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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 09:27:59 +00:00
putty-source/unix/plink.c
Simon Tatham cd8a7181fd Complete rework of terminal userpass input system.
The system for handling seat_get_userpass_input has always been
structured differently between GUI PuTTY and CLI tools like Plink.

In the CLI tools, password input is read directly from the OS
terminal/console device by console_get_userpass_input; this means that
you need to ensure the same terminal input data _hasn't_ already been
consumed by the main event loop and sent on to the backend. This is
achieved by the backend_sendok() method, which tells the event loop
when the backend has finished issuing password prompts, and hence,
when it's safe to start passing standard input to backend_send().

But in the GUI tools, input generated by the terminal window has
always been sent straight to backend_send(), regardless of whether
backend_sendok() says it wants it. So the terminal-based
implementation of username and password prompts has to work by
consuming input data that had _already_ been passed to the backend -
hence, any backend that needs to do that must keep its input on a
bufchain, and pass that bufchain to seat_get_userpass_input.

It's awkward that these two totally different systems coexist in the
first place. And now that SSH proxying needs to present interactive
prompts of its own, it's clear which one should win: the CLI style is
the Right Thing. So this change reworks the GUI side of the mechanism
to be more similar: terminal data now goes into a queue in the Ldisc,
and is not sent on to the backend until the backend says it's ready
for it via backend_sendok(). So terminal-based userpass prompts can
now consume data directly from that queue during the connection setup
stage.

As a result, the 'bufchain *' parameter has vanished from all the
userpass_input functions (both the official implementations of the
Seat trait method, and term_get_userpass_input() to which some of
those implementations delegate). The only function that actually used
that bufchain, namely term_get_userpass_input(), now instead reads
from the ldisc's input queue via a couple of new Ldisc functions.

(Not _trivial_ functions, since input buffered by Ldisc can be a
mixture of raw bytes and session specials like SS_EOL! The input queue
inside Ldisc is a bufchain containing a fiddly binary encoding that
can represent an arbitrary interleaving of those things.)

This greatly simplifies the calls to seat_get_userpass_input in
backends, which now don't have to mess about with passing their own
user_input bufchain around, or toggling their want_user_input flag
back and forth to request data to put on to that bufchain.

But the flip side is that now there has to be some _other_ method for
notifying the terminal when there's more input to be consumed during
an interactive prompt, and for notifying the backend when prompt input
has finished so that it can proceed to the next stage of the protocol.
This is done by a pair of extra callbacks: when more data is put on to
Ldisc's input queue, it triggers a call to term_get_userpass_input,
and when term_get_userpass_input finishes, it calls a callback
function provided in the prompts_t.

Therefore, any use of a prompts_t which *might* be asynchronous must
fill in the latter callback when setting up the prompts_t. In SSH, the
callback is centralised into a common PPL helper function, which
reinvokes the same PPL's process_queue coroutine; in rlogin we have to
set it up ourselves.

I'm sorry for this large and sprawling patch: I tried fairly hard to
break it up into individually comprehensible sub-patches, but I just
couldn't tease out any part of it that would stand sensibly alone.
2021-09-14 13:19:33 +01:00

971 lines
30 KiB
C

/*
* PLink - a command-line (stdin/stdout) variant of PuTTY.
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <stdarg.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <pwd.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include "putty.h"
#include "ssh.h"
#include "storage.h"
#include "tree234.h"
#define MAX_STDIN_BACKLOG 4096
static LogContext *logctx;
static struct termios orig_termios;
void cmdline_error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
console_print_error_msg_fmt_v("plink", fmt, ap);
va_end(ap);
exit(1);
}
static bool local_tty = false; /* do we have a local tty? */
static Backend *backend;
static Conf *conf;
/*
* Default settings that are specific to Unix plink.
