src/apps/snmp/snmp_snmpv2_usm.c

/*
Generated by LwipMibCompiler
*/

#include "lwip/apps/snmp_opts.h"
#if LWIP_SNMP && LWIP_SNMP_V3

#include "lwip/apps/snmp_snmpv2_usm.h"
#include "lwip/apps/snmp.h"
#include "lwip/apps/snmp_core.h"
#include "lwip/apps/snmp_scalar.h"
#include "lwip/apps/snmp_table.h"
#include "lwip/apps/snmpv3.h"
#include "snmpv3_priv.h"

#include "lwip/apps/snmp_snmpv2_framework.h"

#include <string.h>

/* --- usmUser 1.3.6.1.6.3.15.1.2 ----------------------------------------------------- */

static const struct snmp_oid_range usmUserTable_oid_ranges[] = {
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff },
  { 0, 0xff }, { 0, 0xff }, { 0, 0xff }, { 0, 0xff }
};

static void snmp_engineid_to_oid(const char *engineid, u32_t *oid, u32_t len)
{
  u8_t i;

  for (i = 0; i < len; i++) {
    oid[i] = engineid[i];
  }
}

static void snmp_oid_to_name(char *name, const u32_t *oid, size_t len)
{
  u8_t i;

  for (i = 0; i < len; i++) {
    name[i] = (char)oid[i];
  }
}

static void snmp_name_to_oid(const char *name, u32_t *oid, size_t len)
{
  u8_t i;

  for (i = 0; i < len; i++) {
    oid[i] = name[i];
  }
}

static const struct snmp_obj_id *snmp_auth_algo_to_oid(snmpv3_auth_algo_t algo)
{
  if (algo == SNMP_V3_AUTH_ALGO_MD5) {
    return &usmHMACMD5AuthProtocol;
  } else if (algo ==  SNMP_V3_AUTH_ALGO_SHA) {
    return &usmHMACMD5AuthProtocol;
  }

  return &usmNoAuthProtocol;
}

static const struct snmp_obj_id *snmp_priv_algo_to_oid(snmpv3_priv_algo_t algo)
{
  if (algo == SNMP_V3_PRIV_ALGO_DES) {
    return &usmDESPrivProtocol;
  } else if (algo == SNMP_V3_PRIV_ALGO_AES) {
    return &usmAESPrivProtocol;
  }

  return &usmNoPrivProtocol;
}

char username[32];

static snmp_err_t usmusertable_get_instance(const u32_t *column, const u32_t *row_oid, u8_t row_oid_len, struct snmp_node_instance *cell_instance)
{
  const char *engineid;
  u8_t eid_len;

  u32_t engineid_oid[SNMP_V3_MAX_ENGINE_ID_LENGTH];

  u8_t name_len;
  u8_t engineid_len;

  u8_t name_start;
  u8_t engineid_start;

  LWIP_UNUSED_ARG(column);

  snmpv3_get_engine_id(&engineid, &eid_len);

  engineid_len = (u8_t)row_oid[0];
  engineid_start = 1;

  if (engineid_len != eid_len) {
    /* EngineID length does not match! */
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  if (engineid_len > row_oid_len) {
    /* row OID doesn't contain enough data according to engineid_len.*/
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  /* check if incoming OID length and if values are in plausible range */
  if (!snmp_oid_in_range(&row_oid[engineid_start], engineid_len, usmUserTable_oid_ranges, engineid_len)) {
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  snmp_engineid_to_oid(engineid, engineid_oid, engineid_len);

  /* Verify EngineID */
  if (snmp_oid_equal(&row_oid[engineid_start], engineid_len, engineid_oid, engineid_len)) {
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  name_len = (u8_t)row_oid[engineid_start + engineid_len];
  name_start = engineid_start + engineid_len + 1;

  if (name_len > SNMP_V3_MAX_USER_LENGTH) {
    /* specified name is too long */
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  if (1 + engineid_len + 1 + name_len != row_oid_len) {
    /* Length of EngineID and name does not match row oid length. (+2 for length fields)*/
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  /* check if incoming OID length and if values are in plausible range */
  if (!snmp_oid_in_range(&row_oid[name_start], name_len, usmUserTable_oid_ranges, name_len)) {
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  /* Verify if user exists */
  memset(username, 0, sizeof(username));
  snmp_oid_to_name(username, &row_oid[name_start], name_len);
  if (snmpv3_get_user(username, NULL, NULL, NULL, NULL) != ERR_OK) {
    return SNMP_ERR_NOSUCHINSTANCE;
  }

