3 files changed, 361 insertions, 0 deletions

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index d5597b759ba3..77326acd1f57 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -4,6 +4,14 @@ menu "Core Netfilter Configuration"
 config NETFILTER_NETLINK
         tristate
 
+config NETFILTER_NETLINK_ACCT
+tristate "Netfilter NFACCT over NFNETLINK interface"
+        depends on NETFILTER_ADVANCED
+        select NETFILTER_NETLINK
+        help
+          If this option is enabled, the kernel will include support
+          for extended accounting via NFNETLINK.
+
 config NETFILTER_NETLINK_QUEUE
         tristate "Netfilter NFQUEUE over NFNETLINK interface"
         depends on NETFILTER_ADVANCED
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 1a02853df863..4da1c879644f 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -7,6 +7,7 @@ nf_conntrack-$(CONFIG_NF_CONNTRACK_EVENTS) += nf_conntrack_ecache.o
 obj-$(CONFIG_NETFILTER) = netfilter.o
 
 obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
+obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o
 obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
 obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
 
diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
new file mode 100644
index 000000000000..362ab6ca3dc1
--- /dev/null
+++ b/net/netfilter/nfnetlink_acct.c
@@ -0,0 +1,352 @@
+/*
+ * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
+ * (C) 2011 Intra2net AG <http://www.intra2net.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation (or any later at your option).
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+#include <asm/atomic.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_acct.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
+
+static LIST_HEAD(nfnl_acct_list);
+
+struct nf_acct {
+        atomic64_t              pkts;
+        atomic64_t              bytes;
+        struct list_head        head;
+        atomic_t                refcnt;
+        char                    name[NFACCT_NAME_MAX];
+        struct rcu_head         rcu_head;
+};
+
+static int
+nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
+             const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+        struct nf_acct *nfacct, *matching = NULL;
+        char *acct_name;
+
+        if (!tb[NFACCT_NAME])
+                return -EINVAL;
+
+        acct_name = nla_data(tb[NFACCT_NAME]);
+
+        list_for_each_entry(nfacct, &nfnl_acct_list, head) {
+                if (strncmp(nfacct->name, acct_name, NFACCT_NAME_MAX) != 0)
+                        continue;
+
+                if (nlh->nlmsg_flags & NLM_F_EXCL)
+                        return -EEXIST;
+
+                matching = nfacct;
+                break;
+        }
+
+        if (matching) {
+                if (nlh->nlmsg_flags & NLM_F_REPLACE) {
+                        /* reset counters if you request a replacement. */
+                        atomic64_set(&matching->pkts, 0);
+                        atomic64_set(&matching->bytes, 0);
+                        return 0;
+                }
+                return -EBUSY;
+        }
+
+        nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
+        if (nfacct == NULL)
+                return -ENOMEM;
+
+        strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
+
+        if (tb[NFACCT_BYTES]) {
+                atomic64_set(&nfacct->bytes,
+                             be64_to_cpu(nla_get_u64(tb[NFACCT_BYTES])));
+        }
+        if (tb[NFACCT_PKTS]) {
+                atomic64_set(&nfacct->pkts,
+                             be64_to_cpu(nla_get_u64(tb[NFACCT_PKTS])));
+        }
+        atomic_set(&nfacct->refcnt, 1);
+        list_add_tail_rcu(&nfacct->head, &nfnl_acct_list);
+        return 0;
+}
+
+static int
+nfnl_acct_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type,
+                   int event, struct nf_acct *acct)
+{
+        struct nlmsghdr *nlh;
+        struct nfgenmsg *nfmsg;
+        unsigned int flags = pid ? NLM_F_MULTI : 0;
+        u64 pkts, bytes;
+
+        event |= NFNL_SUBSYS_ACCT << 8;
