[SCTP] Addr family cleanup part 2. (jgrimm)

Splitting out yet more code.  New af and pf specific functions. 

include/net/sctp/structs.h

@@ -2,7 +2,7 @@
  * Copyright (c) 1999-2000 Cisco, Inc.
  * Copyright (c) 1999-2001 Motorola, Inc.
  * Copyright (c) 2001 Intel Corp.
- * Copyright (c) 2001 International Business Machines Corp.
+ * Copyright (c) 2001-2002 International Business Machines Corp.
  *
  * This file is part of the SCTP kernel reference Implementation
  *
@@ -257,6 +257,8 @@ typedef struct sctp_func {
 	void            (*from_skb)     (union sctp_addr *,
 					 struct sk_buff *skb,
 					 int saddr);
+	int             (*addr_valid)   (union sctp_addr *);
+	sctp_scope_t    (*scope) (union sctp_addr *);
 	__u16		net_header_len;
 	int		sockaddr_len;
 	sa_family_t	sa_family;
@@ -269,13 +271,14 @@ sctp_func_t *sctp_get_af_specific(sa_family_t);
 typedef struct sctp_pf {
 	void (*event_msgname)(sctp_ulpevent_t *, char *, int *);
 	void (*skb_msgname)(struct sk_buff *, char *, int *);
+	int  (*af_supported)(sa_family_t);
 } sctp_pf_t;
 
 /* SCTP Socket type: UDP or TCP style. */
 typedef enum {
 	SCTP_SOCKET_UDP = 0,
-       SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
-       SCTP_SOCKET_TCP
+	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
+	SCTP_SOCKET_TCP
 } sctp_socket_type_t;
 
 /* Per socket SCTP information. */
@@ -505,7 +508,7 @@ void  *sctp_addto_chunk(sctp_chunk_t *chunk, int len, const void *data);
 int sctp_user_addto_chunk(sctp_chunk_t *chunk, int len, struct iovec *data);
 sctp_chunk_t *sctp_chunkify(struct sk_buff *, const sctp_association_t *,
 			    struct sock *);
-void sctp_init_addrs(sctp_chunk_t *chunk);
+void sctp_init_addrs(sctp_chunk_t *, union sctp_addr *, union sctp_addr *);
 const union sctp_addr *sctp_source(const sctp_chunk_t *chunk);
 
 /* This is a structure for holding either an IPv6 or an IPv4 address.  */

net/sctp/bind_addr.c

 /* SCTP kernel reference Implementation
  * Copyright (c) Cisco 1999,2000
  * Copyright (c) Motorola 1999,2000,2001
- * Copyright (c) International Business Machines Corp., 2001
+ * Copyright (c) International Business Machines Corp., 2001,2002
  * Copyright (c) La Monte H.P. Yarroll 2001
  *
  * This file is part of the SCTP kernel reference implementation.
@@ -196,7 +196,7 @@ int sctp_del_bind_addr(sctp_bind_addr_t *bp, union sctp_addr *del_addr)
  *
  * The second argument is the return value for the length.
  */
-union sctp_params sctp_bind_addrs_to_raw(const sctp_bind_addr_t *bp, 
+union sctp_params sctp_bind_addrs_to_raw(const sctp_bind_addr_t *bp,
 					 int *addrs_len, int priority)
 {
 	union sctp_params addrparms;
@@ -252,7 +252,7 @@ int sctp_raw_to_bind_addrs(sctp_bind_addr_t *bp, __u8 *raw_addr_list,
 		rawaddr = (sctp_addr_param_t *)raw_addr_list;
 
 		switch (param->type) {
-		case SCTP_PARAM_IPV4_ADDRESS:			
+		case SCTP_PARAM_IPV4_ADDRESS:
 		case SCTP_PARAM_IPV6_ADDRESS:
 			sctp_param2sockaddr(&addr, rawaddr, port);
 			retval = sctp_add_bind_addr(bp, &addr, priority);
@@ -422,110 +422,11 @@ int sctp_in_scope(const union sctp_addr *addr, sctp_scope_t scope)
 /* What is the scope of 'addr'?  */
 sctp_scope_t sctp_scope(const union sctp_addr *addr)
 {
-	sctp_scope_t retval = SCTP_SCOPE_GLOBAL;
+	struct sctp_func *af;
 
