diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:18:27 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:19:04 +0200 |
commit | 6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch) | |
tree | 021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /net/netfilter/nfnetlink_cttimeout.c | |
parent | 682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff) | |
parent | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff) |
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/netfilter/nfnetlink_cttimeout.c')
-rw-r--r-- | net/netfilter/nfnetlink_cttimeout.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c new file mode 100644 index 00000000000..2b9e79f5ef0 --- /dev/null +++ b/net/netfilter/nfnetlink_cttimeout.c @@ -0,0 +1,430 @@ +/* + * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org> + * (C) 2012 by Vyatta Inc. <http://www.vyatta.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/rculist.h> +#include <linux/rculist_nulls.h> +#include <linux/types.h> +#include <linux/timer.h> +#include <linux/security.h> +#include <linux/skbuff.h> +#include <linux/errno.h> +#include <linux/netlink.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/slab.h> + +#include <linux/netfilter.h> +#include <net/netlink.h> +#include <net/sock.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_core.h> +#include <net/netfilter/nf_conntrack_l3proto.h> +#include <net/netfilter/nf_conntrack_l4proto.h> +#include <net/netfilter/nf_conntrack_tuple.h> +#include <net/netfilter/nf_conntrack_timeout.h> + +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nfnetlink_cttimeout.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning"); + +static LIST_HEAD(cttimeout_list); + +static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = { + [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING }, + [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 }, + [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 }, + [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED }, +}; + +static int +ctnl_timeout_parse_policy(struct ctnl_timeout *timeout, + struct nf_conntrack_l4proto *l4proto, + const struct nlattr *attr) +{ + int ret = 0; + + if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) { + struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1]; + + nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, + attr, l4proto->ctnl_timeout.nla_policy); + + ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, &timeout->data); + } + return ret; +} + +static int +cttimeout_new_timeout(struct sock *ctnl, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const cda[]) +{ + __u16 l3num; + __u8 l4num; + struct nf_conntrack_l4proto *l4proto; + struct ctnl_timeout *timeout, *matching = NULL; + char *name; + int ret; + + if (!cda[CTA_TIMEOUT_NAME] || + !cda[CTA_TIMEOUT_L3PROTO] || + !cda[CTA_TIMEOUT_L4PROTO] || + !cda[CTA_TIMEOUT_DATA]) + return -EINVAL; + + name = nla_data(cda[CTA_TIMEOUT_NAME]); + l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO])); + l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]); + + list_for_each_entry(timeout, &cttimeout_list, head) { + if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) + continue; + + if (nlh->nlmsg_flags & NLM_F_EXCL) + return -EEXIST; + + matching = timeout; + break; + } + + l4proto = nf_ct_l4proto_find_get(l3num, l4num); + + /* This protocol is not supportted, skip. */ + if (l4proto->l4proto != l4num) { + ret = -EOPNOTSUPP; + goto err_proto_put; + } + + if (matching) { + if (nlh->nlmsg_flags & NLM_F_REPLACE) { + /* You cannot replace one timeout policy by another of + * different kind, sorry. + */ + if (matching->l3num != l3num || + matching->l4proto->l4proto != l4num) { + ret = -EINVAL; + goto err_proto_put; + } + + ret = ctnl_timeout_parse_policy(matching, l4proto, + cda[CTA_TIMEOUT_DATA]); + return ret; + } + ret = -EBUSY; + goto err_proto_put; + } + + timeout = kzalloc(sizeof(struct ctnl_timeout) + + l4proto->ctnl_timeout.obj_size, GFP_KERNEL); + if (timeout == NULL) { + ret = -ENOMEM; + goto err_proto_put; + } + + ret = ctnl_timeout_parse_policy(timeout, l4proto, + cda[CTA_TIMEOUT_DATA]); + if (ret < 0) + goto err; + + strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME])); + timeout->l3num = l3num; + timeout->l4proto = l4proto; + atomic_set(&timeout->refcnt, 1); + list_add_tail_rcu(&timeout->head, &cttimeout_list); + + return 0; +err: + kfree(timeout); +err_proto_put: + nf_ct_l4proto_put(l4proto); + return ret; +} + +static int +ctnl_timeout_fill_info(struct sk_buff *skb, u32 pid, u32 seq, u32 type, + int event, struct ctnl_timeout *timeout) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfmsg; + unsigned int flags = pid ? NLM_F_MULTI : 0; + struct nf_conntrack_l4proto *l4proto = timeout->l4proto; + + event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 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, CTA_TIMEOUT_NAME, timeout->name); + NLA_PUT_BE16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)); + NLA_PUT_U8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto); + NLA_PUT_BE32(skb, CTA_TIMEOUT_USE, + htonl(atomic_read(&timeout->refcnt))); + + if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) { + struct nlattr *nest_parms; + int ret; + + nest_parms = nla_nest_start(skb, + CTA_TIMEOUT_DATA | NLA_F_NESTED); + if (!nest_parms) + goto nla_put_failure; + + ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data); + if (ret < 0) + goto nla_put_failure; + + nla_nest_end(skb, nest_parms); + } + + nlmsg_end(skb, nlh); + return skb->len; + +nlmsg_failure: +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -1; +} + +static int +ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct ctnl_timeout *cur, *last; + + if (cb->args[2]) + return 0; + + last = (struct ctnl_timeout *)cb->args[1]; + if (cb->args[1]) + cb->args[1] = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(cur, &cttimeout_list, head) { + if (last && cur != last) + continue; + + if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, + NFNL_MSG_TYPE(cb->nlh->nlmsg_type), + IPCTNL_MSG_TIMEOUT_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 +cttimeout_get_timeout(struct sock *ctnl, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const cda[]) +{ + int ret = -ENOENT; + char *name; + struct ctnl_timeout *cur; + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + struct netlink_dump_control c = { + .dump = ctnl_timeout_dump, + }; + return netlink_dump_start(ctnl, skb, nlh, &c); + } + + if (!cda[CTA_TIMEOUT_NAME]) + return -EINVAL; + name = nla_data(cda[CTA_TIMEOUT_NAME]); + + list_for_each_entry(cur, &cttimeout_list, head) { + struct sk_buff *skb2; + + if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) + continue; + + skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (skb2 == NULL) { + ret = -ENOMEM; + break; + } + + ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).pid, + nlh->nlmsg_seq, + NFNL_MSG_TYPE(nlh->nlmsg_type), + IPCTNL_MSG_TIMEOUT_NEW, cur); + if (ret <= 0) { + kfree_skb(skb2); + break; + } + ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, + 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 ctnl_timeout_try_del(struct ctnl_timeout *timeout) +{ + int ret = 0; + + /* we want to avoid races with nf_ct_timeout_find_get. */ + if (atomic_dec_and_test(&timeout->refcnt)) { + /* We are protected by nfnl mutex. */ + list_del_rcu(&timeout->head); + nf_ct_l4proto_put(timeout->l4proto); + kfree_rcu(timeout, rcu_head); + } else { + /* still in use, restore reference counter. */ + atomic_inc(&timeout->refcnt); + ret = -EBUSY; + } + return ret; +} + +static int +cttimeout_del_timeout(struct sock *ctnl, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const cda[]) +{ + char *name; + struct ctnl_timeout *cur; + int ret = -ENOENT; + + if (!cda[CTA_TIMEOUT_NAME]) { + list_for_each_entry(cur, &cttimeout_list, head) + ctnl_timeout_try_del(cur); + + return 0; + } + name = nla_data(cda[CTA_TIMEOUT_NAME]); + + list_for_each_entry(cur, &cttimeout_list, head) { + if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) + continue; + + ret = ctnl_timeout_try_del(cur); + if (ret < 0) + return ret; + + break; + } + return ret; +} + +#ifdef CONFIG_NF_CONNTRACK_TIMEOUT +static struct ctnl_timeout *ctnl_timeout_find_get(const char *name) +{ + struct ctnl_timeout *timeout, *matching = NULL; + + rcu_read_lock(); + list_for_each_entry_rcu(timeout, &cttimeout_list, head) { + if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0) + continue; + + if (!try_module_get(THIS_MODULE)) + goto err; + + if (!atomic_inc_not_zero(&timeout->refcnt)) { + module_put(THIS_MODULE); + goto err; + } + matching = timeout; + break; + } +err: + rcu_read_unlock(); + return matching; +} + +static void ctnl_timeout_put(struct ctnl_timeout *timeout) +{ + atomic_dec(&timeout->refcnt); + module_put(THIS_MODULE); +} +#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ + +static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = { + [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout, + .attr_count = CTA_TIMEOUT_MAX, + .policy = cttimeout_nla_policy }, + [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout, + .attr_count = CTA_TIMEOUT_MAX, + .policy = cttimeout_nla_policy }, + [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout, + .attr_count = CTA_TIMEOUT_MAX, + .policy = cttimeout_nla_policy }, +}; + +static const struct nfnetlink_subsystem cttimeout_subsys = { + .name = "conntrack_timeout", + .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT, + .cb_count = IPCTNL_MSG_TIMEOUT_MAX, + .cb = cttimeout_cb, +}; + +MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT); + +static int __init cttimeout_init(void) +{ + int ret; + + ret = nfnetlink_subsys_register(&cttimeout_subsys); + if (ret < 0) { + pr_err("cttimeout_init: cannot register cttimeout with " + "nfnetlink.\n"); + goto err_out; + } +#ifdef CONFIG_NF_CONNTRACK_TIMEOUT + RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get); + RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put); +#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ + return 0; + +err_out: + return ret; +} + +static void __exit cttimeout_exit(void) +{ + struct ctnl_timeout *cur, *tmp; + + pr_info("cttimeout: unregistering from nfnetlink.\n"); + + nfnetlink_subsys_unregister(&cttimeout_subsys); + list_for_each_entry_safe(cur, tmp, &cttimeout_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. + */ + nf_ct_l4proto_put(cur->l4proto); + kfree_rcu(cur, rcu_head); + } +#ifdef CONFIG_NF_CONNTRACK_TIMEOUT + RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL); + RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL); +#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ +} + +module_init(cttimeout_init); +module_exit(cttimeout_exit); |