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/netlink.h>
14 #include <linux/rculist.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/errno.h>
18 #include <net/netlink.h>
20 #include <asm/atomic.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);
35 struct list_head head;
37 char name[NFACCT_NAME_MAX];
38 struct rcu_head rcu_head;
42 nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
43 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
45 struct nf_acct *nfacct, *matching = NULL;
51 acct_name = nla_data(tb[NFACCT_NAME]);
53 list_for_each_entry(nfacct, &nfnl_acct_list, head) {
54 if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
57 if (nlh->nlmsg_flags & NLM_F_EXCL)
65 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
66 /* reset counters if you request a replacement. */
67 atomic64_set(&matching->pkts, 0);
68 atomic64_set(&matching->bytes, 0);
74 nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
78 strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
80 if (tb[NFACCT_BYTES]) {
81 atomic64_set(&nfacct->bytes,
82 be64_to_cpu(nla_get_u64(tb[NFACCT_BYTES])));
84 if (tb[NFACCT_PKTS]) {
85 atomic64_set(&nfacct->pkts,
86 be64_to_cpu(nla_get_u64(tb[NFACCT_PKTS])));
88 atomic_set(&nfacct->refcnt, 1);
89 list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
94 nfnl_acct_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
95 int event, struct nf_acct *acct)
98 struct nfgenmsg *nfmsg;
99 unsigned int flags = pid ? NLM_F_MULTI : 0;
102 event |= NFNL_SUBSYS_ACCT << 8;
103 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
107 nfmsg = nlmsg_data(nlh);
108 nfmsg->nfgen_family = AF_UNSPEC;
109 nfmsg->version = NFNETLINK_V0;
112 NLA_PUT_STRING(skb, NFACCT_NAME, acct->name);
114 if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
115 pkts = atomic64_xchg(&acct->pkts, 0);
116 bytes = atomic64_xchg(&acct->bytes, 0);
118 pkts = atomic64_read(&acct->pkts);
119 bytes = atomic64_read(&acct->bytes);
121 NLA_PUT_BE64(skb, NFACCT_PKTS, cpu_to_be64(pkts));
122 NLA_PUT_BE64(skb, NFACCT_BYTES, cpu_to_be64(bytes));
123 NLA_PUT_BE32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt)));
130 nlmsg_cancel(skb, nlh);
135 nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
137 struct nf_acct *cur, *last;
142 last = (struct nf_acct *)cb->args[1];
147 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
148 if (last && cur != last)
151 if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).pid,
153 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
154 NFNL_MSG_ACCT_NEW, cur) < 0) {
155 cb->args[1] = (unsigned long)cur;
166 nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
167 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
173 if (nlh->nlmsg_flags & NLM_F_DUMP) {
174 return netlink_dump_start(nfnl, skb, nlh, nfnl_acct_dump,
178 if (!tb[NFACCT_NAME])
180 acct_name = nla_data(tb[NFACCT_NAME]);
182 list_for_each_entry(cur, &nfnl_acct_list, head) {
183 struct sk_buff *skb2;
185 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
188 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
194 ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).pid,
196 NFNL_MSG_TYPE(nlh->nlmsg_type),
197 NFNL_MSG_ACCT_NEW, cur);
202 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).pid,
207 /* this avoids a loop in nfnetlink. */
208 return ret == -EAGAIN ? -ENOBUFS : ret;
213 /* try to delete object, fail if it is still in use. */
214 static int nfnl_acct_try_del(struct nf_acct *cur)
218 /* we want to avoid races with nfnl_acct_find_get. */
219 if (atomic_dec_and_test(&cur->refcnt)) {
220 /* We are protected by nfnl mutex. */
221 list_del_rcu(&cur->head);
222 kfree_rcu(cur, rcu_head);
224 /* still in use, restore reference counter. */
225 atomic_inc(&cur->refcnt);
232 nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
233 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
239 if (!tb[NFACCT_NAME]) {
240 list_for_each_entry(cur, &nfnl_acct_list, head)
241 nfnl_acct_try_del(cur);
245 acct_name = nla_data(tb[NFACCT_NAME]);
247 list_for_each_entry(cur, &nfnl_acct_list, head) {
248 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
251 ret = nfnl_acct_try_del(cur);
260 static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
261 [NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
262 [NFACCT_BYTES] = { .type = NLA_U64 },
263 [NFACCT_PKTS] = { .type = NLA_U64 },
266 static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
267 [NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
268 .attr_count = NFACCT_MAX,
269 .policy = nfnl_acct_policy },
270 [NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
271 .attr_count = NFACCT_MAX,
272 .policy = nfnl_acct_policy },
273 [NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
274 .attr_count = NFACCT_MAX,
275 .policy = nfnl_acct_policy },
276 [NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
277 .attr_count = NFACCT_MAX,
278 .policy = nfnl_acct_policy },
281 static const struct nfnetlink_subsystem nfnl_acct_subsys = {
283 .subsys_id = NFNL_SUBSYS_ACCT,
284 .cb_count = NFNL_MSG_ACCT_MAX,
288 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
290 struct nf_acct *nfnl_acct_find_get(const char *acct_name)
292 struct nf_acct *cur, *acct = NULL;
295 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
296 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
299 if (!try_module_get(THIS_MODULE))
302 if (!atomic_inc_not_zero(&cur->refcnt)) {
303 module_put(THIS_MODULE);
314 EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
316 void nfnl_acct_put(struct nf_acct *acct)
318 atomic_dec(&acct->refcnt);
319 module_put(THIS_MODULE);
321 EXPORT_SYMBOL_GPL(nfnl_acct_put);
323 void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
325 atomic64_inc(&nfacct->pkts);
326 atomic64_add(skb->len, &nfacct->bytes);
328 EXPORT_SYMBOL_GPL(nfnl_acct_update);
330 static int __init nfnl_acct_init(void)
334 pr_info("nfnl_acct: registering with nfnetlink.\n");
335 ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
337 pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
345 static void __exit nfnl_acct_exit(void)
347 struct nf_acct *cur, *tmp;
349 pr_info("nfnl_acct: unregistering from nfnetlink.\n");
350 nfnetlink_subsys_unregister(&nfnl_acct_subsys);
352 list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
353 list_del_rcu(&cur->head);
354 /* We are sure that our objects have no clients at this point,
355 * it's safe to release them all without checking refcnt. */
356 kfree_rcu(cur, rcu_head);
360 module_init(nfnl_acct_init);
361 module_exit(nfnl_acct_exit);