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Add support for adding a utmp entry when allocating a new pty.

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Requires the BSD login(3) or SYSV/POSIX getutent()/getutxent().
Currently only creates a new entry if the existing tty has
a utmp entry.
This commit is contained in:
Todd C. Miller
2011-03-08 15:37:40 -05:00
parent 9c9c0223e6
commit 1496bfed6c
6 changed files with 302 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
config.h.in
View File

@@ -313,6 +313,9 @@
/* Define to 1 if you have the `lockf' function. */
#undef HAVE_LOCKF
/* Define to 1 if you have the `login' function. */
#undef HAVE_LOGIN
/* Define to 1 if you have the <login_cap.h> header file. */
#undef HAVE_LOGIN_CAP_H
@@ -552,6 +555,9 @@
/* Define to 1 if you have the <utime.h> header file. */
#undef HAVE_UTIME_H
/* Define to 1 if you have the <utmp.h> header file. */
#undef HAVE_UTMP_H
/* Define to 1 if you have the `vasprintf' function. */
#undef HAVE_VASPRINTF

100
configure vendored
View File

@@ -15039,7 +15039,7 @@ LIBS=$ac_save_LIBS
for ac_func in strrchr sysconf tzset strftime initgroups getgroups fstat \
regcomp setlocale nl_langinfo getaddrinfo mbr_check_membership \
setrlimit64
setrlimit64 sysctl
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -15083,7 +15083,7 @@ done
fi
done
for ac_func in sysctl getutxid getutid
for ac_func in getutxid getutid
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -15092,10 +15092,104 @@ eval as_val=\$$as_ac_var
cat >>confdefs.h <<_ACEOF
#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
_ACEOF
break
utmp=POSIX; break
fi
done
if test "${utmp-NONE}" = "NONE"; then
for ac_func in login
do :
ac_fn_c_check_func "$LINENO" "login" "ac_cv_func_login"
if test "x$ac_cv_func_login" = x""yes; then :
cat >>confdefs.h <<_ACEOF
#define HAVE_LOGIN 1
_ACEOF
UTMP=BSD
for ac_header in util.h utmp.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
eval as_val=\$$as_ac_Header
if test "x$as_val" = x""yes; then :
cat >>confdefs.h <<_ACEOF
#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
_ACEOF
break
fi
done
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for login in -lutil" >&5
$as_echo_n "checking for login in -lutil... " >&6; }
if test "${ac_cv_lib_util_login+set}" = set; then :
$as_echo_n "(cached) " >&6
else
ac_check_lib_save_LIBS=$LIBS
LIBS="-lutil $LIBS"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char login ();
int
main ()
{
return login ();
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_lib_util_login=yes
else
ac_cv_lib_util_login=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
LIBS=$ac_check_lib_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_util_login" >&5
$as_echo "$ac_cv_lib_util_login" >&6; }
if test "x$ac_cv_lib_util_login" = x""yes; then :
UTMP=BSD
for ac_header in util.h utmp.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
eval as_val=\$$as_ac_Header
if test "x$as_val" = x""yes; then :
cat >>confdefs.h <<_ACEOF
#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
_ACEOF
break
fi
done
case "$SUDO_LIBS" in
*-lutil*) ;;
*) SUDO_LIBS="${SUDO_LIBS} -lutil";;
esac
$as_echo "#define HAVE_LOGIN 1" >>confdefs.h
fi
fi
done
fi
for ac_func in openpty
do :

20
configure.in
View File

@@ -1968,12 +1968,28 @@ dnl
AC_FUNC_GETGROUPS
AC_CHECK_FUNCS(strrchr sysconf tzset strftime initgroups getgroups fstat \
regcomp setlocale nl_langinfo getaddrinfo mbr_check_membership \
setrlimit64)
setrlimit64 sysctl)
AC_CHECK_FUNCS(getline, [], [
AC_LIBOBJ(getline)
AC_CHECK_FUNCS(fgetln)
])
AC_CHECK_FUNCS(sysctl getutxid getutid, [break])
AC_CHECK_FUNCS(getutxid getutid, [utmp=POSIX; break])
if test "${utmp-NONE}" = "NONE"; then
AC_CHECK_FUNCS(login, [
UTMP=BSD
AC_CHECK_HEADERS(util.h utmp.h, [break])
], [
AC_CHECK_LIB(util, login, [
UTMP=BSD
AC_CHECK_HEADERS(util.h utmp.h, [break])
case "$SUDO_LIBS" in
*-lutil*) ;;
*) SUDO_LIBS="${SUDO_LIBS} -lutil";;
esac
AC_DEFINE(HAVE_LOGIN)
])
])
fi
AC_CHECK_FUNCS(openpty, [AC_CHECK_HEADERS(util.h pty.h, [break])], [
AC_CHECK_LIB(util, openpty, [

