odhcp6c: sync and accumulate RA & DHCPv6 events correctly

3 files changed, 93 insertions, 54 deletions

diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index a71218c..133ade7 100644
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -25,7 +25,6 @@
 #include <stdbool.h>
 
 #include <net/if.h>
-#include <sys/wait.h>
 #include <sys/syscall.h>
 #include <arpa/inet.h>
 
@@ -46,10 +45,12 @@ static volatile bool signal_usr2 = false;
 static volatile bool signal_term = false;
 
 static int urandom_fd = -1, allow_slaac_only = 0;
-static bool bound = false, release = true;
+static bool bound = false, release = true, ra = false;
 static time_t last_update = 0;
 
 static unsigned int min_update_interval = DEFAULT_MIN_UPDATE_INTERVAL;
+static unsigned int script_sync_delay = 10;
+static unsigned int script_accu_delay = 1;
 
 int main(_unused int argc, char* const argv[])
 {
@@ -222,6 +223,9 @@ int main(_unused int argc, char* const argv[])
 		}
 	}
 
+	if (allow_slaac_only > 0)
+		script_sync_delay = allow_slaac_only;
+
 	openlog("odhcp6c", logopt, LOG_DAEMON);
 	if (!verbosity)
 		setlogmask(LOG_UPTO(LOG_WARNING));
@@ -234,7 +238,6 @@ int main(_unused int argc, char* const argv[])
 	signal(SIGIO, sighandler);
 	signal(SIGHUP, sighandler);
 	signal(SIGINT, sighandler);
-	signal(SIGCHLD, sighandler);
 	signal(SIGTERM, sighandler);
 	signal(SIGUSR1, sighandler);
 	signal(SIGUSR2, sighandler);
@@ -266,7 +269,7 @@ int main(_unused int argc, char* const argv[])
 		}
 	}
 
-	script_call("started");
+	script_call("started", 0, false);
 
 	while (!signal_term) { // Main logic
 		odhcp6c_clear_state(STATE_SERVER_ID);
@@ -316,7 +319,7 @@ int main(_unused int argc, char* const argv[])
 
 			while (!signal_usr2 && !signal_term) {
 				signal_usr1 = false;
-				script_call("informed");
+				script_call("informed", script_sync_delay, true);
 
 				int res = dhcpv6_poll_reconfigure();
 				odhcp6c_signal_process();
@@ -342,7 +345,7 @@ int main(_unused int argc, char* const argv[])
 
 		case DHCPV6_STATEFUL:
 			bound = true;
-			script_call("bound");
+			script_call("bound", script_sync_delay, true);
 			syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
 
 			while (!signal_usr2 && !signal_term) {
@@ -351,7 +354,7 @@ int main(_unused int argc, char* const argv[])
 				int res = dhcpv6_poll_reconfigure();
 				odhcp6c_signal_process();
 				if (res > 0) {
-					script_call("updated");
+					script_call("updated", 0, false);
 					continue;
 				}
 
@@ -366,7 +369,7 @@ int main(_unused int argc, char* const argv[])
 				odhcp6c_signal_process();
 				if (res > 0) { // Renew was succesfull
 					// Publish updates
-					script_call("updated");
+					script_call("updated", 0, false);
 					continue; // Renew was successful
 				}
 
@@ -385,7 +388,7 @@ int main(_unused int argc, char* const argv[])
 				odhcp6c_signal_process();
 
 				if (res > 0)
-					script_call("rebound");
+					script_call("rebound", 0, true);
 				else {
 					break;
 				}
@@ -405,7 +408,7 @@ int main(_unused int argc, char* const argv[])
 
 		// Add all prefixes to lost prefixes
 		bound = false;
-		script_call("unbound");
+		script_call("unbound", 0, true);
 
 		if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
 			dhcpv6_request(DHCPV6_MSG_RELEASE);
@@ -414,7 +417,7 @@ int main(_unused int argc, char* const argv[])
 		odhcp6c_clear_state(STATE_IA_PD);
 	}
 
-	script_call("stopped");
+	script_call("stopped", 0, true);
 	return 0;
 }
 
@@ -484,11 +487,16 @@ bool odhcp6c_signal_process(void)
 
 		bool ra_updated = ra_process();
 
-		if (ra_link_up())
+		if (ra_link_up()) {
 			signal_usr2 = true;
+			ra = false;
+		}
 
