(int len)
Eric Andersen28c70b32000-06-14 20:42:57 +0000184{
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200185 byte outbuf[2 * DATABUFSIZE];
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200186 byte *dst = outbuf;
187 byte *src = (byte*)G.buf;
188 byte *end = src + len;
Eric Andersen28c70b32000-06-14 20:42:57 +0000189
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200190 while (src < end) {
191 byte c = *src++;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200192 if (c == 0x1d) {
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000193 con_escape();
Eric Andersen28c70b32000-06-14 20:42:57 +0000194 return;
195 }
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200196 *dst = c;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200197 if (c == IAC)
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200198 *++dst = c; /* IAC -> IAC IAC */
199 else
200 if (c == '\r' || c == '\n') {
201 /* Enter key sends '\r' in raw mode and '\n' in cooked one.
202 *
203 * See RFC 1123 3.3.1 Telnet End-of-Line Convention.
Denys Vlasenkoaca464d2012-09-13 13:00:49 +0200204 * Using CR LF instead of other allowed possibilities
205 * like CR NUL - easier to talk to HTTP/SMTP servers.
206 */
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200207 *dst = '\r'; /* Enter -> CR LF */
208 *++dst = '\n';
209 }
210 dst++;
Eric Andersen28c70b32000-06-14 20:42:57 +0000211 }
Denys Vlasenko0ffd63c2012-09-17 11:54:35 +0200212 if (dst - outbuf != 0)
213 full_write(netfd, outbuf, dst - outbuf);
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000214}
215
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000216static void handle_net_input(int len)
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000217{
Eric Andersen28c70b32000-06-14 20:42:57 +0000218 int i;
219 int cstart = 0;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000220
Denis Vlasenko1bec1b92007-11-06 02:23:39 +0000221 for (i = 0; i < len; i++) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000222 byte c = G.buf[i];
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000223
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200224 if (G.telstate == TS_NORMAL) { /* most typical state */
Denis Vlasenko1bec1b92007-11-06 02:23:39 +0000225 if (c == IAC) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000226 cstart = i;
227 G.telstate = TS_IAC;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000228 }
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200229 else if (c == '\r') {
230 cstart = i + 1;
231 G.telstate = TS_CR;
232 }
233 /* No IACs were seen so far, no need to copy
234 * bytes within G.buf: */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000235 continue;
236 }
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200237
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000238 switch (G.telstate) {
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200239 case TS_CR:
240 /* Prev char was CR. If cur one is NUL, ignore it.
241 * See RFC 1123 section 3.3.1 for discussion of telnet EOL handling.
242 */
243 G.telstate = TS_COPY;
244 if (c == '\0')
245 break;
246 /* else: fall through - need to handle CR IAC ... properly */
247
248 case TS_COPY: /* Prev char was ordinary */
249 /* Similar to NORMAL, but in TS_COPY we need to copy bytes */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000250 if (c == IAC)
251 G.telstate = TS_IAC;
252 else
253 G.buf[cstart++] = c;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200254 if (c == '\r')
255 G.telstate = TS_CR;
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000256 break;
Eric Andersen28c70b32000-06-14 20:42:57 +0000257
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200258 case TS_IAC: /* Prev char was IAC */
259 if (c == IAC) { /* IAC IAC -> one IAC */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000260 G.buf[cstart++] = c;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200261 G.telstate = TS_COPY;
Denis Vlasenko1bec1b92007-11-06 02:23:39 +0000262 break;
Denis Vlasenko1bec1b92007-11-06 02:23:39 +0000263 }
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000264 /* else */
