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Merge tag 'io_uring-5.11-2021-01-16' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blobb35e8d9a5b37ec14cc6eb39e55d0c1ade1791da8
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 #define NFULNL_COPY_DISABLED 0xff
47 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
48 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
49 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
50 /* max packet size is limited by 16-bit struct nfattr nfa_len field */
51 #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
52
53 #define PRINTR(x, args...) do { if (net_ratelimit()) \
54 printk(x, ## args); } while (0);
55
56 struct nfulnl_instance {
57 struct hlist_node hlist; /* global list of instances */
58 spinlock_t lock;
59 refcount_t use; /* use count */
60
61 unsigned int qlen; /* number of nlmsgs in skb */
62 struct sk_buff *skb; /* pre-allocatd skb */
63 struct timer_list timer;
64 struct net *net;
65 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
66 u32 peer_portid; /* PORTID of the peer process */
67
68 /* configurable parameters */
69 unsigned int flushtimeout; /* timeout until queue flush */
70 unsigned int nlbufsiz; /* netlink buffer allocation size */
71 unsigned int qthreshold; /* threshold of the queue */
72 u_int32_t copy_range;
73 u_int32_t seq; /* instance-local sequential counter */
74 u_int16_t group_num; /* number of this queue */
75 u_int16_t flags;
76 u_int8_t copy_mode;
77 struct rcu_head rcu;
78 };
79
80 #define INSTANCE_BUCKETS 16
81
82 static unsigned int nfnl_log_net_id __read_mostly;
83
84 struct nfnl_log_net {
85 spinlock_t instances_lock;
86 struct hlist_head instance_table[INSTANCE_BUCKETS];
87 atomic_t global_seq;
88 };
89
90 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
91 {
92 return net_generic(net, nfnl_log_net_id);
93 }
94
95 static inline u_int8_t instance_hashfn(u_int16_t group_num)
96 {
97 return ((group_num & 0xff) % INSTANCE_BUCKETS);
98 }
99
100 static struct nfulnl_instance *
101 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
102 {
103 struct hlist_head *head;
104 struct nfulnl_instance *inst;
105
106 head = &log->instance_table[instance_hashfn(group_num)];
107 hlist_for_each_entry_rcu(inst, head, hlist) {
108 if (inst->group_num == group_num)
109 return inst;
110 }
111 return NULL;
112 }
113
114 static inline void
115 instance_get(struct nfulnl_instance *inst)
116 {
117 refcount_inc(&inst->use);
118 }
119
120 static struct nfulnl_instance *
121 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
122 {
123 struct nfulnl_instance *inst;
124
125 rcu_read_lock_bh();
126 inst = __instance_lookup(log, group_num);
127 if (inst && !refcount_inc_not_zero(&inst->use))
128 inst = NULL;
129 rcu_read_unlock_bh();
130
131 return inst;
132 }
133
134 static void nfulnl_instance_free_rcu(struct rcu_head *head)
135 {
136 struct nfulnl_instance *inst =
137 container_of(head, struct nfulnl_instance, rcu);
138
139 put_net(inst->net);
140 kfree(inst);
141 module_put(THIS_MODULE);
142 }
143
144 static void
145 instance_put(struct nfulnl_instance *inst)
146 {
147 if (inst && refcount_dec_and_test(&inst->use))
148 call_rcu(&inst->rcu, nfulnl_instance_free_rcu);
149 }
150
151 static void nfulnl_timer(struct timer_list *t);
152
153 static struct nfulnl_instance *
154 instance_create(struct net *net, u_int16_t group_num,
155 u32 portid, struct user_namespace *user_ns)
156 {
157 struct nfulnl_instance *inst;
158 struct nfnl_log_net *log = nfnl_log_pernet(net);
159 int err;
160
161 spin_lock_bh(&log->instances_lock);
162 if (__instance_lookup(log, group_num)) {
163 err = -EEXIST;
164 goto out_unlock;
165 }
166
167 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
168 if (!inst) {
169 err = -ENOMEM;
170 goto out_unlock;
171 }
172
173 if (!try_module_get(THIS_MODULE)) {
174 kfree(inst);
175 err = -EAGAIN;
176 goto out_unlock;
177 }
178
179 INIT_HLIST_NODE(&inst->hlist);
180 spin_lock_init(&inst->lock);
