Fix Router Advertisement/Solicitation option parsing

2 files changed, 21 insertions, 17 deletions

diff --git a/src/router.c b/src/router.c
index 83da938..0b01a77 100644
--- a/src/router.c
+++ b/src/router.c
@@ -211,7 +211,7 @@ static void send_router_advert(struct uloop_timeout *event)
 
 	struct {
 		struct nd_router_advert h;
-		struct icmpv6_opt lladdr;
+		struct nd_opt_slla lladdr;
 		struct nd_opt_mtu mtu;
 		struct nd_opt_prefix_info prefix[RELAYD_MAX_PREFIXES];
 	} adv = {
@@ -227,7 +227,7 @@ static void send_router_advert(struct uloop_timeout *event)
 		adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
 	else if (iface->route_preference > 0)
 		adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
-	odhcpd_get_mac(iface, adv.lladdr.data);
+	odhcpd_get_mac(iface, adv.lladdr.addr);
 
 	// If not currently shutting down
 	struct odhcpd_ipaddr addrs[RELAYD_MAX_PREFIXES];
@@ -319,14 +319,7 @@ static void send_router_advert(struct uloop_timeout *event)
 	if (!dns_addr)
 		dns_cnt = 0;
 
-	struct {
-		uint8_t type;
-		uint8_t len;
-		uint8_t pad;
-		uint8_t pad2;
-		uint32_t lifetime;
-	} dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, htonl(dns_time)};
-
+	struct nd_opt_recursive_dns dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, htonl(dns_time)};
 
 
 	// DNS Search options
@@ -455,11 +448,12 @@ static void forward_router_advertisement(uint8_t *data, size_t len)
 	icmpv6_for_each_option(opt, &adv[1], end) {
 		if (opt->type == ND_OPT_SOURCE_LINKADDR) {
 			// Store address of source MAC-address
-			mac_ptr = opt->data;
+			mac_ptr = ((struct nd_opt_slla *)opt)->addr;
 		} else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 1) {
+			struct nd_opt_recursive_dns *dns = (struct nd_opt_recursive_dns *)opt;
 			// Check if we have to rewrite DNS
-			dns_ptr = (struct in6_addr*)&opt->data[6];
-			dns_count = (opt->len - 1) / 2;
+			dns_ptr = (struct in6_addr *)&dns[1];
+			dns_count = (dns->len - 1) / 2;
 		}
 	}
 
diff --git a/src/router.h b/src/router.h
index 1e8649c..8d74967 100644
--- a/src/router.h
+++ b/src/router.h
@@ -20,15 +20,25 @@
 struct icmpv6_opt {
 	uint8_t type;
 	uint8_t len;
-	uint8_t data[6];
 };
 
+struct nd_opt_slla {
+	uint8_t type;
+	uint8_t len;
+	uint8_t addr[6];
+};
+
+struct nd_opt_recursive_dns {
+	uint8_t type;
+	uint8_t len;
+	uint8_t pad;
+	uint8_t pad2;
+	uint32_t lifetime;
+};
 
 #define icmpv6_for_each_option(opt, start, end)\
 	for (opt = (struct icmpv6_opt*)(start);\
-	(void*)(opt + 1) <= (void*)(end) && opt->len > 0 &&\
-	(void*)(opt + opt->len) <= (void*)(end); opt += opt->len)
-
+	(void*)(opt + (opt->len << 3)) <= (void*)(end); opt += (opt->len << 3))
 
 #define MaxRtrAdvInterval 600
 #define MinRtrAdvInterval (MaxRtrAdvInterval / 3)