2 * This is a module which is used for queueing IPv4 packets and
3 * communicating with userspace via netlink.
5 * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
6 * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * 2000-03-27: Simplified code (thanks to Andi Kleen for clues).
13 * 2000-05-20: Fixed notifier problems (following Miguel Freitas' report).
14 * 2000-06-19: Fixed so nfmark is copied to metadata (reported by Sebastian
16 * 2000-08-01: Added Nick Williams' MAC support.
17 * 2002-06-25: Code cleanup.
18 * 2005-01-10: Added /proc counter for dropped packets; fixed so
19 * packets aren't delivered to user space if they're going
21 * 2005-05-26: local_bh_{disable,enable} around nf_reinject (Harald Welte)
24 #include <linux/module.h>
25 #include <linux/skbuff.h>
26 #include <linux/init.h>
28 #include <linux/notifier.h>
29 #include <linux/netdevice.h>
30 #include <linux/netfilter.h>
31 #include <linux/netfilter_ipv4/ip_queue.h>
32 #include <linux/netfilter_ipv4/ip_tables.h>
33 #include <linux/netlink.h>
34 #include <linux/spinlock.h>
35 #include <linux/sysctl.h>
36 #include <linux/proc_fs.h>
37 #include <linux/security.h>
38 #include <linux/mutex.h>
40 #include <net/route.h>
42 #define IPQ_QMAX_DEFAULT 1024
43 #define IPQ_PROC_FS_NAME "ip_queue"
44 #define NET_IPQ_QMAX 2088
45 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
47 struct ipq_queue_entry
{
48 struct list_head list
;
53 typedef int (*ipq_cmpfn
)(struct ipq_queue_entry
*, unsigned long);
55 static unsigned char copy_mode
= IPQ_COPY_NONE
;
56 static unsigned int queue_maxlen
= IPQ_QMAX_DEFAULT
;
57 static DEFINE_RWLOCK(queue_lock
);
59 static unsigned int copy_range
;
60 static unsigned int queue_total
;
61 static unsigned int queue_dropped
= 0;
62 static unsigned int queue_user_dropped
= 0;
63 static struct sock
*ipqnl
;
64 static LIST_HEAD(queue_list
);
65 static DEFINE_MUTEX(ipqnl_mutex
);
68 ipq_issue_verdict(struct ipq_queue_entry
*entry
, int verdict
)
70 /* TCP input path (and probably other bits) assume to be called
71 * from softirq context, not from syscall, like ipq_issue_verdict is
72 * called. TCP input path deadlocks with locks taken from timer
73 * softirq, e.g. We therefore emulate this by local_bh_disable() */
76 nf_reinject(entry
->skb
, entry
->info
, verdict
);
83 __ipq_enqueue_entry(struct ipq_queue_entry
*entry
)
85 list_add(&entry
->list
, &queue_list
);
90 * Find and return a queued entry matched by cmpfn, or return the last
91 * entry if cmpfn is NULL.
93 static inline struct ipq_queue_entry
*
94 __ipq_find_entry(ipq_cmpfn cmpfn
, unsigned long data
)
98 list_for_each_prev(p
, &queue_list
) {
99 struct ipq_queue_entry
*entry
= (struct ipq_queue_entry
*)p
;
101 if (!cmpfn
|| cmpfn(entry
, data
))
108 __ipq_dequeue_entry(struct ipq_queue_entry
*entry
)
110 list_del(&entry
->list
);
114 static inline struct ipq_queue_entry
*
115 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn
, unsigned long data
)
117 struct ipq_queue_entry
*entry
;
119 entry
= __ipq_find_entry(cmpfn
, data
);
123 __ipq_dequeue_entry(entry
);
129 __ipq_flush(int verdict
)
131 struct ipq_queue_entry
*entry
;
133 while ((entry
= __ipq_find_dequeue_entry(NULL
, 0)))
134 ipq_issue_verdict(entry
, verdict
);
138 __ipq_set_mode(unsigned char mode
, unsigned int range
)
149 case IPQ_COPY_PACKET
:
152 if (copy_range
