1 files changed, 769 insertions, 0 deletions

diff --git a/busybox/networking/telnet.c b/busybox/networking/telnet.c
new file mode 100644
index 000000000..6ad7712ab
--- /dev/null
+++ b/busybox/networking/telnet.c
@@ -0,0 +1,769 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * telnet implementation for busybox
+ *
+ * Author: Tomi Ollila <too@iki.fi>
+ * Copyright (C) 1994-2000 by Tomi Ollila
+ *
+ * Created: Thu Apr  7 13:29:41 1994 too
+ * Last modified: Fri Jun  9 14:34:24 2000 too
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * HISTORY
+ * Revision 3.1  1994/04/17  11:31:54  too
+ * initial revision
+ * Modified 2000/06/13 for inclusion into BusyBox by Erik Andersen <andersen@codepoet.org>
+ * Modified 2001/05/07 to add ability to pass TTYPE to remote host by Jim McQuillan
+ * <jam@ltsp.org>
+ * Modified 2004/02/11 to add ability to pass the USER variable to remote host
+ * by Fernando Silveira <swrh@gmx.net>
+ *
+ */
+
+#include <termios.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <signal.h>
+#include <arpa/telnet.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include "busybox.h"
+
+#if 0
+static const int DOTRACE = 1;
+#endif
+
+#ifdef DOTRACE
+#include <arpa/inet.h> /* for inet_ntoa()... */
+#define TRACE(x, y) do { if (x) printf y; } while (0)
+#else
+#define TRACE(x, y)
+#endif
+
+#if 0
+#define USE_POLL
+#include <sys/poll.h>
+#else
+#include <sys/time.h>
+#endif
+
+#define DATABUFSIZE  128
+#define IACBUFSIZE   128
+
+static const int CHM_TRY = 0;
+static const int CHM_ON = 1;
+static const int CHM_OFF = 2;
+
+static const int UF_ECHO = 0x01;
+static const int UF_SGA = 0x02;
+
+enum {
+        TS_0 = 1,
+        TS_IAC = 2,
+        TS_OPT = 3,
+        TS_SUB1 = 4,
+        TS_SUB2 = 5,
+};
+
+#define WriteCS(fd, str) write(fd, str, sizeof str -1)
+
+typedef unsigned char byte;
+
+/* use globals to reduce size ??? */ /* test this hypothesis later */
+static struct Globalvars {
+        int             netfd; /* console fd:s are 0 and 1 (and 2) */
+    /* same buffer used both for network and console read/write */
+        char    buf[DATABUFSIZE]; /* allocating so static size is smaller */
+        byte    telstate; /* telnet negotiation state from network input */
+        byte    telwish;  /* DO, DONT, WILL, WONT */
+        byte    charmode;
+        byte    telflags;
+        byte    gotsig;
+        /* buffer to handle telnet negotiations */
+        char    iacbuf[IACBUFSIZE];
+        short   iaclen; /* could even use byte */
+        struct termios termios_def;
+        struct termios termios_raw;
+} G;
+
+#define xUSE_GLOBALVAR_PTR /* xUSE... -> don't use :D (makes smaller code) */
+
+#ifdef USE_GLOBALVAR_PTR
+struct Globalvars * Gptr;
+#define G (*Gptr)
+#endif
+
+static inline void iacflush(void)
+{
+        write(G.netfd, G.iacbuf, G.iaclen);
+        G.iaclen = 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);
+
+/* Some globals */
+static int one = 1;
+
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+static char *ttype;
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static const char *autologin;
+#endif
+
+#ifdef CONFIG_FEATURE_AUTOWIDTH
+static int win_width, win_height;
+#endif
+
+static void doexit(int ev)
+{
+        cookmode();
+        exit(ev);
+}
+
+static void conescape(void)
+{
+        char b;
+
+        if (G.gotsig)   /* came from line  mode... go raw */
+                rawmode();
+
+        WriteCS(1, "\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"
+                        " e     exit telnet\r\n");
+
+        if (read(0, &b, 1) <= 0)
+                doexit(1);
+
+        switch (b)
+        {
+        case 'l':
+                if (!G.gotsig)
+                {
+                        do_linemode();
+                        goto rrturn;
+                }
+                break;
+        case 'c':
+                if (G.gotsig)
+                {
+                        will_charmode();
+                        goto rrturn;
+                }
+                break;
+        case 'z':
+                cookmode();
+                kill(0, SIGTSTP);
+                rawmode();
+                break;
+        case 'e':
+                doexit(0);
+        }
+
+        WriteCS(1, "continuing...\r\n");
+
+        if (G.gotsig)
+                cookmode();
+
+ rrturn:
+        G.gotsig = 0;
+
+}
+static void handlenetoutput(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 to.
