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#include "util/hist.h"  /* perf_hist_config */
15
16#define MAXNAME (256)
17
18#define DEBUG_CACHE_DIR ".debug"
19
20
21char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
22
23static FILE *config_file;
24static const char *config_file_name;
25static int config_linenr;
26static int config_file_eof;
27
28static const char *config_exclusive_filename;
29
30static int get_next_char(void)
31{
32	int c;
33	FILE *f;
34
35	c = '\n';
36	if ((f = config_file) != NULL) {
37		c = fgetc(f);
38		if (c == '\r') {
39			/* DOS like systems */
40			c = fgetc(f);
41			if (c != '\n') {
42				ungetc(c, f);
43				c = '\r';
44			}
45		}
46		if (c == '\n')
47			config_linenr++;
48		if (c == EOF) {
49			config_file_eof = 1;
50			c = '\n';
51		}
52	}
53	return c;
54}
55
56static char *parse_value(void)
57{
58	static char value[1024];
59	int quote = 0, comment = 0, space = 0;
60	size_t len = 0;
61
62	for (;;) {
63		int c = get_next_char();
64
65		if (len >= sizeof(value) - 1)
66			return NULL;
67		if (c == '\n') {
68			if (quote)
69				return NULL;
70			value[len] = 0;
71			return value;
72		}
73		if (comment)
74			continue;
75		if (isspace(c) && !quote) {
76			space = 1;
77			continue;
78		}
79		if (!quote) {
80			if (c == ';' || c == '#') {
81				comment = 1;
82				continue;
83			}
84		}
85		if (space) {
86			if (len)
87				value[len++] = ' ';
88			space = 0;
89		}
90		if (c == '\\') {
91			c = get_next_char();
92			switch (c) {
93			case '\n':
94				continue;
95			case 't':
96				c = '\t';
97				break;
98			case 'b':
99				c = '\b';
100				break;
101			case 'n':
102				c = '\n';
103				break;
104			/* Some characters escape as themselves */
105			case '\\': case '"':
106				break;
107			/* Reject unknown escape sequences */
108			default:
109				return NULL;
110			}
111			value[len++] = c;
112			continue;
113		}
114		if (c == '"') {
115			quote = 1-quote;
116			continue;
117		}
118		value[len++] = c;
119	}
120}
121
122static inline int iskeychar(int c)
123{
124	return isalnum(c) || c == '-' || c == '_';
125}
126
127static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
128{
129	int c;
130	char *value;
131
132	/* Get the full name */
133	for (;;) {
134		c = get_next_char();
135		if (config_file_eof)
136			break;
137		if (!iskeychar(c))
138			break;
139		name[len++] = c;
140		if (len >= MAXNAME)
141			return -1;
142	}
143	name[len] = 0;
144	while (c == ' ' || c == '\t')
145		c = get_next_char();
146
147	value = NULL;
148	if (c != '\n') {
149		if (c != '=')
150			return -1;
151		value = parse_value();
152		if (!value)
153			return -1;
154	}
155	return fn(name, value, data);
156}
157
158static int get_extended_base_var(char *name, int baselen, int c)
159{
160	do {
161		if (c == '\n')
162			return -1;
163		c = get_next_char();
164	} while (isspace(c));
165
166	/* We require the format to be '[base "extension"]' */
167	if (c != '"')
168		return -1;
169	name[baselen++] = '.';
170
171	for (;;) {
172		int ch = get_next_char();
173
174		if (ch == '\n')
175			return -1;
176		if (ch == '"')
177			break;
178		if (ch == '\\') {
179			ch = get_next_char();
180			if (ch == '\n')
181				return -1;
182		}
183		name[baselen++] = ch;
184		if (baselen > MAXNAME / 2)
185			return -1;
186	}
187
188	/* Final ']' */
189	if (get_next_char() != ']')
190		return -1;
191	return baselen;
192}
193
194static int get_base_var(char *name)
195{
196	int baselen = 0;
197
198	for (;;) {
199		int c = get_next_char();
200		if (config_file_eof)
201			return -1;
202		if (c == ']')
203			return baselen;
204		if (isspace(c))
205			return get_extended_base_var(name, baselen, c);
206		if (!iskeychar(c) && c != '.')