> 0xFFFF)
167 net_disable_timestamp();
168 __ipq_set_mode(IPQ_COPY_NONE
, 0);
169 __ipq_flush(NF_DROP
);
172 static struct ipq_queue_entry
*
173 ipq_find_dequeue_entry(ipq_cmpfn cmpfn
, unsigned long data
)
175 struct ipq_queue_entry
*entry
;
177 write_lock_bh(&queue_lock
);
178 entry
= __ipq_find_dequeue_entry(cmpfn
, data
);
179 write_unlock_bh(&queue_lock
);
184 ipq_flush(int verdict
)
186 write_lock_bh(&queue_lock
);
187 __ipq_flush(verdict
);
188 write_unlock_bh(&queue_lock
);
191 static struct sk_buff
*
192 ipq_build_packet_message(struct ipq_queue_entry
*entry
, int *errp
)
194 unsigned char *old_tail
;
198 struct ipq_packet_msg
*pmsg
;
199 struct nlmsghdr
*nlh
;
201 read_lock_bh(&queue_lock
);
206 size
= NLMSG_SPACE(sizeof(*pmsg
));
210 case IPQ_COPY_PACKET
:
211 if (entry
->skb
->ip_summed
== CHECKSUM_HW
&&
212 (*errp
= skb_checksum_help(entry
->skb
,
213 entry
->info
->outdev
== NULL
))) {
214 read_unlock_bh(&queue_lock
);
217 if (copy_range
== 0 || copy_range
> entry
->skb
->len
)
218 data_len
= entry
->skb
->len
;
220 data_len
= copy_range
;
222 size
= NLMSG_SPACE(sizeof(*pmsg
) + data_len
);
227 read_unlock_bh(&queue_lock
);
231 read_unlock_bh(&queue_lock
);
233 skb
= alloc_skb(size
, GFP_ATOMIC
);
238 nlh
= NLMSG_PUT(skb
, 0, 0, IPQM_PACKET
, size
- sizeof(*nlh
));
239 pmsg
= NLMSG_DATA(nlh
);
240 memset(pmsg
, 0, sizeof(*pmsg
));
242 pmsg
->packet_id
= (unsigned long )entry
;
243 pmsg
->data_len
= data_len
;
244 pmsg
->timestamp_sec
= entry
->skb
->tstamp
.off_sec
;
245 pmsg
->timestamp_usec
= entry
->skb
->tstamp
.off_usec
;
246 pmsg
->mark
= entry
->skb
->nfmark
;
247 pmsg
->hook
= entry
->info
->hook
;
248 pmsg
->hw_protocol
= entry
->skb
->protocol
;
250 if (entry
->info
->indev
)
251 strcpy(pmsg
->indev_name
, entry
->info
->indev
->name
);
253 pmsg
->indev_name
[0] = '\0';
255 if (entry
->info
->outdev
)
256 strcpy(pmsg
->outdev_name
, entry
->info
->outdev
->name
);
258 pmsg
->outdev_name
[0] = '\0';
260 if (entry
->info
->indev
&& entry
->skb
->dev
) {
261 pmsg
->hw_type
= entry
->skb
->dev
->type
;
262 if (entry
->skb
->dev
->hard_header_parse
)
264 entry
->skb
->dev
->hard_header_parse(entry
->skb
,
269 if (skb_copy_bits(entry
->skb
, 0, pmsg
->payload
, data_len
))
272 nlh
->nlmsg_len
= skb
->tail
- old_tail
;
279 printk(KERN_ERR
"ip_queue: error creating packet message\n");
284 ipq_enqueue_packet(struct sk_buff
*skb
, struct nf_info
*info
,
285 unsigned int queuenum
, void *data
)
287 int status
= -EINVAL
;
288 struct sk_buff
*nskb
;
289 struct ipq_queue_entry
*entry
;
291 if (copy_mode
== IPQ_COPY_NONE
)
294 entry
= kmalloc(sizeof(*entry
), GFP_ATOMIC
);
296 printk(KERN_ERR
"ip_queue: OOM in ipq_enqueue_packet()\n");
303 nskb
= ipq_build_packet_message(entry
, &status
);
307 write_lock_bh(&queue_lock
);
310 goto err_out_free_nskb
;
312 if (queue_total
>= queue_maxlen
) {
316 printk (KERN_WARNING
"ip_queue: full at %d entries, "
317 "dropping packets(s). Dropped: %d\n", queue_total
,
319 goto err_out_free_nskb
;
322 /* netlink_unicast will either free the nskb or attach it to a socket */
323 status
= netlink_unicast(ipqnl
, nskb
, peer_pid
, MSG_DONTWAIT
);
325 queue_user_dropped
++;
329 __ipq_enqueue_entry(entry
);
331 write_unlock_bh(&queue_lock
);
338 write_unlock_bh(&queue_lock
);
346 ipq_mangle_ipv4(ipq_verdict_msg_t
*v
, struct ipq_queue_entry
