2 * Common framework for low-level network console, dump, and debugger code
4 * Sep 8 2003 Matt Mackall <mpm@selenic.com>
6 * based on the netconsole code from:
8 * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
9 * Copyright (C) 2002 Red Hat, Inc.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/moduleparam.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/string.h>
19 #include <linux/if_arp.h>
20 #include <linux/inetdevice.h>
21 #include <linux/inet.h>
22 #include <linux/interrupt.h>
23 #include <linux/netpoll.h>
24 #include <linux/sched.h>
25 #include <linux/delay.h>
26 #include <linux/rcupdate.h>
27 #include <linux/workqueue.h>
28 #include <linux/slab.h>
29 #include <linux/export.h>
30 #include <linux/if_vlan.h>
33 #include <net/addrconf.h>
34 #include <net/ndisc.h>
35 #include <net/ip6_checksum.h>
36 #include <asm/unaligned.h>
37 #include <trace/events/napi.h>
40 * We maintain a small pool of fully-sized skbs, to make sure the
41 * message gets out even in extreme OOM situations.
44 #define MAX_UDP_CHUNK 1460
47 static struct sk_buff_head skb_pool;
49 static atomic_t trapped;
51 DEFINE_STATIC_SRCU(netpoll_srcu);
53 #define USEC_PER_POLL 50
54 #define NETPOLL_RX_ENABLED 1
55 #define NETPOLL_RX_DROP 2
57 #define MAX_SKB_SIZE \
58 (sizeof(struct ethhdr) + \
59 sizeof(struct iphdr) + \
60 sizeof(struct udphdr) + \
63 static void zap_completion_queue(void);
64 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
65 static void netpoll_async_cleanup(struct work_struct *work);
67 static unsigned int carrier_timeout = 4;
68 module_param(carrier_timeout, uint, 0644);
70 #define np_info(np, fmt, ...) \
71 pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
72 #define np_err(np, fmt, ...) \
73 pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
74 #define np_notice(np, fmt, ...) \
75 pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
77 static void queue_process(struct work_struct *work)
79 struct netpoll_info *npinfo =
80 container_of(work, struct netpoll_info, tx_work.work);
84 while ((skb = skb_dequeue(&npinfo->txq))) {
85 struct net_device *dev = skb->dev;
86 const struct net_device_ops *ops = dev->netdev_ops;
87 struct netdev_queue *txq;
89 if (!netif_device_present(dev) || !netif_running(dev)) {
94 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
96 local_irq_save(flags);
97 __netif_tx_lock(txq, smp_processor_id());
98 if (netif_xmit_frozen_or_stopped(txq) ||
99 ops->ndo_start_xmit(skb, dev) != NETDEV_TX_OK) {
100 skb_queue_head(&npinfo->txq, skb);
101 __netif_tx_unlock(txq);
102 local_irq_restore(flags);
104 schedule_delayed_work(&npinfo->tx_work, HZ/10);
107 __netif_tx_unlock(txq);
108 local_irq_restore(flags);
112 static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
113 unsigned short ulen, __be32 saddr, __be32 daddr)
117 if (uh->check == 0 || skb_csum_unnecessary(skb))
120 psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
122 if (skb->ip_summed == CHECKSUM_COMPLETE &&
123 !csum_fold(csum_add(psum, skb->csum)))
128 return __skb_checksum_complete(skb);
132 * Check whether delayed processing was scheduled for our NIC. If so,
133 * we attempt to grab the poll lock and use ->poll() to pump the card.
134 * If this fails, either we've recursed in ->poll() or it's already
135 * running on another CPU.
137 * Note: we don't mask interrupts with this lock because we're using
138 * trylock here and interrupts are already disabled in the softirq
139 * case. Further, we test the poll_owner to avoid recursion on UP
140 * systems where the lock doesn't exist.
142 * In cases where there is bi-directional communications, reading only
143 * one message at a time can lead to packets being dropped by the
144 * network adapter, forcing superfluous retries and possibly timeouts.
145 * Thus, we set our budget to greater than 1.
147 static int poll_one_napi(struct netpoll_info *npinfo,
148 struct napi_struct *napi, int budget)
152 /* net_rx_action's ->poll() invocations and our's are
153 * synchronized by this test which is only made while
154 * holding the napi->poll_lock.
