diff options
Diffstat (limited to 'lib/sigevent.c')
| -rw-r--r-- | lib/sigevent.c | 36 |
1 files changed, 26 insertions, 10 deletions
diff --git a/lib/sigevent.c b/lib/sigevent.c index c7c1e134..5dfb67cf 100644 --- a/lib/sigevent.c +++ b/lib/sigevent.c @@ -147,8 +147,8 @@ static sigset_t qsig_interrupts[1] ; static sigset_t qsig_reserved[1] ; static void qsig_add(int signo, qsig_event* event) ; -static int signal_set_set(sigset_t* set, sig_handler* handler) ; -static int signal_set(int signo, sig_handler* handler) ; +static int signal_set_set(sigset_t* set, sig_handler* handler, bool required) ; +static int signal_set(int signo, sig_handler* handler, bool required) ; static void __attribute__ ((noreturn)) core_handler(int signo, siginfo_t *info, void *context) ; @@ -362,11 +362,11 @@ signal_init (struct thread_master *m, int sigc, sigsubsets(core_signals, qsig_interrupts) ; /* Install handlers */ - signal_set_set(core_signals, core_handler) ; - signal_set_set(exit_signals, exit_handler) ; - signal_set_set(ignore_signals, NULL) ; - signal_set_set(qsig_signals, quagga_signal_handler) ; - signal_set_set(qsig_interrupts, quagga_interrupt_handler) ; + signal_set_set(core_signals, core_handler, false) ; + signal_set_set(exit_signals, exit_handler, false) ; + signal_set_set(ignore_signals, NULL, false) ; + signal_set_set(qsig_signals, quagga_signal_handler, true) ; + signal_set_set(qsig_interrupts, quagga_interrupt_handler, true) ; /* If using a timer thread to scan for signal events, start that now. */ @@ -695,7 +695,7 @@ quagga_signal_reset(void) * Returns: < 0 => failed -- value is - failing signo ! */ static int -signal_set_set(sigset_t* set, sig_handler* handler) +signal_set_set(sigset_t* set, sig_handler* handler, bool required) { int signo ; @@ -707,7 +707,7 @@ signal_set_set(sigset_t* set, sig_handler* handler) if (s < 0) break ; if (s > 0) - if (signal_set(signo, handler) < 0) + if (signal_set(signo, handler, required) < 0) return -signo ; } ; @@ -727,10 +727,26 @@ signal_set_set(sigset_t* set, sig_handler* handler) #endif static int -signal_set(int signo, sig_handler* handler) +signal_set(int signo, sig_handler* handler, bool required) { struct sigaction act[1] ; + /* If a signal handler is already set for the given signal then we leave + * that as it is -- unless this is one of the "required" signals, used by + * Quagga. + */ + sigaction(signo, NULL, act) ; + + if ((act->sa_handler != SIG_DFL) && (act->sa_handler != SIG_IGN)) + { + if (!required) + return 0 ; + } ; + + /* Set our handler */ + + memset(act, 0, sizeof(struct sigaction)) ; + if (handler == NULL) { act->sa_handler = SIG_IGN ; |