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alistair23-linux/net/core/netpoll.c
Linus Torvalds 496322bc91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 
Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a9 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...
2013-07-09 18:24:39 -07:00

1313 lines
30 KiB
C
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/*
* Common framework for low-level network console, dump, and debugger code
*
* Sep 8 2003 Matt Mackall <mpm@selenic.com>
*
* based on the netconsole code from:
*
* Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
* Copyright (C) 2002 Red Hat, Inc.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/string.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/inet.h>
#include <linux/interrupt.h>
#include <linux/netpoll.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/if_vlan.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/addrconf.h>
#include <net/ndisc.h>
#include <net/ip6_checksum.h>
#include <asm/unaligned.h>
#include <trace/events/napi.h>
/*
* We maintain a small pool of fully-sized skbs, to make sure the
* message gets out even in extreme OOM situations.
*/
#define MAX_UDP_CHUNK 1460
#define MAX_SKBS 32
static struct sk_buff_head skb_pool;
static atomic_t trapped;
DEFINE_STATIC_SRCU(netpoll_srcu);
#define USEC_PER_POLL 50
#define NETPOLL_RX_ENABLED 1
#define NETPOLL_RX_DROP 2
#define MAX_SKB_SIZE \
(sizeof(struct ethhdr) + \
sizeof(struct iphdr) + \
sizeof(struct udphdr) + \
MAX_UDP_CHUNK)
static void zap_completion_queue(void);
static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
static void netpoll_async_cleanup(struct work_struct *work);
static unsigned int carrier_timeout = 4;
module_param(carrier_timeout, uint, 0644);
#define np_info(np, fmt, ...) \
pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
#define np_err(np, fmt, ...) \
pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
#define np_notice(np, fmt, ...) \
pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
static void queue_process(struct work_struct *work)
{
struct netpoll_info *npinfo =
container_of(work, struct netpoll_info, tx_work.work);
struct sk_buff *skb;
unsigned long flags;
while ((skb = skb_dequeue(&npinfo->txq))) {
struct net_device *dev = skb->dev;
const struct net_device_ops *ops = dev->netdev_ops;
struct netdev_queue *txq;
if (!netif_device_present(dev) || !netif_running(dev)) {
__kfree_skb(skb);
continue;
}
txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
local_irq_save(flags);
__netif_tx_lock(txq, smp_processor_id());
if (netif_xmit_frozen_or_stopped(txq) ||
ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
skb_queue_head(&npinfo->txq, skb);
__netif_tx_unlock(txq);
local_irq_restore(flags);
schedule_delayed_work(&npinfo->tx_work, HZ/10);
return;
}
__netif_tx_unlock(txq);
local_irq_restore(flags);
}
}
static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, __be32 saddr, __be32 daddr)
{
__wsum psum;
if (uh->check == 0 || skb_csum_unnecessary(skb))
return 0;
psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
if (skb->ip_summed == CHECKSUM_COMPLETE &&
!csum_fold(csum_add(psum, skb->csum)))
return 0;
skb->csum = psum;
return __skb_checksum_complete(skb);
}
/*
* Check whether delayed processing was scheduled for our NIC. If so,
* we attempt to grab the poll lock and use ->poll() to pump the card.
* If this fails, either we've recursed in ->poll() or it's already
* running on another CPU.
*
* Note: we don't mask interrupts with this lock because we're using
* trylock here and interrupts are already disabled in the softirq
* case. Further, we test the poll_owner to avoid recursion on UP
* systems where the lock doesn't exist.
*
* In cases where there is bi-directional communications, reading only
* one message at a time can lead to packets being dropped by the
* network adapter, forcing superfluous retries and possibly timeouts.
* Thus, we set our budget to greater than 1.
*/
static int poll_one_napi(struct netpoll_info *npinfo,
struct napi_struct *napi, int budget)
{
int work;
/* net_rx_action's ->poll() invocations and our's are
* synchronized by this test which is only made while
* holding the napi->poll_lock.
