From: Steven Barth <steven@midlink.org>
Date: Wed, 8 Oct 2014 09:57:07 +0000 (+0200)
Subject: Ensure signal-safety of signal handlers
X-Git-Tag: debian/1.1+git20160131-1~50
X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=commitdiff_plain;h=6373af63310f32e1408a81f4e4e069a5f0d3e59e

Ensure signal-safety of signal handlers
---

diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index c76c813..7cdf09e 100644
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -480,11 +480,8 @@ bool odhcp6c_signal_process(void)
 		if (ra_link_up())
 			signal_usr2 = true;
 
-		if (ra_updated && (bound || allow_slaac_only == 0))
+		if (ra_updated && (bound || allow_slaac_only >= 0))
 			script_call("ra-updated"); // Immediate process urgent events
-		else if (ra_updated && !bound && allow_slaac_only > 0)
-			script_delay_call("ra-updated", allow_slaac_only);
-
 	}
 
 	return signal_usr1 || signal_usr2 || signal_term;
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index a4343b1..f2924b0 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -325,7 +325,6 @@ int set_rtnetlink_addr(int ifindex, const struct in6_addr *addr,
 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_delay_call(const char *status, int timeout);
 
 bool odhcp6c_signal_process(void);
 uint64_t odhcp6c_get_milli_time(void);
diff --git a/src/ra.c b/src/ra.c
index baaee9b..9c5eb22 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -26,7 +26,6 @@
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <sys/types.h>
-#include <sys/ioctl.h>
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
 
@@ -56,6 +55,15 @@ static char if_name[IF_NAMESIZE] = {0};
 static volatile int rs_attempt = 0;
 static struct in6_addr lladdr = IN6ADDR_ANY_INIT;
 
+struct {
+	struct icmp6_hdr hdr;
+	struct icmpv6_opt lladdr;
+} rs = {
+	.hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}},
+	.lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
+};
+
+
 static void ra_send_rs(int signal __attribute__((unused)));
 
 int ra_init(const char *ifname, const struct in6_addr *ifid)
@@ -93,6 +101,7 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 		.ifi = {.ifi_index = if_index}
 	};
 	send(rtnl, &req, sizeof(req), 0);
+	ra_link_up();
 
 	// Filter ICMPv6 package types
 	struct icmp6_filter filt;
@@ -133,22 +142,12 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 
 static void ra_send_rs(int signal __attribute__((unused)))
 {
-	struct {
-		struct icmp6_hdr hdr;
-		struct icmpv6_opt lladdr;
-	} rs = {
-		.hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}},
-		.lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
-	};
 	const struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index};
-	size_t len = sizeof(rs);
-
-	struct ifreq ifr;
-	memset(&ifr, 0, sizeof(ifr));
-	strncpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name));
-	if ((rs_attempt % 2 == 0) && !ioctl(sock, SIOCGIFHWADDR, &ifr)
-			&& memcmp(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6))
-		memcpy(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6);
+	const struct icmpv6_opt llnull = {ND_OPT_SOURCE_LINKADDR, 1, {0}};
+	size_t len;
+
+	if ((rs_attempt % 2 == 0) && memcmp(&rs.lladdr, &llnull, sizeof(llnull)))
+		len = sizeof(rs);
 	else
 		len = sizeof(struct icmp6_hdr);
 
@@ -197,6 +196,14 @@ bool ra_link_up(void)
 				resp.msg.ifi_index != if_index)
 			continue;
 
+		ssize_t alen = NLMSG_PAYLOAD(&resp.hdr, sizeof(resp.msg));
+		for (struct rtattr *rta = (struct rtattr*)(resp.pad);
+				RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen)) {
+			if (rta->rta_type == IFLA_ADDRESS &&
+					RTA_PAYLOAD(rta) >= sizeof(rs.lladdr.data))
+				memcpy(rs.lladdr.data, RTA_DATA(rta), sizeof(rs.lladdr.data));
+		}
+
 		bool hascarrier = resp.msg.ifi_flags & IFF_LOWER_UP;
 		if (!firstcall && nocarrier != !hascarrier)
 			ret = true;
diff --git a/src/script.c b/src/script.c
index e389cc9..644f61f 100644
--- a/src/script.c
+++ b/src/script.c
@@ -41,8 +41,6 @@ static const int8_t hexvals[] = {
 
 
 static char *argv[4] = {NULL, NULL, NULL, NULL};
-static volatile char *delayed_call = NULL;
-static bool dont_delay = false;
 
 
 int script_init(const char *path, const char *ifname)
@@ -332,25 +330,6 @@ static void s46_to_env(enum odhcp6c_state state, const uint8_t *data, size_t len
 }
 
 
-static void script_call_delayed(int signal __attribute__((unused)))
-{
-	if (delayed_call)
-		script_call((char*)delayed_call);
-}
-
-
-void script_delay_call(const char *status, int timeout)
-{
-	if (dont_delay) {
-		script_call(status);
-	} else if (!delayed_call) {
-		delayed_call = strdup(status);
-		signal(SIGALRM, script_call_delayed);
-		alarm(timeout);
-	}
-}
-
-
 void script_call(const char *status)
 {
 	size_t dns_len, search_len, custom_len, sntp_ip_len, ntp_ip_len, ntp_dns_len;
@@ -358,10 +337,6 @@ void script_call(const char *status)
 	size_t s46_mapt_len, s46_mape_len, s46_lw_len, passthru_len;
 
 	odhcp6c_expire();
-	if (delayed_call) {
-		alarm(0);
-		dont_delay = true;
-	}
 
 	struct in6_addr *addr = odhcp6c_get_state(STATE_SERVER_ADDR, &addr_len);
 	struct in6_addr *dns = odhcp6c_get_state(STATE_DNS, &dns_len);