/*
* 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 <limits.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
#define ASN_APPLICATION ((u_char)0x40)
#define ASN_INTEGER ((u_char)0x02)
#define ASN_OCTET_STR ((u_char)0x04)
#define ASN_IPADDRESS (ASN_APPLICATION | 0)
#define ASN_COUNTER (ASN_APPLICATION | 1)
#define ASN_GAUGE (ASN_APPLICATION | 2)
#define ASN_UNSIGNED (ASN_APPLICATION | 2) /* RFC 1902 - same as GAUGE */
#define ASN_TIMETICKS (ASN_APPLICATION | 3)
#define ASN_COUNTER64 (ASN_APPLICATION | 6)
#define SNMP_GET 0xA0
#define SNMP_GET_NEXT 0xA1
#define SNMP_GET_RESPONSE 0xA2
struct snmp_oid {
uint8_t *oid_match;
int (*fill)(uint8_t *buf, struct snmp_oid *obj);
void **p;
uint8_t oid_len;
uint8_t asn;
uint8_t offset; /* increase it if it is not enough */
};
extern struct pp_instance ppi_static;
static struct wr_servo_state *wr_s_state;
/* temp memory used in case we have to "correct" values before we send them */
static void *tmp_p;
static int32_t tmp_int32;
struct snmp_oid tmp_obj;
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 */);
/* TODO: check if pointer(s) is initialized already */
wr_s_state =
&((struct wr_data *)ppi_static.ext_data)->servo_state;
}
/* These fill the actual information, returning the lenght */
static int fill_name(uint8_t *buf, struct snmp_oid *obj)
{
strcpy((void *)(buf + 2), "wrc");
buf[1] = strlen((void *)(buf + 2));
buf[0] = ASN_OCTET_STR;
return 2 + buf[1];
}
static int fill_tics(uint8_t *buf, struct snmp_oid *obj)
{
uint32_t tics = htonl(timer_get_tics() / 10); /* hundredths... bah! */
memcpy(buf + 2, &tics, sizeof(tics));
buf[1] = sizeof(tics);
buf[0] = ASN_TIMETICKS;
return 2 + sizeof(tics);
}
static int fill_date(uint8_t *buf, struct snmp_oid *obj)
{
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] = ASN_OCTET_STR;
return 2 + buf[1];
}
#define MAX_OCTET_STR_LEN 32
static int fill_struct_asn(uint8_t *buf, struct snmp_oid *obj)
{
uint32_t tmp;
uint8_t *oid_data = buf + 2;
void *src_data = (*(obj->p)) + obj->offset;
uint8_t *len;
buf[0] = obj->asn;
len = &buf[1];
switch(obj->asn){
case ASN_COUNTER:
case ASN_INTEGER:
tmp = htonl(*(uint32_t*)src_data);
memcpy(oid_data, &tmp, sizeof(tmp));
*len = sizeof(tmp);
snmp_verbose("fill_struct_asn 0x%x\n", *(uint32_t*)src_data);
break;
case ASN_OCTET_STR:
*len = strnlen((char *)src_data, MAX_OCTET_STR_LEN - 1);
memcpy(oid_data, src_data, *len + 1);
snmp_verbose("fill_struct_asn %s len %d\n",
(char*)src_data, *len);
break;
default:
break;
}
return 2 + buf[1];
}
static int fill_int32_saturate(uint8_t *buf, struct snmp_oid *obj) {
int64_t tmp_int64;
/* if we want to modify an object we need to do that on a copy,
* otherwise pointers to the values will be overwritten */
tmp_obj = *obj;
tmp_int64 = *(int64_t *)(*(obj->p) + obj->offset);
/* gcc doesn't support printing 64bit values */
snmp_verbose("fill_int32_saturate 64bit value 0x%08x|%08x\n",
(int32_t)((tmp_int64) >> 32), (uint32_t)tmp_int64);
/* saturate int32 */
if (tmp_int64 >= INT_MAX)
tmp_int64 = INT_MAX;
else if (tmp_int64 <= INT_MIN)
tmp_int64 = INT_MIN;
/* fill_struct_asn will print saturated value anyway */
tmp_int32 = (int32_t) tmp_int64;
tmp_obj.offset = 0;
tmp_p = &tmp_int32;
tmp_obj.p = &tmp_p;
return fill_struct_asn(buf, &tmp_obj);
}
static uint8_t oid_start[] = {0x2B}; /* magic entry for snmpwalk (.1.3), when
* real snmpget next is implemented it may be unnecessary */
