linux/net/netfilter/nfnetlink.c

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/* Netfilter messages via netlink socket. Allows for user space
* protocol helpers and general trouble making from userspace.
*
* (C) 2001 by Jay Schulist <jschlst@samba.org>,
* (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
* (C) 2005-2017 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* Initial netfilter messages via netlink development funded and
* generally made possible by Network Robots, Inc. (www.networkrobots.com)
*
* Further development of this code funded by Astaro AG (http://www.astaro.com)
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/uaccess.h>
#include <net/sock.h>
#include <linux/init.h>
#include <net/netlink.h>
#include <linux/netfilter/nfnetlink.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
#define nfnl_dereference_protected(id) \
rcu_dereference_protected(table[(id)].subsys, \
lockdep_nfnl_is_held((id)))
static char __initdata nfversion[] = "0.30";
static struct {
struct mutex mutex;
const struct nfnetlink_subsystem __rcu *subsys;
} table[NFNL_SUBSYS_COUNT];
static const int nfnl_group2type[NFNLGRP_MAX+1] = {
[NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK,
[NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK,
[NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK,
[NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP,
[NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP,
[NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP,
[NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES,
[NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT,
[NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES,
};
void nfnl_lock(__u8 subsys_id)
{
mutex_lock(&table[subsys_id].mutex);
}
EXPORT_SYMBOL_GPL(nfnl_lock);
void nfnl_unlock(__u8 subsys_id)
{
mutex_unlock(&table[subsys_id].mutex);
}
EXPORT_SYMBOL_GPL(nfnl_unlock);
#ifdef CONFIG_PROVE_LOCKING
bool lockdep_nfnl_is_held(u8 subsys_id)
{
return lockdep_is_held(&table[subsys_id].mutex);
}
EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held);
#endif
int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n)
{
nfnl_lock(n->subsys_id);
if (table[n->subsys_id].subsys) {
nfnl_unlock(n->subsys_id);
return -EBUSY;
}
rcu_assign_pointer(table[n->subsys_id].subsys, n);
nfnl_unlock(n->subsys_id);
return 0;
}
EXPORT_SYMBOL_GPL(nfnetlink_subsys_register);
int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n)
{
nfnl_lock(n->subsys_id);
table[n->subsys_id].subsys = NULL;
nfnl_unlock(n->subsys_id);
synchronize_rcu();
return 0;
}
EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister);
static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u16 type)
{
u8 subsys_id = NFNL_SUBSYS_ID(type);
if (subsys_id >= NFNL_SUBSYS_COUNT)
return NULL;
return rcu_dereference(table[subsys_id].subsys);
}
static inline const struct nfnl_callback *
nfnetlink_find_client(u16 type, const struct nfnetlink_subsystem *ss)
{
u8 cb_id = NFNL_MSG_TYPE(type);
if (cb_id >= ss->cb_count)
return NULL;
return &ss->cb[cb_id];
}
int nfnetlink_has_listeners(struct net *net, unsigned int group)
{
return netlink_has_listeners(net->nfnl, group);
}
EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
unsigned int group, int echo, gfp_t flags)
{
return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags);
}
EXPORT_SYMBOL_GPL(nfnetlink_send);
int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error)
{
return netlink_set_err(net->nfnl, portid, group, error);
}
EXPORT_SYMBOL_GPL(nfnetlink_set_err);
int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
int flags)
{
return netlink_unicast(net->nfnl, skb, portid, flags);
}
EXPORT_SYMBOL_GPL(nfnetlink_unicast);
/* Process one complete nfnetlink message. */
static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
const struct nfnl_callback *nc;
const struct nfnetlink_subsystem *ss;
int type, err;
/* All the messages must at least contain nfgenmsg */
if (nlmsg_len(nlh) < sizeof(struct nfgenmsg))
return 0;
type = nlh->nlmsg_type;
replay:
rcu_read_lock();
ss = nfnetlink_get_subsys(type);
if (!ss) {
#ifdef CONFIG_MODULES
rcu_read_unlock();
request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
rcu_read_lock();
ss = nfnetlink_get_subsys(type);
if (!ss)
#endif
{
rcu_read_unlock();
return -EINVAL;
