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mac80211: move MU_MIMO_OWNER flag to ieee80211_vif
[deliverable/linux.git] / net / netfilter / nfnetlink_log.c
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
57 struct 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
83 static int nfnl_log_net_id __read_mostly;
84
85 struct nfnl_log_net {
86 spinlock_t instances_lock;
87 struct hlist_head instance_table[INSTANCE_BUCKETS];
88 atomic_t global_seq;
89 };
90
91 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
92 {
93 return net_generic(net, nfnl_log_net_id);
94 }
95
96 static inline u_int8_t instance_hashfn(u_int16_t group_num)
97 {
98 return ((group_num & 0xff) % INSTANCE_BUCKETS);
99 }
100
101 static 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
115 static inline void
116 instance_get(struct nfulnl_instance *inst)
117 {
118 atomic_inc(&inst->use);
119 }
120
121 static struct nfulnl_instance *
122 instance_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
135 static 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
145 static void
146 instance_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
152 static void nfulnl_timer(unsigned long data);
153
154 static struct nfulnl_instance *
155 instance_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
206 out_unlock:
207 spin_unlock_bh(&log->instances_lock);
208 return ERR_PTR(err);
209 }
210
211 static void __nfulnl_flush(struct nfulnl_instance *inst);
212
213 /* called with BH disabled */
214 static 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
235 static inline void
236 instance_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
244 static int
245 nfulnl_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
277 static int
278 nfulnl_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
296 static void
297 nfulnl_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
304 static void
305 nfulnl_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
312 static int
313 nfulnl_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
322 static struct sk_buff *
323 nfulnl_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 = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
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 = nfnetlink_alloc_skb(net, pkt_size,
340 peer_portid, GFP_ATOMIC);
341 }
342 }
343
344 return skb;
345 }
346
347 static void
348 __nfulnl_send(struct nfulnl_instance *inst)
349 {
350 if (inst->qlen > 1) {
351 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
352 NLMSG_DONE,
353 sizeof(struct nfgenmsg),
354 0);
355 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
356 inst->skb->len, skb_tailroom(inst->skb))) {
357 kfree_skb(inst->skb);
358 goto out;
359 }
360 }
361 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
362 MSG_DONTWAIT);
363 out:
364 inst->qlen = 0;
365 inst->skb = NULL;
366 }
367
368 static void
369 __nfulnl_flush(struct nfulnl_instance *inst)
370 {
371 /* timer holds a reference */
372 if (del_timer(&inst->timer))
373 instance_put(inst);
374 if (inst->skb)
375 __nfulnl_send(inst);
376 }
377
378 static void
379 nfulnl_timer(unsigned long data)
380 {
381 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
382
383 spin_lock_bh(&inst->lock);
384 if (inst->skb)
385 __nfulnl_send(inst);
386 spin_unlock_bh(&inst->lock);
387 instance_put(inst);
388 }
389
390 /* This is an inline function, we don't really care about a long
391 * list of arguments */
392 static inline int
393 __build_packet_message(struct nfnl_log_net *log,
394 struct nfulnl_instance *inst,
395 const struct sk_buff *skb,
396 unsigned int data_len,
397 u_int8_t pf,
398 unsigned int hooknum,
399 const struct net_device *indev,
400 const struct net_device *outdev,
401 const char *prefix, unsigned int plen,
402 const struct nfnl_ct_hook *nfnl_ct,
403 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
404 {
405 struct nfulnl_msg_packet_hdr pmsg;
406 struct nlmsghdr *nlh;
407 struct nfgenmsg *nfmsg;
408 sk_buff_data_t old_tail = inst->skb->tail;
409 struct sock *sk;
410 const unsigned char *hwhdrp;
411
412 nlh = nlmsg_put(inst->skb, 0, 0,
413 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
414 sizeof(struct nfgenmsg), 0);
415 if (!nlh)
416 return -1;
417 nfmsg = nlmsg_data(nlh);
418 nfmsg->nfgen_family = pf;
