xref: /openbmc/linux/tools/perf/util/config.c (revision a91c3fb2) 
1 /*
2  * config.c
3  *
4  * Helper functions for parsing config items.
5  * Originally copied from GIT source.
6  *
7  * Copyright (C) Linus Torvalds, 2005
8  * Copyright (C) Johannes Schindelin, 2005
9  *
10  */
11 #include "util.h"
12 #include "cache.h"
13 #include "exec_cmd.h"
14 
15 #define MAXNAME (256)
16 
17 #define DEBUG_CACHE_DIR ".debug"
18 
19 
20 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
21 
22 static FILE *config_file;
23 static const char *config_file_name;
24 static int config_linenr;
25 static int config_file_eof;
26 
27 static const char *config_exclusive_filename;
28 
29 static int get_next_char(void)
30 {
31 	int c;
32 	FILE *f;
33 
34 	c = '\n';
35 	if ((f = config_file) != NULL) {
36 		c = fgetc(f);
37 		if (c == '\r') {
38 			/* DOS like systems */
39 			c = fgetc(f);
40 			if (c != '\n') {
41 				ungetc(c, f);
42 				c = '\r';
43 			}
44 		}
45 		if (c == '\n')
46 			config_linenr++;
47 		if (c == EOF) {
48 			config_file_eof = 1;
49 			c = '\n';
50 		}
51 	}
52 	return c;
53 }
54 
55 static char *parse_value(void)
56 {
57 	static char value[1024];
58 	int quote = 0, comment = 0, space = 0;
59 	size_t len = 0;
60 
61 	for (;;) {
62 		int c = get_next_char();
63 
64 		if (len >= sizeof(value) - 1)
65 			return NULL;
66 		if (c == '\n') {
67 			if (quote)
68 				return NULL;
69 			value[len] = 0;
70 			return value;
71 		}
72 		if (comment)
73 			continue;
74 		if (isspace(c) && !quote) {
75 			space = 1;
76 			continue;
77 		}
78 		if (!quote) {
79 			if (c == ';' || c == '#') {
80 				comment = 1;
81 				continue;
82 			}
83 		}
84 		if (space) {
85 			if (len)
86 				value[len++] = ' ';
87 			space = 0;
88 		}
89 		if (c == '\\') {
90 			c = get_next_char();
91 			switch (c) {
92 			case '\n':
93 				continue;
94 			case 't':
95 				c = '\t';
96 				break;
97 			case 'b':
98 				c = '\b';
99 				break;
100 			case 'n':
101 				c = '\n';
102 				break;
103 			/* Some characters escape as themselves */
104 			case '\\': case '"':
105 				break;
106 			/* Reject unknown escape sequences */
107 			default:
108 				return NULL;
109 			}
110 			value[len++] = c;
111 			continue;
112 		}
113 		if (c == '"') {
114 			quote = 1-quote;
115 			continue;
116 		}
117 		value[len++] = c;
118 	}
119 }
120 
121 static inline int iskeychar(int c)
122 {
123 	return isalnum(c) || c == '-' || c == '_';
124 }
125 
126 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
127 {
128 	int c;
129 	char *value;
130 
131 	/* Get the full name */
132 	for (;;) {
133 		c = get_next_char();
134 		if (config_file_eof)
135 			break;
136 		if (!iskeychar(c))
137 			break;
138 		name[len++] = c;
139 		if (len >= MAXNAME)
140 			return -1;
141 	}
142 	name[len] = 0;
143 	while (c == ' ' || c == '\t')
144 		c = get_next_char();
145 
146 	value = NULL;
147 	if (c != '\n') {
148 		if (c != '=')
149 			return -1;
150 		value = parse_value();
151 		if (!value)
152 			return -1;
153 	}
154 	return fn(name, value, data);
155 }
156 
157 static int get_extended_base_var(char *name, int baselen, int c)
158 {
159 	do {
160 		if (c == '\n')
161 			return -1;
162 		c = get_next_char();
163 	} while (isspace(c));
164 
165 	/* We require the format to be '[base "extension"]' */
166 	if (c != '"')
167 		return -1;
168 	name[baselen++] = '.';
169 
170 	for (;;) {
171 		int ch = get_next_char();
172 
173 		if (ch == '\n')
174 			return -1;
175 		if (ch == '"')
176 			break;
177 		if (ch == '\\') {
178 			ch = get_next_char();
179 			if (ch == '\n')
180 				return -1;
181 		}
182 		name[baselen++] = ch;
183 		if (baselen > MAXNAME / 2)
184 			return -1;
185 	}
186 
187 	/* Final ']' */
188 	if (get_next_char() != ']')
189 		return -1;
190 	return baselen;
191 }
192 
193 static int get_base_var(char *name)
194 {
195 	int baselen = 0;
196 
197 	for (;;) {
198 		int c = get_next_char();
199 		if (config_file_eof)
200 			return -1;
201 		if (c == ']')
202 			return baselen;
203 		if (isspace(c))
204 			return get_extended_base_var(name, baselen, c);
205 		if (!iskeychar(c) && c != '.')