*/
if (!test_bit(NAPI_STATE_SCHED, &napi->state))
return budget;
npinfo->rx_flags |= NETPOLL_RX_DROP;
atomic_inc(&trapped);
set_bit(NAPI_STATE_NPSVC, &napi->state);
work = napi->poll(napi, budget);
trace_napi_poll(napi);
clear_bit(NAPI_STATE_NPSVC, &napi->state);
atomic_dec(&trapped);
npinfo->rx_flags &= ~NETPOLL_RX_DROP;
return budget - work;
}
static void poll_napi(struct net_device *dev)
{
struct napi_struct *napi;
int budget = 16;
list_for_each_entry(napi, &dev->napi_list, dev_list) {
if (napi->poll_owner != smp_processor_id() &&
spin_trylock(&napi->poll_lock)) {
budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
napi, budget);
spin_unlock(&napi->poll_lock);
if (!budget)
break;
}
}
}
static void service_neigh_queue(struct netpoll_info *npi)
{
if (npi) {
struct sk_buff *skb;
while ((skb = skb_dequeue(&npi->neigh_tx)))
netpoll_neigh_reply(skb, npi);
}
}
static void netpoll_poll_dev(struct net_device *dev)
{
const struct net_device_ops *ops;
struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
/* Don't do any rx activity if the dev_lock mutex is held
* the dev_open/close paths use this to block netpoll activity
* while changing device state
*/
if (down_trylock(&ni->dev_lock))
return;
if (!netif_running(dev)) {
up(&ni->dev_lock);
return;
}
ops = dev->netdev_ops;
if (!ops->ndo_poll_controller) {
up(&ni->dev_lock);
return;
}
/* Process pending work on NIC */
ops->ndo_poll_controller(dev);
poll_napi(dev);
up(&ni->dev_lock);
if (dev->flags & IFF_SLAVE) {
if (ni) {
struct net_device *bond_dev;
struct sk_buff *skb;
struct netpoll_info *bond_ni;
bond_dev = netdev_master_upper_dev_get_rcu(dev);
bond_ni = rcu_dereference_bh(bond_dev->npinfo);
while ((skb = skb_dequeue(&ni->neigh_tx))) {
skb->dev = bond_dev;
skb_queue_tail(&bond_ni->neigh_tx, skb);
}
}
}
service_neigh_queue(ni);
zap_completion_queue();
}
void netpoll_rx_disable(struct net_device *dev)
{
struct netpoll_info *ni;
int idx;
might_sleep();
idx = srcu_read_lock(&netpoll_srcu);
ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
if (ni)
down(&ni->dev_lock);
srcu_read_unlock(&netpoll_srcu, idx);
}
EXPORT_SYMBOL(netpoll_rx_disable);
void netpoll_rx_enable(struct net_device *dev)
{
struct netpoll_info *ni;
rcu_read_lock();
ni = rcu_dereference(dev->npinfo);
if (ni)
up(&ni->dev_lock);
rcu_read_unlock();
}
EXPORT_SYMBOL(netpoll_rx_enable);
static void refill_skbs(void)
{
struct sk_buff *skb;
unsigned long flags;
spin_lock_irqsave(&skb_pool.lock, flags);
while (skb_pool.qlen < MAX_SKBS) {
skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
if (!skb)
break;
__skb_queue_tail(&skb_pool, skb);
}
spin_unlock_irqrestore(&skb_pool.lock, flags);
}
static void zap_completion_queue(void)
{
unsigned long flags;
struct softnet_data *sd = &get_cpu_var(softnet_data);
if (sd->completion_queue) {
struct sk_buff *clist;
local_irq_save(flags);
clist = sd->completion_queue;
sd->completion_queue = NULL;
local_irq_restore(flags);
while (clist != NULL) {
struct sk_buff *skb = clist;
clist = clist->next;
if (skb->destructor) {
atomic_inc(&skb->users);
dev_kfree_skb_any(skb); /* put this one back */
} else {
__kfree_skb(skb);
}
}
}
put_cpu_var(softnet_data);
}
static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
{
int count = 0;
struct sk_buff *skb;
