#ifdef __TANDEM
# include <floss.h>
#endif
#include <config.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <unistd.h>
#include <pwd.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include "sudo.h"
#include "sudo_plugin.h"
static volatile sig_atomic_t signo[NSIG];
static bool tty_present(void);
static void tgetpass_handler(int);
static char *getln(int, char *, size_t, int);
static char *sudo_askpass(const char *, const char *);
static int
suspend(int signo, struct sudo_conv_callback *callback)
{
int rval = 0;
debug_decl(suspend, SUDO_DEBUG_CONV)
if (callback != NULL && SUDO_API_VERSION_GET_MAJOR(callback->version) != SUDO_CONV_CALLBACK_VERSION_MAJOR) {
sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO,
"callback major version mismatch, expected %u, got %u",
SUDO_CONV_CALLBACK_VERSION_MAJOR,
SUDO_API_VERSION_GET_MAJOR(callback->version));
callback = NULL;
}
if (callback != NULL && callback->on_suspend != NULL) {
if (callback->on_suspend(signo, callback->closure) == -1)
rval = -1;
}
kill(getpid(), signo);
if (callback != NULL && callback->on_resume != NULL) {
if (callback->on_resume(signo, callback->closure) == -1)
rval = -1;
}
debug_return_int(rval);
}
char *
tgetpass(const char *prompt, int timeout, int flags,
struct sudo_conv_callback *callback)
{
sigaction_t sa, savealrm, saveint, savehup, savequit, saveterm;
sigaction_t savetstp, savettin, savettou;
char *pass;
static const char *askpass;
static char buf[SUDO_CONV_REPL_MAX + 1];
int i, input, output, save_errno, neednl = 0, need_restart;
debug_decl(tgetpass, SUDO_DEBUG_CONV)
(void) fflush(stdout);
if (askpass == NULL) {
askpass = getenv_unhooked("SUDO_ASKPASS");
if (askpass == NULL || *askpass == '\0')
askpass = sudo_conf_askpass_path();
}
if (!ISSET(flags, TGP_STDIN|TGP_ECHO|TGP_ASKPASS|TGP_NOECHO_TRY) &&
!tty_present()) {
if (askpass == NULL || getenv_unhooked("DISPLAY") == NULL) {
sudo_warnx(U_("no tty present and no askpass program specified"));
debug_return_str(NULL);
}
SET(flags, TGP_ASKPASS);
}
if (ISSET(flags, TGP_ASKPASS)) {
if (askpass == NULL || *askpass == '\0')
sudo_fatalx(U_("no askpass program specified, try setting SUDO_ASKPASS"));
debug_return_str_masked(sudo_askpass(askpass, prompt));
}
restart:
for (i = 0; i < NSIG; i++)
signo[i] = 0;
pass = NULL;
save_errno = 0;
need_restart = 0;
if (ISSET(flags, TGP_STDIN) ||
(input = output = open(_PATH_TTY, O_RDWR)) == -1) {
input = STDIN_FILENO;
output = STDERR_FILENO;
}
if (!ISSET(flags, TGP_ECHO)) {
for (;;) {
if (ISSET(flags, TGP_MASK))
neednl = sudo_term_cbreak(input);
else
neednl = sudo_term_noecho(input);
if (neednl || errno != EINTR)
break;
if (suspend(SIGTTOU, callback) == -1) {
if (input != STDIN_FILENO)
(void) close(input);
debug_return_ptr(NULL);
}
}
}
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_INTERRUPT;
sa.sa_handler = tgetpass_handler;
(void) sigaction(SIGALRM, &sa, &savealrm);
(void) sigaction(SIGINT, &sa, &saveint);
(void) sigaction(SIGHUP, &sa, &savehup);
(void) sigaction(SIGQUIT, &sa, &savequit);
(void) sigaction(SIGTERM, &sa, &saveterm);
(void) sigaction(SIGTSTP, &sa, &savetstp);
(void) sigaction(SIGTTIN, &sa, &savettin);
(void) sigaction(SIGTTOU, &sa, &savettou);
if (prompt) {
if (write(output, prompt, strlen(prompt)) == -1)
goto restore;
}
if (timeout > 0)
alarm(timeout);
pass = getln(input, buf, sizeof(buf), ISSET(flags, TGP_MASK));
alarm(0);
save_errno = errno;
if (neednl || pass == NULL) {
if (write(output, "\n", 1) == -1)
goto restore;
}
