Signed-off-by: Karel Zak <kzak@xxxxxxxxxx>
---
login-utils/login.c | 200 +++++++++++++++++++++++++++------------------------
1 files changed, 106 insertions(+), 94 deletions(-)
diff --git a/login-utils/login.c b/login-utils/login.c
index 950af99..1011206 100644
--- a/login-utils/login.c
+++ b/login-utils/login.c
@@ -117,7 +117,9 @@ struct login_context {
* This bounds the time given to login. Not a define so it can
* be patched on machines where it's too small.
*/
-int timeout = LOGIN_TIMEOUT;
+static int timeout = LOGIN_TIMEOUT;
+static int child_pid = 0;
+static volatile int got_sig = 0;
static void timedout(int);
static void sigint(int);
@@ -334,9 +336,6 @@ static void log_btmp(struct login_context *cxt)
updwtmp(_PATH_BTMP, &ut);
}
-static int child_pid = 0;
-static volatile int got_sig = 0;
-
/*
* This handler allows to inform a shell about signals to login. If you have
* (root) permissions you can kill all login childrent by one signal to login
@@ -822,6 +821,106 @@ static int get_hushlogin_status(struct passwd *pwd)
return 0;
}
+/*
+ * Detach the controlling terminal, fork, restore syslog stuff and create a new
+ * session.
+ */
+static void fork_session(struct login_context *cxt)
+{
+ struct sigaction sa, oldsa_hup, oldsa_term;
+
+ signal(SIGALRM, SIG_DFL);
+ signal(SIGQUIT, SIG_DFL);
+ signal(SIGTSTP, SIG_IGN);
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_IGN;
+ sigaction(SIGINT, &sa, NULL);
+
+ sigaction(SIGHUP, &sa, &oldsa_hup); /* ignore when TIOCNOTTY */
+
+ /*
+ * detach the controlling tty
+ * -- we needn't the tty in parent who waits for child only.
+ * The child calls setsid() that detach from the tty as well.
+ */
+ ioctl(0, TIOCNOTTY, NULL);
+
+ /*
+ * We have care about SIGTERM, because leave PAM session without
+ * pam_close_session() is pretty bad thing.
+ */
+ sa.sa_handler = sig_handler;
+ sigaction(SIGHUP, &sa, NULL);
+ sigaction(SIGTERM, &sa, &oldsa_term);
+
+ closelog();
+
+ /*
+ * We must fork before setuid() because we need to call
+ * pam_close_session() as root.
+ */
+ child_pid = fork();
+ if (child_pid < 0) {
+ /*
+ * fork() error
+ */
+ warn(_("fork failed"));
+
+ pam_setcred(cxt->pamh, PAM_DELETE_CRED);
+ pam_end(cxt->pamh, pam_close_session(cxt->pamh, 0));
+ exit(EXIT_FAILURE);
+ }
+
+ if (child_pid) {
+ /*
+ * parent - wait for child to finish, then cleanup session
+ */
+ close(0);
+ close(1);
+ close(2);
+ sa.sa_handler = SIG_IGN;
+ sigaction(SIGQUIT, &sa, NULL);
+ sigaction(SIGINT, &sa, NULL);
+
+ /* wait as long as any child is there */
+ while (wait(NULL) == -1 && errno == EINTR) ;
+ openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
+
+ pam_setcred(cxt->pamh, PAM_DELETE_CRED);
+ pam_end(cxt->pamh, pam_close_session(cxt->pamh, 0));
+ exit(EXIT_SUCCESS);
+ }
+
+ /*
+ * child
+ */
+ sigaction(SIGHUP, &oldsa_hup, NULL); /* restore old state */
+ sigaction(SIGTERM, &oldsa_term, NULL);
+ if (got_sig)
+ exit(EXIT_FAILURE);
+
+ /*
+ * Problem: if the user's shell is a shell like ash that doesnt do
+ * setsid() or setpgrp(), then a ctrl-\, sending SIGQUIT to every
+ * process in the pgrp, will kill us.
