options.c revision ab3b72cc5d2d3efb3542192f0d72ff2ea4b082f9 
1#include "config.h"
2
3#include <string.h>
4#include <stdlib.h>
5#include <unistd.h>
6#include <fcntl.h>
7#include <errno.h>
8#include <limits.h>
9#include <sys/ioctl.h>
10
11#include <getopt.h>
12
13#include "common.h"
14
15#ifndef SYSCONFDIR
16#define SYSCONFDIR "/etc"
17#endif
18
19#define SYSTEM_CONFIG_FILE SYSCONFDIR "/ltrace.conf"
20#define USER_CONFIG_FILE "~/.ltrace.conf"
21
22struct options_t options = {
23	.align    = DEFAULT_ALIGN,    /* alignment column for results */
24	.user     = NULL,             /* username to run command as */
25	.syscalls = 0,                /* display syscalls */
26	.libcalls = 1,                /* display library calls */
27#ifdef USE_DEMANGLE
28	.demangle = 0,                /* Demangle low-level symbol names */
29#endif
30	.indent = 0,                  /* indent output according to program flow */
31	.output = NULL,               /* output to a specific file */
32	.summary = 0,                 /* Report a summary on program exit */
33	.debug = 0,                   /* debug */
34	.arraylen = DEFAULT_ARRAYLEN, /* maximum # array elements to print */
35	.strlen = DEFAULT_STRLEN,     /* maximum # of bytes printed in strings */
36	.follow = 0,                  /* trace child processes */
37};
38
39char *library[MAX_LIBRARIES];
40int library_num = 0;
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 function names given to option -e: */
51struct opt_e_t *opt_e = NULL;
52int opt_e_enable = 1;
53
54/* List of global function names given to -x: */
55struct opt_x_t *opt_x = NULL;
56
57/* List of filenames give to option -F: */
58struct opt_F_t *opt_F = NULL;	/* alternate configuration file(s) */
59
60#ifdef PLT_REINITALISATION_BP
61/* Set a break on the routine named here in order to re-initialize breakpoints
62   after all the PLTs have been initialzed */
63char *PLTs_initialized_by_here = PLT_REINITALISATION_BP;
64#endif
65
66static void
67err_usage(void) {
68	fprintf(stderr, "Try `%s --help' for more information\n", progname);
69	exit(1);
70}
71
72static void
73usage(void) {
74	fprintf(stdout, "Usage: %s [option ...] [command [arg ...]]\n"
75		"Trace library calls of a given program.\n\n"
76		"  -a, --align=COLUMN  align return values in a secific column.\n"
77		"  -A ARRAYLEN         maximum number of array elements to print.\n"
78		"  -b, --no-signals    don't print signals.\n"
79		"  -c                  count time and calls, and report a summary on exit.\n"
80# ifdef USE_DEMANGLE
81		"  -C, --demangle      decode low-level symbol names into user-level names.\n"
82# endif
83		"  -D, --debug=LEVEL   enable debugging (see -Dh or --debug=help).\n"
84		"  -Dh, --debug=help   show help on debugging.\n"
85		"  -e expr             modify which events to trace.\n"
86		"  -f                  trace children (fork() and clone()).\n"
87		"  -F, --config=FILE   load alternate configuration file (may be repeated).\n"
88		"  -g, --no-plt        disable breakpoints on PLT entries.\n"
89		"  -h, --help          display this help and exit.\n"
90		"  -i                  print instruction pointer at time of library call.\n"
91		"  -l, --library=FILE  print library calls from this library only.\n"
92		"  -L                  do NOT display library calls.\n"
93		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
94		"  -o, --output=FILE   write the trace output to that file.\n"
95		"  -p PID              attach to the process with the process ID pid.\n"
96		"  -r                  print relative timestamps.\n"
97		"  -s STRLEN           specify the maximum string size to print.\n"
98		"  -S                  display system calls.\n"
99		"  -t, -tt, -ttt       print absolute timestamps.\n"
100		"  -T                  show the time spent inside each call.\n"
101		"  -u USERNAME         run command with the userid, groupid of username.\n"
102		"  -V, --version       output version information and exit.\n"
103#if defined(HAVE_LIBUNWIND)
104		"  -w=NR, --where=NR   print backtrace showing NR stack frames at most.\n"
105#endif /* defined(HAVE_LIBUNWIND) */
106		"  -x NAME             treat the global NAME like a library subroutine.\n"
107#ifdef PLT_REINITALISATION_BP
108		"  -X NAME             same as -x; and PLT's will be initialized by here.\n"
109#endif
