~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/netfilter/nfnetlink_acct.c

Version: ~ [ linux-5.4 ] ~ [ linux-5.3.13 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.86 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.156 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.203 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.202 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
  3  * (C) 2011 Intra2net AG <http://www.intra2net.com>
  4  *
  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).
  8  */
  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>
 20 #include <net/sock.h>
 21 
 22 #include <linux/netfilter.h>
 23 #include <linux/netfilter/nfnetlink.h>
 24 #include <linux/netfilter/nfnetlink_acct.h>
 25 
 26 MODULE_LICENSE("GPL");
 27 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
 28 MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
 29 
 30 static LIST_HEAD(nfnl_acct_list);
 31 
 32 struct nf_acct {
 33         atomic64_t              pkts;
 34         atomic64_t              bytes;
 35         struct list_head        head;
 36         atomic_t                refcnt;
 37         char                    name[NFACCT_NAME_MAX];
 38         struct rcu_head         rcu_head;
 39 };
 40 
 41 static int
 42 nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
 43              const struct nlmsghdr *nlh, const struct nlattr * const tb[])
 44 {
 45         struct nf_acct *nfacct, *matching = NULL;
 46         char *acct_name;
 47 
 48         if (!tb[NFACCT_NAME])
 49                 return -EINVAL;
 50 
 51         acct_name = nla_data(tb[NFACCT_NAME]);
 52         if (strlen(acct_name) == 0)
 53                 return -EINVAL;
 54 
 55         list_for_each_entry(nfacct, &nfnl_acct_list, head) {
 56                 if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
 57                         continue;
 58 
 59                 if (nlh->nlmsg_flags & NLM_F_EXCL)
 60                         return -EEXIST;
 61 
 62                 matching = nfacct;
 63                 break;
 64         }
 65 
 66         if (matching) {
 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);
 71                         return 0;
 72                 }
 73                 return -EBUSY;
 74         }
 75 
 76         nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
 77         if (nfacct == NULL)
 78                 return -ENOMEM;
 79 
 80         strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
 81 
 82         if (tb[NFACCT_BYTES]) {
 83                 atomic64_set(&nfacct->bytes,
 84                              be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES])));
 85         }
 86         if (tb[NFACCT_PKTS]) {
 87                 atomic64_set(&nfacct->pkts,
 88                              be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS])));
 89         }
 90         atomic_set(&nfacct->refcnt, 1);
 91         list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
 92         return 0;
 93 }
 94 
 95 static int
 96 nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 97                    int event, struct nf_acct *acct)
 98 {
 99         struct nlmsghdr *nlh;
100         struct nfgenmsg *nfmsg;
101         unsigned int flags = portid ? NLM_F_MULTI : 0;
102         u64 pkts, bytes;
103 
104         event |= NFNL_SUBSYS_ACCT << 8;
105         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
106         if (nlh == NULL)
107                 goto nlmsg_failure;
108 
109         nfmsg = nlmsg_data(nlh);
110         nfmsg->nfgen_family = AF_UNSPEC;
111         nfmsg->version = NFNETLINK_V0;
112         nfmsg->res_id = 0;
113 
114         if (nla_put_string(skb, NFACCT_NAME, acct->name))
115                 goto nla_put_failure;
116 
117         if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
118                 pkts = atomic64_xchg(&acct->pkts, 0);
119                 bytes = atomic64_xchg(&acct->bytes, 0);
120         } else {
121                 pkts = atomic64_read(&acct->pkts);
122                 bytes = atomic64_read(&acct->bytes);
123         }
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;
128 
129         nlmsg_end(skb, nlh);
130         return skb->len;
131 
132 nlmsg_failure:
133 nla_put_failure:
134         nlmsg_cancel(skb, nlh);
135         return -1;
136 }
137 
138 static int
139 nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
140 {
141         struct nf_acct *cur, *last;
142 
143         if (cb->args[2])
144                 return 0;
145 
146         last = (struct nf_acct *)cb->args[1];
147         if (cb->args[1])
148                 cb->args[1] = 0;
149 
150         rcu_read_lock();
151         list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
152                 if (last) {
153                         if (cur != last)
154                                 continue;
155 
156                         last = NULL;
157                 }
158                 if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid,
159                                        cb->nlh->nlmsg_seq,
160                                        NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
161                                        NFNL_MSG_ACCT_NEW, cur) < 0) {
162                         cb->args[1] = (unsigned long)cur;
163                         break;
164                 }
165         }
166         if (!cb->args[1])
167                 cb->args[2] = 1;
168         rcu_read_unlock();
169         return skb->len;
170 }
171 
172 static int
173 nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
174              const struct nlmsghdr *nlh, const struct nlattr * const tb[])
