linux/drivers/net/ipvlan/ipvlan_core.c
Sainath Grandhi 235a9d89da ipvtap: IP-VLAN based tap driver
This patch adds a tap character device driver that is based on the
IP-VLAN network interface, called ipvtap. An ipvtap device can be created
in the same way as an ipvlan device, using 'type ipvtap', and then accessed
using the tap user space interface.

Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11 20:59:41 -05:00

783 lines
18 KiB
C

/* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
*
* 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 "ipvlan.h"
static u32 ipvlan_jhash_secret __read_mostly;
void ipvlan_init_secret(void)
{
net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
}
void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
unsigned int len, bool success, bool mcast)
{
if (likely(success)) {
struct ipvl_pcpu_stats *pcptr;
pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
u64_stats_update_begin(&pcptr->syncp);
pcptr->rx_pkts++;
pcptr->rx_bytes += len;
if (mcast)
pcptr->rx_mcast++;
u64_stats_update_end(&pcptr->syncp);
} else {
this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
}
}
EXPORT_SYMBOL_GPL(ipvlan_count_rx);
static u8 ipvlan_get_v6_hash(const void *iaddr)
{
const struct in6_addr *ip6_addr = iaddr;
return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
IPVLAN_HASH_MASK;
}
static u8 ipvlan_get_v4_hash(const void *iaddr)
{
const struct in_addr *ip4_addr = iaddr;
return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
IPVLAN_HASH_MASK;
}
static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
const void *iaddr, bool is_v6)
{
struct ipvl_addr *addr;
u8 hash;
hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
ipvlan_get_v4_hash(iaddr);
hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode) {
if (is_v6 && addr->atype == IPVL_IPV6 &&
ipv6_addr_equal(&addr->ip6addr, iaddr))
return addr;
else if (!is_v6 && addr->atype == IPVL_IPV4 &&
addr->ip4addr.s_addr ==
((struct in_addr *)iaddr)->s_addr)
return addr;
}
return NULL;
}
void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
{
struct ipvl_port *port = ipvlan->port;
u8 hash;
hash = (addr->atype == IPVL_IPV6) ?
ipvlan_get_v6_hash(&addr->ip6addr) :
ipvlan_get_v4_hash(&addr->ip4addr);
if (hlist_unhashed(&addr->hlnode))
hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
}
void ipvlan_ht_addr_del(struct ipvl_addr *addr)
{
hlist_del_init_rcu(&addr->hlnode);
}
struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
const void *iaddr, bool is_v6)
{
struct ipvl_addr *addr;
list_for_each_entry(addr, &ipvlan->addrs, anode) {
if ((is_v6 && addr->atype == IPVL_IPV6 &&
ipv6_addr_equal(&addr->ip6addr, iaddr)) ||
(!is_v6 && addr->atype == IPVL_IPV4 &&
addr->ip4addr.s_addr == ((struct in_addr *)iaddr)->s_addr))
return addr;
}
return NULL;
}
bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
{
struct ipvl_dev *ipvlan;
ASSERT_RTNL();
list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
if (ipvlan_find_addr(ipvlan, iaddr, is_v6))
return true;
}
return false;
}
static void *ipvlan_get_L3_hdr(struct sk_buff *skb, int *type)
{
void *lyr3h = NULL;
switch (skb->protocol) {
case htons(ETH_P_ARP): {
struct arphdr *arph;
if (unlikely(!pskb_may_pull(skb, sizeof(*arph))))
