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irqchip: Fix dependencies for archs w/o HAS_IOMEM
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blob740cce4685acfab8920a46d5d33e40a68da02f8c
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 int
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 return 0;
304 }
305
306 static int
307 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
308 {
309 spin_lock_bh(&inst->lock);
310 inst->qthreshold = qthresh;
311 spin_unlock_bh(&inst->lock);
312
313 return 0;
314 }
315
316 static int
317 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
318 {
319 spin_lock_bh(&inst->lock);
320 inst->flags = flags;
321 spin_unlock_bh(&inst->lock);
322
323 return 0;
324 }
325
326 static struct sk_buff *
327 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
328 unsigned int pkt_size)
329 {
330 struct sk_buff *skb;
331 unsigned int n;
332
333 /* alloc skb which should be big enough for a whole multipart
334 * message. WARNING: has to be <= 128k due to slab restrictions */
335
336 n = max(inst_size, pkt_size);
337 skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
338 if (!skb) {
339 if (n > pkt_size) {
340 /* try to allocate only as much as we need for current
341 * packet */
342
343 skb = nfnetlink_alloc_skb(net, pkt_size,
344 peer_portid, GFP_ATOMIC);
345 }
346 }
347
348 return skb;
349 }
350
351 static void
352 __nfulnl_send(struct nfulnl_instance *inst)
353 {
354 if (inst->qlen > 1) {
355 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
356 NLMSG_DONE,
357 sizeof(struct nfgenmsg),
358 0);
359 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
360 inst->skb->len, skb_tailroom(inst->skb))) {
361 kfree_skb(inst->skb);
362 goto out;
363 }
364 }
365 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
366 MSG_DONTWAIT);
367 out:
368 inst->qlen = 0;
369 inst->skb = NULL;
370 }
371
372 static void
373 __nfulnl_flush(struct nfulnl_instance *inst)
374 {
375 /* timer holds a reference */
376 if (del_timer(&inst->timer))
377 instance_put(inst);
378 if (inst->skb)
379 __nfulnl_send(inst);
380 }
381
382 static void
383 nfulnl_timer(unsigned long data)
384 {
385 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
386
387 spin_lock_bh(&inst->lock);
388 if (inst->skb)
389 __nfulnl_send(inst);
390 spin_unlock_bh(&inst->lock);
391 instance_put(inst);
392 }
393
394 /* This is an inline function, we don't really care about a long
395 * list of arguments */
396 static inline int
397 __build_packet_message(struct nfnl_log_net *log,
398 struct nfulnl_instance *inst,
399 const struct sk_buff *skb,
400 unsigned int data_len,
401 u_int8_t pf,
402 unsigned int hooknum,
403 const struct net_device *indev,
404 const struct net_device *outdev,
405 const char *prefix, unsigned int plen,
406 const struct nfnl_ct_hook *nfnl_ct,
407 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
408 {
409 struct nfulnl_msg_packet_hdr pmsg;
410 struct nlmsghdr *nlh;
411 struct nfgenmsg *nfmsg;
412 sk_buff_data_t old_tail = inst->skb->tail;
413 struct sock *sk;
414 const unsigned char *hwhdrp;
415
416 nlh = nlmsg_put(inst->skb, 0, 0,
417 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
418 sizeof(struct nfgenmsg), 0);
419 if (!nlh)
420 return -1;
421 nfmsg = nlmsg_data(nlh);
422 nfmsg->nfgen_family = pf;
423 nfmsg->version = NFNETLINK_V0;
424 nfmsg->res_id = htons(inst->group_num);
425
426 memset(&pmsg, 0, sizeof(pmsg));
427 pmsg.hw_protocol = skb->protocol;
428 pmsg.hook = hooknum;
429
430 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
431 goto nla_put_failure;
432
433 if (prefix &&
434 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
435 goto nla_put_failure;
436
437 if (indev) {
438 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
439 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
440 htonl(indev->ifindex)))
441 goto nla_put_failure;
442 #else
443 if (pf == PF_BRIDGE) {
444 /* Case 1: outdev is physical input device, we need to
445 * look for bridge group (when called from