+         */
+
+        int i, j;
+        byte * p = G.buf;
+        byte outbuf[4*DATABUFSIZE];
+
+        for (i = len, j = 0; i > 0; i--, p++)
+        {
+                if (*p == 0x1d)
+                {
+                        conescape();
+                        return;
+                }
+                outbuf[j++] = *p;
+                if (*p == 0xff)
+                    outbuf[j++] = 0xff;
+                else if (*p == 0x0d)
+                    outbuf[j++] = 0x00;
+        }
+        if (j > 0 )
+            write(G.netfd, outbuf, j);
+}
+
+
+static void handlenetinput(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 (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;
+                                 break;
+
+                         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 */
+                                 }
+                                 break;
+                         case TS_OPT: /* WILL, WONT, DO, DONT */
+                                 telopt(c);
+                                 G.telstate = TS_0;
+                                 break;
+                         case TS_SUB1: /* Subnegotiation */
+                         case TS_SUB2: /* Subnegotiation */
+                                 if (subneg(c))
+                                         G.telstate = TS_0;
+                                 break;
+                         }
+        }
+        if (G.telstate)
+        {
+                if (G.iaclen)                   iacflush();
+                if (G.telstate == TS_0) G.telstate = 0;
+
+                len = cstart;
+        }
+
+        if (len)
+                write(1, G.buf, len);
+}
+
+
+/* ******************************* */
+
+static inline void putiac(int c)
+{
+        G.iacbuf[G.iaclen++] = c;
+}
+
+
+static void putiac2(byte wwdd, byte c)
+{
+        if (G.iaclen + 3 > IACBUFSIZE)
+                iacflush();
+
+        putiac(IAC);
+        putiac(wwdd);
+        putiac(c);
+}
+
+#if 0
+static void putiac1(byte c)
+{
+        if (G.iaclen + 2 > IACBUFSIZE)
+                iacflush();
+
+        putiac(IAC);
+        putiac(c);
+}
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+static void putiac_subopt(byte c, char *str)
+{
+        int     len = strlen(str) + 6;   // ( 2 + 1 + 1 + strlen + 2 )
+
+        if (G.iaclen + len > IACBUFSIZE)
+                iacflush();
+
+        putiac(IAC);
+        putiac(SB);
+        putiac(c);
+        putiac(0);
+
+        while(*str)
+                putiac(*str++);
+
+        putiac(IAC);
+        putiac(SE);
+}
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static void putiac_subopt_autologin(void)
+{
+        int len = strlen(autologin) + 6;        // (2 + 1 + 1 + strlen + 2)
+        char *user = "USER";
+
+        if (G.iaclen + len > IACBUFSIZE)
+                iacflush();
+
+        putiac(IAC);
+        putiac(SB);
+        putiac(TELOPT_NEW_ENVIRON);
+        putiac(TELQUAL_IS);
+        putiac(NEW_ENV_VAR);
+
+        while(*user)
+                putiac(*user++);
+
+        putiac(NEW_ENV_VALUE);
+
+        while(*autologin)
+                putiac(*autologin++);
+
+        putiac(IAC);
+        putiac(SE);
+}
+#endif
+
+#ifdef CONFIG_FEATURE_AUTOWIDTH
+static void putiac_naws(byte c, int x, int y)
+{
+        if (G.iaclen + 9 > IACBUFSIZE)
+                iacflush();
+
+        putiac(IAC);
+        putiac(SB);
+        putiac(c);
+
+        putiac((x >> 8) & 0xff);
+        putiac(x & 0xff);
+        putiac((y >> 8) & 0xff);
+        putiac(y & 0xff);
+
+        putiac(IAC);
+        putiac(SE);
+}
+#endif
+
+/* void putiacstring (subneg strings) */
+
+/* ******************************* */
+
+static char const escapecharis[] = "\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);
+                        rawmode();
+                }
+        }
+        else
+        {
+                if (G.charmode != CHM_OFF) {
+                        G.charmode = CHM_OFF;
+                        printf("\r\nEntering line mode%s'^C'.\r\n", escapecharis);
+                        cookmode();
+                }
+        }
+}
+
