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 #include <linux/smp_lock.h>
13 #include <linux/netdevice.h>
14 #include <linux/etherdevice.h>
15 #include <linux/string.h>
16 #include <linux/inetdevice.h>
17 #include <linux/inet.h>
18 #include <linux/interrupt.h>
19 #include <linux/netpoll.h>
20 #include <linux/sched.h>
21 #include <linux/delay.h>
22 #include <linux/rcupdate.h>
23 #include <linux/workqueue.h>
26 #include <asm/unaligned.h>
29 * We maintain a small pool of fully-sized skbs, to make sure the
30 * message gets out even in extreme OOM situations.
33 #define MAX_UDP_CHUNK 1460
35 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
37 static DEFINE_SPINLOCK(skb_list_lock
);
39 static struct sk_buff
*skbs
;
41 static DEFINE_SPINLOCK(queue_lock
);
42 static int queue_depth
;
43 static struct sk_buff
*queue_head
, *queue_tail
;
45 static atomic_t trapped
;
47 #define NETPOLL_RX_ENABLED 1
48 #define NETPOLL_RX_DROP 2
50 #define MAX_SKB_SIZE \
51 (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
52 sizeof(struct iphdr) + sizeof(struct ethhdr))
54 static void zap_completion_queue(void);
56 static void queue_process(void *p
)
62 spin_lock_irqsave(&queue_lock
, flags
);
65 queue_head
= skb
->next
;
66 if (skb
== queue_tail
)
71 spin_unlock_irqrestore(&queue_lock
, flags
);
77 static DECLARE_WORK(send_queue
, queue_process
, NULL
);
79 void netpoll_queue(struct sk_buff
*skb
)
83 if (queue_depth
== MAX_QUEUE_DEPTH
) {
88 spin_lock_irqsave(&queue_lock
, flags
);
92 queue_tail
->next
= skb
;
95 spin_unlock_irqrestore(&queue_lock
, flags
);
97 schedule_work(&send_queue
);
100 static int checksum_udp(struct sk_buff
*skb
, struct udphdr
*uh
,
101 unsigned short ulen
, u32 saddr
, u32 daddr
)
106 if (skb
->ip_summed
== CHECKSUM_HW
)
107 return csum_tcpudp_magic(
108 saddr
, daddr
, ulen
, IPPROTO_UDP
, skb
->csum
);
110 skb
->csum
= csum_tcpudp_nofold(saddr
, daddr
, ulen
, IPPROTO_UDP
, 0);
112 return csum_fold(skb_checksum(skb
, 0, skb
->len
, skb
->csum
));
116 * Check whether delayed processing was scheduled for our NIC. If so,
117 * we attempt to grab the poll lock and use ->poll() to pump the card.
118 * If this fails, either we've recursed in ->poll() or it's already
119 * running on another CPU.
121 * Note: we don't mask interrupts with this lock because we're using
122 * trylock here and interrupts are already disabled in the softirq
123 * case. Further, we test the poll_owner to avoid recursion on UP
124 * systems where the lock doesn't exist.
126 * In cases where there is bi-directional communications, reading only
127 * one message at a time can lead to packets being dropped by the
128 * network adapter, forcing superfluous retries and possibly timeouts.
129 * Thus, we set our budget to greater than 1.