}
}
nc = nfnetlink_find_client(type, ss);
if (!nc) {
rcu_read_unlock();
return -EINVAL;
}
{
int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
struct nlattr *attr = (void *)nlh + min_len;
int attrlen = nlh->nlmsg_len - min_len;
__u8 subsys_id = NFNL_SUBSYS_ID(type);
err = nla_parse(cda, ss->cb[cb_id].attr_count,
attr, attrlen, ss->cb[cb_id].policy);
if (err < 0) {
rcu_read_unlock();
return err;
}
if (nc->call_rcu) {
err = nc->call_rcu(net, net->nfnl, skb, nlh,
(const struct nlattr **)cda);
rcu_read_unlock();
} else {
rcu_read_unlock();
nfnl_lock(subsys_id);
if (nfnl_dereference_protected(subsys_id) != ss ||
nfnetlink_find_client(type, ss) != nc)
err = -EAGAIN;
else if (nc->call)
err = nc->call(net, net->nfnl, skb, nlh,
(const struct nlattr **)cda);
else
err = -EINVAL;
nfnl_unlock(subsys_id);
}
if (err == -EAGAIN)
goto replay;
return err;
}
}
struct nfnl_err {
struct list_head head;
struct nlmsghdr *nlh;
int err;
};
static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err)
{
struct nfnl_err *nfnl_err;
nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL);
if (nfnl_err == NULL)
return -ENOMEM;
nfnl_err->nlh = nlh;
nfnl_err->err = err;
list_add_tail(&nfnl_err->head, list);
return 0;
}
static void nfnl_err_del(struct nfnl_err *nfnl_err)
{
list_del(&nfnl_err->head);
kfree(nfnl_err);
}
static void nfnl_err_reset(struct list_head *err_list)
{
struct nfnl_err *nfnl_err, *next;
list_for_each_entry_safe(nfnl_err, next, err_list, head)
nfnl_err_del(nfnl_err);
}
static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb)
{
struct nfnl_err *nfnl_err, *next;
list_for_each_entry_safe(nfnl_err, next, err_list, head) {
netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, NULL);
nfnl_err_del(nfnl_err);
}
}
enum {
NFNL_BATCH_FAILURE = (1 << 0),
NFNL_BATCH_DONE = (1 << 1),
NFNL_BATCH_REPLAY = (1 << 2),
};
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
u16 subsys_id, u32 genid)
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
{
struct sk_buff *oskb = skb;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
struct net *net = sock_net(skb->sk);
const struct nfnetlink_subsystem *ss;
const struct nfnl_callback *nc;
LIST_HEAD(err_list);
u32 status;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
int err;
if (subsys_id >= NFNL_SUBSYS_COUNT)
return netlink_ack(skb, nlh, -EINVAL, NULL);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
replay:
status = 0;
skb = netlink_skb_clone(oskb, GFP_KERNEL);
if (!skb)
return netlink_ack(oskb, nlh, -ENOMEM, NULL);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
nfnl_lock(subsys_id);
ss = nfnl_dereference_protected(subsys_id);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
if (!ss) {
#ifdef CONFIG_MODULES
nfnl_unlock(subsys_id);
request_module("nfnetlink-subsys-%d", subsys_id);
nfnl_lock(subsys_id);
ss = nfnl_dereference_protected(subsys_id);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
if (!ss)
#endif
{
nfnl_unlock(subsys_id);
netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL);
return kfree_skb(skb);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
}
if (!ss->commit || !ss->abort) {
nfnl_unlock(subsys_id);
netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL);
netfilter: nfnetlink: Fix use after free when it fails to process batch This bug manifests when calling the nft command line tool without nf_tables kernel support. kernel message: [ 44.071555] Netfilter messages via NETLINK v0.30. [ 44.072253] BUG: unable to handle kernel NULL pointer dereference at 0000000000000119 [ 44.072264] IP: [<ffffffff8171db1f>] netlink_getsockbyportid+0xf/0x70 [ 44.072272] PGD 7f2b74067 PUD 7f2b73067 PMD 0 [ 44.072277] Oops: 0000 [#1] SMP [...] [ 44.072369] Call Trace: [ 44.072373] [<ffffffff8171fd81>] netlink_unicast+0x91/0x200 [ 44.072377] [<ffffffff817206c9>] netlink_ack+0x99/0x110 [ 44.072381] [<ffffffffa004b951>] nfnetlink_rcv+0x3c1/0x408 [nfnetlink] [ 44.072385] [<ffffffff8171fde3>] netlink_unicast+0xf3/0x200 [ 44.072389] [<ffffffff817201ef>] netlink_sendmsg+0x2ff/0x740 [ 44.072394] [<ffffffff81044752>] ? __mmdrop+0x62/0x90 [ 44.072398] [<ffffffff816dafdb>] sock_sendmsg+0x8b/0xc0 [ 44.072403] [<ffffffff812f1af5>] ? copy_user_enhanced_fast_string+0x5/0x10 [ 44.072406] [<ffffffff816dbb6c>] ? move_addr_to_kernel+0x2c/0x50 [ 