X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/b47b21989c2dd9c7ce0e973b3730965f9d99b990..f89c329410c18fe1f09d843747fad77babb9f89c:/telnet.c diff --git a/telnet.c b/telnet.c index 8cb02a03..13c2d3c2 100644 --- a/telnet.c +++ b/telnet.c @@ -1,4 +1,3 @@ -#include #include #include @@ -11,75 +10,86 @@ #define TRUE 1 #endif -static Socket s = NULL; - -#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 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 TELQUAL_IS 0 /* option is... */ -#define TELQUAL_SEND 1 /* send option */ -#define TELQUAL_INFO 2 /* ENVIRON: informational version of IS */ +#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 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_TN3270E 40 /* TN3270 enhancements */ +#define TELOPT_XAUTH 41 +#define TELOPT_CHARSET 42 /* Character set */ +#define TELOPT_RSP 43 /* Remote serial port */ +#define TELOPT_COM_PORT_OPTION 44 /* Com port control */ +#define TELOPT_SLE 45 /* Suppress local echo */ +#define TELOPT_STARTTLS 46 /* Start TLS */ +#define TELOPT_KERMIT 47 /* Automatic Kermit file transfer */ +#define TELOPT_SEND_URL 48 +#define TELOPT_FORWARD_X 49 +#define TELOPT_PRAGMA_LOGON 138 +#define TELOPT_SSPI_LOGON 139 +#define TELOPT_PRAGMA_HEARTBEAT 140 +#define TELOPT_EXOPL 255 /* extended-options-list */ + +#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 @@ -89,99 +99,236 @@ static Socket s = NULL; #define LF 10 #define NUL 0 -#define iswritable(x) ( (x) != IAC && (x) != CR ) +#define iswritable(x) \ + ( (x) != IAC && \ + (telnet->opt_states[o_we_bin.index] == ACTIVE || (x) != CR)) -static char *telopt(int opt) { +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); + 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(TN3270E); + i(XAUTH); + i(CHARSET); + i(RSP); + i(COM_PORT_OPTION); + i(SLE); + i(STARTTLS); + i(KERMIT); + i(SEND_URL); + i(FORWARD_X); + i(PRAGMA_LOGON); + i(SSPI_LOGON); + i(PRAGMA_HEARTBEAT); + i(EXOPL); #undef i return ""; } -static void telnet_size(void); +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 - } state; + } initial_state; }; -static struct Opt o_naws = {WILL, WONT, DO, DONT, TELOPT_NAWS, REQUESTED}; -static struct Opt o_tspeed = {WILL, WONT, DO, DONT, TELOPT_TSPEED, REQUESTED}; -static struct Opt o_ttype = {WILL, WONT, DO, DONT, TELOPT_TTYPE, REQUESTED}; -static struct Opt o_oenv = {WILL, WONT, DO, DONT, TELOPT_OLD_ENVIRON, - INACTIVE}; -static struct Opt o_nenv = {WILL, WONT, DO, DONT, TELOPT_NEW_ENVIRON, - REQUESTED}; -static struct Opt o_echo = {DO, DONT, WILL, WONT, TELOPT_ECHO, REQUESTED}; -static struct Opt o_we_sga = {WILL, WONT, DO, DONT, TELOPT_SGA, REQUESTED}; -static struct Opt o_they_sga = {DO, DONT, WILL, WONT, TELOPT_SGA, REQUESTED}; - -static struct Opt *opts[] = { +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, NULL + &o_we_sga, &o_they_sga, &o_we_bin, &o_they_bin, NULL }; -static int echoing = TRUE, editing = TRUE; +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; + + Config cfg; + + Pinger pinger; +} *Telnet; + +#define TELNET_MAX_BACKLOG 4096 -static int in_synch; -static int sb_opt, sb_len; -static char *sb_buf = NULL; -static int sb_size = 0; #define SB_DELTA 1024 -static void c_write1(int c) { - char cc = (char)c; - from_backend(0, &cc, 1); +static void c_write1(Telnet telnet, int c) +{ + int backlog; + char cc = (char) c; + backlog = from_backend(telnet->frontend, 0, &cc, 1); + sk_set_frozen(telnet->s, backlog > TELNET_MAX_BACKLOG); } -static void log_option (char *sender, int cmd, int option) { - char buf[50]; - sprintf(buf, "%s:\t%s %s", sender, - (cmd == WILL ? "WILL" : cmd == WONT ? "WONT" : - cmd == DO ? "DO" : cmd == DONT ? "DONT" : ""), - telopt(option)); - logevent(buf); +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 (int cmd, int option) { +static void send_opt(Telnet telnet, int cmd, int option) +{ unsigned char b[3]; - b[0] = IAC; b[1] = cmd; b[2] = option; - sk_write(s, b, 