[PATCH 1/3] NFS: pnfs IPv6 support

[Weston Andros Adamson <dros@netapp.com>]

Handle ipv6 remote addresses from GETDEVICEINFO

 - supports netid "tcp" for ipv4 and "tcp6" for ipv6 as rfc 5665 specifies
 - added ds_remotestr to avoid having to handle different AFs in every dprintk
 - tested against pynfs 4.1 server, submitting ipv6 support patch to pynfs
 - tested with IPv6 disabled, it compiles cleanly and relies on rpc_pton to
   refuse to accept IPv6 addresses

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
---
 fs/nfs/nfs4filelayout.c    |    7 +-
 fs/nfs/nfs4filelayout.h    |    5 +-
 fs/nfs/nfs4filelayoutdev.c |  255 ++++++++++++++++++++++++++++++++------------
 3 files changed, 191 insertions(+), 76 deletions(-)

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 4269088..b410a9b 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -343,8 +343,7 @@ filelayout_read_pagelist(struct nfs_read_data *data)
 		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 		return PNFS_NOT_ATTEMPTED;
 	}
-	dprintk("%s USE DS:ip %x %hu\n", __func__,
-		ntohl(ds->ds_ip_addr), ntohs(ds->ds_port));
+	dprintk("%s USE DS: %s\n", __func__, ds->ds_remotestr);
 
 	/* No multipath support. Use first DS */
 	data->ds_clp = ds->ds_clp;
@@ -383,9 +382,9 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 		return PNFS_NOT_ATTEMPTED;
 	}
-	dprintk("%s ino %lu sync %d req %Zu@%llu DS:%x:%hu\n", __func__,
+	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s\n", __func__,
 		data->inode->i_ino, sync, (size_t) data->args.count, offset,
-		ntohl(ds->ds_ip_addr), ntohs(ds->ds_port));
+		ds->ds_remotestr);
 
 	data->write_done_cb = filelayout_write_done_cb;
 	data->ds_clp = ds->ds_clp;
diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
index cebe01e..6c6a817 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/nfs4filelayout.h
@@ -49,8 +49,9 @@ enum stripetype4 {
 /* Individual ip address */
 struct nfs4_pnfs_ds {
 	struct list_head	ds_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
-	u32			ds_ip_addr;
-	u32			ds_port;
+	struct sockaddr_storage	ds_addr;
+	size_t			ds_addrlen;
+	char			*ds_remotestr;	/* human readable addr+port */
 	struct nfs_client	*ds_clp;
 	atomic_t		ds_count;
 };
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index 3b7bf13..0adb9be 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -56,28 +56,56 @@ print_ds(struct nfs4_pnfs_ds *ds)
 		printk("%s NULL device\n", __func__);
 		return;
 	}
-	printk("        ip_addr %x port %hu\n"
+	printk("        ds %s\n"
 		"        ref count %d\n"
 		"        client %p\n"
 		"        cl_exchange_flags %x\n",
-		ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
+		ds->ds_remotestr,
 		atomic_read(&ds->ds_count), ds->ds_clp,
 		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
 }
 
 /* nfs4_ds_cache_lock is held */
 static struct nfs4_pnfs_ds *
-_data_server_lookup_locked(u32 ip_addr, u32 port)
+_data_server_lookup_locked(struct sockaddr *addr, size_t addrlen)
 {
 	struct nfs4_pnfs_ds *ds;
-
-	dprintk("_data_server_lookup: ip_addr=%x port=%hu\n",
-			ntohl(ip_addr), ntohs(port));
+	struct sockaddr_in *a, *b;
+	struct sockaddr_in6 *a6, *b6;
 
