diff options
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/net/Makefile | 1 | ||||
| -rw-r--r-- | drivers/net/net_failover.c | 836 |
3 files changed, 849 insertions, 0 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index a029b27fd002..2cdaff90a9ec 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -510,4 +510,16 @@ config NETDEVSIM To compile this driver as a module, choose M here: the module will be called netdevsim. +config NET_FAILOVER + tristate "Failover driver" + select FAILOVER + help + This provides an automated failover mechanism via APIs to create + and destroy a failover master netdev and manages a primary and + standby slave netdevs that get registered via the generic failover + infrastructure. This can be used by paravirtual drivers to enable + an alternate low latency datapath. It alsoenables live migration of + a VM with direct attached VF by failing over to the paravirtual + datapath when the VF is unplugged. + endif # NETDEVICES diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 91e67e375dd4..21cde7e78621 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -78,3 +78,4 @@ obj-$(CONFIG_FUJITSU_ES) += fjes/ thunderbolt-net-y += thunderbolt.o obj-$(CONFIG_THUNDERBOLT_NET) += thunderbolt-net.o obj-$(CONFIG_NETDEVSIM) += netdevsim/ +obj-$(CONFIG_NET_FAILOVER) += net_failover.o diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c new file mode 100644 index 000000000000..8b508e2cf29b --- /dev/null +++ b/drivers/net/net_failover.c @@ -0,0 +1,836 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018, Intel Corporation. */ + +/* This provides a net_failover interface for paravirtual drivers to + * provide an alternate datapath by exporting APIs to create and + * destroy a upper 'net_failover' netdev. The upper dev manages the + * original paravirtual interface as a 'standby' netdev and uses the + * generic failover infrastructure to register and manage a direct + * attached VF as a 'primary' netdev. This enables live migration of + * a VM with direct attached VF by failing over to the paravirtual + * datapath when the VF is unplugged. + * + * Some of the netdev management routines are based on bond/team driver as + * this driver provides active-backup functionality similar to those drivers. + */ + +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/ethtool.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/netdevice.h> +#include <linux/netpoll.h> +#include <linux/rtnetlink.h> +#include <linux/if_vlan.h> +#include <linux/pci.h> +#include <net/sch_generic.h> +#include <uapi/linux/if_arp.h> +#include <net/net_failover.h> + +static bool net_failover_xmit_ready(struct net_device *dev) +{ + return netif_running(dev) && netif_carrier_ok(dev); +} + +static int net_failover_open(struct net_device *dev) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev, *standby_dev; + int err; + + primary_dev = rtnl_dereference(nfo_info->primary_dev); + if (primary_dev) { + err = dev_open(primary_dev); + if (err) + goto err_primary_open; + } + + standby_dev = rtnl_dereference(nfo_info->standby_dev); + if (standby_dev) { + err = dev_open(standby_dev); + if (err) + goto err_standby_open; + } + + if ((primary_dev && net_failover_xmit_ready(primary_dev)) || + (standby_dev && net_failover_xmit_ready(standby_dev))) { + netif_carrier_on(dev); + netif_tx_wake_all_queues(dev); + } + + return 0; + +err_standby_open: + dev_close(primary_dev); +err_primary_open: + netif_tx_disable(dev); + return err; +} + +static int net_failover_close(struct net_device *dev) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *slave_dev; + + netif_tx_disable(dev); + + slave_dev = rtnl_dereference(nfo_info->primary_dev); + if (slave_dev) + dev_close(slave_dev); + + slave_dev = rtnl_dereference(nfo_info->standby_dev); + if (slave_dev) + dev_close(slave_dev); + + return 0; +} + +static netdev_tx_t net_failover_drop_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + atomic_long_inc(&dev->tx_dropped); + dev_kfree_skb_any(skb); + return NETDEV_TX_OK; +} + +static netdev_tx_t net_failover_start_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *xmit_dev; + + /* Try