Trampoline.t.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 <TargetConditionals.h>
  23 #if defined(__arm__) || defined(__arm64__)
  24 #undef TARGET_IPHONE_SIMULATOR
  25 #define TARGET_IPHONE_SIMULATOR 1
  26 #endif
  27 #define _PTHREAD_ATTR_T
  28 #include <pthread_internals.h>
  29 #if defined(__arm__) || defined(__arm64__)
  30 #undef TARGET_IPHONE_SIMULATOR
  31 #endif
  32
  33 #include <mach-o/dyld.h>
  34 #include <mach-o/dyld_images.h>
  35 #include <mach-o/loader.h>
  36 #include <mach-o/nlist.h>
  37
  38 #include "Standard.hpp"
  39 #include "Baton.hpp"
  40
  41 static void $bzero(void *data, size_t size) {
  42     char *bytes(reinterpret_cast<char *>(data));
  43     for (size_t i(0); i != size; ++i)
  44         bytes[i] = 0;
  45 }
  46
  47 static int $strcmp(const char *lhs, const char *rhs) {
  48     while (*lhs == *rhs) {
  49         if (*lhs == '\0')
  50             return 0;
  51         ++lhs, ++rhs;
  52     } return *lhs < *rhs ? -1 : 1;
  53 }
  54
  55 static void $strlcpy(char *dst, const char *src, size_t size) {
  56     if (size == 0)
  57         return;
  58     size_t i(0);
  59     while (i != size - 1) {
  60         char value(src[i]);
  61         if (value == '\0')
  62             break;
  63         dst[i++] = value;
  64     } dst[i] = '\0';
  65 }
  66
  67 #ifdef __LP64__
  68 typedef struct mach_header_64 mach_header_xx;
  69 typedef struct nlist_64 nlist_xx;
  70 typedef struct segment_command_64 segment_command_xx;
  71
  72 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
  73 static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
  74 #else
  75 typedef struct mach_header mach_header_xx;
  76 typedef struct nlist nlist_xx;
  77 typedef struct segment_command segment_command_xx;
  78
  79 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
  80 static const uint32_t MH_MAGIC_XX = MH_MAGIC;
  81 #endif
  82
  83 #define forlc(command, mach, lc, type) \
  84     if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
  85         if (const struct load_command *lcp = load_commands) \
  86             for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
  87                 if ( \
  88                     lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
  89                     reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
  90                 ) \
  91                     return NULL; \
  92                 else if (lcp->cmd != lc) \
  93                     continue; \
  94                 else if (lcp->cmdsize < sizeof(type)) \
  95                     return NULL; \
  96                 else if (const type *command = reinterpret_cast<const type *>(lcp))
  97
  98 static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
  99     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
 100         const dyld_image_info &info(infos->infoArray[i]);
 101         const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
 102         if (mach->magic != MH_MAGIC_XX)
 103             continue;
 104
 105         const char *path(info.imageFilePath);
 106         forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
 107             path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
 108         if ($strcmp(path, name) != 0)
 109             continue;
 110
 111         return mach;
 112     }
 113
 114     return NULL;
 115 }
 116
 117 static void *Symbol(const mach_header_xx *mach, const char *name) {
 118     const struct symtab_command *stp(NULL);
 119     forlc (command, mach, LC_SYMTAB, struct symtab_command)
 120         stp = command;
 121     if (stp == NULL)
 122         return NULL;
 123
 124     size_t slide(_not(size_t));
 125     const nlist_xx *symbols(NULL);
 126     const char *strings(NULL);
 127
 128     forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
 129         if (segment->fileoff == 0)
 130             slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
 131         if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
 132             symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
 133         if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
 134             strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
 135     }
 136
 137     if (slide == _not(size_t) || symbols == NULL || strings == NULL)
 138         return NULL;
 139
 140     for (size_t i(0); i != stp->nsyms; ++i) {
 141         const nlist_xx *symbol(&symbols[i]);