2
src/exec.c
View File

@@ -234,7 +234,7 @@ sudo_execve(struct command_details *details, char *argv[], char *envp[],
log_io = TRUE;
if (!ISSET(details->flags, CD_BACKGROUND)) {
sudo_debug(8, "allocate pty for I/O logging");
pty_setup(details->euid);
pty_setup(details->euid, user_details.tty);
}
}

180
src/exec_pty.c
View File

@@ -52,6 +52,14 @@
#if TIME_WITH_SYS_TIME
# include <time.h>
#endif
#if defined(HAVE_GETUTXID)
# include <utmpx.h>
#elif defined(HAVE_GETUTID)
# include <utmp.h>
#elif defined(HAVE_UTIL_H)
# include <util.h>
# include <utmp.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
@@ -109,6 +117,159 @@ static void sync_ttysize(int src, int dst);
static void deliver_signal(pid_t pid, int signo);
static int safe_close(int fd);
#if defined(HAVE_GETUTXID) || defined(HAVE_GETUTID)
/*
* Create ut_id from tty line and the id from the entry we are cloning.
*/
static void
utmp_setid(const char *line, const char *old_id, char *new_id, size_t idsize)
{
size_t idlen;
/* Skip over "tty" in the id if old entry did too. */
if (strncmp(line, "tty", 3) == 0 &&
strncmp(old_id, "tty", idsize < 3 ? idsize : 3) != 0)
line += 3;
/* Store as much as will fit, skipping parts of the beginning as needed. */
idlen = strlen(line);
if (idlen > idsize) {
line += (idlen - idsize);
idlen = idsize;
}
strncpy(new_id, line, idlen);
}
#endif /* HAVE_GETUTXID || HAVE_GETUTID */
/*
* Clone a utmp entry, updating the line, id, pid and time.
* XXX - if no existing entry, make a new one
*/
static int
utmp_doclone(const char *from_line, const char *to_line)
{
int rval = FALSE;
#ifdef HAVE_GETUTXID
struct utmpx *ut_old, ut_new;
memset(&ut_new, 0, sizeof(ut_new));
strncpy(ut_new.ut_line, from_line, sizeof(ut_new.ut_line));
setutxent();
if ((ut_old = getutxid(&ut_new)) != NULL) {
if (ut_old != &ut_new)
memcpy(&ut_new, ut_old, sizeof(ut_new));
strncpy(ut_new.ut_line, to_line, sizeof(ut_new.ut_line));
utmp_setid(to_line, ut_old->ut_id, ut_new.ut_id, sizeof(ut_new.ut_id));
ut_new.ut_pid = getpid();
gettimeofday(&ut_new.ut_tv, NULL);
ut_new.ut_type = USER_PROCESS;
if (pututxline(&ut_new) != NULL)
rval = TRUE;
}
endutxent();
#elif HAVE_GETUTID
struct utmp *ut_old, ut_new;
memset(&ut_new, 0, sizeof(ut_new));
strncpy(ut_new.ut_line, from_line, sizeof(ut_new.ut_line));
setutent();
if ((ut_old = getutid(&ut_new)) != NULL) {
if (ut_old != &ut_new)
memcpy(&ut_new, ut_old, sizeof(ut_new));
strncpy(ut_new.ut_line, to_line, sizeof(ut_new.ut_line));
utmp_setid(to_line, ut_old->ut_id, ut_new.ut_id, sizeof(ut_new.ut_id));
ut_new.ut_pid = getpid();
ut_new.ut_time = time(NULL);
ut_new.ut_type = USER_PROCESS;
if (pututline(&ut_new) != NULL)
rval = TRUE;
}
endutent();
#elif HAVE_LOGIN
FILE *fp;
struct utmp ut;
/* Find existing entry, update line and add as new. */
if ((fp = fopen(_PATH_UTMP, "r")) != NULL) {
while (fread(&ut, sizeof(ut), 1, fp) == 1) {
if (ut.ut_name[0] &&
strncmp(ut.ut_line, from_line, sizeof(ut.ut_line)) == 0) {
