Move signal handling into dhcpcd.c

Log the PID of the signal caller
Move syslog functions out of the signal handler if we're not
exiting as it's not safe.
Close existing IPv4 sockets when restarting an interface.
Fix control handling keeping current flags and accepting new ones.

1 files changed, 56 insertions, 15 deletions

diff --git a/dhcpcd.c b/dhcpcd.c
index 253d3dfc..25e98072 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -66,7 +66,6 @@ const char copyright[] = "Copyright (c) 2006-2013 Roy Marples";
 #include "net.h"
 #include "platform.h"
 #include "script.h"
-#include "signals.h"
 
 struct if_head *ifaces = NULL;
 char vendor[VENDORCLASSID_MAX_LEN];
@@ -78,6 +77,15 @@ int ifdc = 0;
 char **ifdv = NULL;
 
 sigset_t dhcpcd_sigset;
+const int handle_sigs[] = {
+	SIGALRM,
+	SIGHUP,
+	SIGINT,
+	SIGPIPE,
+	SIGTERM,
+	SIGUSR1,
+	0
+};
 
 static char *cffile;
 static char *pidfile;
@@ -611,6 +619,7 @@ if_reboot(struct interface *ifp, int argc, char **argv)
 	oldopts = ifp->options->options;
 	configure_interface(ifp, argc, argv);
 	dhcp_reboot_newopts(ifp, oldopts);
+	dhcp6_reboot(ifp);
 	start_interface(ifp);
 }
 
@@ -634,8 +643,8 @@ reconf_reboot(int action, int argc, char **argv, int oi)
 				ipv4_applyaddr(ifn);
 			free_interface(ifp);
 		} else {
-			TAILQ_INSERT_TAIL(ifaces, ifp, next);
 			init_state(ifp, argc, argv);
+			TAILQ_INSERT_TAIL(ifaces, ifp, next);
 			start_interface(ifp);
 		}
 	}
@@ -646,11 +655,15 @@ reconf_reboot(int action, int argc, char **argv, int oi)
 
 /* ARGSUSED */
 static void
-sig_reboot(__unused void *arg)
+sig_reboot(void *arg)
 {
+	siginfo_t *siginfo = arg;
 	struct if_options *ifo;
 	int i;
 
+	syslog(LOG_INFO, "received SIGALRM from PID %d, rebinding",
+	    (int)siginfo->si_pid);
+
 	for (i = 0; i < ifac; i++)
 		free(ifav[i]);
 	free(ifav);
@@ -674,17 +687,20 @@ sig_reboot(__unused void *arg)
 }
 
 static void
-sig_reconf(__unused void *arg)
+sig_reconf(void *arg)
 {
+	siginfo_t *siginfo = arg;
 	struct interface *ifp;
 
+	syslog(LOG_INFO, "received SIGUSR from PID %d, reconfiguring",
+	    (int)siginfo->si_pid);
 	TAILQ_FOREACH(ifp, ifaces, next) {
 		ipv4_applyaddr(ifp);
 	}
 }
 
-void
-handle_signal(int sig)
+static void
+handle_signal(int sig, siginfo_t *siginfo, __unused void *context)
 {
 	struct interface *ifp;
 	int do_release;
@@ -692,30 +708,32 @@ handle_signal(int sig)
 	do_release = 0;
 	switch (sig) {
 	case SIGINT:
-		syslog(LOG_INFO, "received SIGINT, stopping");
+		syslog(LOG_INFO, "received SIGINT from PID %d, stopping",
+		    (int)siginfo->si_pid);
 		break;
 	case SIGTERM:
-		syslog(LOG_INFO, "received SIGTERM, stopping");
+		syslog(LOG_INFO, "received SIGTERM from PID %d, stopping",
+		    (int)siginfo->si_pid);
 		break;
 	case SIGALRM:
-		syslog(LOG_INFO, "received SIGALRM, rebinding");
-		eloop_timeout_add_now(sig_reboot, NULL);
+		eloop_timeout_add_now(sig_reboot, siginfo);
 		return;
 	case SIGHUP:
-		syslog(LOG_INFO, "received SIGHUP, releasing");
+		syslog(LOG_INFO, "received SIGHUP from PID %d, releasing",
+		    (int)siginfo->si_pid);
 		do_release = 1;
 		break;
 	case SIGUSR1:
-		syslog(LOG_INFO, "received SIGUSR, reconfiguring");
-		eloop_timeout_add_now(sig_reconf, NULL);
+		eloop_timeout_add_now(sig_reconf, siginfo);
 		return;
 	case SIGPIPE:
 		syslog(LOG_WARNING, "received SIGPIPE");
 		return;
 	default:
 		syslog(LOG_ERR,
-		    "received signal %d, but don't know what to do with it",
-		    sig);
+		    "received signal %d from PID %d, "
+		    "but don't know what to do with it",
+		    sig, (int)siginfo->si_pid);
 		return;
 	}
 
@@ -876,6 +894,29 @@ handle_args(struct fd_list *fd, int argc, char **argv)
 	return 0;
 }
 
+static int
+signal_init(void (*func)(int, siginfo_t *, void *), sigset_t *oldset)
+{
+	unsigned int i;
+	struct sigaction sa;
+	sigset_t newset;
+
+	sigfillset(&newset);
+	if (sigprocmask(SIG_SETMASK, &newset, oldset) == -1)
+		return -1;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = func;
+	sa.sa_flags = SA_SIGINFO;
+	sigemptyset(&sa.sa_mask);
+
+	for (i = 0; handle_sigs[i]; i++) {
+		if (sigaction(handle_sigs[i], &sa, NULL) == -1)
+			return -1;
+	}
+	return 0;
+}
+
 int
 main(int argc, char **argv)
 {