zap_completion_queue();
refill_skbs();
repeat:
skb = alloc_skb(len, GFP_ATOMIC);
if (!skb)
skb = skb_dequeue(&skb_pool);
if (!skb) {
if (++count < 10) {
netpoll_poll_dev(np->dev);
goto repeat;
}
return NULL;
}
atomic_set(&skb->users, 1);
skb_reserve(skb, reserve);
return skb;
}
static int netpoll_owner_active(struct net_device *dev)
{
struct napi_struct *napi;
list_for_each_entry(napi, &dev->napi_list, dev_list) {
if (napi->poll_owner == smp_processor_id())
return 1;
}
return 0;
}
/* call with IRQ disabled */
void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
struct net_device *dev)
{
int status = NETDEV_TX_BUSY;
unsigned long tries;
const struct net_device_ops *ops = dev->netdev_ops;
/* It is up to the caller to keep npinfo alive. */
struct netpoll_info *npinfo;
WARN_ON_ONCE(!irqs_disabled());
npinfo = rcu_dereference_bh(np->dev->npinfo);
if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
__kfree_skb(skb);
return;
}
/* don't get messages out of order, and no recursion */
if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
struct netdev_queue *txq;
txq = netdev_pick_tx(dev, skb);
/* try until next clock tick */
for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
tries > 0; --tries) {
if (__netif_tx_trylock(txq)) {
if (!netif_xmit_stopped(txq)) {
if (vlan_tx_tag_present(skb) &&
!vlan_hw_offload_capable(netif_skb_features(skb),
skb->vlan_proto)) {
skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb));
if (unlikely(!skb))
break;
skb->vlan_tci = 0;
}
status = ops->ndo_start_xmit(skb, dev);
if (status == NETDEV_TX_OK)
txq_trans_update(txq);
}
__netif_tx_unlock(txq);
if (status == NETDEV_TX_OK)
break;
}
/* tickle device maybe there is some cleanup */
netpoll_poll_dev(np->dev);
udelay(USEC_PER_POLL);
}
WARN_ONCE(!irqs_disabled(),
"netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
dev->name, ops->ndo_start_xmit);
}
if (status != NETDEV_TX_OK) {
skb_queue_tail(&npinfo->txq, skb);
schedule_delayed_work(&npinfo->tx_work,0);
}
}
EXPORT_SYMBOL(netpoll_send_skb_on_dev);
void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
{
int total_len, ip_len, udp_len;
struct sk_buff *skb;
struct udphdr *udph;
struct iphdr *iph;
struct ethhdr *eth;
static atomic_t ip_ident;
struct ipv6hdr *ip6h;
udp_len = len + sizeof(*udph);
if (np->ipv6)
ip_len = udp_len + sizeof(*ip6h);
else
ip_len = udp_len + sizeof(*iph);
total_len = ip_len + LL_RESERVED_SPACE(np->dev);
skb = find_skb(np, total_len + np->dev->needed_tailroom,
total_len - len);
if (!skb)
return;
skb_copy_to_linear_data(skb, msg, len);
skb_put(skb, len);
skb_push(skb, sizeof(*udph));
skb_reset_transport_header(skb);
udph = udp_hdr(skb);
udph->source = htons(np->local_port);
udph->dest = htons(np->remote_port);
udph->len = htons(udp_len);
if (np->ipv6) {
udph->check = 0;
udph->check = csum_ipv6_magic(&np->local_ip.in6,
&np->remote_ip.in6,
udp_len, IPPROTO_UDP,
csum_partial(udph, udp_len, 0));
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
skb_push(skb, sizeof(*ip6h));
skb_reset_network_header(skb);
ip6h = ipv6_hdr(skb);
/* ip6h->version = 6; ip6h->priority = 0; */
put_unaligned(0x60, (unsigned char *)ip6h);
ip6h->flow_lbl[0] = 0;
ip6h->flow_lbl[1] = 0;
ip6h->flow_lbl[2] = 0;
ip6h->payload_len = htons(sizeof(struct udphdr) + len);