*e
)
349 struct iphdr
*user_iph
= (struct iphdr
*)v
->payload
;
351 if (v
->data_len
< sizeof(*user_iph
))
353 diff
= v
->data_len
- e
->skb
->len
;
355 skb_trim(e
->skb
, v
->data_len
);
357 if (v
->data_len
> 0xFFFF)
359 if (diff
> skb_tailroom(e
->skb
)) {
360 struct sk_buff
*newskb
;
362 newskb
= skb_copy_expand(e
->skb
,
363 skb_headroom(e
->skb
),
366 if (newskb
== NULL
) {
367 printk(KERN_WARNING
"ip_queue: OOM "
368 "in mangle, dropping packet\n");
372 skb_set_owner_w(newskb
, e
->skb
->sk
);
376 skb_put(e
->skb
, diff
);
378 if (!skb_make_writable(&e
->skb
, v
->data_len
))
380 memcpy(e
->skb
->data
, v
->payload
, v
->data_len
);
381 e
->skb
->ip_summed
= CHECKSUM_NONE
;
387 id_cmp(struct ipq_queue_entry
*e
, unsigned long id
)
389 return (id
== (unsigned long )e
);
393 ipq_set_verdict(struct ipq_verdict_msg
*vmsg
, unsigned int len
)
395 struct ipq_queue_entry
*entry
;
397 if (vmsg
->value
> NF_MAX_VERDICT
)
400 entry
= ipq_find_dequeue_entry(id_cmp
, vmsg
->id
);
404 int verdict
= vmsg
->value
;
406 if (vmsg
->data_len
&& vmsg
->data_len
== len
)
407 if (ipq_mangle_ipv4(vmsg
, entry
) < 0)
410 ipq_issue_verdict(entry
, verdict
);
416 ipq_set_mode(unsigned char mode
, unsigned int range
)
420 write_lock_bh(&queue_lock
);
421 status
= __ipq_set_mode(mode
, range
);
422 write_unlock_bh(&queue_lock
);
427 ipq_receive_peer(struct ipq_peer_msg
*pmsg
,
428 unsigned char type
, unsigned int len
)
432 if (len
< sizeof(*pmsg
))
437 status
= ipq_set_mode(pmsg
->msg
.mode
.value
,
438 pmsg
->msg
.mode
.range
);
442 if (pmsg
->msg
.verdict
.value
> NF_MAX_VERDICT
)
445 status
= ipq_set_verdict(&pmsg
->msg
.verdict
,
446 len
- sizeof(*pmsg
));
455 dev_cmp(struct ipq_queue_entry
*entry
, unsigned long ifindex
)
457 if (entry
->info
->indev
)
458 if (entry
->info
->indev
->ifindex
== ifindex
)
461 if (entry
->info
->outdev
)
462 if (entry
->info
->outdev
->ifindex
== ifindex
)
469 ipq_dev_drop(int ifindex
)
471 struct ipq_queue_entry
*entry
;
473 while ((entry
= ipq_find_dequeue_entry(dev_cmp
, ifindex
)) != NULL
)
474 ipq_issue_verdict(entry
, NF_DROP
);
477 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
480 ipq_rcv_skb(struct sk_buff
*skb
)
482 int status
, type
, pid
, flags
, nlmsglen
, skblen
;
483 struct nlmsghdr
*nlh
;
486 if (skblen
< sizeof(*nlh
))
489 nlh
= (struct nlmsghdr
*)skb
->data
;
490 nlmsglen
= nlh
->nlmsg_len
;
491 if (nlmsglen
< sizeof(*nlh
) || skblen
< nlmsglen
)
494 pid
= nlh
->nlmsg_pid
;
495 flags
= nlh
->nlmsg_flags
;
497 if(pid
<= 0 || !(flags
& NLM_F_REQUEST
) || flags
& NLM_F_MULTI
)
498 RCV_SKB_FAIL(-EINVAL
);
500 if (flags
& MSG_TRUNC
)
501 RCV_SKB_FAIL(-ECOMM
);
503 type
= nlh
->nlmsg_type
;
504 if (type
< NLMSG_NOOP
|| type
>= IPQM_MAX
)
505 RCV_SKB_FAIL(-EINVAL
);
507 if (type
<= IPQM_BASE
)
510 if (security_netlink_recv(skb
))
511 RCV_SKB_FAIL(-EPERM
);
513 write_lock_bh(&queue_lock
);
516 if (peer_pid
!= pid
) {
517 write_unlock_bh(&queue_lock
);
518 RCV_SKB_FAIL(-EBUSY
);
521 net_enable_timestamp();
525 write_unlock_bh(&queue_lock
);
527 status
= ipq_receive_peer(NLMSG_DATA(nlh
), type
,
528 nlmsglen
- NLMSG_LENGTH(0));
530 RCV_SKB_FAIL(status
);
532 if (flags
& NLM_F_ACK
)
533 netlink_ack(skb
, nlh
, 0);
538 ipq_rcv_sk(struct sock
*sk
, int len
)
543 mutex_lock(&ipqnl_mutex
);
545 for (qlen
= skb_queue_len(&sk
->sk_receive_queue
); qlen