-	switch (addr->sa.sa_family) {
-	case AF_INET:
-		/* We are 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>.
-		 * The set of SCTP address scope hopefully can cover both
-		 * types of addresses.
-		 */
-
-		/* 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;
-		}
-		break;
-
-	case AF_INET6:
-		{
-			SCTP_V6(
-				int v6scope;
-				v6scope = ipv6_addr_scope((struct in6_addr *)
-						 &addr->v6.sin6_addr);
-				/* The IPv6 scope is really a set of bit
-				 * fields. See IFA_* in <net/if_inet6.h>.
-				 * Mapping them to the generic SCTP scope
-				 * set is an attempt to have code
-				 * consistencies with the IPv4 scoping.
-				 */
-				switch (v6scope) {
-				case IFA_HOST:
-					retval = SCTP_SCOPE_LOOPBACK;
-					break;
-
-				case IFA_LINK:
-					retval = SCTP_SCOPE_LINK;
-					break;
-
-				case IFA_SITE:
-					retval = SCTP_SCOPE_PRIVATE;
-					break;
-
-				default:
-					retval = SCTP_SCOPE_GLOBAL;
-					break;
-				};
-			);
-			break;
-		}
-
-	default:
-		retval = SCTP_SCOPE_GLOBAL;
-		break;
-	};
-
-	return retval;
-}
-
-/* This function checks if the address is a valid address to be used for
- * SCTP.
- *
- * Output:
- * Return 0 - If the address is a non-unicast or an illegal address.
- * Return 1 - If the address is a unicast.
- */
-int sctp_addr_is_valid(const union sctp_addr *addr)
-{
-	unsigned short sa_family = addr->sa.sa_family;
-
-	switch (sa_family) {
-	case AF_INET:
-		/* Is this a non-unicast address or a unusable SCTP address? */
-		if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr))
-			return 0;
-		break;
-
-	case AF_INET6:
-		SCTP_V6(
-		{
-			int ret = sctp_ipv6_addr_type(&addr->v6.sin6_addr);
-
-			/* Is this a non-unicast address */
-			if (!(ret & IPV6_ADDR_UNICAST))
-				return 0;
-			break;
-		});
-
-	default:
-		return 0;
-	};
+	af = sctp_get_af_specific(addr->sa.sa_family);
+	if (!af)
+		return SCTP_SCOPE_UNUSABLE;
 
-	return 1;
+	return af->scope((union sctp_addr *)addr);
 }

net/sctp/input.c

@@ -132,7 +132,7 @@ int sctp_rcv(struct sk_buff *skb)
 	 * IP broadcast addresses cannot be used in an SCTP transport
 	 * address."
 	 */
-	if (!sctp_addr_is_valid(&src) || !sctp_addr_is_valid(&dest))
+	if (!af->addr_valid(&src) || !af->addr_valid(&dest))
 		goto discard_it;
 
 	asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport);
@@ -172,7 +172,7 @@ int sctp_rcv(struct sk_buff *skb)
 	chunk->sctp_hdr = sh;
 
 	/* Set the source and destination addresses of the incoming chunk.  */
-	sctp_init_addrs(chunk);
+	sctp_init_addrs(chunk, &src, &dest);
 
