1 files changed, 161 insertions, 0 deletions
diff --git a/darwin-bootstrap/bundle-loader.m b/darwin-bootstrap/bundle-loader.m
new file mode 100644
index 0000000..fec2513
--- /dev/null
+++ b/darwin-bootstrap/bundle-loader.m
@@ -0,0 +1,161 @@
+#import <Foundation/Foundation.h>
+#import <CoreFoundation/CoreFoundation.h>
+#include <dlfcn.h>
+extern char ***_NSGetArgv(void);
+
+#define PREFIX "Substitute bundle loader: "
+
+enum test_filters_ret {
+    PASSED,
+    FAILED,
+    INVALID
+};
+
+static double id_to_double(id o) {
+    if ([o isKindOfClass:[NSString class]]) {
+        NSScanner *scan = [NSScanner scannerWithString:o];
+        double d;
+        if (![scan scanDouble:&d] || !scan.atEnd)
+            return NAN;
+        return d;
+    } else if ([o isKindOfClass:[NSNumber class]]) {
+        return [o doubleValue];
+    } else {
+        return NAN;
+    }
+}
+
+static enum test_filters_ret test_filters(NSDictionary *plist_dict) {
+
+    NSDictionary *filter = [plist_dict objectForKey:@"Filter"];
+    if (!filter)
+        return PASSED;
+    if (![filter isKindOfClass:[NSDictionary class]])
+        return INVALID;
+
+    for (NSString *key in [filter allKeys]) {
+        if (!([key isEqualToString:@"CoreFoundationVersion"] ||
+              [key isEqualToString:@"Classes"] ||
+              [key isEqualToString:@"Bundles"] ||
+              [key isEqualToString:@"Executables"])) {
+            return INVALID;
+        }
+    }
+    NSArray *cfv = [filter objectForKey:@"CoreFoundationVersion"];
+    if (cfv) {
+        if (![cfv isKindOfClass:[NSArray class]] ||
+            [cfv count] == 0 ||
+            [cfv count] > 2)
+            return INVALID;
+        double version = kCFCoreFoundationVersionNumber;
+        double minimum = id_to_double([cfv objectAtIndex:0]);
+        if (minimum != minimum)
+            return INVALID;
+        if (version < minimum)
+            return FAILED;
+        id supremum_o = [cfv objectAtIndex:1];
+        if (supremum_o) {
+            double supremum = id_to_double(supremum_o);
+            if (supremum != supremum)
+                return INVALID;
+            if (version >= supremum)
+                return FAILED;
+        }
+    }
+
+    NSArray *classes = [filter objectForKey:@"Classes"];
+    if (classes) {
+        if (![classes isKindOfClass:[NSArray class]])
+            return INVALID;
+        for (NSString *name in classes) {
+            if (![name isKindOfClass:[NSString class]])
+                return INVALID;
+            if (NSClassFromString(name))
+                goto ok1;
+        }
+        return FAILED;
+    ok1:;
+    }
+
+    NSArray *bundles = [filter objectForKey:@"Bundles"];
+    if (bundles) {
+        if (![bundles isKindOfClass:[NSArray class]])
+            return INVALID;
+        for (NSString *identifier in bundles) {
+            if (![identifier isKindOfClass:[NSString class]])
+                return INVALID;
+            if ([NSBundle bundleWithIdentifier:identifier])
+                goto ok2;
+        }
+        return FAILED;
+    ok2:;
+    }
+
+
+    NSArray *executables = [filter objectForKey:@"Executables"];
+    if (executables) {
+        const char *argv0 = (*_NSGetArgv())[0];
+        NSString *exe = nil;
+        if (argv0) {
+            NSString *nsargv0 = [NSString stringWithCString:argv0
+                                          encoding:NSUTF8StringEncoding];
+            exe = [[nsargv0 pathComponents] lastObject];
+        }
+        if (!exe)
+            exe = @"";
+        if (![executables isKindOfClass:[NSArray class]])
+            return INVALID;
+        for (NSString *name in executables) {
+            if (![name isKindOfClass:[NSString class]])
+                return INVALID;
+            if ([name isEqualToString:exe])
+                goto ok3;
+        }
+        return FAILED;
+    ok3:;
+    }
+    return PASSED;
+}
+
+/* this is DYLD_INSERT_LIBRARIES'd, not injected. */
+__attribute__((constructor))
+static void init() {
+    NSError *err;
+    NSString *base = @"/Library/Substitute/DynamicLibraries";
+    NSArray *list = [[NSFileManager defaultManager]
+                     contentsOfDirectoryAtPath:base
+                     error:&err];
+    if (!list)
+        return;
+
+    for (NSString *dylib in list) {
+        if (![[dylib pathExtension] isEqualToString:@"dylib"])
+            continue;
+        NSString *plist = [[dylib stringByDeletingPathExtension]
+                           stringByAppendingPathExtension:@"plist"];
+        NSString *full_plist = [base stringByAppendingPathComponent:plist];
+        NSDictionary *plist_dict = [NSDictionary dictionaryWithContentsOfFile:
+                                    full_plist];
+        if (!plist_dict) {
+            NSLog(@PREFIX "missing, unreadable, or invalid plist '%@' for dylib '%@'; unlike Substrate, we require plists", full_plist, dylib);
+            continue;
+        }
+        enum test_filters_ret ret = test_filters(plist_dict);
+        if (ret == FAILED) {
+            continue;
+        } else if (ret == INVALID) {
+            NSLog(@PREFIX "bad data in plist '%@' for dylib '%@'", full_plist, dylib);
+            continue;
+        }
+        NSString *full_dylib = [base stringByAppendingPathComponent:dylib];
+        const char *c_dylib = [full_dylib cStringUsingEncoding:NSUTF8StringEncoding];
+        if (!c_dylib) {
+            NSLog(@PREFIX "Not loading weird dylib path %@", full_dylib);
+            continue;
+        }
+        NSLog(@"Substitute loading %@", full_dylib);
+        if (!dlopen(c_dylib, RTLD_LAZY)) {
+            NSLog(@PREFIX "Failed to load %@: %s", full_dylib, dlerror());
+        }
+    }
+}