xref: /haiku/src/system/libroot/os/image.cpp (revision 9e25244c5e9051f6cd333820d6332397361abd6c)
1 /*
2  * Copyright 2003-2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
3  * Distributed under the terms of the MIT License.
4  */
5 
6 #include <image.h>
7 #include <image_private.h>
8 
9 #include <stdlib.h>
10 #include <string.h>
11 
12 #include <algorithm>
13 #include <new>
14 
15 #include <fs_attr.h>
16 
17 #include <AutoDeleter.h>
18 
19 #include <libroot_private.h>
20 #include <runtime_loader.h>
21 #include <syscalls.h>
22 #include <syscall_load_image.h>
23 #include <user_runtime.h>
24 
25 
26 struct EnvironmentFilter {
27 	EnvironmentFilter()
28 		:
29 		fBuffer(NULL),
30 		fEntries(NULL),
31 		fBufferSize(0),
32 		fEntryCount(0),
33 		fAdditionalEnvCount(0),
34 		fNextEntryIndex(0)
35 	{
36 	}
37 
38 	~EnvironmentFilter()
39 	{
40 		free(fBuffer);
41 		delete[] fEntries;
42 	}
43 
44 	void Init(const char* path, const char* const* env, size_t envCount)
45 	{
46 		FileDescriptorCloser fd(open(path, O_RDONLY));
47 		if (!fd.IsSet())
48 			return;
49 
50 		static const char* const kEnvAttribute = "SYS:ENV";
51 		attr_info info;
52 		if (fs_stat_attr(fd.Get(), kEnvAttribute, &info) < 0)
53 			return;
54 
55 		_Init(fd.Get(), kEnvAttribute, info.size, env, envCount);
56 	}
57 
58 	size_t AdditionalSlotsNeeded() const
59 	{
60 		return fAdditionalEnvCount;
61 	}
62 
63 	size_t AdditionalSizeNeeded() const
64 	{
65 		return fBufferSize + fAdditionalEnvCount * sizeof(char*);
66 	}
67 
68 	size_t PrepareSlot(const char* env, int32 index, char* buffer)
69 	{
70 		if (fNextEntryIndex < fEntryCount
71 			&& fEntries[fNextEntryIndex].index == index) {
72 			env = fEntries[fNextEntryIndex].replacement;
73 			fNextEntryIndex++;
74 		}
75 
76 		return _FillSlot(env, buffer);
77 	}
78 
79 	void PrepareAdditionalSlots(char**& slot, char*& buffer)
80 	{
81 		for (size_t i = 0; i < fAdditionalEnvCount; i++) {
82 			size_t envSize = _FillSlot(fEntries[i].replacement, buffer);
83 			*slot++ = buffer;
84 			buffer += envSize;
85 		}
86 	}
87 
88 private:
89 	void _Init(int fd, const char* attribute, size_t size,
90 		const char* const* env, size_t envCount)
91 	{
92 		if (size == 0)
93 			return;
94 
95 		// read the attribute
96 		char* buffer = (char*)malloc(size + 1);
97 		if (buffer == NULL)
98 			return;
99 		MemoryDeleter bufferDeleter(buffer);
100 
101 		ssize_t bytesRead = fs_read_attr(fd, attribute, B_STRING_TYPE, 0,
102 			buffer, size);
103 		if (bytesRead < 0 || (size_t)bytesRead != size)
104 			return;
105 		buffer[size] = '\0';
106 
107 		// deescape the buffer and count the entries
108 		size_t entryCount = 1;
109 		char* out = buffer;
110 		for (const char* c = buffer; *c != '\0'; c++) {
111 			if (*c == '\\') {
112 				c++;
113 				if (*c == '\0')
114 					break;
115 				if (*c == '0') {
116 					*out++ = '\0';
117 					entryCount++;
118 				} else
119 					*out++ = *c;
120 			} else
121 				*out++ = *c;
122 		}
123 		*out++ = '\0';
124 		size = out - buffer + 1;
125 
126 		// create an entry array
127 		fEntries = new(std::nothrow) Entry[entryCount];
128 		if (fEntries == NULL)
129 			return;
130 
131 		bufferDeleter.Detach();
132 		fBuffer = buffer;
133 		fBufferSize = size;
134 
135 		// init the entries
136 		out = buffer;
137 		for (size_t i = 0; i < entryCount; i++) {
138 			const char* separator = strchr(out, '=');
139 			if (separator != NULL && separator != out) {
140 				fEntries[fEntryCount].replacement = out;
141 				fEntries[fEntryCount].index = _FindEnvEntry(env, envCount, out,
142 					separator - out);
143 				if (fEntries[fEntryCount].index < 0)
144 					fAdditionalEnvCount++;
145 				fEntryCount++;
146 			}
147 			out += strlen(out) + 1;
148 		}
149 
150 		if (fEntryCount > 1)
151 			std::sort(fEntries, fEntries + fEntryCount);
152 
153 		// Advance fNextEntryIndex to the first entry pointing to an existing
154 		// env variable.
