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netfilter: ipt_ULOG: add net namespace support for ipt_ULOG
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Add pernet support to ipt_ULOG by means of the new nf_log_set
function added in (30e0c6a netfilter: nf_log: prepare net
namespace support for loggers).

This patch also make ulog_buffers and netlink socket
nflognl per netns.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Gao feng authored and Pablo Neira Ayuso committed Apr 5, 2013
1 parent 5b175b7 commit 3554306
Showing 1 changed file with 89 additions and 40 deletions.
129 changes: 89 additions & 40 deletions net/ipv4/netfilter/ipt_ULOG.c
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,7 @@
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ipt_ULOG.h>
#include <net/netfilter/nf_log.h>
#include <net/netns/generic.h>
#include <net/sock.h>
#include <linux/bitops.h>
#include <asm/unaligned.h>
Expand Down Expand Up @@ -78,15 +79,23 @@ typedef struct {
struct timer_list timer; /* the timer function */
} ulog_buff_t;

static ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS]; /* array of buffers */
static int ulog_net_id __read_mostly;
struct ulog_net {
unsigned int nlgroup[ULOG_MAXNLGROUPS];
ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS];
struct sock *nflognl;
spinlock_t lock;
};

static struct sock *nflognl; /* our socket */
static DEFINE_SPINLOCK(ulog_lock); /* spinlock */
static struct ulog_net *ulog_pernet(struct net *net)
{
return net_generic(net, ulog_net_id);
}

/* send one ulog_buff_t to userspace */
static void ulog_send(unsigned int nlgroupnum)
static void ulog_send(struct ulog_net *ulog, unsigned int nlgroupnum)
{
ulog_buff_t *ub = &ulog_buffers[nlgroupnum];
ulog_buff_t *ub = &ulog->ulog_buffers[nlgroupnum];

pr_debug("ulog_send: timer is deleting\n");
del_timer(&ub->timer);
Expand All @@ -103,7 +112,8 @@ static void ulog_send(unsigned int nlgroupnum)
NETLINK_CB(ub->skb).dst_group = nlgroupnum + 1;
pr_debug("throwing %d packets to netlink group %u\n",
ub->qlen, nlgroupnum + 1);
netlink_broadcast(nflognl, ub->skb, 0, nlgroupnum + 1, GFP_ATOMIC);
netlink_broadcast(ulog->nflognl, ub->skb, 0, nlgroupnum + 1,
GFP_ATOMIC);

ub->qlen = 0;
ub->skb = NULL;
Expand All @@ -114,13 +124,16 @@ static void ulog_send(unsigned int nlgroupnum)
/* timer function to flush queue in flushtimeout time */
static void ulog_timer(unsigned long data)
{
struct ulog_net *ulog = container_of((void *)data,
struct ulog_net,
nlgroup[*(unsigned int *)data]);
pr_debug("timer function called, calling ulog_send\n");

/* lock to protect against somebody modifying our structure
* from ipt_ulog_target at the same time */
spin_lock_bh(&ulog_lock);
ulog_send(data);
spin_unlock_bh(&ulog_lock);
spin_lock_bh(&ulog->lock);
ulog_send(ulog, data);
spin_unlock_bh(&ulog->lock);
}

static struct sk_buff *ulog_alloc_skb(unsigned int size)
Expand Down Expand Up @@ -160,6 +173,8 @@ static void ipt_ulog_packet(unsigned int hooknum,
size_t size, copy_len;
struct nlmsghdr *nlh;
struct timeval tv;
struct net *net = dev_net(in ? in : out);
struct ulog_net *ulog = ulog_pernet(net);

/* ffs == find first bit set, necessary because userspace
* is already shifting groupnumber, but we need unshifted.
Expand All @@ -174,9 +189,9 @@ static void ipt_ulog_packet(unsigned int hooknum,

size = NLMSG_SPACE(sizeof(*pm) + copy_len);

ub = &ulog_buffers[groupnum];
ub = &ulog->ulog_buffers[groupnum];

spin_lock_bh(&ulog_lock);
spin_lock_bh(&ulog->lock);

if (!ub->skb) {
if (!(ub->skb = ulog_alloc_skb(size)))
Expand All @@ -186,7 +201,7 @@ static void ipt_ulog_packet(unsigned int hooknum,
/* either the queue len is too high or we don't have
* enough room in nlskb left. send it to userspace. */

ulog_send(groupnum);
ulog_send(ulog, groupnum);

