smux.c

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

  u_char buf[BUFSIZ];
  u_char *ptr;
  int len, length;
  struct in_addr addr;
  unsigned long val;
  u_char *h1, *h1e;

  ptr = buf;
  len = BUFSIZ;
  length = len;

  /* When SMUX connection is not established. */
  if (smux_sock < 0)
    return 0;

  /* SMUX header. */
  ptr = asn_build_header (ptr, &len, (u_char) SMUX_TRAP, 0);

  /* Sub agent enterprise oid. */
  ptr = asn_build_objid (ptr, &len,
			 (u_char) 
			 (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID),
			 smux_oid, smux_oid_len);

  /* IP address. */
  addr.s_addr = 0;
  ptr = asn_build_string (ptr, &len, 
			  (u_char)
			  (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_IPADDRESS),
			  (u_char *)&addr, sizeof (struct in_addr));

  /* Generic trap integer. */
  val = SNMP_TRAP_ENTERPRISESPECIFIC;
  ptr = asn_build_int (ptr, &len, 
		       (u_char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
		       &val, sizeof (int));

  /* Specific trap integer. */
  val = sptrap;
  ptr = asn_build_int (ptr, &len, 
		       (u_char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
		       &val, sizeof (int));

  /* Timeticks timestamp. */
  val = 0;
  ptr = asn_build_unsigned_int (ptr, &len, 
				(u_char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_TIMETICKS),
				&val, sizeof (int));
  
  /* Variables. */
  h1 = ptr;
  ptr = asn_build_sequence (ptr, &len, 
			    (u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
			    0);


  /* Iteration for each objects. */
  h1e = ptr;
  for (i = 0; i < trapobjlen; i++)
    {
      int ret;
      oid oid[MAX_OID_LEN];
      size_t oid_len;
      void *val;
      size_t val_len;
      u_char val_type;

      /* Make OID. */
      oid_copy (oid, name, namelen);
      oid_copy (oid + namelen, trapobj[i].name, trapobj[i].namelen);
      oid_copy (oid + namelen + trapobj[i].namelen, iname, inamelen);
      oid_len = namelen + trapobj[i].namelen + inamelen;

      if (debug_smux)
	smux_oid_dump ("Trap", oid, oid_len);

      ret = smux_get (oid, &oid_len, 1, &val_type, &val, &val_len);

      if (debug_smux)
	zlog_info ("smux_get result %d", ret);

      if (ret == 0)
	ptr = snmp_build_var_op (ptr, oid, &oid_len,
				 val_type, val_len, val, &len);
    }

  /* Now variable size is known, fill in size */
  asn_build_sequence(h1, &length,
		     (u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
		     ptr - h1e);

  /* Fill in size of whole sequence */
  len = BUFSIZ;
  asn_build_header (buf, &len, (u_char) SMUX_TRAP, (ptr - buf) - 2);

  return send (smux_sock, buf, (ptr - buf), 0);
}

int
smux_register (int sock)
{
  u_char buf[BUFSIZ];
  u_char *ptr;
  int len, ret;
  long priority;
  long operation;
  struct subtree *subtree;
  struct listnode *node;

  ret = 0;

  for (node = treelist->head; node; node = node->next)
    {
      ptr = buf;
      len = BUFSIZ;

      subtree = node->data;

      /* SMUX RReq Header. */
      ptr = asn_build_header (ptr, &len, (u_char) SMUX_RREQ, 0);

      /* Register MIB tree. */
      ptr = asn_build_objid (ptr, &len,
			    (u_char)
			    (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID),
			    subtree->name, subtree->name_len);

      /* Priority. */
      priority = -1;
      ptr = asn_build_int (ptr, &len, 
		          (u_char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
		          &priority, sizeof (u_long));

      /* Operation. */
      operation = 2; /* Register R/W */
      ptr = asn_build_int (ptr, &len, 
		          (u_char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
		          &operation, sizeof (u_long));

      if (debug_smux)
        {
          smux_oid_dump ("SMUX register oid", subtree->name, subtree->name_len);
          zlog_info ("SMUX register priority: %ld", priority);
          zlog_info ("SMUX register operation: %ld", operation);
        }

      len = BUFSIZ;
      asn_build_header (buf, &len, (u_char) SMUX_RREQ, (ptr - buf) - 2);
      ret = send (sock, buf, (ptr - buf), 0);
      if (ret < 0)
        return ret;
    }
  return ret;
}

