text: // SPDX-License-Identifier: GPL-2.0-or-later
  /* SCTP kernel implementation
   * (C) Copyright IBM Corp. 2001, 2004
   * Copyright (c) 1999-2000 Cisco, Inc.
   * Copyright (c) 1999-2001 Motorola, Inc.
   * 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
   *
   * Initialization/cleanup for SCTP protocol support.
   *
   * 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@us.ibm.com>
   *    Sridhar Samudrala <sri@us.ibm.com>
   *    Daisy Chang <daisyc@us.ibm.com>
   *    Ardelle Fan <ardelle.fan@intel.com>
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/netdevice.h>
  #include <linux/inetdevice.h>
  #include <linux/seq_file.h>
  #include <linux/memblock.h>
  #include <linux/highmem.h>
  #include <linux/swap.h>
  #include <linux/slab.h>
  #include <net/net_namespace.h>
  #include <net/protocol.h>
  #include <net/ip.h>
  #include <net/ipv6.h>
  #include <net/route.h>
  #include <net/sctp/sctp.h>
  #include <net/addrconf.h>
  #include <net/inet_common.h>
  #include <net/inet_ecn.h>
  
  #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
  
  /* Global data structures. */
  struct sctp_globals sctp_globals __read_mostly;
  
  struct idr sctp_assocs_id;
  DEFINE_SPINLOCK(sctp_assocs_id_lock);
  
  static struct sctp_pf *sctp_pf_inet6_specific;
  static struct sctp_pf *sctp_pf_inet_specific;
  static struct sctp_af *sctp_af_v4_specific;
  static struct sctp_af *sctp_af_v6_specific;
  
  struct kmem_cache *sctp_chunk_cachep __read_mostly;
  struct kmem_cache *sctp_bucket_cachep __read_mostly;
  
  long sysctl_sctp_mem[3];
  int sysctl_sctp_rmem[3];
  int sysctl_sctp_wmem[3];
  
  /* Private helper to extract ipv4 address and stash them in
   * the protocol structure.
   */
  static void sctp_v4_copy_addrlist(struct list_head *addrlist,
  				  struct net_device *dev)
  {
  	struct in_device *in_dev;
  	struct in_ifaddr *ifa;
  	struct sctp_sockaddr_entry *addr;
  
  	rcu_read_lock();
  	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
  		rcu_read_unlock();
  		return;
  	}
  
  	in_dev_for_each_ifa_rcu(ifa, in_dev) {
  		/* Add the address to the local list.  */
  		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  		if (addr) {
  			addr->a.v4.sin_family = AF_INET;
  			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
  			addr->valid = 1;
  			INIT_LIST_HEAD(&addr->list);
  			list_add_tail(&addr->list, addrlist);
  		}
  	}
  
  	rcu_read_unlock();
  }
  
  /* Extract our IP addresses from the system and stash them in the
   * protocol structure.
   */
  static void sctp_get_local_addr_list(struct net *net)
  {
  	struct net_device *dev;
  	struct list_head *pos;
  	struct sctp_af *af;
  
  	rcu_read_lock();
  	for_each_netdev_rcu(net, dev) {
  		list_for_each(pos, &sctp_address_families) {
  			af = list_entry(pos, struct sctp_af, list);
  			af->copy_addrlist(&net->sctp.local_addr_list, dev);
  		}
  	}
  	rcu_read_unlock();
  }
  
  /* Free the existing local addresses.  */
  static void sctp_free_local_addr_list(struct net *net)
  {
  	struct sctp_sockaddr_entry *addr;
  	struct list_head *pos, *temp;
  
  	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
  		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
  		list_del(pos);
  		kfree(addr);
  	}
  }
  
  /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
  int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
  			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
  {
  	struct sctp_sockaddr_entry *addr;
  	union sctp_addr laddr;
  	int error = 0;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
  		if (!addr->valid)
  			continue;
  		if (!sctp_in_scope(net, &addr->a, scope))
  			continue;
  
  		/* Now that the address is in scope, check to see if
  		 * the address type is really supported by the local
  		 * sock as well as the remote peer.
  		 */
  		if (addr->a.sa.sa_family == AF_INET &&
  		    (!(copy_flags & SCTP_ADDR4_ALLOWED) ||
  		     !(copy_flags & SCTP_ADDR4_PEERSUPP)))
  			continue;
  		if (addr->a.sa.sa_family == AF_INET6 &&
  		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
  		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
  			continue;
  
  		laddr = addr->a;
  		/* also works for setting ipv6 address port */
  		laddr.v4.sin_port = htons(bp->port);
  		if (sctp_bind_addr_state(bp, &laddr) != -1)
  			continue;
  
  		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
  					   SCTP_ADDR_SRC, GFP_ATOMIC);
  		if (error)
  			break;
  	}
  
  	rcu_read_unlock();
  	return error;
  }
  
  /* Copy over any ip options */
  static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
  {
  	struct inet_sock *newinet, *inet = inet_sk(sk);
  	struct ip_options_rcu *inet_opt, *newopt = NULL;
  
  	newinet = inet_sk(newsk);
  
  	rcu_read_lock();
  	inet_opt = rcu_dereference(inet->inet_opt);
  	if (inet_opt) {
  		newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
  				      inet_opt->opt.optlen, GFP_ATOMIC);
  		if (newopt)
  			memcpy(newopt, inet_opt, sizeof(*inet_opt) +
  			       inet_opt->opt.optlen);
  		else
  			pr_err("%s: Failed to copy ip options\n", __func__);
  	}
  	RCU_INIT_POINTER(newinet->inet_opt, newopt);
  	rcu_read_unlock();
  }
  