156 if (!test_bit(NAPI_STATE_SCHED, &napi->state))
159 npinfo->rx_flags |= NETPOLL_RX_DROP;
160 atomic_inc(&trapped);
161 set_bit(NAPI_STATE_NPSVC, &napi->state);
163 work = napi->poll(napi, budget);
164 trace_napi_poll(napi);
166 clear_bit(NAPI_STATE_NPSVC, &napi->state);
167 atomic_dec(&trapped);
168 npinfo->rx_flags &= ~NETPOLL_RX_DROP;
170 return budget - work;
173 static void poll_napi(struct net_device *dev)
175 struct napi_struct *napi;
178 list_for_each_entry(napi, &dev->napi_list, dev_list) {
179 if (napi->poll_owner != smp_processor_id() &&
180 spin_trylock(&napi->poll_lock)) {
181 budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
183 spin_unlock(&napi->poll_lock);
191 static void service_neigh_queue(struct netpoll_info *npi)
196 while ((skb = skb_dequeue(&npi->neigh_tx)))
197 netpoll_neigh_reply(skb, npi);
201 static void netpoll_poll_dev(struct net_device *dev)
203 const struct net_device_ops *ops;
204 struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
206 /* Don't do any rx activity if the dev_lock mutex is held
207 * the dev_open/close paths use this to block netpoll activity
208 * while changing device state
210 if (down_trylock(&ni->dev_lock))
213 if (!netif_running(dev)) {
218 ops = dev->netdev_ops;
219 if (!ops->ndo_poll_controller) {
224 /* Process pending work on NIC */
225 ops->ndo_poll_controller(dev);
231 if (dev->flags & IFF_SLAVE) {
233 struct net_device *bond_dev;
235 struct netpoll_info *bond_ni;
237 bond_dev = netdev_master_upper_dev_get_rcu(dev);
238 bond_ni = rcu_dereference_bh(bond_dev->npinfo);
239 while ((skb = skb_dequeue(&ni->neigh_tx))) {
241 skb_queue_tail(&bond_ni->neigh_tx, skb);
246 service_neigh_queue(ni);
248 zap_completion_queue();
251 int netpoll_rx_disable(struct net_device *dev)
253 struct netpoll_info *ni;
256 idx = srcu_read_lock(&netpoll_srcu);
257 ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
260 srcu_read_unlock(&netpoll_srcu, idx);
263 EXPORT_SYMBOL(netpoll_rx_disable);
265 void netpoll_rx_enable(struct net_device *dev)
267 struct netpoll_info *ni;
269 ni = rcu_dereference(dev->npinfo);
274 EXPORT_SYMBOL(netpoll_rx_enable);
276 static void refill_skbs(void)
281 spin_lock_irqsave(&skb_pool.lock, flags);
282 while (skb_pool.qlen < MAX_SKBS) {
283 skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
287 __skb_queue_tail(&skb_pool, skb);
289 spin_unlock_irqrestore(&skb_pool.lock, flags);
292 static void zap_completion_queue(void)
295 struct softnet_data *sd = &get_cpu_var(softnet_data);
297 if (sd->completion_queue) {
298 struct sk_buff *clist;
300 local_irq_save(flags);
301 clist = sd->completion_queue;
302 sd->completion_queue = NULL;
303 local_irq_restore(flags);
305 while (clist != NULL) {
306 struct sk_buff *skb = clist;
308 if (skb->destructor) {
309 atomic_inc(&skb->users);
310 dev_kfree_skb_any(skb); /* put this one back */
317 put_cpu_var(softnet_data);
320 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
325 zap_completion_queue();
329 skb = alloc_skb(len, GFP_ATOMIC);
331 skb = skb_dequeue(&skb_pool);
335 netpoll_poll_dev(np->dev);
341 atomic_set(&skb->users, 1);
342 skb_reserve(skb, reserve);
346 static int netpoll_owner_active(struct net_device *dev)
348 struct napi_struct *napi;
350 list_for_each_entry(napi, &dev->napi_list, dev_list) {
351 if (napi->poll_owner == smp_processor_id())
357 /* call with IRQ disabled */
358 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
359 struct net_device *dev)