 	/* Remember where we came from.  */
 	chunk->transport = transport;

net/sctp/ipv6.c

@@ -181,7 +181,7 @@ struct dst_entry *sctp_v6_get_dst(union sctp_addr *daddr,
 
 
 	SCTP_DEBUG_PRINTK("%s: DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
-			  __FUNCTION__, NIP6(fl.fl6_dst)); 
+			  __FUNCTION__, NIP6(fl.fl6_dst));
 
 	if (saddr) {
 		fl.fl6_src = &saddr->v6.sin6_addr;
@@ -249,7 +249,7 @@ static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 	addr->v6.sin6_family = AF_INET6;
 	addr->v6.sin6_flowinfo = 0; /* FIXME */
 	addr->v6.sin6_scope_id = 0; /* FIXME */
-	
+
 	sh = (struct sctphdr *) skb->h.raw;
 	if (is_saddr) {
 		*port  = ntohs(sh->source);
@@ -262,11 +262,60 @@ static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 }
 
 /* Check if the dst entry's source addr matches the given source addr. */
-int sctp_v6_cmp_saddr(struct dst_entry *dst, union sctp_addr *saddr)
+static int sctp_v6_cmp_saddr(struct dst_entry *dst, union sctp_addr *saddr)
 {
 	struct rt6_info *rt = (struct rt6_info *)dst;
 
-	return ipv6_addr_cmp(&rt->rt6i_src.addr, &saddr->v6.sin6_addr); 
+	return ipv6_addr_cmp(&rt->rt6i_src.addr, &saddr->v6.sin6_addr);
+}
+
+/* This function checks if the address is a valid address to be used for
+ * SCTP.
+ *
+ * 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_v6_addr_valid(union sctp_addr *addr)
+{
+	int ret = sctp_ipv6_addr_type(&addr->v6.sin6_addr);
+
+	/* FIXME:  v4-mapped-v6 address support. */
+
+	/* Is this a non-unicast address */
+	if (!(ret & IPV6_ADDR_UNICAST))
+		return 0;
+
+	return 1;
+}
+
+/* What is the scope of 'addr'?  */
+static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
+{
+	int v6scope;
+	sctp_scope_t retval;
+
+	/* The IPv6 scope is really a set of bit fields.
+	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
+	 */
+
+	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
+	switch (v6scope) {
+	case IFA_HOST:
+		retval = SCTP_SCOPE_LOOPBACK;
+		break;
+	case IFA_LINK:
+		retval = SCTP_SCOPE_LINK;
+		break;
+	case IFA_SITE:
+		retval = SCTP_SCOPE_PRIVATE;
+		break;
+	default:
+		retval = SCTP_SCOPE_GLOBAL;
+		break;
+	};
+
+	return retval;
 }
 
 /* Initialize a PF_INET6 socket msg_name. */
@@ -282,7 +331,7 @@ static void sctp_inet6_msgname(char *msgname, int *addr_len)
 }
 
 /* Initialize a PF_INET msgname from a ulpevent. */
-static void sctp_inet6_event_msgname(sctp_ulpevent_t *event, char *msgname, 
+static void sctp_inet6_event_msgname(sctp_ulpevent_t *event, char *msgname,
 				     int *addrlen)
 {
 	struct sockaddr_in6 *sin6, *sin6from;
@@ -344,6 +393,23 @@ static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 	}
 }
 
+/* Do we support this AF? */
+static int sctp_inet6_af_supported(sa_family_t family)
+{
+	/* FIXME:  v4-mapped-v6 addresses.  The I-D is still waffling
+	 * on what to do with sockaddr formats for PF_INET6 sockets.
+	 * For now assume we'll support both.
+	 */
+	switch (family) {
+	case AF_INET6:
+	case AF_INET:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+
 static struct proto_ops inet6_seqpacket_ops = {
 	.family     = PF_INET6,
 	.release    = inet6_release,
@@ -386,6 +452,8 @@ static sctp_func_t sctp_ipv6_specific = {
 	.copy_addrlist   = sctp_v6_copy_addrlist,
 	.from_skb        = sctp_v6_from_skb,
 	.cmp_saddr	 = sctp_v6_cmp_saddr,
+	.scope           = sctp_v6_scope,
+	.addr_valid      = sctp_v6_addr_valid,
 	.net_header_len  = sizeof(struct ipv6hdr),
 	.sockaddr_len    = sizeof(struct sockaddr_in6),
 	.sa_family       = AF_INET6,
@@ -394,6 +462,7 @@ static sctp_func_t sctp_ipv6_specific = {
 static sctp_pf_t sctp_pf_inet6_specific = {
 	.event_msgname = sctp_inet6_event_msgname,
 	.skb_msgname   = sctp_inet6_skb_msgname,
+	.af_supported  = sctp_inet6_af_supported,
 };
 