  /* Account for the IP options */
  static int sctp_v4_ip_options_len(struct sock *sk)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct ip_options_rcu *inet_opt;
  	int len = 0;
  
  	rcu_read_lock();
  	inet_opt = rcu_dereference(inet->inet_opt);
  	if (inet_opt)
  		len = inet_opt->opt.optlen;
  
  	rcu_read_unlock();
  	return len;
  }
  
  /* Initialize a sctp_addr from in incoming skb.  */
  static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
  			     int is_saddr)
  {
  	/* Always called on head skb, so this is safe */
  	struct sctphdr *sh = sctp_hdr(skb);
  	struct sockaddr_in *sa = &addr->v4;
  
  	addr->v4.sin_family = AF_INET;
  
  	if (is_saddr) {
  		sa->sin_port = sh->source;
  		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
  	} else {
  		sa->sin_port = sh->dest;
  		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
  	}
  	memset(sa->sin_zero, 0, sizeof(sa->sin_zero));
  }
  
  /* Initialize an sctp_addr from a socket. */
  static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
  {
  	addr->v4.sin_family = AF_INET;
  	addr->v4.sin_port = 0;
  	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
  	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
  }
  
  /* Initialize sk->sk_rcv_saddr from sctp_addr. */
  static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
  {
  	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
  }
  
  /* Initialize sk->sk_daddr from sctp_addr. */
  static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
  {
  	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
  }
  
  /* Initialize a sctp_addr from an address parameter. */
  static void sctp_v4_from_addr_param(union sctp_addr *addr,
  				    union sctp_addr_param *param,
  				    __be16 port, int iif)
  {
  	addr->v4.sin_family = AF_INET;
  	addr->v4.sin_port = port;
  	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
  	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
  }
  
  /* Initialize an address parameter from a sctp_addr and return the length
   * of the address parameter.
   */
  static int sctp_v4_to_addr_param(const union sctp_addr *addr,
  				 union sctp_addr_param *param)
  {
  	int length = sizeof(struct sctp_ipv4addr_param);
  
  	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
  	param->v4.param_hdr.length = htons(length);
  	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
  
  	return length;
  }
  
  /* Initialize a sctp_addr from a dst_entry. */
  static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
  			      __be16 port)
  {
  	saddr->v4.sin_family = AF_INET;
  	saddr->v4.sin_port = port;
  	saddr->v4.sin_addr.s_addr = fl4->saddr;
  	memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
  }
  
  /* Compare two addresses exactly. */
  static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
  			    const union sctp_addr *addr2)
  {
  	if (addr1->sa.sa_family != addr2->sa.sa_family)
  		return 0;
  	if (addr1->v4.sin_port != addr2->v4.sin_port)
  		return 0;
  	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
  		return 0;
  
  	return 1;
  }
  
  /* Initialize addr struct to INADDR_ANY. */
  static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
  {
  	addr->v4.sin_family = AF_INET;
  	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
  	addr->v4.sin_port = port;
  	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
  }
  
  /* Is this a wildcard address? */
  static int sctp_v4_is_any(const union sctp_addr *addr)
  {
  	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
  }
  
  /* This function checks if the address is a valid address to be used for
   * SCTP binding.
   *
   * Output:
   * Return 0 - If the address is a non-unicast or an illegal address.
   * Return 1 - If the address is a unicast.
   */
  static int sctp_v4_addr_valid(union sctp_addr *addr,
  			      struct sctp_sock *sp,
  			      const struct sk_buff *skb)
  {
  	/* IPv4 addresses not allowed */
  	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
  		return 0;
  
  	/* Is this a non-unicast address or a unusable SCTP address? */
  	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
  		return 0;
  
  	/* Is this a broadcast address? */
  	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
  		return 0;
  
  	return 1;
  }
  
  /* Should this be available for binding?   */
  static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
  {
  	struct net *net = sock_net(&sp->inet.sk);
  	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
  
  
  	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
  	   ret != RTN_LOCAL &&
  	   !sp->inet.freebind &&
  	   !net->ipv4.sysctl_ip_nonlocal_bind)
  		return 0;
  
  	if (ipv6_only_sock(sctp_opt2sk(sp)))
  		return 0;
  
  	return 1;
  }
  
  /* Checking the loopback, private and other address scopes as defined in
   * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
   * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
   *
   * Level 0 - unusable SCTP addresses
   * Level 1 - loopback address
   * Level 2 - link-local addresses
   * Level 3 - private addresses.
   * Level 4 - global addresses
   * For INIT and INIT-ACK address list, let L be the level of
   * of requested destination address, sender and receiver
   * SHOULD include all of its addresses with level greater
   * than or equal to L.
   *
   * IPv4 scoping can be controlled through sysctl option
   * net.sctp.addr_scope_policy
   */
  static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
  {
  	enum sctp_scope retval;
  
  	/* Check for unusable SCTP addresses. */
  	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
  		retval =  SCTP_SCOPE_UNUSABLE;
  	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_LOOPBACK;
  	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_LINK;
  	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
  		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
  		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_PRIVATE;
  	} else {
  		retval = SCTP_SCOPE_GLOBAL;
  	}
  
  	return retval;
  }
  
  /* Returns a valid dst cache entry for the given source and destination ip
   * addresses. If an association is passed, trys to get a dst entry with a
   * source address that matches an address in the bind address list.
   */
  static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
  				struct flowi *fl, struct sock *sk)
  {
  	struct sctp_association *asoc = t->asoc;
  	struct rtable *rt;
  	struct flowi _fl;
  	struct flowi4 *fl4 = &_fl.u.ip4;
  	struct sctp_bind_addr *bp;
  	struct sctp_sockaddr_entry *laddr;
  	struct dst_entry *dst = NULL;
  	union sctp_addr *daddr = &t->ipaddr;
  	union sctp_addr dst_saddr;
  	__u8 tos = inet_sk(sk)->tos;
  
  	if (t->dscp & SCTP_DSCP_SET_MASK)
  		tos = t->dscp & SCTP_DSCP_VAL_MASK;
  	memset(&_fl, 0x0, sizeof(_fl));
  	fl4->daddr  = daddr->v4.sin_addr.s_addr;
  	fl4->fl4_dport = daddr->v4.sin_port;
  	fl4->flowi4_proto = IPPROTO_SCTP;
  	if (asoc) {
  		fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
  		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
  		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
  	}
  	if (saddr) {
  		fl4->saddr = saddr->v4.sin_addr.s_addr;
  		if (!fl4->fl4_sport)
  			fl4->fl4_sport = saddr->v4.sin_port;
  	}
  
