Message ID | 1438021869-49186-14-git-send-email-dsa@cumulusnetworks.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
On 07/27/2015 08:31 PM, David Ahern wrote: > This driver borrows heavily from IPvlan and teaming drivers. > > Routing domains (VRF-lite) are created by instantiating a VRF master > device with an associated table and enslaving all routed interfaces that > participate in the domain. As part of the enslavement, all connected > routes for the enslaved devices are moved to the table associated with > the VRF device. Outgoing sockets must bind to the VRF device to function. > > Standard FIB rules bind the VRF device to tables and regular fib rule > processing is followed. Routed traffic through the box, is forwarded by > using the VRF device as the IIF and following the IIF rule to a table > that is mated with the VRF. > > Example: > > Create vrf 1: > ip link add vrf1 type vrf table 5 > ip rule add iif vrf1 table 5 > ip rule add oif vrf1 table 5 > ip route add table 5 prohibit default > ip link set vrf1 up > > Add interface to vrf 1: > ip link set eth1 master vrf1 > > Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com> > Signed-off-by: David Ahern <dsa@cumulusnetworks.com> > > v2: > - addressed comments from first RFC > - significant changes to improve simplicity of implementation > --- > drivers/net/Kconfig | 7 + > drivers/net/Makefile | 1 + > drivers/net/vrf.c | 596 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 604 insertions(+) > create mode 100644 drivers/net/vrf.c > > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig > index c18f9e62a9fa..e58468b02987 100644 > --- a/drivers/net/Kconfig > +++ b/drivers/net/Kconfig > @@ -297,6 +297,13 @@ config NLMON > diagnostics, etc. This is mostly intended for developers or support > to debug netlink issues. If unsure, say N. > > +config NET_VRF > + tristate "Virtual Routing and Forwarding (Lite)" > + depends on IP_MULTIPLE_TABLES && IPV6_MULTIPLE_TABLES > + ---help--- > + This option enables the support for mapping interfaces into VRF's. The > + support enables VRF devices. > + > endif # NET_CORE > > config SUNGEM_PHY > diff --git a/drivers/net/Makefile b/drivers/net/Makefile > index c12cb22478a7..ca16dd689b36 100644 > --- a/drivers/net/Makefile > +++ b/drivers/net/Makefile > @@ -25,6 +25,7 @@ obj-$(CONFIG_VIRTIO_NET) += virtio_net.o > obj-$(CONFIG_VXLAN) += vxlan.o > obj-$(CONFIG_GENEVE) += geneve.o > obj-$(CONFIG_NLMON) += nlmon.o > +obj-$(CONFIG_NET_VRF) += vrf.o > > # > # Networking Drivers > diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c > new file mode 100644 > index 000000000000..8669b0f9d749 > --- /dev/null > +++ b/drivers/net/vrf.c > @@ -0,0 +1,596 @@ > +/* > + * vrf.c: device driver to encapsulate a VRF space > + * > + * Copyright (c) 2015 Cumulus Networks > + * > + * Based on dummy, team and ipvlan drivers > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/netdevice.h> > +#include <linux/etherdevice.h> > +#include <linux/ip.h> > +#include <linux/init.h> > +#include <linux/moduleparam.h> > +#include <linux/rtnetlink.h> > +#include <net/rtnetlink.h> > +#include <linux/u64_stats_sync.h> > +#include <linux/hashtable.h> > + > +#include <linux/inetdevice.h> > +#include <net/ip.h> > +#include <net/ip_fib.h> > +#include <net/ip6_route.h> > +#include <net/rtnetlink.h> > +#include <net/route.h> > +#include <net/addrconf.h> > +#include <net/vrf.h> > + > +#define DRV_NAME "vrf" > +#define DRV_VERSION "1.0" > + > +#define vrf_is_slave(dev) ((dev)->flags & IFF_SLAVE) > +#define vrf_is_master(dev) ((dev)->flags & IFF_MASTER) > + > +#define vrf_master_get_rcu(dev) \ > + ((struct net_device *)rcu_dereference(dev->rx_handler_data)) > + > +struct pcpu_dstats { > + u64 tx_pkts; > + u64 tx_bytes; > + u64 tx_drps; > + u64 rx_pkts; > + u64 rx_bytes; > + struct u64_stats_sync syncp; > +}; > + > +struct slave { > + struct list_head list; > + struct net_device *dev; > +}; > + > +struct slave_queue { > + spinlock_t lock; /* lock for slave insert/delete */ ^^^^ I don't think you actually need this lock since all VRF dev operations are done under RTNL so you already got protection against add/del