#
cargo/sources/registry/
mod.rs

    1//! A `Source` for registry-based packages.
    2//!
    3//! # What's a Registry?
    4//!
    5//! [Registries] are central locations where packages can be uploaded to,
    6//! discovered, and searched for. The purpose of a registry is to have a
    7//! location that serves as permanent storage for versions of a crate over time.
    8//!
    9//! Compared to git sources (see [`GitSource`]), a registry provides many
    10//! packages as well as many versions simultaneously. Git sources can also
    11//! have commits deleted through rebasings where registries cannot have their
    12//! versions deleted.
    13//!
    14//! In Cargo, [`RegistryData`] is an abstraction over each kind of actual
    15//! registry, and [`RegistrySource`] connects those implementations to
    16//! [`Source`] trait. Two prominent features these abstractions provide are
    17//!
    18//! * A way to query the metadata of a package from a registry. The metadata
    19//!   comes from the index.
    20//! * A way to download package contents (a.k.a source files) that are required
    21//!   when building the package itself.
    22//!
    23//! We'll cover each functionality later.
    24//!
    25//! [Registries]: https://doc.rust-lang.org/nightly/cargo/reference/registries.html
    26//! [`GitSource`]: super::GitSource
    27//!
    28//! # Different Kinds of Registries
    29//!
    30//! Cargo provides multiple kinds of registries. Each of them serves the index
    31//! and package contents in a slightly different way. Namely,
    32//!
    33//! * [`LocalRegistry`] --- Serves the index and package contents entirely on
    34//!   a local filesystem.
    35//! * [`RemoteRegistry`] --- Serves the index ahead of time from a Git
    36//!   repository, and package contents are downloaded as needed.
    37//! * [`HttpRegistry`] --- Serves both the index and package contents on demand
    38//!   over a HTTP-based registry API. This is the default starting from 1.70.0.
    39//!
    40//! Each registry has its own [`RegistryData`] implementation, and can be
    41//! created from either [`RegistrySource::local`] or [`RegistrySource::remote`].
    42//!
    43//! [`LocalRegistry`]: local::LocalRegistry
    44//! [`RemoteRegistry`]: remote::RemoteRegistry
    45//! [`HttpRegistry`]: http_remote::HttpRegistry
    46//!
    47//! # The Index of a Registry
    48//!
    49//! One of the major difficulties with a registry is that hosting so many
    50//! packages may quickly run into performance problems when dealing with
    51//! dependency graphs. It's infeasible for cargo to download the entire contents
    52//! of the registry just to resolve one package's dependencies, for example. As
    53//! a result, cargo needs some efficient method of querying what packages are
    54//! available on a registry, what versions are available, and what the
    55//! dependencies for each version is.
    56//!
    57//! To solve the problem, a registry must provide an index of package metadata.
    58//! The index of a registry is essentially an easily query-able version of the
    59//! registry's database for a list of versions of a package as well as a list
    60//! of dependencies for each version. The exact format of the index is
    61//! described later.
    62//!
    63//! See the [`index`] module for topics about the management, parsing, caching,
    64//! and versioning for the on-disk index.
    65//!
    66//! ## The Format of The Index
    67//!
    68//! The index is a store for the list of versions for all packages known, so its
    69//! format on disk is optimized slightly to ensure that `ls registry` doesn't
    70//! produce a list of all packages ever known. The index also wants to ensure
    71//! that there's not a million files which may actually end up hitting
    72//! filesystem limits at some point. To this end, a few decisions were made
    73//! about the format of the registry:
    74//!
    75//! 1. Each crate will have one file corresponding to it. Each version for a
    76//!    crate will just be a line in this file (see [`cargo_util_schemas::index::IndexPackage`] for its
    77//!    representation).
    78//! 2. There will be two tiers of directories for crate names, under which
    79//!    crates corresponding to those tiers will be located.
    80//!    (See [`cargo_util::registry::make_dep_path`] for the implementation of
    81//!    this layout hierarchy.)
    82//!
    83//! As an example, this is an example hierarchy of an index:
    84//!
    85//! ```notrust
    86//! .
    87//! ├── 3
    88//! │   └── u
    89//! │       └── url
    90//! ├── bz
    91//! │   └── ip
    92//! │       └── bzip2
    93//! ├── config.json
    94//! ├── en
    95//! │   └── co
    96//! │       └── encoding
    97//! └── li
    98//!     ├── bg
    99//!     │   └── libgit2
    100//!     └── nk
    101//!         └── link-config
    102//! ```
    103//!
    104//! The root of the index contains a `config.json` file with a few entries
    105//! corresponding to the registry (see [`RegistryConfig`] below).
    106//!
    107//! Otherwise, there are three numbered directories (1, 2, 3) for crates with
    108//! names 1, 2, and 3 characters in length. The 1/2 directories simply have the
    109//! crate files underneath them, while the 3 directory is sharded by the first
    110//! letter of the crate name.
    111//!
    112//! Otherwise the top-level directory contains many two-letter directory names,
    113//! each of which has many sub-folders with two letters. At the end of all these
    114//! are the actual crate files themselves.
    115//!
    116//! The purpose of this layout is to hopefully cut down on `ls` sizes as well as
    117//! efficient lookup based on the crate name itself.
    118//!
    119//! See [The Cargo Book: Registry Index][registry-index] for the public
    120//! interface on the index format.
    121//!
    122//! [registry-index]: https://doc.rust-lang.org/nightly/cargo/reference/registry-index.html
    123//!
    124//! ## The Index Files
    125//!
    126//! Each file in the index is the history of one crate over time. Each line in
    127//! the file corresponds to one version of a crate, stored in JSON format (see
    128//! the [`cargo_util_schemas::index::IndexPackage`] structure).
    129//!
    130//! As new versions are published, new lines are appended to this file. **The
    131//! only modifications to this file that should happen over time are yanks of a
    132//! particular version.**
    133//!