  	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
  		 &fl4->saddr);
  
  	rt = ip_route_output_key(sock_net(sk), fl4);
  	if (!IS_ERR(rt)) {
  		dst = &rt->dst;
  		t->dst = dst;
  		memcpy(fl, &_fl, sizeof(_fl));
  	}
  
  	/* If there is no association or if a source address is passed, no
  	 * more validation is required.
  	 */
  	if (!asoc || saddr)
  		goto out;
  
  	bp = &asoc->base.bind_addr;
  
  	if (dst) {
  		/* Walk through the bind address list and look for a bind
  		 * address that matches the source address of the returned dst.
  		 */
  		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
  		rcu_read_lock();
  		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
  			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
  			    (laddr->state != SCTP_ADDR_SRC &&
  			    !asoc->src_out_of_asoc_ok))
  				continue;
  			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
  				goto out_unlock;
  		}
  		rcu_read_unlock();
  
  		/* None of the bound addresses match the source address of the
  		 * dst. So release it.
  		 */
  		dst_release(dst);
  		dst = NULL;
  	}
  
  	/* Walk through the bind address list and try to get a dst that
  	 * matches a bind address as the source address.
  	 */
  	rcu_read_lock();
  	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
  		struct net_device *odev;
  
  		if (!laddr->valid)
  			continue;
  		if (laddr->state != SCTP_ADDR_SRC ||
  		    AF_INET != laddr->a.sa.sa_family)
  			continue;
  
  		fl4->fl4_sport = laddr->a.v4.sin_port;
  		flowi4_update_output(fl4,
  				     asoc->base.sk->sk_bound_dev_if,
  				     RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
  				     daddr->v4.sin_addr.s_addr,
  				     laddr->a.v4.sin_addr.s_addr);
  
  		rt = ip_route_output_key(sock_net(sk), fl4);
  		if (IS_ERR(rt))
  			continue;
  
  		/* Ensure the src address belongs to the output
  		 * interface.
  		 */
  		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
  				     false);
  		if (!odev || odev->ifindex != fl4->flowi4_oif) {
  			if (!dst) {
  				dst = &rt->dst;
  				t->dst = dst;
  				memcpy(fl, &_fl, sizeof(_fl));
  			} else {
  				dst_release(&rt->dst);
  			}
  			continue;
  		}
  
  		dst_release(dst);
  		dst = &rt->dst;
  		t->dst = dst;
  		memcpy(fl, &_fl, sizeof(_fl));
  		break;
  	}
  
  out_unlock:
  	rcu_read_unlock();
  out:
  	if (dst) {
  		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
  			 &fl->u.ip4.daddr, &fl->u.ip4.saddr);
  	} else {
  		t->dst = NULL;
  		pr_debug("no route\n");
  	}
  }
  
  /* For v4, the source address is cached in the route entry(dst). So no need
   * to cache it separately and hence this is an empty routine.
   */
  static void sctp_v4_get_saddr(struct sctp_sock *sk,
  			      struct sctp_transport *t,
  			      struct flowi *fl)
  {
  	union sctp_addr *saddr = &t->saddr;
  	struct rtable *rt = (struct rtable *)t->dst;
  
  	if (rt) {
  		saddr->v4.sin_family = AF_INET;
  		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
  	}
  }
  
  /* What interface did this skb arrive on? */
  static int sctp_v4_skb_iif(const struct sk_buff *skb)
  {
  	return inet_iif(skb);
  }
  
  /* Was this packet marked by Explicit Congestion Notification? */
  static int sctp_v4_is_ce(const struct sk_buff *skb)
  {
  	return INET_ECN_is_ce(ip_hdr(skb)->tos);
  }
  
  /* Create and initialize a new sk for the socket returned by accept(). */
  static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
  					     struct sctp_association *asoc,
  					     bool kern)
  {
  	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
  			sk->sk_prot, kern);
  	struct inet_sock *newinet;
  
  	if (!newsk)
  		goto out;
  
  	sock_init_data(NULL, newsk);
  
  	sctp_copy_sock(newsk, sk, asoc);
  	sock_reset_flag(newsk, SOCK_ZAPPED);
  
  	sctp_v4_copy_ip_options(sk, newsk);
  
  	newinet = inet_sk(newsk);
  
  	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
  
  	sk_refcnt_debug_inc(newsk);
  
  	if (newsk->sk_prot->init(newsk)) {
  		sk_common_release(newsk);
  		newsk = NULL;
  	}
  
  out:
  	return newsk;
  }
  
  static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
  {
  	/* No address mapping for V4 sockets */
  	memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
  	return sizeof(struct sockaddr_in);
  }
  
  /* Dump the v4 addr to the seq file. */
  static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
  {
  	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
  }
  
  static void sctp_v4_ecn_capable(struct sock *sk)
  {
  	INET_ECN_xmit(sk);
  }
  
  static void sctp_addr_wq_timeout_handler(struct timer_list *t)
  {
  	struct net *net = from_timer(net, t, sctp.addr_wq_timer);
  	struct sctp_sockaddr_entry *addrw, *temp;
  	struct sctp_sock *sp;
  
  	spin_lock_bh(&net->sctp.addr_wq_lock);
  
  	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
  		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
  			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
  			 addrw->state, addrw);
  
  #if IS_ENABLED(CONFIG_IPV6)
  		/* Now we send an ASCONF for each association */
  		/* Note. we currently don't handle link local IPv6 addressees */
  		if (addrw->a.sa.sa_family == AF_INET6) {
  			struct in6_addr *in6;
  
  			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
  			    IPV6_ADDR_LINKLOCAL)
  				goto free_next;
  
