[v2,4/5] CIFS: parse and store info on iface queries

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index c3648e9b5ec7..b2390e9a6843 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -294,34 +294,176 @@  smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 	return rsize;
 }
 
-#ifdef CONFIG_CIFS_STATS2
+
+static int
+parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
+			size_t buf_len,
+			struct cifs_server_iface **iface_list,
+			size_t *iface_count)
+{
+	struct network_interface_info_ioctl_rsp *p;
+	struct sockaddr_in *addr4;
+	struct sockaddr_in6 *addr6;
+	struct iface_info_ipv4 *p4;
+	struct iface_info_ipv6 *p6;
+	struct cifs_server_iface *info;
+	ssize_t bytes_left;
+	size_t next = 0;
+	int nb_iface = 0;
+	int rc = 0;
+
+	*iface_list = NULL;
+	*iface_count = 0;
+
+	/*
+	 * Fist pass: count and sanity check
+	 */
+
+	bytes_left = buf_len;
+	p = buf;
+	while (bytes_left >= sizeof(*p)) {
+		nb_iface++;
+		next = le32_to_cpu(p->Next);
+		if (!next) {
+			bytes_left -= sizeof(*p);
+			break;
+		}
+		p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next);
+		bytes_left -= next;
+	}
+
+	if (!nb_iface) {
+		cifs_dbg(VFS, "%s: malformed interface info\n", __func__);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (bytes_left || p->Next)
+		cifs_dbg(VFS, "%s: incomplete interface info\n", __func__);
+
+
+	/*
+	 * Second pass: extract info to internal structure
+	 */
+
+	*iface_list = kcalloc(nb_iface, sizeof(**iface_list), GFP_KERNEL);
+	if (!*iface_list) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	info = *iface_list;
+	bytes_left = buf_len;
+	p = buf;
+	while (bytes_left >= sizeof(*p)) {
+		info->speed = le64_to_cpu(p->LinkSpeed);
+		info->rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE);
+		info->rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE);
+
+		cifs_dbg(FYI, "%s: adding iface %zu\n", __func__, *iface_count);
+		cifs_dbg(FYI, "%s: speed %zu bps\n", __func__, info->speed);
+		cifs_dbg(FYI, "%s: capabilities 0x%08x\n", __func__,
+			 le32_to_cpu(p->Capability));
+
+		switch (p->Family) {
+		/*
+		 * The kernel and wire socket structures have the same
+		 * layout and use network byte order but make the
+		 * conversion explicit in case either one changes.
+		 */
+		case INTERNETWORK:
+			addr4 = (struct sockaddr_in *)&info->sockaddr;
+			p4 = (struct iface_info_ipv4 *)p->Buffer;
+			addr4->sin_family = AF_INET;
+			memcpy(&addr4->sin_addr, &p4->IPv4Address, 4);
+
+			/* [MS-SMB2] 2.2.32.5.1.1 Clients MUST ignore these */
+			addr4->sin_port = cpu_to_be16(CIFS_PORT);
+
+			cifs_dbg(FYI, "%s: ipv4 %pI4\n", __func__,
+				 &addr4->sin_addr);
+			break;
+		case INTERNETWORKV6:
+			addr6 =	(struct sockaddr_in6 *)&info->sockaddr;
+			p6 = (struct iface_info_ipv6 *)p->Buffer;
+			addr6->sin6_family = AF_INET6;
+			memcpy(&addr6->sin6_addr, &p6->IPv6Address, 16);
+
+			/* [MS-SMB2] 2.2.32.5.1.2 Clients MUST ignore these */
+			addr6->sin6_flowinfo = 0;
+			addr6->sin6_scope_id = 0;
+			addr6->sin6_port = cpu_to_be16(CIFS_PORT);
+
+			cifs_dbg(FYI, "%s: ipv6 %pI6\n", __func__,
+				 &addr6->sin6_addr);
+			break;
+		default:
+			cifs_dbg(VFS,
+				 "%s: skipping unsupported socket family\n",
+				 __func__);
+			goto next_iface;
+		}
+
+		(*iface_count)++;
+		info++;
+next_iface:
+		next = le32_to_cpu(p->Next);
+		if (!next)
+			break;
+		p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next);
+		bytes_left -= next;
+	}
+
+	if (!*iface_count) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+out:
+	if (rc) {
+		kfree(*iface_list);
+		*iface_count = 0;
+		*iface_list = NULL;
+	}
+	return rc;
+}
+
+
 static int
 SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
 {
 	int rc;
 	unsigned int ret_data_len = 0;
-	struct network_interface_info_ioctl_rsp *out_buf;
+	struct network_interface_info_ioctl_rsp *out_buf = NULL;
+	struct cifs_server_iface *iface_list;
+	size_t iface_count;
+	struct cifs_ses *ses = tcon->ses;
 
 	rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
 			FSCTL_QUERY_NETWORK_INTERFACE_INFO, true /* is_fsctl */,
 			NULL /* no data input */, 0 /* no data input */,
 			(char **)&out_buf, &ret_data_len);
-	if (rc != 0)
+	if (rc != 0) {
 		cifs_dbg(VFS, "error %d on ioctl to get interface list\n", rc);
-	else if (ret_data_len < sizeof(struct network_interface_info_ioctl_rsp)) {
-		cifs_dbg(VFS, "server returned bad net interface info buf\n");
-		rc = -EINVAL;
-	} else {
-		/* Dump info on first interface */
-		cifs_dbg(FYI, "Adapter Capability 0x%x\t",
-			le32_to_cpu(out_buf->Capability));
-		cifs_dbg(FYI, "Link Speed %lld\n",
-			le64_to_cpu(out_buf->LinkSpeed));
+		goto out;
 	}
+
+	rc = parse_server_interfaces(out_buf, ret_data_len,
+				     &iface_list, &iface_count);
+	if (rc)
+		goto out;
+
+	spin_lock(&ses->iface_lock);
+	kfree(ses->iface_list);
+	ses->iface_list = iface_list;
+	ses->iface_count = iface_count;
+	ses->iface_last_update = jiffies;
+	spin_unlock(&ses->iface_lock);
+
+out:
 	kfree(out_buf);
 	return rc;
 }
-#endif /* STATS2 */
 
 void
 smb2_cached_lease_break(struct work_struct *work)
@@ -399,9 +541,7 @@  smb3_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
 	if (rc)
 		return;
 
-#ifdef CONFIG_CIFS_STATS2
 	SMB3_request_interfaces(xid, tcon);
-#endif /* STATS2 */
 
 	SMB2_QFS_attr(xid, tcon, fid.persistent_fid, fid.volatile_fid,
 			FS_ATTRIBUTE_INFORMATION);