if (!(ub->skb = ulog_alloc_skb(size)))
goto alloc_failure;
Expand Down Expand Up @@ -260,16 +275,16 @@ static void ipt_ulog_packet(unsigned int hooknum,
if (ub->qlen >= loginfo->qthreshold) {
if (loginfo->qthreshold > 1)
nlh->nlmsg_type = NLMSG_DONE;
ulog_send(groupnum);
ulog_send(ulog, groupnum);
}
out_unlock:
spin_unlock_bh(&ulog_lock);
spin_unlock_bh(&ulog->lock);

return;

alloc_failure:
pr_debug("Error building netlink message\n");
spin_unlock_bh(&ulog_lock);
spin_unlock_bh(&ulog->lock);
}

static unsigned int
Expand Down Expand Up @@ -376,54 +391,43 @@ static struct nf_logger ipt_ulog_logger __read_mostly = {
.me = THIS_MODULE,
};

static int __init ulog_tg_init(void)
static int __net_init ulog_tg_net_init(struct net *net)
{
int ret, i;
int i;
struct ulog_net *ulog = ulog_pernet(net);
struct netlink_kernel_cfg cfg = {
.groups = ULOG_MAXNLGROUPS,
};

pr_debug("init module\n");

if (nlbufsiz > 128*1024) {
pr_warning("Netlink buffer has to be <= 128kB\n");
return -EINVAL;
}

spin_lock_init(&ulog->lock);
/* initialize ulog_buffers */
for (i = 0; i < ULOG_MAXNLGROUPS; i++)
setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
setup_timer(&ulog->ulog_buffers[i].timer, ulog_timer, i);

nflognl = netlink_kernel_create(&init_net, NETLINK_NFLOG, &cfg);
if (!nflognl)
ulog->nflognl = netlink_kernel_create(net, NETLINK_NFLOG, &cfg);
if (!ulog->nflognl)
return -ENOMEM;

ret = xt_register_target(&ulog_tg_reg);
if (ret < 0) {
netlink_kernel_release(nflognl);
return ret;
}
if (nflog)
nf_log_register(NFPROTO_IPV4, &ipt_ulog_logger);
nf_log_set(net, NFPROTO_IPV4, &ipt_ulog_logger);

return 0;
}

static void __exit ulog_tg_exit(void)
static void __net_exit ulog_tg_net_exit(struct net *net)
{
ulog_buff_t *ub;
int i;

pr_debug("cleanup_module\n");
struct ulog_net *ulog = ulog_pernet(net);

if (nflog)
nf_log_unregister(&ipt_ulog_logger);
xt_unregister_target(&ulog_tg_reg);
netlink_kernel_release(nflognl);
nf_log_unset(net, &ipt_ulog_logger);

netlink_kernel_release(ulog->nflognl);

/* remove pending timers and free allocated skb's */
for (i = 0; i < ULOG_MAXNLGROUPS; i++) {
ub = &ulog_buffers[i];
ub = &ulog->ulog_buffers[i];
pr_debug("timer is deleting\n");
del_timer(&ub->timer);

Expand All @@ -434,5 +438,50 @@ static void __exit ulog_tg_exit(void)
}
}

static struct pernet_operations ulog_tg_net_ops = {
.init = ulog_tg_net_init,
.exit = ulog_tg_net_exit,
.id = &ulog_net_id,
.size = sizeof(struct ulog_net),
};

static int __init ulog_tg_init(void)
{
int ret;
pr_debug("init module\n");

if (nlbufsiz > 128*1024) {
pr_warn("Netlink buffer has to be <= 128kB\n");
return -EINVAL;
}

ret = register_pernet_subsys(&ulog_tg_net_ops);
if (ret)
goto out_pernet;

ret = xt_register_target(&ulog_tg_reg);
if (ret < 0)
goto out_target;

if (nflog)
nf_log_register(NFPROTO_IPV4, &ipt_ulog_logger);

return 0;

out_target:
unregister_pernet_subsys(&ulog_tg_net_ops);
out_pernet:
return ret;
}

static void __exit ulog_tg_exit(void)
{
pr_debug("cleanup_module\n");
if (nflog)
nf_log_unregister(&ipt_ulog_logger);
xt_unregister_target(&ulog_tg_reg);
unregister_pernet_subsys(&ulog_tg_net_ops);
}

module_init(ulog_tg_init);
module_exit(ulog_tg_exit);

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