ip6h->nexthdr = IPPROTO_UDP;
ip6h->hop_limit = 32;
ip6h->saddr = np->local_ip.in6;
ip6h->daddr = np->remote_ip.in6;
eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
} else {
udph->check = 0;
udph->check = csum_tcpudp_magic(np->local_ip.ip,
np->remote_ip.ip,
udp_len, IPPROTO_UDP,
csum_partial(udph, udp_len, 0));
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
skb_push(skb, sizeof(*iph));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
/* iph->version = 4; iph->ihl = 5; */
put_unaligned(0x45, (unsigned char *)iph);
iph->tos = 0;
put_unaligned(htons(ip_len), &(iph->tot_len));
iph->id = htons(atomic_inc_return(&ip_ident));
iph->frag_off = 0;
iph->ttl = 64;
iph->protocol = IPPROTO_UDP;
iph->check = 0;
put_unaligned(np->local_ip.ip, &(iph->saddr));
put_unaligned(np->remote_ip.ip, &(iph->daddr));
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb->protocol = eth->h_proto = htons(ETH_P_IP);
}
memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
skb->dev = np->dev;
netpoll_send_skb(np, skb);
}
EXPORT_SYMBOL(netpoll_send_udp);
static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
{
int size, type = ARPOP_REPLY;
__be32 sip, tip;
unsigned char *sha;
struct sk_buff *send_skb;
struct netpoll *np, *tmp;
unsigned long flags;
int hlen, tlen;
int hits = 0, proto;
if (list_empty(&npinfo->rx_np))
return;
/* Before checking the packet, we do some early
inspection whether this is interesting at all */
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
if (np->dev == skb->dev)
hits++;
}
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
/* No netpoll struct is using this dev */
if (!hits)
return;
proto = ntohs(eth_hdr(skb)->h_proto);
if (proto == ETH_P_IP) {
struct arphdr *arp;
unsigned char *arp_ptr;
/* No arp on this interface */
if (skb->dev->flags & IFF_NOARP)
return;
if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
return;
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
arp = arp_hdr(skb);
if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
arp->ar_pro != htons(ETH_P_IP) ||
arp->ar_op != htons(ARPOP_REQUEST))
return;
arp_ptr = (unsigned char *)(arp+1);
/* save the location of the src hw addr */
sha = arp_ptr;
arp_ptr += skb->dev->addr_len;
memcpy(&sip, arp_ptr, 4);
arp_ptr += 4;
/* If we actually cared about dst hw addr,
it would get copied here */
arp_ptr += skb->dev->addr_len;
memcpy(&tip, arp_ptr, 4);
/* Should we ignore arp? */
if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
return;
size = arp_hdr_len(skb->dev);
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
if (tip != np->local_ip.ip)
continue;
hlen = LL_RESERVED_SPACE(np->dev);
tlen = np->dev->needed_tailroom;
send_skb = find_skb(np, size + hlen + tlen, hlen);
if (!send_skb)
continue;
skb_reset_network_header(send_skb);
arp = (struct arphdr *) skb_put(send_skb, size);
send_skb->dev = skb->dev;
send_skb->protocol = htons(ETH_P_ARP);
/* Fill the device header for the ARP frame */
if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP,
sha, np->dev->dev_addr,
send_skb->len) < 0) {
kfree_skb(send_skb);
continue;
}
/*
* Fill out the arp protocol part.
*
* we only support ethernet device type,
* which (according to RFC 1390) should
* always equal 1 (Ethernet).
