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 #include <linux/module.h>
13 #include <linux/skbuff.h>
14 #include <linux/init.h>
16 #include <linux/notifier.h>
17 #include <linux/netdevice.h>
18 #include <linux/netfilter.h>
19 #include <linux/netfilter_ipv4/ip_queue.h>
20 #include <linux/netfilter_ipv4/ip_tables.h>
21 #include <linux/netlink.h>
22 #include <linux/spinlock.h>
23 #include <linux/sysctl.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/security.h>
27 #include <linux/mutex.h>
28 #include <net/net_namespace.h>
30 #include <net/route.h>
31 #include <net/netfilter/nf_queue.h>
34 #define IPQ_QMAX_DEFAULT 1024
35 #define IPQ_PROC_FS_NAME "ip_queue"
36 #define NET_IPQ_QMAX 2088
37 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
39 typedef int (*ipq_cmpfn)(struct nf_queue_entry *, unsigned long);
41 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
42 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
43 static DEFINE_RWLOCK(queue_lock);
44 static int peer_pid __read_mostly;
45 static unsigned int copy_range __read_mostly;
46 static unsigned int queue_total;
47 static unsigned int queue_dropped = 0;
48 static unsigned int queue_user_dropped = 0;
49 static struct sock *ipqnl __read_mostly;
50 static LIST_HEAD(queue_list);
51 static DEFINE_MUTEX(ipqnl_mutex);
54 __ipq_enqueue_entry(struct nf_queue_entry *entry)
56 list_add_tail(&entry->list, &queue_list);
61 __ipq_set_mode(unsigned char mode, unsigned int range)
75 if (copy_range > 0xFFFF)
86 static void __ipq_flush(ipq_cmpfn cmpfn, unsigned long data);
92 net_disable_timestamp();
93 __ipq_set_mode(IPQ_COPY_NONE, 0);
97 static struct nf_queue_entry *
98 ipq_find_dequeue_entry(unsigned long id)
100 struct nf_queue_entry *entry = NULL, *i;
102 write_lock_bh(&queue_lock);
104 list_for_each_entry(i, &queue_list, list) {
105 if ((unsigned long)i == id) {
112 list_del(&entry->list);
116 write_unlock_bh(&queue_lock);
121 __ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
123 struct nf_queue_entry *entry, *next;
125 list_for_each_entry_safe(entry, next, &queue_list, list) {
126 if (!cmpfn || cmpfn(entry, data)) {
127 list_del(&entry->list);
129 nf_reinject(entry, NF_DROP);
135 ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
137 write_lock_bh(&queue_lock);
138 __ipq_flush(cmpfn, data);
139 write_unlock_bh(&queue_lock);
142 static struct sk_buff *
143 ipq_build_packet_message(struct nf_queue_entry *entry, int *errp)
145 sk_buff_data_t old_tail;
149 struct ipq_packet_msg *pmsg;
150 struct nlmsghdr *nlh;
153 read_lock_bh(&queue_lock);
158 size = NLMSG_SPACE(sizeof(*pmsg));
162 case IPQ_COPY_PACKET:
163 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
164 entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
165 (*errp = skb_checksum_help(entry->skb))) {
166 read_unlock_bh(&queue_lock);
169 if (copy_range == 0 || copy_range > entry->skb->len)
170 data_len = entry->skb->len;
172 data_len = copy_range;
174 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
179 read_unlock_bh(&queue_lock);
183 read_unlock_bh(&queue_lock);
185 skb = alloc_skb(size, GFP_ATOMIC);
189 old_tail = skb->tail;
190 nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
191 pmsg = NLMSG_DATA(nlh);
192 memset(pmsg, 0, sizeof(*pmsg));
194 pmsg->packet_id = (unsigned long )entry;
195 pmsg->data_len = data_len;
196 tv = ktime_to_timeval(entry->skb->tstamp);
197 pmsg->timestamp_sec = tv.tv_sec;
198 pmsg->timestamp_usec = tv.tv_usec;
199 pmsg->mark = entry->skb->mark;
200 pmsg->hook = entry->hook;
201 pmsg->hw_protocol = entry->skb->protocol;
204 strcpy(pmsg->indev_name, entry->indev->name);
206 pmsg->indev_name[0] = '\0';
209 strcpy(pmsg->outdev_name, entry->outdev->name);
211 pmsg->outdev_name[0] = '\0';
213 if (entry->indev && entry->skb->dev) {
