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