running concurrently. It would simplify the code if you can get rid of it. > + struct list_head all_slaves; > + int num_slaves; > +}; > + > +struct net_vrf { > + struct slave_queue queue; > + struct fib_table *tb; > + u32 tb_id; > +}; > + > +static bool is_ip_rx_frame(struct sk_buff *skb) > +{ > + switch (skb->protocol) { > + case htons(ETH_P_IP): > + case htons(ETH_P_IPV6): > + return true; > + } > + return false; > +} > + > +/* note: already called with rcu_read_lock */ > +static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb) > +{ > + struct sk_buff *skb = *pskb; > + > + if (is_ip_rx_frame(skb)) { > + struct net_device *dev = vrf_master_get_rcu(skb->dev); > + struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); > + > + u64_stats_update_begin(&dstats->syncp); > + dstats->rx_pkts++; > + dstats->rx_bytes += skb->len; > + u64_stats_update_end(&dstats->syncp); > + > + skb->dev = dev; > + > + return RX_HANDLER_ANOTHER; > + } > + return RX_HANDLER_PASS; > +} > + > +static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev, > + struct rtnl_link_stats64 *stats) > +{ > + int i; > + > + for_each_possible_cpu(i) { > + const struct pcpu_dstats *dstats; > + u64 tbytes, tpkts, tdrops, rbytes, rpkts; > + unsigned int start; > + > + dstats = per_cpu_ptr(dev->dstats, i); > + do { > + start = u64_stats_fetch_begin_irq(&dstats->syncp); > + tbytes = dstats->tx_bytes; > + tpkts = dstats->tx_pkts; > + tdrops = dstats->tx_drps; > + rbytes = dstats->rx_bytes; > + rpkts = dstats->rx_pkts; > + } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); > + stats->tx_bytes += tbytes; > + stats->tx_packets += tpkts; > + stats->tx_dropped += tdrops; > + stats->rx_bytes += rbytes; > + stats->rx_packets += rpkts; > + } > + return stats; > +} > + > +static int vrf_process_v4_outbound(struct sk_buff *skb) > +{ > + const struct iphdr *iph = ip_hdr(skb); > + struct net_device *dev = skb->dev; > + struct net *net = dev_net(dev); > + int tb_id = vrf_dev_table(dev); > + int err, ret = NET_XMIT_DROP; > + struct in_device *in_dev; > + struct flowi4 fl4 = { > + .flowi4_tos = RT_TOS(iph->tos), > + .daddr = iph->daddr, > + .saddr = iph->saddr, > + }; > + struct rtable *rth; > + > + struct fib_result res; > + struct fib_table *tbl; > + > + rcu_read_lock(); > + in_dev = __in_dev_get_rcu(dev); > + if (!in_dev) > + goto out; > + > + if (tb_id == 0) > + goto out; > + > + tbl = fib_get_table(net, tb_id); > + if (!tbl) > + goto out; > + > + res.tclassid = 0; > + res.fi = NULL; > + res.table = NULL; > + if (fib_table_lookup(tbl, &fl4, &res, 0) != 0) > + goto out; > + > + dev = FIB_RES_DEV(res); > + > + rth = ip_route_new_rtable(dev, RTCF_LOCAL, res.type, > + IN_DEV_CONF_GET(in_dev, NOPOLICY), > + IN_DEV_CONF_GET(in_dev, NOXFRM), > + true); > + if (!rth) > + goto out; > + > + ip_route_set_nexthop(rth, fl4.daddr, &res); > + > + skb_dst_drop(skb); > + skb_dst_set(skb, &rth->dst); > + err = ip_local_out(skb); > + if (!net_xmit_eval(err)) > + ret = NET_XMIT_SUCCESS; > + > +out: > + rcu_read_unlock(); > + > + if (ret != NET_XMIT_SUCCESS) > + dev->stats.tx_errors++; > + > + return ret; > +} > + > +static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *mdev) > +{ > + struct pcpu_dstats *dstats = this_cpu_ptr(mdev->dstats); > + unsigned int len = skb->len; > + int ret = NET_XMIT_DROP; > + > + if (skb_mac_header_was_set(skb)) { > + skb_pull(skb, sizeof(struct ethhdr)); > + skb->mac_header = (typeof(skb->mac_header))~0U; > + skb_reset_network_header(skb); > + } > + > + if (skb->protocol == htons(ETH_P_IP)) > + ret = vrf_process_v4_outbound(skb); > + > + if (ret == NET_XMIT_SUCCESS) { > + u64_stats_update_begin(&dstats->syncp); > + dstats->tx_pkts++; > + dstats->tx_bytes += len; > + u64_stats_update_end(&dstats->syncp); > + } else { > + dstats->tx_drps++; > + kfree_skb(skb); > + } > + return ret; > +} > + > +/**************************** device handling ********************/ > + > +/* cycle interface to flush neighbor cache and move routes across tables */ > +static void cycle_netdev(struct net_device *dev) > +{ > + unsigned int flags = dev->flags; > + int ret; > + > + if (!netif_running(dev)) > + return; > + > + ret = dev_change_flags(dev, flags & ~IFF_UP); > + if (ret >= 0) > + ret = dev_change_flags(dev, flags); > + > + if (ret < 0) { > + netdev_err(dev, > + "Failed to cycle device %s; route tables might be wrong!