131 static void poll_napi(struct netpoll
*np
)
133 struct netpoll_info
*npinfo
= np
->dev
->npinfo
;
136 if (test_bit(__LINK_STATE_RX_SCHED
, &np
->dev
->state
) &&
137 npinfo
->poll_owner
!= smp_processor_id() &&
138 spin_trylock(&npinfo
->poll_lock
)) {
139 npinfo
->rx_flags
|= NETPOLL_RX_DROP
;
140 atomic_inc(&trapped
);
142 np
->dev
->poll(np
->dev
, &budget
);
144 atomic_dec(&trapped
);
145 npinfo
->rx_flags
&= ~NETPOLL_RX_DROP
;
146 spin_unlock(&npinfo
->poll_lock
);
150 void netpoll_poll(struct netpoll
*np
)
152 if(!np
->dev
|| !netif_running(np
->dev
) || !np
->dev
->poll_controller
)
155 /* Process pending work on NIC */
156 np
->dev
->poll_controller(np
->dev
);
160 zap_completion_queue();
163 static void refill_skbs(void)
168 spin_lock_irqsave(&skb_list_lock
, flags
);
169 while (nr_skbs
< MAX_SKBS
) {
170 skb
= alloc_skb(MAX_SKB_SIZE
, GFP_ATOMIC
);
178 spin_unlock_irqrestore(&skb_list_lock
, flags
);
181 static void zap_completion_queue(void)
184 struct softnet_data
*sd
= &get_cpu_var(softnet_data
);
186 if (sd
->completion_queue
) {
187 struct sk_buff
*clist
;
189 local_irq_save(flags
);
190 clist
= sd
->completion_queue
;
191 sd
->completion_queue
= NULL
;
192 local_irq_restore(flags
);
194 while (clist
!= NULL
) {
195 struct sk_buff
*skb
= clist
;
198 dev_kfree_skb_any(skb
); /* put this one back */
204 put_cpu_var(softnet_data
);
207 static struct sk_buff
* find_skb(struct netpoll
*np
, int len
, int reserve
)
209 int once
= 1, count
= 0;
211 struct sk_buff
*skb
= NULL
;
213 zap_completion_queue();
215 if (nr_skbs
< MAX_SKBS
)
218 skb
= alloc_skb(len
, GFP_ATOMIC
);
221 spin_lock_irqsave(&skb_list_lock
, flags
);
228 spin_unlock_irqrestore(&skb_list_lock
, flags
);
233 if (once
&& (count
== 1000000)) {
234 printk("out of netpoll skbs!\n");
241 atomic_set(&skb
->users
, 1);
242 skb_reserve(skb
, reserve
);
246 static void netpoll_send_skb(struct netpoll
*np
, struct sk_buff
*skb
)
249 struct netpoll_info
*npinfo
;
252 if(!np
|| !np
->dev
|| !netif_running(np
->dev
)) {
257 /* avoid recursion */
258 npinfo
= np
->dev
->npinfo
;
259 if (npinfo
->poll_owner
== smp_processor_id() ||
260 np
->dev
->xmit_lock_owner
== smp_processor_id()) {
268 spin_lock(&np
->dev
->xmit_lock
);
269 np
->dev
->xmit_lock_owner
= smp_processor_id();
272 * network drivers do not expect to be called if the queue is
275 if (netif_queue_stopped(np
->dev
)) {
276 np
->dev
->xmit_lock_owner
= -1;
277 spin_unlock(&np
->dev
->xmit_lock
);
283 status
= np
->dev
->hard_start_xmit(skb
, np
->dev
);
284 np
->dev
->xmit_lock_owner
= -1;
285 spin_unlock(&np
->dev
->xmit_lock
);
294 void netpoll_send_udp(struct netpoll
*np
, const char *msg
, int len
)
296 int total_len
, eth_len
, ip_len
, udp_len
;
302 udp_len
= len
+ sizeof(*udph
);
303 ip_len
= eth_len
= udp_len
