diff options
Diffstat (limited to 'utils')
| -rw-r--r-- | utils/login.c | 97 |
1 files changed, 48 insertions, 49 deletions
diff --git a/utils/login.c b/utils/login.c index c8a9a0ef..7d2d9997 100644 --- a/utils/login.c +++ b/utils/login.c @@ -30,6 +30,7 @@ #include <grp.h> #include <netdb.h> #include <time.h> +#include <assert.h> #include <netinet/in.h> #include <arpa/inet.h> @@ -293,6 +294,26 @@ kill_login (process_t proc_server, pid_t pid, int sig) while (!err && num_pids > 0); } +/* Looks at the login collection LID. If the root process (with PID == LID) + is owned by someone, then exit (0). Otherwise, return true if the root + process still exists, and 0 otherwise. */ +static int +watch_login (process_t proc_server, int lid) +{ + int owned; + error_t err = check_owned (proc_server, lid, &owned); + + if (err == ESRCH) + return 0; + else + assert_perror (err); + + if (owned) + exit (0); /* Our task is done. */ + + return 1; +} + /* Forks a process which will kill the login session headed by PID after TIMEOUT seconds if PID still has no owner. */ static void @@ -300,9 +321,8 @@ dog (time_t timeout, pid_t pid, char **argv) { if (fork () == 0) { - int owned; - error_t err; char buf[25]; /* Be gratuitously pretty. */ + char *name = basename (argv[0]); time_t left = timeout; process_t proc_server = getproc (); @@ -313,46 +333,23 @@ dog (time_t timeout, pid_t pid, char **argv) /* Frob ARGV so that ps show something nice. */ fmt_named_interval (&tv, 0, buf, sizeof buf); - asprintf (&argv[0], "(watchdog for login %d: %s remaining)", pid, buf); + asprintf (&argv[0], "(watchdog for %s %d: %s remaining)", + name, pid, buf); argv[1] = 0; sleep (interval); left -= interval; + + if (watch_login (proc_server, pid)) + break; /* Login collection root has gone away. */ } - err = check_owned (proc_server, pid, &owned); - if (err == ESRCH) - /* The process has gone away. Maybe someone is trying to play games; - just see if *any* of the remaing processes in the login session - are owned, and give up if so (this can be foiled by setuid - processes, &c, but oh well; they can be set non-executable by - nobody). */ + if (watch_login (proc_server, pid)) + /* The root process has gone away. */ { - size_t num_pids = 20; - pid_t _pids[num_pids], *pids = _pids; - - err = proc_getloginpids (proc_server, pid, &pids, &num_pids); - if (! err) - { - int i; - - if (num_pids == 0) - exit (0); /* Login already aborted. Die silently. */ - - for (i = 0; i < num_pids; i++) - if (check_owned (proc_server, pids[i], &owned) == 0 && owned) - exit (0); /* Give up, luser wins. */ - } - - /* None are owned. Kill session after emitting cryptic, yet - stupid, message. */ putc ('\n', stderr); error (0, 0, "Beware of dog."); } - else if (err) - exit (1); /* Impossible error.... XXX */ - else if (owned) - exit (0); /* Use logged in. */ else /* Give normal you-forgot-to-login message. */ { @@ -784,6 +781,9 @@ main(int argc, char *argv[]) if (err) fail (3, err, "Authentication failure", 0); + err = proc_getsid (proc_server, pid, &sid); + assert_perror (err); /* This should never fail. */ + if (!no_login && count_parent_uids () != 0) /* Make a new login collection (but only for real users). */ { @@ -791,22 +791,22 @@ main(int argc, char *argv[]) if (user && *user) setlogin (user); proc_make_login_coll (proc_server); - } - if (eff_uids->num + avail_uids->num == 0 && count_parent_uids () != 0) - /* We're transiting from having some uids to having none, which means - this is probably a new login session. Unless specified otherwise, set - a timer to kill this session if it hasn't aquired any ids by then. - Note that we fork off the timer process before clearing the process - owner: because we're interested in killing unowned processes, proc's - in-same-login-session rule should apply to us (allowing us to kill - them), and this way they can't kill the watchdog (because it *does* - have an owner). */ - { - char *to = envz_get (args, args_len, "NOAUTH_TIMEOUT"); - time_t timeout = to ? atoi (to) : 0; - if (timeout) - dog (timeout, pid, argv); + if (eff_uids->num + avail_uids->num == 0) + /* We're transiting from having some uids to having none, which means + this is probably a new login session. Unless specified otherwise, + set a timer to kill this session if it hasn't aquired any ids by + then. Note that we fork off the timer process before clearing the + process owner: because we're interested in killing unowned + processes, proc's in-same-login-session rule should apply to us + (allowing us to kill them), and this way they can't kill the + watchdog (because it *does* have an owner). */ + { + char *to = envz_get (args, args_len, "NOAUTH_TIMEOUT"); + time_t timeout = to ? atoi (to) : 0; + if (timeout) + dog (timeout, pid, argv); + } } if (eff_uids->num > 0) @@ -996,8 +996,7 @@ main(int argc, char *argv[]) /* No more authentications to fail, so cross our fingers and add our utmp entry. */ - err = proc_getsid (proc_server, pid, &sid); - if (!err && pid == sid) + if (pid == sid) /* Only add utmp entries for the session leader. */ add_utmp_entry (args, args_len, !parent_has_uid (0)); |