1.\"
2.\" Copyright (c) 2001-2003
3.\" Fraunhofer Institute for Open Communication Systems (FhG Fokus).
4.\" All rights reserved.
5.\"
6.\" Author: Harti Brandt <harti@freebsd.org>
7.\"
8.\" Redistribution of this software and documentation and use in source and
9.\" binary forms, with or without modification, are permitted provided that
10.\" the following conditions are met:
11.\"
12.\" 1. Redistributions of source code or documentation must retain the above
13.\" copyright notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\" notice, this list of conditions and the following disclaimer in the
16.\" documentation and/or other materials provided with the distribution.
17.\" 3. Neither the name of the Institute nor the names of its contributors
18.\" may be used to endorse or promote products derived from this software
19.\" without specific prior written permission.
20.\"
21.\" THIS SOFTWARE AND DOCUMENTATION IS PROVIDED BY FRAUNHOFER FOKUS
22.\" AND ITS CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
24.\" FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
25.\" FRAUNHOFER FOKUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
28.\" OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29.\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30.\" NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
31.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32.\"
33.\" $Begemot: bsnmp/snmp_mibII/snmp_mibII.3,v 1.3 2004/04/13 17:01:31 novo Exp $
34.\"
35.Dd August 19, 2002
36.Dt snmp_mibII 3
37.Os
38.Sh NAME
39.Nm mibII ,
40.Nm mibif_notify_f ,
41.Nm mib_netsock ,
42.Nm mib_if_set_dyn ,
43.Nm mib_refresh_iflist ,
44.Nm mib_find_if ,
45.Nm mib_find_if_sys ,
46.Nm mib_find_if_name ,
47.Nm mib_first_if ,
48.Nm mib_next_if ,
49.Nm mib_register_newif ,
50.Nm mib_unregister_newif ,
51.Nm mib_fetch_ifmib ,
52.Nm mib_if_admin ,
53.Nm mib_find_ifa ,
54.Nm mib_first_ififa ,
55.Nm mib_next_ififa ,
56.Nm mib_ifstack_create ,
57.Nm mib_ifstack_delete ,
58.Nm mib_find_rcvaddr ,
59.Nm mib_rcvaddr_create ,
60.Nm mib_rcvaddr_delete ,
61.Nm mibif_notify ,
62.Nm mibif_unnotify
63.Nd "mib-2 module for snmpd.
64.Sh LIBRARY
65.Pq begemotSnmpdModulePath."mibII" = "@MODPATH@snmp_mibII.so"
66.Sh SYNOPSIS
67.In bsnmp/snmpmod.h
68.In bsnmp/snmp_mibII.h
69.Ft typedef void
70.Fn (*mibif_notify_f) "struct mibif *ifp" "enum mibif_notify event" "void *uarg"
71.Vt extern int mib_netsock ;
72.Ft void
73.Fn mib_if_set_dyn "const char *ifname"
74.Ft void
75.Fn mib_refresh_iflist "void"
76.Ft struct mibif *
77.Fn mib_find_if "u_int ifindex"
78.Ft struct mibif *
79.Fn mib_find_if_sys "u_int sysindex"
80.Ft struct mibif *
81.Fn mib_find_if_name "const char *ifname"
82.Ft struct mibif *
83.Fn mib_first_if "void"
84.Ft struct mibif *
85.Fn mib_next_if "const struct mibif *ifp"
86.Ft int
87.Fn mib_register_newif "int (*func)(struct mibif *)" "const struct lmodule *mod"
88.Ft void
89.Fn mib_unregister_newif "const struct lmodule *mod"
90.Ft int
91.Fn mib_fetch_ifmib "struct mibif *ifp"
92.Ft int
93.Fn mib_if_admin "struct mibif *ifp" "int up"
94.Ft struct mibifa *
95.Fn mib_find_ifa "struct in_addr ipa"
96.Ft struct mibifa *
97.Fn mib_first_ififa "const struct mibif *ifp"
98.Ft struct mibifa *
99.Fn mib_next_ififa "struct mibifa *ifa"
100.Ft int
101.Fn mib_ifstack_create "const struct mibif *lower" "const struct mibif *upper"
102.Ft void
103.Fn mib_ifstack_delete "const struct mibif *lower" "const struct mibif *upper"
104.Ft struct mibrcvaddr *
105.Fn mib_find_rcvaddr "u_int ifindex" "const u_char *addr" "size_t addrlen"
106.Ft struct mibrcvaddr *
107.Fn mib_rcvaddr_create "struct mibif *ifp" "const u_char *addr" "size_t addrlen"
108.Ft void
109.Fn mib_rcvaddr_delete "struct mibrcvaddr *addr"
110.Ft void *
111.Fn mibif_notify "struct mibif *ifp" "const struct lmodule *mod" "mibif_notify_f func" "void *uarg"
112.Ft void
113.Fn mibif_unnotify "void *reg"
114.Sh DESCRIPTION
115The
116.Nm snmp_mibII
117module implements parts of the internet standard MIB-2. Most of the relevant
118MIBs are implemented. Some of the tables are restricted to be read-only
119instead of read-write. The exact current implementation can be found in
120.Pa @DEFPATH@mibII_tree.def .