    134//! # Downloading Packages
    135//!
    136//! The purpose of the index was to provide an efficient method to resolve the
    137//! dependency graph for a package. After resolution has been performed, we need
    138//! to download the contents of packages so we can read the full manifest and
    139//! build the source code.
    140//!
    141//! To accomplish this, [`RegistryData::download`] will "make" an HTTP request
    142//! per-package requested to download tarballs into a local cache. These
    143//! tarballs will then be unpacked into a destination folder.
    144//!
    145//! Note that because versions uploaded to the registry are frozen forever that
    146//! the HTTP download and unpacking can all be skipped if the version has
    147//! already been downloaded and unpacked. This caching allows us to only
    148//! download a package when absolutely necessary.
    149//!
    150//! # Filesystem Hierarchy
    151//!
    152//! Overall, the `$HOME/.cargo` looks like this when talking about the registry
    153//! (remote registries, specifically):
    154//!
    155//! ```notrust
    156//! # A folder under which all registry metadata is hosted (similar to
    157//! # $HOME/.cargo/git)
    158//! $HOME/.cargo/registry/
    159//!
    160//!     # For each registry that cargo knows about (keyed by hostname + hash)
    161//!     # there is a folder which is the checked out version of the index for
    162//!     # the registry in this location. Note that this is done so cargo can
    163//!     # support multiple registries simultaneously
    164//!     index/
    165//!         registry1-<hash>/
    166//!         registry2-<hash>/
    167//!         ...
    168//!
    169//!     # This folder is a cache for all downloaded tarballs (`.crate` file)
    170//!     # from a registry. Once downloaded and verified, a tarball never changes.
    171//!     cache/
    172//!         registry1-<hash>/<pkg>-<version>.crate
    173//!         ...
    174//!
    175//!     # Location in which all tarballs are unpacked. Each tarball is known to
    176//!     # be frozen after downloading, so transitively this folder is also
    177//!     # frozen once its unpacked (it's never unpacked again)
    178//!     # CAVEAT: They are not read-only. See rust-lang/cargo#9455.
    179//!     src/
    180//!         registry1-<hash>/<pkg>-<version>/...
    181//!         ...
    182//! ```
    183//!
    184
    185use std::collections::HashSet;
    186use std::fs;
    187use std::fs::{File, OpenOptions};
    188use std::io;
    189use std::io::Read;
    190use std::io::Write;
    191use std::path::{Path, PathBuf};
    192use std::task::{Poll, ready};
    193
    194use anyhow::Context as _;
    195use cargo_util::paths::{self, exclude_from_backups_and_indexing};
    196use flate2::read::GzDecoder;
    197use serde::Deserialize;
    198use serde::Serialize;
    199use tar::Archive;
    200use tracing::debug;
    201
    202use crate::core::dependency::Dependency;
    203use crate::core::global_cache_tracker;
    204use crate::core::{Package, PackageId, SourceId};
    205use crate::sources::PathSource;
    206use crate::sources::source::MaybePackage;
    207use crate::sources::source::QueryKind;
    208use crate::sources::source::Source;
    209use crate::util::cache_lock::CacheLockMode;
    210use crate::util::interning::InternedString;
    211use crate::util::network::PollExt;
    212use crate::util::{CargoResult, Filesystem, GlobalContext, LimitErrorReader, restricted_names};
    213use crate::util::{VersionExt, hex};
    214
    215/// The `.cargo-ok` file is used to track if the source is already unpacked.
    216/// See [`RegistrySource::unpack_package`] for more.
    217///
    218/// Not to be confused with `.cargo-ok` file in git sources.
    219const PACKAGE_SOURCE_LOCK: &str = ".cargo-ok";
    220
    221pub const CRATES_IO_INDEX: &str = "https://github.com/rust-lang/crates.io-index";
    222pub const CRATES_IO_HTTP_INDEX: &str = "sparse+https://index.crates.io/";
    223pub const CRATES_IO_REGISTRY: &str = "crates-io";
    224pub const CRATES_IO_DOMAIN: &str = "crates.io";
    225
    226/// The content inside `.cargo-ok`.
    227/// See [`RegistrySource::unpack_package`] for more.
    228#[derive(Deserialize, Serialize)]
    229#[serde(rename_all = "kebab-case")]
    230struct LockMetadata {
    231    /// The version of `.cargo-ok` file
    232    v: u32,
    233}
    234
    235/// A [`Source`] implementation for a local or a remote registry.
    236///
    237/// This contains common functionality that is shared between each registry
    238/// kind, with the registry-specific logic implemented as part of the
    239/// [`RegistryData`] trait referenced via the `ops` field.
    240///
    241/// For general concepts of registries, see the [module-level documentation](crate::sources::registry).
    242pub struct RegistrySource<'gctx> {
    243    /// A unique name of the source (typically used as the directory name
    244    /// where its cached content is stored).
    245    name: InternedString,
    246    /// The unique identifier of this source.
    247    source_id: SourceId,
    248    /// The path where crate files are extracted (`$CARGO_HOME/registry/src/$REG-HASH`).
    249    src_path: Filesystem,
    250    /// Path to the cache of `.crate` files (`$CARGO_HOME/registry/cache/$REG-HASH`).
    251    cache_path: Filesystem,
    252    /// Local reference to [`GlobalContext`] for convenience.
    253    gctx: &'gctx GlobalContext,
    254    /// Abstraction for interfacing to the different registry kinds.
    255    ops: Box<dyn RegistryData + 'gctx>,
    256    /// Interface for managing the on-disk index.
    257    index: index::RegistryIndex<'gctx>,
    258    /// A set of packages that should be allowed to be used, even if they are
    259    /// yanked.
    260    ///
    261    /// This is populated from the entries in `Cargo.lock` to ensure that
    262    /// `cargo update somepkg` won't unlock yanked entries in `Cargo.lock`.
