bridgehook: fix finding symbols in dyld shared cache

src/bridgehook/main.c

@@ -18,6 +18,7 @@ typedef void* MSImageRef;
 
 int DobbyHook(void *address, void *fake_func, void **out_origin_func);
 int DobbyCodePatch(void *address, uint8_t *buffer, uint32_t buffer_size);
+void *DobbySymbolResolver(const char *image_name, const char *symbol_name_pattern);
 
 BH_EXPORT
 void MSHookFunction(void *address, void *fake_func, void **out_origin_func) {
@@ -56,36 +57,17 @@ void MSCloseImage(const char* file) {
 
 BH_EXPORT
 void *MSFindSymbol(MSImageRef image, const char *name) {
-    void* buf = (char*)image;
-
-    struct load_command *after_header = buf + sizeof(struct mach_header_64);
-    struct mach_header_64 *header = buf;
-    struct symtab_command *symtab_cmd = NULL;
-
-    for (uint32_t i = 0; i < header->ncmds; i++) {
-        if (after_header->cmd == LC_SYMTAB) {
-            symtab_cmd = (struct symtab_command *) after_header;
+    uint32_t file_index = 0;
+    for (uint32_t i = 0; i < _dyld_image_count(); i++) {
+        if (image == _dyld_get_image_header(i)) {
+            file_index = i;
             break;
         }
-
-        after_header = (struct load_command *) ((char *) after_header + after_header->cmdsize);
     }
-
-    if (!symtab_cmd) return NULL;
-
-    struct nlist_64 *symtab = buf + symtab_cmd->symoff;
-    char *strtab = buf + symtab_cmd->stroff;
-
-    for (uint32_t i = 0; i < symtab_cmd->nsyms; i++) {
-        struct nlist_64 *symbol_nlist = symtab + i;
-        char *sym_name = strtab + symbol_nlist->n_un.n_strx;
-
-        if (strcmp(sym_name, name) == 0) {
-            return (buf + symbol_nlist->n_value);
-        }
-    }
-
-    return NULL;
+    if (file_index)
+        return DobbySymbolResolver(_dyld_get_image_name(file_index), name);
+    else
+        return NULL;
 }
 
 BH_EXPORT