return NULL;
arph = arp_hdr(skb);
*type = IPVL_ARP;
lyr3h = arph;
break;
}
case htons(ETH_P_IP): {
u32 pktlen;
struct iphdr *ip4h;
if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
return NULL;
ip4h = ip_hdr(skb);
pktlen = ntohs(ip4h->tot_len);
if (ip4h->ihl < 5 || ip4h->version != 4)
return NULL;
if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
return NULL;
*type = IPVL_IPV4;
lyr3h = ip4h;
break;
}
case htons(ETH_P_IPV6): {
struct ipv6hdr *ip6h;
if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
return NULL;
ip6h = ipv6_hdr(skb);
if (ip6h->version != 6)
return NULL;
*type = IPVL_IPV6;
lyr3h = ip6h;
/* Only Neighbour Solicitation pkts need different treatment */
if (ipv6_addr_any(&ip6h->saddr) &&
ip6h->nexthdr == NEXTHDR_ICMP) {
*type = IPVL_ICMPV6;
lyr3h = ip6h + 1;
}
break;
}
default:
return NULL;
}
return lyr3h;
}
unsigned int ipvlan_mac_hash(const unsigned char *addr)
{
u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
ipvlan_jhash_secret);
return hash & IPVLAN_MAC_FILTER_MASK;
}
void ipvlan_process_multicast(struct work_struct *work)
{
struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
struct ethhdr *ethh;
struct ipvl_dev *ipvlan;
struct sk_buff *skb, *nskb;
struct sk_buff_head list;
unsigned int len;
unsigned int mac_hash;
int ret;
u8 pkt_type;
bool tx_pkt;
__skb_queue_head_init(&list);
spin_lock_bh(&port->backlog.lock);
skb_queue_splice_tail_init(&port->backlog, &list);
spin_unlock_bh(&port->backlog.lock);
while ((skb = __skb_dequeue(&list)) != NULL) {
struct net_device *dev = skb->dev;
bool consumed = false;
ethh = eth_hdr(skb);
tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
mac_hash = ipvlan_mac_hash(ethh->h_dest);
if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
pkt_type = PACKET_BROADCAST;
else
pkt_type = PACKET_MULTICAST;
rcu_read_lock();
list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
if (tx_pkt && (ipvlan->dev == skb->dev))
continue;
if (!test_bit(mac_hash, ipvlan->mac_filters))
continue;
if (!(ipvlan->dev->flags & IFF_UP))
continue;
ret = NET_RX_DROP;
len = skb->len + ETH_HLEN;
nskb = skb_clone(skb, GFP_ATOMIC);
local_bh_disable();
if (nskb) {
consumed = true;
nskb->pkt_type = pkt_type;
nskb->dev = ipvlan->dev;
if (tx_pkt)
ret = dev_forward_skb(ipvlan->dev, nskb);
else
ret = netif_rx(nskb);
}
ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
local_bh_enable();
}
rcu_read_unlock();
if (tx_pkt) {
/* If the packet originated here, send it out. */
skb->dev = port->dev;
skb->pkt_type = pkt_type;
dev_queue_xmit(skb);
} else {
if (consumed)
consume_skb(skb);
else
kfree_skb(skb);
}
if (dev)
dev_put(dev);
}
}
static void ipvlan_skb_crossing_ns(struct sk_buff *skb, struct net_device *dev)
{
bool xnet = true;
if (dev)
xnet = !net_eq(dev_net(skb->dev), dev_net(dev));
skb_scrub_packet(skb, xnet);
if (dev)
skb->dev = dev;
}
static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
bool local)
{
struct ipvl_dev *ipvlan = addr->master;
struct net_device *dev = ipvlan->dev;
unsigned int len;
rx_handler_result_t ret = RX_HANDLER_CONSUMED;
bool success = false;
struct sk_buff *skb = *pskb;
len = skb->len + ETH_HLEN;
/* Only packets exchanged between two local slaves need to have
* device-up check as well as skb-share check.