    263    /// Otherwise, the resolver would think that those entries no longer
    264    /// exist, and it would trigger updates to unrelated packages.
    265    yanked_whitelist: HashSet<PackageId>,
    266    /// Yanked versions that have already been selected during queries.
    267    ///
    268    /// As of this writing, this is for not emitting the `--precise <yanked>`
    269    /// warning twice, with the assumption of (`dep.package_name()` + `--precise`
    270    /// version) being sufficient to uniquely identify the same query result.
    271    selected_precise_yanked: HashSet<(InternedString, semver::Version)>,
    272}
    273
    274/// The [`config.json`] file stored in the index.
    275///
    276/// The config file may look like:
    277///
    278/// ```json
    279/// {
    280///     "dl": "https://example.com/api/{crate}/{version}/download",
    281///     "api": "https://example.com/api",
    282///     "auth-required": false             # unstable feature (RFC 3139)
    283/// }
    284/// ```
    285///
    286/// [`config.json`]: https://doc.rust-lang.org/nightly/cargo/reference/registry-index.html#index-configuration
    287#[derive(Deserialize, Debug, Clone)]
    288#[serde(rename_all = "kebab-case")]
    289pub struct RegistryConfig {
    290    /// Download endpoint for all crates.
    291    ///
    292    /// The string is a template which will generate the download URL for the
    293    /// tarball of a specific version of a crate. The substrings `{crate}` and
    294    /// `{version}` will be replaced with the crate's name and version
    295    /// respectively.  The substring `{prefix}` will be replaced with the
    296    /// crate's prefix directory name, and the substring `{lowerprefix}` will
    297    /// be replaced with the crate's prefix directory name converted to
    298    /// lowercase. The substring `{sha256-checksum}` will be replaced with the
    299    /// crate's sha256 checksum.
    300    ///
    301    /// For backwards compatibility, if the string does not contain any
    302    /// markers (`{crate}`, `{version}`, `{prefix}`, or `{lowerprefix}`), it
    303    /// will be extended with `/{crate}/{version}/download` to
    304    /// support registries like crates.io which were created before the
    305    /// templating setup was created.
    306    ///
    307    /// For more on the template of the download URL, see [Index Configuration](
    308    /// https://doc.rust-lang.org/nightly/cargo/reference/registry-index.html#index-configuration).
    309    pub dl: String,
    310
    311    /// API endpoint for the registry. This is what's actually hit to perform
    312    /// operations like yanks, owner modifications, publish new crates, etc.
    313    /// If this is None, the registry does not support API commands.
    314    pub api: Option<String>,
    315
    316    /// Whether all operations require authentication. See [RFC 3139].
    317    ///
    318    /// [RFC 3139]: https://rust-lang.github.io/rfcs/3139-cargo-alternative-registry-auth.html
    319    #[serde(default)]
    320    pub auth_required: bool,
    321}
    322
    323/// Result from loading data from a registry.
    324pub enum LoadResponse {
    325    /// The cache is valid. The cached data should be used.
    326    CacheValid,
    327
    328    /// The cache is out of date. Returned data should be used.
    329    Data {
    330        raw_data: Vec<u8>,
    331        /// Version of this data to determine whether it is out of date.
    332        index_version: Option<String>,
    333    },
    334
    335    /// The requested crate was found.
    336    NotFound,
    337}
    338
    339/// An abstract interface to handle both a local and remote registry.
    340///
    341/// This allows [`RegistrySource`] to abstractly handle each registry kind.
    342///
    343/// For general concepts of registries, see the [module-level documentation](crate::sources::registry).
    344pub trait RegistryData {
    345    /// Performs initialization for the registry.
    346    ///
    347    /// This should be safe to call multiple times, the implementation is
    348    /// expected to not do any work if it is already prepared.
    349    fn prepare(&self) -> CargoResult<()>;
    350
    351    /// Returns the path to the index.
    352    ///
    353    /// Note that different registries store the index in different formats
    354    /// (remote = git, http & local = files).
    355    fn index_path(&self) -> &Filesystem;
    356
    357    /// Loads the JSON for a specific named package from the index.
    358    ///
    359    /// * `root` is the root path to the index.
    360    /// * `path` is the relative path to the package to load (like `ca/rg/cargo`).
    361    /// * `index_version` is the version of the requested crate data currently
    362    ///    in cache. This is useful for checking if a local cache is outdated.
    363    fn load(
    364        &mut self,
    365        root: &Path,
    366        path: &Path,
    367        index_version: Option<&str>,
    368    ) -> Poll<CargoResult<LoadResponse>>;
    369
    370    /// Loads the `config.json` file and returns it.
    371    ///
    372    /// Local registries don't have a config, and return `None`.
    373    fn config(&mut self) -> Poll<CargoResult<Option<RegistryConfig>>>;
    374
    375    /// Invalidates locally cached data.
    376    fn invalidate_cache(&mut self);
    377
    378    /// If quiet, the source should not display any progress or status messages.
    379    fn set_quiet(&mut self, quiet: bool);
    380
    381    /// Is the local cached data up-to-date?
    382    fn is_updated(&self) -> bool;
    383
    384    /// Prepare to start downloading a `.crate` file.
    385    ///
    386    /// Despite the name, this doesn't actually download anything. If the
    387    /// `.crate` is already downloaded, then it returns [`MaybeLock::Ready`].
    388    /// If it hasn't been downloaded, then it returns [`MaybeLock::Download`]
    389    /// which contains the URL to download. The [`crate::core::package::Downloads`]
    390    /// system handles the actual download process. After downloading, it
    391    /// calls [`Self::finish_download`] to save the downloaded file.
    392    ///
    393    /// `checksum` is currently only used by local registries to verify the
    394    /// file contents (because local registries never actually download
    395    /// anything). Remote registries will validate the checksum in
    396    /// `finish_download`. For already downloaded `.crate` files, it does not
    397    /// validate the checksum, assuming the filesystem does not suffer from
    398    /// corruption or manipulation.