181 /* needs to be two, since we _put() after creation */
182 refcount_set(&inst->use, 2);
183
184 timer_setup(&inst->timer, nfulnl_timer, 0);
185
186 inst->net = get_net(net);
187 inst->peer_user_ns = user_ns;
188 inst->peer_portid = portid;
189 inst->group_num = group_num;
190
191 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
192 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
193 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
194 inst->copy_mode = NFULNL_COPY_PACKET;
195 inst->copy_range = NFULNL_COPY_RANGE_MAX;
196
197 hlist_add_head_rcu(&inst->hlist,
198 &log->instance_table[instance_hashfn(group_num)]);
199
200
201 spin_unlock_bh(&log->instances_lock);
202
203 return inst;
204
205 out_unlock:
206 spin_unlock_bh(&log->instances_lock);
207 return ERR_PTR(err);
208 }
209
210 static void __nfulnl_flush(struct nfulnl_instance *inst);
211
212 /* called with BH disabled */
213 static void
214 __instance_destroy(struct nfulnl_instance *inst)
215 {
216 /* first pull it out of the global list */
217 hlist_del_rcu(&inst->hlist);
218
219 /* then flush all pending packets from skb */
220
221 spin_lock(&inst->lock);
222
223 /* lockless readers wont be able to use us */
224 inst->copy_mode = NFULNL_COPY_DISABLED;
225
226 if (inst->skb)
227 __nfulnl_flush(inst);
228 spin_unlock(&inst->lock);
229
230 /* and finally put the refcount */
231 instance_put(inst);
232 }
233
234 static inline void
235 instance_destroy(struct nfnl_log_net *log,
236 struct nfulnl_instance *inst)
237 {
238 spin_lock_bh(&log->instances_lock);
239 __instance_destroy(inst);
240 spin_unlock_bh(&log->instances_lock);
241 }
242
243 static int
244 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
245 unsigned int range)
246 {
247 int status = 0;
248
249 spin_lock_bh(&inst->lock);
250
251 switch (mode) {
252 case NFULNL_COPY_NONE:
253 case NFULNL_COPY_META:
254 inst->copy_mode = mode;
255 inst->copy_range = 0;
256 break;
257
258 case NFULNL_COPY_PACKET:
259 inst->copy_mode = mode;
260 if (range == 0)
261 range = NFULNL_COPY_RANGE_MAX;
262 inst->copy_range = min_t(unsigned int,
263 range, NFULNL_COPY_RANGE_MAX);
264 break;
265
266 default:
267 status = -EINVAL;
268 break;
269 }
270
271 spin_unlock_bh(&inst->lock);
272
273 return status;
274 }
275
276 static int
277 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
278 {
279 int status;
280
281 spin_lock_bh(&inst->lock);
282 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
283 status = -ERANGE;
284 else if (nlbufsiz > 131072)
285 status = -ERANGE;
286 else {
287 inst->nlbufsiz = nlbufsiz;
288 status = 0;
289 }
290 spin_unlock_bh(&inst->lock);
291
292 return status;
293 }
294
295 static void
296 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
297 {
298 spin_lock_bh(&inst->lock);
299 inst->flushtimeout = timeout;
300 spin_unlock_bh(&inst->lock);
301 }
302
303 static void
304 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
305 {
306 spin_lock_bh(&inst->lock);
307 inst->qthreshold = qthresh;
308 spin_unlock_bh(&inst->lock);
309 }
310
311 static int
312 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
313 {
314 spin_lock_bh(&inst->lock);
315 inst->flags = flags;
316 spin_unlock_bh(&inst->lock);
317
318 return 0;
319 }
320
321 static struct sk_buff *
322 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
323 unsigned int pkt_size)
324 {
325 struct sk_buff *skb;
326 unsigned int n;
327
328 /* alloc skb which should be big enough for a whole multipart
329 * message. WARNING: has to be <= 128k due to slab restrictions */
330
331 n = max(inst_size, pkt_size);
332 skb = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
333 if (!skb) {
334 if (n > pkt_size) {
335 /* try to allocate only as much as we need for current
336 * packet */
337
338 skb = alloc_skb(pkt_size, GFP_ATOMIC);
339 }
340 }
341
342 return skb;
343 }
344
345 static void
346 __nfulnl_send(struct nfulnl_instance *inst)
347 {
348 if (inst->qlen > 1) {
349 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