xmit via primary netdev followed by standby netdev */ + xmit_dev = rcu_dereference_bh(nfo_info->primary_dev); + if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) { + xmit_dev = rcu_dereference_bh(nfo_info->standby_dev); + if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) + return net_failover_drop_xmit(skb, dev); + } + + skb->dev = xmit_dev; + skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping; + + return dev_queue_xmit(skb); +} + +static u16 net_failover_select_queue(struct net_device *dev, + struct sk_buff *skb, void *accel_priv, + select_queue_fallback_t fallback) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev; + u16 txq; + + primary_dev = rcu_dereference(nfo_info->primary_dev); + if (primary_dev) { + const struct net_device_ops *ops = primary_dev->netdev_ops; + + if (ops->ndo_select_queue) + txq = ops->ndo_select_queue(primary_dev, skb, + accel_priv, fallback); + else + txq = fallback(primary_dev, skb); + + qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; + + return txq; + } + + txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; + + /* Save the original txq to restore before passing to the driver */ + qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; + + if (unlikely(txq >= dev->real_num_tx_queues)) { + do { + txq -= dev->real_num_tx_queues; + } while (txq >= dev->real_num_tx_queues); + } + + return txq; +} + +/* fold stats, assuming all rtnl_link_stats64 fields are u64, but + * that some drivers can provide 32bit values only. + */ +static void net_failover_fold_stats(struct rtnl_link_stats64 *_res, + const struct rtnl_link_stats64 *_new, + const struct rtnl_link_stats64 *_old) +{ + const u64 *new = (const u64 *)_new; + const u64 *old = (const u64 *)_old; + u64 *res = (u64 *)_res; + int i; + + for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { + u64 nv = new[i]; + u64 ov = old[i]; + s64 delta = nv - ov; + + /* detects if this particular field is 32bit only */ + if (((nv | ov) >> 32) == 0) + delta = (s64)(s32)((u32)nv - (u32)ov); + + /* filter anomalies, some drivers reset their stats + * at down/up events. + */ + if (delta > 0) + res[i] += delta; + } +} + +static void net_failover_get_stats(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + const struct rtnl_link_stats64 *new; + struct rtnl_link_stats64 temp; + struct net_device *slave_dev; + + spin_lock(&nfo_info->stats_lock); + memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); + + rcu_read_lock(); + + slave_dev = rcu_dereference(nfo_info->primary_dev); + if (slave_dev) { + new = dev_get_stats(slave_dev, &temp); + net_failover_fold_stats(stats, new, &nfo_info->primary_stats); + memcpy(&nfo_info->primary_stats, new, sizeof(*new)); + } + + slave_dev = rcu_dereference(nfo_info->standby_dev); + if (slave_dev) { + new = dev_get_stats(slave_dev, &temp); + net_failover_fold_stats(stats, new, &nfo_info->standby_stats); + memcpy(&nfo_info->standby_stats, new, sizeof(*new)); + } + + rcu_read_unlock(); + + memcpy(&nfo_info->failover_stats, stats, sizeof(*stats)); + spin_unlock(&nfo_info->stats_lock); +} + +static int net_failover_change_mtu(struct net_device *dev, int new_mtu) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev, *standby_dev; + int ret = 0; + + primary_dev = rcu_dereference(nfo_info->primary_dev); + if (primary_dev) { + ret = dev_set_mtu(primary_dev, new_mtu); + if (ret) + return ret; + } + + standby_dev = rcu_dereference(nfo_info->standby_dev); + if (standby_dev) { + ret = dev_set_mtu(standby_dev, new_mtu); + if (ret) { + if (primary_dev) + dev_set_mtu(primary_dev, dev->mtu); + return ret; + } + } + + dev->mtu = new_mtu; + + return 0; +} + +static void net_failover_set_rx_mode(struct net_device *dev) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *slave_dev; + + rcu_read_lock(); + + slave_dev = rcu_dereference(nfo_info->primary_dev); + if (slave_dev) { + dev_uc_sync_multiple(slave_dev, dev); + dev_mc_sync_multiple(slave_dev, dev); + } + + slave_dev = rcu_dereference(nfo_info->standby_dev); + if (slave_dev) { + dev_uc_sync_multiple(slave_dev, dev); + dev_mc_sync_multiple(slave_dev, dev); + } + + rcu_read_unlock(); +} + +static