X-Git-Url: https://git.saurik.com/cycript.git/blobdiff_plain/b3378a02d0a811be38e530933fb9a57a3012a823..470752441c31804e6de07b75f1e183851885ec8b:/Trampoline.t.cpp

diff --git a/Trampoline.t.cpp b/Trampoline.t.cpp
index e52962a..f6832bd 100644
--- a/Trampoline.t.cpp
+++ b/Trampoline.t.cpp
@@ -1,20 +1,20 @@
 /* Cycript - Optimizing JavaScript Compiler/Runtime
- * Copyright (C) 2009-2010  Jay Freeman (saurik)
+ * Copyright (C) 2009-2013  Jay Freeman (saurik)
 */
 
-/* GNU Lesser General Public License, Version 3 {{{ */
+/* GNU General Public License, Version 3 {{{ */
 /*
- * Cycript is free software: you can redistribute it and/or modify it under
- * the terms of the GNU Lesser General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or (at your
- * option) any later version.
+ * Cycript is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License,
+ * or (at your option) any later version.
  *
- * Cycript is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
- * License for more details.
+ * Cycript is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
- * You should have received a copy of the GNU Lesser General Public License
+ * You should have received a copy of the GNU General Public License
  * along with Cycript.  If not, see <http://www.gnu.org/licenses/>.
 **/
 /* }}} */
@@ -22,79 +22,210 @@
 #define _PTHREAD_ATTR_T
 #include <pthread_internals.h>
 
+#include <mach-o/dyld.h>
+#include <mach-o/dyld_images.h>
+#include <mach-o/loader.h>
+
+extern "C" {
+#include <mach-o/nlist.h>
+}
+
 #include "Standard.hpp"
 #include "Baton.hpp"
 
+static void $bzero(void *data, size_t size) {
+    char *bytes(reinterpret_cast<char *>(data));
+    for (size_t i(0); i != size; ++i)
+        bytes[i] = 0;
+}
+
+static int $strcmp(const char *lhs, const char *rhs) {
+    while (*lhs == *rhs) {
+        if (*lhs == '\0')
+            return 0;
+        ++lhs, ++rhs;
+    } return *lhs < *rhs ? -1 : 1;
+}
+
+#ifdef __LP64__
+typedef struct mach_header_64 mach_header_xx;
+typedef struct nlist_64 nlist_xx;
+typedef struct segment_command_64 segment_command_xx;
+
+static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
+static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
+#else
+typedef struct mach_header mach_header_xx;
+typedef struct nlist nlist_xx;
+typedef struct segment_command segment_command_xx;
+
+static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
+static const uint32_t MH_MAGIC_XX = MH_MAGIC;
+#endif
+
+#define forlc(command, mach, lc, type) \
+    if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
+        if (const struct load_command *lcp = load_commands) \
+            for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
+                if ( \
+                    lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
+                    reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
+                ) \
+                    return NULL; \
+                else if (lcp->cmd != lc) \
+                    continue; \
+                else if (lcp->cmdsize < sizeof(type)) \
+                    return NULL; \
+                else if (const type *command = reinterpret_cast<const type *>(lcp))
+
+static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
+    for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
+        const dyld_image_info &info(infos->infoArray[i]);
+        const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
+        if (mach->magic != MH_MAGIC_XX)
+            continue;
+
+        const char *path(info.imageFilePath);
+        forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
+            path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
+        if ($strcmp(path, name) != 0)
+            continue;
+
+        return mach;
+    }
+
+    return NULL;
+}
+
+static void *Symbol(const mach_header_xx *mach, const char *name) {
+    const struct symtab_command *stp(NULL);
+    forlc (command, mach, LC_SYMTAB, struct symtab_command)
+        stp = command;
+    if (stp == NULL)
+        return NULL;
+
+    size_t slide(_not(size_t));
+    const nlist_xx *symbols(NULL);
+    const char *strings(NULL);
+
+    forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
+        if (segment->fileoff == 0)
+            slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
+        if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
+            symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
+        if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
+            strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
+    }
+
+    if (slide == _not(size_t) || symbols == NULL || strings == NULL)
+        return NULL;
+
+    for (size_t i(0); i != stp->nsyms; ++i) {
+        const nlist_xx *symbol(&symbols[i]);
+        if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
+            continue;
+
+        const char *nambuf(strings + symbol->n_un.n_strx);
+        if ($strcmp(name, nambuf) != 0)
+            continue;
+
+        uintptr_t value(symbol->n_value);
+        if (value == 0)
+            continue;
+
+        value += slide;
+        return reinterpret_cast<void *>(value);
+    }
+
+    return NULL;
+}
+
+struct Dynamic {
+    char *(*dlerror)();
+    void *(*dlsym)(void *, const char *);
+};
+
 template <typename Type_>
-static _finline void dlset(Baton *baton, Type_ &function, const char *name, void *handle = RTLD_DEFAULT) {
-    function = reinterpret_cast<Type_>(baton->dlsym(handle, name));
+static _finline void dlset(Dynamic *dynamic, Type_ &function, const char *name, void *handle = RTLD_DEFAULT) {
+    function = reinterpret_cast<Type_>(dynamic->dlsym(handle, name));
     if (function == NULL)
-        baton->dlerror();
+        dynamic->dlerror();
 }
 
