options.c revision fa2aefc32eb4196966a14d1e7def931652f40d46 
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		"  -c                  count time and calls, and report a summary on exit.\n"
79# ifdef USE_DEMANGLE
80		"  -C, --demangle      decode low-level symbol names into user-level names.\n"
81# endif
82		"  -D, --debug=LEVEL   enable debugging (see -Dh or --debug=help).\n"
83		"  -Dh, --debug=help   show help on debugging.\n"
84		"  -e expr             modify which events to trace.\n"
85		"  -f                  trace children (fork() and clone()).\n"
86		"  -F, --config=FILE   load alternate configuration file (may be repeated).\n"
87		"  -g, --no-plt        disable breakpoints on PLT entries.\n"
88		"  -h, --help          display this help and exit.\n"
89		"  -i                  print instruction pointer at time of library call.\n"
90		"  -l, --library=FILE  print library calls from this library only.\n"
91		"  -L                  do NOT display library calls.\n"
92		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
93		"  -o, --output=FILE   write the trace output to that file.\n"
94		"  -p PID              attach to the process with the process ID pid.\n"
95		"  -r                  print relative timestamps.\n"
96		"  -s STRLEN           specify the maximum string size to print.\n"
97		"  -S                  display system calls.\n"
98		"  -t, -tt, -ttt       print absolute timestamps.\n"
99		"  -T                  show the time spent inside each call.\n"
100		"  -u USERNAME         run command with the userid, groupid of username.\n"
101		"  -V, --version       output version information and exit.\n"
102		"  -x NAME             treat the global NAME like a library subroutine.\n"
103#ifdef PLT_REINITALISATION_BP
104		"  -X NAME             same as -x; and PLT's will be initialized by here.\n"
105#endif
106		"\nReport bugs to ltrace-devel@lists.alioth.debian.org\n",
107		progname);
108}
109
110static void
111usage_debug(void) {
112	fprintf(stdout, "%s debugging option, --debug=<octal> or -D<octal>:\n", progname);
113	fprintf(stdout,
114			"\n"
115			" number  ref. in source   description\n"
116			"      1   general           Generally helpful progress information\n"
117			"     10   event             Shows every event received by a traced process\n"
118			"     20   process           Shows actions carried upon a traced processes\n"
119			"     40   function          Shows every entry to internal functions\n"
120			"\n"
121			"Debugging options are mixed using bitwise-or.\n"
122			"Note that the meanings and values are subject to change.\n"
123		   );
124}
125
126static char *
127search_for_command(char *filename) {
128	static char pathname[PATH_MAX];
129	char *path;
130	int m, n;
131
132	if (strchr(filename, '/')) {
133		return filename;
134	}
135	for (path = getenv("PATH"); path && *path; path += m) {
136		if (strchr(path, ':')) {
137			n = strchr(path, ':') - path;
138			m = n + 1;
139		} else {
140			m = n = strlen(path);
141		}
142		if (n + strlen(filename) + 1 >= PATH_MAX) {
143			fprintf(stderr, "Error: filename too long\n");
144			exit(1);
145		}
146		strncpy(pathname, path, n);
147		if (n && pathname[n - 1] != '/') {
148			pathname[n++] = '/';
149		}
150		strcpy(pathname + n, filename);
151		if (!access(pathname, X_OK)) {
152			return pathname;
153		}
154	}
155	return filename;
156}
157
158static void
159guess_cols(void) {
160	struct winsize ws;
161	char *c;
162
163	options.align = DEFAULT_ALIGN;
164	c = getenv("COLUMNS");
165	if (c && *c) {
166		char *endptr;
167		int cols;
168		cols = strtol(c, &endptr, 0);
169		if (cols > 0 && !*endptr) {
170			options.align = cols * 5 / 8;
171		}
172	} else if (ioctl(1, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
173		options.align = ws.ws_col * 5 / 8;
174	} else if (ioctl(2, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
175		options.align = ws.ws_col * 5 / 8;
176	}
177}
178
179char **
180process_options(int argc, char **argv) {
181	progname = argv[0];
182	options.output = stderr;
183	options.no_plt = 0;
184
185	guess_cols();
186
187	while (1) {
188		int c;
189		char *p;
190		int option_index = 0;
191		static struct option long_options[] = {
192			{"align", 1, 0, 'a'},
193			{"config", 1, 0, 'F'},
194			{"debug", 1, 0, 'D'},
195# ifdef USE_DEMANGLE
196			{"demangle", 0, 0, 'C'},
197#endif
198			{"indent", 1, 0, 'n'},
199			{"help", 0, 0, 'h'},
200			{"library", 1, 0, 'l'},
201			{"output", 1, 0, 'o'},
202			{"version", 0, 0, 'V'},
203			{"no-plt", 0, 0, 'g'},
204			{0, 0, 0, 0}
205		};
206		c = getopt_long(argc, argv, "+cfhiLrStTVg"
207# ifdef USE_DEMANGLE
208				"C"
209# endif
210				"a:A:D:e:F:l:n:o:p:s:u:x:X:", long_options,
211				&option_index);
212		if (c == -1) {
213			break;
214		}
215		switch (c) {
216		case 'a':
217			options.align = atoi(optarg);
218			break;
219		case 'A':
220			options.arraylen = atoi(optarg);
221			break;
222		case 'c':
223			options.summary++;
224			break;
