Cosa-SNMP

/**
* @file CosaSNMP.ino
* @version 1.0
*
* @section License
* Copyright (C) 2014-2015, Mikael Patel
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* @section Description
* W5100 Ethernet Controller device driver example code; SNMP agent
* with support for GET/GETNEXT/SET for MIB-2 SYSTEM and Arduino MIB.
*
* @section Circuit
* This sketch is designed for the Ethernet Shield.
* @code
*                       W5100/ethernet
*                                 +--------------+
* (D10)--------------29-|CSN         |
* (D11)--------------28-|MOSI       |
* (D12)--------------27-|MISO       |
* (D13)--------------30-|SCK         |
* (D2)-----[  ]-------56-|IRQ           |
*                                +---------------+
* @endcode
*
* @section Testing
* Test with Linux snmp commands:
* 1. Access the MIB-2 SYSTEM (sysDescr)
*   snmpget -v1 -c public {W5100_IP} 1.3.6.1.2.1.1.1
* 2. Access the Arduino MIB (ardDigitalPin.0)
*   snmpget -v1 -c public {W5100_IP} 1.3.6.1.4.1.36582.1.0
* 3. Walk all available OID tree
*   snmpwalk -v1 -c public {W5100_IP} 1
*
* This file is part of the Arduino Che Cosa project.
*/

#include <DHCP.h>
#include <DNS.h>
#include <SNMP.h>
#include <W5X00.h>
#include <W5100.h>
// #include <W5200.h>

#include "Cosa/Memory.h"
#include "Cosa/InputPin.hh"
#include "Cosa/AnalogPin.hh"
#include "Cosa/Trace.hh"
#include "Cosa/Watchdog.hh"
#include "Cosa/UART.hh"

// Comment this out to remove some tracing and reduce memory usage
#define PRINT_PDU

// Network configuration
// If WS5100 board has a MAC sticker then use here instead of this default
static const uint8_t mac[6] __PROGMEM = { 0xde, 0xad, 0xbe, 0xef, 0xfe, 0xed };
// If no DHCP on network set these
// #define USE_FIXED_IP 192,168,1,100
// #define SUBNET 255,255,255,0

// Disable SD on Ethernet Shield
#define USE_ETHERNET_SHIELD
#if defined(USE_ETHERNET_SHIELD)
#include "Cosa/OutputPin.hh"
OutputPin sd(Board::D4, 1);
#endif

W5100 ethernet(mac);
// W5200 ethernet(mac);

/**
* Arduino MIB OID(1.3.6.1.4.1.36582)
*/
class ARDUINO_MIB : public SNMP::MIB {
private:
 enum {
   ardDigitalPin = 1,        // Digital pin[0..19](0..1), read-only
   ardAnalogPin = 2,         // Analog pin[0..5](0..1023), read-only
   ardVcc = 3,               // Power supply[0](0..VCC), mV, read-only
 } __attribute__((packed));

public:
 static const uint8_t OID[] PROGMEM;
 /**
  * @override SNMP::MIB
  * Return object identity root for Arduino MIB.
  */
 virtual const uint8_t* oid()
 {
   return (OID);
 }

 /**
  * @override SNMP::MIB
  * Handle Arduino MIB objects SNMP requests. Returns true and
  * value for SNMP::GET in given protocol data unit, otherwise false.
  * @param[in,out] pdu protocol data unit.
  * @return bool
  */
 virtual bool is_request(SNMP::PDU& pdu);
};
// Arduino MIB OID(1.3.6.1.4.1.36582)
const uint8_t ARDUINO_MIB::OID[] __PROGMEM = { 8,0x2b,6,1,4,1,130,157,102 };

// SNMP MIB-2 System configuration
static const char descr[] __PROGMEM = "<service description>";
static const char contact[] __PROGMEM = "<contact information>";
static const char name[] __PROGMEM = "<device name>";
static const char location[] __PROGMEM = "<device location>";
SNMP::MIB2_SYSTEM mib2(descr, contact, name, location, ARDUINO_MIB::OID);
SNMP snmp;

bool
ARDUINO_MIB::is_request(SNMP::PDU& pdu)
{
 uint8_t mib_baselen = pgm_read_byte(OID);
 if(pdu.oid.length > (mib_baselen + 2)) return (false);