110		"\nReport bugs to ltrace-devel@lists.alioth.debian.org\n",
111		progname);
112}
113
114static void
115usage_debug(void) {
116	fprintf(stdout, "%s debugging option, --debug=<octal> or -D<octal>:\n", progname);
117	fprintf(stdout,
118			"\n"
119			" number  ref. in source   description\n"
120			"      1   general           Generally helpful progress information\n"
121			"     10   event             Shows every event received by a traced process\n"
122			"     20   process           Shows actions carried upon a traced processes\n"
123			"     40   function          Shows every entry to internal functions\n"
124			"\n"
125			"Debugging options are mixed using bitwise-or.\n"
126			"Note that the meanings and values are subject to change.\n"
127		   );
128}
129
130static char *
131search_for_command(char *filename) {
132	static char pathname[PATH_MAX];
133	char *path;
134	int m, n;
135
136	if (strchr(filename, '/')) {
137		return filename;
138	}
139	for (path = getenv("PATH"); path && *path; path += m) {
140		if (strchr(path, ':')) {
141			n = strchr(path, ':') - path;
142			m = n + 1;
143		} else {
144			m = n = strlen(path);
145		}
146		if (n + strlen(filename) + 1 >= PATH_MAX) {
147			fprintf(stderr, "Error: filename too long\n");
148			exit(1);
149		}
150		strncpy(pathname, path, n);
151		if (n && pathname[n - 1] != '/') {
152			pathname[n++] = '/';
153		}
154		strcpy(pathname + n, filename);
155		if (!access(pathname, X_OK)) {
156			return pathname;
157		}
158	}
159	return filename;
160}
161
162static void
163guess_cols(void) {
164	struct winsize ws;
165	char *c;
166
167	options.align = DEFAULT_ALIGN;
168	c = getenv("COLUMNS");
169	if (c && *c) {
170		char *endptr;
171		int cols;
172		cols = strtol(c, &endptr, 0);
173		if (cols > 0 && !*endptr) {
174			options.align = cols * 5 / 8;
175		}
176	} else if (ioctl(1, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
177		options.align = ws.ws_col * 5 / 8;
178	} else if (ioctl(2, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
179		options.align = ws.ws_col * 5 / 8;
180	}
181}
182
183char **
184process_options(int argc, char **argv) {
185	progname = argv[0];
186	options.output = stderr;
187	options.no_plt = 0;
188	options.no_signals = 0;
189#if defined(HAVE_LIBUNWIND)
190	options.bt_depth = -1;
191#endif /* defined(HAVE_LIBUNWIND) */
192
193	guess_cols();
194
195	while (1) {
196		int c;
197		char *p;
198		int option_index = 0;
199		static struct option long_options[] = {
200			{"align", 1, 0, 'a'},
201			{"config", 1, 0, 'F'},
202			{"debug", 1, 0, 'D'},
203# ifdef USE_DEMANGLE
204			{"demangle", 0, 0, 'C'},
205#endif
206			{"indent", 1, 0, 'n'},
207			{"help", 0, 0, 'h'},
208			{"library", 1, 0, 'l'},
209			{"output", 1, 0, 'o'},
210			{"version", 0, 0, 'V'},
211			{"no-plt", 0, 0, 'g'},
212			{"no-signals", 0, 0, 'b'},
213#if defined(HAVE_LIBUNWIND)
214			{"where", 1, 0, 'w'},
215#endif /* defined(HAVE_LIBUNWIND) */
216			{0, 0, 0, 0}
217		};
218		c = getopt_long(argc, argv, "+cfhiLrStTVgb"
219# ifdef USE_DEMANGLE
220				"C"
221# endif
222#if defined(HAVE_LIBUNWIND)
223				"a:A:D:e:F:l:n:o:p:s:u:x:X:w:", long_options,
224#else /* !defined(HAVE_LIBUNWIND) */
225				"a:A:D:e:F:l:n:o:p:s:u:x:X:", long_options,
226#endif
227				&option_index);
228		if (c == -1) {
229			break;
230		}
231		switch (c) {
232		case 'a':
233			options.align = atoi(optarg);
234			break;
235		case 'A':
236			options.arraylen = atoi(optarg);
237			break;
238		case 'c':
239			options.summary++;
240			break;
241#ifdef USE_DEMANGLE
242		case 'C':
243			options.demangle++;
244			break;
245#endif
246		case 'D':
247			if (optarg[0]=='h') {
248				usage_debug();
249				exit(0);
250			}
251			options.debug = strtoul(optarg,&p,8);
252			if (*p) {
253				fprintf(stderr, "%s: --debug requires an octal argument\n", progname);
254				err_usage();
255			}
256			break;
257		case 'e':
258			{
259				char *str_e = strdup(optarg);
260				if (!str_e) {
261					perror("ltrace: strdup");
262					exit(1);
263				}
264				if (str_e[0] == '!') {
265					opt_e_enable = 0;
266					str_e++;
267				}
268				while (*str_e) {
269					struct opt_e_t *tmp;
270					char *str2 = strchr(str_e, ',');
271					if (str2) {
272						*str2 = '\0';
273					}
274					tmp = malloc(sizeof(struct opt_e_t));
275					if (!tmp) {
276						perror("ltrace: malloc");
277						exit(1);
