ldd.c revision 39354 
144743Smarkm/*
244743Smarkm * Copyright (c) 1993 Paul Kranenburg
344743Smarkm * All rights reserved.
444743Smarkm *
544743Smarkm * Redistribution and use in source and binary forms, with or without
644743Smarkm * modification, are permitted provided that the following conditions
744743Smarkm * are met:
844743Smarkm * 1. Redistributions of source code must retain the above copyright
9272949Spfg *    notice, this list of conditions and the following disclaimer.
10272949Spfg * 2. Redistributions in binary form must reproduce the above copyright
11272949Spfg *    notice, this list of conditions and the following disclaimer in the
1244743Smarkm *    documentation and/or other materials provided with the distribution.
1344743Smarkm * 3. All advertising materials mentioning features or use of this software
14272949Spfg *    must display the following acknowledgement:
15272949Spfg *      This product includes software developed by Paul Kranenburg.
16272949Spfg * 4. The name of the author may not be used to endorse or promote products
1744743Smarkm *    derived from this software without specific prior written permission
1844743Smarkm *
1944743Smarkm * 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 1.16 1998/08/30 18:30:59 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#ifdef __i386__
98	if (vflag) {
99		for (c = 0; c < argc; c++)
100			dump_file(argv[c]);
101		exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
102	}
103#endif
104
105	/* ld.so magic */
106	setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
107	if (fmt1)
108		setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
109	if (fmt2)
110		setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
111
112	rval = 0;
113	for ( ;  argc > 0;  argc--, argv++) {
114		int	fd;
115		union {
116			struct exec aout;
117			Elf_Ehdr elf;
118		} hdr;
119		int	n;
120		int	status;
121		int	file_ok;
122
123		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
124			warn("%s", *argv);
125			rval |= 1;
126			continue;
127		}
128		if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
129			warn("%s: can't read program header", *argv);
130			(void)close(fd);
131			rval |= 1;
132			continue;
133		}
134
135		file_ok = 1;
136		if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
137			/* a.out file */
138			if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
139#if 1 /* Compatibility */
140			    || hdr.aout.a_entry < __LDPGSZ
141#endif
142				) {
143				warnx("%s: not a dynamic executable", *argv);
144				file_ok = 0;
145			}
146		} else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
147			Elf_Ehdr ehdr;
148			Elf_Phdr phdr;
149			int dynamic = 0, i;
150
151			lseek(fd, 0, SEEK_SET);
152			if (read(fd, &ehdr, sizeof ehdr) != sizeof ehdr) {
153				warnx("%s: can't read program header", *argv);
154				file_ok = 0;
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",
161					    *argv);
162					file_ok = 0;
163				}
164				if (phdr.p_type == PT_DYNAMIC)
165					dynamic = 1;
166			}
167			if (!dynamic) {
168				warnx("%s: not a dynamic executable", *argv);
169				file_ok = 0;
170			}
171		} else {
172			warnx("%s: not a dynamic executable", *argv);
173			file_ok = 0;
174		}
175		(void)close(fd);
176		if (!file_ok) {
177			rval |= 1;
178			continue;
179		}
180
181		setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
182		if (fmt1 == NULL && fmt2 == NULL)
183			/* Default formats */
184			printf("%s:\n", *argv);
185
186		fflush(stdout);
187
188		switch (fork()) {
189		case -1:
190			err(1, "fork");
191			break;
192		default:
193			if (wait(&status) <= 0) {
194				warn("wait");
195				rval |= 1;
196			} else if (WIFSIGNALED(status)) {
197				fprintf(stderr, "%s: signal %d\n",
198						*argv, WTERMSIG(status));
199				rval |= 1;
200			} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
201				fprintf(stderr, "%s: exit status %d\n",
202						*argv, WEXITSTATUS(status));
203				rval |= 1;
204			}
205			break;
206		case 0:
207			rval |= execl(*argv, *argv, NULL) != 0;
208			perror(*argv);
209			_exit(1);
210		}
211	}
212
213	return rval;
214}
215