419 nfmsg->version = NFNETLINK_V0;
420 nfmsg->res_id = htons(inst->group_num);
421
422 memset(&pmsg, 0, sizeof(pmsg));
423 pmsg.hw_protocol = skb->protocol;
424 pmsg.hook = hooknum;
425
426 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
427 goto nla_put_failure;
428
429 if (prefix &&
430 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
431 goto nla_put_failure;
432
433 if (indev) {
434 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
435 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
436 htonl(indev->ifindex)))
437 goto nla_put_failure;
438 #else
439 if (pf == PF_BRIDGE) {
440 /* Case 1: outdev is physical input device, we need to
441 * look for bridge group (when called from
442 * netfilter_bridge) */
443 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
444 htonl(indev->ifindex)) ||
445 /* this is the bridge group "brX" */
446 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
447 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
448 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
449 goto nla_put_failure;
450 } else {
451 struct net_device *physindev;
452
453 /* Case 2: indev is bridge group, we need to look for
454 * physical device (when called from ipv4) */
455 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
456 htonl(indev->ifindex)))
457 goto nla_put_failure;
458
459 physindev = nf_bridge_get_physindev(skb);
460 if (physindev &&
461 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
462 htonl(physindev->ifindex)))
463 goto nla_put_failure;
464 }
465 #endif
466 }
467
468 if (outdev) {
469 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
470 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
471 htonl(outdev->ifindex)))
472 goto nla_put_failure;
473 #else
474 if (pf == PF_BRIDGE) {
475 /* Case 1: outdev is physical output device, we need to
476 * look for bridge group (when called from
477 * netfilter_bridge) */
478 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
479 htonl(outdev->ifindex)) ||
480 /* this is the bridge group "brX" */
481 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
482 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
483 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
484 goto nla_put_failure;
485 } else {
486 struct net_device *physoutdev;
487
488 /* Case 2: indev is a bridge group, we need to look
489 * for physical device (when called from ipv4) */
490 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
491 htonl(outdev->ifindex)))
492 goto nla_put_failure;
493
494 physoutdev = nf_bridge_get_physoutdev(skb);
495 if (physoutdev &&
496 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
497 htonl(physoutdev->ifindex)))
498 goto nla_put_failure;
499 }
500 #endif
501 }
502
503 if (skb->mark &&
504 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
505 goto nla_put_failure;
506
507 if (indev && skb->dev &&
508 skb->mac_header != skb->network_header) {
509 struct nfulnl_msg_packet_hw phw;
510 int len;
511
512 memset(&phw, 0, sizeof(phw));
513 len = dev_parse_header(skb, phw.hw_addr);
514 if (len > 0) {
515 phw.hw_addrlen = htons(len);
516 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
517 goto nla_put_failure;
518 }
519 }
520
521 if (indev && skb_mac_header_was_set(skb)) {
522 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
523 nla_put_be16(inst->skb, NFULA_HWLEN,
524 htons(skb->dev->hard_header_len)))
525 goto nla_put_failure;
526
527 hwhdrp = skb_mac_header(skb);
528
529 if (skb->dev->type == ARPHRD_SIT)
530 hwhdrp -= ETH_HLEN;
531
532 if (hwhdrp >= skb->head &&
533 nla_put(inst->skb, NFULA_HWHEADER,
534 skb->dev->hard_header_len, hwhdrp))
535 goto nla_put_failure;
536 }
537
538 if (skb->tstamp.tv64) {
539 struct nfulnl_msg_packet_timestamp ts;
540 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
541 ts.sec = cpu_to_be64(kts.tv_sec);
542 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
543
544 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
545 goto nla_put_failure;
546 }
547
548 /* UID */
549 sk = skb->sk;
550 if (sk && sk_fullsock(sk)) {
551 read_lock_bh(&sk->sk_callback_lock);
552 if (sk->sk_socket && sk->sk_socket->file) {
553 struct file *file = sk->sk_socket->file;
554 const struct cred *cred = file->f_cred;
555 struct user_namespace *user_ns = inst->peer_user_ns;
556 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
