options.c revision 28aab0a66f57a93581d805cf0875aced928310a2 
1#if HAVE_CONFIG_H
2#include "config.h"
3#endif
4
5#include <string.h>
6#include <stdlib.h>
7#include <unistd.h>
8#include <fcntl.h>
9#include <errno.h>
10#include <limits.h>
11
12#if HAVE_GETOPT_H
13#include <getopt.h>
14#endif
15
16#include "ltrace.h"
17#include "options.h"
18#include "defs.h"
19
20#ifndef SYSCONFDIR
21#define SYSCONFDIR "/etc"
22#endif
23
24#define SYSTEM_CONFIG_FILE SYSCONFDIR "/trace.conf"
25#define USER_CONFIG_FILE "~/.ltrace.conf"
26
27#define MAX_LIBRARY		30
28char *library[MAX_LIBRARY];
29int library_num = 0;
30static char *progname;		/* Program name (`ltrace') */
31FILE *output;
32int opt_a = DEFAULT_ACOLUMN;	/* default alignment column for results */
33int opt_c = 0;			/* Count time, calls, and report a summary on program exit */
34int opt_d = 0;			/* debug */
35int opt_i = 0;			/* instruction pointer */
36int opt_s = DEFAULT_STRLEN;	/* default maximum # of bytes printed in strings */
37int opt_S = 0;			/* display syscalls */
38int opt_L = 1;			/* display library calls */
39int opt_f = 0;			/* trace child processes as they are created */
40char *opt_u = NULL;		/* username to run command as */
41int opt_r = 0;			/* print relative timestamp */
42int opt_t = 0;			/* print absolute timestamp */
43#ifdef USE_DEMANGLE
44int opt_C = 0;			/* Demangle low-level symbol names into user-level names */
45#endif
46int opt_n = 0;			/* indent trace output according to program flow */
47int opt_T = 0;			/* show the time spent inside each call */
48
49/* List of pids given to option -p: */
50struct opt_p_t *opt_p = NULL;	/* attach to process with a given pid */
51
52/* List of function names given to option -e: */
53struct opt_e_t *opt_e = NULL;
54int opt_e_enable = 1;
55
56/* List of global function names given to -x: */
57struct opt_x_t *opt_x = NULL;
58
59/* List of filenames give to option -F: */
60struct opt_F_t *opt_F = NULL;	/* alternate configuration file(s) */
61
62#ifdef PLT_REINITALISATION_BP
63/* Set a break on the routine named here in order to re-initialize breakpoints
64   after all the PLTs have been initialzed */
65char *PLTs_initialized_by_here = PLT_REINITALISATION_BP;
66#endif
67
68static void usage(void)
69{
70#if !(HAVE_GETOPT || HAVE_GETOPT_LONG)
71	fprintf(stdout, "Usage: %s [command [arg ...]]\n"
72		"Trace library calls of a given program.\n\n", progname);
73#else
74	fprintf(stdout, "Usage: %s [option ...] [command [arg ...]]\n"
75		"Trace library calls of a given program.\n\n"
76# if HAVE_GETOPT_LONG
77		"  -a, --align=COLUMN  align return values in a secific column.\n"
78# else
79		"  -a COLUMN           align return values in a secific column.\n"
80# endif
81		"  -c                  count time and calls, and report a summary on exit.\n"
82# ifdef USE_DEMANGLE
83#  if HAVE_GETOPT_LONG
84		"  -C, --demangle      decode low-level symbol names into user-level names.\n"
85#  else
86		"  -C                  decode low-level symbol names into user-level names.\n"
87#  endif
88# endif
89# if HAVE_GETOPT_LONG
90		"  -d, --debug         print debugging info.\n"
91# else
92		"  -d                  print debugging info.\n"
93# endif
94		"  -e expr             modify which events to trace.\n"
95		"  -f                  follow forks.\n"
96# if HAVE_GETOPT_LONG
97                "  -F, --config=FILE   load alternate configuration file\n"
98# else
99                "  -F FILE             load alternate configuration file\n"
100# endif
101                "                      (can be repeated).\n"
102# if HAVE_GETOPT_LONG
103		"  -h, --help          display this help and exit.\n"
104# else
105		"  -h                  display this help and exit.\n"
106# endif
107		"  -i                  print instruction pointer at time of library call.\n"
108#  if HAVE_GETOPT_LONG
109		"  -l, --library=FILE  print library calls from this library only.\n"
110#  else
111		"  -l FILE             print library calls from this library only.\n"
112#  endif
113		"  -L                  do NOT display library calls.\n"
114# if HAVE_GETOPT_LONG
115		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