*/
if (local) {
if (unlikely(!(dev->flags & IFF_UP))) {
kfree_skb(skb);
goto out;
}
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
goto out;
*pskb = skb;
}
ipvlan_skb_crossing_ns(skb, dev);
if (local) {
skb->pkt_type = PACKET_HOST;
if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
success = true;
} else {
ret = RX_HANDLER_ANOTHER;
success = true;
}
out:
ipvlan_count_rx(ipvlan, len, success, false);
return ret;
}
static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
void *lyr3h, int addr_type,
bool use_dest)
{
struct ipvl_addr *addr = NULL;
if (addr_type == IPVL_IPV6) {
struct ipv6hdr *ip6h;
struct in6_addr *i6addr;
ip6h = (struct ipv6hdr *)lyr3h;
i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
addr = ipvlan_ht_addr_lookup(port, i6addr, true);
} else if (addr_type == IPVL_ICMPV6) {
struct nd_msg *ndmh;
struct in6_addr *i6addr;
/* Make sure that the NeighborSolicitation ICMPv6 packets
* are handled to avoid DAD issue.
*/
ndmh = (struct nd_msg *)lyr3h;
if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
i6addr = &ndmh->target;
addr = ipvlan_ht_addr_lookup(port, i6addr, true);
}
} else if (addr_type == IPVL_IPV4) {
struct iphdr *ip4h;
__be32 *i4addr;
ip4h = (struct iphdr *)lyr3h;
i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
addr = ipvlan_ht_addr_lookup(port, i4addr, false);
} else if (addr_type == IPVL_ARP) {
struct arphdr *arph;
unsigned char *arp_ptr;
__be32 dip;
arph = (struct arphdr *)lyr3h;
arp_ptr = (unsigned char *)(arph + 1);
if (use_dest)
arp_ptr += (2 * port->dev->addr_len) + 4;
else
arp_ptr += port->dev->addr_len;
memcpy(&dip, arp_ptr, 4);
addr = ipvlan_ht_addr_lookup(port, &dip, false);
}
return addr;
}
static int ipvlan_process_v4_outbound(struct sk_buff *skb)
{
const struct iphdr *ip4h = ip_hdr(skb);
struct net_device *dev = skb->dev;
struct net *net = dev_net(dev);
struct rtable *rt;
int err, ret = NET_XMIT_DROP;
struct flowi4 fl4 = {
.flowi4_oif = dev->ifindex,
.flowi4_tos = RT_TOS(ip4h->tos),
.flowi4_flags = FLOWI_FLAG_ANYSRC,
.daddr = ip4h->daddr,
.saddr = ip4h->saddr,
};
rt = ip_route_output_flow(net, &fl4, NULL);
if (IS_ERR(rt))
goto err;
if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
ip_rt_put(rt);
goto err;
}
skb_dst_set(skb, &rt->dst);
err = ip_local_out(net, skb->sk, skb);
if (unlikely(net_xmit_eval(err)))
dev->stats.tx_errors++;
else
ret = NET_XMIT_SUCCESS;
goto out;
err:
dev->stats.tx_errors++;
kfree_skb(skb);
out:
return ret;
}
static int ipvlan_process_v6_outbound(struct sk_buff *skb)
{
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct net_device *dev = skb->dev;
struct net *net = dev_net(dev);
struct dst_entry *dst;
int err, ret = NET_XMIT_DROP;
struct flowi6 fl6 = {
.flowi6_iif = dev->ifindex,
.daddr = ip6h->daddr,
.saddr = ip6h->saddr,
.flowi6_flags = FLOWI_FLAG_ANYSRC,
.flowlabel = ip6_flowinfo(ip6h),
.flowi6_mark = skb->mark,
.flowi6_proto = ip6h->nexthdr,
};
dst = ip6_route_output(net, NULL, &fl6);
if (dst->error) {
ret = dst->error;
dst_release(dst);
goto err;
}
skb_dst_set(skb, dst);
err = ip6_local_out(net, skb->sk, skb);
if (unlikely(net_xmit_eval(err)))
dev->stats.tx_errors++;
else
ret = NET_XMIT_SUCCESS;
goto out;
err:
dev->stats.tx_errors++;
kfree_skb(skb);
out:
return ret;
}
static int ipvlan_process_outbound(struct sk_buff *skb)
{
struct ethhdr *ethh = eth_hdr(skb);
int ret = NET_XMIT_DROP;
/* In this mode we dont care about multicast and broadcast traffic */
if (is_multicast_ether_addr(ethh->h_dest)) {
pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
ntohs(skb->protocol));
kfree_skb(skb);
goto out;
}
/* The ipvlan is a pseudo-L2 device, so the packets that we receive
* will have L2; which need to discarded and processed further
* in the net-ns of the main-device.
