/*
* This work is part of the White Rabbit project
*
* Copyright (C) 2016 GSI (www.gsi.de)
* Author: Alessandro Rubini <a.rubini@gsi.de>
*
* Released according to the GNU GPL, version 2 or any later version.
*/
#include <string.h>
#include <wrpc.h>
#include "endpoint.h"
#include "ipv4.h"
#include "ptpd_netif.h"
#include "pps_gen.h"
#include "hw/memlayout.h"
#include "hw/etherbone-config.h"
#ifndef htons
#define htons(x) x
#endif
static uint8_t __snmp_queue[256];
static struct wrpc_socket __static_snmp_socket = {
.queue.buff = __snmp_queue,
.queue.size = sizeof(__snmp_queue),
};
static struct wrpc_socket *snmp_socket;
static void snmp_init(void)
{
/* Use UDP engine activated by function arguments */
snmp_socket = ptpd_netif_create_socket(&__static_snmp_socket, NULL,
PTPD_SOCK_UDP, 161 /* snmp */);
}
/* These fill the actual information, returning the lenght */
static int fill_name(uint8_t *buf)
{
strcpy((void *)(buf + 2), "wrc");
buf[1] = strlen((void *)(buf + 2));
buf[0] = 0x04; /* string */
return 2 + buf[1];
}
static int fill_tics(uint8_t *buf)
{
uint32_t tics = htonl(timer_get_tics() / 10); /* hundredths... bah! */
memcpy(buf + 2, &tics, sizeof(tics));
buf[1] = sizeof(tics);
buf[0] = 0x43; /* who knows... */
return 2 + sizeof(tics);
}
static int fill_date(uint8_t *buf)
{
uint64_t secs;
char *datestr;
shw_pps_gen_get_time(&secs, NULL);
datestr = format_time(secs, TIME_FORMAT_SNMP);
memcpy((void *)(buf + 2), datestr, 12);
buf[1] = 8; /* size is hardwired. See mib document or prev. commit */
buf[0] = 0x04; /* string! (one more f word entering the repo... */
return 2 + buf[1];
}
static uint8_t oid_name[] = {0x2B,0x06,0x01,0x02,0x01,0x01,0x05,0x00};
static uint8_t oid_tics[] = {0x2B,0x06,0x01,0x02,0x01,0x19,0x01,0x01,0x00};
static uint8_t oid_date[] = {0x2B,0x06,0x01,0x02,0x01,0x19,0x01,0x02,0x00};
struct snmp_oid {
uint8_t *oid_match;
int oid_len;
int (*fill)(uint8_t *buf);
};
static struct snmp_oid oid_array[] = {
{ oid_name, sizeof(oid_name), fill_name},
{ oid_tics, sizeof(oid_tics), fill_tics},
{ oid_date, sizeof(oid_date), fill_date},
{ 0, }
};
/*
* Perverse... snmpwalk does getnext anyways. Let's support snmpget only
*
* We support the following ones:
* RFC1213-MIB::sysName.0 (string) .1.3.6.1.2.1.1.5.0
* HOST-RESOURCES-MIB::hrSystemUptime.0 (ticks) .1.3.6.1.2.1.25.1.1.0
* HOST-RESOURCES-MIB::hrSystemDate.0 (string) .1.3.6.1.2.1.25.1.2.0
*
* The request for sysname is like this (-c public):
* 30 29 sequence of 0x29
* 02 01 00 int: snmp version 1 (0x00)
* 04 06 70 75 62 6C 69 63 string of 6: "public"
* A0 1C get request of 0x1c
* 02 04 27 05 36 A9 int of 4: request ID
* 02 01 00 int of 1: error
* 02 01 00 int of 1: error
* 30 0E sequence of 0x0e
* 30 0C sequence of 0x0c
* 06 08 2B 06 01 02 01 01 05 00 oid of 8: .1.3.6.1.2.1.1.5.0
* 05 00 null
*
*
* Response for sysname:
* 30 30
* 02 01 00
* 04 06 70 75 62 6C 69 63 "public"
* A2 23
* 02 04 27 05 36 A9 seqID
* 02 01 00
* 02 01 00
* 30 15
* 30 13
* 06 08 2B 06 01 02 01 01 05 00
* 04 07 6C 61 70 74 6F 70 6F "laptopo"
*
*/
/*
* The following array defines the frame format, sizes are ignored on read
* but must be filled on write, so mark them specially
*/
#define BYTE_SIZE 0xff
#define BYTE_IGNORE 0xfe
#define BYTE_PDU 0xfd
static uint8_t match_array[] = {
0x30, BYTE_SIZE,
0x02, 0x01, 0x00,
0x04, 0x06, 0x70, 0x75, 0x62, 0x6C, 0x69, 0x63,
BYTE_PDU, BYTE_SIZE,
0x02, 0x04, BYTE_IGNORE, BYTE_IGNORE, BYTE_IGNORE, BYTE_IGNORE,
0x02, 0x01, 0x00,
0x02, 0x01, 0x00,
0x30, BYTE_SIZE,
0x30, BYTE_SIZE,
0x06, BYTE_IGNORE, /* oid follows */
};
/* And, now, work out your generic frame responder... */
static int snmp_respond(uint8_t *buf)
{
struct snmp_oid *oid;
uint8_t *newbuf;
int i, len;
for (i = 0; i < sizeof(match_array); i++) {
switch (match_array[i]) {
case BYTE_SIZE:
case BYTE_IGNORE:
continue;
case BYTE_PDU:
if (buf[i] != 0xA0)
return -1;
break;
default:
if (buf[i] != match_array[i])
return -1;
}
}
net_verbose("%s: match ok\n", __func__);
newbuf = buf + i;
for (oid = oid_array; oid->oid_len; oid++)
if (!memcmp(oid->oid_match, newbuf, oid->oid_len))
break;
if (!oid->oid_len)
return -1;
net_verbose("%s: oid found: calling %p\n", __func__, oid->fill);
/* Phew.... we matched the OID, so let's call the filler */
newbuf += oid->oid_len;
len = oid->fill(newbuf);
/* now fix all size fields and change PDU */
for (i = 0; i < sizeof(match_array); i++) {
int remain = (sizeof(match_array) - 1) - i;
if (match_array[i] == BYTE_PDU)
buf[i] = 0xA2; /* get response */
if (match_array[i] != BYTE_SIZE)
continue;
net_verbose("offset %i 0x%02x is len %i\n", i, i,
remain + oid->oid_len + len);
buf[i] = remain + oid->oid_len + len;
}
net_verbose("%s: returning %i bytes\n", __func__, len + (newbuf - buf));
return len + (newbuf - buf);
}
/* receive snmp through the UDP mechanism */
static int snmp_poll(void)
{
struct wr_sockaddr addr;
uint8_t buf[200];
int len;
/* no need to wait for IP address: we won't get queries */
len = ptpd_netif_recvfrom(snmp_socket, &addr,
buf, sizeof(buf), NULL);
if (len <= UDP_END + sizeof(match_array))
return 0;
len = snmp_respond(buf + UDP_END);
if (len < 0)
return 0;
len += UDP_END;
fill_udp(buf, len, NULL);
ptpd_netif_sendto(snmp_socket, &addr, buf, len, 0);
return 1;
}
DEFINE_WRC_TASK(snmp) = {
.name = "snmp",
.enable = &link_status,
.init = snmp_init,
.job = snmp_poll,
};