+/* ******************************* */
+
+static void will_charmode(void)
+{
+        G.charmode = CHM_TRY;
+        G.telflags |= (UF_ECHO | UF_SGA);
+        setConMode();
+
+        putiac2(DO, TELOPT_ECHO);
+        putiac2(DO, TELOPT_SGA);
+        iacflush();
+}
+
+static void do_linemode(void)
+{
+        G.charmode = CHM_TRY;
+        G.telflags &= ~(UF_ECHO | UF_SGA);
+        setConMode();
+
+        putiac2(DONT, TELOPT_ECHO);
+        putiac2(DONT, TELOPT_SGA);
+        iacflush();
+}
+
+/* ******************************* */
+
+static inline void to_notsup(char c)
+{
+        if      (G.telwish == WILL)     putiac2(DONT, c);
+        else if (G.telwish == DO)       putiac2(WONT, c);
+}
+
+static inline void to_echo(void)
+{
+        /* if server requests ECHO, don't agree */
+        if      (G.telwish == DO) {     putiac2(WONT, TELOPT_ECHO);     return; }
+        else if (G.telwish == DONT)     return;
+
+        if (G.telflags & UF_ECHO)
+        {
+                if (G.telwish == WILL)
+                        return;
+        }
+        else
+                if (G.telwish == WONT)
+                        return;
+
+        if (G.charmode != CHM_OFF)
+                G.telflags ^= UF_ECHO;
+
+        if (G.telflags & UF_ECHO)
+                putiac2(DO, TELOPT_ECHO);
+        else
+                putiac2(DONT, TELOPT_ECHO);
+
+        setConMode();
+        WriteCS(1, "\r\n");  /* sudden modec */
+}
+
+static inline void to_sga(void)
+{
+        /* daemon always sends will/wont, client do/dont */
+
+        if (G.telflags & UF_SGA)
+        {
+                if (G.telwish == WILL)
+                        return;
+        }
+        else
+                if (G.telwish == WONT)
+                        return;
+
+        if ((G.telflags ^= UF_SGA) & UF_SGA) /* toggle */
+                putiac2(DO, TELOPT_SGA);
+        else
+                putiac2(DONT, TELOPT_SGA);
+
+        return;
+}
+
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+static inline void to_ttype(void)
+{
+        /* Tell server we will (or won't) do TTYPE */
+
+        if(ttype)
+                putiac2(WILL, TELOPT_TTYPE);
+        else
+                putiac2(WONT, TELOPT_TTYPE);
+
+        return;
+}
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+static inline void to_new_environ(void)
+{
+        /* Tell server we will (or will not) do AUTOLOGIN */
+
+        if (autologin)
+                putiac2(WILL, TELOPT_NEW_ENVIRON);
+        else
+                putiac2(WONT, TELOPT_NEW_ENVIRON);
+
+        return;
+}
+#endif
+
+#ifdef CONFIG_FEATURE_AUTOWIDTH
+static inline void to_naws(void)
+{
+        /* Tell server we will do NAWS */
+        putiac2(WILL, TELOPT_NAWS);
+        return;
+}
+#endif
+
+static void telopt(byte c)
+{
+        switch (c)
+        {
+                case TELOPT_ECHO:               to_echo();      break;
+                case TELOPT_SGA:                to_sga();       break;
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+                case TELOPT_TTYPE:              to_ttype();break;
+#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+                case TELOPT_NEW_ENVIRON:        to_new_environ();       break;
+#endif
+#ifdef CONFIG_FEATURE_AUTOWIDTH
+                case TELOPT_NAWS:               to_naws();
+                                                                putiac_naws(c, win_width, win_height);
+                                                                break;
+#endif
+                default:                                to_notsup(c);
+                                                                break;
+        }
+}
+
+
+/* ******************************* */
+
+/* subnegotiation -- ignore all (except TTYPE,NAWS) */
+
+static int subneg(byte c)
+{
+        switch (G.telstate)
+        {
+        case TS_SUB1:
+                if (c == IAC)
+                        G.telstate = TS_SUB2;
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+                else
+                if (c == TELOPT_TTYPE)
+                        putiac_subopt(TELOPT_TTYPE,ttype);
+#endif
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+                else