+ sizeof(*iph
);
304 total_len
= eth_len
+ ETH_HLEN
+ NET_IP_ALIGN
;
306 skb
= find_skb(np
, total_len
, total_len
- len
);
310 memcpy(skb
->data
, msg
, len
);
313 udph
= (struct udphdr
*) skb_push(skb
, sizeof(*udph
));
314 udph
->source
= htons(np
->local_port
);
315 udph
->dest
= htons(np
->remote_port
);
316 udph
->len
= htons(udp_len
);
319 iph
= (struct iphdr
*)skb_push(skb
, sizeof(*iph
));
321 /* iph->version = 4; iph->ihl = 5; */
322 put_unaligned(0x45, (unsigned char *)iph
);
324 put_unaligned(htons(ip_len
), &(iph
->tot_len
));
328 iph
->protocol
= IPPROTO_UDP
;
330 put_unaligned(htonl(np
->local_ip
), &(iph
->saddr
));
331 put_unaligned(htonl(np
->remote_ip
), &(iph
->daddr
));
332 iph
->check
= ip_fast_csum((unsigned char *)iph
, iph
->ihl
);
334 eth
= (struct ethhdr
*) skb_push(skb
, ETH_HLEN
);
336 eth
->h_proto
= htons(ETH_P_IP
);
337 memcpy(eth
->h_source
, np
->local_mac
, 6);
338 memcpy(eth
->h_dest
, np
->remote_mac
, 6);
342 netpoll_send_skb(np
, skb
);
345 static void arp_reply(struct sk_buff
*skb
)
347 struct netpoll_info
*npinfo
= skb
->dev
->npinfo
;
349 unsigned char *arp_ptr
;
350 int size
, type
= ARPOP_REPLY
, ptype
= ETH_P_ARP
;
353 struct sk_buff
*send_skb
;
354 struct netpoll
*np
= NULL
;
356 spin_lock_irqsave(&npinfo
->rx_lock
, flags
);
357 if (npinfo
->rx_np
&& npinfo
->rx_np
->dev
== skb
->dev
)
359 spin_unlock_irqrestore(&npinfo
->rx_lock
, flags
);
364 /* No arp on this interface */
365 if (skb
->dev
->flags
& IFF_NOARP
)
368 if (!pskb_may_pull(skb
, (sizeof(struct arphdr
) +
369 (2 * skb
->dev
->addr_len
) +
373 skb
->h
.raw
= skb
->nh
.raw
= skb
->data
;
376 if ((arp
->ar_hrd
!= htons(ARPHRD_ETHER
) &&
377 arp
->ar_hrd
!= htons(ARPHRD_IEEE802
)) ||
378 arp
->ar_pro
!= htons(ETH_P_IP
) ||
379 arp
->ar_op
!= htons(ARPOP_REQUEST
))
382 arp_ptr
= (unsigned char *)(arp
+1) + skb
->dev
->addr_len
;
383 memcpy(&sip
, arp_ptr
, 4);
384 arp_ptr
+= 4 + skb
->dev
->addr_len
;
385 memcpy(&tip
, arp_ptr
, 4);
387 /* Should we ignore arp? */
388 if (tip
!= htonl(np
->local_ip
) || LOOPBACK(tip
) || MULTICAST(tip
))
391 size
= sizeof(struct arphdr
) + 2 * (skb
->dev
->addr_len
+ 4);
392 send_skb
= find_skb(np
, size
+ LL_RESERVED_SPACE(np
->dev
),
393 LL_RESERVED_SPACE(np
->dev
));
398 send_skb
->nh
.raw
= send_skb
->data
;
399 arp
= (struct arphdr
*) skb_put(send_skb
, size
);
400 send_skb
->dev
= skb
->dev
;
401 send_skb
->protocol
= htons(ETH_P_ARP
);
403 /* Fill the device header for the ARP frame */
405 if (np
->dev
->hard_header
&&
406 np
->dev
->hard_header(send_skb
, skb
->dev
, ptype
,
407 np
->remote_mac
, np
->local_mac
,
408 send_skb
->len
) < 0) {
414 * Fill out the arp protocol part.
416 * we only support ethernet device type,
417 * which (according to RFC 1390) should always equal 1 (Ethernet).