214 pmsg->hw_type = entry->skb->dev->type;
215 pmsg->hw_addrlen = dev_parse_header(entry->skb,
220 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
223 nlh->nlmsg_len = skb->tail - old_tail;
230 printk(KERN_ERR "ip_queue: error creating packet message\n");
235 ipq_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
237 int status = -EINVAL;
238 struct sk_buff *nskb;
240 if (copy_mode == IPQ_COPY_NONE)
243 nskb = ipq_build_packet_message(entry, &status);
247 write_lock_bh(&queue_lock);
250 goto err_out_free_nskb;
252 if (queue_total >= queue_maxlen) {
256 printk (KERN_WARNING "ip_queue: full at %d entries, "
257 "dropping packets(s). Dropped: %d\n", queue_total,
259 goto err_out_free_nskb;
262 /* netlink_unicast will either free the nskb or attach it to a socket */
263 status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
265 queue_user_dropped++;
269 __ipq_enqueue_entry(entry);
271 write_unlock_bh(&queue_lock);
278 write_unlock_bh(&queue_lock);
283 ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct nf_queue_entry *e)
286 struct iphdr *user_iph = (struct iphdr *)v->payload;
287 struct sk_buff *nskb;
289 if (v->data_len < sizeof(*user_iph))
291 diff = v->data_len - e->skb->len;
293 if (pskb_trim(e->skb, v->data_len))
295 } else if (diff > 0) {
296 if (v->data_len > 0xFFFF)
298 if (diff > skb_tailroom(e->skb)) {
299 nskb = skb_copy_expand(e->skb, 0,
300 diff - skb_tailroom(e->skb),
303 printk(KERN_WARNING "ip_queue: error "
304 "in mangle, dropping packet\n");
310 skb_put(e->skb, diff);
312 if (!skb_make_writable(e->skb, v->data_len))
314 skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
315 e->skb->ip_summed = CHECKSUM_NONE;
321 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
323 struct nf_queue_entry *entry;
325 if (vmsg->value > NF_MAX_VERDICT)
328 entry = ipq_find_dequeue_entry(vmsg->id);
332 int verdict = vmsg->value;
334 if (vmsg->data_len && vmsg->data_len == len)
335 if (ipq_mangle_ipv4(vmsg, entry) < 0)
338 nf_reinject(entry, verdict);
344 ipq_set_mode(unsigned char mode, unsigned int range)
348 write_lock_bh(&queue_lock);
349 status = __ipq_set_mode(mode, range);
350 write_unlock_bh(&queue_lock);
355 ipq_receive_peer(struct ipq_peer_msg *pmsg,
356 unsigned char type, unsigned int len)
360 if (len < sizeof(*pmsg))
365 status = ipq_set_mode(pmsg->msg.mode.value,
366 pmsg->msg.mode.range);
370 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
373 status = ipq_set_verdict(&pmsg->msg.verdict,
374 len - sizeof(*pmsg));
383 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
386 if (entry->indev->ifindex == ifindex)
389 if (entry->outdev->ifindex == ifindex)
391 #ifdef CONFIG_BRIDGE_NETFILTER
392 if (entry->skb->nf_bridge) {
393 if (entry->skb->nf_bridge->physindev &&
394 entry->skb->nf_bridge->physindev->ifindex == ifindex)
396 if (entry->skb->nf_bridge->physoutdev &&
397 entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
405 ipq_dev_drop(int ifindex)
407 ipq_flush(dev_cmp, ifindex);
410 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
413 __ipq_rcv_skb(struct sk_buff *skb)
415 int status, type, pid, flags, nlmsglen, skblen;
416 struct nlmsghdr *nlh;
419 if (skblen < sizeof(*nlh))
422 nlh = nlmsg_hdr(skb);
423 nlmsglen = nlh->nlmsg_len;
424 if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
427 pid = nlh->nlmsg_pid;
428 flags = nlh->nlmsg_flags;
430 if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
431 RCV_SKB_FAIL(-EINVAL);
433 if (flags & MSG_TRUNC)
434 RCV_SKB_FAIL(-ECOMM);
436 type = nlh->nlmsg_type;
437 if (type < NLMSG_NOOP || type >= IPQM_MAX)
438 RCV_SKB_FAIL(-EINVAL);
440 if (type <= IPQM_BASE)
443 if (security_netlink_recv(skb, CAP_NET_ADMIN))
444 RCV_SKB_FAIL(-EPERM);
446 write_lock_bh(&queue_lock);
449 if (peer_pid != pid) {
