1 files changed, 417 insertions, 0 deletions

diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
new file mode 100644
index 000000000..efffde7f2
--- /dev/null
+++ b/net/sctp/endpointola.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* SCTP kernel implementation
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2002 International Business Machines, Corp.
+ * Copyright (c) 2001 Intel Corp.
+ * Copyright (c) 2001 Nokia, Inc.
+ * Copyright (c) 2001 La Monte H.P. Yarroll
+ *
+ * This file is part of the SCTP kernel implementation
+ *
+ * This abstraction represents an SCTP endpoint.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ *    lksctp developers <linux-sctp@vger.kernel.org>
+ *
+ * Written or modified by:
+ *    La Monte H.P. Yarroll <piggy@acm.org>
+ *    Karl Knutson <karl@athena.chicago.il.us>
+ *    Jon Grimm <jgrimm@austin.ibm.com>
+ *    Daisy Chang <daisyc@us.ibm.com>
+ *    Dajiang Zhang <dajiang.zhang@nokia.com>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/in.h>
+#include <linux/random.h>	/* get_random_bytes() */
+#include <net/sock.h>
+#include <net/ipv6.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/* Forward declarations for internal helpers. */
+static void sctp_endpoint_bh_rcv(struct work_struct *work);
+
+/*
+ * Initialize the base fields of the endpoint structure.
+ */
+static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
+						struct sock *sk,
+						gfp_t gfp)
+{
+	struct net *net = sock_net(sk);
+	struct sctp_shared_key *null_key;
+
+	ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
+	if (!ep->digest)
+		return NULL;
+
+	ep->asconf_enable = net->sctp.addip_enable;
+	ep->auth_enable = net->sctp.auth_enable;
+	if (ep->auth_enable) {
+		if (sctp_auth_init(ep, gfp))
+			goto nomem;
+		if (ep->asconf_enable) {
+			sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF);
+			sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF_ACK);
+		}
+	}
+
+	/* Initialize the base structure. */
+	/* What type of endpoint are we?  */
+	ep->base.type = SCTP_EP_TYPE_SOCKET;
+
+	/* Initialize the basic object fields. */
+	refcount_set(&ep->base.refcnt, 1);
+	ep->base.dead = false;
+
+	/* Create an input queue.  */
+	sctp_inq_init(&ep->base.inqueue);
+
+	/* Set its top-half handler */
+	sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
+
+	/* Initialize the bind addr area */
+	sctp_bind_addr_init(&ep->base.bind_addr, 0);
+
+	/* Create the lists of associations.  */
+	INIT_LIST_HEAD(&ep->asocs);
+
+	/* Use SCTP specific send buffer space queues.  */
+	ep->sndbuf_policy = net->sctp.sndbuf_policy;
+
+	sk->sk_data_ready = sctp_data_ready;
+	sk->sk_write_space = sctp_write_space;
+	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+	/* Get the receive buffer policy for this endpoint */
+	ep->rcvbuf_policy = net->sctp.rcvbuf_policy;
+
+	/* Initialize the secret key used with cookie. */
+	get_random_bytes(ep->secret_key, sizeof(ep->secret_key));
+
+	/* SCTP-AUTH extensions*/
+	INIT_LIST_HEAD(&ep->endpoint_shared_keys);
+	null_key = sctp_auth_shkey_create(0, gfp);
+	if (!null_key)
+		goto nomem_shkey;
+
+	list_add(&null_key->key_list, &ep->endpoint_shared_keys);
+
+	/* Add the null key to the endpoint shared keys list and
+	 * set the hmcas and chunks pointers.
+	 */
+	ep->prsctp_enable = net->sctp.prsctp_enable;
+	ep->reconf_enable = net->sctp.reconf_enable;
+	ep->ecn_enable = net->sctp.ecn_enable;
+
+	/* Remember who we are attached to.  */
+	ep->base.sk = sk;
+	ep->base.net = sock_net(sk);
+	sock_hold(ep->base.sk);
+
+	return ep;
+
+nomem_shkey:
+	sctp_auth_free(ep);
+nomem:
+	kfree(ep->digest);
+	return NULL;
+
+}
+
+/* Create a sctp_endpoint with all that boring stuff initialized.
+ * Returns NULL if there isn't enough memory.