  /* Save name in reference pointer to make it easier to handle later on */
  cell_instance->reference.ptr = username;
  cell_instance->reference_len = name_len;

  /* user was found */
  return SNMP_ERR_NOERROR;
}

/*
 * valid oid options
 * <oid>
 * <oid>.<EngineID length>
 * <oid>.<EngineID length>.<partial EngineID>
 * <oid>.<EngineID length>.<EngineID>
 * <oid>.<EngineID length>.<EngineID>.<UserName length>
 * <oid>.<EngineID length>.<EngineID>.<UserName length>.<partial UserName>
 * <oid>.<EngineID length>.<EngineID>.<UserName length>.<UserName>
 *
 */
static snmp_err_t usmusertable_get_next_instance(const u32_t *column, struct snmp_obj_id *row_oid, struct snmp_node_instance *cell_instance)
{
  const char *engineid;
  u8_t eid_len;

  u32_t engineid_oid[SNMP_V3_MAX_ENGINE_ID_LENGTH];

  u8_t name_len;
  u8_t engineid_len;

  u8_t name_start;
  u8_t engineid_start = 1;
  u8_t i;

  struct snmp_next_oid_state state;

  u32_t result_temp[LWIP_ARRAYSIZE(usmUserTable_oid_ranges)];

  LWIP_UNUSED_ARG(column);

  snmpv3_get_engine_id(&engineid, &eid_len);

  /* If EngineID might be given */
  if (row_oid->len > 0) {
    engineid_len = (u8_t)row_oid->id[0];
    engineid_start = 1;

    if (engineid_len != eid_len) {
      /* EngineID length does not match! */
      return SNMP_ERR_NOSUCHINSTANCE;
    }

    if (engineid_len > row_oid->len) {
      /* Verify partial EngineID */
      snmp_engineid_to_oid(engineid, engineid_oid, row_oid->len - 1);
      if (!snmp_oid_equal(&row_oid->id[engineid_start], row_oid->len - 1, engineid_oid, row_oid->len - 1)) {
        return SNMP_ERR_NOSUCHINSTANCE;
      }
    } else {
      /* Verify complete EngineID */
      snmp_engineid_to_oid(engineid, engineid_oid, engineid_len);
      if (!snmp_oid_equal(&row_oid->id[engineid_start], engineid_len, engineid_oid, engineid_len)) {
        return SNMP_ERR_NOSUCHINSTANCE;
      }
    }

    /* At this point, the given EngineID (partially) matches the local EngineID.*/

    /* If name might also be given */
    if (row_oid->len > engineid_start + engineid_len) {
      name_len = (u8_t)row_oid->id[engineid_start + engineid_len];
      name_start = engineid_start + engineid_len + 1;

      if (name_len > SNMP_V3_MAX_USER_LENGTH) {
        /* specified name is too long, max length is 32 according to mib file.*/
        return SNMP_ERR_NOSUCHINSTANCE;
      }

      if (row_oid->len < engineid_len + name_len + 2) {
        /* Partial name given according to oid.*/
        u8_t tmplen = row_oid->len - engineid_len - 2;
        if (!snmp_oid_in_range(&row_oid->id[name_start], tmplen, usmUserTable_oid_ranges, tmplen)) {
          return SNMP_ERR_NOSUCHINSTANCE;
        }
      } else {
        /* Full name given according to oid. Also test for too much data.*/
        u8_t tmplen = row_oid->len - engineid_len - 2;
        if (!snmp_oid_in_range(&row_oid->id[name_start], name_len, usmUserTable_oid_ranges, tmplen)) {
          return SNMP_ERR_NOSUCHINSTANCE;
        }
      }

      /* At this point the EngineID and (partial) UserName match the local EngineID and UserName.*/
    }
  }

