Interface functions to the SNMP toolkit
The module snmp contains interface functions to the SNMP toolkit.
See Also
calendar(3)
Summary
Types
The Erlang representation of the SNMP BITS (pseudo) data type.
The input to the validator fun looks like this
A string, that is a file path to a directory.
0 is used when error status is noError and when error status is an actual
error; error index is pos_integer/0.
We should really specify all of these, but they are so numerous... Also,
normally all you need to know is that 'noError' is ok and everything else is
an error.
This is basically a copy of the dlog_size().
Represent an ASN.1 OBJECT IDENTIFIER.
The data type DateAndTime, an OCTET STRING, as specified in RFC1903.
Denotes the last part of the OID which specifies the index of the row in the table (see RFC1212, 4.1.6 for more information about INDEX).
For the lowest verbosity silence, nothing is printed. The higher the
verbosity, the more is printed.
The type is used when a functions return is to be ignored.
Functions
Utility function for converting a value of type BITS to OCTET-STRING,
according to RFC1906, section 8.
Changes the log size of the Audit Trail Log. The application must be configured to use the audit trail log function. Please refer to disk_log(3) in Kernel Reference Manual for a description of how to change the log size.
A simple interactive configuration tool. Simple configuration files can be generated, but more complex configurations still have to be edited manually.
Returns current date and time as the data type DateAndTime, as specified in RFC1903. This is an OCTET STRING.
Converts a DateAndTime list to a printable string, according to the DISPLAY-HINT definition in RFC2579, with the extension that it also allows the values "hours from UTC" = 14 together with "minutes from UTC" = 0.
Converts a DateAndTime list to a printable string, according to the DISPLAY-HINT definition in RFC2579.
Converts a DateAndTime list to a list of possible universal time(s). The universal time value on the same format as defined in calendar(3).
Stop the tracer.
Starts a dbg tracer that prints trace events to stdout (using plain io:format after a minor formatting).
Converts a local time value to a list of possible DateAndTime list(s). The local time value on the same format as defined in calendar(3).
Converts an Audit Trail Log to a readable format and prints it on stdio. See
log_to_txt/8 for more info.
Converts an Audit Trail Log to a readable text file, where each item has a trailing TAB character, and any TAB character in the body of an item has been replaced by ESC TAB.
Utility function for converting a value of type OCTET-STRING to BITS,
according to RFC1906, section 8.
Generates a key that can be used as an authentication or privacy key using MD5, SHA, SHA224, SHA256, SHA384 or SHA512. The key is localized for EngineID.
Utility function(s) to produce a formatted printout of the versions info
generated by the versions1 function
Utility function to produce a formatted printout of the versions info generated
by the versions1 and versions2 functions
Read a compiled mib.
This function is used to reset (disable) trace for the given module(s).
This function is used to set up default trace on function(s) for the given module or modules. The scope of the trace will be all exported functions (both the call info and the return value). Timestamp info will also be included.
This function is used to set up trace on function(s) for the given module or modules.
Starts the SNMP application.
The SNMP application consists of several entities, of which the agent is one. This function starts the agent entity of the application.
The SNMP application consists of several entities, of which the manager is one. This function starts the manager entity of the application.
Stops the SNMP application.
Converts a universal time value to a DateAndTime list. The universal time value on the same format as defined in calendar(3).
Checks if DateAndTime is a correct DateAndTime value, as specified in RFC2579.
This function can be used in instrumentation functions to validate a DateAndTime
value.
Utility functions used to retrieve some system and application info.
Types
-type algorithm() :: md5 | sha | sha224 | sha256 | sha384 | sha512.
-type atl_type() :: read | write | read_write.
-type bits() :: integer().
The Erlang representation of the SNMP BITS (pseudo) data type.
-type column() :: pos_integer().
-type community() :: snmp_community_mib:name().
-type context_name() :: snmp_community_mib:context_name().
-type date_and_time_validator() :: fun((Kind :: date_and_time_validator_kind(), Data :: term()) -> boolean()).
The input to the validator fun looks like this:
Kind Data
-------------- ----------------------
year {Year1, Year2}
month Month
day Day
hour Hour
minute Minute
seconds Seconds
deci_seconds DeciSeconds
diff [Sign, Hour, Minute]
valid_date {Year, Month, Day}-type date_and_time_validator_kind() ::
year | month | day | hour | minute | seconds | deci_seconds | diff | valid_date.