*/
char *platform_default_s(const char *name)
{
if (!strcmp(name, "TermType"))
return dupstr(getenv("TERM"));
if (!strcmp(name, "SerialLine"))
return dupstr("/dev/ttyS0");
return NULL;
}
bool platform_default_b(const char *name, bool def)
{
return def;
}
int platform_default_i(const char *name, int def)
{
return def;
}
FontSpec *platform_default_fontspec(const char *name)
{
return fontspec_new("");
}
Filename *platform_default_filename(const char *name)
{
if (!strcmp(name, "LogFileName"))
return filename_from_str("putty.log");
else
return filename_from_str("");
}
char *x_get_default(const char *key)
{
return NULL; /* this is a stub */
}
static void plink_echoedit_update(Seat *seat, bool echo, bool edit)
{
/* Update stdin read mode to reflect changes in line discipline. */
struct termios mode;
if (!local_tty) return;
mode = orig_termios;
if (echo)
mode.c_lflag |= ECHO;
else
mode.c_lflag &= ~ECHO;
if (edit) {
mode.c_iflag |= ICRNL;
mode.c_lflag |= ISIG | ICANON;
mode.c_oflag |= OPOST;
} else {
mode.c_iflag &= ~ICRNL;
mode.c_lflag &= ~(ISIG | ICANON);
mode.c_oflag &= ~OPOST;
/* Solaris sets these to unhelpful values */
mode.c_cc[VMIN] = 1;
mode.c_cc[VTIME] = 0;
/* FIXME: perhaps what we do with IXON/IXOFF should be an
* argument to the echoedit_update() method, to allow
* implementation of SSH-2 "xon-xoff" and Rlogin's
* equivalent? */
mode.c_iflag &= ~IXON;
mode.c_iflag &= ~IXOFF;
}
/*
* Mark parity errors and (more important) BREAK on input. This
* is more complex than it need be because POSIX-2001 suggests
* that escaping of valid 0xff in the input stream is dependent on
* IGNPAR being clear even though marking of BREAK isn't. NetBSD
* 2.0 goes one worse and makes it dependent on INPCK too. We
* deal with this by forcing these flags into a useful state and
* then faking the state in which we found them in from_tty() if
* we get passed a parity or framing error.
*/
mode.c_iflag = (mode.c_iflag | INPCK | PARMRK) & ~IGNPAR;
tcsetattr(STDIN_FILENO, TCSANOW, &mode);
}
/* Helper function to extract a special character from a termios. */
static char *get_ttychar(struct termios *t, int index)
{
cc_t c = t->c_cc[index];
#if defined(_POSIX_VDISABLE)
if (c == _POSIX_VDISABLE)
return dupstr("");
#endif
return dupprintf("^<%d>", c);
}
static char *plink_get_ttymode(Seat *seat, const char *mode)
{
/*
* Propagate appropriate terminal modes from the local terminal,
* if any.
*/
if (!local_tty) return NULL;
#define GET_CHAR(ourname, uxname) \
do { \
if (strcmp(mode, ourname) == 0) \
return get_ttychar(&orig_termios, uxname); \
} while(0)
#define GET_BOOL(ourname, uxname, uxmemb, transform) \
do { \
if (strcmp(mode, ourname) == 0) { \
bool b = (orig_termios.uxmemb & uxname) != 0; \
transform; \
return dupprintf("%d", b); \
} \
} while (0)
/*
* Modes that want to be the same on all terminal devices involved.
*/
