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-rw-r--r--tools/plink/telnet.c2267
1 files changed, 1135 insertions, 1132 deletions
diff --git a/tools/plink/telnet.c b/tools/plink/telnet.c
index c024538b9..098db292c 100644
--- a/tools/plink/telnet.c
+++ b/tools/plink/telnet.c
@@ -1,1132 +1,1135 @@
-/*
- * Telnet backend.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "putty.h"
-
-#ifndef FALSE
-#define FALSE 0
-#endif
-#ifndef TRUE
-#define TRUE 1
-#endif
-
-#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 GA 249 /* you may reverse the line */
-#define EL 248 /* erase the current line */
-#define EC 247 /* erase the current character */
-#define AYT 246 /* are you there */
-#define AO 245 /* abort output--but let prog finish */
-#define IP 244 /* interrupt process--permanently */
-#define BREAK 243 /* break */
-#define DM 242 /* data mark--for connect. cleaning */
-#define NOP 241 /* nop */
-#define EOR 239 /* end of record (transparent mode) */
-#define ABORT 238 /* Abort process */
-#define SUSP 237 /* Suspend process */
-#define xEOF 236 /* End of file: EOF is already used... */
-
-#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 */
-#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
-#define BSD_VAR 1
-#define BSD_VALUE 0
-#define RFC_VAR 0
-#define RFC_VALUE 1
-
-#define CR 13
-#define LF 10
-#define NUL 0
-
-#define iswritable(x) \
- ( (x) != IAC && \
- (telnet->opt_states[o_we_bin.index] == ACTIVE || (x) != CR))
-
-static char *telopt(int opt)
-{
-#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);
-
-struct Opt {
- int send; /* what we initially send */
- int nsend; /* -ve send if requested to stop it */
- int ack, nak; /* +ve and -ve acknowledgements */
- int option; /* the option code */
- int index; /* index into telnet->opt_states[] */
- enum {
- REQUESTED, ACTIVE, INACTIVE, REALLY_INACTIVE
- } initial_state;
-};
-
-enum {
- OPTINDEX_NAWS,
- OPTINDEX_TSPEED,
- OPTINDEX_TTYPE,
- OPTINDEX_OENV,
- OPTINDEX_NENV,
- OPTINDEX_ECHO,
- OPTINDEX_WE_SGA,
- OPTINDEX_THEY_SGA,
- OPTINDEX_WE_BIN,
- OPTINDEX_THEY_BIN,
- NUM_OPTS
-};
-
-static const struct Opt o_naws =
- { WILL, WONT, DO, DONT, TELOPT_NAWS, OPTINDEX_NAWS, REQUESTED };
-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_echo =
- { DO, DONT, WILL, WONT, TELOPT_ECHO, OPTINDEX_ECHO, REQUESTED };
-static const struct Opt o_we_sga =
- { WILL, WONT, DO, DONT, TELOPT_SGA, OPTINDEX_WE_SGA, REQUESTED };
-static const struct Opt o_they_sga =
- { DO, DONT, WILL, WONT, TELOPT_SGA, OPTINDEX_THEY_SGA, REQUESTED };
-static const struct Opt o_we_bin =
- { WILL, WONT, DO, DONT, TELOPT_BINARY, OPTINDEX_WE_BIN, INACTIVE };
-static const struct Opt o_they_bin =
- { DO, DONT, WILL, WONT, TELOPT_BINARY, OPTINDEX_THEY_BIN, INACTIVE };
-
-static const struct Opt *const opts[] = {
- &o_naws, &o_tspeed, &o_ttype, &o_oenv, &o_nenv, &o_echo,
- &o_we_sga, &o_they_sga, &o_we_bin, &o_they_bin, NULL
-};
-
-typedef struct telnet_tag {
- const struct plug_function_table *fn;
- /* the above field _must_ be first in the structure */
-
- Socket s;
-
- void *frontend;
- void *ldisc;
- int term_width, term_height;
-
- int opt_states[NUM_OPTS];
-
- int echoing, editing;
- int activated;
- int bufsize;
- int in_synch;
- int sb_opt, sb_len;
- unsigned char *sb_buf;
- int sb_size;
-
- enum {
- TOP_LEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
- SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
- } state;
-
- Conf *conf;
-
- Pinger pinger;
-} *Telnet;
-
-#define TELNET_MAX_BACKLOG 4096
-
-#define SB_DELTA 1024
-
-static void c_write(Telnet telnet, char *buf, int len)
-{
- int backlog;
- backlog = from_backend(telnet->frontend, 0, buf, len);
- sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
-}
-
-static void log_option(Telnet telnet, char *sender, int cmd, int option)
-{
- char *buf;
- /*
- * The strange-looking "<?""?>" below is there to avoid a
- * trigraph - a double question mark followed by > maps to a
- * closing brace character!
- */
- buf = dupprintf("%s:\t%s %s", sender,
- (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" :
- cmd == DO ? "DO" : cmd == DONT ? "DONT" : "<?""?>"),
- telopt(option));
- logevent(telnet->frontend, buf);
- sfree(buf);
-}
-
-static void send_opt(Telnet telnet, int cmd, int option)
-{
- unsigned char b[3];
-
- b[0] = IAC;
- b[1] = cmd;
- b[2] = option;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 3);
- log_option(telnet, "client", cmd, option);
-}
-
-static void deactivate_option(Telnet telnet, const struct Opt *o)
-{
- if (telnet->opt_states[o->index] == REQUESTED ||
- telnet->opt_states[o->index] == ACTIVE)
- send_opt(telnet, o->nsend, o->option);
- telnet->opt_states[o->index] = REALLY_INACTIVE;
-}
-
-/*
- * Generate side effects of enabling or disabling an option.
- */
-static void option_side_effects(Telnet telnet, const struct Opt *o, int enabled)
-{
- if (o->option == TELOPT_ECHO && o->send == DO)
- telnet->echoing = !enabled;
- else if (o->option == TELOPT_SGA && o->send == DO)
- telnet->editing = !enabled;
- if (telnet->ldisc) /* cause ldisc to notice the change */
- ldisc_send(telnet->ldisc, NULL, 0, 0);
-
- /* Ensure we get the minimum options */
- if (!telnet->activated) {
- if (telnet->opt_states[o_echo.index] == INACTIVE) {
- telnet->opt_states[o_echo.index] = REQUESTED;
- send_opt(telnet, o_echo.send, o_echo.option);
- }
- if (telnet->opt_states[o_we_sga.index] == INACTIVE) {
- telnet->opt_states[o_we_sga.index] = REQUESTED;
- send_opt(telnet, o_we_sga.send, o_we_sga.option);
- }
- if (telnet->opt_states[o_they_sga.index] == INACTIVE) {
- telnet->opt_states[o_they_sga.index] = REQUESTED;
- send_opt(telnet, o_they_sga.send, o_they_sga.option);
- }
- telnet->activated = TRUE;
- }
-}
-
-static void activate_option(Telnet telnet, const struct Opt *o)
-{
- if (o->send == WILL && o->option == TELOPT_NAWS)
- telnet_size(telnet, telnet->term_width, telnet->term_height);
- if (o->send == WILL &&
- (o->option == TELOPT_NEW_ENVIRON ||
- o->option == TELOPT_OLD_ENVIRON)) {
- /*
- * We may only have one kind of ENVIRON going at a time.
