xref: /freebsd/share/man/man4/ng_one2many.4 (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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33.\" Author: Archie Cobbs <archie@FreeBSD.org>
34.\"
35.\" $FreeBSD$
36.\"
37.Dd November 13, 2012
38.Dt NG_ONE2MANY 4
39.Os
40.Sh NAME
41.Nm ng_one2many
42.Nd packet multiplexing netgraph node type
43.Sh SYNOPSIS
44.In sys/types.h
45.In netgraph/ng_one2many.h
46.Sh DESCRIPTION
47The
48.Nm one2many
49provides a simple mechanism for routing packets over several links
50in a one-to-many (and in the reverse direction, many-to-one) fashion.
51There is a single hook named
52.Dv one ,
53and multiple hooks named
54.Dv many0 ,
55.Dv many1 ,
56etc.
57Packets received on any of the
58.Dv many
59hooks are forwarded out the
60.Dv one
61hook.
62Packets received on the
63.Dv one
64hook are forwarded out one or more of the
65.Dv many
66hooks; which hook(s) is determined by the node's configured
67transmit algorithm.
68Packets are not altered in any way.
69.Pp
70Each of the connected many links may be considered to be up or down.
71Packets are never delivered out a many hook that is down.
72How a link is determined to be up or down depends on the node's
73configured link failure detection algorithm.
74.Pp
75Before an interface or link can be plumbed into a group, its status
76must be marked as being
77.Dq up .
78This is normally setup during the initial boot stages by
79.Xr rc.conf 5 .
80It is also possible to change an interface's status to
81.Dq up
82by using the
83.Xr ifconfig 8
84utility.
85.Sh TRANSMIT ALGORITHMS
86.Bl -tag -width foo
87.It Dv NG_ONE2MANY_XMIT_ROUNDROBIN
88Packets are delivered out the many hooks in sequential order.
89Each packet goes out on a different
90.Dv many
91hook.
92.It Dv NG_ONE2MANY_XMIT_ALL
93Packets are delivered out all the
94.Dv many
95hooks.
96Each packet goes out each
97.Dv many
98hook.
99.It Dv NG_ONE2MANY_XMIT_FAILOVER
100Packets are delivered out the first active
101.Dv many
102hook.
103.El
104.Pp
105In the future other algorithms may be added as well.
106.Sh LINK FAILURE DETECTION
107The node distinguishes between active and failed links.
108Data is sent only to active links.
109The following link failure detection algorithms are available:
110.Bl -tag -width foo
111.It Dv NG_ONE2MANY_FAIL_MANUAL
112The node is explicitly told which of the links are up via the
113.Dv NGM_ONE2MANY_SET_CONFIG
114control message (see below).
115Newly connected links are down until configured otherwise.
116.It Dv NG_ONE2MANY_FAIL_NOTIFY
117The node listens to flow control message from
118.Va many
119hooks, and considers link failed if
120.Dv NGM_LINK_IS_DOWN
121is received.
122If the
123.Dv NGM_LINK_IS_UP
124message is received, node considers link active.
125.El
126.Pp
127In the future other algorithms may be added as well.
128.Pp
129When all links are considered failed, node sends the
130.Dv NGM_LINK_IS_DOWN
131message towards the
132.Va one
133hook.
134When at least one link comes up, node sends the
135.Dv NGM_LINK_IS_UP
136message towards the
137.Va one
138hook.
139.Sh HOOKS
140This node type supports up to
141.Dv NG_ONE2MANY_MAX_LINKS
142hooks named
143.Dv many0 ,
144.Dv many1 ,
145etc.,
146plus a single hook named
147.Dv one .
148.Sh CONTROL MESSAGES
149This node type supports the generic control messages, plus the
150following:
151.Bl -tag -width foo
152.It Dv NGM_ONE2MANY_SET_CONFIG Pq Ic setconfig
153Sets the node configuration using a
154.Dv "struct ng_one2many_link_config"
155as the control message argument:
156.Bd -literal
157/* Node configuration structure */
158struct ng_one2many_config {
159  uint32_t    xmitAlg;        /* how to distribute packets */
160  uint32_t    failAlg;        /* how to detect link failure */
161  u_char      enabledLinks[NG_ONE2MANY_MAX_LINKS];
162};
163.Ed
164.Pp
165Currently, the valid settings for the
166.Dv xmitAlg
167field are
168.Dv NG_ONE2MANY_XMIT_ROUNDROBIN
169(default) or
170.Dv NG_ONE2MANY_XMIT_ALL .