*/
arp->ar_hrd = htons(np->dev->type);
arp->ar_pro = htons(ETH_P_IP);
arp->ar_hln = np->dev->addr_len;
arp->ar_pln = 4;
arp->ar_op = htons(type);
arp_ptr = (unsigned char *)(arp + 1);
memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
arp_ptr += np->dev->addr_len;
memcpy(arp_ptr, &tip, 4);
arp_ptr += 4;
memcpy(arp_ptr, sha, np->dev->addr_len);
arp_ptr += np->dev->addr_len;
memcpy(arp_ptr, &sip, 4);
netpoll_send_skb(np, send_skb);
/* If there are several rx_hooks for the same address,
we're fine by sending a single reply */
break;
}
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
} else if( proto == ETH_P_IPV6) {
#if IS_ENABLED(CONFIG_IPV6)
struct nd_msg *msg;
u8 *lladdr = NULL;
struct ipv6hdr *hdr;
struct icmp6hdr *icmp6h;
const struct in6_addr *saddr;
const struct in6_addr *daddr;
struct inet6_dev *in6_dev = NULL;
struct in6_addr *target;
in6_dev = in6_dev_get(skb->dev);
if (!in6_dev || !in6_dev->cnf.accept_ra)
return;
if (!pskb_may_pull(skb, skb->len))
return;
msg = (struct nd_msg *)skb_transport_header(skb);
__skb_push(skb, skb->data - skb_transport_header(skb));
if (ipv6_hdr(skb)->hop_limit != 255)
return;
if (msg->icmph.icmp6_code != 0)
return;
if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
return;
saddr = &ipv6_hdr(skb)->saddr;
daddr = &ipv6_hdr(skb)->daddr;
size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
continue;
hlen = LL_RESERVED_SPACE(np->dev);
tlen = np->dev->needed_tailroom;
send_skb = find_skb(np, size + hlen + tlen, hlen);
if (!send_skb)
continue;
send_skb->protocol = htons(ETH_P_IPV6);
send_skb->dev = skb->dev;
skb_reset_network_header(send_skb);
hdr = (struct ipv6hdr *) skb_put(send_skb, sizeof(struct ipv6hdr));
*(__be32*)hdr = htonl(0x60000000);
hdr->payload_len = htons(size);
hdr->nexthdr = IPPROTO_ICMPV6;
hdr->hop_limit = 255;
hdr->saddr = *saddr;
hdr->daddr = *daddr;
icmp6h = (struct icmp6hdr *) skb_put(send_skb, sizeof(struct icmp6hdr));
icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
icmp6h->icmp6_router = 0;
icmp6h->icmp6_solicited = 1;
target = (struct in6_addr *) skb_put(send_skb, sizeof(struct in6_addr));
*target = msg->target;
icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
IPPROTO_ICMPV6,
csum_partial(icmp6h,
size, 0));
if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
lladdr, np->dev->dev_addr,
send_skb->len) < 0) {
kfree_skb(send_skb);
continue;
}
netpoll_send_skb(np, send_skb);
/* If there are several rx_hooks for the same address,
we're fine by sending a single reply */
break;
}
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
#endif
}
}
static bool pkt_is_ns(struct sk_buff *skb)
{
struct nd_msg *msg;
struct ipv6hdr *hdr;
if (skb->protocol != htons(ETH_P_ARP))
return false;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
return false;
msg = (struct nd_msg *)skb_transport_header(skb);
__skb_push(skb, skb->data - skb_transport_header(skb));
hdr = ipv6_hdr(skb);
if (hdr->nexthdr != IPPROTO_ICMPV6)
return false;
if (hdr->hop_limit != 255)
return false;
if (msg->icmph.icmp6_code != 0)
return false;
if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
return false;
return true;
}
int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
{
int proto, len, ulen;
int hits = 0;
const struct iphdr *iph;
struct udphdr *uh;
struct netpoll *np, *tmp;
if (list_empty(&npinfo->rx_np))
goto out;
if (skb->dev->type != ARPHRD_ETHER)
goto out;
/* check if netpoll clients need ARP */
if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
skb_queue_tail(&npinfo->neigh_tx, skb);
return 1;
} else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
skb_queue_tail(&npinfo->neigh_tx, skb);
return 1;
}
if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
skb = vlan_untag(skb);
if (unlikely(!skb))
goto out;
}
proto = ntohs(eth_hdr(skb)->h_proto);
if (proto != ETH_P_IP && proto != ETH_P_IPV6)
goto out;
if (skb->pkt_type == PACKET_OTHERHOST)
goto out;
if (skb_shared(skb))
goto out;
if (proto == ETH_P_IP) {
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto out;
iph = (struct iphdr *)skb->data;
if (iph->ihl < 5 || iph->version != 4)
goto out;
if (!pskb_may_pull(skb, iph->ihl*4))
goto out;
iph = (struct iphdr *)skb->data;
if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
goto out;
len = ntohs(iph->tot_len);
if (skb->len < len || len < iph->ihl*4)
goto out;
/*
* Our transport medium may have padded the buffer out.