/* Try to connect to SNMP agent. */
int
smux_connect (struct thread *t)
{
  int ret;

  if (debug_smux)
    zlog_info ("SMUX connect try %d", fail + 1);

  /* Clear thread poner of myself. */
  smux_connect_thread = NULL;

  /* Make socket.  Try to connect. */
  smux_sock = smux_socket ();
  if (smux_sock < 0)
    {
      if (++fail < SMUX_MAX_FAILURE)
	smux_event (SMUX_CONNECT, 0);
      return 0;
    }

  /* Send OPEN PDU. */
  ret = smux_open (smux_sock);
  if (ret < 0)
    {
      zlog_warn ("SMUX open message send failed: %s", strerror (errno));
      close (smux_sock);
      smux_sock = -1;
      if (++fail < SMUX_MAX_FAILURE)
	smux_event (SMUX_CONNECT, 0);
      return -1;
    }

  /* Send any outstanding register PDUs. */
  ret = smux_register (smux_sock);
  if (ret < 0)
    {
      zlog_warn ("SMUX register message send failed: %s", strerror (errno));
      close (smux_sock);
      smux_sock = -1;
      if (++fail < SMUX_MAX_FAILURE)
	smux_event (SMUX_CONNECT, 0);
      return -1;
    }

  /* Everything goes fine. */
  smux_event (SMUX_READ, smux_sock);

  return 0;
}

/* Clear all SMUX related resources. */
void
smux_stop ()
{
  if (smux_read_thread)
    thread_cancel (smux_read_thread);
  if (smux_connect_thread)
    thread_cancel (smux_connect_thread);

  if (smux_sock >= 0)
    {
      close (smux_sock);
      smux_sock = -1;
    }
}

extern struct thread_master *master;

void
smux_event (enum smux_event event, int sock)
{
  switch (event)
    {
    case SMUX_SCHEDULE:
      smux_connect_thread = thread_add_event (master, smux_connect, NULL, 0);
      break;
    case SMUX_CONNECT:
      smux_connect_thread = thread_add_timer (master, smux_connect, NULL, 10);
      break;
    case SMUX_READ:
      smux_read_thread = thread_add_read (master, smux_read, NULL, sock);
      break;
    default:
      break;
    }
}

int
smux_str2oid (char *str, oid *oid, size_t *oid_len)
{
  int len;
  int val;

  len = 0;
  val = 0;
  *oid_len = 0;

  if (*str == '.')
    str++;
  if (*str == '\0')
    return 0;

  while (1)
    {
      if (! isdigit (*str))
	return -1;

      while (isdigit (*str))
	{
	  val *= 10;
	  val += (*str - '0');
	  str++;
	}

      if (*str == '\0')
	break;
      if (*str != '.')
	return -1;

      oid[len++] = val;
      val = 0;
      str++;
    }

  oid[len++] = val;
  *oid_len = len;

  return 0;
}

oid *
smux_oid_dup (oid *objid, size_t objid_len)
{
  oid *new;

  new = XMALLOC (MTYPE_TMP, sizeof (oid) * objid_len);
  oid_copy (new, objid, objid_len);

  return new;
}

int
smux_peer_oid (struct vty *vty, char *oid_str, char *passwd_str)
{
  int ret;
  oid oid[MAX_OID_LEN];
  size_t oid_len;

  ret = smux_str2oid (oid_str, oid, &oid_len);
  if (ret != 0)
    {
      vty_out (vty, "object ID malformed%s", VTY_NEWLINE);
      return CMD_WARNING;
    }

  if (smux_oid && smux_oid != smux_default_oid)
    free (smux_oid);

  if (smux_passwd && smux_passwd != smux_default_passwd)
    {
      free (smux_passwd);
      smux_passwd = NULL;
    }

  smux_oid = smux_oid_dup (oid, oid_len);
  smux_oid_len = oid_len;

  if (passwd_str)
    smux_passwd = strdup (passwd_str);

  return CMD_SUCCESS;
}

int
smux_header_generic (struct variable *v, oid *name, size_t *length, int exact,
		     size_t *var_len, WriteMethod **write_method)
{
  oid fulloid[MAX_OID_LEN];
  int ret;

  oid_copy (fulloid, v->name, v->namelen);
  fulloid[v->namelen] = 0;
  /* Check against full instance. */
  ret = oid_compare (name, *length, fulloid, v->namelen + 1);

  /* Check single instance. */
  if ((exact && (ret != 0)) || (!exact && (ret >= 0)))
	return MATCH_FAILED;

