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15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/init.h>
18#include <linux/ipv6.h>
19#include <linux/notifier.h>
20#include <linux/netdevice.h>
21#include <linux/netfilter.h>
22#include <linux/netlink.h>
23#include <linux/spinlock.h>
24#include <linux/sysctl.h>
25#include <linux/proc_fs.h>
26#include <linux/seq_file.h>
27#include <linux/mutex.h>
28#include <linux/slab.h>
29#include <net/net_namespace.h>
30#include <net/sock.h>
31#include <net/ipv6.h>
32#include <net/ip6_route.h>
33#include <net/netfilter/nf_queue.h>
34#include <linux/netfilter_ipv4/ip_queue.h>
35#include <linux/netfilter_ipv4/ip_tables.h>
36#include <linux/netfilter_ipv6/ip6_tables.h>
37
38#define IPQ_QMAX_DEFAULT 1024
39#define IPQ_PROC_FS_NAME "ip6_queue"
40#define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
41
42typedef int (*ipq_cmpfn)(struct nf_queue_entry *, unsigned long);
43
44static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
45static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
46static DEFINE_SPINLOCK(queue_lock);
47static int peer_pid __read_mostly;
48static unsigned int copy_range __read_mostly;
49static unsigned int queue_total;
50static unsigned int queue_dropped = 0;
51static unsigned int queue_user_dropped = 0;
52static struct sock *ipqnl __read_mostly;
53static LIST_HEAD(queue_list);
54static DEFINE_MUTEX(ipqnl_mutex);
55
56static inline void
57__ipq_enqueue_entry(struct nf_queue_entry *entry)
58{
59 list_add_tail(&entry->list, &queue_list);
60 queue_total++;
61}
62
63static inline int
64__ipq_set_mode(unsigned char mode, unsigned int range)
65{
66 int status = 0;
67
68 switch(mode) {
69 case IPQ_COPY_NONE:
70 case IPQ_COPY_META:
71 copy_mode = mode;
72 copy_range = 0;
73 break;
74
75 case IPQ_COPY_PACKET:
76 if (range > 0xFFFF)
77 range = 0xFFFF;
78 copy_range = range;
79 copy_mode = mode;
80 break;
81
82 default:
83 status = -EINVAL;
84
85 }
86 return status;
87}
88
89static void __ipq_flush(ipq_cmpfn cmpfn, unsigned long data);
90
91static inline void
92__ipq_reset(void)
93{
94 peer_pid = 0;
95 net_disable_timestamp();
96 __ipq_set_mode(IPQ_COPY_NONE, 0);
97 __ipq_flush(NULL, 0);
98}
99
100static struct nf_queue_entry *
101ipq_find_dequeue_entry(unsigned long id)
102{
103 struct nf_queue_entry *entry = NULL, *i;
104
105 spin_lock_bh(&queue_lock);
106
107 list_for_each_entry(i, &queue_list, list) {
108 if ((unsigned long)i == id) {
109 entry = i;
110 break;
111 }
112 }
113
114 if (entry) {
115 list_del(&entry->list);
116 queue_total--;
117 }
118
119 spin_unlock_bh(&queue_lock);
120 return entry;
121}
122
123static void
124__ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
125{
126 struct nf_queue_entry *entry, *next;
127
128 list_for_each_entry_safe(entry, next, &queue_list, list) {
129 if (!cmpfn || cmpfn(entry, data)) {
130 list_del(&entry->list);
131 queue_total--;
132 nf_reinject(entry, NF_DROP);
133 }
134 }
135}
136
137static void
138ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
139{
140 spin_lock_bh(&queue_lock);
141 __ipq_flush(cmpfn, data);
142 spin_unlock_bh(&queue_lock);
143}
144
145static struct sk_buff *
146ipq_build_packet_message(struct nf_queue_entry *entry, int *errp)
147{
148 sk_buff_data_t old_tail;
149 size_t size = 0;
150 size_t data_len = 0;
151 struct sk_buff *skb;
152 struct ipq_packet_msg *pmsg;
153 struct nlmsghdr *nlh;
154 struct timeval tv;
155
156 switch (ACCESS_ONCE(copy_mode)) {
157 case IPQ_COPY_META:
158 case IPQ_COPY_NONE:
159 size = NLMSG_SPACE(sizeof(*pmsg));
160 break;
161
162 case IPQ_COPY_PACKET:
163 if (entry->skb->ip_summed == CHECKSUM_PARTIAL &&
164 (*errp = skb_checksum_help(entry->skb)))
165 return NULL;
166
167 data_len = ACCESS_ONCE(copy_range);