  			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
  			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
  			    addrw->state == SCTP_ADDR_NEW) {
  				unsigned long timeo_val;
  
  				pr_debug("%s: this is on DAD, trying %d sec "
  					 "later\n", __func__,
  					 SCTP_ADDRESS_TICK_DELAY);
  
  				timeo_val = jiffies;
  				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
  				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
  				break;
  			}
  		}
  #endif
  		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
  			struct sock *sk;
  
  			sk = sctp_opt2sk(sp);
  			/* ignore bound-specific endpoints */
  			if (!sctp_is_ep_boundall(sk))
  				continue;
  			bh_lock_sock(sk);
  			if (sctp_asconf_mgmt(sp, addrw) < 0)
  				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
  			bh_unlock_sock(sk);
  		}
  #if IS_ENABLED(CONFIG_IPV6)
  free_next:
  #endif
  		list_del(&addrw->list);
  		kfree(addrw);
  	}
  	spin_unlock_bh(&net->sctp.addr_wq_lock);
  }
  
  static void sctp_free_addr_wq(struct net *net)
  {
  	struct sctp_sockaddr_entry *addrw;
  	struct sctp_sockaddr_entry *temp;
  
  	spin_lock_bh(&net->sctp.addr_wq_lock);
  	del_timer(&net->sctp.addr_wq_timer);
  	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
  		list_del(&addrw->list);
  		kfree(addrw);
  	}
  	spin_unlock_bh(&net->sctp.addr_wq_lock);
  }
  
  /* lookup the entry for the same address in the addr_waitq
   * sctp_addr_wq MUST be locked
   */
  static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
  					struct sctp_sockaddr_entry *addr)
  {
  	struct sctp_sockaddr_entry *addrw;
  
  	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
  		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
  			continue;
  		if (addrw->a.sa.sa_family == AF_INET) {
  			if (addrw->a.v4.sin_addr.s_addr ==
  			    addr->a.v4.sin_addr.s_addr)
  				return addrw;
  		} else if (addrw->a.sa.sa_family == AF_INET6) {
  			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
  			    &addr->a.v6.sin6_addr))
  				return addrw;
  		}
  	}
  	return NULL;
  }
  
  void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
  {
  	struct sctp_sockaddr_entry *addrw;
  	unsigned long timeo_val;
  
  	/* first, we check if an opposite message already exist in the queue.
  	 * If we found such message, it is removed.
  	 * This operation is a bit stupid, but the DHCP client attaches the
  	 * new address after a couple of addition and deletion of that address
  	 */
  
  	spin_lock_bh(&net->sctp.addr_wq_lock);
  	/* Offsets existing events in addr_wq */
  	addrw = sctp_addr_wq_lookup(net, addr);
  	if (addrw) {
  		if (addrw->state != cmd) {
  			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
  				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
  				 &net->sctp.addr_waitq);
  
  			list_del(&addrw->list);
  			kfree(addrw);
  		}
  		spin_unlock_bh(&net->sctp.addr_wq_lock);
  		return;
  	}
  
  	/* OK, we have to add the new address to the wait queue */
  	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  	if (addrw == NULL) {
  		spin_unlock_bh(&net->sctp.addr_wq_lock);
  		return;
  	}
  	addrw->state = cmd;
  	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
  
  	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
  		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
  
  	if (!timer_pending(&net->sctp.addr_wq_timer)) {
  		timeo_val = jiffies;
  		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
  		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
  	}
  	spin_unlock_bh(&net->sctp.addr_wq_lock);
  }
  
  /* Event handler for inet address addition/deletion events.
   * The sctp_local_addr_list needs to be protocted by a spin lock since
   * multiple notifiers (say IPv4 and IPv6) may be running at the same
   * time and thus corrupt the list.
   * The reader side is protected with RCU.
   */
  static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
  			       void *ptr)
  {
  	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
  	struct sctp_sockaddr_entry *addr = NULL;
  	struct sctp_sockaddr_entry *temp;
  	struct net *net = dev_net(ifa->ifa_dev->dev);
  	int found = 0;
  
  	switch (ev) {
  	case NETDEV_UP:
  		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  		if (addr) {
  			addr->a.v4.sin_family = AF_INET;
  			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
  			addr->valid = 1;
  			spin_lock_bh(&net->sctp.local_addr_lock);
  			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
  			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
  			spin_unlock_bh(&net->sctp.local_addr_lock);
  		}
  		break;
  	case NETDEV_DOWN:
  		spin_lock_bh(&net->sctp.local_addr_lock);
  		list_for_each_entry_safe(addr, temp,
  					&net->sctp.local_addr_list, list) {
  			if (addr->a.sa.sa_family == AF_INET &&
  					addr->a.v4.sin_addr.s_addr ==
  					ifa->ifa_local) {
  				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
  				found = 1;
  				addr->valid = 0;
  				list_del_rcu(&addr->list);
  				break;
  			}
  		}
  		spin_unlock_bh(&net->sctp.local_addr_lock);
  		if (found)
  			kfree_rcu(addr, rcu);
  		break;
  	}
  
  	return NOTIFY_DONE;
  }
  
  /*
   * Initialize the control inode/socket with a control endpoint data
   * structure.  This endpoint is reserved exclusively for the OOTB processing.
   */
  static int sctp_ctl_sock_init(struct net *net)
  {
  	int err;
  	sa_family_t family = PF_INET;
  
  	if (sctp_get_pf_specific(PF_INET6))
  		family = PF_INET6;
  
  	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
  				   SOCK_SEQPACKET, IPPROTO_SCTP, net);
  
  	/* If IPv6 socket could not be created, try the IPv4 socket */
  	if (err < 0 && family == PF_INET6)
  		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
  					   SOCK_SEQPACKET, IPPROTO_SCTP,
  					   net);
  
  	if (err < 0) {
  		pr_err("Failed to create the SCTP control socket\n");
  		return err;
  	}
  	return 0;
  }
  
  /* Register address family specific functions. */
  int sctp_register_af(struct sctp_af *af)
  {
  	switch (af->sa_family) {
  	case AF_INET:
  		if (sctp_af_v4_specific)
  			return 0;
  		sctp_af_v4_specific = af;
  		break;
  	case AF_INET6:
  		if (sctp_af_v6_specific)
  			return 0;
  		sctp_af_v6_specific = af;
  		break;
  	default:
  		return 0;
  	}
  
  	INIT_LIST_HEAD(&af->list);
  	list_add_tail(&af->list, &sctp_address_families);
  	return 1;
  }
  
