execute.c

DHCP服务器源码

	if (!ptr || !*ptr) {
		log_error ("%s(%d): null pointer", file, line);
#if defined (POINTER_DEBUG)
		abort ();
#else
		return 0;
#endif
	}

	(*ptr) -> refcnt--;
	rc_register (file, line, ptr, *ptr, (*ptr) -> refcnt, 1, RC_MISC);
	if ((*ptr) -> refcnt > 0) {
		*ptr = (struct executable_statement *)0;
		return 1;
	}

	if ((*ptr) -> refcnt < 0) {
		log_error ("%s(%d): negative refcnt!", file, line);
#if defined (DEBUG_RC_HISTORY)
		dump_rc_history (*ptr);
#endif
#if defined (POINTER_DEBUG)
		abort ();
#else
		return 0;
#endif
	}

	if ((*ptr) -> next)
		executable_statement_dereference (&(*ptr) -> next, file, line);

	switch ((*ptr) -> op) {
	      case statements_statement:
		if ((*ptr) -> data.statements)
			executable_statement_dereference
				(&(*ptr) -> data.statements, file, line);
		break;

	      case on_statement:
		if ((*ptr) -> data.on.statements)
			executable_statement_dereference
				(&(*ptr) -> data.on.statements, file, line);
		break;

	      case switch_statement:
		if ((*ptr) -> data.s_switch.statements)
			executable_statement_dereference
				(&(*ptr) -> data.on.statements, file, line);
		if ((*ptr) -> data.s_switch.expr)
			expression_dereference (&(*ptr) -> data.s_switch.expr,
						file, line);
		break;

	      case case_statement:
		if ((*ptr) -> data.s_switch.expr)
			expression_dereference (&(*ptr) -> data.c_case,
						file, line);
		break;

	      case if_statement:
		if ((*ptr) -> data.ie.expr)
			expression_dereference (&(*ptr) -> data.ie.expr,
						file, line);
		if ((*ptr) -> data.ie.tc)
			executable_statement_dereference
				(&(*ptr) -> data.ie.tc, file, line);
		if ((*ptr) -> data.ie.fc)
			executable_statement_dereference
				(&(*ptr) -> data.ie.fc, file, line);
		break;

	      case eval_statement:
		if ((*ptr) -> data.eval)
			expression_dereference (&(*ptr) -> data.eval,
						file, line);
		break;

	      case return_statement:
		if ((*ptr) -> data.eval)
			expression_dereference (&(*ptr) -> data.eval,
						file, line);
		break;

	      case set_statement:
		if ((*ptr)->data.set.name)
			dfree ((*ptr)->data.set.name, file, line);
		if ((*ptr)->data.set.expr)
			expression_dereference (&(*ptr) -> data.set.expr,
						file, line);
		break;

	      case unset_statement:
		if ((*ptr)->data.unset)
			dfree ((*ptr)->data.unset, file, line);
		break;

	      case supersede_option_statement:
	      case send_option_statement:
	      case default_option_statement:
	      case append_option_statement:
	      case prepend_option_statement:
		if ((*ptr) -> data.option)
			option_cache_dereference (&(*ptr) -> data.option,
						  file, line);
		break;

	      default:
		/* Nothing to do. */
		break;
	}

	dfree ((*ptr), file, line);
	*ptr = (struct executable_statement *)0;
	return 1;
}

void write_statements (file, statements, indent)
	FILE *file;
	struct executable_statement *statements;
	int indent;
{
	struct executable_statement *r, *x;
	int result;
	int status;
	const char *s, *t, *dot;
	int col;

	if (!statements)
		return;

	for (r = statements; r; r = r -> next) {
		switch (r -> op) {
		      case statements_statement:
			write_statements (file, r -> data.statements, indent);
			break;

		      case on_statement:
			indent_spaces (file, indent);
			fprintf (file, "on ");
			s = "";
			if (r -> data.on.evtypes & ON_EXPIRY) {
				fprintf (file, "%sexpiry", s);
				s = " or ";
			}
			if (r -> data.on.evtypes & ON_COMMIT) {
				fprintf (file, "%scommit", s);
				s = "or";
			}
			if (r -> data.on.evtypes & ON_RELEASE) {
				fprintf (file, "%srelease", s);
				s = "or";
			}
			if (r -> data.on.statements) {
				fprintf (file, " {");
				write_statements (file,
						  r -> data.on.statements,
						  indent + 2);
				indent_spaces (file, indent);
				fprintf (file, "}");
			} else {
				fprintf (file, ";");
			}
			break;

		      case switch_statement:
			indent_spaces (file, indent);
			fprintf (file, "switch (");
			col = write_expression (file,
						r -> data.s_switch.expr,
						indent + 7, indent + 7, 1);
			col = token_print_indent (file, col, indent + 7,
						  "", "", ")");
			token_print_indent (file,
					    col, indent, " ", "", "{");
			write_statements (file, r -> data.s_switch.statements,
					  indent + 2);
			indent_spaces (file, indent);
			fprintf (file, "}");
			break;
			
