rns-hooks-abi 0.1.2

Shared ABI definitions for rns-hooks host and SDK
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

/// Base address in WASM linear memory where the host writes context.
pub const ARENA_BASE: usize = 0x1000;

/// Context type discriminants.
pub const CTX_TYPE_PACKET: u32 = 0;
pub const CTX_TYPE_INTERFACE: u32 = 1;
pub const CTX_TYPE_TICK: u32 = 2;
pub const CTX_TYPE_ANNOUNCE: u32 = 3;
pub const CTX_TYPE_LINK: u32 = 4;
pub const CTX_TYPE_BACKBONE_PEER: u32 = 5;

/// Read the context type discriminant from an arena pointer.
///
/// # Safety
/// `ptr` must point to a valid arena context written by the host.
pub unsafe fn context_type(ptr: *const u8) -> u32 {
    (ptr as *const u32).read()
}

/// Packet context layout — matches host `ArenaPacket` byte-for-byte.
#[repr(C)]
pub struct PacketContext {
    pub context_type: u32,
    pub flags: u8,
    pub hops: u8,
    _pad: [u8; 2],
    pub destination_hash: [u8; 16],
    pub context: u8,
    _pad2: [u8; 3],
    pub packet_hash: [u8; 32],
    _pad3: u32,
    pub interface_id: u64,
    pub data_offset: u32,
    pub data_len: u32,
}

/// Interface context layout — matches host `ArenaInterface`.
#[repr(C)]
pub struct InterfaceContext {
    pub context_type: u32,
    _pad: u32,
    pub interface_id: u64,
}

/// Tick context layout — matches host `ArenaTick`.
#[repr(C)]
pub struct TickContext {
    pub context_type: u32,
}

/// Announce context layout — matches host `ArenaAnnounce`.
#[repr(C)]
pub struct AnnounceContext {
    pub context_type: u32,
    pub hops: u8,
    _pad: [u8; 3],
    pub destination_hash: [u8; 16],
    pub interface_id: u64,
}

/// Link context layout — matches host `ArenaLink`.
#[repr(C)]
pub struct LinkContext {
    pub context_type: u32,
    _pad: u32,
    pub link_id: [u8; 16],
    pub interface_id: u64,
}

/// Backbone peer lifecycle context layout — matches host `ArenaBackbonePeer`.
#[repr(C, packed)]
#[derive(Clone, Copy)]
pub struct BackbonePeerContext {
    pub context_type: u32,
    pub peer_ip_family: u8,
    pub peer_port: u16,
    pub had_received_data: u8,
    pub server_interface_id: u64,
    pub peer_interface_id: u64,
    pub connected_for_secs: u64,
    pub penalty_level: u8,
    _pad: [u8; 7],
    pub blacklist_for_secs: u64,
    pub peer_ip: [u8; 16],
}

#[cfg(test)]
mod tests {
    use super::*;

    fn write_u16(data: &mut [u8], offset: usize, value: u16) {
        data[offset..offset + 2].copy_from_slice(&value.to_le_bytes());
    }

    fn write_u32(data: &mut [u8], offset: usize, value: u32) {
        data[offset..offset + 4].copy_from_slice(&value.to_le_bytes());
    }

    fn write_u64(data: &mut [u8], offset: usize, value: u64) {
        data[offset..offset + 8].copy_from_slice(&value.to_le_bytes());
    }

    #[test]
    fn backbone_peer_context_matches_host_layout() {
        assert_eq!(core::mem::size_of::<BackbonePeerContext>(), 64);
        let mut raw = [0u8; 64];
        write_u32(&mut raw, 0, CTX_TYPE_BACKBONE_PEER);
        raw[4] = 4;
        write_u16(&mut raw, 5, 4242);
        raw[7] = 1;
        write_u64(&mut raw, 8, 11);
        write_u64(&mut raw, 16, 22);
        write_u64(&mut raw, 24, 33);
        raw[32] = 4;
        write_u64(&mut raw, 40, 44);
        raw[48..64].copy_from_slice(&[172, 20, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);

        let ctx = unsafe { core::ptr::read_unaligned(raw.as_ptr() as *const BackbonePeerContext) };
        let context_type = ctx.context_type;
        let peer_ip_family = ctx.peer_ip_family;
        let peer_port = ctx.peer_port;
        let had_received_data = ctx.had_received_data;
        let server_interface_id = ctx.server_interface_id;
        let peer_interface_id = ctx.peer_interface_id;
        let connected_for_secs = ctx.connected_for_secs;
        let penalty_level = ctx.penalty_level;
        let blacklist_for_secs = ctx.blacklist_for_secs;
        let peer_ip = ctx.peer_ip;

        assert_eq!(context_type, CTX_TYPE_BACKBONE_PEER);
        assert_eq!(peer_ip_family, 4);
        assert_eq!(peer_port, 4242);
        assert_eq!(had_received_data, 1);
        assert_eq!(server_interface_id, 11);
        assert_eq!(peer_interface_id, 22);
        assert_eq!(connected_for_secs, 33);
        assert_eq!(penalty_level, 4);
        assert_eq!(blacklist_for_secs, 44);
        assert_eq!(peer_ip[0..4], [172, 20, 0, 3]);
    }
}