121The module also exports a number of functions and global variables for use
122by other modules, that need to handle network interfaces. This man page describes
123these functions.
124.Ss DIRECT NETWORK ACCESS
125The
126.Nm
127module opens a socket that is used to execute all network related
128.Xr ioctl 2
129functions. This socket is globally available under the name
130.Va mib_netsock .
131.Ss NETWORK INTERFACES
132The
133.Nm
134module handles a list of all currently existing network interfaces. It allows
135other modules to handle their own interface lists with special information
136by providing a mechanism to register to events that change the interface list
137(see below). The basic data structure is the interface structure:
138.Bd -literal -offset indent
139struct mibif {
140 TAILQ_ENTRY(mibif) link;
141 u_int flags;
142 u_int index; /* logical ifindex */
143 u_int sysindex;
144 char name[IFNAMSIZ];
145 char descr[256];
146 struct ifmibdata mib;
147 u_int32_t mibtick;
148 void *specmib;
149 size_t specmiblen;
150 u_char *physaddr;
151 u_int physaddrlen;
152 int has_connector;
153 int trap_enable;
154 u_int32_t counter_disc;
155 mibif_notify_f xnotify;
156 void *xnotify_data;
157 const struct lmodule *xnotify_mod;
158};
159.Ed
160.Pp
161The
162.Nm
163module tries to implement the semantic if
164.Va ifIndex
165as described in RFC-2863. This RFC states, that an interface indexes may not
166be reused. That means, for example, if
167.Pa tun
168is a synthetic interface type and the system creates the interface
169.Pa tun0 ,
170destroys this interfaces and again creates a
171.Pa tun 0 ,
172then these interfaces must have different interface indexes, because in fact
173they are different interfaces. If, on the other hand, there is a hardware
174interface
175.Pa xl0
176and this interface disappears, because its driver is unloaded and appears
177again, because the driver is loaded again, the interface index must stay
178the same.
179.Nm
180implements this by differentiating between real and synthetic (dynamic)
181interfaces. An interface type can be declared dynamic by calling the function
182.Fn mib_if_set_dyn
183with the name if the interface type (for example
184.Qq tun ).
185For real interfaces, the module keeps the mapping between the interface name
186and its
187.Va ifIndex
188in a special list, if the interface is unloaded. For dynamic interfaces
189a new
190.Va ifIndex
191is generated each time the interface comes into existance. This
192means, that the interface index as seen by SNMP is not the same index
193as used by the system. The SNMP
194.Va ifIndex
195is held in field
196.Va index ,
197the system's interface index is
198.Va sysindex .
199.Pp
200A call to
201.Nm mib_refresh_iflist
202causes the entire interface list to be re-created.
203.Pp
204The interface list can be traversed with the functions
205.Fn mib_first_if
206and
207.Fn mib_next_if .
208Be sure not to change the interface list while traversing the list with
209these two calls.
210.Pp
211There are three functions to find an interface by name or index.
212.Fn mib_find_if
213finds an interface by searching for an SNMP
214.Va ifIndex ,
215.Fn mib_find_if_sys
216finds an interface by searching for a system interface index and
217.Fn mib_find_if_name
218finds an interface by looking for an interface name. Each of the
219function returns
220.Li NULL
221if the interface cannot be found.
222.Pp
223The function
224.Fn mib_fetch_ifmib
225causes the interface MIB to be refreshed from the kernel.