446 * netfilter_bridge) */
447 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
448 htonl(indev->ifindex)) ||
449 /* this is the bridge group "brX" */
450 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
451 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
452 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
453 goto nla_put_failure;
454 } else {
455 struct net_device *physindev;
456
457 /* Case 2: indev is bridge group, we need to look for
458 * physical device (when called from ipv4) */
459 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
460 htonl(indev->ifindex)))
461 goto nla_put_failure;
462
463 physindev = nf_bridge_get_physindev(skb);
464 if (physindev &&
465 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
466 htonl(physindev->ifindex)))
467 goto nla_put_failure;
468 }
469 #endif
470 }
471
472 if (outdev) {
473 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
474 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
475 htonl(outdev->ifindex)))
476 goto nla_put_failure;
477 #else
478 if (pf == PF_BRIDGE) {
479 /* Case 1: outdev is physical output device, we need to
480 * look for bridge group (when called from
481 * netfilter_bridge) */
482 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
483 htonl(outdev->ifindex)) ||
484 /* this is the bridge group "brX" */
485 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
486 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
487 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
488 goto nla_put_failure;
489 } else {
490 struct net_device *physoutdev;
491
492 /* Case 2: indev is a bridge group, we need to look
493 * for physical device (when called from ipv4) */
494 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
495 htonl(outdev->ifindex)))
496 goto nla_put_failure;
497
498 physoutdev = nf_bridge_get_physoutdev(skb);
499 if (physoutdev &&
500 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
501 htonl(physoutdev->ifindex)))
502 goto nla_put_failure;
503 }
504 #endif
505 }
506
507 if (skb->mark &&
508 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
509 goto nla_put_failure;
510
511 if (indev && skb->dev &&
512 skb->mac_header != skb->network_header) {
513 struct nfulnl_msg_packet_hw phw;
514 int len;
515
516 memset(&phw, 0, sizeof(phw));
517 len = dev_parse_header(skb, phw.hw_addr);
518 if (len > 0) {
519 phw.hw_addrlen = htons(len);
520 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
521 goto nla_put_failure;
522 }
523 }
524
525 if (indev && skb_mac_header_was_set(skb)) {
526 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
527 nla_put_be16(inst->skb, NFULA_HWLEN,
528 htons(skb->dev->hard_header_len)))
529 goto nla_put_failure;
530
531 hwhdrp = skb_mac_header(skb);
532
533 if (skb->dev->type == ARPHRD_SIT)
534 hwhdrp -= ETH_HLEN;
535
536 if (hwhdrp >= skb->head &&
537 nla_put(inst->skb, NFULA_HWHEADER,
538 skb->dev->hard_header_len, hwhdrp))
539 goto nla_put_failure;
540 }
541
542 if (skb->tstamp.tv64) {
543 struct nfulnl_msg_packet_timestamp ts;
544 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
545 ts.sec = cpu_to_be64(kts.tv_sec);
546 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
547
548 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
549 goto nla_put_failure;
550 }
551
552 /* UID */
553 sk = skb->sk;
554 if (sk && sk_fullsock(sk)) {
555 read_lock_bh(&sk->sk_callback_lock);
556 if (sk->sk_socket && sk->sk_socket->file) {
557 struct file *file = sk->sk_socket->file;
558 const struct cred *cred = file->f_cred;
559 struct user_namespace *user_ns = inst->peer_user_ns;
560 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
561 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
562 read_unlock_bh(&sk->sk_callback_lock);
563 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
564 nla_put_be32(inst->skb, NFULA_GID, gid))
565 goto nla_put_failure;
566 } else
567 read_unlock_bh(&sk->sk_callback_lock);
568 }
569
570 /* local sequence number */
571 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