361 int status = NETDEV_TX_BUSY;
363 const struct net_device_ops *ops = dev->netdev_ops;
364 /* It is up to the caller to keep npinfo alive. */
365 struct netpoll_info *npinfo;
367 WARN_ON_ONCE(!irqs_disabled());
369 npinfo = rcu_dereference_bh(np->dev->npinfo);
370 if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
375 /* don't get messages out of order, and no recursion */
376 if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
377 struct netdev_queue *txq;
379 txq = netdev_pick_tx(dev, skb);
381 /* try until next clock tick */
382 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
383 tries > 0; --tries) {
384 if (__netif_tx_trylock(txq)) {
385 if (!netif_xmit_stopped(txq)) {
386 if (vlan_tx_tag_present(skb) &&
387 !vlan_hw_offload_capable(netif_skb_features(skb),
389 skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb));
395 status = ops->ndo_start_xmit(skb, dev);
396 if (status == NETDEV_TX_OK)
397 txq_trans_update(txq);
399 __netif_tx_unlock(txq);
401 if (status == NETDEV_TX_OK)
406 /* tickle device maybe there is some cleanup */
407 netpoll_poll_dev(np->dev);
409 udelay(USEC_PER_POLL);
412 WARN_ONCE(!irqs_disabled(),
413 "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
414 dev->name, ops->ndo_start_xmit);
418 if (status != NETDEV_TX_OK) {
419 skb_queue_tail(&npinfo->txq, skb);
420 schedule_delayed_work(&npinfo->tx_work,0);
423 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
425 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
427 int total_len, ip_len, udp_len;
432 static atomic_t ip_ident;
433 struct ipv6hdr *ip6h;
435 udp_len = len + sizeof(*udph);
437 ip_len = udp_len + sizeof(*ip6h);
439 ip_len = udp_len + sizeof(*iph);
441 total_len = ip_len + LL_RESERVED_SPACE(np->dev);
443 skb = find_skb(np, total_len + np->dev->needed_tailroom,
448 skb_copy_to_linear_data(skb, msg, len);
451 skb_push(skb, sizeof(*udph));
452 skb_reset_transport_header(skb);
454 udph->source = htons(np->local_port);
455 udph->dest = htons(np->remote_port);
456 udph->len = htons(udp_len);
460 udph->check = csum_ipv6_magic(&np->local_ip.in6,
462 udp_len, IPPROTO_UDP,
463 csum_partial(udph, udp_len, 0));
464 if (udph->check == 0)
465 udph->check = CSUM_MANGLED_0;
467 skb_push(skb, sizeof(*ip6h));
468 skb_reset_network_header(skb);
469 ip6h = ipv6_hdr(skb);
471 /* ip6h->version = 6; ip6h->priority = 0; */
472 put_unaligned(0x60, (unsigned char *)ip6h);
473 ip6h->flow_lbl[0] = 0;
474 ip6h->flow_lbl[1] = 0;
475 ip6h->flow_lbl[2] = 0;
477 ip6h->payload_len = htons(sizeof(struct udphdr) + len);
478 ip6h->nexthdr = IPPROTO_UDP;
479 ip6h->hop_limit = 32;
480 ip6h->saddr = np->local_ip.in6;
481 ip6h->daddr = np->remote_ip.in6;
483 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
484 skb_reset_mac_header(skb);
485 skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
488 udph->check = csum_tcpudp_magic(np->local_ip.ip,
490 udp_len, IPPROTO_UDP,
491 csum_partial(udph, udp_len, 0));
492 if (udph->check == 0)
493 udph->check = CSUM_MANGLED_0;
495 skb_push(skb, sizeof(*iph));
496 skb_reset_network_header(skb);
499 /* iph->version = 4; iph->ihl = 5; */
500 put_unaligned(0x45, (unsigned char *)iph);
502 put_unaligned(htons(ip_len), &(iph->tot_len));
503 iph->id = htons(atomic_inc_return(&ip_ident));
506 iph->protocol = IPPROTO_UDP;
508 put_unaligned(np->local_ip.ip, &(iph->saddr));
509 put_unaligned(np->remote_ip.ip, &(iph->daddr));
510 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
