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/* unix_interact.c
*
* Interact with the user.
*
*/
/* lsh, an implementation of the ssh protocol
*
* Copyright (C) 1999 Niels Mller
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include "interact.h"
#include "format.h"
#include "io.h"
#include "lsh_string.h"
#include "resource.h"
#include "suspend.h"
#include "tty.h"
#include "werror.h"
#include "xalloc.h"
#include "unix_interact.c.x"
/* Depends on the tty being line buffered. FIXME: Doesn't distinguish
between errors, empty input, and EOF. */
static uint32_t
read_line(int fd, uint32_t size, uint8_t *buffer)
{
uint32_t i = 0;
while (i < size)
{
int res = read(fd, buffer + i, size - i);
if (!res)
/* User pressed EOF (^D) */
return i;
else if (res < 0)
switch(errno)
{
case EAGAIN:
case EINTR:
break;
default:
/* I/O error */
werror("unix_interact.c: read_line, %e\n", errno);
return 0;
}
else
{
uint32_t j;
for (j = 0; j < (unsigned) res; j++, i++)
if (buffer[i] == '\n')
return i;
}
}
/* We have filled our buffer already; continue reading until end of line */
#define BUFSIZE 512
for (;;)
{
uint8_t b[BUFSIZE];
int res = read(fd, b, BUFSIZE);
if (!res)
/* EOF */
return size;
else if (res < 0)
switch(errno)
{
case EAGAIN:
case EINTR:
break;
default:
/* I/O error */
werror("tty_read_line %e\n", errno);
return 0;
}
else
{
uint32_t j;
for (j = 0; j < (unsigned) res; j++)
if (b[j] == '\n')
return size;
}
}
#undef BUFSIZE
}
/* NOTE: If there are more than one instance of this class, window
* changes can be missed, as only one of them will have its signal
* handler installed properly. */
/* GABA:
(class
(name window_subscriber)
(super resource)
(vars
(interact object unix_interact)
(next object window_subscriber)
(callback object window_change_callback)))
*/
static void
do_kill_window_subscriber(struct resource *s)
{
CAST(window_subscriber, self, s);
if (self->super.alive)
{
self->super.alive = 0;
assert(self->interact->nsubscribers);
assert(self->interact->winch_handler);
if (!--self->interact->nsubscribers)
{
KILL_RESOURCE(self->interact->winch_handler);
self->interact->winch_handler = NULL;
}
}
}
/* FIXME: Remove subscribers list, and register multiple liboop signal
* handlers instead? */
/* GABA:
(class
(name unix_interact)
(super interact)
(vars
(tty_fd . int)
(askpass . "const char *")
; Signal handler
(winch_handler object resource)
(nsubscribers . unsigned)
(subscribers object window_subscriber)))
*/
#define IS_TTY(self) ((self)->tty_fd >= 0)
static int
unix_is_tty(struct interact *s)
{
CAST(unix_interact, self, s);
return IS_TTY(self);
}
/* FIXME: Rewrite to operate on tty_fd. */
static struct lsh_string *
read_password(struct unix_interact *self,
const struct lsh_string *prompt)
{
if (self->askpass)
{
const char *argv[3];
int null = open("/dev/null", O_RDONLY);
if (null < 0)
{
werror("Failed to open /dev/null!\n");
return NULL;
}
argv[0] = self->askpass;
argv[1] = lsh_get_cstring(prompt);
if (!argv[1])
{
close(null);
return NULL;
}
argv[2] = NULL;
trace("unix_interact.c: spawning askpass program `%z'\n",
self->askpass);
return lsh_popen_read(self->askpass, argv, null, 100);
}
else
{
/* NOTE: Ignores max_length; instead getpass's limit applies. */
char *password;
const char *cprompt;
if (!IS_TTY(self))
return NULL;
cprompt = lsh_get_cstring(prompt);
if (!cprompt)
return NULL;
/* NOTE: This function uses a static buffer. */
password = getpass(cprompt);
if (!password)
return NULL;
return make_string(password);
}
}
static struct lsh_string *
unix_read_password(struct interact *s,
uint32_t max_length UNUSED,
const struct lsh_string *prompt)
{
CAST(unix_interact, self, s);
struct lsh_string *password;
trace("unix_interact.c:unix_read_password\n");
password = read_password(self, prompt);
lsh_string_free(prompt);
return password;
}
static void
unix_set_askpass(struct interact *s,
const char *askpass)
{
CAST(unix_interact, self, s);
trace("unix_interact.c:unix_set_askpass\n");
assert(askpass);
self->askpass = askpass;
}
static int
unix_yes_or_no(struct interact *s,
const struct lsh_string *prompt,
int def, int free)
{
#define TTY_BUFSIZE 10
CAST(unix_interact, self, s);
if (!IS_TTY(self) || quiet_flag)
{
if (free)
lsh_string_free(prompt);
return def;
}
else
{
uint8_t buffer[TTY_BUFSIZE];
const struct exception *e;
e = write_raw(self->tty_fd, STRING_LD(prompt));
if (free)
lsh_string_free(prompt);
if (e)
return def;
if (!read_line(self->tty_fd, TTY_BUFSIZE, buffer))
return def;
switch (buffer[0])
{
case 'y':
