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 (src == NULL)
  57         src = "(null)";
  58     if (size == 0)
  59         return;
  60     size_t i(0);
  61     while (i != size - 1) {
  62         char value(src[i]);
  63         if (value == '\0')
  64             break;
  65         dst[i++] = value;
  66     } dst[i] = '\0';
  67 }
  68
  69 #ifdef __LP64__
  70 typedef struct mach_header_64 mach_header_xx;
  71 typedef struct nlist_64 nlist_xx;
  72 typedef struct segment_command_64 segment_command_xx;
  73
  74 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
  75 static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
  76 #else
  77 typedef struct mach_header mach_header_xx;
  78 typedef struct nlist nlist_xx;
  79 typedef struct segment_command segment_command_xx;
  80
  81 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
  82 static const uint32_t MH_MAGIC_XX = MH_MAGIC;
  83 #endif
  84
  85 #define forlc(command, mach, lc, type) \
  86     if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
  87         if (const struct load_command *lcp = load_commands) \
  88             for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
  89                 if ( \
  90                     lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
  91                     reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
  92                 ) \
  93                     return NULL; \
  94                 else if (lcp->cmd != lc) \
  95                     continue; \
  96                 else if (lcp->cmdsize < sizeof(type)) \
  97                     return NULL; \
  98                 else if (const type *command = reinterpret_cast<const type *>(lcp))
  99
 100 static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
 101     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
 102         const dyld_image_info &info(infos->infoArray[i]);
 103         const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
 104         if (mach->magic != MH_MAGIC_XX)
 105             continue;
 106
 107         const char *path(info.imageFilePath);
 108         forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
 109             path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
 110         if ($strcmp(path, name) != 0)
 111             continue;
 112
 113         return mach;
 114     }
 115
 116     return NULL;
 117 }
 118
 119 static void *Symbol(const mach_header_xx *mach, const char *name) {
 120     const struct symtab_command *stp(NULL);
 121     forlc (command, mach, LC_SYMTAB, struct symtab_command)
 122         stp = command;
 123     if (stp == NULL)
 124         return NULL;
 125
 126     size_t slide(_not(size_t));
 127     const nlist_xx *symbols(NULL);
 128     const char *strings(NULL);
 129
 130     forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
 131         if (segment->fileoff == 0)
 132             slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
 133         if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
 134             symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
 135         if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
 136             strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
 137     }
 138
 139     if (slide == _not(size_t) || symbols == NULL || strings == NULL)
 140         return NULL;
 141
 142     for (size_t i(0); i != stp->nsyms; ++i) {
 143         const nlist_xx *symbol(&symbols[i]);
 144         if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
 145             continue;
 146
 147         const char *nambuf(strings + symbol->n_un.n_strx);
 148         if ($strcmp(name, nambuf) != 0)
 149             continue;
 150
 151         uintptr_t value(symbol->n_value);
 152         if (value == 0)
 153             continue;
 154
 155 #ifdef __arm__
 156         if ((symbol->n_desc & N_ARM_THUMB_DEF) != 0)
 157             value |= 0x00000001;
 158 #endif
 159
 160         value += slide;
 161         return reinterpret_cast<void *>(value);
 162     }
 163
 164     return NULL;
 165 }
 166
 167 template <typename Type_>
 168 static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
 169     function = reinterpret_cast<Type_>(Symbol(mach, name));
 170 }
 171
 172 static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
 173     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 174     return Library(infos, name);
 175 }
 176
 177 void *Routine(void *arg) {
 178     Baton *baton(reinterpret_cast<Baton *>(arg));
 179
 180     const mach_header_xx *dyld(NULL);
 181     if (dyld == NULL)
 182         dyld = Library(baton, "/usr/lib/system/libdyld.dylib");
 183     if (dyld == NULL)
 184         dyld = Library(baton, "/usr/lib/libSystem.B.dylib");
 185
 186     char *(*$dlerror)();
 187     cyset($dlerror, "_dlerror", dyld);
 188
 189     void *(*$dlopen)(const char *, int);
 190     cyset($dlopen, "_dlopen", dyld);
 191
 192     void *handle($dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
 193     if (handle == NULL) {
 194         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 195         return NULL;
 196     }
 197
 198     void *(*$dlsym)(void *, const char *);
 199     cyset($dlsym, "_dlsym", dyld);
 200
 201     void (*CYHandleServer)(pid_t, char *, size_t);
 202     CYHandleServer = reinterpret_cast<void (*)(pid_t, char *, size_t)>($dlsym(handle, "CYHandleServer"));
 203     if (CYHandleServer == NULL) {
 204         $strlcpy(baton->error, $dlerror(), sizeof(baton->error));
 205         return NULL;
 206     }
 207
 208     CYHandleServer(baton->pid, baton->error, sizeof(baton->error));
 209     return NULL;
 210 }
 211
 212 extern "C" void Start(Baton *baton) {
 213     struct _pthread self;
 214     $bzero(&self, sizeof(self));
 215
 216     const mach_header_xx *pthread(NULL);
 217     if (pthread == NULL)
 218         pthread = Library(baton, "/usr/lib/system/libsystem_pthread.dylib");
 219     if (pthread == NULL)
 220         pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
 221     if (pthread == NULL)
 222         pthread = Library(baton, "/usr/lib/libSystem.B.dylib");
 223
 224     void (*$__pthread_set_self)(void **);
 225     cyset($__pthread_set_self, "___pthread_set_self", pthread);
 226
 227     self.tsd[0] = &self;
 228     $__pthread_set_self(&self.tsd[0]);
 229
 230     int (*$pthread_attr_init)(pthread_attr_t *);
 231     cyset($pthread_attr_init, "_pthread_attr_init", pthread);
 232
 233 #if 0
 234     pthread_attr_t attr;
 235     $pthread_attr_init(&attr);
 236
 237     int (*$pthread_attr_setdetachstate)(pthread_attr_t *, int);
 238     cyset($pthread_attr_setdetachstate, "_pthread_attr_setdetachstate", pthread);
 239
 240     $pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 241 #endif
 242
 243     int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
 244     cyset($pthread_create, "_pthread_create", pthread);
 245
 246     pthread_t thread;
 247     $pthread_create(&thread, NULL, &Routine, baton);
 248
 249 #if 0
 250     int (*$pthread_attr_destroy)(pthread_attr_t *);
 251     cyset($pthread_attr_destroy, "_pthread_attr_destroy", pthread);
 252
 253     $pthread_attr_destroy(&attr);
 254 #endif
 255
 256     int (*$pthread_join)(pthread_t, void **);
 257     cyset($pthread_join, "_pthread_join", pthread);
 258
 259     void *status;
 260     $pthread_join(thread, &status);
 261
 262     const mach_header_xx *kernel(NULL);
 263     if (kernel == NULL)
 264         kernel = Library(baton, "/usr/lib/system/libsystem_kernel.dylib");
 265     if (kernel == NULL)
 266         kernel = Library(baton, "/usr/lib/libSystem.B.dylib");
 267
 268     mach_port_t (*$mach_thread_self)();
 269     cyset($mach_thread_self, "_mach_thread_self", kernel);
 270
 271     kern_return_t (*$thread_terminate)(thread_act_t);
 272     cyset($thread_terminate, "_thread_terminate", kernel);
 273
 274     $thread_terminate($mach_thread_self());
 275 }