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mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
linux/net/core/netpoll.c
Uday Shankar f8a10bed32 netconsole: allow selection of egress interface via MAC address
Currently, netconsole has two methods of configuration - module
parameter and configfs. The former interface allows for netconsole
activation earlier during boot (by specifying the module parameter on
the kernel command line), so it is preferred for debugging issues which
arise before userspace is up/the configfs interface can be used. The
module parameter syntax requires specifying the egress interface name.
This requirement makes it hard to use for a couple reasons:
- The egress interface name can be hard or impossible to predict. For
  example, installing a new network card in a system can change the
  interface names assigned by the kernel.
- When constructing the module parameter, one may have trouble
  determining the original (kernel-assigned) name of the interface
  (which is the name that should be given to netconsole) if some stable
  interface naming scheme is in effect. A human can usually look at
  kernel logs to determine the original name, but this is very painful
  if automation is constructing the parameter.

For these reasons, allow selection of the egress interface via MAC
address when configuring netconsole using the module parameter. Update
the netconsole documentation with an example of the new syntax.
Selection of egress interface by MAC address via configfs is far less
interesting (since when this interface can be used, one should be able
to easily convert between MAC address and interface name), so it is left
unimplemented.

Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Tested-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250312-netconsole-v6-2-3437933e79b8@purestorage.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19 19:17:58 +01:00

920 lines
21 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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 <linux/unaligned.h>
#include <trace/events/napi.h>
#include <linux/kconfig.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
#define USEC_PER_POLL 50
#define MAX_SKB_SIZE \
(sizeof(struct ethhdr) + \
sizeof(struct iphdr) + \
sizeof(struct udphdr) + \
MAX_UDP_CHUNK)
static void zap_completion_queue(void);
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 netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
struct net_device *dev,
struct netdev_queue *txq)
{
netdev_tx_t status = NETDEV_TX_OK;
netdev_features_t features;
features = netif_skb_features(skb);
if (skb_vlan_tag_present(skb) &&
!vlan_hw_offload_capable(features, skb->vlan_proto)) {
skb = __vlan_hwaccel_push_inside(skb);
if (unlikely(!skb)) {
/* This is actually a packet drop, but we
* don't want the code that calls this
* function to try and operate on a NULL skb.
*/
goto out;
}
}
status = netdev_start_xmit(skb, dev, txq, false);
out:
return status;
}
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;
struct netdev_queue *txq;
unsigned int q_index;
if (!netif_device_present(dev) || !netif_running(dev)) {
kfree_skb(skb);
continue;
}
local_irq_save(flags);
/* check if skb->queue_mapping is still valid */
q_index = skb_get_queue_mapping(skb);
if (unlikely(q_index >= dev->real_num_tx_queues)) {
q_index = q_index % dev->real_num_tx_queues;
skb_set_queue_mapping(skb, q_index);
}
txq = netdev_get_tx_queue(dev, q_index);
HARD_TX_LOCK(dev, txq, smp_processor_id());
if (netif_xmit_frozen_or_stopped(txq) ||
!dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
skb_queue_head(&npinfo->txq, skb);
HARD_TX_UNLOCK(dev, txq);
local_irq_restore(flags);
schedule_delayed_work(&npinfo->tx_work, HZ/10);
return;
}
HARD_TX_UNLOCK(dev, txq);
local_irq_restore(flags);
}
}
static int netif_local_xmit_active(struct net_device *dev)
{
int i;
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
return 1;
}
return 0;
}
static void poll_one_napi(struct napi_struct *napi)
{
int work;
/* If we set this bit but see that it has already been set,
* that indicates that napi has been disabled and we need
* to abort this operation
*/
if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
return;
/* We explicitly pass the polling call a budget of 0 to
* indicate that we are clearing the Tx path only.
*/
work = napi->poll(napi, 0);
WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
trace_napi_poll(napi, work, 0);
clear_bit(NAPI_STATE_NPSVC, &napi->state);
}
static void poll_napi(struct net_device *dev)
{
struct napi_struct *napi;
int cpu = smp_processor_id();
list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
poll_one_napi(napi);
smp_store_release(&napi->poll_owner, -1);
}
}
}
void netpoll_poll_dev(struct net_device *dev)
{
struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
const struct net_device_ops *ops;
/* 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 (!ni || down_trylock(&ni->dev_lock))
return;
/* Some drivers will take the same locks in poll and xmit,
* we can't poll if local CPU is already in xmit.
