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/*
* Rlogin backend.
*/
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <ctype.h>
#include "putty.h"
#define RLOGIN_MAX_BACKLOG 4096
typedef struct Rlogin Rlogin;
struct Rlogin {
Socket *s;
bool closed_on_socket_error;
int bufsize;
bool socket_connected;
bool firstbyte;
bool cansize;
int term_width, term_height;
Seat *seat;
LogContext *logctx;
Ldisc *ldisc;
char *description;
Conf *conf;
/* In case we need to read a username from the terminal before starting */
prompts_t *prompt;
Plug plug;
Backend backend;
Interactor interactor;
};
static void rlogin_startup(Rlogin *rlogin, SeatPromptResult spr,
const char *ruser);
static void rlogin_try_username_prompt(void *ctx);
static void c_write(Rlogin *rlogin, const void *buf, size_t len)
{
size_t backlog = seat_stdout(rlogin->seat, buf, len);
sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
}
static void rlogin_log(Plug *plug, PlugLogType type, SockAddr *addr, int port,
const char *error_msg, int error_code)
{
Rlogin *rlogin = container_of(plug, Rlogin, plug);
backend_socket_log(rlogin->seat, rlogin->logctx, type, addr, port,
error_msg, error_code,
rlogin->conf, rlogin->socket_connected);
if (type == PLUGLOG_CONNECT_SUCCESS) {
rlogin->socket_connected = true;
char *ruser = get_remote_username(rlogin->conf);
if (ruser) {
/*
* If we already know the remote username, call
* rlogin_startup, which will send the initial protocol
* greeting including local username, remote username,
* terminal type and terminal speed.
*/
/* Next terminal output will come from server */
seat_set_trust_status(rlogin->seat, false);
rlogin_startup(rlogin, SPR_OK, ruser);
sfree(ruser);
} else {
/*
* Otherwise, set up a prompts_t asking for the local
* username. If it completes synchronously, call
* rlogin_startup as above; otherwise, wait until it does.
*/
rlogin->prompt = new_prompts();
rlogin->prompt->to_server = true;
rlogin->prompt->from_server = false;
rlogin->prompt->name = dupstr("Rlogin login name");
rlogin->prompt->callback = rlogin_try_username_prompt;
rlogin->prompt->callback_ctx = rlogin;
add_prompt(rlogin->prompt, dupstr("rlogin username: "), true);
rlogin_try_username_prompt(rlogin);
}
}
}
static void rlogin_closing(Plug *plug, PlugCloseType type,
const char *error_msg)
{
Rlogin *rlogin = container_of(plug, Rlogin, 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 (rlogin->s) {
sk_close(rlogin->s);
rlogin->s = NULL;
if (error_msg)
rlogin->closed_on_socket_error = true;
seat_notify_remote_exit(rlogin->seat);
seat_notify_remote_disconnect(rlogin->seat);
}
if (type != PLUGCLOSE_NORMAL) {
/* A socket error has occurred. */
logevent(rlogin->logctx, error_msg);
if (type != PLUGCLOSE_USER_ABORT)
seat_connection_fatal(rlogin->seat, "%s", error_msg);
}
/* Otherwise, the remote side closed the connection normally. */
}
static void rlogin_receive(
Plug *plug, int urgent, const char *data, size_t len)
{
Rlogin *rlogin = container_of(plug, Rlogin, plug);
if (len == 0)
return;
if (urgent == 2) {
char c;
c = *data++;
len--;
if (c == '\x80') {
rlogin->cansize = true;
backend_size(&rlogin->backend,
rlogin->term_width, rlogin->term_height);
}
/*
* We should flush everything (aka Telnet SYNCH) if we see
* 0x02, and we should turn off and on _local_ flow control
* on 0x10 and 0x20 respectively. I'm not convinced it's
* worth it...
*/
} else {
/*
* Main rlogin protocol. This is really simple: the first
* byte is expected to be NULL and is ignored, and the rest
* is printed.