*/
if (skb_mac_header_was_set(skb)) {
skb_pull(skb, sizeof(*ethh));
skb->mac_header = (typeof(skb->mac_header))~0U;
skb_reset_network_header(skb);
}
if (skb->protocol == htons(ETH_P_IPV6))
ret = ipvlan_process_v6_outbound(skb);
else if (skb->protocol == htons(ETH_P_IP))
ret = ipvlan_process_v4_outbound(skb);
else {
pr_warn_ratelimited("Dropped outbound packet type=%x\n",
ntohs(skb->protocol));
kfree_skb(skb);
}
out:
return ret;
}
static void ipvlan_multicast_enqueue(struct ipvl_port *port,
struct sk_buff *skb, bool tx_pkt)
{
if (skb->protocol == htons(ETH_P_PAUSE)) {
kfree_skb(skb);
return;
}
/* Record that the deferred packet is from TX or RX path. By
* looking at mac-addresses on packet will lead to erronus decisions.
* (This would be true for a loopback-mode on master device or a
* hair-pin mode of the switch.)
*/
IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;
spin_lock(&port->backlog.lock);
if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
if (skb->dev)
dev_hold(skb->dev);
__skb_queue_tail(&port->backlog, skb);
spin_unlock(&port->backlog.lock);
schedule_work(&port->wq);
} else {
spin_unlock(&port->backlog.lock);
atomic_long_inc(&skb->dev->rx_dropped);
kfree_skb(skb);
}
}
static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
{
const struct ipvl_dev *ipvlan = netdev_priv(dev);
void *lyr3h;
struct ipvl_addr *addr;
int addr_type;
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (!lyr3h)
goto out;
addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
if (addr)
return ipvlan_rcv_frame(addr, &skb, true);
out:
ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
return ipvlan_process_outbound(skb);
}
static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
{
const struct ipvl_dev *ipvlan = netdev_priv(dev);
struct ethhdr *eth = eth_hdr(skb);
struct ipvl_addr *addr;
void *lyr3h;
int addr_type;
if (ether_addr_equal(eth->h_dest, eth->h_source)) {
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (lyr3h) {
addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
if (addr)
return ipvlan_rcv_frame(addr, &skb, true);
}
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
return NET_XMIT_DROP;
/* Packet definitely does not belong to any of the
* virtual devices, but the dest is local. So forward
* the skb for the main-dev. At the RX side we just return
* RX_PASS for it to be processed further on the stack.
*/
return dev_forward_skb(ipvlan->phy_dev, skb);
} else if (is_multicast_ether_addr(eth->h_dest)) {
ipvlan_skb_crossing_ns(skb, NULL);
ipvlan_multicast_enqueue(ipvlan->port, skb, true);
return NET_XMIT_SUCCESS;
}
ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
return dev_queue_xmit(skb);
}
int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ipvl_dev *ipvlan = netdev_priv(dev);
struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
if (!port)
goto out;
if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
goto out;
switch(port->mode) {
case IPVLAN_MODE_L2:
return ipvlan_xmit_mode_l2(skb, dev);
case IPVLAN_MODE_L3:
case IPVLAN_MODE_L3S:
return ipvlan_xmit_mode_l3(skb, dev);
}
/* Should not reach here */
WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
port->mode);
out:
kfree_skb(skb);
return NET_XMIT_DROP;
}
static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
{
struct ethhdr *eth = eth_hdr(skb);
struct ipvl_addr *addr;
void *lyr3h;
int addr_type;
if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (!lyr3h)
return true;
addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
if (addr)
return false;
}
return true;
}
static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
struct ipvl_port *port)
{
void *lyr3h;
int addr_type;
struct ipvl_addr *addr;
struct sk_buff *skb = *pskb;
rx_handler_result_t ret = RX_HANDLER_PASS;
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (!lyr3h)
goto out;
addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
if (addr)
ret = ipvlan_rcv_frame(addr, pskb, false);
out:
return ret;
}
static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
struct ipvl_port *port)
{
struct sk_buff *skb = *pskb;
struct ethhdr *eth = eth_hdr(skb);
rx_handler_result_t ret = RX_HANDLER_PASS;
void *lyr3h;
int addr_type;
if (is_multicast_ether_addr(eth->h_dest)) {
if (ipvlan_external_frame(skb, port)) {
struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
/* External frames are queued for device local
* distribution, but a copy is given to master
* straight away to avoid sending duplicates later
* when work-queue processes this frame. This is
* achieved by returning RX_HANDLER_PASS.