265 switch (c) {
266 case SB:
267 G.telstate = TS_SUB1;
268 break;
269 case DO:
270 case DONT:
271 case WILL:
272 case WONT:
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200273 G.telwish = c;
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000274 G.telstate = TS_OPT;
275 break;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200276 /* DATA MARK must be added later */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000277 default:
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200278 G.telstate = TS_COPY;
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000279 }
280 break;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200281
282 case TS_OPT: /* Prev chars were IAC WILL/WONT/DO/DONT */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000283 telopt(c);
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200284 G.telstate = TS_COPY;
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000285 break;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200286
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000287 case TS_SUB1: /* Subnegotiation */
288 case TS_SUB2: /* Subnegotiation */
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200289 subneg(c); /* can change G.telstate */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000290 break;
291 }
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000292 }
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200293
294 if (G.telstate != TS_NORMAL) {
295 /* We had some IACs, or CR */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000296 if (G.iaclen)
297 iac_flush();
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200298 if (G.telstate == TS_COPY) /* we aren't in the middle of IAC */
299 G.telstate = TS_NORMAL;
Glenn L McGrath78b0e372001-06-26 02:06:08 +0000300 len = cstart;
Eric Andersen28c70b32000-06-14 20:42:57 +0000301 }
302
Glenn L McGrath78b0e372001-06-26 02:06:08 +0000303 if (len)
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200304 full_write(STDOUT_FILENO, G.buf, len);
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000305}
306
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000307static void put_iac(int c)
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000308{
Eric Andersen28c70b32000-06-14 20:42:57 +0000309 G.iacbuf[G.iaclen++] = c;
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000310}
311
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000312static void put_iac2(byte wwdd, byte c)
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000313{
Eric Andersen28c70b32000-06-14 20:42:57 +0000314 if (G.iaclen + 3 > IACBUFSIZE)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000315 iac_flush();
Eric Andersen28c70b32000-06-14 20:42:57 +0000316
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000317 put_iac(IAC);
318 put_iac(wwdd);
319 put_iac(c);
Erik Andersenf7c49ef2000-02-22 17:17:45 +0000320}
321
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000322#if ENABLE_FEATURE_TELNET_TTYPE
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000323static void put_iac_subopt(byte c, char *str)
Eric Andersen7e1273e2001-05-07 17:57:45 +0000324{
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000325 int len = strlen(str) + 6; // ( 2 + 1 + 1 + strlen + 2 )
Eric Andersen7e1273e2001-05-07 17:57:45 +0000326
327 if (G.iaclen + len > IACBUFSIZE)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000328 iac_flush();
Eric Andersen7e1273e2001-05-07 17:57:45 +0000329
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000330 put_iac(IAC);
331 put_iac(SB);
332 put_iac(c);
333 put_iac(0);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000334
Denis Vlasenkobf0a2012006-12-26 10:42:51 +0000335 while (*str)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000336 put_iac(*str++);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000337
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000338 put_iac(IAC);
339 put_iac(SE);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000340}
341#endif
342
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000343#if ENABLE_FEATURE_TELNET_AUTOLOGIN