  /* init struct to search next oid */
  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(usmUserTable_oid_ranges));

  for (i = 0; i < snmpv3_get_amount_of_users(); i++) {
    u32_t test_oid[LWIP_ARRAYSIZE(usmUserTable_oid_ranges)];

    test_oid[0] = eid_len;
    snmp_engineid_to_oid(engineid, &test_oid[1], eid_len);

    snmpv3_get_username(username, i);

    test_oid[1 + eid_len] = strlen(username);
    snmp_name_to_oid(username, &test_oid[2 + eid_len], strlen(username));

    /* check generated OID: is it a candidate for the next one? */
    snmp_next_oid_check(&state, test_oid, (u8_t)(1 + eid_len + 1 + strlen(username)), LWIP_PTR_NUMERIC_CAST(void *, i));
  }

  /* did we find a next one? */
  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
    /* store username for subsequent operations (get/test/set) */
    memset(username, 0, sizeof(username));
    snmpv3_get_username(username, LWIP_PTR_NUMERIC_CAST(u8_t, state.reference));
    cell_instance->reference.ptr = username;
    cell_instance->reference_len = strlen(username);
    return SNMP_ERR_NOERROR;
  }

  /* not found */
  return SNMP_ERR_NOSUCHINSTANCE;
}

static s16_t usmusertable_get_value(struct snmp_node_instance *cell_instance, void *value)
{
  snmpv3_user_storagetype_t storage_type;

  switch (SNMP_TABLE_GET_COLUMN_FROM_OID(cell_instance->instance_oid.id)) {
    case 3: /* usmUserSecurityName */
      MEMCPY(value, cell_instance->reference.ptr, cell_instance->reference_len);
      return (s16_t)cell_instance->reference_len;
    case 4: /* usmUserCloneFrom */
      MEMCPY(value, snmp_zero_dot_zero.id, snmp_zero_dot_zero.len * sizeof(u32_t));
      return snmp_zero_dot_zero.len * sizeof(u32_t);
    case 5: { /* usmUserAuthProtocol */
      const struct snmp_obj_id *auth_algo;
      snmpv3_auth_algo_t auth_algo_val;
      snmpv3_get_user((const char *)cell_instance->reference.ptr, &auth_algo_val, NULL, NULL, NULL);
      auth_algo = snmp_auth_algo_to_oid(auth_algo_val);
      MEMCPY(value, auth_algo->id, auth_algo->len * sizeof(u32_t));
      return auth_algo->len * sizeof(u32_t);
    }
    case 6: /* usmUserAuthKeyChange */
      return 0;
    case 7: /* usmUserOwnAuthKeyChange */
      return 0;
    case 8: { /* usmUserPrivProtocol */
      const struct snmp_obj_id *priv_algo;
      snmpv3_priv_algo_t priv_algo_val;
      snmpv3_get_user((const char *)cell_instance->reference.ptr, NULL, NULL, &priv_algo_val, NULL);
      priv_algo = snmp_priv_algo_to_oid(priv_algo_val);
      MEMCPY(value, priv_algo->id, priv_algo->len * sizeof(u32_t));
      return priv_algo->len * sizeof(u32_t);
    }
    case 9: /* usmUserPrivKeyChange */
      return 0;
    case 10: /* usmUserOwnPrivKeyChange */
      return 0;
    case 11: /* usmUserPublic */
      /* TODO: Implement usmUserPublic */
      return 0;
    case 12: /* usmUserStorageType */
      snmpv3_get_user_storagetype((const char *)cell_instance->reference.ptr, &storage_type);
      *(s32_t *)value = storage_type;
      return sizeof(s32_t);
    case 13: /* usmUserStatus */
      *(s32_t *)value = 1; /* active */
      return sizeof(s32_t);
    default:
      LWIP_DEBUGF(SNMP_MIB_DEBUG, ("usmusertable_get_value(): unknown id: %"S32_F"\n", SNMP_TABLE_GET_COLUMN_FROM_OID(cell_instance->instance_oid.id)));
      return 0;
  }
}