168 if (data_len == 0 || data_len > entry->skb->len)
169 data_len = entry->skb->len;
170
171 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
172 break;
173
174 default:
175 *errp = -EINVAL;
176 return NULL;
177 }
178
179 skb = alloc_skb(size, GFP_ATOMIC);
180 if (!skb)
181 goto nlmsg_failure;
182
183 old_tail = skb->tail;
184 nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
185 pmsg = NLMSG_DATA(nlh);
186 memset(pmsg, 0, sizeof(*pmsg));
187
188 pmsg->packet_id = (unsigned long )entry;
189 pmsg->data_len = data_len;
190 tv = ktime_to_timeval(entry->skb->tstamp);
191 pmsg->timestamp_sec = tv.tv_sec;
192 pmsg->timestamp_usec = tv.tv_usec;
193 pmsg->mark = entry->skb->mark;
194 pmsg->hook = entry->hook;
195 pmsg->hw_protocol = entry->skb->protocol;
196
197 if (entry->indev)
198 strcpy(pmsg->indev_name, entry->indev->name);
199 else
200 pmsg->indev_name[0] = '\0';
201
202 if (entry->outdev)
203 strcpy(pmsg->outdev_name, entry->outdev->name);
204 else
205 pmsg->outdev_name[0] = '\0';
206
207 if (entry->indev && entry->skb->dev) {
208 pmsg->hw_type = entry->skb->dev->type;
209 pmsg->hw_addrlen = dev_parse_header(entry->skb, pmsg->hw_addr);
210 }
211
212 if (data_len)
213 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
214 BUG();
215
216 nlh->nlmsg_len = skb->tail - old_tail;
217 return skb;
218
219nlmsg_failure:
220 *errp = -EINVAL;
221 printk(KERN_ERR "ip6_queue: error creating packet message\n");
222 return NULL;
223}
224
225static int
226ipq_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
227{
228 int status = -EINVAL;
229 struct sk_buff *nskb;
230
231 if (copy_mode == IPQ_COPY_NONE)
232 return -EAGAIN;
233
234 nskb = ipq_build_packet_message(entry, &status);
235 if (nskb == NULL)
236 return status;
237
238 spin_lock_bh(&queue_lock);
239
240 if (!peer_pid)
241 goto err_out_free_nskb;
242
243 if (queue_total >= queue_maxlen) {
244 queue_dropped++;
245 status = -ENOSPC;
246 if (net_ratelimit())
247 printk (KERN_WARNING "ip6_queue: fill at %d entries, "
248 "dropping packet(s). Dropped: %d\n", queue_total,
249 queue_dropped);
250 goto err_out_free_nskb;
251 }
252
253
254 status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
255 if (status < 0) {
256 queue_user_dropped++;
257 goto err_out_unlock;
258 }
259
260 __ipq_enqueue_entry(entry);
261
262 spin_unlock_bh(&queue_lock);
263 return status;
264
265err_out_free_nskb:
266 kfree_skb(nskb);
267
268err_out_unlock:
269 spin_unlock_bh(&queue_lock);
270 return status;
271}
272
273static int
274ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct nf_queue_entry *e)
275{
276 int diff;
277 struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
278 struct sk_buff *nskb;
279
280 if (v->data_len < sizeof(*user_iph))
281 return 0;
282 diff = v->data_len - e->skb->len;
283 if (diff < 0) {
284 if (pskb_trim(e->skb, v->data_len))
285 return -ENOMEM;
286 } else if (diff > 0) {
287 if (v->data_len > 0xFFFF)
288 return -EINVAL;
289 if (diff > skb_tailroom(e->skb)) {
290 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
291 diff, GFP_ATOMIC);
292 if (!nskb) {
293 printk(KERN_WARNING "ip6_queue: OOM "
294 "in mangle, dropping packet\n");
295 return -ENOMEM;
296 }
297 kfree_skb(e->skb);
298 e->skb = nskb;
299 }
300 skb_put(e->skb, diff);
301 }
302 if (!skb_make_writable(e->skb, v->data_len))
303 return -ENOMEM;
304 skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
305 e->skb->ip_summed = CHECKSUM_NONE;
306
307 return 0;
308}
309
310static int
311ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
312{
313 struct nf_queue_entry *entry;
314
315 if (vmsg->value > NF_MAX_VERDICT)
316 return -EINVAL;
317
318 entry = ipq_find_dequeue_entry(vmsg->id);
319 if (entry == NULL)
320 return -ENOENT;
321 else {
322 int verdict = vmsg->value;
