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);
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]);
52 if (strlen(acct_name) == 0)
55 list_for_each_entry(nfacct, &nfnl_acct_list, head) {
56 if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
59 if (nlh->nlmsg_flags & NLM_F_EXCL)
67 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
68 /* reset counters if you request a replacement. */
69 atomic64_set(&matching->pkts, 0);
70 atomic64_set(&matching->bytes, 0);
76 nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
80 strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
82 if (tb[NFACCT_BYTES]) {
83 atomic64_set(&nfacct->bytes,
84 be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
86 if (tb[NFACCT_PKTS]) {
87 atomic64_set(&nfacct->pkts,
88 be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
90 atomic_set(&nfacct->refcnt, 1);
91 list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
96 nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
97 int event, struct nf_acct *acct)
100 struct nfgenmsg *nfmsg;
101 unsigned int flags = portid ? NLM_F_MULTI : 0;
104 event |= NFNL_SUBSYS_ACCT << 8;
105 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
109 nfmsg = nlmsg_data(nlh);
110 nfmsg->nfgen_family = AF_UNSPEC;
111 nfmsg->version = NFNETLINK_V0;
114 if (nla_put_string(skb, NFACCT_NAME, acct->name))
115 goto nla_put_failure;
117 if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
118 pkts = atomic64_xchg(&acct->pkts, 0);
119 bytes = atomic64_xchg(&acct->bytes, 0);
121 pkts = atomic64_read(&acct->pkts);
122 bytes = atomic64_read(&acct->bytes);
124 if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts)) ||
125 nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) ||
126 nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
127 goto nla_put_failure;
134 nlmsg_cancel(skb, nlh);
139 nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
141 struct nf_acct *cur, *last;
146 last = (struct nf_acct *)cb->args[1];
151 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
158 if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
160 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
161 NFNL_MSG_ACCT_NEW, cur) < 0) {
162 cb->args[1] = (unsigned long)cur;
173 nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
174 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
180 if (nlh->nlmsg_flags & NLM_F_DUMP) {
181 struct netlink_dump_control c = {
182 .dump = nfnl_acct_dump,
184 return netlink_dump_start(nfnl, skb, nlh, &c);
187 if (!tb[NFACCT_NAME])
189 acct_name = nla_data(tb[NFACCT_NAME]);
191 list_for_each_entry(cur, &nfnl_acct_list, head) {
192 struct sk_buff *skb2;
194 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
197 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
203 ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
205 NFNL_MSG_TYPE(nlh->nlmsg_type),
206 NFNL_MSG_ACCT_NEW, cur);
211 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
216 /* this avoids a loop in nfnetlink. */
217 return ret == -EAGAIN ? -ENOBUFS : ret;
222 /* try to delete object, fail if it is still in use. */
223 static int nfnl_acct_try_del(struct nf_acct *cur)
227 /* we want to avoid races with nfnl_acct_find_get. */
228 if (atomic_dec_and_test(&cur->refcnt)) {
229 /* We are protected by nfnl mutex. */
230 list_del_rcu(&cur->head);
231 kfree_rcu(cur, rcu_head);
233 /* still in use, restore reference counter. */
234 atomic_inc(&cur->refcnt);
241 nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
242 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
248 if (!tb[NFACCT_NAME]) {
249 list_for_each_entry(cur, &nfnl_acct_list, head)
250 nfnl_acct_try_del(cur);
254 acct_name = nla_data(tb[NFACCT_NAME]);
256 list_for_each_entry(cur, &nfnl_acct_list, head) {
257 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
260 ret = nfnl_acct_try_del(cur);
269 static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
270 [NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
271 [NFACCT_BYTES] = { .type = NLA_U64 },
272 [NFACCT_PKTS] = { .type = NLA_U64 },
275 static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
276 [NFNL_MSG_ACCT_NEW] = { .call = nfnl_acct_new,
277 .attr_count = NFACCT_MAX,
278 .policy = nfnl_acct_policy },
279 [NFNL_MSG_ACCT_GET] = { .call = nfnl_acct_get,
280 .attr_count = NFACCT_MAX,
281 .policy = nfnl_acct_policy },
282 [NFNL_MSG_ACCT_GET_CTRZERO] = { .call = nfnl_acct_get,
283 .attr_count = NFACCT_MAX,
284 .policy = nfnl_acct_policy },
285 [NFNL_MSG_ACCT_DEL] = { .call = nfnl_acct_del,
286 .attr_count = NFACCT_MAX,
287 .policy = nfnl_acct_policy },
290 static const struct nfnetlink_subsystem nfnl_acct_subsys = {
292 .subsys_id = NFNL_SUBSYS_ACCT,
293 .cb_count = NFNL_MSG_ACCT_MAX,
297 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
299 struct nf_acct *nfnl_acct_find_get(const char *acct_name)
301 struct nf_acct *cur, *acct = NULL;
304 list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
305 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
308 if (!try_module_get(THIS_MODULE))
311 if (!atomic_inc_not_zero(&cur->refcnt)) {
312 module_put(THIS_MODULE);
323 EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
325 void nfnl_acct_put(struct nf_acct *acct)
327 atomic_dec(&acct->refcnt);
328 module_put(THIS_MODULE);
330 EXPORT_SYMBOL_GPL(nfnl_acct_put);
332 void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
334 atomic64_inc(&nfacct->pkts);
335 atomic64_add(skb->len, &nfacct->bytes);
337 EXPORT_SYMBOL_GPL(nfnl_acct_update);
339 static int __init nfnl_acct_init(void)
343 pr_info("nfnl_acct: registering with nfnetlink.\n");
344 ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
346 pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
354 static void __exit nfnl_acct_exit(void)
356 struct nf_acct *cur, *tmp;
358 pr_info("nfnl_acct: unregistering from nfnetlink.\n");
359 nfnetlink_subsys_unregister(&nfnl_acct_subsys);
361 list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
362 list_del_rcu(&cur->head);
363 /* We are sure that our objects have no clients at this point,
364 * it's safe to release them all without checking refcnt. */
365 kfree_rcu(cur, rcu_head);
369 module_init(nfnl_acct_init);
370 module_exit(nfnl_acct_exit);