inline size_t Packet_v<Ptr_type>::fill(const uint8_t* buffer, size_t length)
{
size_t rem = ip_capacity() - udp_length();
if(rem == 0) return 0;
size_t total = std::min(length, rem);
// copy from buffer to packet buffer
memcpy(udp_data() + udp_data_length(), buffer, total);
// set new packet length
set_length(udp_data_length() + total);
return total;
}
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;
}
uint16_t udp_length() const noexcept
{ return udp_header_length() + udp_data_length(); }
