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putty-source/unix/plink.c
Simon Tatham a2ff884512 Richer data type for interactive prompt results. 
All the seat functions that request an interactive prompt of some kind
to the user - both the main seat_get_userpass_input and the various
confirmation dialogs for things like host keys - were using a simple
int return value, with the general semantics of 0 = "fail", 1 =
"proceed" (and in the case of seat_get_userpass_input, answers to the
prompts were provided), and -1 = "request in progress, wait for a
callback".

In this commit I change all those functions' return types to a new
struct called SeatPromptResult, whose primary field is an enum
replacing those simple integer values.

The main purpose is that the enum has not three but _four_ values: the
"fail" result has been split into 'user abort' and 'software abort'.
The distinction is that a user abort occurs as a result of an
interactive UI action, such as the user clicking 'cancel' in a dialog
box or hitting ^D or ^C at a terminal password prompt - and therefore,
there's no need to display an error message telling the user that the
interactive operation has failed, because the user already knows,
because they _did_ it. 'Software abort' is from any other cause, where
PuTTY is the first to know there was a problem, and has to tell the
user.

We already had this 'user abort' vs 'software abort' distinction in
other parts of the code - the SSH backend has separate termination
functions which protocol layers can call. But we assumed that any
failure from an interactive prompt request fell into the 'user abort'
category, which is not true. A couple of examples: if you configure a
host key fingerprint in your saved session via the SSH > Host keys
pane, and the server presents a host key that doesn't match it, then
verify_ssh_host_key would report that the user had aborted the
connection, and feel no need to tell the user what had gone wrong!
Similarly, if a password provided on the command line was not
accepted, then (after I fixed the semantics of that in the previous
commit) the same wrong handling would occur.

So now, those Seat prompt functions too can communicate whether the
user or the software originated a connection abort. And in the latter
case, we also provide an error message to present to the user. Result:
in those two example cases (and others), error messages should no
longer go missing.

Implementation note: to avoid the hassle of having the error message
in a SeatPromptResult being a dynamically allocated string (and hence,
every recipient of one must always check whether it's non-NULL and
free it on every exit path, plus being careful about copying the
struct around), I've instead arranged that the structure contains a
function pointer and a couple of parameters, so that the string form
of the message can be constructed on demand. That way, the only users
who need to free it are the ones who actually _asked_ for it in the
first place, which is a much smaller set.

(This is one of the rare occasions that I regret not having C++'s
extra features available in this code base - a unique_ptr or
shared_ptr to a string would have been just the thing here, and the
compiler would have done all the hard work for me of remembering where
to insert the frees!)
2021-12-28 18:08:31 +00:00

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/*
* 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, SeatOutputType type, const void *data, size_t len)
{
bool is_stderr = type != SEAT_OUTPUT_STDOUT;
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 SeatPromptResult plink_get_userpass_input(Seat *seat, prompts_t *p)
{
SeatPromptResult spr;
spr = cmdline_get_passwd_input(p);
if (spr.kind == SPRK_INCOMPLETE)
spr = console_get_userpass_input(p);
return spr;
}
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,
.banner = nullseat_banner_to_stderr,
.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,
.confirm_ssh_host_key = console_confirm_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,
.has_mixed_input_stream = console_has_mixed_input_stream,
.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(" -pwfile file login with password read from specified file\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_dataz(cmdbuf, 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_lc);
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_lc);
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 */
}
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