323
324 if (vmsg->data_len && vmsg->data_len == len)
325 if (ipq_mangle_ipv6(vmsg, entry) < 0)
326 verdict = NF_DROP;
327
328 nf_reinject(entry, verdict);
329 return 0;
330 }
331}
332
333static int
334ipq_set_mode(unsigned char mode, unsigned int range)
335{
336 int status;
337
338 spin_lock_bh(&queue_lock);
339 status = __ipq_set_mode(mode, range);
340 spin_unlock_bh(&queue_lock);
341 return status;
342}
343
344static int
345ipq_receive_peer(struct ipq_peer_msg *pmsg,
346 unsigned char type, unsigned int len)
347{
348 int status = 0;
349
350 if (len < sizeof(*pmsg))
351 return -EINVAL;
352
353 switch (type) {
354 case IPQM_MODE:
355 status = ipq_set_mode(pmsg->msg.mode.value,
356 pmsg->msg.mode.range);
357 break;
358
359 case IPQM_VERDICT:
360 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
361 status = -EINVAL;
362 else
363 status = ipq_set_verdict(&pmsg->msg.verdict,
364 len - sizeof(*pmsg));
365 break;
366 default:
367 status = -EINVAL;
368 }
369 return status;
370}
371
372static int
373dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
374{
375 if (entry->indev)
376 if (entry->indev->ifindex == ifindex)
377 return 1;
378
379 if (entry->outdev)
380 if (entry->outdev->ifindex == ifindex)
381 return 1;
382#ifdef CONFIG_BRIDGE_NETFILTER
383 if (entry->skb->nf_bridge) {
384 if (entry->skb->nf_bridge->physindev &&
385 entry->skb->nf_bridge->physindev->ifindex == ifindex)
386 return 1;
387 if (entry->skb->nf_bridge->physoutdev &&
388 entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
389 return 1;
390 }
391#endif
392 return 0;
393}
394
395static void
396ipq_dev_drop(int ifindex)
397{
398 ipq_flush(dev_cmp, ifindex);
399}
400
401#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
402
403static inline void
404__ipq_rcv_skb(struct sk_buff *skb)
405{
406 int status, type, pid, flags, nlmsglen, skblen;
407 struct nlmsghdr *nlh;
408
409 skblen = skb->len;
410 if (skblen < sizeof(*nlh))
411 return;
412
413 nlh = nlmsg_hdr(skb);
414 nlmsglen = nlh->nlmsg_len;
415 if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
416 return;
417
418 pid = nlh->nlmsg_pid;
419 flags = nlh->nlmsg_flags;
420
421 if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
422 RCV_SKB_FAIL(-EINVAL);
423
424 if (flags & MSG_TRUNC)
425 RCV_SKB_FAIL(-ECOMM);
426
427 type = nlh->nlmsg_type;
428 if (type < NLMSG_NOOP || type >= IPQM_MAX)
429 RCV_SKB_FAIL(-EINVAL);
430
431 if (type <= IPQM_BASE)
432 return;
433
434 if (security_netlink_recv(skb, CAP_NET_ADMIN))
435 RCV_SKB_FAIL(-EPERM);
436
437 spin_lock_bh(&queue_lock);
438
439 if (peer_pid) {
440 if (peer_pid != pid) {
441 spin_unlock_bh(&queue_lock);
442 RCV_SKB_FAIL(-EBUSY);
443 }
444 } else {
445 net_enable_timestamp();
446 peer_pid = pid;
447 }
448
449 spin_unlock_bh(&queue_lock);
450
451 status = ipq_receive_peer(NLMSG_DATA(nlh), type,
452 nlmsglen - NLMSG_LENGTH(0));
453 if (status < 0)
454 RCV_SKB_FAIL(status);
455
456 if (flags & NLM_F_ACK)
457 netlink_ack(skb, nlh, 0);
458}
459
460static void
461ipq_rcv_skb(struct sk_buff *skb)
462{
463 mutex_lock(&ipqnl_mutex);
464 __ipq_rcv_skb(skb);
465 mutex_unlock(&ipqnl_mutex);
466}
467
468static int
469ipq_rcv_dev_event(struct notifier_block *this,
470 unsigned long event, void *ptr)
471{
472 struct net_device *dev = ptr;
473
474 if (!net_eq(dev_net(dev), &init_net))
475 return NOTIFY_DONE;
476
477
478 if (event == NETDEV_DOWN)
479 ipq_dev_drop(dev->ifindex);
480 return NOTIFY_DONE;
481}
482
483static struct notifier_block ipq_dev_notifier = {
484 .notifier_call = ipq_rcv_dev_event,
485};
486
487static int
488ipq_rcv_nl_event(struct notifier_block *this,
489 unsigned long event, void *ptr)
490{
491 struct netlink_notify *n = ptr;
492
493 if (event == NETLINK_URELEASE && n->protocol == NETLINK_IP6_FW) {