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};
static uint8_t oid_wrsPtpServoUpdates[] = {0x2B,6,1,4,1,96,100,7,5,1,15,1};
static uint8_t oid_wrsPtpDeltaTxM[] = {0x2B,6,1,4,1,96,100,7,5,1,16,1};
static uint8_t oid_wrsPtpDeltaRxM[] = {0x2B,6,1,4,1,96,100,7,5,1,17,1};
static uint8_t oid_wrsPtpDeltaTxS[] = {0x2B,6,1,4,1,96,100,7,5,1,18,1};
static uint8_t oid_wrsPtpDeltaRxS[] = {0x2B,6,1,4,1,96,100,7,5,1,19,1};
#define OID_FIELD_STRUCT(_oid, _fname, _asn, _type, _pointer, _field) { \
.oid_match = _oid, \
.oid_len = sizeof(_oid), \
.fill = _fname, \
.asn = _asn, \
.p = (void **)_pointer, \
.offset = offsetof(_type, _field), \
}
#define OID_FIELD(_oid, _fname, _asn) { \
.oid_match = _oid, \
.oid_len = sizeof(_oid), \
.fill = _fname, \
.asn = _asn, \
}
static struct snmp_oid oid_array[] = {
OID_FIELD(oid_start, fill_name, 0), /* return whatever, used only for walks */
OID_FIELD(oid_name, fill_name, 0),
OID_FIELD(oid_tics, fill_tics, 0),
OID_FIELD(oid_date, fill_date, 0),
OID_FIELD_STRUCT(oid_wrsPtpServoUpdates, fill_struct_asn, ASN_COUNTER, struct wr_servo_state, &wr_s_state, update_count),
OID_FIELD_STRUCT(oid_wrsPtpDeltaTxM, fill_struct_asn, ASN_INTEGER, struct wr_servo_state, &wr_s_state, delta_tx_m),
OID_FIELD_STRUCT(oid_wrsPtpDeltaRxM, fill_struct_asn, ASN_INTEGER, struct wr_servo_state, &wr_s_state, delta_rx_m),
OID_FIELD_STRUCT(oid_wrsPtpDeltaTxS, fill_struct_asn, ASN_INTEGER, struct wr_servo_state, &wr_s_state, delta_tx_s),
OID_FIELD_STRUCT(oid_wrsPtpDeltaRxS, fill_struct_asn, ASN_INTEGER, struct wr_servo_state, &wr_s_state, delta_rx_s),
{ 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 */
};
static void print_oid_verbose(uint8_t *oid, int len) {
/*uint8_t * oid_end = oid + len;*/
int i;
snmp_verbose(".1.3");
for (i = 1; i < len; i++)
snmp_verbose(".%d", *(oid + i));
}
/* And, now, work out your generic frame responder... */
static int snmp_respond(uint8_t *buf)
{
struct snmp_oid *oid;
uint8_t *newbuf;
int i;
uint8_t len;
uint8_t snmp_mode;
uint8_t incoming_oid_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] != SNMP_GET && buf[i] != SNMP_GET_NEXT)
return -1;
snmp_mode = buf[i];
break;
default:
if (buf[i] != match_array[i])
return -1;
}
}
snmp_verbose("%s: header match ok\n", __func__);
newbuf = buf + i;
/* save size of incoming oid */
incoming_oid_len = buf[i - 1];
for (oid = oid_array; oid->oid_len; oid++)
if (oid->oid_len == incoming_oid_len &&
!memcmp(oid->oid_match, newbuf, oid->oid_len))
break;
if (!oid->oid_len)
return -1;
if (snmp_mode == SNMP_GET_NEXT) {
/* for SNMP_GET_NEXT go to next OID */
oid++;
if (!oid->oid_len) {
/* we got request with last available OID */
return -1;
}
memcpy(newbuf, oid->oid_match, oid->oid_len);
/* update OID len, since it might be different */
*(newbuf - 1) = oid->oid_len;
}
snmp_verbose("%s: oid found: ", __func__);
print_oid_verbose(oid->oid_match, oid->oid_len);
snmp_verbose(" calling %p\n", oid->fill);
/* Phew.... we matched the OID, so let's call the filler */
newbuf += oid->oid_len;
len = oid->fill(newbuf, oid);
/* 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] = SNMP_GET_RESPONSE;
if (match_array[i] != BYTE_SIZE)
continue;
snmp_verbose("offset %i 0x%02x is len %i\n", i, i,
remain + oid->oid_len + len);
buf[i] = remain + oid->oid_len + len;
}
snmp_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,
};