Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This is a module which is used for logging packets to userspace via
4 * nfetlink.
5 *
6 * (C) 2005 by Harald Welte <laforge@netfilter.org>
7 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
8 *
9 * Based on the old ipv4-only ipt_ULOG.c:
10 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/if_arp.h>
18#include <linux/init.h>
19#include <linux/ip.h>
20#include <linux/ipv6.h>
21#include <linux/netdevice.h>
22#include <linux/netfilter.h>
23#include <linux/netfilter_bridge.h>
24#include <net/netlink.h>
25#include <linux/netfilter/nfnetlink.h>
26#include <linux/netfilter/nfnetlink_log.h>
27#include <linux/netfilter/nf_conntrack_common.h>
28#include <linux/spinlock.h>
29#include <linux/sysctl.h>
30#include <linux/proc_fs.h>
31#include <linux/security.h>
32#include <linux/list.h>
33#include <linux/slab.h>
34#include <net/sock.h>
35#include <net/netfilter/nf_log.h>
36#include <net/netns/generic.h>
37
38#include <linux/atomic.h>
39#include <linux/refcount.h>
40
41
42#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
43#include "../bridge/br_private.h"
44#endif
45
46#if IS_ENABLED(CONFIG_NF_CONNTRACK)
47#include <net/netfilter/nf_conntrack.h>
48#endif
49
50#define NFULNL_COPY_DISABLED 0xff
51#define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
52#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
53#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
54/* max packet size is limited by 16-bit struct nfattr nfa_len field */
55#define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
56
57#define PRINTR(x, args...) do { if (net_ratelimit()) \
58 printk(x, ## args); } while (0);
59
60struct nfulnl_instance {
61 struct hlist_node hlist; /* global list of instances */
62 spinlock_t lock;
63 refcount_t use; /* use count */
64
65 unsigned int qlen; /* number of nlmsgs in skb */
66 struct sk_buff *skb; /* pre-allocatd skb */
67 struct timer_list timer;
68 struct net *net;
69 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
70 u32 peer_portid; /* PORTID of the peer process */
71
72 /* configurable parameters */
73 unsigned int flushtimeout; /* timeout until queue flush */
74 unsigned int nlbufsiz; /* netlink buffer allocation size */
75 unsigned int qthreshold; /* threshold of the queue */
76 u_int32_t copy_range;
77 u_int32_t seq; /* instance-local sequential counter */
78 u_int16_t group_num; /* number of this queue */
79 u_int16_t flags;
80 u_int8_t copy_mode;
81 struct rcu_head rcu;
82};
83
84#define INSTANCE_BUCKETS 16
85
86static unsigned int nfnl_log_net_id __read_mostly;
87
88struct nfnl_log_net {
89 spinlock_t instances_lock;
90 struct hlist_head instance_table[INSTANCE_BUCKETS];
91 atomic_t global_seq;
92};
93
94static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
95{
96 return net_generic(net, nfnl_log_net_id);
97}
98
99static inline u_int8_t instance_hashfn(u_int16_t group_num)
100{
101 return ((group_num & 0xff) % INSTANCE_BUCKETS);
102}
103
104static struct nfulnl_instance *
105__instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
106{
107 struct hlist_head *head;
108 struct nfulnl_instance *inst;
109
110 head = &log->instance_table[instance_hashfn(group_num)];
111 hlist_for_each_entry_rcu(inst, head, hlist) {
112 if (inst->group_num == group_num)
113 return inst;
114 }
115 return NULL;
116}
117
118static inline void
119instance_get(struct nfulnl_instance *inst)
120{
121 refcount_inc(&inst->use);
122}
123
124static struct nfulnl_instance *
125instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
126{
127 struct nfulnl_instance *inst;
128
129 rcu_read_lock_bh();
130 inst = __instance_lookup(log, group_num);
131 if (inst && !refcount_inc_not_zero(&inst->use))
132 inst = NULL;
133 rcu_read_unlock_bh();
134
135 return inst;
136}
137
138static void nfulnl_instance_free_rcu(struct rcu_head *head)
139{
140 struct nfulnl_instance *inst =
141 container_of(head, struct nfulnl_instance, rcu);
142
143 put_net(inst->net);
144 kfree(inst);
145 module_put(THIS_MODULE);
146}
147
148static void
149instance_put(struct nfulnl_instance *inst)
150{
151 if (inst && refcount_dec_and_test(&inst->use))
152 call_rcu(&inst->rcu, nfulnl_instance_free_rcu);
153}
154
155static void nfulnl_timer(struct timer_list *t);
156
157static struct nfulnl_instance *
158instance_create(struct net *net, u_int16_t group_num,
159 u32 portid, struct user_namespace *user_ns)
160{
161 struct nfulnl_instance *inst;
162 struct nfnl_log_net *log = nfnl_log_pernet(net);
163 int err;
164
165 spin_lock_bh(&log->instances_lock);
166 if (__instance_lookup(log, group_num)) {
167 err = -EEXIST;
168 goto out_unlock;
169 }
170
171 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
172 if (!inst) {
173 err = -ENOMEM;
174 goto out_unlock;
175 }
176
177 if (!try_module_get(THIS_MODULE)) {
178 kfree(inst);
179 err = -EAGAIN;
180 goto out_unlock;
181 }
182
183 INIT_HLIST_NODE(&inst->hlist);
184 spin_lock_init(&inst->lock);
185 /* needs to be two, since we _put() after creation */
186 refcount_set(&inst->use, 2);
187
188 timer_setup(&inst->timer, nfulnl_timer, 0);
189
190 inst->net = get_net(net);
191 inst->peer_user_ns = user_ns;
192 inst->peer_portid = portid;
193 inst->group_num = group_num;
194
195 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
196 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
197 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
198 inst->copy_mode = NFULNL_COPY_PACKET;
199 inst->copy_range = NFULNL_COPY_RANGE_MAX;
200
201 hlist_add_head_rcu(&inst->hlist,
202 &log->instance_table[instance_hashfn(group_num)]);
203
204
205 spin_unlock_bh(&log->instances_lock);
206
207 return inst;
208
209out_unlock:
210 spin_unlock_bh(&log->instances_lock);
211 return ERR_PTR(err);
212}
213
214static void __nfulnl_flush(struct nfulnl_instance *inst);
215
216/* called with BH disabled */
217static void
218__instance_destroy(struct nfulnl_instance *inst)
219{
220 /* first pull it out of the global list */
221 hlist_del_rcu(&inst->hlist);
222
223 /* then flush all pending packets from skb */
224
225 spin_lock(&inst->lock);
226
227 /* lockless readers wont be able to use us */
228 inst->copy_mode = NFULNL_COPY_DISABLED;
229
230 if (inst->skb)
231 __nfulnl_flush(inst);
232 spin_unlock(&inst->lock);
233
234 /* and finally put the refcount */
235 instance_put(inst);
236}
237
238static inline void
239instance_destroy(struct nfnl_log_net *log,
240 struct nfulnl_instance *inst)
241{
242 spin_lock_bh(&log->instances_lock);
243 __instance_destroy(inst);
244 spin_unlock_bh(&log->instances_lock);
245}
246
247static int
248nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
249 unsigned int range)
250{
251 int status = 0;
252
253 spin_lock_bh(&inst->lock);
254
255 switch (mode) {
256 case NFULNL_COPY_NONE:
257 case NFULNL_COPY_META:
258 inst->copy_mode = mode;
259 inst->copy_range = 0;
260 break;
261
262 case NFULNL_COPY_PACKET:
263 inst->copy_mode = mode;
264 if (range == 0)