    399    fn download(&mut self, pkg: PackageId, checksum: &str) -> CargoResult<MaybeLock>;
    400
    401    /// Finish a download by saving a `.crate` file to disk.
    402    ///
    403    /// After [`crate::core::package::Downloads`] has finished a download,
    404    /// it will call this to save the `.crate` file. This is only relevant
    405    /// for remote registries. This should validate the checksum and save
    406    /// the given data to the on-disk cache.
    407    ///
    408    /// Returns a [`File`] handle to the `.crate` file, positioned at the start.
    409    fn finish_download(&mut self, pkg: PackageId, checksum: &str, data: &[u8])
    410    -> CargoResult<File>;
    411
    412    /// Returns whether or not the `.crate` file is already downloaded.
    413    fn is_crate_downloaded(&self, _pkg: PackageId) -> bool {
    414        true
    415    }
    416
    417    /// Validates that the global package cache lock is held.
    418    ///
    419    /// Given the [`Filesystem`], this will make sure that the package cache
    420    /// lock is held. If not, it will panic. See
    421    /// [`GlobalContext::acquire_package_cache_lock`] for acquiring the global lock.
    422    ///
    423    /// Returns the [`Path`] to the [`Filesystem`].
    424    fn assert_index_locked<'a>(&self, path: &'a Filesystem) -> &'a Path;
    425
    426    /// Block until all outstanding `Poll::Pending` requests are `Poll::Ready`.
    427    fn block_until_ready(&mut self) -> CargoResult<()>;
    428}
    429
    430/// The status of [`RegistryData::download`] which indicates if a `.crate`
    431/// file has already been downloaded, or if not then the URL to download.
    432pub enum MaybeLock {
    433    /// The `.crate` file is already downloaded. [`File`] is a handle to the
    434    /// opened `.crate` file on the filesystem.
    435    Ready(File),
    436    /// The `.crate` file is not downloaded, here's the URL to download it from.
    437    ///
    438    /// `descriptor` is just a text string to display to the user of what is
    439    /// being downloaded.
    440    Download {
    441        url: String,
    442        descriptor: String,
    443        authorization: Option<String>,
    444    },
    445}
    446
    447mod download;
    448mod http_remote;
    449pub(crate) mod index;
    450pub use index::IndexSummary;
    451mod local;
    452mod remote;
    453
    454/// Generates a unique name for [`SourceId`] to have a unique path to put their
    455/// index files.
    456fn short_name(id: SourceId, is_shallow: bool) -> String {
    457    // CAUTION: This should not change between versions. If you change how
    458    // this is computed, it will orphan previously cached data, forcing the
    459    // cache to be rebuilt and potentially wasting significant disk space. If
    460    // you change it, be cautious of the impact. See `test_cratesio_hash` for
    461    // a similar discussion.
    462    let hash = hex::short_hash(&id);
    463    let ident = id.url().host_str().unwrap_or("").to_string();
    464    let mut name = format!("{}-{}", ident, hash);
    465    if is_shallow {
    466        name.push_str("-shallow");
    467    }
    468    name
    469}
    470
    471impl<'gctx> RegistrySource<'gctx> {
    472    /// Creates a [`Source`] of a "remote" registry.
    473    /// It could be either an HTTP-based [`http_remote::HttpRegistry`] or
    474    /// a Git-based [`remote::RemoteRegistry`].
    475    ///
    476    /// * `yanked_whitelist` --- Packages allowed to be used, even if they are yanked.
    477    pub fn remote(
    478        source_id: SourceId,
    479        yanked_whitelist: &HashSet<PackageId>,
    480        gctx: &'gctx GlobalContext,
    481    ) -> CargoResult<RegistrySource<'gctx>> {
    482        assert!(source_id.is_remote_registry());
    483        let name = short_name(
    484            source_id,
    485            gctx.cli_unstable()
    486                .git
    487                .map_or(false, |features| features.shallow_index)
    488                && !source_id.is_sparse(),
    489        );
    490        let ops = if source_id.is_sparse() {
    491            Box::new(http_remote::HttpRegistry::new(source_id, gctx, &name)?) as Box<_>
    492        } else {
    493            Box::new(remote::RemoteRegistry::new(source_id, gctx, &name)) as Box<_>
    494        };
    495
    496        Ok(RegistrySource::new(
    497            source_id,
    498            gctx,
    499            &name,
    500            ops,
    501            yanked_whitelist,
    502        ))
    503    }
    504
    505    /// Creates a [`Source`] of a local registry, with [`local::LocalRegistry`] under the hood.
    506    ///
    507    /// * `path` --- The root path of a local registry on the file system.
    508    /// * `yanked_whitelist` --- Packages allowed to be used, even if they are yanked.
    509    pub fn local(
    510        source_id: SourceId,
    511        path: &Path,
    512        yanked_whitelist: &HashSet<PackageId>,
    513        gctx: &'gctx GlobalContext,
    514    ) -> RegistrySource<'gctx> {
    515        let name = short_name(source_id, false);
    516        let ops = local::LocalRegistry::new(path, gctx, &name);
    517        RegistrySource::new(source_id, gctx, &name, Box::new(ops), yanked_whitelist)
    518    }
    519
    520    /// Creates a source of a registry. This is a inner helper function.
    521    ///
    522    /// * `name` --- Name of a path segment which may affect where `.crate`
    523    ///   tarballs, the registry index and cache are stored. Expect to be unique.
    524    /// * `ops` --- The underlying [`RegistryData`] type.
    525    /// * `yanked_whitelist` --- Packages allowed to be used, even if they are yanked.