226.Pp
227The function
228.Fn mib_if_admin
229can be used to change the interface administrative state to up
230(argument is 1) or down (argument is 0).
231.Ss INTERFACE EVENTS
232A module can register itself to receive a notification when a new entry is
233created in the interface list. This is done by calling
234.Fn mib_register_newif .
235A module can register only one function, a second call to
236.Fn mib_register_newif
237causes the registration to be overwritten. The registration can be removed
238with a call to
239.Fn mib_unregister_newif .
240If is unregistered automatically, when the registering module is unloaded.
241.Pp
242A module can also register to events on a specific interface. This is done
243by calling
244.Fn mibif_notify .
245This causes the given callback
246.Fa func
247to be called with the interface pointer, a notification code and
248the user argument
249.Fa uarg
250when any of the following events occur:
251.Bl -tag -width "XXXXX"
252.It Li MIBIF_NOTIFY_DESTROY
253The interface is destroyed.
254.El
255.Pp
256This mechanism can be used to implement interface type specific MIB parts
257in other modules. The registration can be removed with
258.Fn mib_unnotify
259which the return value from
260.Fa mib_notify .
261Any notification registration is removed automatically when the interface
262is destroyed or the registering module is unloaded.
263.Em Note that only one module can register to any given interface .
264.Ss INTERFACE ADDRESSES
265The
266.Nm
267module handles a table of interface IP-addresses. These addresses are held
268in a
269.Bd -literal -offset indent
270struct mibifa {
271 TAILQ_ENTRY(mibifa) link;
272 struct in_addr inaddr;
273 struct in_addr inmask;
274 struct in_addr inbcast;
275 struct asn_oid index;
276 u_int ifindex;
277 u_int flags;
278};
279.Ed
280.Pp
281The (ordered) list of IP-addresses on a given interface can be traversed by
282calling
283.Fn mib_first_ififa
284and
285.Fn mib_next_ififa .
286The list should not be considered read-only.
287.Ss INTERFACE RECEIVE ADDRESSES
288The internet MIB-2 contains a table of interface receive addresses. These
289addresses are handled in:
290.Bd -literal -offset indent
291struct mibrcvaddr {
292 TAILQ_ENTRY(mibrcvaddr) link;
293 struct asn_oid index;
294 u_int ifindex;
295 u_char addr[ASN_MAXOIDLEN];
296 size_t addrlen;
297 u_int flags;
298};
299enum {
300 MIBRCVADDR_VOLATILE = 0x00000001,
301 MIBRCVADDR_BCAST = 0x00000002,
302 MIBRCVADDR_HW = 0x00000004,
303};
304.Ed
305.Pp
306Note, that the assignment of
307.Li MIBRCVADDR_BCAST
308is based on a list of known interface types. The flags should be handled
309by modules inplementing interface type specific MIBs.
310.Pp
311A receive address can be created with
312.Fn mib_rcvaddr_create
313and deleted with
314.Fn mib_rcvaddr_delete .
315This needs to be done only for addresses that are not automatically handled
316by the system.
317.Pp
318A receive address can be found with
319.Fn mib_find_rcvaddr .
320.Ss INTERFACE STACK TABLE
321The
322.Nm
323module maintains also the interface stack table. Because for complex stacks,
324there is no system supported generic way of getting this information, interface
325type specific modules need to help setting up stack entries. The
326.Nm
327module handles only the top and bottom entries.
328.Pp
329A table entry is created with
330.Fn mib_ifstack_create
331and deleted with
332.Fn mib_ifstack_delete .
333Both functions need the pointers to the interfaces. Entries are automatically
334deleted if any of the interfaces of the entry is destroyed. The functions handle
335both the stack table and the reverse stack table.
336.Sh FILES
337.Bl -tag -width ".It Pa @DEFPATH@mibII_tree.def" -compact
338.It Pa @DEFPATH@mibII_tree.def
339The description of the MIB tree implemented by
340.Nm .
341.It Pa /usr/local/share/snmp/mibs
342.It Pa @MIBSPATH@
343The various internet MIBs.
344.Sh SEE ALSO
345.Xr snmpmod 3 ,
346.Xr gensnmptree 1
347.Sh STANDARDS
348This implementation conforms to the applicable IETF RFCs.
