about summary refs log tree commit diff
path: root/tvix/nar-bridge/src/narinfo.rs
blob: 4706be64d5b42a2c96ffa0a1ae221bd058d7c902 (plain) (blame)
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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
use axum::http::StatusCode;
use bytes::Bytes;
use nix_compat::{narinfo::NarInfo, nixbase32};
use tracing::{instrument, warn, Span};
use tvix_castore::proto::{self as castorepb, node::Node};
use tvix_store::proto::PathInfo;

use crate::AppState;

/// The size limit for NARInfo uploads nar-bridge receives
const NARINFO_LIMIT: usize = 2 * 1024 * 1024;

#[instrument(skip(path_info_service))]
pub async fn head(
    axum::extract::Path(narinfo_str): axum::extract::Path<String>,
    axum::extract::State(AppState {
        path_info_service, ..
    }): axum::extract::State<AppState>,
) -> Result<&'static str, StatusCode> {
    let digest = parse_narinfo_str(&narinfo_str)?;
    Span::current().record("path_info.digest", &narinfo_str[0..32]);

    if path_info_service
        .get(digest)
        .await
        .map_err(|e| {
            warn!(err=%e, "failed to get PathInfo");
            StatusCode::INTERNAL_SERVER_ERROR
        })?
        .is_some()
    {
        Ok("")
    } else {
        warn!("PathInfo not found");
        Err(StatusCode::NOT_FOUND)
    }
}

#[instrument(skip(path_info_service))]
pub async fn get(
    axum::extract::Path(narinfo_str): axum::extract::Path<String>,
    axum::extract::State(AppState {
        path_info_service, ..
    }): axum::extract::State<AppState>,
) -> Result<String, StatusCode> {
    let digest = parse_narinfo_str(&narinfo_str)?;
    Span::current().record("path_info.digest", &narinfo_str[0..32]);

    // fetch the PathInfo
    let path_info = path_info_service
        .get(digest)
        .await
        .map_err(|e| {
            warn!(err=%e, "failed to get PathInfo");
            StatusCode::INTERNAL_SERVER_ERROR
        })?
        .ok_or(StatusCode::NOT_FOUND)?;

    let store_path = path_info.validate().map_err(|e| {
        warn!(err=%e, "invalid PathInfo");
        StatusCode::INTERNAL_SERVER_ERROR
    })?;

    let mut narinfo = path_info.to_narinfo(store_path).ok_or_else(|| {
        warn!(path_info=?path_info, "PathInfo contained no NAR data");
        StatusCode::INTERNAL_SERVER_ERROR
    })?;

    // encode the (unnamed) root node in the NAR url itself.
    let root_node = path_info
        .node
        .as_ref()
        .and_then(|n| n.node.as_ref())
        .expect("root node must not be none")
        .clone()
        .rename("".into());

    let mut buf = Vec::new();
    Node::encode(&root_node, &mut buf);

    let url = format!(
        "nar/tvix-castore/{}?narsize={}",
        data_encoding::BASE64URL_NOPAD.encode(&buf),
        narinfo.nar_size,
    );

    narinfo.url = &url;

    Ok(narinfo.to_string())
}

#[instrument(skip(path_info_service, root_nodes, request))]
pub async fn put(
    axum::extract::Path(narinfo_str): axum::extract::Path<String>,
    axum::extract::State(AppState {
        path_info_service,
        root_nodes,
        ..
    }): axum::extract::State<AppState>,
    request: axum::extract::Request,
) -> Result<&'static str, StatusCode> {
    let _narinfo_digest = parse_narinfo_str(&narinfo_str)?;
    Span::current().record("path_info.digest", &narinfo_str[0..32]);

    let narinfo_bytes: Bytes = axum::body::to_bytes(request.into_body(), NARINFO_LIMIT)
        .await
        .map_err(|e| {
            warn!(err=%e, "unable to fetch body");
            StatusCode::BAD_REQUEST
        })?;

    // Parse the narinfo from the body.
    let narinfo_str = std::str::from_utf8(narinfo_bytes.as_ref()).map_err(|e| {
        warn!(err=%e, "unable decode body as string");
        StatusCode::BAD_REQUEST
    })?;

    let narinfo = NarInfo::parse(narinfo_str).map_err(|e| {
        warn!(err=%e, "unable to parse narinfo");
        StatusCode::BAD_REQUEST
    })?;

    // Extract the NARHash from the PathInfo.
    Span::current().record("path_info.nar_info", nixbase32::encode(&narinfo.nar_hash));

    // populate the pathinfo.
    let mut pathinfo = PathInfo::from(&narinfo);

    // Lookup root node with peek, as we don't want to update the LRU list.
    // We need to be careful to not hold the RwLock across the await point.
    let maybe_root_node = root_nodes
        .read()
        .peek(&narinfo.nar_hash)
        .map(|v| v.to_owned());

    match maybe_root_node {
        Some(root_node) => {
            // Set the root node from the lookup.
            // We need to rename the node to the narinfo storepath basename, as
            // that's where it's stored in PathInfo.
            pathinfo.node = Some(castorepb::Node {
                node: Some(root_node.rename(narinfo.store_path.to_string().into())),
            });

            // Persist the PathInfo.
            path_info_service.put(pathinfo).await.map_err(|e| {
                warn!(err=%e, "failed to persist the PathInfo");
                StatusCode::INTERNAL_SERVER_ERROR
            })?;

            Ok("")
        }
        None => {
            warn!("received narinfo with unknown NARHash");
            Err(StatusCode::BAD_REQUEST)
        }
    }
}

/// Parses a `3mzh8lvgbynm9daj7c82k2sfsfhrsfsy.narinfo` string and returns the
/// nixbase32-decoded digest.
fn parse_narinfo_str(s: &str) -> Result<[u8; 20], StatusCode> {
    if !s.is_char_boundary(32) {
        warn!("invalid string, no char boundary at 32");
        return Err(StatusCode::NOT_FOUND);
    }

    Ok(match s.split_at(32) {
        (hash_str, ".narinfo") => {
            // we know this is 32 bytes
            let hash_str_fixed: [u8; 32] = hash_str.as_bytes().try_into().unwrap();
            nixbase32::decode_fixed(hash_str_fixed).map_err(|e| {
                warn!(err=%e, "invalid digest");
                StatusCode::NOT_FOUND
            })?
        }
        _ => {
            warn!("invalid string");
            return Err(StatusCode::NOT_FOUND);
        }
    })
}

#[cfg(test)]
mod test {
    use super::parse_narinfo_str;
    use hex_literal::hex;

    #[test]
    fn success() {
        assert_eq!(
            hex!("8a12321522fd91efbd60ebb2481af88580f61600"),
            parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44la.narinfo").unwrap()
        );
    }

    #[test]
    fn failure() {
        assert!(parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44la").is_err());
        assert!(parse_narinfo_str("/00bgd045z0d4icpbc2yyz4gx48ak44la").is_err());
        assert!(parse_narinfo_str("000000").is_err());
        assert!(parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44l🦊.narinfo").is_err());
    }
}