+/*
+ * Telnet backend.
+ */
+
#include <stdio.h>
#include <stdlib.h>
#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 */
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 "<unknown>";
+#define telnet_str(x,y) case TELOPT_##x: return #x;
+ switch (opt) {
+ TELOPTS(telnet_str)
+ default:
+ return "<unknown>";
+ }
+#undef telnet_str
}
static void telnet_size(void *handle, int width, int height);
{ 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 =
SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
} 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);
}
}
/*
* 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)
b[1] = SB;
b[2] = TELOPT_TSPEED;
b[3] = TELQUAL_IS;
- strcpy((char *)(b + 4), cfg.termspeed);
- n = 4 + strlen(cfg.termspeed);
+ strcpy((char *)(b + 4), telnet->cfg.termspeed);
+ n = 4 + strlen(telnet->cfg.termspeed);
b[n] = IAC;
b[n + 1] = SE;
telnet->bufsize = sk_write(telnet->s, (char *)b, n + 2);
logevent(telnet->frontend, "server:\tSB TSPEED SEND");
- logbuf = dupprintf("client:\tSB TSPEED IS %s", cfg.termspeed);
+ logbuf = dupprintf("client:\tSB TSPEED IS %s", telnet->cfg.termspeed);
logevent(telnet->frontend, logbuf);
sfree(logbuf);
} else
b[1] = SB;
b[2] = TELOPT_TTYPE;
b[3] = TELQUAL_IS;
- for (n = 0; cfg.termtype[n]; n++)
- b[n + 4] = (cfg.termtype[n] >= 'a'
- && cfg.termtype[n] <=
- 'z' ? cfg.termtype[n] + 'A' -
- 'a' : cfg.termtype[n]);
+ for (n = 0; telnet->cfg.termtype[n]; n++)
+ b[n + 4] = (telnet->cfg.termtype[n] >= 'a'
+ && telnet->cfg.termtype[n] <=
+ 'z' ? telnet->cfg.termtype[n] + 'A' -
+ 'a' : telnet->cfg.termtype[n]);
b[n + 4] = IAC;
b[n + 5] = SE;
telnet->bufsize = sk_write(telnet->s, (char *)b, n + 6);
logevent(telnet->frontend, logbuf);
sfree(logbuf);
if (telnet->sb_opt == TELOPT_OLD_ENVIRON) {
- if (cfg.rfc_environ) {
+ if (telnet->cfg.rfc_environ) {
value = RFC_VALUE;
var = RFC_VAR;
} else {
b[2] = telnet->sb_opt;
b[3] = TELQUAL_IS;
n = 4;
- e = cfg.environmt;
+ e = telnet->cfg.environmt;
while (*e) {
b[n++] = var;
while (*e && *e != '\t')
b[n++] = *e++;
e++;
}
- if (*cfg.username) {
- b[n++] = var;
- b[n++] = 'U';
- b[n++] = 'S';
- b[n++] = 'E';
- b[n++] = 'R';
- b[n++] = value;
- e = 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 ? "<nothing>" :
+ (*telnet->cfg.environmt ? "<stuff>" : ""));
+ 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 ? "<nothing>" : "<stuff>");
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
}
break;
}
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++;
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
} else {
/* ignore everything else; print it if it's IAC */
if (c == IAC) {
- c_write1(telnet, c);
+ ADDTOBUF(c);
}
telnet->state = TOP_LEVEL;
}
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;
break;
}
}
+
+ if (outbuflen)
+ c_write(telnet, outbuf, outbuflen);
+ sfree(outbuf);
+}
+
+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, char *error_msg, int error_code,
+static int telnet_closing(Plug plug, const char *error_msg, int error_code,
int calling_back)
{
Telnet telnet = (Telnet) plug;
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;
}
* 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,
- 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;
telnet->echoing = TRUE;
telnet->editing = TRUE;
telnet->sb_buf = NULL;
telnet->sb_size = 0;
telnet->frontend = frontend_handle;
- telnet->term_width = cfg.width;
- telnet->term_height = cfg.height;
+ 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;
/*
*/
{
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);
- 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 */
/*
* 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);
+ 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.
*/
- if (cfg.passive_telnet) {
+ if (telnet->cfg.passive_telnet) {
const struct Opt *const *o;
for (o = opts; *o; o++)
*/
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
+ * any subsequent negotiations.
+ */
+static void telnet_reconfig(void *handle, Config *cfg)
+{
+ Telnet telnet = (Telnet) handle;
+ pinger_reconfig(telnet->pinger, &telnet->cfg, cfg);
+ telnet->cfg = *cfg; /* STRUCTURE COPY */
+}
+
/*
* Called to send data down the Telnet connection.
*/
{
Telnet telnet = (Telnet) handle;
unsigned char *p, *end;
- static unsigned char iac[2] = { IAC, IAC };
- static unsigned char cr[2] = { CR, NUL };
+ static const unsigned char iac[2] = { IAC, IAC };
+ static const unsigned char cr[2] = { CR, NUL };
#if 0
- static unsigned char nl[2] = { CR, LF };
+ static const unsigned char nl[2] = { CR, LF };
#endif
if (telnet->s == NULL)
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;
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)
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
};