X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/347e5401f43649bf0f3e3eed57b11d02b2fdf8be..eaf1e20af0294d79a176d2ac3b35fd4143163051:/telnet.c diff --git a/telnet.c b/telnet.c index c45f20ff..50388337 100644 --- a/telnet.c +++ b/telnet.c @@ -1,3 +1,7 @@ +/* + * Telnet backend. + */ + #include #include @@ -196,12 +200,10 @@ 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 = @@ -244,6 +246,8 @@ typedef struct telnet_tag { } state; Config cfg; + + Pinger pinger; } *Telnet; #define TELNET_MAX_BACKLOG 4096 @@ -394,9 +398,12 @@ 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) @@ -518,8 +525,13 @@ static void process_subneg(Telnet telnet) 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 ? "" : ""); + logbuf = dupprintf("client:\tSB %s IS %s%s%s%s", + telopt(telnet->sb_opt), + *telnet->cfg.username ? "USER=" : "", + telnet->cfg.username, + *telnet->cfg.username ? " " : "", + n == 6 ? "" : + (*telnet->cfg.environmt ? "" : "")); logevent(telnet->frontend, logbuf); sfree(logbuf); } @@ -611,18 +623,11 @@ 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; @@ -638,7 +643,23 @@ static void do_telnet_read(Telnet telnet, char *buf, int len) } } -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; @@ -646,12 +667,13 @@ 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; } @@ -678,20 +700,22 @@ 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; @@ -704,6 +728,8 @@ 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; /* @@ -711,13 +737,18 @@ 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 */ @@ -725,19 +756,12 @@ 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. @@ -763,6 +787,11 @@ 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); + return NULL; } @@ -773,6 +802,8 @@ static void telnet_free(void *handle) sfree(telnet->sb_buf); if (telnet->s) sk_close(telnet->s); + if (telnet->pinger) + pinger_free(telnet->pinger); sfree(telnet); } /* @@ -783,6 +814,7 @@ static void telnet_free(void *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 */ } @@ -928,9 +960,10 @@ 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; @@ -958,9 +991,34 @@ 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 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 Socket telnet_socket(void *handle) { Telnet telnet = (Telnet) handle; @@ -1002,8 +1060,19 @@ 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; } @@ -1015,6 +1084,7 @@ Backend telnet_backend = { telnet_sendbuffer, telnet_size, telnet_special, + telnet_get_specials, telnet_socket, telnet_exitcode, telnet_sendok, @@ -1022,5 +1092,6 @@ Backend telnet_backend = { telnet_provide_ldisc, telnet_provide_logctx, telnet_unthrottle, + telnet_cfg_info, 23 };