--- /dev/null
+.TH SNMP_AGENT_API 3 "02 Apr 2001" VVERSIONINFO "Net-SNMP"
+.UC 5
+.SH NAME
+snmp_agent_api \- embedding an agent into a external application
+.SH SYNOPSIS
+.nf
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+#include <net-snmp/agent/net-snmp-agent-includes.h>
+
+int
+main (int argc, char *argv[])
+{
+ int agentx_subagent = 1; /* Change this if you're a master agent. */
+
+ snmp_enable_stderrlog();
+
+ /* If we're an AgentX subagent... */
+ if (agentx_subagent) {
+ /* ...make us an AgentX client. */
+ netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
+ NETSNMP_DS_AGENT_ROLE, 1);
+ }
+
+ init_agent("yourappname");
+
+ /* Initialize your MIB code here. */
+ init_my_mib_code();
+
+ /* `yourappname' will be used to read yourappname.conf files. */
+ init_snmp("yourappname");
+
+ /* If we're going to be a SNMP master agent... */
+ if (!agentx_subagent)
+ init_master_agent(); /* Listen on default port (161). */
+
+ /* Your main loop here... */
+ while (whatever) {
+ /* if you use select(), see snmp_api(3) */
+ /* --- OR --- */
+ agent_check_and_process(0); /* 0 == don't block */
+ }
+
+ /* At shutdown time: */
+ snmp_shutdown("yourappname");
+}
+
+Then:
+$(CC) ... `net-snmp-config --agent-libs`
+
+.fi
+.SH DESCRIPTION
+.PP
+Our goal is to create a easy to use interface to the Net-SNMP package
+such that you can take code that you have written that has been
+designed to be a Net-SNMP MIB module and embed it into an external
+application where you can either chose to be a SNMP master agent or an
+AgentX sub-agent using the same MIB module code. Our suggestion is
+that you use our (or another) SNMP agent as the AgentX master agent
+and chose to become an AgentX subagent which then attaches to the
+master.
+.PP
+The Net-SNMP package provides a pair of libraries that enables easy
+embedding of an SNMP or AgentX agent into an external software
+package. AgentX is an extensible protocol designed to allow multiple
+SNMP sub-agents all run on one machine under a single SNMP master
+agent. It is defined in RFC 2741.
+.PP
+You will need to perform a few tasks in order to accomplish
+this. First off, you will need to initialize both the SNMP library and
+the SNMP agent library. As indicated above, this is done slightly
+differently depending on whether or not you are going to perform as a
+master agent or an AgentX sub-agent.
+.SH CONFIGURATION
+.PP
+If you intend to operate as an AgentX sub-agent, you will have to
+configured the Net-SNMP package with agentx support (which is turned
+on by default, so just don't turn it off)
+.PP
+Additionally, you will need to link against the net-snmp libraries
+(use the output of "net-snmp-config --agent-libs" to get a library
+list) and call subagent_pre_init() as indicated above.
+.SH COMPILING
+.PP
+In order to make use of any of the above API, you will need to link
+against at least the four libraries listed above.
+.SH FUNCTIONS
+.PP This is a brief description of the functions called above and
+where to find out more information on them. It is certainly not a
+complete list of what is available within all the net-snmp libraries.
+.IP "snmp_enable_stderrlog()"
+Logs error output from the SNMP agent to the standard error stream.
+.IP "netsnmp_ds_set_boolean()"
+Please see the
+.IR default_store(3)
+manual page for more information
+about this API.
+.IP "init_agent(char *name)"
+Initializes the embedded agent. This should be called before the
+.BR "init_snmp()"
+call.
+.I name
+is used to dictate what .conf file to read when
+.BR "init_snmp()"
+is called later.
+.IP "init_snmp(char *name)"
+Initializes the SNMP library. Note that one of the things this will
+do will be to read configuration files in an effort to configure your
+application. It will attempt to read the configuration files named by
+the
+.I name
+string that you passed in. It can be used to configure access
+control, for instance. Please see the
+.IR read_config(3) ", " snmp_config(5) ", and " snmpd.conf(5)
+manual pages for further details on this subject.
+.IP "init_master_agent(void)"
+Initializes the master agent and causes it to listen for SNMP requests
+on its default UDP port of 161.
+.IP "agent_check_and_process(int block)"
+This checks for packets arriving on the SNMP port and processes them
+if some are found. If
+.I block
+is non-zero, the function call will block until a packet arrives or an
+alarm must be run (see
+.IR snmp_alarm(3) ).
+The return value from this function is a positive integer if packets
+were processed, zero if an alarm occurred and -1 if an error occured.
+.IP "snmp_shutdown(char *name);"
+This shuts down the agent, saving any needed persistent storage, etc.
+.SH "SEE ALSO"
+http://www.net-snmp.org/tutorial-5/toolkit/, select(2), snmp_api(3),
+default_store(3), snmp_alarm(3), read_config(3), snmp_config(5),
+snmpd.conf(5)
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