* Created: Thu Apr 7 13:29:41 1994 too
* Last modified: Fri Jun 9 14:34:24 2000 too
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* HISTORY
* Revision 3.1 1994/04/17 11:31:54 too
*
*/
-#include <termios.h>
+//usage:#if ENABLE_FEATURE_TELNET_AUTOLOGIN
+//usage:#define telnet_trivial_usage
+//usage: "[-a] [-l USER] HOST [PORT]"
+//usage:#define telnet_full_usage "\n\n"
+//usage: "Connect to telnet server\n"
+//usage: "\n -a Automatic login with $USER variable"
+//usage: "\n -l USER Automatic login as USER"
+//usage:
+//usage:#else
+//usage:#define telnet_trivial_usage
+//usage: "HOST [PORT]"
+//usage:#define telnet_full_usage "\n\n"
+//usage: "Connect to telnet server"
+//usage:#endif
+
#include <arpa/telnet.h>
#include <netinet/in.h>
#include "libbb.h"
+#ifdef __BIONIC__
+/* should be in arpa/telnet.h */
+# define IAC 255 /* interpret as command: */
+# define DONT 254 /* you are not to use option */
+# define DO 253 /* please, you use option */
+# define WONT 252 /* I won't use option */
+# define WILL 251 /* I will use option */
+# define SB 250 /* interpret as subnegotiation */
+# define SE 240 /* end sub negotiation */
+# define TELOPT_ECHO 1 /* echo */
+# define TELOPT_SGA 3 /* suppress go ahead */
+# define TELOPT_TTYPE 24 /* terminal type */
+# define TELOPT_NAWS 31 /* window size */
+#endif
+
#ifdef DOTRACE
-#define TRACE(x, y) do { if (x) printf y; } while (0)
+# define TRACE(x, y) do { if (x) printf y; } while (0)
#else
-#define TRACE(x, y)
+# define TRACE(x, y)
#endif
enum {
UF_ECHO = 0x01,
UF_SGA = 0x02,
- TS_0 = 1,
+ TS_NORMAL = 0,
+ TS_COPY = 1,
TS_IAC = 2,
TS_OPT = 3,
TS_SUB1 = 4,
TS_SUB2 = 5,
+ TS_CR = 6,
};
typedef unsigned char byte;
+enum { netfd = 3 };
+
struct globals {
- int netfd; /* console fd:s are 0 and 1 (and 2) */
- short iaclen; /* could even use byte */
+ int iaclen; /* could even use byte, but it's a loss on x86 */
byte telstate; /* telnet negotiation state from network input */
byte telwish; /* DO, DONT, WILL, WONT */
byte charmode;
byte telflags;
- byte gotsig;
byte do_termios;
#if ENABLE_FEATURE_TELNET_TTYPE
char *ttype;
char iacbuf[IACBUFSIZE];
struct termios termios_def;
struct termios termios_raw;
-};
+} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
-void BUG_telnet_globals_too_big(void);
#define INIT_G() do { \
- if (sizeof(G) > COMMON_BUFSIZE) \
- BUG_telnet_globals_too_big(); \
- /* memset(&G, 0, sizeof G); - already is */ \
+ struct G_sizecheck { \
+ char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \
+ }; \
} while (0)
-/* Function prototypes */
+
static void rawmode(void);
static void cookmode(void);
static void do_linemode(void);
static void will_charmode(void);
static void telopt(byte c);
-static int subneg(byte c);
+static void subneg(byte c);
-static void iacflush(void)
+static void iac_flush(void)
{
- write(G.netfd, G.iacbuf, G.iaclen);
+ full_write(netfd, G.iacbuf, G.iaclen);
G.iaclen = 0;
}
-#define write_str(fd, str) write(fd, str, sizeof(str) - 1)
-
-static void doexit(int ev) ATTRIBUTE_NORETURN;
+static void doexit(int ev) NORETURN;
static void doexit(int ev)
{
cookmode();
exit(ev);
}
-static void conescape(void)
+static void con_escape(void)
{
char b;