207			return -1;
208		if (baselen > MAXNAME / 2)
209			return -1;
210		name[baselen++] = tolower(c);
211	}
212}
213
214static int perf_parse_file(config_fn_t fn, void *data)
215{
216	int comment = 0;
217	int baselen = 0;
218	static char var[MAXNAME];
219
220	/* U+FEFF Byte Order Mark in UTF8 */
221	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
222	const unsigned char *bomptr = utf8_bom;
223
224	for (;;) {
225		int line, c = get_next_char();
226
227		if (bomptr && *bomptr) {
228			/* We are at the file beginning; skip UTF8-encoded BOM
229			 * if present. Sane editors won't put this in on their
230			 * own, but e.g. Windows Notepad will do it happily. */
231			if ((unsigned char) c == *bomptr) {
232				bomptr++;
233				continue;
234			} else {
235				/* Do not tolerate partial BOM. */
236				if (bomptr != utf8_bom)
237					break;
238				/* No BOM at file beginning. Cool. */
239				bomptr = NULL;
240			}
241		}
242		if (c == '\n') {
243			if (config_file_eof)
244				return 0;
245			comment = 0;
246			continue;
247		}
248		if (comment || isspace(c))
249			continue;
250		if (c == '#' || c == ';') {
251			comment = 1;
252			continue;
253		}
254		if (c == '[') {
255			baselen = get_base_var(var);
256			if (baselen <= 0)
257				break;
258			var[baselen++] = '.';
259			var[baselen] = 0;
260			continue;
261		}
262		if (!isalpha(c))
263			break;
264		var[baselen] = tolower(c);
265
266		/*
267		 * The get_value function might or might not reach the '\n',
268		 * so saving the current line number for error reporting.
269		 */
270		line = config_linenr;
271		if (get_value(fn, data, var, baselen+1) < 0) {
272			config_linenr = line;
273			break;
274		}
275	}
276	die("bad config file line %d in %s", config_linenr, config_file_name);
277}
278
279static int parse_unit_factor(const char *end, unsigned long *val)
280{
281	if (!*end)
282		return 1;
283	else if (!strcasecmp(end, "k")) {
284		*val *= 1024;
285		return 1;
286	}
287	else if (!strcasecmp(end, "m")) {
288		*val *= 1024 * 1024;
289		return 1;
290	}
291	else if (!strcasecmp(end, "g")) {
292		*val *= 1024 * 1024 * 1024;
293		return 1;
294	}
295	return 0;
296}
297
298static int perf_parse_llong(const char *value, long long *ret)
299{
300	if (value && *value) {
301		char *end;
302		long long val = strtoll(value, &end, 0);
303		unsigned long factor = 1;
304
305		if (!parse_unit_factor(end, &factor))
306			return 0;
307		*ret = val * factor;
308		return 1;
309	}
310	return 0;
311}
312
313static int perf_parse_long(const char *value, long *ret)
314{
315	if (value && *value) {
316		char *end;
317		long val = strtol(value, &end, 0);
318		unsigned long factor = 1;
319		if (!parse_unit_factor(end, &factor))
320			return 0;
321		*ret = val * factor;
322		return 1;
323	}
324	return 0;
325}
326
327static void die_bad_config(const char *name)
328{
329	if (config_file_name)
330		die("bad config value for '%s' in %s", name, config_file_name);
331	die("bad config value for '%s'", name);
332}
333
334u64 perf_config_u64(const char *name, const char *value)
335{
336	long long ret = 0;
337
338	if (!perf_parse_llong(value, &ret))
339		die_bad_config(name);
340	return (u64) ret;
341}
342
343int perf_config_int(const char *name, const char *value)
344{
345	long ret = 0;
346	if (!perf_parse_long(value, &ret))
347		die_bad_config(name);
348	return ret;
349}
350
351static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
352{
353	*is_bool = 1;
354	if (!value)
355		return 1;
356	if (!*value)
357		return 0;
358	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
359		return 1;
360	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
361		return 0;
362	*is_bool = 0;
363	return perf_config_int(name, value);
364}
365
366int perf_config_bool(const char *name, const char *value)
367{
368	int discard;
369	return !!perf_config_bool_or_int(name, value, &discard);
370}
371
372const char *perf_config_dirname(const char *name, const char *value)
373{
374	if (!name)
375		return NULL;
376	return value;
377}
378
379static int perf_default_core_config(const char *var __maybe_unused,
380				    const char *value __maybe_unused)
381{
382	/* Add other config variables here. */
383	return 0;
384}
385
386static int perf_ui_config(const char *var, const char *value)
387{
388	/* Add other config variables here. */
389	if (!strcmp(var, "ui.show-headers")) {
390		symbol_conf.show_hist_headers = perf_config_bool(var, value);
391		return 0;
392	}
393	return 0;
394}
395
396int perf_default_config(const char *var, const char *value,
397			void *dummy __maybe_unused)
398{
399	if (!prefixcmp(var, "core."))