278					}
279					tmp->name = str_e;
280					tmp->next = opt_e;
281					opt_e = tmp;
282					if (str2) {
283						str_e = str2 + 1;
284					} else {
285						break;
286					}
287				}
288				break;
289			}
290		case 'f':
291			options.follow = 1;
292			break;
293		case 'F':
294			{
295				struct opt_F_t *tmp = malloc(sizeof(struct opt_F_t));
296				if (!tmp) {
297					perror("ltrace: malloc");
298					exit(1);
299				}
300				tmp->filename = strdup(optarg);
301				tmp->next = opt_F;
302				opt_F = tmp;
303				break;
304			}
305		case 'g':
306			options.no_plt = 1;
307			break;
308		case 'h':
309			usage();
310			exit(0);
311		case 'i':
312			opt_i++;
313			break;
314		case 'l':
315			if (library_num == MAX_LIBRARIES) {
316				fprintf(stderr,
317					"Too many libraries.  Maximum is %i.\n",
318					MAX_LIBRARIES);
319				exit(1);
320			}
321			library[library_num++] = optarg;
322			break;
323		case 'L':
324			options.libcalls = 0;
325			break;
326		case 'n':
327			options.indent = atoi(optarg);
328			break;
329#if defined(HAVE_LIBUNWIND)
330		case 'w':
331			options.bt_depth = atoi(optarg);
332			break;
333#endif /* defined(HAVE_LIBUNWIND) */
334		case 'o':
335			options.output = fopen(optarg, "w");
336			if (!options.output) {
337				fprintf(stderr,
338					"Can't open %s for output: %s\n",
339					optarg, strerror(errno));
340				exit(1);
341			}
342			setvbuf(options.output, (char *)NULL, _IOLBF, 0);
343			fcntl(fileno(options.output), F_SETFD, FD_CLOEXEC);
344			break;
345		case 'p':
346			{
347				struct opt_p_t *tmp = malloc(sizeof(struct opt_p_t));
348				if (!tmp) {
349					perror("ltrace: malloc");
350					exit(1);
351				}
352				tmp->pid = atoi(optarg);
353				tmp->next = opt_p;
354				opt_p = tmp;
355				break;
356			}
357		case 'r':
358			opt_r++;
359			break;
360		case 's':
361			options.strlen = atoi(optarg);
362			break;
363		case 'S':
364			options.syscalls = 1;
365			break;
366		case 't':
367			opt_t++;
368			break;
369		case 'T':
370			opt_T++;
371			break;
372		case 'u':
373			options.user = optarg;
374			break;
375		case 'V':
376			printf("ltrace version " PACKAGE_VERSION ".\n"
377					"Copyright (C) 1997-2009 Juan Cespedes <cespedes@debian.org>.\n"
378					"This is free software; see the GNU General Public Licence\n"
379					"version 2 or later for copying conditions.  There is NO warranty.\n");
380			exit(0);
381			break;
382		case 'b':
383			options.no_signals = 1;
384			break;
385		case 'X':
386#ifdef PLT_REINITALISATION_BP
387			PLTs_initialized_by_here = optarg;
388#else
389			fprintf(stderr, "WARNING: \"-X\" not used for this "
390				"architecture: assuming you meant \"-x\"\n");
391#endif
392			/* Fall Thru */
393
394		case 'x':
395			{
396				struct opt_x_t *p = opt_x;
397
398				/* First, check for duplicate. */
399				while (p && strcmp(p->name, optarg)) {
400					p = p->next;
401				}
402				if (p) {
403					break;
404				}
405
406				/* If not duplicate, add to list. */
407				p = malloc(sizeof(struct opt_x_t));
408				if (!p) {
409					perror("ltrace: malloc");
410					exit(1);
411				}
412				p->name = optarg;
413				p->found = 0;
414				p->next = opt_x;
415				opt_x = p;
416				break;
417			}
418
419		default:
420			err_usage();
421		}
422	}
423	argc -= optind;
424	argv += optind;
425
426	if (!opt_F) {
427		opt_F = malloc(sizeof(struct opt_F_t));
428		opt_F->next = malloc(sizeof(struct opt_F_t));
429		opt_F->next->next = NULL;
430		opt_F->filename = USER_CONFIG_FILE;
431		opt_F->next->filename = SYSTEM_CONFIG_FILE;
432	}
433	/* Reverse the config file list since it was built by
434	 * prepending, and it would make more sense to process the
435	 * files in the order they were given. Probably it would make
436	 * more sense to keep a tail pointer instead? */
437	{
438		struct opt_F_t *egg = NULL;
439		struct opt_F_t *chicken;
440		while (opt_F) {
441			chicken = opt_F->next;
442			opt_F->next = egg;
443			egg = opt_F;
444			opt_F = chicken;
445		}
446		opt_F = egg;
447	}
448
449	if (!opt_p && argc < 1) {
450		fprintf(stderr, "%s: too few arguments\n", progname);
451		err_usage();
452	}
453	if (opt_r && opt_t) {
454		fprintf(stderr, "%s: Incompatible options -r and -t\n",
455			progname);
456		err_usage();
457	}
458	if (argc > 0) {
459		command = search_for_command(argv[0]);
460	}
461	return &argv[0];
462}
463