- if (G.gotsig) /* came from line mode... go raw */
+ if (bb_got_signal) /* came from line mode... go raw */
rawmode();
- write_str(1, "\r\nConsole escape. Commands are:\r\n\n"
+ full_write1_str("\r\nConsole escape. Commands are:\r\n\n"
" l go to line mode\r\n"
" c go to character mode\r\n"
" z suspend telnet\r\n"
switch (b) {
case 'l':
- if (!G.gotsig) {
+ if (!bb_got_signal) {
do_linemode();
- goto rrturn;
+ goto ret;
}
break;
case 'c':
- if (G.gotsig) {
+ if (bb_got_signal) {
will_charmode();
- goto rrturn;
+ goto ret;
}
break;
case 'z':
doexit(EXIT_SUCCESS);
}
- write_str(1, "continuing...\r\n");
+ full_write1_str("continuing...\r\n");
- if (G.gotsig)
+ if (bb_got_signal)
cookmode();
-
- rrturn:
- G.gotsig = 0;
-
+ ret:
+ bb_got_signal = 0;
}
-static void handlenetoutput(int len)
+static void handle_net_output(int len)
{
- /* here we could do smart tricks how to handle 0xFF:s in output
- * stream like writing twice every sequence of FF:s (thus doing
- * many write()s. But I think interactive telnet application does
- * not need to be 100% 8-bit clean, so changing every 0xff:s to
- * 0x7f:s
- *
- * 2002-mar-21, Przemyslaw Czerpak (druzus@polbox.com)
- * I don't agree.
- * first - I cannot use programs like sz/rz
- * second - the 0x0D is sent as one character and if the next
- * char is 0x0A then it's eaten by a server side.
- * third - whay doy you have to make 'many write()s'?
- * I don't understand.
- * So I implemented it. It's realy useful for me. I hope that
- * others people will find it interesting too.
- */
-
- int i, j;
- byte * p = (byte*)G.buf;
- byte outbuf[4*DATABUFSIZE];
-
- for (i = len, j = 0; i > 0; i--, p++) {
- if (*p == 0x1d) {
- conescape();
+ byte outbuf[2 * DATABUFSIZE];
+ byte *dst = outbuf;
+ byte *src = (byte*)G.buf;
+ byte *end = src + len;
+
+ while (src < end) {
+ byte c = *src++;
+ if (c == 0x1d) {
+ con_escape();
return;
}
- outbuf[j++] = *p;
- if (*p == 0xff)
- outbuf[j++] = 0xff;
- else if (*p == 0x0d)
- outbuf[j++] = 0x00;
+ *dst = c;
+ if (c == IAC)
+ *++dst = c; /* IAC -> IAC IAC */
+ else
+ if (c == '\r' || c == '\n') {
+ /* Enter key sends '\r' in raw mode and '\n' in cooked one.
+ *
+ * See RFC 1123 3.3.1 Telnet End-of-Line Convention.
+ * Using CR LF instead of other allowed possibilities
+ * like CR NUL - easier to talk to HTTP/SMTP servers.
+ */
+ *dst = '\r'; /* Enter -> CR LF */
+ *++dst = '\n';
+ }
+ dst++;
}
- if (j > 0)
- write(G.netfd, outbuf, j);
+ if (dst - outbuf != 0)
+ full_write(netfd, outbuf, dst - outbuf);
}
-static void handlenetinput(int len)
+static void handle_net_input(int len)
{
int i;
int cstart = 0;
for (i = 0; i < len; i++) {
byte c = G.buf[i];
- if (G.telstate == 0) { /* most of the time state == 0 */
+ if (G.telstate == TS_NORMAL) { /* most typical state */
if (c == IAC) {
cstart = i;
G.telstate = TS_IAC;
}
- } else
- switch (G.telstate) {
- case TS_0:
- if (c == IAC)
- G.telstate = TS_IAC;
- else
- G.buf[cstart++] = c;
+ else if (c == '\r') {
+ cstart = i + 1;
+ G.telstate = TS_CR;
+ }
+ /* No IACs were seen so far, no need to copy
+ * bytes within G.buf: */
+ continue;
+ }
+
+ switch (G.telstate) {
+ case TS_CR:
+ /* Prev char was CR. If cur one is NUL, ignore it.