350 NLMSG_DONE,
351 sizeof(struct nfgenmsg),
352 0);
353 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
354 inst->skb->len, skb_tailroom(inst->skb))) {
355 kfree_skb(inst->skb);
356 goto out;
357 }
358 }
359 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid);
360 out:
361 inst->qlen = 0;
362 inst->skb = NULL;
363 }
364
365 static void
366 __nfulnl_flush(struct nfulnl_instance *inst)
367 {
368 /* timer holds a reference */
369 if (del_timer(&inst->timer))
370 instance_put(inst);
371 if (inst->skb)
372 __nfulnl_send(inst);
373 }
374
375 static void
376 nfulnl_timer(struct timer_list *t)
377 {
378 struct nfulnl_instance *inst = from_timer(inst, t, timer);
379
380 spin_lock_bh(&inst->lock);
381 if (inst->skb)
382 __nfulnl_send(inst);
383 spin_unlock_bh(&inst->lock);
384 instance_put(inst);
385 }
386
387 static u32 nfulnl_get_bridge_size(const struct sk_buff *skb)
388 {
389 u32 size = 0;
390
391 if (!skb_mac_header_was_set(skb))
392 return 0;
393
394 if (skb_vlan_tag_present(skb)) {
395 size += nla_total_size(0); /* nested */
396 size += nla_total_size(sizeof(u16)); /* id */
397 size += nla_total_size(sizeof(u16)); /* tag */
398 }
399
400 if (skb->network_header > skb->mac_header)
401 size += nla_total_size(skb->network_header - skb->mac_header);
402
403 return size;
404 }
405
406 static int nfulnl_put_bridge(struct nfulnl_instance *inst, const struct sk_buff *skb)
407 {
408 if (!skb_mac_header_was_set(skb))
409 return 0;
410
411 if (skb_vlan_tag_present(skb)) {
412 struct nlattr *nest;
413
414 nest = nla_nest_start(inst->skb, NFULA_VLAN);
415 if (!nest)
416 goto nla_put_failure;
417
418 if (nla_put_be16(inst->skb, NFULA_VLAN_TCI, htons(skb->vlan_tci)) ||
419 nla_put_be16(inst->skb, NFULA_VLAN_PROTO, skb->vlan_proto))
420 goto nla_put_failure;
421
422 nla_nest_end(inst->skb, nest);
423 }
424
425 if (skb->mac_header < skb->network_header) {
426 int len = (int)(skb->network_header - skb->mac_header);
427
428 if (nla_put(inst->skb, NFULA_L2HDR, len, skb_mac_header(skb)))
429 goto nla_put_failure;
430 }
431
432 return 0;
433
434 nla_put_failure:
435 return -1;
436 }
437
438 /* This is an inline function, we don't really care about a long
439 * list of arguments */
440 static inline int
441 __build_packet_message(struct nfnl_log_net *log,
442 struct nfulnl_instance *inst,
443 const struct sk_buff *skb,
444 unsigned int data_len,
445 u_int8_t pf,
446 unsigned int hooknum,
447 const struct net_device *indev,
448 const struct net_device *outdev,
449 const char *prefix, unsigned int plen,
450 const struct nfnl_ct_hook *nfnl_ct,
451 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
452 {
453 struct nfulnl_msg_packet_hdr pmsg;
454 struct nlmsghdr *nlh;
455 struct nfgenmsg *nfmsg;
456 sk_buff_data_t old_tail = inst->skb->tail;
457 struct sock *sk;
458 const unsigned char *hwhdrp;
459
460 nlh = nlmsg_put(inst->skb, 0, 0,
461 nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
462 sizeof(struct nfgenmsg), 0);
463 if (!nlh)
464 return -1;
465 nfmsg = nlmsg_data(nlh);
466 nfmsg->nfgen_family = pf;
467 nfmsg->version = NFNETLINK_V0;
468 nfmsg->res_id = htons(inst->group_num);
469
470 memset(&pmsg, 0, sizeof(pmsg));
471 pmsg.hw_protocol = skb->protocol;
472 pmsg.hook = hooknum;
473
474 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
475 goto nla_put_failure;
476
477 if (prefix &&
478 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
479 goto nla_put_failure;
480
481 if (indev) {
482 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
483 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
484 htonl(indev->ifindex)))
485 goto nla_put_failure;
486 #else
487 if (pf == PF_BRIDGE) {
488 /* Case 1: outdev is physical input device, we need to
489 * look for bridge group (when called from
490 * netfilter_bridge) */
491 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
492 htonl(indev->ifindex)) ||
493 /* this is the bridge group "brX" */
494 /* rcu_read_lock()ed by nf_hook_thresh or
495 * nf_log_packet.
