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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/core/netpoll.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/core/netpoll.c')
-rw-r--r--net/core/netpoll.c878
1 files changed, 878 insertions, 0 deletions
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
new file mode 100644
index 000000000..4ac8d0ad9
--- /dev/null
+++ b/net/core/netpoll.c
@@ -0,0 +1,878 @@
+// 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 <asm/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
+
+static struct sk_buff_head skb_pool;
+
+DEFINE_STATIC_SRCU(netpoll_srcu);
+
+#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 explicilty 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;
+ 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_poll_disable);
+
+void netpoll_poll_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_poll_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_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();
+ 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;
+ }
+
+ 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 (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;
+ 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;
+ npinfo = rcu_dereference_bh(dev->npinfo);
+
+ if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
+ dev_kfree_skb_irq(skb);
+ return NET_XMIT_DROP;
+ }
+
+ /* 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);
+ }
+ return NETDEV_TX_OK;
+}
+
+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);
+
+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;
+
+ 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;
+
+ 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;
+
+ 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 '%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;
+ 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 */
+ if ((delim = strchr(cur, ',')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ strscpy(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 (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);
+
+int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
+{
+ struct netpoll_info *npinfo;
+ const struct net_device_ops *ops;
+ int err;
+
+ np->dev = ndev;
+ strscpy(np->dev_name, ndev->name, IFNAMSIZ);
+
+ if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
+ 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_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 = np->dev->netdev_ops;
+ if (ops->ndo_netpoll_setup) {
+ err = ops->ndo_netpoll_setup(ndev, npinfo);
+ if (err)
+ goto free_npinfo;
+ }
+ } else {
+ npinfo = rtnl_dereference(ndev->npinfo);
+ refcount_inc(&npinfo->refcnt);
+ }
+
+ npinfo->netpoll = np;
+
+ /* 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[0]) {
+ 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, NULL);
+
+ 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) {
+ 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",
+ np->dev_name);
+ err = -EDESTADDRREQ;
+ goto put;
+ }
+
+ np->local_ip.ip = ifa->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) !=
+ !!(ipv6_addr_type(&np->remote_ip.in6) & 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);
+ if (err)
+ goto put;
+ netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL);
+ 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->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;
+
+ synchronize_srcu(&netpoll_srcu);
+
+ 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);
+}
+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 netpoll_cleanup(struct netpoll *np)
+{
+ rtnl_lock();
+ if (!np->dev)
+ goto out;
+ __netpoll_cleanup(np);
+ netdev_put(np->dev, &np->dev_tracker);
+ np->dev = NULL;
+out:
+ rtnl_unlock();
+}
+EXPORT_SYMBOL(netpoll_cleanup);