-#define Framework(framework) \
-    "/System/Library/Frameworks/" #framework ".framework/" #framework
+template <typename Type_>
+static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
+    function = reinterpret_cast<Type_>(Symbol(mach, name));
+}
+
+static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
+    struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
+    return Library(infos, name);
+}
 
 void *Routine(void *arg) {
     Baton *baton(reinterpret_cast<Baton *>(arg));
 
-    void *(*dlopen)(const char *, int);
-    dlset(baton, dlopen, "dlopen");
+    const mach_header_xx *dyld(Library(baton, "/usr/lib/system/libdyld.dylib"));
 
-    if (baton->dlsym(RTLD_DEFAULT, "JSEvaluateScript") == NULL)
-        dlopen(Framework(JavaScriptCore), RTLD_GLOBAL | RTLD_LAZY);
+    Dynamic dynamic;
+    cyset(dynamic.dlerror, "_dlerror", dyld);
+    cyset(dynamic.dlsym, "_dlsym", dyld);
 
-    void *(*objc_getClass)(const char *);
-    dlset(baton, objc_getClass, "objc_getClass");
+    int (*pthread_detach)(pthread_t);
+    dlset(&dynamic, pthread_detach, "pthread_detach");
 
-    if (objc_getClass("WebUndefined") == NULL)
-        dlopen(Framework(WebKit), RTLD_GLOBAL | RTLD_LAZY);
+    pthread_t (*pthread_self)();
+    dlset(&dynamic, pthread_self, "pthread_self");
+
+    pthread_detach(pthread_self());
+
+    void *(*dlopen)(const char *, int);
+    dlset(&dynamic, dlopen, "dlopen");
 
     void *handle(dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
     if (handle == NULL) {
-        baton->dlerror();
+        dynamic.dlerror();
         return NULL;
     }
 
     void (*CYHandleServer)(pid_t);
-    dlset(baton, CYHandleServer, "CYHandleServer", handle);
+    dlset(&dynamic, CYHandleServer, "CYHandleServer", handle);
+    if (CYHandleServer == NULL) {
+        dynamic.dlerror();
+        return NULL;
+    }
 
     CYHandleServer(baton->pid);
-
     return NULL;
 }
 
-static void $bzero(void *data, size_t size) {
-    char *bytes(reinterpret_cast<char *>(data));
-    for (size_t i(0); i != size; ++i)
-        bytes[i] = 0;
-}
-
 extern "C" void Start(Baton *baton) {
     struct _pthread self;
     $bzero(&self, sizeof(self));
 
-    // this code comes from _pthread_set_self
+    const mach_header_xx *pthread(Library(baton, "/usr/lib/system/libsystem_pthread.dylib"));
+    if (pthread == NULL)
+        pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
+
+    void (*$__pthread_set_self)(pthread_t);
+    cyset($__pthread_set_self, "___pthread_set_self", pthread);
+
     self.tsd[0] = &self;
-    baton->__pthread_set_self(&self);
+    $__pthread_set_self(&self);
 
-    int (*pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
-    dlset(baton, pthread_create, "pthread_create");
+    int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
+    cyset($pthread_create, "_pthread_create", pthread);
 
     pthread_t thread;
-    baton->pthread_create(&thread, NULL, &Routine, baton);
-
-    int (*pthread_join)(pthread_t, void **);
-    dlset(baton, pthread_join, "pthread_join");
+    $pthread_create(&thread, NULL, &Routine, baton);
 
-    void *result;
-    baton->pthread_join(thread, &result);
+    const mach_header_xx *kernel(Library(baton, "/usr/lib/system/libsystem_kernel.dylib"));
 
-    mach_port_t (*mach_thread_self)();
-    dlset(baton, mach_thread_self, "mach_thread_self");
+    mach_port_t (*$mach_thread_self)();
+    cyset($mach_thread_self, "_mach_thread_self", kernel);
 
-    kern_return_t (*thread_terminate)(thread_act_t);
-    dlset(baton, thread_terminate, "thread_terminate");
+    kern_return_t (*$thread_terminate)(thread_act_t);
+    cyset($thread_terminate, "_thread_terminate", kernel);
 
-    baton->thread_terminate(baton->mach_thread_self());
+    $thread_terminate($mach_thread_self());
 }