X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Ftelnet.c;h=8b0df7f5c4f0211304b3d87ac5531ac180179883;hb=6a4f2231221c2c4f7ca82f081f442e31a6cfd051;hp=f6fad684cff529995852ae3ce1c9125f006343f8;hpb=ec07420eb914f6ca62273c54790853ccf22636e8;p=oweals%2Fbusybox.git diff --git a/networking/telnet.c b/networking/telnet.c index f6fad684c..8b0df7f5c 100644 --- a/networking/telnet.c +++ b/networking/telnet.c @@ -18,17 +18,81 @@ * * Modified 2004/02/11 to add ability to pass the USER variable to remote host * by Fernando Silveira - * */ +//config:config TELNET +//config: bool "telnet (8.7 kb)" +//config: default y +//config: help +//config: Telnet is an interface to the TELNET protocol, but is also commonly +//config: used to test other simple protocols. +//config: +//config:config FEATURE_TELNET_TTYPE +//config: bool "Pass TERM type to remote host" +//config: default y +//config: depends on TELNET +//config: help +//config: Setting this option will forward the TERM environment variable to the +//config: remote host you are connecting to. This is useful to make sure that +//config: things like ANSI colors and other control sequences behave. +//config: +//config:config FEATURE_TELNET_AUTOLOGIN +//config: bool "Pass USER type to remote host" +//config: default y +//config: depends on TELNET +//config: help +//config: Setting this option will forward the USER environment variable to the +//config: remote host you are connecting to. This is useful when you need to +//config: log into a machine without telling the username (autologin). This +//config: option enables '-a' and '-l USER' options. +//config: +//config:config FEATURE_TELNET_WIDTH +//config: bool "Enable window size autodetection" +//config: default y +//config: depends on TELNET + +//applet:IF_TELNET(APPLET(telnet, BB_DIR_USR_BIN, BB_SUID_DROP)) + +//kbuild:lib-$(CONFIG_TELNET) += telnet.o + +//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" +#include "common_bufsiz.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 { @@ -68,7 +132,7 @@ struct globals { #if ENABLE_FEATURE_TELNET_AUTOLOGIN const char *autologin; #endif -#if ENABLE_FEATURE_AUTOWIDTH +#if ENABLE_FEATURE_TELNET_WIDTH unsigned win_width, win_height; #endif /* same buffer used both for network and console read/write */ @@ -78,11 +142,10 @@ struct globals { struct termios termios_def; struct termios termios_raw; } FIX_ALIASING; -#define G (*(struct globals*)&bb_common_bufsiz1) +#define G (*(struct globals*)bb_common_bufsiz1) #define INIT_G() do { \ - struct G_sizecheck { \ - char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \ - }; \ + setup_common_bufsiz(); \ + BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \ } while (0) @@ -95,12 +158,10 @@ static void subneg(byte c); static void iac_flush(void) { - write(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) NORETURN; static void doexit(int ev) { @@ -115,7 +176,7 @@ static void con_escape(void) 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" @@ -146,7 +207,7 @@ static void con_escape(void) doexit(EXIT_SUCCESS); } - write_str(1, "continuing...\r\n"); + full_write1_str("continuing...\r\n"); if (bb_got_signal) cookmode(); @@ -156,40 +217,35 @@ static void con_escape(void) 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 - why do you have to make 'many write()s'? - * I don't understand. - * So I implemented it. It's really useful for me. I hope that - * other people will find it interesting too. - */ byte outbuf[2 * DATABUFSIZE]; - byte *p = (byte*)G.buf; - int j = 0; + byte *dst = outbuf; + byte *src = (byte*)G.buf; + byte *end = src + len; - for (; len > 0; len--, p++) { - byte c = *p; + while (src < end) { + byte c = *src++; if (c == 0x1d) { con_escape(); return; } - outbuf[j++] = c; + *dst = c; if (c == IAC) - outbuf[j++] = c; /* IAC -> IAC IAC */ - else if (c == '\r') - outbuf[j++] = '\0'; /* CR -> CR NUL */ + *++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) - full_write(netfd, outbuf, j); + if (dst - outbuf != 0) + full_write(netfd, outbuf, dst - outbuf); } static void handle_net_input(int len) @@ -288,15 +344,16 @@ static void put_iac(int c) G.iacbuf[G.iaclen++] = c; } -static void put_iac2(byte wwdd, byte c) +static void put_iac2_merged(unsigned wwdd_and_c) { if (G.iaclen + 3 > IACBUFSIZE) iac_flush(); put_iac(IAC); - put_iac(wwdd); - put_iac(c); + put_iac(wwdd_and_c >> 8); + put_iac(wwdd_and_c & 0xff); } +#define put_iac2(wwdd,c) put_iac2_merged(((wwdd)<<8) + (c)) #if ENABLE_FEATURE_TELNET_TTYPE static void put_iac_subopt(byte c, char *str) @@ -348,7 +405,7 @@ static void put_iac_subopt_autologin(void) } #endif -#if ENABLE_FEATURE_AUTOWIDTH +#if ENABLE_FEATURE_TELNET_WIDTH static void put_iac_naws(byte c, int x, int y) { if (G.iaclen + 9 > IACBUFSIZE) @@ -358,30 +415,31 @@ static void put_iac_naws(byte c, int x, int y) put_iac(SB); put_iac(c); - put_iac((x >> 8) & 0xff); - put_iac(x & 0xff); - put_iac((y >> 8) & 0xff); - put_iac(y & 0xff); + /* "... & 0xff" implicitly done below */ + put_iac(x >> 8); + put_iac(x); + put_iac(y >> 8); + put_iac(y); 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(); } } @@ -484,7 +542,7 @@ static void to_new_environ(void) } #endif -#if ENABLE_FEATURE_AUTOWIDTH +#if ENABLE_FEATURE_TELNET_WIDTH static void to_naws(void) { /* Tell server we will do NAWS */ @@ -507,7 +565,7 @@ static void telopt(byte c) case TELOPT_NEW_ENVIRON: to_new_environ(); break; #endif -#if ENABLE_FEATURE_AUTOWIDTH +#if ENABLE_FEATURE_TELNET_WIDTH case TELOPT_NAWS: to_naws(); put_iac_naws(c, G.win_width, G.win_height); @@ -569,7 +627,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv) INIT_G(); -#if ENABLE_FEATURE_AUTOWIDTH +#if ENABLE_FEATURE_TELNET_WIDTH get_terminal_width_height(0, &G.win_width, &G.win_height); #endif @@ -584,8 +642,10 @@ int telnet_main(int argc UNUSED_PARAM, char **argv) } #if ENABLE_FEATURE_TELNET_AUTOLOGIN - if (1 & getopt32(argv, "al:", &G.autologin)) + if (1 == getopt32(argv, "al:", &G.autologin)) { + /* Only -a without -l USER picks $USER from envvar */ G.autologin = getenv("USER"); + } argv += optind; #else argv++; @@ -599,7 +659,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv) xmove_fd(create_and_connect_stream_or_die(host, port), netfd); - setsockopt(netfd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); + setsockopt_keepalive(netfd); signal(SIGINT, record_signo);