420 arp
->ar_hrd
= htons(np
->dev
->type
);
421 arp
->ar_pro
= htons(ETH_P_IP
);
422 arp
->ar_hln
= np
->dev
->addr_len
;
424 arp
->ar_op
= htons(type
);
426 arp_ptr
=(unsigned char *)(arp
+ 1);
427 memcpy(arp_ptr
, np
->dev
->dev_addr
, np
->dev
->addr_len
);
428 arp_ptr
+= np
->dev
->addr_len
;
429 memcpy(arp_ptr
, &tip
, 4);
431 memcpy(arp_ptr
, np
->remote_mac
, np
->dev
->addr_len
);
432 arp_ptr
+= np
->dev
->addr_len
;
433 memcpy(arp_ptr
, &sip
, 4);
435 netpoll_send_skb(np
, send_skb
);
438 int __netpoll_rx(struct sk_buff
*skb
)
440 int proto
, len
, ulen
;
443 struct netpoll
*np
= skb
->dev
->npinfo
->rx_np
;
447 if (skb
->dev
->type
!= ARPHRD_ETHER
)
450 /* check if netpoll clients need ARP */
451 if (skb
->protocol
== __constant_htons(ETH_P_ARP
) &&
452 atomic_read(&trapped
)) {
457 proto
= ntohs(eth_hdr(skb
)->h_proto
);
458 if (proto
!= ETH_P_IP
)
460 if (skb
->pkt_type
== PACKET_OTHERHOST
)
465 iph
= (struct iphdr
*)skb
->data
;
466 if (!pskb_may_pull(skb
, sizeof(struct iphdr
)))
468 if (iph
->ihl
< 5 || iph
->version
!= 4)
470 if (!pskb_may_pull(skb
, iph
->ihl
*4))
472 if (ip_fast_csum((u8
*)iph
, iph
->ihl
) != 0)
475 len
= ntohs(iph
->tot_len
);
476 if (skb
->len
< len
|| len
< iph
->ihl
*4)
479 if (iph
->protocol
!= IPPROTO_UDP
)
483 uh
= (struct udphdr
*)(((char *)iph
) + iph
->ihl
*4);
484 ulen
= ntohs(uh
->len
);
488 if (checksum_udp(skb
, uh
, ulen
, iph
->saddr
, iph
->daddr
) < 0)
490 if (np
->local_ip
&& np
->local_ip
!= ntohl(iph
->daddr
))
492 if (np
->remote_ip
&& np
->remote_ip
!= ntohl(iph
->saddr
))
494 if (np
->local_port
&& np
->local_port
!= ntohs(uh
->dest
))
497 np
->rx_hook(np
, ntohs(uh
->source
),
499 ulen
- sizeof(struct udphdr
));
505 if (atomic_read(&trapped
)) {
513 int netpoll_parse_options(struct netpoll
*np
, char *opt
)
515 char *cur
=opt
, *delim
;
518 if ((delim
= strchr(cur
, '@')) == NULL
)
521 np
->local_port
=simple_strtol(cur
, NULL
, 10);
525 printk(KERN_INFO
"%s: local port %d\n", np
->name
, np
->local_port
);
528 if ((delim
= strchr(cur
, '/')) == NULL
)
531 np
->local_ip
=ntohl(in_aton(cur
));
534 printk(KERN_INFO
"%s: local IP %d.%d.%d.%d\n",
535 np
->name
, HIPQUAD(np
->local_ip
));
540 /* parse out dev name */
541 if ((delim
= strchr(cur
, ',')) == NULL
)
544 strlcpy(np
->dev_name
, cur
, sizeof(np
->dev_name
));
549 printk(KERN_INFO
"%s: interface %s\n", np
->name
, np
->dev_name
);
553 if ((delim
= strchr(cur
, '@')) == NULL
)
556 np
->remote_port
=simple_strtol(cur
, NULL
, 10);
560 printk(KERN_INFO
"%s: remote port %d\n", np
->name
, np
->remote_port
);
563 if ((delim
= strchr(cur
, '/')) == NULL
)
566 np
->remote_ip
=ntohl(in_aton(cur
));
569 printk(KERN_INFO
"%s: remote IP %d.%d.%d.%d\n",
570 np
->name
, HIPQUAD(np
->remote_ip
));
575 if ((delim
= strchr(cur
, ':')) == NULL
)
578 np
->remote_mac
[0]=simple_strtol(cur
, NULL
, 16);
580 if ((delim
= strchr(cur
, ':')) == NULL
)
583 np
->remote_mac
[1]=simple_strtol(cur
, NULL
, 16);
585 if ((delim
= strchr(cur
, ':')) == NULL
)
588 np
->remote_mac
[2]=simple_strtol(cur
, NULL
, 16);
590 if ((delim
= strchr(cur
, ':')) == NULL
)
593 np
->remote_mac
[3]=simple_strtol(cur
, NULL
, 16);
595 if ((delim
= strchr(cur