- * This is a hack, but who cares.
- */
- deactivate_option(telnet, o->option ==
- TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv);
- }
- option_side_effects(telnet, o, 1);
-}
-
-static void refused_option(Telnet telnet, const struct Opt *o)
-{
- if (o->send == WILL && o->option == TELOPT_NEW_ENVIRON &&
- telnet->opt_states[o_oenv.index] == INACTIVE) {
- send_opt(telnet, WILL, TELOPT_OLD_ENVIRON);
- telnet->opt_states[o_oenv.index] = REQUESTED;
- }
- option_side_effects(telnet, o, 0);
-}
-
-static void proc_rec_opt(Telnet telnet, int cmd, int option)
-{
- const struct Opt *const *o;
-
- log_option(telnet, "server", cmd, option);
- for (o = opts; *o; o++) {
- if ((*o)->option == option && (*o)->ack == cmd) {
- switch (telnet->opt_states[(*o)->index]) {
- case REQUESTED:
- telnet->opt_states[(*o)->index] = ACTIVE;
- activate_option(telnet, *o);
- break;
- case ACTIVE:
- break;
- case INACTIVE:
- telnet->opt_states[(*o)->index] = ACTIVE;
- send_opt(telnet, (*o)->send, option);
- activate_option(telnet, *o);
- break;
- case REALLY_INACTIVE:
- send_opt(telnet, (*o)->nsend, option);
- break;
- }
- return;
- } else if ((*o)->option == option && (*o)->nak == cmd) {
- switch (telnet->opt_states[(*o)->index]) {
- case REQUESTED:
- telnet->opt_states[(*o)->index] = INACTIVE;
- refused_option(telnet, *o);
- break;
- case ACTIVE:
- telnet->opt_states[(*o)->index] = INACTIVE;
- send_opt(telnet, (*o)->nsend, option);
- option_side_effects(telnet, *o, 0);
- break;
- case INACTIVE:
- case REALLY_INACTIVE:
- break;
- }
- return;
- }
- }
- /*
- * If we reach here, the option was one we weren't prepared to
- * 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.
- */
- if (cmd == WILL || cmd == DO)
- send_opt(telnet, (cmd == WILL ? DONT : WONT), option);
-}
-
-static void process_subneg(Telnet telnet)
-{
- unsigned char *b, *p, *q;
- int var, value, n, bsize;
- char *e, *eval, *ekey, *user;
-
- switch (telnet->sb_opt) {
- case TELOPT_TSPEED:
- if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
- char *logbuf;
- char *termspeed = conf_get_str(telnet->conf, CONF_termspeed);
- b = snewn(20 + strlen(termspeed), unsigned char);
- b[0] = IAC;
- b[1] = SB;
- b[2] = TELOPT_TSPEED;
- b[3] = TELQUAL_IS;
- strcpy((char *)(b + 4), termspeed);
- n = 4 + strlen(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", termspeed);
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- sfree(b);
- } else
- logevent(telnet->frontend, "server:\tSB TSPEED <something weird>");
- break;
- case TELOPT_TTYPE:
- if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
- char *logbuf;
- char *termtype = conf_get_str(telnet->conf, CONF_termtype);
- b = snewn(20 + strlen(termtype), unsigned char);
- b[0] = IAC;
- b[1] = SB;
- b[2] = TELOPT_TTYPE;
- b[3] = TELQUAL_IS;
- for (n = 0; termtype[n]; n++)
- b[n + 4] = (termtype[n] >= 'a' && termtype[n] <= 'z' ?
- termtype[n] + 'A' - 'a' :
- termtype[n]);
- b[n + 4] = IAC;
- b[n + 5] = SE;
- telnet->bufsize = sk_write(telnet->s, (char *)b, n + 6);
- b[n + 4] = 0;
- logevent(telnet->frontend, "server:\tSB TTYPE SEND");
- logbuf = dupprintf("client:\tSB TTYPE IS %s", b + 4);
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- sfree(b);
- } else
- logevent(telnet->frontend, "server:\tSB TTYPE <something weird>\r\n");
- break;
- case TELOPT_OLD_ENVIRON:
- case TELOPT_NEW_ENVIRON:
- p = telnet->sb_buf;
- q = p + telnet->sb_len;
- if (p < q && *p == TELQUAL_SEND) {
- char *logbuf;
- p++;
- logbuf = dupprintf("server:\tSB %s SEND", telopt(telnet->sb_opt));
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- if (telnet->sb_opt == TELOPT_OLD_ENVIRON) {
- if (conf_get_int(telnet->conf, CONF_rfc_environ)) {
- value = RFC_VALUE;
- var = RFC_VAR;
- } else {
- value = BSD_VALUE;
- var = BSD_VAR;
- }
- /*
- * Try to guess the sense of VAR and VALUE.
- */
- while (p < q) {
- if (*p == RFC_VAR) {
- value = RFC_VALUE;
- var = RFC_VAR;
- } else if (*p == BSD_VAR) {
- value = BSD_VALUE;
- var = BSD_VAR;
- }
- p++;
- }
- } else {
- /*
- * With NEW_ENVIRON, the sense of VAR and VALUE
- * isn't in doubt.
- */
- value = RFC_VALUE;
- var = RFC_VAR;
- }
- bsize = 20;
- for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- NULL, &ekey);
- eval != NULL;
- eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- ekey, &ekey))
- bsize += strlen(ekey) + strlen(eval) + 2;
- user = get_remote_username(telnet->conf);
- if (user)
- bsize += 6 + strlen(user);
-
- b = snewn(bsize, unsigned char);
- b[0] = IAC;
- b[1] = SB;
- b[2] = telnet->sb_opt;
- b[3] = TELQUAL_IS;
- n = 4;
- for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- NULL, &ekey);
- eval != NULL;
- eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- ekey, &ekey)) {
- b[n++] = var;
- for (e = ekey; *e; e++)
- b[n++] = *e;
- b[n++] = value;
- for (e = eval; *e; e++)
- b[n++] = *e;
- }
- if (user) {
- b[n++] = var;
- b[n++] = 'U';
- b[n++] = 'S';
- b[n++] = 'E';
- b[n++] = 'R';
- b[n++] = value;
- for (e = user; *e; e++)
- b[n++] = *e;
- }
- b[n++] = IAC;
- b[n++] = SE;
- telnet->bufsize = sk_write(telnet->s, (char *)b, n);
- if (n == 6) {
- logbuf = dupprintf("client:\tSB %s IS <nothing>",
- telopt(telnet->sb_opt));
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- } else {
- logbuf = dupprintf("client:\tSB %s IS:",
- telopt(telnet->sb_opt));
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- NULL, &ekey);
- eval != NULL;
- eval = conf_get_str_strs(telnet->conf, CONF_environmt,
- ekey, &ekey)) {
- logbuf = dupprintf("\t%s=%s", ekey, eval);
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- }
- if (user) {
- logbuf = dupprintf("\tUSER=%s", user);
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
- }
- }
- sfree(b);
- sfree(user);
- }
- 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++;
-
- switch (telnet->state) {
- case TOP_LEVEL:
- case SEENCR:
- if (c == NUL && telnet->state == SEENCR)
- telnet->state = TOP_LEVEL;
- else if (c == IAC)
- telnet->state = SEENIAC;
- else {
- if (!telnet->in_synch)
- ADDTOBUF(c);
-
-#if 1
- /* I can't get the F***ing winsock to insert the urgent IAC
- * into the right position! Even with SO_OOBINLINE it gives
- * it to recv too soon. And of course the DM byte (that
- * arrives in the same packet!) appears several K later!!
