| /* |
| * (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/atomic.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 <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"); |
| |
| struct nf_acct { |
| atomic64_t pkts; |
| atomic64_t bytes; |
| unsigned long flags; |
| struct list_head head; |
| atomic_t refcnt; |
| char name[NFACCT_NAME_MAX]; |
| struct rcu_head rcu_head; |
| char data[0]; |
| }; |
| |
| struct nfacct_filter { |
| u32 value; |
| u32 mask; |
| }; |
| |
| #define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS | NFACCT_F_QUOTA_BYTES) |
| #define NFACCT_OVERQUOTA_BIT 2 /* NFACCT_F_OVERQUOTA */ |
| |
| static int nfnl_acct_new(struct net *net, 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; |
| unsigned int size = 0; |
| u32 flags = 0; |
| |
| if (!tb[NFACCT_NAME]) |
| return -EINVAL; |
| |
| acct_name = nla_data(tb[NFACCT_NAME]); |
| if (strlen(acct_name) == 0) |
| return -EINVAL; |
| |
| list_for_each_entry(nfacct, &net->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); |
| smp_mb__before_atomic(); |
| /* reset overquota flag if quota is enabled. */ |
| if ((matching->flags & NFACCT_F_QUOTA)) |
| clear_bit(NFACCT_OVERQUOTA_BIT, |
| &matching->flags); |
| return 0; |
| } |
| return -EBUSY; |
| } |
| |
| if (tb[NFACCT_FLAGS]) { |
| flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS])); |
| if (flags & ~NFACCT_F_QUOTA) |
| return -EOPNOTSUPP; |
| if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA) |
| return -EINVAL; |
| if (flags & NFACCT_F_OVERQUOTA) |
| return -EINVAL; |
| if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA]) |
| return -EINVAL; |
| |
| size += sizeof(u64); |
| } |
| |
| nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL); |
| if (nfacct == NULL) |
| return -ENOMEM; |
| |
| if (flags & NFACCT_F_QUOTA) { |
| u64 *quota = (u64 *)nfacct->data; |
| |
| *quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA])); |
| nfacct->flags = flags; |
| } |
| |
| strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX); |
| |
| if (tb[NFACCT_BYTES]) { |
| atomic64_set(&nfacct->bytes, |
| be64_to_cpu(nla_get_be64(tb[NFACCT_BYTES]))); |
| } |
| if (tb[NFACCT_PKTS]) { |
| atomic64_set(&nfacct->pkts, |
| be64_to_cpu(nla_get_be64(tb[NFACCT_PKTS]))); |
| } |
| atomic_set(&nfacct->refcnt, 1); |
| list_add_tail_rcu(&nfacct->head, &net->nfnl_acct_list); |
| return 0; |
| } |
| |
| static int |
| nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
| int event, struct nf_acct *acct) |
| { |
| struct nlmsghdr *nlh; |
| struct nfgenmsg *nfmsg; |
| unsigned int flags = portid ? NLM_F_MULTI : 0; |
| u64 pkts, bytes; |
| u32 old_flags; |
| |
| event |= NFNL_SUBSYS_ACCT << 8; |
| nlh = nlmsg_put(skb, portid, 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; |
| |
| if (nla_put_string(skb, NFACCT_NAME, acct->name)) |
| goto nla_put_failure; |
| |
| old_flags = acct->flags; |
| if (type == NFNL_MSG_ACCT_GET_CTRZERO) { |
| pkts = atomic64_xchg(&acct->pkts, 0); |
| bytes = atomic64_xchg(&acct->bytes, 0); |
| smp_mb__before_atomic(); |
| if (acct->flags & NFACCT_F_QUOTA) |
| clear_bit(NFACCT_OVERQUOTA_BIT, &acct->flags); |
| } else { |
| pkts = atomic64_read(&acct->pkts); |
| bytes = atomic64_read(&acct->bytes); |
| } |
| if (nla_put_be64(skb, NFACCT_PKTS, cpu_to_be64(pkts), |
| NFACCT_PAD) || |
| nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes), |
| NFACCT_PAD) || |
| nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt)))) |