+ */
+
+ /* start new session */
+ setsid();
+
+ /* make sure we have a controlling tty */
+ open_tty(cxt->tty_path);
+ openlog("login", LOG_ODELAY, LOG_AUTHPRIV); /* reopen */
+
+ /*
+ * TIOCSCTTY: steal tty from other process group.
+ */
+ if (ioctl(0, TIOCSCTTY, 1))
+ syslog(LOG_ERR, _("TIOCSCTTY failed: %m"));
+ signal(SIGINT, SIG_DFL);
+}
+
int main(int argc, char **argv)
{
extern int optind;
@@ -836,7 +935,6 @@ int main(int argc, char **argv)
char *buff;
int childArgc = 0;
int retcode;
- struct sigaction sa, oldsa_hup, oldsa_term;
char *pwdbuf = NULL;
struct passwd *pwd = NULL, _pwd;
@@ -1120,97 +1218,11 @@ int main(int argc, char **argv)
#endif
}
- signal(SIGALRM, SIG_DFL);
- signal(SIGQUIT, SIG_DFL);
- signal(SIGTSTP, SIG_IGN);
-
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = SIG_IGN;
- sigaction(SIGINT, &sa, NULL);
-
- sigaction(SIGHUP, &sa, &oldsa_hup); /* ignore when TIOCNOTTY */
-
/*
- * detach the controlling tty
- * -- we needn't the tty in parent who waits for child only.
- * The child calls setsid() that detach from the tty as well.
+ * Detach the controlling terminal, fork() and create, new session
+ * and reinilizalize syslog stuff.
*/
- ioctl(0, TIOCNOTTY, NULL);
-
- /*
- * We have care about SIGTERM, because leave PAM session without
- * pam_close_session() is pretty bad thing.
- */
- sa.sa_handler = sig_handler;
- sigaction(SIGHUP, &sa, NULL);
- sigaction(SIGTERM, &sa, &oldsa_term);
-
- closelog();
-
- /*
- * We must fork before setuid() because we need to call
- * pam_close_session() as root.
- */
-
- child_pid = fork();
- if (child_pid < 0) {
- /*
- * fork() error
- */
- warn(_("fork failed"));
-
- pam_setcred(cxt.pamh, PAM_DELETE_CRED);
- pam_end(cxt.pamh, pam_close_session(cxt.pamh, 0));
- exit(EXIT_FAILURE);
- }
-
- if (child_pid) {
- /*
- * parent - wait for child to finish, then cleanup session
- */
- close(0);
- close(1);
- close(2);
- sa.sa_handler = SIG_IGN;
- sigaction(SIGQUIT, &sa, NULL);
- sigaction(SIGINT, &sa, NULL);
-
- /* wait as long as any child is there */
- while (wait(NULL) == -1 && errno == EINTR) ;
- openlog("login", LOG_ODELAY, LOG_AUTHPRIV);
-
- pam_setcred(cxt.pamh, PAM_DELETE_CRED);
- pam_end(cxt.pamh, pam_close_session(cxt.pamh, 0));
- exit(EXIT_SUCCESS);
- }
-
- /* child */
-
- /* restore to old state */
- sigaction(SIGHUP, &oldsa_hup, NULL);
- sigaction(SIGTERM, &oldsa_term, NULL);
- if (got_sig)
- exit(EXIT_FAILURE);
-
- /*
- * Problem: if the user's shell is a shell like ash that doesnt do
- * setsid() or setpgrp(), then a ctrl-\, sending SIGQUIT to every
- * process in the pgrp, will kill us.
- */
-
- /* start new session */
- setsid();
-
- /* make sure we have a controlling tty */
- open_tty(cxt.tty_path);
- openlog("login", LOG_ODELAY, LOG_AUTHPRIV); /* reopen */
-
- /*
- * TIOCSCTTY: steal tty from other process group.
- */
- if (ioctl(0, TIOCSCTTY, 1))
- syslog(LOG_ERR, _("TIOCSCTTY failed: %m"));
- signal(SIGINT, SIG_DFL);
+ fork_session(&cxt);
/* discard permissions last so can't get killed and drop core */
if (setuid(pwd->pw_uid) < 0 && pwd->pw_uid) {
--
1.7.6.4
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