\n", > + dev->name); > + } > +} > + > +/* queue->lock must be held */ > +static struct slave *__vrf_find_slave_dev(struct slave_queue *queue, > + struct net_device *dev) > +{ > + struct list_head *this, *head; > + > + head = &queue->all_slaves; > + list_for_each(this, head) { ^^^^ list_for_each_entry() > + struct slave *slave = list_entry(this, struct slave, list); > + > + if (slave->dev == dev) > + return slave; > + } > + > + return NULL; > +} > + > +/* inverse of __vrf_insert_slave; queue->lock must be held */ > +static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave) > +{ > + dev_put(slave->dev); > + list_del(&slave->list); > + queue->num_slaves--; > +} > + > +/* queue->lock must be held */ > +static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave) > +{ > + dev_hold(slave->dev); > + list_add(&slave->list, &queue->all_slaves); > + queue->num_slaves++; > +} > + > +static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev) > +{ > + struct net_vrf_dev *vrf_ptr = kmalloc(sizeof(*vrf_ptr), GFP_KERNEL); > + struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL); > + struct slave *duplicate_slave; > + struct net_vrf *vrf = netdev_priv(dev); > + struct slave_queue *queue = &vrf->queue; > + int ret = -ENOMEM; > + > + if (!slave || !vrf_ptr) > + goto out_fail; > + > + slave->dev = port_dev; > + > + vrf_ptr->ifindex = dev->ifindex; > + vrf_ptr->tb_id = vrf->tb_id; > + > + spin_lock_bh(&queue->lock); > + > + duplicate_slave = __vrf_find_slave_dev(queue, port_dev); > + if (duplicate_slave) { > + spin_unlock_bh(&queue->lock); > + ret = -EBUSY; > + goto out_fail; > + } > + > + __vrf_insert_slave(queue, slave); > + > + spin_unlock_bh(&queue->lock); > + > + /* register the packet handler for slave ports */ > + ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev); > + if (ret) { > + netdev_err(port_dev, > + "Device %s failed to register rx_handler\n", > + port_dev->name); > + goto out_remove; > + } > + > + ret = netdev_master_upper_dev_link(port_dev, dev); > + if (ret < 0) > + goto out_unregister; > + > + port_dev->flags |= IFF_SLAVE; > + > + rcu_assign_pointer(port_dev->vrf_ptr, vrf_ptr); > + cycle_netdev(port_dev); > + > + return 0; > + > +out_unregister: > + netdev_rx_handler_unregister(port_dev); > +out_remove: > + __vrf_remove_slave(queue, slave); > +out_fail: > + kfree(vrf_ptr); > + kfree(slave); > + return ret; > +} > + > +static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev) > +{ > + ASSERT_RTNL(); These asserts are not needed, the ndo_slave_add/del always run with rtnl and many drivers rely on that. > + > + if (!dev || !port_dev || dev_net(dev) != dev_net(port_dev)) > + return -ENODEV; I don't think the !dev or !port_dev can happen. Also the net can't be different looking at do_set_master() in rtnetlink.c > + > + if (!vrf_is_master(dev) || vrf_is_master(port_dev) || Hmm, this means that bonds won't be able to be VRF slaves. They have the IFF_MASTER flag set. > + vrf_is_slave(port_dev)) > + return -EINVAL; > + > + return do_vrf_add_slave(dev, port_dev); > +} > + > +/* inverse of do_vrf_add_slave */ > +static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + struct slave_queue *queue = &vrf->queue; > + struct net_vrf_dev *vrf_ptr = NULL; > + struct slave *slave; > + > + vrf_ptr = rcu_dereference(dev->vrf_ptr); > + RCU_INIT_POINTER(dev->vrf_ptr, NULL); I think this isn't safe, you should wait for a grace period before freeing the pointer. Actually you can just move the kfree() below the netdev_rx_handler_unregister() since it does synchronize_rcu() anyway. > + kfree(vrf_ptr); > + > + netdev_upper_dev_unlink(port_dev, dev); > + port_dev->flags &= ~IFF_SLAVE; > + > + netdev_rx_handler_unregister(dev); > + > + cycle_netdev(port_dev); > + > + spin_lock_bh(&queue->lock); > + > + slave = __vrf_find_slave_dev(queue, port_dev); > + if (slave) > + __vrf_remove_slave(queue, slave); > + > + spin_unlock_bh(&queue->lock); > + > + kfree(slave); > + > + return 