patch-2.4.23 linux-2.4.23/net/sctp/protocol.c

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diff -urN linux-2.4.22/net/sctp/protocol.c linux-2.4.23/net/sctp/protocol.c
@@ -0,0 +1,1082 @@
+/* SCTP kernel reference 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 reference Implementation
+ *
+ * Initialization/cleanup for SCTP protocol support.
+ *
+ * The SCTP reference implementation 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, or (at your option)
+ * any later version.
+ *
+ * The SCTP reference implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ *                 ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ *    lksctp developers <lksctp-developers@lists.sourceforge.net>
+ *
+ * Or submit a bug report through the following website:
+ *    http://www.sf.net/projects/lksctp
+ *
+ * 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>
+ *
+ * Any bugs reported given to us we will try to fix... any fixes shared will
+ * be incorporated into the next SCTP release.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <net/protocol.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/sctp/sctp.h>
+#include <net/addrconf.h>
+#include <net/inet_common.h>
+
+/* Global data structures. */
+struct sctp_protocol sctp_proto;
+struct proc_dir_entry	*proc_net_sctp;
+DEFINE_SNMP_STAT(struct sctp_mib, sctp_statistics);
+
+/* This is the global socket data structure used for responding to
+ * the Out-of-the-blue (OOTB) packets.  A control sock will be created
+ * for this socket at the initialization time.
+ */
+static struct socket *sctp_ctl_socket;
+
+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;
+
+extern struct net_proto_family inet_family_ops;
+
+extern int sctp_snmp_proc_init(void);
+extern int sctp_snmp_proc_exit(void);
+
+/* Return the address of the control sock. */
+struct sock *sctp_get_ctl_sock(void)
+{
+	return sctp_ctl_socket->sk;
+}
+
+/* Set up the proc fs entry for the SCTP protocol. */
+__init int sctp_proc_init(void)
+{
+	int rc = 0;
+
+	if (!proc_net_sctp) {
+		struct proc_dir_entry *ent;
+		ent = proc_mkdir("net/sctp", 0);
+		if (ent) {
+			ent->owner = THIS_MODULE;
+			proc_net_sctp = ent;
+		} else
+			rc = -ENOMEM;
+	}
+
+	if (sctp_snmp_proc_init())
+		rc = -ENOMEM;
+
+	return rc;
+}
+
+/* Clean up the proc fs entry for the SCTP protocol. */
+void sctp_proc_exit(void)
+{
+
+	sctp_snmp_proc_exit();
+
+	if (proc_net_sctp) {
+		proc_net_sctp = NULL;
+		remove_proc_entry("net/sctp", 0);
+	}
+}
+
+/* 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 sockaddr_storage_list *addr;
+
+	read_lock(&inetdev_lock);
+	if ((in_dev = __in_dev_get(dev)) == NULL) {
+		read_unlock(&inetdev_lock);
+		return;
+	}
+
+	read_lock(&in_dev->lock);
+	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
+		/* Add the address to the local list.  */
+		addr = t_new(struct sockaddr_storage_list, GFP_ATOMIC);
+		if (addr) {
+			addr->a.v4.sin_family = AF_INET;
+			addr->a.v4.sin_port = 0;
+			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
+			list_add_tail(&addr->list, addrlist);
+		}
+	}
+
+	read_unlock(&in_dev->lock);
+	read_unlock(&inetdev_lock);
+}
+
+/* Extract our IP addresses from the system and stash them in the
+ * protocol structure.