557 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
558 read_unlock_bh(&sk->sk_callback_lock);
559 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
560 nla_put_be32(inst->skb, NFULA_GID, gid))
561 goto nla_put_failure;
562 } else
563 read_unlock_bh(&sk->sk_callback_lock);
564 }
565
566 /* local sequence number */
567 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
568 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
569 goto nla_put_failure;
570
571 /* global sequence number */
572 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
573 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
574 htonl(atomic_inc_return(&log->global_seq))))
575 goto nla_put_failure;
576
577 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
578 NFULA_CT, NFULA_CT_INFO) < 0)
579 goto nla_put_failure;
580
581 if (data_len) {
582 struct nlattr *nla;
583 int size = nla_attr_size(data_len);
584
585 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
586 goto nla_put_failure;
587
588 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
589 nla->nla_type = NFULA_PAYLOAD;
590 nla->nla_len = size;
591
592 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
593 BUG();
594 }
595
596 nlh->nlmsg_len = inst->skb->tail - old_tail;
597 return 0;
598
599 nla_put_failure:
600 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
601 return -1;
602 }
603
604 static struct nf_loginfo default_loginfo = {
605 .type = NF_LOG_TYPE_ULOG,
606 .u = {
607 .ulog = {
608 .copy_len = 0xffff,
609 .group = 0,
610 .qthreshold = 1,
611 },
612 },
613 };
614
615 /* log handler for internal netfilter logging api */
616 void
617 nfulnl_log_packet(struct net *net,
618 u_int8_t pf,
619 unsigned int hooknum,
620 const struct sk_buff *skb,
621 const struct net_device *in,
622 const struct net_device *out,
623 const struct nf_loginfo *li_user,
624 const char *prefix)
625 {
626 size_t size;
627 unsigned int data_len;
628 struct nfulnl_instance *inst;
629 const struct nf_loginfo *li;
630 unsigned int qthreshold;
631 unsigned int plen;
632 struct nfnl_log_net *log = nfnl_log_pernet(net);
633 const struct nfnl_ct_hook *nfnl_ct = NULL;
634 struct nf_conn *ct = NULL;
635 enum ip_conntrack_info uninitialized_var(ctinfo);
636
637 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
638 li = li_user;
639 else
640 li = &default_loginfo;
641
642 inst = instance_lookup_get(log, li->u.ulog.group);
643 if (!inst)
644 return;
645
646 plen = 0;
647 if (prefix)
648 plen = strlen(prefix) + 1;
649
650 /* FIXME: do we want to make the size calculation conditional based on
651 * what is actually present? way more branches and checks, but more
652 * memory efficient... */
653 size = nlmsg_total_size(sizeof(struct nfgenmsg))
654 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
655 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
656 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
657 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
658 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
659 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
660 #endif
661 + nla_total_size(sizeof(u_int32_t)) /* mark */
662 + nla_total_size(sizeof(u_int32_t)) /* uid */
663 + nla_total_size(sizeof(u_int32_t)) /* gid */
664 + nla_total_size(plen) /* prefix */
665 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
666 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
667 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
668
669 if (in && skb_mac_header_was_set(skb)) {
670 size += nla_total_size(skb->dev->hard_header_len)
671 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
672 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
673 }
674
675 spin_lock_bh(&inst->lock);
676
677 if (inst->flags & NFULNL_CFG_F_SEQ)
678 size += nla_total_size(sizeof(u_int32_t));
679 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
680 size += nla_total_size(sizeof(u_int32_t));
681 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
682 nfnl_ct = rcu_dereference(nfnl_ct_hook);
683 if (nfnl_ct != NULL) {
684 ct = nfnl_ct->get_ct(skb, &ctinfo);
685 if (ct != NULL)
686 size += nfnl_ct->build_size(ct);
687 }
688 }
689
690 qthreshold = inst->qthreshold;
691 /* per-rule qthreshold overrides per-instance */
692 if (li->u.ulog.qthreshold)