+ */
+struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
+{
+	struct sctp_endpoint *ep;
+
+	/* Build a local endpoint. */
+	ep = kzalloc(sizeof(*ep), gfp);
+	if (!ep)
+		goto fail;
+
+	if (!sctp_endpoint_init(ep, sk, gfp))
+		goto fail_init;
+
+	SCTP_DBG_OBJCNT_INC(ep);
+	return ep;
+
+fail_init:
+	kfree(ep);
+fail:
+	return NULL;
+}
+
+/* Add an association to an endpoint.  */
+void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
+			    struct sctp_association *asoc)
+{
+	struct sock *sk = ep->base.sk;
+
+	/* If this is a temporary association, don't bother
+	 * since we'll be removing it shortly and don't
+	 * want anyone to find it anyway.
+	 */
+	if (asoc->temp)
+		return;
+
+	/* Now just add it to our list of asocs */
+	list_add_tail(&asoc->asocs, &ep->asocs);
+
+	/* Increment the backlog value for a TCP-style listening socket. */
+	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
+		sk_acceptq_added(sk);
+}
+
+/* Free the endpoint structure.  Delay cleanup until
+ * all users have released their reference count on this structure.
+ */
+void sctp_endpoint_free(struct sctp_endpoint *ep)
+{
+	ep->base.dead = true;
+
+	inet_sk_set_state(ep->base.sk, SCTP_SS_CLOSED);
+
+	/* Unlink this endpoint, so we can't find it again! */
+	sctp_unhash_endpoint(ep);
+
+	sctp_endpoint_put(ep);
+}
+
+/* Final destructor for endpoint.  */
+static void sctp_endpoint_destroy_rcu(struct rcu_head *head)
+{
+	struct sctp_endpoint *ep = container_of(head, struct sctp_endpoint, rcu);
+	struct sock *sk = ep->base.sk;
+
+	sctp_sk(sk)->ep = NULL;
+	sock_put(sk);
+
+	kfree(ep);
+	SCTP_DBG_OBJCNT_DEC(ep);
+}
+
+static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
+{
+	struct sock *sk;
+
+	if (unlikely(!ep->base.dead)) {
+		WARN(1, "Attempt to destroy undead endpoint %p!\n", ep);
+		return;
+	}
+
+	/* Free the digest buffer */
+	kfree(ep->digest);
+
+	/* SCTP-AUTH: Free up AUTH releated data such as shared keys
+	 * chunks and hmacs arrays that were allocated
+	 */
+	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+	sctp_auth_free(ep);
+
+	/* Cleanup. */
+	sctp_inq_free(&ep->base.inqueue);
+	sctp_bind_addr_free(&ep->base.bind_addr);
+
+	memset(ep->secret_key, 0, sizeof(ep->secret_key));
+
+	sk = ep->base.sk;
+	/* Remove and free the port */
+	if (sctp_sk(sk)->bind_hash)
+		sctp_put_port(sk);
+
+	call_rcu(&ep->rcu, sctp_endpoint_destroy_rcu);
+}
+
+/* Hold a reference to an endpoint. */
+int sctp_endpoint_hold(struct sctp_endpoint *ep)
+{
+	return refcount_inc_not_zero(&ep->base.refcnt);
+}
+
+/* Release a reference to an endpoint and clean up if there are
+ * no more references.
+ */
+void sctp_endpoint_put(struct sctp_endpoint *ep)
+{
+	if (refcount_dec_and_test(&ep->base.refcnt))
+		sctp_endpoint_destroy(ep);
+}
+
+/* Is this the endpoint we are looking for?  */
+struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
+					       struct net *net,
+					       const union sctp_addr *laddr)
+{
+	struct sctp_endpoint *retval = NULL;
+
+	if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) &&
+	    net_eq(ep->base.net, net)) {
+		if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
+					 sctp_sk(ep->base.sk)))
+			retval = ep;
+	}
+
+	return retval;
+}
+
+/* Find the association that goes with this chunk.
+ * We lookup the transport from hashtable at first, then get association
+ * through t->assoc.
+ */
+struct sctp_association *sctp_endpoint_lookup_assoc(
+	const struct sctp_endpoint *ep,
+	const union sctp_addr *paddr,
+	struct sctp_transport **transport)
+{
+	struct sctp_association *asoc = NULL;
+	struct sctp_transport *t;
+
+	*transport = NULL;
+
+	/* If the local port is not set, there can't be any associations
+	 * on this endpoint.