+ */
+static void __sctp_get_local_addr_list(struct sctp_protocol *proto)
+{
+	struct net_device *dev;
+	struct list_head *pos;
+	struct sctp_af *af;
+
+	read_lock(&dev_base_lock);
+	for (dev = dev_base; dev; dev = dev->next) {
+		list_for_each(pos, &proto->address_families) {
+			af = list_entry(pos, struct sctp_af, list);
+			af->copy_addrlist(&proto->local_addr_list, dev);
+		}
+	}
+	read_unlock(&dev_base_lock);
+}
+
+static void sctp_get_local_addr_list(struct sctp_protocol *proto)
+{
+	unsigned long flags;
+
+	sctp_spin_lock_irqsave(&sctp_proto.local_addr_lock, flags);
+	__sctp_get_local_addr_list(&sctp_proto);
+	sctp_spin_unlock_irqrestore(&sctp_proto.local_addr_lock, flags);
+}
+
+/* Free the existing local addresses.  */
+static void __sctp_free_local_addr_list(struct sctp_protocol *proto)
+{
+	struct sockaddr_storage_list *addr;
+	struct list_head *pos, *temp;
+
+	list_for_each_safe(pos, temp, &proto->local_addr_list) {
+		addr = list_entry(pos, struct sockaddr_storage_list, list);
+		list_del(pos);
+		kfree(addr);
+	}
+}
+
+/* Free the existing local addresses.  */
+static void sctp_free_local_addr_list(struct sctp_protocol *proto)
+{
+	unsigned long flags;
+
+	sctp_spin_lock_irqsave(&proto->local_addr_lock, flags);
+	__sctp_free_local_addr_list(proto);
+	sctp_spin_unlock_irqrestore(&proto->local_addr_lock, flags);
+}
+
+/* Copy the local addresses which are valid for 'scope' into 'bp'.  */
+int sctp_copy_local_addr_list(struct sctp_protocol *proto,
+			      struct sctp_bind_addr *bp, sctp_scope_t scope,
+			      int gfp, int copy_flags)
+{
+	struct sockaddr_storage_list *addr;
+	int error = 0;
+	struct list_head *pos;
+	unsigned long flags;
+
+	sctp_spin_lock_irqsave(&proto->local_addr_lock, flags);
+	list_for_each(pos, &proto->local_addr_list) {
+		addr = list_entry(pos, struct sockaddr_storage_list, list);
+		if (sctp_in_scope(&addr->a, scope)) {
+			/* 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 ((((AF_INET == addr->a.sa.sa_family) &&
+			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
+			    (((AF_INET6 == addr->a.sa.sa_family) &&
+			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
+			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
+				error = sctp_add_bind_addr(bp, &addr->a, 
+							   GFP_ATOMIC);
+				if (error)
+					goto end_copy;
+			}
+		}
+	}
+
+end_copy:
+	sctp_spin_unlock_irqrestore(&proto->local_addr_lock, flags);
+	return error;
+}
+
+/* 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)
+{
+	void *from;
+	__u16 *port;
+	struct sctphdr *sh;
+
+	port = &addr->v4.sin_port;
+	addr->v4.sin_family = AF_INET;
+
+	sh = (struct sctphdr *) skb->h.raw;
+	if (is_saddr) {
+		*port  = ntohs(sh->source);
+		from = &skb->nh.iph->saddr;
+	} else {
+		*port = ntohs(sh->dest);
+		from = &skb->nh.iph->daddr;
+	}
+	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
+}
+
+/* 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 = (sk)->num;
+	addr->v4.sin_addr.s_addr = (sk)->rcv_saddr;
+}
+
+/* Initialize sk->rcv_saddr from sctp_addr. */
+static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
+{
+	(sk)->rcv_saddr = addr->v4.sin_addr.s_addr;
+}
+
+/* Initialize sk->daddr from sctp_addr. */
+static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
+{
+	(sk)->daddr = addr->v4.sin_addr.s_addr;
+}
+
+/* Initialize a sctp_addr from a dst_entry. */
+static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct dst_entry *dst,
+			      unsigned short port)
+{
+	struct rtable *rt = (struct rtable *)dst;
+	saddr->v4.sin_family = AF_INET;
+	saddr->v4.sin_port = port;
+	saddr->v4.sin_addr.s_addr = rt->rt_src;
+}
+
+/* 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, unsigned short port)
+{
+	addr->v4.sin_family = AF_INET;
+	addr->v4.sin_addr.s_addr = INADDR_ANY;
+	addr->v4.sin_port = port;
+}
+
+/* Is this a wildcard address? */
+static int sctp_v4_is_any(const union sctp_addr *addr)
+{
+	return 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)
+{
+	/* Is this a non-unicast address or a unusable SCTP address? */
+	if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr))
+		return 0;
+
+	return 1;
+}
+
+/* Should this be available for binding?   */
+static int sctp_v4_available(const union sctp_addr *addr)
+{
+	int ret = inet_addr_type(addr->v4.sin_addr.s_addr);
+
+	/* FIXME: ip_nonlocal_bind sysctl support. */
+
+	if (addr->v4.sin_addr.s_addr != INADDR_ANY && ret != RTN_LOCAL)
+		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.
