Merge pull request #9306 from NixOS/accessor-no-follow-symlink

Clarify `SourceAccessor` methods should never implicitly follow symlinks
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John Ericson 2023-12-08 21:22:37 -05:00 committed by GitHub
commit 6aba2fdb4d
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@ -26,6 +26,13 @@ struct SourceAccessor
/** /**
* Return the contents of a file as a string. * Return the contents of a file as a string.
*
* @note Unlike Unix, this method should *not* follow symlinks. Nix
* by default wants to manipulate symlinks explicitly, and not
* implictly follow them, as they are frequently untrusted user data
* and thus may point to arbitrary locations. Acting on the targets
* targets of symlinks should only occasionally be done, and only
* with care.
*/ */
virtual std::string readFile(const CanonPath & path); virtual std::string readFile(const CanonPath & path);
@ -34,7 +41,10 @@ struct SourceAccessor
* called with the size of the file before any data is written to * called with the size of the file before any data is written to
* the sink. * the sink.
* *
* Note: subclasses of `SourceAccessor` need to implement at least * @note Like the other `readFile`, this method should *not* follow
* symlinks.
*
* @note subclasses of `SourceAccessor` need to implement at least
* one of the `readFile()` variants. * one of the `readFile()` variants.
*/ */
virtual void readFile( virtual void readFile(
@ -87,6 +97,9 @@ struct SourceAccessor
typedef std::map<std::string, DirEntry> DirEntries; typedef std::map<std::string, DirEntry> DirEntries;
/**
* @note Like `readFile`, this method should *not* follow symlinks.
*/
virtual DirEntries readDirectory(const CanonPath & path) = 0; virtual DirEntries readDirectory(const CanonPath & path) = 0;
virtual std::string readLink(const CanonPath & path) = 0; virtual std::string readLink(const CanonPath & path) = 0;