+	 */
+	if (!ep->base.bind_addr.port)
+		return NULL;
+
+	rcu_read_lock();
+	t = sctp_epaddr_lookup_transport(ep, paddr);
+	if (!t)
+		goto out;
+
+	*transport = t;
+	asoc = t->asoc;
+out:
+	rcu_read_unlock();
+	return asoc;
+}
+
+/* Look for any peeled off association from the endpoint that matches the
+ * given peer address.
+ */
+bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
+				 const union sctp_addr *paddr)
+{
+	struct sctp_sockaddr_entry *addr;
+	struct net *net = ep->base.net;
+	struct sctp_bind_addr *bp;
+
+	bp = &ep->base.bind_addr;
+	/* This function is called with the socket lock held,
+	 * so the address_list can not change.
+	 */
+	list_for_each_entry(addr, &bp->address_list, list) {
+		if (sctp_has_association(net, &addr->a, paddr))
+			return true;
+	}
+
+	return false;
+}
+
+/* Do delayed input processing.  This is scheduled by sctp_rcv().
+ * This may be called on BH or task time.
+ */
+static void sctp_endpoint_bh_rcv(struct work_struct *work)
+{
+	struct sctp_endpoint *ep =
+		container_of(work, struct sctp_endpoint,
+			     base.inqueue.immediate);
+	struct sctp_association *asoc;
+	struct sock *sk;
+	struct net *net;
+	struct sctp_transport *transport;
+	struct sctp_chunk *chunk;
+	struct sctp_inq *inqueue;
+	union sctp_subtype subtype;
+	enum sctp_state state;
+	int error = 0;
+	int first_time = 1;	/* is this the first time through the loop */
+
+	if (ep->base.dead)
+		return;
+
+	asoc = NULL;
+	inqueue = &ep->base.inqueue;
+	sk = ep->base.sk;
+	net = sock_net(sk);
+
+	while (NULL != (chunk = sctp_inq_pop(inqueue))) {
+		subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
+
+		/* If the first chunk in the packet is AUTH, do special
+		 * processing specified in Section 6.3 of SCTP-AUTH spec
+		 */
+		if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
+			struct sctp_chunkhdr *next_hdr;
+
+			next_hdr = sctp_inq_peek(inqueue);
+			if (!next_hdr)
+				goto normal;
+
+			/* If the next chunk is COOKIE-ECHO, skip the AUTH
+			 * chunk while saving a pointer to it so we can do
+			 * Authentication later (during cookie-echo
+			 * processing).
+			 */
+			if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
+				chunk->auth_chunk = skb_clone(chunk->skb,
+								GFP_ATOMIC);
+				chunk->auth = 1;
+				continue;
+			}
+		}
+normal:
+		/* We might have grown an association since last we
+		 * looked, so try again.
+		 *
+		 * This happens when we've just processed our
+		 * COOKIE-ECHO chunk.
+		 */
+		if (NULL == chunk->asoc) {
+			asoc = sctp_endpoint_lookup_assoc(ep,
+							  sctp_source(chunk),
+							  &transport);
+			chunk->asoc = asoc;
+			chunk->transport = transport;
+		}
+
+		state = asoc ? asoc->state : SCTP_STATE_CLOSED;
+		if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
+			continue;
+
+		/* Remember where the last DATA chunk came from so we
+		 * know where to send the SACK.
+		 */
+		if (asoc && sctp_chunk_is_data(chunk))
+			asoc->peer.last_data_from = chunk->transport;
+		else {
+			SCTP_INC_STATS(ep->base.net, SCTP_MIB_INCTRLCHUNKS);
+			if (asoc)
+				asoc->stats.ictrlchunks++;
+		}
+
+		if (chunk->transport)
+			chunk->transport->last_time_heard = ktime_get();
+
+		error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state,
+				   ep, asoc, chunk, GFP_ATOMIC);
+
+		if (error && chunk)
+			chunk->pdiscard = 1;
+
+		/* Check to see if the endpoint is freed in response to
+		 * the incoming chunk. If so, get out of the while loop.
+		 */
+		if (!sctp_sk(sk)->ep)
+			break;
+
+		if (first_time)
+			first_time = 0;
+	}
+}