+ * See RFC 1123 section 3.3.1 for discussion of telnet EOL handling.
+ */
+ G.telstate = TS_COPY;
+ if (c == '\0')
break;
+ /* else: fall through - need to handle CR IAC ... properly */
- case TS_IAC:
- if (c == IAC) { /* IAC IAC -> 0xFF */
- G.buf[cstart++] = c;
- G.telstate = TS_0;
- break;
- }
- /* else */
- switch (c) {
- case SB:
- G.telstate = TS_SUB1;
- break;
- case DO:
- case DONT:
- case WILL:
- case WONT:
- G.telwish = c;
- G.telstate = TS_OPT;
- break;
- default:
- G.telstate = TS_0; /* DATA MARK must be added later */
- }
+ case TS_COPY: /* Prev char was ordinary */
+ /* Similar to NORMAL, but in TS_COPY we need to copy bytes */
+ if (c == IAC)
+ G.telstate = TS_IAC;
+ else
+ G.buf[cstart++] = c;
+ if (c == '\r')
+ G.telstate = TS_CR;
+ break;
+
+ case TS_IAC: /* Prev char was IAC */
+ if (c == IAC) { /* IAC IAC -> one IAC */
+ G.buf[cstart++] = c;
+ G.telstate = TS_COPY;
break;
- case TS_OPT: /* WILL, WONT, DO, DONT */
- telopt(c);
- G.telstate = TS_0;
+ }
+ /* else */
+ switch (c) {
+ case SB:
+ G.telstate = TS_SUB1;
break;
- case TS_SUB1: /* Subnegotiation */
- case TS_SUB2: /* Subnegotiation */
- if (subneg(c))
- G.telstate = TS_0;
+ case DO:
+ case DONT:
+ case WILL:
+ case WONT:
+ G.telwish = c;
+ G.telstate = TS_OPT;
break;
+ /* DATA MARK must be added later */
+ default:
+ G.telstate = TS_COPY;
}
+ break;
+
+ case TS_OPT: /* Prev chars were IAC WILL/WONT/DO/DONT */
+ telopt(c);
+ G.telstate = TS_COPY;
+ break;
+
+ case TS_SUB1: /* Subnegotiation */
+ case TS_SUB2: /* Subnegotiation */
+ subneg(c); /* can change G.telstate */
+ break;
+ }
}
- if (G.telstate) {
- if (G.iaclen) iacflush();
- if (G.telstate == TS_0) G.telstate = 0;
+
+ if (G.telstate != TS_NORMAL) {
+ /* We had some IACs, or CR */
+ if (G.iaclen)
+ iac_flush();
+ if (G.telstate == TS_COPY) /* we aren't in the middle of IAC */
+ G.telstate = TS_NORMAL;
len = cstart;
}
if (len)
- write(STDOUT_FILENO, G.buf, len);
+ full_write(STDOUT_FILENO, G.buf, len);
}
-static void putiac(int c)
+static void put_iac(int c)
{
G.iacbuf[G.iaclen++] = c;
}
-static void putiac2(byte wwdd, byte c)
+static void put_iac2(byte wwdd, byte c)
{
if (G.iaclen + 3 > IACBUFSIZE)
- iacflush();
+ iac_flush();
- putiac(IAC);
- putiac(wwdd);
- putiac(c);
+ put_iac(IAC);
+ put_iac(wwdd);
+ put_iac(c);
}
#if ENABLE_FEATURE_TELNET_TTYPE
-static void putiac_subopt(byte c, char *str)
+static void put_iac_subopt(byte c, char *str)
{
- int len = strlen(str) + 6; // ( 2 + 1 + 1 + strlen + 2 )
+ int len = strlen(str) + 6; // ( 2 + 1 + 1 + strlen + 2 )
if (G.iaclen + len > IACBUFSIZE)
- iacflush();
+ iac_flush();
- putiac(IAC);