+ */
+static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
+{
+	sctp_scope_t retval;
+
+	/* Should IPv4 scoping be a sysctl configurable option
+	 * so users can turn it off (default on) for certain
+	 * unconventional networking environments?
+	 */
+
+	/* Check for unusable SCTP addresses. */
+	if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr)) {
+		retval =  SCTP_SCOPE_UNUSABLE;
+	} else if (LOOPBACK(addr->v4.sin_addr.s_addr)) {
+		retval = SCTP_SCOPE_LOOPBACK;
+	} else if (IS_IPV4_LINK_ADDRESS(&addr->v4.sin_addr.s_addr)) {
+		retval = SCTP_SCOPE_LINK;
+	} else if (IS_IPV4_PRIVATE_ADDRESS(&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.
+ */
+struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
+				  union sctp_addr *daddr,
+				  union sctp_addr *saddr)
+{
+	struct rtable *rt;
+	struct rt_key key;
+	sctp_bind_addr_t *bp;
+	rwlock_t *addr_lock;
+	struct sockaddr_storage_list *laddr;
+	struct list_head *pos;
+	struct dst_entry *dst = NULL;
+	union sctp_addr dst_saddr;
+	
+	memset(&key, 0x0, sizeof(struct rt_key));
+	key.dst = daddr->v4.sin_addr.s_addr;
+	
+	if (saddr)
+		key.src = saddr->v4.sin_addr.s_addr;
+
+	SCTP_DEBUG_PRINTK("%s: DST:%u.%u.%u.%u, SRC:%u.%u.%u.%u - ",
+			  __FUNCTION__, NIPQUAD(key.dst),
+			  NIPQUAD(key.src));
+
+	if (!ip_route_output_key(&rt, &key)) {
+		dst = &rt->u.dst;
+	}
+
+	/* 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;
+	addr_lock = &asoc->base.addr_lock;
+
+	if (dst) {
+		/* Walk through the bind address list and look for a bind
+		 * address that matches the source address of the returned dst.
+		 */
+		sctp_read_lock(addr_lock);
+		list_for_each(pos, &bp->address_list) {
+			laddr = list_entry(pos, struct sockaddr_storage_list,
+					   list);
+			sctp_v4_dst_saddr(&dst_saddr, dst, bp->port);
+			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
+				goto out_unlock;
+		}
+		sctp_read_unlock(addr_lock);
+
+		/* 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.
+	 */
+	sctp_read_lock(addr_lock);
+	list_for_each(pos, &bp->address_list) {
+		laddr = list_entry(pos, struct sockaddr_storage_list, list);
+
+		if (AF_INET == laddr->a.sa.sa_family) {
+			key.src = laddr->a.v4.sin_addr.s_addr;
+			if (!ip_route_output_key(&rt, &key)) {
+				dst = &rt->u.dst;
+				goto out_unlock;
+			}
+		}
+	}
+
+out_unlock:
+	sctp_read_unlock(addr_lock);
+out:
+	if (dst)
+		SCTP_DEBUG_PRINTK("rt_dst:%u.%u.%u.%u, rt_src:%u.%u.%u.%u\n",
+			  	  NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_src));
+	else
+		SCTP_DEBUG_PRINTK("NO ROUTE\n");
+
+	return dst;
+}
+
+/* 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.
