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
  26 #ifdef __APPLE__
  27 #include "TargetConditionals.h"
  28 #endif
  29
  30 #ifdef TARGET_OS_IPHONE
  31 #include <mach/vm_map.h>
  32 #define mach_vm_allocate vm_allocate
  33 #define mach_vm_protect vm_protect
  34 #define mach_vm_write vm_write
  35 #define mach_vm_address_t vm_address_t
  36 #else
  37 #include <mach/mach_vm.h>
  38 #endif
  39
  40 #include <mach/machine/thread_status.h>
  41
  42 #include <cstdio>
  43 #include <pthread.h>
  44 #include <unistd.h>
  45
  46 #include "Baton.hpp"
  47 #include "Exception.hpp"
  48 #include "Pooling.hpp"
  49 #include "Trampoline.t.hpp"
  50
  51 extern "C" void CYHandleServer(pid_t);
  52
  53 void InjectLibrary(pid_t pid) {
  54     Dl_info addr;
  55     _assert(dladdr(reinterpret_cast<void *>(&CYHandleServer), &addr) != 0);
  56     const char *library(addr.dli_fname);
  57
  58     mach_port_t self(mach_task_self()), task;
  59     _krncall(task_for_pid(self, pid, &task));
  60
  61     mach_msg_type_number_t count;
  62
  63     task_dyld_info info;
  64     count = TASK_DYLD_INFO_COUNT;
  65     _krncall(task_info(task, TASK_DYLD_INFO, reinterpret_cast<task_info_t>(&info), &count));
  66     _assert(count == TASK_DYLD_INFO_COUNT);
  67     _assert(info.all_image_info_addr != 0);
  68
  69     thread_act_t thread;
  70     _krncall(thread_create(task, &thread));
  71
  72     thread_state_flavor_t flavor;
  73 #if defined (__i386__) || defined(__x86_64__)
  74     x86_thread_state_t state;
  75     flavor = x86_THREAD_STATE;
  76     count = x86_THREAD_STATE_COUNT;
  77 #elif defined(__arm__)
  78     arm_thread_state_t state;
  79     flavor = ARM_THREAD_STATE;
  80     count = ARM_THREAD_STATE_COUNT;
  81 #else
  82     #error XXX: implement
  83 #endif
  84
  85     memset(&state, 0, sizeof(state));
  86     mach_msg_type_number_t read(count);
  87     _krncall(thread_get_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), &read));
  88     _assert(read == count);
  89
  90     Trampoline *trampoline;
  91     size_t align;
  92     size_t push;
  93
  94 #if defined(__i386__) || defined(__x86_64__)
  95     switch (state.tsh.flavor) {
  96         case i386_THREAD_STATE:
  97             trampoline = &Trampoline_i386_;
  98             align = 4;
  99             push = 5;
 100             break;
 101         case x86_THREAD_STATE64:
 102             trampoline = &Trampoline_x86_64_;
 103             align = 8;
 104             push = 2;
 105             break;
 106         default:
 107             _assert(false);
 108     }
 109 #elif defined(__arm__)
 110     trampoline = &Trampoline_armv6_;
 111     align = 4;
 112     push = 0;
 113 #else
 114     #error XXX: implement
 115 #endif
 116
 117     static const size_t Stack_(8 * 1024);
 118     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
 119     depth = (depth + align + 1) / align * align;
 120
 121     CYPool pool;
 122     uint8_t *local(pool.malloc<uint8_t>(depth));
 123     Baton *baton(reinterpret_cast<Baton *>(local));
 124
 125     baton->dyld = info.all_image_info_addr;
 126     baton->pid = getpid();
 127     memcpy(baton->library, library, length);
 128
 129     mach_vm_size_t size(depth + Stack_);
 130     mach_vm_address_t stack;
 131     _krncall(mach_vm_allocate(task, &stack, size, true));
 132
 133     mach_vm_address_t data(stack + Stack_);
 134     _krncall(mach_vm_write(task, data, reinterpret_cast<mach_vm_address_t>(baton), depth));
 135
 136     mach_vm_address_t code;
 137     _krncall(mach_vm_allocate(task, &code, trampoline->size_, true));
 138     _krncall(mach_vm_write(task, code, reinterpret_cast<mach_vm_address_t>(trampoline->data_), trampoline->size_));
 139     _krncall(mach_vm_protect(task, code, trampoline->size_, false, VM_PROT_READ | VM_PROT_EXECUTE));
 140
 141     uint32_t frame[push];
 142     if (sizeof(frame) != 0)
 143         memset(frame, 0, sizeof(frame));
 144
 145 #if defined(__i386__) || defined(__x86_64__)
 146     switch (state.tsh.flavor) {
 147         case i386_THREAD_STATE:
 148             frame[1] = data;
 149             state.uts.ts32.__eip = code + trampoline->entry_;
 150             state.uts.ts32.__esp = stack + Stack_ - sizeof(frame);
 151             break;
 152         case x86_THREAD_STATE64:
 153             state.uts.ts64.__rdi = data;
 154             state.uts.ts64.__rip = code + trampoline->entry_;
 155             state.uts.ts64.__rsp = stack + Stack_ - sizeof(frame);
 156             break;
 157         default:
 158             _assert(false);
 159     }
 160 #elif defined(__arm__)
 161     state.__r[0] = data;
 162     state.__pc = code + trampoline->entry_;
 163     state.__sp = stack + Stack_ - sizeof(frame);
 164
 165     if ((state.__pc & 0x1) != 0) {
 166         state.__pc &= ~0x1;
 167         state.__cpsr |= 0x20;
 168     }
 169 #else
 170     #error XXX: implement
 171 #endif
 172
 173     if (sizeof(frame) != 0)
 174         _krncall(mach_vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<mach_vm_address_t>(frame), sizeof(frame)));
 175
 176     _krncall(thread_set_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), count));
 177     _krncall(thread_resume(thread));
 178
 179     _krncall(mach_port_deallocate(self, task));
 180 }