496 */
497 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
498 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
499 goto nla_put_failure;
500 } else {
501 struct net_device *physindev;
502
503 /* Case 2: indev is bridge group, we need to look for
504 * physical device (when called from ipv4) */
505 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
506 htonl(indev->ifindex)))
507 goto nla_put_failure;
508
509 physindev = nf_bridge_get_physindev(skb);
510 if (physindev &&
511 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
512 htonl(physindev->ifindex)))
513 goto nla_put_failure;
514 }
515 #endif
516 }
517
518 if (outdev) {
519 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
520 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
521 htonl(outdev->ifindex)))
522 goto nla_put_failure;
523 #else
524 if (pf == PF_BRIDGE) {
525 /* Case 1: outdev is physical output device, we need to
526 * look for bridge group (when called from
527 * netfilter_bridge) */
528 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
529 htonl(outdev->ifindex)) ||
530 /* this is the bridge group "brX" */
531 /* rcu_read_lock()ed by nf_hook_thresh or
532 * nf_log_packet.
533 */
534 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
535 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
536 goto nla_put_failure;
537 } else {
538 struct net_device *physoutdev;
539
540 /* Case 2: indev is a bridge group, we need to look
541 * for physical device (when called from ipv4) */
542 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
543 htonl(outdev->ifindex)))
544 goto nla_put_failure;
545
546 physoutdev = nf_bridge_get_physoutdev(skb);
547 if (physoutdev &&
548 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
549 htonl(physoutdev->ifindex)))
550 goto nla_put_failure;
551 }
552 #endif
553 }
554
555 if (skb->mark &&
556 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
557 goto nla_put_failure;
558
559 if (indev && skb->dev &&
560 skb->mac_header != skb->network_header) {
561 struct nfulnl_msg_packet_hw phw;
562 int len;
563
564 memset(&phw, 0, sizeof(phw));
565 len = dev_parse_header(skb, phw.hw_addr);
566 if (len > 0) {
567 phw.hw_addrlen = htons(len);
568 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
569 goto nla_put_failure;
570 }
571 }
572
573 if (indev && skb_mac_header_was_set(skb)) {
574 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
575 nla_put_be16(inst->skb, NFULA_HWLEN,
576 htons(skb->dev->hard_header_len)))
577 goto nla_put_failure;
578
579 hwhdrp = skb_mac_header(skb);
580
581 if (skb->dev->type == ARPHRD_SIT)
582 hwhdrp -= ETH_HLEN;
583
584 if (hwhdrp >= skb->head &&
585 nla_put(inst->skb, NFULA_HWHEADER,
586 skb->dev->hard_header_len, hwhdrp))
587 goto nla_put_failure;
588 }
589
590 if (hooknum <= NF_INET_FORWARD && skb->tstamp) {
591 struct nfulnl_msg_packet_timestamp ts;
592 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
593 ts.sec = cpu_to_be64(kts.tv_sec);
594 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
595
596 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
597 goto nla_put_failure;
598 }
599
600 /* UID */
601 sk = skb->sk;
602 if (sk && sk_fullsock(sk)) {
603 read_lock_bh(&sk->sk_callback_lock);
604 if (sk->sk_socket && sk->sk_socket->file) {
605 struct file *file = sk->sk_socket->file;
606 const struct cred *cred = file->f_cred;
607 struct user_namespace *user_ns = inst->peer_user_ns;
608 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
609 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
610 read_unlock_bh(&sk->sk_callback_lock);
611 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
612 nla_put_be32(inst->skb, NFULA_GID, gid))
613 goto nla_put_failure;
614 } else
615 read_unlock_bh(&sk->sk_callback_lock);
616 }
617
618 /* local sequence number */
619 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
620 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
621 goto nla_put_failure;
622
623 /* global sequence number */
624 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
625 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
626 htonl(atomic_inc_return(&log->global_seq))))