-type dir() :: string().
A string, that is a file path to a directory.
-type engine_id() :: snmp_framework_mib:engine_id().
-type error_index() :: non_neg_integer().
0 is used when error status is noError and when error status is an actual
error; error index is pos_integer/0.
-type error_status() :: noError | atom().
We should really specify all of these, but they are so numerous... Also,
normally all you need to know is that 'noError' is ok and everything else is
an error.
-type log_size() :: infinity | pos_integer() | {MaxNoBytes :: pos_integer(), MaxNoFiles :: pos_integer()}.
This is basically a copy of the dlog_size().
-type log_time() :: calendar:datetime() | {local_time, calendar:datetime()} | {universal_time, calendar:datetime()}.
-type mib_name() :: string().
-type mms() :: snmp_framework_mib:max_message_size().
-type octet() :: 0..255.
-type octet_string() :: [octet()].
-type oid() :: [non_neg_integer()].
Represent an ASN.1 OBJECT IDENTIFIER.
-type pdu_type() :: snmp_pdus:pdu_type().
-type rfc1903_date_and_time() :: octet_string().
The data type DateAndTime, an OCTET STRING, as specified in RFC1903.
-type row_index() :: oid().
Denotes the last part of the OID which specifies the index of the row in the table (see RFC1212, 4.1.6 for more information about INDEX).
-type row_pointer() :: oid().
Note
"Represents a pointer to a conceptual row. The value is the name of the instance of the first accessible columnar object in the conceptual row."
OBJECT IDENTIFIER
Defined by SNMPv2-TC.
-type sec_level() :: snmp_framework_mib:security_level().
-type sec_model() :: snmp_framework_mib:security_model().
-type sec_name() :: snmp_framework_mib:admin_string().
-type taddress() :: snmpa_conf:transportAddress().
-type tdomain() :: transportDomainUdpIpv4 | transportDomainUdpIpv6.
-type time_interval() :: 0..2147483647.
Note
"A period of time, measured in units of 0.01 seconds."
INTEGER (0..2147483647)
Defined by SNMPv2-TC.
-type usm_auth_key() :: snmp_user_based_sm_mib:auth_key().
-type usm_auth_protocol() :: snmp_user_based_sm_mib:auth_protocol().
-type usm_name() :: snmp_user_based_sm_mib:name().
-type usm_priv_key() :: snmp_user_based_sm_mib:priv_key().
-type usm_priv_protocol() :: snmp_user_based_sm_mib:priv_protocol().
-type variable_info() :: #variable_info{defval :: term()}.
-type verbosity() :: silence | info | log | debug | trace.
For the lowest verbosity silence, nothing is printed. The higher the
verbosity, the more is printed.
-type version() :: v1 | v2 | v3.
-type void() :: term().
The type is used when a functions return is to be ignored.
Functions
bits_to_octet_string(B :: bits()) -> octet_string()
Utility function for converting a value of type BITS to OCTET-STRING,
according to RFC1906, section 8.
Changes the log size of the Audit Trail Log. The application must be configured to use the audit trail log function. Please refer to disk_log(3) in Kernel Reference Manual for a description of how to change the log size.
The change is permanent, as long as the log is not deleted. That means, the log size is remembered across reboots.
A simple interactive configuration tool. Simple configuration files can be generated, but more complex configurations still have to be edited manually.
The tool is a textual based tool that asks some questions and generates
sys.config and *.conf files.
Note that if the application shall support version 3, then the crypto app must be started before running this function (password generation).
Note also that some of the configuration files for the agent and manager share the same names. This means that they have to be stored in different directories!
Types
DateAndTime = rfc1903_date_and_time()
Returns current date and time as the data type DateAndTime, as specified in RFC1903. This is an OCTET STRING.
date_and_time_to_string2(DAT :: rfc1903_date_and_time()) -> string()
Converts a DateAndTime list to a printable string, according to the DISPLAY-HINT definition in RFC2579, with the extension that it also allows the values "hours from UTC" = 14 together with "minutes from UTC" = 0.
date_and_time_to_string(DAT, Validate) -> string()
Converts a DateAndTime list to a printable string, according to the DISPLAY-HINT definition in RFC2579.
