options.c revision f670eea50e959eeb9da53d70cad8d43c19494ef0 
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		"  -h, --help          display this help and exit.\n"
88		"  -i                  print instruction pointer at time of library call.\n"
89		"  -l, --library=FILE  print library calls from this library only.\n"
90		"  -L                  do NOT display library calls.\n"
91		"  -n, --indent=NR     indent output by NR spaces for each call level nesting.\n"
92		"  -o, --output=FILE   write the trace output to that file.\n"
93		"  -p PID              attach to the process with the process ID pid.\n"
94		"  -r                  print relative timestamps.\n"
95		"  -s STRLEN           specify the maximum string size to print.\n"
96		"  -S                  display system calls.\n"
97		"  -t, -tt, -ttt       print absolute timestamps.\n"
98		"  -T                  show the time spent inside each call.\n"
99		"  -u USERNAME         run command with the userid, groupid of username.\n"
100		"  -V, --version       output version information and exit.\n"
101		"  -x NAME             treat the global NAME like a library subroutine.\n"
102#ifdef PLT_REINITALISATION_BP
103		"  -X NAME             same as -x; and PLT's will be initialized by here.\n"
104#endif
105		"\nReport bugs to ltrace-devel@lists.alioth.debian.org\n",
106		progname);
107}
108
109static void
110usage_debug(void) {
111	fprintf(stdout, "%s debugging option, --debug=<octal> or -D<octal>:\n", progname);
112	fprintf(stdout,
113			"\n"
114			" number  ref. in source   description\n"
115			"      1   general           Generally helpful progress information\n"
116			"     10   event             Shows every event received by a traced process\n"
117			"     20   process           Shows actions carried upon a traced processes\n"
118			"     40   function          Shows every entry to internal functions\n"
119			"\n"
120			"Debugging options are mixed using bitwise-or.\n"
121			"Note that the meanings and values are subject to change.\n"
122		   );
123}
124
125static char *
126search_for_command(char *filename) {
127	static char pathname[PATH_MAX];
128	char *path;
129	int m, n;
130
131	if (strchr(filename, '/')) {
132		return filename;
133	}
134	for (path = getenv("PATH"); path && *path; path += m) {
135		if (strchr(path, ':')) {
136			n = strchr(path, ':') - path;
137			m = n + 1;
138		} else {
139			m = n = strlen(path);
140		}
141		if (n + strlen(filename) + 1 >= PATH_MAX) {
142			fprintf(stderr, "Error: filename too long\n");
143			exit(1);
144		}
145		strncpy(pathname, path, n);
146		if (n && pathname[n - 1] != '/') {
147			pathname[n++] = '/';
148		}
149		strcpy(pathname + n, filename);
150		if (!access(pathname, X_OK)) {
151			return pathname;
152		}
153	}
154	return filename;
155}
156
157static void
158guess_cols(void) {
159	struct winsize ws;
160	char *c;
161
162	options.align = DEFAULT_ALIGN;
163	c = getenv("COLUMNS");
164	if (c && *c) {
165		char *endptr;
166		int cols;
167		cols = strtol(c, &endptr, 0);
168		if (cols > 0 && !*endptr) {
169			options.align = cols * 5 / 8;
170		}
171	} else if (ioctl(1, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
172		options.align = ws.ws_col * 5 / 8;
173	} else if (ioctl(2, TIOCGWINSZ, &ws) != -1 && ws.ws_col > 0) {
174		options.align = ws.ws_col * 5 / 8;
175	}
176}
177
178char **
179process_options(int argc, char **argv) {
180	progname = argv[0];
181	options.output = stderr;
182
183	guess_cols();
184
185	while (1) {
186		int c;
187		char *p;
188		int option_index = 0;
189		static struct option long_options[] = {
190			{"align", 1, 0, 'a'},
191			{"config", 1, 0, 'F'},
192			{"debug", 1, 0, 'D'},
193# ifdef USE_DEMANGLE
194			{"demangle", 0, 0, 'C'},
195#endif
196			{"indent", 1, 0, 'n'},
197			{"help", 0, 0, 'h'},
198			{"library", 1, 0, 'l'},
199			{"output", 1, 0, 'o'},
200			{"version", 0, 0, 'V'},
201			{0, 0, 0, 0}
202		};
203		c = getopt_long(argc, argv, "+cfhiLrStTV"
204# ifdef USE_DEMANGLE
205				"C"
206# endif
207				"a:A:D:e:F:l:n:o:p:s:u:x:X:", long_options,
208				&option_index);
209		if (c == -1) {
210			break;
211		}
212		switch (c) {
213		case 'a':
214			options.align = atoi(optarg);
215			break;
216		case 'A':
217			options.arraylen = atoi(optarg);
218			break;
219		case 'c':
220			options.summary++;
221			break;
222#ifdef USE_DEMANGLE
223		case 'C':
224			options.demangle++;
225			break;
226#endif
227		case 'D':
228			if (optarg[0]=='h') {
229				usage_debug();
230				exit(0);
231			}
232			options.debug = strtoul(optarg,&p,8);
233			if (*p) {
234				fprintf(stderr, "%s: --debug requires an octal argument\n", progname);