* Now We trim to the true length of the frame.
*/
if (pskb_trim_rcsum(skb, len))
goto out;
iph = (struct iphdr *)skb->data;
if (iph->protocol != IPPROTO_UDP)
goto out;
len -= iph->ihl*4;
uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
ulen = ntohs(uh->len);
if (ulen != len)
goto out;
if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
goto out;
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
continue;
if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
continue;
if (np->local_port && np->local_port != ntohs(uh->dest))
continue;
np->rx_hook(np, ntohs(uh->source),
(char *)(uh+1),
ulen - sizeof(struct udphdr));
hits++;
}
} else {
#if IS_ENABLED(CONFIG_IPV6)
const struct ipv6hdr *ip6h;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
ip6h = (struct ipv6hdr *)skb->data;
if (ip6h->version != 6)
goto out;
len = ntohs(ip6h->payload_len);
if (!len)
goto out;
if (len + sizeof(struct ipv6hdr) > skb->len)
goto out;
if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
goto out;
ip6h = ipv6_hdr(skb);
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
goto out;
uh = udp_hdr(skb);
ulen = ntohs(uh->len);
if (ulen != skb->len)
goto out;
if (udp6_csum_init(skb, uh, IPPROTO_UDP))
goto out;
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
continue;
if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
continue;
if (np->local_port && np->local_port != ntohs(uh->dest))
continue;
np->rx_hook(np, ntohs(uh->source),
(char *)(uh+1),
ulen - sizeof(struct udphdr));
hits++;
}
#endif
}
if (!hits)
goto out;
kfree_skb(skb);
return 1;
out:
if (atomic_read(&trapped)) {
kfree_skb(skb);
return 1;
}
return 0;
}
void netpoll_print_options(struct netpoll *np)
{
np_info(np, "local port %d\n", np->local_port);
if (np->ipv6)
np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
else
np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
np_info(np, "interface '%s'\n", np->dev_name);
np_info(np, "remote port %d\n", np->remote_port);
if (np->ipv6)
np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
else
np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
np_info(np, "remote ethernet address %pM\n", np->remote_mac);
}
EXPORT_SYMBOL(netpoll_print_options);
static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
{
const char *end;
if (!strchr(str, ':') &&
in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
if (!*end)
return 0;
}
if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
#if IS_ENABLED(CONFIG_IPV6)
if (!*end)
return 1;
#else
return -1;
#endif
}
return -1;
}
int netpoll_parse_options(struct netpoll *np, char *opt)
{
char *cur=opt, *delim;
int ipv6;
if (*cur != '@') {
if ((delim = strchr(cur, '@')) == NULL)
goto parse_failed;
*delim = 0;
if (kstrtou16(cur, 10, &np->local_port))
goto parse_failed;
cur = delim;
}
cur++;
if (*cur != '/') {
if ((delim = strchr(cur, '/')) == NULL)
goto parse_failed;
*delim = 0;
ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
if (ipv6 < 0)
goto parse_failed;
else
np->ipv6 = (bool)ipv6;
cur = delim;
}
cur++;
if (*cur != ',') {
/* parse out dev name */
if ((delim = strchr(cur, ',')) == NULL)
goto parse_failed;
*delim = 0;
strlcpy(np->dev_name, cur, sizeof(np->dev_name));
cur = delim;
}
cur++;
if (*cur != '@') {