  /* Get the table of functions for manipulating a particular address
   * family.
   */
  struct sctp_af *sctp_get_af_specific(sa_family_t family)
  {
  	switch (family) {
  	case AF_INET:
  		return sctp_af_v4_specific;
  	case AF_INET6:
  		return sctp_af_v6_specific;
  	default:
  		return NULL;
  	}
  }
  
  /* Common code to initialize a AF_INET msg_name. */
  static void sctp_inet_msgname(char *msgname, int *addr_len)
  {
  	struct sockaddr_in *sin;
  
  	sin = (struct sockaddr_in *)msgname;
  	*addr_len = sizeof(struct sockaddr_in);
  	sin->sin_family = AF_INET;
  	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
  }
  
  /* Copy the primary address of the peer primary address as the msg_name. */
  static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
  				    int *addr_len)
  {
  	struct sockaddr_in *sin, *sinfrom;
  
  	if (msgname) {
  		struct sctp_association *asoc;
  
  		asoc = event->asoc;
  		sctp_inet_msgname(msgname, addr_len);
  		sin = (struct sockaddr_in *)msgname;
  		sinfrom = &asoc->peer.primary_addr.v4;
  		sin->sin_port = htons(asoc->peer.port);
  		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
  	}
  }
  
  /* Initialize and copy out a msgname from an inbound skb. */
  static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
  {
  	if (msgname) {
  		struct sctphdr *sh = sctp_hdr(skb);
  		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
  
  		sctp_inet_msgname(msgname, len);
  		sin->sin_port = sh->source;
  		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
  	}
  }
  
  /* Do we support this AF? */
  static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
  {
  	/* PF_INET only supports AF_INET addresses. */
  	return AF_INET == family;
  }
  
  /* Address matching with wildcards allowed. */
  static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
  			      const union sctp_addr *addr2,
  			      struct sctp_sock *opt)
  {
  	/* PF_INET only supports AF_INET addresses. */
  	if (addr1->sa.sa_family != addr2->sa.sa_family)
  		return 0;
  	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
  	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
  		return 1;
  	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
  		return 1;
  
  	return 0;
  }
  
  /* Verify that provided sockaddr looks bindable.  Common verification has
   * already been taken care of.
   */
  static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
  {
  	return sctp_v4_available(addr, opt);
  }
  
  /* Verify that sockaddr looks sendable.  Common verification has already
   * been taken care of.
   */
  static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
  {
  	return 1;
  }
  
  /* Fill in Supported Address Type information for INIT and INIT-ACK
   * chunks.  Returns number of addresses supported.
   */
  static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
  				     __be16 *types)
  {
  	types[0] = SCTP_PARAM_IPV4_ADDRESS;
  	return 1;
  }
  
  /* Wrapper routine that calls the ip transmit routine. */
  static inline int sctp_v4_xmit(struct sk_buff *skb,
  			       struct sctp_transport *transport)
  {
  	struct inet_sock *inet = inet_sk(skb->sk);
  	__u8 dscp = inet->tos;
  
  	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
  		 skb->len, &transport->fl.u.ip4.saddr,
  		 &transport->fl.u.ip4.daddr);
  
  	if (transport->dscp & SCTP_DSCP_SET_MASK)
  		dscp = transport->dscp & SCTP_DSCP_VAL_MASK;
  
  	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
  			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
  
  	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
  
  	return __ip_queue_xmit(&inet->sk, skb, &transport->fl, dscp);
  }
  
  static struct sctp_af sctp_af_inet;
  
  static struct sctp_pf sctp_pf_inet = {
  	.event_msgname = sctp_inet_event_msgname,
  	.skb_msgname   = sctp_inet_skb_msgname,
  	.af_supported  = sctp_inet_af_supported,
  	.cmp_addr      = sctp_inet_cmp_addr,
  	.bind_verify   = sctp_inet_bind_verify,
  	.send_verify   = sctp_inet_send_verify,
  	.supported_addrs = sctp_inet_supported_addrs,
  	.create_accept_sk = sctp_v4_create_accept_sk,
  	.addr_to_user  = sctp_v4_addr_to_user,
  	.to_sk_saddr   = sctp_v4_to_sk_saddr,
  	.to_sk_daddr   = sctp_v4_to_sk_daddr,
  	.copy_ip_options = sctp_v4_copy_ip_options,
  	.af            = &sctp_af_inet
  };
  
  /* Notifier for inetaddr addition/deletion events.  */
  static struct notifier_block sctp_inetaddr_notifier = {
  	.notifier_call = sctp_inetaddr_event,
  };
  
  /* Socket operations.  */
  static const struct proto_ops inet_seqpacket_ops = {
  	.family		   = PF_INET,
  	.owner		   = THIS_MODULE,
  	.release	   = inet_release,	/* Needs to be wrapped... */
  	.bind		   = inet_bind,
  	.connect	   = sctp_inet_connect,
  	.socketpair	   = sock_no_socketpair,
  	.accept		   = inet_accept,
  	.getname	   = inet_getname,	/* Semantics are different.  */
  	.poll		   = sctp_poll,
  	.ioctl		   = inet_ioctl,
  	.gettstamp	   = sock_gettstamp,
  	.listen		   = sctp_inet_listen,
  	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
  	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
  	.getsockopt	   = sock_common_getsockopt,
  	.sendmsg	   = inet_sendmsg,
  	.recvmsg	   = inet_recvmsg,
  	.mmap		   = sock_no_mmap,
  	.sendpage	   = sock_no_sendpage,
  #ifdef CONFIG_COMPAT
  	.compat_setsockopt = compat_sock_common_setsockopt,
  	.compat_getsockopt = compat_sock_common_getsockopt,
  #endif
  };
  
  /* Registration with AF_INET family.  */
  static struct inet_protosw sctp_seqpacket_protosw = {
  	.type       = SOCK_SEQPACKET,
  	.protocol   = IPPROTO_SCTP,
  	.prot       = &sctp_prot,
  	.ops        = &inet_seqpacket_ops,
  	.flags      = SCTP_PROTOSW_FLAG
  };
  static struct inet_protosw sctp_stream_protosw = {
  	.type       = SOCK_STREAM,
  	.protocol   = IPPROTO_SCTP,
  	.prot       = &sctp_prot,
  	.ops        = &inet_seqpacket_ops,
  	.flags      = SCTP_PROTOSW_FLAG
  };
  
