static int ip6_rcv(struct sk_buff *skb, struct net_device *dev) {
ip6hdr_t *ip6h = ip6_hdr(skb);
const struct net_proto *nproto;
if (ip6h->version != 6) {
dev->stats.rx_err++;
skb_free(skb);
return 0; /* error: invalid hdr */
}
if (skb->dev->hdr_len + IP6_HEADER_SIZE
+ ntohs(ip6h->payload_len) > skb->len) {
dev->stats.rx_length_errors++;
skb_free(skb);
return 0; /* error: invalid length */
}
/* Check recipiant */
assert(skb->dev != NULL);
assert(inetdev_get_by_dev(skb->dev) != NULL);
if (0 != memcmp(&inetdev_get_by_dev(skb->dev)->ifa6_address,
&skb->nh.ip6h->daddr, sizeof(struct in6_addr))) {
// skb_free(skb);
// return 0; /* error: not for us */
}
/* Setup transport layer header */
skb->h.raw = skb->nh.raw + IP6_HEADER_SIZE;
nproto = net_proto_lookup(ETH_P_IPV6, ip6h->nexthdr);
if (nproto != NULL) {
return nproto->handle(skb);
}
// printk("ipv6 packet accepted, %#x\n", ip6h->nexthdr);
skb_free(skb);
return 0; /* error: nobody wants this packet */
}
static int udp_rcv(struct sk_buff *skb) {
struct sock *sk;
assert(skb != NULL);
assert(ip_check_version(ip_hdr(skb))
|| ip6_check_version(ip6_hdr(skb)));
/* Check CRC */
if (MODOPS_VERIFY_CHKSUM) {
uint16_t old_check;
old_check = skb->h.uh->check;
udp_set_check_field(skb->h.uh, skb->nh.raw);
if (old_check != skb->h.uh->check) {
return 0; /* error: bad checksum */
}
}
sk = sock_lookup(NULL, udp_sock_ops,
ip_check_version(ip_hdr(skb))
? udp4_rcv_tester : udp6_rcv_tester,
skb);
if (sk != NULL) {
if (ip_check_version(ip_hdr(skb))
? udp4_accept_dst(sk, skb)
: udp6_accept_dst(sk, skb)) {
sock_rcv(sk, skb, skb->h.raw + UDP_HEADER_SIZE,
udp_data_length(udp_hdr(skb)));
}
else {
skb_free(skb);
}
}
else {
icmp_discard(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH);
}
return 0;
}