349.Sh AUTHORS
350.An Hartmut Brandt Aq harti@freebsd.org
2.\" Copyright (c) 2001-2003
3.\" Fraunhofer Institute for Open Communication Systems (FhG Fokus).
4.\" All rights reserved.
5.\"
6.\" Author: Harti Brandt <harti@freebsd.org>
7.\"
8.\" Redistribution of this software and documentation and use in source and
9.\" binary forms, with or without modification, are permitted provided that
10.\" the following conditions are met:
11.\"
12.\" 1. Redistributions of source code or documentation must retain the above
13.\" copyright notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\" notice, this list of conditions and the following disclaimer in the
16.\" documentation and/or other materials provided with the distribution.
17.\" 3. Neither the name of the Institute nor the names of its contributors
18.\" may be used to endorse or promote products derived from this software
19.\" without specific prior written permission.
20.\"
21.\" THIS SOFTWARE AND DOCUMENTATION IS PROVIDED BY FRAUNHOFER FOKUS
22.\" AND ITS CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
23.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
24.\" FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
25.\" FRAUNHOFER FOKUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
28.\" OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29.\" LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30.\" NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
31.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32.\"
33.\" $Begemot: bsnmp/snmp_mibII/snmp_mibII.3,v 1.3 2004/04/13 17:01:31 novo Exp $
34.\"
35.Dd August 19, 2002
36.Dt snmp_mibII 3
37.Os
38.Sh NAME
39.Nm mibII ,
40.Nm mibif_notify_f ,
41.Nm mib_netsock ,
42.Nm mib_if_set_dyn ,
43.Nm mib_refresh_iflist ,
44.Nm mib_find_if ,
45.Nm mib_find_if_sys ,
46.Nm mib_find_if_name ,
47.Nm mib_first_if ,
48.Nm mib_next_if ,
49.Nm mib_register_newif ,
50.Nm mib_unregister_newif ,
51.Nm mib_fetch_ifmib ,
52.Nm mib_if_admin ,
53.Nm mib_find_ifa ,
54.Nm mib_first_ififa ,
55.Nm mib_next_ififa ,
56.Nm mib_ifstack_create ,
57.Nm mib_ifstack_delete ,
58.Nm mib_find_rcvaddr ,
59.Nm mib_rcvaddr_create ,
60.Nm mib_rcvaddr_delete ,
61.Nm mibif_notify ,
62.Nm mibif_unnotify
63.Nd "mib-2 module for snmpd.
64.Sh LIBRARY
65.Pq begemotSnmpdModulePath."mibII" = "@MODPATH@snmp_mibII.so"
66.Sh SYNOPSIS
67.In bsnmp/snmpmod.h
68.In bsnmp/snmp_mibII.h
69.Ft typedef void
70.Fn (*mibif_notify_f) "struct mibif *ifp" "enum mibif_notify event" "void *uarg"
71.Vt extern int mib_netsock ;
72.Ft void
73.Fn mib_if_set_dyn "const char *ifname"
74.Ft void
75.Fn mib_refresh_iflist "void"
76.Ft struct mibif *
77.Fn mib_find_if "u_int ifindex"
78.Ft struct mibif *
79.Fn mib_find_if_sys "u_int sysindex"
80.Ft struct mibif *
81.Fn mib_find_if_name "const char *ifname"
82.Ft struct mibif *
83.Fn mib_first_if "void"
84.Ft struct mibif *
85.Fn mib_next_if "const struct mibif *ifp"
86.Ft int
87.Fn mib_register_newif "int (*func)(struct mibif *)" "const struct lmodule *mod"
88.Ft void
89.Fn mib_unregister_newif "const struct lmodule *mod"
90.Ft int
91.Fn mib_fetch_ifmib "struct mibif *ifp"
92.Ft int
93.Fn mib_if_admin "struct mibif *ifp" "int up"
94.Ft struct mibifa *
95.Fn mib_find_ifa "struct in_addr ipa"
96.Ft struct mibifa *
97.Fn mib_first_ififa "const struct mibif *ifp"
98.Ft struct mibifa *
99.Fn mib_next_ififa "struct mibifa *ifa"
100.Ft int
101.Fn mib_ifstack_create "const struct mibif *lower" "const struct mibif *upper"
102.Ft void
103.Fn mib_ifstack_delete "const struct mibif *lower" "const struct mibif *upper"
104.Ft struct mibrcvaddr *
105.Fn mib_find_rcvaddr "u_int ifindex" "const u_char *addr" "size_t addrlen"
106.Ft struct mibrcvaddr *
107.Fn mib_rcvaddr_create "struct mibif *ifp" "const u_char *addr" "size_t addrlen"
108.Ft void
109.Fn mib_rcvaddr_delete "struct mibrcvaddr *addr"
110.Ft void *
111.Fn mibif_notify "struct mibif *ifp" "const struct lmodule *mod" "mibif_notify_f func" "void *uarg"
112.Ft void
113.Fn mibif_unnotify "void *reg"
114.Sh DESCRIPTION
115The
116.Nm snmp_mibII
117module implements parts of the internet standard MIB-2. Most of the relevant
118MIBs are implemented. Some of the tables are restricted to be read-only
119instead of read-write. The exact current implementation can be found in
120.Pa @DEFPATH@mibII_tree.def .