3); - log_option("client", cmd, option); + 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 (struct Opt *o) { - if (o->state == REQUESTED || o->state == ACTIVE) - send_opt (o->nsend, o->option); - o->state = REALLY_INACTIVE; +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(struct Opt *o, int enabled) { +static void option_side_effects(Telnet telnet, const struct Opt *o, int enabled) +{ if (o->option == TELOPT_ECHO && o->send == DO) - echoing = !enabled; - else if (o->option = TELOPT_SGA && o->send == DO) - editing = !enabled; - ldisc_send(NULL, 0); /* cause ldisc to notice the change */ + 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 (struct Opt *o) { +static void activate_option(Telnet telnet, const struct Opt *o) +{ if (o->send == WILL && o->option == TELOPT_NAWS) - telnet_size(); + telnet_size(telnet, telnet->term_width, telnet->term_height); if (o->send == WILL && (o->option == TELOPT_NEW_ENVIRON || o->option == TELOPT_OLD_ENVIRON)) { @@ -189,53 +336,56 @@ static void activate_option (struct Opt *o) { * We may only have one kind of ENVIRON going at a time. * This is a hack, but who cares. */ - deactivate_option (o->option==TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv); + deactivate_option(telnet, o->option == + TELOPT_NEW_ENVIRON ? &o_oenv : &o_nenv); } - option_side_effects(o, 1); + option_side_effects(telnet, o, 1); } -static void refused_option (struct Opt *o) { +static void refused_option(Telnet telnet, const struct Opt *o) +{ if (o->send == WILL && o->option == TELOPT_NEW_ENVIRON && - o_oenv.state == INACTIVE) { - send_opt (WILL, TELOPT_OLD_ENVIRON); - o_oenv.state = REQUESTED; + telnet->opt_states[o_oenv.index] == INACTIVE) { + send_opt(telnet, WILL, TELOPT_OLD_ENVIRON); + telnet->opt_states[o_oenv.index] = REQUESTED; } - option_side_effects(o, 0); + option_side_effects(telnet, o, 0); } -static void proc_rec_opt (int cmd, int option) { - struct Opt **o; +static void proc_rec_opt(Telnet telnet, int cmd, int option) +{ + const struct Opt *const *o; - log_option ("server", cmd, option); + log_option(telnet, "server", cmd, option); for (o = opts; *o; o++) { if ((*o)->option == option && (*o)->ack == cmd) { - switch ((*o)->state) { + switch (telnet->opt_states[(*o)->index]) { case REQUESTED: - (*o)->state = ACTIVE; - activate_option (*o); + telnet->opt_states[(*o)->index] = ACTIVE; + activate_option(telnet, *o); break; case ACTIVE: break; case INACTIVE: - (*o)->state = ACTIVE; - send_opt ((*o)->send, option); - activate_option (*o); + telnet->opt_states[(*o)->index] = ACTIVE; + send_opt(telnet, (*o)->send, option); + activate_option(telnet, *o); break; case REALLY_INACTIVE: - send_opt ((*o)->nsend, option); + send_opt(telnet, (*o)->nsend, option); break; } return; } else if ((*o)->option == option && (*o)->nak == cmd) { - switch ((*o)->state) { + switch (telnet->opt_states[(*o)->index]) { case REQUESTED: - (*o)->state = INACTIVE; - refused_option (*o); + telnet->opt_states[(*o)->index] = INACTIVE; + refused_option(telnet, *o); break; case ACTIVE: - (*o)->state = INACTIVE; - send_opt ((*o)->nsend, option); - option_side_effects(*o, 0); + telnet->opt_states[(*o)->index] = INACTIVE; + send_opt(telnet, (*o)->nsend, option); + option_side_effects(telnet, *o, 0); break; case INACTIVE: case REALLY_INACTIVE: @@ -248,58 +398,70 @@ static void proc_rec_opt (int cmd, int option) { * If we reach here, the option was one we weren't prepared to * cope with. So send a negative ack. */ - send_opt ((cmd == WILL ? DONT : WONT), option); + send_opt(telnet, (cmd == WILL ? DONT : WONT), option); } -static void process_subneg (void) { +static void process_subneg(Telnet telnet) +{ unsigned char b[2048], *p, *q; int var, value, n; char *e; - switch (sb_opt) { + switch (telnet->sb_opt) { case TELOPT_TSPEED: - if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) { - char