strncpy(ut.ut_line, to_line, sizeof(ut.ut_line));
login(&ut);
rval = TRUE;
break;
}
}
fclose(fp);
}
#endif
return rval;
}
static int
utmp_clone(const char *from_line, const char *to_line)
{
/* Strip off /dev/ prefix from to/from line as needed. */
if (strncmp(from_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
from_line += sizeof(_PATH_DEV) - 1;
if (strncmp(to_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
to_line += sizeof(_PATH_DEV) - 1;
return utmp_doclone(from_line, to_line);
}
/*
* Remove (zero out) the utmp entry for a line.
*/
static int
utmp_doremove(const char *line)
{
int rval = FALSE;
#ifdef HAVE_GETUTXID
struct utmpx *ut, key;
memset(&key, 0, sizeof(key));
strncpy(key.ut_line, line, sizeof(key.ut_line));
setutxent();
if ((ut = getutxid(&key)) != NULL) {
ut->ut_type = DEAD_PROCESS;
(void)gettimeofday(&ut->ut_tv, NULL);
if (pututxline(ut) != NULL)
rval = TRUE;
}
endutxent();
#elif HAVE_GETUTID
struct utmp *ut, key;
memset(&key, 0, sizeof(key));
strncpy(key.ut_line, line, sizeof(key.ut_line));
setutent();
if ((ut = getutid(&key)) != NULL) {
ut->ut_type = DEAD_PROCESS;
ut->ut_time = time(NULL);
if (pututline(ut) != NULL)
rval = TRUE;
}
endutent();
#elif HAVE_LOGIN
if (logout(line) != 0)
rval = TRUE;
#endif /* HAVE_GETUTXID */
return rval;
}
static int
utmp_remove(const char *line)
{
/* Strip off /dev/ prefix from to/from line as needed. */
if (strncmp(line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
line += sizeof(_PATH_DEV) - 1;
return utmp_doremove(line);
}
/*
* Cleanup hook for error()/errorx()
*/
@@ -120,6 +281,7 @@ cleanup(int gotsignal)
#ifdef HAVE_SELINUX
selinux_restore_tty();
#endif
utmp_remove(slavename);
}
/*
@@ -128,13 +290,28 @@ cleanup(int gotsignal)
* and slavename globals.
*/
void
pty_setup(uid_t uid)
pty_setup(uid_t uid, const char *tty)
{
io_fds[SFD_USERTTY] = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
if (io_fds[SFD_USERTTY] != -1) {
int sfd;
if (!get_pty(&io_fds[SFD_MASTER], &io_fds[SFD_SLAVE],
slavename, sizeof(slavename), uid))
error(1, "Can't get pty");
/*
* Add entry to utmp/utmpx.
* Temporarily point stdin to the pty slave for the benefit of
* legacy utmp handling that uses ttyslot().
*/
if ((sfd = dup(STDIN_FILENO)) == -1)
error(1, "Can't save stdin");
if (dup2(io_fds[SFD_SLAVE], STDIN_FILENO) == -1)
error(1, "Can't dup2 stdin");
utmp_clone(tty, slavename);
if (dup2(sfd, STDIN_FILENO) == -1)
error(1, "Can't restore stdin");
close(sfd);
}
}
@@ -654,6 +831,7 @@ pty_close(struct command_status *cstat)
}
}
}
utmp_remove(slavename);
}
/*

2
src/sudo_exec.h
View File

@@ -39,7 +39,7 @@ int suspend_parent(int signo);
void fd_set_iobs(fd_set *fdsr, fd_set *fdsw);
void handler(int s);
void pty_close(struct command_status *cstat);
void pty_setup(uid_t uid);
void pty_setup(uid_t uid, const char *tty);
void terminate_child(pid_t pid, int use_pgrp);
extern int signal_pipe[2];