512 eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
513 skb_reset_mac_header(skb);
514 skb->protocol = eth->h_proto = htons(ETH_P_IP);
517 memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
518 memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
522 netpoll_send_skb(np, skb);
524 EXPORT_SYMBOL(netpoll_send_udp);
526 static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
528 int size, type = ARPOP_REPLY;
531 struct sk_buff *send_skb;
532 struct netpoll *np, *tmp;
537 if (list_empty(&npinfo->rx_np))
540 /* Before checking the packet, we do some early
541 inspection whether this is interesting at all */
542 spin_lock_irqsave(&npinfo->rx_lock, flags);
543 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
544 if (np->dev == skb->dev)
547 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
549 /* No netpoll struct is using this dev */
553 proto = ntohs(eth_hdr(skb)->h_proto);
554 if (proto == ETH_P_IP) {
556 unsigned char *arp_ptr;
557 /* No arp on this interface */
558 if (skb->dev->flags & IFF_NOARP)
561 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
564 skb_reset_network_header(skb);
565 skb_reset_transport_header(skb);
568 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
569 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
570 arp->ar_pro != htons(ETH_P_IP) ||
571 arp->ar_op != htons(ARPOP_REQUEST))
574 arp_ptr = (unsigned char *)(arp+1);
575 /* save the location of the src hw addr */
577 arp_ptr += skb->dev->addr_len;
578 memcpy(&sip, arp_ptr, 4);
580 /* If we actually cared about dst hw addr,
581 it would get copied here */
582 arp_ptr += skb->dev->addr_len;
583 memcpy(&tip, arp_ptr, 4);
585 /* Should we ignore arp? */
586 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
589 size = arp_hdr_len(skb->dev);
591 spin_lock_irqsave(&npinfo->rx_lock, flags);
592 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
593 if (tip != np->local_ip.ip)
596 hlen = LL_RESERVED_SPACE(np->dev);
597 tlen = np->dev->needed_tailroom;
598 send_skb = find_skb(np, size + hlen + tlen, hlen);
602 skb_reset_network_header(send_skb);
603 arp = (struct arphdr *) skb_put(send_skb, size);
604 send_skb->dev = skb->dev;
605 send_skb->protocol = htons(ETH_P_ARP);
607 /* Fill the device header for the ARP frame */
608 if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP,
609 sha, np->dev->dev_addr,
610 send_skb->len) < 0) {
616 * Fill out the arp protocol part.
618 * we only support ethernet device type,
619 * which (according to RFC 1390) should
620 * always equal 1 (Ethernet).
623 arp->ar_hrd = htons(np->dev->type);
624 arp->ar_pro = htons(ETH_P_IP);
625 arp->ar_hln = np->dev->addr_len;
627 arp->ar_op = htons(type);
629 arp_ptr = (unsigned char *)(arp + 1);
630 memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
631 arp_ptr += np->dev->addr_len;
632 memcpy(arp_ptr, &tip, 4);
634 memcpy(arp_ptr, sha, np->dev->addr_len);
635 arp_ptr += np->dev->addr_len;
636 memcpy(arp_ptr, &sip, 4);
638 netpoll_send_skb(np, send_skb);
640 /* If there are several rx_hooks for the same address,
641 we're fine by sending a single reply */
644 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
645 } else if( proto == ETH_P_IPV6) {
646 #if IS_ENABLED(CONFIG_IPV6)
650 struct icmp6hdr *icmp6h;
651 const struct in6_addr *saddr;
652 const struct in6_addr *daddr;
653 struct inet6_dev *in6_dev = NULL;
654 struct in6_addr *target;
656 in6_dev = in6_dev_get(skb->dev);