693 if (qthreshold > li->u.ulog.qthreshold)
694 qthreshold = li->u.ulog.qthreshold;
695
696
697 switch (inst->copy_mode) {
698 case NFULNL_COPY_META:
699 case NFULNL_COPY_NONE:
700 data_len = 0;
701 break;
702
703 case NFULNL_COPY_PACKET:
704 if (inst->copy_range > skb->len)
705 data_len = skb->len;
706 else
707 data_len = inst->copy_range;
708
709 size += nla_total_size(data_len);
710 break;
711
712 case NFULNL_COPY_DISABLED:
713 default:
714 goto unlock_and_release;
715 }
716
717 if (inst->skb && size > skb_tailroom(inst->skb)) {
718 /* either the queue len is too high or we don't have
719 * enough room in the skb left. flush to userspace. */
720 __nfulnl_flush(inst);
721 }
722
723 if (!inst->skb) {
724 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
725 inst->nlbufsiz, size);
726 if (!inst->skb)
727 goto alloc_failure;
728 }
729
730 inst->qlen++;
731
732 __build_packet_message(log, inst, skb, data_len, pf,
733 hooknum, in, out, prefix, plen,
734 nfnl_ct, ct, ctinfo);
735
736 if (inst->qlen >= qthreshold)
737 __nfulnl_flush(inst);
738 /* timer_pending always called within inst->lock, so there
739 * is no chance of a race here */
740 else if (!timer_pending(&inst->timer)) {
741 instance_get(inst);
742 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
743 add_timer(&inst->timer);
744 }
745
746 unlock_and_release:
747 spin_unlock_bh(&inst->lock);
748 instance_put(inst);
749 return;
750
751 alloc_failure:
752 /* FIXME: statistics */
753 goto unlock_and_release;
754 }
755 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
756
757 static int
758 nfulnl_rcv_nl_event(struct notifier_block *this,
759 unsigned long event, void *ptr)
760 {
761 struct netlink_notify *n = ptr;
762 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
763
764 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
765 int i;
766
767 /* destroy all instances for this portid */
768 spin_lock_bh(&log->instances_lock);
769 for (i = 0; i < INSTANCE_BUCKETS; i++) {
770 struct hlist_node *t2;
771 struct nfulnl_instance *inst;
772 struct hlist_head *head = &log->instance_table[i];
773
774 hlist_for_each_entry_safe(inst, t2, head, hlist) {
775 if (n->portid == inst->peer_portid)
776 __instance_destroy(inst);
777 }
778 }
779 spin_unlock_bh(&log->instances_lock);
780 }
781 return NOTIFY_DONE;
782 }
783
784 static struct notifier_block nfulnl_rtnl_notifier = {
785 .notifier_call = nfulnl_rcv_nl_event,
786 };
787
788 static int nfulnl_recv_unsupp(struct net *net, struct sock *ctnl,
789 struct sk_buff *skb, const struct nlmsghdr *nlh,
790 const struct nlattr * const nfqa[])
791 {
792 return -ENOTSUPP;
793 }
794
795 static struct nf_logger nfulnl_logger __read_mostly = {
796 .name = "nfnetlink_log",
797 .type = NF_LOG_TYPE_ULOG,
798 .logfn = &nfulnl_log_packet,
799 .me = THIS_MODULE,
800 };
801
802 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
803 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
804 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
805 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
806 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
807 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
808 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
809 };
810
811 static int nfulnl_recv_config(struct net *net, struct sock *ctnl,
812 struct sk_buff *skb, const struct nlmsghdr *nlh,
813 const struct nlattr * const nfula[])
814 {
815 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
816 u_int16_t group_num = ntohs(nfmsg->res_id);
817 struct nfulnl_instance *inst;
818 struct nfulnl_msg_config_cmd *cmd = NULL;
819 struct nfnl_log_net *log = nfnl_log_pernet(net);
820 int ret = 0;
821 u16 flags = 0;
822
823 if (nfula[NFULA_CFG_CMD]) {
824 u_int8_t pf = nfmsg->nfgen_family;
825 cmd = nla_data(nfula[NFULA_CFG_CMD]);
826
827 /* Commands without queue context */
828 switch (cmd->command) {
829 case NFULNL_CFG_CMD_PF_BIND:
830 return nf_log_bind_pf(net, pf, &nfulnl_logger);
831 case NFULNL_CFG_CMD_PF_UNBIND:
832 nf_log_unbind_pf(net, pf);
833 return 0;
834 }
835 }
836
837 inst = instance_lookup_get(log, group_num);
838 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
839 ret = -EPERM;
840 goto out_put;
841 }
842
843 /* Check if we support these flags in first place, dependencies should
844 * be there too not to break atomicity.
