xref: /dragonfly/usr.bin/ldd/ldd.c (revision 6e285212)
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  * $FreeBSD: src/usr.bin/ldd/ldd.c,v 1.18.2.7 2002/02/27 18:35:53 sobomax Exp $
31  * $DragonFly: src/usr.bin/ldd/ldd.c,v 1.2 2003/06/17 04:29:27 dillon Exp $
32  */
33 
34 #include <sys/wait.h>
35 #include <machine/elf.h>
36 #include <a.out.h>
37 #include <dlfcn.h>
38 #include <err.h>
39 #include <fcntl.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43 
44 extern void	dump_file __P((const char *));
45 extern int	error_count;
46 
47 void
48 usage()
49 {
50 	fprintf(stderr, "usage: ldd [-v] [-f format] program ...\n");
51 	exit(1);
52 }
53 
54 int
55 main(argc, argv)
56 int	argc;
57 char	*argv[];
58 {
59 	char		*fmt1 = NULL, *fmt2 = NULL;
60 	int		rval;
61 	int		c;
62 	int		vflag = 0;
63 
64 	while ((c = getopt(argc, argv, "vf:")) != -1) {
65 		switch (c) {
66 		case 'v':
67 			vflag++;
68 			break;
69 		case 'f':
70 			if (fmt1) {
71 				if (fmt2)
72 					errx(1, "too many formats");
73 				fmt2 = optarg;
74 			} else
75 				fmt1 = optarg;
76 			break;
77 		default:
78 			usage();
79 			/*NOTREACHED*/
80 		}
81 	}
82 	argc -= optind;
83 	argv += optind;
84 
85 	if (vflag && fmt1)
86 		errx(1, "-v may not be used with -f");
87 
88 	if (argc <= 0) {
89 		usage();
90 		/*NOTREACHED*/
91 	}
92 
93 #ifdef __i386__
94 	if (vflag) {
95 		for (c = 0; c < argc; c++)
96 			dump_file(argv[c]);
97 		exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
98 	}
99 #endif
100 
101 	/* ld.so magic */
102 	setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
103 	if (fmt1)
104 		setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
105 	if (fmt2)
106 		setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
107 
108 	rval = 0;
109 	for ( ;  argc > 0;  argc--, argv++) {
110 		int	fd;
111 		union {
112 			struct exec aout;
113 			Elf_Ehdr elf;
114 		} hdr;
115 		int	n;
116 		int	status;
117 		int	file_ok;
118 		int	is_shlib;
119 
120 		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
121 			warn("%s", *argv);
122 			rval |= 1;
123 			continue;
124 		}
125 		if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
126 			warn("%s: can't read program header", *argv);
127 			(void)close(fd);
128 			rval |= 1;
129 			continue;
130 		}
131 
132 		file_ok = 1;
133 		is_shlib = 0;
134 		if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
135 			/* a.out file */
136 			if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
137 #if 1 /* Compatibility */
138 			    || hdr.aout.a_entry < __LDPGSZ
139 #endif
140 				) {
141 				warnx("%s: not a dynamic executable", *argv);
142 				file_ok = 0;
143 			}
144 		} else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
145 			Elf_Ehdr ehdr;
146 			Elf_Phdr phdr;
147 			int dynamic = 0, i;
148 
149 			if (lseek(fd, 0, SEEK_SET) == -1 ||
150 			    read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
151 			    lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
152 			   ) {
153 				warnx("%s: can't read program header", *argv);
154 				file_ok = 0;
155 			} else {
156 				for (i = 0; i < ehdr.e_phnum; i++) {
157 					if (read(fd, &phdr, ehdr.e_phentsize)
158 					   != sizeof phdr) {
159 						warnx("%s: can't read program header",
160 						    *argv);
161 						file_ok = 0;
162 						break;
163 					}
164 					if (phdr.p_type == PT_DYNAMIC)
165 						dynamic = 1;
166 				}
167 			}
168 			if (!dynamic) {
169 				warnx("%s: not a dynamic executable", *argv);
170 				file_ok = 0;
171 			} else if (hdr.elf.e_type == ET_DYN) {
172 				if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
173 					is_shlib = 1;
174 				} else {
175 					warnx("%s: not a FreeBSD ELF shared "
176 					      "object", *argv);
177 					file_ok = 0;
178 				}
179 			}
180 		} else {
181 			warnx("%s: not a dynamic executable", *argv);
182 			file_ok = 0;
183 		}
184 		(void)close(fd);
185 		if (!file_ok) {
186 			rval |= 1;
187 			continue;
188 		}
189 
190 		setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
191 		if (fmt1 == NULL && fmt2 == NULL)
192 			/* Default formats */
193 			printf("%s:\n", *argv);
194 
195 		fflush(stdout);
196 
197 		switch (fork()) {
198 		case -1:
199 			err(1, "fork");
200 			break;
201 		default:
202 			if (wait(&status) <= 0) {
203 				warn("wait");
204 				rval |= 1;
205 			} else if (WIFSIGNALED(status)) {
206 				fprintf(stderr, "%s: signal %d\n",
207 						*argv, WTERMSIG(status));
208 				rval |= 1;
209 			} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
210 				fprintf(stderr, "%s: exit status %d\n",
211 						*argv, WEXITSTATUS(status));
212 				rval |= 1;
213 			}
214 			break;
215 		case 0:
216 			if (is_shlib == 0) {
217 				execl(*argv, *argv, (char *)NULL);
218 				warn("%s", *argv);
219 			} else {
220 				dlopen(*argv, RTLD_TRACE);
221 				warnx("%s: %s", *argv, dlerror());
222 			}
223 			_exit(1);
224 		}
225 	}
226 
227 	return rval;
228 }
229