0; > +} > + > +static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) > +{ > + ASSERT_RTNL(); > + > + if (!dev || !port_dev) > + return -ENODEV; ^ I really don't think any of this can happen. > + > + if (!vrf_is_master(dev)) > + return -EINVAL; > + > + return do_vrf_del_slave(dev, port_dev); > +} > + > +static int vrf_dev_init(struct net_device *dev) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + > + spin_lock_init(&vrf->queue.lock); > + INIT_LIST_HEAD(&vrf->queue.all_slaves); > + > + dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); > + if (!dev->dstats) > + return -ENOMEM; > + > + dev->flags = IFF_MASTER | IFF_NOARP; > + > + return 0; > +} > + > +static void vrf_dev_uninit(struct net_device *dev) > +{ > + free_percpu(dev->dstats); > +} > + > +static int vrf_dev_close(struct net_device *dev) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + struct slave_queue *queue = &vrf->queue; > + struct list_head *this, *head; > + > + head = &queue->all_slaves; > + list_for_each(this, head) { ^^^ list_for_each_entry() > + struct slave *slave = list_entry(this, struct slave, list); > + > + slave->dev->vrf_ptr->ifindex = 0; > + slave->dev->vrf_ptr->tb_id = 0; > + } > + > + if (dev->flags & IFF_MASTER) > + dev->flags &= ~IFF_UP; > + > + return 0; > +} > + > +static int vrf_dev_open(struct net_device *dev) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + struct slave_queue *queue = &vrf->queue; > + struct list_head *this, *head; > + > + head = &queue->all_slaves; > + list_for_each(this, head) { ^^^ list_for_each_entry() > + struct slave *slave = list_entry(this, struct slave, list); > + > + slave->dev->vrf_ptr->ifindex = dev->ifindex; > + slave->dev->vrf_ptr->tb_id = vrf->tb_id; > + } > + > + if (dev->flags & IFF_MASTER) > + dev->flags |= IFF_UP; > + > + if (!vrf->tb) > + return -EINVAL; > + > + return 0; > +} > + > +static const struct net_device_ops vrf_netdev_ops = { > + .ndo_init = vrf_dev_init, > + .ndo_uninit = vrf_dev_uninit, > + .ndo_open = vrf_dev_open, > + .ndo_stop = vrf_dev_close, > + .ndo_start_xmit = vrf_xmit, > + .ndo_get_stats64 = vrf_get_stats64, > + .ndo_add_slave = vrf_add_slave, > + .ndo_del_slave = vrf_del_slave, > +}; > + > +static void vrf_get_drvinfo(struct net_device *dev, > + struct ethtool_drvinfo *info) > +{ > + strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); > + strlcpy(info->version, DRV_VERSION, sizeof(info->version)); > +} > + > +static const struct ethtool_ops vrf_ethtool_ops = { > + .get_drvinfo = vrf_get_drvinfo, > +}; > + > +static void vrf_setup(struct net_device *dev) > +{ > + ether_setup(dev); > + > + /* Initialize the device structure. */ > + dev->netdev_ops = &vrf_netdev_ops; > + dev->ethtool_ops = &vrf_ethtool_ops; > + dev->destructor = free_netdev; > + > + /* Fill in device structure with ethernet-generic values. */ > + eth_hw_addr_random(dev); > +} > + > +static int vrf_validate(struct nlattr *tb[], struct nlattr *data[]) > +{ > + if (tb[IFLA_ADDRESS]) { > + if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) > + return -EINVAL; > + if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) > + return -EADDRNOTAVAIL; > + } > + return 0; > +} > + > +static int vrf_newlink(struct net *src_net, struct net_device *dev, > + struct nlattr *tb[], struct nlattr *data[]) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + int err; > + > + if (!data || !data[IFLA_VRF_TABLE]) > + return -EINVAL; > + > + vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); > + > + /* reserve a table for this VRF device */ > + err = -ERANGE; > + vrf->tb = fib_new_table(dev_net(dev), vrf->tb_id); > + if (!vrf->tb) > + goto out_fail; > + > + dev->priv_flags |= IFF_VRF_MASTER; > + > + err = -ENOMEM; > + dev->vrf_ptr = kmalloc(sizeof(*dev->vrf_ptr), GFP_KERNEL); > + if (!dev->vrf_ptr) > + goto out_fail; > + > + dev->vrf_ptr->ifindex = dev->ifindex; > + dev->vrf_ptr->tb_id = vrf->tb_id; > + > + err = register_netdevice(dev); > + if (err < 0) > + goto out_fail; > + > + return 0; > + > +out_fail: > + kfree(dev->vrf_ptr); > + free_netdev(dev); > + return err; > +} > + > +static void vrf_dellink(struct