*/
if (rlogin->firstbyte) {
if (data[0] == '\0') {
data++;
len--;
}
rlogin->firstbyte = false;
}
if (len > 0)
c_write(rlogin, data, len);
}
}
static void rlogin_sent(Plug *plug, size_t bufsize)
{
Rlogin *rlogin = container_of(plug, Rlogin, plug);
rlogin->bufsize = bufsize;
seat_sent(rlogin->seat, rlogin->bufsize);
}
static void rlogin_startup(Rlogin *rlogin, SeatPromptResult spr,
const char *ruser)
{
char z = 0;
char *p;
if (spr.kind == SPRK_USER_ABORT) {
/* User aborted at the username prompt. */
sk_close(rlogin->s);
rlogin->s = NULL;
seat_notify_remote_exit(rlogin->seat);
} else if (spr.kind == SPRK_SW_ABORT) {
/* Something else went wrong at the username prompt, so we
* have to show some kind of error. */
sk_close(rlogin->s);
rlogin->s = NULL;
char *err = spr_get_error_message(spr);
seat_connection_fatal(rlogin->seat, "%s", err);
sfree(err);
} else {
sk_write(rlogin->s, &z, 1);
p = conf_get_str(rlogin->conf, CONF_localusername);
sk_write(rlogin->s, p, strlen(p));
sk_write(rlogin->s, &z, 1);
sk_write(rlogin->s, ruser, strlen(ruser));
sk_write(rlogin->s, &z, 1);
p = conf_get_str(rlogin->conf, CONF_termtype);
sk_write(rlogin->s, p, strlen(p));
sk_write(rlogin->s, "/", 1);
p = conf_get_str(rlogin->conf, CONF_termspeed);
sk_write(rlogin->s, p, strspn(p, "0123456789"));
rlogin->bufsize = sk_write(rlogin->s, &z, 1);
}
rlogin->prompt = NULL;
if (rlogin->ldisc)
ldisc_check_sendok(rlogin->ldisc);
}
static const PlugVtable Rlogin_plugvt = {
.log = rlogin_log,
.closing = rlogin_closing,
.receive = rlogin_receive,
.sent = rlogin_sent,
};
static char *rlogin_description(Interactor *itr)
{
Rlogin *rlogin = container_of(itr, Rlogin, interactor);
return dupstr(rlogin->description);
}
static LogPolicy *rlogin_logpolicy(Interactor *itr)
{
Rlogin *rlogin = container_of(itr, Rlogin, interactor);
return log_get_policy(rlogin->logctx);
}
static Seat *rlogin_get_seat(Interactor *itr)
{
Rlogin *rlogin = container_of(itr, Rlogin, interactor);
return rlogin->seat;
}
static void rlogin_set_seat(Interactor *itr, Seat *seat)
{
Rlogin *rlogin = container_of(itr, Rlogin, interactor);
rlogin->seat = seat;
}
static const InteractorVtable Rlogin_interactorvt = {
.description = rlogin_description,
.logpolicy = rlogin_logpolicy,
.get_seat = rlogin_get_seat,
.set_seat = rlogin_set_seat,
};
/*
* Called to set up the rlogin 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 char *rlogin_init(const BackendVtable *vt, Seat *seat,
Backend **backend_handle, LogContext *logctx,
Conf *conf, const char *host, int port,
char **realhost, bool nodelay, bool keepalive)
{
SockAddr *addr;
const char *err;
Rlogin *rlogin;
int addressfamily;
char *loghost;
rlogin = snew(Rlogin);
memset(rlogin, 0, sizeof(Rlogin));
rlogin->plug.vt = &Rlogin_plugvt;
rlogin->backend.vt = vt;
rlogin->interactor.vt = &Rlogin_interactorvt;
rlogin->backend.interactor = &rlogin->interactor;
rlogin->s = NULL;
rlogin->closed_on_socket_error = false;
rlogin->seat = seat;
rlogin->logctx = logctx;
rlogin->term_width = conf_get_int(conf, CONF_width);
rlogin->term_height = conf_get_int(conf, CONF_height);
rlogin->socket_connected = false;
rlogin->firstbyte = true;
rlogin->cansize = false;
rlogin->prompt = NULL;
rlogin->conf = conf_copy(conf);
rlogin->description = default_description(vt, host, port);
*backend_handle = &rlogin->backend;
addressfamily = conf_get_int(conf, CONF_addressfamily);
/*
* Try to find host.
*/
addr = name_lookup(host, port, realhost, conf, addressfamily,
rlogin->logctx, "rlogin connection");
if ((err = sk_addr_error(addr)) != NULL) {
sk_addr_free(addr);
return dupstr(err);
}
if (port < 0)
port = 513; /* default rlogin port */
/*
* Open socket.
*/
rlogin->s = new_connection(addr, *realhost, port, true, false,
nodelay, keepalive, &rlogin->plug, conf,
&rlogin->interactor);
if ((err = sk_socket_error(rlogin->s)) != NULL)
return dupstr(err);
loghost = conf_get_str(conf, CONF_loghost);
if (*loghost) {
char *colon;
sfree(*realhost);
*realhost = dupstr(loghost);
colon = host_strrchr(*realhost, ':');
if (colon)
*colon++ = '\0';
}
return NULL;
}
static void rlogin_free(Backend *be)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
if (is_tempseat(rlogin->seat))
tempseat_free(rlogin->seat);
if (rlogin->prompt)
free_prompts(rlogin->prompt);
if (rlogin->s)
sk_close(rlogin->s);
conf_free(rlogin->conf);
sfree(rlogin->description);
sfree(rlogin);
}
/*
* Stub routine (we don't have any need to reconfigure this backend).