206 			return -1;
207 		if (baselen > MAXNAME / 2)
208 			return -1;
209 		name[baselen++] = tolower(c);
210 	}
211 }
212 
213 static int perf_parse_file(config_fn_t fn, void *data)
214 {
215 	int comment = 0;
216 	int baselen = 0;
217 	static char var[MAXNAME];
218 
219 	/* U+FEFF Byte Order Mark in UTF8 */
220 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
221 	const unsigned char *bomptr = utf8_bom;
222 
223 	for (;;) {
224 		int c = get_next_char();
225 		if (bomptr && *bomptr) {
226 			/* We are at the file beginning; skip UTF8-encoded BOM
227 			 * if present. Sane editors won't put this in on their
228 			 * own, but e.g. Windows Notepad will do it happily. */
229 			if ((unsigned char) c == *bomptr) {
230 				bomptr++;
231 				continue;
232 			} else {
233 				/* Do not tolerate partial BOM. */
234 				if (bomptr != utf8_bom)
235 					break;
236 				/* No BOM at file beginning. Cool. */
237 				bomptr = NULL;
238 			}
239 		}
240 		if (c == '\n') {
241 			if (config_file_eof)
242 				return 0;
243 			comment = 0;
244 			continue;
245 		}
246 		if (comment || isspace(c))
247 			continue;
248 		if (c == '#' || c == ';') {
249 			comment = 1;
250 			continue;
251 		}
252 		if (c == '[') {
253 			baselen = get_base_var(var);
254 			if (baselen <= 0)
255 				break;
256 			var[baselen++] = '.';
257 			var[baselen] = 0;
258 			continue;
259 		}
260 		if (!isalpha(c))
261 			break;
262 		var[baselen] = tolower(c);
263 		if (get_value(fn, data, var, baselen+1) < 0)
264 			break;
265 	}
266 	die("bad config file line %d in %s", config_linenr, config_file_name);
267 }
268 
269 static int parse_unit_factor(const char *end, unsigned long *val)
270 {
271 	if (!*end)
272 		return 1;
273 	else if (!strcasecmp(end, "k")) {
274 		*val *= 1024;
275 		return 1;
276 	}
277 	else if (!strcasecmp(end, "m")) {
278 		*val *= 1024 * 1024;
279 		return 1;
280 	}
281 	else if (!strcasecmp(end, "g")) {
282 		*val *= 1024 * 1024 * 1024;
283 		return 1;
284 	}
285 	return 0;
286 }
287 
288 static int perf_parse_long(const char *value, long *ret)
289 {
290 	if (value && *value) {
291 		char *end;
292 		long val = strtol(value, &end, 0);
293 		unsigned long factor = 1;
294 		if (!parse_unit_factor(end, &factor))
295 			return 0;
296 		*ret = val * factor;
297 		return 1;
298 	}
299 	return 0;
300 }
301 
302 static void die_bad_config(const char *name)
303 {
304 	if (config_file_name)
305 		die("bad config value for '%s' in %s", name, config_file_name);
306 	die("bad config value for '%s'", name);
307 }
308 
309 int perf_config_int(const char *name, const char *value)
310 {
311 	long ret = 0;
312 	if (!perf_parse_long(value, &ret))
313 		die_bad_config(name);
314 	return ret;
315 }
316 
317 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
318 {
319 	*is_bool = 1;
320 	if (!value)
321 		return 1;
322 	if (!*value)
323 		return 0;
324 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
325 		return 1;
326 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
327 		return 0;
328 	*is_bool = 0;
329 	return perf_config_int(name, value);
330 }
331 
332 int perf_config_bool(const char *name, const char *value)
333 {
334 	int discard;
335 	return !!perf_config_bool_or_int(name, value, &discard);
336 }
337 
338 const char *perf_config_dirname(const char *name, const char *value)
339 {
340 	if (!name)
341 		return NULL;
342 	return value;
343 }
344 
345 static int perf_default_core_config(const char *var __maybe_unused,
346 				    const char *value __maybe_unused)
347 {
348 	/* Add other config variables here. */
349 	return 0;
350 }
351 
352 int perf_default_config(const char *var, const char *value,
353 			void *dummy __maybe_unused)
354 {
355 	if (!prefixcmp(var, "core."))