  /* Register with IP layer.  */
  static const struct net_protocol sctp_protocol = {
  	.handler     = sctp_rcv,
  	.err_handler = sctp_v4_err,
  	.no_policy   = 1,
  	.netns_ok    = 1,
  	.icmp_strict_tag_validation = 1,
  };
  
  /* IPv4 address related functions.  */
  static struct sctp_af sctp_af_inet = {
  	.sa_family	   = AF_INET,
  	.sctp_xmit	   = sctp_v4_xmit,
  	.setsockopt	   = ip_setsockopt,
  	.getsockopt	   = ip_getsockopt,
  	.get_dst	   = sctp_v4_get_dst,
  	.get_saddr	   = sctp_v4_get_saddr,
  	.copy_addrlist	   = sctp_v4_copy_addrlist,
  	.from_skb	   = sctp_v4_from_skb,
  	.from_sk	   = sctp_v4_from_sk,
  	.from_addr_param   = sctp_v4_from_addr_param,
  	.to_addr_param	   = sctp_v4_to_addr_param,
  	.cmp_addr	   = sctp_v4_cmp_addr,
  	.addr_valid	   = sctp_v4_addr_valid,
  	.inaddr_any	   = sctp_v4_inaddr_any,
  	.is_any		   = sctp_v4_is_any,
  	.available	   = sctp_v4_available,
  	.scope		   = sctp_v4_scope,
  	.skb_iif	   = sctp_v4_skb_iif,
  	.is_ce		   = sctp_v4_is_ce,
  	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
  	.ecn_capable	   = sctp_v4_ecn_capable,
  	.net_header_len	   = sizeof(struct iphdr),
  	.sockaddr_len	   = sizeof(struct sockaddr_in),
  	.ip_options_len	   = sctp_v4_ip_options_len,
  #ifdef CONFIG_COMPAT
  	.compat_setsockopt = compat_ip_setsockopt,
  	.compat_getsockopt = compat_ip_getsockopt,
  #endif
  };
  
  struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
  {
  	switch (family) {
  	case PF_INET:
  		return sctp_pf_inet_specific;
  	case PF_INET6:
  		return sctp_pf_inet6_specific;
  	default:
  		return NULL;
  	}
  }
  
  /* Register the PF specific function table.  */
  int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
  {
  	switch (family) {
  	case PF_INET:
  		if (sctp_pf_inet_specific)
  			return 0;
  		sctp_pf_inet_specific = pf;
  		break;
  	case PF_INET6:
  		if (sctp_pf_inet6_specific)
  			return 0;
  		sctp_pf_inet6_specific = pf;
  		break;
  	default:
  		return 0;
  	}
  	return 1;
  }
  
  static inline int init_sctp_mibs(struct net *net)
  {
  	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
  	if (!net->sctp.sctp_statistics)
  		return -ENOMEM;
  	return 0;
  }
  
  static inline void cleanup_sctp_mibs(struct net *net)
  {
  	free_percpu(net->sctp.sctp_statistics);
  }
  
  static void sctp_v4_pf_init(void)
  {
  	/* Initialize the SCTP specific PF functions. */
  	sctp_register_pf(&sctp_pf_inet, PF_INET);
  	sctp_register_af(&sctp_af_inet);
  }
  
  static void sctp_v4_pf_exit(void)
  {
  	list_del(&sctp_af_inet.list);
  }
  
  static int sctp_v4_protosw_init(void)
  {
  	int rc;
  
  	rc = proto_register(&sctp_prot, 1);
  	if (rc)
  		return rc;
  
  	/* Register SCTP(UDP and TCP style) with socket layer.  */
  	inet_register_protosw(&sctp_seqpacket_protosw);
  	inet_register_protosw(&sctp_stream_protosw);
  
  	return 0;
  }
  
  static void sctp_v4_protosw_exit(void)
  {
  	inet_unregister_protosw(&sctp_stream_protosw);
  	inet_unregister_protosw(&sctp_seqpacket_protosw);
  	proto_unregister(&sctp_prot);
  }
  
  static int sctp_v4_add_protocol(void)
  {
  	/* Register notifier for inet address additions/deletions. */
  	register_inetaddr_notifier(&sctp_inetaddr_notifier);
  
  	/* Register SCTP with inet layer.  */
  	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
  		return -EAGAIN;
  
  	return 0;
  }
  
  static void sctp_v4_del_protocol(void)
  {
  	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
  	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
  }
  
  static int __net_init sctp_defaults_init(struct net *net)
  {
  	int status;
  
  	/*
  	 * 14. Suggested SCTP Protocol Parameter Values
  	 */
  	/* The following protocol parameters are RECOMMENDED:  */
  	/* RTO.Initial              - 3  seconds */
  	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
  	/* RTO.Min                  - 1  second */
  	net->sctp.rto_min	 		= SCTP_RTO_MIN;
  	/* RTO.Max                 -  60 seconds */
  	net->sctp.rto_max 			= SCTP_RTO_MAX;
  	/* RTO.Alpha                - 1/8 */
  	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
  	/* RTO.Beta                 - 1/4 */
  	net->sctp.rto_beta			= SCTP_RTO_BETA;
  
  	/* Valid.Cookie.Life        - 60  seconds */
  	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;
  
  	/* Whether Cookie Preservative is enabled(1) or not(0) */
  	net->sctp.cookie_preserve_enable 	= 1;
  
  	/* Default sctp sockets to use md5 as their hmac alg */
  #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
  	net->sctp.sctp_hmac_alg			= "md5";
  #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
  	net->sctp.sctp_hmac_alg			= "sha1";
  #else
  	net->sctp.sctp_hmac_alg			= NULL;
  #endif
  
  	/* Max.Burst		    - 4 */
  	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
  
  	/* Disable of Primary Path Switchover by default */
  	net->sctp.ps_retrans = SCTP_PS_RETRANS_MAX;
  
  	/* Enable pf state by default */
  	net->sctp.pf_enable = 1;
  