845 */
846 if (nfula[NFULA_CFG_FLAGS]) {
847 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
848
849 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
850 !rcu_access_pointer(nfnl_ct_hook)) {
851 #ifdef CONFIG_MODULES
852 nfnl_unlock(NFNL_SUBSYS_ULOG);
853 request_module("ip_conntrack_netlink");
854 nfnl_lock(NFNL_SUBSYS_ULOG);
855 if (rcu_access_pointer(nfnl_ct_hook)) {
856 ret = -EAGAIN;
857 goto out_put;
858 }
859 #endif
860 ret = -EOPNOTSUPP;
861 goto out_put;
862 }
863 }
864
865 if (cmd != NULL) {
866 switch (cmd->command) {
867 case NFULNL_CFG_CMD_BIND:
868 if (inst) {
869 ret = -EBUSY;
870 goto out_put;
871 }
872
873 inst = instance_create(net, group_num,
874 NETLINK_CB(skb).portid,
875 sk_user_ns(NETLINK_CB(skb).sk));
876 if (IS_ERR(inst)) {
877 ret = PTR_ERR(inst);
878 goto out;
879 }
880 break;
881 case NFULNL_CFG_CMD_UNBIND:
882 if (!inst) {
883 ret = -ENODEV;
884 goto out;
885 }
886
887 instance_destroy(log, inst);
888 goto out_put;
889 default:
890 ret = -ENOTSUPP;
891 goto out_put;
892 }
893 } else if (!inst) {
894 ret = -ENODEV;
895 goto out;
896 }
897
898 if (nfula[NFULA_CFG_MODE]) {
899 struct nfulnl_msg_config_mode *params =
900 nla_data(nfula[NFULA_CFG_MODE]);
901
902 nfulnl_set_mode(inst, params->copy_mode,
903 ntohl(params->copy_range));
904 }
905
906 if (nfula[NFULA_CFG_TIMEOUT]) {
907 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
908
909 nfulnl_set_timeout(inst, ntohl(timeout));
910 }
911
912 if (nfula[NFULA_CFG_NLBUFSIZ]) {
913 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
914
915 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
916 }
917
918 if (nfula[NFULA_CFG_QTHRESH]) {
919 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
920
921 nfulnl_set_qthresh(inst, ntohl(qthresh));
922 }
923
924 if (nfula[NFULA_CFG_FLAGS])
925 nfulnl_set_flags(inst, flags);
926
927 out_put:
928 instance_put(inst);
929 out:
930 return ret;
931 }
932
933 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
934 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
935 .attr_count = NFULA_MAX, },
936 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
937 .attr_count = NFULA_CFG_MAX,
938 .policy = nfula_cfg_policy },
939 };
940
941 static const struct nfnetlink_subsystem nfulnl_subsys = {
942 .name = "log",
943 .subsys_id = NFNL_SUBSYS_ULOG,
944 .cb_count = NFULNL_MSG_MAX,
945 .cb = nfulnl_cb,
946 };
947
948 #ifdef CONFIG_PROC_FS
949 struct iter_state {
950 struct seq_net_private p;
951 unsigned int bucket;
952 };
953
954 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
955 {
956 struct nfnl_log_net *log;
957 if (!st)
958 return NULL;
959
960 log = nfnl_log_pernet(net);
961
962 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
963 struct hlist_head *head = &log->instance_table[st->bucket];
964
965 if (!hlist_empty(head))
966 return rcu_dereference_bh(hlist_first_rcu(head));
967 }
968 return NULL;
969 }
970
971 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
972 struct hlist_node *h)
973 {
974 h = rcu_dereference_bh(hlist_next_rcu(h));
975 while (!h) {
976 struct nfnl_log_net *log;
977 struct hlist_head *head;
978
979 if (++st->bucket >= INSTANCE_BUCKETS)
980 return NULL;
981
982 log = nfnl_log_pernet(net);
983 head = &log->instance_table[st->bucket];
984 h = rcu_dereference_bh(hlist_first_rcu(head));
985 }
986 return h;
987 }
988
989 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
990 loff_t pos)
991 {
992 struct hlist_node *head;
993 head = get_first(net, st);
994
995 if (head)
996 while (pos && (head = get_next(net, st, head)))
997 pos--;
998 return pos ? NULL : head;
999 }
1000
1001 static void *seq_start(struct seq_file *s, loff_t *pos)
1002 __acquires(rcu_bh)
1003 {
1004 rcu_read_lock_bh();
1005 return get_idx(seq_file_net(s), s->private, *pos);
1006 }
1007
1008 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1009 {
1010 (*pos)++;
1011 return get_next(seq_file_net(s), s->private, v);
1012 }
1013