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000344static void put_iac_subopt_autologin(void)
Eric Andersen539ffc92004-02-22 12:25:47 +0000345{
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000346 int len = strlen(G.autologin) + 6; // (2 + 1 + 1 + strlen + 2)
Denys Vlasenko25b10d92010-04-27 08:54:24 +0200347 const char *p = "USER";
Eric Andersen539ffc92004-02-22 12:25:47 +0000348
349 if (G.iaclen + len > IACBUFSIZE)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000350 iac_flush();
Eric Andersen539ffc92004-02-22 12:25:47 +0000351
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000352 put_iac(IAC);
353 put_iac(SB);
354 put_iac(TELOPT_NEW_ENVIRON);
355 put_iac(TELQUAL_IS);
356 put_iac(NEW_ENV_VAR);
Eric Andersen539ffc92004-02-22 12:25:47 +0000357
Denys Vlasenko25b10d92010-04-27 08:54:24 +0200358 while (*p)
359 put_iac(*p++);
Eric Andersen539ffc92004-02-22 12:25:47 +0000360
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000361 put_iac(NEW_ENV_VALUE);
Eric Andersen539ffc92004-02-22 12:25:47 +0000362
Denys Vlasenko25b10d92010-04-27 08:54:24 +0200363 p = G.autologin;
364 while (*p)
365 put_iac(*p++);
Eric Andersen539ffc92004-02-22 12:25:47 +0000366
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000367 put_iac(IAC);
368 put_iac(SE);
Eric Andersen539ffc92004-02-22 12:25:47 +0000369}
370#endif
371
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000372#if ENABLE_FEATURE_AUTOWIDTH
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000373static void put_iac_naws(byte c, int x, int y)
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000374{
375 if (G.iaclen + 9 > IACBUFSIZE)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000376 iac_flush();
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000377
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000378 put_iac(IAC);
379 put_iac(SB);
380 put_iac(c);
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000381
Denys Vlasenkof76fd172013-05-12 02:13:24 +0200382 /* "... & 0xff" implicitly done below */
383 put_iac(x >> 8);
384 put_iac(x);
385 put_iac(y >> 8);
386 put_iac(y);
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000387
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000388 put_iac(IAC);
389 put_iac(SE);
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000390}
391#endif
392
Eric Andersencd8c4362001-11-10 11:22:46 +0000393static void setConMode(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000394{
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000395 if (G.telflags & UF_ECHO) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000396 if (G.charmode == CHM_TRY) {
397 G.charmode = CHM_ON;
Denys Vlasenko57f07bf2012-09-17 11:53:09 +0200398 printf("\r\nEntering %s mode"
399 "\r\nEscape character is '^%c'.\r\n", "character", ']');
Eric Andersen28c70b32000-06-14 20:42:57 +0000400 rawmode();
401 }
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000402 } else {
Eric Andersen28c70b32000-06-14 20:42:57 +0000403 if (G.charmode != CHM_OFF) {
404 G.charmode = CHM_OFF;
Denys Vlasenko57f07bf2012-09-17 11:53:09 +0200405 printf("\r\nEntering %s mode"
406 "\r\nEscape character is '^%c'.\r\n", "line", 'C');
Eric Andersen28c70b32000-06-14 20:42:57 +0000407 cookmode();
408 }
409 }
410}
411
Eric Andersencd8c4362001-11-10 11:22:46 +0000412static void will_charmode(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000413{
414 G.charmode = CHM_TRY;
415 G.telflags |= (UF_ECHO | UF_SGA);
416 setConMode();
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000417
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000418 put_iac2(DO, TELOPT_ECHO);
419 put_iac2(DO, TELOPT_SGA);
420 iac_flush();
Eric Andersen28c70b32000-06-14 20:42:57 +0000421}
422
Eric Andersencd8c4362001-11-10 11:22:46 +0000423static void do_linemode(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000424{
425 G.charmode = CHM_TRY;
426 G.telflags &= ~(UF_ECHO | UF_SGA);
427 setConMode();
428
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000429 put_iac2(DONT, TELOPT_ECHO);
430 put_iac2(DONT, TELOPT_SGA);
431 iac_flush();
Eric Andersen28c70b32000-06-14 20:42:57 +0000432}