The validation fun, Validate, allows for a more "flexible" validation of the
DateAndTime argument. Whenever the data is found to not follow RFC2579, the
fun is called to allow a more "lax" validation. See the
validate_date_and_time/2 function for
more info on the Validate fun.
date_and_time_to_universal_time_dst(DAT :: rfc1903_date_and_time()) -> UTCs
Types
UTCs = [calendar:datetime1970()]
Converts a DateAndTime list to a list of possible universal time(s). The universal time value on the same format as defined in calendar(3).
disable_trace() -> void()
Stop the tracer.
enable_trace() -> void()
Starts a dbg tracer that prints trace events to stdout (using plain io:format after a minor formatting).
local_time_to_date_and_time_dst(Local :: calendar:datetime1970()) -> DATs
Types
DATs = [rfc1903_date_and_time()]
Converts a local time value to a list of possible DateAndTime list(s). The local time value on the same format as defined in calendar(3).
-spec log_to_io(LogDir, Mibs, LogName, LogFile) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_io(LogDir, Mibs, LogName, LogFile, Block) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Block :: boolean(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term(); (LogDir, Mibs, LogName, LogFile, Start) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Start :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_io(LogDir, Mibs, LogName, LogFile, Block, Start) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Block :: boolean(), Start :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term(); (LogDir, Mibs, LogName, LogFile, Start, Stop) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Start :: null | log_time(), Stop :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_io(LogDir, Mibs, LogName, LogFile, Block, Start, Stop) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], LogName :: string(), LogFile :: string(), Block :: boolean(), Start :: null | log_time(), Stop :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
Converts an Audit Trail Log to a readable format and prints it on stdio. See
log_to_txt/8 for more info.
-spec log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Block :: boolean(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term(); (LogDir, Mibs, OutFile, LogName, LogFile, Start) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Start :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block, Start) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Block :: boolean(), Start :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term(); (LogDir, Mibs, OutFile, LogName, LogFile, Start, Stop) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Start :: null | log_time(), Stop :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
-spec log_to_txt(LogDir, Mibs, OutFile, LogName, LogFile, Block, Start, Stop) -> ok | {ok, Cnt} | {error, Reason} when LogDir :: string(), Mibs :: [mib_name()], OutFile :: string(), LogName :: string(), LogFile :: string(), Block :: boolean(), Start :: null | log_time(), Stop :: null | log_time(), Cnt :: {NumOK, NumERR}, NumOK :: non_neg_integer(), NumERR :: pos_integer(), Reason :: term().
Converts an Audit Trail Log to a readable text file, where each item has a trailing TAB character, and any TAB character in the body of an item has been replaced by ESC TAB.
The function can be used on a running system, or by copying the entire log directory and calling this function. SNMP must be running in order to provide MIB information.
LogDir is the name of the directory where the audit trail log is stored.
Mibs is a list of Mibs to be used. The function uses the information in the
Mibs to convert for example object identifiers to their symbolic name. OutFile
is the name of the generated text-file. LogName is the name of the log,
LogFile is the name of the log file. Start is the start (first) date and
time from which log events will be converted and Stop is the stop (last) date
and time to which log events will be converted. The Block argument indicates
if the log should be blocked during conversion. This could be useful when
converting large logs (when otherwise the log could wrap during conversion).
Defaults to true.
The format of an audit trail log text item is as follows:
Tag Addr - Community [TimeStamp] VsnPDU
where Tag is request, response, report, trap or inform; Addr is
IP:Port (or comma space separated list of such); Community is the community
parameter (SNMP version v1 and v2), or SecLevel:"AuthEngineID":"UserName"
(SNMP v3); TimeStamp is a date and time stamp, and Vsn is the SNMP version.
PDU is a textual version of the protocol data unit. There is a new line
between Vsn and PDU.
If the entire log is successfully converted, the function will return ok. If
one of more entries fail to convert, the function will instead return
{ok, {NumOK, NumERR}}, where the counters indicate how many valid and
erroneous entries where found. If instead {error, Reason} is returned, the
conversion encountered a fatal error and where either never done of aborted
midway.
octet_string_to_bits(S :: octet_string()) -> bits()
Utility function for converting a value of type OCTET-STRING to BITS,
according to RFC1906, section 8.