- *
- * Oh well, we do get the DM in the right place so I'll
- * just stop hiding on the next 0xf2 and hope for the best.
- */
- else if (c == DM)
- telnet->in_synch = 0;
-#endif
- if (c == CR && telnet->opt_states[o_they_bin.index] != ACTIVE)
- telnet->state = SEENCR;
- else
- telnet->state = TOP_LEVEL;
- }
- break;
- case SEENIAC:
- if (c == DO)
- telnet->state = SEENDO;
- else if (c == DONT)
- telnet->state = SEENDONT;
- else if (c == WILL)
- telnet->state = SEENWILL;
- else if (c == WONT)
- telnet->state = SEENWONT;
- else if (c == SB)
- telnet->state = SEENSB;
- else if (c == DM) {
- telnet->in_synch = 0;
- telnet->state = TOP_LEVEL;
- } else {
- /* ignore everything else; print it if it's IAC */
- if (c == IAC) {
- ADDTOBUF(c);
- }
- telnet->state = TOP_LEVEL;
- }
- break;
- case SEENWILL:
- proc_rec_opt(telnet, WILL, c);
- telnet->state = TOP_LEVEL;
- break;
- case SEENWONT:
- proc_rec_opt(telnet, WONT, c);
- telnet->state = TOP_LEVEL;
- break;
- case SEENDO:
- proc_rec_opt(telnet, DO, c);
- telnet->state = TOP_LEVEL;
- break;
- case SEENDONT:
- proc_rec_opt(telnet, DONT, c);
- telnet->state = TOP_LEVEL;
- break;
- case SEENSB:
- telnet->sb_opt = c;
- telnet->sb_len = 0;
- telnet->state = SUBNEGOT;
- break;
- case SUBNEGOT:
- if (c == IAC)
- telnet->state = SUBNEG_IAC;
- else {
- subneg_addchar:
- if (telnet->sb_len >= telnet->sb_size) {
- telnet->sb_size += SB_DELTA;
- telnet->sb_buf = sresize(telnet->sb_buf, telnet->sb_size,
- unsigned char);
- }
- telnet->sb_buf[telnet->sb_len++] = c;
- telnet->state = SUBNEGOT; /* in case we came here by goto */
- }
- break;
- case SUBNEG_IAC:
- if (c != SE)
- goto subneg_addchar; /* yes, it's a hack, I know, but... */
- else {
- process_subneg(telnet);
- telnet->state = TOP_LEVEL;
- }
- 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, const char *error_msg, int error_code,
- int calling_back)
-{
- Telnet telnet = (Telnet) plug;
-
- /*
- * We don't implement independent EOF in each direction for Telnet
- * connections; as soon as we get word that the remote side has
- * sent us EOF, we wind up the whole connection.
- */
-
- if (telnet->s) {
- sk_close(telnet->s);
- telnet->s = NULL;
- notify_remote_exit(telnet->frontend);
- }
- if (error_msg) {
- logevent(telnet->frontend, error_msg);
- connection_fatal(telnet->frontend, "%s", error_msg);
- }
- /* Otherwise, the remote side closed the connection normally. */
- return 0;
-}
-
-static int telnet_receive(Plug plug, int urgent, char *data, int len)
-{
- Telnet telnet = (Telnet) plug;
- if (urgent)
- telnet->in_synch = TRUE;
- do_telnet_read(telnet, data, len);
- return 1;
-}
-
-static void telnet_sent(Plug plug, int bufsize)
-{
- Telnet telnet = (Telnet) plug;
- telnet->bufsize = bufsize;
-}
-
-/*
- * Called to set up the Telnet connection.
- *
- * Returns an error message, or NULL on success.
- *
- * Also places the canonical host name into `realhost'. It must be
- * freed by the caller.
- */
-static const char *telnet_init(void *frontend_handle, void **backend_handle,
- Conf *conf, 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;
- const char *err;
- Telnet telnet;
- char *loghost;
- int addressfamily;
-
- telnet = snew(struct telnet_tag);
- telnet->fn = &fn_table;
- telnet->conf = conf_copy(conf);
- telnet->s = NULL;
- telnet->echoing = TRUE;
- telnet->editing = TRUE;
- telnet->activated = FALSE;
- telnet->sb_buf = NULL;
- telnet->sb_size = 0;
- telnet->frontend = frontend_handle;
- telnet->term_width = conf_get_int(telnet->conf, CONF_width);
- telnet->term_height = conf_get_int(telnet->conf, CONF_height);
- telnet->state = TOP_LEVEL;
- telnet->ldisc = NULL;
- telnet->pinger = NULL;
- *backend_handle = telnet;
-
- /*
- * Try to find host.
- */
- {
- char *buf;
- addressfamily = conf_get_int(telnet->conf, CONF_addressfamily);
- buf = dupprintf("Looking up host \"%s\"%s", host,
- (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
- (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
- "")));
- logevent(telnet->frontend, buf);
- sfree(buf);
- }
- addr = name_lookup(host, port, realhost, telnet->conf, addressfamily);
- if ((err = sk_addr_error(addr)) != NULL) {
- sk_addr_free(addr);
- return err;
- }
-
- if (port < 0)
- port = 23; /* default telnet port */
-
- /*
- * Open socket.
- */
- telnet->s = new_connection(addr, *realhost, port, 0, 1,
- nodelay, keepalive, (Plug) telnet, telnet->conf);
- if ((err = sk_socket_error(telnet->s)) != NULL)
- return err;
-
- telnet->pinger = pinger_new(telnet->conf, &telnet_backend, telnet);
-
- /*
- * Initialise option states.
- */
- if (conf_get_int(telnet->conf, CONF_passive_telnet)) {
- const struct Opt *const *o;
-
- for (o = opts; *o; o++)
- telnet->opt_states[(*o)->index] = INACTIVE;
- } else {
- const struct Opt *const *o;
-
- for (o = opts; *o; o++) {
- telnet->opt_states[(*o)->index] = (*o)->initial_state;
- if (telnet->opt_states[(*o)->index] == REQUESTED)
- send_opt(telnet, (*o)->send, (*o)->option);
- }
- telnet->activated = TRUE;
- }
-
- /*
- * Set up SYNCH state.