*/
if (!netif_running(dev) || netif_local_xmit_active(dev)) {
up(&ni->dev_lock);
return;
}
ops = dev->netdev_ops;
if (ops->ndo_poll_controller)
ops->ndo_poll_controller(dev);
poll_napi(dev);
up(&ni->dev_lock);
zap_completion_queue();
}
EXPORT_SYMBOL(netpoll_poll_dev);
void netpoll_poll_disable(struct net_device *dev)
{
struct netpoll_info *ni;
might_sleep();
ni = rtnl_dereference(dev->npinfo);
if (ni)
down(&ni->dev_lock);
}
void netpoll_poll_enable(struct net_device *dev)
{
struct netpoll_info *ni;
ni = rtnl_dereference(dev->npinfo);
if (ni)
up(&ni->dev_lock);
}
static void refill_skbs(struct netpoll *np)
{
struct sk_buff_head *skb_pool;
struct sk_buff *skb;
unsigned long flags;
skb_pool = &np->skb_pool;
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_irq_freeable(skb)) {
refcount_set(&skb->users, 1);
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();
repeat:
skb = alloc_skb(len, GFP_ATOMIC);
if (!skb) {
skb = skb_dequeue(&np->skb_pool);
schedule_work(&np->refill_wq);
}
if (!skb) {
if (++count < 10) {
netpoll_poll_dev(np->dev);
goto repeat;
}
return NULL;
}
refcount_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_rcu(napi, &dev->napi_list, dev_list) {
if (READ_ONCE(napi->poll_owner) == smp_processor_id())
return 1;
}
return 0;
}
/* call with IRQ disabled */
static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
netdev_tx_t status = NETDEV_TX_BUSY;
netdev_tx_t ret = NET_XMIT_DROP;
struct net_device *dev;
unsigned long tries;
/* It is up to the caller to keep npinfo alive. */
struct netpoll_info *npinfo;
lockdep_assert_irqs_disabled();
dev = np->dev;
rcu_read_lock();
npinfo = rcu_dereference_bh(dev->npinfo);
if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
dev_kfree_skb_irq(skb);
goto out;
}
/* 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_core_pick_tx(dev, skb, NULL);
/* try until next clock tick */
for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
tries > 0; --tries) {
if (HARD_TX_TRYLOCK(dev, txq)) {
if (!netif_xmit_stopped(txq))
status = netpoll_start_xmit(skb, dev, txq);
HARD_TX_UNLOCK(dev, txq);
if (dev_xmit_complete(status))
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 (%pS)\n",
dev->name, dev->netdev_ops->ndo_start_xmit);
}
if (!dev_xmit_complete(status)) {
skb_queue_tail(&npinfo->txq, skb);
schedule_delayed_work(&npinfo->tx_work,0);
}
ret = NETDEV_TX_OK;
out:
rcu_read_unlock();
return ret;
}
netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
unsigned long flags;
netdev_tx_t ret;
if (unlikely(!np)) {
dev_kfree_skb_irq(skb);
ret = NET_XMIT_DROP;
} else {
local_irq_save(flags);
ret = __netpoll_send_skb(np, skb);
local_irq_restore(flags);
}
return ret;
}
EXPORT_SYMBOL(netpoll_send_skb);
int 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;
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
WARN_ON_ONCE(!irqs_disabled());
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 -ENOMEM;
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; */
*(unsigned char *)ip6h = 0x60;
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 = 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; */
*(unsigned char *)iph = 0x45;
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 = skb_push(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb->protocol = eth->h_proto = htons(ETH_P_IP);
}
ether_addr_copy(eth->h_source, np->dev->dev_addr);
ether_addr_copy(eth->h_dest, np->remote_mac);
skb->dev = np->dev;
return (int)netpoll_send_skb(np, skb);
}
EXPORT_SYMBOL(netpoll_send_udp);
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 name '%s'\n", np->dev_name);
np_info(np, "local ethernet address '%pM'\n", np->dev_mac);
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;
}
static void skb_pool_flush(struct netpoll *np)
{
struct sk_buff_head *skb_pool;
cancel_work_sync(&np->refill_wq);
skb_pool = &np->skb_pool;
skb_queue_purge_reason(skb_pool, SKB_CONSUMED);
}
int netpoll_parse_options(struct netpoll *np, char *opt)
{
char *cur=opt, *delim;
int ipv6;
bool ipversion_set = false;
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 != '/') {
ipversion_set = true;
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 or dev_mac */
if ((delim = strchr(cur, ',')) == NULL)
goto parse_failed;
*delim = 0;
np->dev_name[0] = '\0';
eth_broadcast_addr(np->dev_mac);
if (!strchr(cur, ':'))
strscpy(np->dev_name, cur, sizeof(np->dev_name));
else if (!mac_pton(cur, np->dev_mac))
goto parse_failed;
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 (ipversion_set && 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);
static void refill_skbs_work_handler(struct work_struct *work)
{
struct netpoll *np =
container_of(work, struct netpoll, refill_wq);
refill_skbs(np);
}
int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
{
struct netpoll_info *npinfo;
const struct net_device_ops *ops;
int err;
skb_queue_head_init(&np->skb_pool);
if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
np_err(np, "%s doesn't support polling, aborting\n",
ndev->name);
err = -ENOTSUPP;
goto out;
}
npinfo = rtnl_dereference(ndev->npinfo);
if (!npinfo) {
npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
if (!npinfo) {
err = -ENOMEM;
goto out;
}
sema_init(&npinfo->dev_lock, 1);
skb_queue_head_init(&npinfo->txq);
INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
refcount_set(&npinfo->refcnt, 1);
ops = ndev->netdev_ops;
if (ops->ndo_netpoll_setup) {
err = ops->ndo_netpoll_setup(ndev);
if (err)
goto free_npinfo;
}
} else {
refcount_inc(&npinfo->refcnt);
}
np->dev = ndev;
strscpy(np->dev_name, ndev->name, IFNAMSIZ);
npinfo->netpoll = np;
/* fill up the skb queue */
refill_skbs(np);
INIT_WORK(&np->refill_wq, refill_skbs_work_handler);
/* 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);
/*
* Returns a pointer to a string representation of the identifier used
* to select the egress interface for the given netpoll instance. buf
* must be a buffer of length at least MAC_ADDR_STR_LEN + 1.
