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-rw-r--r--net/core/netpoll.c852
1 files changed, 852 insertions, 0 deletions
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
new file mode 100644
index 0000000..dadac62
--- /dev/null
+++ b/net/core/netpoll.c
@@ -0,0 +1,852 @@
+/*
+ * 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.
+ */
+
+#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 <net/tcp.h>
+#include <net/udp.h>
+#include <asm/unaligned.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 MAX_QUEUE_DEPTH (MAX_SKBS / 2)
+
+static struct sk_buff_head skb_pool;
+
+static atomic_t trapped;
+
+#define USEC_PER_POLL 50
+#define NETPOLL_RX_ENABLED 1
+#define NETPOLL_RX_DROP 2
+
+#define MAX_SKB_SIZE \
+ (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
+ sizeof(struct iphdr) + sizeof(struct ethhdr))
+
+static void zap_completion_queue(void);
+static void arp_reply(struct sk_buff *skb);
+
+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;
+
+ 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_tx_queue_stopped(txq) ||
+ netif_tx_queue_frozen(txq) ||
+ dev->hard_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);
+
+ 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(dev->npinfo, napi, budget);
+ spin_unlock(&napi->poll_lock);
+
+ if (!budget)
+ break;
+ }
+ }
+}
+
+static void service_arp_queue(struct netpoll_info *npi)
+{
+ if (npi) {
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&npi->arp_tx)))
+ arp_reply(skb);
+ }
+}
+
+void netpoll_poll(struct netpoll *np)
+{
+ struct net_device *dev = np->dev;
+
+ if (!dev || !netif_running(dev) || !dev->poll_controller)
+ return;
+
+ /* Process pending work on NIC */
+ dev->poll_controller(dev);
+
+ poll_napi(dev);
+
+ service_arp_queue(dev->npinfo);
+
+ zap_completion_queue();
+}
+
+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(np);
+ 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;
+}
+
+static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+{
+ int status = NETDEV_TX_BUSY;
+ unsigned long tries;
+ struct net_device *dev = np->dev;
+ struct netpoll_info *npinfo = 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;
+ unsigned long flags;
+
+ txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
+
+ local_irq_save(flags);
+ /* try until next clock tick */
+ for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
+ tries > 0; --tries) {
+ if (__netif_tx_trylock(txq)) {
+ if (!netif_tx_queue_stopped(txq))
+ status = dev->hard_start_xmit(skb, dev);
+ __netif_tx_unlock(txq);
+
+ if (status == NETDEV_TX_OK)
+ break;
+
+ }
+
+ /* tickle device maybe there is some cleanup */
+ netpoll_poll(np);
+
+ udelay(USEC_PER_POLL);
+ }
+ local_irq_restore(flags);
+ }
+
+ if (status != NETDEV_TX_OK) {
+ skb_queue_tail(&npinfo->txq, skb);
+ schedule_delayed_work(&npinfo->tx_work,0);
+ }
+}
+
+void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
+{
+ int total_len, eth_len, ip_len, udp_len;
+ struct sk_buff *skb;
+ struct udphdr *udph;
+ struct iphdr *iph;
+ struct ethhdr *eth;
+
+ udp_len = len + sizeof(*udph);
+ ip_len = eth_len = udp_len + sizeof(*iph);
+ total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
+
+ skb = find_skb(np, total_len, total_len - len);
+ if (!skb)
+ return;
+
+ skb_copy_to_linear_data(skb, msg, len);
+ skb->len += 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);
+ udph->check = 0;
+ udph->check = csum_tcpudp_magic(htonl(np->local_ip),
+ htonl(np->remote_ip),
+ udp_len, IPPROTO_UDP,
+ csum_partial((unsigned char *)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 = 0;
+ iph->frag_off = 0;
+ iph->ttl = 64;
+ iph->protocol = IPPROTO_UDP;
+ iph->check = 0;
+ put_unaligned(htonl(np->local_ip), &(iph->saddr));
+ put_unaligned(htonl(np->remote_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);
+}
+
+static void arp_reply(struct sk_buff *skb)
+{
+ struct netpoll_info *npinfo = skb->dev->npinfo;
+ struct arphdr *arp;
+ unsigned char *arp_ptr;
+ int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
+ __be32 sip, tip;
+ unsigned char *sha;
+ struct sk_buff *send_skb;