restore:
(void) sigaction(SIGALRM, &savealrm, NULL);
(void) sigaction(SIGINT, &saveint, NULL);
(void) sigaction(SIGHUP, &savehup, NULL);
(void) sigaction(SIGQUIT, &savequit, NULL);
(void) sigaction(SIGTERM, &saveterm, NULL);
(void) sigaction(SIGTSTP, &savetstp, NULL);
(void) sigaction(SIGTTIN, &savettin, NULL);
(void) sigaction(SIGTTOU, &savettou, NULL);
if (!ISSET(flags, TGP_ECHO)) {
for (;;) {
if (sudo_term_restore(input, 1) || errno != EINTR)
break;
signo[SIGTTOU] = 0;
if (suspend(SIGTTOU, callback) == -1) {
pass = NULL;
break;
}
}
}
if (input != STDIN_FILENO)
(void) close(input);
for (i = 0; i < NSIG; i++) {
if (signo[i]) {
switch (i) {
case SIGTSTP:
case SIGTTIN:
case SIGTTOU:
if (suspend(i, callback) == 0)
need_restart = 1;
break;
default:
kill(getpid(), i);
break;
}
}
}
if (need_restart)
goto restart;
if (save_errno)
errno = save_errno;
debug_return_str_masked(pass);
}
static char *
sudo_askpass(const char *askpass, const char *prompt)
{
static char buf[SUDO_CONV_REPL_MAX + 1], *pass;
int pfd[2], status;
pid_t child;
debug_decl(sudo_askpass, SUDO_DEBUG_CONV)
if (pipe(pfd) == -1)
sudo_fatal(U_("unable to create pipe"));
child = sudo_debug_fork();
if (child == -1)
sudo_fatal(U_("unable to fork"));
if (child == 0) {
if (dup2(pfd[1], STDOUT_FILENO) == -1) {
sudo_warn("dup2");
_exit(255);
}
if (setuid(ROOT_UID) == -1)
sudo_warn("setuid(%d)", ROOT_UID);
if (setgid(user_details.gid)) {
sudo_warn(U_("unable to set gid to %u"), (unsigned int)user_details.gid);
_exit(255);
}
if (setuid(user_details.uid)) {
sudo_warn(U_("unable to set uid to %u"), (unsigned int)user_details.uid);
_exit(255);
}
closefrom(STDERR_FILENO + 1);
execl(askpass, askpass, prompt, (char *)NULL);
sudo_warn(U_("unable to run %s"), askpass);
_exit(255);
}
(void) close(pfd[1]);
pass = getln(pfd[0], buf, sizeof(buf), 0);
(void) close(pfd[0]);
for (;;) {
pid_t rv = waitpid(child, &status, 0);
if (rv == -1 && errno != EINTR)
break;
if (rv != -1 && !WIFSTOPPED(status))
break;
}
if (pass == NULL)
errno = EINTR;
debug_return_str_masked(pass);
}
extern int sudo_term_erase, sudo_term_kill;
static char *
getln(int fd, char *buf, size_t bufsiz, int feedback)
{
size_t left = bufsiz;
ssize_t nr = -1;
char *cp = buf;
char c = '\0';
debug_decl(getln, SUDO_DEBUG_CONV)
if (left == 0) {
errno = EINVAL;
debug_return_str(NULL);
}
while (--left) {
nr = read(fd, &c, 1);
if (nr != 1 || c == '\n' || c == '\r')
break;
if (feedback) {
if (c == sudo_term_kill) {
while (cp > buf) {
if (write(fd, "\b \b", 3) == -1)
break;
--cp;
}
left = bufsiz;
continue;
} else if (c == sudo_term_erase) {
if (cp > buf) {
if (write(fd, "\b \b", 3) == -1)
break;
--cp;
left++;
}
continue;
}
ignore_result(write(fd, "*", 1));
}
*cp++ = c;
}
*cp = '\0';
if (feedback) {
while (cp > buf) {
if (write(fd, "\b \b", 3) == -1)
break;
--cp;
}
}
debug_return_str_masked(nr == 1 ? buf : NULL);
}
static void
tgetpass_handler(int s)
{
if (s != SIGALRM)
signo[s] = 1;
}
static bool
tty_present(void)
{
#if defined(HAVE_STRUCT_KINFO_PROC2_P_TDEV) || defined(HAVE_STRUCT_KINFO_PROC_P_TDEV) || defined(HAVE_STRUCT_KINFO_PROC_KI_TDEV) || defined(HAVE_STRUCT_KINFO_PROC_KP_EPROC_E_TDEV) || defined(HAVE_STRUCT_PSINFO_PR_TTYDEV) || defined(HAVE_PSTAT_GETPROC) || defined(__linux__)
debug_decl(tty_present, SUDO_DEBUG_UTIL)
debug_return_bool(user_details.tty != NULL);
#else
int fd;
debug_decl(tty_present, SUDO_DEBUG_UTIL)
if ((fd = open(_PATH_TTY, O_RDWR)) != -1)
close(fd);
debug_return_bool(fd != -1);
#endif
}