1 files changed, 74 insertions, 101 deletions

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 5165571f397a..9c6d0508e63a 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -181,7 +181,7 @@ out:
 }
 
 
-static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
+static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
 	struct ipv6_pinfo *np = inet6_sk(sk);
@@ -202,7 +202,9 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
 	security_req_classify_flow(req, flowi6_to_flowi(&fl6));
 
 
-	final_p = fl6_update_dst(&fl6, np->opt, &final);
+	rcu_read_lock();
+	final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
+	rcu_read_unlock();
 
 	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 	if (IS_ERR(dst)) {
@@ -219,7 +221,10 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
 							 &ireq->ir_v6_loc_addr,
 							 &ireq->ir_v6_rmt_addr);
 		fl6.daddr = ireq->ir_v6_rmt_addr;
-		err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
+		rcu_read_lock();
+		err = ip6_xmit(sk, skb, &fl6, rcu_dereference(np->opt),
+			       np->tclass);
+		rcu_read_unlock();
 		err = net_xmit_eval(err);
 	}
 
@@ -234,7 +239,7 @@ static void dccp_v6_reqsk_destructor(struct request_sock *req)
 	kfree_skb(inet_rsk(req)->pktopts);
 }
 
-static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
+static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
 {
 	const struct ipv6hdr *rxip6h;
 	struct sk_buff *skb;
@@ -290,37 +295,6 @@ static struct request_sock_ops dccp6_request_sock_ops = {
 	.syn_ack_timeout = dccp_syn_ack_timeout,
 };
 
-static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
-{
-	const struct dccp_hdr *dh = dccp_hdr(skb);
-	const struct ipv6hdr *iph = ipv6_hdr(skb);
-	struct request_sock *req;
-	struct sock *nsk;
-
-	req = inet6_csk_search_req(sk, dh->dccph_sport, &iph->saddr,
-				   &iph->daddr, inet6_iif(skb));
-	if (req) {
-		nsk = dccp_check_req(sk, skb, req);
-		if (!nsk)
-			reqsk_put(req);
-		return nsk;
-	}
-	nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
-					 &iph->saddr, dh->dccph_sport,
-					 &iph->daddr, ntohs(dh->dccph_dport),
-					 inet6_iif(skb));
-	if (nsk != NULL) {
-		if (nsk->sk_state != DCCP_TIME_WAIT) {
-			bh_lock_sock(nsk);
-			return nsk;
-		}
-		inet_twsk_put(inet_twsk(nsk));
-		return NULL;
-	}
-
-	return sk;
-}
-
 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 {
 	struct request_sock *req;
@@ -350,7 +324,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
 		goto drop;
 
-	req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk);
+	req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
 	if (req == NULL)
 		goto drop;
 
@@ -398,7 +372,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	if (dccp_v6_send_response(sk, req))
 		goto drop_and_free;
 
-	inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
+	inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
 	return 0;
 
 drop_and_free:
@@ -408,13 +382,17 @@ drop:
 	return -1;
 }
 
-static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
+static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
 					      struct sk_buff *skb,
 					      struct request_sock *req,
-					      struct dst_entry *dst)
+					      struct dst_entry *dst,
+					      struct request_sock *req_unhash,
+					      bool *own_req)
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
-	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
+	struct ipv6_pinfo *newnp;
+	const struct ipv6_pinfo *np = inet6_sk(sk);
+	struct ipv6_txoptions *opt;
 	struct inet_sock *newinet;
 	struct dccp6_sock *newdp6;
 	struct sock *newsk;
@@ -423,7 +401,8 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 		/*
 		 *	v6 mapped
 		 */
-		newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
+		newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
+						  req_unhash, own_req);
 		if (newsk == NULL)
 			return NULL;
 
@@ -462,22 +441,11 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 	if (sk_acceptq_is_full(sk))
 		goto out_overflow;
 
-	if (dst == NULL) {
-		struct in6_addr *final_p, final;
+	if (!dst) {
 		struct flowi6 fl6;
 
-		memset(&fl6, 0, sizeof(fl6));
-		fl6.flowi6_proto = IPPROTO_DCCP;
-		fl6.daddr = ireq->ir_v6_rmt_addr;
-		final_p = fl6_update_dst(&fl6, np->opt, &final);
-		fl6.saddr = ireq->ir_v6_loc_addr;
-		fl6.flowi6_oif = sk->sk_bound_dev_if;
-		fl6.fl6_dport = ireq->ir_rmt_port;
-		fl6.fl6_sport = htons(ireq->ir_num);
-		security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
-
-		dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
-		if (IS_ERR(dst))
+		dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
+		if (!dst)
 			goto out;
 	}
 
@@ -491,7 +459,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 	 * comment in that function for the gory details. -acme
 	 */
 
-	__ip6_dst_store(newsk, dst, NULL, NULL);
+	ip6_dst_store(newsk, dst, NULL, NULL);
 	newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
 						      NETIF_F_TSO);
 	newdp6 = (struct dccp6_sock *)newsk;
@@ -515,15 +483,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 	/* Clone RX bits */
 	newnp->rxopt.all = np->rxopt.all;
 
