SUNRPC: Replace svc_addr_u by sockaddr_storage

For IPv6 local address, lockd can not callback to client for
missing scope id when binding address at inet6_bind:

324 if (addr_type & IPV6_ADDR_LINKLOCAL) {
325 if (addr_len >= sizeof(struct sockaddr_in6) &&
326 addr->sin6_scope_id) {
327 /* Override any existing binding, if another one
328 * is supplied by user.
329 */
330 sk->sk_bound_dev_if = addr->sin6_scope_id;
331 }
332
333 /* Binding to link-local address requires an interface */
334 if (!sk->sk_bound_dev_if) {
335 err = -EINVAL;
336 goto out_unlock;
337 }

Replacing svc_addr_u by sockaddr_storage, let rqstp->rq_daddr contains more info
besides address.

Reviewed-by: Jeff Layton <[e-mail]>
Reviewed-by: Chuck Lever <[e-mail]>
Signed-off-by: Mi Jinlong <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>

fs/lockd/host.c

···
 	struct hlist_node *pos;
 	struct nlm_host	*host = NULL;
 	struct nsm_handle *nsm = NULL;
-	struct sockaddr_in sin = {
-		.sin_family	= AF_INET,
-	};
-	struct sockaddr_in6 sin6 = {
-		.sin6_family	= AF_INET6,
-	};
-	struct sockaddr *src_sap;
-	size_t src_len = rqstp->rq_addrlen;
+	struct sockaddr *src_sap = svc_daddr(rqstp);
+	size_t src_len = rqstp->rq_daddrlen;
 	struct nlm_lookup_host_info ni = {
 		.server		= 1,
 		.sap		= svc_addr(rqstp),
···
 			(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
 
 	mutex_lock(&nlm_host_mutex);
-
-	switch (ni.sap->sa_family) {
-	case AF_INET:
-		sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
-		src_sap = (struct sockaddr *)&sin;
-		break;
-	case AF_INET6:
-		ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
-		src_sap = (struct sockaddr *)&sin6;
-		break;
-	default:
-		dprintk("lockd: %s failed; unrecognized address family\n",
-			__func__);
-		goto out;
-	}
 
 	if (time_after_eq(jiffies, next_gc))
 		nlm_gc_hosts();

fs/nfsd/nfs4state.c

···
 	return NULL;
 }
 
-static void rpc_svcaddr2sockaddr(struct sockaddr *sa, unsigned short family, union svc_addr_u *svcaddr)
-{
-	switch (family) {
-	case AF_INET:
-		((struct sockaddr_in *)sa)->sin_family = AF_INET;
-		((struct sockaddr_in *)sa)->sin_addr = svcaddr->addr;
-		return;
-	case AF_INET6:
-		((struct sockaddr_in6 *)sa)->sin6_family = AF_INET6;
-		((struct sockaddr_in6 *)sa)->sin6_addr = svcaddr->addr6;
-		return;
-	}
-}
-
 static void
 gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se, struct svc_rqst *rqstp)
 {
···
 
 	conn->cb_prog = se->se_callback_prog;
 	conn->cb_ident = se->se_callback_ident;
-	rpc_svcaddr2sockaddr((struct sockaddr *)&conn->cb_saddr, expected_family, &rqstp->rq_daddr);
+	memcpy(&conn->cb_saddr, &rqstp->rq_daddr, rqstp->rq_daddrlen);
 	return;
 out_err:
 	conn->cb_addr.ss_family = AF_UNSPEC;

include/linux/sunrpc/svc.h

···
 	iov->iov_len += sizeof(__be32);
 }
 
-union svc_addr_u {
-    struct in_addr	addr;
-    struct in6_addr	addr6;
-};
-
 /*
  * The context of a single thread, including the request currently being
  * processed.
···
 	struct list_head	rq_list;	/* idle list */
 	struct list_head	rq_all;		/* all threads list */
 	struct svc_xprt *	rq_xprt;	/* transport ptr */
+
 	struct sockaddr_storage	rq_addr;	/* peer address */
 	size_t			rq_addrlen;
+	struct sockaddr_storage	rq_daddr;	/* dest addr of request
+						 *  - reply from here */
+	size_t			rq_daddrlen;
 
 	struct svc_serv *	rq_server;	/* RPC service definition */
 	struct svc_pool *	rq_pool;	/* thread pool */
···
 	u32			rq_prot;	/* IP protocol */
 	unsigned short
 				rq_secure  : 1;	/* secure port */
-
-	union svc_addr_u	rq_daddr;	/* dest addr of request
-						 *  - reply from here */
 
 	void *			rq_argp;	/* decoded arguments */
 	void *			rq_resp;	/* xdr'd results */
···
 	return (struct sockaddr *) &rqst->rq_addr;
 }
 