44.072410] [<ffffffff816db423>] ___sys_sendmsg+0x3c3/0x3d0 [ 44.072415] [<ffffffff811301ba>] ? handle_mm_fault+0xa9a/0xc60 [ 44.072420] [<ffffffff811362d6>] ? mmap_region+0x166/0x5a0 [ 44.072424] [<ffffffff817da84c>] ? __do_page_fault+0x1dc/0x510 [ 44.072428] [<ffffffff812b8b2c>] ? apparmor_capable+0x1c/0x60 [ 44.072435] [<ffffffff817d6e9a>] ? _raw_spin_unlock_bh+0x1a/0x20 [ 44.072439] [<ffffffff816dfc86>] ? release_sock+0x106/0x150 [ 44.072443] [<ffffffff816dc212>] __sys_sendmsg+0x42/0x80 [ 44.072446] [<ffffffff816dc262>] SyS_sendmsg+0x12/0x20 [ 44.072450] [<ffffffff817df616>] system_call_fastpath+0x1a/0x1f Signed-off-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-05-04 19:35:37 +08:00
return kfree_skb(skb);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
if (genid && ss->valid_genid && !ss->valid_genid(net, genid)) {
nfnl_unlock(subsys_id);
netlink_ack(oskb, nlh, -ERESTART, NULL);
return kfree_skb(skb);
}
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
while (skb->len >= nlmsg_total_size(0)) {
int msglen, type;
nlh = nlmsg_hdr(skb);
err = 0;
netfilter: nfnetlink: correctly validate length of batch messages If nlh->nlmsg_len is zero then an infinite loop is triggered because 'skb_pull(skb, msglen);' pulls zero bytes. The calculation in nlmsg_len() underflows if 'nlh->nlmsg_len < NLMSG_HDRLEN' which bypasses the length validation and will later trigger an out-of-bound read. If the length validation does fail then the malformed batch message is copied back to userspace. However, we cannot do this because the nlh->nlmsg_len can be invalid. This leads to an out-of-bounds read in netlink_ack: [ 41.455421] ================================================================== [ 41.456431] BUG: KASAN: slab-out-of-bounds in memcpy+0x1d/0x40 at addr ffff880119e79340 [ 41.456431] Read of size 4294967280 by task a.out/987 [ 41.456431] ============================================================================= [ 41.456431] BUG kmalloc-512 (Not tainted): kasan: bad access detected [ 41.456431] ----------------------------------------------------------------------------- ... [ 41.456431] Bytes b4 ffff880119e79310: 00 00 00 00 d5 03 00 00 b0 fb fe ff 00 00 00 00 ................ [ 41.456431] Object ffff880119e79320: 20 00 00 00 10 00 05 00 00 00 00 00 00 00 00 00 ............... [ 41.456431] Object ffff880119e79330: 14 00 0a 00 01 03 fc 40 45 56 11 22 33 10 00 05 .......@EV."3... [ 41.456431] Object ffff880119e79340: f0 ff ff ff 88 99 aa bb 00 14 00 0a 00 06 fe fb ................ ^^ start of batch nlmsg with nlmsg_len=4294967280 ... [ 41.456431] Memory state around the buggy address: [ 41.456431] ffff880119e79400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 41.456431] ffff880119e79480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 41.456431] >ffff880119e79500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 41.456431] ^ [ 41.456431] ffff880119e79580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 41.456431] ffff880119e79600: fc fc fc fc fc fc fc fc fc fc fb fb fb fb fb fb [ 41.456431] ================================================================== Fix this with better validation of nlh->nlmsg_len and by setting NFNL_BATCH_FAILURE if any batch message fails length validation. CAP_NET_ADMIN is required to trigger the bugs. Fixes: 9ea2aa8b7dba ("netfilter: nfnetlink: validate nfnetlink header from batch") Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-03 02:36:45 +08:00
if (nlh->nlmsg_len < NLMSG_HDRLEN ||
skb->len < nlh->nlmsg_len ||
nlmsg_len(nlh) < sizeof(struct nfgenmsg)) {
nfnl_err_reset(&err_list);
status |= NFNL_BATCH_FAILURE;
goto done;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
/* Only requests are handled by the kernel */
if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) {
err = -EINVAL;
goto ack;
}
type = nlh->nlmsg_type;
if (type == NFNL_MSG_BATCH_BEGIN) {
/* Malformed: Batch begin twice */
nfnl_err_reset(&err_list);
status |= NFNL_BATCH_FAILURE;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
goto done;
} else if (type == NFNL_MSG_BATCH_END) {
status |= NFNL_BATCH_DONE;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
goto done;
} else if (type < NLMSG_MIN_TYPE) {
err = -EINVAL;
goto ack;
}
/* We only accept a batch with messages for the same
* subsystem.
