options.c revision 8b00d5bb6a0925ece06aad0d9df0a85e8dbd7b57 
1#include "config.h"
2
3#include <sys/ioctl.h>
4#include <assert.h>
5#include <errno.h>
6#include <error.h>
7#include <fcntl.h>
8#include <getopt.h>
9#include <limits.h>
10#include <stdlib.h>
11#include <string.h>
12#include <unistd.h>
13
14#include "common.h"
15#include "filter.h"
16#include "glob.h"
17
18#ifndef SYSCONFDIR
19#define SYSCONFDIR "/etc"
20#endif
21
22#define SYSTEM_CONFIG_FILE SYSCONFDIR "/ltrace.conf"
23#define USER_CONFIG_FILE "~/.ltrace.conf"
24
25struct options_t options = {
26	.align    = DEFAULT_ALIGN,    /* alignment column for results */
27	.user     = NULL,             /* username to run command as */
28	.syscalls = 0,                /* display syscalls */
29#ifdef USE_DEMANGLE
30	.demangle = 0,                /* Demangle low-level symbol names */
31#endif
32	.indent = 0,                  /* indent output according to program flow */
33	.output = NULL,               /* output to a specific file */
34	.summary = 0,                 /* Report a summary on program exit */
35	.debug = 0,                   /* debug */
36	.arraylen = DEFAULT_ARRAYLEN, /* maximum # array elements to print */
37	.strlen = DEFAULT_STRLEN,     /* maximum # of bytes printed in strings */
38	.follow = 0,                  /* trace child processes */
39};
40
41static char *progname;		/* Program name (`ltrace') */
42int opt_i = 0;			/* instruction pointer */
43int opt_r = 0;			/* print relative timestamp */
44int opt_t = 0;			/* print absolute timestamp */
45int opt_T = 0;			/* show the time spent inside each call */
46
47/* List of pids given to option -p: */
48struct opt_p_t *opt_p = NULL;	/* attach to process with a given pid */
49
50/* List of filenames give to option -F: */
51struct opt_F_t *opt_F = NULL;	/* alternate configuration file(s) */
52
53#ifdef PLT_REINITALISATION_BP
54/* Set a break on the routine named here in order to re-initialize breakpoints
55   after all the PLTs have been initialzed */
56char *PLTs_initialized_by_here = PLT_REINITALISATION_BP;
57#endif
58
59static void
60err_usage(void) {
61	fprintf(stderr, "Try `%s --help' for more information\n", progname);
62	exit(1);
63}
64
65static void
66usage(void) {
67	fprintf(stdout, "Usage: %s [option ...] [command [arg ...]]\n"
68		"Trace library calls of a given program.\n\n"
69		"  -a, --align=COLUMN  align return values in a secific column.\n"
70		"  -A ARRAYLEN         maximum number of array elements to print.\n"
71		"  -b, --no-signals    don't print signals.\n"
72		"  -c                  count time and calls, and report a summary on exit.\n"
73# ifdef USE_DEMANGLE
74		"  -C, --demangle      decode low-level symbol names into user-level names.\n"
75# endif
76		"  -D, --debug=LEVEL   enable debugging (see -Dh or --debug=help).\n"
77		"  -Dh, --debug=help   show help on debugging.\n"
78		"  -e expr             modify which events to trace.\n"
79		"  -f                  trace children (fork() and clone()).\n"
80		"  -F, --config=FILE   load alternate configuration file (may be repeated).\n"
81		"  -g, --no-plt        disable breakpoints on PLT entries.\n"
82		"  -h, --help          display this help and exit.\n"
83		"  -i                  print instruction pointer at time of library call.\n"
84		"  -l, --library=FILE  print library calls from this library only.\n"
85		"  -L                  do NOT display library calls.\n"
86		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
87		"  -o, --output=FILE   write the trace output to that file.\n"