450 write_unlock_bh(&queue_lock);
451 RCV_SKB_FAIL(-EBUSY);
454 net_enable_timestamp();
458 write_unlock_bh(&queue_lock);
460 status = ipq_receive_peer(NLMSG_DATA(nlh), type,
461 nlmsglen - NLMSG_LENGTH(0));
463 RCV_SKB_FAIL(status);
465 if (flags & NLM_F_ACK)
466 netlink_ack(skb, nlh, 0);
471 ipq_rcv_skb(struct sk_buff *skb)
473 mutex_lock(&ipqnl_mutex);
475 mutex_unlock(&ipqnl_mutex);
479 ipq_rcv_dev_event(struct notifier_block *this,
480 unsigned long event, void *ptr)
482 struct net_device *dev = ptr;
484 if (dev_net(dev) != &init_net)
487 /* Drop any packets associated with the downed device */
488 if (event == NETDEV_DOWN)
489 ipq_dev_drop(dev->ifindex);
493 static struct notifier_block ipq_dev_notifier = {
494 .notifier_call = ipq_rcv_dev_event,
498 ipq_rcv_nl_event(struct notifier_block *this,
499 unsigned long event, void *ptr)
501 struct netlink_notify *n = ptr;
503 if (event == NETLINK_URELEASE &&
504 n->protocol == NETLINK_FIREWALL && n->pid) {
505 write_lock_bh(&queue_lock);
506 if ((n->net == &init_net) && (n->pid == peer_pid))
508 write_unlock_bh(&queue_lock);
513 static struct notifier_block ipq_nl_notifier = {
514 .notifier_call = ipq_rcv_nl_event,
518 static struct ctl_table_header *ipq_sysctl_header;
520 static ctl_table ipq_table[] = {
522 .ctl_name = NET_IPQ_QMAX,
523 .procname = NET_IPQ_QMAX_NAME,
524 .data = &queue_maxlen,
525 .maxlen = sizeof(queue_maxlen),
527 .proc_handler = proc_dointvec
533 #ifdef CONFIG_PROC_FS
534 static int ip_queue_show(struct seq_file *m, void *v)
536 read_lock_bh(&queue_lock);
542 "Queue length : %u\n"
543 "Queue max. length : %u\n"
544 "Queue dropped : %u\n"
545 "Netlink dropped : %u\n",
554 read_unlock_bh(&queue_lock);
558 static int ip_queue_open(struct inode *inode, struct file *file)
560 return single_open(file, ip_queue_show, NULL);
563 static const struct file_operations ip_queue_proc_fops = {
564 .open = ip_queue_open,
567 .release = single_release,
568 .owner = THIS_MODULE,
572 static const struct nf_queue_handler nfqh = {
574 .outfn = &ipq_enqueue_packet,
577 static int __init ip_queue_init(void)
579 int status = -ENOMEM;
580 struct proc_dir_entry *proc __maybe_unused;
582 netlink_register_notifier(&ipq_nl_notifier);
583 ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
584 ipq_rcv_skb, NULL, THIS_MODULE);
586 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
587 goto cleanup_netlink_notifier;
590 #ifdef CONFIG_PROC_FS
591 proc = proc_create(IPQ_PROC_FS_NAME, 0, init_net.proc_net,
592 &ip_queue_proc_fops);
594 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
598 register_netdevice_notifier(&ipq_dev_notifier);
600 ipq_sysctl_header = register_sysctl_paths(net_ipv4_ctl_path, ipq_table);
602 status = nf_register_queue_handler(PF_INET, &nfqh);
604 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
611 unregister_sysctl_table(ipq_sysctl_header);
613 unregister_netdevice_notifier(&ipq_dev_notifier);
614 proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
615 cleanup_ipqnl: __maybe_unused
616 netlink_kernel_release(ipqnl);
617 mutex_lock(&ipqnl_mutex);
618 mutex_unlock(&ipqnl_mutex);
620 cleanup_netlink_notifier:
621 netlink_unregister_notifier(&ipq_nl_notifier);
625 static void __exit ip_queue_fini(void)
627 nf_unregister_queue_handlers(&nfqh);
632 unregister_sysctl_table(ipq_sysctl_header);
634 unregister_netdevice_notifier(&ipq_dev_notifier);
635 proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
637 netlink_kernel_release(ipqnl);
638 mutex_lock(&ipqnl_mutex);
639 mutex_unlock(&ipqnl_mutex);
641 netlink_unregister_notifier(&ipq_nl_notifier);
644 MODULE_DESCRIPTION("IPv4 packet queue handler");
645 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
646 MODULE_LICENSE("GPL");
648 module_init(ip_queue_init);
649 module_exit(ip_queue_fini);