- */
- telnet->in_synch = FALSE;
-
- /*
- * We can send special commands from the start.
- */
- update_specials_menu(telnet->frontend);
-
- /*
- * loghost overrides realhost, if specified.
- */
- loghost = conf_get_str(telnet->conf, CONF_loghost);
- if (*loghost) {
- char *colon;
-
- sfree(*realhost);
- *realhost = dupstr(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);
- conf_free(telnet->conf);
- 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, Conf *conf)
-{
- Telnet telnet = (Telnet) handle;
- pinger_reconfig(telnet->pinger, telnet->conf, conf);
- conf_free(telnet->conf);
- telnet->conf = conf_copy(conf);
-}
-
-/*
- * Called to send data down the Telnet connection.
- */
-static int telnet_send(void *handle, char *buf, int len)
-{
- Telnet telnet = (Telnet) handle;
- unsigned char *p, *end;
- static const unsigned char iac[2] = { IAC, IAC };
- static const unsigned char cr[2] = { CR, NUL };
-#if 0
- static const unsigned char nl[2] = { CR, LF };
-#endif
-
- if (telnet->s == NULL)
- return 0;
-
- p = (unsigned char *)buf;
- end = (unsigned char *)(buf + len);
- while (p < end) {
- unsigned char *q = p;
-
- while (p < end && iswritable(*p))
- p++;
- telnet->bufsize = sk_write(telnet->s, (char *)q, p - q);
-
- while (p < end && !iswritable(*p)) {
- telnet->bufsize =
- sk_write(telnet->s, (char *)(*p == IAC ? iac : cr), 2);
- p++;
- }
- }
-
- return telnet->bufsize;
-}
-
-/*
- * Called to query the current socket sendability status.
- */
-static int telnet_sendbuffer(void *handle)
-{
- Telnet telnet = (Telnet) handle;
- return telnet->bufsize;
-}
-
-/*
- * Called to set the size of the window from Telnet's POV.
- */
-static void telnet_size(void *handle, int width, int height)
-{
- Telnet telnet = (Telnet) handle;
- unsigned char b[24];
- int n;
- char *logbuf;
-
- telnet->term_width = width;
- telnet->term_height = height;
-
- if (telnet->s == NULL || telnet->opt_states[o_naws.index] != ACTIVE)
- return;
- n = 0;
- b[n++] = IAC;
- b[n++] = SB;
- b[n++] = TELOPT_NAWS;
- b[n++] = telnet->term_width >> 8;
- if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
- b[n++] = telnet->term_width & 0xFF;
- if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
- b[n++] = telnet->term_height >> 8;
- if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
- b[n++] = telnet->term_height & 0xFF;
- if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
- b[n++] = IAC;
- b[n++] = SE;
- telnet->bufsize = sk_write(telnet->s, (char *)b, n);
- logbuf = dupprintf("client:\tSB NAWS %d,%d",
- telnet->term_width, telnet->term_height);
- logevent(telnet->frontend, logbuf);
- sfree(logbuf);
-}
-
-/*
- * Send Telnet special codes.
- */
-static void telnet_special(void *handle, Telnet_Special code)
-{
- Telnet telnet = (Telnet) handle;
- unsigned char b[2];
-
- if (telnet->s == NULL)
- return;
-
- b[0] = IAC;
- switch (code) {
- case TS_AYT:
- b[1] = AYT;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_BRK:
- b[1] = BREAK;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_EC:
- b[1] = EC;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_EL:
- b[1] = EL;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_GA:
- b[1] = GA;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_NOP:
- b[1] = NOP;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_ABORT:
- b[1] = ABORT;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_AO:
- b[1] = AO;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_IP:
- b[1] = IP;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_SUSP:
- b[1] = SUSP;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_EOR:
- b[1] = EOR;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_EOF:
- b[1] = xEOF;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
- break;
- case TS_EOL:
- /* 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", 1);
- else
- telnet->bufsize = sk_write(telnet->s, "\r\n", 2);
- break;
- case TS_SYNCH:
- b[1] = DM;
- telnet->bufsize = sk_write(telnet->s, (char *)b, 1);
- telnet->bufsize = sk_write_oob(telnet->s, (char *)(b + 1), 1);
- break;
- case TS_RECHO:
- if (telnet->opt_states[o_echo.index] == INACTIVE ||
- telnet->opt_states[o_echo.index] == REALLY_INACTIVE) {
- telnet->opt_states[o_echo.index] = REQUESTED;
- send_opt(telnet, o_echo.send, o_echo.option);
- }
- break;
- case TS_LECHO:
- if (telnet->opt_states[o_echo.index] == ACTIVE) {
- telnet->opt_states[o_echo.index] = REQUESTED;
- send_opt(telnet, o_echo.nsend, o_echo.option);
- }
- break;
- case TS_PING:
- if (telnet->opt_states[o_they_sga.index] == ACTIVE) {
- b[1] = NOP;
- 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 int telnet_connected(void *handle)
-{
- Telnet telnet = (Telnet) handle;
- return telnet->s != NULL;
-}
-
-static int telnet_sendok(void *handle)
-{
- /* Telnet telnet = (Telnet) handle; */
- return 1;
-}
-
-static void telnet_unthrottle(void *handle, int backlog)
-{
- Telnet telnet = (Telnet) handle;
- sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
-}
-
-static int telnet_ldisc(void *handle, int option)
-{
- Telnet telnet = (Telnet) handle;
- if (option == LD_ECHO)
- return telnet->echoing;
- if (option == LD_EDIT)
- return telnet->editing;
- return FALSE;
-}
-
-static void telnet_provide_ldisc(void *handle, void *ldisc)
-{
- Telnet telnet = (Telnet) handle;
- telnet->ldisc = ldisc;
-}
-
-static void telnet_provide_logctx(void *handle, void *logctx)
-{
- /* This is a stub. */
-}
-
-static int telnet_exitcode(void *handle)
-{
- 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_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
-};
+/*
+ * Telnet backend.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+
+#include "putty.h"
+
+#ifndef FALSE
+#define FALSE 0
+#endif