+ */
+void sctp_v4_get_saddr(struct sctp_association *asoc,
+		       struct dst_entry *dst,
+		       union sctp_addr *daddr,
+		       union sctp_addr *saddr)
+{
+	struct rtable *rt = (struct rtable *)dst;
+
+	if (rt) {
+		saddr->v4.sin_family = AF_INET;
+		saddr->v4.sin_port = asoc->base.bind_addr.port;  
+		saddr->v4.sin_addr.s_addr = rt->rt_src; 
+	}
+}
+
+/* What interface did this skb arrive on? */
+int sctp_v4_skb_iif(const struct sk_buff *skb)
+{
+     	return ((struct rtable *)skb->dst)->rt_iif;
+}
+
+/* Create and initialize a new sk for the socket returned by accept(). */
+struct sock *sctp_v4_create_accept_sk(struct sock *sk,
+				      struct sctp_association *asoc)
+{
+	struct sock *newsk;
+	struct inet_opt *inet = inet_sk(sk);
+	struct inet_opt *newinet;
+
+	newsk = sk_alloc(PF_INET, GFP_KERNEL, sizeof(struct sock));
+	if (!newsk)
+		goto out;
+
+	sock_init_data(NULL, newsk);
+	sk_set_owner(newsk, THIS_MODULE);
+
+	newsk->type = SOCK_STREAM;
+
+	newsk->prot = sk->prot;
+	newsk->no_check = sk->no_check;
+	newsk->reuse = sk->reuse;
+	newsk->shutdown = sk->shutdown;
+
+	newsk->destruct = inet_sock_destruct;
+	newsk->zapped = 0;
+	newsk->family = PF_INET;
+	newsk->protocol = IPPROTO_SCTP;
+	newsk->backlog_rcv = sk->prot->backlog_rcv;
+
+	newinet = inet_sk(newsk);
+
+	/* Initialize sk's sport, dport, rcv_saddr and daddr for
+	 * getsockname() and getpeername()
+	 */
+	newsk->sport = sk->sport;
+	newsk->saddr = sk->saddr;
+	newsk->rcv_saddr = sk->rcv_saddr;
+	newsk->dport = htons(asoc->peer.port);
+	newsk->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
+	newinet->pmtudisc = inet->pmtudisc;
+      	newinet->id = 0;
+
+	newinet->ttl = sysctl_ip_default_ttl;
+	newinet->mc_loop = 1;
+	newinet->mc_ttl = 1;
+	newinet->mc_index = 0;
+	newinet->mc_list = NULL;
+
+#ifdef INET_REFCNT_DEBUG
+	atomic_inc(&inet_sock_nr);
+#endif
+
+	if (0 != newsk->prot->init(newsk)) {
+		inet_sock_release(newsk);
+		newsk = NULL;
+	}
+
+out:
+	return newsk;
+}
+
+/* Event handler for inet address addition/deletion events.
+ * Basically, whenever there is an event, we re-build our local address list.
+ */
+static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
+			       void *ptr)
+{
+	unsigned long flags;
+
+	sctp_spin_lock_irqsave(&sctp_proto.local_addr_lock, flags);
+	__sctp_free_local_addr_list(&sctp_proto);
+	__sctp_get_local_addr_list(&sctp_proto);
+	sctp_spin_unlock_irqrestore(&sctp_proto.local_addr_lock, flags);
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * Initialize the control inode/socket with a control endpoint data
+ * structure.  This endpoint is reserved exclusively for the OOTB processing.
+ */
+int sctp_ctl_sock_init(void)
+{
+	int err;
+	sa_family_t family;
+
+	if (sctp_get_pf_specific(PF_INET6))
+		family = PF_INET6;
+	else
+		family = PF_INET;
+
+	err = sock_create(family, SOCK_SEQPACKET, IPPROTO_SCTP,
+			  &sctp_ctl_socket);
+	if (err < 0) {
+		printk(KERN_ERR
+		       "SCTP: Failed to create the SCTP control socket.\n");
+		return err;
+	}
+	sctp_ctl_socket->sk->allocation = GFP_ATOMIC;
+	inet_sk(sctp_ctl_socket->sk)->ttl = MAXTTL;
+
+	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_proto.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) {
+		sctp_inet_msgname(msgname, addr_len);
+		sin = (struct sockaddr_in *)msgname;
+		sinfrom = &event->event_asoc->peer.primary_addr.v4;
+		sin->sin_port = htons(event->event_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)
+{
+	struct sctphdr *sh;
+	struct sockaddr_in *sin;
+
+	if (msgname) {
+		sctp_inet_msgname(msgname, len);
+		sin = (struct sockaddr_in *)msgname;
+		sh = (struct sctphdr *)skb->h.raw;
+		sin->sin_port = sh->source;
+		sin->sin_addr.s_addr = skb->nh.iph->saddr;
+	}
+}
+
+/* Do we support this AF? */
+static int sctp_inet_af_supported(sa_family_t family)
+{
+	/* 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_opt *opt)
+{
+	/* PF_INET only supports AF_INET addresses. */
+	if (addr1->sa.sa_family != addr2->sa.sa_family)
+		return 0;
+	if (INADDR_ANY == addr1->v4.sin_addr.s_addr ||
+	    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_opt *opt, union sctp_addr *addr)
+{
+	return sctp_v4_available(addr);
+}
+
+/* Verify that sockaddr looks sendable.  Common verification has already
+ * been taken care of.
