uloop: Do not override signal handlers not installed by us

Signed-off-by: Michel Stam <m.stam@fugro.nl>

diff --git a/uloop.c b/uloop.c
index 9fedcce078e836ebb46c8997838aac7c8f7336c4..9a77ce49a5a7c2444a768eac3eb5059f52681fb3 100644 (file)
--- a/uloop.c
+++ b/uloop.c
@@ -558,28 +558,37 @@ static void uloop_sigchld(int signo)
        do_sigchld = true;
 }
 
-static void uloop_setup_signals(bool add)
+static void uloop_install_handler(int signum, void (*handler)(int), struct sigaction* old, bool add)
 {
-       static struct sigaction old_sigint, old_sigchld;
        struct sigaction s;
+       struct sigaction *act;
 
-       memset(&s, 0, sizeof(struct sigaction));
+       act = NULL;
+       sigaction(signum, NULL, &s);
 
        if (add) {
-               s.sa_handler = uloop_handle_sigint;
-               s.sa_flags = 0;
-       } else {
-               s = old_sigint;
+               if (s.sa_handler == SIG_DFL) { /* Do not override existing custom signal handlers */
+                       memcpy(old, &s, sizeof(struct sigaction));
+                       s.sa_handler = handler;
+                       s.sa_flags = 0;
+                       act = &s;
+               }
+       }
+       else if (s.sa_handler == handler) { /* Do not restore if someone modified our handler */
+                       act = old;
        }
 
-       sigaction(SIGINT, &s, &old_sigint);
+       if (act != NULL)
+               sigaction(signum, act, NULL);
+}
 
-       if (add)
-               s.sa_handler = uloop_sigchld;
-       else
-               s = old_sigchld;
+static void uloop_setup_signals(bool add)
+{
+       static struct sigaction old_sigint, old_sigchld, old_sigterm;
 
-       sigaction(SIGCHLD, &s, &old_sigchld);
+       uloop_install_handler(SIGINT, uloop_handle_sigint, &old_sigint, add);
+       uloop_install_handler(SIGTERM, uloop_handle_sigint, &old_sigterm, add);
+       uloop_install_handler(SIGCHLD, uloop_sigchld, &old_sigchld, add);
 }
 
 static int uloop_get_next_timeout(struct timeval *tv)