[NETFILTER] nfnetlink_log: add sequence numbers for log events
By using a sequence number for every logged netfilter event, we can
determine from userspace whether logging information was lots somewhere
downstream.
The user has a choice of either having per-instance local sequence
counters, or using a global sequence counter, or both.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 3b3c781..54cbbaa 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -11,6 +11,10 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
+ * 2006-01-26 Harald Welte <laforge@netfilter.org>
+ * - Add optional local and global sequence number to detect lost
+ * events from userspace
+ *
*/
#include <linux/module.h>
#include <linux/skbuff.h>
@@ -68,11 +72,14 @@
unsigned int nlbufsiz; /* netlink buffer allocation size */
unsigned int qthreshold; /* threshold of the queue */
u_int32_t copy_range;
+ u_int32_t seq; /* instance-local sequential counter */
u_int16_t group_num; /* number of this queue */
+ u_int16_t flags;
u_int8_t copy_mode;
};
static DEFINE_RWLOCK(instances_lock);
+static atomic_t global_seq;
#define INSTANCE_BUCKETS 16
static struct hlist_head instance_table[INSTANCE_BUCKETS];
@@ -310,6 +317,16 @@
return 0;
}
+static int
+nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
+{
+ spin_lock_bh(&inst->lock);
+ inst->flags = ntohs(flags);
+ spin_unlock_bh(&inst->lock);
+
+ return 0;
+}
+
static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
unsigned int pkt_size)
{
@@ -377,6 +394,8 @@
spin_unlock_bh(&inst->lock);
}
+/* This is an inline function, we don't really care about a long
+ * list of arguments */
static inline int
__build_packet_message(struct nfulnl_instance *inst,
const struct sk_buff *skb,
@@ -515,6 +534,17 @@
read_unlock_bh(&skb->sk->sk_callback_lock);
}
+ /* local sequence number */
+ if (inst->flags & NFULNL_CFG_F_SEQ) {
+ tmp_uint = htonl(inst->seq++);
+ NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
+ }
+ /* global sequence number */
+ if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
+ tmp_uint = atomic_inc_return(&global_seq);
+ NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
+ }
+
if (data_len) {
struct nfattr *nfa;
int size = NFA_LENGTH(data_len);
@@ -607,6 +637,11 @@
spin_lock_bh(&inst->lock);
+ if (inst->flags & NFULNL_CFG_F_SEQ)
+ size += NFA_SPACE(sizeof(u_int32_t));
+ if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
+ size += NFA_SPACE(sizeof(u_int32_t));
+
qthreshold = inst->qthreshold;
/* per-rule qthreshold overrides per-instance */
if (qthreshold > li->u.ulog.qthreshold)
@@ -736,10 +771,14 @@
[NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
[NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
[NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
+ [NFULA_IFINDEX_PHYSINDEV-1] = sizeof(u_int32_t),
+ [NFULA_IFINDEX_PHYSOUTDEV-1] = sizeof(u_int32_t),
[NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
[NFULA_PAYLOAD-1] = 0,
[NFULA_PREFIX-1] = 0,
[NFULA_UID-1] = sizeof(u_int32_t),
+ [NFULA_SEQ-1] = sizeof(u_int32_t),
+ [NFULA_SEQ_GLOBAL-1] = sizeof(u_int32_t),
};
static const int nfula_cfg_min[NFULA_CFG_MAX] = {
@@ -748,6 +787,7 @@
[NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
[NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
[NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
+ [NFULA_CFG_FLAGS-1] = sizeof(u_int16_t),
};
static int
@@ -859,6 +899,12 @@
nfulnl_set_qthresh(inst, ntohl(qthresh));
}
+ if (nfula[NFULA_CFG_FLAGS-1]) {
+ u_int16_t flags =
+ *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
+ nfulnl_set_flags(inst, ntohl(flags));
+ }
+
out_put:
instance_put(inst);
return ret;