[DCCP]: Initial implementation
Development to this point was done on a subversion repository at:
http://oops.ghostprotocols.net:81/cgi-bin/viewcvs.cgi/dccp-2.6/
This repository will be kept at this site for the foreseable future,
so that interested parties can see the history of this code,
attributions, etc.
If I ever decide to take this offline I'll provide the full history at
some other suitable place.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
new file mode 100644
index 0000000..810f0c2
--- /dev/null
+++ b/net/dccp/minisocks.c
@@ -0,0 +1,199 @@
+/*
+ * net/dccp/minisocks.c
+ *
+ * An implementation of the DCCP protocol
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/dccp.h>
+#include <linux/skbuff.h>
+#include <linux/timer.h>
+
+#include <net/sock.h>
+#include <net/xfrm.h>
+#include <net/inet_timewait_sock.h>
+
+#include "ccid.h"
+#include "dccp.h"
+
+void dccp_time_wait(struct sock *sk, int state, int timeo)
+{
+ /* FIXME: Implement */
+ dccp_pr_debug("Want to help? Start here\n");
+ dccp_set_state(sk, state);
+}
+
+/* This is for handling early-kills of TIME_WAIT sockets. */
+void dccp_tw_deschedule(struct inet_timewait_sock *tw)
+{
+ dccp_pr_debug("Want to help? Start here\n");
+ __inet_twsk_kill(tw, &dccp_hashinfo);
+}
+
+struct sock *dccp_create_openreq_child(struct sock *sk,
+ const struct request_sock *req,
+ const struct sk_buff *skb)
+{
+ /*
+ * Step 3: Process LISTEN state
+ *
+ * // Generate a new socket and switch to that socket
+ * Set S := new socket for this port pair
+ */
+ struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
+
+ if (newsk != NULL) {
+ const struct dccp_request_sock *dreq = dccp_rsk(req);
+ struct inet_connection_sock *newicsk = inet_csk(sk);
+ struct dccp_sock *newdp = dccp_sk(newsk);
+
+ newdp->dccps_hc_rx_ackpkts = NULL;
+ newdp->dccps_role = DCCP_ROLE_SERVER;
+ newicsk->icsk_rto = TCP_TIMEOUT_INIT;
+
+ if (newdp->dccps_options.dccpo_send_ack_vector) {
+ newdp->dccps_hc_rx_ackpkts = dccp_ackpkts_alloc(DCCP_MAX_ACK_VECTOR_LEN,
+ GFP_ATOMIC);
+ /*
+ * XXX: We're using the same CCIDs set on the parent, i.e. sk_clone
+ * copied the master sock and left the CCID pointers for this child,
+ * that is why we do the __ccid_get calls.
+ */
+ if (unlikely(newdp->dccps_hc_rx_ackpkts == NULL))
+ goto out_free;
+ }
+
+ if (unlikely(ccid_hc_rx_init(newdp->dccps_hc_rx_ccid, newsk) != 0 ||
+ ccid_hc_tx_init(newdp->dccps_hc_tx_ccid, newsk) != 0)) {
+ dccp_ackpkts_free(newdp->dccps_hc_rx_ackpkts);
+ ccid_hc_rx_exit(newdp->dccps_hc_rx_ccid, newsk);
+ ccid_hc_tx_exit(newdp->dccps_hc_tx_ccid, newsk);
+out_free:
+ /* It is still raw copy of parent, so invalidate
+ * destructor and make plain sk_free() */
+ newsk->sk_destruct = NULL;
+ sk_free(newsk);
+ return NULL;
+ }
+
+ __ccid_get(newdp->dccps_hc_rx_ccid);
+ __ccid_get(newdp->dccps_hc_tx_ccid);
+
+ /*
+ * Step 3: Process LISTEN state
+ *
+ * Choose S.ISS (initial seqno) or set from Init Cookie
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
+ */
+
+ /* See dccp_v4_conn_request */
+ newdp->dccps_options.dccpo_sequence_window = req->rcv_wnd;
+
+ newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;
+ dccp_update_gsr(newsk, dreq->dreq_isr);
+
+ newdp->dccps_iss = dreq->dreq_iss;
+ dccp_update_gss(newsk, dreq->dreq_iss);
+
+ dccp_init_xmit_timers(newsk);
+
+ DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
+ }
+ return newsk;
+}
+
+/*
+ * Process an incoming packet for RESPOND sockets represented
+ * as an request_sock.
+ */
+struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req,
+ struct request_sock **prev)
+{
+ struct sock *child = NULL;
+
+ /* Check for retransmitted REQUEST */
+ if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
+ if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dccp_rsk(req)->dreq_isr)) {
+ struct dccp_request_sock *dreq = dccp_rsk(req);
+
+ dccp_pr_debug("Retransmitted REQUEST\n");
+ /* Send another RESPONSE packet */
+ dccp_set_seqno(&dreq->dreq_iss, dreq->dreq_iss + 1);
+ dccp_set_seqno(&dreq->dreq_isr, DCCP_SKB_CB(skb)->dccpd_seq);
+ req->rsk_ops->rtx_syn_ack(sk, req, NULL);
+ }
+ /* Network Duplicate, discard packet */
+ return NULL;
+ }
+
+ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
+
+ if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
+ dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
+ goto drop;
+
+ /* Invalid ACK */
+ if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) {
+ dccp_pr_debug("Invalid ACK number: ack_seq=%llu, dreq_iss=%llu\n",
+ DCCP_SKB_CB(skb)->dccpd_ack_seq, dccp_rsk(req)->dreq_iss);
+ goto drop;
+ }
+
+ child = dccp_v4_request_recv_sock(sk, skb, req, NULL);
+ if (child == NULL)
+ goto listen_overflow;
+
+ /* FIXME: deal with options */
+
+ inet_csk_reqsk_queue_unlink(sk, req, prev);
+ inet_csk_reqsk_queue_removed(sk, req);
+ inet_csk_reqsk_queue_add(sk, req, child);
+out:
+ return child;
+listen_overflow:
+ dccp_pr_debug("listen_overflow!\n");
+ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
+drop:
+ if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
+ req->rsk_ops->send_reset(skb);
+
+ inet_csk_reqsk_queue_drop(sk, req, prev);
+ goto out;
+}
+
+/*
+ * Queue segment on the new socket if the new socket is active,
+ * otherwise we just shortcircuit this and continue with
+ * the new socket.
+ */
+int dccp_child_process(struct sock *parent, struct sock *child,
+ struct sk_buff *skb)
+{
+ int ret = 0;
+ const int state = child->sk_state;
+
+ if (!sock_owned_by_user(child)) {
+ ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb), skb->len);
+
+ /* Wakeup parent, send SIGIO */
+ if (state == DCCP_RESPOND && child->sk_state != state)
+ parent->sk_data_ready(parent, 0);
+ } else {
+ /* Alas, it is possible again, because we do lookup
+ * in main socket hash table and lock on listening
+ * socket does not protect us more.
+ */
+ sk_add_backlog(child, skb);
+ }
+
+ bh_unlock_sock(child);
+ sock_put(child);
+ return ret;
+}