xref: /aosp_15_r20/external/iptables/extensions/libxt_NFLOG.man (revision a71a954618bbadd4a345637e5edcf36eec826889)
1*a71a9546SAutomerger Merge WorkerThis target provides logging of matching packets. When this target is
2*a71a9546SAutomerger Merge Workerset for a rule, the Linux kernel will pass the packet to the loaded
3*a71a9546SAutomerger Merge Workerlogging backend to log the packet. This is usually used in combination
4*a71a9546SAutomerger Merge Workerwith nfnetlink_log as logging backend, which will multicast the packet
5*a71a9546SAutomerger Merge Workerthrough a
6*a71a9546SAutomerger Merge Worker.IR netlink
7*a71a9546SAutomerger Merge Workersocket to the specified multicast group. One or more userspace processes
8*a71a9546SAutomerger Merge Workermay subscribe to the group to receive the packets. Like LOG, this is a
9*a71a9546SAutomerger Merge Workernon-terminating target, i.e. rule traversal continues at the next rule.
10*a71a9546SAutomerger Merge Worker.TP
11*a71a9546SAutomerger Merge Worker\fB\-\-nflog\-group\fP \fInlgroup\fP
12*a71a9546SAutomerger Merge WorkerThe netlink group (0 - 2^16\-1) to which packets are (only applicable for
13*a71a9546SAutomerger Merge Workernfnetlink_log). The default value is 0.
14*a71a9546SAutomerger Merge Worker.TP
15*a71a9546SAutomerger Merge Worker\fB\-\-nflog\-prefix\fP \fIprefix\fP
16*a71a9546SAutomerger Merge WorkerA prefix string to include in the log message, up to 64 characters
17*a71a9546SAutomerger Merge Workerlong, useful for distinguishing messages in the logs.
18*a71a9546SAutomerger Merge Worker.TP
19*a71a9546SAutomerger Merge Worker\fB\-\-nflog\-range\fP \fIsize\fP
20*a71a9546SAutomerger Merge WorkerThis option has never worked, use --nflog-size instead
21*a71a9546SAutomerger Merge Worker.TP
22*a71a9546SAutomerger Merge Worker\fB\-\-nflog\-size\fP \fIsize\fP
23*a71a9546SAutomerger Merge WorkerThe number of bytes to be copied to userspace (only applicable for
24*a71a9546SAutomerger Merge Workernfnetlink_log). nfnetlink_log instances may specify their own
25*a71a9546SAutomerger Merge Workerrange, this option overrides it.
26*a71a9546SAutomerger Merge Worker.TP
27*a71a9546SAutomerger Merge Worker\fB\-\-nflog\-threshold\fP \fIsize\fP
28*a71a9546SAutomerger Merge WorkerNumber of packets to queue inside the kernel before sending them
29*a71a9546SAutomerger Merge Workerto userspace (only applicable for nfnetlink_log). Higher values
30*a71a9546SAutomerger Merge Workerresult in less overhead per packet, but increase delay until the
31*a71a9546SAutomerger Merge Workerpackets reach userspace. The default value is 1.
32*a71a9546SAutomerger Merge Worker.BR
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