 	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
-		if (ds->ds_ip_addr == ip_addr &&
-		    ds->ds_port == port) {
-			return ds;
+		if (addr->sa_family != ds->ds_addr.ss_family)
+			continue;
+
+		switch (addr->sa_family) {
+		case AF_INET:
+			a = (struct sockaddr_in *)addr;
+			b = (struct sockaddr_in *)&ds->ds_addr;
+
+			if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
+			    a->sin_port == b->sin_port)
+				return ds;
+			break;
+
+		case AF_INET6:
+			a6 = (struct sockaddr_in6 *)addr;
+			b6 = (struct sockaddr_in6 *)&ds->ds_addr;
+
+			/* LINKLOCAL addresses must have matching scope_id */
+			if (ipv6_addr_scope(&a6->sin6_addr) ==
+			    IPV6_ADDR_SCOPE_LINKLOCAL &&
+			    a6->sin6_scope_id != b6->sin6_scope_id)
+				continue;
+
+			if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
+			    a6->sin6_port == b6->sin6_port)
+				return ds;
+			break;
+
+		default:
+			dprintk("%s: unhandled address family: %u\n",
+				__func__, addr->sa_family);
+			return NULL;
 		}
 	}
 	return NULL;
@@ -91,19 +119,14 @@ static int
 nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 {
 	struct nfs_client *clp;
-	struct sockaddr_in sin;
 	int status = 0;
 
-	dprintk("--> %s ip:port %x:%hu au_flavor %d\n", __func__,
-		ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
+	dprintk("--> %s addr %s au_flavor %d\n", __func__, ds->ds_remotestr,
 		mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);
 
-	sin.sin_family = AF_INET;
-	sin.sin_addr.s_addr = ds->ds_ip_addr;
-	sin.sin_port = ds->ds_port;
-
-	clp = nfs4_set_ds_client(mds_srv->nfs_client, (struct sockaddr *)&sin,
-				 sizeof(sin), IPPROTO_TCP);
+	clp = nfs4_set_ds_client(mds_srv->nfs_client,
+				 (struct sockaddr *)&ds->ds_addr,
+				 ds->ds_addrlen, IPPROTO_TCP);
 	if (IS_ERR(clp)) {
 		status = PTR_ERR(clp);
 		goto out;
@@ -115,8 +138,8 @@ nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 			goto out_put;
 		}
 		ds->ds_clp = clp;
-		dprintk("%s [existing] ip=%x, port=%hu\n", __func__,
-			ntohl(ds->ds_ip_addr), ntohs(ds->ds_port));
+		dprintk("%s [existing] server=%s\n", __func__,
+			ds->ds_remotestr);
 		goto out;
 	}
 
@@ -135,8 +158,7 @@ nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 		goto out_put;
 
 	ds->ds_clp = clp;
-	dprintk("%s [new] ip=%x, port=%hu\n", __func__, ntohl(ds->ds_ip_addr),
-		ntohs(ds->ds_port));
+	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
 out:
 	return status;
 out_put:
@@ -153,6 +175,7 @@ destroy_ds(struct nfs4_pnfs_ds *ds)
 
 	if (ds->ds_clp)
 		nfs_put_client(ds->ds_clp);
+	kfree(ds->ds_remotestr);
 	kfree(ds);
 }
 
@@ -179,31 +202,85 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 	kfree(dsaddr);
 }
 
+/*
+ * Create a string with a human readable address and port to avoid
+ * complicated setup around many dprinks.
+ */
+static char *
+nfs4_pnfs_remotestr(struct sockaddr *ds_addr, gfp_t gfp_flags)
+{
+	char buf[INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN];
+	char *remotestr;
+	char *startsep = "";
+	char *endsep = "";
+	size_t len;
+	uint16_t port;
+
+	switch (ds_addr->sa_family) {
+	case AF_INET:
+		port = ((struct sockaddr_in *)ds_addr)->sin_port;
+		break;
+	case AF_INET6:
+		startsep = "[";
+		endsep = "]";
+		port = ((struct sockaddr_in6 *)ds_addr)->sin6_port;
+		break;
+	default:
+		dprintk("%s: Unknown address family %u\n",
+			__func__, ds_addr->sa_family);
+		return NULL;
+	}
+
+	if (!rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf))) {
+		dprintk("%s: error printing addr\n", __func__);
+		return NULL;
+	}
+
+	len = strlen(buf) + strlen(startsep) + strlen(endsep) + 1 + 5 + 1;
+	remotestr = kzalloc(len, gfp_flags);
+
+	if (unlikely(!remotestr)) {
+		dprintk("%s: couldn't alloc remotestr\n", __func__);
+		return NULL;
+	}
+
+	snprintf(remotestr, len, "%s%s%s:%u",
+		 startsep, buf, endsep, ntohs(port));
+
+	return remotestr;
+}
+
 static struct nfs4_pnfs_ds *
-nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port, gfp_t gfp_flags)
+nfs4_pnfs_ds_add(struct sockaddr *addr, size_t addrlen, gfp_t gfp_flags)
 {
-	struct nfs4_pnfs_ds *tmp_ds, *ds;
+	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
+	char *remotestr;
 
 	ds = kzalloc(sizeof(*tmp_ds), gfp_flags);
 	if (!ds)
 		goto out;
 
