Exemple #1
0
/*
 * The three way handshake has completed - we got a valid ACK or DATAACK -
 * now create the new socket.
 *
 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
 */
struct sock *dccp_v4_request_recv_sock(const struct sock *sk,
				       struct sk_buff *skb,
				       struct request_sock *req,
				       struct dst_entry *dst,
				       struct request_sock *req_unhash,
				       bool *own_req)
{
	struct inet_request_sock *ireq;
	struct inet_sock *newinet;
	struct sock *newsk;

	if (sk_acceptq_is_full(sk))
		goto exit_overflow;

	newsk = dccp_create_openreq_child(sk, req, skb);
	if (newsk == NULL)
		goto exit_nonewsk;

	newinet		   = inet_sk(newsk);
	ireq		   = inet_rsk(req);
	sk_daddr_set(newsk, ireq->ir_rmt_addr);
	sk_rcv_saddr_set(newsk, ireq->ir_loc_addr);
	newinet->inet_saddr	= ireq->ir_loc_addr;
	RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt));
	newinet->mc_index  = inet_iif(skb);
	newinet->mc_ttl	   = ip_hdr(skb)->ttl;
	newinet->inet_id   = jiffies;

	if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
		goto put_and_exit;

	sk_setup_caps(newsk, dst);

	dccp_sync_mss(newsk, dst_mtu(dst));

	if (__inet_inherit_port(sk, newsk) < 0)
		goto put_and_exit;
	*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
	if (*own_req)
		ireq->ireq_opt = NULL;
	else
		newinet->inet_opt = NULL;
	return newsk;

exit_overflow:
	__NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
exit_nonewsk:
	dst_release(dst);
exit:
	__NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
	return NULL;
put_and_exit:
	newinet->inet_opt = NULL;
	inet_csk_prepare_forced_close(newsk);
	dccp_done(newsk);
	goto exit;
}
Exemple #2
0
int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
{
	struct inet_request_sock *ireq;
	struct request_sock *req;
	struct dccp_request_sock *dreq;
	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);

	/* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
	if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
		return 0;	/* discard, don't send a reset here */

	if (dccp_bad_service_code(sk, service)) {
		dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
		goto drop;
	}
	/*
	 * TW buckets are converted to open requests without
	 * limitations, they conserve resources and peer is
	 * evidently real one.
	 */
	dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
	if (inet_csk_reqsk_queue_is_full(sk))
		goto drop;

	/*
	 * Accept backlog is full. If we have already queued enough
	 * of warm entries in syn queue, drop request. It is better than
	 * clogging syn queue with openreqs with exponentially increasing
	 * timeout.
	 */
	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
		goto drop;

	req = inet_reqsk_alloc(&dccp_request_sock_ops, sk, true);
	if (req == NULL)
		goto drop;

	if (dccp_reqsk_init(req, dccp_sk(sk), skb))
		goto drop_and_free;

	dreq = dccp_rsk(req);
	if (dccp_parse_options(sk, dreq, skb))
		goto drop_and_free;

	if (security_inet_conn_request(sk, skb, req))
		goto drop_and_free;

	ireq = inet_rsk(req);
	sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr);
	sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr);
	ireq->ireq_family = AF_INET;
	ireq->ir_iif = sk->sk_bound_dev_if;

	/*
	 * Step 3: Process LISTEN state
	 *
	 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
	 *
	 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
	 */
	dreq->dreq_isr	   = dcb->dccpd_seq;
	dreq->dreq_gsr	   = dreq->dreq_isr;
	dreq->dreq_iss	   = dccp_v4_init_sequence(skb);
	dreq->dreq_gss     = dreq->dreq_iss;
	dreq->dreq_service = service;

	if (dccp_v4_send_response(sk, req))
		goto drop_and_free;

	inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
	return 0;

drop_and_free:
	reqsk_free(req);
drop:
	DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
	return -1;
}
Exemple #3
0
int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
	struct inet_sock *inet = inet_sk(sk);
	struct dccp_sock *dp = dccp_sk(sk);
	__be16 orig_sport, orig_dport;
	__be32 daddr, nexthop;
	struct flowi4 *fl4;
	struct rtable *rt;
	int err;
	struct ip_options_rcu *inet_opt;

	dp->dccps_role = DCCP_ROLE_CLIENT;

	if (addr_len < sizeof(struct sockaddr_in))
		return -EINVAL;

	if (usin->sin_family != AF_INET)
		return -EAFNOSUPPORT;

	nexthop = daddr = usin->sin_addr.s_addr;

	inet_opt = rcu_dereference_protected(inet->inet_opt,
					     sock_owned_by_user(sk));
	if (inet_opt != NULL && inet_opt->opt.srr) {
		if (daddr == 0)
			return -EINVAL;
		nexthop = inet_opt->opt.faddr;
	}

	orig_sport = inet->inet_sport;
	orig_dport = usin->sin_port;
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
			      RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
			      IPPROTO_DCCP,
			      orig_sport, orig_dport, sk);
	if (IS_ERR(rt))
		return PTR_ERR(rt);

	if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
		ip_rt_put(rt);
		return -ENETUNREACH;
	}

	if (inet_opt == NULL || !inet_opt->opt.srr)
		daddr = fl4->daddr;

	if (inet->inet_saddr == 0)
		inet->inet_saddr = fl4->saddr;
	sk_rcv_saddr_set(sk, inet->inet_saddr);
	inet->inet_dport = usin->sin_port;
	sk_daddr_set(sk, daddr);

	inet_csk(sk)->icsk_ext_hdr_len = 0;
	if (inet_opt)
		inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
	/*
	 * Socket identity is still unknown (sport may be zero).
	 * However we set state to DCCP_REQUESTING and not releasing socket
	 * lock select source port, enter ourselves into the hash tables and
	 * complete initialization after this.
	 */
	dccp_set_state(sk, DCCP_REQUESTING);
	err = inet_hash_connect(&dccp_death_row, sk);
	if (err != 0)
		goto failure;

	rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
			       inet->inet_sport, inet->inet_dport, sk);
	if (IS_ERR(rt)) {
		err = PTR_ERR(rt);
		rt = NULL;
		goto failure;
	}
	/* OK, now commit destination to socket.  */
	sk_setup_caps(sk, &rt->dst);

	dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr,
						    inet->inet_daddr,
						    inet->inet_sport,
						    inet->inet_dport);
	inet->inet_id = dp->dccps_iss ^ jiffies;

	err = dccp_connect(sk);
	rt = NULL;
	if (err != 0)
		goto failure;
out:
	return err;
failure:
	/*
	 * This unhashes the socket and releases the local port, if necessary.
	 */
	dccp_set_state(sk, DCCP_CLOSED);
	ip_rt_put(rt);
	sk->sk_route_caps = 0;
	inet->inet_dport = 0;
	goto out;
}