| goto nla_put_failure; |
| if (acct->flags & NFACCT_F_QUOTA) { |
| u64 *quota = (u64 *)acct->data; |
| |
| if (nla_put_be32(skb, NFACCT_FLAGS, htonl(old_flags)) || |
| nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota), |
| NFACCT_PAD)) |
| goto nla_put_failure; |
| } |
| 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 net *net = sock_net(skb->sk); |
| struct nf_acct *cur, *last; |
| const struct nfacct_filter *filter = cb->data; |
| |
| 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, &net->nfnl_acct_list, head) { |
| if (last) { |
| if (cur != last) |
| continue; |
| |
| last = NULL; |
| } |
| |
| if (filter && (cur->flags & filter->mask) != filter->value) |
| continue; |
| |
| if (nfnl_acct_fill_info(skb, NETLINK_CB(cb->skb).portid, |
| 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_done(struct netlink_callback *cb) |
| { |
| kfree(cb->data); |
| return 0; |
| } |
| |
| static const struct nla_policy filter_policy[NFACCT_FILTER_MAX + 1] = { |
| [NFACCT_FILTER_MASK] = { .type = NLA_U32 }, |
| [NFACCT_FILTER_VALUE] = { .type = NLA_U32 }, |
| }; |
| |
| static struct nfacct_filter * |
| nfacct_filter_alloc(const struct nlattr * const attr) |
| { |
| struct nfacct_filter *filter; |
| struct nlattr *tb[NFACCT_FILTER_MAX + 1]; |
| int err; |
| |
| err = nla_parse_nested(tb, NFACCT_FILTER_MAX, attr, filter_policy); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| if (!tb[NFACCT_FILTER_MASK] || !tb[NFACCT_FILTER_VALUE]) |
| return ERR_PTR(-EINVAL); |
| |
| filter = kzalloc(sizeof(struct nfacct_filter), GFP_KERNEL); |
| if (!filter) |
| return ERR_PTR(-ENOMEM); |
| |
| filter->mask = ntohl(nla_get_be32(tb[NFACCT_FILTER_MASK])); |
| filter->value = ntohl(nla_get_be32(tb[NFACCT_FILTER_VALUE])); |
| |
| return filter; |
| } |
| |
| static int nfnl_acct_get(struct net *net, struct sock *nfnl, |
| struct sk_buff *skb, const struct nlmsghdr *nlh, |
| const struct nlattr * const tb[]) |
| { |
| int ret = -ENOENT; |
| struct nf_acct *cur; |
| char *acct_name; |
| |
| if (nlh->nlmsg_flags & NLM_F_DUMP) { |
| struct netlink_dump_control c = { |
| .dump = nfnl_acct_dump, |
| .done = nfnl_acct_done, |
| }; |
| |
| if (tb[NFACCT_FILTER]) { |
| struct nfacct_filter *filter; |
| |
| filter = nfacct_filter_alloc(tb[NFACCT_FILTER]); |
| if (IS_ERR(filter)) |
| return PTR_ERR(filter); |
| |
| c.data = filter; |
| } |
| return netlink_dump_start(nfnl, skb, nlh, &c); |
| } |
| |
| if (!tb[NFACCT_NAME]) |
| return -EINVAL; |
| acct_name = nla_data(tb[NFACCT_NAME]); |
| |
| list_for_each_entry(cur, &net->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) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| ret = nfnl_acct_fill_info(skb2, NETLINK_CB(skb).portid, |
| nlh->nlmsg_seq, |
| NFNL_MSG_TYPE(nlh->nlmsg_type), |
| NFNL_MSG_ACCT_NEW, cur); |
| if (ret <= 0) { |
| kfree_skb(skb2); |
| break; |
| } |
| ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, |
| MSG_DONTWAIT); |
| if (ret > 0) |
| ret = 0; |
| |
| /* this avoids a loop in nfnetlink. */ |
| return ret == -EAGAIN ? -ENOBUFS : ret; |
| } |
| 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_put. So only when the current |
| * refcnt is 1, we decrease it to 0. |
| */ |
| if (atomic_cmpxchg(&cur->refcnt, 1, 0) == 1) { |
| /* We are protected by nfnl mutex. */ |
| list_del_rcu(&cur->head); |
| kfree_rcu(cur, rcu_head); |
| } else { |
| ret = -EBUSY; |
| } |
| return ret; |
| } |
| |