1014 static void seq_stop(struct seq_file *s, void *v)
1015 __releases(rcu_bh)
1016 {
1017 rcu_read_unlock_bh();
1018 }
1019
1020 static int seq_show(struct seq_file *s, void *v)
1021 {
1022 const struct nfulnl_instance *inst = v;
1023
1024 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1025 inst->group_num,
1026 inst->peer_portid, inst->qlen,
1027 inst->copy_mode, inst->copy_range,
1028 inst->flushtimeout, atomic_read(&inst->use));
1029
1030 return 0;
1031 }
1032
1033 static const struct seq_operations nful_seq_ops = {
1034 .start = seq_start,
1035 .next = seq_next,
1036 .stop = seq_stop,
1037 .show = seq_show,
1038 };
1039
1040 static int nful_open(struct inode *inode, struct file *file)
1041 {
1042 return seq_open_net(inode, file, &nful_seq_ops,
1043 sizeof(struct iter_state));
1044 }
1045
1046 static const struct file_operations nful_file_ops = {
1047 .owner = THIS_MODULE,
1048 .open = nful_open,
1049 .read = seq_read,
1050 .llseek = seq_lseek,
1051 .release = seq_release_net,
1052 };
1053
1054 #endif /* PROC_FS */
1055
1056 static int __net_init nfnl_log_net_init(struct net *net)
1057 {
1058 unsigned int i;
1059 struct nfnl_log_net *log = nfnl_log_pernet(net);
1060 #ifdef CONFIG_PROC_FS
1061 struct proc_dir_entry *proc;
1062 kuid_t root_uid;
1063 kgid_t root_gid;
1064 #endif
1065
1066 for (i = 0; i < INSTANCE_BUCKETS; i++)
1067 INIT_HLIST_HEAD(&log->instance_table[i]);
1068 spin_lock_init(&log->instances_lock);
1069
1070 #ifdef CONFIG_PROC_FS
1071 proc = proc_create("nfnetlink_log", 0440,
1072 net->nf.proc_netfilter, &nful_file_ops);
1073 if (!proc)
1074 return -ENOMEM;
1075
1076 root_uid = make_kuid(net->user_ns, 0);
1077 root_gid = make_kgid(net->user_ns, 0);
1078 if (uid_valid(root_uid) && gid_valid(root_gid))
1079 proc_set_user(proc, root_uid, root_gid);
1080 #endif
1081 return 0;
1082 }
1083
1084 static void __net_exit nfnl_log_net_exit(struct net *net)
1085 {
1086 #ifdef CONFIG_PROC_FS
1087 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1088 #endif
1089 nf_log_unset(net, &nfulnl_logger);
1090 }
1091
1092 static struct pernet_operations nfnl_log_net_ops = {
1093 .init = nfnl_log_net_init,
1094 .exit = nfnl_log_net_exit,
1095 .id = &nfnl_log_net_id,
1096 .size = sizeof(struct nfnl_log_net),
1097 };
1098
1099 static int __init nfnetlink_log_init(void)
1100 {
1101 int status;
1102
1103 status = register_pernet_subsys(&nfnl_log_net_ops);
1104 if (status < 0) {
1105 pr_err("failed to register pernet ops\n");
1106 goto out;
1107 }
1108
1109 netlink_register_notifier(&nfulnl_rtnl_notifier);
1110 status = nfnetlink_subsys_register(&nfulnl_subsys);
1111 if (status < 0) {
1112 pr_err("failed to create netlink socket\n");
1113 goto cleanup_netlink_notifier;
1114 }
1115
1116 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1117 if (status < 0) {
1118 pr_err("failed to register logger\n");
1119 goto cleanup_subsys;
1120 }
1121
1122 return status;
1123
1124 cleanup_subsys:
1125 nfnetlink_subsys_unregister(&nfulnl_subsys);
1126 cleanup_netlink_notifier:
1127 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1128 unregister_pernet_subsys(&nfnl_log_net_ops);
1129 out:
1130 return status;
1131 }
1132
1133 static void __exit nfnetlink_log_fini(void)
1134 {
1135 nf_log_unregister(&nfulnl_logger);
1136 nfnetlink_subsys_unregister(&nfulnl_subsys);
1137 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1138 unregister_pernet_subsys(&nfnl_log_net_ops);
1139 }
1140
1141 MODULE_DESCRIPTION("netfilter userspace logging");
1142 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1143 MODULE_LICENSE("GPL");
1144 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1145 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1146 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1147 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1148
1149 module_init(nfnetlink_log_init);
1150 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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