572 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
573 goto nla_put_failure;
574
575 /* global sequence number */
576 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
577 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
578 htonl(atomic_inc_return(&log->global_seq))))
579 goto nla_put_failure;
580
581 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
582 NFULA_CT, NFULA_CT_INFO) < 0)
583 goto nla_put_failure;
584
585 if (data_len) {
586 struct nlattr *nla;
587 int size = nla_attr_size(data_len);
588
589 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
590 goto nla_put_failure;
591
592 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
593 nla->nla_type = NFULA_PAYLOAD;
594 nla->nla_len = size;
595
596 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
597 BUG();
598 }
599
600 nlh->nlmsg_len = inst->skb->tail - old_tail;
601 return 0;
602
603 nla_put_failure:
604 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
605 return -1;
606 }
607
608 static struct nf_loginfo default_loginfo = {
609 .type = NF_LOG_TYPE_ULOG,
610 .u = {
611 .ulog = {
612 .copy_len = 0xffff,
613 .group = 0,
614 .qthreshold = 1,
615 },
616 },
617 };
618
619 /* log handler for internal netfilter logging api */
620 void
621 nfulnl_log_packet(struct net *net,
622 u_int8_t pf,
623 unsigned int hooknum,
624 const struct sk_buff *skb,
625 const struct net_device *in,
626 const struct net_device *out,
627 const struct nf_loginfo *li_user,
628 const char *prefix)
629 {
630 size_t size;
631 unsigned int data_len;
632 struct nfulnl_instance *inst;
633 const struct nf_loginfo *li;
634 unsigned int qthreshold;
635 unsigned int plen;
636 struct nfnl_log_net *log = nfnl_log_pernet(net);
637 const struct nfnl_ct_hook *nfnl_ct = NULL;
638 struct nf_conn *ct = NULL;
639 enum ip_conntrack_info uninitialized_var(ctinfo);
640
641 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
642 li = li_user;
643 else
644 li = &default_loginfo;
645
646 inst = instance_lookup_get(log, li->u.ulog.group);
647 if (!inst)
648 return;
649
650 plen = 0;
651 if (prefix)
652 plen = strlen(prefix) + 1;
653
654 /* FIXME: do we want to make the size calculation conditional based on
655 * what is actually present? way more branches and checks, but more
656 * memory efficient... */
657 size = nlmsg_total_size(sizeof(struct nfgenmsg))
658 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
659 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
660 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
661 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
662 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
663 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
664 #endif
665 + nla_total_size(sizeof(u_int32_t)) /* mark */
666 + nla_total_size(sizeof(u_int32_t)) /* uid */
667 + nla_total_size(sizeof(u_int32_t)) /* gid */
668 + nla_total_size(plen) /* prefix */
669 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
670 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
671 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
672
673 if (in && skb_mac_header_was_set(skb)) {
674 size += nla_total_size(skb->dev->hard_header_len)
675 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
676 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
677 }
678
679 spin_lock_bh(&inst->lock);
680
681 if (inst->flags & NFULNL_CFG_F_SEQ)
682 size += nla_total_size(sizeof(u_int32_t));
683 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
684 size += nla_total_size(sizeof(u_int32_t));
685 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
686 nfnl_ct = rcu_dereference(nfnl_ct_hook);
687 if (nfnl_ct != NULL) {
688 ct = nfnl_ct->get_ct(skb, &ctinfo);
689 if (ct != NULL)
690 size += nfnl_ct->build_size(ct);
691 }
692 }
693
694 qthreshold = inst->qthreshold;
695 /* per-rule qthreshold overrides per-instance */
696 if (li->u.ulog.qthreshold)
697 if (qthreshold > li->u.ulog.qthreshold)
698 qthreshold = li->u.ulog.qthreshold;
699
700