  	/* Ignore pf exposure feature by default */
  	net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET;
  
  	/* Association.Max.Retrans  - 10 attempts
  	 * Path.Max.Retrans         - 5  attempts (per destination address)
  	 * Max.Init.Retransmits     - 8  attempts
  	 */
  	net->sctp.max_retrans_association	= 10;
  	net->sctp.max_retrans_path		= 5;
  	net->sctp.max_retrans_init		= 8;
  
  	/* Sendbuffer growth	    - do per-socket accounting */
  	net->sctp.sndbuf_policy			= 0;
  
  	/* Rcvbuffer growth	    - do per-socket accounting */
  	net->sctp.rcvbuf_policy			= 0;
  
  	/* HB.interval              - 30 seconds */
  	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
  
  	/* delayed SACK timeout */
  	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;
  
  	/* Disable ADDIP by default. */
  	net->sctp.addip_enable = 0;
  	net->sctp.addip_noauth = 0;
  	net->sctp.default_auto_asconf = 0;
  
  	/* Enable PR-SCTP by default. */
  	net->sctp.prsctp_enable = 1;
  
  	/* Disable RECONF by default. */
  	net->sctp.reconf_enable = 0;
  
  	/* Disable AUTH by default. */
  	net->sctp.auth_enable = 0;
  
  	/* Enable ECN by default. */
  	net->sctp.ecn_enable = 1;
  
  	/* Set SCOPE policy to enabled */
  	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
  
  	/* Set the default rwnd update threshold */
  	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
  
  	/* Initialize maximum autoclose timeout. */
  	net->sctp.max_autoclose		= INT_MAX / HZ;
  
  	status = sctp_sysctl_net_register(net);
  	if (status)
  		goto err_sysctl_register;
  
  	/* Allocate and initialise sctp mibs.  */
  	status = init_sctp_mibs(net);
  	if (status)
  		goto err_init_mibs;
  
  #ifdef CONFIG_PROC_FS
  	/* Initialize proc fs directory.  */
  	status = sctp_proc_init(net);
  	if (status)
  		goto err_init_proc;
  #endif
  
  	sctp_dbg_objcnt_init(net);
  
  	/* Initialize the local address list. */
  	INIT_LIST_HEAD(&net->sctp.local_addr_list);
  	spin_lock_init(&net->sctp.local_addr_lock);
  	sctp_get_local_addr_list(net);
  
  	/* Initialize the address event list */
  	INIT_LIST_HEAD(&net->sctp.addr_waitq);
  	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
  	spin_lock_init(&net->sctp.addr_wq_lock);
  	net->sctp.addr_wq_timer.expires = 0;
  	timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
  
  	return 0;
  
  #ifdef CONFIG_PROC_FS
  err_init_proc:
  	cleanup_sctp_mibs(net);
  #endif
  err_init_mibs:
  	sctp_sysctl_net_unregister(net);
  err_sysctl_register:
  	return status;
  }
  
  static void __net_exit sctp_defaults_exit(struct net *net)
  {
  	/* Free the local address list */
  	sctp_free_addr_wq(net);
  	sctp_free_local_addr_list(net);
  
  #ifdef CONFIG_PROC_FS
  	remove_proc_subtree("sctp", net->proc_net);
  	net->sctp.proc_net_sctp = NULL;
  #endif
  	cleanup_sctp_mibs(net);
  	sctp_sysctl_net_unregister(net);
  }
  
  static struct pernet_operations sctp_defaults_ops = {
  	.init = sctp_defaults_init,
  	.exit = sctp_defaults_exit,
  };
  
  static int __net_init sctp_ctrlsock_init(struct net *net)
  {
  	int status;
  
  	/* Initialize the control inode/socket for handling OOTB packets.  */
  	status = sctp_ctl_sock_init(net);
  	if (status)
  		pr_err("Failed to initialize the SCTP control sock\n");
  
  	return status;
  }
  
  static void __net_exit sctp_ctrlsock_exit(struct net *net)
  {
  	/* Free the control endpoint.  */
  	inet_ctl_sock_destroy(net->sctp.ctl_sock);
  }
  
  static struct pernet_operations sctp_ctrlsock_ops = {
  	.init = sctp_ctrlsock_init,
  	.exit = sctp_ctrlsock_exit,
  };
  
  /* Initialize the universe into something sensible.  */
  static __init int sctp_init(void)
  {
  	int i;
  	int status = -EINVAL;
  	unsigned long goal;
  	unsigned long limit;
  	unsigned long nr_pages = totalram_pages();
  	int max_share;
  	int order;
  	int num_entries;
  	int max_entry_order;
  
  	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
  
  	/* Allocate bind_bucket and chunk caches. */
  	status = -ENOBUFS;
  	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
  					       sizeof(struct sctp_bind_bucket),
  					       0, SLAB_HWCACHE_ALIGN,
  					       NULL);
  	if (!sctp_bucket_cachep)
  		goto out;
  
  	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
  					       sizeof(struct sctp_chunk),
  					       0, SLAB_HWCACHE_ALIGN,
  					       NULL);
  	if (!sctp_chunk_cachep)
  		goto err_chunk_cachep;
  
  	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
  	if (status)
  		goto err_percpu_counter_init;
  
  	/* Implementation specific variables. */
  
  	/* Initialize default stream count setup information. */
  	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
  	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
  
  	/* Initialize handle used for association ids. */
  	idr_init(&sctp_assocs_id);
  
  	limit = nr_free_buffer_pages() / 8;
  	limit = max(limit, 128UL);
  	sysctl_sctp_mem[0] = limit / 4 * 3;
  	sysctl_sctp_mem[1] = limit;
  	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
  
  	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
  	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
  	max_share = min(4UL*1024*1024, limit);
  
  	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
  	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
  	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
  
  	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
  	sysctl_sctp_wmem[1] = 16*1024;
  	sysctl_sctp_wmem[2] = max(64*1024, max_share);
  
  	/* Size and allocate the association hash table.
  	 * The methodology is similar to that of the tcp hash tables.
  	 * Though not identical.  Start by getting a goal size
  	 */
  	if (nr_pages >= (128 * 1024))
  		goal = nr_pages >> (22 - PAGE_SHIFT);
  	else
  		goal = nr_pages >> (24 - PAGE_SHIFT);
  