- putiac(SB);
- putiac(c);
- putiac(0);
+ put_iac(IAC);
+ put_iac(SB);
+ put_iac(c);
+ put_iac(0);
while (*str)
- putiac(*str++);
+ put_iac(*str++);
- putiac(IAC);
- putiac(SE);
+ put_iac(IAC);
+ put_iac(SE);
}
#endif
#if ENABLE_FEATURE_TELNET_AUTOLOGIN
-static void putiac_subopt_autologin(void)
+static void put_iac_subopt_autologin(void)
{
int len = strlen(G.autologin) + 6; // (2 + 1 + 1 + strlen + 2)
- const char *user = "USER";
+ const char *p = "USER";
if (G.iaclen + len > IACBUFSIZE)
- iacflush();
+ iac_flush();
- putiac(IAC);
- putiac(SB);
- putiac(TELOPT_NEW_ENVIRON);
- putiac(TELQUAL_IS);
- putiac(NEW_ENV_VAR);
+ put_iac(IAC);
+ put_iac(SB);
+ put_iac(TELOPT_NEW_ENVIRON);
+ put_iac(TELQUAL_IS);
+ put_iac(NEW_ENV_VAR);
- while (*user)
- putiac(*user++);
+ while (*p)
+ put_iac(*p++);
- putiac(NEW_ENV_VALUE);
+ put_iac(NEW_ENV_VALUE);
- while (*G.autologin)
- putiac(*G.autologin++);
+ p = G.autologin;
+ while (*p)
+ put_iac(*p++);
- putiac(IAC);
- putiac(SE);
+ put_iac(IAC);
+ put_iac(SE);
}
#endif
#if ENABLE_FEATURE_AUTOWIDTH
-static void putiac_naws(byte c, int x, int y)
+static void put_iac_naws(byte c, int x, int y)
{
if (G.iaclen + 9 > IACBUFSIZE)
- iacflush();
+ iac_flush();
- putiac(IAC);
- putiac(SB);
- putiac(c);
+ put_iac(IAC);
+ put_iac(SB);
+ put_iac(c);
- putiac((x >> 8) & 0xff);
- putiac(x & 0xff);
- putiac((y >> 8) & 0xff);
- putiac(y & 0xff);
+ /* "... & 0xff" implicitly done below */
+ put_iac(x >> 8);
+ put_iac(x);
+ put_iac(y >> 8);
+ put_iac(y);
- putiac(IAC);
- putiac(SE);
+ put_iac(IAC);
+ put_iac(SE);
}
#endif
-static char const escapecharis[] ALIGN1 = "\r\nEscape character is ";
-
static void setConMode(void)
{
if (G.telflags & UF_ECHO) {
if (G.charmode == CHM_TRY) {
G.charmode = CHM_ON;
- printf("\r\nEntering character mode%s'^]'.\r\n", escapecharis);
+ printf("\r\nEntering %s mode"
+ "\r\nEscape character is '^%c'.\r\n", "character", ']');
rawmode();
}
} else {
if (G.charmode != CHM_OFF) {
G.charmode = CHM_OFF;
- printf("\r\nEntering line mode%s'^C'.\r\n", escapecharis);
+ printf("\r\nEntering %s mode"
+ "\r\nEscape character is '^%c'.\r\n", "line", 'C');
cookmode();
}
}
G.telflags |= (UF_ECHO | UF_SGA);
setConMode();
- putiac2(DO, TELOPT_ECHO);
- putiac2(DO, TELOPT_SGA);
- iacflush();
+ put_iac2(DO, TELOPT_ECHO);
+ put_iac2(DO, TELOPT_SGA);
+ iac_flush();
}
static void do_linemode(void)
G.telflags &= ~(UF_ECHO | UF_SGA);
setConMode();
- putiac2(DONT, TELOPT_ECHO);
- putiac2(DONT, TELOPT_SGA);
- iacflush();
+ put_iac2(DONT, TELOPT_ECHO);
+ put_iac2(DONT, TELOPT_SGA);
+ iac_flush();
}
static void to_notsup(char c)
{
if (G.telwish == WILL)
- putiac2(DONT, c);
