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32 .Nd "NAT netgraph node type"
38 node performs network address translation (NAT) of packets
44 engine for packet aliasing.
45 At this moment it supports only the basic functionality of the library.
47 This node type has two hooks:
48 .Bl -tag -width indent
50 Packets received on this hook are considered outgoing and will be
51 masqueraded to a configured address.
53 Packets coming on this hook are considered incoming and will be
57 This node type supports the generic control messages, plus the following:
58 .Bl -tag -width indent
59 .It Dv NGM_NAT_SET_IPADDR Pq Li setaliasaddr
60 Configure aliasing address for a node.
61 After both hooks have been connected and aliasing address was configured,
62 a node is ready for aliasing operation.
63 .It Dv NGM_NAT_SET_MODE Pq Li setmode
64 Set node's operation mode using supplied
65 .Vt "struct ng_nat_mode".
71 /* Supported flags: */
72 #define NG_NAT_LOG 0x01
73 #define NG_NAT_DENY_INCOMING 0x02
74 #define NG_NAT_SAME_PORTS 0x04
75 #define NG_NAT_UNREGISTERED_ONLY 0x10
76 #define NG_NAT_RESET_ON_ADDR_CHANGE 0x20
77 #define NG_NAT_PROXY_ONLY 0x40
78 #define NG_NAT_REVERSE 0x80
80 .It Dv NGM_NAT_SET_TARGET Pq Li settarget
81 Configure target address for a node.
82 When an incoming packet not associated with any pre-existing aliasing
83 link arrives at the host machine, it will be sent to the specified address.
86 This node shuts down upon receipt of a
88 control message, or when both hooks are disconnected.
90 In the following example, the packets are injected into a
95 .Bd -literal -offset indent
97 ngctl mkpeer ipfw: nat 60 out
98 ngctl name ipfw:60 nat
99 ngctl connect ipfw: nat: 61 in
100 ngctl msg nat: setaliasaddr x.y.35.8
102 # Divert traffic into NAT node
103 ipfw add 300 netgraph 61 all from any to any in via fxp0
104 ipfw add 400 netgraph 60 all from any to any out via fxp0
106 # Let packets continue with after being (de)aliased
107 sysctl net.inet.ip.fw.one_pass=0
112 node can be inserted right after the
115 In the following example, we perform masquerading on a
116 serial line with HDLC encapsulation.
117 .Bd -literal -offset indent
118 /usr/sbin/ngctl -f- <<-SEQ
119 mkpeer cp0: cisco rawdata downstream
120 name cp0:rawdata hdlc
121 mkpeer hdlc: nat inet in
123 mkpeer nat: iface out inet
124 msg nat: setaliasaddr x.y.8.35
126 ifconfig ng0 x.y.8.35 x.y.8.1
136 node type was implemented in
139 .An Gleb Smirnoff Aq glebius@FreeBSD.org