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