diff options
Diffstat (limited to 'net/openvswitch/vport-gre.c')
-rw-r--r-- | net/openvswitch/vport-gre.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c new file mode 100644 index 0000000..3a8d190 --- /dev/null +++ b/net/openvswitch/vport-gre.c @@ -0,0 +1,274 @@ +/* + * Copyright (c) 2007-2013 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 + */ + +#ifdef CONFIG_NET_IPGRE_DEMUX +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/if.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/if_tunnel.h> +#include <linux/if_vlan.h> +#include <linux/in.h> +#include <linux/if_vlan.h> +#include <linux/in.h> +#include <linux/in_route.h> +#include <linux/inetdevice.h> +#include <linux/jhash.h> +#include <linux/list.h> +#include <linux/kernel.h> +#include <linux/workqueue.h> +#include <linux/rculist.h> +#include <net/route.h> +#include <net/xfrm.h> + +#include <net/icmp.h> +#include <net/ip.h> +#include <net/ip_tunnels.h> +#include <net/gre.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/protocol.h> + +#include "datapath.h" +#include "vport.h" + +/* Returns the least-significant 32 bits of a __be64. */ +static __be32 be64_get_low32(__be64 x) +{ +#ifdef __BIG_ENDIAN + return (__force __be32)x; +#else + return (__force __be32)((__force u64)x >> 32); +#endif +} + +static __be16 filter_tnl_flags(__be16 flags) +{ + return flags & (TUNNEL_CSUM | TUNNEL_KEY); +} + +static struct sk_buff *__build_header(struct sk_buff *skb, + int tunnel_hlen) +{ + const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key; + struct tnl_ptk_info tpi; + + skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM)); + if (IS_ERR(skb)) + return NULL; + + tpi.flags = filter_tnl_flags(tun_key->tun_flags); + tpi.proto = htons(ETH_P_TEB); + tpi.key = be64_get_low32(tun_key->tun_id); + tpi.seq = 0; + gre_build_header(skb, &tpi, tunnel_hlen); + + return skb; +} + +static __be64 key_to_tunnel_id(__be32 key, __be32 seq) +{ +#ifdef __BIG_ENDIAN + return (__force __be64)((__force u64)seq << 32 | (__force u32)key); +#else + return (__force __be64)((__force u64)key << 32 | (__force u32)seq); +#endif +} + +/* Called with rcu_read_lock and BH disabled. */ +static int gre_rcv(struct sk_buff *skb, + const struct tnl_ptk_info *tpi) +{ + struct ovs_key_ipv4_tunnel tun_key; + struct ovs_net *ovs_net; + struct vport *vport; + __be64 key; + + ovs_net = net_generic(dev_net(skb->dev), ovs_net_id); + vport = rcu_dereference(ovs_net->vport_net.gre_vport); + if (unlikely(!vport)) + return PACKET_REJECT; + + key = key_to_tunnel_id(tpi->key, tpi->seq); + ovs_flow_tun_key_init(&tun_key, ip_hdr(skb), key, + filter_tnl_flags(tpi->flags)); + + ovs_vport_receive(vport, skb, &tun_key); + return PACKET_RCVD; +} + +static int gre_tnl_send(struct vport *vport, struct sk_buff *skb) +{ + struct net *net = ovs_dp_get_net(vport->dp); + struct flowi4 fl; + struct rtable *rt; + int min_headroom; + int tunnel_hlen; + __be16 df; + int err; + + if (unlikely(!OVS_CB(skb)->tun_key)) { + err = -EINVAL; + goto error; + } + + /* Route lookup */ + memset(&fl, 0, sizeof(fl)); + fl.daddr = OVS_CB(skb)->tun_key->ipv4_dst; + fl.saddr = OVS_CB(skb)->tun_key->ipv4_src; + fl.flowi4_tos = RT_TOS(OVS_CB(skb)->tun_key->ipv4_tos); + fl.flowi4_mark = skb->mark; + fl.flowi4_proto = IPPROTO_GRE; + + rt = ip_route_output_key(net, &fl); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + tunnel_hlen = ip_gre_calc_hlen(OVS_CB(skb)->tun_key->tun_flags); + + min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len + + tunnel_hlen + sizeof(struct iphdr) + + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0); + if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { + int head_delta = SKB_DATA_ALIGN(min_headroom - + skb_headroom(skb) + + 16); + err = pskb_expand_head(skb, max_t(int, head_delta, 0), + 0, GFP_ATOMIC); + if (unlikely(err)) + goto err_free_rt; + } + + if (vlan_tx_tag_present(skb)) { + if (unlikely(!__vlan_put_tag(skb, + skb->vlan_proto, + vlan_tx_tag_get(skb)))) { + err = -ENOMEM; + goto err_free_rt; + } + skb->vlan_tci = 0; + } + + /* Push Tunnel header. */ + skb = __build_header(skb, tunnel_hlen); + if (unlikely(!skb)) { + err = 0; + goto err_free_rt; + } + + df = OVS_CB(skb)->tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? + htons(IP_DF) : 0; + + skb->local_df = 1; + + return iptunnel_xmit(net, rt, skb, fl.saddr, + OVS_CB(skb)->tun_key->ipv4_dst, IPPROTO_GRE, + OVS_CB(skb)->tun_key->ipv4_tos, + OVS_CB(skb)->tun_key->ipv4_ttl, df); +err_free_rt: + ip_rt_put(rt); +error: + return err; +} + +static struct gre_cisco_protocol gre_protocol = { + .handler = gre_rcv, + .priority = 1, +}; + +static int gre_ports; +static int gre_init(void) +{ + int err; + + gre_ports++; + if (gre_ports > 1) + return 0; + + err = gre_cisco_register(&gre_protocol); + if (err) + pr_warn("cannot register gre protocol handler\n"); + + return err; +} + +static void gre_exit(void) +{ + gre_ports--; + if (gre_ports > 0) + return; + + gre_cisco_unregister(&gre_protocol); +} + +static const char *gre_get_name(const struct vport *vport) +{ + return vport_priv(vport); +} + +static struct vport *gre_create(const struct vport_parms *parms) +{ + struct net *net = ovs_dp_get_net(parms->dp); + struct ovs_net *ovs_net; + struct vport *vport; + int err; + + err = gre_init(); + if (err) + return ERR_PTR(err); + + ovs_net = net_generic(net, ovs_net_id); + if (ovsl_dereference(ovs_net->vport_net.gre_vport)) { + vport = ERR_PTR(-EEXIST); + goto error; + } + + vport = ovs_vport_alloc(IFNAMSIZ, &ovs_gre_vport_ops, parms); + if (IS_ERR(vport)) + goto error; + + strncpy(vport_priv(vport), parms->name, IFNAMSIZ); + rcu_assign_pointer(ovs_net->vport_net.gre_vport, vport); + return vport; + +error: + gre_exit(); + return vport; +} + +static void gre_tnl_destroy(struct vport *vport) +{ + struct net *net = ovs_dp_get_net(vport->dp); + struct ovs_net *ovs_net; + + ovs_net = net_generic(net, ovs_net_id); + + rcu_assign_pointer(ovs_net->vport_net.gre_vport, NULL); + ovs_vport_deferred_free(vport); + gre_exit(); +} + +const struct vport_ops ovs_gre_vport_ops = { + .type = OVS_VPORT_TYPE_GRE, + .create = gre_create, + .destroy = gre_tnl_destroy, + .get_name = gre_get_name, + .send = gre_tnl_send, +}; +#endif |