		      case case_statement:
			indent_spaces (file, indent - 1);
			fprintf (file, "case ");
			col = write_expression (file,
						r -> data.s_switch.expr,
						indent + 5, indent + 5, 1);
			token_print_indent (file, col, indent + 5,
					    "", "", ":");
			break;
			
		      case default_statement:
			indent_spaces (file, indent - 1);
			fprintf (file, "default: ");
			break;

		      case if_statement:
			indent_spaces (file, indent);
			fprintf (file, "if ");
			x = r;
			col = write_expression (file,
						x -> data.ie.expr,
						indent + 3, indent + 3, 1);
		      else_if:
			token_print_indent (file, col, indent, " ", "", "{");
			write_statements (file, x -> data.ie.tc, indent + 2);
			if (x -> data.ie.fc &&
			    x -> data.ie.fc -> op == if_statement &&
			    !x -> data.ie.fc -> next) {
				indent_spaces (file, indent);
				fprintf (file, "} elsif ");
				x = x -> data.ie.fc;
				col = write_expression (file,
							x -> data.ie.expr,
							indent + 6,
							indent + 6, 1);
				goto else_if;
			}
			if (x -> data.ie.fc) {
				indent_spaces (file, indent);
				fprintf (file, "} else {");
				write_statements (file, x -> data.ie.fc,
						  indent + 2);
			}
			indent_spaces (file, indent);
			fprintf (file, "}");
			break;

		      case eval_statement:
			indent_spaces (file, indent);
			fprintf (file, "eval ");
			col = write_expression (file, r -> data.eval,
						indent + 5, indent + 5, 1);
			fprintf (file, ";");
			break;

		      case return_statement:
			indent_spaces (file, indent);
			fprintf (file, "return;");
			break;

		      case add_statement:
			indent_spaces (file, indent);
			fprintf (file, "add \"%s\"", r -> data.add -> name);
			break;

		      case break_statement:
			indent_spaces (file, indent);
			fprintf (file, "break;");
			break;

		      case supersede_option_statement:
		      case send_option_statement:
			s = "supersede";
			goto option_statement;

		      case default_option_statement:
			s = "default";
			goto option_statement;

		      case append_option_statement:
			s = "append";
			goto option_statement;

		      case prepend_option_statement:
			s = "prepend";
		      option_statement:
			/* Note: the reason we don't try to pretty print
			   the option here is that the format of the option
			   may change in dhcpd.conf, and then when this
			   statement was read back, it would cause a syntax
			   error. */
			if (r -> data.option -> option -> universe ==
			    &dhcp_universe) {
				t = "";
				dot = "";
			} else {
				t = (r -> data.option -> option ->
				     universe -> name);
				dot = ".";
			}
			indent_spaces (file, indent);
			fprintf (file, "%s %s%s%s = ", s, t, dot,
				 r -> data.option -> option -> name);
			col = (indent + strlen (s) + strlen (t) +
			       strlen (dot) + strlen (r -> data.option ->
						      option -> name) + 4);
			if (r -> data.option -> expression)
				write_expression
					(file,
					 r -> data.option -> expression,
					 col, indent + 8, 1);
			else
				token_indent_data_string
					(file, col, indent + 8, "", "",
					 &r -> data.option -> data);
					 
			fprintf (file, ";"); /* XXX */
			break;

		      case set_statement:
			indent_spaces (file, indent);
			fprintf (file, "set ");
			col = token_print_indent (file, indent + 4, indent + 4,
						  "", "", r -> data.set.name);
			col = token_print_indent (file, col, indent + 4,
						  " ", " ", "=");
			col = write_expression (file, r -> data.set.expr,
						indent + 3, indent + 3, 0);
			col = token_print_indent (file, col, indent + 4,
						  " ", "", ";");
			break;
			
		      case unset_statement:
			indent_spaces (file, indent);
			fprintf (file, "unset ");
			col = token_print_indent (file, indent + 6, indent + 6,
						  "", "", r -> data.set.name);
			col = token_print_indent (file, col, indent + 6,
						  " ", "", ";");
			break;

		      case log_statement:
			indent_spaces (file, indent);
			fprintf (file, "log ");
			col = token_print_indent (file, col, indent + 4,
						  "", "", "(");
			switch (r -> data.log.priority) {
			case log_priority_fatal:
				col = token_print_indent
					(file, col, indent + 4, "",
					 " ", "fatal,");
				break;
			case log_priority_error:
				col = token_print_indent
					(file, col, indent + 4, "",
					 " ", "error,");
				break;
			case log_priority_debug:
				col = token_print_indent
					(file, col, indent + 4, "",
					 " ", "debug,");
				break;
			case log_priority_info:
				col = token_print_indent
					(file, col, indent + 4, "",
					 " ", "info,");
				break;
			}
			col = write_expression (file, r -> data.log.expr,
						indent + 4, indent + 4, 0);
			col = token_print_indent (file, col, indent + 4,
						  "", "", ");");