    526    fn new(
    527        source_id: SourceId,
    528        gctx: &'gctx GlobalContext,
    529        name: &str,
    530        ops: Box<dyn RegistryData + 'gctx>,
    531        yanked_whitelist: &HashSet<PackageId>,
    532    ) -> RegistrySource<'gctx> {
    533        RegistrySource {
    534            name: name.into(),
    535            src_path: gctx.registry_source_path().join(name),
    536            cache_path: gctx.registry_cache_path().join(name),
    537            gctx,
    538            source_id,
    539            index: index::RegistryIndex::new(source_id, ops.index_path(), gctx),
    540            yanked_whitelist: yanked_whitelist.clone(),
    541            ops,
    542            selected_precise_yanked: HashSet::new(),
    543        }
    544    }
    545
    546    /// Decode the [configuration](RegistryConfig) stored within the registry.
    547    ///
    548    /// This requires that the index has been at least checked out.
    549    pub fn config(&mut self) -> Poll<CargoResult<Option<RegistryConfig>>> {
    550        self.ops.config()
    551    }
    552
    553    /// Unpacks a downloaded package into a location where it's ready to be
    554    /// compiled.
    555    ///
    556    /// No action is taken if the source looks like it's already unpacked.
    557    ///
    558    /// # History of interruption detection with `.cargo-ok` file
    559    ///
    560    /// Cargo has always included a `.cargo-ok` file ([`PACKAGE_SOURCE_LOCK`])
    561    /// to detect if extraction was interrupted, but it was originally empty.
    562    ///
    563    /// In 1.34, Cargo was changed to create the `.cargo-ok` file before it
    564    /// started extraction to implement fine-grained locking. After it was
    565    /// finished extracting, it wrote two bytes to indicate it was complete.
    566    /// It would use the length check to detect if it was possibly interrupted.
    567    ///
    568    /// In 1.36, Cargo changed to not use fine-grained locking, and instead used
    569    /// a global lock. The use of `.cargo-ok` was no longer needed for locking
    570    /// purposes, but was kept to detect when extraction was interrupted.
    571    ///
    572    /// In 1.49, Cargo changed to not create the `.cargo-ok` file before it
    573    /// started extraction to deal with `.crate` files that inexplicably had
    574    /// a `.cargo-ok` file in them.
    575    ///
    576    /// In 1.64, Cargo changed to detect `.crate` files with `.cargo-ok` files
    577    /// in them in response to [CVE-2022-36113], which dealt with malicious
    578    /// `.crate` files making `.cargo-ok` a symlink causing cargo to write "ok"
    579    /// to any arbitrary file on the filesystem it has permission to.
    580    ///
    581    /// In 1.71, `.cargo-ok` changed to contain a JSON `{ v: 1 }` to indicate
    582    /// the version of it. A failure of parsing will result in a heavy-hammer
    583    /// approach that unpacks the `.crate` file again. This is in response to a
    584    /// security issue that the unpacking didn't respect umask on Unix systems.
    585    ///
    586    /// This is all a long-winded way of explaining the circumstances that might
    587    /// cause a directory to contain a `.cargo-ok` file that is empty or
    588    /// otherwise corrupted. Either this was extracted by a version of Rust
    589    /// before 1.34, in which case everything should be fine. However, an empty
    590    /// file created by versions 1.36 to 1.49 indicates that the extraction was
    591    /// interrupted and that we need to start again.
    592    ///
    593    /// Another possibility is that the filesystem is simply corrupted, in
    594    /// which case deleting the directory might be the safe thing to do. That
    595    /// is probably unlikely, though.
    596    ///
    597    /// To be safe, we delete the directory and start over again if an empty
    598    /// `.cargo-ok` file is found.
    599    ///
    600    /// [CVE-2022-36113]: https://blog.rust-lang.org/2022/09/14/cargo-cves.html#arbitrary-file-corruption-cve-2022-36113
    601    fn unpack_package(&self, pkg: PackageId, tarball: &File) -> CargoResult<PathBuf> {
    602        let package_dir = format!("{}-{}", pkg.name(), pkg.version());
    603        let dst = self.src_path.join(&package_dir);
    604        let path = dst.join(PACKAGE_SOURCE_LOCK);
    605        let path = self
    606            .gctx
    607            .assert_package_cache_locked(CacheLockMode::DownloadExclusive, &path);
    608        let unpack_dir = path.parent().unwrap();
    609        match fs::read_to_string(path) {
    610            Ok(ok) => match serde_json::from_str::<LockMetadata>(&ok) {
    611                Ok(lock_meta) if lock_meta.v == 1 => {
    612                    self.gctx
    613                        .deferred_global_last_use()?
    614                        .mark_registry_src_used(global_cache_tracker::RegistrySrc {
    615                            encoded_registry_name: self.name,
    616                            package_dir: package_dir.into(),
    617                            size: None,
    618                        });
    619                    return Ok(unpack_dir.to_path_buf());
    620                }
    621                _ => {
    622                    if ok == "ok" {
    623                        tracing::debug!("old `ok` content found, clearing cache");
    624                    } else {
    625                        tracing::warn!("unrecognized .cargo-ok content, clearing cache: {ok}");
    626                    }
    627                    // See comment of `unpack_package` about why removing all stuff.
    628                    paths::remove_dir_all(dst.as_path_unlocked())?;
    629                }
    630            },
    631            Err(e) if e.kind() == io::ErrorKind::NotFound => {}
    632            Err(e) => anyhow::bail!("unable to read .cargo-ok file at {path:?}: {e}"),
    633        }
    634        dst.create_dir()?;
    635
    636        let bytes_written = unpack(self.gctx, tarball, unpack_dir, &|_| true)?;
    637
    638        // Now that we've finished unpacking, create and write to the lock file to indicate that
    639        // unpacking was successful.
    640        let mut ok = OpenOptions::new()
    641            .create_new(true)
    642            .read(true)
    643            .write(true)
    644            .open(&path)
    645            .with_context(|| format!("failed to open `{}`", path.display()))?;
    646
    647        let lock_meta = LockMetadata { v: 1 };
    648        write!(ok, "{}", serde_json::to_string(&lock_meta).unwrap())?;
    649
    650        self.gctx
    651            .deferred_global_last_use()?