433
Rob Landley88621d72006-08-29 19:41:06 +0000434static void to_notsup(char c)
Eric Andersen28c70b32000-06-14 20:42:57 +0000435{
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000436 if (G.telwish == WILL)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000437 put_iac2(DONT, c);
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000438 else if (G.telwish == DO)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000439 put_iac2(WONT, c);
Eric Andersen28c70b32000-06-14 20:42:57 +0000440}
441
Rob Landley88621d72006-08-29 19:41:06 +0000442static void to_echo(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000443{
444 /* if server requests ECHO, don't agree */
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000445 if (G.telwish == DO) {
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000446 put_iac2(WONT, TELOPT_ECHO);
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000447 return;
448 }
449 if (G.telwish == DONT)
450 return;
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000451
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000452 if (G.telflags & UF_ECHO) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000453 if (G.telwish == WILL)
454 return;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000455 } else if (G.telwish == WONT)
456 return;
Eric Andersen28c70b32000-06-14 20:42:57 +0000457
458 if (G.charmode != CHM_OFF)
459 G.telflags ^= UF_ECHO;
460
461 if (G.telflags & UF_ECHO)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000462 put_iac2(DO, TELOPT_ECHO);
Eric Andersen28c70b32000-06-14 20:42:57 +0000463 else
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000464 put_iac2(DONT, TELOPT_ECHO);
Eric Andersen28c70b32000-06-14 20:42:57 +0000465
466 setConMode();
Denys Vlasenko729ecb82010-06-07 14:14:26 +0200467 full_write1_str("\r\n"); /* sudden modec */
Eric Andersen28c70b32000-06-14 20:42:57 +0000468}
469
Rob Landley88621d72006-08-29 19:41:06 +0000470static void to_sga(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000471{
472 /* daemon always sends will/wont, client do/dont */
473
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000474 if (G.telflags & UF_SGA) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000475 if (G.telwish == WILL)
476 return;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000477 } else if (G.telwish == WONT)
478 return;
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000479
Denis Vlasenko1bec1b92007-11-06 02:23:39 +0000480 G.telflags ^= UF_SGA; /* toggle */
481 if (G.telflags & UF_SGA)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000482 put_iac2(DO, TELOPT_SGA);
Eric Andersen28c70b32000-06-14 20:42:57 +0000483 else
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000484 put_iac2(DONT, TELOPT_SGA);
Eric Andersen28c70b32000-06-14 20:42:57 +0000485}
486
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000487#if ENABLE_FEATURE_TELNET_TTYPE
Rob Landley88621d72006-08-29 19:41:06 +0000488static void to_ttype(void)
Eric Andersen7e1273e2001-05-07 17:57:45 +0000489{
490 /* Tell server we will (or won't) do TTYPE */
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000491 if (G.ttype)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000492 put_iac2(WILL, TELOPT_TTYPE);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000493 else
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000494 put_iac2(WONT, TELOPT_TTYPE);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000495}
496#endif
497
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000498#if ENABLE_FEATURE_TELNET_AUTOLOGIN
Rob Landley88621d72006-08-29 19:41:06 +0000499static void to_new_environ(void)
Eric Andersen539ffc92004-02-22 12:25:47 +0000500{
501 /* Tell server we will (or will not) do AUTOLOGIN */
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000502 if (G.autologin)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000503 put_iac2(WILL, TELOPT_NEW_ENVIRON);
Eric Andersen539ffc92004-02-22 12:25:47 +0000504 else
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000505 put_iac2(WONT, TELOPT_NEW_ENVIRON);