; qlen
--) {
546 skb
= skb_dequeue(&sk
->sk_receive_queue
);
551 mutex_unlock(&ipqnl_mutex
);
555 ipq_rcv_dev_event(struct notifier_block
*this,
556 unsigned long event
, void *ptr
)
558 struct net_device
*dev
= ptr
;
560 /* Drop any packets associated with the downed device */
561 if (event
== NETDEV_DOWN
)
562 ipq_dev_drop(dev
->ifindex
);
566 static struct notifier_block ipq_dev_notifier
= {
567 .notifier_call
= ipq_rcv_dev_event
,
571 ipq_rcv_nl_event(struct notifier_block
*this,
572 unsigned long event
, void *ptr
)
574 struct netlink_notify
*n
= ptr
;
576 if (event
== NETLINK_URELEASE
&&
577 n
->protocol
== NETLINK_FIREWALL
&& n
->pid
) {
578 write_lock_bh(&queue_lock
);
579 if (n
->pid
== peer_pid
)
581 write_unlock_bh(&queue_lock
);
586 static struct notifier_block ipq_nl_notifier
= {
587 .notifier_call
= ipq_rcv_nl_event
,
590 static struct ctl_table_header
*ipq_sysctl_header
;
592 static ctl_table ipq_table
[] = {
594 .ctl_name
= NET_IPQ_QMAX
,
595 .procname
= NET_IPQ_QMAX_NAME
,
596 .data
= &queue_maxlen
,
597 .maxlen
= sizeof(queue_maxlen
),
599 .proc_handler
= proc_dointvec
604 static ctl_table ipq_dir_table
[] = {
606 .ctl_name
= NET_IPV4
,
614 static ctl_table ipq_root_table
[] = {
619 .child
= ipq_dir_table
624 #ifdef CONFIG_PROC_FS
626 ipq_get_info(char *buffer
, char **start
, off_t offset
, int length
)
630 read_lock_bh(&queue_lock
);
632 len
= sprintf(buffer
,
636 "Queue length : %u\n"
637 "Queue max. length : %u\n"
638 "Queue dropped : %u\n"
639 "Netlink dropped : %u\n",
648 read_unlock_bh(&queue_lock
);
650 *start
= buffer
+ offset
;
658 #endif /* CONFIG_PROC_FS */
660 static struct nf_queue_handler nfqh
= {
662 .outfn
= &ipq_enqueue_packet
,
665 static int __init
ip_queue_init(void)
667 int status
= -ENOMEM
;
668 struct proc_dir_entry
*proc
;
670 netlink_register_notifier(&ipq_nl_notifier
);
671 ipqnl
= netlink_kernel_create(NETLINK_FIREWALL
, 0, ipq_rcv_sk
,
674 printk(KERN_ERR
"ip_queue: failed to create netlink socket\n");
675 goto cleanup_netlink_notifier
;
678 proc
= proc_net_create(IPQ_PROC_FS_NAME
, 0, ipq_get_info
);
680 proc
->owner
= THIS_MODULE
;
682 printk(KERN_ERR
"ip_queue: failed to create proc entry\n");
686 register_netdevice_notifier(&ipq_dev_notifier
);
687 ipq_sysctl_header
= register_sysctl_table(ipq_root_table
, 0);
689 status
= nf_register_queue_handler(PF_INET
, &nfqh
);
691 printk(KERN_ERR
"ip_queue: failed to register queue handler\n");
697 unregister_sysctl_table(ipq_sysctl_header
);
698 unregister_netdevice_notifier(&ipq_dev_notifier
);
699 proc_net_remove(IPQ_PROC_FS_NAME
);
702 sock_release(ipqnl
->sk_socket
);
703 mutex_lock(&ipqnl_mutex
);
704 mutex_unlock(&ipqnl_mutex
);
706 cleanup_netlink_notifier
:
707 netlink_unregister_notifier(&ipq_nl_notifier
);
711 static void __exit
ip_queue_fini(void)
713 nf_unregister_queue_handlers(&nfqh
);
717 unregister_sysctl_table(ipq_sysctl_header
);
718 unregister_netdevice_notifier(&ipq_dev_notifier
);
719 proc_net_remove(IPQ_PROC_FS_NAME
);
721 sock_release(ipqnl
->sk_socket
);
722 mutex_lock(&ipqnl_mutex
);
723 mutex_unlock(&ipqnl_mutex
);
725 netlink_unregister_notifier(&ipq_nl_notifier
);
728 MODULE_DESCRIPTION("IPv4 packet queue handler");
729 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
730 MODULE_LICENSE("GPL");
732 module_init(ip_queue_init
);
733 module_exit(ip_queue_fini
);