*/
if (NFNL_SUBSYS_ID(type) != subsys_id) {
err = -EINVAL;
goto ack;
}
nc = nfnetlink_find_client(type, ss);
if (!nc) {
err = -EINVAL;
goto ack;
}
{
int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
struct nlattr *attr = (void *)nlh + min_len;
int attrlen = nlh->nlmsg_len - min_len;
err = nla_parse(cda, ss->cb[cb_id].attr_count,
attr, attrlen, ss->cb[cb_id].policy);
if (err < 0)
goto ack;
if (nc->call_batch) {
err = nc->call_batch(net, net->nfnl, skb, nlh,
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
(const struct nlattr **)cda);
}
/* The lock was released to autoload some module, we
* have to abort and start from scratch using the
* original skb.
*/
if (err == -EAGAIN) {
status |= NFNL_BATCH_REPLAY;
goto next;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
}
ack:
if (nlh->nlmsg_flags & NLM_F_ACK || err) {
/* Errors are delivered once the full batch has been
* processed, this avoids that the same error is
* reported several times when replaying the batch.
*/
if (nfnl_err_add(&err_list, nlh, err) < 0) {
/* We failed to enqueue an error, reset the
* list of errors and send OOM to userspace
* pointing to the batch header.
*/
nfnl_err_reset(&err_list);
netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM,
NULL);
status |= NFNL_BATCH_FAILURE;
goto done;
}
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
/* We don't stop processing the batch on errors, thus,
* userspace gets all the errors that the batch
* triggers.
*/
if (err)
status |= NFNL_BATCH_FAILURE;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
next:
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
if (msglen > skb->len)
msglen = skb->len;
skb_pull(skb, msglen);
}
done:
if (status & NFNL_BATCH_REPLAY) {
ss->abort(net, oskb);
nfnl_err_reset(&err_list);
nfnl_unlock(subsys_id);
kfree_skb(skb);
goto replay;
} else if (status == NFNL_BATCH_DONE) {
ss->commit(net, oskb);
} else {
ss->abort(net, oskb);
}
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
nfnl_err_deliver(&err_list, oskb);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
nfnl_unlock(subsys_id);
kfree_skb(skb);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
}
static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = {
[NFNL_BATCH_GENID] = { .type = NLA_U32 },
};
static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh)
{
int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
struct nlattr *attr = (void *)nlh + min_len;
struct nlattr *cda[NFNL_BATCH_MAX + 1];
int attrlen = nlh->nlmsg_len - min_len;
struct nfgenmsg *nfgenmsg;
int msglen, err;
u32 gen_id = 0;
u16 res_id;
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
if (msglen > skb->len)
msglen = skb->len;
if (nlh->nlmsg_len < NLMSG_HDRLEN ||
skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg))
return;
err = nla_parse(cda, NFNL_BATCH_MAX, attr, attrlen, nfnl_batch_policy);
if (err < 0) {
netlink_ack(skb, nlh, err, NULL);
return;
}
if (cda[NFNL_BATCH_GENID])
gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID]));
nfgenmsg = nlmsg_data(nlh);
skb_pull(skb, msglen);
/* Work around old nft using host byte order */
if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES)
res_id = NFNL_SUBSYS_NFTABLES;
else
res_id = ntohs(nfgenmsg->res_id);
nfnetlink_rcv_batch(skb, nlh, res_id, gen_id);
}
static void nfnetlink_rcv(struct sk_buff *skb)
{
struct nlmsghdr *nlh = nlmsg_hdr(skb);
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
if (nlh->nlmsg_len < NLMSG_HDRLEN ||
skb->len < nlh->nlmsg_len)
return;
if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
netlink_ack(skb, nlh, -EPERM, NULL);
return;
}
if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN)
nfnetlink_rcv_skb_batch(skb, nlh);
else