+	/* this is only used for debugging, so it's ok if its NULL */
+	remotestr = nfs4_pnfs_remotestr(addr, gfp_flags);
+
 	spin_lock(&nfs4_ds_cache_lock);
-	tmp_ds = _data_server_lookup_locked(ip_addr, port);
+	tmp_ds = _data_server_lookup_locked(addr, addrlen);
 	if (tmp_ds == NULL) {
-		ds->ds_ip_addr = ip_addr;
-		ds->ds_port = port;
+		memcpy(&ds->ds_addr, addr, addrlen);
+		ds->ds_addrlen = addrlen;
+		ds->ds_remotestr = remotestr;
 		atomic_set(&ds->ds_count, 1);
 		INIT_LIST_HEAD(&ds->ds_node);
 		ds->ds_clp = NULL;
 		list_add(&ds->ds_node, &nfs4_data_server_cache);
-		dprintk("%s add new data server ip 0x%x\n", __func__,
-			ds->ds_ip_addr);
+		dprintk("%s add new data server %s\n", __func__,
+			ds->ds_remotestr);
 	} else {
+		kfree(remotestr);
 		kfree(ds);
 		atomic_inc(&tmp_ds->ds_count);
-		dprintk("%s data server found ip 0x%x, inc'ed ds_count to %d\n",
-			__func__, tmp_ds->ds_ip_addr,
+		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
+			__func__, ds->ds_remotestr,
 			atomic_read(&tmp_ds->ds_count));
 		ds = tmp_ds;
 	}
@@ -213,18 +290,21 @@ out:
 }
 
 /*
- * Currently only support ipv4, and one multi-path address.
+ * Currently only supports ipv4, ipv6 and one multi-path address.
  */
 static struct nfs4_pnfs_ds *
 decode_and_add_ds(struct xdr_stream *streamp, struct inode *inode, gfp_t gfp_flags)
 {
 	struct nfs4_pnfs_ds *ds = NULL;
-	char *buf;
-	const char *ipend, *pstr;
-	u32 ip_addr, port;
-	int nlen, rlen, i;
+	char *buf, *portstr;
+	struct sockaddr_storage ss;
+	size_t sslen;
+	u32 port;
+	int nlen, rlen;
 	int tmp[2];
 	__be32 *p;
+	char *netid, *match_netid;
+	size_t match_netid_len;
 
 	/* r_netid */
 	p = xdr_inline_decode(streamp, 4);
@@ -236,62 +316,97 @@ decode_and_add_ds(struct xdr_stream *streamp, struct inode *inode, gfp_t gfp_fla
 	if (unlikely(!p))
 		goto out_err;
 
-	/* Check that netid is "tcp" */
-	if (nlen != 3 ||  memcmp((char *)p, "tcp", 3)) {
-		dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
+	netid = kmalloc(nlen+1, gfp_flags);
+	if (unlikely(!netid))
 		goto out_err;
-	}
 
-	/* r_addr */
+	netid[nlen] = '\0';
+	memcpy(netid, p, nlen);
+
+	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
 	p = xdr_inline_decode(streamp, 4);
 	if (unlikely(!p))
-		goto out_err;
+		goto out_free_netid;
 	rlen = be32_to_cpup(p);
 
 	p = xdr_inline_decode(streamp, rlen);
 	if (unlikely(!p))
-		goto out_err;
+		goto out_free_netid;
 
-	/* ipv6 length plus port is legal */
-	if (rlen > INET6_ADDRSTRLEN + 8) {
+	/* port is ".ABC.DEF", 8 chars max */
+	if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
 		dprintk("%s: Invalid address, length %d\n", __func__,
 			rlen);
-		goto out_err;
+		goto out_free_netid;
 	}
 	buf = kmalloc(rlen + 1, gfp_flags);
 	if (!buf) {
 		dprintk("%s: Not enough memory\n", __func__);
-		goto out_err;
+		goto out_free_netid;
 	}
 	buf[rlen] = '\0';
 	memcpy(buf, p, rlen);
 