/* All the special characters supported by SSH */
#if defined(VINTR)
GET_CHAR("INTR", VINTR);
#endif
#if defined(VQUIT)
GET_CHAR("QUIT", VQUIT);
#endif
#if defined(VERASE)
GET_CHAR("ERASE", VERASE);
#endif
#if defined(VKILL)
GET_CHAR("KILL", VKILL);
#endif
#if defined(VEOF)
GET_CHAR("EOF", VEOF);
#endif
#if defined(VEOL)
GET_CHAR("EOL", VEOL);
#endif
#if defined(VEOL2)
GET_CHAR("EOL2", VEOL2);
#endif
#if defined(VSTART)
GET_CHAR("START", VSTART);
#endif
#if defined(VSTOP)
GET_CHAR("STOP", VSTOP);
#endif
#if defined(VSUSP)
GET_CHAR("SUSP", VSUSP);
#endif
#if defined(VDSUSP)
GET_CHAR("DSUSP", VDSUSP);
#endif
#if defined(VREPRINT)
GET_CHAR("REPRINT", VREPRINT);
#endif
#if defined(VWERASE)
GET_CHAR("WERASE", VWERASE);
#endif
#if defined(VLNEXT)
GET_CHAR("LNEXT", VLNEXT);
#endif
#if defined(VFLUSH)
GET_CHAR("FLUSH", VFLUSH);
#endif
#if defined(VSWTCH)
GET_CHAR("SWTCH", VSWTCH);
#endif
#if defined(VSTATUS)
GET_CHAR("STATUS", VSTATUS);
#endif
#if defined(VDISCARD)
GET_CHAR("DISCARD", VDISCARD);
#endif
/* Modes that "configure" other major modes. These should probably be
* considered as user preferences. */
/* Configuration of ICANON */
#if defined(ECHOK)
GET_BOOL("ECHOK", ECHOK, c_lflag, );
#endif
#if defined(ECHOKE)
GET_BOOL("ECHOKE", ECHOKE, c_lflag, );
#endif
#if defined(ECHOE)
GET_BOOL("ECHOE", ECHOE, c_lflag, );
#endif
#if defined(ECHONL)
GET_BOOL("ECHONL", ECHONL, c_lflag, );
#endif
#if defined(XCASE)
GET_BOOL("XCASE", XCASE, c_lflag, );
#endif
#if defined(IUTF8)
GET_BOOL("IUTF8", IUTF8, c_iflag, );
#endif
/* Configuration of ECHO */
#if defined(ECHOCTL)
GET_BOOL("ECHOCTL", ECHOCTL, c_lflag, );
#endif
/* Configuration of IXON/IXOFF */
#if defined(IXANY)
GET_BOOL("IXANY", IXANY, c_iflag, );
#endif
/* Configuration of OPOST */
#if defined(OLCUC)
GET_BOOL("OLCUC", OLCUC, c_oflag, );
#endif
#if defined(ONLCR)
GET_BOOL("ONLCR", ONLCR, c_oflag, );
#endif
#if defined(OCRNL)
GET_BOOL("OCRNL", OCRNL, c_oflag, );
#endif
#if defined(ONOCR)
GET_BOOL("ONOCR", ONOCR, c_oflag, );
#endif
#if defined(ONLRET)
GET_BOOL("ONLRET", ONLRET, c_oflag, );
#endif
/*
* Modes that want to be set in only one place, and that we have
* squashed locally.
*/
#if defined(ISIG)
GET_BOOL("ISIG", ISIG, c_lflag, );
#endif
#if defined(ICANON)
GET_BOOL("ICANON", ICANON, c_lflag, );
#endif
#if defined(ECHO)
GET_BOOL("ECHO", ECHO, c_lflag, );
#endif
#if defined(IXON)
GET_BOOL("IXON", IXON, c_iflag, );
#endif
#if defined(IXOFF)
GET_BOOL("IXOFF", IXOFF, c_iflag, );
#endif
#if defined(OPOST)
GET_BOOL("OPOST", OPOST, c_oflag, );
#endif
/*
* We do not propagate the following modes:
* - Parity/serial settings, which are a local affair and don't
* make sense propagated over SSH's 8-bit byte-stream.
* IGNPAR PARMRK INPCK CS7 CS8 PARENB PARODD
* - Things that want to be enabled in one place that we don't
* squash locally.
* IUCLC
* - Status bits.