net_device *dev, struct list_head *head) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + > + kfree(dev->vrf_ptr); > + fib_free_table(vrf->tb); > +} > + > +static size_t vrf_nl_getsize(const struct net_device *dev) > +{ > + return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ > +} > + > +static int vrf_fillinfo(struct sk_buff *skb, > + const struct net_device *dev) > +{ > + struct net_vrf *vrf = netdev_priv(dev); > + > + return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); > +} > + > +static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { > + [IFLA_VRF_TABLE] = { .type = NLA_U32 }, > +}; > + > +static struct rtnl_link_ops vrf_link_ops __read_mostly = { > + .kind = DRV_NAME, > + .priv_size = sizeof(struct net_vrf), > + > + .get_size = vrf_nl_getsize, > + .policy = vrf_nl_policy, > + .validate = vrf_validate, > + .fill_info = vrf_fillinfo, > + > + .newlink = vrf_newlink, > + .dellink = vrf_dellink, > + .setup = vrf_setup, > + .maxtype = IFLA_VRF_MAX, > +}; > + > +static int __init vrf_init_module(void) > +{ > + return rtnl_link_register(&vrf_link_ops); > +} > + > +static void __exit vrf_cleanup_module(void) > +{ > + rtnl_link_unregister(&vrf_link_ops); > +} > + > +module_init(vrf_init_module); > +module_exit(vrf_cleanup_module); > +MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS_RTNL_LINK(DRV_NAME); > +MODULE_VERSION(DRV_VERSION); > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 7/27/15 2:01 PM, Nikolay Aleksandrov wrote: >> + >> + if (!vrf_is_master(dev) || vrf_is_master(port_dev) || > > Hmm, this means that bonds won't be able to be VRF slaves. > They have the IFF_MASTER flag set. Right, will change to the IFF_VRF_MASTER flag. > >> + vrf_is_slave(port_dev)) >> + return -EINVAL; >> + >> + return do_vrf_add_slave(dev, port_dev); >> +} >> + >> +/* inverse of do_vrf_add_slave */ >> +static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) >> +{ >> + struct net_vrf *vrf = netdev_priv(dev); >> + struct slave_queue *queue = &vrf->queue; >> + struct net_vrf_dev *vrf_ptr = NULL; >> + struct slave *slave; >> + >> + vrf_ptr = rcu_dereference(dev->vrf_ptr); >> + RCU_INIT_POINTER(dev->vrf_ptr, NULL); > > I think this isn't safe, you should wait for a grace period before freeing the > pointer. Actually you can just move the kfree() below the netdev_rx_handler_unregister() > since it does synchronize_rcu() anyway. ok And ack on all other comments.. Thanks for the review, David -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index c18f9e62a9fa..e58468b02987 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -297,6 +297,13 @@ config NLMON diagnostics, etc. This is mostly intended for developers or support to debug netlink issues. If unsure, say N. +config NET_VRF + tristate "Virtual Routing and Forwarding (Lite)" + depends on IP_MULTIPLE_TABLES && IPV6_MULTIPLE_TABLES + ---help--- + This option enables the support for mapping interfaces into VRF's. The + support enables VRF devices. + endif # NET_CORE config SUNGEM_PHY diff --git a/drivers/net/Makefile b/drivers/net/Makefile index c12cb22478a7..ca16dd689b36 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_VIRTIO_NET) += virtio_net.o obj-$(CONFIG_VXLAN) += vxlan.o obj-$(CONFIG_GENEVE) += geneve.o obj-$(CONFIG_NLMON) += nlmon.o +obj-$(CONFIG_NET_VRF) += vrf.o # # Networking Drivers diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c new file mode 100644 index 000000000000..8669b0f9d749 --- /dev/null +++ b/drivers/net/vrf.c @@ -0,0 +1,596 @@ +/* + * vrf.c: device driver to encapsulate a VRF space + * + * Copyright (c) 2015 Cumulus Networks + * + * Based on dummy, team and ipvlan drivers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/ip.