*/
static char *egress_dev(struct netpoll *np, char *buf)
{
if (np->dev_name[0])
return np->dev_name;
snprintf(buf, MAC_ADDR_STR_LEN, "%pM", np->dev_mac);
return buf;
}
int netpoll_setup(struct netpoll *np)
{
struct net *net = current->nsproxy->net_ns;
char buf[MAC_ADDR_STR_LEN + 1];
struct net_device *ndev = NULL;
bool ip_overwritten = false;
struct in_device *in_dev;
int err;
rtnl_lock();
if (np->dev_name[0])
ndev = __dev_get_by_name(net, np->dev_name);
else if (is_valid_ether_addr(np->dev_mac))
ndev = dev_getbyhwaddr(net, ARPHRD_ETHER, np->dev_mac);
if (!ndev) {
np_err(np, "%s doesn't exist, aborting\n", egress_dev(np, buf));
err = -ENODEV;
goto unlock;
}
netdev_hold(ndev, &np->dev_tracker, GFP_KERNEL);
if (netdev_master_upper_dev_get(ndev)) {
np_err(np, "%s is a slave device, aborting\n",
egress_dev(np, buf));
err = -EBUSY;
goto put;
}
if (!netif_running(ndev)) {
unsigned long atmost;
np_info(np, "device %s not up yet, forcing it\n",
egress_dev(np, buf));
err = dev_open(ndev, NULL);
if (err) {
np_err(np, "failed to open %s\n", ndev->name);
goto put;
}
rtnl_unlock();
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);
}
rtnl_lock();
}
if (!np->local_ip.ip) {
if (!np->ipv6) {
const struct in_ifaddr *ifa;
in_dev = __in_dev_get_rtnl(ndev);
if (!in_dev)
goto put_noaddr;
ifa = rtnl_dereference(in_dev->ifa_list);
if (!ifa) {
put_noaddr:
np_err(np, "no IP address for %s, aborting\n",
egress_dev(np, buf));
err = -EDESTADDRREQ;
goto put;
}
np->local_ip.ip = ifa->ifa_local;
ip_overwritten = true;
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) !=
!!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
continue;
np->local_ip.in6 = ifp->addr;
ip_overwritten = true;
err = 0;
break;
}
read_unlock_bh(&idev->lock);
}
if (err) {
np_err(np, "no IPv6 address for %s, aborting\n",
egress_dev(np, buf));
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",
egress_dev(np, buf));
err = -EINVAL;
goto put;
#endif
}
}
err = __netpoll_setup(np, ndev);
if (err)
goto flush;
rtnl_unlock();
return 0;
flush:
skb_pool_flush(np);
put:
DEBUG_NET_WARN_ON_ONCE(np->dev);
if (ip_overwritten)
memset(&np->local_ip, 0, sizeof(np->local_ip));
netdev_put(ndev, &np->dev_tracker);
unlock:
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(netpoll_setup);
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->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;
npinfo = rtnl_dereference(np->dev->npinfo);
if (!npinfo)
return;
if (refcount_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_INIT_POINTER(np->dev->npinfo, NULL);
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
} else
RCU_INIT_POINTER(np->dev->npinfo, NULL);
skb_pool_flush(np);
}
EXPORT_SYMBOL_GPL(__netpoll_cleanup);
void __netpoll_free(struct netpoll *np)
{
ASSERT_RTNL();
/* Wait for transmitting packets to finish before freeing. */
synchronize_rcu();
__netpoll_cleanup(np);
kfree(np);
}
EXPORT_SYMBOL_GPL(__netpoll_free);
void do_netpoll_cleanup(struct netpoll *np)
{
__netpoll_cleanup(np);
netdev_put(np->dev, &np->dev_tracker);
np->dev = NULL;
}
EXPORT_SYMBOL(do_netpoll_cleanup);
void netpoll_cleanup(struct netpoll *np)
{
rtnl_lock();
if (!np->dev)
goto out;
do_netpoll_cleanup(np);
out:
rtnl_unlock();
}
EXPORT_SYMBOL(netpoll_cleanup);