, ':')) == NULL
)
598 np
->remote_mac
[4]=simple_strtol(cur
, NULL
, 16);
600 np
->remote_mac
[5]=simple_strtol(cur
, NULL
, 16);
603 printk(KERN_INFO
"%s: remote ethernet address "
604 "%02x:%02x:%02x:%02x:%02x:%02x\n",
616 printk(KERN_INFO
"%s: couldn't parse config at %s!\n",
621 int netpoll_setup(struct netpoll
*np
)
623 struct net_device
*ndev
= NULL
;
624 struct in_device
*in_dev
;
625 struct netpoll_info
*npinfo
;
629 ndev
= dev_get_by_name(np
->dev_name
);
631 printk(KERN_ERR
"%s: %s doesn't exist, aborting.\n",
632 np
->name
, np
->dev_name
);
638 npinfo
= kmalloc(sizeof(*npinfo
), GFP_KERNEL
);
642 npinfo
->rx_np
= NULL
;
643 npinfo
->poll_lock
= SPIN_LOCK_UNLOCKED
;
644 npinfo
->poll_owner
= -1;
645 npinfo
->rx_lock
= SPIN_LOCK_UNLOCKED
;
647 npinfo
= ndev
->npinfo
;
649 if (!ndev
->poll_controller
) {
650 printk(KERN_ERR
"%s: %s doesn't support polling, aborting.\n",
651 np
->name
, np
->dev_name
);
655 if (!netif_running(ndev
)) {
656 unsigned long atmost
, atleast
;
658 printk(KERN_INFO
"%s: device %s not up yet, forcing it\n",
659 np
->name
, np
->dev_name
);
662 if (dev_change_flags(ndev
, ndev
->flags
| IFF_UP
) < 0) {
663 printk(KERN_ERR
"%s: failed to open %s\n",
664 np
->name
, np
->dev_name
);
670 atleast
= jiffies
+ HZ
/10;
671 atmost
= jiffies
+ 4*HZ
;
672 while (!netif_carrier_ok(ndev
)) {
673 if (time_after(jiffies
, atmost
)) {
675 "%s: timeout waiting for carrier\n",
682 /* If carrier appears to come up instantly, we don't
683 * trust it and pause so that we don't pump all our
684 * queued console messages into the bitbucket.
687 if (time_before(jiffies
, atleast
)) {
688 printk(KERN_NOTICE
"%s: carrier detect appears"
689 " untrustworthy, waiting 4 seconds\n",
695 if (!memcmp(np
->local_mac
, "\0\0\0\0\0\0", 6) && ndev
->dev_addr
)
696 memcpy(np
->local_mac
, ndev
->dev_addr
, 6);
700 in_dev
= __in_dev_get(ndev
);
702 if (!in_dev
|| !in_dev
->ifa_list
) {
704 printk(KERN_ERR
"%s: no IP address for %s, aborting\n",
705 np
->name
, np
->dev_name
);
709 np
->local_ip
= ntohl(in_dev
->ifa_list
->ifa_local
);
711 printk(KERN_INFO
"%s: local IP %d.%d.%d.%d\n",
712 np
->name
, HIPQUAD(np
->local_ip
));
716 spin_lock_irqsave(&npinfo
->rx_lock
, flags
);
717 npinfo
->rx_flags
|= NETPOLL_RX_ENABLED
;
719 spin_unlock_irqrestore(&npinfo
->rx_lock
, flags
);
721 /* last thing to do is link it to the net device structure */
722 ndev
->npinfo
= npinfo
;
734 void netpoll_cleanup(struct netpoll
*np
)
736 struct netpoll_info
*npinfo
;
740 npinfo
= np
->dev
->npinfo
;
741 if (npinfo
&& npinfo
->rx_np
== np
) {
742 spin_lock_irqsave(&npinfo
->rx_lock
, flags
);
743 npinfo
->rx_np
= NULL
;
744 npinfo
->rx_flags
&= ~NETPOLL_RX_ENABLED
;
745 spin_unlock_irqrestore(&npinfo
->rx_lock
, flags
);
753 int netpoll_trap(void)
755 return atomic_read(&trapped
);
758 void netpoll_set_trap(int trap
)
761 atomic_inc(&trapped
);
763 atomic_dec(&trapped
);
766 EXPORT_SYMBOL(netpoll_set_trap
);
767 EXPORT_SYMBOL(netpoll_trap
);
768 EXPORT_SYMBOL(netpoll_parse_options
);
769 EXPORT_SYMBOL(netpoll_setup
);
770 EXPORT_SYMBOL(netpoll_cleanup
);
771 EXPORT_SYMBOL(netpoll_send_udp
);
772 EXPORT_SYMBOL(netpoll_poll
);
773 EXPORT_SYMBOL(netpoll_queue
);