/* --- usmMIBObjects 1.3.6.1.6.3.15.1 ----------------------------------------------------- */
static s16_t usmstats_scalars_get_value(const struct snmp_scalar_array_node_def *node, void *value)
{
  u32_t *uint_ptr = (u32_t *)value;
  switch (node->oid) {
    case 1: /* usmStatsUnsupportedSecLevels */
      *uint_ptr = snmp_stats.unsupportedseclevels;
      break;
    case 2: /* usmStatsNotInTimeWindows */
      *uint_ptr = snmp_stats.notintimewindows;
      break;
    case 3: /* usmStatsUnknownUserNames */
      *uint_ptr = snmp_stats.unknownusernames;
      break;
    case 4: /* usmStatsUnknownEngineIDs */
      *uint_ptr = snmp_stats.unknownengineids;
      break;
    case 5: /* usmStatsWrongDigests */
      *uint_ptr = snmp_stats.wrongdigests;
      break;
    case 6: /* usmStatsDecryptionErrors */
      *uint_ptr = snmp_stats.decryptionerrors;
      break;
    default:
      LWIP_DEBUGF(SNMP_MIB_DEBUG, ("usmstats_scalars_get_value(): unknown id: %"S32_F"\n", node->oid));
      return 0;
  }

  return sizeof(*uint_ptr);
}

/* --- snmpUsmMIB  ----------------------------------------------------- */

/* --- usmUser 1.3.6.1.6.3.15.1.2 ----------------------------------------------------- */

static const struct snmp_table_col_def usmusertable_columns[] = {
  {3,  SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserSecurityName */
  {4,  SNMP_ASN1_TYPE_OBJECT_ID,    SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserCloneFrom */
  {5,  SNMP_ASN1_TYPE_OBJECT_ID,    SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserAuthProtocol */
  {6,  SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserAuthKeyChange */
  {7,  SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserOwnAuthKeyChange */
  {8,  SNMP_ASN1_TYPE_OBJECT_ID,    SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserPrivProtocol */
  {9,  SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserPrivKeyChange */
  {10, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserOwnPrivKeyChange */
  {11, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserPublic */
  {12, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserStorageType */
  {13, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY}, /* usmUserStatus */
};
static const struct snmp_table_node usmusertable = SNMP_TABLE_CREATE(2, usmusertable_columns, usmusertable_get_instance, usmusertable_get_next_instance, usmusertable_get_value, NULL, NULL);

static const struct snmp_node *const usmuser_subnodes[] = {
  &usmusertable.node.node
};
static const struct snmp_tree_node usmuser_treenode = SNMP_CREATE_TREE_NODE(2, usmuser_subnodes);

/* --- usmMIBObjects 1.3.6.1.6.3.15.1 ----------------------------------------------------- */
static const struct snmp_scalar_array_node_def usmstats_scalars_nodes[] = {
  {1, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsUnsupportedSecLevels */
  {2, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsNotInTimeWindows */
  {3, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsUnknownUserNames */
  {4, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsUnknownEngineIDs */
  {5, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsWrongDigests */
  {6, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}, /* usmStatsDecryptionErrors */
};
static const struct snmp_scalar_array_node usmstats_scalars = SNMP_SCALAR_CREATE_ARRAY_NODE(1, usmstats_scalars_nodes, usmstats_scalars_get_value, NULL, NULL);

static const struct snmp_node *const usmmibobjects_subnodes[] = {
  &usmstats_scalars.node.node,
  &usmuser_treenode.node
};
static const struct snmp_tree_node usmmibobjects_treenode = SNMP_CREATE_TREE_NODE(1, usmmibobjects_subnodes);

/* --- snmpUsmMIB  ----------------------------------------------------- */
static const struct snmp_node *const snmpusmmib_subnodes[] = {
  &usmmibobjects_treenode.node
};
static const struct snmp_tree_node snmpusmmib_root = SNMP_CREATE_TREE_NODE(15, snmpusmmib_subnodes);
static const u32_t snmpusmmib_base_oid[] = {1, 3, 6, 1, 6, 3, 15};
const struct snmp_mib snmpusmmib = {snmpusmmib_base_oid, LWIP_ARRAYSIZE(snmpusmmib_base_oid), &snmpusmmib_root.node};

#endif /* LWIP_SNMP */