627 goto nla_put_failure;
628
629 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
630 NFULA_CT, NFULA_CT_INFO) < 0)
631 goto nla_put_failure;
632
633 if ((pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE) &&
634 nfulnl_put_bridge(inst, skb) < 0)
635 goto nla_put_failure;
636
637 if (data_len) {
638 struct nlattr *nla;
639 int size = nla_attr_size(data_len);
640
641 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
642 goto nla_put_failure;
643
644 nla = skb_put(inst->skb, nla_total_size(data_len));
645 nla->nla_type = NFULA_PAYLOAD;
646 nla->nla_len = size;
647
648 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
649 BUG();
650 }
651
652 nlh->nlmsg_len = inst->skb->tail - old_tail;
653 return 0;
654
655 nla_put_failure:
656 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
657 return -1;
658 }
659
660 static const struct nf_loginfo default_loginfo = {
661 .type = NF_LOG_TYPE_ULOG,
662 .u = {
663 .ulog = {
664 .copy_len = 0xffff,
665 .group = 0,
666 .qthreshold = 1,
667 },
668 },
669 };
670
671 /* log handler for internal netfilter logging api */
672 static void
673 nfulnl_log_packet(struct net *net,
674 u_int8_t pf,
675 unsigned int hooknum,
676 const struct sk_buff *skb,
677 const struct net_device *in,
678 const struct net_device *out,
679 const struct nf_loginfo *li_user,
680 const char *prefix)
681 {
682 size_t size;
683 unsigned int data_len;
684 struct nfulnl_instance *inst;
685 const struct nf_loginfo *li;
686 unsigned int qthreshold;
687 unsigned int plen = 0;
688 struct nfnl_log_net *log = nfnl_log_pernet(net);
689 const struct nfnl_ct_hook *nfnl_ct = NULL;
690 struct nf_conn *ct = NULL;
691 enum ip_conntrack_info ctinfo;
692
693 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
694 li = li_user;
695 else
696 li = &default_loginfo;
697
698 inst = instance_lookup_get(log, li->u.ulog.group);
699 if (!inst)
700 return;
701
702 if (prefix)
703 plen = strlen(prefix) + 1;
704
705 /* FIXME: do we want to make the size calculation conditional based on
706 * what is actually present? way more branches and checks, but more
707 * memory efficient... */
708 size = nlmsg_total_size(sizeof(struct nfgenmsg))
709 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
710 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
711 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
712 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
713 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
714 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
715 #endif
716 + nla_total_size(sizeof(u_int32_t)) /* mark */
717 + nla_total_size(sizeof(u_int32_t)) /* uid */
718 + nla_total_size(sizeof(u_int32_t)) /* gid */
719 + nla_total_size(plen) /* prefix */
720 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
721 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
722 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
723
724 if (in && skb_mac_header_was_set(skb)) {
725 size += nla_total_size(skb->dev->hard_header_len)
726 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
727 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
728 }
729
730 spin_lock_bh(&inst->lock);
731
732 if (inst->flags & NFULNL_CFG_F_SEQ)
733 size += nla_total_size(sizeof(u_int32_t));
734 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
735 size += nla_total_size(sizeof(u_int32_t));
736 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
737 nfnl_ct = rcu_dereference(nfnl_ct_hook);
738 if (nfnl_ct != NULL) {
739 ct = nfnl_ct->get_ct(skb, &ctinfo);
740 if (ct != NULL)
741 size += nfnl_ct->build_size(ct);
742 }
743 }
744 if (pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE)
745 size += nfulnl_get_bridge_size(skb);
746
747 qthreshold = inst->qthreshold;
748 /* per-rule qthreshold overrides per-instance */
749 if (li->u.ulog.qthreshold)
750 if (qthreshold > li->u.ulog.qthreshold)
751 qthreshold = li->u.ulog.qthreshold;
752
753
754 switch (inst->copy_mode) {
755 case NFULNL_COPY_META:
756 case NFULNL_COPY_NONE:
757 data_len = 0;
758 break;
759
760 case NFULNL_COPY_PACKET:
761 data_len = inst->copy_range;
762 if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