121The module also exports a number of functions and global variables for use
122by other modules, that need to handle network interfaces. This man page describes
123these functions.
124.Ss DIRECT NETWORK ACCESS
125The
126.Nm
127module opens a socket that is used to execute all network related
128.Xr ioctl 2
129functions. This socket is globally available under the name
130.Va mib_netsock .
131.Ss NETWORK INTERFACES
132The
133.Nm
134module handles a list of all currently existing network interfaces. It allows
135other modules to handle their own interface lists with special information
136by providing a mechanism to register to events that change the interface list
137(see below). The basic data structure is the interface structure:
138.Bd -literal -offset indent
139struct mibif {
140 TAILQ_ENTRY(mibif) link;
141 u_int flags;
142 u_int index; /* logical ifindex */
143 u_int sysindex;
144 char name[IFNAMSIZ];
145 char descr[256];
146 struct ifmibdata mib;
147 u_int32_t mibtick;
148 void *specmib;
149 size_t specmiblen;
150 u_char *physaddr;
151 u_int physaddrlen;
152 int has_connector;
153 int trap_enable;
154 u_int32_t counter_disc;
155 mibif_notify_f xnotify;
156 void *xnotify_data;
157 const struct lmodule *xnotify_mod;
158};
159.Ed
160.Pp
161The
162.Nm
163module tries to implement the semantic if
164.Va ifIndex
165as described in RFC-2863. This RFC states, that an interface indexes may not
166be reused. That means, for example, if
167.Pa tun
168is a synthetic interface type and the system creates the interface
169.Pa tun0 ,
170destroys this interfaces and again creates a
171.Pa tun 0 ,
172then these interfaces must have different interface indexes, because in fact
173they are different interfaces. If, on the other hand, there is a hardware
174interface
175.Pa xl0
176and this interface disappears, because its driver is unloaded and appears
177again, because the driver is loaded again, the interface index must stay
178the same.
179.Nm
180implements this by differentiating between real and synthetic (dynamic)
181interfaces. An interface type can be declared dynamic by calling the function
182.Fn mib_if_set_dyn
183with the name if the interface type (for example
184.Qq tun ).
185For real interfaces, the module keeps the mapping between the interface name
186and its
187.Va ifIndex
188in a special list, if the interface is unloaded. For dynamic interfaces
189a new
190.Va ifIndex
191is generated each time the interface comes into existance. This
192means, that the interface index as seen by SNMP is not the same index
193as used by the system. The SNMP
194.Va ifIndex
195is held in field
196.Va index ,
197the system's interface index is
198.Va sysindex .
199.Pp
200A call to
201.Nm mib_refresh_iflist
202causes the entire interface list to be re-created.
203.Pp
204The interface list can be traversed with the functions
205.Fn mib_first_if
206and
207.Fn mib_next_if .
208Be sure not to change the interface list while traversing the list with
209these two calls.
210.Pp
211There are three functions to find an interface by name or index.
212.Fn mib_find_if
213finds an interface by searching for an SNMP
214.Va ifIndex ,
215.Fn mib_find_if_sys
216finds an interface by searching for a system interface index and
217.Fn mib_find_if_name
218finds an interface by looking for an interface name. Each of the
219function returns
220.Li NULL
221if the interface cannot be found.
222.Pp
223The function
224.Fn mib_fetch_ifmib
225causes the interface MIB to be refreshed from the kernel.