case 'Y':
return 1;
default:
return 0;
}
#undef TTY_BUFSIZE
}
}
/* The prompts are typically not trusted, but it's the callers
responsibility to sanity check them. */
static int
unix_dialog(struct interact *s,
const struct interact_dialog *dialog)
{
#define DIALOG_BUFSIZE 150
CAST(unix_interact, self, s);
const struct exception *e;
unsigned i;
e = write_raw(self->tty_fd, STRING_LD(dialog->instruction));
if (e)
return 0;
for (i = 0; i < dialog->nprompt; i++)
{
struct lsh_string *prompt = dialog->prompt[i];
if (dialog->echo[i])
{
uint8_t buffer[DIALOG_BUFSIZE];
uint32_t length;
e = write_raw(self->tty_fd, STRING_LD(prompt));
if (e)
return 0;
length = read_line(self->tty_fd, DIALOG_BUFSIZE, buffer);
if (!length)
return 0;
dialog->response[i] = ssh_format("%ls", length, buffer);
}
else
{
if (!(dialog->response[i] = read_password(self, prompt)))
return 0;
}
}
return 1;
}
/* GABA:
(class
(name unix_termios)
(super terminal_attributes)
(vars
(ios . "struct termios")))
*/
static struct terminal_attributes *
do_make_raw(struct terminal_attributes *s)
{
CAST(unix_termios, self, s);
CLONED(unix_termios, res, self);
CFMAKERAW(&res->ios);
/* Modify VMIN and VTIME, to save some bandwidth and make traffic
* analysis of interactive sessions a little harder. */
res->ios.c_cc[VMIN] = 4;
/* Inter-character timer, in units of 0.1s */
res->ios.c_cc[VTIME] = 1;
return &res->super;
}
static struct lsh_string *
do_encode(struct terminal_attributes *s)
{
CAST(unix_termios, self, s);
return tty_encode_term_mode(&self->ios);
}
static struct terminal_attributes *
unix_get_attributes(struct interact *s)
{
CAST(unix_interact, self, s);
if (!IS_TTY(self))
return NULL;
else
{
NEW(unix_termios, res);
res->super.make_raw = do_make_raw;
res->super.encode = do_encode;
if (!tty_getattr(self->tty_fd, &res->ios) < 0)
{
KILL(res);
return NULL;
}
return &res->super;
}
}
static int
unix_set_attributes(struct interact *s,
struct terminal_attributes *a)
{
CAST(unix_interact, self, s);
CAST(unix_termios, attr, a);
return IS_TTY(self)
&& tty_setattr(self->tty_fd, &attr->ios);
}
static int
unix_window_size(struct interact *s,
struct terminal_dimensions *d)
{
CAST(unix_interact, self, s);
return IS_TTY(self)
&& tty_getwinsize(self->tty_fd, d);
}
/* GABA:
(class
(name winch_handler)
(super lsh_callback)
(vars
(interact object unix_interact)))
*/
static void
do_winch_handler(struct lsh_callback *s)
{
CAST(winch_handler, self, s);
struct unix_interact *i = self->interact;
assert(!!i->nsubscribers == !!i->winch_handler);
if (i->subscribers)
{
struct window_subscriber *s;
struct window_subscriber **s_p;
unsigned alive;
for (alive = 0, s_p = &i->subscribers; (s = *s_p) ;)
{
if (!s->super.alive)
*s_p = s->next;
else
{
WINDOW_CHANGE_CALLBACK(s->callback, &i->super);
s_p = &s->next;
alive++;
}
}
assert(alive == i->nsubscribers);
}
}
static struct lsh_callback *
make_winch_handler(struct unix_interact *i)
{
NEW(winch_handler, self);
self->super.f = do_winch_handler;
self->interact = i;
return &self->super;
}
static struct resource *
unix_window_change_subscribe(struct interact *s,
struct window_change_callback *callback)
{
CAST(unix_interact, self, s);
NEW(window_subscriber, subscriber);
init_resource(&subscriber->super, do_kill_window_subscriber);
subscriber->interact = self;
subscriber->next = self->subscribers;
subscriber->callback = callback;
self->subscribers = subscriber;
self->nsubscribers++;
if (!self->winch_handler)
{
/* This is the first subscriber */
self->winch_handler
= io_signal_handler(SIGWINCH,
make_winch_handler(self));
}
return &subscriber->super;
}
struct interact *
make_unix_interact(void)
{
NEW(unix_interact, self);
self->super.is_tty = unix_is_tty;
self->super.read_password = unix_read_password;
self->super.set_askpass = unix_set_askpass;
self->super.yes_or_no = unix_yes_or_no;
self->super.dialog = unix_dialog;
self->super.get_attributes = unix_get_attributes;
self->super.set_attributes = unix_set_attributes;
self->super.window_size = unix_window_size;
self->super.window_change_subscribe = unix_window_change_subscribe;
self->tty_fd = -1;
self->askpass = NULL;
#if HAVE_STDTTY_FILENO
if (isatty(STDTTY_FILENO))
self->tty_fd = STDTTY_FILENO;
#else /* ! HAVE_STDTTY_FILENO */
self->tty_fd = open("/dev/tty", O_RDWR);
#endif
if (self->tty_fd >= 0)
{
io_set_close_on_exec(self->tty_fd);
/* Restore and reset tty if process is suspended. */
suspend_handle_tty(self->tty_fd);
}
return &self->super;
}
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