    652            .mark_registry_src_used(global_cache_tracker::RegistrySrc {
    653                encoded_registry_name: self.name,
    654                package_dir: package_dir.into(),
    655                size: Some(bytes_written),
    656            });
    657
    658        Ok(unpack_dir.to_path_buf())
    659    }
    660
    661    /// Unpacks the `.crate` tarball of the package in a given directory.
    662    ///
    663    /// Returns the path to the crate tarball directory,
    664    /// which is always `<unpack_dir>/<pkg>-<version>`.
    665    ///
    666    /// This holds an assumption that the associated tarball already exists.
    667    pub fn unpack_package_in(
    668        &self,
    669        pkg: &PackageId,
    670        unpack_dir: &Path,
    671        include: &dyn Fn(&Path) -> bool,
    672    ) -> CargoResult<PathBuf> {
    673        let path = self.cache_path.join(pkg.tarball_name());
    674        let path = self
    675            .gctx
    676            .assert_package_cache_locked(CacheLockMode::DownloadExclusive, &path);
    677        let dst = unpack_dir.join(format!("{}-{}", pkg.name(), pkg.version()));
    678        let tarball =
    679            File::open(path).with_context(|| format!("failed to open {}", path.display()))?;
    680        unpack(self.gctx, &tarball, &dst, include)?;
    681        Ok(dst)
    682    }
    683
    684    /// Turns the downloaded `.crate` tarball file into a [`Package`].
    685    ///
    686    /// This unconditionally sets checksum for the returned package, so it
    687    /// should only be called after doing integrity check. That is to say,
    688    /// you need to call either [`RegistryData::download`] or
    689    /// [`RegistryData::finish_download`] before calling this method.
    690    fn get_pkg(&mut self, package: PackageId, path: &File) -> CargoResult<Package> {
    691        let path = self
    692            .unpack_package(package, path)
    693            .with_context(|| format!("failed to unpack package `{}`", package))?;
    694        let mut src = PathSource::new(&path, self.source_id, self.gctx);
    695        src.load()?;
    696        let mut pkg = match src.download(package)? {
    697            MaybePackage::Ready(pkg) => pkg,
    698            MaybePackage::Download { .. } => unreachable!(),
    699        };
    700
    701        // After we've loaded the package configure its summary's `checksum`
    702        // field with the checksum we know for this `PackageId`.
    703        let cksum = self
    704            .index
    705            .hash(package, &mut *self.ops)
    706            .expect("a downloaded dep now pending!?")
    707            .expect("summary not found");
    708        pkg.manifest_mut()
    709            .summary_mut()
    710            .set_checksum(cksum.to_string());
    711
    712        Ok(pkg)
    713    }
    714}
    715
    716impl<'gctx> Source for RegistrySource<'gctx> {
    717    fn query(
    718        &mut self,
    719        dep: &Dependency,
    720        kind: QueryKind,
    721        f: &mut dyn FnMut(IndexSummary),
    722    ) -> Poll<CargoResult<()>> {
    723        let mut req = dep.version_req().clone();
    724
    725        // Handle `cargo update --precise` here.
    726        if let Some((_, requested)) = self
    727            .source_id
    728            .precise_registry_version(dep.package_name().as_str())
    729            .filter(|(c, to)| {
    730                if to.is_prerelease() && self.gctx.cli_unstable().unstable_options {
    731                    req.matches_prerelease(c)
    732                } else {
    733                    req.matches(c)
    734                }
    735            })
    736        {
    737            req.precise_to(&requested);
    738        }
    739
    740        let mut called = false;
    741        let callback = &mut |s| {
    742            called = true;
    743            f(s);
    744        };
    745
    746        // If this is a locked dependency, then it came from a lock file and in
    747        // theory the registry is known to contain this version. If, however, we
    748        // come back with no summaries, then our registry may need to be
    749        // updated, so we fall back to performing a lazy update.
    750        if kind == QueryKind::Exact && req.is_locked() && !self.ops.is_updated() {
    751            debug!("attempting query without update");
    752            ready!(
    753                self.index
    754                    .query_inner(dep.package_name(), &req, &mut *self.ops, &mut |s| {
    755                        if matches!(s, IndexSummary::Candidate(_) | IndexSummary::Yanked(_))
    756                            && dep.matches(s.as_summary())
    757                        {
    758                            // We are looking for a package from a lock file so we do not care about yank
    759                            callback(s)
    760                        }
    761                    },)
    762            )?;
    763            if called {
    764                Poll::Ready(Ok(()))
    765            } else {
    766                debug!("falling back to an update");
    767                self.invalidate_cache();
    768                Poll::Pending
    769            }
    770        } else {
    771            let mut precise_yanked_in_use = false;
    772            ready!(
    773                self.index
    774                    .query_inner(dep.package_name(), &req, &mut *self.ops, &mut |s| {
    775                        let matched = match kind {
    776                            QueryKind::Exact | QueryKind::RejectedVersions => {
    777                                if req.is_precise() && self.gctx.cli_unstable().unstable_options {
    778                                    dep.matches_prerelease(s.as_summary())
    779                                } else {
    780                                    dep.matches(s.as_summary())
    781                                }
    782                            }
    783                            QueryKind::AlternativeNames => true,
    784                            QueryKind::Normalized => true,
    785                        };
    786                        if !matched {
    787                            return;
    788                        }
    789                        // Next filter out all yanked packages. Some yanked packages may
    790                        // leak through if they're in a whitelist (aka if they were
    791                        // previously in `Cargo.lock`
    792                        match s {
    793                            s @ _ if kind == QueryKind::RejectedVersions => callback(s),
    794                            s @ IndexSummary::Candidate(_) => callback(s),
    795                            s @ IndexSummary::Yanked(_) => {
    796                                if self.yanked_whitelist.contains(&s.package_id()) {
    797                                    callback(s);
    798                                } else if req.is_precise() {
    799                                    precise_yanked_in_use = true;
    800                                    callback(s);