763 (li->u.ulog.copy_len < data_len))
764 data_len = li->u.ulog.copy_len;
765
766 if (data_len > skb->len)
767 data_len = skb->len;
768
769 size += nla_total_size(data_len);
770 break;
771
772 case NFULNL_COPY_DISABLED:
773 default:
774 goto unlock_and_release;
775 }
776
777 if (inst->skb && size > skb_tailroom(inst->skb)) {
778 /* either the queue len is too high or we don't have
779 * enough room in the skb left. flush to userspace. */
780 __nfulnl_flush(inst);
781 }
782
783 if (!inst->skb) {
784 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
785 inst->nlbufsiz, size);
786 if (!inst->skb)
787 goto alloc_failure;
788 }
789
790 inst->qlen++;
791
792 __build_packet_message(log, inst, skb, data_len, pf,
793 hooknum, in, out, prefix, plen,
794 nfnl_ct, ct, ctinfo);
795
796 if (inst->qlen >= qthreshold)
797 __nfulnl_flush(inst);
798 /* timer_pending always called within inst->lock, so there
799 * is no chance of a race here */
800 else if (!timer_pending(&inst->timer)) {
801 instance_get(inst);
802 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
803 add_timer(&inst->timer);
804 }
805
806 unlock_and_release:
807 spin_unlock_bh(&inst->lock);
808 instance_put(inst);
809 return;
810
811 alloc_failure:
812 /* FIXME: statistics */
813 goto unlock_and_release;
814 }
815
816 static int
817 nfulnl_rcv_nl_event(struct notifier_block *this,
818 unsigned long event, void *ptr)
819 {
820 struct netlink_notify *n = ptr;
821 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
822
823 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
824 int i;
825
826 /* destroy all instances for this portid */
827 spin_lock_bh(&log->instances_lock);
828 for (i = 0; i < INSTANCE_BUCKETS; i++) {
829 struct hlist_node *t2;
830 struct nfulnl_instance *inst;
831 struct hlist_head *head = &log->instance_table[i];
832
833 hlist_for_each_entry_safe(inst, t2, head, hlist) {
834 if (n->portid == inst->peer_portid)
835 __instance_destroy(inst);
836 }
837 }
838 spin_unlock_bh(&log->instances_lock);
839 }
840 return NOTIFY_DONE;
841 }
842
843 static struct notifier_block nfulnl_rtnl_notifier = {
844 .notifier_call = nfulnl_rcv_nl_event,
845 };
846
847 static int nfulnl_recv_unsupp(struct net *net, struct sock *ctnl,
848 struct sk_buff *skb, const struct nlmsghdr *nlh,
849 const struct nlattr * const nfqa[],
850 struct netlink_ext_ack *extack)
851 {
852 return -ENOTSUPP;
853 }
854
855 static struct nf_logger nfulnl_logger __read_mostly = {
856 .name = "nfnetlink_log",
857 .type = NF_LOG_TYPE_ULOG,
858 .logfn = nfulnl_log_packet,
859 .me = THIS_MODULE,
860 };
861
862 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
863 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
864 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
865 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
866 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
867 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
868 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
869 };
870
871 static int nfulnl_recv_config(struct net *net, struct sock *ctnl,
872 struct sk_buff *skb, const struct nlmsghdr *nlh,
873 const struct nlattr * const nfula[],
874 struct netlink_ext_ack *extack)
875 {
876 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
877 u_int16_t group_num = ntohs(nfmsg->res_id);
878 struct nfulnl_instance *inst;
879 struct nfulnl_msg_config_cmd *cmd = NULL;
880 struct nfnl_log_net *log = nfnl_log_pernet(net);
881 int ret = 0;
882 u16 flags = 0;
883
884 if (nfula[NFULA_CFG_CMD]) {
885 u_int8_t pf = nfmsg->nfgen_family;
886 cmd = nla_data(nfula[NFULA_CFG_CMD]);
887
888 /* Commands without queue context */
889 switch (cmd->command) {
890 case NFULNL_CFG_CMD_PF_BIND:
891 return nf_log_bind_pf(net, pf, &nfulnl_logger);
892 case NFULNL_CFG_CMD_PF_UNBIND:
893 nf_log_unbind_pf(net, pf);
894 return 0;
895 }
896 }
897
898 inst = instance_lookup_get(log, group_num);
899 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
900 ret = -EPERM;
901 goto out_put;
902 }
903
904 /* Check if we support these flags in first place, dependencies should
905 * be there too not to break atomicity.