+ */
+static int sctp_inet_send_verify(struct sctp_opt *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_opt *opt,
+				     __u16 *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, int ipfragok)
+{
+	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
+			  "src:%u.%u.%u.%u, dst:%u.%u.%u.%u\n",
+			  __FUNCTION__, skb, skb->len,
+			  NIPQUAD(((struct rtable *)skb->dst)->rt_src),
+			  NIPQUAD(((struct rtable *)skb->dst)->rt_dst));
+
+	SCTP_INC_STATS(SctpOutSCTPPacks);
+	return ip_queue_xmit(skb, ipfragok);
+}
+
+struct sctp_af sctp_ipv4_specific;
+
+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,
+	.af            = &sctp_ipv4_specific,
+};
+
+/* Notifier for inetaddr addition/deletion events.  */
+struct notifier_block sctp_inetaddr_notifier = {
+	.notifier_call = sctp_inetaddr_event,
+};
+
+/* Socket operations.  */
+struct proto_ops inet_seqpacket_ops = {
+	.family      = PF_INET,
+	.release     = inet_release,       /* Needs to be wrapped... */
+	.bind        = inet_bind,
+	.connect     = inet_dgram_connect,
+	.socketpair  = sock_no_socketpair,
+	.accept      = inet_accept,
+	.getname     = inet_getname,      /* Semantics are different.  */
+	.poll        = sctp_poll,
+	.ioctl       = inet_ioctl,
+	.listen      = sctp_inet_listen,
+	.shutdown    = inet_shutdown,     /* Looks harmless.  */
+	.setsockopt  = inet_setsockopt,   /* IP_SOL IP_OPTION is a problem. */
+	.getsockopt  = inet_getsockopt,
+	.sendmsg     = inet_sendmsg,
+	.recvmsg     = inet_recvmsg,
+	.mmap        = sock_no_mmap,
+	.sendpage    = sock_no_sendpage,
+};
+
+/* 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,
+	.capability = -1,
+	.no_check   = 0,
+	.flags      = SCTP_PROTOSW_FLAG
+};
+static struct inet_protosw sctp_stream_protosw = {
+	.type       = SOCK_STREAM,
+	.protocol   = IPPROTO_SCTP,
+	.prot       = &sctp_prot,
+	.ops        = &inet_seqpacket_ops,
+	.capability = -1,
+	.no_check   = 0,
+	.flags      = SCTP_PROTOSW_FLAG
+};
+
+/* Register with IP layer.  */
+static struct inet_protocol sctp_protocol = {
+	.handler     = sctp_rcv,
+	.err_handler = sctp_v4_err,
+	.protocol    = IPPROTO_SCTP,
+	.name        = "SCTP"
+};
+
+/* IPv4 address related functions.  */
+struct sctp_af sctp_ipv4_specific = {
+	.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,
+	.to_sk_saddr    = sctp_v4_to_sk_saddr,
+	.to_sk_daddr    = sctp_v4_to_sk_daddr,
+	.dst_saddr      = sctp_v4_dst_saddr,
+	.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,
+	.net_header_len = sizeof(struct iphdr),
+	.sockaddr_len   = sizeof(struct sockaddr_in),
+	.sa_family      = AF_INET,
+};
+
+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 int __init init_sctp_mibs(void)
+{
+	return 0;
+}
+
+static void cleanup_sctp_mibs(void)
+{
+}
+
+/* Initialize the universe into something sensible.  */
+__init int sctp_init(void)
+{
+	int i;
+	int status = 0;
+
+	/* SCTP_DEBUG sanity check. */
+	if (!sctp_sanity_check())
+		return -EINVAL;
+
+	/* Add SCTP to inet_protos hash table.  */