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/rtnetlink.h> +#include <net/rtnetlink.h> +#include <linux/u64_stats_sync.h> +#include <linux/hashtable.h> + +#include <linux/inetdevice.h> +#include <net/ip.h> +#include <net/ip_fib.h> +#include <net/ip6_route.h> +#include <net/rtnetlink.h> +#include <net/route.h> +#include <net/addrconf.h> +#include <net/vrf.h> + +#define DRV_NAME "vrf" +#define DRV_VERSION "1.0" + +#define vrf_is_slave(dev) ((dev)->flags & IFF_SLAVE) +#define vrf_is_master(dev) ((dev)->flags & IFF_MASTER) + +#define vrf_master_get_rcu(dev) \ + ((struct net_device *)rcu_dereference(dev->rx_handler_data)) + +struct pcpu_dstats { + u64 tx_pkts; + u64 tx_bytes; + u64 tx_drps; + u64 rx_pkts; + u64 rx_bytes; + struct u64_stats_sync syncp; +}; + +struct slave { + struct list_head list; + struct net_device *dev; +}; + +struct slave_queue { + spinlock_t lock; /* lock for slave insert/delete */ + struct list_head all_slaves; + int num_slaves; +}; + +struct net_vrf { + struct slave_queue queue; + struct fib_table *tb; + u32 tb_id; +}; + +static bool is_ip_rx_frame(struct sk_buff *skb) +{ + switch (skb->protocol) { + case htons(ETH_P_IP): + case htons(ETH_P_IPV6): + return true; + } + return false; +} + +/* note: already called with rcu_read_lock */ +static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb) +{ + struct sk_buff *skb = *pskb; + + if (is_ip_rx_frame(skb)) { + struct net_device *dev = vrf_master_get_rcu(skb->dev); + struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); + + u64_stats_update_begin(&dstats->syncp); + dstats->rx_pkts++; + dstats->rx_bytes += skb->len; + u64_stats_update_end(&dstats->syncp); + + skb->dev = dev; + + return RX_HANDLER_ANOTHER; + } + return RX_HANDLER_PASS; +} + +static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + int i; + + for_each_possible_cpu(i) { + const struct pcpu_dstats *dstats; + u64 tbytes, tpkts, tdrops, rbytes, rpkts; + unsigned int start; + + dstats = per_cpu_ptr(dev->dstats, i); + do { + start = u64_stats_fetch_begin_irq(&dstats->syncp); + tbytes = dstats->tx_bytes; + tpkts = dstats->tx_pkts; + tdrops = dstats->tx_drps; + rbytes = dstats->rx_bytes; + rpkts = dstats->rx_pkts; + } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); + stats->tx_bytes += tbytes; + stats->tx_packets += tpkts; + stats->tx_dropped += tdrops; + stats->rx_bytes += rbytes; + stats->rx_packets += rpkts; + } + return stats; +} + +static int vrf_process_v4_outbound(struct sk_buff *skb) +{ + const struct iphdr *iph = ip_hdr(skb); + struct net_device *dev = skb->dev; + struct net *net = dev_net(dev); + int tb_id = vrf_dev_table(dev); + int err, ret = NET_XMIT_DROP; + struct in_device *in_dev; + struct flowi4 fl4 = { + .flowi4_tos = RT_TOS(iph->tos), + .daddr = iph->daddr, + .saddr = iph->saddr, + }; + struct rtable *rth; + + struct fib_result res; + struct fib_table *tbl; + + rcu_read_lock(); + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + goto out; + + if (tb_id == 0) + goto out; + + tbl = fib_get_table(net, tb_id); + if (!tbl) + goto out; + + res.tclassid = 0; + res.fi = NULL; + res.table = NULL; + if (fib_table_lookup(tbl, &fl4, &res, 0) != 0) + goto out; + + dev = FIB_RES_DEV(res); + + rth = ip_route_new_rtable(dev, RTCF_LOCAL, res.type, + IN_DEV_CONF_GET(in_dev, NOPOLICY), + IN_DEV_CONF_GET(in_dev, NOXFRM), + true); + if (!rth) + goto out; + + ip_route_set_nexthop(rth, fl4.daddr, &res); + + skb_dst_drop(skb); + skb_dst_set(skb, &rth->dst); + err = ip_local_out(skb); + if (!net_xmit_eval(err)) + ret = NET_XMIT_SUCCESS; + +out: + rcu_read_unlock(); + + if (ret != NET_XMIT_SUCCESS) + dev->stats.tx_errors++; + + return ret; +} + +static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *mdev) +{ + struct pcpu_dstats *dstats = this_cpu_ptr(mdev->dstats); + unsigned int len = skb->len; + int ret = NET_XMIT_DROP; + + if (skb_mac_header_was_set(skb)) { + skb_pull(skb, sizeof(struct ethhdr)); + skb->mac_header = (typeof(skb->mac_header))~0U; + skb_reset_network_header(skb); + } + + if (skb->protocol == htons(ETH_P_IP)) + ret = vrf_process_v4_outbound(skb); + + if (ret == NET_XMIT_SUCCESS) { + u64_stats_update_begin(&dstats->syncp); + dstats->tx_pkts++; + dstats->tx_bytes += len; + u64_stats_update_end(&dstats->syncp); + } else { + dstats->tx_drps++; + kfree_skb(skb); + } + return ret; +} + +/**************************** device handling ********************/ + +/* cycle interface to flush neighbor cache and move routes across tables */ +static void cycle_netdev(struct net_device *dev) +{ + unsigned int flags = dev->flags; + int ret; + + if (!netif_running(dev)) + return; + + ret = dev_change_flags(dev, flags & ~IFF_UP); + if (ret >= 0) + ret = dev_change_flags(dev, flags); + + if (ret < 0) { + netdev_err(dev, + "Failed to cycle device %s; route tables might be wrong!