701 switch (inst->copy_mode) {
702 case NFULNL_COPY_META:
703 case NFULNL_COPY_NONE:
704 data_len = 0;
705 break;
706
707 case NFULNL_COPY_PACKET:
708 if (inst->copy_range > skb->len)
709 data_len = skb->len;
710 else
711 data_len = inst->copy_range;
712
713 size += nla_total_size(data_len);
714 break;
715
716 case NFULNL_COPY_DISABLED:
717 default:
718 goto unlock_and_release;
719 }
720
721 if (inst->skb && size > skb_tailroom(inst->skb)) {
722 /* either the queue len is too high or we don't have
723 * enough room in the skb left. flush to userspace. */
724 __nfulnl_flush(inst);
725 }
726
727 if (!inst->skb) {
728 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
729 inst->nlbufsiz, size);
730 if (!inst->skb)
731 goto alloc_failure;
732 }
733
734 inst->qlen++;
735
736 __build_packet_message(log, inst, skb, data_len, pf,
737 hooknum, in, out, prefix, plen,
738 nfnl_ct, ct, ctinfo);
739
740 if (inst->qlen >= qthreshold)
741 __nfulnl_flush(inst);
742 /* timer_pending always called within inst->lock, so there
743 * is no chance of a race here */
744 else if (!timer_pending(&inst->timer)) {
745 instance_get(inst);
746 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
747 add_timer(&inst->timer);
748 }
749
750 unlock_and_release:
751 spin_unlock_bh(&inst->lock);
752 instance_put(inst);
753 return;
754
755 alloc_failure:
756 /* FIXME: statistics */
757 goto unlock_and_release;
758 }
759 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
760
761 static int
762 nfulnl_rcv_nl_event(struct notifier_block *this,
763 unsigned long event, void *ptr)
764 {
765 struct netlink_notify *n = ptr;
766 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
767
768 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
769 int i;
770
771 /* destroy all instances for this portid */
772 spin_lock_bh(&log->instances_lock);
773 for (i = 0; i < INSTANCE_BUCKETS; i++) {
774 struct hlist_node *t2;
775 struct nfulnl_instance *inst;
776 struct hlist_head *head = &log->instance_table[i];
777
778 hlist_for_each_entry_safe(inst, t2, head, hlist) {
779 if (n->portid == inst->peer_portid)
780 __instance_destroy(inst);
781 }
782 }
783 spin_unlock_bh(&log->instances_lock);
784 }
785 return NOTIFY_DONE;
786 }
787
788 static struct notifier_block nfulnl_rtnl_notifier = {
789 .notifier_call = nfulnl_rcv_nl_event,
790 };
791
792 static int
793 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
794 const struct nlmsghdr *nlh,
795 const struct nlattr * const nfqa[])
796 {
797 return -ENOTSUPP;
798 }
799
800 static struct nf_logger nfulnl_logger __read_mostly = {
801 .name = "nfnetlink_log",
802 .type = NF_LOG_TYPE_ULOG,
803 .logfn = &nfulnl_log_packet,
804 .me = THIS_MODULE,
805 };
806
807 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
808 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
809 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
810 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
811 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
812 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
813 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
814 };
815
816 static int
817 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
818 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 net *net = sock_net(ctnl);
826 struct nfnl_log_net *log = nfnl_log_pernet(net);
827 int ret = 0;
828 u16 flags = 0;
829
830 if (nfula[NFULA_CFG_CMD]) {
831 u_int8_t pf = nfmsg->nfgen_family;
832 cmd = nla_data(nfula[NFULA_CFG_CMD]);
833
834 /* Commands without queue context */
835 switch (cmd->command) {
836 case NFULNL_CFG_CMD_PF_BIND:
837 return nf_log_bind_pf(net, pf, &nfulnl_logger);
838 case NFULNL_CFG_CMD_PF_UNBIND:
839 nf_log_unbind_pf(net, pf);
840 return 0;
841 }
842 }
843
844 inst = instance_lookup_get(log, group_num);
845 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
846 ret = -EPERM;
847 goto out_put;
848 }
849
850 /* Check if we support these flags in first place, dependencies should
851 * be there too not to break atomicity.