+	inet_add_protocol(&sctp_protocol);
+
+	/* Add SCTP(TCP and UDP style) to inetsw linked list.  */
+	inet_register_protosw(&sctp_seqpacket_protosw);
+	inet_register_protosw(&sctp_stream_protosw);
+
+	/* Allocate and initialise sctp mibs.  */
+	status = init_sctp_mibs();
+	if (status)
+		goto err_init_mibs;
+
+	/* Initialize proc fs directory.  */
+	sctp_proc_init();
+
+	/* Initialize object count debugging.  */
+	sctp_dbg_objcnt_init();
+
+	/* Initialize the SCTP specific PF functions. */
+	sctp_register_pf(&sctp_pf_inet, PF_INET);
+	/*
+	 * 14. Suggested SCTP Protocol Parameter Values
+	 */
+	/* The following protocol parameters are RECOMMENDED:  */
+	/* RTO.Initial              - 3  seconds */
+	sctp_proto.rto_initial		= SCTP_RTO_INITIAL;
+	/* RTO.Min                  - 1  second */
+	sctp_proto.rto_min	 	= SCTP_RTO_MIN;
+	/* RTO.Max                 -  60 seconds */
+	sctp_proto.rto_max 		= SCTP_RTO_MAX;
+	/* RTO.Alpha                - 1/8 */
+	sctp_proto.rto_alpha	        = SCTP_RTO_ALPHA;
+	/* RTO.Beta                 - 1/4 */
+	sctp_proto.rto_beta		= SCTP_RTO_BETA;
+
+	/* Valid.Cookie.Life        - 60  seconds */
+	sctp_proto.valid_cookie_life	= 60 * HZ;
+
+	/* Whether Cookie Preservative is enabled(1) or not(0) */
+	sctp_proto.cookie_preserve_enable = 1;
+
+	/* Max.Burst		    - 4 */
+	sctp_proto.max_burst = SCTP_MAX_BURST;
+
+	/* Association.Max.Retrans  - 10 attempts
+	 * Path.Max.Retrans         - 5  attempts (per destination address)
+	 * Max.Init.Retransmits     - 8  attempts
+	 */
+	sctp_proto.max_retrans_association = 10;
+	sctp_proto.max_retrans_path	= 5;
+	sctp_proto.max_retrans_init	= 8;
+
+	/* HB.interval              - 30 seconds */
+	sctp_proto.hb_interval		= 30 * HZ;
+
+	/* Implementation specific variables. */
+
+	/* Initialize default stream count setup information. */
+	sctp_proto.max_instreams    = SCTP_DEFAULT_INSTREAMS;
+	sctp_proto.max_outstreams   = SCTP_DEFAULT_OUTSTREAMS;
+
+	/* Allocate and initialize the association hash table.  */
+	sctp_proto.assoc_hashsize = 4096;
+	sctp_proto.assoc_hashbucket = (sctp_hashbucket_t *)
+		kmalloc(4096 * sizeof(sctp_hashbucket_t), GFP_KERNEL);
+	if (!sctp_proto.assoc_hashbucket) {
+		printk(KERN_ERR "SCTP: Failed association hash alloc.\n");
+		status = -ENOMEM;
+		goto err_ahash_alloc;
+	}
+	for (i = 0; i < sctp_proto.assoc_hashsize; i++) {
+		sctp_proto.assoc_hashbucket[i].lock = RW_LOCK_UNLOCKED;
+		sctp_proto.assoc_hashbucket[i].chain = NULL;
+	}
+
+	/* Allocate and initialize the endpoint hash table.  */
+	sctp_proto.ep_hashsize = 64;
+	sctp_proto.ep_hashbucket = (sctp_hashbucket_t *)
+		kmalloc(64 * sizeof(sctp_hashbucket_t), GFP_KERNEL);
+	if (!sctp_proto.ep_hashbucket) {
+		printk(KERN_ERR "SCTP: Failed endpoint_hash alloc.\n");
+		status = -ENOMEM;
+		goto err_ehash_alloc;
+	}
+
+	for (i = 0; i < sctp_proto.ep_hashsize; i++) {
+		sctp_proto.ep_hashbucket[i].lock = RW_LOCK_UNLOCKED;
+		sctp_proto.ep_hashbucket[i].chain = NULL;
+	}
+
+	/* Allocate and initialize the SCTP port hash table.  */
