xref: /netbsd-src/usr.bin/ldd/ldd_elfxx.c (revision c686ebaab6f021d88083635c6050eb60df3245d4)
1 /*	$NetBSD: ldd_elfxx.c,v 1.8 2021/07/22 17:39:53 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Paul Kranenburg.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright 1996 John D. Polstra.
34  * Copyright 1996 Matt Thomas <matt@3am-software.com>
35  * All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *      This product includes software developed by John Polstra.
48  * 4. The name of the author may not be used to endorse or promote products
49  *    derived from this software without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 #include <sys/cdefs.h>
64 #ifndef lint
65 __RCSID("$NetBSD: ldd_elfxx.c,v 1.8 2021/07/22 17:39:53 christos Exp $");
66 #endif /* not lint */
67 
68 #include <sys/types.h>
69 #include <sys/mman.h>
70 #include <sys/wait.h>
71 #include <sys/stat.h>
72 
73 #include <dirent.h>
74 #include <err.h>
75 #include <errno.h>
76 #include <fcntl.h>
77 #include <stdarg.h>
78 #include <stdio.h>
79 #include <stdlib.h>
80 #include <string.h>
81 #include <unistd.h>
82 #include <ctype.h>
83 
84 #include "debug.h"
85 #include "rtld.h"
86 #include "ldd.h"
87 
88 static void print_needed(Obj_Entry *, const char *, const char *);
89 static void fmtprint(const char *, Obj_Entry *, const char *, const char *);
90 
91 /*
92  * elfxx_ldd() - bit-size independent ELF ldd implementation.
93  * returns 0 on success and -1 on failure.
94  */
95 int
ELFNAME(ldd)96 ELFNAME(ldd)(int fd, char *prog, char *path, const char *fmt1, const char *fmt2)
97 {
98 	struct stat st;
99 
100 	if (lseek(fd, 0, SEEK_SET) < 0 ||
101 	    fstat(fd, &st) < 0) {
102 		_rtld_error("%s: %s", path, strerror(errno));
103 		return -1;
104 	}
105 
106 	_rtld_pagesz = sysconf(_SC_PAGESIZE);
107 
108 #ifdef RTLD_ARCH_SUBDIR
109 	_rtld_add_paths(path, &_rtld_default_paths,
110 	    RTLD_DEFAULT_LIBRARY_PATH "/" RTLD_ARCH_SUBDIR);
111 #endif
112 	_rtld_add_paths(path, &_rtld_default_paths, RTLD_DEFAULT_LIBRARY_PATH);
113 
114 	_rtld_paths = NULL;
115 	_rtld_trust = (st.st_mode & (S_ISUID | S_ISGID)) == 0;
116 	if (_rtld_trust)
117 		_rtld_add_paths(path, &_rtld_paths, getenv("LD_LIBRARY_PATH"));
118 
119 	_rtld_process_hints(path, &_rtld_paths, &_rtld_xforms, _PATH_LD_HINTS);
120 	_rtld_objmain = _rtld_map_object(xstrdup(path), fd, &st);
121 	if (_rtld_objmain == NULL)
122 		return -1;
123 
124 	_rtld_objmain->path = xstrdup(path);
125 	_rtld_digest_dynamic(path, _rtld_objmain);
126 
127 	/* Link the main program into the list of objects. */
128 	*_rtld_objtail = _rtld_objmain;
129 	_rtld_objtail = &_rtld_objmain->next;
130 	++_rtld_objmain->refcount;
131 
132 	(void) _rtld_load_needed_objects(_rtld_objmain, 0);
133 
134 	if (fmt1 == NULL)
135 		printf("%s:\n", prog);
136 	main_local = path;
137 	main_progname = _rtld_objmain->path;
138 	print_needed(_rtld_objmain, fmt1, fmt2);
139 
140 	while (_rtld_objlist != NULL) {
141 		Obj_Entry *obj = _rtld_objlist;
142 		_rtld_objlist = obj->next;
143 		while (obj->rpaths != NULL) {
144 			const Search_Path *rpath = obj->rpaths;
