Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 274 insertions, 0 deletions

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
new file mode 100644
index 000000000..e91838a7b
--- /dev/null
+++ b/net/dccp/minisocks.c
@@ -0,0 +1,274 @@
+/*
+ *  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/dccp.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/timer.h>
+
+#include <net/sock.h>
+#include <net/xfrm.h>
+#include <net/inet_timewait_sock.h>
+
+#include "ackvec.h"
+#include "ccid.h"
+#include "dccp.h"
+#include "feat.h"
+
+struct inet_timewait_death_row dccp_death_row = {
+	.sysctl_max_tw_buckets = NR_FILE * 2,
+	.hashinfo	= &dccp_hashinfo,
+};
+
+EXPORT_SYMBOL_GPL(dccp_death_row);
+
+void dccp_time_wait(struct sock *sk, int state, int timeo)
+{
+	struct inet_timewait_sock *tw;
+
+	tw = inet_twsk_alloc(sk, &dccp_death_row, state);
+
+	if (tw != NULL) {
+		const struct inet_connection_sock *icsk = inet_csk(sk);
+		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
+#if IS_ENABLED(CONFIG_IPV6)
+		if (tw->tw_family == PF_INET6) {
+			tw->tw_v6_daddr = sk->sk_v6_daddr;
+			tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
+			tw->tw_ipv6only = sk->sk_ipv6only;
+		}
+#endif
+
+		/* Get the TIME_WAIT timeout firing. */
+		if (timeo < rto)
+			timeo = rto;
+
+		if (state == DCCP_TIME_WAIT)
+			timeo = DCCP_TIMEWAIT_LEN;
+
+		/* tw_timer is pinned, so we need to make sure BH are disabled
+		 * in following section, otherwise timer handler could run before
+		 * we complete the initialization.
+		 */
+		local_bh_disable();
+		inet_twsk_schedule(tw, timeo);
+		/* Linkage updates.
+		 * Note that access to tw after this point is illegal.
+		 */
+		inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
+		local_bh_enable();
+	} else {
+		/* Sorry, if we're out of memory, just CLOSE this
+		 * socket up.  We've got bigger problems than
+		 * non-graceful socket closings.
+		 */
+		DCCP_WARN("time wait bucket table overflow\n");
+	}
+
+	dccp_done(sk);
+}
+
+struct sock *dccp_create_openreq_child(const 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_lock(sk, req, GFP_ATOMIC);
+
+	if (newsk != NULL) {
+		struct dccp_request_sock *dreq = dccp_rsk(req);
+		struct inet_connection_sock *newicsk = inet_csk(newsk);
+		struct dccp_sock *newdp = dccp_sk(newsk);
+
+		newdp->dccps_role	    = DCCP_ROLE_SERVER;
+		newdp->dccps_hc_rx_ackvec   = NULL;
+		newdp->dccps_service_list   = NULL;
+		newdp->dccps_hc_rx_ccid     = NULL;
+		newdp->dccps_hc_tx_ccid     = NULL;
+		newdp->dccps_service	    = dreq->dreq_service;
+		newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
+		newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
+		newicsk->icsk_rto	    = DCCP_TIMEOUT_INIT;
+
+		INIT_LIST_HEAD(&newdp->dccps_featneg);
+		/*
+		 * Step 3: Process LISTEN state
+		 *
+		 *    Choose S.ISS (initial seqno) or set from Init Cookies
+		 *    Initialize S.GAR := S.ISS
+		 *    Set S.ISR, S.GSR from packet (or Init Cookies)
+		 *
+		 *    Setting AWL/AWH and SWL/SWH happens as part of the feature
+		 *    activation below, as these windows all depend on the local
+		 *    and remote Sequence Window feature values (7.5.2).
+		 */
+		newdp->dccps_iss = dreq->dreq_iss;
+		newdp->dccps_gss = dreq->dreq_gss;
+		newdp->dccps_gar = newdp->dccps_iss;
+		newdp->dccps_isr = dreq->dreq_isr;
+		newdp->dccps_gsr = dreq->dreq_gsr;
+
+		/*
+		 * Activate features: initialise CCIDs, sequence windows etc.
+		 */
+		if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
+			sk_free_unlock_clone(newsk);
+			return NULL;
+		}
+		dccp_init_xmit_timers(newsk);
+
+		__DCCP_INC_STATS(DCCP_MIB_PASSIVEOPENS);
+	}
+	return newsk;
+}
+
+EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
+
+/*
+ * 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 sock *child = NULL;
+	struct dccp_request_sock *dreq = dccp_rsk(req);
+	bool own_req;
+
+	/* TCP/DCCP listeners became lockless.
+	 * DCCP stores complex state in its request_sock, so we need
+	 * a protection for them, now this code runs without being protected
+	 * by the parent (listener) lock.
+	 */
+	spin_lock_bh(&dreq->dreq_lock);
+
+	/* Check for retransmitted REQUEST */
+	if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
+
+		if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
+			dccp_pr_debug("Retransmitted REQUEST\n");
+			dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq;
+			/*
+			 * Send another RESPONSE packet
+			 * To protect against Request floods, increment retrans
+			 * counter (backoff, monitored by dccp_response_timer).
+			 */
+			inet_rtx_syn_ack(sk, req);
+		}
+		/* Network Duplicate, discard packet */
+		goto out;
+	}
+
+	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 (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
+				dreq->dreq_iss, dreq->dreq_gss)) {
+		dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
+			      "dreq_iss=%llu, dreq_gss=%llu\n",
+			      (unsigned long long)
+			      DCCP_SKB_CB(skb)->dccpd_ack_seq,
+			      (unsigned long long) dreq->dreq_iss,
+			      (unsigned long long) dreq->dreq_gss);
+		goto drop;
+	}
+
+	if (dccp_parse_options(sk, dreq, skb))
+		 goto drop;
+
+	child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
+							 req, &own_req);
+	if (child) {
+		child = inet_csk_complete_hashdance(sk, child, req, own_req);
+		goto out;
+	}
+
+	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(sk, skb);
+
+	inet_csk_reqsk_queue_drop(sk, req);
+out:
+	spin_unlock_bh(&dreq->dreq_lock);
+	return child;
+}
+
+EXPORT_SYMBOL_GPL(dccp_check_req);
+
+/*
+ *  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);
+	} 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;
+}
+
+EXPORT_SYMBOL_GPL(dccp_child_process);
+
+void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
+			 struct request_sock *rsk)
+{
+	DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
+}
+
+EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
+
+int dccp_reqsk_init(struct request_sock *req,
+		    struct dccp_sock const *dp, struct sk_buff const *skb)
+{
+	struct dccp_request_sock *dreq = dccp_rsk(req);
+
+	spin_lock_init(&dreq->dreq_lock);
+	inet_rsk(req)->ir_rmt_port = dccp_hdr(skb)->dccph_sport;
+	inet_rsk(req)->ir_num	   = ntohs(dccp_hdr(skb)->dccph_dport);
+	inet_rsk(req)->acked	   = 0;
+	dreq->dreq_timestamp_echo  = 0;
+
+	/* inherit feature negotiation options from listening socket */
+	return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
+}
+
+EXPORT_SYMBOL_GPL(dccp_reqsk_init);