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 __attribute__((__unused__))
  48 static void $memcpy(char *dst, const char *src, size_t size) {
  49     for (size_t i(0); i != size; ++i)
  50         dst[i] = src[i];
  51 }
  52
  53 static int $strcmp(const char *lhs, const char *rhs) {
  54     while (*lhs == *rhs) {
  55         if (*lhs == '\0')
  56             return 0;
  57         ++lhs, ++rhs;
  58     } return *lhs < *rhs ? -1 : 1;
  59 }
  60
  61 static void $strlcpy(char *dst, const char *src, size_t size) {
  62     if (src == NULL)
  63         src = "(null)";
  64     if (size == 0)
  65         return;
  66     size_t i(0);
  67     while (i != size - 1) {
  68         char value(src[i]);
  69         if (value == '\0')
  70             break;
  71         dst[i++] = value;
  72     } dst[i] = '\0';
  73 }
  74
  75 __attribute__((__unused__))
  76 static char *$strstr(const char *haystack, const char *needle) {
  77     if (*needle == '\0')
  78         return NULL;
  79     for (; *haystack != '\0'; ++haystack)
  80         for (size_t i(0); ; ++i)
  81             if (needle[i] == '\0')
  82                 return const_cast<char *>(haystack);
  83             else if (needle[i] != haystack[i])
  84                 break;
  85     return NULL;
  86 }
  87
  88 __attribute__((__unused__))
  89 static size_t $strlen(const char *data) {
  90     for (size_t i(0); ; ++i)
  91         if (data[i] == '\0')
  92             return i;
  93 }
  94
  95 __attribute__((__unused__))
  96 static void $snprintfp(char *dst, size_t size, const void *pointer) {
  97     uintptr_t value(reinterpret_cast<uintptr_t>(pointer));
  98     char buffer[32];
  99     char *end(buffer + sizeof(buffer));
 100     *--end = '\0';
 101     if (value == 0)
 102         *--end = '0';
 103     else do {
 104         unsigned digit(value & 0xf);
 105         value >>= 4;
 106         *--end = (digit < 10 ? '0' : 'a' - 10) + digit;
 107     } while (value != 0);
 108     *--end = 'x';
 109     *--end = '0';
 110     $strlcpy(dst, end, size);
 111 }
 112
 113 #ifdef __LP64__
 114 typedef struct mach_header_64 mach_header_xx;
 115 typedef struct nlist_64 nlist_xx;
 116 typedef struct segment_command_64 segment_command_xx;
 117
 118 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
 119 static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
 120 #else
 121 typedef struct mach_header mach_header_xx;
 122 typedef struct nlist nlist_xx;
 123 typedef struct segment_command segment_command_xx;
 124
 125 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
 126 static const uint32_t MH_MAGIC_XX = MH_MAGIC;
 127 #endif
 128
 129 #define forlc(command, mach, lc, type) \
 130     if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
 131         if (const struct load_command *lcp = load_commands) \
 132             for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
 133                 if ( \
 134                     lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
 135                     reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
 136                 ) \
 137                     break; \
 138                 else if (lcp->cmd != lc) \
 139                     continue; \
 140                 else if (lcp->cmdsize < sizeof(type)) \
 141                     break; \
 142                 else if (const type *command = reinterpret_cast<const type *>(lcp))
 143
 144 static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
 145     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
 146         const dyld_image_info &info(infos->infoArray[i]);
 147         const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
 148         if (mach->magic != MH_MAGIC_XX)
 149             continue;
 150
 151         const char *path(info.imageFilePath);
 152         forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
 153             path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
 154         if ($strcmp(path, name) != 0)
 155             continue;
 156
 157         return mach;
 158     }
 159
 160     return NULL;
 161 }
 162
 163 static void *Symbol(const mach_header_xx *mach, const char *name) {
 164     const struct symtab_command *stp(NULL);
 165     forlc (command, mach, LC_SYMTAB, struct symtab_command)
 166         stp = command;
 167     if (stp == NULL)
 168         return NULL;
 169
 170     size_t slide(_not(size_t));
 171     const nlist_xx *symbols(NULL);
 172     const char *strings(NULL);
 173
 174     forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
 175         if (segment->fileoff == 0)
 176             slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
 177         if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
 178             symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
 179         if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
 180             strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
 181     }
 182
 183     if (slide == _not(size_t) || symbols == NULL || strings == NULL)
 184         return NULL;
 185
 186     for (size_t i(0); i != stp->nsyms; ++i) {
 187         const nlist_xx *symbol(&symbols[i]);
 188         if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