906 */
907 if (nfula[NFULA_CFG_FLAGS]) {
908 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
909
910 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
911 !rcu_access_pointer(nfnl_ct_hook)) {
912 #ifdef CONFIG_MODULES
913 nfnl_unlock(NFNL_SUBSYS_ULOG);
914 request_module("ip_conntrack_netlink");
915 nfnl_lock(NFNL_SUBSYS_ULOG);
916 if (rcu_access_pointer(nfnl_ct_hook)) {
917 ret = -EAGAIN;
918 goto out_put;
919 }
920 #endif
921 ret = -EOPNOTSUPP;
922 goto out_put;
923 }
924 }
925
926 if (cmd != NULL) {
927 switch (cmd->command) {
928 case NFULNL_CFG_CMD_BIND:
929 if (inst) {
930 ret = -EBUSY;
931 goto out_put;
932 }
933
934 inst = instance_create(net, group_num,
935 NETLINK_CB(skb).portid,
936 sk_user_ns(NETLINK_CB(skb).sk));
937 if (IS_ERR(inst)) {
938 ret = PTR_ERR(inst);
939 goto out;
940 }
941 break;
942 case NFULNL_CFG_CMD_UNBIND:
943 if (!inst) {
944 ret = -ENODEV;
945 goto out;
946 }
947
948 instance_destroy(log, inst);
949 goto out_put;
950 default:
951 ret = -ENOTSUPP;
952 goto out_put;
953 }
954 } else if (!inst) {
955 ret = -ENODEV;
956 goto out;
957 }
958
959 if (nfula[NFULA_CFG_MODE]) {
960 struct nfulnl_msg_config_mode *params =
961 nla_data(nfula[NFULA_CFG_MODE]);
962
963 nfulnl_set_mode(inst, params->copy_mode,
964 ntohl(params->copy_range));
965 }
966
967 if (nfula[NFULA_CFG_TIMEOUT]) {
968 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
969
970 nfulnl_set_timeout(inst, ntohl(timeout));
971 }
972
973 if (nfula[NFULA_CFG_NLBUFSIZ]) {
974 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
975
976 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
977 }
978
979 if (nfula[NFULA_CFG_QTHRESH]) {
980 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
981
982 nfulnl_set_qthresh(inst, ntohl(qthresh));
983 }
984
985 if (nfula[NFULA_CFG_FLAGS])
986 nfulnl_set_flags(inst, flags);
987
988 out_put:
989 instance_put(inst);
990 out:
991 return ret;
992 }
993
994 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
995 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
996 .attr_count = NFULA_MAX, },
997 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
998 .attr_count = NFULA_CFG_MAX,
999 .policy = nfula_cfg_policy },
1000 };
1001
1002 static const struct nfnetlink_subsystem nfulnl_subsys = {
1003 .name = "log",
1004 .subsys_id = NFNL_SUBSYS_ULOG,
1005 .cb_count = NFULNL_MSG_MAX,
1006 .cb = nfulnl_cb,
1007 };
1008
1009 #ifdef CONFIG_PROC_FS
1010 struct iter_state {
1011 struct seq_net_private p;
1012 unsigned int bucket;
1013 };
1014
1015 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
1016 {
1017 struct nfnl_log_net *log;
1018 if (!st)
1019 return NULL;
1020
1021 log = nfnl_log_pernet(net);
1022
1023 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1024 struct hlist_head *head = &log->instance_table[st->bucket];
1025
1026 if (!hlist_empty(head))
1027 return rcu_dereference_bh(hlist_first_rcu(head));
1028 }
1029 return NULL;
1030 }
1031
1032 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
1033 struct hlist_node *h)
1034 {
1035 h = rcu_dereference_bh(hlist_next_rcu(h));
1036 while (!h) {
1037 struct nfnl_log_net *log;
1038 struct hlist_head *head;
1039
1040 if (++st->bucket >= INSTANCE_BUCKETS)
1041 return NULL;
1042
1043 log = nfnl_log_pernet(net);
1044 head = &log->instance_table[st->bucket];
1045 h = rcu_dereference_bh(hlist_first_rcu(head));
1046 }
1047 return h;
1048 }
1049
1050 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
1051 loff_t pos)
1052 {
1053 struct hlist_node *head;
1054 head = get_first(net, st);
1055
1056 if (head)
1057 while (pos && (head = get_next(net, st, head)))
1058 pos--;
1059 return pos ? NULL : head;
1060 }
1061
1062 static void *seq_start(struct seq_file *s, loff_t *pos)
1063 __acquires(rcu_bh)
1064 {
1065 rcu_read_lock_bh();
1066 return get_idx(seq_file_net(s), s->private, *pos);
1067 }
1068
1069 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1070 {
1071 (*pos)++;