+#ifndef TRUE
+#define TRUE 1
+#endif
+
+#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 GA 249 /* you may reverse the line */
+#define EL 248 /* erase the current line */
+#define EC 247 /* erase the current character */
+#define AYT 246 /* are you there */
+#define AO 245 /* abort output--but let prog finish */
+#define IP 244 /* interrupt process--permanently */
+#define BREAK 243 /* break */
+#define DM 242 /* data mark--for connect. cleaning */
+#define NOP 241 /* nop */
+#define EOR 239 /* end of record (transparent mode) */
+#define ABORT 238 /* Abort process */
+#define SUSP 237 /* Suspend process */
+#define xEOF 236 /* End of file: EOF is already used... */
+
+#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 */
+#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */
+#define BSD_VAR 1
+#define BSD_VALUE 0
+#define RFC_VAR 0
+#define RFC_VALUE 1
+
+#define CR 13
+#define LF 10
+#define NUL 0
+
+#define iswritable(x) \
+ ( (x) != IAC && \
+ (telnet->opt_states[o_we_bin.index] == ACTIVE || (x) != CR))
+
+static char *telopt(int opt)
+{
+#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);
+
+struct Opt {
+ int send; /* what we initially send */
+ int nsend; /* -ve send if requested to stop it */
+ int ack, nak; /* +ve and -ve acknowledgements */
+ int option; /* the option code */
+ int index; /* index into telnet->opt_states[] */
+ enum {
+ REQUESTED, ACTIVE, INACTIVE, REALLY_INACTIVE
+ } initial_state;
+};
+
+enum {
+ OPTINDEX_NAWS,
+ OPTINDEX_TSPEED,
+ OPTINDEX_TTYPE,
+ OPTINDEX_OENV,
+ OPTINDEX_NENV,
+ OPTINDEX_ECHO,
+ OPTINDEX_WE_SGA,
+ OPTINDEX_THEY_SGA,
+ OPTINDEX_WE_BIN,
+ OPTINDEX_THEY_BIN,
+ NUM_OPTS
+};
+
+static const struct Opt o_naws =
+ { WILL, WONT, DO, DONT, TELOPT_NAWS, OPTINDEX_NAWS, REQUESTED };
+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_echo =
+ { DO, DONT, WILL, WONT, TELOPT_ECHO, OPTINDEX_ECHO, REQUESTED };
+static const struct Opt o_we_sga =
+ { WILL, WONT, DO, DONT, TELOPT_SGA, OPTINDEX_WE_SGA, REQUESTED };
+static const struct Opt o_they_sga =
+ { DO, DONT, WILL, WONT, TELOPT_SGA, OPTINDEX_THEY_SGA, REQUESTED };
+static const struct Opt o_we_bin =
+ { WILL, WONT, DO, DONT, TELOPT_BINARY, OPTINDEX_WE_BIN, INACTIVE };
+static const struct Opt o_they_bin =
+ { DO, DONT, WILL, WONT, TELOPT_BINARY, OPTINDEX_THEY_BIN, INACTIVE };
+
+static const struct Opt *const opts[] = {
+ &o_naws, &o_tspeed, &o_ttype, &o_oenv, &o_nenv, &o_echo,
+ &o_we_sga, &o_they_sga, &o_we_bin, &o_they_bin, NULL
+};
+
+typedef struct telnet_tag {
+ const struct plug_function_table *fn;
+ /* the above field _must_ be first in the structure */
+
+ Socket s;
+ int closed_on_socket_error;
+
+ void *frontend;
+ void *ldisc;
+ int term_width, term_height;
+
+ int opt_states[NUM_OPTS];
+
+ int echoing, editing;
+ int activated;
+ int bufsize;
+ int in_synch;
+ int sb_opt, sb_len;
+ unsigned char *sb_buf;
+ int sb_size;
+
+ enum {
+ TOP_LEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT,
+ SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR
+ } state;
+
+ Conf *conf;
+
+ Pinger pinger;
+} *Telnet;
+
+#define TELNET_MAX_BACKLOG 4096
+
+#define SB_DELTA 1024
+
+static void c_write(Telnet telnet, char *buf, int len)
+{
+ int backlog;
+ backlog = from_backend(telnet->frontend, 0, buf, len);
+ sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
+}
+
+static void log_option(Telnet telnet, char *sender, int cmd, int option)
+{
+ char *buf;
+ /*
+ * The strange-looking "<?""?>" below is there to avoid a
+ * trigraph - a double question mark followed by > maps to a
+ * closing brace character!
+ */
+ buf = dupprintf("%s:\t%s %s", sender,
+ (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" :
+ cmd == DO ? "DO" : cmd == DONT ? "DONT" : "<?""?>"),
+ telopt(option));
+ logevent(telnet->frontend, buf);
+ sfree(buf);
+}
+
+static void send_opt(Telnet telnet, int cmd, int option)
+{
+ unsigned char b[3];
+
+ b[0] = IAC;
+ b[1] = cmd;
+ b[2] = option;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 3);
+ log_option(telnet, "client", cmd, option);
+}
+
+static void deactivate_option(Telnet telnet, const struct Opt *o)
+{
+ if (telnet->opt_states[o->index] == REQUESTED ||
+ telnet->opt_states[o->index] == ACTIVE)
+ send_opt(telnet, o->nsend, o->option);
+ telnet->opt_states[o->index] = REALLY_INACTIVE;
+}
+
+/*
+ * Generate side effects of enabling or disabling an option.
+ */
+static void option_side_effects(Telnet telnet, const struct Opt *o, int enabled)
+{
+ if (o->option == TELOPT_ECHO && o->send == DO)
+ telnet->echoing = !enabled;
+ else if (o->option == TELOPT_SGA && o->send == DO)
+ telnet->editing = !enabled;
+ if (telnet->ldisc) /* cause ldisc to notice the change */
+ ldisc_send(telnet->ldisc, NULL, 0, 0);
+
+ /* Ensure we get the minimum options */
+ if (!telnet->activated) {
+ if (telnet->opt_states[o_echo.index] == INACTIVE) {
+ telnet->opt_states[o_echo.index] = REQUESTED;
+ send_opt(telnet, o_echo.send, o_echo.option);
+ }
+ if (telnet->opt_states[o_we_sga.index] == INACTIVE) {
+ telnet->opt_states[o_we_sga.index] = REQUESTED;
+ send_opt(telnet, o_we_sga.send, o_we_sga.option);
+ }
+ if (telnet->opt_states[o_they_sga.index] == INACTIVE) {
+ telnet->opt_states[o_they_sga.index] = REQUESTED;
+ send_opt(telnet, o_they_sga.send, o_they_sga.option);
+ }
+ telnet->activated = TRUE;
+ }
+}
+
+static void activate_option(Telnet telnet, const struct Opt *o)
+{
+ if (o->send == WILL && o->option == TELOPT_NAWS)
+ telnet_size(telnet, telnet->term_width, telnet->term_height);
+ if (o->send == WILL &&
+ (o->option == TELOPT_NEW_ENVIRON ||
+ o->option == TELOPT_OLD_ENVIRON)) {
+ /*
+ * We may only have one kind of ENVIRON going at a time.
+ * This is a hack, but who cares.