235				err_usage();
236			}
237			break;
238		case 'e':
239			{
240				char *str_e = strdup(optarg);
241				if (!str_e) {
242					perror("ltrace: strdup");
243					exit(1);
244				}
245				if (str_e[0] == '!') {
246					opt_e_enable = 0;
247					str_e++;
248				}
249				while (*str_e) {
250					struct opt_e_t *tmp;
251					char *str2 = strchr(str_e, ',');
252					if (str2) {
253						*str2 = '\0';
254					}
255					tmp = malloc(sizeof(struct opt_e_t));
256					if (!tmp) {
257						perror("ltrace: malloc");
258						exit(1);
259					}
260					tmp->name = str_e;
261					tmp->next = opt_e;
262					opt_e = tmp;
263					if (str2) {
264						str_e = str2 + 1;
265					} else {
266						break;
267					}
268				}
269				break;
270			}
271		case 'f':
272			options.follow = 1;
273			break;
274		case 'F':
275			{
276				struct opt_F_t *tmp = malloc(sizeof(struct opt_F_t));
277				if (!tmp) {
278					perror("ltrace: malloc");
279					exit(1);
280				}
281				tmp->filename = strdup(optarg);
282				tmp->next = opt_F;
283				opt_F = tmp;
284				break;
285			}
286		case 'h':
287			usage();
288			exit(0);
289		case 'i':
290			opt_i++;
291			break;
292		case 'l':
293			if (library_num == MAX_LIBRARIES) {
294				fprintf(stderr,
295					"Too many libraries.  Maximum is %i.\n",
296					MAX_LIBRARIES);
297				exit(1);
298			}
299			library[library_num++] = optarg;
300			break;
301		case 'L':
302			options.libcalls = 0;
303			break;
304		case 'n':
305			options.indent = atoi(optarg);
306			break;
307		case 'o':
308			options.output = fopen(optarg, "w");
309			if (!options.output) {
310				fprintf(stderr,
311					"Can't open %s for output: %s\n",
312					optarg, strerror(errno));
313				exit(1);
314			}
315			setvbuf(options.output, (char *)NULL, _IOLBF, 0);
316			fcntl(fileno(options.output), F_SETFD, FD_CLOEXEC);
317			break;
318		case 'p':
319			{
320				struct opt_p_t *tmp = malloc(sizeof(struct opt_p_t));
321				if (!tmp) {
322					perror("ltrace: malloc");
323					exit(1);
324				}
325				tmp->pid = atoi(optarg);
326				tmp->next = opt_p;
327				opt_p = tmp;
328				break;
329			}
330		case 'r':
331			opt_r++;
332			break;
333		case 's':
334			options.strlen = atoi(optarg);
335			break;
336		case 'S':
337			options.syscalls = 1;
338			break;
339		case 't':
340			opt_t++;
341			break;
342		case 'T':
343			opt_T++;
344			break;
345		case 'u':
346			options.user = optarg;
347			break;
348		case 'V':
349			printf("ltrace version " PACKAGE_VERSION ".\n"
350					"Copyright (C) 1997-2009 Juan Cespedes <cespedes@debian.org>.\n"
351					"This is free software; see the GNU General Public Licence\n"
352					"version 2 or later for copying conditions.  There is NO warranty.\n");
353			exit(0);
354		case 'X':
355#ifdef PLT_REINITALISATION_BP
356			PLTs_initialized_by_here = optarg;
357#else
358			fprintf(stderr, "WARNING: \"-X\" not used for this "
359				"architecture: assuming you meant \"-x\"\n");
360#endif
361			/* Fall Thru */
362
363		case 'x':
364			{
365				struct opt_x_t *p = opt_x;
366
367				/* First, check for duplicate. */
368				while (p && strcmp(p->name, optarg)) {
369					p = p->next;
370				}
371				if (p) {
372					break;
373				}
374
375				/* If not duplicate, add to list. */
376				p = malloc(sizeof(struct opt_x_t));
377				if (!p) {
378					perror("ltrace: malloc");
379					exit(1);
380				}
381				p->name = optarg;
382				p->found = 0;
383				p->next = opt_x;
384				opt_x = p;
385				break;
386			}
387
388		default:
389			err_usage();
390		}
391	}
392	argc -= optind;
393	argv += optind;
394
395	if (!opt_F) {
396		opt_F = malloc(sizeof(struct opt_F_t));
397		opt_F->next = malloc(sizeof(struct opt_F_t));
398		opt_F->next->next = NULL;
399		opt_F->filename = USER_CONFIG_FILE;
400		opt_F->next->filename = SYSTEM_CONFIG_FILE;
401	}
402	/* Reverse the config file list since it was built by
403	 * prepending, and it would make more sense to process the
404	 * files in the order they were given. Probably it would make
405	 * more sense to keep a tail pointer instead? */
406	{
407		struct opt_F_t *egg = NULL;
408		struct opt_F_t *chicken;
409		while (opt_F) {
410			chicken = opt_F->next;
411			opt_F->next = egg;
412			egg = opt_F;
413			opt_F = chicken;
414		}
415		opt_F = egg;
416	}
417
418	if (!opt_p && argc < 1) {
419		fprintf(stderr, "%s: too few arguments\n", progname);
420		err_usage();
421	}
422	if (opt_r && opt_t) {
423		fprintf(stderr, "%s: Incompatible options -r and -t\n",
424			progname);
425		err_usage();
426	}
427	if (argc > 0) {
428		command = search_for_command(argv[0]);
429	}
430	return &argv[0];
431}
432