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|
/*
* GENEVE: Generic Network Virtualization Encapsulation
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/hash.h>
#include <net/rtnetlink.h>
#include <net/geneve.h>
#define GENEVE_NETDEV_VER "0.6"
#define GENEVE_UDP_PORT 6081
#define GENEVE_N_VID (1u << 24)
#define GENEVE_VID_MASK (GENEVE_N_VID - 1)
#define VNI_HASH_BITS 10
#define VNI_HASH_SIZE (1<<VNI_HASH_BITS)
static bool log_ecn_error = true;
module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
/* per-network namespace private data for this module */
struct geneve_net {
struct list_head geneve_list;
struct hlist_head vni_list[VNI_HASH_SIZE];
};
/* Pseudo network device */
struct geneve_dev {
struct hlist_node hlist; /* vni hash table */
struct net *net; /* netns for packet i/o */
struct net_device *dev; /* netdev for geneve tunnel */
struct geneve_sock *sock; /* socket used for geneve tunnel */
u8 vni[3]; /* virtual network ID for tunnel */
u8 ttl; /* TTL override */
u8 tos; /* TOS override */
struct sockaddr_in remote; /* IPv4 address for link partner */
struct list_head next; /* geneve's per namespace list */
};
static int geneve_net_id;
static inline __u32 geneve_net_vni_hash(u8 vni[3])
{
__u32 vnid;
vnid = (vni[0] << 16) | (vni[1] << 8) | vni[2];
return hash_32(vnid, VNI_HASH_BITS);
}
/* geneve receive/decap routine */
static void geneve_rx(struct geneve_sock *gs, struct sk_buff *skb)
{
struct genevehdr *gnvh = geneve_hdr(skb);
struct geneve_dev *dummy, *geneve = NULL;
struct geneve_net *gn;
struct iphdr *iph = NULL;
struct pcpu_sw_netstats *stats;
struct hlist_head *vni_list_head;
int err = 0;
__u32 hash;
iph = ip_hdr(skb); /* Still outer IP header... */
gn = gs->rcv_data;
/* Find the device for this VNI */
hash = geneve_net_vni_hash(gnvh->vni);
vni_list_head = &gn->vni_list[hash];
hlist_for_each_entry_rcu(dummy, vni_list_head, hlist) {
if (!memcmp(gnvh->vni, dummy->vni, sizeof(dummy->vni)) &&
iph->saddr == dummy->remote.sin_addr.s_addr) {
geneve = dummy;
break;
}
}
if (!geneve)
goto drop;
/* Drop packets w/ critical options,
* since we don't support any...
*/
if (gnvh->critical)
goto drop;
skb_reset_mac_header(skb);
skb_scrub_packet(skb, !net_eq(geneve->net, dev_net(geneve->dev)));
skb->protocol = eth_type_trans(skb, geneve->dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
/* Ignore packet loops (and multicast echo) */
if (ether_addr_equal(eth_hdr(skb)->h_source, geneve->dev->dev_addr))
goto drop;
skb_reset_network_header(skb);
iph = ip_hdr(skb); /* Now inner IP header... */
err = IP_ECN_decapsulate(iph, skb);
if (unlikely(err)) {
if (log_ecn_error)
net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
&iph->saddr, iph->tos);
if (err > 1) {
++geneve->dev->stats.rx_frame_errors;
++geneve->dev->stats.rx_errors;
goto drop;
}
}
stats = this_cpu_ptr(geneve->dev->tstats);
u64_stats_update_begin(&stats->syncp);
stats->rx_packets++;
stats->rx_bytes += skb->len;
u64_stats_update_end(&stats->syncp);
netif_rx(skb);
return;
drop:
/* Consume bad packet */
kfree_skb(skb);
}
/* Setup stats when device is created */
static int geneve_init(struct net_device *dev)
{
dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
if (!dev->tstats)
return -ENOMEM;
return 0;
}
static void geneve_uninit(struct net_device *dev)
{
free_percpu(dev->tstats);
}
static int geneve_open(struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
struct net *net = geneve->net;
struct geneve_net *gn = net_generic(geneve->net, geneve_net_id);
struct geneve_sock *gs;
gs = geneve_sock_add(net, htons(GENEVE_UDP_PORT), geneve_rx, gn,
false, false);
if (IS_ERR(gs))
return PTR_ERR(gs);
geneve->sock = gs;
return 0;
}
static int geneve_stop(struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs = geneve->sock;
geneve_sock_release(gs);
return 0;
}
static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs = geneve->sock;
struct rtable *rt = NULL;
const struct iphdr *iip; /* interior IP header */
struct flowi4 fl4;
int err;
__be16 sport;
__u8 tos, ttl;
iip = ip_hdr(skb);
skb_reset_mac_header(skb);
/* TODO: port min/max limits should be configurable */
sport = udp_flow_src_port(dev_net(dev), skb, 0, 0, true);
tos = geneve->tos;
if (tos == 1)
tos = ip_tunnel_get_dsfield(iip, skb);
memset(&fl4, 0, sizeof(fl4));
fl4.flowi4_tos = RT_TOS(tos);
fl4.daddr = geneve->remote.sin_addr.s_addr;
rt = ip_route_output_key(geneve->net, &fl4);
if (IS_ERR(rt)) {
netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
dev->stats.tx_carrier_errors++;
goto tx_error;
}
if (rt->dst.dev == dev) { /* is this necessary? */
netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
dev->stats.collisions++;
goto rt_tx_error;
}
tos = ip_tunnel_ecn_encap(tos, iip, skb);
ttl = geneve->ttl;
if (!ttl && IN_MULTICAST(ntohl(fl4.daddr)))
ttl = 1;
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
/* no need to handle local destination and encap bypass...yet... */
err = geneve_xmit_skb(gs, rt, skb, fl4.saddr, fl4.daddr,
tos, ttl, 0, sport, htons(GENEVE_UDP_PORT), 0,
geneve->vni, 0, NULL, false,
!net_eq(
|