ldd.c revision 35575 
1/*
2 * Copyright (c) 1993 Paul Kranenburg
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by Paul Kranenburg.
16 * 4. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 *	$Id: ldd.c,v 1.14 1997/09/02 21:54:39 jdp Exp $
31 */
32
33#include <sys/types.h>
34#include <sys/stat.h>
35#include <sys/file.h>
36#include <sys/time.h>
37#include <sys/resource.h>
38#include <sys/wait.h>
39#include <a.out.h>
40#include <elf.h>
41#include <err.h>
42#include <fcntl.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <unistd.h>
47
48extern void	dump_file __P((const char *));
49extern int	error_count;
50
51void
52usage()
53{
54	fprintf(stderr, "usage: ldd [-v] [-f format] program ...\n");
55	exit(1);
56}
57
58int
59main(argc, argv)
60int	argc;
61char	*argv[];
62{
63	char		*fmt1 = NULL, *fmt2 = NULL;
64	int		rval;
65	int		c;
66	int		vflag = 0;
67
68	while ((c = getopt(argc, argv, "vf:")) != EOF) {
69		switch (c) {
70		case 'v':
71			vflag++;
72			break;
73		case 'f':
74			if (fmt1) {
75				if (fmt2)
76					errx(1, "Too many formats");
77				fmt2 = optarg;
78			} else
79				fmt1 = optarg;
80			break;
81		default:
82			usage();
83			/*NOTREACHED*/
84		}
85	}
86	argc -= optind;
87	argv += optind;
88
89	if (vflag && fmt1)
90		errx(1, "-v may not be used with -f");
91
92	if (argc <= 0) {
93		usage();
94		/*NOTREACHED*/
95	}
96
97	if (vflag) {
98		for (c = 0; c < argc; c++)
99			dump_file(argv[c]);
100		exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
101	}
102
103	/* ld.so magic */
104	setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
105	if (fmt1)
106		setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
107	if (fmt2)
108		setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
109
110	rval = 0;
111	while (argc--) {
112		int	fd;
113		struct exec hdr;
114		int	status;
115
116		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
117			warn("%s", *argv);
118			rval |= 1;
119			argv++;
120			continue;
121		}
122		if (read(fd, &hdr, sizeof hdr) != sizeof hdr) {
123			warnx("%s: can't read program header", *argv);
124			(void)close(fd);
125			rval |= 1;
126			argv++;
127			continue;
128		}
129
130		if (!N_BADMAG(hdr)) {
131			/* a.out file */
132			if ((N_GETFLAG(hdr) & EX_DPMASK) != EX_DYNAMIC
133#if 1 /* Compatibility */
134			    || hdr.a_entry < __LDPGSZ
135#endif
136				) {
137				warnx("%s: not a dynamic executable", *argv);
138				(void)close(fd);
139				rval |= 1;
140				argv++;
141				continue;
142			}
143		} else if (IS_ELF(*(Elf32_Ehdr*)&hdr)) {
144			Elf32_Ehdr ehdr;
145			Elf32_Phdr phdr;
146			int dynamic = 0, i;
147
148			lseek(fd, 0, SEEK_SET);
149			if (read(fd, &ehdr, sizeof ehdr) != sizeof ehdr) {
150				warnx("%s: can't read program header", *argv);
151				(void)close(fd);
152				rval |= 1;
153				argv++;
154				continue;
155			}
156			lseek(fd, 0, ehdr.e_phoff);
157			for (i = 0; i < ehdr.e_phnum; i++) {
158				if (read(fd, &phdr, ehdr.e_phentsize)
159				   != sizeof phdr) {
160					warnx("%s: can't read program header", *argv);
161					(void)close(fd);
162					rval |= 1;
163					argv++;
164					continue;
165				}
166				if (phdr.p_type == PT_DYNAMIC)
167					dynamic = 1;
168			}
169			if (!dynamic) {
170				warnx("%s: not a dynamic executable", *argv);
171				(void)close(fd);
172				rval |= 1;
173				argv++;
174				continue;
175			}
176		}
177		(void)close(fd);
178
179		setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
180		if (fmt1 == NULL && fmt2 == NULL)
181			/* Default formats */
182			printf("%s:\n", *argv);
183
184		fflush(stdout);
185
186		switch (fork()) {
187		case -1:
188			err(1, "fork");
189			break;
190		default:
191			if (wait(&status) <= 0) {
192				warn("wait");
193				rval |= 1;
194			} else if (WIFSIGNALED(status)) {
195				fprintf(stderr, "%s: signal %d\n",
196						*argv, WTERMSIG(status));
197				rval |= 1;
198			} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
199				fprintf(stderr, "%s: exit status %d\n",
200						*argv, WEXITSTATUS(status));
201				rval |= 1;
202			}
203			break;
204		case 0:
205			rval |= execl(*argv, *argv, NULL) != 0;
206			perror(*argv);
207			_exit(1);
208		}
209		argv++;
210	}
211
212	return rval;
213}
214