Eric Andersen539ffc92004-02-22 12:25:47 +0000506}
507#endif
508
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000509#if ENABLE_FEATURE_AUTOWIDTH
Rob Landley88621d72006-08-29 19:41:06 +0000510static void to_naws(void)
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000511{
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000512 /* Tell server we will do NAWS */
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000513 put_iac2(WILL, TELOPT_NAWS);
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000514}
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000515#endif
516
Eric Andersen28c70b32000-06-14 20:42:57 +0000517static void telopt(byte c)
518{
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000519 switch (c) {
520 case TELOPT_ECHO:
521 to_echo(); break;
522 case TELOPT_SGA:
523 to_sga(); break;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000524#if ENABLE_FEATURE_TELNET_TTYPE
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000525 case TELOPT_TTYPE:
526 to_ttype(); break;
Eric Andersen7e1273e2001-05-07 17:57:45 +0000527#endif
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000528#if ENABLE_FEATURE_TELNET_AUTOLOGIN
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000529 case TELOPT_NEW_ENVIRON:
530 to_new_environ(); break;
Eric Andersen539ffc92004-02-22 12:25:47 +0000531#endif
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000532#if ENABLE_FEATURE_AUTOWIDTH
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000533 case TELOPT_NAWS:
534 to_naws();
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000535 put_iac_naws(c, G.win_width, G.win_height);
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000536 break;
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000537#endif
Denis Vlasenkobaca1752007-03-11 13:43:10 +0000538 default:
539 to_notsup(c);
540 break;
Eric Andersen28c70b32000-06-14 20:42:57 +0000541 }
542}
543
Eric Andersen0e28e1f2002-04-26 07:20:47 +0000544/* subnegotiation -- ignore all (except TTYPE,NAWS) */
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200545static void subneg(byte c)
Eric Andersen28c70b32000-06-14 20:42:57 +0000546{
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000547 switch (G.telstate) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000548 case TS_SUB1:
549 if (c == IAC)
550 G.telstate = TS_SUB2;
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000551#if ENABLE_FEATURE_TELNET_TTYPE
Eric Andersen7e1273e2001-05-07 17:57:45 +0000552 else
Denys Vlasenko25b10d92010-04-27 08:54:24 +0200553 if (c == TELOPT_TTYPE && G.ttype)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000554 put_iac_subopt(TELOPT_TTYPE, G.ttype);
Eric Andersen7e1273e2001-05-07 17:57:45 +0000555#endif
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000556#if ENABLE_FEATURE_TELNET_AUTOLOGIN
Eric Andersen539ffc92004-02-22 12:25:47 +0000557 else
Denys Vlasenko25b10d92010-04-27 08:54:24 +0200558 if (c == TELOPT_NEW_ENVIRON && G.autologin)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000559 put_iac_subopt_autologin();
Eric Andersen539ffc92004-02-22 12:25:47 +0000560#endif
Eric Andersen28c70b32000-06-14 20:42:57 +0000561 break;
562 case TS_SUB2:
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200563 if (c == SE) {
564 G.telstate = TS_COPY;
565 return;
566 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000567 G.telstate = TS_SUB1;
Denys Vlasenko036dbb92010-10-29 02:12:22 +0200568 break;
Eric Andersen28c70b32000-06-14 20:42:57 +0000569 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000570}
571
Eric Andersencd8c4362001-11-10 11:22:46 +0000572static void rawmode(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000573{
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000574 if (G.do_termios)
575 tcsetattr(0, TCSADRAIN, &G.termios_raw);
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000576}
Eric Andersen28c70b32000-06-14 20:42:57 +0000577
Eric Andersencd8c4362001-11-10 11:22:46 +0000578static void cookmode(void)
Eric Andersen28c70b32000-06-14 20:42:57 +0000579{
Denis Vlasenko54e3d1f2007-03-19 14:52:26 +0000580 if (G.do_termios)