+ put_iac2(DONT, c);
else if (G.telwish == DO)
- putiac2(WONT, c);
+ put_iac2(WONT, c);
}
static void to_echo(void)
{
/* if server requests ECHO, don't agree */
if (G.telwish == DO) {
- putiac2(WONT, TELOPT_ECHO);
+ put_iac2(WONT, TELOPT_ECHO);
return;
}
if (G.telwish == DONT)
G.telflags ^= UF_ECHO;
if (G.telflags & UF_ECHO)
- putiac2(DO, TELOPT_ECHO);
+ put_iac2(DO, TELOPT_ECHO);
else
- putiac2(DONT, TELOPT_ECHO);
+ put_iac2(DONT, TELOPT_ECHO);
setConMode();
- write_str(1, "\r\n"); /* sudden modec */
+ full_write1_str("\r\n"); /* sudden modec */
}
static void to_sga(void)
G.telflags ^= UF_SGA; /* toggle */
if (G.telflags & UF_SGA)
- putiac2(DO, TELOPT_SGA);
+ put_iac2(DO, TELOPT_SGA);
else
- putiac2(DONT, TELOPT_SGA);
+ put_iac2(DONT, TELOPT_SGA);
}
#if ENABLE_FEATURE_TELNET_TTYPE
static void to_ttype(void)
{
/* Tell server we will (or won't) do TTYPE */
-
if (G.ttype)
- putiac2(WILL, TELOPT_TTYPE);
+ put_iac2(WILL, TELOPT_TTYPE);
else
- putiac2(WONT, TELOPT_TTYPE);
+ put_iac2(WONT, TELOPT_TTYPE);
}
#endif
static void to_new_environ(void)
{
/* Tell server we will (or will not) do AUTOLOGIN */
-
if (G.autologin)
- putiac2(WILL, TELOPT_NEW_ENVIRON);
+ put_iac2(WILL, TELOPT_NEW_ENVIRON);
else
- putiac2(WONT, TELOPT_NEW_ENVIRON);
+ put_iac2(WONT, TELOPT_NEW_ENVIRON);
}
#endif
static void to_naws(void)
{
/* Tell server we will do NAWS */
- putiac2(WILL, TELOPT_NAWS);
+ put_iac2(WILL, TELOPT_NAWS);
}
#endif
#if ENABLE_FEATURE_AUTOWIDTH
case TELOPT_NAWS:
to_naws();
- putiac_naws(c, G.win_width, G.win_height);
+ put_iac_naws(c, G.win_width, G.win_height);
break;
#endif
default:
}
/* subnegotiation -- ignore all (except TTYPE,NAWS) */
-static int subneg(byte c)
+static void subneg(byte c)
{
switch (G.telstate) {
case TS_SUB1:
G.telstate = TS_SUB2;
#if ENABLE_FEATURE_TELNET_TTYPE
else
- if (c == TELOPT_TTYPE)
- putiac_subopt(TELOPT_TTYPE, G.ttype);
+ if (c == TELOPT_TTYPE && G.ttype)
+ put_iac_subopt(TELOPT_TTYPE, G.ttype);
#endif
#if ENABLE_FEATURE_TELNET_AUTOLOGIN
else
- if (c == TELOPT_NEW_ENVIRON)
- putiac_subopt_autologin();
+ if (c == TELOPT_NEW_ENVIRON && G.autologin)
+ put_iac_subopt_autologin();
#endif
break;
case TS_SUB2:
- if (c == SE)
- return TRUE;
+ if (c == SE) {
+ G.telstate = TS_COPY;
+ return;
+ }
G.telstate = TS_SUB1;
- /* break; */
+ break;
}
- return FALSE;
-}
-
-static void fgotsig(int sig)
-{
- G.gotsig = sig;
}
-
static void rawmode(void)
{
if (G.do_termios)
tcsetattr(0, TCSADRAIN, &G.termios_def);
}
-/* poll gives smaller (-70 bytes) code */
-#define USE_POLL 1
-
int telnet_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int telnet_main(int argc, char **argv)
