Mach/Inject.cpp

   1 #include <dlfcn.h>
   2 #include <mach/mach.h>
   3
   4 extern "C" {
   5 #include <mach-o/nlist.h>
   6 }
   7
   8 #include <cstdio>
   9 #include <pthread.h>
  10 #include <unistd.h>
  11
  12 #include "Baton.hpp"
  13 #include "Exception.hpp"
  14 #include "Pooling.hpp"
  15 #include "Trampoline.t.hpp"
  16
  17 extern "C" void __pthread_set_self(pthread_t);
  18
  19 template <typename Type_>
  20 static void nlset(Type_ &function, struct nlist *nl, size_t index) {
  21     struct nlist &name(nl[index]);
  22     uintptr_t value(name.n_value);
  23     _assert(value != 0);
  24     if ((name.n_desc & N_ARM_THUMB_DEF) != 0)
  25         value |= 0x00000001;
  26     function = value;
  27 }
  28
  29 void InjectLibrary(pid_t pid) {
  30     // XXX: break this into the build environment
  31     const char *library("/usr/lib/libcycript.dylib");
  32
  33     static const size_t Stack_(8 * 1024);
  34     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
  35     depth = (depth + sizeof(uintptr_t) + 1) / sizeof(uintptr_t) * sizeof(uintptr_t);
  36
  37     CYPool pool;
  38     uint8_t *local(reinterpret_cast<uint8_t *>(apr_palloc(pool, depth)));
  39     Baton *baton(reinterpret_cast<Baton *>(local));
  40
  41     uintptr_t set_self_internal;
  42     uintptr_t set_self_external;
  43
  44     struct nlist nl[3];
  45     memset(nl, 0, sizeof(nl));
  46     nl[0].n_un.n_name = (char *) "__pthread_set_self";
  47     nl[1].n_un.n_name = (char *) "___pthread_set_self";
  48     nlist("/usr/lib/libSystem.B.dylib", nl);
  49     nlset(set_self_internal, nl, 0);
  50     nlset(set_self_external, nl, 1);
  51
  52     baton->_pthread_set_self = reinterpret_cast<void (*)(pthread_t)>(reinterpret_cast<uintptr_t>(&__pthread_set_self) - set_self_external + set_self_internal);
  53
  54     baton->pthread_create = &pthread_create;
  55     baton->pthread_join = &pthread_join;
  56
  57     baton->dlopen = &dlopen;
  58     baton->dlsym = &dlsym;
  59
  60     baton->mach_thread_self = &mach_thread_self;
  61     baton->thread_terminate = &thread_terminate;
  62
  63     baton->pid = getpid();
  64     memcpy(baton->library, library, length);
  65
  66     vm_size_t size(depth + Stack_);
  67
  68     mach_port_t self(mach_task_self()), task;
  69     _krncall(task_for_pid(self, pid, &task));
  70
  71     vm_address_t stack;
  72     _krncall(vm_allocate(task, &stack, size, true));
  73     vm_address_t data(stack + Stack_);
  74
  75     vm_write(task, data, reinterpret_cast<vm_address_t>(baton), depth);
  76
  77     vm_address_t code;
  78     _krncall(vm_allocate(task, &code, sizeof(Trampoline_), true));
  79     vm_write(task, code, reinterpret_cast<vm_address_t>(Trampoline_), sizeof(Trampoline_));
  80     _krncall(vm_protect(task, code, sizeof(Trampoline_), false, VM_PROT_READ | VM_PROT_EXECUTE));
  81
  82     thread_act_t thread;
  83     _krncall(thread_create(task, &thread));
  84
  85     thread_state_flavor_t flavor;
  86     mach_msg_type_number_t count;
  87     size_t push;
  88
  89 #if defined(__arm__)
  90     arm_thread_state_t state;
  91     flavor = ARM_THREAD_STATE;
  92     count = ARM_THREAD_STATE_COUNT;
  93     push = 0;
  94 #elif defined(__i386__) || defined(__x86_64__)
  95     i386_thread_state_t state;
  96     flavor = i386_THREAD_STATE;
  97     count = i386_THREAD_STATE_COUNT;
  98     push = 5;
  99 #else
 100     #error XXX: implement
 101 #endif
 102
 103     uintptr_t frame[push];
 104     if (sizeof(frame) != 0)
 105         memset(frame, 0, sizeof(frame));
 106
 107     memset(&state, 0, sizeof(state));
 108
 109     mach_msg_type_number_t read(count);
 110     _krncall(thread_get_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), &read));
 111     _assert(count == count);
 112
 113 #if defined(__arm__)
 114     state.r[0] = data;
 115     state.sp = stack + Stack_;
 116     state.pc = code;
 117
 118     if ((state.pc & 0x1) != 0) {
 119         state.pc &= ~0x1;
 120         state.cpsr |= 0x20;
 121     }
 122 #elif defined(__i386__) || defined(__x86_64__)
 123     frame[0] = 0;
 124     frame[1] = data;
 125
 126     state.__eip = code;
 127     state.__esp = stack + Stack_ - sizeof(frame);
 128 #else
 129     #error XXX: implement
 130 #endif
 131
 132     if (sizeof(frame) != 0)
 133         vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<vm_address_t>(frame), sizeof(frame));
 134
 135     _krncall(thread_set_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), count));
 136     _krncall(thread_resume(thread));
 137
 138     _krncall(mach_port_deallocate(self, task));
 139 }