*/
if (nskb) {
ipvlan_skb_crossing_ns(nskb, NULL);
ipvlan_multicast_enqueue(port, nskb, false);
}
}
} else {
struct ipvl_addr *addr;
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (!lyr3h)
return ret;
addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
if (addr)
ret = ipvlan_rcv_frame(addr, pskb, false);
}
return ret;
}
rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
if (!port)
return RX_HANDLER_PASS;
switch (port->mode) {
case IPVLAN_MODE_L2:
return ipvlan_handle_mode_l2(pskb, port);
case IPVLAN_MODE_L3:
return ipvlan_handle_mode_l3(pskb, port);
case IPVLAN_MODE_L3S:
return RX_HANDLER_PASS;
}
/* Should not reach here */
WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
port->mode);
kfree_skb(skb);
return RX_HANDLER_CONSUMED;
}
static struct ipvl_addr *ipvlan_skb_to_addr(struct sk_buff *skb,
struct net_device *dev)
{
struct ipvl_addr *addr = NULL;
struct ipvl_port *port;
void *lyr3h;
int addr_type;
if (!dev || !netif_is_ipvlan_port(dev))
goto out;
port = ipvlan_port_get_rcu(dev);
if (!port || port->mode != IPVLAN_MODE_L3S)
goto out;
lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
if (!lyr3h)
goto out;
addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
out:
return addr;
}
struct sk_buff *ipvlan_l3_rcv(struct net_device *dev, struct sk_buff *skb,
u16 proto)
{
struct ipvl_addr *addr;
struct net_device *sdev;
addr = ipvlan_skb_to_addr(skb, dev);
if (!addr)
goto out;
sdev = addr->master->dev;
switch (proto) {
case AF_INET:
{
int err;
struct iphdr *ip4h = ip_hdr(skb);
err = ip_route_input_noref(skb, ip4h->daddr, ip4h->saddr,
ip4h->tos, sdev);
if (unlikely(err))
goto out;
break;
}
case AF_INET6:
{
struct dst_entry *dst;
struct ipv6hdr *ip6h = ipv6_hdr(skb);
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct flowi6 fl6 = {
.flowi6_iif = sdev->ifindex,
.daddr = ip6h->daddr,
.saddr = ip6h->saddr,
.flowlabel = ip6_flowinfo(ip6h),
.flowi6_mark = skb->mark,
.flowi6_proto = ip6h->nexthdr,
};
skb_dst_drop(skb);
dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6, flags);
skb_dst_set(skb, dst);
break;
}
default:
break;
}
out:
return skb;
}
unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
struct ipvl_addr *addr;
unsigned int len;
addr = ipvlan_skb_to_addr(skb, skb->dev);
if (!addr)
goto out;
skb->dev = addr->master->dev;
len = skb->len + ETH_HLEN;
ipvlan_count_rx(addr->master, len, true, false);
out:
return NF_ACCEPT;
}