265 range = NFULNL_COPY_RANGE_MAX;
266 inst->copy_range = min_t(unsigned int,
267 range, NFULNL_COPY_RANGE_MAX);
268 break;
269
270 default:
271 status = -EINVAL;
272 break;
273 }
274
275 spin_unlock_bh(&inst->lock);
276
277 return status;
278}
279
280static int
281nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
282{
283 int status;
284
285 spin_lock_bh(&inst->lock);
286 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
287 status = -ERANGE;
288 else if (nlbufsiz > 131072)
289 status = -ERANGE;
290 else {
291 inst->nlbufsiz = nlbufsiz;
292 status = 0;
293 }
294 spin_unlock_bh(&inst->lock);
295
296 return status;
297}
298
299static void
300nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
301{
302 spin_lock_bh(&inst->lock);
303 inst->flushtimeout = timeout;
304 spin_unlock_bh(&inst->lock);
305}
306
307static void
308nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
309{
310 spin_lock_bh(&inst->lock);
311 inst->qthreshold = qthresh;
312 spin_unlock_bh(&inst->lock);
313}
314
315static int
316nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
317{
318 spin_lock_bh(&inst->lock);
319 inst->flags = flags;
320 spin_unlock_bh(&inst->lock);
321
322 return 0;
323}
324
325static struct sk_buff *
326nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
327 unsigned int pkt_size)
328{
329 struct sk_buff *skb;
330 unsigned int n;
331
332 /* alloc skb which should be big enough for a whole multipart
333 * message. WARNING: has to be <= 128k due to slab restrictions */
334
335 n = max(inst_size, pkt_size);
336 skb = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
337 if (!skb) {
338 if (n > pkt_size) {
339 /* try to allocate only as much as we need for current
340 * packet */
341
342 skb = alloc_skb(pkt_size, GFP_ATOMIC);
343 }
344 }
345
346 return skb;
347}
348
349static void
350__nfulnl_send(struct nfulnl_instance *inst)
351{
352 if (inst->qlen > 1) {
353 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
354 NLMSG_DONE,
355 sizeof(struct nfgenmsg),
356 0);
357 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
358 inst->skb->len, skb_tailroom(inst->skb))) {
359 kfree_skb(inst->skb);
360 goto out;
361 }
362 }
363 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid);
364out:
365 inst->qlen = 0;
366 inst->skb = NULL;
367}
368
369static void
370__nfulnl_flush(struct nfulnl_instance *inst)
371{
372 /* timer holds a reference */
373 if (del_timer(&inst->timer))
374 instance_put(inst);
375 if (inst->skb)
376 __nfulnl_send(inst);
377}
378
379static void
380nfulnl_timer(struct timer_list *t)
381{
382 struct nfulnl_instance *inst = from_timer(inst, t, timer);
383
384 spin_lock_bh(&inst->lock);
385 if (inst->skb)
386 __nfulnl_send(inst);
387 spin_unlock_bh(&inst->lock);
388 instance_put(inst);
389}
390
391static u32 nfulnl_get_bridge_size(const struct sk_buff *skb)
392{
393 u32 size = 0;
394
395 if (!skb_mac_header_was_set(skb))
396 return 0;
397
398 if (skb_vlan_tag_present(skb)) {
399 size += nla_total_size(0); /* nested */
400 size += nla_total_size(sizeof(u16)); /* id */
401 size += nla_total_size(sizeof(u16)); /* tag */
402 }
403
404 if (skb->network_header > skb->mac_header)
405 size += nla_total_size(skb->network_header - skb->mac_header);
406
407 return size;
408}
409
410static int nfulnl_put_bridge(struct nfulnl_instance *inst, const struct sk_buff *skb)
411{
412 if (!skb_mac_header_was_set(skb))
413 return 0;
414
415 if (skb_vlan_tag_present(skb)) {
416 struct nlattr *nest;
417
418 nest = nla_nest_start(inst->skb, NFULA_VLAN);
419 if (!nest)
420 goto nla_put_failure;
421
422 if (nla_put_be16(inst->skb, NFULA_VLAN_TCI, htons(skb->vlan_tci)) ||
423 nla_put_be16(inst->skb, NFULA_VLAN_PROTO, skb->vlan_proto))
424 goto nla_put_failure;
425
426 nla_nest_end(inst->skb, nest);
427 }
428
429 if (skb->mac_header < skb->network_header) {
430 int len = (int)(skb->network_header - skb->mac_header);
431
432 if (nla_put(inst->skb, NFULA_L2HDR, len, skb_mac_header(skb)))
433 goto nla_put_failure;
434 }
435
436 return 0;
437
438nla_put_failure:
439 return -1;
440}
441
442/* This is an inline function, we don't really care about a long
443 * list of arguments */
444static inline int
445__build_packet_message(struct nfnl_log_net *log,
446 struct nfulnl_instance *inst,
447 const struct sk_buff *skb,
448 unsigned int data_len,
449 u_int8_t pf,
450 unsigned int hooknum,
451 const struct net_device *indev,
452 const struct net_device *outdev,
453 const char *prefix, unsigned int plen,
454 const struct nfnl_ct_hook *nfnl_ct,
455 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
456{
457 struct nfulnl_msg_packet_hdr pmsg;
458 struct nlmsghdr *nlh;
459 sk_buff_data_t old_tail = inst->skb->tail;
460 struct sock *sk;
461 const unsigned char *hwhdrp;
462
463 nlh = nfnl_msg_put(inst->skb, 0, 0,
464 nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
465 0, pf, NFNETLINK_V0, htons(inst->group_num));
466 if (!nlh)
467 return -1;
468
469 memset(&pmsg, 0, sizeof(pmsg));
470 pmsg.hw_protocol = skb->protocol;
471 pmsg.hook = hooknum;
472
473 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
474 goto nla_put_failure;
475
476 if (prefix &&
477 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
478 goto nla_put_failure;
479
480 if (indev) {
481#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
482 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
483 htonl(indev->ifindex)))
484 goto nla_put_failure;
485#else
486 if (pf == PF_BRIDGE) {
487 /* Case 1: outdev is physical input device, we need to
488 * look for bridge group (when called from
489 * netfilter_bridge) */
490 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
491 htonl(indev->ifindex)) ||
492 /* this is the bridge group "brX" */
493 /* rcu_read_lock()ed by nf_hook_thresh or
494 * nf_log_packet.
495 */
496 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
497 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
498 goto nla_put_failure;
499 } else {
500 struct net_device *physindev;
501
502 /* Case 2: indev is bridge group, we need to look for
503 * physical device (when called from ipv4) */
504 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
505 htonl(indev->ifindex)))
506 goto nla_put_failure;
507
508 physindev = nf_bridge_get_physindev(skb);
509 if (physindev &&
510 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
511 htonl(physindev->ifindex)))
512 goto nla_put_failure;
513 }
514#endif
515 }
516
517 if (outdev) {
518#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
519 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
520 htonl(outdev->ifindex)))
521 goto nla_put_failure;
522#else
523 if (pf == PF_BRIDGE) {
524 /* Case 1: outdev is physical output device, we need to
525 * look for bridge group (when called from
526 * netfilter_bridge) */
527 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
528 htonl(outdev->ifindex)) ||
529 /* this is the bridge group "brX" */
530 /* rcu_read_lock()ed by nf_hook_thresh or
531 * nf_log_packet.