1072 return get_next(seq_file_net(s), s->private, v);
1073 }
1074
1075 static void seq_stop(struct seq_file *s, void *v)
1076 __releases(rcu_bh)
1077 {
1078 rcu_read_unlock_bh();
1079 }
1080
1081 static int seq_show(struct seq_file *s, void *v)
1082 {
1083 const struct nfulnl_instance *inst = v;
1084
1085 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1086 inst->group_num,
1087 inst->peer_portid, inst->qlen,
1088 inst->copy_mode, inst->copy_range,
1089 inst->flushtimeout, refcount_read(&inst->use));
1090
1091 return 0;
1092 }
1093
1094 static const struct seq_operations nful_seq_ops = {
1095 .start = seq_start,
1096 .next = seq_next,
1097 .stop = seq_stop,
1098 .show = seq_show,
1099 };
1100 #endif /* PROC_FS */
1101
1102 static int __net_init nfnl_log_net_init(struct net *net)
1103 {
1104 unsigned int i;
1105 struct nfnl_log_net *log = nfnl_log_pernet(net);
1106 #ifdef CONFIG_PROC_FS
1107 struct proc_dir_entry *proc;
1108 kuid_t root_uid;
1109 kgid_t root_gid;
1110 #endif
1111
1112 for (i = 0; i < INSTANCE_BUCKETS; i++)
1113 INIT_HLIST_HEAD(&log->instance_table[i]);
1114 spin_lock_init(&log->instances_lock);
1115
1116 #ifdef CONFIG_PROC_FS
1117 proc = proc_create_net("nfnetlink_log", 0440, net->nf.proc_netfilter,
1118 &nful_seq_ops, sizeof(struct iter_state));
1119 if (!proc)
1120 return -ENOMEM;
1121
1122 root_uid = make_kuid(net->user_ns, 0);
1123 root_gid = make_kgid(net->user_ns, 0);
1124 if (uid_valid(root_uid) && gid_valid(root_gid))
1125 proc_set_user(proc, root_uid, root_gid);
1126 #endif
1127 return 0;
1128 }
1129
1130 static void __net_exit nfnl_log_net_exit(struct net *net)
1131 {
1132 struct nfnl_log_net *log = nfnl_log_pernet(net);
1133 unsigned int i;
1134
1135 #ifdef CONFIG_PROC_FS
1136 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1137 #endif
1138 nf_log_unset(net, &nfulnl_logger);
1139 for (i = 0; i < INSTANCE_BUCKETS; i++)
1140 WARN_ON_ONCE(!hlist_empty(&log->instance_table[i]));
1141 }
1142
1143 static struct pernet_operations nfnl_log_net_ops = {
1144 .init = nfnl_log_net_init,
1145 .exit = nfnl_log_net_exit,
1146 .id = &nfnl_log_net_id,
1147 .size = sizeof(struct nfnl_log_net),
1148 };
1149
1150 static int __init nfnetlink_log_init(void)
1151 {
1152 int status;
1153
1154 status = register_pernet_subsys(&nfnl_log_net_ops);
1155 if (status < 0) {
1156 pr_err("failed to register pernet ops\n");
1157 goto out;
1158 }
1159
1160 netlink_register_notifier(&nfulnl_rtnl_notifier);
1161 status = nfnetlink_subsys_register(&nfulnl_subsys);
1162 if (status < 0) {
1163 pr_err("failed to create netlink socket\n");
1164 goto cleanup_netlink_notifier;
1165 }
1166
1167 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1168 if (status < 0) {
1169 pr_err("failed to register logger\n");
1170 goto cleanup_subsys;
1171 }
1172
1173 return status;
1174
1175 cleanup_subsys:
1176 nfnetlink_subsys_unregister(&nfulnl_subsys);
1177 cleanup_netlink_notifier:
1178 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1179 unregister_pernet_subsys(&nfnl_log_net_ops);
1180 out:
1181 return status;
1182 }
1183
1184 static void __exit nfnetlink_log_fini(void)
1185 {
1186 nfnetlink_subsys_unregister(&nfulnl_subsys);
1187 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1188 unregister_pernet_subsys(&nfnl_log_net_ops);
1189 nf_log_unregister(&nfulnl_logger);
1190 }
1191
1192 MODULE_DESCRIPTION("netfilter userspace logging");
1193 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1194 MODULE_LICENSE("GPL");
1195 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1196 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1197 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1198 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1199 MODULE_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
1200 MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
1201
1202 module_init(nfnetlink_log_init);
1203 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support