			break;
			
		      default:
			log_fatal ("bogus statement type %d\n", r -> op);
		}
	}
}

/* Find a case statement in the sequence of executable statements that
   matches the expression, and if found, return the following statement.
   If no case statement matches, try to find a default statement and
   return that (the default statement can precede all the case statements).
   Otherwise, return the null statement. */

int find_matching_case (struct executable_statement **ep,
			struct packet *packet, struct lease *lease,
			struct client_state *client_state,
			struct option_state *in_options,
			struct option_state *out_options,
			struct binding_scope **scope,
			struct expression *expr,
			struct executable_statement *stmt)
{
	int status, sub;
	struct executable_statement *s;
	unsigned long foo;

	if (is_data_expression (expr)) {
		struct executable_statement *e;
		struct data_string cd, ds;
		memset (&ds, 0, sizeof ds);
		memset (&cd, 0, sizeof cd);

		status = (evaluate_data_expression (&ds, packet, lease,
						    client_state, in_options,
						    out_options, scope, expr,
						    MDL));
		if (status) {
		    for (s = stmt; s; s = s -> next) {
			if (s -> op == case_statement) {
				sub = (evaluate_data_expression
				       (&cd, packet, lease, client_state,
					in_options, out_options,
					scope, s -> data.c_case, MDL));
				if (sub && cd.len == ds.len &&
				    !memcmp (cd.data, ds.data, cd.len))
				{
					data_string_forget (&cd, MDL);
					data_string_forget (&ds, MDL);
					executable_statement_reference
						(ep, s -> next, MDL);
					return 1;
				}
				data_string_forget (&cd, MDL);
			}
		    }
		    data_string_forget (&ds, MDL);
		}
	} else {
		unsigned long n, c;
		status = evaluate_numeric_expression (&n, packet, lease,
						      client_state,
						      in_options, out_options,
						      scope, expr);

		if (status) {
		    for (s = stmt; s; s = s -> next) {
			if (s -> op == case_statement) {
				sub = (evaluate_numeric_expression
				       (&c, packet, lease, client_state,
					in_options, out_options,
					scope, s -> data.c_case));
				if (sub && n == c) {
					executable_statement_reference
						(ep, s -> next, MDL);
					return 1;
				}
			}
		    }
		}
	}

	/* If we didn't find a matching case statement, look for a default
	   statement and return the statement following it. */
	for (s = stmt; s; s = s -> next)
		if (s -> op == default_statement)
			break;
	if (s) {
		executable_statement_reference (ep, s -> next, MDL);
		return 1;
	}
	return 0;
}

int executable_statement_foreach (struct executable_statement *stmt,
				  int (*callback) (struct
						   executable_statement *,
						   void *, int),
				  void *vp, int condp)
{
	struct executable_statement *foo;
	int ok = 0;
	int result;

	for (foo = stmt; foo; foo = foo -> next) {
	    if ((*callback) (foo, vp, condp) != 0)
		ok = 1;
	    switch (foo -> op) {
	      case null_statement:
		break;
	      case if_statement:
		if (executable_statement_foreach (foo -> data.ie.tc,
						  callback, vp, 1))
			ok = 1;
		if (executable_statement_foreach (foo -> data.ie.fc,
						  callback, vp, 1))
			ok = 1;
		break;
	      case add_statement:
		break;
	      case eval_statement:
		break;
	      case break_statement:
		break;
	      case default_option_statement:
		break;
	      case supersede_option_statement:
		break;
	      case append_option_statement:
		break;
	      case prepend_option_statement:
		break;
	      case send_option_statement:
		break;
	      case statements_statement:
		if ((executable_statement_foreach
		     (foo -> data.statements, callback, vp, condp)))
			ok = 1;
		break;
	      case on_statement:
		if ((executable_statement_foreach
		     (foo -> data.on.statements, callback, vp, 1)))
			ok = 1;
		break;
	      case switch_statement:
		if ((executable_statement_foreach
		     (foo -> data.s_switch.statements, callback, vp, 1)))
			ok = 1;
		break;
	      case case_statement:
		break;
	      case default_statement:
		break;
	      case set_statement:
		break;
	      case unset_statement:
		break;
	      case let_statement:
		if ((executable_statement_foreach
		     (foo -> data.let.statements, callback, vp, 0)))
			ok = 1;
		break;
	      case define_statement:
		break;
	      case log_statement:
	      case return_statement:
		break;
	    }
	}
	return ok;
}