| /* |
| * 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 |
| */ |
| |
| #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/in_route.h> |
| #include <linux/inetdevice.h> |
| #include <linux/jhash.h> |
| #include <linux/list.h> |
| #include <linux/kernel.h> |
| #include <linux/module.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" |
| |
| static struct vport_ops ovs_gre_vport_ops; |
| |
| /* 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) |
| { |
| struct tnl_ptk_info tpi; |
| const struct ovs_key_ipv4_tunnel *tun_key; |
| |
| tun_key = &OVS_CB(skb)->egress_tun_info->tunnel; |
| |
| skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM)); |
| if (IS_ERR(skb)) |
| return skb; |
| |
| 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_tunnel_info tun_info; |
| 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_info_init(&tun_info, ip_hdr(skb), 0, 0, key, |
| filter_tnl_flags(tpi->flags), NULL, 0); |
| |
| ovs_vport_receive(vport, skb, &tun_info); |
| return PACKET_RCVD; |
| } |
| |
| /* Called with rcu_read_lock and BH disabled. */ |
| static int gre_err(struct sk_buff *skb, u32 info, |
| const struct tnl_ptk_info *tpi) |
| { |
| struct ovs_net *ovs_net; |
| struct vport *vport; |
| |
| 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; |
| else |
| 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 ovs_key_ipv4_tunnel *tun_key; |
| struct flowi4 fl; |
| struct rtable *rt; |
| int min_headroom; |
| int tunnel_hlen; |
| __be16 df; |
| int err; |
| |
| if (unlikely(!OVS_CB(skb)->egress_tun_info)) { |
| err = -EINVAL; |
| goto err_free_skb; |
| } |
| |
| tun_key = &OVS_CB(skb)->egress_tun_info->tunnel; |
| /* Route lookup */ |
| memset(&fl, 0, sizeof(fl)); |
| fl.daddr = tun_key->ipv4_dst; |
| fl.saddr = tun_key->ipv4_src; |
| fl.flowi4_tos = RT_TOS(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)) { |
| err = PTR_ERR(rt); |
| goto err_free_skb; |
| } |
| |
| tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags); |
| |
| min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len |
| + tunnel_hlen + sizeof(struct iphdr) |
| + (skb_vlan_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; |
| } |
| |
| skb = vlan_hwaccel_push_inside(skb); |
| if (unlikely(!skb)) { |
| err = -ENOMEM; |
| goto err_free_rt; |
| } |
| |
| /* Push Tunnel header. */ |
| skb = __build_header(skb, tunnel_hlen); |
| if (IS_ERR(skb)) { |
| err = PTR_ERR(skb); |
| skb = NULL; |
| goto err_free_rt; |
| } |
| |
| df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? |
| htons(IP_DF) : 0; |
| |
| skb->ignore_df = 1; |
| |
| return iptunnel_xmit(skb->sk, rt, skb, fl.saddr, |
| tun_key->ipv4_dst, IPPROTO_GRE, |
| tun_key->ipv4_tos, tun_key->ipv4_ttl, df, false); |
| err_free_rt: |
| ip_rt_put(rt); |
| err_free_skb: |
| kfree_skb(skb); |
| return err; |
| } |
| |
| static struct gre_cisco_protocol gre_protocol = { |
| .handler = gre_rcv, |
| .err_handler = gre_err, |
| .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_INIT_POINTER(ovs_net->vport_net.gre_vport, NULL); |
| ovs_vport_deferred_free(vport); |
| gre_exit(); |
| } |
| |
| static int gre_get_egress_tun_info(struct vport *vport, struct sk_buff *skb, |
| struct ovs_tunnel_info *egress_tun_info) |
| { |
| return ovs_tunnel_get_egress_info(egress_tun_info, |
| ovs_dp_get_net(vport->dp), |
| OVS_CB(skb)->egress_tun_info, |
| IPPROTO_GRE, skb->mark, 0, 0); |
| } |
| |
| static 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, |
| .get_egress_tun_info = gre_get_egress_tun_info, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init ovs_gre_tnl_init(void) |
| { |
| return ovs_vport_ops_register(&ovs_gre_vport_ops); |
| } |
| |
| static void __exit ovs_gre_tnl_exit(void) |
| { |
| ovs_vport_ops_unregister(&ovs_gre_vport_ops); |
| } |
| |
| module_init(ovs_gre_tnl_init); |
| module_exit(ovs_gre_tnl_exit); |
| |
| MODULE_DESCRIPTION("OVS: GRE switching port"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("vport-type-3"); |