88		"  -p PID              attach to the process with the process ID pid.\n"
89		"  -r                  print relative timestamps.\n"
90		"  -s STRLEN           specify the maximum string size to print.\n"
91		"  -S                  display system calls.\n"
92		"  -t, -tt, -ttt       print absolute timestamps.\n"
93		"  -T                  show the time spent inside each call.\n"
94		"  -u USERNAME         run command with the userid, groupid of username.\n"
95		"  -V, --version       output version information and exit.\n"
96#if defined(HAVE_LIBUNWIND)
97		"  -w=NR, --where=NR   print backtrace showing NR stack frames at most.\n"
98#endif /* defined(HAVE_LIBUNWIND) */
99		"  -x NAME             treat the global NAME like a library subroutine.\n"
100#ifdef PLT_REINITALISATION_BP
101		"  -X NAME             same as -x; and PLT's will be initialized by here.\n"
102#endif
103		"\nReport bugs to ltrace-devel@lists.alioth.debian.org\n",
104		progname);
105}
106
107static void
108usage_debug(void) {
109	fprintf(stdout, "%s debugging option, --debug=<octal> or -D<octal>:\n", progname);
110	fprintf(stdout,
111			"\n"
112			" number  ref. in source   description\n"
113			"      1   general           Generally helpful progress information\n"
114			"     10   event             Shows every event received by a traced process\n"
115			"     20   process           Shows actions carried upon a traced processes\n"
116			"     40   function          Shows every entry to internal functions\n"
117			"\n"
118			"Debugging options are mixed using bitwise-or.\n"
119			"Note that the meanings and values are subject to change.\n"
120		   );
121}
122
123static char *
124search_for_command(char *filename) {
125	static char pathname[PATH_MAX];
126	char *path;
127	int m, n;
128
129	if (strchr(filename, '/')) {
130		return filename;
131	}
132	for (path = getenv("PATH"); path && *path; path += m) {
133		if (strchr(path, ':')) {
134			n = strchr(path, ':') - path;
135			m = n + 1;
136		} else {
137			m = n = strlen(path);
138		}
139		if (n + strlen(filename) + 1 >= PATH_MAX) {
140			fprintf(stderr, "Error: filename too long\n");
141			exit(1);
142		}
143		strncpy(pathname, path, n);
144		if (n && pathname[n - 1] != '/') {
145			pathname[n++] = '/';
146		}
147		strcpy(pathname + n, filename);
148		if (!access(pathname, X_OK)) {
149			return pathname;
150		}
151	}
152	return filename;
153}
154
155static void
156guess_cols(void) {
157	struct winsize ws;
158	char *c;
159
160	options.align = DEFAULT_ALIGN;
161	c = getenv("COLUMNS");
162	if (c && *c) {
163		char *endptr;
164		int cols;
165		cols = strtol(c, &endptr, 0);
166		if (cols > 0 && !*endptr) {
167			options.align = cols * 5 / 8;
168		}
169	} else if (ioctl(1, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
170		options.align = ws.ws_col * 5 / 8;
171	} else if (ioctl(2, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
172		options.align = ws.ws_col * 5 / 8;
173	}
174}
175
176static void
177add_filter_rule(struct filter *filt, const char *expr,
178		enum filter_rule_type type,
179		const char *sym, int sym_re_p,
180		const char *lib, int lib_re_p)
181{
182	struct filter_rule *rule = malloc(sizeof(*rule));
183	struct filter_lib_matcher *matcher = malloc(sizeof(*matcher));
184
185	if (rule == NULL || matcher == NULL) {
186		error(0, errno, "rule near '%s' will be ignored", expr);
187	fail:
188		free(rule);
189		free(matcher);
190		return;
191	}
192
193	regex_t symbol_re;
194	int status = (sym_re_p ? regcomp : globcomp)(&symbol_re, sym, 0);
