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
20char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
21
22static FILE *config_file;
23static const char *config_file_name;
24static int config_linenr;
25static int config_file_eof;
26
27static const char *config_exclusive_filename;
28
29static 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
55static 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
121static inline int iskeychar(int c)
122{
123	return isalnum(c) || c == '-' || c == '_';
124}
125
126static 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
157static 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
193static 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
213static 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
269static 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
288static 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
302static 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
309int 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
317static 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
332int 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
338const char *perf_config_dirname(const char *name, const char *value)
339{
340	if (!name)
341		return NULL;
342	return value;
343}
344
345static 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
352int 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
362static 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
380static 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
388static 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
394static int perf_config_system(void)
395{
396	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
397}
398
399static int perf_config_global(void)
400{
401	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
402}
403
404int 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;
443out_free:
444		free(user_config);
445	}
446out:
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 */
456int config_error_nonbool(const char *var)
457{
458	return error("Missing value for '%s'", var);
459}
460
461struct buildid_dir_config {
462	char *dir;
463};
464
465static 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
482static 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
489void 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