+ */
+ deactivate_option(telnet, o->option ==
+ TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv);
+ }
+ option_side_effects(telnet, o, 1);
+}
+
+static void refused_option(Telnet telnet, const struct Opt *o)
+{
+ if (o->send == WILL && o->option == TELOPT_NEW_ENVIRON &&
+ telnet->opt_states[o_oenv.index] == INACTIVE) {
+ send_opt(telnet, WILL, TELOPT_OLD_ENVIRON);
+ telnet->opt_states[o_oenv.index] = REQUESTED;
+ }
+ option_side_effects(telnet, o, 0);
+}
+
+static void proc_rec_opt(Telnet telnet, int cmd, int option)
+{
+ const struct Opt *const *o;
+
+ log_option(telnet, "server", cmd, option);
+ for (o = opts; *o; o++) {
+ if ((*o)->option == option && (*o)->ack == cmd) {
+ switch (telnet->opt_states[(*o)->index]) {
+ case REQUESTED:
+ telnet->opt_states[(*o)->index] = ACTIVE;
+ activate_option(telnet, *o);
+ break;
+ case ACTIVE:
+ break;
+ case INACTIVE:
+ telnet->opt_states[(*o)->index] = ACTIVE;
+ send_opt(telnet, (*o)->send, option);
+ activate_option(telnet, *o);
+ break;
+ case REALLY_INACTIVE:
+ send_opt(telnet, (*o)->nsend, option);
+ break;
+ }
+ return;
+ } else if ((*o)->option == option && (*o)->nak == cmd) {
+ switch (telnet->opt_states[(*o)->index]) {
+ case REQUESTED:
+ telnet->opt_states[(*o)->index] = INACTIVE;
+ refused_option(telnet, *o);
+ break;
+ case ACTIVE:
+ telnet->opt_states[(*o)->index] = INACTIVE;
+ send_opt(telnet, (*o)->nsend, option);
+ option_side_effects(telnet, *o, 0);
+ break;
+ case INACTIVE:
+ case REALLY_INACTIVE:
+ break;
+ }
+ return;
+ }
+ }
+ /*
+ * If we reach here, the option was one we weren't prepared to
+ * 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.
+ */
+ if (cmd == WILL || cmd == DO)
+ send_opt(telnet, (cmd == WILL ? DONT : WONT), option);
+}
+
+static void process_subneg(Telnet telnet)
+{
+ unsigned char *b, *p, *q;
+ int var, value, n, bsize;
+ char *e, *eval, *ekey, *user;
+
+ switch (telnet->sb_opt) {
+ case TELOPT_TSPEED:
+ if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
+ char *logbuf;
+ char *termspeed = conf_get_str(telnet->conf, CONF_termspeed);
+ b = snewn(20 + strlen(termspeed), unsigned char);
+ b[0] = IAC;
+ b[1] = SB;
+ b[2] = TELOPT_TSPEED;
+ b[3] = TELQUAL_IS;
+ strcpy((char *)(b + 4), termspeed);
+ n = 4 + strlen(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", termspeed);
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ sfree(b);
+ } else
+ logevent(telnet->frontend, "server:\tSB TSPEED <something weird>");
+ break;
+ case TELOPT_TTYPE:
+ if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) {
+ char *logbuf;
+ char *termtype = conf_get_str(telnet->conf, CONF_termtype);
+ b = snewn(20 + strlen(termtype), unsigned char);
+ b[0] = IAC;
+ b[1] = SB;
+ b[2] = TELOPT_TTYPE;
+ b[3] = TELQUAL_IS;
+ for (n = 0; termtype[n]; n++)
+ b[n + 4] = (termtype[n] >= 'a' && termtype[n] <= 'z' ?
+ termtype[n] + 'A' - 'a' :
+ termtype[n]);
+ b[n + 4] = IAC;
+ b[n + 5] = SE;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, n + 6);
+ b[n + 4] = 0;
+ logevent(telnet->frontend, "server:\tSB TTYPE SEND");
+ logbuf = dupprintf("client:\tSB TTYPE IS %s", b + 4);
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ sfree(b);
+ } else
+ logevent(telnet->frontend, "server:\tSB TTYPE <something weird>\r\n");
+ break;
+ case TELOPT_OLD_ENVIRON:
+ case TELOPT_NEW_ENVIRON:
+ p = telnet->sb_buf;
+ q = p + telnet->sb_len;
+ if (p < q && *p == TELQUAL_SEND) {
+ char *logbuf;
+ p++;
+ logbuf = dupprintf("server:\tSB %s SEND", telopt(telnet->sb_opt));
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ if (telnet->sb_opt == TELOPT_OLD_ENVIRON) {
+ if (conf_get_int(telnet->conf, CONF_rfc_environ)) {
+ value = RFC_VALUE;
+ var = RFC_VAR;
+ } else {
+ value = BSD_VALUE;
+ var = BSD_VAR;
+ }
+ /*
+ * Try to guess the sense of VAR and VALUE.
+ */
+ while (p < q) {
+ if (*p == RFC_VAR) {
+ value = RFC_VALUE;
+ var = RFC_VAR;
+ } else if (*p == BSD_VAR) {
+ value = BSD_VALUE;
+ var = BSD_VAR;
+ }
+ p++;
+ }
+ } else {
+ /*
+ * With NEW_ENVIRON, the sense of VAR and VALUE
+ * isn't in doubt.
+ */
+ value = RFC_VALUE;
+ var = RFC_VAR;
+ }
+ bsize = 20;
+ for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ NULL, &ekey);
+ eval != NULL;
+ eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ ekey, &ekey))
+ bsize += strlen(ekey) + strlen(eval) + 2;
+ user = get_remote_username(telnet->conf);
+ if (user)
+ bsize += 6 + strlen(user);
+
+ b = snewn(bsize, unsigned char);
+ b[0] = IAC;
+ b[1] = SB;
+ b[2] = telnet->sb_opt;
+ b[3] = TELQUAL_IS;
+ n = 4;
+ for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ NULL, &ekey);
+ eval != NULL;
+ eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ ekey, &ekey)) {
+ b[n++] = var;
+ for (e = ekey; *e; e++)
+ b[n++] = *e;
+ b[n++] = value;
+ for (e = eval; *e; e++)
+ b[n++] = *e;
+ }
+ if (user) {
+ b[n++] = var;
+ b[n++] = 'U';
+ b[n++] = 'S';
+ b[n++] = 'E';
+ b[n++] = 'R';
+ b[n++] = value;
+ for (e = user; *e; e++)
+ b[n++] = *e;
+ }
+ b[n++] = IAC;
+ b[n++] = SE;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, n);
+ if (n == 6) {
+ logbuf = dupprintf("client:\tSB %s IS <nothing>",
+ telopt(telnet->sb_opt));
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ } else {
+ logbuf = dupprintf("client:\tSB %s IS:",
+ telopt(telnet->sb_opt));
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ for (eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ NULL, &ekey);
+ eval != NULL;
+ eval = conf_get_str_strs(telnet->conf, CONF_environmt,
+ ekey, &ekey)) {
+ logbuf = dupprintf("\t%s=%s", ekey, eval);
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ }
+ if (user) {
+ logbuf = dupprintf("\tUSER=%s", user);
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+ }
+ }
+ sfree(b);
+ sfree(user);
+ }
+ 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++;
+
+ switch (telnet->state) {
+ case TOP_LEVEL:
+ case SEENCR:
+ if (c == NUL && telnet->state == SEENCR)
+ telnet->state = TOP_LEVEL;
+ else if (c == IAC)
+ telnet->state = SEENIAC;
+ else {
+ if (!telnet->in_synch)
+ ADDTOBUF(c);
+
+#if 1
+ /* I can't get the F***ing winsock to insert the urgent IAC
+ * into the right position! Even with SO_OOBINLINE it gives
+ * it to recv too soon. And of course the DM byte (that
+ * arrives in the same packet!) appears several K later!!