195	if (status != 0) {
196		char buf[100];
197		regerror(status, &symbol_re, buf, sizeof buf);
198		error(0, 0, "rule near '%s' will be ignored: %s", expr, buf);
199		goto fail;
200	}
201
202	if (strcmp(lib, "MAIN") == 0) {
203		filter_lib_matcher_main_init(matcher);
204	} else {
205		enum filter_lib_matcher_type type
206			= lib[0] == '/' ? FLM_PATHNAME : FLM_SONAME;
207
208		regex_t lib_re;
209		status = (lib_re_p ? regcomp : globcomp)(&lib_re, lib, 0);
210		if (status != 0) {
211			char buf[100];
212			regerror(status, &lib_re, buf, sizeof buf);
213			error(0, 0, "rule near '%s' will be ignored: %s",
214			      expr, buf);
215
216			regfree(&symbol_re);
217			goto fail;
218		}
219		filter_lib_matcher_name_init(matcher, type, lib_re);
220	}
221
222	filter_rule_init(rule, type, matcher, symbol_re);
223	filter_add_rule(filt, rule);
224}
225
226static int
227parse_filter(struct filter *filt, char *expr)
228{
229	/* Filter is a chain of sym@lib rules separated by '-'.  If
230	 * the filter expression starts with '-', the missing initial
231	 * rule is implicitly *@*.  */
232
233	enum filter_rule_type type = FR_ADD;
234
235	while (*expr != 0) {
236		size_t s = strcspn(expr, "@-");
237		char *symname = expr;
238		char *libname;
239		char *next = expr + s + 1;
240		enum filter_rule_type this_type = type;
241
242		if (expr[s] == 0) {
243			libname = "*";
244			expr = next - 1;
245
246		} else if (expr[s] == '-') {
247			libname = "*";
248			expr = next;
249			type = FR_SUBTRACT;
250
251		} else {
252			assert(expr[s] == '@');
253			expr[s] = 0;
254			s = strcspn(next, "-");
255			if (s == 0) {
256				libname = "*";
257				expr = next;
258			} else if (next[s] == 0) {
259				expr = next + s;
260				libname = next;
261
262			} else {
263				assert(next[s] == '-');
264				type = FR_SUBTRACT;
265				next[s] = 0;
266				expr = next + s + 1;
267				libname = next;
268			}
269		}
270
271		assert(*libname != 0);
272		char *symend = symname + strlen(symname) - 1;
273		char *libend = libname + strlen(libname) - 1;
274		int sym_is_re = 0;
275		int lib_is_re = 0;
276
277		/*
278		 * /xxx/@... and ...@/xxx/ means that xxx are regular
279		 * expressions.  They are globs otherwise.
280		 *
281		 * /xxx@yyy/ is the same as /xxx/@/yyy/
282		 *
283		 * @/xxx matches library path name
284		 * @.xxx matches library relative path name
285		 */
286		if (symname[0] == '/') {
287			if (symname != symend && symend[0] == '/') {
288				++symname;
289				*symend-- = 0;
290				sym_is_re = 1;
291
292			} else {
293				sym_is_re = 1;
294				lib_is_re = 1;
295				++symname;
296
297				/* /XXX@YYY/ is the same as
298				 * /XXX/@/YYY/.  */
299				if (libend[0] != '/')
300					error(0, 0, "unmatched '/'"
301					      " in symbol name");
302				else
303					*libend-- = 0;
304			}
305		}
306
307		/* If libname ends in '/', then we expect '/' in the
308		 * beginning too.  Otherwise the initial '/' is part
309		 * of absolute file name.  */
310		if (!lib_is_re && libend[0] == '/') {
311			lib_is_re = 1;
312			*libend-- = 0;
313			if (libname != libend && libname[0] == '/')
314				++libname;
315			else
316				error(0, 0, "unmatched '/' in library name");
317		}
318
319		if (*symname == 0) /* /@AA/ */
320			symname = "*";
321		if (*libname == 0) /* /aa@/ */
322			libname = "*";
323
324		add_filter_rule(filt, expr, this_type,
325				symname, sym_is_re,
326				libname, lib_is_re);
327	}
328
329	return 0;
330}
331
332static struct filter *
333recursive_parse_chain(char *expr)
