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
  57     size_t flength(strlen(addr.dli_fname));
  58     char library[flength + 4 + 1];
  59     memcpy(library, addr.dli_fname, flength);
  60     library[flength] = '\0';
  61     _assert(strcmp(library + flength - 6, ".dylib") == 0);
  62     strcpy(library + flength - 6, "-any.dylib");
  63
  64     mach_port_t self(mach_task_self()), task;
  65     _krncall(task_for_pid(self, pid, &task));
  66
  67     mach_msg_type_number_t count;
  68
  69     task_dyld_info info;
  70     count = TASK_DYLD_INFO_COUNT;
  71     _krncall(task_info(task, TASK_DYLD_INFO, reinterpret_cast<task_info_t>(&info), &count));
  72     _assert(count == TASK_DYLD_INFO_COUNT);
  73     _assert(info.all_image_info_addr != 0);
  74
  75     thread_act_t thread;
  76     _krncall(thread_create(task, &thread));
  77
  78 #if defined (__i386__) || defined(__x86_64__)
  79     x86_thread_state_t state;
  80 #elif defined(__arm__)
  81     arm_thread_state_t state;
  82 #else
  83     #error XXX: implement
  84 #endif
  85
  86     memset(&state, 0, sizeof(state));
  87     mach_msg_type_number_t read(MACHINE_THREAD_STATE_COUNT);
  88     _krncall(thread_get_state(thread, MACHINE_THREAD_STATE, reinterpret_cast<thread_state_t>(&state), &read));
  89     _assert(read == MACHINE_THREAD_STATE_COUNT);
  90
  91     Trampoline *trampoline;
  92     size_t align;
  93     size_t push;
  94
  95 #if defined(__i386__) || defined(__x86_64__)
  96     switch (state.tsh.flavor) {
  97         case i386_THREAD_STATE:
  98             trampoline = &Trampoline_i386_;
  99             align = 4;
 100             push = 5;
 101             break;
 102         case x86_THREAD_STATE64:
 103             trampoline = &Trampoline_x86_64_;
 104             align = 8;
 105             push = 2;
 106             break;
 107         default:
 108             _assert(false);
 109     }
 110 #elif defined(__arm__)
 111     trampoline = &Trampoline_armv6_;
 112     align = 4;
 113     push = 0;
 114 #else
 115     #error XXX: implement
 116 #endif
 117
 118     static const size_t Stack_(8 * 1024);
 119     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
 120     depth = (depth + align + 1) / align * align;
 121
 122     CYPool pool;
 123     uint8_t *local(pool.malloc<uint8_t>(depth));
 124     Baton *baton(reinterpret_cast<Baton *>(local));
 125
 126     baton->dyld = info.all_image_info_addr;
 127     baton->pid = getpid();
 128     memcpy(baton->library, library, length);
 129
 130     mach_vm_size_t size(depth + Stack_);
 131     mach_vm_address_t stack;
 132     _krncall(mach_vm_allocate(task, &stack, size, true));
 133
 134     mach_vm_address_t data(stack + Stack_);
 135     _krncall(mach_vm_write(task, data, reinterpret_cast<mach_vm_address_t>(baton), depth));
 136
 137     mach_vm_address_t code;
 138     _krncall(mach_vm_allocate(task, &code, trampoline->size_, true));
 139     _krncall(mach_vm_write(task, code, reinterpret_cast<mach_vm_address_t>(trampoline->data_), trampoline->size_));
 140     _krncall(mach_vm_protect(task, code, trampoline->size_, false, VM_PROT_READ | VM_PROT_EXECUTE));
 141
 142     uint32_t frame[push];
 143     if (sizeof(frame) != 0)
 144         memset(frame, 0, sizeof(frame));
 145
 146 #if defined(__i386__) || defined(__x86_64__)
 147     switch (state.tsh.flavor) {
 148         case i386_THREAD_STATE:
 149             frame[1] = data;
 150             state.uts.ts32.__eip = code + trampoline->entry_;
 151             state.uts.ts32.__esp = stack + Stack_ - sizeof(frame);
 152             break;
 153         case x86_THREAD_STATE64:
 154             state.uts.ts64.__rdi = data;
 155             state.uts.ts64.__rip = code + trampoline->entry_;
 156             state.uts.ts64.__rsp = stack + Stack_ - sizeof(frame);
 157             break;
 158         default:
 159             _assert(false);
 160     }
 161 #elif defined(__arm__)
 162     state.__r[0] = data;
 163     state.__pc = code + trampoline->entry_;
 164     state.__sp = stack + Stack_ - sizeof(frame);
 165
 166     if ((state.__pc & 0x1) != 0) {
 167         state.__pc &= ~0x1;
 168         state.__cpsr |= 0x20;
 169     }
 170 #else
 171     #error XXX: implement
 172 #endif
 173
 174     if (sizeof(frame) != 0)
 175         _krncall(mach_vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<mach_vm_address_t>(frame), sizeof(frame)));
 176
 177     _krncall(thread_set_state(thread, MACHINE_THREAD_STATE, reinterpret_cast<thread_state_t>(&state), MACHINE_THREAD_STATE_COUNT));
 178     _krncall(thread_resume(thread));
 179
 180     _krncall(mach_port_deallocate(self, task));
 181 }