X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/c85623f918b8a6c639afc15604414f9b113bb20d..9916cc1e8d26f1caef36fc1ee525819e6ca62f42:/telnet.c diff --git a/telnet.c b/telnet.c index 91d0cab4..20ccc83e 100644 --- a/telnet.c +++ b/telnet.c @@ -1,3 +1,7 @@ +/* + * Telnet backend. + */ + #include #include @@ -32,47 +36,65 @@ #define SUSP 237 /* Suspend process */ #define xEOF 236 /* End of file: EOF is already used... */ -#define TELOPT_BINARY 0 /* 8-bit data path */ -#define TELOPT_ECHO 1 /* echo */ -#define TELOPT_RCP 2 /* prepare to reconnect */ -#define TELOPT_SGA 3 /* suppress go ahead */ -#define TELOPT_NAMS 4 /* approximate message size */ -#define TELOPT_STATUS 5 /* give status */ -#define TELOPT_TM 6 /* timing mark */ -#define TELOPT_RCTE 7 /* remote controlled transmission and echo */ -#define TELOPT_NAOL 8 /* negotiate about output line width */ -#define TELOPT_NAOP 9 /* negotiate about output page size */ -#define TELOPT_NAOCRD 10 /* negotiate about CR disposition */ -#define TELOPT_NAOHTS 11 /* negotiate about horizontal tabstops */ -#define TELOPT_NAOHTD 12 /* negotiate about horizontal tab disposition */ -#define TELOPT_NAOFFD 13 /* negotiate about formfeed disposition */ -#define TELOPT_NAOVTS 14 /* negotiate about vertical tab stops */ -#define TELOPT_NAOVTD 15 /* negotiate about vertical tab disposition */ -#define TELOPT_NAOLFD 16 /* negotiate about output LF disposition */ -#define TELOPT_XASCII 17 /* extended ascic character set */ -#define TELOPT_LOGOUT 18 /* force logout */ -#define TELOPT_BM 19 /* byte macro */ -#define TELOPT_DET 20 /* data entry terminal */ -#define TELOPT_SUPDUP 21 /* supdup protocol */ -#define TELOPT_SUPDUPOUTPUT 22 /* supdup output */ -#define TELOPT_SNDLOC 23 /* send location */ -#define TELOPT_TTYPE 24 /* terminal type */ -#define TELOPT_EOR 25 /* end or record */ -#define TELOPT_TUID 26 /* TACACS user identification */ -#define TELOPT_OUTMRK 27 /* output marking */ -#define TELOPT_TTYLOC 28 /* terminal location number */ -#define TELOPT_3270REGIME 29 /* 3270 regime */ -#define TELOPT_X3PAD 30 /* X.3 PAD */ -#define TELOPT_NAWS 31 /* window size */ -#define TELOPT_TSPEED 32 /* terminal speed */ -#define TELOPT_LFLOW 33 /* remote flow control */ -#define TELOPT_LINEMODE 34 /* Linemode option */ -#define TELOPT_XDISPLOC 35 /* X Display Location */ -#define TELOPT_OLD_ENVIRON 36 /* Old - Environment variables */ -#define TELOPT_AUTHENTICATION 37 /* Authenticate */ -#define TELOPT_ENCRYPT 38 /* Encryption option */ -#define TELOPT_NEW_ENVIRON 39 /* New - Environment variables */ -#define TELOPT_EXOPL 255 /* extended-options-list */ +#define TELOPTS(X) \ + X(BINARY, 0) /* 8-bit data path */ \ + X(ECHO, 1) /* echo */ \ + X(RCP, 2) /* prepare to reconnect */ \ + X(SGA, 3) /* suppress go ahead */ \ + X(NAMS, 4) /* approximate message size */ \ + X(STATUS, 5) /* give status */ \ + X(TM, 6) /* timing mark */ \ + X(RCTE, 7) /* remote controlled transmission and echo */ \ + X(NAOL, 8) /* negotiate about output line width */ \ + X(NAOP, 9) /* negotiate about output page size */ \ + X(NAOCRD, 10) /* negotiate about CR disposition */ \ + X(NAOHTS, 11) /* negotiate about horizontal tabstops */ \ + X(NAOHTD, 12) /* negotiate about horizontal tab disposition */ \ + X(NAOFFD, 13) /* negotiate about formfeed disposition */ \ + X(NAOVTS, 14) /* negotiate about vertical tab stops */ \ + X(NAOVTD, 15) /* negotiate about vertical tab disposition */ \ + X(NAOLFD, 16) /* negotiate about output LF disposition */ \ + X(XASCII, 17) /* extended ascic character set */ \ + X(LOGOUT, 18) /* force logout */ \ + X(BM, 19) /* byte macro */ \ + X(DET, 20) /* data entry terminal */ \ + X(SUPDUP, 21) /* supdup protocol */ \ + X(SUPDUPOUTPUT, 22) /* supdup output */ \ + X(SNDLOC, 23) /* send location */ \ + X(TTYPE, 24) /* terminal type */ \ + X(EOR, 25) /* end or record */ \ + X(TUID, 26) /* TACACS user identification */ \ + X(OUTMRK, 27) /* output marking */ \ + X(TTYLOC, 28) /* terminal location number */ \ + X(3270REGIME, 29) /* 3270 regime */ \ + X(X3PAD, 30) /* X.3 PAD */ \ + X(NAWS, 31) /* window size */ \ + X(TSPEED, 32) /* terminal speed */ \ + X(LFLOW, 33) /* remote flow control */ \ + X(LINEMODE, 34) /* Linemode option */ \ + X(XDISPLOC, 35) /* X Display Location */ \ + X(OLD_ENVIRON, 36) /* Old - Environment variables */ \ + X(AUTHENTICATION, 37) /* Authenticate */ \ + X(ENCRYPT, 38) /* Encryption option */ \ + X(NEW_ENVIRON, 39) /* New - Environment variables */ \ + X(TN3270E, 40) /* TN3270 enhancements */ \ + X(XAUTH, 41) \ + X(CHARSET, 42) /* Character set */ \ + X(RSP, 43) /* Remote serial port */ \ + X(COM_PORT_OPTION, 44) /* Com port control */ \ + X(SLE, 45) /* Suppress local echo */ \ + X(STARTTLS, 46) /* Start TLS */ \ + X(KERMIT, 47) /* Automatic Kermit file transfer */ \ + X(SEND_URL, 48) \ + X(FORWARD_X, 49) \ + X(PRAGMA_LOGON, 138) \ + X(SSPI_LOGON, 139) \ + X(PRAGMA_HEARTBEAT, 140) \ + X(EXOPL, 255) /* extended-options-list */ + +#define telnet_enum(x,y) TELOPT_##x = y, +enum { TELOPTS(telnet_enum) dummy=0 }; +#undef telnet_enum #define TELQUAL_IS 0 /* option is... */ #define TELQUAL_SEND 1 /* send option */ @@ -92,49 +114,13 @@ static char *telopt(int opt) { -#define i(x) if (opt == TELOPT_ ## x) return #x; - i(BINARY); - i(ECHO); - i(RCP); - i(SGA); - i(NAMS); - i(STATUS); - i(TM); - i(RCTE); - i(NAOL); - i(NAOP); - i(NAOCRD); - i(NAOHTS); - i(NAOHTD); - i(NAOFFD); - i(NAOVTS); - i(NAOVTD); - i(NAOLFD); - i(XASCII); - i(LOGOUT); - i(BM); - i(DET); - i(SUPDUP); - i(SUPDUPOUTPUT); - i(SNDLOC); - i(TTYPE); - i(EOR); - i(TUID); - i(OUTMRK); - i(TTYLOC); - i(X3PAD); - i(NAWS); - i(TSPEED); - i(LFLOW); - i(LINEMODE); - i(XDISPLOC); - i(OLD_ENVIRON); - i(AUTHENTICATION); - i(ENCRYPT); - i(NEW_ENVIRON); - i(EXOPL); -#undef i - return ""; +#define telnet_str(x,y) case TELOPT_##x: return #x; + switch (opt) { + TELOPTS(telnet_str) + default: + return ""; + } +#undef telnet_str } static void telnet_size(void *handle, int width, int height); @@ -170,12 +156,10 @@ static const struct Opt o_tspeed = { WILL, WONT, DO, DONT, TELOPT_TSPEED, OPTINDEX_TSPEED, REQUESTED }; static const struct Opt o_ttype = { WILL, WONT, DO, DONT, TELOPT_TTYPE, OPTINDEX_TTYPE, REQUESTED }; -static const struct Opt o_oenv = { WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON, - OPTINDEX_OENV, INACTIVE -}; -static const struct Opt o_nenv = { WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON, - OPTINDEX_NENV, REQUESTED -}; +static const struct Opt o_oenv = + { WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON, OPTINDEX_OENV, INACTIVE }; +static const struct Opt o_nenv = + { WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON, OPTINDEX_NENV, REQUESTED }; static const struct Opt o_echo = { DO, DONT, WILL, WONT, TELOPT_ECHO, OPTINDEX_ECHO, REQUESTED }; static const struct Opt o_we_sga = @@ -218,17 +202,18 @@ typedef struct telnet_tag { } state; Config cfg; + + Pinger pinger; } *Telnet; #define TELNET_MAX_BACKLOG 4096 #define SB_DELTA 1024 -static void c_write1(Telnet telnet, int c) +static void c_write(Telnet telnet, char *buf, int len) { int backlog; - char cc = (char) c; - backlog = from_backend(telnet->frontend, 0, &cc, 1); + backlog = from_backend(telnet->frontend, 0, buf, len); sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG); } @@ -368,9 +353,12 @@ static void proc_rec_opt(Telnet telnet, int cmd, int option) } /* * If we reach here, the option was one we weren't prepared to - * cope with. So send a negative ack. + * cope with. If the request was positive (WILL or DO), we send + * a negative ack to indicate refusal. If the request was + * negative (WONT / DONT), we must do nothing. */ - send_opt(telnet, (cmd == WILL ? DONT : WONT), option); + if (cmd == WILL || cmd == DO) + send_opt(telnet, (cmd == WILL ? DONT : WONT), option); } static void process_subneg(Telnet telnet) @@ -478,24 +466,33 @@ static void process_subneg(Telnet telnet) b[n++] = *e++; e++; } - if (*telnet->cfg.username) { - b[n++] = var; - b[n++] = 'U'; - b[n++] = 'S'; - b[n++] = 'E'; - b[n++] = 'R'; - b[n++] = value; - e = telnet->cfg.username; - while (*e) - b[n++] = *e++; + { + char user[sizeof(telnet->cfg.username)]; + (void) get_remote_username(&telnet->cfg, user, sizeof(user)); + if (*user) { + b[n++] = var; + b[n++] = 'U'; + b[n++] = 'S'; + b[n++] = 'E'; + b[n++] = 'R'; + b[n++] = value; + e = user; + while (*e) + b[n++] = *e++; + } + b[n++] = IAC; + b[n++] = SE; + telnet->bufsize = sk_write(telnet->s, (char *)b, n); + logbuf = dupprintf("client:\tSB %s IS %s%s%s%s", + telopt(telnet->sb_opt), + *user ? "USER=" : "", + user, + *user ? " " : "", + n == 6 ? "" : + (*telnet->cfg.environmt ? "" : "")); + logevent(telnet->frontend, logbuf); + sfree(logbuf); } - b[n++] = IAC; - b[n++] = SE; - telnet->bufsize = sk_write(telnet->s, (char *)b, n); - logbuf = dupprintf("client:\tSB %s IS %s", telopt(telnet->sb_opt), - n == 6 ? "" : ""); - logevent(telnet->frontend, logbuf); - sfree(logbuf); } break; } @@ -503,6 +500,16 @@ static void process_subneg(Telnet telnet) static void do_telnet_read(Telnet telnet, char *buf, int len) { + char *outbuf = NULL; + int outbuflen = 0, outbufsize = 0; + +#define ADDTOBUF(c) do { \ + if (outbuflen >= outbufsize) { \ + outbufsize = outbuflen + 256; \ + outbuf = sresize(outbuf, outbufsize, char); \ + } \ + outbuf[outbuflen++] = (c); \ +} while (0) while (len--) { int c = (unsigned char) *buf++; @@ -516,7 +523,7 @@ static void do_telnet_read(Telnet telnet, char *buf, int len) telnet->state = SEENIAC; else { if (!telnet->in_synch) - c_write1(telnet, c); + ADDTOBUF(c); #if 1 /* I can't get the F***ing winsock to insert the urgent IAC @@ -553,7 +560,7 @@ static void do_telnet_read(Telnet telnet, char *buf, int len) } else { /* ignore everything else; print it if it's IAC */ if (c == IAC) { - c_write1(telnet, c); + ADDTOBUF(c); } telnet->state = TOP_LEVEL; } @@ -585,18 +592,11 @@ static void do_telnet_read(Telnet telnet, char *buf, int len) else { subneg_addchar: if (telnet->sb_len >= telnet->sb_size) { - unsigned char *newbuf; telnet->sb_size += SB_DELTA; - newbuf = (telnet->sb_buf ? - srealloc(telnet->sb_buf, telnet->sb_size) : - smalloc(telnet->sb_size)); - if (newbuf) - telnet->sb_buf = newbuf; - else - telnet->sb_size -= SB_DELTA; + telnet->sb_buf = sresize(telnet->sb_buf, telnet->sb_size, + unsigned char); } - if (telnet->sb_len < telnet->sb_size) - telnet->sb_buf[telnet->sb_len++] = c; + telnet->sb_buf[telnet->sb_len++] = c; telnet->state = SUBNEGOT; /* in case we came here by goto */ } break; @@ -610,9 +610,29 @@ static void do_telnet_read(Telnet telnet, char *buf, int len) break; } } + + if (outbuflen) + c_write(telnet, outbuf, outbuflen); + sfree(outbuf); } -static