+ *
+ * Oh well, we do get the DM in the right place so I'll
+ * just stop hiding on the next 0xf2 and hope for the best.
+ */
+ else if (c == DM)
+ telnet->in_synch = 0;
+#endif
+ if (c == CR && telnet->opt_states[o_they_bin.index] != ACTIVE)
+ telnet->state = SEENCR;
+ else
+ telnet->state = TOP_LEVEL;
+ }
+ break;
+ case SEENIAC:
+ if (c == DO)
+ telnet->state = SEENDO;
+ else if (c == DONT)
+ telnet->state = SEENDONT;
+ else if (c == WILL)
+ telnet->state = SEENWILL;
+ else if (c == WONT)
+ telnet->state = SEENWONT;
+ else if (c == SB)
+ telnet->state = SEENSB;
+ else if (c == DM) {
+ telnet->in_synch = 0;
+ telnet->state = TOP_LEVEL;
+ } else {
+ /* ignore everything else; print it if it's IAC */
+ if (c == IAC) {
+ ADDTOBUF(c);
+ }
+ telnet->state = TOP_LEVEL;
+ }
+ break;
+ case SEENWILL:
+ proc_rec_opt(telnet, WILL, c);
+ telnet->state = TOP_LEVEL;
+ break;
+ case SEENWONT:
+ proc_rec_opt(telnet, WONT, c);
+ telnet->state = TOP_LEVEL;
+ break;
+ case SEENDO:
+ proc_rec_opt(telnet, DO, c);
+ telnet->state = TOP_LEVEL;
+ break;
+ case SEENDONT:
+ proc_rec_opt(telnet, DONT, c);
+ telnet->state = TOP_LEVEL;
+ break;
+ case SEENSB:
+ telnet->sb_opt = c;
+ telnet->sb_len = 0;
+ telnet->state = SUBNEGOT;
+ break;
+ case SUBNEGOT:
+ if (c == IAC)
+ telnet->state = SUBNEG_IAC;
+ else {
+ subneg_addchar:
+ if (telnet->sb_len >= telnet->sb_size) {
+ telnet->sb_size += SB_DELTA;
+ telnet->sb_buf = sresize(telnet->sb_buf, telnet->sb_size,
+ unsigned char);
+ }
+ telnet->sb_buf[telnet->sb_len++] = c;
+ telnet->state = SUBNEGOT; /* in case we came here by goto */
+ }
+ break;
+ case SUBNEG_IAC:
+ if (c != SE)
+ goto subneg_addchar; /* yes, it's a hack, I know, but... */
+ else {
+ process_subneg(telnet);
+ telnet->state = TOP_LEVEL;
+ }
+ 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);
+ sfree(msg);
+}
+
+static int telnet_closing(Plug plug, const char *error_msg, int error_code,
+ int calling_back)
+{
+ Telnet telnet = (Telnet) plug;
+
+ /*
+ * We don't implement independent EOF in each direction for Telnet
+ * connections; as soon as we get word that the remote side has
+ * sent us EOF, we wind up the whole connection.
+ */
+
+ if (telnet->s) {
+ sk_close(telnet->s);
+ telnet->s = NULL;
+ if (error_msg)
+ telnet->closed_on_socket_error = TRUE;
+ notify_remote_exit(telnet->frontend);
+ }
+ if (error_msg) {
+ logevent(telnet->frontend, error_msg);
+ connection_fatal(telnet->frontend, "%s", error_msg);
+ }
+ /* Otherwise, the remote side closed the connection normally. */
+ return 0;
+}
+
+static int telnet_receive(Plug plug, int urgent, char *data, int len)
+{
+ Telnet telnet = (Telnet) plug;
+ if (urgent)
+ telnet->in_synch = TRUE;
+ do_telnet_read(telnet, data, len);
+ return 1;
+}
+
+static void telnet_sent(Plug plug, int bufsize)
+{
+ Telnet telnet = (Telnet) plug;
+ telnet->bufsize = bufsize;
+}
+
+/*
+ * Called to set up the Telnet connection.
+ *
+ * Returns an error message, or NULL on success.
+ *
+ * Also places the canonical host name into `realhost'. It must be
+ * freed by the caller.
+ */
+static const char *telnet_init(void *frontend_handle, void **backend_handle,
+ Conf *conf, 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;
+ const char *err;
+ Telnet telnet;
+ char *loghost;
+ int addressfamily;
+
+ telnet = snew(struct telnet_tag);
+ telnet->fn = &fn_table;
+ telnet->conf = conf_copy(conf);
+ telnet->s = NULL;
+ telnet->closed_on_socket_error = FALSE;
+ telnet->echoing = TRUE;
+ telnet->editing = TRUE;
+ telnet->activated = FALSE;
+ telnet->sb_buf = NULL;
+ telnet->sb_size = 0;
+ telnet->frontend = frontend_handle;
+ telnet->term_width = conf_get_int(telnet->conf, CONF_width);
+ telnet->term_height = conf_get_int(telnet->conf, CONF_height);
+ telnet->state = TOP_LEVEL;
+ telnet->ldisc = NULL;
+ telnet->pinger = NULL;
+ *backend_handle = telnet;
+
+ /*
+ * Try to find host.
+ */
+ {
+ char *buf;
+ addressfamily = conf_get_int(telnet->conf, CONF_addressfamily);
+ buf = dupprintf("Looking up host \"%s\"%s", host,
+ (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
+ (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" :
+ "")));
+ logevent(telnet->frontend, buf);
+ sfree(buf);
+ }
+ addr = name_lookup(host, port, realhost, telnet->conf, addressfamily);
+ if ((err = sk_addr_error(addr)) != NULL) {
+ sk_addr_free(addr);
+ return err;
+ }
+
+ if (port < 0)
+ port = 23; /* default telnet port */
+
+ /*
+ * Open socket.
+ */
+ telnet->s = new_connection(addr, *realhost, port, 0, 1,
+ nodelay, keepalive, (Plug) telnet, telnet->conf);
+ if ((err = sk_socket_error(telnet->s)) != NULL)
+ return err;
+
+ telnet->pinger = pinger_new(telnet->conf, &telnet_backend, telnet);
+
+ /*
+ * Initialise option states.
+ */
+ if (conf_get_int(telnet->conf, CONF_passive_telnet)) {
+ const struct Opt *const *o;
+
+ for (o = opts; *o; o++)
+ telnet->opt_states[(*o)->index] = INACTIVE;
+ } else {
+ const struct Opt *const *o;
+
+ for (o = opts; *o; o++) {
+ telnet->opt_states[(*o)->index] = (*o)->initial_state;
+ if (telnet->opt_states[(*o)->index] == REQUESTED)
+ send_opt(telnet, (*o)->send, (*o)->option);
+ }
+ telnet->activated = TRUE;
+ }
+
+ /*
+ * Set up SYNCH state.