-		if (ra_updated && (bound || allow_slaac_only >= 0))
-			script_call("ra-updated"); // Immediate process urgent events
+		if (ra_updated && (bound || allow_slaac_only >= 0)) {
+			script_call("ra-updated", (!ra && !bound) ?
+					script_sync_delay : script_accu_delay, false);
+			ra = true;
+		}
 	}
 
 	return signal_usr1 || signal_usr2 || signal_term;
@@ -669,9 +677,7 @@ bool odhcp6c_is_bound(void)
 
 static void sighandler(int signal)
 {
-	if (signal == SIGCHLD)
-		while (waitpid(-1, NULL, WNOHANG) > 0);
-	else if (signal == SIGUSR1)
+	if (signal == SIGUSR1)
 		signal_usr1 = true;
 	else if (signal == SIGUSR2)
 		signal_usr2 = true;
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index c9a7398..d202790 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -324,7 +324,7 @@ int ra_conf_retransmit(int newvalue);
 
 int script_init(const char *path, const char *ifname);
 ssize_t script_unhexlify(uint8_t *dst, size_t len, const char *src);
-void script_call(const char *status);
+void script_call(const char *status, int delay, bool resume);
 
 bool odhcp6c_signal_process(void);
 uint64_t odhcp6c_get_milli_time(void);
diff --git a/src/script.c b/src/script.c
index dbdd89b..3d313cf 100644
--- a/src/script.c
+++ b/src/script.c
@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <inttypes.h>
 #include <arpa/inet.h>
+#include <sys/wait.h>
 #include <netinet/in.h>
 
 #include "odhcp6c.h"
@@ -39,14 +40,27 @@ static const int8_t hexvals[] = {
 };
 
 
+static char action[16] = "";
+static char *argv[4] = {NULL, NULL, action, NULL};
+static volatile pid_t running = 0;
+static time_t started;
 
-static char *argv[4] = {NULL, NULL, NULL, NULL};
 
+static void script_sighandle(int signal)
+{
+	if (signal == SIGCHLD) {
+		pid_t child;
+		while ((child = waitpid(-1, NULL, WNOHANG)) > 0)
+			if (running == child)
+				running = 0;
+	}
+}
 
 int script_init(const char *path, const char *ifname)
 {
 	argv[0] = (char*)path;
 	argv[1] = (char*)ifname;
+	signal(SIGCHLD, script_sighandle);
 	return 0;
 }
 
@@ -336,41 +350,61 @@ static void s46_to_env(enum odhcp6c_state state, const uint8_t *data, size_t len
 }
 