/* dst port */
if ((delim = strchr(cur, '@')) == NULL)
goto parse_failed;
*delim = 0;
if (*cur == ' ' || *cur == '\t')
np_info(np, "warning: whitespace is not allowed\n");
if (kstrtou16(cur, 10, &np->remote_port))
goto parse_failed;
cur = delim;
}
cur++;
/* dst ip */
if ((delim = strchr(cur, '/')) == NULL)
goto parse_failed;
*delim = 0;
ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
if (ipv6 < 0)
goto parse_failed;
else if (np->ipv6 != (bool)ipv6)
goto parse_failed;
else
np->ipv6 = (bool)ipv6;
cur = delim + 1;
if (*cur != 0) {
/* MAC address */
if (!mac_pton(cur, np->remote_mac))
goto parse_failed;
}
netpoll_print_options(np);
return 0;
parse_failed:
np_info(np, "couldn't parse config at '%s'!\n", cur);
return -1;
}
EXPORT_SYMBOL(netpoll_parse_options);
int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
{
struct netpoll_info *npinfo;
const struct net_device_ops *ops;
unsigned long flags;
int err;
np->dev = ndev;
strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
!ndev->netdev_ops->ndo_poll_controller) {
np_err(np, "%s doesn't support polling, aborting\n",
np->dev_name);
err = -ENOTSUPP;
goto out;
}
if (!ndev->npinfo) {
npinfo = kmalloc(sizeof(*npinfo), gfp);
if (!npinfo) {
err = -ENOMEM;
goto out;
}
npinfo->rx_flags = 0;
INIT_LIST_HEAD(&npinfo->rx_np);
spin_lock_init(&npinfo->rx_lock);
sema_init(&npinfo->dev_lock, 1);
skb_queue_head_init(&npinfo->neigh_tx);
skb_queue_head_init(&npinfo->txq);
INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
atomic_set(&npinfo->refcnt, 1);
ops = np->dev->netdev_ops;
if (ops->ndo_netpoll_setup) {
err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
if (err)
goto free_npinfo;
}
} else {
npinfo = rtnl_dereference(ndev->npinfo);
atomic_inc(&npinfo->refcnt);
}
npinfo->netpoll = np;
if (np->rx_hook) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
npinfo->rx_flags |= NETPOLL_RX_ENABLED;
list_add_tail(&np->rx, &npinfo->rx_np);
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
/* last thing to do is link it to the net device structure */
rcu_assign_pointer(ndev->npinfo, npinfo);
return 0;
free_npinfo:
kfree(npinfo);
out:
return err;
}
EXPORT_SYMBOL_GPL(__netpoll_setup);
int netpoll_setup(struct netpoll *np)
{
struct net_device *ndev = NULL;
struct in_device *in_dev;
int err;
rtnl_lock();
if (np->dev_name) {
struct net *net = current->nsproxy->net_ns;
ndev = __dev_get_by_name(net, np->dev_name);
}
if (!ndev) {
np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
err = -ENODEV;
goto unlock;
}
dev_hold(ndev);
if (netdev_master_upper_dev_get(ndev)) {
np_err(np, "%s is a slave device, aborting\n", np->dev_name);
err = -EBUSY;
goto put;
}
if (!netif_running(ndev)) {
unsigned long atmost, atleast;
np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
err = dev_open(ndev);
if (err) {
np_err(np, "failed to open %s\n", ndev->name);
goto put;
}
rtnl_unlock();
atleast = jiffies + HZ/10;
atmost = jiffies + carrier_timeout * HZ;
while (!netif_carrier_ok(ndev)) {
if (time_after(jiffies, atmost)) {
np_notice(np, "timeout waiting for carrier\n");
break;
}
msleep(1);
}
/* If carrier appears to come up instantly, we don't
* trust it and pause so that we don't pump all our
* queued console messages into the bitbucket.