\n", + dev->name); + } +} + +/* queue->lock must be held */ +static struct slave *__vrf_find_slave_dev(struct slave_queue *queue, + struct net_device *dev) +{ + struct list_head *this, *head; + + head = &queue->all_slaves; + list_for_each(this, head) { + struct slave *slave = list_entry(this, struct slave, list); + + if (slave->dev == dev) + return slave; + } + + return NULL; +} + +/* inverse of __vrf_insert_slave; queue->lock must be held */ +static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave) +{ + dev_put(slave->dev); + list_del(&slave->list); + queue->num_slaves--; +} + +/* queue->lock must be held */ +static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave) +{ + dev_hold(slave->dev); + list_add(&slave->list, &queue->all_slaves); + queue->num_slaves++; +} + +static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev) +{ + struct net_vrf_dev *vrf_ptr = kmalloc(sizeof(*vrf_ptr), GFP_KERNEL); + struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL); + struct slave *duplicate_slave; + struct net_vrf *vrf = netdev_priv(dev); + struct slave_queue *queue = &vrf->queue; + int ret = -ENOMEM; + + if (!slave || !vrf_ptr) + goto out_fail; + + slave->dev = port_dev; + + vrf_ptr->ifindex = dev->ifindex; + vrf_ptr->tb_id = vrf->tb_id; + + spin_lock_bh(&queue->lock); + + duplicate_slave = __vrf_find_slave_dev(queue, port_dev); + if (duplicate_slave) { + spin_unlock_bh(&queue->lock); + ret = -EBUSY; + goto out_fail; + } + + __vrf_insert_slave(queue, slave); + + spin_unlock_bh(&queue->lock); + + /* register the packet handler for slave ports */ + ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev); + if (ret) { + netdev_err(port_dev, + "Device %s failed to register rx_handler\n", + port_dev->name); + goto out_remove; + } + + ret = netdev_master_upper_dev_link(port_dev, dev); + if (ret < 0) + goto out_unregister; + + port_dev->flags |= IFF_SLAVE; + + rcu_assign_pointer(port_dev->vrf_ptr, vrf_ptr); + cycle_netdev(port_dev); + + return 0; + +out_unregister: + netdev_rx_handler_unregister(port_dev); +out_remove: + __vrf_remove_slave(queue, slave); +out_fail: + kfree(vrf_ptr); + kfree(slave); + return ret; +} + +static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev) +{ + ASSERT_RTNL(); + + if (!dev || !port_dev || dev_net(dev) != dev_net(port_dev)) + return -ENODEV; + + if (!vrf_is_master(dev) || vrf_is_master(port_dev) || + vrf_is_slave(port_dev)) + return -EINVAL; + + return do_vrf_add_slave(dev, port_dev); +} + +/* inverse of do_vrf_add_slave */ +static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + struct slave_queue *queue = &vrf->queue; + struct net_vrf_dev *vrf_ptr = NULL; + struct slave *slave; + + vrf_ptr = rcu_dereference(dev->vrf_ptr); + RCU_INIT_POINTER(dev->vrf_ptr, NULL); + kfree(vrf_ptr); + + netdev_upper_dev_unlink(port_dev, dev); + port_dev->flags &= ~IFF_SLAVE; + + netdev_rx_handler_unregister(dev); + + cycle_netdev(port_dev); + + spin_lock_bh(&queue->lock); + + slave = __vrf_find_slave_dev(queue, port_dev); + if (slave) + __vrf_remove_slave(queue, slave); + + spin_unlock_bh(&queue->lock); + + kfree(slave); + + return 0; +} + +static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) +{ + ASSERT_RTNL(); + + if (!dev || !port_dev) + return -ENODEV; + + if (!vrf_is_master(dev)) + return -EINVAL; + + return do_vrf_del_slave(dev, port_dev); +} + +static int vrf_dev_init(struct net_device *dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + + spin_lock_init(&vrf->queue.lock); + INIT_LIST_HEAD(&vrf->queue.all_slaves); + + dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); + if (!dev->dstats) + return -ENOMEM; + + dev->flags = IFF_MASTER | IFF_NOARP; + + return 0; +} + +static void vrf_dev_uninit(struct net_device *dev) +{ + free_percpu(dev->dstats); +} + +static int vrf_dev_close(struct net_device *dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + struct slave_queue *queue = &vrf->queue; + struct list_head *this, *head; + + head = &queue->all_slaves; + list_for_each(this, head) { + struct slave *slave = list_entry(this, struct slave, list); + + slave->dev->vrf_ptr->ifindex = 0; + slave->dev->vrf_ptr->tb_id = 0; + } + + if (dev->flags & IFF_MASTER) + dev->flags &= ~IFF_UP; + + return 0; +} + +static int vrf_dev_open(struct net_device *dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + struct slave_queue *queue = &vrf->queue; + struct list_head *this, *head; + + head = &queue->all_slaves; + list_for_each(this, head) { + struct slave *slave = list_entry(this, struct slave, list); + + slave->dev->vrf_ptr->ifindex = dev->ifindex; + slave->dev->vrf_ptr->tb_id = vrf->tb_id; + } + + if (dev->flags & IFF_MASTER) + dev->flags |= IFF_UP; + + if (!vrf->tb) + return -EINVAL; + + return 0; +} + +static const struct net_device_ops vrf_netdev_ops = { + .ndo_init = vrf_dev_init, + .ndo_uninit = vrf_dev_uninit, + .ndo_open = vrf_dev_open, + .ndo_stop = vrf_dev_close, + .ndo_start_xmit = vrf_xmit, + .ndo_get_stats64 = vrf_get_stats64, + .ndo_add_slave = vrf_add_slave, + .ndo_del_slave = vrf_del_slave, +}; + +static void vrf_get_drvinfo(struct net_device *dev, + struct ethtool_drvinfo *info) +{ + strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); + strlcpy(info->version, DRV_VERSION, sizeof(info->version)); +} + +static const struct ethtool_ops vrf_ethtool_ops = { + .get_drvinfo = vrf_get_drvinfo, +}; + +static void vrf_setup(struct net_device *dev) +{ + ether_setup(dev); + + /* Initialize the device structure. */ + dev->netdev_ops = &vrf_netdev_ops; + dev->ethtool_ops = &vrf_ethtool_ops; + dev->destructor = free_netdev; + + /* Fill in device structure with ethernet-generic values. */ + eth_hw_addr_random(dev); +} + +static int vrf_validate(struct nlattr *tb[], struct nlattr *data[]) +{ + if (tb[IFLA_ADDRESS]) { + if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) + return -EINVAL; + if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) + return -EADDRNOTAVAIL; + } + return 0; +} + +static int vrf_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[]) +{ + struct net_vrf *vrf = netdev_priv(dev); + int err; + + if (!data || !data[IFLA_VRF_TABLE]) + return -EINVAL; + + vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); + + /* reserve a table for this VRF device */ + err = -ERANGE; + vrf->tb = fib_new_table(dev_net(dev), vrf->tb_id); + if (!vrf->tb) + goto out_fail; + + dev->priv_flags |= IFF_VRF_MASTER; + + err = -ENOMEM; + dev->vrf_ptr = kmalloc(sizeof(*dev->vrf_ptr), GFP_KERNEL); + if (!dev->vrf_ptr) + goto out_fail; + + dev->vrf_ptr->ifindex = dev->ifindex; + dev->vrf_ptr->tb_id = vrf->tb_id; + + err = register_netdevice(dev); + if (err < 0) + goto out_fail; + + return 0; + +out_fail: + kfree(dev->vrf_ptr); + free_netdev(dev); + return err; +} + +static void vrf_dellink(struct net_device *dev, struct list_head *head) +{ + struct net_vrf *vrf = netdev_priv(dev); + + kfree(dev->vrf_ptr); + fib_free_table(vrf->tb); +} + +static size_t vrf_nl_getsize(const struct net_device *dev) +{ + return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ +} + +static int vrf_fillinfo(struct sk_buff *skb, + const struct net_device *dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + + return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); +} + +static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { + [IFLA_VRF_TABLE] = { .type = NLA_U32 }, +}; + +static struct rtnl_link_ops vrf_link_ops __read_mostly = { + .kind = DRV_NAME, + .priv_size = sizeof(struct net_vrf), + + .get_size = vrf_nl_getsize, + .policy = vrf_nl_policy, + .validate = vrf_validate, + .fill_info = vrf_fillinfo, + + .newlink = vrf_newlink, + .dellink = vrf_dellink, + .setup = vrf_setup, + .maxtype = IFLA_VRF_MAX, +}; + +static int __init vrf_init_module(void) +{ + return rtnl_link_register(&vrf_link_ops); +} + +static void __exit vrf_cleanup_module(void) +{ + rtnl_link_unregister(&vrf_link_ops); +} + +module_init(vrf_init_module); +module_exit(vrf_cleanup_module); +MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK(DRV_NAME); +MODULE_VERSION(DRV_VERSION);