581 tcsetattr(0, TCSADRAIN, &G.termios_def);
Eric Andersen28c70b32000-06-14 20:42:57 +0000582}
583
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000584int telnet_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenko1101d1c2008-07-21 09:22:28 +0000585int telnet_main(int argc UNUSED_PARAM, char **argv)
Eric Andersen28c70b32000-06-14 20:42:57 +0000586{
Denis Vlasenko9de420c2007-01-10 09:28:01 +0000587 char *host;
588 int port;
Glenn L McGrath78b0e372001-06-26 02:06:08 +0000589 int len;
Eric Andersen28c70b32000-06-14 20:42:57 +0000590 struct pollfd ufds[2];
Eric Andersen28c70b32000-06-14 20:42:57 +0000591
Denis Vlasenko74324c82007-06-04 10:16:52 +0000592 INIT_G();
Eric Andersen28c70b32000-06-14 20:42:57 +0000593
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000594#if ENABLE_FEATURE_AUTOWIDTH
595 get_terminal_width_height(0, &G.win_width, &G.win_height);
596#endif
597
598#if ENABLE_FEATURE_TELNET_TTYPE
599 G.ttype = getenv("TERM");
600#endif
601
Paul Foxf2ddc052005-07-20 19:55:19 +0000602 if (tcgetattr(0, &G.termios_def) >= 0) {
603 G.do_termios = 1;
Paul Foxf2ddc052005-07-20 19:55:19 +0000604 G.termios_raw = G.termios_def;
605 cfmakeraw(&G.termios_raw);
606 }
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000607
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000608#if ENABLE_FEATURE_TELNET_AUTOLOGIN
Denis Vlasenkofe7cd642007-08-18 15:32:12 +0000609 if (1 & getopt32(argv, "al:", &G.autologin))
Denis Vlasenkof24cdf12007-03-19 14:47:09 +0000610 G.autologin = getenv("USER");
Denis Vlasenko6536a9b2007-01-12 10:35:23 +0000611 argv += optind;
Eric Andersen539ffc92004-02-22 12:25:47 +0000612#else
Denis Vlasenko6536a9b2007-01-12 10:35:23 +0000613 argv++;
Eric Andersen539ffc92004-02-22 12:25:47 +0000614#endif
Denis Vlasenko6536a9b2007-01-12 10:35:23 +0000615 if (!*argv)
616 bb_show_usage();
617 host = *argv++;
618 port = bb_lookup_port(*argv ? *argv++ : "telnet", "tcp", 23);
619 if (*argv) /* extra params?? */
620 bb_show_usage();
621
Denis Vlasenko1101d1c2008-07-21 09:22:28 +0000622 xmove_fd(create_and_connect_stream_or_die(host, port), netfd);
Eric Andersen28c70b32000-06-14 20:42:57 +0000623
Denys Vlasenkoc52cbea2015-08-24 19:48:03 +0200624 setsockopt_keepalive(netfd);
Eric Andersen28c70b32000-06-14 20:42:57 +0000625
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000626 signal(SIGINT, record_signo);
Eric Andersen28c70b32000-06-14 20:42:57 +0000627
Denys Vlasenkoec074202010-10-29 02:33:38 +0200628 ufds[0].fd = STDIN_FILENO;
629 ufds[0].events = POLLIN;
630 ufds[1].fd = netfd;
631 ufds[1].events = POLLIN;
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000632
Denis Vlasenko9de420c2007-01-10 09:28:01 +0000633 while (1) {
Denys Vlasenkoec074202010-10-29 02:33:38 +0200634 if (poll(ufds, 2, -1) < 0) {
Eric Andersen28c70b32000-06-14 20:42:57 +0000635 /* error, ignore and/or log something, bay go to loop */
Denis Vlasenko08ea11a2008-09-11 19:51:11 +0000636 if (bb_got_signal)
Denis Vlasenko9f2f8082008-11-11 02:56:39 +0000637 con_escape();
Eric Andersen28c70b32000-06-14 20:42:57 +0000638 else
639 sleep(1);
Denys Vlasenkoec074202010-10-29 02:33:38 +0200640 continue;
641 }
Eric Andersen28c70b32000-06-14 20:42:57 +0000642
Denys Vlasenkoec074202010-10-29 02:33:38 +0200643// FIXME: reads can block. Need full bidirectional buffering.
Eric Andersen28c70b32000-06-14 20:42:57 +0000644
Denys Vlasenkoec074202010-10-29 02:33:38 +0200645 if (ufds[0].revents) {
646 len = safe_read(STDIN_FILENO, G.buf, DATABUFSIZE);
647 if (len <= 0)
648 doexit(EXIT_SUCCESS);
649 TRACE(0, ("Read con: %d\n", len));
650 handle_net_output(len);
651 }
652
653 if (ufds[1].revents) {
654 len = safe_read(netfd, G.buf, DATABUFSIZE);
655 if (len <= 0) {
656 full_write1_str("Connection closed by foreign host\r\n");
657 doexit(EXIT_FAILURE);
Eric Andersen28c70b32000-06-14 20:42:57 +0000658 }
Denys Vlasenkoec074202010-10-29 02:33:38 +0200659 TRACE(0, ("Read netfd (%d): %d\n", netfd, len));
660 handle_net_input(len);
Eric Andersen28c70b32000-06-14 20:42:57 +0000661 }
Denis Vlasenko1101d1c2008-07-21 09:22:28 +0000662 } /* while (1) */
Eric Andersen28c70b32000-06-14 20:42:57 +0000663}