+static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr_in *) &rqst->rq_daddr;
+}
+
+static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr_in6 *) &rqst->rq_daddr;
+}
+
+static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
+{
+	return (struct sockaddr *) &rqst->rq_daddr;
+}
+
 /*
  * Check buffer bounds after decoding arguments
  */
···
 	struct svc_xprt		*xprt;
 	struct sockaddr_storage	addr;	/* where reply must go */
 	size_t			addrlen;
-	union svc_addr_u	daddr;	/* where reply must come from */
+	struct sockaddr_storage	daddr;	/* where reply must come from */
+	size_t			daddrlen;
 	struct cache_deferred_req handle;
 	size_t			xprt_hlen;
 	int			argslen;

net/sunrpc/svc_xprt.c

···
  */
 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
 {
-	struct sockaddr *sin;
-
 	memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
 	rqstp->rq_addrlen = xprt->xpt_remotelen;
 
···
 	 * Destination address in request is needed for binding the
 	 * source address in RPC replies/callbacks later.
 	 */
-	sin = (struct sockaddr *)&xprt->xpt_local;
-	switch (sin->sa_family) {
-	case AF_INET:
-		rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
-		break;
-	case AF_INET6:
-		rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
-		break;
-	}
+	memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen);
+	rqstp->rq_daddrlen = xprt->xpt_locallen;
 }
 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
 

net/sunrpc/svcsock.c

···
 			cmh->cmsg_level = SOL_IP;
 			cmh->cmsg_type = IP_PKTINFO;
 			pki->ipi_ifindex = 0;
-			pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
+			pki->ipi_spec_dst.s_addr =
+				 svc_daddr_in(rqstp)->sin_addr.s_addr;
 			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 		}
 		break;
 
 	case AF_INET6: {
 			struct in6_pktinfo *pki = CMSG_DATA(cmh);
+			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 
 			cmh->cmsg_level = SOL_IPV6;
 			cmh->cmsg_type = IPV6_PKTINFO;
-			pki->ipi6_ifindex = 0;
-			ipv6_addr_copy(&pki->ipi6_addr,
-					&rqstp->rq_daddr.addr6);
+			pki->ipi6_ifindex = daddr->sin6_scope_id;
+			ipv6_addr_copy(&pki->ipi6_addr,	&daddr->sin6_addr);
 			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 		}
 		break;
···
 				     struct cmsghdr *cmh)
 {
 	struct in_pktinfo *pki = CMSG_DATA(cmh);
+	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
+
 	if (cmh->cmsg_type != IP_PKTINFO)
 		return 0;
-	rqstp->rq_daddr.addr.s_addr = pki->ipi_spec_dst.s_addr;
+
+	daddr->sin_family = AF_INET;
+	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
 	return 1;
 }
 
···
 				     struct cmsghdr *cmh)
 {
 	struct in6_pktinfo *pki = CMSG_DATA(cmh);
+	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
+
 	if (cmh->cmsg_type != IPV6_PKTINFO)
 		return 0;
-	ipv6_addr_copy(&rqstp->rq_daddr.addr6, &pki->ipi6_addr);
+
+	daddr->sin6_family = AF_INET6;
+	ipv6_addr_copy(&daddr->sin6_addr, &pki->ipi6_addr);
+	daddr->sin6_scope_id = pki->ipi6_ifindex;
 	return 1;
 }
 
···
 		skb_free_datagram_locked(svsk->sk_sk, skb);
 		return 0;
 	}
+	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 
 	if (skb_is_nonlinear(skb)) {
 		/* we have to copy */