/* vi: set sw=4 ts=4: */
-/* signalpipe.c
- *
+/*
* Signal pipe infrastructure. A reliable way of delivering signals.
*
* Russ Dill <Russ.Dill@asu.edu> December 2003
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-
#include "common.h"
-
-static int signal_pipe[2];
+/* Global variable: we access it from signal handler */
+static struct fd_pair signal_pipe;
static void signal_handler(int sig)
{
unsigned char ch = sig; /* use char, avoid dealing with partial writes */
- if (write(signal_pipe[1], &ch, 1) != 1)
- bb_perror_msg("cannot send signal");
+ if (write(signal_pipe.wr, &ch, 1) != 1)
+ bb_perror_msg("can't send signal");
}
-
/* Call this before doing anything else. Sets up the socket pair
* and installs the signal handler */
-void udhcp_sp_setup(void)
+void FAST_FUNC udhcp_sp_setup(void)
{
/* was socketpair, but it needs AF_UNIX in kernel */
- xpipe(signal_pipe);
- close_on_exec_on(signal_pipe[0]);
- close_on_exec_on(signal_pipe[1]);
- ndelay_on(signal_pipe[1]);
- signal(SIGUSR1, signal_handler);
- signal(SIGUSR2, signal_handler);
- signal(SIGTERM, signal_handler);
+ xpiped_pair(signal_pipe);
+ close_on_exec_on(signal_pipe.rd);
+ close_on_exec_on(signal_pipe.wr);
+ ndelay_on(signal_pipe.wr);
+ bb_signals(0
+ + (1 << SIGUSR1)
+ + (1 << SIGUSR2)
+ + (1 << SIGTERM)
+ , signal_handler);
}
-
/* Quick little function to setup the rfds. Will return the
* max_fd for use with select. Limited in that you can only pass
* one extra fd */
-int udhcp_sp_fd_set(fd_set *rfds, int extra_fd)
+int FAST_FUNC udhcp_sp_fd_set(fd_set *rfds, int extra_fd)
{
FD_ZERO(rfds);
- FD_SET(signal_pipe[0], rfds);
+ FD_SET(signal_pipe.rd, rfds);
if (extra_fd >= 0) {
close_on_exec_on(extra_fd);
FD_SET(extra_fd, rfds);
}
- return signal_pipe[0] > extra_fd ? signal_pipe[0] : extra_fd;
+ return signal_pipe.rd > extra_fd ? signal_pipe.rd : extra_fd;
}
-
/* Read a signal from the signal pipe. Returns 0 if there is
* no signal, -1 on error (and sets errno appropriately), and
* your signal on success */
-int udhcp_sp_read(fd_set *rfds)
+int FAST_FUNC udhcp_sp_read(const fd_set *rfds)
{
unsigned char sig;
- if (!FD_ISSET(signal_pipe[0], rfds))
+ if (!FD_ISSET(signal_pipe.rd, rfds))
return 0;
- if (read(signal_pipe[0], &sig, 1) != 1)
+ if (safe_read(signal_pipe.rd, &sig, 1) != 1)
return -1;
return sig;