+int telnet_main(int argc UNUSED_PARAM, char **argv)
{
char *host;
int port;
int len;
-#ifdef USE_POLL
struct pollfd ufds[2];
-#else
- fd_set readfds;
- int maxfd;
-#endif
INIT_G();
cfmakeraw(&G.termios_raw);
}
- if (argc < 2)
- bb_show_usage();
-
#if ENABLE_FEATURE_TELNET_AUTOLOGIN
if (1 & getopt32(argv, "al:", &G.autologin))
G.autologin = getenv("USER");
if (*argv) /* extra params?? */
bb_show_usage();
- G.netfd = create_and_connect_stream_or_die(host, port);
+ xmove_fd(create_and_connect_stream_or_die(host, port), netfd);
- setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
+ setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
- signal(SIGINT, fgotsig);
+ signal(SIGINT, record_signo);
-#ifdef USE_POLL
- ufds[0].fd = 0; ufds[1].fd = G.netfd;
- ufds[0].events = ufds[1].events = POLLIN;
-#else
- FD_ZERO(&readfds);
- FD_SET(STDIN_FILENO, &readfds);
- FD_SET(G.netfd, &readfds);
- maxfd = G.netfd + 1;
-#endif
+ ufds[0].fd = STDIN_FILENO;
+ ufds[0].events = POLLIN;
+ ufds[1].fd = netfd;
+ ufds[1].events = POLLIN;
while (1) {
-#ifndef USE_POLL
- fd_set rfds = readfds;
-
- switch (select(maxfd, &rfds, NULL, NULL, NULL))
-#else
- switch (poll(ufds, 2, -1))
-#endif
- {
- case 0:
- /* timeout */
- case -1:
+ if (poll(ufds, 2, -1) < 0) {
/* error, ignore and/or log something, bay go to loop */
- if (G.gotsig)
- conescape();
+ if (bb_got_signal)
+ con_escape();
else
sleep(1);
- break;
- default:
+ continue;
+ }
-#ifdef USE_POLL
- if (ufds[0].revents) /* well, should check POLLIN, but ... */
-#else
- if (FD_ISSET(STDIN_FILENO, &rfds))
-#endif
- {
- len = read(STDIN_FILENO, G.buf, DATABUFSIZE);
- if (len <= 0)
- doexit(EXIT_SUCCESS);
- TRACE(0, ("Read con: %d\n", len));
- handlenetoutput(len);
- }
+// FIXME: reads can block. Need full bidirectional buffering.
-#ifdef USE_POLL
- if (ufds[1].revents) /* well, should check POLLIN, but ... */
-#else
- if (FD_ISSET(G.netfd, &rfds))
-#endif
- {
- len = read(G.netfd, G.buf, DATABUFSIZE);
- if (len <= 0) {
- write_str(1, "Connection closed by foreign host\r\n");
- doexit(EXIT_FAILURE);
- }
- TRACE(0, ("Read netfd (%d): %d\n", G.netfd, len));
- handlenetinput(len);
+ if (ufds[0].revents) {
+ len = safe_read(STDIN_FILENO, G.buf, DATABUFSIZE);
+ if (len <= 0)
+ doexit(EXIT_SUCCESS);
+ TRACE(0, ("Read con: %d\n", len));
+ handle_net_output(len);
+ }
+
+ if (ufds[1].revents) {
+ len = safe_read(netfd, G.buf, DATABUFSIZE);
+ if (len <= 0) {
+ full_write1_str("Connection closed by foreign host\r\n");
+ doexit(EXIT_FAILURE);
}
+ TRACE(0, ("Read netfd (%d): %d\n", netfd, len));
+ handle_net_input(len);
}
- }
+ } /* while (1) */
}