*/
static void rlogin_reconfig(Backend *be, Conf *conf)
{
}
static void rlogin_try_username_prompt(void *ctx)
{
Rlogin *rlogin = (Rlogin *)ctx;
SeatPromptResult spr = seat_get_userpass_input(
interactor_announce(&rlogin->interactor), rlogin->prompt);
if (spr.kind == SPRK_INCOMPLETE)
return;
/* Next terminal output will come from server */
seat_set_trust_status(rlogin->seat, false);
/* Send the rlogin setup protocol data, and then we're ready to
* start receiving normal input to send down the wire, which
* rlogin_startup will signal to rlogin_sendok by nulling out
* rlogin->prompt. */
rlogin_startup(
rlogin, spr, prompt_get_result_ref(rlogin->prompt->prompts[0]));
}
/*
* Called to send data down the rlogin connection.
*/
static void rlogin_send(Backend *be, const char *buf, size_t len)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
if (rlogin->s == NULL)
return;
rlogin->bufsize = sk_write(rlogin->s, buf, len);
}
/*
* Called to query the current socket sendability status.
*/
static size_t rlogin_sendbuffer(Backend *be)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
return rlogin->bufsize;
}
/*
* Called to set the size of the window
*/
static void rlogin_size(Backend *be, int width, int height)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
rlogin->term_width = width;
rlogin->term_height = height;
if (rlogin->s == NULL || !rlogin->cansize)
return;
b[6] = rlogin->term_width >> 8;
b[7] = rlogin->term_width & 0xFF;
b[4] = rlogin->term_height >> 8;
b[5] = rlogin->term_height & 0xFF;
rlogin->bufsize = sk_write(rlogin->s, b, 12);
return;
}
/*
* Send rlogin special codes.
*/
static void rlogin_special(Backend *be, SessionSpecialCode code, int arg)
{
/* Do nothing! */
return;
}
/*
* Return a list of the special codes that make sense in this
* protocol.
*/
static const SessionSpecial *rlogin_get_specials(Backend *be)
{
return NULL;
}
static bool rlogin_connected(Backend *be)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
return rlogin->s != NULL;
}
static bool rlogin_sendok(Backend *be)
{
/*
* We only want to receive input data if the socket is connected
* and we're not still at the username prompt stage.
*/
Rlogin *rlogin = container_of(be, Rlogin, backend);
return rlogin->socket_connected && !rlogin->prompt;
}
static void rlogin_unthrottle(Backend *be, size_t backlog)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG);
}
static bool rlogin_ldisc(Backend *be, int option)
{
/* Rlogin *rlogin = container_of(be, Rlogin, backend); */
return false;
}
static void rlogin_provide_ldisc(Backend *be, Ldisc *ldisc)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
rlogin->ldisc = ldisc;
}
static int rlogin_exitcode(Backend *be)
{
Rlogin *rlogin = container_of(be, Rlogin, backend);
if (rlogin->s != NULL)
return -1; /* still connected */
else if (rlogin->closed_on_socket_error)
return INT_MAX; /* a socket error counts as an unclean exit */
else
/* If we ever implement RSH, we'll probably need to do this properly */
return 0;
}
/*
* cfg_info for rlogin does nothing at all.
*/
static int rlogin_cfg_info(Backend *be)
{
return 0;
}
const BackendVtable rlogin_backend = {
.init = rlogin_init,
.free = rlogin_free,
.reconfig = rlogin_reconfig,
.send = rlogin_send,
.sendbuffer = rlogin_sendbuffer,
.size = rlogin_size,
.special = rlogin_special,
.get_specials = rlogin_get_specials,
.connected = rlogin_connected,
.exitcode = rlogin_exitcode,
.sendok = rlogin_sendok,
.ldisc_option_state = rlogin_ldisc,
.provide_ldisc = rlogin_provide_ldisc,
.unthrottle = rlogin_unthrottle,
.cfg_info = rlogin_cfg_info,
.id = "rlogin",
.displayname_tc = "Rlogin",
.displayname_lc = "Rlogin", /* proper name, so capitalise it anyway */
.protocol = PROT_RLOGIN,
.default_port = 513,
};
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