532 */
533 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
534 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
535 goto nla_put_failure;
536 } else {
537 struct net_device *physoutdev;
538
539 /* Case 2: indev is a bridge group, we need to look
540 * for physical device (when called from ipv4) */
541 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
542 htonl(outdev->ifindex)))
543 goto nla_put_failure;
544
545 physoutdev = nf_bridge_get_physoutdev(skb);
546 if (physoutdev &&
547 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
548 htonl(physoutdev->ifindex)))
549 goto nla_put_failure;
550 }
551#endif
552 }
553
554 if (skb->mark &&
555 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
556 goto nla_put_failure;
557
558 if (indev && skb->dev &&
559 skb->mac_header != skb->network_header) {
560 struct nfulnl_msg_packet_hw phw;
561 int len;
562
563 memset(&phw, 0, sizeof(phw));
564 len = dev_parse_header(skb, phw.hw_addr);
565 if (len > 0) {
566 phw.hw_addrlen = htons(len);
567 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
568 goto nla_put_failure;
569 }
570 }
571
572 if (indev && skb_mac_header_was_set(skb)) {
573 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
574 nla_put_be16(inst->skb, NFULA_HWLEN,
575 htons(skb->dev->hard_header_len)))
576 goto nla_put_failure;
577
578 hwhdrp = skb_mac_header(skb);
579
580 if (skb->dev->type == ARPHRD_SIT)
581 hwhdrp -= ETH_HLEN;
582
583 if (hwhdrp >= skb->head &&
584 nla_put(inst->skb, NFULA_HWHEADER,
585 skb->dev->hard_header_len, hwhdrp))
586 goto nla_put_failure;
587 }
588
589 if (hooknum <= NF_INET_FORWARD && skb->tstamp) {
590 struct nfulnl_msg_packet_timestamp ts;
591 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
592 ts.sec = cpu_to_be64(kts.tv_sec);
593 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
594
595 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
596 goto nla_put_failure;
597 }
598
599 /* UID */
600 sk = skb->sk;
601 if (sk && sk_fullsock(sk)) {
602 read_lock_bh(&sk->sk_callback_lock);
603 if (sk->sk_socket && sk->sk_socket->file) {
604 struct file *file = sk->sk_socket->file;
605 const struct cred *cred = file->f_cred;
606 struct user_namespace *user_ns = inst->peer_user_ns;
607 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
608 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
609 read_unlock_bh(&sk->sk_callback_lock);
610 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
611 nla_put_be32(inst->skb, NFULA_GID, gid))
612 goto nla_put_failure;
613 } else
614 read_unlock_bh(&sk->sk_callback_lock);
615 }
616
617 /* local sequence number */
618 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
619 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
620 goto nla_put_failure;
621
622 /* global sequence number */
623 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
624 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
625 htonl(atomic_inc_return(&log->global_seq))))
626 goto nla_put_failure;
627
628 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
629 NFULA_CT, NFULA_CT_INFO) < 0)
630 goto nla_put_failure;
631
632 if ((pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE) &&
633 nfulnl_put_bridge(inst, skb) < 0)
634 goto nla_put_failure;
635
636 if (data_len) {
637 struct nlattr *nla;
638 int size = nla_attr_size(data_len);
639
640 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
641 goto nla_put_failure;
642
643 nla = skb_put(inst->skb, nla_total_size(data_len));
644 nla->nla_type = NFULA_PAYLOAD;
645 nla->nla_len = size;
646
647 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
648 BUG();
649 }
650
651 nlh->nlmsg_len = inst->skb->tail - old_tail;
652 return 0;
653
654nla_put_failure:
655 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
656 return -1;
657}
658
659static const struct nf_loginfo default_loginfo = {
660 .type = NF_LOG_TYPE_ULOG,
661 .u = {
662 .ulog = {
663 .copy_len = 0xffff,
664 .group = 0,
665 .qthreshold = 1,
666 },
667 },
668};
669
670/* log handler for internal netfilter logging api */
671static void
672nfulnl_log_packet(struct net *net,
673 u_int8_t pf,
674 unsigned int hooknum,
675 const struct sk_buff *skb,
676 const struct net_device *in,
677 const struct net_device *out,
678 const struct nf_loginfo *li_user,
679 const char *prefix)
680{
681 size_t size;
682 unsigned int data_len;
683 struct nfulnl_instance *inst;
684 const struct nf_loginfo *li;
685 unsigned int qthreshold;
686 unsigned int plen = 0;
687 struct nfnl_log_net *log = nfnl_log_pernet(net);
688 const struct nfnl_ct_hook *nfnl_ct = NULL;
689 struct nf_conn *ct = NULL;
690 enum ip_conntrack_info ctinfo;
691
692 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
693 li = li_user;
694 else
695 li = &default_loginfo;
696
697 inst = instance_lookup_get(log, li->u.ulog.group);
698 if (!inst)
699 return;
700
701 if (prefix)
702 plen = strlen(prefix) + 1;
703
704 /* FIXME: do we want to make the size calculation conditional based on
705 * what is actually present? way more branches and checks, but more
706 * memory efficient... */
707 size = nlmsg_total_size(sizeof(struct nfgenmsg))
708 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
709 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
710 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
711#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
712 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
713 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
714#endif
715 + nla_total_size(sizeof(u_int32_t)) /* mark */
716 + nla_total_size(sizeof(u_int32_t)) /* uid */
717 + nla_total_size(sizeof(u_int32_t)) /* gid */
718 + nla_total_size(plen) /* prefix */
719 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
720 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
721 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
722
723 if (in && skb_mac_header_was_set(skb)) {
724 size += nla_total_size(skb->dev->hard_header_len)
725 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
726 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
727 }
728
729 spin_lock_bh(&inst->lock);
730
731 if (inst->flags & NFULNL_CFG_F_SEQ)
732 size += nla_total_size(sizeof(u_int32_t));
733 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
734 size += nla_total_size(sizeof(u_int32_t));
735#if IS_ENABLED(CONFIG_NF_CONNTRACK)
736 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
737 nfnl_ct = rcu_dereference(nfnl_ct_hook);
738 if (nfnl_ct != NULL) {
739 ct = nf_ct_get(skb, &ctinfo);
740 if (ct != NULL)
741 size += nfnl_ct->build_size(ct);
742 }
743 }
744#endif
745 if (pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE)
746 size += nfulnl_get_bridge_size(skb);
747
748 qthreshold = inst->qthreshold;
749 /* per-rule qthreshold overrides per-instance */
750 if (li->u.ulog.qthreshold)
751 if (qthreshold > li->u.ulog.qthreshold)
752 qthreshold = li->u.ulog.qthreshold;
753
754
755 switch (inst->copy_mode) {
756 case NFULNL_COPY_META:
757 case NFULNL_COPY_NONE:
758 data_len = 0;
759 break;
760
761 case NFULNL_COPY_PACKET:
762 data_len = inst->copy_range;
763 if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
764 (li->u.ulog.copy_len < data_len))
765 data_len = li->u.ulog.copy_len;
766
767 if (data_len > skb->len)
768 data_len = skb->len;
769
770 size += nla_total_size(data_len);
771 break;
772
773 case NFULNL_COPY_DISABLED:
774 default:
775 goto unlock_and_release;
776 }
777
778 if (inst->skb && size > skb_tailroom(inst->skb)) {
779 /* either the queue len is too high or we don't have
780 * enough room in the skb left. flush to userspace. */
781 __nfulnl_flush(inst);
782 }
783
784 if (!inst->skb) {
785 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
786 inst->nlbufsiz, size);
787 if (!inst->skb)
788 goto alloc_failure;
789 }
790
791 inst->qlen++;
792
793 __build_packet_message(log, inst, skb, data_len, pf,
794 hooknum, in, out, prefix, plen,
795 nfnl_ct, ct, ctinfo);
796
797 if (inst->qlen >= qthreshold)
798 __nfulnl_flush(inst);
799 /* timer_pending always called within inst->lock, so there
800 * is no chance of a race here */
801 else if (!timer_pending(&inst->timer)) {
802 instance_get(inst);
803 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
804 add_timer(&inst->timer);
805 }
806
807unlock_and_release:
808 spin_unlock_bh(&inst->lock);
809 instance_put(inst);
810 return;
811
812alloc_failure:
813 /* FIXME: statistics */
814 goto unlock_and_release;
815}
816
817static int
818nfulnl_rcv_nl_event(struct notifier_block *this,
819 unsigned long event, void *ptr)
820{
821 struct netlink_notify *n = ptr;
822 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
823
824 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
825 int i;
826
827 /* destroy all instances for this portid */
828 spin_lock_bh(&log->instances_lock);
829 for (i = 0; i < INSTANCE_BUCKETS; i++) {
830 struct hlist_node *t2;
831 struct nfulnl_instance *inst;
832 struct hlist_head *head = &log->instance_table[i];
833
834 hlist_for_each_entry_safe(inst, t2, head, hlist) {
835 if (n->portid == inst->peer_portid)
836 __instance_destroy(inst);
837 }
838 }
839 spin_unlock_bh(&log->instances_lock);
840 }
841 return NOTIFY_DONE;
842}
843
844static struct notifier_block nfulnl_rtnl_notifier = {
845 .notifier_call = nfulnl_rcv_nl_event,
846};
847
848static int nfulnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info,
849 const struct nlattr * const nfula[])
850{
851 return -ENOTSUPP;
852}
853
854static struct nf_logger nfulnl_logger __read_mostly = {
855 .name = "nfnetlink_log",
856 .type = NF_LOG_TYPE_ULOG,
857 .logfn = nfulnl_log_packet,
858 .me = THIS_MODULE,
859};
860
861static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
862 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
863 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
864 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
865 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
866 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
867 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
868};
869
870static int nfulnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info,
871 const struct nlattr * const nfula[])
872{
873 struct nfnl_log_net *log = nfnl_log_pernet(info->net);
874 u_int16_t group_num = ntohs(info->nfmsg->res_id);
875 struct nfulnl_msg_config_cmd *cmd = NULL;
876 struct nfulnl_instance *inst;
877 u16 flags = 0;
878 int ret = 0;
879
880 if (nfula[NFULA_CFG_CMD]) {
881 u_int8_t pf = info->nfmsg->nfgen_family;
882 cmd = nla_data(nfula[NFULA_CFG_CMD]);
883
884 /* Commands without queue context */
885 switch (cmd->command) {
886 case NFULNL_CFG_CMD_PF_BIND:
887 return nf_log_bind_pf(info->net, pf, &nfulnl_logger);
888 case NFULNL_CFG_CMD_PF_UNBIND:
889 nf_log_unbind_pf(info->net, pf);
890 return 0;
891 }
892 }
893
894 inst = instance_lookup_get(log, group_num);
895 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
896 ret = -EPERM;
897 goto out_put;
898 }
899
900 /* Check if we support these flags in first place, dependencies should
901 * be there too not to break atomicity.