334{
335	/* Event expression grammar:
336	 *
337	 *  Chain ::= Filter FilterList
338	 *  FilterList ::= eps | ',' Filter FilterList
339	 *  Filter ::= Rule RuleList
340	 *  RuleList ::= eps | '-' Rule RuleList
341	 *  Rule ::= eps | Glob Soname
342	 *  Soname ::= eps | '@' Glob | '@' '/' Filename
343	 *  Glob ::= '/' Regex '/'
344	 */
345
346	struct filter *filt = malloc(sizeof(*filt));
347	if (filt == NULL) {
348		error(0, errno, "(part of) filter will be ignored: '%s'", expr);
349		return NULL;
350	}
351
352	filter_init(filt);
353	struct filter *next = NULL;
354	char *it;
355	int escape = 0;
356	for (it = expr; ; ++it) {
357		if (*it == 0)
358			goto done;
359
360		if (escape) {
361			escape = 0;
362			continue;
363		}
364
365		if (*it == '\\') {
366			escape = 1;
367
368		} else if (*it == ',') {
369			*it = 0;
370			next = recursive_parse_chain(it + 1);
371		done:
372			filt->next = next;
373			if (parse_filter(filt, expr) < 0) {
374				fprintf(stderr,
375					"Filter '%s' will be ignored.\n", expr);
376				free(filt);
377				filt = next;
378			}
379			return filt;
380		}
381	}
382}
383
384static void
385parse_filter_chain(const char *expr, struct filter **retp)
386{
387	char *str = strdup(expr);
388	if (str == NULL) {
389		error(0, errno, "filter '%s' will be ignored", expr);
390		return;
391	}
392	*retp = recursive_parse_chain(str);
393}
394
395char **
396process_options(int argc, char **argv)
397{
398	progname = argv[0];
399	options.output = stderr;
400	options.no_signals = 0;
401#if defined(HAVE_LIBUNWIND)
402	options.bt_depth = -1;
403#endif /* defined(HAVE_LIBUNWIND) */
404
405	guess_cols();
406
407	int libcalls = 1;
408
409	while (1) {
410		int c;
411		char *p;
412		int option_index = 0;
413		static struct option long_options[] = {
414			{"align", 1, 0, 'a'},
415			{"config", 1, 0, 'F'},
416			{"debug", 1, 0, 'D'},
417# ifdef USE_DEMANGLE
418			{"demangle", 0, 0, 'C'},
419#endif
420			{"indent", 1, 0, 'n'},
421			{"help", 0, 0, 'h'},
422			{"library", 1, 0, 'l'},
423			{"output", 1, 0, 'o'},
424			{"version", 0, 0, 'V'},
425			{"no-signals", 0, 0, 'b'},
426#if defined(HAVE_LIBUNWIND)
427			{"where", 1, 0, 'w'},
428#endif /* defined(HAVE_LIBUNWIND) */
429			{0, 0, 0, 0}
430		};
431		c = getopt_long(argc, argv, "+cfhiLrStTVb"
432# ifdef USE_DEMANGLE
433				"C"
434# endif
435#if defined(HAVE_LIBUNWIND)
436				"a:A:D:e:F:l:n:o:p:s:u:x:X:w:", long_options,
437#else /* !defined(HAVE_LIBUNWIND) */
438				"a:A:D:e:F:l:n:o:p:s:u:x:X:", long_options,
439#endif
440				&option_index);
441		if (c == -1) {
442			break;
443		}
444		switch (c) {
445		case 'a':
446			options.align = atoi(optarg);
447			break;
448		case 'A':
449			options.arraylen = atoi(optarg);
450			break;
451		case 'b':
452			options.no_signals = 1;
453			break;
454		case 'c':
455			options.summary++;
456			break;
457#ifdef USE_DEMANGLE
458		case 'C':
459			options.demangle++;
460			break;
461#endif
462		case 'D':
463			if (optarg[0]=='h') {
464				usage_debug();
465				exit(0);
466			}
467			options.debug = strtoul(optarg,&p,8);
468			if (*p) {
469				fprintf(stderr, "%s: --debug requires an octal argument\n", progname);
470				err_usage();
471			}
472			break;
473
474		case 'e':
475			parse_filter_chain(optarg, &options.plt_filter);
476			break;
477
478		case 'f':
479			options.follow = 1;
480			break;
481		case 'F':
482			{
483				struct opt_F_t *tmp = malloc(sizeof(struct opt_F_t));
484				if (!tmp) {
485					perror("ltrace: malloc");
486					exit(1);
487				}
