xref: /dragonfly/usr.bin/ldd/ldd.c (revision 43b4d1bd)
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 1.4 2004/08/19 23:41:07 joerg Exp $
32  */
33 
34 #include <sys/param.h>
35 #include <sys/wait.h>
36 #include <machine/elf.h>
37 #include <a.out.h>
38 #include <dlfcn.h>
39 #include <err.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <unistd.h>
44 
45 extern void	dump_file(const char *);
46 extern int	error_count;
47 
48 void
49 usage(void)
50 {
51 	fprintf(stderr, "usage: ldd [-v] [-f format] program ...\n");
52 	exit(1);
53 }
54 
55 int
56 main(int argc, char **argv)
57 {
58 	char		*fmt1 = NULL, *fmt2 = NULL;
59 	int		rval;
60 	int		c;
61 	int		vflag = 0;
62 
63 	while ((c = getopt(argc, argv, "vf:")) != -1) {
64 		switch (c) {
65 		case 'v':
66 			vflag++;
67 			break;
68 		case 'f':
69 			if (fmt1) {
70 				if (fmt2)
71 					errx(1, "too many formats");
72 				fmt2 = optarg;
73 			} else
74 				fmt1 = optarg;
75 			break;
76 		default:
77 			usage();
78 			/*NOTREACHED*/
79 		}
80 	}
81 	argc -= optind;
82 	argv += optind;
83 
84 	if (vflag && fmt1)
85 		errx(1, "-v may not be used with -f");
86 
87 	if (argc <= 0) {
88 		usage();
89 		/*NOTREACHED*/
90 	}
91 
92 #ifdef __i386__
93 	if (vflag) {
94 		for (c = 0; c < argc; c++)
95 			dump_file(argv[c]);
96 		exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
97 	}
98 #endif
99 
100 	/* ld.so magic */
101 	setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
102 	if (fmt1)
103 		setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
104 	if (fmt2)
105 		setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
106 
107 	rval = 0;
108 	for ( ;  argc > 0;  argc--, argv++) {
109 		int	fd;
110 		union {
111 			struct exec aout;
112 			Elf_Ehdr elf;
113 		} hdr;
114 		int	n;
115 		int	status;
116 		int	file_ok;
117 		int	is_shlib;
118 
119 		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
120 			warn("%s", *argv);
121 			rval |= 1;
122 			continue;
123 		}
124 		if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
125 			warn("%s: can't read program header", *argv);
126 			(void)close(fd);
127 			rval |= 1;
128 			continue;
129 		}
130 
131 		file_ok = 1;
132 		is_shlib = 0;
133 		if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
134 			/* a.out file */
135 			if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
136 #if 1 /* Compatibility */
137 			    || hdr.aout.a_entry < __LDPGSZ
138 #endif
139 				) {
140 				warnx("%s: not a dynamic executable", *argv);
141 				file_ok = 0;
142 			}
143 		} else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
144 			Elf_Ehdr ehdr;
145 			Elf_Phdr phdr;
146 			int dynamic = 0, i;
147 
148 			if (lseek(fd, 0, SEEK_SET) == -1 ||
149 			    read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
150 			    lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
151 			   ) {
152 				warnx("%s: can't read program header", *argv);
153 				file_ok = 0;
154 			} else {
155 				for (i = 0; i < ehdr.e_phnum; i++) {
156 					if (read(fd, &phdr, ehdr.e_phentsize)
157 					   != sizeof phdr) {
158 						warnx("%s: can't read program header",
159 						    *argv);
160 						file_ok = 0;
161 						break;
162 					}
163 					if (phdr.p_type == PT_DYNAMIC)
164 						dynamic = 1;
165 				}
166 			}
167 			if (!dynamic) {
168 				warnx("%s: not a dynamic executable", *argv);
169 				file_ok = 0;
170 			} else if (hdr.elf.e_type == ET_DYN) {
171 				if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
172 					is_shlib = 1;
173 				} else {
174 					warnx("%s: not a FreeBSD ELF shared "
175 					      "object", *argv);
176 					file_ok = 0;
177 				}
178 			}
179 		} else {
180 			warnx("%s: not a dynamic executable", *argv);
181 			file_ok = 0;
182 		}
183 		(void)close(fd);
184 		if (!file_ok) {
185 			rval |= 1;
186 			continue;
187 		}
188 
189 		setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
190 		if (fmt1 == NULL && fmt2 == NULL)
191 			/* Default formats */
192 			printf("%s:\n", *argv);
193 
194 		fflush(stdout);
195 
196 		switch (fork()) {
197 		case -1:
198 			err(1, "fork");
199 			break;
200 		default:
201 			if (wait(&status) <= 0) {
202 				warn("wait");
203 				rval |= 1;
204 			} else if (WIFSIGNALED(status)) {
205 				fprintf(stderr, "%s: signal %d\n",
206 						*argv, WTERMSIG(status));
207 				rval |= 1;
208 			} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
209 				fprintf(stderr, "%s: exit status %d\n",
210 						*argv, WEXITSTATUS(status));
211 				rval |= 1;
212 			}
213 			break;
214 		case 0:
215 			if (is_shlib == 0) {
216 				execl(*argv, *argv, (char *)NULL);
217 				warn("%s", *argv);
218 			} else {
219 				dlopen(*argv, RTLD_TRACE);
220 				warnx("%s: %s", *argv, dlerror());
221 			}
222 			_exit(1);
223 		}
224 	}
225 
226 	return rval;
227 }
228