summaryrefslogtreecommitdiffstats
path: root/extensions/libxt_NFLOG.man
blob: 318e63053ffd6bda886d89b8ce905c1e0256ee54 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
This target provides logging of matching packets. When this target is
set for a rule, the Linux kernel will pass the packet to the loaded
logging backend to log the packet. This is usually used in combination
with nfnetlink_log as logging backend, which will multicast the packet
through a
.IR netlink
socket to the specified multicast group. One or more userspace processes
may subscribe to the group to receive the packets. Like LOG, this is a
non-terminating target, i.e. rule traversal continues at the next rule.
.TP
\fB\-\-nflog\-group\fP \fInlgroup\fP
The netlink group (0 - 2^16\-1) to which packets are (only applicable for
nfnetlink_log). The default value is 0.
.TP
\fB\-\-nflog\-prefix\fP \fIprefix\fP
A prefix string to include in the log message, up to 64 characters
long, useful for distinguishing messages in the logs.
.TP
\fB\-\-nflog\-range\fP \fIsize\fP
This option has never worked, use --nflog-size instead
.TP
\fB\-\-nflog\-size\fP \fIsize\fP
The number of bytes to be copied to userspace (only applicable for
nfnetlink_log). nfnetlink_log instances may specify their own
range, this option overrides it.
.TP
\fB\-\-nflog\-threshold\fP \fIsize\fP
Number of packets to queue inside the kernel before sending them
to userspace (only applicable for nfnetlink_log). Higher values
result in less overhead per packet, but increase delay until the
packets reach userspace. The default value is 1.
.BR