net: Add Open vSwitch kernel components.

Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments.  In addition to supporting a variety of features
expected in a traditional hardware switch, it enables fine-grained
programmatic extension and flow-based control of the network.
This control is useful in a wide variety of applications but is
particularly important in multi-server virtualization deployments,
which are often characterized by highly dynamic endpoints and the need
to maintain logical abstractions for multiple tenants.

The Open vSwitch datapath provides an in-kernel fast path for packet
forwarding.  It is complemented by a userspace daemon, ovs-vswitchd,
which is able to accept configuration from a variety of sources and
translate it into packet processing rules.

See http://openvswitch.org for more information and userspace
utilities.

Signed-off-by: Jesse Gross <jesse@nicira.com>

1 files changed, 396 insertions, 0 deletions

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
new file mode 100644
index 0000000..6cd7601
--- /dev/null
+++ b/net/openvswitch/vport.c
@@ -0,0 +1,396 @@
+/*
+ * Copyright (c) 2007-2011 Nicira Networks.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#include <linux/dcache.h>
+#include <linux/etherdevice.h>
+#include <linux/if.h>
+#include <linux/if_vlan.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/rcupdate.h>
+#include <linux/rtnetlink.h>
+#include <linux/compat.h>
+#include <linux/version.h>
+
+#include "vport.h"
+#include "vport-internal_dev.h"
+
+/* List of statically compiled vport implementations.  Don't forget to also
+ * add yours to the list at the bottom of vport.h. */
+static const struct vport_ops *vport_ops_list[] = {
+	&ovs_netdev_vport_ops,
+	&ovs_internal_vport_ops,
+};
+
+/* Protected by RCU read lock for reading, RTNL lock for writing. */
+static struct hlist_head *dev_table;
+#define VPORT_HASH_BUCKETS 1024
+
+/**
+ *	ovs_vport_init - initialize vport subsystem
+ *
+ * Called at module load time to initialize the vport subsystem.
+ */
+int ovs_vport_init(void)
+{
+	dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
+			    GFP_KERNEL);
+	if (!dev_table)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ *	ovs_vport_exit - shutdown vport subsystem
+ *
+ * Called at module exit time to shutdown the vport subsystem.
+ */
+void ovs_vport_exit(void)
+{
+	kfree(dev_table);
+}
+
+static struct hlist_head *hash_bucket(const char *name)
+{
+	unsigned int hash = full_name_hash(name, strlen(name));
+	return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
+}
+
+/**
+ *	ovs_vport_locate - find a port that has already been created
+ *
+ * @name: name of port to find
+ *
+ * Must be called with RTNL or RCU read lock.
+ */
+struct vport *ovs_vport_locate(const char *name)
+{
+	struct hlist_head *bucket = hash_bucket(name);
+	struct vport *vport;
+	struct hlist_node *node;
+
+	hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
+		if (!strcmp(name, vport->ops->get_name(vport)))
+			return vport;
+
+	return NULL;
+}
+
+/**
+ *	ovs_vport_alloc - allocate and initialize new vport
+ *
+ * @priv_size: Size of private data area to allocate.
+ * @ops: vport device ops
+ *
+ * Allocate and initialize a new vport defined by @ops.  The vport will contain
+ * a private data area of size @priv_size that can be accessed using
+ * vport_priv().  vports that are no longer needed should be released with
+ * vport_free().
+ */
+struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
+			  const struct vport_parms *parms)
+{
+	struct vport *vport;
+	size_t alloc_size;
+
+	alloc_size = sizeof(struct vport);
+	if (priv_size) {
+		alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
+		alloc_size += priv_size;
+	}
+
+	vport = kzalloc(alloc_size, GFP_KERNEL);
+	if (!vport)
+		return ERR_PTR(-ENOMEM);
+
+	vport->dp = parms->dp;
+	vport->port_no = parms->port_no;
+	vport->upcall_pid = parms->upcall_pid;
+	vport->ops = ops;
+
+	vport->percpu_stats = alloc_percpu(struct vport_percpu_stats);
+	if (!vport->percpu_stats)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&vport->stats_lock);
+
+	return vport;
+}
+
+/**
+ *	ovs_vport_free - uninitialize and free vport
+ *
+ * @vport: vport to free
+ *
+ * Frees a vport allocated with vport_alloc() when it is no longer needed.
+ *
+ * The caller must ensure that an RCU grace period has passed since the last
+ * time @vport was in a datapath.
+ */
+void ovs_vport_free(struct vport *vport)
+{
+	free_percpu(vport->percpu_stats);
+	kfree(vport);
+}
+
+/**
+ *	ovs_vport_add - add vport device (for kernel callers)
+ *
+ * @parms: Information about new vport.
+ *
+ * Creates a new vport with the specified configuration (which is dependent on
+ * device type).  RTNL lock must be held.
+ */
+struct vport *ovs_vport_add(const struct vport_parms *parms)
+{
+	struct vport *vport;
+	int err = 0;
+	int i;
+
+	ASSERT_RTNL();
+
+	for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
+		if (vport_ops_list[i]->type == parms->type) {
+			vport = vport_ops_list[i]->create(parms);
+			if (IS_ERR(vport)) {
+				err = PTR_ERR(vport);
+				goto out;
+			}
+
+			hlist_add_head_rcu(&vport->hash_node,
+					   hash_bucket(vport->ops->get_name(vport)));
+			return vport;
+		}
+	}
+
+	err = -EAFNOSUPPORT;
+
+out:
+	return ERR_PTR(err);
+}
+
+/**
+ *	ovs_vport_set_options - modify existing vport device (for kernel callers)
+ *
+ * @vport: vport to modify.
+ * @port: New configuration.
+ *