488				tmp->filename = strdup(optarg);
489				tmp->next = opt_F;
490				opt_F = tmp;
491				break;
492			}
493		case 'h':
494			usage();
495			exit(0);
496		case 'i':
497			opt_i++;
498			break;
499		case 'l':
500			assert(!"-l support not yet implemented");
501			abort();
502			break;
503		case 'L':
504			libcalls = 0;
505			break;
506		case 'n':
507			options.indent = atoi(optarg);
508			break;
509		case 'o':
510			options.output = fopen(optarg, "w");
511			if (!options.output) {
512				fprintf(stderr,
513					"Can't open %s for output: %s\n",
514					optarg, strerror(errno));
515				exit(1);
516			}
517			setvbuf(options.output, (char *)NULL, _IOLBF, 0);
518			fcntl(fileno(options.output), F_SETFD, FD_CLOEXEC);
519			break;
520		case 'p':
521			{
522				struct opt_p_t *tmp = malloc(sizeof(struct opt_p_t));
523				if (!tmp) {
524					perror("ltrace: malloc");
525					exit(1);
526				}
527				tmp->pid = atoi(optarg);
528				tmp->next = opt_p;
529				opt_p = tmp;
530				break;
531			}
532		case 'r':
533			opt_r++;
534			break;
535		case 's':
536			options.strlen = atoi(optarg);
537			break;
538		case 'S':
539			options.syscalls = 1;
540			break;
541		case 't':
542			opt_t++;
543			break;
544		case 'T':
545			opt_T++;
546			break;
547		case 'u':
548			options.user = optarg;
549			break;
550		case 'V':
551			printf("ltrace version " PACKAGE_VERSION ".\n"
552					"Copyright (C) 1997-2009 Juan Cespedes <cespedes@debian.org>.\n"
553					"This is free software; see the GNU General Public Licence\n"
554					"version 2 or later for copying conditions.  There is NO warranty.\n");
555			exit(0);
556			break;
557#if defined(HAVE_LIBUNWIND)
558		case 'w':
559			options.bt_depth = atoi(optarg);
560			break;
561#endif /* defined(HAVE_LIBUNWIND) */
562		case 'X':
563#ifdef PLT_REINITALISATION_BP
564			PLTs_initialized_by_here = optarg;
565#else
566			fprintf(stderr, "WARNING: \"-X\" not used for this "
567				"architecture: assuming you meant \"-x\"\n");
568#endif
569			/* Fall Thru */
570
571		case 'x':
572			parse_filter_chain(optarg, &options.static_filter);
573			break;
574
575		default:
576			err_usage();
577		}
578	}
579	argc -= optind;
580	argv += optind;
581
582	if (!opt_F) {
583		opt_F = malloc(sizeof(struct opt_F_t));
584		opt_F->next = malloc(sizeof(struct opt_F_t));
585		opt_F->next->next = NULL;
586		opt_F->filename = USER_CONFIG_FILE;
587		opt_F->next->filename = SYSTEM_CONFIG_FILE;
588	}
589	/* Reverse the config file list since it was built by
590	 * prepending, and it would make more sense to process the
591	 * files in the order they were given. Probably it would make
592	 * more sense to keep a tail pointer instead? */
593	{
594		struct opt_F_t *egg = NULL;
595		struct opt_F_t *chicken;
596		while (opt_F) {
597			chicken = opt_F->next;
598			opt_F->next = egg;
599			egg = opt_F;
600			opt_F = chicken;
601		}
602		opt_F = egg;
603	}
604
605	/* Set default filter.  Use @MAIN for now, as that's what
606	 * ltrace used to have in the past.  XXX Maybe we should make
607	 * this "*" instead.  */
608	if (options.plt_filter == NULL && libcalls) {
609		parse_filter_chain("@MAIN", &options.plt_filter);
610		options.hide_caller = 1;
611	}
612
613	if (!opt_p && argc < 1) {
614		fprintf(stderr, "%s: too few arguments\n", progname);
615		err_usage();
616	}
617	if (opt_r && opt_t) {
618		fprintf(stderr, "%s: Incompatible options -r and -t\n",
619			progname);
620		err_usage();
621	}
622	if (argc > 0) {
623		command = search_for_command(argv[0]);
624	}
625	return &argv[0];
626}
627