226.Pp
227The function
228.Fn mib_if_admin
229can be used to change the interface administrative state to up
230(argument is 1) or down (argument is 0).
231.Ss INTERFACE EVENTS
232A module can register itself to receive a notification when a new entry is
233created in the interface list. This is done by calling
234.Fn mib_register_newif .
235A module can register only one function, a second call to
236.Fn mib_register_newif
237causes the registration to be overwritten. The registration can be removed
238with a call to
239.Fn mib_unregister_newif .
240If is unregistered automatically, when the registering module is unloaded.
241.Pp
242A module can also register to events on a specific interface. This is done
243by calling
244.Fn mibif_notify .
245This causes the given callback
246.Fa func
247to be called with the interface pointer, a notification code and
248the user argument
249.Fa uarg
250when any of the following events occur:
251.Bl -tag -width "XXXXX"
252.It Li MIBIF_NOTIFY_DESTROY
253The interface is destroyed.
254.El
255.Pp
256This mechanism can be used to implement interface type specific MIB parts
257in other modules. The registration can be removed with
258.Fn mib_unnotify
259which the return value from
260.Fa mib_notify .
261Any notification registration is removed automatically when the interface
262is destroyed or the registering module is unloaded.
263.Em Note that only one module can register to any given interface .
264.Ss INTERFACE ADDRESSES
265The
266.Nm
267module handles a table of interface IP-addresses. These addresses are held
268in a
269.Bd -literal -offset indent
270struct mibifa {
271 TAILQ_ENTRY(mibifa) link;
272 struct in_addr inaddr;
273 struct in_addr inmask;
274 struct in_addr inbcast;
275 struct asn_oid index;
276 u_int ifindex;
277 u_int flags;
278};
279.Ed
280.Pp
281The (ordered) list of IP-addresses on a given interface can be traversed by
282calling
283.Fn mib_first_ififa
284and
285.Fn mib_next_ififa .
286The list should not be considered read-only.
287.Ss INTERFACE RECEIVE ADDRESSES
288The internet MIB-2 contains a table of interface receive addresses. These
289addresses are handled in:
290.Bd -literal -offset indent
291struct mibrcvaddr {
292 TAILQ_ENTRY(mibrcvaddr) link;
293 struct asn_oid index;
294 u_int ifindex;
295 u_char addr[ASN_MAXOIDLEN];
296 size_t addrlen;
297 u_int flags;
298};
299enum {
300 MIBRCVADDR_VOLATILE = 0x00000001,
301 MIBRCVADDR_BCAST = 0x00000002,
302 MIBRCVADDR_HW = 0x00000004,
303};
304.Ed
305.Pp
306Note, that the assignment of
307.Li MIBRCVADDR_BCAST
308is based on a list of known interface types. The flags should be handled
309by modules inplementing interface type specific MIBs.
310.Pp
311A receive address can be created with
312.Fn mib_rcvaddr_create
313and deleted with
314.Fn mib_rcvaddr_delete .
315This needs to be done only for addresses that are not automatically handled
316by the system.
317.Pp
318A receive address can be found with
319.Fn mib_find_rcvaddr .
320.Ss INTERFACE STACK TABLE
321The
322.Nm
323module maintains also the interface stack table. Because for complex stacks,
324there is no system supported generic way of getting this information, interface
325type specific modules need to help setting up stack entries. The
326.Nm
327module handles only the top and bottom entries.
328.Pp
329A table entry is created with
330.Fn mib_ifstack_create
331and deleted with
332.Fn mib_ifstack_delete .
333Both functions need the pointers to the interfaces. Entries are automatically
334deleted if any of the interfaces of the entry is destroyed. The functions handle
335both the stack table and the reverse stack table.
336.Sh FILES
337.Bl -tag -width ".It Pa @DEFPATH@mibII_tree.def" -compact
338.It Pa @DEFPATH@mibII_tree.def
339The description of the MIB tree implemented by
340.Nm .
341.It Pa /usr/local/share/snmp/mibs
342.It Pa @MIBSPATH@
343The various internet MIBs.
344.Sh SEE ALSO
345.Xr snmpmod 3 ,
346.Xr gensnmptree 1
347.Sh STANDARDS
348This implementation conforms to the applicable IETF RFCs.
349.Sh AUTHORS
350.An Hartmut Brandt Aq harti@freebsd.org