X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Ftelnet.c;h=58a691916e37454a60b58c463c3d522c0726d3a1;hb=11181335f9a97feddb30da4d09f9cd3739b8badd;hp=78229cd01cd8481d9dd15ae9445a6e10ca2c1aa7;hpb=1bec1b980e3cf5ad604fb0c2038a3ab83d9ab5f5;p=oweals%2Fbusybox.git diff --git a/networking/telnet.c b/networking/telnet.c index 78229cd01..58a691916 100644 --- a/networking/telnet.c +++ b/networking/telnet.c @@ -8,7 +8,7 @@ * 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 @@ -21,15 +21,44 @@ * */ -#include +//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 #include #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 { @@ -43,23 +72,25 @@ 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; @@ -68,7 +99,7 @@ struct globals { const char *autologin; #endif #if ENABLE_FEATURE_AUTOWIDTH - int win_width, win_height; + unsigned win_width, win_height; #endif /* same buffer used both for network and console read/write */ char buf[DATABUFSIZE]; @@ -76,43 +107,42 @@ struct globals { 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); + 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" @@ -121,20 +151,20 @@ static void conescape(void) " z suspend telnet\r\n" " e exit telnet\r\n"); - if (read(0, &b, 1) <= 0) - doexit(1); + if (read(STDIN_FILENO, &b, 1) <= 0) + doexit(EXIT_FAILURE); 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': @@ -143,58 +173,51 @@ static void conescape(void) rawmode(); break; case 'e': - doexit(0); + doexit(EXIT_SUCCESS); } write_str(1, "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; @@ -202,161 +225,188 @@ static void handlenetinput(int len) 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(1, 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); + put_iac((x >> 8) & 0xff); + put_iac(x & 0xff); + put_iac((y >> 8) & 0xff); + put_iac(y & 0xff); - 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(); } } @@ -368,9 +418,9 @@ static void will_charmode(void) 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) @@ -379,24 +429,24 @@ 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) @@ -412,12 +462,12 @@ static void to_echo(void) 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) @@ -432,20 +482,19 @@ 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 @@ -453,11 +502,10 @@ static void to_ttype(void) 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 @@ -465,7 +513,7 @@ static void to_new_environ(void) static void to_naws(void) { /* Tell server we will do NAWS */ - putiac2(WILL, TELOPT_NAWS); + put_iac2(WILL, TELOPT_NAWS); } #endif @@ -487,7 +535,7 @@ static void telopt(byte c) #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: @@ -497,7 +545,7 @@ static void telopt(byte c) } /* subnegotiation -- ignore all (except TTYPE,NAWS) */ -static int subneg(byte c) +static void subneg(byte c) { switch (G.telstate) { case TS_SUB1: @@ -505,30 +553,25 @@ static int subneg(byte c) 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) @@ -541,21 +584,13 @@ static void cookmode(void) 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(); @@ -573,9 +608,6 @@ int telnet_main(int argc, char **argv) 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"); @@ -590,69 +622,45 @@ int telnet_main(int argc, char **argv) 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(0, &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(0, &rfds)) -#endif - { - len = read(0, G.buf, DATABUFSIZE); - if (len <= 0) - doexit(0); - 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(1); - } - 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) */ }