-	/* Clone pktoptions received with SYN */
 	newnp->pktoptions = NULL;
-	if (ireq->pktopts != NULL) {
-		newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
-		consume_skb(ireq->pktopts);
-		ireq->pktopts = NULL;
-		if (newnp->pktoptions)
-			skb_set_owner_r(newnp->pktoptions, newsk);
-	}
 	newnp->opt	  = NULL;
 	newnp->mcast_oif  = inet6_iif(skb);
 	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
@@ -534,13 +494,15 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 	 * Yes, keeping reference count would be much more clever, but we make
 	 * one more one thing there: reattach optmem to newsk.
 	 */
-	if (np->opt != NULL)
-		newnp->opt = ipv6_dup_options(newsk, np->opt);
-
+	opt = rcu_dereference(np->opt);
+	if (opt) {
+		opt = ipv6_dup_options(newsk, opt);
+		RCU_INIT_POINTER(newnp->opt, opt);
+	}
 	inet_csk(newsk)->icsk_ext_hdr_len = 0;
-	if (newnp->opt != NULL)
-		inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
-						     newnp->opt->opt_flen);
+	if (opt)
+		inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
+						    opt->opt_flen;
 
 	dccp_sync_mss(newsk, dst_mtu(dst));
 
@@ -552,7 +514,15 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 		dccp_done(newsk);
 		goto out;
 	}
-	__inet_hash(newsk, NULL);
+	*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
+	/* Clone pktoptions received with SYN, if we own the req */
+	if (*own_req && ireq->pktopts) {
+		newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
+		consume_skb(ireq->pktopts);
+		ireq->pktopts = NULL;
+		if (newnp->pktoptions)
+			skb_set_owner_r(newnp->pktoptions, newsk);
+	}
 
 	return newsk;
 
@@ -651,24 +621,6 @@ static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 	 * NOTE: the check for the packet types is done in
 	 *	 dccp_rcv_state_process
 	 */
-	if (sk->sk_state == DCCP_LISTEN) {
-		struct sock *nsk = dccp_v6_hnd_req(sk, skb);
-
-		if (nsk == NULL)
-			goto discard;
-		/*
-		 * Queue it on the new socket if the new socket is active,
-		 * otherwise we just shortcircuit this and continue with
-		 * the new socket..
-		 */
-		if (nsk != sk) {
-			if (dccp_child_process(sk, nsk, skb))
-				goto reset;
-			if (opt_skb != NULL)
-				__kfree_skb(opt_skb);
-			return 0;
-		}
-	}
 
 	if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
 		goto reset;
@@ -715,16 +667,11 @@ static int dccp_v6_rcv(struct sk_buff *skb)
 	else
 		DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
 
-	/* Step 2:
-	 *	Look up flow ID in table and get corresponding socket */
+lookup:
 	sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
 			        dh->dccph_sport, dh->dccph_dport,
 				inet6_iif(skb));
-	/*
-	 * Step 2:
-	 *	If no socket ...
-	 */
-	if (sk == NULL) {
+	if (!sk) {
 		dccp_pr_debug("failed to look up flow ID in table and "
 			      "get corresponding socket\n");
 		goto no_dccp_socket;
@@ -742,6 +689,31 @@ static int dccp_v6_rcv(struct sk_buff *skb)
 		goto no_dccp_socket;
 	}
 
+	if (sk->sk_state == DCCP_NEW_SYN_RECV) {
+		struct request_sock *req = inet_reqsk(sk);
+		struct sock *nsk = NULL;
+
+		sk = req->rsk_listener;
+		if (likely(sk->sk_state == DCCP_LISTEN)) {
+			nsk = dccp_check_req(sk, skb, req);
+		} else {
+			inet_csk_reqsk_queue_drop_and_put(sk, req);
+			goto lookup;
+		}
+		if (!nsk) {
+			reqsk_put(req);
+			goto discard_it;
+		}
+		if (nsk == sk) {
+			sock_hold(sk);
+			reqsk_put(req);
+		} else if (dccp_child_process(sk, nsk, skb)) {
+			dccp_v6_ctl_send_reset(sk, skb);
+			goto discard_it;
+		} else {
+			return 0;
+		}
+	}
 	/*
 	 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
 	 *	o if MinCsCov = 0, only packets with CsCov = 0 are accepted
@@ -793,6 +765,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct in6_addr *saddr = NULL, *final_p, final;
+	struct ipv6_txoptions *opt;
 	struct flowi6 fl6;
 	struct dst_entry *dst;
 	int addr_type;
@@ -892,7 +865,8 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 	fl6.fl6_sport = inet->inet_sport;
 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 
-	final_p = fl6_update_dst(&fl6, np->opt, &final);
+	opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
+	final_p = fl6_update_dst(&fl6, opt, &final);
 
 	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 	if (IS_ERR(dst)) {
@@ -909,12 +883,11 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 	np->saddr = *saddr;
 	inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 
-	__ip6_dst_store(sk, dst, NULL, NULL);
+	ip6_dst_store(sk, dst, NULL, NULL);
 
 	icsk->icsk_ext_hdr_len = 0;
-	if (np->opt != NULL)
-		icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
-					  np->opt->opt_nflen);
+	if (opt)
+		icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
 
 	inet->inet_dport = usin->sin6_port;