116# else
117		"  -n NR               indent output by NR spaces for each call level nesting.\n"
118# endif
119# if HAVE_GETOPT_LONG
120		"  -o, --output=FILE   write the trace output to that file.\n"
121# else
122		"  -o FILE             write the trace output to that file.\n"
123# endif
124		"  -p PID              attach to the process with the process ID pid.\n"
125		"  -r                  print relative timestamps.\n"
126		"  -s STRLEN           specify the maximum string size to print.\n"
127		"  -S                  display system calls.\n"
128		"  -t, -tt, -ttt       print absolute timestamps.\n"
129		"  -T                  show the time spent inside each call.\n"
130		"  -u USERNAME         run command with the userid, groupid of username.\n"
131# if HAVE_GETOPT_LONG
132		"  -V, --version       output version information and exit.\n"
133# else
134		"  -V                  output version information and exit.\n"
135# endif
136		"  -x NAME             treat the global NAME like a library subroutine.\n"
137#ifdef PLT_REINITALISATION_BP
138		"  -X NAME             same as -x; and PLT's will be initialized by here.\n"
139#endif
140		"\nReport bugs to ltrace-devel@lists.alioth.debian.org\n",
141		progname);
142#endif
143}
144
145static char *search_for_command(char *filename)
146{
147	static char pathname[PATH_MAX];
148	char *path;
149	int m, n;
150
151	if (strchr(filename, '/')) {
152		return filename;
153	}
154	for (path = getenv("PATH"); path && *path; path += m) {
155		if (strchr(path, ':')) {
156			n = strchr(path, ':') - path;
157			m = n + 1;
158		} else {
159			m = n = strlen(path);
160		}
161		if (n + strlen(filename) + 1 >= PATH_MAX) {
162			fprintf(stderr, "Error: filename too long\n");
163			exit(1);
164		}
165		strncpy(pathname, path, n);
166		if (n && pathname[n - 1] != '/') {
167			pathname[n++] = '/';
168		}
169		strcpy(pathname + n, filename);
170		if (!access(pathname, X_OK)) {
171			return pathname;
172		}
173	}
174	return filename;
175}
176
177char **process_options(int argc, char **argv)
178{
179	progname = argv[0];
180	output = stderr;
181
182#if HAVE_GETOPT || HAVE_GETOPT_LONG
183	while (1) {
184		int c;
185#if HAVE_GETOPT_LONG
186		int option_index = 0;
187		static struct option long_options[] = {
188			{"align", 1, 0, 'a'},
189                        {"config", 1, 0, 'F'},
190			{"debug", 0, 0, 'd'},
191# ifdef USE_DEMANGLE
192			{"demangle", 0, 0, 'C'},
193#endif
194			{"indent", 1, 0, 'n'},
195			{"help", 0, 0, 'h'},
196			{"library", 1, 0, 'l'},
197			{"output", 1, 0, 'o'},
198			{"version", 0, 0, 'V'},
199			{0, 0, 0, 0}
200		};
201		c = getopt_long(argc, argv, "+cdfhiLrStTV"
202# ifdef USE_DEMANGLE
203				"C"
204# endif
205				"a:e:F:l:n:o:p:s:u:x:X:", long_options,
206				&option_index);
207#else
208		c = getopt(argc, argv, "+cdfhiLrStTV"
209# ifdef USE_DEMANGLE
210			   "C"
211# endif
212			   "a:e:F:l:n:o:p:s:u:x:X:");
213#endif
214		if (c == -1) {
215			break;
216		}
217		switch (c) {
218		case 'a':
219			opt_a = atoi(optarg);
220			break;
221		case 'c':
222			opt_c++;
223			break;
224#ifdef USE_DEMANGLE
225		case 'C':
226			opt_C++;
227			break;
228#endif
229		case 'd':
230			opt_d++;
231			break;
232		case 'e':
233			{
234				char *str_e = strdup(optarg);
235				if (!str_e) {
236					perror("ltrace: strdup");
237					exit(1);
238				}
239				if (str_e[0] == '!') {
240					opt_e_enable = 0;
241					str_e++;
242				}
243				while (*str_e) {
244					struct opt_e_t *tmp;
245					char *str2 = strchr(str_e, ',');
246					if (str2) {
247						*str2 = '\0';
248					}
249					tmp = malloc(sizeof(struct opt_e_t));
250					if (!tmp) {
251						perror("ltrace: malloc");
252						exit(1);
253					}
254					tmp->name = str_e;
255					tmp->next = opt_e;
256					opt_e = tmp;
257					if (str2) {
258						str_e = str2 + 1;
259					} else {
260						break;
261					}
262				}
263				break;
264			}
265		case 'f':
266			opt_f = 1;
267			break;
268                case 'F':
269                	{
270                          struct opt_F_t *tmp = malloc(sizeof(struct opt_F_t));