* PENDIN
* - Things I don't know what to do with. (FIXME)
* ISTRIP IMAXBEL NOFLSH TOSTOP IEXTEN
* INLCR IGNCR ICRNL
*/
#undef GET_CHAR
#undef GET_BOOL
/* Fall through to here for unrecognised names, or ones that are
* unsupported on this platform */
return NULL;
}
void cleanup_termios(void)
{
if (local_tty)
tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
}
static bufchain stdout_data, stderr_data;
static bufchain_sink stdout_bcs, stderr_bcs;
static StripCtrlChars *stdout_scc, *stderr_scc;
static BinarySink *stdout_bs, *stderr_bs;
static enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof;
size_t try_output(bool is_stderr)
{
bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
int fd = (is_stderr ? STDERR_FILENO : STDOUT_FILENO);
ssize_t ret;
if (bufchain_size(chain) > 0) {
bool prev_nonblock = nonblock(fd);
ptrlen senddata;
do {
senddata = bufchain_prefix(chain);
ret = write(fd, senddata.ptr, senddata.len);
if (ret > 0)
bufchain_consume(chain, ret);
} while (ret == senddata.len && bufchain_size(chain) != 0);
if (!prev_nonblock)
no_nonblock(fd);
if (ret < 0 && errno != EAGAIN) {
perror(is_stderr ? "stderr: write" : "stdout: write");
exit(1);
}
}
if (outgoingeof == EOF_PENDING && bufchain_size(&stdout_data) == 0) {
close(STDOUT_FILENO);
outgoingeof = EOF_SENT;
}
return bufchain_size(&stdout_data) + bufchain_size(&stderr_data);
}
static size_t plink_output(
Seat *seat, bool is_stderr, const void *data, size_t len)
{
assert(is_stderr || outgoingeof == EOF_NO);
BinarySink *bs = is_stderr ? stderr_bs : stdout_bs;
put_data(bs, data, len);
return try_output(is_stderr);
}
static bool plink_eof(Seat *seat)
{
assert(outgoingeof == EOF_NO);
outgoingeof = EOF_PENDING;
try_output(false);
return false; /* do not respond to incoming EOF with outgoing */
}
static int plink_get_userpass_input(Seat *seat, prompts_t *p)
{
int ret;
ret = cmdline_get_passwd_input(p);
if (ret == -1)
ret = console_get_userpass_input(p);
return ret;
}
static bool plink_seat_interactive(Seat *seat)
{
return (!*conf_get_str(conf, CONF_remote_cmd) &&
!*conf_get_str(conf, CONF_remote_cmd2) &&
!*conf_get_str(conf, CONF_ssh_nc_host));
}
static const SeatVtable plink_seat_vt = {
.output = plink_output,
.eof = plink_eof,
.sent = nullseat_sent,
.get_userpass_input = plink_get_userpass_input,
.notify_session_started = nullseat_notify_session_started,
.notify_remote_exit = nullseat_notify_remote_exit,
.notify_remote_disconnect = nullseat_notify_remote_disconnect,
.connection_fatal = console_connection_fatal,
.update_specials_menu = nullseat_update_specials_menu,
.get_ttymode = plink_get_ttymode,
.set_busy_status = nullseat_set_busy_status,
.verify_ssh_host_key = console_verify_ssh_host_key,
.confirm_weak_crypto_primitive = console_confirm_weak_crypto_primitive,
.confirm_weak_cached_hostkey = console_confirm_weak_cached_hostkey,
.is_utf8 = nullseat_is_never_utf8,
.echoedit_update = plink_echoedit_update,
.get_x_display = nullseat_get_x_display,
.get_windowid = nullseat_get_windowid,
.get_window_pixel_size = nullseat_get_window_pixel_size,
.stripctrl_new = console_stripctrl_new,
.set_trust_status = console_set_trust_status,
.can_set_trust_status = console_can_set_trust_status,
.verbose = cmdline_seat_verbose,
.interactive = plink_seat_interactive,
.get_cursor_position = nullseat_get_cursor_position,
};
static Seat plink_seat[1] = {{ &plink_seat_vt }};
/*
* Handle data from a local tty in PARMRK format.
*/
static void from_tty(void *vbuf, unsigned len)
{
char *p, *q, *end, *buf = vbuf;
static enum {NORMAL, FF, FF00} state = NORMAL;
p = buf; end = buf + len;
while (p < end) {
switch (state) {
case NORMAL:
if (*p == '\xff') {
p++;
state = FF;
} else {
q = memchr(p, '\xff', end - p);
if (q == NULL) q = end;
backend_send(backend, p, q - p);
p = q;
}
break;
case FF:
if (*p == '\xff') {
backend_send(backend, p, 1);
p++;
state = NORMAL;
} else if (*p == '\0') {
p++;
state = FF00;
} else abort();
break;
case FF00:
if (*p == '\0') {
backend_special(backend, SS_BRK, 0);
} else {
/*
* Pretend that PARMRK wasn't set. This involves
* faking what INPCK and IGNPAR would have done if
* we hadn't overridden them. Unfortunately, we
* can't do this entirely correctly because INPCK
* distinguishes between framing and parity
* errors, but PARMRK format represents both in
* the same way. We assume that parity errors are
* more common than framing errors, and hence
* treat all input errors as being subject to
* INPCK.