175 {
176         int ret = -ENOENT;
177         struct nf_acct *cur;
178         char *acct_name;
179 
180         if (nlh->nlmsg_flags & NLM_F_DUMP) {
181                 struct netlink_dump_control c = {
182                         .dump = nfnl_acct_dump,
183                 };
184                 return netlink_dump_start(nfnl, skb, nlh, &c);
185         }
186 
187         if (!tb[NFACCT_NAME])
188                 return -EINVAL;
189         acct_name = nla_data(tb[NFACCT_NAME]);
190 
191         list_for_each_entry(cur, &nfnl_acct_list, head) {
192                 struct sk_buff *skb2;
193 
194                 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
195                         continue;
196 
197                 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
198                 if (skb2 == NULL) {
199                         ret = -ENOMEM;
200                         break;
201                 }
202 
203                 ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid,
204                                          nlh->nlmsg_seq,
205                                          NFNL_MSG_TYPE(nlh->nlmsg_type),
206                                          NFNL_MSG_ACCT_NEW, cur);
207                 if (ret <= 0) {
208                         kfree_skb(skb2);
209                         break;
210                 }
211                 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
212                                         MSG_DONTWAIT);
213                 if (ret > 0)
214                         ret = 0;
215 
216                 /* this avoids a loop in nfnetlink. */
217                 return ret == -EAGAIN ? -ENOBUFS : ret;
218         }
219         return ret;
220 }
221 
222 /* try to delete object, fail if it is still in use. */
223 static int nfnl_acct_try_del(struct nf_acct *cur)
224 {
225         int ret = 0;
226 
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);
232         } else {
233                 /* still in use, restore reference counter. */
234                 atomic_inc(&cur->refcnt);
235                 ret = -EBUSY;
236         }
237         return ret;
238 }
239 
240 static int
241 nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
242              const struct nlmsghdr *nlh, const struct nlattr * const tb[])
243 {
244         char *acct_name;
245         struct nf_acct *cur;
246         int ret = -ENOENT;
247 
248         if (!tb[NFACCT_NAME]) {
249                 list_for_each_entry(cur, &nfnl_acct_list, head)
250                         nfnl_acct_try_del(cur);
251 
252                 return 0;
253         }
254         acct_name = nla_data(tb[NFACCT_NAME]);
255 
256         list_for_each_entry(cur, &nfnl_acct_list, head) {
257                 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
258                         continue;
259 
260                 ret = nfnl_acct_try_del(cur);
261                 if (ret < 0)
262                         return ret;
263 
264                 break;
265         }
266         return ret;
267 }
268 
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 },
273 };
274 
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 },
288 };
289 
290 static const struct nfnetlink_subsystem nfnl_acct_subsys = {
291         .name                           = "acct",
292         .subsys_id                      = NFNL_SUBSYS_ACCT,
293         .cb_count                       = NFNL_MSG_ACCT_MAX,
294         .cb                             = nfnl_acct_cb,
295 };
296 
297 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
298 
299 struct nf_acct *nfnl_acct_find_get(const char *acct_name)
300 {
301         struct nf_acct *cur, *acct = NULL;
302 
303         rcu_read_lock();
304         list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
305                 if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
306                         continue;
307 
308                 if (!try_module_get(THIS_MODULE))
309                         goto err;
310 
311                 if (!atomic_inc_not_zero(&cur->refcnt)) {
312                         module_put(THIS_MODULE);
313                         goto err;
314                 }
315 
316                 acct = cur;
317                 break;
318         }
319 err:
320         rcu_read_unlock();
321         return acct;
322 }
323 EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
324 
325 void nfnl_acct_put(struct nf_acct *acct)
326 {
327         atomic_dec(&acct->refcnt);
328         module_put(THIS_MODULE);
329 }
330 EXPORT_SYMBOL_GPL(nfnl_acct_put);
331 
332 void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
333 {
334         atomic64_inc(&nfacct->pkts);
335         atomic64_add(skb->len, &nfacct->bytes);
336 }
337 EXPORT_SYMBOL_GPL(nfnl_acct_update);
338 
339 static int __init nfnl_acct_init(void)
340 {
341         int ret;
342 
343         pr_info("nfnl_acct: registering with nfnetlink.\n");
344         ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
345         if (ret < 0) {
346                 pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
347                 goto err_out;
348         }
349         return 0;
350 err_out:
351         return ret;
352 }
353 
354 static void __exit nfnl_acct_exit(void)
355 {
356         struct nf_acct *cur, *tmp;
357 
358         pr_info("nfnl_acct: unregistering from nfnetlink.\n");
359         nfnetlink_subsys_unregister(&nfnl_acct_subsys);
360 
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);
366         }
367 }
368 
369 module_init(nfnl_acct_init);
370 module_exit(nfnl_acct_exit);
371 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp