netfilter: ipt_ULOG: add net namespace support for ipt_ULOG

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>

1 files changed, 89 insertions, 40 deletions

diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 7d168dcbd135..642ecfb711bc 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -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>
@@ -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);
@@ -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;
@@ -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)
@@ -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.
@@ -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)))
@@ -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;
@@ -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
@@ -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);
 
@@ -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);