linux/drivers/net/ipvlan/ipvlan_core.c
WANG Cong 0fba37a3af ipvlan: use rcu_deference_bh() in ipvlan_queue_xmit()
In tx path rcu_read_lock_bh() is held, so we need rcu_deference_bh().
This fixes the following warning:

 ===============================
 [ INFO: suspicious RCU usage. ]
 4.1.0-rc1+ #1007 Not tainted
 -------------------------------
 drivers/net/ipvlan/ipvlan.h:106 suspicious rcu_dereference_check() usage!

 other info that might help us debug this:

 rcu_scheduler_active = 1, debug_locks = 0
 1 lock held by dhclient/1076:
  #0:  (rcu_read_lock_bh){......}, at: [<ffffffff817e8d84>] rcu_lock_acquire+0x0/0x26

 stack backtrace:
 CPU: 2 PID: 1076 Comm: dhclient Not tainted 4.1.0-rc1+ #1007
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000001 ffff8800d381bac8 ffffffff81a4154f 000000003c1a3c19
  ffff8800d4d0a690 ffff8800d381baf8 ffffffff810b849f ffff880117d41148
  ffff880117d40000 ffff880117d40068 0000000000000156 ffff8800d381bb18
 Call Trace:
  [<ffffffff81a4154f>] dump_stack+0x4c/0x65
  [<ffffffff810b849f>] lockdep_rcu_suspicious+0x107/0x110
  [<ffffffff8165a522>] ipvlan_port_get_rcu+0x47/0x4e
  [<ffffffff8165ad14>] ipvlan_queue_xmit+0x35/0x450
  [<ffffffff817ea45d>] ? rcu_read_unlock+0x3e/0x5f
  [<ffffffff810a20bf>] ? local_clock+0x19/0x22
  [<ffffffff810b4781>] ? __lock_is_held+0x39/0x52
  [<ffffffff8165b64c>] ipvlan_start_xmit+0x1b/0x44
  [<ffffffff817edf7f>] dev_hard_start_xmit+0x2ae/0x467
  [<ffffffff817ee642>] __dev_queue_xmit+0x50a/0x60c
  [<ffffffff817ee7a7>] dev_queue_xmit_sk+0x13/0x15
  [<ffffffff81997596>] dev_queue_xmit+0x10/0x12
  [<ffffffff8199b41c>] packet_sendmsg+0xb6b/0xbdf
  [<ffffffff810b5ea7>] ? mark_lock+0x2e/0x226
  [<ffffffff810a1fcc>] ? sched_clock_cpu+0x9e/0xb7
  [<ffffffff817d56f9>] sock_sendmsg_nosec+0x12/0x1d
  [<ffffffff817d7257>] sock_sendmsg+0x29/0x2e
  [<ffffffff817d72cc>] sock_write_iter+0x70/0x91
  [<ffffffff81199563>] __vfs_write+0x7e/0xa7
  [<ffffffff811996bc>] vfs_write+0x92/0xe8
  [<ffffffff811997d7>] SyS_write+0x47/0x7e
  [<ffffffff81a4d517>] system_call_fastpath+0x12/0x6f

Fixes: 2ad7bf3638 ("ipvlan: Initial check-in of the IPVLAN driver.")
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15 21:33:40 -07:00

654 lines
15 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));
}
static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
unsigned int len, bool success, bool mcast)
{
if (!ipvlan)
return;
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);
}
}
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;
}
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 hlocal, dlocal;
__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) {
ethh = eth_hdr(skb);
hlocal = ether_addr_equal(ethh->h_source, port->dev->dev_addr);
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;
dlocal = false;
rcu_read_lock();
list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
if (hlocal && (ipvlan->dev == skb->dev)) {
dlocal = true;
continue;
}
if (!test_bit(mac_hash, ipvlan->mac_filters))
continue;
ret = NET_RX_DROP;
len = skb->len + ETH_HLEN;
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb)
goto acct;
nskb->pkt_type = pkt_type;
nskb->dev = ipvlan->dev;
if (hlocal)
ret = dev_forward_skb(ipvlan->dev, nskb);
else
ret = netif_rx(nskb);
acct:
ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
}
rcu_read_unlock();
if (dlocal) {
/* If the packet originated here, send it out. */
skb->dev = port->dev;
skb->pkt_type = pkt_type;
dev_queue_xmit(skb);
} else {
kfree_skb(skb);
}
}
}
static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
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;
len = skb->len + ETH_HLEN;
if (unlikely(!(dev->flags & IFF_UP))) {
kfree_skb(skb);
goto out;
}
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
goto out;
skb->dev = dev;
skb->pkt_type = PACKET_HOST;
if (local) {
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 rtable *rt;
int err, ret = NET_XMIT_DROP;
struct flowi4 fl4 = {
.flowi4_oif = dev_get_iflink(dev),
.flowi4_tos = RT_TOS(ip4h->tos),
.flowi4_flags = FLOWI_FLAG_ANYSRC,
.daddr = ip4h->daddr,
.saddr = ip4h->saddr,
};
rt = ip_route_output_flow(dev_net(dev), &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_drop(skb);
skb_dst_set(skb, &rt->dst);
err = ip_local_out(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 dst_entry *dst;
int err, ret = NET_XMIT_DROP;
struct flowi6 fl6 = {
.flowi6_iif = skb->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(dev_net(dev), NULL, &fl6);
if (dst->error) {
ret = dst->error;
dst_release(dst);
goto err;
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
err = ip6_local_out(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,
const struct ipvl_dev *ipvlan)
{
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)
{
if (skb->protocol == htons(ETH_P_PAUSE)) {
kfree_skb(skb);
return;
}
spin_lock(&port->backlog.lock);
if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
__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:
skb->dev = ipvlan->phy_dev;
return ipvlan_process_outbound(skb, ipvlan);
}
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_multicast_enqueue(ipvlan->port, skb);
return NET_XMIT_SUCCESS;
}
skb->dev = 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:
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, skb, 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_multicast_enqueue(port, nskb);
}
} 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, skb, 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);
}
/* Should not reach here */
WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
port->mode);
kfree_skb(skb);
return NET_RX_DROP;
}