netfilter: nfnetlink: add batch support and use it from nf_tables This patch adds a batch support to nfnetlink. Basically, it adds two new control messages: * NFNL_MSG_BATCH_BEGIN, that indicates the beginning of a batch, the nfgenmsg->res_id indicates the nfnetlink subsystem ID. * NFNL_MSG_BATCH_END, that results in the invocation of the ss->commit callback function. If not specified or an error ocurred in the batch, the ss->abort function is invoked instead. The end message represents the commit operation in nftables, the lack of end message results in an abort. This patch also adds the .call_batch function that is only called from the batch receival path. This patch adds atomic rule updates and dumps based on bitmask generations. This allows to atomically commit a set of rule-set updates incrementally without altering the internal state of existing nf_tables expressions/matches/targets. The idea consists of using a generation cursor of 1 bit and a bitmask of 2 bits per rule. Assuming the gencursor is 0, then the genmask (expressed as a bitmask) can be interpreted as: 00 active in the present, will be active in the next generation. 01 inactive in the present, will be active in the next generation. 10 active in the present, will be deleted in the next generation. ^ gencursor Once you invoke the transition to the next generation, the global gencursor is updated: 00 active in the present, will be active in the next generation. 01 active in the present, needs to zero its future, it becomes 00. 10 inactive in the present, delete now. ^ gencursor If a dump is in progress and nf_tables enters a new generation, the dump will stop and return -EBUSY to let userspace know that it has to retry again. In order to invalidate dumps, a global genctr counter is increased everytime nf_tables enters a new generation. This new operation can be used from the user-space utility that controls the firewall, eg. nft -f restore The rule updates contained in `file' will be applied atomically. cat file ----- add filter INPUT ip saddr 1.1.1.1 counter accept #1 del filter INPUT ip daddr 2.2.2.2 counter drop #2 -EOF- Note that the rule 1 will be inactive until the transition to the next generation, the rule 2 will be evicted in the next generation. There is a penalty during the rule update due to the branch misprediction in the packet matching framework. But that should be quickly resolved once the iteration over the commit list that contain rules that require updates is finished. Event notification happens once the rule-set update has been committed. So we skip notifications is case the rule-set update is aborted, which can happen in case that the rule-set is tested to apply correctly. This patch squashed the following patches from Pablo: * nf_tables: atomic rule updates and dumps * nf_tables: get rid of per rule list_head for commits * nf_tables: use per netns commit list * nfnetlink: add batch support and use it from nf_tables * nf_tables: all rule updates are transactional * nf_tables: attach replacement rule after stale one * nf_tables: do not allow deletion/replacement of stale rules * nf_tables: remove unused NFTA_RULE_FLAGS Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-14 17:05:33 +08:00
netlink_rcv_skb(skb, &nfnetlink_rcv_msg);
}
#ifdef CONFIG_MODULES
static int nfnetlink_bind(struct net *net, int group)
{
const struct nfnetlink_subsystem *ss;
int type;
if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX)
return 0;
type = nfnl_group2type[group];
rcu_read_lock();
ss = nfnetlink_get_subsys(type << 8);
rcu_read_unlock();
if (!ss)
request_module("nfnetlink-subsys-%d", type);
return 0;
}
#endif
static int __net_init nfnetlink_net_init(struct net *net)
{
struct sock *nfnl;
struct netlink_kernel_cfg cfg = {
.groups = NFNLGRP_MAX,
.input = nfnetlink_rcv,
#ifdef CONFIG_MODULES
.bind = nfnetlink_bind,
#endif
};
nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg);
if (!nfnl)
return -ENOMEM;
net->nfnl_stash = nfnl;
rcu_assign_pointer(net->nfnl, nfnl);
return 0;
}
static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list)
{
struct net *net;
list_for_each_entry(net, net_exit_list, exit_list)
RCU_INIT_POINTER(net->nfnl, NULL);
synchronize_net();
list_for_each_entry(net, net_exit_list, exit_list)
netlink_kernel_release(net->nfnl_stash);
}
static struct pernet_operations nfnetlink_net_ops = {
.init = nfnetlink_net_init,
.exit_batch = nfnetlink_net_exit_batch,
};
static int __init nfnetlink_init(void)
{
int i;
for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++)
BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE);
for (i=0; i<NFNL_SUBSYS_COUNT; i++)
mutex_init(&table[i].mutex);
pr_info("Netfilter messages via NETLINK v%s.\n", nfversion);
return register_pernet_subsys(&nfnetlink_net_ops);
}
static void __exit nfnetlink_exit(void)
{
pr_info("Removing netfilter NETLINK layer.\n");
unregister_pernet_subsys(&nfnetlink_net_ops);
}
module_init(nfnetlink_init);
module_exit(nfnetlink_exit);