*/
if (orig_termios.c_iflag & INPCK) {
/* If IGNPAR is set, we throw away the character. */
if (!(orig_termios.c_iflag & IGNPAR)) {
/* PE/FE get passed on as NUL. */
*p = 0;
backend_send(backend, p, 1);
}
} else {
/* INPCK not set. Assume we got a parity error. */
backend_send(backend, p, 1);
}
}
p++;
state = NORMAL;
}
}
}
static int signalpipe[2];
void sigwinch(int signum)
{
if (write(signalpipe[1], "x", 1) <= 0)
/* not much we can do about it */;
}
/*
* Short description of parameters.
*/
static void usage(void)
{
printf("Plink: command-line connection utility\n");
printf("%s\n", ver);
printf("Usage: plink [options] [user@]host [command]\n");
printf(" (\"host\" can also be a PuTTY saved session name)\n");
printf("Options:\n");
printf(" -V print version information and exit\n");
printf(" -pgpfp print PGP key fingerprints and exit\n");
printf(" -v show verbose messages\n");
printf(" -load sessname Load settings from saved session\n");
printf(" -ssh -telnet -rlogin -raw -serial\n");
printf(" force use of a particular protocol\n");
printf(" -ssh-connection\n");
printf(" force use of the bare ssh-connection protocol\n");
printf(" -P port connect to specified port\n");
printf(" -l user connect with specified username\n");
printf(" -batch disable all interactive prompts\n");
printf(" -proxycmd command\n");
printf(" use 'command' as local proxy\n");
printf(" -sercfg configuration-string (e.g. 19200,8,n,1,X)\n");
printf(" Specify the serial configuration (serial only)\n");
printf("The following options only apply to SSH connections:\n");
printf(" -pw passw login with specified password\n");
printf(" -D [listen-IP:]listen-port\n");
printf(" Dynamic SOCKS-based port forwarding\n");
printf(" -L [listen-IP:]listen-port:host:port\n");
printf(" Forward local port to remote address\n");
printf(" -R [listen-IP:]listen-port:host:port\n");
printf(" Forward remote port to local address\n");
printf(" -X -x enable / disable X11 forwarding\n");
printf(" -A -a enable / disable agent forwarding\n");
printf(" -t -T enable / disable pty allocation\n");
printf(" -1 -2 force use of particular SSH protocol version\n");
printf(" -4 -6 force use of IPv4 or IPv6\n");
printf(" -C enable compression\n");
printf(" -i key private key file for user authentication\n");
printf(" -noagent disable use of Pageant\n");
printf(" -agent enable use of Pageant\n");
printf(" -no-trivial-auth\n");
printf(" disconnect if SSH authentication succeeds trivially\n");
printf(" -noshare disable use of connection sharing\n");
printf(" -share enable use of connection sharing\n");
printf(" -hostkey keyid\n");
printf(" manually specify a host key (may be repeated)\n");
printf(" -sanitise-stderr, -sanitise-stdout, "
"-no-sanitise-stderr, -no-sanitise-stdout\n");
printf(" do/don't strip control chars from standard "
"output/error\n");
printf(" -no-antispoof omit anti-spoofing prompt after "
"authentication\n");
printf(" -m file read remote command(s) from file\n");
printf(" -s remote command is an SSH subsystem (SSH-2 only)\n");
printf(" -N don't start a shell/command (SSH-2 only)\n");
printf(" -nc host:port\n");
printf(" open tunnel in place of session (SSH-2 only)\n");
printf(" -sshlog file\n");
printf(" -sshrawlog file\n");
printf(" log protocol details to a file\n");
printf(" -logoverwrite\n");
printf(" -logappend\n");
printf(" control what happens when a log file already exists\n");
printf(" -shareexists\n");
printf(" test whether a connection-sharing upstream exists\n");