657 if (!in6_dev || !in6_dev->cnf.accept_ra)
660 if (!pskb_may_pull(skb, skb->len))
663 msg = (struct nd_msg *)skb_transport_header(skb);
665 __skb_push(skb, skb->data - skb_transport_header(skb));
667 if (ipv6_hdr(skb)->hop_limit != 255)
669 if (msg->icmph.icmp6_code != 0)
671 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
674 saddr = &ipv6_hdr(skb)->saddr;
675 daddr = &ipv6_hdr(skb)->daddr;
677 size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
679 spin_lock_irqsave(&npinfo->rx_lock, flags);
680 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
681 if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
684 hlen = LL_RESERVED_SPACE(np->dev);
685 tlen = np->dev->needed_tailroom;
686 send_skb = find_skb(np, size + hlen + tlen, hlen);
690 send_skb->protocol = htons(ETH_P_IPV6);
691 send_skb->dev = skb->dev;
693 skb_reset_network_header(send_skb);
694 skb_put(send_skb, sizeof(struct ipv6hdr));
695 hdr = ipv6_hdr(send_skb);
697 *(__be32*)hdr = htonl(0x60000000);
699 hdr->payload_len = htons(size);
700 hdr->nexthdr = IPPROTO_ICMPV6;
701 hdr->hop_limit = 255;
705 send_skb->transport_header = send_skb->tail;
706 skb_put(send_skb, size);
708 icmp6h = (struct icmp6hdr *)skb_transport_header(skb);
709 icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
710 icmp6h->icmp6_router = 0;
711 icmp6h->icmp6_solicited = 1;
712 target = (struct in6_addr *)(skb_transport_header(send_skb) + sizeof(struct icmp6hdr));
713 *target = msg->target;
714 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
719 if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
720 lladdr, np->dev->dev_addr,
721 send_skb->len) < 0) {
726 netpoll_send_skb(np, send_skb);
728 /* If there are several rx_hooks for the same address,
729 we're fine by sending a single reply */
732 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
737 static bool pkt_is_ns(struct sk_buff *skb)
742 if (skb->protocol != htons(ETH_P_ARP))
744 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
747 msg = (struct nd_msg *)skb_transport_header(skb);
748 __skb_push(skb, skb->data - skb_transport_header(skb));
751 if (hdr->nexthdr != IPPROTO_ICMPV6)
753 if (hdr->hop_limit != 255)
755 if (msg->icmph.icmp6_code != 0)
757 if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
763 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
765 int proto, len, ulen;
767 const struct iphdr *iph;
769 struct netpoll *np, *tmp;
771 if (list_empty(&npinfo->rx_np))
774 if (skb->dev->type != ARPHRD_ETHER)
777 /* check if netpoll clients need ARP */
778 if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
779 skb_queue_tail(&npinfo->neigh_tx, skb);
781 } else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
782 skb_queue_tail(&npinfo->neigh_tx, skb);
786 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
787 skb = vlan_untag(skb);
792 proto = ntohs(eth_hdr(skb)->h_proto);
793 if (proto != ETH_P_IP && proto != ETH_P_IPV6)
795 if (skb->pkt_type == PACKET_OTHERHOST)
800 if (proto == ETH_P_IP) {
801 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
803 iph = (struct iphdr *)skb->data;
804 if (iph->ihl < 5 || iph->version != 4)
806 if (!pskb_may_pull(skb, iph->ihl*4))
808 iph = (struct iphdr *)skb->data;
809 if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
812 len = ntohs(iph->tot_len);
813 if (skb->len < len || len < iph->ihl*4)
817 * Our transport medium may have padded the buffer out.
818 * Now We trim to the true length of the frame.