    801                                }
    802                            }
    803                            IndexSummary::Unsupported(summary, v) => {
    804                                tracing::debug!(
    805                                    "unsupported schema version {} ({} {})",
    806                                    v,
    807                                    summary.name(),
    808                                    summary.version()
    809                                );
    810                            }
    811                            IndexSummary::Invalid(summary) => {
    812                                tracing::debug!(
    813                                    "invalid ({} {})",
    814                                    summary.name(),
    815                                    summary.version()
    816                                );
    817                            }
    818                            IndexSummary::Offline(summary) => {
    819                                tracing::debug!(
    820                                    "offline ({} {})",
    821                                    summary.name(),
    822                                    summary.version()
    823                                );
    824                            }
    825                        }
    826                    })
    827            )?;
    828            if precise_yanked_in_use {
    829                let name = dep.package_name();
    830                let version = req
    831                    .precise_version()
    832                    .expect("--precise <yanked-version> in use");
    833                if self.selected_precise_yanked.insert((name, version.clone())) {
    834                    let mut shell = self.gctx.shell();
    835                    shell.warn(format_args!(
    836                        "selected package `{name}@{version}` was yanked by the author"
    837                    ))?;
    838                    shell.note("if possible, try a compatible non-yanked version")?;
    839                }
    840            }
    841            if called {
    842                return Poll::Ready(Ok(()));
    843            }
    844            let mut any_pending = false;
    845            if kind == QueryKind::AlternativeNames || kind == QueryKind::Normalized {
    846                // Attempt to handle misspellings by searching for a chain of related
    847                // names to the original name. The resolver will later
    848                // reject any candidates that have the wrong name, and with this it'll
    849                // along the way produce helpful "did you mean?" suggestions.
    850                // For now we only try the canonical lysing `-` to `_` and vice versa.
    851                // More advanced fuzzy searching become in the future.
    852                for name_permutation in [
    853                    dep.package_name().replace('-', "_"),
    854                    dep.package_name().replace('_', "-"),
    855                ] {
    856                    let name_permutation = name_permutation.into();
    857                    if name_permutation == dep.package_name() {
    858                        continue;
    859                    }
    860                    any_pending |= self
    861                        .index
    862                        .query_inner(name_permutation, &req, &mut *self.ops, &mut |s| {
    863                            if !s.is_yanked() {
    864                                f(s);
    865                            } else if kind == QueryKind::AlternativeNames {
    866                                f(s);
    867                            }
    868                        })?
    869                        .is_pending();
    870                }
    871            }
    872            if any_pending {
    873                Poll::Pending
    874            } else {
    875                Poll::Ready(Ok(()))
    876            }
    877        }
    878    }
    879
    880    fn supports_checksums(&self) -> bool {
    881        true
    882    }
    883
    884    fn requires_precise(&self) -> bool {
    885        false
    886    }
    887
    888    fn source_id(&self) -> SourceId {
    889        self.source_id
    890    }
    891
    892    fn invalidate_cache(&mut self) {
    893        self.index.clear_summaries_cache();
    894        self.ops.invalidate_cache();
    895    }
    896
    897    fn set_quiet(&mut self, quiet: bool) {
    898        self.ops.set_quiet(quiet);
    899    }
    900
    901    fn download(&mut self, package: PackageId) -> CargoResult<MaybePackage> {
    902        let hash = loop {
    903            match self.index.hash(package, &mut *self.ops)? {
    904                Poll::Pending => self.block_until_ready()?,
    905                Poll::Ready(hash) => break hash,
    906            }
    907        };
    908        match self.ops.download(package, hash)? {
    909            MaybeLock::Ready(file) => self.get_pkg(package, &file).map(MaybePackage::Ready),
    910            MaybeLock::Download {
    911                url,
    912                descriptor,
    913                authorization,
    914            } => Ok(MaybePackage::Download {
    915                url,
    916                descriptor,
    917                authorization,
    918            }),
    919        }
    920    }
    921
    922    fn finish_download(&mut self, package: PackageId, data: Vec<u8>) -> CargoResult<Package> {
    923        let hash = loop {
    924            match self.index.hash(package, &mut *self.ops)? {
    925                Poll::Pending => self.block_until_ready()?,
    926                Poll::Ready(hash) => break hash,
    927            }
    928        };
    929        let file = self.ops.finish_download(package, hash, &data)?;
    930        self.get_pkg(package, &file)
    931    }
    932
    933    fn fingerprint(&self, pkg: &Package) -> CargoResult<String> {
    934        Ok(pkg.package_id().version().to_string())
    935    }
    936
    937    fn describe(&self) -> String {
    938        self.source_id.display_index()
    939    }
    940
    941    fn add_to_yanked_whitelist(&mut self, pkgs: &[PackageId]) {
    942        self.yanked_whitelist.extend(pkgs);
    943    }
    944
    945    fn is_yanked(&mut self, pkg: PackageId) -> Poll<CargoResult<bool>> {
    946        self.index.is_yanked(pkg, &mut *self.ops)
    947    }
    948
    949    fn block_until_ready(&mut self) -> CargoResult<()> {
    950        // Before starting to work on the registry, make sure that
    951        // `<cargo_home>/registry` is marked as excluded from indexing and
    952        // backups. Older versions of Cargo didn't do this, so we do it here
    953        // regardless of whether `<cargo_home>` exists.
    954        //
    955        // This does not use `create_dir_all_excluded_from_backups_atomic` for
    956        // the same reason: we want to exclude it even if the directory already
    957        // exists.
    958        //
    959        // IO errors in creating and marking it are ignored, e.g. in case we're on a
    960        // read-only filesystem.
