1snmpm_user(3) Erlang Module Definition snmpm_user(3)
2
6 snmpm_user - Behaviour module for the SNMP manager user.
7
9 This module defines the behaviour of the manager user. A snmpm_user
10 compliant module must export the following functions:
11 * handle_error/3
13 * handle_agent/4
15 * handle_pdu/4
17 * handle_trap/3
19 * handle_inform/3
21 * handle_report/3
23 * handle_invalid_result/2
25 The semantics of them and their exact signatures are explained below.
27 Some of the function has no defined return value (void()), they can of
29 course return anything. But the functions that do have specified return
30 value(s) must adhere to this. None of the functions can use exit of
31 throw to return.
32 If the manager is not configured to use any particular transport do‐
34 main, the behaviour handle_agent/4 will for backwards copmpatibility
35 reasons be called with the old IpAddr and PortNumber arguments
36
38 snmp_gen_info() = {ErrorStatus :: atom(),
39 ErrorIndex :: pos_integer(),
40 Varbinds :: [snmp:varbind()]}
41 snmp_v1_trap_info() :: {Enteprise :: snmp:oid(),
42 Generic :: integer(),
43 Spec :: integer(),
44 Timestamp :: integer(),
45 Varbinds :: [snmp:varbind()]}
46
49 handle_error(ReqId, Reason, UserData) -> void()
50 Types:
52 ReqId = netif | integer()
54 Reason = {unexpected_pdu, SnmpInfo} | {invalid_sec_info,
55 SecInfo, SnmpInfo} | {empty_message, Addr, Port} | term()
56 SnmpInfo = snmp_gen_info()
57 SecInfo = term()
58 Addr = ip_address()
59 Port = integer()
60 UserData = term()
61 This function is called when the manager needs to communicate an
63 "asynchronous" error to the user: e.g. failure to send an asyn‐
64 chronous message (i.e. encoding error), a received message was
65 discarded due to security error, the manager failed to generate
66 a response message to a received inform-request, or when receiv‐
67 ing an unexpected PDU from an agent (could be an expired async
68 request).
69 If ReqId is less then 0, it means that this information was not
71 available to the manager (that info was never retrieved before
72 the message was discarded).
73 For SnmpInfo see handle_agent below.
75 Note that there is a special case when the value of ReqId has
77 the value of the atom netif. This means that the NetIF process
78 has suffered a "fatal" error and been restarted. With possible
79 loss of traffic!
80 handle_agent(Domain, Addr, Type, SnmpInfo, UserData) -> Reply
82 Types:
84 Domain = transportDomainUdpIpv4 | transportDomainUdpIpv6
86 Addr = {inet:ip_address(), inet:port_number()}
87 Type = pdu | trap | report | inform
88 SnmpInfo = SnmpPduInfo | SnmpTrapInfo | SnmpReportInfo | Sn‐
89 mpInformInfo
90 SnmpPduInfo = snmp_gen_info()
91 SnmpTrapInfo = snmp_v1_trap_info()
92 SnmpReportInfo = snmp_gen_info()
93 SnmpInformInfo = snmp_gen_info()
94 UserData = term()
95 Reply = ignore | {register, UserId, TargetName, AgentConfig}
96 UserId = term()
97 TargetName = target_name()
98 AgentConfig = [agent_config()]
99 This function is called when a message is received from an un‐
101 known agent.
102 Note that this will always be the default user that is called.
104 For more info about the agent_config(), see register_agent.
106 The arguments Type and SnmpInfo relates in the following way:
108 * pdu - SnmpPduInfo (see handle_pdu for more info).
110 * trap - SnmpTrapInfo (see handle_trap for more info).
112 * report - SnmpReportInfo (see handle_report for more info).
114 * inform - SnmpInformInfo (see handle_inform for more info).
116 The only user which would return {register, UserId, TargetName,
118 AgentConfig} is the default user.
119 handle_pdu(TargetName, ReqId, SnmpPduInfo, UserData) -> void()
121 Types:
123 TargetName = target_name()
125 ReqId = term()
126 SnmpPduInfo = snmp_gen_info()
127 UserData = term()
128 Handle the reply to an asynchronous request, such as async_get,
130 async_get_next or async_set.
131 It could also be a late reply to a synchronous request.
133 ReqId is returned by the asynchronous request function.
135 handle_trap(TargetName, SnmpTrapInfo, UserData) -> Reply
137 Types:
139 TargetName = TargetName2 = target_name()
141 SnmpTrapInfo = snmp_v1_trap_info() | snmp_gen_info()
142 UserData = term()
143 Reply = ignore | unregister | {register, UserId, TargetName2,
144 AgentConfig}
145 UserId = term()
146 AgentConfig = [agent_config()]
147 Handle a trap/notification message from an agent.
149 For more info about the agent_config(), see register_agent
151 The only user which would return {register, UserId, TargetName2,
153 agent_info()} is the default user.
154 handle_inform(TargetName, SnmpInformInfo, UserData) -> Reply
156 Types:
158 TargetName = TargetName2 = target_name()
160 SnmpInformInfo = snmp_gen_info()
161 UserData = term()
162 Reply = ignore | no_reply | unregister | {register, UserId,
163 TargetName2, AgentConfig}
164 UserId = term()
165 AgentConfig = [agent_config()]
166 Handle a inform message.
168 For more info about the agent_config(), see register_agent
170 The only user which would return {register, UserId, TargetName2,
172 AgentConfig} is the default user.
173 If the inform request behaviour configuration option is set to
175 user or {user, integer()}, the response (acknowledgment) to this
176 inform-request will be sent when this function returns.
177 handle_report(TargetName, SnmpReportInfo, UserData) -> Reply
179 Types:
181 TargetName = TargetName2 = target_name()
183 Addr = ip_address()
184 Port = integer()
185 SnmpReportInfo = snmp_gen_info()
186 UserData = term()
187 Reply = ignore | unregister | {register, UserId, TargetName2,
188 AgentConfig}
189 UserId = term()
190 AgentConfig = [agent_config()]
191 Handle a report message.
193 For more info about the agent_config(), see register_agent
195 The only user which would return {register, UserId, TargetName2,
197 AgentConfig} is the default user.
198 handle_invalid_result(IN, OUT) -> void()
200 Types:
202 IN = {Func, Args}
204 Func = atom()
205 Args = list()
206 OUT = {crash, CrashInfo} | {result, InvalidResult}
207 CrashInfo = {ErrorType, Error, Stacktrace}
208 ErrorType = atom()
209 Error = term()
210 Stacktrace = list()
211 InvalidResult = term()
212 If any of the other callback functions crashes (exit, throw or a
214 plain crash) or return an invalid result (if a valid return has
215 been specified), this function is called. The purpose is to al‐
216 low the user handle this error (for instance to issue an error
217 report).
218 IN reprecents the function called (and its arguments). OUT rep‐
220 resents the unexpected/invalid result.
221Ericsson AB snmp 5.15 snmpm_user(3)