+ * Modifies an existing device with the specified configuration (which is
+ * dependent on device type).  RTNL lock must be held.
+ */
+int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
+{
+	ASSERT_RTNL();
+
+	if (!vport->ops->set_options)
+		return -EOPNOTSUPP;
+	return vport->ops->set_options(vport, options);
+}
+
+/**
+ *	ovs_vport_del - delete existing vport device
+ *
+ * @vport: vport to delete.
+ *
+ * Detaches @vport from its datapath and destroys it.  It is possible to fail
+ * for reasons such as lack of memory.  RTNL lock must be held.
+ */
+void ovs_vport_del(struct vport *vport)
+{
+	ASSERT_RTNL();
+
+	hlist_del_rcu(&vport->hash_node);
+
+	vport->ops->destroy(vport);
+}
+
+/**
+ *	ovs_vport_get_stats - retrieve device stats
+ *
+ * @vport: vport from which to retrieve the stats
+ * @stats: location to store stats
+ *
+ * Retrieves transmit, receive, and error stats for the given device.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
+ */
+void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
+{
+	int i;
+
+	memset(stats, 0, sizeof(*stats));
+
+	/* We potentially have 2 sources of stats that need to be combined:
+	 * those we have collected (split into err_stats and percpu_stats) from
+	 * set_stats() and device error stats from netdev->get_stats() (for
+	 * errors that happen  downstream and therefore aren't reported through
+	 * our vport_record_error() function).
+	 * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
+	 * netdev-stats can be directly read over netlink-ioctl.
+	 */
+
+	spin_lock_bh(&vport->stats_lock);
+
+	stats->rx_errors	= vport->err_stats.rx_errors;
+	stats->tx_errors	= vport->err_stats.tx_errors;
+	stats->tx_dropped	= vport->err_stats.tx_dropped;
+	stats->rx_dropped	= vport->err_stats.rx_dropped;
+
+	spin_unlock_bh(&vport->stats_lock);
+
+	for_each_possible_cpu(i) {
+		const struct vport_percpu_stats *percpu_stats;
+		struct vport_percpu_stats local_stats;
+		unsigned int start;
+
+		percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
+
+		do {
+			start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
+			local_stats = *percpu_stats;
+		} while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));
+
+		stats->rx_bytes		+= local_stats.rx_bytes;
+		stats->rx_packets	+= local_stats.rx_packets;
+		stats->tx_bytes		+= local_stats.tx_bytes;
+		stats->tx_packets	+= local_stats.tx_packets;
+	}
+}
+
+/**
+ *	ovs_vport_get_options - retrieve device options
+ *
+ * @vport: vport from which to retrieve the options.
+ * @skb: sk_buff where options should be appended.
+ *
+ * Retrieves the configuration of the given device, appending an
+ * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
+ * vport-specific attributes to @skb.
+ *
+ * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
+ * negative error code if a real error occurred.  If an error occurs, @skb is
+ * left unmodified.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
+ */
+int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
+{
+	struct nlattr *nla;
+
+	nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
+	if (!nla)
+		return -EMSGSIZE;
+
+	if (vport->ops->get_options) {
+		int err = vport->ops->get_options(vport, skb);
+		if (err) {
+			nla_nest_cancel(skb, nla);
+			return err;
+		}
+	}
+
+	nla_nest_end(skb, nla);
+	return 0;
+}
+
+/**
+ *	ovs_vport_receive - pass up received packet to the datapath for processing
+ *
+ * @vport: vport that received the packet
+ * @skb: skb that was received
+ *
+ * Must be called with rcu_read_lock.  The packet cannot be shared and
+ * skb->data should point to the Ethernet header.  The caller must have already
+ * called compute_ip_summed() to initialize the checksumming fields.
+ */
+void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
+{
+	struct vport_percpu_stats *stats;
+
+	stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
+
+	u64_stats_update_begin(&stats->sync);
+	stats->rx_packets++;
+	stats->rx_bytes += skb->len;
+	u64_stats_update_end(&stats->sync);
+
+	ovs_dp_process_received_packet(vport, skb);
+}
+
+/**
+ *	ovs_vport_send - send a packet on a device
+ *
+ * @vport: vport on which to send the packet
+ * @skb: skb to send
+ *
+ * Sends the given packet and returns the length of data sent.  Either RTNL
+ * lock or rcu_read_lock must be held.
+ */
+int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
+{
+	int sent = vport->ops->send(vport, skb);
+
+	if (likely(sent)) {
+		struct vport_percpu_stats *stats;
+
+		stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
+
+		u64_stats_update_begin(&stats->sync);
+		stats->tx_packets++;
+		stats->tx_bytes += sent;
+		u64_stats_update_end(&stats->sync);
+	}
+	return sent;
+}
+
+/**
+ *	ovs_vport_record_error - indicate device error to generic stats layer
+ *
+ * @vport: vport that encountered the error
+ * @err_type: one of enum vport_err_type types to indicate the error type
+ *
+ * If using the vport generic stats layer indicate that an error of the given
+ * type has occured.
+ */
+void ovs_vport_record_error(struct vport *vport, enum vport_err_type err_type)
+{
+	spin_lock(&vport->stats_lock);
+
+	switch (err_type) {
+	case VPORT_E_RX_DROPPED:
+		vport->err_stats.rx_dropped++;
+		break;
+
+	case VPORT_E_RX_ERROR:
+		vport->err_stats.rx_errors++;
+		break;
+
+	case VPORT_E_TX_DROPPED:
+		vport->err_stats.tx_dropped++;
+		break;
+
+	case VPORT_E_TX_ERROR:
+		vport->err_stats.tx_errors++;
+		break;
+	};
+
+	spin_unlock(&vport->stats_lock);
+}