 142         if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
 143             continue;
 144
 145         const char *nambuf(strings + symbol->n_un.n_strx);
 146         if ($strcmp(name, nambuf) != 0)
 147             continue;
 148
 149         uintptr_t value(symbol->n_value);
 150         if (value == 0)
 151             continue;
 152
 153 #ifdef __arm__
 154         if ((symbol->n_desc & N_ARM_THUMB_DEF) != 0)
 155             value |= 0x00000001;
 156 #endif
 157
 158         value += slide;
 159         return reinterpret_cast<void *>(value);
 160     }
 161
 162     return NULL;
 163 }
 164
 165 template <typename Type_>
 166 static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
 167     function = reinterpret_cast<Type_>(Symbol(mach, name));
 168 }
 169
 170 static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
 171     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 172     return Library(infos, name);
 173 }
 174
 175 void *Routine(void *arg) {
 176     Baton *baton(reinterpret_cast<Baton *>(arg));
 177
 178     const mach_header_xx *dyld(NULL);
 179     if (dyld == NULL)
 180         dyld = Library(baton, "/usr/lib/system/libdyld.dylib");
 181     if (dyld == NULL)
 182         dyld = Library(baton, "/usr/lib/libSystem.B.dylib");
 183
 184     char *(*$dlerror)();
 185     cyset($dlerror, "_dlerror", dyld);
 186
 187     void *(*$dlopen)(const char *, int);
 188     cyset($dlopen, "_dlopen", dyld);
 189
 190     void *handle($dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
 191     if (handle == NULL) {
 192         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 193         return NULL;
 194     }
 195
 196     void *(*$dlsym)(void *, const char *);
 197     cyset($dlsym, "_dlsym", dyld);
 198
 199     void (*CYHandleServer)(pid_t);
 200     CYHandleServer = reinterpret_cast<void (*)(pid_t)>($dlsym(handle, "CYHandleServer"));
 201     if (CYHandleServer == NULL) {
 202         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 203         return NULL;
 204     }
 205
 206     CYHandleServer(baton->pid);
 207     return NULL;
 208 }
 209
 210 extern "C" void Start(Baton *baton) {
 211     struct _pthread self;
 212     $bzero(&self, sizeof(self));
 213
 214     const mach_header_xx *pthread(NULL);
 215     if (pthread == NULL)
 216         pthread = Library(baton, "/usr/lib/system/libsystem_pthread.dylib");
 217     if (pthread == NULL)
 218         pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
 219     if (pthread == NULL)
 220         pthread = Library(baton, "/usr/lib/libSystem.B.dylib");
 221
 222     void (*$__pthread_set_self)(void **);
 223     cyset($__pthread_set_self, "___pthread_set_self", pthread);
 224
 225     self.tsd[0] = &self;
 226     $__pthread_set_self(&self.tsd[0]);
 227
 228     int (*$pthread_attr_init)(pthread_attr_t *);
 229     cyset($pthread_attr_init, "_pthread_attr_init", pthread);
 230
 231 #if 0
 232     pthread_attr_t attr;
 233     $pthread_attr_init(&attr);
 234
 235     int (*$pthread_attr_setdetachstate)(pthread_attr_t *, int);
 236     cyset($pthread_attr_setdetachstate, "_pthread_attr_setdetachstate", pthread);
 237
 238     $pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 239 #endif
 240
 241     int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
 242     cyset($pthread_create, "_pthread_create", pthread);
 243
 244     pthread_t thread;
 245     $pthread_create(&thread, NULL, &Routine, baton);
 246
 247 #if 0
 248     int (*$pthread_attr_destroy)(pthread_attr_t *);
 249     cyset($pthread_attr_destroy, "_pthread_attr_destroy", pthread);
 250
 251     $pthread_attr_destroy(&attr);
 252 #endif
 253
 254     int (*$pthread_join)(pthread_t, void **);
 255     cyset($pthread_join, "_pthread_join", pthread);
 256
 257     void *status;
 258     $pthread_join(thread, &status);
 259
 260     const mach_header_xx *kernel(NULL);
 261     if (kernel == NULL)
 262         kernel = Library(baton, "/usr/lib/system/libsystem_kernel.dylib");
 263     if (kernel == NULL)
 264         kernel = Library(baton, "/usr/lib/libSystem.B.dylib");
 265
 266     mach_port_t (*$mach_thread_self)();
 267     cyset($mach_thread_self, "_mach_thread_self", kernel);
 268
 269     kern_return_t (*$thread_terminate)(thread_act_t);
 270     cyset($thread_terminate, "_thread_terminate", kernel);
 271
 272     $thread_terminate($mach_thread_self());
 273 }