902 */
903 if (nfula[NFULA_CFG_FLAGS]) {
904 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
905
906 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
907 !rcu_access_pointer(nfnl_ct_hook)) {
908#ifdef CONFIG_MODULES
909 nfnl_unlock(NFNL_SUBSYS_ULOG);
910 request_module("ip_conntrack_netlink");
911 nfnl_lock(NFNL_SUBSYS_ULOG);
912 if (rcu_access_pointer(nfnl_ct_hook)) {
913 ret = -EAGAIN;
914 goto out_put;
915 }
916#endif
917 ret = -EOPNOTSUPP;
918 goto out_put;
919 }
920 }
921
922 if (cmd != NULL) {
923 switch (cmd->command) {
924 case NFULNL_CFG_CMD_BIND:
925 if (inst) {
926 ret = -EBUSY;
927 goto out_put;
928 }
929
930 inst = instance_create(info->net, group_num,
931 NETLINK_CB(skb).portid,
932 sk_user_ns(NETLINK_CB(skb).sk));
933 if (IS_ERR(inst)) {
934 ret = PTR_ERR(inst);
935 goto out;
936 }
937 break;
938 case NFULNL_CFG_CMD_UNBIND:
939 if (!inst) {
940 ret = -ENODEV;
941 goto out;
942 }
943
944 instance_destroy(log, inst);
945 goto out_put;
946 default:
947 ret = -ENOTSUPP;
948 goto out_put;
949 }
950 } else if (!inst) {
951 ret = -ENODEV;
952 goto out;
953 }
954
955 if (nfula[NFULA_CFG_MODE]) {
956 struct nfulnl_msg_config_mode *params =
957 nla_data(nfula[NFULA_CFG_MODE]);
958
959 nfulnl_set_mode(inst, params->copy_mode,
960 ntohl(params->copy_range));
961 }
962
963 if (nfula[NFULA_CFG_TIMEOUT]) {
964 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
965
966 nfulnl_set_timeout(inst, ntohl(timeout));
967 }
968
969 if (nfula[NFULA_CFG_NLBUFSIZ]) {
970 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
971
972 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
973 }
974
975 if (nfula[NFULA_CFG_QTHRESH]) {
976 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
977
978 nfulnl_set_qthresh(inst, ntohl(qthresh));
979 }
980
981 if (nfula[NFULA_CFG_FLAGS])
982 nfulnl_set_flags(inst, flags);
983
984out_put:
985 instance_put(inst);
986out:
987 return ret;
988}
989
990static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
991 [NFULNL_MSG_PACKET] = {
992 .call = nfulnl_recv_unsupp,
993 .type = NFNL_CB_MUTEX,
994 .attr_count = NFULA_MAX,
995 },
996 [NFULNL_MSG_CONFIG] = {
997 .call = nfulnl_recv_config,
998 .type = NFNL_CB_MUTEX,
999 .attr_count = NFULA_CFG_MAX,
1000 .policy = nfula_cfg_policy
1001 },
1002};
1003
1004static const struct nfnetlink_subsystem nfulnl_subsys = {
1005 .name = "log",
1006 .subsys_id = NFNL_SUBSYS_ULOG,
1007 .cb_count = NFULNL_MSG_MAX,
1008 .cb = nfulnl_cb,
1009};
1010
1011#ifdef CONFIG_PROC_FS
1012struct iter_state {
1013 struct seq_net_private p;
1014 unsigned int bucket;
1015};
1016
1017static struct hlist_node *get_first(struct net *net, struct iter_state *st)
1018{
1019 struct nfnl_log_net *log;
1020 if (!st)
1021 return NULL;
1022
1023 log = nfnl_log_pernet(net);
1024
1025 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1026 struct hlist_head *head = &log->instance_table[st->bucket];
1027
1028 if (!hlist_empty(head))
1029 return rcu_dereference_bh(hlist_first_rcu(head));
1030 }
1031 return NULL;
1032}
1033
1034static struct hlist_node *get_next(struct net *net, struct iter_state *st,
1035 struct hlist_node *h)
1036{
1037 h = rcu_dereference_bh(hlist_next_rcu(h));
1038 while (!h) {
1039 struct nfnl_log_net *log;
1040 struct hlist_head *head;
1041
1042 if (++st->bucket >= INSTANCE_BUCKETS)
1043 return NULL;
1044
1045 log = nfnl_log_pernet(net);
1046 head = &log->instance_table[st->bucket];
1047 h = rcu_dereference_bh(hlist_first_rcu(head));
1048 }
1049 return h;
1050}
1051
1052static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
1053 loff_t pos)
1054{
1055 struct hlist_node *head;
1056 head = get_first(net, st);
1057
1058 if (head)
1059 while (pos && (head = get_next(net, st, head)))
1060 pos--;
1061 return pos ? NULL : head;
1062}
1063
1064static void *seq_start(struct seq_file *s, loff_t *pos)
1065 __acquires(rcu_bh)
1066{
1067 rcu_read_lock_bh();
1068 return get_idx(seq_file_net(s), s->private, *pos);
1069}
1070
1071static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1072{
1073 (*pos)++;
1074 return get_next(seq_file_net(s), s->private, v);
1075}
1076
1077static void seq_stop(struct seq_file *s, void *v)
1078 __releases(rcu_bh)
1079{
1080 rcu_read_unlock_bh();
1081}
1082
1083static int seq_show(struct seq_file *s, void *v)
1084{
1085 const struct nfulnl_instance *inst = v;
1086
1087 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1088 inst->group_num,
1089 inst->peer_portid, inst->qlen,
1090 inst->copy_mode, inst->copy_range,
1091 inst->flushtimeout, refcount_read(&inst->use));
1092
1093 return 0;
1094}
1095
1096static const struct seq_operations nful_seq_ops = {
1097 .start = seq_start,
1098 .next = seq_next,
1099 .stop = seq_stop,
1100 .show = seq_show,
1101};
1102#endif /* PROC_FS */
1103
1104static int __net_init nfnl_log_net_init(struct net *net)
1105{
1106 unsigned int i;
1107 struct nfnl_log_net *log = nfnl_log_pernet(net);
1108#ifdef CONFIG_PROC_FS
1109 struct proc_dir_entry *proc;
1110 kuid_t root_uid;
1111 kgid_t root_gid;
1112#endif
1113
1114 for (i = 0; i < INSTANCE_BUCKETS; i++)
1115 INIT_HLIST_HEAD(&log->instance_table[i]);
1116 spin_lock_init(&log->instances_lock);
1117
1118#ifdef CONFIG_PROC_FS
1119 proc = proc_create_net("nfnetlink_log", 0440, net->nf.proc_netfilter,
1120 &nful_seq_ops, sizeof(struct iter_state));
1121 if (!proc)
1122 return -ENOMEM;
1123
1124 root_uid = make_kuid(net->user_ns, 0);
1125 root_gid = make_kgid(net->user_ns, 0);
1126 if (uid_valid(root_uid) && gid_valid(root_gid))
1127 proc_set_user(proc, root_uid, root_gid);
1128#endif
1129 return 0;
1130}
1131
1132static void __net_exit nfnl_log_net_exit(struct net *net)
1133{
1134 struct nfnl_log_net *log = nfnl_log_pernet(net);
1135 unsigned int i;
1136
1137#ifdef CONFIG_PROC_FS
1138 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1139#endif
1140 nf_log_unset(net, &nfulnl_logger);
1141 for (i = 0; i < INSTANCE_BUCKETS; i++)
1142 WARN_ON_ONCE(!hlist_empty(&log->instance_table[i]));
1143}
1144
1145static struct pernet_operations nfnl_log_net_ops = {
1146 .init = nfnl_log_net_init,
1147 .exit = nfnl_log_net_exit,
1148 .id = &nfnl_log_net_id,
1149 .size = sizeof(struct nfnl_log_net),
1150};
1151
1152static int __init nfnetlink_log_init(void)
1153{
1154 int status;
1155
1156 status = register_pernet_subsys(&nfnl_log_net_ops);
1157 if (status < 0) {
1158 pr_err("failed to register pernet ops\n");
1159 goto out;
1160 }
1161
1162 netlink_register_notifier(&nfulnl_rtnl_notifier);
1163 status = nfnetlink_subsys_register(&nfulnl_subsys);
1164 if (status < 0) {
1165 pr_err("failed to create netlink socket\n");
1166 goto cleanup_netlink_notifier;
1167 }
1168
1169 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1170 if (status < 0) {
1171 pr_err("failed to register logger\n");
1172 goto cleanup_subsys;
1173 }
1174
1175 return status;
1176
1177cleanup_subsys:
1178 nfnetlink_subsys_unregister(&nfulnl_subsys);
1179cleanup_netlink_notifier:
1180 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1181 unregister_pernet_subsys(&nfnl_log_net_ops);
1182out:
1183 return status;
1184}
1185
1186static void __exit nfnetlink_log_fini(void)
1187{
1188 nfnetlink_subsys_unregister(&nfulnl_subsys);
1189 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1190 unregister_pernet_subsys(&nfnl_log_net_ops);
1191 nf_log_unregister(&nfulnl_logger);
1192}
1193
1194MODULE_DESCRIPTION("netfilter userspace logging");
1195MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1196MODULE_LICENSE("GPL");
1197MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1198MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1199MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1200MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1201MODULE_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
1202MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
1203
1204module_init(nfnetlink_log_init);
1205module_exit(nfnetlink_log_fini);
1/*
2 * This is a module which is used for logging packets to userspace via
3 * nfetlink.