 189             continue;
 190
 191         const char *nambuf(strings + symbol->n_un.n_strx);
 192         if ($strcmp(name, nambuf) != 0)
 193             continue;
 194
 195         uintptr_t value(symbol->n_value);
 196         if (value == 0)
 197             continue;
 198
 199 #ifdef __arm__
 200         if ((symbol->n_desc & N_ARM_THUMB_DEF) != 0)
 201             value |= 0x00000001;
 202 #endif
 203
 204         value += slide;
 205         return reinterpret_cast<void *>(value);
 206     }
 207
 208     return NULL;
 209 }
 210
 211 template <typename Type_>
 212 static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
 213     function = reinterpret_cast<Type_>(Symbol(mach, name));
 214 }
 215
 216 static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
 217     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 218     return Library(infos, name);
 219 }
 220
 221 #if defined(__i386__) || defined(__x86_64__)
 222 static bool Simulator(struct dyld_all_image_infos *infos) {
 223     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
 224         const dyld_image_info &info(infos->infoArray[i]);
 225         const char *path(info.imageFilePath);
 226         if ($strstr(path, "/SDKs/iPhoneSimulator") != NULL)
 227             return true;
 228     } return false;
 229 }
 230
 231 static bool Simulator(Baton *baton) {
 232     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 233     return Simulator(infos);
 234 }
 235 #endif
 236
 237 void *Routine(void *arg) {
 238     Baton *baton(reinterpret_cast<Baton *>(arg));
 239
 240     const mach_header_xx *dyld(NULL);
 241     if (dyld == NULL)
 242         dyld = Library(baton, "/usr/lib/system/libdyld.dylib");
 243     if (dyld == NULL)
 244         dyld = Library(baton, "/usr/lib/libSystem.B.dylib");
 245
 246     char *(*$dlerror)();
 247     cyset($dlerror, "_dlerror", dyld);
 248
 249     void *(*$dlopen)(const char *, int);
 250     cyset($dlopen, "_dlopen", dyld);
 251
 252 #if defined(__i386__) || defined(__x86_64__)
 253     size_t length($strlen(baton->library));
 254     if (length >= 10 && $strcmp(baton->library + length - 10, "-###.dylib") == 0)
 255         $memcpy(baton->library + length - 10, Simulator(baton) ? "-sim" : "-sys", 4);
 256 #endif
 257
 258     void *handle($dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
 259     if (handle == NULL) {
 260         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 261         return NULL;
 262     }
 263
 264     void *(*$dlsym)(void *, const char *);
 265     cyset($dlsym, "_dlsym", dyld);
 266
 267     void (*CYHandleServer)(pid_t);
 268     CYHandleServer = reinterpret_cast<void (*)(pid_t)>($dlsym(handle, "CYHandleServer"));
 269     if (CYHandleServer == NULL) {
 270         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 271         return NULL;
 272     }
 273
 274     CYHandleServer(baton->pid);
 275     return NULL;
 276 }
 277
 278 extern "C" void Start(Baton *baton) {
 279     struct _pthread self;
 280     $bzero(&self, sizeof(self));
 281
 282     const mach_header_xx *pthread(NULL);
 283     if (pthread == NULL)
 284         pthread = Library(baton, "/usr/lib/system/libsystem_pthread.dylib");
 285     if (pthread == NULL)
 286         pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
 287     if (pthread == NULL)
 288         pthread = Library(baton, "/usr/lib/libSystem.B.dylib");
 289
 290     void (*$__pthread_set_self)(void **);
 291     cyset($__pthread_set_self, "___pthread_set_self", pthread);
 292
 293     self.tsd[0] = &self;
 294     $__pthread_set_self(&self.tsd[0]);
 295
 296     int (*$pthread_attr_init)(pthread_attr_t *);
 297     cyset($pthread_attr_init, "_pthread_attr_init", pthread);
 298
 299 #if 0
 300     pthread_attr_t attr;
 301     $pthread_attr_init(&attr);
 302
 303     int (*$pthread_attr_setdetachstate)(pthread_attr_t *, int);
 304     cyset($pthread_attr_setdetachstate, "_pthread_attr_setdetachstate", pthread);
 305
 306     $pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 307 #endif
 308
 309     int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
 310     cyset($pthread_create, "_pthread_create", pthread);
 311
 312     pthread_t thread;
 313     $pthread_create(&thread, NULL, &Routine, baton);
 314
 315 #if 0
 316     int (*$pthread_attr_destroy)(pthread_attr_t *);
 317     cyset($pthread_attr_destroy, "_pthread_attr_destroy", pthread);
 318
 319     $pthread_attr_destroy(&attr);
 320 #endif
 321
 322     int (*$pthread_join)(pthread_t, void **);
 323     cyset($pthread_join, "_pthread_join", pthread);
 324
 325     void *status;
 326     $pthread_join(thread, &status);
 327
 328     const mach_header_xx *kernel(NULL);
 329     if (kernel == NULL)
 330         kernel = Library(baton, "/usr/lib/system/libsystem_kernel.dylib");
 331     if (kernel == NULL)
 332         kernel = Library(baton, "/usr/lib/libSystem.B.dylib");
 333
 334     mach_port_t (*$mach_thread_self)();
 335     cyset($mach_thread_self, "_mach_thread_self", kernel);
 336
 337     kern_return_t (*$thread_terminate)(thread_act_t);
 338     cyset($thread_terminate, "_thread_terminate", kernel);
 339
 340     $thread_terminate($mach_thread_self());
 341 }