diff options
Diffstat (limited to 'net/openvswitch/vport.c')
-rw-r--r-- | net/openvswitch/vport.c | 522 |
1 files changed, 522 insertions, 0 deletions
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c new file mode 100644 index 000000000..19f676556 --- /dev/null +++ b/net/openvswitch/vport.c @@ -0,0 +1,522 @@ +/* + * Copyright (c) 2007-2014 Nicira, Inc. + * + * 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/etherdevice.h> +#include <linux/if.h> +#include <linux/if_vlan.h> +#include <linux/jhash.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 <net/net_namespace.h> +#include <linux/module.h> + +#include "datapath.h" +#include "vport.h" +#include "vport-internal_dev.h" + +static LIST_HEAD(vport_ops_list); + +/* Protected by RCU read lock for reading, ovs_mutex 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 = kcalloc(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 struct net *net, const char *name) +{ + unsigned int hash = jhash(name, strlen(name), (unsigned long) net); + return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)]; +} + +int __ovs_vport_ops_register(struct vport_ops *ops) +{ + int err = -EEXIST; + struct vport_ops *o; + + ovs_lock(); + list_for_each_entry(o, &vport_ops_list, list) + if (ops->type == o->type) + goto errout; + + list_add_tail(&ops->list, &vport_ops_list); + err = 0; +errout: + ovs_unlock(); + return err; +} +EXPORT_SYMBOL_GPL(__ovs_vport_ops_register); + +void ovs_vport_ops_unregister(struct vport_ops *ops) +{ + ovs_lock(); + list_del(&ops->list); + ovs_unlock(); +} +EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister); + +/** + * ovs_vport_locate - find a port that has already been created + * + * @name: name of port to find + * + * Must be called with ovs or RCU read lock. + */ +struct vport *ovs_vport_locate(const struct net *net, const char *name) +{ + struct hlist_head *bucket = hash_bucket(net, name); + struct vport *vport; + + hlist_for_each_entry_rcu(vport, bucket, hash_node) + if (!strcmp(name, ovs_vport_name(vport)) && + net_eq(ovs_dp_get_net(vport->dp), net)) + 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->ops = ops; + INIT_HLIST_NODE(&vport->dp_hash_node); + + if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) { + kfree(vport); + return ERR_PTR(-EINVAL); + } + + return vport; +} +EXPORT_SYMBOL_GPL(ovs_vport_alloc); + +/** + * 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) +{ + /* vport is freed from RCU callback or error path, Therefore + * it is safe to use raw dereference. + */ + kfree(rcu_dereference_raw(vport->upcall_portids)); + kfree(vport); +} +EXPORT_SYMBOL_GPL(ovs_vport_free); + +static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms) +{ + struct vport_ops *ops; + + list_for_each_entry(ops, &vport_ops_list, list) + if (ops->type == parms->type) + return ops; + + return NULL; +} + +/** + * 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). ovs_mutex must be held. + */ +struct vport *ovs_vport_add(const struct vport_parms *parms) +{ + struct vport_ops *ops; + struct vport *vport; + + ops = ovs_vport_lookup(parms); + if (ops) { + struct hlist_head *bucket; + + if (!try_module_get(ops->owner)) + return ERR_PTR(-EAFNOSUPPORT); + + vport = ops->create(parms); + if (IS_ERR(vport)) { + module_put(ops->owner); + return vport; + } + + bucket = hash_bucket(ovs_dp_get_net(vport->dp), + ovs_vport_name(vport)); + hlist_add_head_rcu(&vport->hash_node, bucket); + return vport; + } + + /* Unlock to attempt module load and return -EAGAIN if load + * was successful as we need to restart the port addition + * workflow. + */ + ovs_unlock(); + request_module("vport-type-%d", parms->type); + ovs_lock(); + + if (!ovs_vport_lookup(parms)) + return ERR_PTR(-EAFNOSUPPORT); + else + return ERR_PTR(-EAGAIN); +} + +/** + * ovs_vport_set_options - modify existing vport device (for kernel callers) + * + * @vport: vport to modify. + * @options: New configuration. + * + * Modifies an existing device with the specified configuration (which is + * dependent on device type). ovs_mutex must be held. + */ +int ovs_vport_set_options(struct vport *vport, struct nlattr *options) +{ + 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. ovs_mutex must + * be held. + */ +void ovs_vport_del(struct vport *vport) +{ + ASSERT_OVSL(); + + hlist_del_rcu(&vport->hash_node); + module_put(vport->ops->owner); + 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 ovs_mutex or rcu_read_lock. + */ +void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats) +{ + const struct rtnl_link_stats64 *dev_stats; + struct rtnl_link_stats64 temp; + + dev_stats = dev_get_stats(vport->dev, &temp); + stats->rx_errors = dev_stats->rx_errors; + stats->tx_errors = dev_stats->tx_errors; + stats->tx_dropped = dev_stats->tx_dropped; + stats->rx_dropped = dev_stats->rx_dropped; + + stats->rx_bytes = dev_stats->rx_bytes; + stats->rx_packets = dev_stats->rx_packets; + stats->tx_bytes = dev_stats->tx_bytes; + stats->tx_packets = dev_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 ovs_mutex or rcu_read_lock. + */ +int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb) +{ + struct nlattr *nla; + int err; + + if (!vport->ops->get_options) + return 0; + + nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS); + if (!nla) + return -EMSGSIZE; + + 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_set_upcall_portids - set upcall portids of @vport. + * + * @vport: vport to modify. + * @ids: new configuration, an array of port ids. + * + * Sets the vport's upcall_portids to @ids. + * + * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed + * as an array of U32. + * + * Must be called with ovs_mutex. + */ +int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids) +{ + struct vport_portids *old, *vport_portids; + + if (!nla_len(ids) || nla_len(ids) % sizeof(u32)) + return -EINVAL; + + old = ovsl_dereference(vport->upcall_portids); + + vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids), + GFP_KERNEL); + if (!vport_portids) + return -ENOMEM; + + vport_portids->n_ids = nla_len(ids) / sizeof(u32); + vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids); + nla_memcpy(vport_portids->ids, ids, nla_len(ids)); + + rcu_assign_pointer(vport->upcall_portids, vport_portids); + + if (old) + kfree_rcu(old, rcu); + return 0; +} + +/** + * ovs_vport_get_upcall_portids - get the upcall_portids of @vport. + * + * @vport: vport from which to retrieve the portids. + * @skb: sk_buff where portids should be appended. + * + * Retrieves the configuration of the given vport, appending the + * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall + * portids to @skb. + * + * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room. + * If an error occurs, @skb is left unmodified. Must be called with + * ovs_mutex or rcu_read_lock. + */ +int ovs_vport_get_upcall_portids(const struct vport *vport, + struct sk_buff *skb) +{ + struct vport_portids *ids; + + ids = rcu_dereference_ovsl(vport->upcall_portids); + + if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS) + return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID, + ids->n_ids * sizeof(u32), (void *)ids->ids); + else + return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]); +} + +/** + * ovs_vport_find_upcall_portid - find the upcall portid to send upcall. + * + * @vport: vport from which the missed packet is received. + * @skb: skb that the missed packet was received. + * + * Uses the skb_get_hash() to select the upcall portid to send the + * upcall. + * + * Returns the portid of the target socket. Must be called with rcu_read_lock. + */ +u32 ovs_vport_find_upcall_portid(const struct vport *vport, struct sk_buff *skb) +{ + struct vport_portids *ids; + u32 ids_index; + u32 hash; + + ids = rcu_dereference(vport->upcall_portids); + + if (ids->n_ids == 1 && ids->ids[0] == 0) + return 0; + + hash = skb_get_hash(skb); + ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids); + return ids->ids[ids_index]; +} + +/** + * ovs_vport_receive - pass up received packet to the datapath for processing + * + * @vport: vport that received the packet + * @skb: skb that was received + * @tun_key: tunnel (if any) that carried packet + * + * Must be called with rcu_read_lock. The packet cannot be shared and + * skb->data should point to the Ethernet header. + */ +int ovs_vport_receive(struct vport *vport, struct sk_buff *skb, + const struct ip_tunnel_info *tun_info) +{ + struct sw_flow_key key; + int error; + + OVS_CB(skb)->input_vport = vport; + OVS_CB(skb)->mru = 0; + OVS_CB(skb)->cutlen = 0; + if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) { + u32 mark; + + mark = skb->mark; + skb_scrub_packet(skb, true); + skb->mark = mark; + tun_info = NULL; + } + + /* Extract flow from 'skb' into 'key'. */ + error = ovs_flow_key_extract(tun_info, skb, &key); + if (unlikely(error)) { + kfree_skb(skb); + return error; + } + ovs_dp_process_packet(skb, &key); + return 0; +} + +static int packet_length(const struct sk_buff *skb, + struct net_device *dev) +{ + int length = skb->len - dev->hard_header_len; + + if (!skb_vlan_tag_present(skb) && + eth_type_vlan(skb->protocol)) + length -= VLAN_HLEN; + + /* Don't subtract for multiple VLAN tags. Most (all?) drivers allow + * (ETH_LEN + VLAN_HLEN) in addition to the mtu value, but almost none + * account for 802.1ad. e.g. is_skb_forwardable(). + */ + + return length > 0 ? length : 0; +} + +void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto) +{ + int mtu = vport->dev->mtu; + + switch (vport->dev->type) { + case ARPHRD_NONE: + if (mac_proto == MAC_PROTO_ETHERNET) { + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + skb->protocol = htons(ETH_P_TEB); + } else if (mac_proto != MAC_PROTO_NONE) { + WARN_ON_ONCE(1); + goto drop; + } + break; + case ARPHRD_ETHER: + if (mac_proto != MAC_PROTO_ETHERNET) + goto drop; + break; + default: + goto drop; + } + + if (unlikely(packet_length(skb, vport->dev) > mtu && + !skb_is_gso(skb))) { + net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n", + vport->dev->name, + packet_length(skb, vport->dev), mtu); + vport->dev->stats.tx_errors++; + goto drop; + } + + skb->dev = vport->dev; + vport->ops->send(skb); + return; + +drop: + kfree_skb(skb); +} |