1 files changed, 264 insertions, 0 deletions

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
new file mode 100644
index 0000000000000..ce5dff4ac22ea
--- /dev/null
+++ b/net/dccp/minisocks.c
@@ -0,0 +1,264 @@
+/*
+ *  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"
+
+struct inet_timewait_death_row dccp_death_row = {
+	.sysctl_max_tw_buckets = NR_FILE * 2,
+	.period		= DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
+	.death_lock	= SPIN_LOCK_UNLOCKED,
+	.hashinfo	= &dccp_hashinfo,
+	.tw_timer	= TIMER_INITIALIZER(inet_twdr_hangman, 0,
+					    (unsigned long)&dccp_death_row),
+	.twkill_work	= __WORK_INITIALIZER(dccp_death_row.twkill_work,
+					     inet_twdr_twkill_work,
+					     &dccp_death_row),
+/* Short-time timewait calendar */
+
+	.twcal_hand	= -1,
+	.twcal_timer	= TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
+					    (unsigned long)&dccp_death_row),
+};
+
+void dccp_time_wait(struct sock *sk, int state, int timeo)
+{
+	struct inet_timewait_sock *tw = NULL;
+
+	if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
+		tw = inet_twsk_alloc(sk, state);
+
+	if (tw != NULL) {
+		const struct inet_connection_sock *icsk = inet_csk(sk);
+		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
+
+		/* Linkage updates. */
+		__inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
+
+		/* Get the TIME_WAIT timeout firing. */
+		if (timeo < rto)
+			timeo = rto;
+
+		tw->tw_timeout = DCCP_TIMEWAIT_LEN;
+		if (state == DCCP_TIME_WAIT)
+			timeo = DCCP_TIMEWAIT_LEN;
+
+		inet_twsk_schedule(tw, &dccp_death_row, timeo,
+				   DCCP_TIMEWAIT_LEN);
+		inet_twsk_put(tw);
+	} else {
+		/* Sorry, if we're out of memory, just CLOSE this
+		 * socket up.  We've got bigger problems than
+		 * non-graceful socket closings.
+		 */
+		LIMIT_NETDEBUG(KERN_INFO "DCCP: time wait bucket "
+					 "table overflow\n");
+	}
+
+	dccp_done(sk);
+}
+
+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 = DCCP_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);
+
+		/*
+		 * SWL and AWL are initially adjusted so that they are not less than
+		 * the initial Sequence Numbers received and sent, respectively:
+		 *	SWL := max(GSR + 1 - floor(W/4), ISR),
+		 *	AWL := max(GSS - W' + 1, ISS).
+		 * These adjustments MUST be applied only at the beginning of the
+		 * connection.
+		 */
+		dccp_set_seqno(&newdp->dccps_swl,
+			       max48(newdp->dccps_swl, newdp->dccps_isr));
+		dccp_set_seqno(&newdp->dccps_awl,
+			       max48(newdp->dccps_awl, newdp->dccps_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",
+			      (unsigned long long)
+			      DCCP_SKB_CB(skb)->dccpd_ack_seq,
+			      (unsigned long long)
+			      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;
+}