 /* Initialize IPv6 support and register with inet6 stack.  */

net/sctp/protocol.c

@@ -5,42 +5,42 @@
  * 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 
+ *
+ * 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 
+ *
+ * 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.  
- * 
+ * 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: 
+ * 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>
- * 
+ *
  * Any bugs reported given to us we will try to fix... any fixes shared will
  * be incorporated into the next SCTP release.
  */
@@ -103,7 +103,7 @@ void sctp_proc_exit(void)
 /* Private helper to extract ipv4 address and stash them in
  * the protocol structure.
  */
-static void sctp_v4_copy_addrlist(struct list_head *addrlist, 
+static void sctp_v4_copy_addrlist(struct list_head *addrlist,
 				  struct net_device *dev)
 {
 	struct in_device *in_dev;
@@ -227,10 +227,10 @@ struct dst_entry *sctp_v4_get_dst(union sctp_addr *daddr,
 				  union sctp_addr *saddr)
 {
 	struct rtable *rt;
-	struct flowi fl = { 
-		.nl_u = { 
+	struct flowi fl = {
+		.nl_u = {
 			.ip4_u = { .daddr =
-				   daddr->v4.sin_addr.s_addr, }}, 
+				   daddr->v4.sin_addr.s_addr, }},
 		.proto = IPPROTO_SCTP,
 	};
 
@@ -280,7 +280,52 @@ int sctp_v4_cmp_saddr(struct dst_entry *dst, union sctp_addr *saddr)
 {
 	struct rtable *rt = (struct rtable *)dst;
 
-	return (rt->rt_src == saddr->v4.sin_addr.s_addr); 
+	return (rt->rt_src == saddr->v4.sin_addr.s_addr);
+}
+
+/* This function checks if the address is a valid address to be used for
+ * SCTP.
+ *
+ * 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;
+}
+
+/* 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>.
+ */
+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;
 }
 
 /* Event handler for inet device events.
@@ -352,13 +397,13 @@ sctp_func_t *sctp_get_af_specific(sa_family_t family)
 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(sctp_ulpevent_t *event, char *msgname, int *addr_len)
 {
@@ -371,26 +416,34 @@ static void sctp_inet_event_msgname(sctp_ulpevent_t *event, char *msgname, int *
 		sin->sin_port = htons(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 *addr_len)
+static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
 {
-	struct sctphdr *sh; 
+	struct sctphdr *sh;
 	struct sockaddr_in *sin;
 
 	if (msgname) {
-		sctp_inet_msgname(msgname, addr_len);
+		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);
+}
 
 static sctp_pf_t sctp_pf_inet = {
 	.event_msgname = sctp_inet_event_msgname,
-	.skb_msgname = sctp_inet_skb_msgname,
+	.skb_msgname   = sctp_inet_skb_msgname,
+	.af_supported  = sctp_inet_af_supported,
 };
 
 
@@ -446,6 +499,8 @@ struct sctp_func sctp_ipv4_specific = {
 	.copy_addrlist  = sctp_v4_copy_addrlist,
 	.from_skb       = sctp_v4_from_skb,
 	.cmp_saddr	= sctp_v4_cmp_saddr,
+	.addr_valid     = sctp_v4_addr_valid,
+	.scope          = sctp_v4_scope,
 	.net_header_len = sizeof(struct iphdr),
 	.sockaddr_len   = sizeof(struct sockaddr_in),
 	.sa_family      = AF_INET,

net/sctp/sm_make_chunk.c

@@ -1031,47 +1031,11 @@ sctp_chunk_t *sctp_chunkify(struct sk_buff *skb, const sctp_association_t *asoc,
 }
 
