1 /* 2 * Copyright 2005-2009, Axel Dörfler, axeld@pinc-software.de. 3 * Distributed under the terms of the MIT License. 4 * 5 * Copyright 2002, Manuel J. Petit. All rights reserved. 6 * Distributed under the terms of the NewOS License. 7 */ 8 9 10 #include "runtime_loader_private.h" 11 12 #include <syscalls.h> 13 #include <user_runtime.h> 14 15 #include <directories.h> 16 17 #include <string.h> 18 #include <stdlib.h> 19 #include <sys/stat.h> 20 21 #include <algorithm> 22 23 24 struct user_space_program_args *gProgramArgs; 25 26 27 static const char * 28 search_path_for_type(image_type type) 29 { 30 const char *path = NULL; 31 32 switch (type) { 33 case B_APP_IMAGE: 34 path = getenv("PATH"); 35 break; 36 case B_LIBRARY_IMAGE: 37 path = getenv("LIBRARY_PATH"); 38 break; 39 case B_ADD_ON_IMAGE: 40 path = getenv("ADDON_PATH"); 41 break; 42 43 default: 44 return NULL; 45 } 46 47 if (path != NULL) 48 return path; 49 50 // The environment variables may not have been set yet - in that case, 51 // we're returning some useful defaults. 52 // Since the kernel does not set any variables, this is also needed 53 // to start the root shell. 54 55 switch (type) { 56 case B_APP_IMAGE: 57 return kUserBinDirectory 58 // TODO: Remove! 59 ":" kCommonBinDirectory 60 ":" kGlobalBinDirectory 61 ":" kAppsDirectory 62 ":" kPreferencesDirectory 63 ":" kSystemAppsDirectory 64 ":" kSystemPreferencesDirectory 65 ":" kCommonDevelopToolsBinDirectory; 66 67 case B_LIBRARY_IMAGE: 68 return kAppLocalLibDirectory 69 ":" kUserLibDirectory 70 // TODO: Remove! 71 ":" kCommonLibDirectory 72 ":" kSystemLibDirectory; 73 74 case B_ADD_ON_IMAGE: 75 return kAppLocalAddonsDirectory 76 ":" kUserAddonsDirectory 77 // TODO: Remove! 78 ":" kSystemAddonsDirectory; 79 80 default: 81 return NULL; 82 } 83 } 84 85 86 static int 87 try_open_executable(const char *dir, int dirLength, const char *name, 88 const char *programPath, const char *compatibilitySubDir, char *path, 89 size_t pathLength) 90 { 91 size_t nameLength = strlen(name); 92 struct stat stat; 93 status_t status; 94 95 // construct the path 96 if (dirLength > 0) { 97 char *buffer = path; 98 size_t subDirLen = 0; 99 100 if (programPath == NULL) 101 programPath = gProgramArgs->program_path; 102 103 if (dirLength >= 2 && strncmp(dir, "%A", 2) == 0) { 104 // Replace %A with current app folder path (of course, 105 // this must be the first part of the path) 106 char *lastSlash = strrchr(programPath, '/'); 107 int bytesCopied; 108 109 // copy what's left (when the application name is removed) 110 if (lastSlash != NULL) { 111 strlcpy(buffer, programPath, 112 std::min((long)pathLength, lastSlash + 1 - programPath)); 113 } else 114 strlcpy(buffer, ".", pathLength); 115 116 bytesCopied = strlen(buffer); 117 buffer += bytesCopied; 118 pathLength -= bytesCopied; 119 dir += 2; 120 dirLength -= 2; 121 } else if (compatibilitySubDir != NULL) { 122 // We're looking for a library or an add-on and the executable has 123 // not been compiled with a compiler compatible with the one the 124 // OS has been built with. Thus we only look in specific subdirs. 125 subDirLen = strlen(compatibilitySubDir) + 1; 126 } 127 128 if (dirLength + 1 + subDirLen + nameLength >= pathLength) 129 return B_NAME_TOO_LONG; 130 131 memcpy(buffer, dir, dirLength); 132 buffer[dirLength] = '/'; 133 if (subDirLen > 0) { 134 memcpy(buffer + dirLength + 1, compatibilitySubDir, subDirLen - 1); 135 buffer[dirLength + subDirLen] = '/'; 136 } 137 strcpy(buffer + dirLength + 1 + subDirLen, name); 138 } else { 139 if (nameLength >= pathLength) 140 return B_NAME_TOO_LONG; 141 142 strcpy(path + dirLength + 1, name); 143 } 144 145 TRACE(("runtime_loader: try_open_container(): %s\n", path)); 146 147 // Test if the target is a symbolic link, and correct the path in this case 148 149 status = _kern_read_stat(-1, path, false, &stat, sizeof(struct stat)); 150 if (status < B_OK) 151 return status; 152 153 if (S_ISLNK(stat.st_mode)) { 154 char buffer[PATH_MAX]; 155 size_t length = PATH_MAX - 1; 156 