Special cased rules for ownership for now.

Fortune for rng's current commit: Blessing − 吉

src/plugin/searcher.rs

@@ -47,6 +47,8 @@ pub mod locations {
 	    const ROOT_OWNED_ONLY = 1 << 4;
 	    /// Only qualify user-owned files (can be unioned with other `_OWNED_ONLY` constants)
 	    const USER_OWNED_ONLY = 1 << 5;
+	    /// Owned by user or by root.
+	    const USER_OR_ROOT_OWNED = Self::ROOT_OWNED_ONLY.bits | Self::USER_OWNED_ONLY.bits;
 	    /// Disqualify files that are accessible at all by anyone other than the current user (or root, which can accesss everything.)
 	    const USER_ACCESSIBLE_ONLY = 1 << 6;
 	    /// Disallow *all* untrusted files.
@@ -124,10 +126,59 @@ pub mod locations {
 		    }
 		    set!($name => |_, _| _panic_with_msg()) 
 		};
-		($name:ident: $($func_body:tt)+) => {
-		    set!($name => |path, filename| { $($func_body)+})
+		/*FUCK THIS, I HATE ITERATON IN MACROS< WHY DOES IT HAVE TO BE SO RECURSIVELY LEAKILY RETARDED AAAA(@ compose ($f_name:ident, $f_file:ident) via $operator:tt $ignore:tt; $first:ident, $second:ident $($rest:tt)*)
+		=> (table[Self::$first.bits() as usize]($f_name, $f_file) $operator set!(@ compose ($f_name, $f_file) via $operator &&; Self::$second.bits(), $($rest)*));
+		(@ compose ($f_name:ident, $f_file:ident) $(via $operator:tt)?; $($first:ident)? $(,)?)
+		=> ($(table[Self::$first.bits() as usize])?);
+		($name:ident $(; use $operator:tt)? => $($other:ident),+) => {
+		set!($name => |path, filename| {
+		set!(@ compose (path, filename) via $($operator)? &&; $($other),+)
+	    });
+	    }*/
+	    }
+
+	    /// In lookups, use process EUID instead of UID.
+	    const USE_EFFECTIVE_UID: bool = true;
+
+	    /// Get UID or **E**UID.
+	    #[inline(always)] 
+	    fn get_uid<const E: bool>() -> u32
+	    {
+		extern "C" {
+		    fn getuid() -> u32; // uid_t
+		    //XXX: Should we use process's UID or EUID? It seems we should use EUID.
+		    fn geteuid() -> u32; // uid_t
+		}
+		// SAFETY: These are effectively pure.
+		unsafe {
+		    if E {
+			geteuid()
+		    } else {
+			getuid()
+		    }
 		}
 	    }
+
+	    #[inline(always)] 
+	    fn check_uid<const CACHED: bool>(against: impl PartialEq<u32>) -> bool
+	    {
+		//TODO: Allow these to be reset, somehow? Idk... Make them regular static atomics?
+		lazy_static! {
+		    static ref USER_UID_CACHED: u32 = get_uid::<false>();
+		    static ref USER_EUID_CACHED: u32 = get_uid::<true>();
+		}
+		
+		against == if CACHED {
+		    if USE_EFFECTIVE_UID {
+			*USER_EUID_CACHED
+		    } else {
+			*USER_UID_CACHED
+		    }
+		} else {
+		    get_uid::<USE_EFFECTIVE_UID>()
+		}
+	    }
+
 	    
 	    set!(NAME_MATCH as ! "This should already have been checked");
 	    set!(NON_SYMLINK => |path: &Path, _| !path.is_symlink());
@@ -163,15 +214,10 @@ pub mod locations {
 	    });
 	    set!(USER_OWNED_ONLY => |path, _| {
 		use std::os::unix::fs::MetadataExt as _;
-		extern "C" {
-		    fn getuid() -> u32; // uid_t
-		    //XXX: Should we use process's UID or EUID? It seems we should use EUID.
-		    fn geteuid() -> u32; // uid_t
-		}
-		// SAFETY: This is a pure function for all that matters.
-		let user_id = unsafe { geteuid() };
+		
+		//let user_id = get_uid::<USE_EFFECTIVE_UID>();
 		path.metadata()
-		    .map(move |meta| meta.uid() == user_id)
+		    .map(move |meta| check_uid::<true>(meta.uid()))
 		    .unwrap_or(false)
 	    });
 	    set!(USER_ACCESSIBLE_ONLY => |path, _| {
@@ -192,6 +238,19 @@ pub mod locations {
 		    .map(|meta| !meta.permissions().mode() & OTHER_ACCESSORS == 0) //XXX: Test this
 		    .unwrap_or(false)
 	    });
+	    set!(USER_OR_ROOT_OWNED => |path, _| {
+		use std::os::unix::fs::MetadataExt as _;
+		
+		//let user_id = get_uid::<USE_EFFECTIVE_UID>();
+		path.metadata()
+		    .map(move |meta| match meta.uid() {
+			0 => true,
+			uid if check_uid::<true>(uid) => true,
+			_ => false
+		    })
+		    .unwrap_or(false)
+	    });
+	    //set!(USER_OR_ROOT_OWNED; use || => USER_OWNED_ONLY, ROOT_OWNED_ONLY);
 	    //TODO: Composition of functions should be done via OR, how to insert all possible compositions into table? We get confusing error messages when we try inside `set!()`
 	    table
 	}
@@ -398,16 +457,36 @@ impl PathLookup
 		return true;
 	    }
 
+	    macro_rules! check {
+		($name:ident) => {
+		    if RULES.contains(Rule::$name) {
+			Rule::RULE_FUNCTION_CHECK_TABLE[Rule::$name.bits() as usize](path, filename)
+		    } else {
+			true
+		    }
+		};
+		(try $($op:tt)? $name:ident) => {
+		    if $($op)? check!($name) {
+			return false;
+		    }
+		}
+	    }
+
+	    // XXX: Ugh, for now, this shit must be checked independently.
+	    check!(try ! USER_OR_ROOT_OWNED);
+
+	    // Check rest of rules in sequence. Hopefully this will be unrolled since the first `if` statement is all const-fn on a static constant.
 	    while bit > 0
 	    {
 		// SAFETY: We know `INACCESSIBLE` is the largest
 		if RULES.contains(unsafe { Rule::from_bits_unchecked(bit) }) {
-		    
+		    if !Rule::RULE_FUNCTION_CHECK_TABLE[bit as usize](path, filename) {
+			return false;
+		    }
 		}
 		bit >>= 1;
 	    }
-	    
-	    todo!("TODO: extra Untrusted lookup rules checked on `path` here.")
+	    true
 	}
 	lazy_static! {
 	    static ref TRUSTED_EXT_REGEX_MAP: Vec<Regex> =