Generates a key that can be used as an authentication or privacy key using MD5, SHA, SHA224, SHA256, SHA384 or SHA512. The key is localized for EngineID.
print_version_info(Prefix :: string() | non_neg_integer()) -> void()
Utility function(s) to produce a formatted printout of the versions info
generated by the versions1 function
This is the same as doing, e.g.:
{ok, V} = snmp:versions1(),
snmp:print_versions(V).print_versions(Prefix, Versions) -> void()
Utility function to produce a formatted printout of the versions info generated
by the versions1 and versions2 functions
Example:
{ok, V} = snmp:versions1(),
snmp:print_versions(V).read_mib(FileName :: string()) -> Result
Read a compiled mib.
This function is used to reset (disable) trace for the given module(s).
Types
TargetOpt = {return_trace, boolean()} | {scope, Scope}
Scope = all_functions | exported_functions | FunctionName | {FunctionName, FunctionArity}
FunctionName = atom()
FunctionArity = non_neg_integer()
This function is used to set up default trace on function(s) for the given module or modules. The scope of the trace will be all exported functions (both the call info and the return value). Timestamp info will also be included.
set_trace(Targets, TraceOpts) -> void()
Types
Targets = module() | [module() | {module(), [TargetOpt]}]
TraceOpts = disable | [TraceOpt]
TargetOpt = {return_trace, boolean()} | {scope, Scope}
Scope = all_functions | exported_functions | FunctionName | {FunctionName, FunctionArity}
FunctionName = atom()
FunctionArity = non_neg_integer()
TraceOpt = {timestamp, boolean()} | TargetOpt
This function is used to set up trace on function(s) for the given module or modules.
The example below sets up trace on the exported functions (default) of module
snmp_generic and all functions of module snmp_generic_mnesia. With return
values (which is default) and timestamps in both cases (which is also default):
snmp:enable_trace(),
snmp:set_trace([snmp_generic,
{snmp_generic_mnesia, [{scope, all_functions}]}]),
.
.
.
snmp:set_trace(snmp_generic, disable),
.
.
.
snmp:disable_trace(),Types
Type = p | permanent | tr | transient | te | temporary
Result = ok | {error, Reason}
Reason = term()
Starts the SNMP application.
See application for more info.
start_agent(Type :: application:start_type()) -> Result
The SNMP application consists of several entities, of which the agent is one. This function starts the agent entity of the application.
Note that the only way to actually start the agent in this way is to add the
agent related config after starting the application (e.g it cannot be part of
the normal application config; sys.config). This is done by calling:
application:set_env(snmp, agent, Conf).
The default value for Type is normal.
start_manager(Type :: application:start_type()) -> Result
The SNMP application consists of several entities, of which the manager is one. This function starts the manager entity of the application.
Note that the only way to actually start the manager in this way is to add the
manager related config after starting the application (e.g it cannot be part of
the normal application config; sys.config). This is done by calling:
application:set_env(snmp, manager, Conf).
The default value for Type is normal.
Stops the SNMP application.
See application for more info.
This function has existed for long time, but not had a proper since tag, so to simplify we set the since tag to when it was documented.
universal_time_to_date_and_time(UTC :: calendar:datetime()) -> DateAndTime
Types
DateAndTime = rfc1903_date_and_time()
Converts a universal time value to a DateAndTime list. The universal time value on the same format as defined in calendar(3).
validate_date_and_time(DateAndTime, Validate) -> boolean()
Checks if DateAndTime is a correct DateAndTime value, as specified in RFC2579.
This function can be used in instrumentation functions to validate a DateAndTime
value.
The validation fun, Validate, allows for a more "flexible" validation of the
DateAndTime argument. Whenever the data is found to not follow RFC2579, the
fun is called to allow a more "lax" validation.
Types
Result = {ok, VersionsInfo} | {error, Reason}
Reason = VersionInfo = term()
VersionsInfo = [VersionInfo]
Utility functions used to retrieve some system and application info.
The difference between the two functions is in how they get the modules to
check. versions1 uses the app-file and versions2 uses the function
application:get_key.