// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2007-2014 Nicira, Inc. */ #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 * * @net: network namespace * @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, lockdep_ovsl_is_held()) 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 * @parms: information about new vport. * * 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(). Some parameters of the vport will be initialized from @parms. * @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) { 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_noflag(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 there is only one portid, select it in the fast-path. */ if (ids->n_ids == 1) return ids->ids[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_info: 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))) { vport->dev->stats.tx_errors++; if (vport->dev->flags & IFF_UP) net_warn_ratelimited("%s: dropped over-mtu packet: " "%d > %d\n", vport->dev->name, packet_length(skb, vport->dev), mtu); goto drop; } skb->dev = vport->dev; vport->ops->send(skb); return; drop: kfree_skb(skb); }