+        nlh = nlmsg_put(skb, pid, seq, event, sizeof(*nfmsg), flags);
+        if (nlh == NULL)
+                goto nlmsg_failure;
+
+        nfmsg = nlmsg_data(nlh);
+        nfmsg->nfgen_family = AF_UNSPEC;
+        nfmsg->version = NFNETLINK_V0;
+        nfmsg->res_id = 0;
+
+        NLA_PUT_STRING(skb, NFACCT_NAME, acct->name);
+
+        if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
+                pkts = atomic64_xchg(&acct->pkts, 0);
+                bytes = atomic64_xchg(&acct->bytes, 0);
+        } else {
+                pkts = atomic64_read(&acct->pkts);
+                bytes = atomic64_read(&acct->bytes);
+        }
+        NLA_PUT_BE64(skb, NFACCT_PKTS, cpu_to_be64(pkts));
+        NLA_PUT_BE64(skb, NFACCT_BYTES, cpu_to_be64(bytes));
+        NLA_PUT_BE32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt)));
+
+        nlmsg_end(skb, nlh);
+        return skb->len;
+
+nlmsg_failure:
+nla_put_failure:
+        nlmsg_cancel(skb, nlh);
+        return -1;
+}
+
+static int
+nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        struct nf_acct *cur, *last;
+
+        if (cb->args[2])
+                return 0;
+
+        last = (struct nf_acct *)cb->args[1];
+        if (cb->args[1])
+                cb->args[1] = 0;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
+                if (last && cur != last)
+                        continue;
+
+                if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).pid,
+                                       cb->nlh->nlmsg_seq,
+                                       NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
+                                       NFNL_MSG_ACCT_NEW, cur) < 0) {
+                        cb->args[1] = (unsigned long)cur;
+                        break;
+                }
+        }
+        if (!cb->args[1])
+                cb->args[2] = 1;
+        rcu_read_unlock();
+        return skb->len;
+}
+
+static int
+nfnl_acct_get(struct sock *nfnl, struct sk_buff *skb,
+             const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+        int ret = 0;
+        struct nf_acct *cur;
+        char *acct_name;
+
+        if (nlh->nlmsg_flags & NLM_F_DUMP) {
+                return netlink_dump_start(nfnl, skb, nlh, nfnl_acct_dump,
+                                          NULL, 0);
+        }
+
+        if (!tb[NFACCT_NAME])
+                return -EINVAL;
+        acct_name = nla_data(tb[NFACCT_NAME]);
+
+        list_for_each_entry(cur, &nfnl_acct_list, head) {
+                struct sk_buff *skb2;
+
+                if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
+                        continue;
+
+                skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+                if (skb2 == NULL)
+                        break;
+
+                ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).pid,
+                                         nlh->nlmsg_seq,
+                                         NFNL_MSG_TYPE(nlh->nlmsg_type),
+                                         NFNL_MSG_ACCT_NEW, cur);
+                if (ret <= 0)
+                        kfree_skb(skb2);
+
+                break;
+        }
+        return ret;
+}
+
+/* try to delete object, fail if it is still in use. */
+static int nfnl_acct_try_del(struct nf_acct *cur)
+{
+        int ret = 0;
+
+        /* we want to avoid races with nfnl_acct_find_get. */
+        if (atomic_dec_and_test(&cur->refcnt)) {
+                /* We are protected by nfnl mutex. */
+                list_del_rcu(&cur->head);
+                kfree_rcu(cur, rcu_head);
+        } else {
+                /* still in use, restore reference counter. */
+                atomic_inc(&cur->refcnt);
+                ret = -EBUSY;
+        }
+        return ret;
+}
+
+static int
+nfnl_acct_del(struct sock *nfnl, struct sk_buff *skb,
+             const struct nlmsghdr *nlh, const struct nlattr * const tb[])
+{
+        char *acct_name;
+        struct nf_acct *cur;
+        int ret = -ENOENT;
+
+        if (!tb[NFACCT_NAME]) {