820 if (pskb_trim_rcsum(skb, len))
823 iph = (struct iphdr *)skb->data;
824 if (iph->protocol != IPPROTO_UDP)
828 uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
829 ulen = ntohs(uh->len);
833 if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
835 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
836 if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
838 if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
840 if (np->local_port && np->local_port != ntohs(uh->dest))
843 np->rx_hook(np, ntohs(uh->source),
845 ulen - sizeof(struct udphdr));
849 #if IS_ENABLED(CONFIG_IPV6)
850 const struct ipv6hdr *ip6h;
852 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
854 ip6h = (struct ipv6hdr *)skb->data;
855 if (ip6h->version != 6)
857 len = ntohs(ip6h->payload_len);
860 if (len + sizeof(struct ipv6hdr) > skb->len)
862 if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
864 ip6h = ipv6_hdr(skb);
865 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
868 ulen = ntohs(uh->len);
869 if (ulen != skb->len)
871 if (udp6_csum_init(skb, uh, IPPROTO_UDP))
873 list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
874 if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
876 if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
878 if (np->local_port && np->local_port != ntohs(uh->dest))
881 np->rx_hook(np, ntohs(uh->source),
883 ulen - sizeof(struct udphdr));
896 if (atomic_read(&trapped)) {
904 void netpoll_print_options(struct netpoll *np)
906 np_info(np, "local port %d\n", np->local_port);
908 np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
910 np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
911 np_info(np, "interface '%s'\n", np->dev_name);
912 np_info(np, "remote port %d\n", np->remote_port);
914 np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
916 np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
917 np_info(np, "remote ethernet address %pM\n", np->remote_mac);
919 EXPORT_SYMBOL(netpoll_print_options);
921 static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
925 if (!strchr(str, ':') &&
926 in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
930 if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
931 #if IS_ENABLED(CONFIG_IPV6)
941 int netpoll_parse_options(struct netpoll *np, char *opt)
943 char *cur=opt, *delim;
947 if ((delim = strchr(cur, '@')) == NULL)
950 if (kstrtou16(cur, 10, &np->local_port))
957 if ((delim = strchr(cur, '/')) == NULL)
960 ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
964 np->ipv6 = (bool)ipv6;
970 /* parse out dev name */
971 if ((delim = strchr(cur, ',')) == NULL)
974 strlcpy(np->dev_name, cur, sizeof(np->dev_name));
981 if ((delim = strchr(cur, '@')) == NULL)
984 if (*cur == ' ' || *cur == '\t')
985 np_info(np, "warning: whitespace is not allowed\n");
986 if (kstrtou16(cur, 10, &np->remote_port))
993 if ((delim = strchr(cur, '/')) == NULL)
996 ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
999 else if (np->ipv6 != (bool)ipv6)
1002 np->ipv6 = (bool)ipv6;
1007 if (!mac_pton(cur, np->remote_mac))
1011 netpoll_print_options(np);
1016 np_info(np, "couldn't parse config at '%s'!\n", cur);
1019 EXPORT_SYMBOL(netpoll_parse_options);
1021 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
1023 struct netpoll_info *npinfo;
1024 const struct net_device_ops *ops;
1025 unsigned long flags;
1029 strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
1030 INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
1032 if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
1033 !ndev->netdev_ops->ndo_poll_controller) {
1034 np_err(np, "%s doesn't support polling, aborting\n",
1040 if (!ndev->npinfo) {
1041 npinfo = kmalloc(sizeof(*npinfo), gfp);
1047 npinfo->rx_flags = 0;
1048 INIT_LIST_HEAD(&npinfo->rx_np);
1050 spin_lock_init(&npinfo->rx_lock);
1051 sema_init(&npinfo->dev_lock, 1);
1052 skb_queue_head_init(&npinfo->neigh_tx);
1053 skb_queue_head_init(&npinfo->txq);
1054 INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
1056 atomic_set(&npinfo->refcnt, 1);
1058 ops = np->dev->netdev_ops;
1059 if (ops->ndo_netpoll_setup) {
1060 err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
1065 npinfo = rtnl_dereference(ndev->npinfo);
1066 atomic_inc(&npinfo->refcnt);
1069 npinfo->netpoll = np;
1072 spin_lock_irqsave(&npinfo->rx_lock, flags);
1073 npinfo->rx_flags |= NETPOLL_RX_ENABLED;
1074 list_add_tail(&np->rx, &npinfo->rx_np);
1075 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1078 /* last thing to do is link it to the net device structure */
1079 rcu_assign_pointer(ndev->npinfo, npinfo);
1088 EXPORT_SYMBOL_GPL(__netpoll_setup);
1090 int netpoll_setup(struct netpoll *np)
1092 struct net_device *ndev = NULL;
1093 struct in_device *in_dev;
1098 struct net *net = current->nsproxy->net_ns;
1099 ndev = __dev_get_by_name(net, np->dev_name);
1102 np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
1108 if (netdev_master_upper_dev_get(ndev)) {
1109 np_err(np, "%s is a slave device, aborting\n", np->dev_name);
1114 if (!netif_running(ndev)) {
1115 unsigned long atmost, atleast;
1117 np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
1119 err = dev_open(ndev);
1122 np_err(np, "failed to open %s\n", ndev->name);
1127 atleast = jiffies + HZ/10;
1128 atmost = jiffies + carrier_timeout * HZ;
1129 while (!netif_carrier_ok(ndev)) {
1130 if (time_after(jiffies, atmost)) {
1131 np_notice(np, "timeout waiting for carrier\n");
1137 /* If carrier appears to come up instantly, we don't
1138 * trust it and pause so that we don't pump all our
1139 * queued console messages into the bitbucket.
1142 if (time_before(jiffies, atleast)) {
1143 np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
1149 if (!np->local_ip.ip) {
1151 in_dev = __in_dev_get_rtnl(ndev);
1153 if (!in_dev || !in_dev->ifa_list) {
1154 np_err(np, "no IP address for %s, aborting\n",
1156 err = -EDESTADDRREQ;
1160 np->local_ip.ip = in_dev->ifa_list->ifa_local;
1161 np_info(np, "local IP %pI4\n", &np->local_ip.ip);
1163 #if IS_ENABLED(CONFIG_IPV6)
1164 struct inet6_dev *idev;
1166 err = -EDESTADDRREQ;
1167 idev = __in6_dev_get(ndev);
1169 struct inet6_ifaddr *ifp;
1171 read_lock_bh(&idev->lock);
1172 list_for_each_entry(ifp, &idev->addr_list, if_list) {
1173 if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
1175 np->local_ip.in6 = ifp->addr;
1179 read_unlock_bh(&idev->lock);
1182 np_err(np, "no IPv6 address for %s, aborting\n",
1186 np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
1188 np_err(np, "IPv6 is not supported %s, aborting\n",
1196 /* fill up the skb queue */
1199 err = __netpoll_setup(np, ndev, GFP_KERNEL);
1212 EXPORT_SYMBOL(netpoll_setup);
1214 static int __init netpoll_init(void)
1216 skb_queue_head_init(&skb_pool);
1219 core_initcall(netpoll_init);
1221 static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
1223 struct netpoll_info *npinfo =
1224 container_of(rcu_head, struct netpoll_info, rcu);
1226 skb_queue_purge(&npinfo->neigh_tx);
1227 skb_queue_purge(&npinfo->txq);
1229 /* we can't call cancel_delayed_work_sync here, as we are in softirq */
1230 cancel_delayed_work(&npinfo->tx_work);
1232 /* clean after last, unfinished work */
1233 __skb_queue_purge(&npinfo->txq);
1234 /* now cancel it again */
1235 cancel_delayed_work(&npinfo->tx_work);
1239 void __netpoll_cleanup(struct netpoll *np)
1241 struct netpoll_info *npinfo;
1242 unsigned long flags;
1244 /* rtnl_dereference would be preferable here but
1245 * rcu_cleanup_netpoll path can put us in here safely without
1246 * holding the rtnl, so plain rcu_dereference it is
1248 npinfo = rtnl_dereference(np->dev->npinfo);
1252 if (!list_empty(&npinfo->rx_np)) {
1253 spin_lock_irqsave(&npinfo->rx_lock, flags);
1255 if (list_empty(&npinfo->rx_np))
1256 npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
1257 spin_unlock_irqrestore(&npinfo->rx_lock, flags);
1260 synchronize_srcu(&netpoll_srcu);
1262 if (atomic_dec_and_test(&npinfo->refcnt)) {
1263 const struct net_device_ops *ops;
1265 ops = np->dev->netdev_ops;
1266 if (ops->ndo_netpoll_cleanup)
1267 ops->ndo_netpoll_cleanup(np->dev);
1269 rcu_assign_pointer(np->dev->npinfo, NULL);
1270 call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
1273 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
1275 static void netpoll_async_cleanup(struct work_struct *work)
1277 struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
1280 __netpoll_cleanup(np);
1285 void __netpoll_free_async(struct netpoll *np)
1287 schedule_work(&np->cleanup_work);
1289 EXPORT_SYMBOL_GPL(__netpoll_free_async);
1291 void netpoll_cleanup(struct netpoll *np)
1297 __netpoll_cleanup(np);
1303 EXPORT_SYMBOL(netpoll_cleanup);
1305 int netpoll_trap(void)
1307 return atomic_read(&trapped);
1309 EXPORT_SYMBOL(netpoll_trap);
1311 void netpoll_set_trap(int trap)
1314 atomic_inc(&trapped);
1316 atomic_dec(&trapped);
1318 EXPORT_SYMBOL(netpoll_set_trap);