155 		while (fNextEntryIndex < fEntryCount
156 			&& fEntries[fNextEntryIndex].index < 0) {
157 			fNextEntryIndex++;
158 		}
159 	}
160 
161 	int32 _FindEnvEntry(const char* const* env, size_t envCount,
162 		const char* variable, size_t variableLength)
163 	{
164 		for (size_t i = 0; i < envCount; i++) {
165 			if (strncmp(env[i], variable, variableLength) == 0
166 				&& env[i][variableLength] == '=') {
167 				return i;
168 			}
169 		}
170 
171 		return -1;
172 	}
173 
174 	size_t _FillSlot(const char* env, char* buffer)
175 	{
176 		size_t envSize = strlen(env) + 1;
177 		memcpy(buffer, env, envSize);
178 		return envSize;
179 	}
180 
181 private:
182 	struct Entry {
183 		char*	replacement;
184 		int32	index;
185 
186 		bool operator<(const Entry& other) const
187 		{
188 			return index < other.index;
189 		}
190 	};
191 
192 private:
193 	char*	fBuffer;
194 	Entry*	fEntries;
195 	size_t	fBufferSize;
196 	size_t	fEntryCount;
197 	size_t	fAdditionalEnvCount;
198 	size_t	fNextEntryIndex;
199 };
200 
201 
202 thread_id
203 __load_image_at_path(const char* path, int32 argCount, const char **args,
204 	const char **environ)
205 {
206 	char invoker[B_FILE_NAME_LENGTH];
207 	char **newArgs = NULL;
208 	int32 envCount = 0;
209 	thread_id thread;
210 
211 	if (argCount < 1 || environ == NULL)
212 		return B_BAD_VALUE;
213 
214 	// test validity of executable + support for scripts
215 	{
216 		status_t status = __test_executable(path, invoker);
217 		if (status < B_OK)
218 			return status;
219 
220 		if (invoker[0]) {
221 			status = __parse_invoke_line(invoker, &newArgs,
222 				(char * const **)&args, &argCount, path);
223 			if (status < B_OK)
224 				return status;
225 		}
226 	}
227 
228 	// count environment variables
229 	while (environ[envCount] != NULL)
230 		envCount++;
231 
232 	char** flatArgs = NULL;
233 	size_t flatArgsSize;
234 	status_t status = __flatten_process_args(args, argCount, environ,
235 		&envCount, path, &flatArgs, &flatArgsSize);
236 
237 	if (status == B_OK) {
238 		thread = _kern_load_image(flatArgs, flatArgsSize, argCount, envCount,
239 			B_NORMAL_PRIORITY, B_WAIT_TILL_LOADED, -1, 0);
240 
241 		free(flatArgs);
242 	} else
243 		thread = status;
244 
245 	free(newArgs);
246 	return thread;
247 }
248 
249 
250 thread_id
251 load_image(int32 argCount, const char **args, const char **environ)
252 {
253 	return __load_image_at_path(args[0], argCount, args, environ);
254 }
255 
256 
257 image_id
258 load_add_on(char const *name)
259 {
260 	if (name == NULL)
261 		return B_BAD_VALUE;
262 
263 	return __gRuntimeLoader->load_add_on(name, 0);
264 }
265 
266 
267 status_t
268 unload_add_on(image_id id)
269 {
270 	return __gRuntimeLoader->unload_add_on(id);
271 }
272 
273 
274 status_t
275 get_image_symbol(image_id id, char const *symbolName, int32 symbolType,
276 	void **_location)
277 {
278 	return __gRuntimeLoader->get_image_symbol(id, symbolName, symbolType,
279 		false, NULL, _location);
280 }
281 
282 
283 status_t
