Mach/Inject.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2013  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU General Public License, Version 3 {{{ */
   6 /*
   7  * Cycript is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation, either version 3 of the License,
  10  * or (at your option) any later version.
  11  *
  12  * Cycript is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Cycript.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include <dlfcn.h>
  23
  24 #include <mach/mach.h>
  25 #include <mach/mach_vm.h>
  26
  27 #include <mach/machine/thread_status.h>
  28
  29 #include <cstdio>
  30 #include <pthread.h>
  31 #include <unistd.h>
  32
  33 #include "Baton.hpp"
  34 #include "Exception.hpp"
  35 #include "Pooling.hpp"
  36 #include "Trampoline.t.hpp"
  37
  38 extern "C" void CYHandleServer(pid_t);
  39
  40 void InjectLibrary(pid_t pid) {
  41     Dl_info addr;
  42     _assert(dladdr(reinterpret_cast<void *>(&CYHandleServer), &addr) != 0);
  43     const char *library(addr.dli_fname);
  44
  45     mach_port_t self(mach_task_self()), task;
  46     _krncall(task_for_pid(self, pid, &task));
  47
  48     mach_msg_type_number_t count;
  49
  50     task_dyld_info info;
  51     count = TASK_DYLD_INFO_COUNT;
  52     _krncall(task_info(task, TASK_DYLD_INFO, reinterpret_cast<task_info_t>(&info), &count));
  53     _assert(count == TASK_DYLD_INFO_COUNT);
  54     _assert(info.all_image_info_addr != 0);
  55
  56     thread_act_t thread;
  57     _krncall(thread_create(task, &thread));
  58
  59     thread_state_flavor_t flavor;
  60 #if defined (__i386__) || defined(__x86_64__)
  61     x86_thread_state_t state;
  62     flavor = x86_THREAD_STATE;
  63     count = x86_THREAD_STATE_COUNT;
  64 #elif defined(__arm__)
  65     arm_thread_state_t state;
  66     flavor = ARM_THREAD_STATE;
  67     count = ARM_THREAD_STATE_COUNT;
  68 #else
  69     #error XXX: implement
  70 #endif
  71
  72     memset(&state, 0, sizeof(state));
  73     mach_msg_type_number_t read(count);
  74     _krncall(thread_get_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), &read));
  75     _assert(read == count);
  76
  77     Trampoline *trampoline;
  78     size_t align;
  79     size_t push;
  80
  81 #if defined(__i386__) || defined(__x86_64__)
  82     switch (state.tsh.flavor) {
  83         case i386_THREAD_STATE:
  84             trampoline = &Trampoline_i386_;
  85             align = 4;
  86             push = 5;
  87             break;
  88         case x86_THREAD_STATE64:
  89             trampoline = &Trampoline_x86_64_;
  90             align = 8;
  91             push = 2;
  92             break;
  93         default:
  94             _assert(false);
  95     }
  96 #elif defined(__arm__)
  97     trampoline = &Trampoline_armv6_;
  98     align = 4;
  99     push = 0;
 100 #else
 101     #error XXX: implement
 102 #endif
 103
 104     static const size_t Stack_(8 * 1024);
 105     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
 106     depth = (depth + align + 1) / align * align;
 107
 108     CYPool pool;
 109     uint8_t *local(pool.malloc<uint8_t>(depth));
 110     Baton *baton(reinterpret_cast<Baton *>(local));
 111
 112     baton->dyld = info.all_image_info_addr;
 113     baton->pid = getpid();
 114     memcpy(baton->library, library, length);
 115
 116     mach_vm_size_t size(depth + Stack_);
 117     mach_vm_address_t stack;
 118     _krncall(mach_vm_allocate(task, &stack, size, true));
 119
 120     mach_vm_address_t data(stack + Stack_);
 121     _krncall(mach_vm_write(task, data, reinterpret_cast<mach_vm_address_t>(baton), depth));
 122
 123     mach_vm_address_t code;
 124     _krncall(mach_vm_allocate(task, &code, trampoline->size_, true));
 125     _krncall(mach_vm_write(task, code, reinterpret_cast<mach_vm_address_t>(trampoline->data_), trampoline->size_));
 126     _krncall(mach_vm_protect(task, code, trampoline->size_, false, VM_PROT_READ | VM_PROT_EXECUTE));
 127
 128     uint32_t frame[push];
 129     if (sizeof(frame) != 0)
 130         memset(frame, 0, sizeof(frame));
 131
 132 #if defined(__i386__) || defined(__x86_64__)
 133     switch (state.tsh.flavor) {
 134         case i386_THREAD_STATE:
 135             frame[1] = data;
 136             state.uts.ts32.__eip = code + trampoline->entry_;
 137             state.uts.ts32.__esp = stack + Stack_ - sizeof(frame);
 138             break;
 139         case x86_THREAD_STATE64:
 140             state.uts.ts64.__rdi = data;
 141             state.uts.ts64.__rip = code + trampoline->entry_;
 142             state.uts.ts64.__rsp = stack + Stack_ - sizeof(frame);
 143             break;
 144         default:
 145             _assert(false);
 146     }
 147 #elif defined(__arm__)
 148     state.__r[0] = data;
 149     state.__pc = code + trampoline->entry_;
 150     state.__sp = stack + Stack_ - sizeof(frame);
 151
 152     if ((state.__pc & 0x1) != 0) {
 153         state.__pc &= ~0x1;
 154         state.__cpsr |= 0x20;
 155     }
 156 #else
 157     #error XXX: implement
 158 #endif
 159
 160     if (sizeof(frame) != 0)
 161         _krncall(mach_vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<mach_vm_address_t>(frame), sizeof(frame)));
 162
 163     _krncall(thread_set_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), count));
 164     _krncall(thread_resume(thread));
 165
 166     _krncall(mach_port_deallocate(self, task));
 167 }