+                if (c == TELOPT_NEW_ENVIRON)
+                        putiac_subopt_autologin();
+#endif
+                break;
+        case TS_SUB2:
+                if (c == SE)
+                        return TRUE;
+                G.telstate = TS_SUB1;
+                /* break; */
+        }
+        return FALSE;
+}
+
+/* ******************************* */
+
+static void fgotsig(int sig)
+{
+        G.gotsig = sig;
+}
+
+
+static void rawmode(void)
+{
+        tcsetattr(0, TCSADRAIN, &G.termios_raw);
+}
+
+static void cookmode(void)
+{
+        tcsetattr(0, TCSADRAIN, &G.termios_def);
+}
+
+extern int telnet_main(int argc, char** argv)
+{
+        int len;
+        struct sockaddr_in s_in;
+#ifdef USE_POLL
+        struct pollfd ufds[2];
+#else
+        fd_set readfds;
+        int maxfd;
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+        int opt;
+#endif
+
+#ifdef CONFIG_FEATURE_AUTOWIDTH
+        get_terminal_width_height(0, &win_width, &win_height);
+#endif
+
+#ifdef CONFIG_FEATURE_TELNET_TTYPE
+    ttype = getenv("TERM");
+#endif
+
+        memset(&G, 0, sizeof G);
+
+        if (tcgetattr(0, &G.termios_def) < 0)
+                exit(1);
+
+        G.termios_raw = G.termios_def;
+        cfmakeraw(&G.termios_raw);
+
+        if (argc < 2)
+                bb_show_usage();
+
+#ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN
+        autologin = NULL;
+        while ((opt = getopt(argc, argv, "al:")) != EOF) {
+                switch (opt) {
+                        case 'l':
+                                autologin = optarg;
+                                break;
+                        case 'a':
+                                autologin = getenv("USER");
+                                break;
+                        case '?':
+                                bb_show_usage();
+                                break;
+                }
+        }
+        if (optind < argc) {
+                bb_lookup_host(&s_in, argv[optind++]);
+                s_in.sin_port = bb_lookup_port((optind < argc) ? argv[optind++] :
+                                "telnet", "tcp", 23);
+                if (optind < argc)
+                        bb_show_usage();
+        } else
+                bb_show_usage();
+#else
+        bb_lookup_host(&s_in, argv[1]);
+        s_in.sin_port = bb_lookup_port((argc == 3) ? argv[2] : "telnet", "tcp", 23);
+#endif
+
+        G.netfd = xconnect(&s_in);
+
+        setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof one);
+
+        signal(SIGINT, fgotsig);
+
+#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(0, &readfds);
+        FD_SET(G.netfd, &readfds);
+        maxfd = G.netfd + 1;
+#endif
+
+        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:
+                        /* error, ignore and/or log something, bay go to loop */
+                        if (G.gotsig)
+                                conescape();
+                        else
+                                sleep(1);
+                        break;
+                default:
+
+#ifdef USE_POLL
+                        if (ufds[0].revents) /* well, should check POLLIN, but ... */
+#else
+                        if (FD_ISSET(0, &rfds))
+#endif
+                        {
+                                len = read(0, G.buf, DATABUFSIZE);
+
+                                if (len <= 0)
+                                        doexit(0);
+
+                                TRACE(0, ("Read con: %d\n", len));
+
+                                handlenetoutput(len);
+                        }
+
+#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)
+                                {
+                                        WriteCS(1, "Connection closed by foreign host.\r\n");
+                                        doexit(1);
+                                }
+                                TRACE(0, ("Read netfd (%d): %d\n", G.netfd, len));
+
+                                handlenetinput(len);
+                        }
+                }
+        }
+}
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/