 // Match with Arduino MIB OID root
 int sys = pdu.oid.match(oid());
 if (sys < -1) return (false); // MIB is greater than what we deal with
 int index = ((pdu.oid.length == (mib_baselen + 2)) ? pdu.oid.name[mib_baselen+1] : -1);
 // Get next value request; adjust sys and index references to next
 if (pdu.type == SNMP::PDU_GET_NEXT) {
   if (sys <= 0) {
       memcpy_P(&pdu.oid, OID, mib_baselen + 1);
       sys = ardDigitalPin;
   }
   switch (sys) {
   case ardDigitalPin:
     if (index < 19)
       index += 1;
     else {
       index = 0;
       sys = ardAnalogPin;
     }
     break;
   case ardAnalogPin:
     if (index < 5)
       index += 1;
     else {
       index = 0;
       sys = ardVcc;
     }
     break;
   case ardVcc:
     return (false);
   }
   pdu.oid.name[mib_baselen] = sys;
   pdu.oid.name[mib_baselen + 1] = index;
   pdu.oid.length = mib_baselen + 2;
   pdu.type = SNMP::PDU_GET;
 }

 // Check request type
 if ((index < 0) || (sys < ardDigitalPin) || (sys > ardVcc)) return (false);

 // Get value for digital or analog pin, or power supply voltage
 if (pdu.type == SNMP::PDU_GET) {
   switch (sys) {
   case ardDigitalPin:
     if (index > 19)
       pdu.error_status = SNMP::NO_SUCH_NAME;
     else {
       Board::DigitalPin pin;
       pin = (Board::DigitalPin) pgm_read_byte(&digital_pin_map[index]);
       pdu.value.encode(SNMP::SYNTAX_INT, (int16_t) InputPin::read(pin));
     }
     break;
   case ardAnalogPin:
     if (index > 5)
       pdu.error_status = SNMP::NO_SUCH_NAME;
     else {
       Board::AnalogPin pin;
       pin = (Board::AnalogPin) pgm_read_byte(&analog_pin_map[index]);
       pdu.value.encode(SNMP::SYNTAX_INT, (int16_t) AnalogPin::sample(pin));
     }
     break;
   case ardVcc:
     if (index > 0)
       pdu.error_status = SNMP::NO_SUCH_NAME;
     else
       pdu.value.encode(SNMP::SYNTAX_INT, (int16_t) AnalogPin::bandgap());
     break;
   }
 }

 // Set value is not allowed (yet)
 else if (pdu.type == SNMP::PDU_SET) {
   pdu.error_status = SNMP::READ_ONLY;
 }
 return (true);
}

ARDUINO_MIB arduino;

void setup()
{
 uint8_t ip[4]
#if defined(USE_FIXED_IP)
   = { USE_FIXED_IP };
#else
   ;
#endif
 uint8_t subnet[4]
#if defined(SUBNET)
   = { SUBNET };
#else
   ;
#endif

 // Start watchdog and uart. Use uart for trace output
 uart.begin(9600);
 trace.begin(&uart, PSTR("CosaSNMP: started"));
 Watchdog::begin();
 AnalogPin::powerup();

 // Start ethernet controller and request network address for hostname
#if defined(USE_FIXED_IP)
 ASSERT(ethernet.begin(ip, subnet);
#else
 ASSERT(ethernet.begin_P(PSTR("CosaSNMPAgent")));
#endif

 // Print the given or default network address
 ethernet.addr(ip, subnet);
 trace << PSTR("IP = ");
 INET::print_addr(trace, ip);
 trace << endl;

 // Print some memory statistics
 TRACE(free_memory());
 TRACE(sizeof(W5100));
 TRACE(sizeof(SNMP));
 TRACE(sizeof(SNMP::OID));
 TRACE(sizeof(SNMP::VALUE));
 TRACE(sizeof(SNMP::PDU));
 TRACE(sizeof(SNMP::MIB2_SYSTEM));
 TRACE(sizeof(ARDUINO_MIB));

 // Start the SNMP manager with a connection-less socket
 ASSERT(snmp.begin(ethernet.socket(Socket::UDP, SNMP::PORT), &mib2, &arduino));
}

void loop()
{
 // Service SNMP requests with given MIB handlers
 SNMP::PDU pdu;
 if (snmp.request(pdu) < 0) return;

#if defined(PRINT_PDU)
 // Print available memory and resulting protocol data unit
 TRACE(free_memory());
 trace << pdu << endl;
#endif
}