356 		return perf_default_core_config(var, value);
357 
358 	/* Add other config variables here. */
359 	return 0;
360 }
361 
362 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
363 {
364 	int ret;
365 	FILE *f = fopen(filename, "r");
366 
367 	ret = -1;
368 	if (f) {
369 		config_file = f;
370 		config_file_name = filename;
371 		config_linenr = 1;
372 		config_file_eof = 0;
373 		ret = perf_parse_file(fn, data);
374 		fclose(f);
375 		config_file_name = NULL;
376 	}
377 	return ret;
378 }
379 
380 static const char *perf_etc_perfconfig(void)
381 {
382 	static const char *system_wide;
383 	if (!system_wide)
384 		system_wide = system_path(ETC_PERFCONFIG);
385 	return system_wide;
386 }
387 
388 static int perf_env_bool(const char *k, int def)
389 {
390 	const char *v = getenv(k);
391 	return v ? perf_config_bool(k, v) : def;
392 }
393 
394 static int perf_config_system(void)
395 {
396 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
397 }
398 
399 static int perf_config_global(void)
400 {
401 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
402 }
403 
404 int perf_config(config_fn_t fn, void *data)
405 {
406 	int ret = 0, found = 0;
407 	const char *home = NULL;
408 
409 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
410 	if (config_exclusive_filename)
411 		return perf_config_from_file(fn, config_exclusive_filename, data);
412 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
413 		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
414 					    data);
415 		found += 1;
416 	}
417 
418 	home = getenv("HOME");
419 	if (perf_config_global() && home) {
420 		char *user_config = strdup(mkpath("%s/.perfconfig", home));
421 		struct stat st;
422 
423 		if (user_config == NULL) {
424 			warning("Not enough memory to process %s/.perfconfig, "
425 				"ignoring it.", home);
426 			goto out;
427 		}
428 
429 		if (stat(user_config, &st) < 0)
430 			goto out_free;
431 
432 		if (st.st_uid && (st.st_uid != geteuid())) {
433 			warning("File %s not owned by current user or root, "
434 				"ignoring it.", user_config);
435 			goto out_free;
436 		}
437 
438 		if (!st.st_size)
439 			goto out_free;
440 
441 		ret += perf_config_from_file(fn, user_config, data);
442 		found += 1;
443 out_free:
444 		free(user_config);
445 	}
446 out:
447 	if (found == 0)
448 		return -1;
449 	return ret;
450 }
451 
452 /*
453  * Call this to report error for your variable that should not
454  * get a boolean value (i.e. "[my] var" means "true").
455  */
456 int config_error_nonbool(const char *var)
457 {
458 	return error("Missing value for '%s'", var);
459 }
460 
461 struct buildid_dir_config {
462 	char *dir;
463 };
464 
465 static int buildid_dir_command_config(const char *var, const char *value,
466 				      void *data)
467 {
468 	struct buildid_dir_config *c = data;
469 	const char *v;
470 
471 	/* same dir for all commands */
472 	if (!prefixcmp(var, "buildid.") && !strcmp(var + 8, "dir")) {
473 		v = perf_config_dirname(var, value);
474 		if (!v)
475 			return -1;
476 		strncpy(c->dir, v, MAXPATHLEN-1);
477 		c->dir[MAXPATHLEN-1] = '\0';
478 	}
479 	return 0;
480 }
481 
482 static void check_buildid_dir_config(void)
483 {
484 	struct buildid_dir_config c;
485 	c.dir = buildid_dir;
486 	perf_config(buildid_dir_command_config, &c);
487 }
488 
489 void set_buildid_dir(void)
490 {
491 	buildid_dir[0] = '\0';
492 
493 	/* try config file */
494 	check_buildid_dir_config();
495 
496 	/* default to $HOME/.debug */
497 	if (buildid_dir[0] == '\0') {
498 		char *v = getenv("HOME");
499 		if (v) {
500 			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
501 				 v, DEBUG_CACHE_DIR);
502 		} else {
503 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
504 		}
505 		buildid_dir[MAXPATHLEN-1] = '\0';
506 	}
507 	/* for communicating with external commands */
508 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
509 }
510