  	/* Then compute the page order for said goal */
  	order = get_order(goal);
  
  	/* Now compute the required page order for the maximum sized table we
  	 * want to create
  	 */
  	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
  				    sizeof(struct sctp_bind_hashbucket));
  
  	/* Limit the page order by that maximum hash table size */
  	order = min(order, max_entry_order);
  
  	/* Allocate and initialize the endpoint hash table.  */
  	sctp_ep_hashsize = 64;
  	sctp_ep_hashtable =
  		kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
  	if (!sctp_ep_hashtable) {
  		pr_err("Failed endpoint_hash alloc\n");
  		status = -ENOMEM;
  		goto err_ehash_alloc;
  	}
  	for (i = 0; i < sctp_ep_hashsize; i++) {
  		rwlock_init(&sctp_ep_hashtable[i].lock);
  		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
  	}
  
  	/* Allocate and initialize the SCTP port hash table.
  	 * Note that order is initalized to start at the max sized
  	 * table we want to support.  If we can't get that many pages
  	 * reduce the order and try again
  	 */
  	do {
  		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
  			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
  	} while (!sctp_port_hashtable && --order > 0);
  
  	if (!sctp_port_hashtable) {
  		pr_err("Failed bind hash alloc\n");
  		status = -ENOMEM;
  		goto err_bhash_alloc;
  	}
  
  	/* Now compute the number of entries that will fit in the
  	 * port hash space we allocated
  	 */
  	num_entries = (1UL << order) * PAGE_SIZE /
  		      sizeof(struct sctp_bind_hashbucket);
  
  	/* And finish by rounding it down to the nearest power of two
  	 * this wastes some memory of course, but its needed because
  	 * the hash function operates based on the assumption that
  	 * that the number of entries is a power of two
  	 */
  	sctp_port_hashsize = rounddown_pow_of_two(num_entries);
  
  	for (i = 0; i < sctp_port_hashsize; i++) {
  		spin_lock_init(&sctp_port_hashtable[i].lock);
  		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
  	}
  
  	status = sctp_transport_hashtable_init();
  	if (status)
  		goto err_thash_alloc;
  
  	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
  		num_entries);
  
  	sctp_sysctl_register();
  
  	INIT_LIST_HEAD(&sctp_address_families);
  	sctp_v4_pf_init();
  	sctp_v6_pf_init();
  	sctp_sched_ops_init();
  
  	status = register_pernet_subsys(&sctp_defaults_ops);
  	if (status)
  		goto err_register_defaults;
  
  	status = sctp_v4_protosw_init();
  	if (status)
  		goto err_protosw_init;
  
  	status = sctp_v6_protosw_init();
  	if (status)
  		goto err_v6_protosw_init;
  
  	status = register_pernet_subsys(&sctp_ctrlsock_ops);
  	if (status)
  		goto err_register_ctrlsock;
  
  	status = sctp_v4_add_protocol();
  	if (status)
  		goto err_add_protocol;
  
  	/* Register SCTP with inet6 layer.  */
  	status = sctp_v6_add_protocol();
  	if (status)
  		goto err_v6_add_protocol;
  
  	if (sctp_offload_init() < 0)
  		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
  
  out:
  	return status;
  err_v6_add_protocol:
  	sctp_v4_del_protocol();
  err_add_protocol:
  	unregister_pernet_subsys(&sctp_ctrlsock_ops);
  err_register_ctrlsock:
  	sctp_v6_protosw_exit();
  err_v6_protosw_init:
  	sctp_v4_protosw_exit();
  err_protosw_init:
  	unregister_pernet_subsys(&sctp_defaults_ops);
  err_register_defaults:
  	sctp_v4_pf_exit();
  	sctp_v6_pf_exit();
  	sctp_sysctl_unregister();
  	free_pages((unsigned long)sctp_port_hashtable,
  		   get_order(sctp_port_hashsize *
  			     sizeof(struct sctp_bind_hashbucket)));
  err_bhash_alloc:
  	sctp_transport_hashtable_destroy();
  err_thash_alloc:
  	kfree(sctp_ep_hashtable);
  err_ehash_alloc:
  	percpu_counter_destroy(&sctp_sockets_allocated);
  err_percpu_counter_init:
  	kmem_cache_destroy(sctp_chunk_cachep);
  err_chunk_cachep:
  	kmem_cache_destroy(sctp_bucket_cachep);
  	goto out;
  }
  
  /* Exit handler for the SCTP protocol.  */
  static __exit void sctp_exit(void)
  {
  	/* BUG.  This should probably do something useful like clean
  	 * up all the remaining associations and all that memory.
  	 */
  
  	/* Unregister with inet6/inet layers. */
  	sctp_v6_del_protocol();
  	sctp_v4_del_protocol();
  
  	unregister_pernet_subsys(&sctp_ctrlsock_ops);
  
  	/* Free protosw registrations */
  	sctp_v6_protosw_exit();
  	sctp_v4_protosw_exit();
  
  	unregister_pernet_subsys(&sctp_defaults_ops);
  
  	/* Unregister with socket layer. */
  	sctp_v6_pf_exit();
  	sctp_v4_pf_exit();
  
  	sctp_sysctl_unregister();
  
  	free_pages((unsigned long)sctp_port_hashtable,
  		   get_order(sctp_port_hashsize *
  			     sizeof(struct sctp_bind_hashbucket)));
  	kfree(sctp_ep_hashtable);
  	sctp_transport_hashtable_destroy();
  
  	percpu_counter_destroy(&sctp_sockets_allocated);
  
  	rcu_barrier(); /* Wait for completion of call_rcu()'s */
  
  	kmem_cache_destroy(sctp_chunk_cachep);
  	kmem_cache_destroy(sctp_bucket_cachep);
  }
  
  module_init(sctp_init);
  module_exit(sctp_exit);
  
  /*
   * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
   */
  MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
  MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
  MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
  MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
  module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
  MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
  MODULE_LICENSE("GPL");
  