| static int nfnl_acct_del(struct net *net, struct sock *nfnl, |
| struct sk_buff *skb, const struct nlmsghdr *nlh, |
| const struct nlattr * const tb[]) |
| { |
| struct nf_acct *cur, *tmp; |
| int ret = -ENOENT; |
| char *acct_name; |
| |
| if (!tb[NFACCT_NAME]) { |
| list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head) |
| nfnl_acct_try_del(cur); |
| |
| return 0; |
| } |
| acct_name = nla_data(tb[NFACCT_NAME]); |
| |
| list_for_each_entry(cur, &net->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 }, |
| [NFACCT_FLAGS] = { .type = NLA_U32 }, |
| [NFACCT_QUOTA] = { .type = NLA_U64 }, |
| [NFACCT_FILTER] = {.type = NLA_NESTED }, |
| }; |
| |
| 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(struct net *net, const char *acct_name) |
| { |
| struct nf_acct *cur, *acct = NULL; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(cur, &net->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) |
| { |
| if (atomic_dec_and_test(&acct->refcnt)) |
| kfree_rcu(acct, rcu_head); |
| |
| 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 void nfnl_overquota_report(struct net *net, struct nf_acct *nfacct) |
| { |
| int ret; |
| struct sk_buff *skb; |
| |
| skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); |
| if (skb == NULL) |
| return; |
| |
| ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0, |
| nfacct); |
| if (ret <= 0) { |
| kfree_skb(skb); |
| return; |
| } |
| netlink_broadcast(net->nfnl, skb, 0, NFNLGRP_ACCT_QUOTA, |
| GFP_ATOMIC); |
| } |
| |
| int nfnl_acct_overquota(struct net *net, const struct sk_buff *skb, |
| struct nf_acct *nfacct) |
| { |
| u64 now; |
| u64 *quota; |
| int ret = NFACCT_UNDERQUOTA; |
| |
| /* no place here if we don't have a quota */ |
| if (!(nfacct->flags & NFACCT_F_QUOTA)) |
| return NFACCT_NO_QUOTA; |
| |
| quota = (u64 *)nfacct->data; |
| now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ? |
| atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes); |
| |
| ret = now > *quota; |
| |
| if (now >= *quota && |
| !test_and_set_bit(NFACCT_OVERQUOTA_BIT, &nfacct->flags)) { |
| nfnl_overquota_report(net, nfacct); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(nfnl_acct_overquota); |
| |
| static int __net_init nfnl_acct_net_init(struct net *net) |
| { |
| INIT_LIST_HEAD(&net->nfnl_acct_list); |
| |
| return 0; |
| } |
| |
| static void __net_exit nfnl_acct_net_exit(struct net *net) |
| { |
| struct nf_acct *cur, *tmp; |
| |
| list_for_each_entry_safe(cur, tmp, &net->nfnl_acct_list, head) { |
| list_del_rcu(&cur->head); |
| |
| if (atomic_dec_and_test(&cur->refcnt)) |
| kfree_rcu(cur, rcu_head); |
| } |
| } |
| |
| static struct pernet_operations nfnl_acct_ops = { |
| .init = nfnl_acct_net_init, |
| .exit = nfnl_acct_net_exit, |
| }; |
| |
| static int __init nfnl_acct_init(void) |
| { |
| int ret; |
| |
| ret = register_pernet_subsys(&nfnl_acct_ops); |
| if (ret < 0) { |
| pr_err("nfnl_acct_init: failed to register pernet ops\n"); |
| goto err_out; |
| } |
| |
| 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 cleanup_pernet; |
| } |
| return 0; |
| |
| cleanup_pernet: |
| unregister_pernet_subsys(&nfnl_acct_ops); |
| err_out: |
| return ret; |
| } |
| |
| static void __exit nfnl_acct_exit(void) |
| { |
| pr_info("nfnl_acct: unregistering from nfnetlink.\n"); |
| nfnetlink_subsys_unregister(&nfnl_acct_subsys); |
| unregister_pernet_subsys(&nfnl_acct_ops); |
| } |
| |
| module_init(nfnl_acct_init); |
| module_exit(nfnl_acct_exit); |