exit(1);
}
static void version(void)
{
char *buildinfo_text = buildinfo("\n");
printf("plink: %s\n%s\n", ver, buildinfo_text);
sfree(buildinfo_text);
exit(0);
}
void frontend_net_error_pending(void) {}
const bool share_can_be_downstream = true;
const bool share_can_be_upstream = true;
const bool buildinfo_gtk_relevant = false;
const unsigned cmdline_tooltype =
TOOLTYPE_HOST_ARG |
TOOLTYPE_HOST_ARG_CAN_BE_SESSION |
TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX |
TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD;
static bool seen_stdin_eof = false;
static bool plink_pw_setup(void *vctx, pollwrapper *pw)
{
pollwrap_add_fd_rwx(pw, signalpipe[0], SELECT_R);
if (!seen_stdin_eof &&
backend_connected(backend) &&
backend_sendok(backend) &&
backend_sendbuffer(backend) < MAX_STDIN_BACKLOG) {
/* If we're OK to send, then try to read from stdin. */
pollwrap_add_fd_rwx(pw, STDIN_FILENO, SELECT_R);
}
if (bufchain_size(&stdout_data) > 0) {
/* If we have data for stdout, try to write to stdout. */
pollwrap_add_fd_rwx(pw, STDOUT_FILENO, SELECT_W);
}
if (bufchain_size(&stderr_data) > 0) {
/* If we have data for stderr, try to write to stderr. */
pollwrap_add_fd_rwx(pw, STDERR_FILENO, SELECT_W);
}
return true;
}
static void plink_pw_check(void *vctx, pollwrapper *pw)
{
if (pollwrap_check_fd_rwx(pw, signalpipe[0], SELECT_R)) {
char c[1];
struct winsize size;
if (read(signalpipe[0], c, 1) <= 0)
/* ignore error */;
/* ignore its value; it'll be `x' */
if (ioctl(STDIN_FILENO, TIOCGWINSZ, (void *)&size) >= 0)
backend_size(backend, size.ws_col, size.ws_row);
}
if (pollwrap_check_fd_rwx(pw, STDIN_FILENO, SELECT_R)) {
char buf[4096];
int ret;
if (backend_connected(backend)) {
ret = read(STDIN_FILENO, buf, sizeof(buf));
noise_ultralight(NOISE_SOURCE_IOLEN, ret);
if (ret < 0) {
perror("stdin: read");
exit(1);
} else if (ret == 0) {
backend_special(backend, SS_EOF, 0);
seen_stdin_eof = true;
} else {
if (local_tty)
from_tty(buf, ret);
else
backend_send(backend, buf, ret);
}
}
}
if (pollwrap_check_fd_rwx(pw, STDOUT_FILENO, SELECT_W)) {
backend_unthrottle(backend, try_output(false));
}
if (pollwrap_check_fd_rwx(pw, STDERR_FILENO, SELECT_W)) {
backend_unthrottle(backend, try_output(true));
}
}
static bool plink_continue(void *vctx, bool found_any_fd,
bool ran_any_callback)
{
if (!backend_connected(backend) &&
bufchain_size(&stdout_data) == 0 && bufchain_size(&stderr_data) == 0)
return false; /* terminate main loop */
return true;
}
int main(int argc, char **argv)
{
int exitcode;
bool errors;
enum TriState sanitise_stdout = AUTO, sanitise_stderr = AUTO;
bool use_subsystem = false;
bool just_test_share_exists = false;
struct winsize size;
const struct BackendVtable *backvt;
/*
* Initialise port and protocol to sensible defaults. (These
* will be overridden by more or less anything.)
*/
settings_set_default_protocol(PROT_SSH);
settings_set_default_port(22);
bufchain_init(&stdout_data);
bufchain_init(&stderr_data);
bufchain_sink_init(&stdout_bcs, &stdout_data);
bufchain_sink_init(&stderr_bcs, &stderr_data);
stdout_bs = BinarySink_UPCAST(&stdout_bcs);
stderr_bs = BinarySink_UPCAST(&stderr_bcs);
outgoingeof = EOF_NO;
stderr_tty_init();
/*
* Process the command line.
*/
conf = conf_new();
do_defaults(NULL, conf);
settings_set_default_protocol(conf_get_int(conf, CONF_protocol));
settings_set_default_port(conf_get_int(conf, CONF_port));
errors = false;
{
/*
* Override the default protocol if PLINK_PROTOCOL is set.