852 */
853 if (nfula[NFULA_CFG_FLAGS]) {
854 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
855
856 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
857 !rcu_access_pointer(nfnl_ct_hook)) {
858 #ifdef CONFIG_MODULES
859 nfnl_unlock(NFNL_SUBSYS_ULOG);
860 request_module("ip_conntrack_netlink");
861 nfnl_lock(NFNL_SUBSYS_ULOG);
862 if (rcu_access_pointer(nfnl_ct_hook)) {
863 ret = -EAGAIN;
864 goto out_put;
865 }
866 #endif
867 ret = -EOPNOTSUPP;
868 goto out_put;
869 }
870 }
871
872 if (cmd != NULL) {
873 switch (cmd->command) {
874 case NFULNL_CFG_CMD_BIND:
875 if (inst) {
876 ret = -EBUSY;
877 goto out_put;
878 }
879
880 inst = instance_create(net, group_num,
881 NETLINK_CB(skb).portid,
882 sk_user_ns(NETLINK_CB(skb).sk));
883 if (IS_ERR(inst)) {
884 ret = PTR_ERR(inst);
885 goto out;
886 }
887 break;
888 case NFULNL_CFG_CMD_UNBIND:
889 if (!inst) {
890 ret = -ENODEV;
891 goto out;
892 }
893
894 instance_destroy(log, inst);
895 goto out_put;
896 default:
897 ret = -ENOTSUPP;
898 break;
899 }
900 } else if (!inst) {
901 ret = -ENODEV;
902 goto out;
903 }
904
905 if (nfula[NFULA_CFG_MODE]) {
906 struct nfulnl_msg_config_mode *params =
907 nla_data(nfula[NFULA_CFG_MODE]);
908
909 nfulnl_set_mode(inst, params->copy_mode,
910 ntohl(params->copy_range));
911 }
912
913 if (nfula[NFULA_CFG_TIMEOUT]) {
914 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
915
916 nfulnl_set_timeout(inst, ntohl(timeout));
917 }
918
919 if (nfula[NFULA_CFG_NLBUFSIZ]) {
920 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
921
922 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
923 }
924
925 if (nfula[NFULA_CFG_QTHRESH]) {
926 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
927
928 nfulnl_set_qthresh(inst, ntohl(qthresh));
929 }
930
931 if (nfula[NFULA_CFG_FLAGS])
932 nfulnl_set_flags(inst, flags);
933
934 out_put:
935 instance_put(inst);
936 out:
937 return ret;
938 }
939
940 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
941 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
942 .attr_count = NFULA_MAX, },
943 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
944 .attr_count = NFULA_CFG_MAX,
945 .policy = nfula_cfg_policy },
946 };
947
948 static const struct nfnetlink_subsystem nfulnl_subsys = {
949 .name = "log",
950 .subsys_id = NFNL_SUBSYS_ULOG,
951 .cb_count = NFULNL_MSG_MAX,
952 .cb = nfulnl_cb,
953 };
954
955 #ifdef CONFIG_PROC_FS
956 struct iter_state {
957 struct seq_net_private p;
958 unsigned int bucket;
959 };
960
961 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
962 {
963 struct nfnl_log_net *log;
964 if (!st)
965 return NULL;
966
967 log = nfnl_log_pernet(net);
968
969 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
970 struct hlist_head *head = &log->instance_table[st->bucket];
971
972 if (!hlist_empty(head))
973 return rcu_dereference_bh(hlist_first_rcu(head));
974 }
975 return NULL;
976 }
977
978 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
979 struct hlist_node *h)
980 {
981 h = rcu_dereference_bh(hlist_next_rcu(h));
982 while (!h) {
983 struct nfnl_log_net *log;
984 struct hlist_head *head;
985
986 if (++st->bucket >= INSTANCE_BUCKETS)
987 return NULL;
988
989 log = nfnl_log_pernet(net);
990 head = &log->instance_table[st->bucket];
991 h = rcu_dereference_bh(hlist_first_rcu(head));
992 }
993 return h;
994 }
995
996 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
997 loff_t pos)
998 {
999 struct hlist_node *head;
1000 head = get_first(net, st);
1001
1002 if (head)
1003 while (pos && (head = get_next(net, st, head)))
1004 pos--;
1005 return pos ? NULL : head;
1006 }
1007
1008 static void *seq_start(struct seq_file *s, loff_t *pos)
1009 __acquires(rcu_bh)
1010 {
1011 rcu_read_lock_bh();
1012 return get_idx(seq_file_net(s), s->private, *pos);