 /* Set chunk->source and dest based on the IP header in chunk->skb.  */
-void sctp_init_addrs(sctp_chunk_t *chunk)
+void sctp_init_addrs(sctp_chunk_t *chunk, union sctp_addr *src,
+		     union sctp_addr *dest)
 {
-	union sctp_addr *source, *dest;
-	struct sk_buff *skb;
-	struct sctphdr *sh;
-	struct iphdr *ih4;
-	struct ipv6hdr *ih6;
-
-	source = &chunk->source;
-	dest = &chunk->dest;
-	skb = chunk->skb;
-	ih4 = skb->nh.iph;
-	ih6 = skb->nh.ipv6h;
-	sh = chunk->sctp_hdr;
-
-	switch (ih4->version) {
-	case 4:
-		source->v4.sin_family = AF_INET;
-		source->v4.sin_port = ntohs(sh->source);
-		source->v4.sin_addr.s_addr = ih4->saddr;
-		dest->v4.sin_family = AF_INET;
-		dest->v4.sin_port = ntohs(sh->dest);
-		dest->v4.sin_addr.s_addr = ih4->daddr;
-		break;
-
-	case 6:
-		SCTP_V6(
-			source->v6.sin6_family = AF_INET6;
-			source->v6.sin6_port = ntohs(sh->source);
-			source->v6.sin6_addr = ih6->saddr;
-			dest->v6.sin6_family = AF_INET6;
-			dest->v6.sin6_port = ntohs(sh->dest);
-			dest->v6.sin6_addr = ih6->daddr;
-			/* FIXME:  What do we do with scope, etc. ? */
-			break;
-		)
-
-	default:
-		/* This is a bogus address type, just bail.  */
-		break;
-	};
+	memcpy(&chunk->source, src, sizeof(union sctp_addr));
+	memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
 }
 
 /* Extract the source address from a chunk.  */

net/sctp/socket.c

@@ -2691,38 +2691,33 @@ static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int no
 	return NULL;
 }
 
-static inline int sctp_verify_addr(struct sock *sk, struct sockaddr *addr, int addrlen)
+/* Verify that this is a valid address. */
+static int sctp_verify_addr(struct sock *sk, struct sockaddr *addr, int len)
 {
-	union sctp_addr *sa;
+	struct sctp_func *af;
 
-	if (addrlen < sizeof (struct sockaddr))
+	/* Check minimum size.  */
+	if (len < sizeof (struct sockaddr))
 		return -EINVAL;
 
-	sa = (union sctp_addr *)addr;
-	switch (sa->sa.sa_family) {
-	case AF_INET:
-		if (addrlen < sizeof(struct sockaddr_in))
-			return -EINVAL;
-		break;
-
-	case AF_INET6:
-		if (PF_INET == sk->family)
-			return -EINVAL;
-		SCTP_V6(
-			if (addrlen < sizeof(struct sockaddr_in6))
-				return -EINVAL;
-			break;
-		);
+	/* Do we support this address family in general? */
+	af = sctp_get_af_specific(addr->sa_family);
+	if (!af)
+		return -EINVAL;
 
-	default:
+	/* Does this PF support this AF? */
+	if (!sctp_sk(sk)->pf->af_supported(addr->sa_family))
+		return -EINVAL;
+     
+	/* Verify the minimum for this AF sockaddr. */
+	if (len < af->sockaddr_len)
 		return -EINVAL;
-	};
 
-	/* Disallow any illegal addresses to be used as destinations.  */
-	if (!sctp_addr_is_valid(sa))
+	/* Is this a valid SCTP address?  */
+	if (!af->addr_valid((union sctp_addr *)addr)) 
 		return -EINVAL;
 
-	return 0;
+	return 0;	
 }
 
 /* Get the sndbuf space available at the time on the association.  */