int telnet_closing(Plug plug, char *error_msg, int error_code, +static void telnet_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) +{ + Telnet telnet = (Telnet) plug; + char addrbuf[256], *msg; + + sk_getaddr(addr, addrbuf, lenof(addrbuf)); + + if (type == 0) + msg = dupprintf("Connecting to %s port %d", addrbuf, port); + else + msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); + + logevent(telnet->frontend, msg); +} + +static int telnet_closing(Plug plug, const char *error_msg, int error_code, int calling_back) { Telnet telnet = (Telnet) plug; @@ -620,12 +640,13 @@ static int telnet_closing(Plug plug, char *error_msg, int error_code, if (telnet->s) { sk_close(telnet->s); telnet->s = NULL; + notify_remote_exit(telnet->frontend); } if (error_msg) { - /* A socket error has occurred. */ logevent(telnet->frontend, error_msg); - connection_fatal("%s", error_msg); - } /* Otherwise, the remote side closed the connection normally. */ + connection_fatal(telnet->frontend, "%s", error_msg); + } + /* Otherwise, the remote side closed the connection normally. */ return 0; } @@ -652,20 +673,22 @@ static void telnet_sent(Plug plug, int bufsize) * Also places the canonical host name into `realhost'. It must be * freed by the caller. */ -static char *telnet_init(void *frontend_handle, void **backend_handle, - Config *cfg, - char *host, int port, char **realhost, int nodelay) +static const char *telnet_init(void *frontend_handle, void **backend_handle, + Config *cfg, + char *host, int port, char **realhost, + int nodelay, int keepalive) { static const struct plug_function_table fn_table = { + telnet_log, telnet_closing, telnet_receive, telnet_sent }; SockAddr addr; - char *err; + const char *err; Telnet telnet; - telnet = smalloc(sizeof(*telnet)); + telnet = snew(struct telnet_tag); telnet->fn = &fn_table; telnet->cfg = *cfg; /* STRUCTURE COPY */ telnet->s = NULL; @@ -678,6 +701,8 @@ static char *telnet_init(void *frontend_handle, void **backend_handle, telnet->term_width = telnet->cfg.width; telnet->term_height = telnet->cfg.height; telnet->state = TOP_LEVEL; + telnet->ldisc = NULL; + telnet->pinger = NULL; *backend_handle = telnet; /* @@ -685,13 +710,18 @@ static char *telnet_init(void *frontend_handle, void **backend_handle, */ { char *buf; - buf = dupprintf("Looking up host \"%s\"", host); + buf = dupprintf("Looking up host \"%s\"%s", host, + (cfg->addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : + (cfg->addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : + ""))); logevent(telnet->frontend, buf); sfree(buf); } - addr = name_lookup(host, port, realhost, &telnet->cfg); - if ((err = sk_addr_error(addr)) != NULL) + addr = name_lookup(host, port, realhost, &telnet->cfg, cfg->addressfamily); + if ((err = sk_addr_error(addr)) != NULL) { + sk_addr_free(addr); return err; + } if (port < 0) port = 23; /* default telnet port */ @@ -699,19 +729,12 @@ static char *telnet_init(void *frontend_handle, void **backend_handle, /* * Open socket. */ - { - char *buf, addrbuf[100]; - sk_getaddr(addr, addrbuf, 100); - buf = dupprintf("Connecting to %s port %d", addrbuf, port); - logevent(telnet->frontend, buf); - sfree(buf); - } telnet->s = new_connection(addr, *realhost, port, 0, 1, - nodelay, (Plug) telnet, &telnet->cfg); + nodelay, keepalive, (Plug) telnet, &telnet->cfg); if ((err = sk_socket_error(telnet->s)) != NULL) return err; - sk_addr_free(addr); + telnet->pinger = pinger_new(&telnet->cfg, &telnet_backend, telnet); /* * Initialise option states. @@ -737,9 +760,44 @@ static char *telnet_init(void *frontend_handle, void **backend_handle, */ telnet->in_synch = FALSE; + /* + * We can send special commands from the start. + */ + update_specials_menu(telnet->frontend); + + /* + * loghost overrides realhost, if specified. + */ + if (*telnet->cfg.loghost) { + char *colon; + + sfree(*realhost); + *realhost = dupstr(telnet->cfg.loghost); + colon = strrchr(*realhost, ':'); + if (colon) { + /* + * FIXME: if we ever update this aspect of ssh.c for + * IPv6 literal management, this should change in line + * with it. + */ + *colon++ = '\0'; + } + } + return NULL; } +static void telnet_free(void *handle) +{ + Telnet telnet = (Telnet) handle; + + sfree(telnet->sb_buf); + if (telnet->s) + sk_close(telnet->s); + if (telnet->pinger) + pinger_free(telnet->pinger); + sfree(telnet); +} /* * Reconfigure the Telnet backend. There's no immediate action * necessary, in this backend: we just save the fresh config for @@ -748,6 +806,7 @@ static char *telnet_init(void *frontend_handle, void **backend_handle, static void telnet_reconfig(void *handle, Config *cfg) { Telnet telnet = (Telnet) handle; + pinger_reconfig(telnet->pinger, &telnet->cfg, cfg); telnet->cfg = *cfg; /* STRUCTURE COPY */ } @@ -893,9 +952,10 @@ static void telnet_special(void *handle, Telnet_Special code) telnet->bufsize = sk_write(telnet->s, (char *)b, 2); break; case TS_EOL: - /* In BINARY mode, CR-LF becomes just CR. */ + /* In BINARY mode, CR-LF becomes just CR - + * and without the NUL suffix too. */ if (telnet->opt_states[o_we_bin.index] == ACTIVE) - telnet->bufsize = sk_write(telnet->s, "\r", 2); + telnet->bufsize = sk_write(telnet->s, "\r", 1); else telnet->bufsize = sk_write(telnet->s, "\r\n", 2); break; @@ -923,13 +983,38 @@ static void telnet_special(void *handle, Telnet_Special code) telnet->bufsize = sk_write(telnet->s, (char *)b, 2); } break; + default: + break; /* never heard of it */ } } -static Socket telnet_socket(void *handle) +static const struct telnet_special *telnet_get_specials(void *handle) +{ + static const struct telnet_special specials[] = { + {"Are You There", TS_AYT}, + {"Break", TS_BRK}, + {"Synch", TS_SYNCH}, + {"Erase Character", TS_EC}, + {"Erase Line", TS_EL}, + {"Go Ahead", TS_GA}, + {"No Operation", TS_NOP}, + {NULL, TS_SEP}, + {"Abort Process", TS_ABORT}, + {"Abort Output", TS_AO}, + {"Interrupt Process", TS_IP}, + {"Suspend Process", TS_SUSP}, + {NULL, TS_SEP}, + {"End Of Record", TS_EOR}, + {"End Of File", TS_EOF}, + {NULL, TS_EXITMENU} + }; + return specials; +} + +static int telnet_connected(void *handle) { Telnet telnet = (Telnet) handle; - return telnet->s; + return telnet->s != NULL; } static int telnet_sendok(void *handle) @@ -967,24 +1052,40 @@ static void telnet_provide_logctx(void *handle, void *logctx) static int telnet_exitcode(void *handle) { - /* Telnet telnet = (Telnet) handle; */ - /* Telnet doesn't transmit exit codes back to the client */ + Telnet telnet = (Telnet) handle; + if (telnet->s != NULL) + return -1; /* still connected */ + else + /* Telnet doesn't transmit exit codes back to the client */ + return 0; +} + +/* + * cfg_info for Telnet does nothing at all. + */ +static int telnet_cfg_info(void *handle) +{ return 0; } Backend telnet_backend = { telnet_init, + telnet_free, telnet_reconfig, telnet_send, telnet_sendbuffer, telnet_size, telnet_special, - telnet_socket, + telnet_get_specials, + telnet_connected, telnet_exitcode, telnet_sendok, telnet_ldisc, telnet_provide_ldisc, telnet_provide_logctx, telnet_unthrottle, + telnet_cfg_info, + "telnet", + PROT_TELNET, 23 };