*/
char *p = getenv("PLINK_PROTOCOL");
if (p) {
const struct BackendVtable *vt = backend_vt_from_name(p);
if (vt) {
settings_set_default_protocol(vt->protocol);
settings_set_default_port(vt->default_port);
conf_set_int(conf, CONF_protocol, vt->protocol);
conf_set_int(conf, CONF_port, vt->default_port);
}
}
}
while (--argc) {
char *p = *++argv;
int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
1, conf);
if (ret == -2) {
fprintf(stderr,
"plink: option \"%s\" requires an argument\n", p);
errors = true;
} else if (ret == 2) {
--argc, ++argv;
} else if (ret == 1) {
continue;
} else if (!strcmp(p, "-batch")) {
console_batch_mode = true;
} else if (!strcmp(p, "-s")) {
/* Save status to write to conf later. */
use_subsystem = true;
} else if (!strcmp(p, "-V") || !strcmp(p, "--version")) {
version();
} else if (!strcmp(p, "--help")) {
usage();
exit(0);
} else if (!strcmp(p, "-pgpfp")) {
pgp_fingerprints();
exit(1);
} else if (!strcmp(p, "-o")) {
if (argc <= 1) {
fprintf(stderr,
"plink: option \"-o\" requires an argument\n");
errors = true;
} else {
--argc;
/* Explicitly pass "plink" in place of appname for
* error reporting purposes. appname will have been
* set by be_foo.c to something more generic, probably
* "PuTTY". */
provide_xrm_string(*++argv, "plink");
}
} else if (!strcmp(p, "-shareexists")) {
just_test_share_exists = true;
} else if (!strcmp(p, "-fuzznet")) {
conf_set_int(conf, CONF_proxy_type, PROXY_FUZZ);
conf_set_str(conf, CONF_proxy_telnet_command, "%host");
} else if (!strcmp(p, "-sanitise-stdout") ||
!strcmp(p, "-sanitize-stdout")) {
sanitise_stdout = FORCE_ON;
} else if (!strcmp(p, "-no-sanitise-stdout") ||
!strcmp(p, "-no-sanitize-stdout")) {
sanitise_stdout = FORCE_OFF;
} else if (!strcmp(p, "-sanitise-stderr") ||
!strcmp(p, "-sanitize-stderr")) {
sanitise_stderr = FORCE_ON;
} else if (!strcmp(p, "-no-sanitise-stderr") ||
!strcmp(p, "-no-sanitize-stderr")) {
sanitise_stderr = FORCE_OFF;
} else if (!strcmp(p, "-no-antispoof")) {
console_antispoof_prompt = false;
} else if (*p != '-') {
strbuf *cmdbuf = strbuf_new();
while (argc > 0) {
if (cmdbuf->len > 0)
put_byte(cmdbuf, ' '); /* add space separator */
put_datapl(cmdbuf, ptrlen_from_asciz(p));
if (--argc > 0)
p = *++argv;
}
conf_set_str(conf, CONF_remote_cmd, cmdbuf->s);
conf_set_str(conf, CONF_remote_cmd2, "");
conf_set_bool(conf, CONF_nopty, true); /* command => no tty */
strbuf_free(cmdbuf);
break; /* done with cmdline */
} else {
fprintf(stderr, "plink: unknown option \"%s\"\n", p);
errors = true;
}
}
if (errors)
return 1;
if (!cmdline_host_ok(conf)) {
usage();
}
prepare_session(conf);
/*
* Perform command-line overrides on session configuration.
*/
cmdline_run_saved(conf);
/*
* If we have no better ideas for the remote username, use the local
* one, as 'ssh' does.
*/
if (conf_get_str(conf, CONF_username)[0] == '\0') {
char *user = get_username();
if (user) {
conf_set_str(conf, CONF_username, user);
sfree(user);
}
}
/*
* Apply subsystem status.
*/
if (use_subsystem)
conf_set_bool(conf, CONF_ssh_subsys, true);
/*
* Select protocol. This is farmed out into a table in a
* separate file to enable an ssh-free variant.
*/
backvt = backend_vt_from_proto(conf_get_int(conf, CONF_protocol));
if (!backvt) {
fprintf(stderr,
"Internal fault: Unsupported protocol found\n");
return 1;
}
if (backvt->flags & BACKEND_NEEDS_TERMINAL) {
fprintf(stderr,
"Plink doesn't support %s, which needs terminal emulation\n",
backvt->displayname);
return 1;
}
/*
* Block SIGPIPE, so that we'll get EPIPE individually on
* particular network connections that go wrong.
*/
putty_signal(SIGPIPE, SIG_IGN);
/*
* Set up the pipe we'll use to tell us about SIGWINCH.