*/
if (time_before(jiffies, atleast)) {
np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
msleep(4000);
}
rtnl_lock();
}
if (!np->local_ip.ip) {
if (!np->ipv6) {
in_dev = __in_dev_get_rtnl(ndev);
if (!in_dev || !in_dev->ifa_list) {
np_err(np, "no IP address for %s, aborting\n",
np->dev_name);
err = -EDESTADDRREQ;
goto put;
}
np->local_ip.ip = in_dev->ifa_list->ifa_local;
np_info(np, "local IP %pI4\n", &np->local_ip.ip);
} else {
#if IS_ENABLED(CONFIG_IPV6)
struct inet6_dev *idev;
err = -EDESTADDRREQ;
idev = __in6_dev_get(ndev);
if (idev) {
struct inet6_ifaddr *ifp;
read_lock_bh(&idev->lock);
list_for_each_entry(ifp, &idev->addr_list, if_list) {
if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
continue;
np->local_ip.in6 = ifp->addr;
err = 0;
break;
}
read_unlock_bh(&idev->lock);
}
if (err) {
np_err(np, "no IPv6 address for %s, aborting\n",
np->dev_name);
goto put;
} else
np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
#else
np_err(np, "IPv6 is not supported %s, aborting\n",
np->dev_name);
err = -EINVAL;
goto put;
#endif
}
}
/* fill up the skb queue */
refill_skbs();
err = __netpoll_setup(np, ndev, GFP_KERNEL);
if (err)
goto put;
rtnl_unlock();
return 0;
put:
dev_put(ndev);
unlock:
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(netpoll_setup);
static int __init netpoll_init(void)
{
skb_queue_head_init(&skb_pool);
return 0;
}
core_initcall(netpoll_init);
static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
{
struct netpoll_info *npinfo =
container_of(rcu_head, struct netpoll_info, rcu);
skb_queue_purge(&npinfo->neigh_tx);
skb_queue_purge(&npinfo->txq);
/* we can't call cancel_delayed_work_sync here, as we are in softirq */
cancel_delayed_work(&npinfo->tx_work);
/* clean after last, unfinished work */
__skb_queue_purge(&npinfo->txq);
/* now cancel it again */
cancel_delayed_work(&npinfo->tx_work);
kfree(npinfo);
}
void __netpoll_cleanup(struct netpoll *np)
{
struct netpoll_info *npinfo;
unsigned long flags;
/* rtnl_dereference would be preferable here but
* rcu_cleanup_netpoll path can put us in here safely without
* holding the rtnl, so plain rcu_dereference it is
*/
npinfo = rtnl_dereference(np->dev->npinfo);
if (!npinfo)
return;
if (!list_empty(&npinfo->rx_np)) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_del(&np->rx);
if (list_empty(&npinfo->rx_np))
npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
synchronize_srcu(&netpoll_srcu);
if (atomic_dec_and_test(&npinfo->refcnt)) {
const struct net_device_ops *ops;
ops = np->dev->netdev_ops;
if (ops->ndo_netpoll_cleanup)
ops->ndo_netpoll_cleanup(np->dev);
rcu_assign_pointer(np->dev->npinfo, NULL);
call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
}
}
EXPORT_SYMBOL_GPL(__netpoll_cleanup);
static void netpoll_async_cleanup(struct work_struct *work)
{
struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
rtnl_lock();
__netpoll_cleanup(np);
rtnl_unlock();
kfree(np);
}
void __netpoll_free_async(struct netpoll *np)
{
schedule_work(&np->cleanup_work);
}
EXPORT_SYMBOL_GPL(__netpoll_free_async);
void netpoll_cleanup(struct netpoll *np)
{
if (!np->dev)
return;
rtnl_lock();
__netpoll_cleanup(np);
rtnl_unlock();
dev_put(np->dev);
np->dev = NULL;
}
EXPORT_SYMBOL(netpoll_cleanup);
int netpoll_trap(void)
{
return atomic_read(&trapped);
}
EXPORT_SYMBOL(netpoll_trap);
void netpoll_set_trap(int trap)
{
if (trap)
atomic_inc(&trapped);
else
atomic_dec(&trapped);
}
EXPORT_SYMBOL(netpoll_set_trap);
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