// Copyright 2024 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.net.routes;

using fuchsia.net;

/// The priority of the rule set, all rule sets are linearized based on this.
///
/// Rules of a `RuleSet` with a smaller [`RuleSetPriority`] are executed before
/// rules of a `RuleSet` with a larger [`RuleSetPriority`]. That is, `RuleSet`
/// with priority 0 has the top priority.
@available(added=HEAD)
alias RuleSetPriority = uint32;

/// The index of a rule within a provided rule set.
///
/// Rules within the same `RuleSet` are oredered based on the index. Rule at
/// index 0 is evaluated first among the entire set.
@available(added=HEAD)
alias RuleIndex = uint32;

/// Actions of a rule if the selector matches.
@available(added=HEAD)
type RuleAction = flexible union {
    /// Look for a route in the indicated route table. If there is no matching
    /// route in the target table, the lookup will continue to consider the
    /// next rule.
    1: lookup TableId;
    /// Return network is unreachable. This is contrary to if a `lookup` table
    /// is empty or no matching routes, this decision is terminal and stops
    /// the lookup process from continuing.
    2: unreachable struct {};
};

/// A selector to be used against the mark value.
@available(added=HEAD)
type MarkSelector = flexible union {
    /// This mark domain does not have a mark.
    1: unmarked struct {};
    2: marked struct {
        /// Mask to apply before comparing to the range in `between`.
        mask uint32;
        /// The mark is between the given range.
        between struct {
            /// start of the range, inclusive.
            start uint32;
            /// end of the range, inclusive.
            end uint32;
        };
    };
};

/// The common selector that can be applied to both IPv4 and IPv6 packets.
///
/// A selector matches a packet if all of the present fields match the
/// corresponding properties.
@available(added=HEAD)
type BaseSelector = table {
    /// Matches the packet iff the packet was locally generated.
    1: locally_generated bool;

    /// Matches the packet iff the socket that was bound to the device using
    /// `SO_BINDTODEVICE`.
    2: bound_device fuchsia.net.InterfaceId;

    /// The selector for the MARK_1 domain.
    3: mark_1_selector MarkSelector;

    /// The selector for the MARK_2 domain.
    4: mark_2_selector MarkSelector;
};