+                list_for_each_entry(cur, &nfnl_acct_list, head)
+                        nfnl_acct_try_del(cur);
+
+                return 0;
+        }
+        acct_name = nla_data(tb[NFACCT_NAME]);
+
+        list_for_each_entry(cur, &nfnl_acct_list, head) {
+                if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX) != 0)
+                        continue;
+
+                ret = nfnl_acct_try_del(cur);
+                if (ret < 0)
+                        return ret;
+
+                break;
+        }
+        return ret;
+}
+
+static const struct nla_policy nfnl_acct_policy[NFACCT_MAX+1] = {
+        [NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
+        [NFACCT_BYTES] = { .type = NLA_U64 },
+        [NFACCT_PKTS] = { .type = NLA_U64 },
+};
+
+static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
+        [NFNL_MSG_ACCT_NEW]             = { .call = nfnl_acct_new,
+                                            .attr_count = NFACCT_MAX,
+                                            .policy = nfnl_acct_policy },
+        [NFNL_MSG_ACCT_GET]             = { .call = nfnl_acct_get,
+                                            .attr_count = NFACCT_MAX,
+                                            .policy = nfnl_acct_policy },
+        [NFNL_MSG_ACCT_GET_CTRZERO]     = { .call = nfnl_acct_get,
+                                            .attr_count = NFACCT_MAX,
+                                            .policy = nfnl_acct_policy },
+        [NFNL_MSG_ACCT_DEL]             = { .call = nfnl_acct_del,
+                                            .attr_count = NFACCT_MAX,
+                                            .policy = nfnl_acct_policy },
+};
+
+static const struct nfnetlink_subsystem nfnl_acct_subsys = {
+        .name                           = "acct",
+        .subsys_id                      = NFNL_SUBSYS_ACCT,
+        .cb_count                       = NFNL_MSG_ACCT_MAX,
+        .cb                             = nfnl_acct_cb,
+};
+
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ACCT);
+
+struct nf_acct *nfnl_acct_find_get(const char *acct_name)
+{
+        struct nf_acct *cur, *acct = NULL;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(cur, &nfnl_acct_list, head) {
+                if (strncmp(cur->name, acct_name, NFACCT_NAME_MAX)!= 0)
+                        continue;
+
+                if (!try_module_get(THIS_MODULE))
+                        goto err;
+
+                if (!atomic_inc_not_zero(&cur->refcnt)) {
+                        module_put(THIS_MODULE);
+                        goto err;
+                }
+
+                acct = cur;
+                break;
+        }
+err:
+        rcu_read_unlock();
+        return acct;
+}
+EXPORT_SYMBOL_GPL(nfnl_acct_find_get);
+
+void nfnl_acct_put(struct nf_acct *acct)
+{
+        atomic_dec(&acct->refcnt);
+        module_put(THIS_MODULE);
+}
+EXPORT_SYMBOL_GPL(nfnl_acct_put);
+
+void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
+{
+        atomic64_inc(&nfacct->pkts);
+        atomic64_add(skb->len, &nfacct->bytes);
+}
+EXPORT_SYMBOL_GPL(nfnl_acct_update);
+
+static int __init nfnl_acct_init(void)
+{
+        int ret;
+
+        pr_info("nfnl_acct: registering with nfnetlink.\n");
+        ret = nfnetlink_subsys_register(&nfnl_acct_subsys);
+        if (ret < 0) {
+                pr_err("nfnl_acct_init: cannot register with nfnetlink.\n");
+                goto err_out;
+        }
+        return 0;
+err_out:
+        return ret;
+}
+
+static void __exit nfnl_acct_exit(void)
+{
+        struct nf_acct *cur, *tmp;
+
+        pr_info("nfnl_acct: unregistering from nfnetlink.\n");
+        nfnetlink_subsys_unregister(&nfnl_acct_subsys);
+
+        list_for_each_entry_safe(cur, tmp, &nfnl_acct_list, head) {
+                list_del_rcu(&cur->head);
+                /* We are sure that our objects have no clients at this point,
+                 * it's safe to release them all without checking refcnt. */
+                kfree_rcu(cur, rcu_head);
+        }
+}
+
+module_init(nfnl_acct_init);
+module_exit(nfnl_acct_exit);