4 *
5 * (C) 2005 by Harald Welte <laforge@netfilter.org>
6 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
7 *
8 * Based on the old ipv4-only ipt_ULOG.c:
9 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/skbuff.h>
20#include <linux/if_arp.h>
21#include <linux/init.h>
22#include <linux/ip.h>
23#include <linux/ipv6.h>
24#include <linux/netdevice.h>
25#include <linux/netfilter.h>
26#include <linux/netfilter_bridge.h>
27#include <net/netlink.h>
28#include <linux/netfilter/nfnetlink.h>
29#include <linux/netfilter/nfnetlink_log.h>
30#include <linux/netfilter/nf_conntrack_common.h>
31#include <linux/spinlock.h>
32#include <linux/sysctl.h>
33#include <linux/proc_fs.h>
34#include <linux/security.h>
35#include <linux/list.h>
36#include <linux/slab.h>
37#include <net/sock.h>
38#include <net/netfilter/nf_log.h>
39#include <net/netns/generic.h>
40#include <net/netfilter/nfnetlink_log.h>
41
42#include <linux/atomic.h>
43
44#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
45#include "../bridge/br_private.h"
46#endif
47
48#define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
49#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
50#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
51/* max packet size is limited by 16-bit struct nfattr nfa_len field */
52#define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
53
54#define PRINTR(x, args...) do { if (net_ratelimit()) \
55 printk(x, ## args); } while (0);
56
57struct nfulnl_instance {
58 struct hlist_node hlist; /* global list of instances */
59 spinlock_t lock;
60 atomic_t use; /* use count */
61
62 unsigned int qlen; /* number of nlmsgs in skb */
63 struct sk_buff *skb; /* pre-allocatd skb */
64 struct timer_list timer;
65 struct net *net;
66 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
67 u32 peer_portid; /* PORTID of the peer process */
68
69 /* configurable parameters */
70 unsigned int flushtimeout; /* timeout until queue flush */
71 unsigned int nlbufsiz; /* netlink buffer allocation size */
72 unsigned int qthreshold; /* threshold of the queue */
73 u_int32_t copy_range;
74 u_int32_t seq; /* instance-local sequential counter */
75 u_int16_t group_num; /* number of this queue */
76 u_int16_t flags;
77 u_int8_t copy_mode;
78 struct rcu_head rcu;
79};
80
81#define INSTANCE_BUCKETS 16
82
83static unsigned int nfnl_log_net_id __read_mostly;
84
85struct nfnl_log_net {
86 spinlock_t instances_lock;
87 struct hlist_head instance_table[INSTANCE_BUCKETS];
88 atomic_t global_seq;
89};
90
91static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
92{
93 return net_generic(net, nfnl_log_net_id);
94}
95
96static inline u_int8_t instance_hashfn(u_int16_t group_num)
97{
98 return ((group_num & 0xff) % INSTANCE_BUCKETS);
99}
100
101static struct nfulnl_instance *
102__instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
103{
104 struct hlist_head *head;
105 struct nfulnl_instance *inst;
106
107 head = &log->instance_table[instance_hashfn(group_num)];
108 hlist_for_each_entry_rcu(inst, head, hlist) {
109 if (inst->group_num == group_num)
110 return inst;
111 }
112 return NULL;
113}
114
115static inline void
116instance_get(struct nfulnl_instance *inst)
117{
118 atomic_inc(&inst->use);
119}
120
121static struct nfulnl_instance *
122instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
123{
124 struct nfulnl_instance *inst;
125
126 rcu_read_lock_bh();
127 inst = __instance_lookup(log, group_num);
128 if (inst && !atomic_inc_not_zero(&inst->use))
129 inst = NULL;
130 rcu_read_unlock_bh();
131
132 return inst;
133}
134
135static void nfulnl_instance_free_rcu(struct rcu_head *head)
136{
137 struct nfulnl_instance *inst =
138 container_of(head, struct nfulnl_instance, rcu);
139
140 put_net(inst->net);
141 kfree(inst);
142 module_put(THIS_MODULE);
143}
144
145static void
146instance_put(struct nfulnl_instance *inst)
147{
148 if (inst && atomic_dec_and_test(&inst->use))
149 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
150}
151
152static void nfulnl_timer(unsigned long data);
153
154static struct nfulnl_instance *
155instance_create(struct net *net, u_int16_t group_num,
156 u32 portid, struct user_namespace *user_ns)
157{
158 struct nfulnl_instance *inst;
159 struct nfnl_log_net *log = nfnl_log_pernet(net);
160 int err;
161
162 spin_lock_bh(&log->instances_lock);
163 if (__instance_lookup(log, group_num)) {
164 err = -EEXIST;
165 goto out_unlock;
166 }
167
168 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
169 if (!inst) {
170 err = -ENOMEM;
171 goto out_unlock;
172 }
173
174 if (!try_module_get(THIS_MODULE)) {
175 kfree(inst);
176 err = -EAGAIN;
177 goto out_unlock;
178 }
179
180 INIT_HLIST_NODE(&inst->hlist);
181 spin_lock_init(&inst->lock);
182 /* needs to be two, since we _put() after creation */
183 atomic_set(&inst->use, 2);
184
185 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
186
187 inst->net = get_net(net);
188 inst->peer_user_ns = user_ns;
189 inst->peer_portid = portid;
190 inst->group_num = group_num;
191
192 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
193 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
194 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
195 inst->copy_mode = NFULNL_COPY_PACKET;
196 inst->copy_range = NFULNL_COPY_RANGE_MAX;
197
198 hlist_add_head_rcu(&inst->hlist,
199 &log->instance_table[instance_hashfn(group_num)]);
200
201
202 spin_unlock_bh(&log->instances_lock);
203
204 return inst;
205
206out_unlock:
207 spin_unlock_bh(&log->instances_lock);
208 return ERR_PTR(err);
209}
210
211static void __nfulnl_flush(struct nfulnl_instance *inst);
212
213/* called with BH disabled */
214static void
215__instance_destroy(struct nfulnl_instance *inst)
216{
217 /* first pull it out of the global list */
218 hlist_del_rcu(&inst->hlist);
219
220 /* then flush all pending packets from skb */
221
222 spin_lock(&inst->lock);
223
224 /* lockless readers wont be able to use us */
225 inst->copy_mode = NFULNL_COPY_DISABLED;
226
227 if (inst->skb)
228 __nfulnl_flush(inst);
229 spin_unlock(&inst->lock);
230
231 /* and finally put the refcount */
232 instance_put(inst);
233}
234
235static inline void
236instance_destroy(struct nfnl_log_net *log,
237 struct nfulnl_instance *inst)
238{
239 spin_lock_bh(&log->instances_lock);
240 __instance_destroy(inst);
241 spin_unlock_bh(&log->instances_lock);
242}
243
244static int
245nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
246 unsigned int range)
247{
248 int status = 0;
249
250 spin_lock_bh(&inst->lock);
251
252 switch (mode) {
253 case NFULNL_COPY_NONE:
254 case NFULNL_COPY_META:
255 inst->copy_mode = mode;
256 inst->copy_range = 0;
257 break;
258
259 case NFULNL_COPY_PACKET:
260 inst->copy_mode = mode;
261 if (range == 0)
262 range = NFULNL_COPY_RANGE_MAX;
263 inst->copy_range = min_t(unsigned int,
264 range, NFULNL_COPY_RANGE_MAX);
265 break;
266
267 default:
268 status = -EINVAL;
269 break;
270 }
271
272 spin_unlock_bh(&inst->lock);
273
274 return status;
275}
276
277static int
278nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
279{
280 int status;
281
282 spin_lock_bh(&inst->lock);
283 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
284 status = -ERANGE;
285 else if (nlbufsiz > 131072)
286 status = -ERANGE;
287 else {
288 inst->nlbufsiz = nlbufsiz;
289 status = 0;
290 }
291 spin_unlock_bh(&inst->lock);
292
293 return status;
294}
295
296static void
297nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
298{
299 spin_lock_bh(&inst->lock);
300 inst->flushtimeout = timeout;
301 spin_unlock_bh(&inst->lock);
302}
303
304static void
305nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
306{
307 spin_lock_bh(&inst->lock);
308 inst->qthreshold = qthresh;
309 spin_unlock_bh(&inst->lock);
310}
311
312static int
313nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
314{
315 spin_lock_bh(&inst->lock);
316 inst->flags = flags;
317 spin_unlock_bh(&inst->lock);
318
319 return 0;
320}
321
322static struct sk_buff *
323nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
324 unsigned int pkt_size)
325{
326 struct sk_buff *skb;
327 unsigned int n;
328
329 /* alloc skb which should be big enough for a whole multipart
330 * message. WARNING: has to be <= 128k due to slab restrictions */
331
332 n = max(inst_size, pkt_size);
333 skb = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
334 if (!skb) {
335 if (n > pkt_size) {
336 /* try to allocate only as much as we need for current
337 * packet */
338
339 skb = alloc_skb(pkt_size, GFP_ATOMIC);
340 }
341 }
342
343 return skb;
344}
345
346static void
347__nfulnl_send(struct nfulnl_instance *inst)
348{
349 if (inst->qlen > 1) {
350 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
351 NLMSG_DONE,
352 sizeof(struct nfgenmsg),
353 0);
354 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
355 inst->skb->len, skb_tailroom(inst->skb))) {
356 kfree_skb(inst->skb);
357 goto out;
358 }
359 }
360 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
361 MSG_DONTWAIT);
362out:
363 inst->qlen = 0;
364 inst->skb = NULL;
365}
366
367static void
368__nfulnl_flush(struct nfulnl_instance *inst)
369{
370 /* timer holds a reference */
371 if (del_timer(&inst->timer))
372 instance_put(inst);
373 if (inst->skb)
374 __nfulnl_send(inst);
375}
376
377static void
378nfulnl_timer(unsigned long data)
379{
380 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
381
382 spin_lock_bh(&inst->lock);
383 if (inst->skb)
384 __nfulnl_send(inst);
385 spin_unlock_bh(&inst->lock);
386 instance_put(inst);
387}
388
389/* This is an inline function, we don't really care about a long
390 * list of arguments */
391static inline int
392__build_packet_message(struct nfnl_log_net *log,
393 struct nfulnl_instance *inst,
394 const struct sk_buff *skb,
395 unsigned int data_len,
396 u_int8_t pf,
397 unsigned int hooknum,
398 const struct net_device *indev,
399 const struct net_device *outdev,
400 const char *prefix, unsigned int plen,
401 const struct nfnl_ct_hook *nfnl_ct,
402 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
403{
404 struct nfulnl_msg_packet_hdr pmsg;
405 struct nlmsghdr *nlh;
406 struct nfgenmsg *nfmsg;
407 sk_buff_data_t old_tail = inst->skb->tail;
408 struct sock *sk;
409 const unsigned char *hwhdrp;
410
411 nlh = nlmsg_put(inst->skb, 0, 0,
412 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
413 sizeof(struct nfgenmsg), 0);
414 if (!nlh)
415 return -1;
416 nfmsg = nlmsg_data(nlh);
417 nfmsg->nfgen_family = pf;
418 nfmsg->version = NFNETLINK_V0;
419 nfmsg->res_id = htons(inst->group_num);
420
421 memset(&pmsg, 0, sizeof(pmsg));
422 pmsg.hw_protocol = skb->protocol;
423 pmsg.hook = hooknum;
424
425 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
426 goto nla_put_failure;
427
428 if (prefix &&
429 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
430 goto nla_put_failure;
431
432 if (indev) {
433#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
434 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
435 htonl(indev->ifindex)))
436 goto nla_put_failure;
437#else
438 if (pf == PF_BRIDGE) {
439 /* Case 1: outdev is physical input device, we need to
440 * look for bridge group (when called from
441 * netfilter_bridge) */
442 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
443 htonl(indev->ifindex)) ||
444 /* this is the bridge group "brX" */
445 /* rcu_read_lock()ed by nf_hook_thresh or
446 * nf_log_packet.
447 */
448 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
449 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
450 goto nla_put_failure;
451 } else {
452 struct net_device *physindev;
453
454 /* Case 2: indev is bridge group, we need to look for
455 * physical device (when called from ipv4) */
456 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
457 htonl(indev->ifindex)))
458 goto nla_put_failure;
459
460 physindev = nf_bridge_get_physindev(skb);
461 if (physindev &&
462 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
463 htonl(physindev->ifindex)))
464 goto nla_put_failure;
465 }
466#endif
467 }
468
469 if (outdev) {
470#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
471 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
472 htonl(outdev->ifindex)))
473 goto nla_put_failure;
474#else
475 if (pf == PF_BRIDGE) {
476 /* Case 1: outdev is physical output device, we need to
477 * look for bridge group (when called from
478 * netfilter_bridge) */
479 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
480 htonl(outdev->ifindex)) ||
481 /* this is the bridge group "brX" */
482 /* rcu_read_lock()ed by nf_hook_thresh or
483 * nf_log_packet.
484 */
485 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
486 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
487 goto nla_put_failure;
488 } else {
489 struct net_device *physoutdev;
490
491 /* Case 2: indev is a bridge group, we need to look
492 * for physical device (when called from ipv4) */
493 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
494 htonl(outdev->ifindex)))
495 goto nla_put_failure;
496
497 physoutdev = nf_bridge_get_physoutdev(skb);
498 if (physoutdev &&
499 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
500 htonl(physoutdev->ifindex)))
501 goto nla_put_failure;
502 }
503#endif
504 }
505
506 if (skb->mark &&
507 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
508 goto nla_put_failure;
509
510 if (indev && skb->dev &&
511 skb->mac_header != skb->network_header) {
512 struct nfulnl_msg_packet_hw phw;
513 int len;
514
515 memset(&phw, 0, sizeof(phw));
516 len = dev_parse_header(skb, phw.hw_addr);
517 if (len > 0) {
518 phw.hw_addrlen = htons(len);
519 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
520 goto nla_put_failure;
521 }
522 }
523
524 if (indev && skb_mac_header_was_set(skb)) {
525 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
526 nla_put_be16(inst->skb, NFULA_HWLEN,
527 htons(skb->dev->hard_header_len)))
528 goto nla_put_failure;
529
530 hwhdrp = skb_mac_header(skb);
531
532 if (skb->dev->type == ARPHRD_SIT)
533 hwhdrp -= ETH_HLEN;
534
535 if (hwhdrp >= skb->head &&
536 nla_put(inst->skb, NFULA_HWHEADER,
537 skb->dev->hard_header_len, hwhdrp))
538 goto nla_put_failure;
539 }
540
541 if (skb->tstamp) {
542 struct nfulnl_msg_packet_timestamp ts;
543 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
544 ts.sec = cpu_to_be64(kts.tv_sec);
545 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
546
547 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
548 goto nla_put_failure;
549 }
550
551 /* UID */
552 sk = skb->sk;
553 if (sk && sk_fullsock(sk)) {
554 read_lock_bh(&sk->sk_callback_lock);
555 if (sk->sk_socket && sk->sk_socket->file) {
556 struct file *file = sk->sk_socket->file;
557 const struct cred *cred = file->f_cred;
558 struct user_namespace *user_ns = inst->peer_user_ns;
559 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
560 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
561 read_unlock_bh(&sk->sk_callback_lock);
562 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
563 nla_put_be32(inst->skb, NFULA_GID, gid))
564 goto nla_put_failure;
565 } else
566 read_unlock_bh(&sk->sk_callback_lock);
567 }
568
569 /* local sequence number */
570 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
571 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
572 goto nla_put_failure;
573
574 /* global sequence number */
575 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
576 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
577 htonl(atomic_inc_return(&log->global_seq))))
578 goto nla_put_failure;
579
580 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
581 NFULA_CT, NFULA_CT_INFO) < 0)
582 goto nla_put_failure;
583
584 if (data_len) {
585 struct nlattr *nla;
586 int size = nla_attr_size(data_len);
587
588 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
589 goto nla_put_failure;
590
591 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
592 nla->nla_type = NFULA_PAYLOAD;
593 nla->nla_len = size;
594
595 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
596 BUG();
597 }
598
599 nlh->nlmsg_len = inst->skb->tail - old_tail;
600 return 0;
601
602nla_put_failure:
603 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
604 return -1;
605}
606
607static struct nf_loginfo default_loginfo = {
608 .type = NF_LOG_TYPE_ULOG,
609 .u = {
610 .ulog = {
611 .copy_len = 0xffff,
612 .group = 0,
613 .qthreshold = 1,
614 },
615 },
616};
617
618/* log handler for internal netfilter logging api */
619void
620nfulnl_log_packet(struct net *net,
621 u_int8_t pf,
622 unsigned int hooknum,
623 const struct sk_buff *skb,
624 const struct net_device *in,
625 const struct net_device *out,
626 const struct nf_loginfo *li_user,
627 const char *prefix)
628{
629 size_t size;
630 unsigned int data_len;
631 struct nfulnl_instance *inst;
632 const struct nf_loginfo *li;
633 unsigned int qthreshold;
634 unsigned int plen;
635 struct nfnl_log_net *log = nfnl_log_pernet(net);
636 const struct nfnl_ct_hook *nfnl_ct = NULL;
637 struct nf_conn *ct = NULL;
638 enum ip_conntrack_info uninitialized_var(ctinfo);
639
640 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
641 li = li_user;
642 else
643 li = &default_loginfo;
644
645 inst = instance_lookup_get(log, li->u.ulog.group);
646 if (!inst)
647 return;
648
649 plen = 0;
650 if (prefix)
651 plen = strlen(prefix) + 1;
652
653 /* FIXME: do we want to make the size calculation conditional based on
654 * what is actually present? way more branches and checks, but more
655 * memory efficient... */
656 size = nlmsg_total_size(sizeof(struct nfgenmsg))
657 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
658 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
659 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
660#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
661 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
662 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
663#endif
664 + nla_total_size(sizeof(u_int32_t)) /* mark */
665 + nla_total_size(sizeof(u_int32_t)) /* uid */
666 + nla_total_size(sizeof(u_int32_t)) /* gid */
667 + nla_total_size(plen) /* prefix */
668 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
669 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
670 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
671
672 if (in && skb_mac_header_was_set(skb)) {
673 size += nla_total_size(skb->dev->hard_header_len)
674 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
675 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
676 }
677
678 spin_lock_bh(&inst->lock);
679
680 if (inst->flags & NFULNL_CFG_F_SEQ)
681 size += nla_total_size(sizeof(u_int32_t));
682 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
683 size += nla_total_size(sizeof(u_int32_t));
684 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
685 nfnl_ct = rcu_dereference(nfnl_ct_hook);
686 if (nfnl_ct != NULL) {
687 ct = nfnl_ct->get_ct(skb, &ctinfo);
688 if (ct != NULL)
689 size += nfnl_ct->build_size(ct);
690 }
691 }
692
693 qthreshold = inst->qthreshold;
694 /* per-rule qthreshold overrides per-instance */
695 if (li->u.ulog.qthreshold)
696 if (qthreshold > li->u.ulog.qthreshold)
697 qthreshold = li->u.ulog.qthreshold;
698
699
700 switch (inst->copy_mode) {
701 case NFULNL_COPY_META:
702 case NFULNL_COPY_NONE:
703 data_len = 0;
704 break;
705
706 case NFULNL_COPY_PACKET:
707 data_len = inst->copy_range;
708 if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
709 (li->u.ulog.copy_len < data_len))
710 data_len = li->u.ulog.copy_len;
711
712 if (data_len > skb->len)
713 data_len = skb->len;
714
715 size += nla_total_size(data_len);
716 break;
717
718 case NFULNL_COPY_DISABLED:
719 default:
720 goto unlock_and_release;
721 }
722
723 if (inst->skb && size > skb_tailroom(inst->skb)) {
724 /* either the queue len is too high or we don't have
725 * enough room in the skb left. flush to userspace. */
726 __nfulnl_flush(inst);
727 }
728
729 if (!inst->skb) {
730 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
731 inst->nlbufsiz, size);
732 if (!inst->skb)
733 goto alloc_failure;
734 }
735
736 inst->qlen++;
737
738 __build_packet_message(log, inst, skb, data_len, pf,
739 hooknum, in, out, prefix, plen,
740 nfnl_ct, ct, ctinfo);
741
742 if (inst->qlen >= qthreshold)
743 __nfulnl_flush(inst);
744 /* timer_pending always called within inst->lock, so there
745 * is no chance of a race here */
746 else if (!timer_pending(&inst->timer)) {
747 instance_get(inst);
748 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
749 add_timer(&inst->timer);
750 }
751
752unlock_and_release:
753 spin_unlock_bh(&inst->lock);
754 instance_put(inst);
755 return;
756
757alloc_failure:
758 /* FIXME: statistics */
759 goto unlock_and_release;
760}
761EXPORT_SYMBOL_GPL(nfulnl_log_packet);
762
763static int
764nfulnl_rcv_nl_event(struct notifier_block *this,
765 unsigned long event, void *ptr)
766{
767 struct netlink_notify *n = ptr;
768 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
769
770 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
771 int i;
772
773 /* destroy all instances for this portid */
774 spin_lock_bh(&log->instances_lock);
775 for (i = 0; i < INSTANCE_BUCKETS; i++) {
776 struct hlist_node *t2;
777 struct nfulnl_instance *inst;
778 struct hlist_head *head = &log->instance_table[i];
779
780 hlist_for_each_entry_safe(inst, t2, head, hlist) {
781 if (n->portid == inst->peer_portid)
782 __instance_destroy(inst);
783 }
784 }
785 spin_unlock_bh(&log->instances_lock);
786 }
787 return NOTIFY_DONE;
788}
789
790static struct notifier_block nfulnl_rtnl_notifier = {
791 .notifier_call = nfulnl_rcv_nl_event,
792};
793
794static int nfulnl_recv_unsupp(struct net *net, struct sock *ctnl,
795 struct sk_buff *skb, const struct nlmsghdr *nlh,
796 const struct nlattr * const nfqa[])
797{
798 return -ENOTSUPP;
799}
800
801static struct nf_logger nfulnl_logger __read_mostly = {
802 .name = "nfnetlink_log",
803 .type = NF_LOG_TYPE_ULOG,
804 .logfn = &nfulnl_log_packet,
805 .me = THIS_MODULE,
806};
807
808static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
809 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
810 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
811 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
812 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
813 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
814 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
815};
816
817static int nfulnl_recv_config(struct net *net, struct sock *ctnl,
818 struct sk_buff *skb, const struct nlmsghdr *nlh,
819 const struct nlattr * const nfula[])
820{
821 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
822 u_int16_t group_num = ntohs(nfmsg->res_id);
823 struct nfulnl_instance *inst;
824 struct nfulnl_msg_config_cmd *cmd = NULL;
825 struct nfnl_log_net *log = nfnl_log_pernet(net);
826 int ret = 0;
827 u16 flags = 0;
828
829 if (nfula[NFULA_CFG_CMD]) {
830 u_int8_t pf = nfmsg->nfgen_family;
831 cmd = nla_data(nfula[NFULA_CFG_CMD]);
832
833 /* Commands without queue context */
834 switch (cmd->command) {
835 case NFULNL_CFG_CMD_PF_BIND:
836 return nf_log_bind_pf(net, pf, &nfulnl_logger);
837 case NFULNL_CFG_CMD_PF_UNBIND:
838 nf_log_unbind_pf(net, pf);
839 return 0;
840 }
841 }
842
843 inst = instance_lookup_get(log, group_num);
844 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
845 ret = -EPERM;
846 goto out_put;
847 }
848
849 /* Check if we support these flags in first place, dependencies should
850 * be there too not to break atomicity.
851 */
852 if (nfula[NFULA_CFG_FLAGS]) {
853 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
854
855 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
856 !rcu_access_pointer(nfnl_ct_hook)) {
857#ifdef CONFIG_MODULES
858 nfnl_unlock(NFNL_SUBSYS_ULOG);
859 request_module("ip_conntrack_netlink");
860 nfnl_lock(NFNL_SUBSYS_ULOG);
861 if (rcu_access_pointer(nfnl_ct_hook)) {
862 ret = -EAGAIN;
863 goto out_put;
864 }
865#endif
866 ret = -EOPNOTSUPP;
867 goto out_put;
868 }
869 }
870
871 if (cmd != NULL) {
872 switch (cmd->command) {
873 case NFULNL_CFG_CMD_BIND:
874 if (inst) {
875 ret = -EBUSY;
876 goto out_put;
877 }
878
879 inst = instance_create(net, group_num,
880 NETLINK_CB(skb).portid,
881 sk_user_ns(NETLINK_CB(skb).sk));
882 if (IS_ERR(inst)) {
883 ret = PTR_ERR(inst);
884 goto out;
885 }
886 break;
887 case NFULNL_CFG_CMD_UNBIND:
888 if (!inst) {
889 ret = -ENODEV;
890 goto out;
891 }
892
893 instance_destroy(log, inst);
894 goto out_put;
895 default:
896 ret = -ENOTSUPP;
897 goto out_put;
898 }
899 } else if (!inst) {
900 ret = -ENODEV;
901 goto out;
902 }
903
904 if (nfula[NFULA_CFG_MODE]) {
905 struct nfulnl_msg_config_mode *params =
906 nla_data(nfula[NFULA_CFG_MODE]);
907
908 nfulnl_set_mode(inst, params->copy_mode,
909 ntohl(params->copy_range));
910 }
911
912 if (nfula[NFULA_CFG_TIMEOUT]) {
913 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
914
915 nfulnl_set_timeout(inst, ntohl(timeout));
916 }
917
918 if (nfula[NFULA_CFG_NLBUFSIZ]) {
919 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
920
921 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
922 }
923
924 if (nfula[NFULA_CFG_QTHRESH]) {
925 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
926
927 nfulnl_set_qthresh(inst, ntohl(qthresh));
928 }
929
930 if (nfula[NFULA_CFG_FLAGS])
931 nfulnl_set_flags(inst, flags);
932
933out_put:
934 instance_put(inst);
935out:
936 return ret;
937}
938
939static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
940 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
941 .attr_count = NFULA_MAX, },
942 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
943 .attr_count = NFULA_CFG_MAX,
944 .policy = nfula_cfg_policy },
945};
946
947static const struct nfnetlink_subsystem nfulnl_subsys = {
948 .name = "log",
949 .subsys_id = NFNL_SUBSYS_ULOG,
950 .cb_count = NFULNL_MSG_MAX,
951 .cb = nfulnl_cb,
952};
953
954#ifdef CONFIG_PROC_FS
955struct iter_state {
956 struct seq_net_private p;
957 unsigned int bucket;
958};
959
960static struct hlist_node *get_first(struct net *net, struct iter_state *st)
961{
962 struct nfnl_log_net *log;
963 if (!st)
964 return NULL;
965
966 log = nfnl_log_pernet(net);
967
968 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
969 struct hlist_head *head = &log->instance_table[st->bucket];
970
971 if (!hlist_empty(head))
972 return rcu_dereference_bh(hlist_first_rcu(head));
973 }
974 return NULL;
975}
976
977static struct hlist_node *get_next(struct net *net, struct iter_state *st,
978 struct hlist_node *h)
979{
980 h = rcu_dereference_bh(hlist_next_rcu(h));
981 while (!h) {
982 struct nfnl_log_net *log;
983 struct hlist_head *head;
984
985 if (++st->bucket >= INSTANCE_BUCKETS)
986 return NULL;
987
988 log = nfnl_log_pernet(net);
989 head = &log->instance_table[st->bucket];
990 h = rcu_dereference_bh(hlist_first_rcu(head));
991 }
992 return h;
993}
994
995static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
996 loff_t pos)
997{
998 struct hlist_node *head;
999 head = get_first(net, st);
1000
1001 if (head)
1002 while (pos && (head = get_next(net, st, head)))
1003 pos--;
1004 return pos ? NULL : head;
1005}
1006
1007static void *seq_start(struct seq_file *s, loff_t *pos)
1008 __acquires(rcu_bh)
1009{
1010 rcu_read_lock_bh();
1011 return get_idx(seq_file_net(s), s->private, *pos);
1012}
1013
1014static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1015{
1016 (*pos)++;
1017 return get_next(seq_file_net(s), s->private, v);
1018}
1019
1020static void seq_stop(struct seq_file *s, void *v)
1021 __releases(rcu_bh)
1022{
1023 rcu_read_unlock_bh();
1024}
1025
1026static int seq_show(struct seq_file *s, void *v)
1027{
1028 const struct nfulnl_instance *inst = v;
1029
1030 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1031 inst->group_num,
1032 inst->peer_portid, inst->qlen,
1033 inst->copy_mode, inst->copy_range,
1034 inst->flushtimeout, atomic_read(&inst->use));
1035
1036 return 0;
1037}
1038
1039static const struct seq_operations nful_seq_ops = {
1040 .start = seq_start,
1041 .next = seq_next,
1042 .stop = seq_stop,
1043 .show = seq_show,
1044};
1045
1046static int nful_open(struct inode *inode, struct file *file)
1047{
1048 return seq_open_net(inode, file, &nful_seq_ops,
1049 sizeof(struct iter_state));
1050}
1051
1052static const struct file_operations nful_file_ops = {
1053 .owner = THIS_MODULE,
1054 .open = nful_open,
1055 .read = seq_read,
1056 .llseek = seq_lseek,
1057 .release = seq_release_net,
1058};
1059
1060#endif /* PROC_FS */
1061
1062static int __net_init nfnl_log_net_init(struct net *net)
1063{
1064 unsigned int i;
1065 struct nfnl_log_net *log = nfnl_log_pernet(net);
1066#ifdef CONFIG_PROC_FS
1067 struct proc_dir_entry *proc;
1068 kuid_t root_uid;
1069 kgid_t root_gid;
1070#endif
1071
1072 for (i = 0; i < INSTANCE_BUCKETS; i++)
1073 INIT_HLIST_HEAD(&log->instance_table[i]);
1074 spin_lock_init(&log->instances_lock);
1075
1076#ifdef CONFIG_PROC_FS
1077 proc = proc_create("nfnetlink_log", 0440,
1078 net->nf.proc_netfilter, &nful_file_ops);
1079 if (!proc)
1080 return -ENOMEM;
1081
1082 root_uid = make_kuid(net->user_ns, 0);
1083 root_gid = make_kgid(net->user_ns, 0);
1084 if (uid_valid(root_uid) && gid_valid(root_gid))
1085 proc_set_user(proc, root_uid, root_gid);
1086#endif
1087 return 0;
1088}
1089
1090static void __net_exit nfnl_log_net_exit(struct net *net)
1091{
1092#ifdef CONFIG_PROC_FS
1093 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1094#endif
1095 nf_log_unset(net, &nfulnl_logger);
1096}
1097
1098static struct pernet_operations nfnl_log_net_ops = {
1099 .init = nfnl_log_net_init,
1100 .exit = nfnl_log_net_exit,
1101 .id = &nfnl_log_net_id,
1102 .size = sizeof(struct nfnl_log_net),
1103};
1104
1105static int __init nfnetlink_log_init(void)
1106{
1107 int status;
1108
1109 status = register_pernet_subsys(&nfnl_log_net_ops);
1110 if (status < 0) {
1111 pr_err("failed to register pernet ops\n");
1112 goto out;
1113 }
1114
1115 netlink_register_notifier(&nfulnl_rtnl_notifier);
1116 status = nfnetlink_subsys_register(&nfulnl_subsys);
1117 if (status < 0) {
1118 pr_err("failed to create netlink socket\n");
1119 goto cleanup_netlink_notifier;
1120 }
1121
1122 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1123 if (status < 0) {
1124 pr_err("failed to register logger\n");
1125 goto cleanup_subsys;
1126 }
1127
1128 return status;
1129
1130cleanup_subsys:
1131 nfnetlink_subsys_unregister(&nfulnl_subsys);
1132cleanup_netlink_notifier:
1133 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1134 unregister_pernet_subsys(&nfnl_log_net_ops);
1135out:
1136 return status;
1137}
1138
1139static void __exit nfnetlink_log_fini(void)
1140{
1141 nf_log_unregister(&nfulnl_logger);
1142 nfnetlink_subsys_unregister(&nfulnl_subsys);
1143 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1144 unregister_pernet_subsys(&nfnl_log_net_ops);
1145}
1146
1147MODULE_DESCRIPTION("netfilter userspace logging");
1148MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1149MODULE_LICENSE("GPL");
1150MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1151MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1152MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1153MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1154MODULE_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
1155MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
1156
1157module_init(nfnetlink_log_init);
1158module_exit(nfnetlink_log_fini);