/**
* [Server only]
* Handle a new connection from a client. Set up connection details and
* initialize sequence numbers.
*
* pkt: The SYN segment from the client.
* returns: The conn_t associated with the new connection.
*/
conn_t *tcp_new_connection(char *pkt) { ASSERT_SERVER_ONLY;
/* Ignore if too many clients are connected. */
if (num_connected >= MAX_NUM_CLIENTS) {
fprintf(stderr, "[ERROR] Maximum number of clients (%d) reached\n",
MAX_NUM_CLIENTS);
return NULL;
}
num_connected++;
iphdr_t *ip_hdr = (iphdr_t *) pkt;
tcphdr_t *syn = (tcphdr_t *) (pkt + IP_HDR_SIZE);
/* Set up connection details and add to list of connections. */
conn_t *conn = calloc(sizeof(conn_t), 1);
conn_setup(conn, ntohl(ip_hdr->saddr), ntohs(syn->th_sport), unix_socket);
conn->their_init_seqno = ntohl(syn->th_seq);
conn->ackno = conn->their_init_seqno + 1;
conn_add(conn);
/* Send a SYN-ACK to the client. */
send_synack(conn);
/* Get window size of the client. */
ctcp_cfg->send_window = ntohs(syn->window);
ctcp_config_t *config_copy = calloc(sizeof(ctcp_config_t), 1);
memcpy(config_copy, ctcp_cfg, sizeof(ctcp_config_t));
/* Student code. */
ctcp_state_t *state = ctcp_init(conn, config_copy);
conn->state = state;
fprintf(stderr, "[INFO] Client connected\n");
return conn;
}
void
MulticastSession::syn_received(const Message_Block_Ptr& control)
{
if (this->active_) return; // pub send syn, then doesn't receive them.
const TransportHeader& header =
this->link_->receive_strategy()->received_header();
// Not from the remote peer for this session.
if (this->remote_peer_ != header.source_) return;
Serializer serializer(control.get(), header.swap_bytes());
MulticastPeer local_peer;
serializer >> local_peer; // sent as remote_peer
// Ignore sample if not destined for us:
if (local_peer != this->link_->local_peer()) return;
VDBG_LVL((LM_DEBUG, "(%P|%t) MulticastSession[%C]::syn_received "
"local %#08x%08x remote %#08x%08x\n",
this->link()->config()->name().c_str(),
(unsigned int)(this->link()->local_peer() >> 32),
(unsigned int) this->link()->local_peer(),
(unsigned int)(this->remote_peer_ >> 32),
(unsigned int) this->remote_peer_), 2);
{
ACE_GUARD(ACE_SYNCH_MUTEX, guard, this->ack_lock_);
if (!this->acked_) {
this->acked_ = true;
syn_hook(header.sequence_);
}
}
// MULTICAST_SYN control samples are always positively
// acknowledged by a matching remote peer:
send_synack();
this->link_->transport()->passive_connection(this->link_->local_peer(), this->remote_peer_);
}
void
ReliableSession::syn_received(ACE_Message_Block* control)
{
if (this->active_) return; // pub send syn, then doesn't receive them.
const TransportHeader& header =
this->link_->receive_strategy()->received_header();
// Not from the remote peer for this session.
if (this->remote_peer_ != header.source_) return;
Serializer serializer(control, header.swap_bytes());
MulticastPeer local_peer;
serializer >> local_peer; // sent as remote_peer
// Ignore sample if not destined for us:
if (local_peer != this->link_->local_peer()) return;
{
ACE_GUARD(ACE_SYNCH_MUTEX,
guard,
this->ack_lock_);
if (!this->acked_) {
this->acked_ = true;
// Establish a baseline for detecting reception gaps:
this->nak_sequence_.reset(header.sequence_);
}
}
// MULTICAST_SYN control samples are always positively
// acknowledged by a matching remote peer:
send_synack();
}
