2 * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2011 Intra2net AG <http://www.intra2net.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation (or any later at your option).
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/skbuff.h>
13 #include <linux/atomic.h>
14 #include <linux/netlink.h>
15 #include <linux/rculist.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <net/netlink.h>
22 #include <linux/netfilter.h>
23 #include <linux/netfilter/nfnetlink.h>
24 #include <linux/netfilter/nfnetlink_acct.h>
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
28 MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
30 static LIST_HEAD(nfnl_acct_list);
36 struct list_head head;
38 char name[NFACCT_NAME_MAX];
39 struct rcu_head rcu_head;
43 #define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS | NFACCT_F_QUOTA_BYTES)
44 #define NFACCT_OVERQUOTA_BIT 2 /* NFACCT_F_OVERQUOTA */
47 nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
48 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
50 struct nf_acct *nfacct, *matching = NULL;
52 unsigned int size = 0;
58 acct_name = nla_data(tb[NFACCT_NAME]);
59 if (strlen(acct_name) == 0)
62 list_for_each_entry(nfacct, &nfnl_acct_list, head) {
63 if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
66 if (nlh->nlmsg_flags & NLM_F_EXCL)
74 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
75 /* reset counters if you request a replacement. */
76 atomic64_set(&matching->pkts, 0);
77 atomic64_set(&matching->bytes, 0);
78 smp_mb__before_atomic();
79 /* reset overquota flag if quota is enabled. */
80 if ((matching->flags & NFACCT_F_QUOTA))
81 clear_bit(NFACCT_OVERQUOTA_BIT,
88 if (tb[NFACCT_FLAGS]) {
89 flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
90 if (flags & ~NFACCT_F_QUOTA)
92 if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
94 if (flags & NFACCT_F_OVERQUOTA)
100 nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
104 if (flags & NFACCT_F_QUOTA) {
105 u64 *quota = (u64 *)nfacct->data;
107 *quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
108 nfacct->flags = flags;
111 strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
113 if (tb[NFACCT_BYTES]) {
114 atomic64_set(&nfacct->bytes,
115 be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
117 if (tb[NFACCT_PKTS]) {
118 atomic64_set(&nfacct->pkts,
119 be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
121 atomic_set(&nfacct->refcnt, 1);
122 list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
127 nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
128 int event, struct nf_acct *acct)
130 struct nlmsghdr *nlh;
131 struct nfgenmsg *nfmsg;
132 unsigned int flags = portid ? NLM_F_MULTI : 0;
136 event |= NFNL_SUBSYS_ACCT << 8;
137 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
141 nfmsg = nlmsg_data(nlh);
142 nfmsg->nfgen_family = AF_UNSPEC;
143 nfmsg->version = NFNETLINK_V0;
146 if (nla_put_string(skb, NFACCT_NAME, acct->name))
147 goto nla_put_failure;
149 old_flags = acct->flags;
150 if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
151 pkts = atomic64_xchg(&acct->pkts, 0);
152 bytes = atomic64_xchg(&acct->bytes, 0);
153 smp_mb__before_atomic();
154 if (acct->flags & NFACCT_F_QUOTA)
155 clear_bit(NFACCT_OVERQUOTA_BIT, &acct->flags);
157 pkts = atomic64_read(&acct->pkts);
158 bytes = atomic64_read(&acct->bytes);
160 if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) ||
161 nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) ||
162 nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
163 goto nla_put_failure;
164 if (acct->flags & NFACCT_F_QUOTA) {
165 u64 *quota = (u64 *)acct->data;
167 if (nla_put_be32(skb, NFACCT_FLAGS, htonl(old_flags)) ||
168 nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota)))
169 goto nla_put_failure;
176 nlmsg_cancel(skb, nlh);
181 nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
183 struct nf_acct *cur, *last;
188 last = (struct nf_acct *)cb->args[1];
193 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
200 if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
202 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
203 NFNL_MSG_ACCT_NEW, cur) < 0) {
204 cb->args[1] = (unsigned long)cur;
215 nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
216 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
222 if (nlh->nlmsg_flags & NLM_F_DUMP) {
223 struct netlink_dump_control c = {
224 .dump = nfnl_acct_dump,
226 return netlink_dump_start(nfnl, skb, nlh, &c);
229 if (!tb[NFACCT_NAME])
231 acct_name = nla_data(tb[NFACCT_NAME]);