171The valid settings for
172.Dv failAlg
173are
174.Dv NG_ONE2MANY_FAIL_MANUAL
175(default) or
176.Dv NG_ONE2MANY_FAIL_NOTIFY .
177.It Dv NGM_ONE2MANY_GET_CONFIG Pq Ic getconfig
178Returns the current node configuration in a
179.Dv "struct ng_one2many_link_config" .
180.It Dv NGM_ONE2MANY_GET_STATS Pq Ic getstats
181This command takes a 32 bit link number as an argument and
182returns a
183.Dv "struct ng_one2many_link_stats"
184containing statistics for the corresponding
185.Dv many
186link, which may or may not be currently connected:
187.Bd -literal
188/* Statistics structure (one for each link) */
189struct ng_one2many_link_stats {
190  uint64_t   recvOctets;     /* total octets rec'd on link */
191  uint64_t   recvPackets;    /* total pkts rec'd on link */
192  uint64_t   xmitOctets;     /* total octets xmit'd on link */
193  uint64_t   xmitPackets;    /* total pkts xmit'd on link */
194  uint64_t   memoryFailures; /* times couldn't get mem or mbuf */
195};
196.Ed
197.Pp
198To access statistics for the
199.Dv one
200link, use the link number
201.Dv -1 .
202.It Dv NGM_ONE2MANY_CLR_STATS Pq Ic clrstats
203This command takes a 32 bit link number as an argument and
204clears the statistics for that link.
205.It Dv NGM_ONE2MANY_GETCLR_STATS Pq Ic getclrstats
206Same as
207.Dv NGM_ONE2MANY_GET_STATS ,
208but also atomically clears the statistics for the link as well.
209.El
210.Sh SHUTDOWN
211This node shuts down upon receipt of a
212.Dv NGM_SHUTDOWN
213control message, or when all hooks have been disconnected.
214.Sh EXAMPLES
215The following commands will set up Ethernet interfaces
216.Dv fxp0
217to deliver packets alternating over the physical interfaces
218corresponding to networking interfaces
219.Dv fxp0
220through
221.Dv fxp3 :
222.Bd -literal
223  # Plumb nodes together
224
225  ngctl mkpeer fxp0: one2many upper one
226  ngctl connect fxp0: fxp0:upper lower many0
227  ngctl connect fxp1: fxp0:upper lower many1
228  ngctl connect fxp2: fxp0:upper lower many2
229  ngctl connect fxp3: fxp0:upper lower many3
230
231  # Allow fxp1 through fxp3 to xmit/recv fxp0 frames
232
233  ngctl msg fxp1: setpromisc 1
234  ngctl msg fxp2: setpromisc 1
235  ngctl msg fxp3: setpromisc 1
236  ngctl msg fxp1: setautosrc 0
237  ngctl msg fxp2: setautosrc 0
238  ngctl msg fxp3: setautosrc 0
239
240  # Configure all four links as up
241
242  ngctl msg fxp0:upper \\
243    setconfig "{ xmitAlg=1 failAlg=1 enabledLinks=[ 1 1 1 1 ] }"
244
245  # Bring up interface
246
247  ifconfig fxp0 192.168.1.1 netmask 0xfffffffc
248.Ed
249.Pp
250With a similar setup on a peer machine (using the address
251192.168.1.2), a point-to-point
252Ethernet connection with four times normal bandwidth is
253achieved.
254.Sh SEE ALSO
255.Xr netgraph 4 ,
256.Xr ng_bridge 4 ,
257.Xr ng_ether 4 ,
258.Xr ng_hub 4 ,
259.Xr ifconfig 8 ,
260.Xr ngctl 8
261.Sh HISTORY
262The
263.Nm
264node type was implemented in
265.Fx 4.2 .
266.Sh AUTHORS
267.An -nosplit
268The
269.Nm one2many
270netgraph node (with round-robin algorithm) was written by
271.An Archie Cobbs Aq Mt archie@FreeBSD.org .
272The all algorithm was added by
273.An Rogier R. Mulhuijzen Aq Mt drwilco@drwilco.net .
274.Sh BUGS
275More transmit and link failure algorithms should be supported.
276A good candidate is Cisco's Etherchannel.
277