char *lastSlash; 157 158 // it's a link, indeed 159 status = _kern_read_link(-1, path, buffer, &length); 160 if (status < B_OK) 161 return status; 162 buffer[length] = '\0'; 163 164 lastSlash = strrchr(path, '/'); 165 if (buffer[0] != '/' && lastSlash != NULL) { 166 // relative path 167 strlcpy(lastSlash + 1, buffer, lastSlash + 1 - path + pathLength); 168 } else 169 strlcpy(path, buffer, pathLength); 170 } 171 172 return _kern_open(-1, path, O_RDONLY, 0); 173 } 174 175 176 static int 177 search_executable_in_path_list(const char *name, const char *pathList, 178 int pathListLen, const char *programPath, const char *compatibilitySubDir, 179 char *pathBuffer, size_t pathBufferLength) 180 { 181 const char *pathListEnd = pathList + pathListLen; 182 status_t status = B_ENTRY_NOT_FOUND; 183 184 TRACE(("runtime_loader: search_container_in_path_list() %s in %.*s\n", name, 185 pathListLen, pathList)); 186 187 while (pathListLen > 0) { 188 const char *pathEnd = pathList; 189 int fd; 190 191 // find the next ':' or run till the end of the string 192 while (pathEnd < pathListEnd && *pathEnd != ':') 193 pathEnd++; 194 195 fd = try_open_executable(pathList, pathEnd - pathList, name, 196 programPath, compatibilitySubDir, pathBuffer, pathBufferLength); 197 if (fd >= 0) { 198 // see if it's a dir 199 struct stat stat; 200 status = _kern_read_stat(fd, NULL, true, &stat, sizeof(struct stat)); 201 if (status == B_OK) { 202 if (!S_ISDIR(stat.st_mode)) 203 return fd; 204 status = B_IS_A_DIRECTORY; 205 } 206 _kern_close(fd); 207 } 208 209 pathListLen = pathListEnd - pathEnd - 1; 210 pathList = pathEnd + 1; 211 } 212 213 return status; 214 } 215 216 217 int 218 open_executable(char *name, image_type type, const char *rpath, 219 const char *programPath, const char *compatibilitySubDir) 220 { 221 char buffer[PATH_MAX]; 222 int fd = B_ENTRY_NOT_FOUND; 223 224 if (strchr(name, '/')) { 225 // the name already contains a path, we don't have to search for it 226 fd = _kern_open(-1, name, O_RDONLY, 0); 227 if (fd >= 0 || type == B_APP_IMAGE) 228 return fd; 229 230 // can't search harder an absolute path add-on name! 231 if (type == B_ADD_ON_IMAGE && name[0] == '/') 232 return fd; 233 234 // Even though ELF specs don't say this, we give shared libraries 235 // and relative path based add-ons another chance and look 236 // them up in the usual search paths - at 237 // least that seems to be what BeOS does, and since it doesn't hurt... 238 if (type == B_LIBRARY_IMAGE) { 239 // For library (but not add-on), strip any path from name. 240 // Relative path of add-on is kept. 241 const char* paths = strrchr(name, '/') + 1; 242 memmove(name, paths, strlen(paths) + 1); 243 } 244 } 245 246 // try rpath (DT_RPATH) 247 if (rpath != NULL) { 248 // It consists of a colon-separated search path list. Optionally a 249 // second search path list follows, separated from the first by a 250 // semicolon. 251 const char *semicolon = strchr(rpath, ';'); 252 const char *firstList = (semicolon ? rpath : NULL); 253 const char *secondList = (semicolon ? semicolon + 1 : rpath); 254 // If there is no ';', we set only secondList to simplify things. 255 if (firstList) { 256 fd = search_executable_in_path_list(name, firstList, 257 semicolon - firstList, programPath, NULL, buffer, 258 sizeof(buffer)); 259 } 260 if (fd < 0) { 261 fd = search_executable_in_path_list(name, secondList, 262 strlen(secondList), programPath, NULL, buffer, sizeof(buffer)); 263 } 264 } 265 266 // If not found yet, let's evaluate the system path variables to find the 267 // shared object. 268 if (fd < 0) { 269 if (const char *paths = search_path_for_type(type)) { 270 fd = search_executable_in_path_list(name, paths, strlen(paths), 271 programPath, compatibilitySubDir, buffer, sizeof(buffer)); 272 273 // If not found and a compatibility sub directory has been 274 // specified, look again in the standard search paths. 