table: Helps you implement a table.(3)

NAME
table: Helps you implement a table. - This handler helps you implement a table by doing some of the processing for you. More...

  Modules
table_array: Helps you implement a table when data can be stored locally. The data is stored in a sorted array, using a binary search for lookups.
The table_array handler is used (automatically) in conjuntion with the table handler.

table_data: Helps you implement a table with datamatted storage.
This helper helps you implement a table where all the indexes are expected to be stored within the agent itself and not in some external storage location.

table_iterator: The table iterator helper is designed to simplify the task of writing a table handler for the net-snmp agent when the data being accessed is not in an oid sorted form and must be accessed externally.
Functionally, it is a specialized version of the more generic table helper but easies the burden of GETNEXT processing by manually looping through all the data indexes retrieved through function calls which should be supplied by the module that wishes help.

  Functions
netsnmp_mib_handler * netsnmp_get_table_handler (netsnmp_table_registration_info *tabreq)
Given a netsnmp_table_registration_info object, creates a table handler.
int netsnmp_register_table (netsnmp_handler_registration *reginfo, netsnmp_table_registration_info *tabreq)
creates a table handler given the netsnmp_table_registration_info object, inserts it into the request chain and then calls netsnmp_register_handler() to register the table into the agent.
NETSNMP_INLINE netsnmp_table_request_info * netsnmp_extract_table_info (netsnmp_request_info *request)
Extracts the processed table information from a given request.
netsnmp_table_registration_info * netsnmp_find_table_registration_info (netsnmp_handler_registration *reginfo)
extracts the registered netsnmp_table_registration_info object from a netsnmp_handler_registration object
int table_helper_handler (netsnmp_mib_handler *handler, netsnmp_handler_registration *reginfo, netsnmp_agent_request_info *reqinfo, netsnmp_request_info *requests)
implements the table helper handler
int netsnmp_table_build_result (netsnmp_handler_registration *reginfo, netsnmp_request_info *reqinfo, netsnmp_table_request_info *table_info, u_char type, u_char *result, size_t result_len)
Builds the result to be returned to the agent given the table information.
int netsnmp_table_build_oid (netsnmp_handler_registration *reginfo, netsnmp_request_info *reqinfo, netsnmp_table_request_info *table_info)
given a registration info object, a request object and the table info object it builds the request->requestvb->name oid from the index values and column information found in the table_info object.
int netsnmp_table_build_oid_from_index (netsnmp_handler_registration *reginfo, netsnmp_request_info *reqinfo, netsnmp_table_request_info *table_info)
Builds an oid from index information.
int netsnmp_update_variable_list_from_index (netsnmp_table_request_info *tri)
parses an OID into table indexses
int netsnmp_update_indexes_from_variable_list (netsnmp_table_request_info *tri)
builds an oid given a set of indexes.
int netsnmp_check_getnext_reply (netsnmp_request_info *request, oid *prefix, size_t prefix_len, netsnmp_variable_list *newvar, netsnmp_variable_list **outvar)
checks the original request against the current data being passed in if its greater than the request oid but less than the current valid return, set the current valid return to the new value.

DETAILED DESCRIPTION

This handler helps you implement a table by doing some of the processing for you.

This handler truly shows the power of the new handler mechanism. By creating a table handler and injecting it into your calling chain, or by using the netsnmp_register_table() function to register your table, you get access to some pre-parsed information. Specifically, the table handler pulls out the column number and indexes from the request oid so that you don't have to do the complex work to do that parsing within your own code.

To do this, the table handler needs to know up front how your table is structured. To inform it about this, you fill in a table_registeration_info structure that is passed to the table handler. It contains the asn index types for the table as well as the minimum and maximum column that should be used.

FUNCTION DOCUMENTATION

  int netsnmp_check_getnext_reply (netsnmp_request_info * request, oid * prefix, size_t prefix_len, netsnmp_variable_list * newvar, netsnmp_variable_list ** outvar)

checks the original request against the current data being passed in if its greater than the request oid but less than the current valid return, set the current valid return to the new value.

returns 1 if outvar was replaced with the oid from newvar (success). returns 0 if not.

Definition at line 700 of file table.c.

References variable_list::name, variable_list::name_length, netsnmp_request_info_s::requestvb, snmp_oid_compare(), snmp_set_var_typed_value(), variable_list::type, variable_list::val, and variable_list::val_len.

  NETSNMP_INLINE netsnmp_table_request_info* netsnmp_extract_table_info (netsnmp_request_info * request)

Extracts the processed table information from a given request.

Call this from subhandlers on a request to extract the processed netsnmp_request_info information. The resulting information includes the index values and the column number.

Parameters:

request
    populated netsnmp request structure

Returns:
populated netsnmp_table_request_info structure

Definition at line 123 of file table.c.

References netsnmp_request_get_list_data().

Referenced by netsnmp_insert_iterator_context(), netsnmp_table_data_helper_handler(), netsnmp_table_data_set_helper_handler(), netsnmp_table_iterator_helper_handler(), and table_helper_handler().

  netsnmp_table_registration_info* netsnmp_find_table_registration_info (netsnmp_handler_registration * reginfo)

extracts the registered netsnmp_table_registration_info object from a netsnmp_handler_registration object

Definition at line 132 of file table.c.

References netsnmp_find_handler_data_by_name().

Referenced by netsnmp_table_data_helper_handler(), and netsnmp_table_iterator_helper_handler().

  netsnmp_mib_handler* netsnmp_get_table_handler (netsnmp_table_registration_info * tabreq)

Given a netsnmp_table_registration_info object, creates a table handler.