+ struct netpoll *np = NULL;
+
+ if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
+ np = npinfo->rx_np;
+ if (!np)
+ return;
+
+ /* 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 (tip != htonl(np->local_ip) ||
+ ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
+ return;
+
+ size = arp_hdr_len(skb->dev);
+ send_skb = find_skb(np, size + LL_ALLOCATED_SPACE(np->dev),
+ LL_RESERVED_SPACE(np->dev));
+
+ if (!send_skb)
+ return;
+
+ 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, ptype,
+ sha, np->dev->dev_addr,
+ send_skb->len) < 0) {
+ kfree_skb(send_skb);
+ return;
+ }
+
+ /*
+ * 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);
+}
+
+int __netpoll_rx(struct sk_buff *skb)
+{
+ int proto, len, ulen;
+ struct iphdr *iph;
+ struct udphdr *uh;
+ struct netpoll_info *npi = skb->dev->npinfo;
+ struct netpoll *np = npi->rx_np;
+
+ if (!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(&npi->arp_tx, skb);
+ return 1;
+ }
+
+ proto = ntohs(eth_hdr(skb)->h_proto);
+ if (proto != ETH_P_IP)
+ goto out;
+ if (skb->pkt_type == PACKET_OTHERHOST)
+ goto out;
+ if (skb_shared(skb))
+ goto out;
+
+ iph = (struct iphdr *)skb->data;
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ goto out;
+ if (iph->ihl < 5 || iph->version != 4)
+ goto out;
+ if (!pskb_may_pull(skb, iph->ihl*4))
+ goto out;
+ 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;
+
+ 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;
+ if (np->local_ip && np->local_ip != ntohl(iph->daddr))
+ goto out;
+ if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
+ goto out;
+ if (np->local_port && np->local_port != ntohs(uh->dest))
+ goto out;
+
+ np->rx_hook(np, ntohs(uh->source),
+ (char *)(uh+1),
+ ulen - sizeof(struct udphdr));
+
+ kfree_skb(skb);
+ return 1;
+
+out:
+ if (atomic_read(&trapped)) {
+ kfree_skb(skb);
+ return 1;
+ }
+
+ return 0;
+}
+
+void netpoll_print_options(struct netpoll *np)
+{
+ DECLARE_MAC_BUF(mac);
+ printk(KERN_INFO "%s: local port %d\n",
+ np->name, np->local_port);
+ printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
+ np->name, HIPQUAD(np->local_ip));
+ printk(KERN_INFO "%s: interface %s\n",
+ np->name, np->dev_name);
+ printk(KERN_INFO "%s: remote port %d\n",
+ np->name, np->remote_port);
+ printk(KERN_INFO "%s: remote IP %d.%d.%d.%d\n",
+ np->name, HIPQUAD(np->remote_ip));
+ printk(KERN_INFO "%s: remote ethernet address %s\n",
+ np->name, print_mac(mac, np->remote_mac));
+}
+
+int netpoll_parse_options(struct netpoll *np, char *opt)
+{
+ char *cur=opt, *delim;
+
+ if (*cur != '@') {
+ if ((delim = strchr(cur, '@')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->local_port = simple_strtol(cur, NULL, 10);
+ cur = delim;
+ }
+ cur++;
+
+ if (*cur != '/') {
+ if ((delim = strchr(cur, '/')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->local_ip = ntohl(in_aton(cur));
+ 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;
+ np->remote_port = simple_strtol(cur, NULL, 10);
+ cur = delim;
+ }
+ cur++;
+
+ /* dst ip */
+ if ((delim = strchr(cur, '/')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_ip = ntohl(in_aton(cur));
+ cur = delim + 1;
+
+ if (*cur != 0) {
+ /* MAC address */
+ if ((delim = strchr(cur, ':')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_mac[0] = simple_strtol(cur, NULL, 16);
+ cur = delim + 1;
+ if ((delim = strchr(cur, ':')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_mac[1] = simple_strtol(cur, NULL, 16);
+ cur = delim + 1;
+ if ((delim = strchr(cur, ':')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_mac[2] = simple_strtol(cur, NULL, 16);
+ cur = delim + 1;
+ if ((delim = strchr(cur, ':')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_mac[3] = simple_strtol(cur, NULL, 16);
+ cur = delim + 1;
+ if ((delim = strchr(cur, ':')) == NULL)
+ goto parse_failed;
+ *delim = 0;
+ np->remote_mac[4] = simple_strtol(cur, NULL, 16);
+ cur = delim + 1;
+ np->remote_mac[5] = simple_strtol(cur, NULL, 16);
+ }
+
+ netpoll_print_options(np);
+
+ return 0;
+
+ parse_failed:
+ printk(KERN_INFO "%s: couldn't parse config at %s!\n",
+ np->name, cur);