494 spin_lock_bh(&queue_lock);
495 if ((net_eq(n->net, &init_net)) && (n->pid == peer_pid))
496 __ipq_reset();
497 spin_unlock_bh(&queue_lock);
498 }
499 return NOTIFY_DONE;
500}
501
502static struct notifier_block ipq_nl_notifier = {
503 .notifier_call = ipq_rcv_nl_event,
504};
505
506#ifdef CONFIG_SYSCTL
507static struct ctl_table_header *ipq_sysctl_header;
508
509static ctl_table ipq_table[] = {
510 {
511 .procname = NET_IPQ_QMAX_NAME,
512 .data = &queue_maxlen,
513 .maxlen = sizeof(queue_maxlen),
514 .mode = 0644,
515 .proc_handler = proc_dointvec
516 },
517 { }
518};
519#endif
520
521#ifdef CONFIG_PROC_FS
522static int ip6_queue_show(struct seq_file *m, void *v)
523{
524 spin_lock_bh(&queue_lock);
525
526 seq_printf(m,
527 "Peer PID : %d\n"
528 "Copy mode : %hu\n"
529 "Copy range : %u\n"
530 "Queue length : %u\n"
531 "Queue max. length : %u\n"
532 "Queue dropped : %u\n"
533 "Netfilter dropped : %u\n",
534 peer_pid,
535 copy_mode,
536 copy_range,
537 queue_total,
538 queue_maxlen,
539 queue_dropped,
540 queue_user_dropped);
541
542 spin_unlock_bh(&queue_lock);
543 return 0;
544}
545
546static int ip6_queue_open(struct inode *inode, struct file *file)
547{
548 return single_open(file, ip6_queue_show, NULL);
549}
550
551static const struct file_operations ip6_queue_proc_fops = {
552 .open = ip6_queue_open,
553 .read = seq_read,
554 .llseek = seq_lseek,
555 .release = single_release,
556 .owner = THIS_MODULE,
557};
558#endif
559
560static const struct nf_queue_handler nfqh = {
561 .name = "ip6_queue",
562 .outfn = &ipq_enqueue_packet,
563};
564
565static int __init ip6_queue_init(void)
566{
567 int status = -ENOMEM;
568 struct proc_dir_entry *proc __maybe_unused;
569
570 netlink_register_notifier(&ipq_nl_notifier);
571 ipqnl = netlink_kernel_create(&init_net, NETLINK_IP6_FW, 0,
572 ipq_rcv_skb, NULL, THIS_MODULE);
573 if (ipqnl == NULL) {
574 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
575 goto cleanup_netlink_notifier;
576 }
577
578#ifdef CONFIG_PROC_FS
579 proc = proc_create(IPQ_PROC_FS_NAME, 0, init_net.proc_net,
580 &ip6_queue_proc_fops);
581 if (!proc) {
582 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
583 goto cleanup_ipqnl;
584 }
585#endif
586 register_netdevice_notifier(&ipq_dev_notifier);
587#ifdef CONFIG_SYSCTL
588 ipq_sysctl_header = register_sysctl_paths(net_ipv6_ctl_path, ipq_table);
589#endif
590 status = nf_register_queue_handler(NFPROTO_IPV6, &nfqh);
591 if (status < 0) {
592 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
593 goto cleanup_sysctl;
594 }
595 return status;
596
597cleanup_sysctl:
598#ifdef CONFIG_SYSCTL
599 unregister_sysctl_table(ipq_sysctl_header);
600#endif
601 unregister_netdevice_notifier(&ipq_dev_notifier);
602 proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
603
604cleanup_ipqnl: __maybe_unused
605 netlink_kernel_release(ipqnl);
606 mutex_lock(&ipqnl_mutex);
607 mutex_unlock(&ipqnl_mutex);
608
609cleanup_netlink_notifier:
610 netlink_unregister_notifier(&ipq_nl_notifier);
611 return status;
612}
613
614static void __exit ip6_queue_fini(void)
615{
616 nf_unregister_queue_handlers(&nfqh);
617
618 ipq_flush(NULL, 0);
619
620#ifdef CONFIG_SYSCTL
621 unregister_sysctl_table(ipq_sysctl_header);
622#endif
623 unregister_netdevice_notifier(&ipq_dev_notifier);
624 proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
625
626 netlink_kernel_release(ipqnl);
627 mutex_lock(&ipqnl_mutex);
628 mutex_unlock(&ipqnl_mutex);
629
630 netlink_unregister_notifier(&ipq_nl_notifier);
631}
632
633MODULE_DESCRIPTION("IPv6 packet queue handler");
634MODULE_LICENSE("GPL");
635MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_IP6_FW);
636
637module_init(ip6_queue_init);
638module_exit(ip6_queue_fini);
639