+ */
+ telnet->in_synch = FALSE;
+
+ /*
+ * We can send special commands from the start.
+ */
+ update_specials_menu(telnet->frontend);
+
+ /*
+ * loghost overrides realhost, if specified.
+ */
+ loghost = conf_get_str(telnet->conf, CONF_loghost);
+ if (*loghost) {
+ char *colon;
+
+ sfree(*realhost);
+ *realhost = dupstr(loghost);
+
+ colon = host_strrchr(*realhost, ':');
+ if (colon)
+ *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);
+ conf_free(telnet->conf);
+ 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, Conf *conf)
+{
+ Telnet telnet = (Telnet) handle;
+ pinger_reconfig(telnet->pinger, telnet->conf, conf);
+ conf_free(telnet->conf);
+ telnet->conf = conf_copy(conf);
+}
+
+/*
+ * Called to send data down the Telnet connection.
+ */
+static int telnet_send(void *handle, char *buf, int len)
+{
+ Telnet telnet = (Telnet) handle;
+ unsigned char *p, *end;
+ static const unsigned char iac[2] = { IAC, IAC };
+ static const unsigned char cr[2] = { CR, NUL };
+#if 0
+ static const unsigned char nl[2] = { CR, LF };
+#endif
+
+ if (telnet->s == NULL)
+ return 0;
+
+ p = (unsigned char *)buf;
+ end = (unsigned char *)(buf + len);
+ while (p < end) {
+ unsigned char *q = p;
+
+ while (p < end && iswritable(*p))
+ p++;
+ telnet->bufsize = sk_write(telnet->s, (char *)q, p - q);
+
+ while (p < end && !iswritable(*p)) {
+ telnet->bufsize =
+ sk_write(telnet->s, (char *)(*p == IAC ? iac : cr), 2);
+ p++;
+ }
+ }
+
+ return telnet->bufsize;
+}
+
+/*
+ * Called to query the current socket sendability status.
+ */
+static int telnet_sendbuffer(void *handle)
+{
+ Telnet telnet = (Telnet) handle;
+ return telnet->bufsize;
+}
+
+/*
+ * Called to set the size of the window from Telnet's POV.
+ */
+static void telnet_size(void *handle, int width, int height)
+{
+ Telnet telnet = (Telnet) handle;
+ unsigned char b[24];
+ int n;
+ char *logbuf;
+
+ telnet->term_width = width;
+ telnet->term_height = height;
+
+ if (telnet->s == NULL || telnet->opt_states[o_naws.index] != ACTIVE)
+ return;
+ n = 0;
+ b[n++] = IAC;
+ b[n++] = SB;
+ b[n++] = TELOPT_NAWS;
+ b[n++] = telnet->term_width >> 8;
+ if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
+ b[n++] = telnet->term_width & 0xFF;
+ if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
+ b[n++] = telnet->term_height >> 8;
+ if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
+ b[n++] = telnet->term_height & 0xFF;
+ if (b[n-1] == IAC) b[n++] = IAC; /* duplicate any IAC byte occurs */
+ b[n++] = IAC;
+ b[n++] = SE;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, n);
+ logbuf = dupprintf("client:\tSB NAWS %d,%d",
+ telnet->term_width, telnet->term_height);
+ logevent(telnet->frontend, logbuf);
+ sfree(logbuf);
+}
+
+/*
+ * Send Telnet special codes.
+ */
+static void telnet_special(void *handle, Telnet_Special code)
+{
+ Telnet telnet = (Telnet) handle;
+ unsigned char b[2];
+
+ if (telnet->s == NULL)
+ return;
+
+ b[0] = IAC;
+ switch (code) {
+ case TS_AYT:
+ b[1] = AYT;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_BRK:
+ b[1] = BREAK;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_EC:
+ b[1] = EC;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_EL:
+ b[1] = EL;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_GA:
+ b[1] = GA;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_NOP:
+ b[1] = NOP;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_ABORT:
+ b[1] = ABORT;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_AO:
+ b[1] = AO;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_IP:
+ b[1] = IP;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_SUSP:
+ b[1] = SUSP;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_EOR:
+ b[1] = EOR;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_EOF:
+ b[1] = xEOF;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 2);
+ break;
+ case TS_EOL:
+ /* 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", 1);
+ else
+ telnet->bufsize = sk_write(telnet->s, "\r\n", 2);
+ break;
+ case TS_SYNCH:
+ b[1] = DM;
+ telnet->bufsize = sk_write(telnet->s, (char *)b, 1);
+ telnet->bufsize = sk_write_oob(telnet->s, (char *)(b + 1), 1);
+ break;
+ case TS_RECHO:
+ if (telnet->opt_states[o_echo.index] == INACTIVE ||
+ telnet->opt_states[o_echo.index] == REALLY_INACTIVE) {
+ telnet->opt_states[o_echo.index] = REQUESTED;
+ send_opt(telnet, o_echo.send, o_echo.option);
+ }
+ break;
+ case TS_LECHO:
+ if (telnet->opt_states[o_echo.index] == ACTIVE) {
+ telnet->opt_states[o_echo.index] = REQUESTED;
+ send_opt(telnet, o_echo.nsend, o_echo.option);
+ }
+ break;
+ case TS_PING:
+ if (telnet->opt_states[o_they_sga.index] == ACTIVE) {
+ b[1] = NOP;
+ 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 int telnet_connected(void *handle)
+{
+ Telnet telnet = (Telnet) handle;
+ return telnet->s != NULL;
+}
+
+static int telnet_sendok(void *handle)
+{
+ /* Telnet telnet = (Telnet) handle; */
+ return 1;
+}
+
+static void telnet_unthrottle(void *handle, int backlog)
+{
+ Telnet telnet = (Telnet) handle;
+ sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG);
+}
+
+static int telnet_ldisc(void *handle, int option)
+{
+ Telnet telnet = (Telnet) handle;
+ if (option == LD_ECHO)
+ return telnet->echoing;
+ if (option == LD_EDIT)
+ return telnet->editing;
+ return FALSE;
+}
+
+static void telnet_provide_ldisc(void *handle, void *ldisc)
+{
+ Telnet telnet = (Telnet) handle;
+ telnet->ldisc = ldisc;
+}
+
+static void telnet_provide_logctx(void *handle, void *logctx)
+{
+ /* This is a stub. */
+}
+
+static int telnet_exitcode(void *handle)
+{
+ Telnet telnet = (Telnet) handle;
+ if (telnet->s != NULL)
+ return -1; /* still connected */
+ else if (telnet->closed_on_socket_error)
+ return INT_MAX; /* a socket error counts as an unclean exit */
+ 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_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
+};
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-09 15:14:28 +0000