Add of the RDNSS option to ICMPv6 Router Advertisement (RA).

[l2tpns.git] / icmp.c

diff --git a/icmp.c b/icmp.c
index d2f53e0..58c28f2 100644 (file)
--- a/icmp.c
+++ b/icmp.c
@@ -87,11 +87,21 @@ static uint16_t _checksum(uint8_t *addr, int count)
        return htons((uint16_t) sum);
 }
 
+struct nd_opt_rdnss_info_l2tpns
+{
+       uint8_t  nd_opt_rdnssi_type;
+       uint8_t  nd_opt_rdnssi_len;
+       uint16_t nd_opt_rdnssi_pref_flag_reserved;
+       uint32_t nd_opt_rdnssi_lifetime;
+       struct in6_addr nd_opt_rdnssi[0];
+};
+
 void send_ipv6_ra(sessionidt s, tunnelidt t, struct in6_addr *ip)
 {
        struct nd_opt_prefix_info *pinfo;
        struct ip6_hdr *p_ip6_hdr;
        struct nd_router_advert *p_nra;
+       struct nd_opt_rdnss_info_l2tpns *p_rdnss;
        uint8_t b[MAXETHER + 20];
        struct ipv6_pseudo_hdr pseudo_hdr;
        int l;
@@ -151,19 +161,44 @@ void send_ipv6_ra(sessionidt s, tunnelidt t, struct in6_addr *ip)
        else
                pinfo->nd_opt_pi_prefix     = config->ipv6_prefix;
 
-       // // Length of payload (not header)
-       p_ip6_hdr->ip6_plen = htons(sizeof(*pinfo) + sizeof(*p_nra));
+       // Length of payload (not header)
+       l = sizeof(*pinfo) + sizeof(*p_nra);
+
+       if (config->default_ipv6_dns1.s6_addr32[0])
+       {
+               struct in6_addr *ptr_in6_addr;
+               p_rdnss = (struct nd_opt_rdnss_info_l2tpns *) &pinfo[1];
+
+               p_rdnss->nd_opt_rdnssi_type = 25; //RDNSS OPTION INFORMATION;
+               p_rdnss->nd_opt_rdnssi_len = 3; // 1 + 2 * nb DNS
+               p_rdnss->nd_opt_rdnssi_lifetime = htonl(config->dns6_lifetime);
+               ptr_in6_addr = &p_rdnss->nd_opt_rdnssi[0];
+               memcpy(ptr_in6_addr, &config->default_ipv6_dns1, sizeof(*ptr_in6_addr));
+
+               l += sizeof(*p_rdnss)  + sizeof(*ptr_in6_addr);
+               if (config->default_ipv6_dns2.s6_addr32[0])
+               {
+                       ptr_in6_addr = &p_rdnss->nd_opt_rdnssi[1];
+                       memcpy(ptr_in6_addr, &config->default_ipv6_dns2, sizeof(*ptr_in6_addr));
+                       p_rdnss->nd_opt_rdnssi_len += 2; // 1 + 2 * nb DNS
+                       l += sizeof(*ptr_in6_addr);
+               }
+       }
 
-       l = sizeof(*pinfo) + sizeof(*p_nra) + sizeof(*p_ip6_hdr);
+       // Length of payload (not header)
+       p_ip6_hdr->ip6_plen = htons(l);
 
        /* Use pseudo hearder for checksum calculation */
        memset(&pseudo_hdr, 0, sizeof(pseudo_hdr));
        memcpy(&pseudo_hdr.src, &p_ip6_hdr->ip6_src, 16);
        memcpy(&pseudo_hdr.dest, &p_ip6_hdr->ip6_dst, 16);
-       pseudo_hdr.ulp_length = htonl(sizeof(*pinfo) + sizeof(*p_nra)); // Lenght whitout Ipv6 header
+       pseudo_hdr.ulp_length = htonl(l); // Lenght whitout Ipv6 header
        pseudo_hdr.nexthdr = IPPROTO_ICMPV6;
        // Checksum is over the icmp6 payload plus the pseudo header
-       p_nra->nd_ra_cksum = ipv6_checksum(&pseudo_hdr, (uint8_t *) p_nra, (sizeof(*pinfo) + sizeof(*p_nra)));
+       p_nra->nd_ra_cksum = ipv6_checksum(&pseudo_hdr, (uint8_t *) p_nra, l);
+
+       // Length + hearder length
+       l += sizeof(*p_ip6_hdr);
 
        tunnelsend(b, l + (((uint8_t *) p_ip6_hdr)-b), t); // send it...
        return;