275 if (fd == B_ENTRY_NOT_FOUND && compatibilitySubDir != NULL) { 276 fd = search_executable_in_path_list(name, paths, strlen(paths), 277 programPath, NULL, buffer, sizeof(buffer)); 278 } 279 } 280 } 281 282 if (fd >= 0) { 283 // we found it, copy path! 284 TRACE(("runtime_loader: open_executable(%s): found at %s\n", name, buffer)); 285 strlcpy(name, buffer, PATH_MAX); 286 } 287 288 return fd; 289 } 290 291 292 /*! 293 Tests if there is an executable file at the provided path. It will 294 also test if the file has a valid ELF header or is a shell script. 295 Even if the runtime loader does not need to be able to deal with 296 both types, the caller will give scripts a proper treatment. 297 */ 298 status_t 299 test_executable(const char *name, char *invoker) 300 { 301 char path[B_PATH_NAME_LENGTH]; 302 char buffer[B_FILE_NAME_LENGTH]; 303 // must be large enough to hold the ELF header 304 status_t status; 305 ssize_t length; 306 int fd; 307 308 if (name == NULL) 309 return B_BAD_VALUE; 310 311 strlcpy(path, name, sizeof(path)); 312 313 fd = open_executable(path, B_APP_IMAGE, NULL, NULL, NULL); 314 if (fd < B_OK) 315 return fd; 316 317 // see if it's executable at all 318 status = _kern_access(-1, path, X_OK, false); 319 if (status != B_OK) 320 goto out; 321 322 // read and verify the ELF header 323 324 length = _kern_read(fd, 0, buffer, sizeof(buffer)); 325 if (length < 0) { 326 status = length; 327 goto out; 328 } 329 330 status = elf_verify_header(buffer, length); 331 if (status == B_NOT_AN_EXECUTABLE) { 332 // test for shell scripts 333 if (!strncmp(buffer, "#!", 2)) { 334 char *end; 335 buffer[min_c((size_t)length, sizeof(buffer) - 1)] = '\0'; 336 337 end = strchr(buffer, '\n'); 338 if (end == NULL) { 339 status = E2BIG; 340 goto out; 341 } else 342 end[0] = '\0'; 343 344 if (invoker) 345 strcpy(invoker, buffer + 2); 346 347 status = B_OK; 348 } 349 } else if (status == B_OK) { 350 elf_ehdr *elfHeader = (elf_ehdr *)buffer; 351 if (elfHeader->e_entry == 0) { 352 // we don't like to open shared libraries 353 status = B_NOT_AN_EXECUTABLE; 354 } else if (invoker) 355 invoker[0] = '\0'; 356 } 357 358 out: 359 _kern_close(fd); 360 return status; 361 } 362 363 364 /*! 365 This is the main entry point of the runtime loader as 366 specified by its ld-script. 367 */ 368 int 369 runtime_loader(void *_args) 370 { 371 void *entry = NULL; 372 int returnCode; 373 374 gProgramArgs = (struct user_space_program_args *)_args; 375 376 // Relocate the args and env arrays -- they are organized in a contiguous 377 // buffer which the kernel just copied into user space without adjusting the 378 // pointers. 379 { 380 int32 i; 381 addr_t relocationOffset = 0; 382 383 if (gProgramArgs->arg_count > 0) 384 relocationOffset = (addr_t)gProgramArgs->args[0]; 385 else if (gProgramArgs->env_count > 0) 386 relocationOffset = (addr_t)gProgramArgs->env[0]; 387 388 // That's basically: <new buffer address> - <old buffer address>. 389 // It looks a little complicated, since we don't have the latter one at 390 // hand and thus need to reconstruct it (<first string pointer> - 391 // <arguments + environment array sizes>). 392 relocationOffset = (addr_t)gProgramArgs->args - relocationOffset 393 + (gProgramArgs->arg_count + gProgramArgs->env_count + 2) 394 * sizeof(char*); 395 396 for (i = 0; i < gProgramArgs->arg_count; i++) 397 gProgramArgs->args[i] += relocationOffset; 398 399 for (i = 0; i < gProgramArgs->env_count; i++) 400 gProgramArgs->env[i] += relocationOffset; 401 } 402 403 #if DEBUG_RLD 404 close(0); open("/dev/console", 0); /* stdin */ 405 close(1); open("/dev/console", 0); /* stdout */ 406 close(2); open("/dev/console", 0); /* stderr */ 407 #endif 408 409 if (heap_init() < B_OK) 410 return 1; 411 412 rldexport_init(); 413 rldelf_init(); 414 415 load_program(gProgramArgs->program_path, &entry); 416 417 if (entry == NULL) 418 return -1; 419 420 // call the program entry point (usually _start()) 421 returnCode = ((int (*)(int, void *, void *))entry)(gProgramArgs->arg_count, 422 gProgramArgs->args, gProgramArgs->env); 423 424 terminate_program(); 425 426 return returnCode; 427 } 428