+	sctp_proto.port_hashsize = 4096;
+	sctp_proto.port_hashtable = (sctp_bind_hashbucket_t *)
+		kmalloc(4096 * sizeof(sctp_bind_hashbucket_t), GFP_KERNEL);
+	if (!sctp_proto.port_hashtable) {
+		printk(KERN_ERR "SCTP: Failed bind hash alloc.");
+		status = -ENOMEM;
+		goto err_bhash_alloc;
+	}
+
+	sctp_proto.port_alloc_lock = SPIN_LOCK_UNLOCKED;
+	sctp_proto.port_rover = sysctl_local_port_range[0] - 1;
+	for (i = 0; i < sctp_proto.port_hashsize; i++) {
+		sctp_proto.port_hashtable[i].lock = SPIN_LOCK_UNLOCKED;
+		sctp_proto.port_hashtable[i].chain = NULL;
+	}
+
+	sctp_sysctl_register();
+
+	INIT_LIST_HEAD(&sctp_proto.address_families);
+	sctp_register_af(&sctp_ipv4_specific);
+
+	status = sctp_v6_init();
+	if (status)
+		goto err_v6_init;
+
+	/* Initialize the control inode/socket for handling OOTB packets.  */
+	if ((status = sctp_ctl_sock_init())) {
+		printk (KERN_ERR
+			"SCTP: Failed to initialize the SCTP control sock.\n");
+		goto err_ctl_sock_init;
+	}
+
+	/* Initialize the local address list. */
+	INIT_LIST_HEAD(&sctp_proto.local_addr_list);
+	sctp_proto.local_addr_lock = SPIN_LOCK_UNLOCKED;
+
+	/* Register notifier for inet address additions/deletions. */
+	register_inetaddr_notifier(&sctp_inetaddr_notifier);
+
+	sctp_get_local_addr_list(&sctp_proto);
+
+	__unsafe(THIS_MODULE);
+	return 0;
+
+err_ctl_sock_init:
+	sctp_v6_exit();
+err_v6_init:
+	sctp_sysctl_unregister();
+	list_del(&sctp_ipv4_specific.list);
+	kfree(sctp_proto.port_hashtable);
+err_bhash_alloc:
+	kfree(sctp_proto.ep_hashbucket);
+err_ehash_alloc:
+	kfree(sctp_proto.assoc_hashbucket);
+err_ahash_alloc:
+	sctp_dbg_objcnt_exit();
+	sctp_proc_exit();
+	cleanup_sctp_mibs();
+err_init_mibs:
+	inet_del_protocol(&sctp_protocol);
+	inet_unregister_protosw(&sctp_seqpacket_protosw);
+	inet_unregister_protosw(&sctp_stream_protosw);
+	return status;
+}
+
+/* Exit handler for the SCTP protocol.  */
+__exit void sctp_exit(void)
+{
+	/* BUG.  This should probably do something useful like clean
+	 * up all the remaining associations and all that memory.
+	 */
+
+	/* Unregister notifier for inet address additions/deletions. */
+	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
+
+	/* Free the local address list.  */
+	sctp_free_local_addr_list(&sctp_proto);
+
+	/* Free the control endpoint.  */
+	sock_release(sctp_ctl_socket);
+
+	sctp_v6_exit();
+	sctp_sysctl_unregister();
+	list_del(&sctp_ipv4_specific.list);
+
+	kfree(sctp_proto.assoc_hashbucket);
+	kfree(sctp_proto.ep_hashbucket);
+	kfree(sctp_proto.port_hashtable);
+
+	sctp_dbg_objcnt_exit();
+	sctp_proc_exit();
+	cleanup_sctp_mibs();
+
+	inet_del_protocol(&sctp_protocol);
+	inet_unregister_protosw(&sctp_seqpacket_protosw);
+	inet_unregister_protosw(&sctp_stream_protosw);
+}
+
+module_init(sctp_init);
+module_exit(sctp_exit);
+
+MODULE_AUTHOR("Linux Kernel SCTP developers <lksctp-developers@lists.sourceforge.net>");
+MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
+MODULE_LICENSE("GPL");

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)