    961        let registry_base = self.gctx.registry_base_path();
    962        let _ = registry_base.create_dir();
    963        exclude_from_backups_and_indexing(&registry_base.into_path_unlocked());
    964
    965        self.ops.block_until_ready()
    966    }
    967}
    968
    969impl RegistryConfig {
    970    /// File name of [`RegistryConfig`].
    971    const NAME: &'static str = "config.json";
    972}
    973
    974/// Get the maximum unpack size that Cargo permits
    975/// based on a given `size` of your compressed file.
    976///
    977/// Returns the larger one between `size * max compression ratio`
    978/// and a fixed max unpacked size.
    979///
    980/// In reality, the compression ratio usually falls in the range of 2:1 to 10:1.
    981/// We choose 20:1 to cover almost all possible cases hopefully.
    982/// Any ratio higher than this is considered as a zip bomb.
    983///
    984/// In the future we might want to introduce a configurable size.
    985///
    986/// Some of the real world data from common compression algorithms:
    987///
    988/// * <https://www.zlib.net/zlib_tech.html>
    989/// * <https://cran.r-project.org/web/packages/brotli/vignettes/brotli-2015-09-22.pdf>
    990/// * <https://blog.cloudflare.com/results-experimenting-brotli/>
    991/// * <https://tukaani.org/lzma/benchmarks.html>
    992fn max_unpack_size(gctx: &GlobalContext, size: u64) -> u64 {
    993    const SIZE_VAR: &str = "__CARGO_TEST_MAX_UNPACK_SIZE";
    994    const RATIO_VAR: &str = "__CARGO_TEST_MAX_UNPACK_RATIO";
    995    const MAX_UNPACK_SIZE: u64 = 512 * 1024 * 1024; // 512 MiB
    996    const MAX_COMPRESSION_RATIO: usize = 20; // 20:1
    997
    998    let max_unpack_size = if cfg!(debug_assertions) && gctx.get_env(SIZE_VAR).is_ok() {
    999        // For integration test only.
    1000        gctx.get_env(SIZE_VAR)
    1001            .unwrap()
    1002            .parse()
    1003            .expect("a max unpack size in bytes")
    1004    } else {
    1005        MAX_UNPACK_SIZE
    1006    };
    1007    let max_compression_ratio = if cfg!(debug_assertions) && gctx.get_env(RATIO_VAR).is_ok() {
    1008        // For integration test only.
    1009        gctx.get_env(RATIO_VAR)
    1010            .unwrap()
    1011            .parse()
    1012            .expect("a max compression ratio in bytes")
    1013    } else {
    1014        MAX_COMPRESSION_RATIO
    1015    };
    1016
    1017    u64::max(max_unpack_size, size * max_compression_ratio as u64)
    1018}
    1019
    1020/// Set the current [`umask`] value for the given tarball. No-op on non-Unix
    1021/// platforms.
    1022///
    1023/// On Windows, tar only looks at user permissions and tries to set the "read
    1024/// only" attribute, so no-op as well.
    1025///
    1026/// [`umask`]: https://man7.org/linux/man-pages/man2/umask.2.html
    1027#[allow(unused_variables)]
    1028fn set_mask<R: Read>(tar: &mut Archive<R>) {
    1029    #[cfg(unix)]
    1030    tar.set_mask(crate::util::get_umask());
    1031}
    1032
    1033/// Unpack a tarball with zip bomb and overwrite protections.
    1034fn unpack(
    1035    gctx: &GlobalContext,
    1036    tarball: &File,
    1037    unpack_dir: &Path,
    1038    include: &dyn Fn(&Path) -> bool,
    1039) -> CargoResult<u64> {
    1040    let mut tar = {
    1041        let size_limit = max_unpack_size(gctx, tarball.metadata()?.len());
    1042        let gz = GzDecoder::new(tarball);
    1043        let gz = LimitErrorReader::new(gz, size_limit);
    1044        let mut tar = Archive::new(gz);
    1045        set_mask(&mut tar);
    1046        tar
    1047    };
    1048    let mut bytes_written = 0;
    1049    let prefix = unpack_dir.file_name().unwrap();
    1050    let parent = unpack_dir.parent().unwrap();
    1051    for entry in tar.entries()? {
    1052        let mut entry = entry.context("failed to iterate over archive")?;
    1053        let entry_path = entry
    1054            .path()
    1055            .context("failed to read entry path")?
    1056            .into_owned();
    1057
    1058        if let Ok(path) = entry_path.strip_prefix(prefix) {
    1059            if !include(path) {
    1060                continue;
    1061            }
    1062        } else {
    1063            // We're going to unpack this tarball into the global source
    1064            // directory, but we want to make sure that it doesn't accidentally
    1065            // (or maliciously) overwrite source code from other crates. Cargo
    1066            // itself should never generate a tarball that hits this error, and
    1067            // crates.io should also block uploads with these sorts of tarballs,
    1068            // but be extra sure by adding a check here as well.
    1069            anyhow::bail!(
    1070                "invalid tarball downloaded, contains \
    1071                     a file at {entry_path:?} which isn't under {prefix:?}",
    1072            )
    1073        }
    1074
    1075        // Prevent unpacking the lockfile from the crate itself.
    1076        if entry_path
    1077            .file_name()
    1078            .map_or(false, |p| p == PACKAGE_SOURCE_LOCK)
    1079        {
    1080            continue;
    1081        }
    1082        // Unpacking failed
    1083        bytes_written += entry.size();
    1084        let mut result = entry.unpack_in(parent).map_err(anyhow::Error::from);
    1085        if cfg!(windows) && restricted_names::is_windows_reserved_path(&entry_path) {
    1086            result = result.with_context(|| {
    1087                format!(
    1088                    "`{}` appears to contain a reserved Windows path, \
    1089                        it cannot be extracted on Windows",
    1090                    entry_path.display()
    1091                )
    1092            });
    1093        }
    1094        result.with_context(|| format!("failed to unpack entry at `{}`", entry_path.display()))?;
    1095    }
    1096
    1097    Ok(bytes_written)
    1098}