284 get_image_symbol_etc(image_id id, char const *symbolName, int32 symbolType,
285 	bool recursive, image_id *_inImage, void **_location)
286 {
287 	return __gRuntimeLoader->get_image_symbol(id, symbolName, symbolType,
288 		recursive, _inImage, _location);
289 }
290 
291 
292 status_t
293 get_nth_image_symbol(image_id id, int32 num, char *nameBuffer, int32 *_nameLength,
294 	int32 *_symbolType, void **_location)
295 {
296 	return __gRuntimeLoader->get_nth_image_symbol(id, num, nameBuffer, _nameLength, _symbolType, _location);
297 }
298 
299 
300 status_t
301 _get_image_info(image_id id, image_info *info, size_t infoSize)
302 {
303 	return _kern_get_image_info(id, info, infoSize);
304 }
305 
306 
307 status_t
308 _get_next_image_info(team_id team, int32 *cookie, image_info *info, size_t infoSize)
309 {
310 	return _kern_get_next_image_info(team, cookie, info, infoSize);
311 }
312 
313 
314 void
315 clear_caches(void *address, size_t length, uint32 flags)
316 {
317 	_kern_clear_caches(address, length, flags);
318 }
319 
320 
321 //	#pragma mark -
322 
323 
324 status_t
325 __look_up_in_path(const char *file, char *buffer)
326 {
327 	// get the PATH
328 	const char* paths = getenv("PATH");
329 	if (paths == NULL)
330 		return B_ENTRY_NOT_FOUND;
331 
332 	int fileNameLen = strlen(file);
333 
334 	// iterate through the paths
335 	const char* pathEnd = paths - 1;
336 	while (pathEnd != NULL) {
337 		paths = pathEnd + 1;
338 		pathEnd = strchr(paths, ':');
339 		int pathLen = (pathEnd ? pathEnd - paths : strlen(paths));
340 
341 		// We skip empty paths and those that would become too long.
342 		// The latter is not really correct, but practically irrelevant.
343 		if (pathLen == 0
344 			|| pathLen + 1 + fileNameLen >= B_PATH_NAME_LENGTH) {
345 			continue;
346 		}
347 
348 		// concatinate the program path
349 		char path[B_PATH_NAME_LENGTH];
350 		memcpy(path, paths, pathLen);
351 		path[pathLen] = '\0';
352 
353 		if (path[pathLen - 1] != '/')
354 			strcat(path, "/");
355 		strcat(path, file);
356 
357 		// check whether it is a file
358 		struct stat st;
359 		if (stat(path, &st) != 0 || !S_ISREG(st.st_mode))
360 			continue;
361 
362 		// if executable, we've found what we are looking for
363 		if (access(path, X_OK) == 0) {
364 			strlcpy(buffer, path, B_PATH_NAME_LENGTH);
365 			return B_OK;
366 		}
367 	}
368 
369 	return B_ENTRY_NOT_FOUND;
370 }
371 
372 
373 static char *
374 next_argument(char **_start, bool separate)
375 {
376 	char *line = *_start;
377 	char quote = 0;
378 	int32 i;
379 
380 	// eliminate leading spaces
381 	while (line[0] == ' ')
382 		line++;
383 
384 	if (line[0] == '"' || line[0] == '\'') {
385 		quote = line[0];
386 		line++;
387 	}
388 
389 	if (!line[0])
390 		return NULL;
391 
392 	for (i = 0;; i++) {
393 		if (line[i] == '\\' && line[i + 1] != '\0')
394 			continue;
395 
396 		if (line[i] == '\0') {
397 			*_start = &line[i];
398 			return line;
399 		}
400 		if ((!quote && line[i] == ' ') || line[i] == quote) {
401 			// argument separator!