145 			obj->rpaths = rpath->sp_next;
146 			xfree(__UNCONST(rpath->sp_path));
147 			xfree(__UNCONST(rpath));
148 		}
149 		while (obj->needed != NULL) {
150 			const Needed_Entry *needed = obj->needed;
151 			obj->needed = needed->next;
152 			xfree(__UNCONST(needed));
153 		}
154 		(void) munmap(obj->mapbase, obj->mapsize);
155 		xfree(obj->path);
156 		xfree(obj);
157 	}
158 
159 	_rtld_objmain = NULL;
160 	_rtld_objtail = &_rtld_objlist;
161 	/* Need to free _rtld_paths? */
162 
163 	return 0;
164 }
165 
166 void
fmtprint(const char * libname,Obj_Entry * obj,const char * fmt1,const char * fmt2)167 fmtprint(const char *libname, Obj_Entry *obj, const char *fmt1,
168     const char *fmt2)
169 {
170 	const char *libpath = obj ? obj->path : "not found";
171 	char libnamebuf[200];
172 	char *libmajor = NULL;
173 	const char *fmt;
174 	char *cp;
175 	int c;
176 
177 	if (strncmp(libname, "lib", 3) == 0 &&
178 	    (cp = strstr(libname, ".so")) != NULL) {
179 		size_t i = cp - (libname + 3);
180 
181 		if (i >= sizeof(libnamebuf))
182 			i = sizeof(libnamebuf) - 1;
183 		(void)memcpy(libnamebuf, libname + 3, i);
184 		libnamebuf[i] = '\0';
185 		if (cp[3] && isdigit((unsigned char)cp[4]))
186 			libmajor = &cp[4];
187 		libname = libnamebuf;
188 	}
189 
190 	if (fmt1 == NULL)
191 		fmt1 = libmajor != NULL ?
192 		    "\t-l%o.%m => %p\n" :
193 		    "\t-l%o => %p\n";
194 	if (fmt2 == NULL)
195 		fmt2 = "\t%o => %p\n";
196 
197 	fmt = libname == libnamebuf ? fmt1 : fmt2;
198 	while ((c = *fmt++) != '\0') {
199 		switch (c) {
200 		default:
201 			putchar(c);
202 			continue;
203 		case '\\':
204 			switch (c = *fmt) {
205 			case '\0':
206 				continue;
207 			case 'n':
208 				putchar('\n');
209 				break;
210 			case 't':
211 				putchar('\t');
212 				break;
213 			}
214 			break;
215 		case '%':
216 			switch (c = *fmt) {
217 			case '\0':
218 				continue;
219 			case '%':
220 			default:
221 				putchar(c);
222 				break;
223 			case 'A':
224 				printf("%s", main_local);
225 				break;
226 			case 'a':
227 				printf("%s", main_progname);
228 				break;
229 			case 'o':
230 				printf("%s", libname);
231 				break;
232 			case 'm':
233 				printf("%s", libmajor);
234 				break;
235 			case 'n':
236 				/* XXX: not supported for elf */
237 				break;
238 			case 'p':
239 				printf("%s", libpath);
240 				break;
241 			case 'x':
242 				printf("%p", obj ? obj->mapbase : 0);
243 				break;
244 			}
245 			break;
246 		}
247 		++fmt;
248 	}
249 }
250 
251 void
print_needed(Obj_Entry * obj,const char * fmt1,const char * fmt2)252 print_needed(Obj_Entry *obj, const char *fmt1, const char *fmt2)
253 {
254 	const Needed_Entry *needed;
255 
256 	for (needed = obj->needed; needed != NULL; needed = needed->next) {
257 		const char *libname = obj->strtab + needed->name;
258 
259 		if (needed->obj != NULL) {
260 			if (!needed->obj->printed) {
261 				fmtprint(libname, needed->obj, fmt1, fmt2);
262 				needed->obj->printed = 1;
263 				print_needed(needed->obj, fmt1, fmt2);
264 			}
265 		} else {
266 			fmtprint(libname, needed->obj, fmt1, fmt2);
267 		}
268 	}
269 }
270