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
get_next_char(void)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
parse_value(void)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
iskeychar(int c)121 static inline int iskeychar(int c)
122 {
123 return isalnum(c) || c == '-';
124 }
125
get_value(config_fn_t fn,void * data,char * name,unsigned int len)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
get_extended_base_var(char * name,int baselen,int c)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
get_base_var(char * name)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
perf_parse_file(config_fn_t fn,void * data)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
parse_unit_factor(const char * end,unsigned long * val)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
perf_parse_long(const char * value,long * ret)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
die_bad_config(const char * name)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
perf_config_int(const char * name,const char * value)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
perf_config_bool_or_int(const char * name,const char * value,int * is_bool)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
perf_config_bool(const char * name,const char * value)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
perf_config_dirname(const char * name,const char * value)338 const char *perf_config_dirname(const char *name, const char *value)
339 {
340 if (!name)
341 return NULL;
342 return value;
343 }
344
perf_default_core_config(const char * var __used,const char * value __used)345 static int perf_default_core_config(const char *var __used, const char *value __used)
346 {
347 /* Add other config variables here. */
348 return 0;
349 }
350
perf_default_config(const char * var,const char * value,void * dummy __used)351 int perf_default_config(const char *var, const char *value, void *dummy __used)
352 {
353 if (!prefixcmp(var, "core."))
354 return perf_default_core_config(var, value);
355
356 /* Add other config variables here. */
357 return 0;
358 }
359
perf_config_from_file(config_fn_t fn,const char * filename,void * data)360 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
361 {
362 int ret;
363 FILE *f = fopen(filename, "r");
364
365 ret = -1;
366 if (f) {
367 config_file = f;
368 config_file_name = filename;
369 config_linenr = 1;
370 config_file_eof = 0;
371 ret = perf_parse_file(fn, data);
372 fclose(f);
373 config_file_name = NULL;
374 }
375 return ret;
376 }
377
perf_etc_perfconfig(void)378 static const char *perf_etc_perfconfig(void)
379 {
380 static const char *system_wide;
381 if (!system_wide)
382 system_wide = system_path(ETC_PERFCONFIG);
383 return system_wide;
384 }
385
perf_env_bool(const char * k,int def)386 static int perf_env_bool(const char *k, int def)
387 {
388 const char *v = getenv(k);
389 return v ? perf_config_bool(k, v) : def;
390 }
391
perf_config_system(void)392 static int perf_config_system(void)
393 {
394 return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
395 }
396
perf_config_global(void)397 static int perf_config_global(void)
398 {
399 return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
400 }
401
perf_config(config_fn_t fn,void * data)402 int perf_config(config_fn_t fn, void *data)
403 {
404 int ret = 0, found = 0;
405 const char *home = NULL;
406
407 /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
408 if (config_exclusive_filename)
409 return perf_config_from_file(fn, config_exclusive_filename, data);
410 if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
411 ret += perf_config_from_file(fn, perf_etc_perfconfig(),
412 data);
413 found += 1;
414 }
415
416 home = getenv("HOME");
417 if (perf_config_global() && home) {
418 char *user_config = strdup(mkpath("%s/.perfconfig", home));
419 struct stat st;
420
421 if (user_config == NULL) {
422 warning("Not enough memory to process %s/.perfconfig, "
423 "ignoring it.", home);
424 goto out;
425 }
426
427 if (stat(user_config, &st) < 0)
428 goto out_free;
429
430 if (st.st_uid && (st.st_uid != geteuid())) {
431 warning("File %s not owned by current user or root, "
432 "ignoring it.", user_config);
433 goto out_free;
434 }
435
436 if (!st.st_size)
437 goto out_free;
438
439 ret += perf_config_from_file(fn, user_config, data);
440 found += 1;
441 out_free:
442 free(user_config);
443 }
444 out:
445 if (found == 0)
446 return -1;
447 return ret;
448 }
449
450 /*
451 * Call this to report error for your variable that should not
452 * get a boolean value (i.e. "[my] var" means "true").
453 */
config_error_nonbool(const char * var)454 int config_error_nonbool(const char *var)
455 {
456 return error("Missing value for '%s'", var);
457 }
458
459 struct buildid_dir_config {
460 char *dir;
461 };
462
buildid_dir_command_config(const char * var,const char * value,void * data)463 static int buildid_dir_command_config(const char *var, const char *value,
464 void *data)
465 {
466 struct buildid_dir_config *c = data;
467 const char *v;
468
469 /* same dir for all commands */
470 if (!prefixcmp(var, "buildid.") && !strcmp(var + 8, "dir")) {
471 v = perf_config_dirname(var, value);
472 if (!v)
473 return -1;
474 strncpy(c->dir, v, MAXPATHLEN-1);
475 c->dir[MAXPATHLEN-1] = '\0';
476 }
477 return 0;
478 }
479
check_buildid_dir_config(void)480 static void check_buildid_dir_config(void)
481 {
482 struct buildid_dir_config c;
483 c.dir = buildid_dir;
484 perf_config(buildid_dir_command_config, &c);
485 }
486
set_buildid_dir(void)487 void set_buildid_dir(void)
488 {
489 buildid_dir[0] = '\0';
490
491 /* try config file */
492 check_buildid_dir_config();
493
494 /* default to $HOME/.debug */
495 if (buildid_dir[0] == '\0') {
496 char *v = getenv("HOME");
497 if (v) {
498 snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
499 v, DEBUG_CACHE_DIR);
500 } else {
501 strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
502 }
503 buildid_dir[MAXPATHLEN-1] = '\0';
504 }
505 /* for communicating with external commands */
506 setenv("PERF_BUILDID_DIR", buildid_dir, 1);
507 }
508