*/
if (pipe(signalpipe) < 0) {
perror("pipe");
exit(1);
}
/* We don't want the signal handler to block if the pipe's full. */
nonblock(signalpipe[0]);
nonblock(signalpipe[1]);
cloexec(signalpipe[0]);
cloexec(signalpipe[1]);
putty_signal(SIGWINCH, sigwinch);
/*
* Now that we've got the SIGWINCH handler installed, try to find
* out the initial terminal size.
*/
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &size) >= 0) {
conf_set_int(conf, CONF_width, size.ws_col);
conf_set_int(conf, CONF_height, size.ws_row);
}
/*
* Decide whether to sanitise control sequences out of standard
* output and standard error.
*
* If we weren't given a command-line override, we do this if (a)
* the fd in question is pointing at a terminal, and (b) we aren't
* trying to allocate a terminal as part of the session.
*
* (Rationale: the risk of control sequences is that they cause
* confusion when sent to a local terminal, so if there isn't one,
* no problem. Also, if we allocate a remote terminal, then we
* sent a terminal type, i.e. we told it what kind of escape
* sequences we _like_, i.e. we were expecting to receive some.)
*/
if (sanitise_stdout == FORCE_ON ||
(sanitise_stdout == AUTO && isatty(STDOUT_FILENO) &&
conf_get_bool(conf, CONF_nopty))) {
stdout_scc = stripctrl_new(stdout_bs, true, L'\0');
stdout_bs = BinarySink_UPCAST(stdout_scc);
}
if (sanitise_stderr == FORCE_ON ||
(sanitise_stderr == AUTO && isatty(STDERR_FILENO) &&
conf_get_bool(conf, CONF_nopty))) {
stderr_scc = stripctrl_new(stderr_bs, true, L'\0');
stderr_bs = BinarySink_UPCAST(stderr_scc);
}
sk_init();
uxsel_init();
/*
* Plink doesn't provide any way to add forwardings after the
* connection is set up, so if there are none now, we can safely set
* the "simple" flag.
*/
if (conf_get_int(conf, CONF_protocol) == PROT_SSH &&
!conf_get_bool(conf, CONF_x11_forward) &&
!conf_get_bool(conf, CONF_agentfwd) &&
!conf_get_str_nthstrkey(conf, CONF_portfwd, 0))
conf_set_bool(conf, CONF_ssh_simple, true);
if (just_test_share_exists) {
if (!backvt->test_for_upstream) {
fprintf(stderr, "Connection sharing not supported for this "
"connection type (%s)'\n", backvt->displayname);
return 1;
}
if (backvt->test_for_upstream(conf_get_str(conf, CONF_host),
conf_get_int(conf, CONF_port), conf))
return 0;
else
return 1;
}
/*
* Start up the connection.
*/
logctx = log_init(console_cli_logpolicy, conf);
{
char *error, *realhost;
/* nodelay is only useful if stdin is a terminal device */
bool nodelay = conf_get_bool(conf, CONF_tcp_nodelay) && isatty(0);
/* This is a good place for a fuzzer to fork us. */
#ifdef __AFL_HAVE_MANUAL_CONTROL
__AFL_INIT();
#endif
error = backend_init(backvt, plink_seat, &backend, logctx, conf,
conf_get_str(conf, CONF_host),
conf_get_int(conf, CONF_port),
&realhost, nodelay,
conf_get_bool(conf, CONF_tcp_keepalives));
if (error) {
fprintf(stderr, "Unable to open connection:\n%s\n", error);
sfree(error);
return 1;
}
ldisc_create(conf, NULL, backend, plink_seat);
sfree(realhost);
}
/*
* Set up the initial console mode. We don't care if this call
* fails, because we know we aren't necessarily running in a
* console.
*/
local_tty = (tcgetattr(STDIN_FILENO, &orig_termios) == 0);
atexit(cleanup_termios);
seat_echoedit_update(plink_seat, 1, 1);
cli_main_loop(plink_pw_setup, plink_pw_check, plink_continue, NULL);
exitcode = backend_exitcode(backend);
if (exitcode < 0) {
fprintf(stderr, "Remote process exit code unavailable\n");
exitcode = 1; /* this is an error condition */
}
cleanup_exit(exitcode);
return exitcode; /* shouldn't happen, but placates gcc */
}