  /* In case of getnext, fill in full instance. */
  memcpy (name, fulloid, (v->namelen + 1) * sizeof (oid));
  *length = v->namelen + 1;

  *write_method = 0;
  *var_len = sizeof(long);    /* default to 'long' results */

  return MATCH_SUCCEEDED;
}

int
smux_peer_default ()
{
  if (smux_oid != smux_default_oid)
    {
      free (smux_oid);
      smux_oid = smux_default_oid;
      smux_oid_len = smux_default_oid_len;
    }
  if (smux_passwd != smux_default_passwd)
    {
      free (smux_passwd);
      smux_passwd = smux_default_passwd;
    }
  return CMD_SUCCESS;
}

DEFUN (smux_peer,
       smux_peer_cmd,
       "smux peer OID",
       "SNMP MUX protocol settings\n"
       "SNMP MUX peer settings\n"
       "Object ID used in SMUX peering\n")
{
  return smux_peer_oid (vty, argv[0], NULL);
}

DEFUN (smux_peer_password,
       smux_peer_password_cmd,
       "smux peer OID PASSWORD",
       "SNMP MUX protocol settings\n"
       "SNMP MUX peer settings\n"
       "SMUX peering object ID\n"
       "SMUX peering password\n")
{
  return smux_peer_oid (vty, argv[0], argv[1]);
}

DEFUN (no_smux_peer,
       no_smux_peer_cmd,
       "no smux peer OID",
       NO_STR
       "SNMP MUX protocol settings\n"
       "SNMP MUX peer settings\n"
       "Object ID used in SMUX peering\n")
{
  return smux_peer_default ();
}

DEFUN (no_smux_peer_password,
       no_smux_peer_password_cmd,
       "no smux peer OID PASSWORD",
       NO_STR
       "SNMP MUX protocol settings\n"
       "SNMP MUX peer settings\n"
       "SMUX peering object ID\n"
       "SMUX peering password\n")
{
  return smux_peer_default ();
}

int
config_write_smux (struct vty *vty)
{
  int first = 1;
  int i;

  if (smux_oid != smux_default_oid || smux_passwd != smux_default_passwd)
    {
      vty_out (vty, "smux peer ");
      for (i = 0; i < smux_oid_len; i++)
	{
	  vty_out (vty, "%s%d", first ? "" : ".", (int) smux_oid[i]);
	  first = 0;
	}
      vty_out (vty, " %s%s", smux_passwd, VTY_NEWLINE);
    }
  return 0;
}

/* Register subtree to smux master tree. */
void
smux_register_mib (char *descr, struct variable *var, size_t width, int num, 
		   oid name[], size_t namelen)
{
  struct subtree *tree;

  tree = (struct subtree *)malloc(sizeof(struct subtree));
  oid_copy (tree->name, name, namelen);
  tree->name_len = namelen;
  tree->variables = var;
  tree->variables_num = num;
  tree->variables_width = width;
  tree->registered = 0;
  listnode_add_sort(treelist, tree);
}

void
smux_reset ()
{
  /* Setting configuration to default. */
  smux_peer_default ();
}

/* Compare function to keep treelist sorted */
static int
smux_tree_cmp(struct subtree *tree1, struct subtree *tree2)
{
  return oid_compare(tree1->name, tree1->name_len, 
		     tree2->name, tree2->name_len);
}

/* Initialize some values then schedule first SMUX connection. */
void
smux_init (oid defoid[], size_t defoid_len)
{
  /* Set default SMUX oid. */
  smux_default_oid = defoid;
  smux_default_oid_len = defoid_len;

  smux_oid = smux_default_oid;
  smux_oid_len = smux_default_oid_len;
  smux_passwd = smux_default_passwd;
  
  /* Make MIB tree. */
  treelist = list_new();
  treelist->cmp = (int (*)(void *, void *))smux_tree_cmp;

  /* Install commands. */
  install_node (&smux_node, config_write_smux);

  install_element (CONFIG_NODE, &smux_peer_cmd);
  install_element (CONFIG_NODE, &smux_peer_password_cmd);
  install_element (CONFIG_NODE, &no_smux_peer_cmd);
  install_element (CONFIG_NODE, &no_smux_peer_password_cmd);
}

void
smux_start(void)
{
  /* Schedule first connection. */
  smux_event (SMUX_SCHEDULE, 0);
}
#endif /* HAVE_SNMP */