271                          if (!tmp) {
272                            perror("ltrace: malloc");
273                            exit(1);
274                          }
275                          tmp->filename = strdup(optarg);
276                          tmp->next = opt_F;
277                          opt_F = tmp;
278                          break;
279                        }
280		case 'h':
281			usage();
282			exit(0);
283		case 'i':
284			opt_i++;
285			break;
286		case 'l':
287			if (library_num == MAX_LIBRARY) {
288				fprintf(stderr,
289					"Too many libraries.  Maximum is %i.\n",
290					MAX_LIBRARY);
291				exit(1);
292			}
293			library[library_num++] = optarg;
294			break;
295		case 'L':
296			opt_L = 0;
297			break;
298		case 'n':
299			opt_n = atoi(optarg);
300			break;
301		case 'o':
302			output = fopen(optarg, "w");
303			if (!output) {
304				fprintf(stderr,
305					"Can't open %s for output: %s\n",
306					optarg, strerror(errno));
307				exit(1);
308			}
309			setvbuf(output, (char *)NULL, _IOLBF, 0);
310			fcntl(fileno(output), F_SETFD, FD_CLOEXEC);
311			break;
312		case 'p':
313			{
314				struct opt_p_t *tmp =
315				    malloc(sizeof(struct opt_p_t));
316				if (!tmp) {
317					perror("ltrace: malloc");
318					exit(1);
319				}
320				tmp->pid = atoi(optarg);
321				tmp->next = opt_p;
322				opt_p = tmp;
323				break;
324			}
325		case 'r':
326			opt_r++;
327			break;
328		case 's':
329			opt_s = atoi(optarg);
330			break;
331		case 'S':
332			opt_S = 1;
333			break;
334		case 't':
335			opt_t++;
336			break;
337		case 'T':
338			opt_T++;
339			break;
340		case 'u':
341			opt_u = optarg;
342			break;
343		case 'V':
344			printf("ltrace version " PACKAGE_VERSION ".\n"
345			       "Copyright (C) 1997-2006 Juan Cespedes <cespedes@debian.org>.\n"
346			       "This is free software; see the GNU General Public Licence\n"
347			       "version 2 or later for copying conditions.  There is NO warranty.\n");
348			exit(0);
349		case 'X':
350#ifdef PLT_REINITALISATION_BP
351			PLTs_initialized_by_here = optarg;
352#else
353			fprintf(stderr, "WANRING: \"-X\" not used for this "
354				"architecture: assuming you meant \"-x\"\n");
355#endif
356			/* Fall Thru */
357
358		case 'x':
359			{
360				struct opt_x_t *p = opt_x;
361
362				/* First, check for duplicate. */
363				while (p && strcmp(p->name, optarg)) {
364					p = p->next;
365				}
366				if (p) {
367					break;
368				}
369
370				/* If not duplicate, add to list. */
371				p = malloc(sizeof(struct opt_x_t));
372				if (!p) {
373					perror("ltrace: malloc");
374					exit(1);
375				}
376				p->name = optarg;
377				p->found = 0;
378				p->next = opt_x;
379				opt_x = p;
380				break;
381			}
382
383		default:
384#if HAVE_GETOPT_LONG
385			fprintf(stderr,
386				"Try `%s --help' for more information\n",
387				progname);
388#else
389			fprintf(stderr, "Try `%s -h' for more information\n",
390				progname);
391#endif
392			exit(1);
393		}
394	}
395	argc -= optind;
396	argv += optind;
397#endif
398
399        if (!opt_F) {
400	    opt_F = malloc(sizeof(struct opt_F_t));
401	    opt_F->next = malloc(sizeof(struct opt_F_t));
402	    opt_F->next->next = NULL;
403	    opt_F->filename = USER_CONFIG_FILE;
404	    opt_F->next->filename = SYSTEM_CONFIG_FILE;
405        }
406	/* Reverse the config file list since it was built by
407	 * prepending, and it would make more sense to process the
408	 * files in the order they were given. Probably it would make
409	 * more sense to keep a tail pointer instead? */
410	{
411	    struct opt_F_t *egg = NULL;
412	    struct opt_F_t *chicken;
413	    while (opt_F) {
414		chicken = opt_F->next;
415		opt_F->next = egg;
416		egg = opt_F;
417		opt_F = chicken;
418	    }
419	    opt_F = egg;
420	}
421
422	if (!opt_p && argc < 1) {
423		fprintf(stderr, "%s: too few arguments\n", progname);
424		usage();
425		exit(1);
426	}
427	if (opt_r && opt_t) {
428		fprintf(stderr, "%s: Incompatible options -r and -t\n",
429			progname);
430		exit(1);
431	}
432	if (argc > 0) {
433		command = search_for_command(argv[0]);
434	}
435	return &argv[0];
436}
437