-	/* replace the port dots with dashes for the in4_pton() delimiter*/
-	for (i = 0; i < 2; i++) {
-		char *res = strrchr(buf, '.');
-		if (!res) {
-			dprintk("%s: Failed finding expected dots in port\n",
-				__func__);
-			goto out_free;
-		}
-		*res = '-';
+	/* replace port '.' with '-' */
+	portstr = strrchr(buf, '.');
+	if (!portstr) {
+		dprintk("%s: Failed finding expected dot in port\n",
+			__func__);
+		goto out_free_buf;
+	}
+	*portstr = '-';
+
+	/* find '.' between address and port */
+	portstr = strrchr(buf, '.');
+	if (!portstr) {
+		dprintk("%s: Failed finding expected dot between address and "
+			"port\n", __func__);
+		goto out_free_buf;
 	}
+	*portstr = '\0';
 
-	/* Currently only support ipv4 address */
-	if (in4_pton(buf, rlen, (u8 *)&ip_addr, '-', &ipend) == 0) {
-		dprintk("%s: Only ipv4 addresses supported\n", __func__);
-		goto out_free;
+	if (!rpc_pton(buf, portstr-buf, (struct sockaddr *)&ss, sizeof(ss))) {
+		dprintk("%s: Error parsing address %s\n", __func__, buf);
+		goto out_free_buf;
 	}
 
-	/* port */
-	pstr = ipend;
-	sscanf(pstr, "-%d-%d", &tmp[0], &tmp[1]);
+	portstr++;
+	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
 	port = htons((tmp[0] << 8) | (tmp[1]));
 
-	ds = nfs4_pnfs_ds_add(inode, ip_addr, port, gfp_flags);
-	dprintk("%s: Decoded address and port %s\n", __func__, buf);
-out_free:
+	switch (ss.ss_family) {
+	case AF_INET:
+		((struct sockaddr_in *)&ss)->sin_port = port;
+		sslen = sizeof(struct sockaddr_in);
+		match_netid = "tcp";
+		match_netid_len = 3;
+		break;
+
+	case AF_INET6:
+		((struct sockaddr_in6 *)&ss)->sin6_port = port;
+		sslen = sizeof(struct sockaddr_in6);
+		match_netid = "tcp6";
+		match_netid_len = 4;
+		break;
+
+	default:
+		dprintk("%s: unsupported address family: %u\n",
+			__func__, ss.ss_family);
+		goto out_free_buf;
+	}
+
+	if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
+		dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
+			__func__, netid, match_netid);
+		goto out_free_buf;
+	}
+
+	ds = nfs4_pnfs_ds_add((struct sockaddr *)&ss, sslen, gfp_flags);
+	dprintk("%s: Added DS %s\n", __func__, ds->ds_remotestr);
+out_free_buf:
 	kfree(buf);
+out_free_netid:
+	kfree(netid);
 out_err:
 	return ds;
 }
@@ -591,13 +706,13 @@ nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
 
 static void
 filelayout_mark_devid_negative(struct nfs4_file_layout_dsaddr *dsaddr,
-			       int err, u32 ds_addr)
+			       int err, const char *ds_remotestr)
 {
 	u32 *p = (u32 *)&dsaddr->id_node.deviceid;
 
-	printk(KERN_ERR "NFS: data server %x connection error %d."
+	printk(KERN_ERR "NFS: data server %s connection error %d."
 		" Deviceid [%x%x%x%x] marked out of use.\n",
-		ds_addr, err, p[0], p[1], p[2], p[3]);
+		ds_remotestr, err, p[0], p[1], p[2], p[3]);
 
 	spin_lock(&nfs4_ds_cache_lock);
 	dsaddr->flags |= NFS4_DEVICE_ID_NEG_ENTRY;
@@ -628,7 +743,7 @@ nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
 		err = nfs4_ds_connect(s, ds);
 		if (err) {
 			filelayout_mark_devid_negative(dsaddr, err,
-						       ntohl(ds->ds_ip_addr));
+						       ds->ds_remotestr);
 			return NULL;
 		}
 	}
-- 
1.7.5.2