logbuf[sizeof(cfg.termspeed)+80]; - b[0] = IAC; b[1] = SB; b[2] = TELOPT_TSPEED; + if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) { + char *logbuf; + b[0] = IAC; + b[1] = SB; + b[2] = TELOPT_TSPEED; b[3] = TELQUAL_IS; - strcpy(b+4, cfg.termspeed); - n = 4 + strlen(cfg.termspeed); - b[n] = IAC; b[n+1] = SE; - sk_write(s, b, n+2); - logevent("server:\tSB TSPEED SEND"); - sprintf(logbuf, "client:\tSB TSPEED IS %s", cfg.termspeed); - logevent (logbuf); + 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", telnet->cfg.termspeed); + logevent(telnet->frontend, logbuf); + sfree(logbuf); } else - logevent ("server:\tSB TSPEED "); + logevent(telnet->frontend, "server:\tSB TSPEED "); break; case TELOPT_TTYPE: - if (sb_len == 1 && sb_buf[0] == TELQUAL_SEND) { - char logbuf[sizeof(cfg.termtype)+80]; - b[0] = IAC; b[1] = SB; b[2] = TELOPT_TTYPE; + if (telnet->sb_len == 1 && telnet->sb_buf[0] == TELQUAL_SEND) { + char *logbuf; + b[0] = IAC; + 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]); - b[n+4] = IAC; b[n+5] = SE; - sk_write(s, b, n+6); - b[n+4] = 0; - logevent("server:\tSB TTYPE SEND"); - sprintf(logbuf, "client:\tSB TTYPE IS %s", b+4); - logevent(logbuf); + 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); + 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); } else - logevent("server:\tSB TTYPE \r\n"); + logevent(telnet->frontend, "server:\tSB TTYPE \r\n"); break; case TELOPT_OLD_ENVIRON: - case TELOPT_NEW_ENVIRON: - p = sb_buf; - q = p + sb_len; + case TELOPT_NEW_ENVIRON: + p = telnet->sb_buf; + q = p + telnet->sb_len; if (p < q && *p == TELQUAL_SEND) { - char logbuf[50]; + char *logbuf; p++; - sprintf (logbuf, "server:\tSB %s SEND", telopt(sb_opt)); - logevent (logbuf); - if (sb_opt == TELOPT_OLD_ENVIRON) { - if (cfg.rfc_environ) { + logbuf = dupprintf("server:\tSB %s SEND", telopt(telnet->sb_opt)); + logevent(telnet->frontend, logbuf); + sfree(logbuf); + if (telnet->sb_opt == TELOPT_OLD_ENVIRON) { + if (telnet->cfg.rfc_environ) { value = RFC_VALUE; var = RFC_VAR; } else { @@ -327,54 +489,67 @@ static void process_subneg (void) { value = RFC_VALUE; var = RFC_VAR; } - b[0] = IAC; b[1] = SB; b[2] = sb_opt; + b[0] = IAC; + b[1] = SB; + 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++; - if (*e == '\t') e++; + while (*e && *e != '\t') + b[n++] = *e++; + if (*e == '\t') + e++; b[n++] = value; - while (*e) b[n++] = *e++; + while (*e) + 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++; + 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++; } - b[n++] = IAC; b[n++] = SE; - sk_write(s, b, n); - sprintf(logbuf, "client:\tSB %s IS %s", telopt(sb_opt), - n==6 ? "" : ""); - logevent (logbuf); + 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), + *telnet->cfg.username ? "USER=" : "", + telnet->cfg.username, + *telnet->cfg.username ? " " : "", + n == 6 ? "" : + (*telnet->cfg.environmt ? "" : "")); + logevent(telnet->frontend, logbuf); + sfree(logbuf); } break; } } -static enum { - TOPLEVEL, SEENIAC, SEENWILL, SEENWONT, SEENDO, SEENDONT, - SEENSB, SUBNEGOT, SUBNEG_IAC, SEENCR -} telnet_state = TOPLEVEL; - -static void do_telnet_read (char *buf, int len) { +static void do_telnet_read(Telnet telnet, char *buf, int len) +{ while (len--) { int c = (unsigned char) *buf++; - switch (telnet_state) { - case TOPLEVEL: + switch (telnet->state) { + case TOP_LEVEL: case SEENCR: - if (c == NUL && telnet_state == SEENCR) - telnet_state = TOPLEVEL; + if (c == NUL && telnet->state == SEENCR) + telnet->state = TOP_LEVEL; else if (c == IAC) - telnet_state = SEENIAC; + telnet->state = SEENIAC; else { - if (!in_synch) - c_write1(c); + if (!telnet->in_synch) + c_write1(telnet, c); #if 1 /* I can't get the F***ing winsock to insert the urgent IAC @@ -385,120 +560,170 @@ static void do_telnet_read (char *buf, int len) { * 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) in_synch = 0; + else if (c == DM) + telnet->in_synch = 0; #endif - if (c == CR) - telnet_state = SEENCR; + if (c == CR && telnet->opt_states[o_they_bin.index] != ACTIVE) + telnet->state = SEENCR; else - telnet_state = TOPLEVEL; + 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; + 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) { - in_synch = 0; - telnet_state = TOPLEVEL; - } - else { + telnet->in_synch = 0; + telnet->state = TOP_LEVEL; + } else { /* ignore everything else; print it if it's IAC */ if (c == IAC) { - c_write1(c); + c_write1(telnet, c); } - telnet_state = TOPLEVEL; + telnet->state = TOP_LEVEL; } break; case SEENWILL: - proc_rec_opt (WILL, c); - telnet_state = TOPLEVEL; + proc_rec_opt(telnet, WILL, c); + telnet->state = TOP_LEVEL; break; case SEENWONT: - proc_rec_opt (WONT, c); - telnet_state = TOPLEVEL; + proc_rec_opt(telnet, WONT, c); + telnet->state = TOP_LEVEL; break; case SEENDO: - proc_rec_opt (DO, c); - telnet_state = TOPLEVEL; + proc_rec_opt(telnet, DO, c); + telnet->state = TOP_LEVEL; break; case SEENDONT: - proc_rec_opt (DONT, c); - telnet_state = TOPLEVEL; + proc_rec_opt(telnet, DONT, c); + telnet->state = TOP_LEVEL; break; case SEENSB: - sb_opt = c; - sb_len = 0; - telnet_state = SUBNEGOT; + telnet->sb_opt = c; + telnet->sb_len = 0; + telnet->state = SUBNEGOT; break; case SUBNEGOT: if (c == IAC) - telnet_state = SUBNEG_IAC; + telnet->state = SUBNEG_IAC; else { - subneg_addchar: - if (sb_len >= sb_size) { - char *newbuf; - sb_size += SB_DELTA; - newbuf = (sb_buf ? - srealloc(sb_buf, sb_size) : - smalloc(sb_size)); - if (newbuf) - sb_buf = newbuf; - else - sb_size -= SB_DELTA; + 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); } - if (sb_len < sb_size) - sb_buf[sb_len++] = c; - telnet_state = SUBNEGOT;/* in case we came here by goto */ + 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_state = TOPLEVEL; + process_subneg(telnet); + telnet->state = TOP_LEVEL; } break; } } } -static int telnet_receive(Socket skt, int urgent, char *data, int len) { - if (urgent==3) { - /* A socket error has occurred. */ - sk_close(s); - s = NULL; - connection_fatal(data); - return 0; - } else if (!len) { - /* Connection has closed. */ - sk_close(s); - s = NULL; - return 0; +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); } - do_telnet_read (data, len); + if (error_msg) { + /* A socket error has occurred. */ + 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'. + * Also places the canonical host name into `realhost'. It must be + * freed by the caller. */ -static char *telnet_init (char *host, int port, char **realhost) { +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_closing, + telnet_receive, + telnet_sent + }; SockAddr addr; - char *err; + const char *err; + Telnet 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->activated = FALSE; + telnet->sb_buf = NULL; + telnet->sb_size = 0; + telnet->frontend = frontend_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; /* * Try to find host. */ - addr = sk_namelookup(host, realhost); - if ( (err = sk_addr_error(addr)) ) + { + char *buf; + buf = dupprintf("Looking up host \"%s\"", host); + logevent(telnet->frontend, buf); + sfree(buf); + } + addr = name_lookup(host, port, realhost, &telnet->cfg); + if ((err = sk_addr_error(addr)) != NULL) { + sk_addr_free(addr); return err; + } if (port < 0) port = 23; /* default telnet port */ @@ -506,143 +731,349 @@ static char *telnet_init (char *host, int port, char **realhost) { /* * Open socket. */ - s = sk_new(addr, port, 0, telnet_receive); - if ( (err = sk_socket_error(s)) ) + { + 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, 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. */ - { - struct Opt **o; + if (telnet->cfg.passive_telnet) { + const struct Opt *const *o; for (o = opts; *o; o++) - if ((*o)->state == REQUESTED) - send_opt ((*o)->send, (*o)->option); + 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. */ - in_synch = FALSE; + telnet->in_synch = FALSE; + + /* + * We can send special commands from the start. + */ + update_specials_menu(telnet->frontend); 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. */ -static void telnet_send (char *buf, int len) { - char *p; - static unsigned char iac[2] = { IAC, IAC }; - static unsigned char cr[2] = { CR, NUL }; - static unsigned char nl[2] = { CR, LF }; +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 (s == NULL) - return; + if (telnet->s == NULL) + return 0; - p = buf; - while (p < buf+len) { - char *q = p; + p = (unsigned char *)buf; + end = (unsigned char *)(buf + len); + while (p < end) { + unsigned char *q = p; - while (iswritable((unsigned char)*p) && p < buf+len) p++; - sk_write(s, q, p-q); + while (p < end && iswritable(*p)) + p++; + telnet->bufsize = sk_write(telnet->s, (char *)q, p - q); - while (p < buf+len && !iswritable((unsigned char)*p)) { - sk_write(s, (unsigned char)*p == IAC ? iac : nl, 2); + 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) { - unsigned char b[16]; - char logbuf[50]; +static void telnet_size(void *handle, int width, int height) +{ + Telnet telnet = (Telnet) handle; + unsigned char b[24]; + int n; + char *logbuf; - if (s == NULL || o_naws.state != ACTIVE) + telnet->term_width = width; + telnet->term_height = height; + + if (telnet->s == NULL || telnet->opt_states[o_naws.index] != ACTIVE) return; - b[0] = IAC; b[1] = SB; b[2] = TELOPT_NAWS; - b[3] = cols >> 8; b[4] = cols & 0xFF; - b[5] = rows >> 8; b[6] = rows & 0xFF; - b[7] = IAC; b[8] = SE; - sk_write(s, b, 9); - sprintf(logbuf, "client:\tSB NAWS %d,%d", - ((unsigned char)b[3] << 8) + (unsigned char)b[4], - ((unsigned char)b[5] << 8) + (unsigned char)b[6]); - logevent (logbuf); + 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 (Telnet_Special code) { +static void telnet_special(void *handle, Telnet_Special code) +{ + Telnet telnet = (Telnet) handle; unsigned char b[2]; - if (s == NULL) + if (telnet->s == NULL) return; b[0] = IAC; switch (code) { - case TS_AYT: b[1] = AYT; sk_write(s, b, 2); break; - case TS_BRK: b[1] = BREAK; sk_write(s, b, 2); break; - case TS_EC: b[1] = EC; sk_write(s, b, 2); break; - case TS_EL: b[1] = EL; sk_write(s, b, 2); break; - case TS_GA: b[1] = GA; sk_write(s, b, 2); break; - case TS_NOP: b[1] = NOP; sk_write(s, b, 2); break; - case TS_ABORT: b[1] = ABORT; sk_write(s, b, 2); break; - case TS_AO: b[1] = AO; sk_write(s, b, 2); break; - case TS_IP: b[1] = IP; sk_write(s, b, 2); break; - case TS_SUSP: b[1] = SUSP; sk_write(s, b, 2); break; - case TS_EOR: b[1] = EOR; sk_write(s, b, 2); break; - case TS_EOF: b[1] = xEOF; sk_write(s, b, 2); break; + 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; - sk_write (s, b, 1); - sk_write_oob (s, b+1, 1); - break; + 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 (o_echo.state == INACTIVE || o_echo.state == REALLY_INACTIVE) { - o_echo.state = REQUESTED; - send_opt (o_echo.send, o_echo.option); + 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 (o_echo.state == ACTIVE) { - o_echo.state = REQUESTED; - send_opt (o_echo.nsend, o_echo.option); + 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 (o_they_sga.state == ACTIVE) { - b[1] = NOP; - sk_write(s, b, 2); + 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; + break; + default: + break; /* never heard of it */ } } -static Socket telnet_socket(void) { return s; } +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; + return telnet->s; +} -static int telnet_sendok(void) { return 1; } +static int telnet_sendok(void *handle) +{ + /* Telnet telnet = (Telnet) handle; */ + return 1; +} -static int telnet_ldisc(int option) { - if (option == LD_ECHO) return echoing; - if (option == LD_EDIT) return editing; +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_socket, + telnet_exitcode, telnet_sendok, telnet_ldisc, + telnet_provide_ldisc, + telnet_provide_logctx, + telnet_unthrottle, + telnet_cfg_info, 23 };