 
-void script_call(const char *status)
+void script_call(const char *status, int delay, bool resume)
 {
-	size_t dns_len, search_len, custom_len, sntp_ip_len, ntp_ip_len, ntp_dns_len;
-	size_t sip_ip_len, sip_fqdn_len, aftr_name_len, cer_len, addr_len;
-	size_t s46_mapt_len, s46_mape_len, s46_lw_len, passthru_len;
-
-	odhcp6c_expire();
-
-	struct in6_addr *addr = odhcp6c_get_state(STATE_SERVER_ADDR, &addr_len);
-	struct in6_addr *dns = odhcp6c_get_state(STATE_DNS, &dns_len);
-	uint8_t *search = odhcp6c_get_state(STATE_SEARCH, &search_len);
-	uint8_t *custom = odhcp6c_get_state(STATE_CUSTOM_OPTS, &custom_len);
-	struct in6_addr *sntp = odhcp6c_get_state(STATE_SNTP_IP, &sntp_ip_len);
-	struct in6_addr *ntp = odhcp6c_get_state(STATE_NTP_IP, &ntp_ip_len);
-	uint8_t *ntp_dns = odhcp6c_get_state(STATE_NTP_FQDN, &ntp_dns_len);
-	struct in6_addr *sip = odhcp6c_get_state(STATE_SIP_IP, &sip_ip_len);
-	uint8_t *sip_fqdn = odhcp6c_get_state(STATE_SIP_FQDN, &sip_fqdn_len);
-	uint8_t *aftr_name = odhcp6c_get_state(STATE_AFTR_NAME, &aftr_name_len);
-	struct in6_addr *cer = odhcp6c_get_state(STATE_CER, &cer_len);
-	uint8_t *s46_mapt = odhcp6c_get_state(STATE_S46_MAPT, &s46_mapt_len);
-	uint8_t *s46_mape = odhcp6c_get_state(STATE_S46_MAPE, &s46_mape_len);
-	uint8_t *s46_lw = odhcp6c_get_state(STATE_S46_LW, &s46_lw_len);
-	uint8_t *passthru = odhcp6c_get_state(STATE_PASSTHRU, &passthru_len);
-
-	size_t prefix_len, address_len, ra_pref_len,
-		ra_route_len, ra_dns_len, ra_search_len;
-	uint8_t *prefix = odhcp6c_get_state(STATE_IA_PD, &prefix_len);
-	uint8_t *address = odhcp6c_get_state(STATE_IA_NA, &address_len);
-	uint8_t *ra_pref = odhcp6c_get_state(STATE_RA_PREFIX, &ra_pref_len);
-	uint8_t *ra_route = odhcp6c_get_state(STATE_RA_ROUTE, &ra_route_len);
-	uint8_t *ra_dns = odhcp6c_get_state(STATE_RA_DNS, &ra_dns_len);
-	uint8_t *ra_search = odhcp6c_get_state(STATE_RA_SEARCH, &ra_search_len);
-
-	// Don't set environment before forking, because env is leaky.
-	if (fork() == 0) {
+	time_t now = odhcp6c_get_milli_time() / 1000;
+
+	if (running) {
+		kill(running, SIGTERM);
+		delay -= now - started;
+	}
+
+	if (resume || !action[0])
+		strncpy(action, status, sizeof(action) - 1);
+
+	pid_t pid = fork();
+	if (pid > 0) {
+		running = pid;
+		started = now;
+
+		if (!resume)
+			action[0] = 0;
+	} else if (pid == 0) {
+		size_t dns_len, search_len, custom_len, sntp_ip_len, ntp_ip_len, ntp_dns_len;
+		size_t sip_ip_len, sip_fqdn_len, aftr_name_len, cer_len, addr_len;
+		size_t s46_mapt_len, s46_mape_len, s46_lw_len, passthru_len;
+
+		signal(SIGTERM, SIG_DFL);
+		if (delay > 0) {
+			sleep(delay);
+			odhcp6c_expire();
+		}
+
+		struct in6_addr *addr = odhcp6c_get_state(STATE_SERVER_ADDR, &addr_len);
+		struct in6_addr *dns = odhcp6c_get_state(STATE_DNS, &dns_len);
+		uint8_t *search = odhcp6c_get_state(STATE_SEARCH, &search_len);
+		uint8_t *custom = odhcp6c_get_state(STATE_CUSTOM_OPTS, &custom_len);
+		struct in6_addr *sntp = odhcp6c_get_state(STATE_SNTP_IP, &sntp_ip_len);
+		struct in6_addr *ntp = odhcp6c_get_state(STATE_NTP_IP, &ntp_ip_len);
+		uint8_t *ntp_dns = odhcp6c_get_state(STATE_NTP_FQDN, &ntp_dns_len);
+		struct in6_addr *sip = odhcp6c_get_state(STATE_SIP_IP, &sip_ip_len);
+		uint8_t *sip_fqdn = odhcp6c_get_state(STATE_SIP_FQDN, &sip_fqdn_len);
+		uint8_t *aftr_name = odhcp6c_get_state(STATE_AFTR_NAME, &aftr_name_len);
+		struct in6_addr *cer = odhcp6c_get_state(STATE_CER, &cer_len);
+		uint8_t *s46_mapt = odhcp6c_get_state(STATE_S46_MAPT, &s46_mapt_len);
+		uint8_t *s46_mape = odhcp6c_get_state(STATE_S46_MAPE, &s46_mape_len);
+		uint8_t *s46_lw = odhcp6c_get_state(STATE_S46_LW, &s46_lw_len);
+		uint8_t *passthru = odhcp6c_get_state(STATE_PASSTHRU, &passthru_len);
+
+		size_t prefix_len, address_len, ra_pref_len,
+			ra_route_len, ra_dns_len, ra_search_len;
+		uint8_t *prefix = odhcp6c_get_state(STATE_IA_PD, &prefix_len);
+		uint8_t *address = odhcp6c_get_state(STATE_IA_NA, &address_len);
+		uint8_t *ra_pref = odhcp6c_get_state(STATE_RA_PREFIX, &ra_pref_len);
+		uint8_t *ra_route = odhcp6c_get_state(STATE_RA_ROUTE, &ra_route_len);
+		uint8_t *ra_dns = odhcp6c_get_state(STATE_RA_DNS, &ra_dns_len);
+		uint8_t *ra_search = odhcp6c_get_state(STATE_RA_SEARCH, &ra_search_len);
+
 		ipv6_to_env("SERVER", addr, addr_len / sizeof(*addr));
 		ipv6_to_env("RDNSS", dns, dns_len / sizeof(*dns));
 		ipv6_to_env("SNTP_IP", sntp, sntp_ip_len / sizeof(*sntp));
@@ -406,7 +440,6 @@ void script_call(const char *status)
 		script_hexlify(&buf[9], passthru, passthru_len);
 		putenv(buf);
 
-		argv[2] = (char*)status;
 		execv(argv[0], argv);
 		_exit(128);
 	}