233 list_for_each_entry(cur, &nfnl_acct_list, head) {
234 struct sk_buff *skb2;
236 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
239 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
245 ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
247 NFNL_MSG_TYPE(nlh->nlmsg_type),
248 NFNL_MSG_ACCT_NEW, cur);
253 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
258 /* this avoids a loop in nfnetlink. */
259 return ret == -EAGAIN ? -ENOBUFS : ret;
264 /* try to delete object, fail if it is still in use. */
265 static int nfnl_acct_try_del(struct nf_acct *cur)
269 /* we want to avoid races with nfnl_acct_find_get. */
270 if (atomic_dec_and_test(&cur->refcnt)) {
271 /* We are protected by nfnl mutex. */
272 list_del_rcu(&cur->head);
273 kfree_rcu(cur, rcu_head);
275 /* still in use, restore reference counter. */
276 atomic_inc(&cur->refcnt);
283 nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
284 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
290 if (!tb[NFACCT_NAME]) {
291 list_for_each_entry(cur, &nfnl_acct_list, head)
292 nfnl_acct_try_del(cur);
296 acct_name = nla_data(tb[NFACCT_NAME]);
298 list_for_each_entry(cur, &nfnl_acct_list, head) {
299 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
302 ret = nfnl_acct_try_del(cur);
311 static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
312 [NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
313 [NFACCT_BYTES] = { .type = NLA_U64 },
314 [NFACCT_PKTS] = { .type = NLA_U64 },
315 [NFACCT_FLAGS] = { .type = NLA_U32 },
316 [NFACCT_QUOTA] = { .type = NLA_U64 },
319 static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
320 [NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
321 .attr_count = NFACCT_MAX,
322 .policy = nfnl_acct_policy },
323 [NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
324 .attr_count = NFACCT_MAX,
325 .policy = nfnl_acct_policy },
326 [NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
327 .attr_count = NFACCT_MAX,
328 .policy = nfnl_acct_policy },
329 [NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
330 .attr_count = NFACCT_MAX,
331 .policy = nfnl_acct_policy },
334 static const struct nfnetlink_subsystem nfnl_acct_subsys = {
336 .subsys_id = NFNL_SUBSYS_ACCT,
337 .cb_count = NFNL_MSG_ACCT_MAX,
341 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
343 struct nf_acct *nfnl_acct_find_get(const char *acct_name)
345 struct nf_acct *cur, *acct = NULL;
348 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
349 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
352 if (!try_module_get(THIS_MODULE))
355 if (!atomic_inc_not_zero(&cur->refcnt)) {
356 module_put(THIS_MODULE);
367 EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
369 void nfnl_acct_put(struct nf_acct *acct)
371 atomic_dec(&acct->refcnt);
372 module_put(THIS_MODULE);
374 EXPORT_SYMBOL_GPL(nfnl_acct_put);
376 void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
378 atomic64_inc(&nfacct->pkts);
379 atomic64_add(skb->len, &nfacct->bytes);
381 EXPORT_SYMBOL_GPL(nfnl_acct_update);
383 static void nfnl_overquota_report(struct nf_acct *nfacct)
388 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
392 ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
398 netlink_broadcast(init_net.nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
402 int nfnl_acct_overquota(const struct sk_buff *skb, struct nf_acct *nfacct)
406 int ret = NFACCT_UNDERQUOTA;
408 /* no place here if we don't have a quota */
409 if (!(nfacct->flags & NFACCT_F_QUOTA))
410 return NFACCT_NO_QUOTA;
412 quota = (u64 *)nfacct->data;
413 now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
414 atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
419 !test_and_set_bit(NFACCT_OVERQUOTA_BIT, &nfacct->flags)) {
420 nfnl_overquota_report(nfacct);
425 EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
427 static int __init nfnl_acct_init(void)
431 pr_info("nfnl_acct: registering with nfnetlink.\n");
432 ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
434 pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
442 static void __exit nfnl_acct_exit(void)
444 struct nf_acct *cur, *tmp;
446 pr_info("nfnl_acct: unregistering from nfnetlink.\n");
447 nfnetlink_subsys_unregister(&nfnl_acct_subsys);
449 list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
450 list_del_rcu(&cur->head);
451 /* We are sure that our objects have no clients at this point,
452 * it's safe to release them all without checking refcnt. */
453 kfree_rcu(cur, rcu_head);
457 module_init(nfnl_acct_init);
458 module_exit(nfnl_acct_exit);