You can use this table handler by injecting it into a calling chain. When the handler gets called, it'll do processing and store it's information into the request->parent_data structure.

The table helper handler pulls out the column number and indexes from the request oid so that you don't have to do the complex work of parsing within your own code.

Parameters:

tabreq
    is a pointer to a netsnmp_table_registration_info struct. The table handler needs to know up front how your table is structured. A netsnmp_table_registeration_info structure that is passed to the table handler should contain the asn index types for the table as well as the minimum and maximum column that should be used.

Returns:
Returns a pointer to a netsnmp_mib_handler struct which contains the handler's name and the access method

Definition at line 83 of file table.c.

References netsnmp_table_registration_info_s::indexes, netsnmp_mib_handler_s::myvoid, netsnmp_create_handler(), netsnmp_table_registration_info_s::number_indexes, snmp_log(), and table_helper_handler().

Referenced by netsnmp_register_table().

  int netsnmp_register_table (netsnmp_handler_registration * reginfo, netsnmp_table_registration_info * tabreq)

creates a table handler given the netsnmp_table_registration_info object, inserts it into the request chain and then calls netsnmp_register_handler() to register the table into the agent.

Definition at line 106 of file table.c.

References netsnmp_get_table_handler(), netsnmp_inject_handler(), and netsnmp_register_handler().

Referenced by netsnmp_register_table_data(), netsnmp_register_table_iterator(), and netsnmp_table_container_register().

  int netsnmp_table_build_oid (netsnmp_handler_registration * reginfo, netsnmp_request_info * reqinfo, netsnmp_table_request_info * table_info)

given a registration info object, a request object and the table info object it builds the request->requestvb->name oid from the index values and column information found in the table_info object.

Definition at line 611 of file table.c.

References netsnmp_table_request_info_s::colnum, netsnmp_table_request_info_s::indexes, variable_list::name, variable_list::name_length, netsnmp_request_info_s::requestvb, netsnmp_handler_registration_s::rootoid, and netsnmp_handler_registration_s::rootoid_len.

Referenced by netsnmp_table_build_result().

  int netsnmp_table_build_oid_from_index (netsnmp_handler_registration * reginfo, netsnmp_request_info * reqinfo, netsnmp_table_request_info * table_info)

Builds an oid from index information.

Definition at line 642 of file table.c.

References netsnmp_table_request_info_s::colnum, netsnmp_table_request_info_s::index_oid, netsnmp_table_request_info_s::index_oid_len, variable_list::name, variable_list::name_length, variable_list::name_loc, netsnmp_request_info_s::requestvb, netsnmp_handler_registration_s::rootoid, netsnmp_handler_registration_s::rootoid_len, and SNMP_FREE.

  int netsnmp_table_build_result (netsnmp_handler_registration * reginfo, netsnmp_request_info * reqinfo, netsnmp_table_request_info * table_info, u_char type, u_char * result, size_t result_len)

Builds the result to be returned to the agent given the table information.

Use this function to return results from lowel level handlers to the agent. It takes care of building the proper resulting oid (containing proper indexing) and inserts the result value into the returning varbind.

Definition at line 578 of file table.c.

References variable_list::name, variable_list::name_loc, netsnmp_table_build_oid(), netsnmp_request_info_s::requestvb, and snmp_set_var_typed_value().

  int netsnmp_update_indexes_from_variable_list (netsnmp_table_request_info * tri)

builds an oid given a set of indexes.

Definition at line 682 of file table.c.

References netsnmp_table_request_info_s::index_oid, netsnmp_table_request_info_s::index_oid_len, and netsnmp_table_request_info_s::indexes.

  int netsnmp_update_variable_list_from_index (netsnmp_table_request_info * tri)

parses an OID into table indexses

Definition at line 671 of file table.c.

References netsnmp_table_request_info_s::index_oid, netsnmp_table_request_info_s::index_oid_len, netsnmp_table_request_info_s::indexes, and parse_oid_indexes().

  int table_helper_handler (netsnmp_mib_handler * handler, netsnmp_handler_registration * reginfo, netsnmp_agent_request_info * reqinfo, netsnmp_request_info * requests)

implements the table helper handler

Definition at line 140 of file table.c.

References netsnmp_table_request_info_s::colnum, netsnmp_mib_handler_s::handler_name, netsnmp_table_request_info_s::index_oid, netsnmp_table_request_info_s::index_oid_len, netsnmp_table_request_info_s::indexes, netsnmp_table_registration_info_s::indexes, netsnmp_table_registration_info_s::max_column, netsnmp_table_registration_info_s::min_column, netsnmp_agent_request_info_s::mode, netsnmp_mib_handler_s::myvoid, variable_list::name, variable_list::name_length, variable_list::name_loc, netsnmp_call_next_handler(), netsnmp_extract_table_info(), netsnmp_request_add_list_data(), netsnmp_set_request_error(), netsnmp_request_info_s::next, netsnmp_mib_handler_s::next, variable_list::next_variable, netsnmp_table_registration_info_s::number_indexes, netsnmp_table_request_info_s::number_indexes, netsnmp_request_info_s::processed, netsnmp_table_request_info_s::reg_info, netsnmp_request_info_s::requestvb, netsnmp_handler_registration_s::rootoid, netsnmp_handler_registration_s::rootoid_len, snmp_log(), SNMP_MALLOC_TYPEDEF, snmp_oid_compare(), sprint_realloc_by_type(), netsnmp_request_info_s::status, variable_list::type, and netsnmp_table_registration_info_s::valid_columns.

Referenced by netsnmp_get_table_handler().