400		return perf_default_core_config(var, value);
401
402	if (!prefixcmp(var, "hist."))
403		return perf_hist_config(var, value);
404
405	if (!prefixcmp(var, "ui."))
406		return perf_ui_config(var, value);
407
408	if (!prefixcmp(var, "call-graph."))
409		return perf_callchain_config(var, value);
410
411	/* Add other config variables here. */
412	return 0;
413}
414
415static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
416{
417	int ret;
418	FILE *f = fopen(filename, "r");
419
420	ret = -1;
421	if (f) {
422		config_file = f;
423		config_file_name = filename;
424		config_linenr = 1;
425		config_file_eof = 0;
426		ret = perf_parse_file(fn, data);
427		fclose(f);
428		config_file_name = NULL;
429	}
430	return ret;
431}
432
433static const char *perf_etc_perfconfig(void)
434{
435	static const char *system_wide;
436	if (!system_wide)
437		system_wide = system_path(ETC_PERFCONFIG);
438	return system_wide;
439}
440
441static int perf_env_bool(const char *k, int def)
442{
443	const char *v = getenv(k);
444	return v ? perf_config_bool(k, v) : def;
445}
446
447static int perf_config_system(void)
448{
449	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
450}
451
452static int perf_config_global(void)
453{
454	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
455}
456
457int perf_config(config_fn_t fn, void *data)
458{
459	int ret = 0, found = 0;
460	const char *home = NULL;
461
462	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
463	if (config_exclusive_filename)
464		return perf_config_from_file(fn, config_exclusive_filename, data);
465	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
466		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
467					    data);
468		found += 1;
469	}
470
471	home = getenv("HOME");
472	if (perf_config_global() && home) {
473		char *user_config = strdup(mkpath("%s/.perfconfig", home));
474		struct stat st;
475
476		if (user_config == NULL) {
477			warning("Not enough memory to process %s/.perfconfig, "
478				"ignoring it.", home);
479			goto out;
480		}
481
482		if (stat(user_config, &st) < 0)
483			goto out_free;
484
485		if (st.st_uid && (st.st_uid != geteuid())) {
486			warning("File %s not owned by current user or root, "
487				"ignoring it.", user_config);
488			goto out_free;
489		}
490
491		if (!st.st_size)
492			goto out_free;
493
494		ret += perf_config_from_file(fn, user_config, data);
495		found += 1;
496out_free:
497		free(user_config);
498	}
499out:
500	if (found == 0)
501		return -1;
502	return ret;
503}
504
505/*
506 * Call this to report error for your variable that should not
507 * get a boolean value (i.e. "[my] var" means "true").
508 */
509int config_error_nonbool(const char *var)
510{
511	return error("Missing value for '%s'", var);
512}
513
514struct buildid_dir_config {
515	char *dir;
516};
517
518static int buildid_dir_command_config(const char *var, const char *value,
519				      void *data)
520{
521	struct buildid_dir_config *c = data;
522	const char *v;
523
524	/* same dir for all commands */
525	if (!strcmp(var, "buildid.dir")) {
526		v = perf_config_dirname(var, value);
527		if (!v)
528			return -1;
529		strncpy(c->dir, v, MAXPATHLEN-1);
530		c->dir[MAXPATHLEN-1] = '\0';
531	}
532	return 0;
533}
534
535static void check_buildid_dir_config(void)
536{
537	struct buildid_dir_config c;
538	c.dir = buildid_dir;
539	perf_config(buildid_dir_command_config, &c);
540}
541
542void set_buildid_dir(const char *dir)
543{
544	if (dir)
545		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
546
547	/* try config file */
548	if (buildid_dir[0] == '\0')
549		check_buildid_dir_config();
550
551	/* default to $HOME/.debug */
552	if (buildid_dir[0] == '\0') {
553		char *v = getenv("HOME");
554		if (v) {
555			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
556				 v, DEBUG_CACHE_DIR);
557		} else {
558			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
559		}
560		buildid_dir[MAXPATHLEN-1] = '\0';
561	}
562	/* for communicating with external commands */
563	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
564}
565