int net_failover_vlan_rx_add_vid(struct net_device *dev, __be16 proto, + u16 vid) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev, *standby_dev; + int ret = 0; + + primary_dev = rcu_dereference(nfo_info->primary_dev); + if (primary_dev) { + ret = vlan_vid_add(primary_dev, proto, vid); + if (ret) + return ret; + } + + standby_dev = rcu_dereference(nfo_info->standby_dev); + if (standby_dev) { + ret = vlan_vid_add(standby_dev, proto, vid); + if (ret) + if (primary_dev) + vlan_vid_del(primary_dev, proto, vid); + } + + return ret; +} + +static int net_failover_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, + u16 vid) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *slave_dev; + + slave_dev = rcu_dereference(nfo_info->primary_dev); + if (slave_dev) + vlan_vid_del(slave_dev, proto, vid); + + slave_dev = rcu_dereference(nfo_info->standby_dev); + if (slave_dev) + vlan_vid_del(slave_dev, proto, vid); + + return 0; +} + +static const struct net_device_ops failover_dev_ops = { + .ndo_open = net_failover_open, + .ndo_stop = net_failover_close, + .ndo_start_xmit = net_failover_start_xmit, + .ndo_select_queue = net_failover_select_queue, + .ndo_get_stats64 = net_failover_get_stats, + .ndo_change_mtu = net_failover_change_mtu, + .ndo_set_rx_mode = net_failover_set_rx_mode, + .ndo_vlan_rx_add_vid = net_failover_vlan_rx_add_vid, + .ndo_vlan_rx_kill_vid = net_failover_vlan_rx_kill_vid, + .ndo_validate_addr = eth_validate_addr, + .ndo_features_check = passthru_features_check, +}; + +#define FAILOVER_NAME "net_failover" +#define FAILOVER_VERSION "0.1" + +static void nfo_ethtool_get_drvinfo(struct net_device *dev, + struct ethtool_drvinfo *drvinfo) +{ + strlcpy(drvinfo->driver, FAILOVER_NAME, sizeof(drvinfo->driver)); + strlcpy(drvinfo->version, FAILOVER_VERSION, sizeof(drvinfo->version)); +} + +static int nfo_ethtool_get_link_ksettings(struct net_device *dev, + struct ethtool_link_ksettings *cmd) +{ + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *slave_dev; + + slave_dev = rtnl_dereference(nfo_info->primary_dev); + if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { + slave_dev = rtnl_dereference(nfo_info->standby_dev); + if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { + cmd->base.duplex = DUPLEX_UNKNOWN; + cmd->base.port = PORT_OTHER; + cmd->base.speed = SPEED_UNKNOWN; + + return 0; + } + } + + return __ethtool_get_link_ksettings(slave_dev, cmd); +} + +static const struct ethtool_ops failover_ethtool_ops = { + .get_drvinfo = nfo_ethtool_get_drvinfo, + .get_link = ethtool_op_get_link, + .get_link_ksettings = nfo_ethtool_get_link_ksettings, +}; + +/* Called when slave dev is injecting data into network stack. + * Change the associated network device from lower dev to failover dev. + * note: already called with rcu_read_lock + */ +static rx_handler_result_t net_failover_handle_frame(struct sk_buff **pskb) +{ + struct sk_buff *skb = *pskb; + struct net_device *dev = rcu_dereference(skb->dev->rx_handler_data); + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev, *standby_dev; + + primary_dev = rcu_dereference(nfo_info->primary_dev); + standby_dev = rcu_dereference(nfo_info->standby_dev); + + if (primary_dev && skb->dev == standby_dev) + return RX_HANDLER_EXACT; + + skb->dev = dev; + + return RX_HANDLER_ANOTHER; +} + +static void net_failover_compute_features(struct net_device *dev) +{ + u32 vlan_features = FAILOVER_VLAN_FEATURES & NETIF_F_ALL_FOR_ALL; + netdev_features_t enc_features = FAILOVER_ENC_FEATURES; + unsigned short max_hard_header_len = ETH_HLEN; + unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE | + IFF_XMIT_DST_RELEASE_PERM; + struct net_failover_info *nfo_info = netdev_priv(dev); + struct net_device *primary_dev, *standby_dev; + + primary_dev = rcu_dereference(nfo_info->primary_dev); + if (primary_dev) { + vlan_features = + netdev_increment_features(vlan_features, + primary_dev->vlan_features, + FAILOVER_VLAN_FEATURES); + enc_features = + netdev_increment_features(enc_features, + primary_dev->hw_enc_features, + FAILOVER_ENC_FEATURES); + + dst_release_flag &= primary_dev->priv_flags; + if (primary_dev->hard_header_len > max_hard_header_len) + max_hard_header_len = primary_dev->hard_header_len; + } + + standby_dev = rcu_dereference(nfo_info->standby_dev); + if (standby_dev) { + vlan_features = + netdev_increment_features(vlan_features, + standby_dev->vlan_features, + FAILOVER_VLAN_FEATURES); + enc_features = + netdev_increment_features(enc_features, + standby_dev->hw_enc_features, + FAILOVER_ENC_FEATURES); + + dst_release_flag &= standby_dev->priv_flags; + if (standby_dev->hard_header_len > max_hard_header_len) + max_hard_header_len = standby_dev->hard_header_len; + } + + dev->vlan_features = vlan_features; + dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL; + dev->hard_header_len = max_hard_header_len; + + dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; + if (dst_release_flag == (IFF_XMIT_DST_RELEASE | + IFF_XMIT_DST_RELEASE_PERM)) + dev->priv_flags |= IFF_XMIT_DST_RELEASE; + + netdev_change_features(dev); +} + +static void net_failover_lower_state_changed(struct net_device *slave_dev, + struct net_device *primary_dev, + struct net_device *standby_dev) +{ + struct netdev_lag_lower_state_info info; + + if (netif_carrier_ok(slave_dev)) + info.link_up = true; + else + info.link_up = false; + + if (slave_dev == primary_dev) { + if (netif_running(primary_dev)) + info.tx_enabled = true; + else + info.tx_enabled = false; + } else { + if ((primary_dev && netif_running(primary_dev)) || + (!netif_running(standby_dev))) + info.tx_enabled = false; + else + info.tx_enabled = true; + } + + netdev_lower_state_changed(slave_dev, &info); +} + +static int net_failover_slave_pre_register(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *standby_dev, *primary_dev; + struct net_failover_info *nfo_info; + bool slave_is_standby; + + nfo_info = netdev_priv(failover_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + primary_dev = rtnl_dereference(nfo_info->primary_dev); + slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; + if (slave_is_standby ? standby_dev : primary_dev) { + netdev_err(failover_dev, "%s attempting to register as slave dev when %s already present\n", + slave_dev->name, + slave_is_standby ? "standby" : "primary"); + return -EINVAL; + } + + /* We want to allow only a direct attached VF device as a primary + * netdev. As there is no easy way to check for a VF device, restrict + * this to a pci device. + */ + if (!slave_is_standby && (!slave_dev->dev.parent || + !dev_is_pci(slave_dev->dev.parent))) + return -EINVAL; + + if (failover_dev->features & NETIF_F_VLAN_CHALLENGED && + vlan_uses_dev(failover_dev)) { + netdev_err(failover_dev, "Device %s is VLAN challenged and failover device has VLAN set up\n", + failover_dev->name); + return -EINVAL; + } + + return 0; +} + +static int net_failover_slave_register(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *standby_dev, *primary_dev; + struct net_failover_info *nfo_info; + bool slave_is_standby; + u32 orig_mtu; + int err; + + /* Align MTU of slave with failover dev */ + orig_mtu = slave_dev->mtu; + err = dev_set_mtu(slave_dev, failover_dev->mtu); + if (err) { + netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n", + slave_dev->name, failover_dev->mtu); + goto done; + } + + dev_hold(slave_dev); + + if (netif_running(failover_dev)) { + err = dev_open(slave_dev); + if (err && (err != -EBUSY)) { + netdev_err(failover_dev, "Opening slave %s failed err:%d\n", + slave_dev->name, err); + goto err_dev_open; + } + } + + netif_addr_lock_bh(failover_dev); + dev_uc_sync_multiple(slave_dev, failover_dev); + dev_uc_sync_multiple(slave_dev, failover_dev); + netif_addr_unlock_bh(failover_dev); + + err = vlan_vids_add_by_dev(slave_dev, failover_dev); + if (err) { + netdev_err(failover_dev, "Failed to add vlan ids to device %s err:%d\n", + slave_dev->name, err); + goto err_vlan_add; + } + + nfo_info = netdev_priv(failover_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + primary_dev = rtnl_dereference(nfo_info->primary_dev); + slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; + + if (slave_is_standby) { + rcu_assign_pointer(nfo_info->standby_dev, slave_dev); + standby_dev = slave_dev; + dev_get_stats(standby_dev, &nfo_info->standby_stats); + } else { + rcu_assign_pointer(nfo_info->primary_dev, slave_dev); + primary_dev = slave_dev; + dev_get_stats(primary_dev, &nfo_info->primary_stats); + failover_dev->min_mtu = slave_dev->min_mtu; + failover_dev->max_mtu = slave_dev->max_mtu; + } + + net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); + net_failover_compute_features(failover_dev); + + call_netdevice_notifiers(NETDEV_JOIN, slave_dev); + + netdev_info(failover_dev, "failover %s slave:%s registered\n", + slave_is_standby ? "standby" : "primary", slave_dev->name); + + return 0; + +err_vlan_add: + dev_uc_unsync(slave_dev, failover_dev); + dev_mc_unsync(slave_dev, failover_dev); + dev_close(slave_dev); +err_dev_open: + dev_put(slave_dev); + dev_set_mtu(slave_dev, orig_mtu); +done: + return err; +} + +static int net_failover_slave_pre_unregister(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *standby_dev, *primary_dev; + struct net_failover_info *nfo_info; + + nfo_info = netdev_priv(failover_dev); + primary_dev = rtnl_dereference(nfo_info->primary_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + + if (slave_dev != primary_dev && slave_dev != standby_dev) + return -ENODEV; + + return 0; +} + +static int net_failover_slave_unregister(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *standby_dev, *primary_dev; + struct net_failover_info *nfo_info; + bool slave_is_standby; + + nfo_info = netdev_priv(failover_dev); + primary_dev = rtnl_dereference(nfo_info->primary_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + + vlan_vids_del_by_dev(slave_dev, failover_dev); + dev_uc_unsync(slave_dev, failover_dev); + dev_mc_unsync(slave_dev, failover_dev); + dev_close(slave_dev); + + nfo_info = netdev_priv(failover_dev); + dev_get_stats(failover_dev, &nfo_info->failover_stats); + + slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; + if (slave_is_standby) { + RCU_INIT_POINTER(nfo_info->standby_dev, NULL); + } else { + RCU_INIT_POINTER(nfo_info->primary_dev, NULL); + if (standby_dev) { + failover_dev->min_mtu = standby_dev->min_mtu; + failover_dev->max_mtu = standby_dev->max_mtu; + } + } + + dev_put(slave_dev); + + net_failover_compute_features(failover_dev); + + netdev_info(failover_dev, "failover %s slave:%s unregistered\n", + slave_is_standby ? "standby" : "primary", slave_dev->name); + + return 0; +} + +static int net_failover_slave_link_change(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *primary_dev, *standby_dev; + struct net_failover_info *nfo_info; + + nfo_info = netdev_priv(failover_dev); + + primary_dev = rtnl_dereference(nfo_info->primary_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + + if (slave_dev != primary_dev && slave_dev != standby_dev) + return -ENODEV; + + if ((primary_dev && net_failover_xmit_ready(primary_dev)) || + (standby_dev && net_failover_xmit_ready(standby_dev))) { + netif_carrier_on(failover_dev); + netif_tx_wake_all_queues(failover_dev); + } else { + dev_get_stats(failover_dev, &nfo_info->failover_stats); + netif_carrier_off(failover_dev); + netif_tx_stop_all_queues(failover_dev); + } + + net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); + + return 0; +} + +static int net_failover_slave_name_change(struct net_device *slave_dev, + struct net_device *failover_dev) +{ + struct net_device *primary_dev, *standby_dev; + struct net_failover_info *nfo_info; + + nfo_info = netdev_priv(failover_dev); + + primary_dev = rtnl_dereference(nfo_info->primary_dev); + standby_dev = rtnl_dereference(nfo_info->standby_dev); + + if (slave_dev != primary_dev && slave_dev != standby_dev) + return -ENODEV; + + /* We need to bring up the slave after the rename by udev in case + * open failed with EBUSY when it was registered. + */ + dev_open(slave_dev); + + return 0; +} + +static struct failover_ops net_failover_ops = { + .slave_pre_register = net_failover_slave_pre_register, + .slave_register = net_failover_slave_register, + .slave_pre_unregister = net_failover_slave_pre_unregister, + .slave_unregister = net_failover_slave_unregister, + .slave_link_change = net_failover_slave_link_change, + .slave_name_change = net_failover_slave_name_change, + .slave_handle_frame = net_failover_handle_frame, +}; + +/** + * net_failover_create - Create and register a failover instance + * + * @dev: standby netdev + * + * Creates a failover netdev and registers a failover instance for a standby + * netdev. Used by paravirtual drivers that use 3-netdev model. + * The failover netdev acts as a master device and controls 2 slave devices - + * the original standby netdev and a VF netdev with the same MAC gets + * registered as primary netdev. + * + * Return: pointer to failover instance + */ +struct failover *net_failover_create(struct net_device *standby_dev) +{ + struct device *dev = standby_dev->dev.parent; + struct net_device *failover_dev; + struct failover *failover; + int err; + + /* Alloc at least 2 queues, for now we are going with 16 assuming + * that VF devices being enslaved won't have too many queues. + */ + failover_dev = alloc_etherdev_mq(sizeof(struct net_failover_info), 16); + if (!failover_dev) { + dev_err(dev, "Unable to allocate failover_netdev!\n"); + return ERR_PTR(-ENOMEM); + } + + dev_net_set(failover_dev, dev_net(standby_dev)); + SET_NETDEV_DEV(failover_dev, dev); + + failover_dev->netdev_ops = &failover_dev_ops; + failover_dev->ethtool_ops = &failover_ethtool_ops; + + /* Initialize the device options */ + failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; + failover_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | + IFF_TX_SKB_SHARING); + + /* don't acquire failover netdev's netif_tx_lock when transmitting */ + failover_dev->features |= NETIF_F_LLTX; + + /* Don't allow failover devices to change network namespaces. */ + failover_dev->features |= NETIF_F_NETNS_LOCAL; + + failover_dev->hw_features = FAILOVER_VLAN_FEATURES | + NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_CTAG_RX | + NETIF_F_HW_VLAN_CTAG_FILTER; + + failover_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL; + failover_dev->features |= failover_dev->hw_features; + + memcpy(failover_dev->dev_addr, standby_dev->dev_addr, + failover_dev->addr_len); + + failover_dev->min_mtu = standby_dev->min_mtu; + failover_dev->max_mtu = standby_dev->max_mtu; + + err = register_netdev(failover_dev); + if (err) { + dev_err(dev, "Unable to register failover_dev!\n"); + goto err_register_netdev; + } + + netif_carrier_off(failover_dev); + + failover = failover_register(failover_dev, &net_failover_ops); + if (IS_ERR(failover)) + goto err_failover_register; + + return failover; + +err_failover_register: + unregister_netdev(failover_dev); +err_register_netdev: + free_netdev(failover_dev); + + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(net_failover_create); + +/** + * net_failover_destroy - Destroy a failover instance + * + * @failover: pointer to failover instance + * + * Unregisters any slave netdevs associated with the failover instance by + * calling failover_slave_unregister(). + * unregisters the failover instance itself and finally frees the failover + * netdev. Used by paravirtual drivers that use 3-netdev model. + * + */ +void net_failover_destroy(struct failover *failover) +{ + struct net_failover_info *nfo_info; + struct net_device *failover_dev; + struct net_device *slave_dev; + + if (!failover) + return; + + failover_dev = rcu_dereference(failover->failover_dev); + nfo_info = netdev_priv(failover_dev); + + netif_device_detach(failover_dev); + + rtnl_lock(); + + slave_dev = rtnl_dereference(nfo_info->primary_dev); + if (slave_dev) + failover_slave_unregister(slave_dev); + + slave_dev = rtnl_dereference(nfo_info->standby_dev); + if (slave_dev) + failover_slave_unregister(slave_dev); + + failover_unregister(failover); + + unregister_netdevice(failover_dev); + + rtnl_unlock(); + + free_netdev(failover_dev); +} +EXPORT_SYMBOL_GPL(net_failover_destroy); + +static __init int +net_failover_init(void) +{ + return 0; +} +module_init(net_failover_init); + +static __exit +void net_failover_exit(void) +{ +} +module_exit(net_failover_exit); + +MODULE_DESCRIPTION("Failover driver for Paravirtual drivers"); +MODULE_LICENSE("GPL v2"); |