+ return -1;
+}
+
+int netpoll_setup(struct netpoll *np)
+{
+ struct net_device *ndev = NULL;
+ struct in_device *in_dev;
+ struct netpoll_info *npinfo;
+ unsigned long flags;
+ int err;
+
+ if (np->dev_name)
+ ndev = dev_get_by_name(&init_net, np->dev_name);
+ if (!ndev) {
+ printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
+ np->name, np->dev_name);
+ return -ENODEV;
+ }
+
+ np->dev = ndev;
+ if (!ndev->npinfo) {
+ npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
+ if (!npinfo) {
+ err = -ENOMEM;
+ goto release;
+ }
+
+ npinfo->rx_flags = 0;
+ npinfo->rx_np = NULL;
+
+ spin_lock_init(&npinfo->rx_lock);
+ skb_queue_head_init(&npinfo->arp_tx);
+ skb_queue_head_init(&npinfo->txq);
+ INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
+
+ atomic_set(&npinfo->refcnt, 1);
+ } else {
+ npinfo = ndev->npinfo;
+ atomic_inc(&npinfo->refcnt);
+ }
+
+ if (!ndev->poll_controller) {
+ printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
+ np->name, np->dev_name);
+ err = -ENOTSUPP;
+ goto release;
+ }
+
+ if (!netif_running(ndev)) {
+ unsigned long atmost, atleast;
+
+ printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
+ np->name, np->dev_name);
+
+ rtnl_lock();
+ err = dev_open(ndev);
+ rtnl_unlock();
+
+ if (err) {
+ printk(KERN_ERR "%s: failed to open %s\n",
+ np->name, ndev->name);
+ goto release;
+ }
+
+ atleast = jiffies + HZ/10;
+ atmost = jiffies + 4*HZ;
+ while (!netif_carrier_ok(ndev)) {
+ if (time_after(jiffies, atmost)) {
+ printk(KERN_NOTICE
+ "%s: timeout waiting for carrier\n",
+ np->name);
+ break;
+ }
+ cond_resched();
+ }
+
+ /* 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)) {
+ printk(KERN_NOTICE "%s: carrier detect appears"
+ " untrustworthy, waiting 4 seconds\n",
+ np->name);
+ msleep(4000);
+ }
+ }
+
+ if (!np->local_ip) {
+ rcu_read_lock();
+ in_dev = __in_dev_get_rcu(ndev);
+
+ if (!in_dev || !in_dev->ifa_list) {
+ rcu_read_unlock();
+ printk(KERN_ERR "%s: no IP address for %s, aborting\n",
+ np->name, np->dev_name);
+ err = -EDESTADDRREQ;
+ goto release;
+ }
+
+ np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
+ rcu_read_unlock();
+ printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
+ np->name, HIPQUAD(np->local_ip));
+ }
+
+ if (np->rx_hook) {
+ spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_flags |= NETPOLL_RX_ENABLED;
+ npinfo->rx_np = np;
+ spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ }
+
+ /* fill up the skb queue */
+ refill_skbs();
+
+ /* last thing to do is link it to the net device structure */
+ ndev->npinfo = npinfo;
+
+ /* avoid racing with NAPI reading npinfo */
+ synchronize_rcu();
+
+ return 0;
+
+ release:
+ if (!ndev->npinfo)
+ kfree(npinfo);
+ np->dev = NULL;
+ dev_put(ndev);
+ return err;
+}
+
+static int __init netpoll_init(void)
+{
+ skb_queue_head_init(&skb_pool);
+ return 0;
+}
+core_initcall(netpoll_init);
+
+void netpoll_cleanup(struct netpoll *np)
+{
+ struct netpoll_info *npinfo;
+ unsigned long flags;
+
+ if (np->dev) {
+ npinfo = np->dev->npinfo;
+ if (npinfo) {
+ if (npinfo->rx_np == np) {
+ spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_np = NULL;
+ npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
+ spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ }
+
+ if (atomic_dec_and_test(&npinfo->refcnt)) {
+ skb_queue_purge(&npinfo->arp_tx);
+ skb_queue_purge(&npinfo->txq);
+ cancel_rearming_delayed_work(&npinfo->tx_work);
+
+ /* clean after last, unfinished work */
+ __skb_queue_purge(&npinfo->txq);
+ kfree(npinfo);
+ np->dev->npinfo = NULL;
+ }
+ }
+
+ dev_put(np->dev);
+ }
+
+ np->dev = NULL;
+}
+
+int netpoll_trap(void)
+{
+ return atomic_read(&trapped);
+}
+
+void netpoll_set_trap(int trap)
+{
+ if (trap)
+ atomic_inc(&trapped);
+ else
+ atomic_dec(&trapped);
+}
+
+EXPORT_SYMBOL(netpoll_set_trap);
+EXPORT_SYMBOL(netpoll_trap);
+EXPORT_SYMBOL(netpoll_print_options);
+EXPORT_SYMBOL(netpoll_parse_options);
+EXPORT_SYMBOL(netpoll_setup);
+EXPORT_SYMBOL(netpoll_cleanup);
+EXPORT_SYMBOL(netpoll_send_udp);
+EXPORT_SYMBOL(netpoll_poll);
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