225#ifdef USE_DEMANGLE
226		case 'C':
227			options.demangle++;
228			break;
229#endif
230		case 'D':
231			if (optarg[0]=='h') {
232				usage_debug();
233				exit(0);
234			}
235			options.debug = strtoul(optarg,&p,8);
236			if (*p) {
237				fprintf(stderr, "%s: --debug requires an octal argument\n", progname);
238				err_usage();
239			}
240			break;
241		case 'e':
242			{
243				char *str_e = strdup(optarg);
244				if (!str_e) {
245					perror("ltrace: strdup");
246					exit(1);
247				}
248				if (str_e[0] == '!') {
249					opt_e_enable = 0;
250					str_e++;
251				}
252				while (*str_e) {
253					struct opt_e_t *tmp;
254					char *str2 = strchr(str_e, ',');
255					if (str2) {
256						*str2 = '\0';
257					}
258					tmp = malloc(sizeof(struct opt_e_t));
259					if (!tmp) {
260						perror("ltrace: malloc");
261						exit(1);
262					}
263					tmp->name = str_e;
264					tmp->next = opt_e;
265					opt_e = tmp;
266					if (str2) {
267						str_e = str2 + 1;
268					} else {
269						break;
270					}
271				}
272				break;
273			}
274		case 'f':
275			options.follow = 1;
276			break;
277		case 'F':
278			{
279				struct opt_F_t *tmp = malloc(sizeof(struct opt_F_t));
280				if (!tmp) {
281					perror("ltrace: malloc");
282					exit(1);
283				}
284				tmp->filename = strdup(optarg);
285				tmp->next = opt_F;
286				opt_F = tmp;
287				break;
288			}
289		case 'g':
290			options.no_plt = 1;
291			break;
292		case 'h':
293			usage();
294			exit(0);
295		case 'i':
296			opt_i++;
297			break;
298		case 'l':
299			if (library_num == MAX_LIBRARIES) {
300				fprintf(stderr,
301					"Too many libraries.  Maximum is %i.\n",
302					MAX_LIBRARIES);
303				exit(1);
304			}
305			library[library_num++] = optarg;
306			break;
307		case 'L':
308			options.libcalls = 0;
309			break;
310		case 'n':
311			options.indent = atoi(optarg);
312			break;
313		case 'o':
314			options.output = fopen(optarg, "w");
315			if (!options.output) {
316				fprintf(stderr,
317					"Can't open %s for output: %s\n",
318					optarg, strerror(errno));
319				exit(1);
320			}
321			setvbuf(options.output, (char *)NULL, _IOLBF, 0);
322			fcntl(fileno(options.output), F_SETFD, FD_CLOEXEC);
323			break;
324		case 'p':
325			{
326				struct opt_p_t *tmp = malloc(sizeof(struct opt_p_t));
327				if (!tmp) {
328					perror("ltrace: malloc");
329					exit(1);
330				}
331				tmp->pid = atoi(optarg);
332				tmp->next = opt_p;
333				opt_p = tmp;
334				break;
335			}
336		case 'r':
337			opt_r++;
338			break;
339		case 's':
340			options.strlen = atoi(optarg);
341			break;
342		case 'S':
343			options.syscalls = 1;
344			break;
345		case 't':
346			opt_t++;
347			break;
348		case 'T':
349			opt_T++;
350			break;
351		case 'u':
352			options.user = optarg;
353			break;
354		case 'V':
355			printf("ltrace version " PACKAGE_VERSION ".\n"
356					"Copyright (C) 1997-2009 Juan Cespedes <cespedes@debian.org>.\n"
357					"This is free software; see the GNU General Public Licence\n"
358					"version 2 or later for copying conditions.  There is NO warranty.\n");
359			exit(0);
360			break;
361		case 'X':
362#ifdef PLT_REINITALISATION_BP
363			PLTs_initialized_by_here = optarg;
364#else
365			fprintf(stderr, "WARNING: \"-X\" not used for this "
366				"architecture: assuming you meant \"-x\"\n");
367#endif
368			/* Fall Thru */
369
370		case 'x':
371			{
372				struct opt_x_t *p = opt_x;
373
374				/* First, check for duplicate. */
375				while (p && strcmp(p->name, optarg)) {
376					p = p->next;
377				}
378				if (p) {
379					break;
380				}
381
382				/* If not duplicate, add to list. */
383				p = malloc(sizeof(struct opt_x_t));
384				if (!p) {
385					perror("ltrace: malloc");
386					exit(1);
387				}
388				p->name = optarg;
389				p->found = 0;
390				p->next = opt_x;
391				opt_x = p;
392				break;
393			}
394
395		default:
396			err_usage();
397		}
398	}
399	argc -= optind;
400	argv += optind;
401
402	if (!opt_F) {
403		opt_F = malloc(sizeof(struct opt_F_t));
404		opt_F->next = malloc(sizeof(struct opt_F_t));
405		opt_F->next->next = NULL;
406		opt_F->filename = USER_CONFIG_FILE;
407		opt_F->next->filename = SYSTEM_CONFIG_FILE;
408	}
409	/* Reverse the config file list since it was built by
410	 * prepending, and it would make more sense to process the
411	 * files in the order they were given. Probably it would make
412	 * more sense to keep a tail pointer instead? */
413	{
414		struct opt_F_t *egg = NULL;
415		struct opt_F_t *chicken;
416		while (opt_F) {
417			chicken = opt_F->next;
418			opt_F->next = egg;
419			egg = opt_F;
420			opt_F = chicken;
421		}
422		opt_F = egg;
423	}
424
425	if (!opt_p && argc < 1) {
426		fprintf(stderr, "%s: too few arguments\n", progname);
427		err_usage();
428	}
429	if (opt_r && opt_t) {
430		fprintf(stderr, "%s: Incompatible options -r and -t\n",
431			progname);
432		err_usage();
433	}
434	if (argc > 0) {
435		command = search_for_command(argv[0]);
436	}
437	return &argv[0];
438}
439