402 			if (separate)
403 				line[i] = '\0';
404 			*_start = &line[i + 1];
405 			return line;
406 		}
407 	}
408 
409 	return NULL;
410 }
411 
412 
413 status_t
414 __parse_invoke_line(char *invoker, char ***_newArgs,
415 	char * const **_oldArgs, int32 *_argCount, const char *arg0)
416 {
417 	int32 i, count = 0;
418 	char *arg = invoker;
419 	char **newArgs;
420 
421 	// count arguments in the line
422 
423 	while (next_argument(&arg, false)) {
424 		count++;
425 	}
426 
427 	// this is a shell script and requires special treatment
428 	newArgs = (char**)malloc((*_argCount + count + 1) * sizeof(void *));
429 	if (newArgs == NULL)
430 		return B_NO_MEMORY;
431 
432 	// copy invoker and old arguments and to newArgs
433 
434 	for (i = 0; (arg = next_argument(&invoker, true)) != NULL; i++) {
435 		newArgs[i] = arg;
436 	}
437 	for (i = 0; i < *_argCount; i++) {
438 		if (i == 0)
439 			newArgs[i + count] = (char*)arg0;
440 		else
441 			newArgs[i + count] = (char *)(*_oldArgs)[i];
442 	}
443 
444 	newArgs[i + count] = NULL;
445 
446 	*_newArgs = newArgs;
447 	*_oldArgs = (char * const *)newArgs;
448 	*_argCount += count;
449 
450 	return B_OK;
451 }
452 
453 
454 status_t
455 __get_next_image_dependency(image_id id, uint32 *cookie, const char **_name)
456 {
457 	return __gRuntimeLoader->get_next_image_dependency(id, cookie, _name);
458 }
459 
460 
461 status_t
462 __test_executable(const char *path, char *invoker)
463 {
464 	return __gRuntimeLoader->test_executable(path, invoker);
465 }
466 
467 
468 /*!	Allocates a flat buffer and copies the argument and environment strings
469 	into it. The buffer starts with a char* array which contains pointers to
470 	the strings of the arguments and environment, followed by the strings. Both
471 	arguments and environment arrays are NULL-terminated.
472 
473 	If executablePath is non-NULL, it should refer to the executable to be
474 	executed. If the executable file specifies changes to environment variable
475 	values, those will be performed.
476 */
477 status_t
478 __flatten_process_args(const char* const* args, int32 argCount,
479 	const char* const* env, int32* _envCount, const char* executablePath,
480 	char*** _flatArgs, size_t* _flatSize)
481 {
482 	if (args == NULL || _envCount == NULL || (env == NULL && *_envCount != 0))
483 		return B_BAD_VALUE;
484 
485 	int32 envCount = *_envCount;
486 
487 	// determine total needed size
488 	int32 argSize = 0;
489 	for (int32 i = 0; i < argCount; i++) {
490 		if (args[i] == NULL)
491 			return B_BAD_VALUE;
492 		argSize += strlen(args[i]) + 1;
493 	}
494 
495 	int32 envSize = 0;
496 	for (int32 i = 0; i < envCount; i++) {
497 		if (env[i] == NULL)
498 			return B_BAD_VALUE;
499 		envSize += strlen(env[i]) + 1;
500 	}
501 
502 	EnvironmentFilter envFilter;
503 	if (executablePath != NULL)
504 		envFilter.Init(executablePath, env, envCount);
505 
506 	int32 totalSlotCount = argCount + envCount + 2
507 		+ envFilter.AdditionalSlotsNeeded();
508 	int32 size = totalSlotCount * sizeof(char*) + argSize + envSize
509 		+ envFilter.AdditionalSizeNeeded();
510 	if (size > MAX_PROCESS_ARGS_SIZE)
511 		return B_TOO_MANY_ARGS;
512 
513 	// allocate space
514 	char** flatArgs = (char**)malloc(size);
515 	if (flatArgs == NULL)
516 		return B_NO_MEMORY;
517 
518 	char** slot = flatArgs;
519 	char* stringSpace = (char*)(flatArgs + totalSlotCount);
520 
521 	// copy arguments and environment
522 	for (int32 i = 0; i < argCount; i++) {
523 		int32 argSize = strlen(args[i]) + 1;
524 		memcpy(stringSpace, args[i], argSize);
525 		*slot++ = stringSpace;
526 		stringSpace += argSize;
527 	}
528 
529 	*slot++ = NULL;
530 
531 	for (int32 i = 0; i < envCount; i++) {
532 		size_t envSize = envFilter.PrepareSlot(env[i], i, stringSpace);
533 		*slot++ = stringSpace;
534 		stringSpace += envSize;
535 	}
536 
537 	envFilter.PrepareAdditionalSlots(slot, stringSpace);
538 
539 	*slot++ = NULL;
540 
541 	*_envCount = envCount + envFilter.AdditionalSlotsNeeded();
542 	*_flatArgs = flatArgs;
543 	*_flatSize = stringSpace - (char*)flatArgs;
544 	return B_OK;
545 }
546 
547 
548 extern "C" void _call_init_routines_(void);
549 void
550 _call_init_routines_(void)
551 {
552 	// This is called by the original BeOS startup code.
553 	// We don't need it, because our loader already does the job, right?
554 }
555 
556