1013 }
1014
1015 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1016 {
1017 (*pos)++;
1018 return get_next(seq_file_net(s), s->private, v);
1019 }
1020
1021 static void seq_stop(struct seq_file *s, void *v)
1022 __releases(rcu_bh)
1023 {
1024 rcu_read_unlock_bh();
1025 }
1026
1027 static int seq_show(struct seq_file *s, void *v)
1028 {
1029 const struct nfulnl_instance *inst = v;
1030
1031 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1032 inst->group_num,
1033 inst->peer_portid, inst->qlen,
1034 inst->copy_mode, inst->copy_range,
1035 inst->flushtimeout, atomic_read(&inst->use));
1036
1037 return 0;
1038 }
1039
1040 static const struct seq_operations nful_seq_ops = {
1041 .start = seq_start,
1042 .next = seq_next,
1043 .stop = seq_stop,
1044 .show = seq_show,
1045 };
1046
1047 static int nful_open(struct inode *inode, struct file *file)
1048 {
1049 return seq_open_net(inode, file, &nful_seq_ops,
1050 sizeof(struct iter_state));
1051 }
1052
1053 static const struct file_operations nful_file_ops = {
1054 .owner = THIS_MODULE,
1055 .open = nful_open,
1056 .read = seq_read,
1057 .llseek = seq_lseek,
1058 .release = seq_release_net,
1059 };
1060
1061 #endif /* PROC_FS */
1062
1063 static int __net_init nfnl_log_net_init(struct net *net)
1064 {
1065 unsigned int i;
1066 struct nfnl_log_net *log = nfnl_log_pernet(net);
1067
1068 for (i = 0; i < INSTANCE_BUCKETS; i++)
1069 INIT_HLIST_HEAD(&log->instance_table[i]);
1070 spin_lock_init(&log->instances_lock);
1071
1072 #ifdef CONFIG_PROC_FS
1073 if (!proc_create("nfnetlink_log", 0440,
1074 net->nf.proc_netfilter, &nful_file_ops))
1075 return -ENOMEM;
1076 #endif
1077 return 0;
1078 }
1079
1080 static void __net_exit nfnl_log_net_exit(struct net *net)
1081 {
1082 #ifdef CONFIG_PROC_FS
1083 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1084 #endif
1085 nf_log_unset(net, &nfulnl_logger);
1086 }
1087
1088 static struct pernet_operations nfnl_log_net_ops = {
1089 .init = nfnl_log_net_init,
1090 .exit = nfnl_log_net_exit,
1091 .id = &nfnl_log_net_id,
1092 .size = sizeof(struct nfnl_log_net),
1093 };
1094
1095 static int __init nfnetlink_log_init(void)
1096 {
1097 int status;
1098
1099 status = register_pernet_subsys(&nfnl_log_net_ops);
1100 if (status < 0) {
1101 pr_err("failed to register pernet ops\n");
1102 goto out;
1103 }
1104
1105 netlink_register_notifier(&nfulnl_rtnl_notifier);
1106 status = nfnetlink_subsys_register(&nfulnl_subsys);
1107 if (status < 0) {
1108 pr_err("failed to create netlink socket\n");
1109 goto cleanup_netlink_notifier;
1110 }
1111
1112 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1113 if (status < 0) {
1114 pr_err("failed to register logger\n");
1115 goto cleanup_subsys;
1116 }
1117
1118 return status;
1119
1120 cleanup_subsys:
1121 nfnetlink_subsys_unregister(&nfulnl_subsys);
1122 cleanup_netlink_notifier:
1123 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1124 unregister_pernet_subsys(&nfnl_log_net_ops);
1125 out:
1126 return status;
1127 }
1128
1129 static void __exit nfnetlink_log_fini(void)
1130 {
1131 nf_log_unregister(&nfulnl_logger);
1132 nfnetlink_subsys_unregister(&nfulnl_subsys);
1133 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1134 unregister_pernet_subsys(&nfnl_log_net_ops);
1135 }
1136
1137 MODULE_DESCRIPTION("netfilter userspace logging");
1138 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1139 MODULE_LICENSE("GPL");
1140 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1141 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1142 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1143 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1144
1145 module_init(nfnetlink_log_init);
1146 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support